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CROSS REFERENCE TO RELEATED APPLICATIONS
This is a Section 371 filing of International Application No. PCT/FR2005/050170 filed Mar. 16, 20005, and published, in French, as International Publication No. WO 2005/11763 A1 on Dec. 15, 2005, and claims priority of French Application No. 04.51049 filed on May 27, 2004, all of which applications are hereby incorporated by reference herein, in their entirety.
TECHNICAL FIELD
The invention basically relates to a strap obtained by weaving, whereof the primary feature resides in the fact that it has areas of variable widths.
In the rest of the specification, and in the claims, the term “width” means the smallest dimension of the strap in the general plane in which it is inscribed. The term strap should itself be interpreted in its primary acceptance, that is a flat band. In doing so, in the context of the invention, it is important to distinguish between the width of the strap and its thickness, consisting of its dimension in a direction perpendicular to the plane containing the strap.
The invention further relates to products suitable for using such a strap. It also relates primarily to a loop or ring, and in general, any structure closed on itself, prepared from this woven strap and, more particularly, intended for the field of mountaineering and climbing, safety and lifting, and also, in general, for all fields involving a load.
It also relates to leads for animals, straps for musical instruments, bracelets, purely decorative or watch straps, bag handles, etc.
PRIOR ART
In the more specific framework of climbing, the climbers use rings prepared from a strap, generally woven, in particular but repeated situations. This ring is, for example, joined to the shoulder-belt worn by the user and, furthermore, to a snap hook fixed at an appropriate anchoring point. This ring may also serve as a support element for the knees or feet of the user.
In a known manner, such rings must combine both mechanical strength and lightness. Moreover, at least some of them must meet standards, such as in particular standard NF EN 566 “Ring” of April 1997. This states that for a 9 millimeter wide strap ring, the mechanical strength must be greater than or equal to 2,200 daN.
To prepare such a ring, it has been proposed, for example in document WO03/059462, to use a loop consisting of a tubular fabric or mesh provided with two ends, these two ends being joined to each other at a connecting point by the introduction of one of the two ends into the other end, and by stitching said ends at this connecting point.
While from the mechanical standpoint, such a loop or such a ring is likely to meet the prescribed requirements and optionally, those of the standard recalled above, it nevertheless has the following drawbacks:
firstly, the cost of production of such a loop is encumbered by the labor necessary for its production, insofar as it is necessary to thread one of the ends of the component material into the other, an operation which can only be done manually, and which also requires a certain dexterity; secondly, the component material is conventionally produced on looms of a type known per se, and the resulting band is cut at regular intervals corresponding to the desired length of the loop; this cutting is generally performed using a hot blade, which, in addition to the cutting, also seals the tubular fabric or mesh, which must therefore be reopened, to permit the introduction of one of its ends into the other, thereby also representing a time consuming operation.
In the more general field of straps, and in particularly in the context of leads for animals and other gripping handles for bags and baskets, the user usually wishes to enjoy a degree of comfort at the level of the pulling or gripping area. In doing so, it has been proposed to add to these areas elements of a different nature from that of the active area of the lead or the handles. However, here also, such an operation further increases the production costs.
SUMMARY OF THE INVENTION
The invention primarily relates to a strap obtained by weaving, satisfactorily meeting a number of objectives discussed above.
More particularly, the invention relates to a woven strap comprising at least two consecutive or continuous areas or parts of different widths, the modification of said widths being obtained by changing the weave.
The strap according to the invention may also have a plurality of areas of modified width, particularly for a decorative function.
Furthermore, and according to the invention, the strap has a modification of width at one or both of its two ends, reflected by the presence of a tubular structure, also resulting from a change of weave.
In this context, the invention thus relates to a loop or such a ring, suitable for use in the fields considered, and particularly climbing, indeed in any activity using a load, which is simultaneously lightweight, mechanically strong, and relatively easy to prepare in order to reduce the manufacturing costs.
This loop or this ring consists of a strap prepared by weaving, whereof the two ends are joined to each other by stitching.
It is characterized:
in that limitatively, the stitching areas of each of the two ends are tubular, the rest of the ring being flat. and in that said stitching areas are superimposed on one another.
In doing so, considering that only the stitching areas, that is the two ends of the strap making up the loop or ring, are tubular, a significant reduction in weight is achieved.
Advantageously, the length of one of the stitching areas of one of the ends is greater than the other. In doing so, and according to another advantageous feature of the invention, a wear and/or overload indicator is located in the immediate neighborhood of the stitching area. This indicator consists of the folding upon itself of the base of the stitching area thereby forming a triple thickness at this level, followed by stitching of these three thicknesses, said wear and/or overload indicator also being prepared in the tubular part of the strap.
Advantageously, a ribbon is inserted between at least two of the folds of said wear and/or overload indicator. This ribbon is preferably brightly colored compared with the rest of the strap making up the loop or ring, for the obvious purpose of attracting the user's attention upon the breakage of the wear and/or overload indicator.
According to the invention, the stitching of the folds making up the wear and/or overload indicator is carried out using a stitching robot, wherein the respective needle yarn and spool yarn diameters are different.
In this configuration, the tubular area of one of the ends is folded upon itself or at the level of the width change, in order to define a gripping handle.
BRIEF DESCRIPTION OF THE FIGURES
The manner in which the invention can be implemented and the advantages resulting therefrom will appear more clearly from the embodiments that follow, provided for information and nonlimiting, with reference to the figures appended hereto.
FIG. 1 is a schematic representation of a cross section of a lead for animals, using a strap of the invention.
FIG. 2 is a flat view of the strap of FIG. 1 .
FIG. 3 is a view similar to that of FIG. 2 , of another embodiment of the invention.
FIG. 4 is a schematic perspective view of a ring of the prior art.
FIG. 5 is a schematic representation of the ring of the invention.
FIG. 6 is a flat view of part of the ring of FIG. 5 , for particularly illustrating the stitching area.
FIG. 7 is a view similar to that of FIG. 6 with an overload and/or wear indicator after breakage.
FIGS. 8 a to 8 d illustrate the operation of the wear and/or overload indicator of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 therefore illustrates a lead using a strap ( 10 ) according to the invention. In this particular case, a snap hook ( 13 ) has been materialized at the level of one of the ends, intended in a known manner for the fixing of the lead to the collar, with which the animal is provided, and a handle ( 14 ) at the other end.
This handle ( 14 ) is produced by the stitching ( 15 ) of the strap on itself. A handle incorporated in the strap is thereby obtained.
According to the invention, the area of the strap making up the handle has a different width from the rest of the lead.
The strap ( 10 ) is a flat strap. It is prepared on a loom of the type marketed by MULLER (CH). The two distinct areas of the lead, that is the main part, of variable length, and the end constituting the handle ( 14 ), are prepared by modifying the weave of the loom. Thus the longer area, separating the two ends, is prepared with a twill weave, whereas the handle area is prepared with a taffeta weave. The reverse configuration is equally feasible.
At the level of the handle ( 14 ), a greater width is thereby provided, designed to enhance the user's comfort. Advantageously, the stitching area ( 15 ) of the end of the strap on itself occurs at the level of this change in width.
The strap is prepared from any material compatible with the intended application in terms of mechanical strength. Thus, if high mechanical strength is required, for example for a strap used as a bag handle, said material may consist of high tenacity polyethylene, such as, for example, marketed under the registered trademark Dyneema®.
Furthermore, in view of the weaving technique employed, the strap, and hence the product resulting therefrom, is capable of having all types of decoration, such as for example Jacquard. The width may also vary substantially, according to the intended application.
In a different version of the invention, it may even be feasible to arrange, in the main area of the strap, that is between its two ends, a plurality of variations in width, as illustrated in FIG. 3 . The technology employed is identical to that previously described, and only the pitch of the weave variations is different.
Alternatively, the variation in width of the strap also results from the passage from flat mode to tubular mode. Thus the handle consists of a tubular part. In doing so, the thickness of the strap is increased at this level, optimizing the feeling of comfort.
For this purpose, during the manufacturing phase with twill weave, to prepare the flat area of the strap, the warp yarns work side by side in pairs, while with a taffeta weave, to prepare the tubular area, said warp yarns become individualized, specifically to permit the production of such a tubular area.
As may have been understood, the strap of the invention can be prepared continuously, with periodic change of weave, to produce flat areas of variable width, or alternating flat areas and tubular areas. The band thereby prepared is also cut automatically using a heated blade, incidentally causing the sealing of the component yarns, for example, polyethylene. As may be imagined, in the presence of tubular areas, this cutting area limitatively occurs at the level of said tubular areas, so that the latter are systemically blocked due to the heating of the yarns.
These various embodiments are therefore suitable for implementation for the preparation of various products, such as leads for animals, collars, handles for bags and other baskets, bracelets, watch straps, straps for musical instruments, such as guitar, accordion, etc.
One particular application of the present invention relates to rings and other loops in the areas of safety, lifting, mountaineering and climbing, and in general, in all areas involving a load.
Thus, in relation to FIG. 4 , a loop or ring has been shown, more particularly intended for climbing according to the prior art. This loop or ring comprises a tubular strap ( 1 ) prepared by weaving, of which the two ends ( 2 , 3 ) are joined to each other by the introduction, in the example described, of the end ( 2 ) into the end ( 3 ), followed by stitching of the stitching area ( 4 ) thereby defined. This introduction is made possible by the tubular nature of the strap ( 1 ).
It may be understood, considering the tubular nature of the strap ( 1 ), that this stitch is therefore made on four thicknesses.
The particular application of the invention to this field is more particularly described in relation to the following figures and, in general, to FIG. 5 . According to the invention, the strap ( 10 ) used to prepare the loop or ring of the invention is a flat strap, whereof only the ends ( 5 , 6 ) are tubular. According to the invention, the strap ( 10 ) is therefore not tubular between its ends. It thus has a reduced width at this level, and, for example, in the illustration described, a width of 9 millimeters, whereas the width of the stitching area is typically 15 millimeters.
This strap ( 10 ) is also produced on a loom of the type marketed by MULLER (CH). The three distinct areas of the ring, that is the central band and the two ends, are prepared by modifying the weave of the loom. Thus the longer area, separating the two ends ( 5 , 6 ), is prepared with a twill weave, whereas the tubular areas, corresponding to the two ends, are prepared with a taffeta weave.
During the phase of manufacture with twill weave, the warp yarns work side by side in pairs, whereas with the taffeta weave, said warp yarns are individualized, specifically for preparing a tubular area. This tubular area is wider, as may be observed in FIGS. 6 and 7 .
According to the invention, the strap is prepared from high tenacity polyethylene, like the material marketed under the registered trademark Dyneema®. This material has mechanical properties compatible with the use of the ring in question.
According to the invention, the two ends ( 5 , 6 ) of the strap ( 10 ) are joined to each other by stitching by superimposing them upon one another. Four thicknesses are accordingly provided at this level, that is two thicknesses for each of the ends, the number of these thicknesses being inherent in the tubular nature of the strap at this level, and at this level only.
The stitching is carried out, for example, on stitching robots operating in (X, Y), of the type marketed by JUKI. Such a robot is suitable particularly for obtaining a number of stitching lines ( 11 ), substantially parallel to each other, and further describing an alternation of broken lines or “zigzags”. In the example described, the stitching area ( 7 ) comprises nine of these stitching lines. At this level, the diameter of the needle yarn of the stitching robot is equal to the diameter of the spool of said robot. The type of yarn is, for example, polyamide (nylon). It is suitable for conferring on the ring resulting from the closure of the strap thus prepared, a mechanical strength higher than or equal to 2,200 daN for a nominal strap width of 9 mm in the inter-end area, and 15 mm for the ends, that is, at the level of the stitching area ( 7 ), that is according to standard NF EN 566.
As already stated, the strap making up the ring of the invention is prepared on looms of a type known per se. Accordingly, it is prepared continuously, with periodic change of weave, to produce the flat areas and the tubular areas. The band thus prepared is also cut automatically, using a heated blade, incidentally causing the sealing of the component yarns of polyethylene. As may be understood, this cutting area limitatively occurs at the level of the tubular areas, so that the latter are systematically blocked by the heating of the yarns. However, this blocking has no effect, particularly in terms of labor and hence in terms of cost, because contrary to the prior art, there is no introduction of one of the ends into the other, but a superimposition of said ends.
According to one feature of this particular form of the invention, the ring is also provided with a wear and/or overload indicator ( 8 ). This is arranged at one ( 5 ) of the two ends of the strap ( 10 ). For this purpose, the tubular area of the end ( 5 ) has a greater length than the tubular area of the end ( 6 ), specifically to permit the production of this wear and/or overload indicator.
This is prepared by folding in three thicknesses at the base of said end ( 5 ) of the strap ( 10 ), as may be observed particularly in FIG. 5 . It extends along a length X.
After folding, therefore arranged flat, like the stitching area in ( 7 ) previously described, this area ( 8 ) is stitched, also using a stitching robot, for example of the JUKI type, following the same principle of a succession of stitching lines ( 12 ), substantially parallel to each other and forming zigzags.
However, for the preparation of this wear and/or overload indicator, the diameter of the needle yarn is different from the diameter of the spool yarn of said robot. In the present case, a smaller diameter is selected for the spool yarn compared with the diameter of the needle yarn. Furthermore, the number of stitching lines ( 12 ), without regard to the type of stitching yarn, depends on the value at which the overload and/or wear indicator is intended to break. Thus, this tripping or this breakage will occur when the spool yarns, forming loops after the actual stitching operation, will break due to their smaller diameter than that of the loops prepared by the needle yarn, and closed on said spool yarn loops in case of overload, or when the stitching yarns become worn out by repeated friction of the ring, and hence of the indicator ( 8 ) area, on rocks in particular.
When the wear and/or overload indicator has played its role, it extends along a length of 3× ( FIG. 7 ).
The various steps of tripping of the wear and/or overload indicator are shown in relation to FIGS. 8 a to 8 d with:
FIG. 8 a : state of indicator at rest, FIG. 8 b : incipient deformation of the indicator by pulling, FIG. 8 c : end of deformation and breakage of the stitching yarn, And finally, FIG. 8 d : breakage of the indicator with elongation of the ring by twice the respective length X of the indicator, due to the manner in which it is prepared.
Despite the effective breakage of the indicator ( 8 ) the ring or loop preserves a mechanical strength greater than or equal to its nominal value and in the example described, greater than or equal to 2,200 daN. In fact, this breakage does not affect the actual stitching area ( 7 ) on the one hand, because the stitching yarns of this area (needle and spool) have the same diameter, and on the other, the number of stitching lines ( 11 ) at this level is greater than the number of stitching lines ( 12 ) of the indicator ( 8 ). Furthermore, since this breakage is likely to occur only at a tubular area of the strap, it does not disorganize the intrinsic structure inherent in the weaving mode, because only the stitching yarns are concerned.
Advantageously, the interior of one or the other of the fold areas of the wear and/or overload indicator is provided with a ribbon ( 9 ) advantageously colored, for the purpose of attracting the attention of the user of the ring when said indicator actually breaks. This ring is simply stitched, for example by running straight stitches on the back and front of the strap, obviously directly at the actual indicator ( 8 ) area.
The value of the ring or loop of the invention is clearly understandable, due to its ease of production, incurring no excessive loss of time, and hence, unlikely to encumber the manufacturing cost, and also due to the use of such a wear and/or overload indicator, optimizing the conditions of safety and use of such a ring.
And in general, it is easy to understand the value of the strap of the invention, which, in a relatively simple and automated manner, provides the availability of an element that can be varied virtually to infinity, both in terms of dimensions and in terms of decoration, for any use involving a pulling or a lifting function, or even a simply decorative function, while optimizing the user's comfort.
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A woven strap comprises at least two continuous parts having different widths, wherein the change in width results from a modification of the respective weave of said parts. The strap can thus be used to create a loop or a ring in order to attach or bear a load. The two ends of the strap are joined to each other by stitching. Only the stitching areas of each of the two ends are tubular. The rest of the ring is flat and the stitching areas are placed on top of each other. The loop or ring can include an integrated wear and tear and/or overload indicator.
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FIELD OF THE INVENTION
This invention teaches a novel method of delivering oxygen to patients with severe lung disease that requires them to be prescribed supplemental oxygen. Because oxygen is delivered more efficiently, small and more portable oxygen canisters may be carried by patients on ambulatory and portable oxygen systems.
BACKGROUND OF THE INVENTION
The collective of knowledge and understanding of pulmonary rehabilitation has shown that patients with chronic lung diseases (CLD) such as chronic obstructive pulmonary disease (COPD), can live comfortable, productive and enjoyable lives if they can remain active. Patients on long-term home oxygen are limited by the portability of their system. It has been demonstrated that patients with CLD will live longer by using their oxygen continuously and that depriving them of oxygen during exertion may cause dangerous tissue hypoxia (lack of oxygen). As their impairment gradually worsens, these patients live progressively more confined existence. They find it difficult to leave their homes and gradually find themselves limited to living space of a chair or bed. This severely hurts their ability to live quality lives, and they become depressed and a burden to their families. The goal of pulmonary rehabilitation is to reverse this trend, mobilize and make these patients more active. Pulmonary rehabilitation is remarkably effective in meeting this goal.
The physiological goal of oxygen therapy is to maintain arterial oxygen saturation above 90 percent for all living conditions including wakeful rest, sleep and exertion. Because of the unique capacity for hemoglobin on the red blood cell to carry oxygen, little is gained by maintaining oxygen saturation above 90 percent, except to assure that it does not drop below 90 percent. Adding much more oxygen is wasteful and will impose an unnecessary weight burden for the patient using portable oxygen.
The Oxygen consensus
Conferences and the most recent conference of the American Thoracic Society and European Respiratory Society Standards for the Diagnosis and Treatment of COPD have emphasized the importance of maintaining an active lifestyle and the importance of a portable oxygen system.
In response to the need for mobility, coupled with the necessity for oxygen therapy in order to protect the body tissues from tissue hypoxia, there is a need to deliver oxygen to patient more efficiently. Providing adequate supplies of oxygen improves oxygen transport to the muscles, improving both strength and endurance and becoming an essential ingredient in pulmonary rehabilitation. The oxygen therapy apparatus disclosed in U.S. Pat. No. 4,572,177, co-invented by me together with Robert E. Phillips and Ben A. Otsap, teaches an oxygen conservation system. That system is very useful in the conservation of oxygen. This disclosure teaches further advancement in controlling the flow of oxygen to the patient to improve upon alveolar gas exchange and oxygen transport to the exercising muscle.
SUMMARY OF THE INVENTION
In order to aid in the understanding of this invention, it can be stated in essentially summary form that it is directed to the efficient delivery of oxygen to the patient. The system has a structure preferably in the form of a small reservoir chamber for storing oxygen during exhalation, when it is ordinarily wasted so that volume can be delivered upon the next inhalation. It includes the functions of metering, switching, storing and releasing oxygen. The system includes a nasal cannula, which receives the oxygen from the structure at an advantageous time during inhalation so that most of the oxygen effectively participates and contributes to alveolar gas exchange.
It is a purpose and advantage of this invention to provide an oxygen flow control system which includes gas dynamic switching that regulates, stores and releases oxygen to the nasal cannula, timed to the portion of the inspiratory cycle in which alveolar gas exchange takes place.
It is another purpose and advantage of this invention to provide a structure with a gas dynamic valve so that oxygen flow is diverted to storage except during the beginning of inhalation.
It is another purpose and advantage of this invention to provide an oxygen flow control system which permits a nasal cannula structure of lightweight tubing over the users ears on its way to the nasal prongs of the nasal cannula.
It is another purpose and advantage of this invention to provide an oxygen flow control system which includes an oxygen switch which switches oxygen flow to the storage reservoir inside the cannula when the cannula pressure rises to exhalation pressure and directs the oxygen flow when the cannula pressure at the nasal prongs drops to inspiratory pressure.
Other purposes and advantages of this invention will become apparent from the following description because the Summary set forth above is inherently incapable of indicating the many purposes, advantages, features and facets which are important to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view the preferred embodiment of the oxygen delivery cannula system of this invention.
FIG. 2 is an enlarged front view of the nasal cannula with the supply tubes broken away.
FIG. 3 is an isometric view of the pendant structure with the near half of the upper structure broken away to show the upper portion of the pendant structure in section.
FIG. 4 is a longitudinal section through the pendant structure, as seen generally along line 4 - 4 of FIG. 3 .
FIG. 5 is a longitudinal section taken through the pendant structure, as seen generally along line 5 - 5 of FIG. 3 .
FIG. 6 is a schematic plan view showing flow during inspiration.
FIG. 7 is a schematic plan view showing flow during exhalation or non-flow at the cannula.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The oxygen delivery cannula system of this invention is generally indicated at 10 in FIG. 1 . It includes an oxygen supply tube 12 which is connected by fitting 14 to a continuous source of gaseous oxygen under pressure. The supply tube 12 is connected to pendant structure 16 , the structure of which is described in detail below. Outlet tubes 18 and 20 receive oxygen from the pendant structure and are connected to the ends of nasal cannula 22 . The nasal cannula 22 delivers gaseous oxygen to the patient 24 , shown in dashed lines.
As seen in FIGS. 3 , 4 , and 5 the pendant structure 16 is formed of three substantially rigid parts made of injection moldable synthetic polymer composition material, and a flexible reservoir. Bottom panel 26 is the lower most panel in the pendant structure assembly. It is substantially circular in outline and is formed with a plurality of spaces and walls for various functional purposes. Its underside lies against the user's chest. Inlet opening 28 receives the supply tube 12 , while outlet openings 30 and 32 receive the outlet tubes 20 and 18 , respectively. Upright walls, one of which is indicated at 34 in FIGS. 4 and 5 define an inlet channel 36 . These walls extend to walls which define an internal orifice slot 38 . Beyond orifice slot 38 , upright walls 40 , 42 , 44 and 46 form a Y-shaped outlet passage 48 . The Y-shaped outlet passage 48 terminates in outlet openings 30 and 32 . These walls are best seen in FIGS. 6 and 7 . Between orifice slot 38 and Y-shaped outlet passage 48 , the side walls of the flow passage are formed into right and left lobes 50 and 52 . The body panel 26 thus defines the principal passages which have, at this point, open tops, so that the structure can be readily injection-molded of thermoplastic synthetic polymer composition material.
Passage cover 54 overlies the inlet channel and overlies the passages and lobes. The passage cover 54 acts to close the top of the passages except for reservoir openings 56 and 58 which are over the lobes. The passage cover 54 preferably covers only the passages to leave some reservoir spaces 60 and 62 on each side of the lobes and the Y-shaped outlet passage.
The flexible reservoir membrane 64 has a circular seal lip 66 which is clamped between body panel 28 and cover 68 , see FIGS. 3 , 4 and 5 . The flexible material of the reservoir membrane extends inwardly from the seal lip and lies down against the top rib 70 of the body panel 26 for a short distance inward from the circular seal lip. The flexible reservoir membrane is formed in a doorknob shape, which is a figure of revolution formed with two flat walls, which terminate in a hemi-circle of revolution. The flexible material of the flexible reservoir membrane 64 is elastomeric but rolls instead of stretches so that it does not exert significant pressure on the contained gas. The reservoir membrane elastomeric material very slightly favors flow into the reservoir. The space 69 under the flexible membrane 64 and the spaces 60 and 62 form the total reservoir volume space. The doorknob shape of the flexible reservoir membrane permits it to increase and decrease in its interior volume without stretching. In order to prevent the reservoir space outside of the flexible reservoir from exerting other than atmospheric pressure on the flexible reservoir, cover 68 is vented by vent slots 71 , which have sufficient opening to not limit reservoir movement.
Outlet tubes 18 and 20 are positioned in connector ports 32 and 30 . The outlet tubes 18 and 20 are usually clear flexible polymer tubes and are sized to extend over the patient's ears to retain the two cannula tubes 72 and 74 in the patient's nares. The nasal cannula 22 is a one-piece structure, including the cannula tubes 72 and 74 . It is preferably a polymer material and has the tubes 18 and 20 pressed therein. The length of the cannula tubes is such as to extend farther into the nares. This is possible because the cannula tubes have faces 76 and 78 , which are formed at a 45 degree angle with respect to the direction of outlet oxygen through the tubular cannula and at approximately 90 degree angle with respect to each other. The angular cut provides a larger oxygen discharge area and thus a lower velocity than a square cut. This angle also distributes the oxygen toward the septum and toward the interior nasal passages.
The outlet tubes 18 and 20 can be small and flexible because they handle only oxygen. This small diameter and good flexibility permit the tube to be comfortably positioned over the patient's ears. The pendant structure 16 controls the flow of oxygen from the orifice to and from the reservoir and to the outlet tubes 18 and 20 in such a manner that oxygen is conserved as compared to continuous flow, non-conserved oxygen. Assuming that the system is full of oxygen and there is flow through the orifice 38 of about ½ liter per minute (about ¼ of standard continuous flow oxygen), the patient starts to inhale. This reduces the outlet pressure at the cannula tubes, and oxygen immediately flows into the nasal passages. Oxygen flow in the pendant structure 16 is that shown in FIGS. 6 and 7 . Oxygen is present at the cannula tubes at the beginning of inhalation, at which time that oxygen is most effective because it is drawn deeply into the lungs.
At the beginning of inhalation, the entire system is full of oxygen including all the way up to the cannula outlets. Also, pressure is reduced at the cannula outlets, and oxygen flows therefrom. The orifice 38 has the reservoir openings 56 and 58 adjacent thereto so that the orifice flow acts as a Venturi to withdraw oxygen from the reservoir 69 , see FIG. 6 . A normal inhalation withdraws, with the help of this Venturi effect, oxygen from the reservoir. At the end of inhalation, the oxygen continues to flow from the orifice 38 , but the higher back pressure at the cannula outlets at the end of inhalation defeats the jet in the gas dynamic valve structure and causes the oxygen to flow to the reservoir, as shown in FIG. 7 . The reservoir fills, and then the oxygen flows through the cannula tubes 18 and 20 , which are filled by oxygen flow so that oxygen is present at the cannula outlets at the beginning of the next inhalation. There is no significant exhalation into the cannula.
At the end of inhalation, the pressure builds up close to atmospheric in the tubes 18 and 20 up to the main passage 48 . This buildup of pressure defeats the jet and switches the flow of oxygen from the flow paths shown in FIG. 6 to the flow shown in FIG. 7 . Thus, the interior passages to the lobes 50 and 52 and the Y-shaped outlet passage 46 together with orifice 38 act as a gas dynamic valve. When the pressure in main passage 48 is about at atmospheric pressure, the flow is diverted into the reservoir through reservoir openings 56 and 58 . When the pressure in main passage 48 goes below atmospheric caused by inhalation by the patient, oxygen flow into passage 48 comes from the orifice 38 and entrains flow from the reservoir 64 through reservoir openings 56 and 58 , helped by venturi action. This permits an effective flow at the cannula during inhalation at a rate equivalent to 2 liters per minute of uninterrupted oxygen flow to fully supply the patient's needs, even though the actual flow rate through the orifice slot 38 is only about ½ liter per minute. During the ¾ of the time when the patient is not inhaling, the oxygen flow goes back into the reservoir. The reservoir has a volume of about 0.025 liter so that at a respiration rate of 20 breaths per minute, the ½ liter per minute oxygen flow through the orifice fills the reservoir and outlet tubes to the cannula. At the next breath, there is oxygen at the cannula.
The patient need not exhale through his nose to cause the gas dynamic valve to switch flow to the reservoir. The fact that he is no longer inhaling causes the back pressure to switch to filling the reservoir. No exhalation into the cannula or outlet tubes 18 and 20 occurs, but oxygen remains available at the cannula tubes in the nares. One advantage of this balance of pressure is that there is no need to exhale down through the outlet tubes back to the pendant to cause the pendant to switch from supply to reservoir-filling condition. This permits a smaller outlet tube which can be worn comfortable over the ear, as shown in FIG. 1 .
Another advantage of not requiring exhalation into the cannula is that pursed-lip breathing can be exercised. This is a breathing condition in which exhalation is through pursed lips in order to raise the pressure in the lungs to increase the transfer of oxygen to the bloodstream. Pursed-lip breathing, as compared to regular breathing, can increase blood oxygen content in the order of 10 percentage points. This breathing method causes hyperinflation, increases oxygenation and breathing efficiency and reduces breathlessness.
This invention has been described in its presently preferred embodiment, and it is clear that it is susceptible to numerous modifications, modes and embodiments within the ability of those skilled in the art and without the exercise of the inventive faculty. Accordingly, the scope of this invention is defined by the scope of the following claims.
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The pulmonary oxygen flow control system delivers oxygen from a source of pressure to a nasal cannula worn by the patient. Between the source and the nasal cannula is a pendant flow structure which includes an orifice followed by a gas dynamic valve. When the downstream pressure in the cannula is high, the gas dynamic valve diverts the oxygen flow through the orifice to a flexible reservoir. Upon inhalation, the pressure at the cannula falls so that the gas dynamic valve delivers the orifice flow to the cannula and also utilizes a Venturi effect to withdraw oxygen from the reservoir and deliver it to the cannula. The cannula has nasal tubes which have angular faces and which are positioned farther into the nares to deliver the oxygen more efficiently.
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FIELD OF THE INVENTION
This invention relates to the growth of semiconductor epitaxial layers on a substrate.
BACKGROUND TO THE INVENTION
It is common practice to grow compound semiconductor epitaxial layers on a substrate by liquid phase epitaxy (LPE). The basis of LPE growth is the production of supersaturation in a growth solution, such that the deposition of solid material occurs onto the substrate. The temperature of the substrate and the growth solution is used to control deposition of solid material onto the substrate.
In the step cooling technique, the substrate and the growth solution are cooled to a temperature below the saturation temperature of the solution. The substrate is slid under the growth solution and a constant temperature is maintained during the growth period. The growth is terminated by sliding the substrate out of the solution.
In the equilibrium cooling technique, both substrate and growth solution are at the saturation temperature of the growth solution. Growth begins when the substrate is brought into contact with the growth solution and both are cooled at a uniform rate. The growth is terminated by sliding the substrate out of the solution.
The supercooling technique is a combination of the step cooling and equilibrium cooling techniques. The substrate is brought into contact with the solution when both are at a temperature below the saturation temperature of the growth solution. The growth solution and the substrate are further cooled during growth.
Thus both the growth rate and the material composition of the layers are controlled by temperature. Heat generation and removal are very slow processes and so it is generally very difficult to obtain temperature uniformity and responsive temperature variation at the same time using LPE techniques. This limits the quality of the structures produced as well as the flexibility in designing complicated growth recipes for novel epitaxial layer structures. For example, the growth temperature may be either kept constant or lowered but is never raised nor raised and lowered in a varying profile.
U.S. Pat. No. 4,594,128 describes an apparatus and method for the low cost growth of an epitaxial layer on a substrate from a solution. Temperature is used to control the deposition of solid material onto the substrate and therefore this procedure suffers from the problems of slow heat generation and heat removal, and temperature uniformity disclosed above. Gas pressure is used to move growth solution into contact with the substrate.
U.S. Pat. No. 4,315,477 and U.S. Pat. No. 5,375,557 are directed towards the production of mercury cadmium telluride (HgCdTe) epitaxial layers. The growth chambers are maintained at a high pressure to reduce the vaporisation of the components from the growth source. In both cases, the formation of epitaxial layers is induced by reducing the temperature of the growth solution to induce crystallisation on a substrate, encountering the problems discussed above.
It would be advantageous to have an LPE system in which it is easy to control supersaturation and the composition of the layers. In addition, it would be advantageous to be able to implement iterative growth easily and to have greater flexibility in designing the growth process.
SUMMARY OF THE INVENTION
According to the invention we provide a method of growing semiconductor epitaxial layers on a substrate comprising the steps of providing a substrate, providing at least a first growth solution and optionally one or more further growth solutions, and
(i) exposing the substrate to the first growth solution, the growth solution being under a supersaturated condition such that a first layer grows on the surface of the substrate; and, (ii) optionally exposing the substrate to one or more further growth solutions, the further growth solution or solutions being under a supersaturated condition such that one or more further layers grow on the surface of the first layer; and (iii) varying the pressure of the system to change the degree of supersaturation of the first growth solution or one or more further growth solutions to affect the growth of the first layer or one or more further layers.
Thus in the invention we use variation in pressure to control the degree of supersaturation of growth solutions. We describe this technique as “variable pressure LPE”.
Variable pressure LPE has several advantages over standard LPE.
Control of supersaturation is facilitated in pressure variable LPE as it is pressure of the growth solution which is used to control supersaturation. Controlling pressure is a developed technique, and the pressure can be changed rapidly and accurately.
It is also easy to control the solid layer ingredients in variable pressure LPE. The phase diagram as a function of pressure is monotonous and quasi-linear, whilst in contrast, the phase diagram as a function of temperature in standard LPE is complicated and non-monotonous. Monotonous in this context means that the function is single valued, i.e. one atomic fraction value corresponds to one value of the growth pressure.
Since the pressure can be controlled very rapidly in variable pressure LPE, it is possible to grow graded layers whereby the composition is varied across a particular epitaxial layer. The profile of the material composition and hence the band gap will be dependent on the manner in which the pressure is varied.
Furthermore, it is easy to implement iterative growth using variable pressure LPE. The pressure can be controlled as desired in the course of a growth process using variable pressure LPE which brings about great flexibility in the growth process. This results in better quality of the epitaxial layers.
By, realising supersaturation in the growth solution by changing the pressure, supersaturation is much easier to control. The pressure can be changed rapidly and accurately using vacuum pumps, pressure controllers and vacuum gauges.
Standard LPE equipment can be used to implement variable pressure LPE growth with some simple modifications to allow the pressure to be varied.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a first method according to the invention.
FIG. 2 is a schematic illustration of a further method according to the invention.
FIG. 3 shows a schematic illustration of a system in which the method of the invention may be implemented.
FIGS. 4 to 7 illustrate relationships between composition and pressure for a saturated solution of the quaternary InGaAsSb.
FIG. 8 illustrates part of an apparatus in which variable pressure LPE may be carried out.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, we provide a method for growing a semiconductor epitaxial layer or layers over a substrate.
The epitaxial layers are deposited from a growth solution (also called a growth source or melt) containing the desired materials. Material is deposited from the growth solution onto the substrate when the substrate is brought into contact with a supersaturated growth solution.
The supersaturation of the growth solution or solutions is controlled by varying the pressure of the growth solution. As the pressure of the growth solution can be changed rapidly and controlled accurately, the composition of the epitaxial layers can be controlled using the pressure.
The pressure may be varied between the growth of layers. A schematic illustration of a method for this is shown in FIG. 1 .
The growth ingredients for different layers are prepared, their exact weights having been determined using phase diagram calculations. The furnace chamber is then brought to atmospheric pressure and the growth ingredients for the different layers and the substrate placed in the graphite boat before loading the boat into the furnace chamber. The chamber is then sealed.
A flow of hydrogen gas is started and the temperature of the furnace chamber ramped up above the saturation temperature of the growth solution in order to bake and homogenise the growth solution. Preferably the temperature is between 5 and 30° C. above the saturation temperature. More preferably, the temperature is between 8 and 20° C. above the saturation temperature, for example 10° C. above the saturation temperature.
The temperature of the furnace chamber is then lowered to the desired growth temperature. This may be the saturation temperature or below the saturation temperature of the growth solution. Preferably, the temperature is between 0 and 15° C. below the saturation temperature, for example 5° C. below the saturation temperature. Once an equilibrium state has been reached at this temperature, the pressure of the growth solution is changed to the desired value for growth of the first epitaxial layer.
The graphite boat containing the substrate is moved under the first growth solution and contacted with it for sufficient time to grow a layer of the desired thickness. The substrate in the graphite boat is then moved out of contact with the growth solution.
When growing a single epitaxial layer, the temperature of the furnace is returned to room temperature, the pressure returned to atmospheric pressure and the hydrogen gas flow terminated. When growing multiple epitaxial layers, the pressure is changed to the desired value for growth of the second epitaxial layer. This may involve either raising or lowering the pressure. The substrate is then brought into contact with the second growth solution for sufficient time in order to grow a layer of the desired thickness. For growing more than two epitaxial layers, the steps of
(i) changing the pressure, (ii) contacting the substrate with a growth solution, (iii) growing an epitaxial layer of the desired thickness (iv) removing the substrate from contact with the growth solution
are repeated until the desired layers have been grown. The temperature of the furnace chamber is lowered to room temperature, the pressure returned to atmospheric pressure and the flow of hydrogen terminated.
FIG. 2 is a schematic illustration of a method in which compositionally graded layers are grown.
The growth ingredients are first prepared, their exact weights having been determined using phase diagram calculations. The furnace chamber is brought to atmospheric pressure. The growth ingredients and the substrate are loaded into the graphite boat before loading the graphite boat into the furnace chamber and sealing the chamber.
A flow of hydrogen gas is started and the temperature of the furnace chamber ramped up above the saturation temperature of the growth solution in order to bake and homogenise the growth solution. Preferably the temperature is between 5 and 30° C. above the saturation temperature. More preferably, the temperature is between 8 and 20° C. above the saturation temperature, for example 10° C. above the saturation temperature.
The temperature of the furnace chamber is then lowered to the desired growth temperature. This may be the saturation temperature or below the saturation temperature of the growth solution. Preferably, the temperature is between 0 and 15° C. below the saturation temperature, for example 5° C. below the saturation temperature. Upon reaching an equilibrium state at this temperature, the pressure is varied to the desired value and the substrate contacted with the growth solution in order to grow an epitaxial layer on the substrate. During growth of the epitaxial layer the pressure is varied, producing a compositionally graded layer.
When a layer of the desired thickness has been grown, the substrate is removed from contact with the growth solution. If a single epitaxial layer is being grown, the temperature of the furnace is returned to room temperature, the pressure returned to atmospheric pressure and the flow of hydrogen is then terminated. If more than one epitaxial layer is to be grown, the pressure is changed to the desired value for the growth of the next layer. The substrate is then contacted with the next growth solution and the pressure varied during growth of the epitaxial layer. The substrate is then moved out of contact with this growth solution and the steps of
(i) changing the pressure, (ii) contacting the substrate with the growth solution, (iii) varying the pressure during epitaxial growth and (iv) moving the substrate out of contact with the growth solution
are repeated until the desired layers are grown. The temperature of the furnace is then returned to room temperature, the pressure of the furnace returned to atmospheric pressure and the flow of hydrogen gas terminated.
It is possible according to the invention to combine compositionally-graded layers with other layers. Thus the process of the invention may be used to grow two or more different compositionally-graded layers, or one or more compositionally-graded layers together with one or more single-composition layers. These layers may be grown in any order.
FIG. 3 illustrates the components of a system that can be used to carry out variable pressure LPE. The system generally comprises a furnace, temperature controller, a graphite boat to house the growth solutions and substrate, a pressure control system and a hydrogen flow system. Hydrogen gas is used to prevent oxide formation. The substrate for epitaxial growth is placed in the graphite boat on, a slider, and is moved below a growth solution to grow an epitaxial layer.
The LPE furnace should have high temperature stability and flat temperature profiles across the graphite boat housing the growth solutions. The temperature profile of the furnace should have a reasonably long region in the centre where the temperature is constant to within ±1° C. The length of this flat zone region depends on the dimensions of the graphite boat used. In addition, the temperature ramping must be carried out accurately according to the desired profile. Typical ramp down rates are between 0.3 and 0.5° C./min. The temperature of the growth solution should be set to a value suitable for epitaxial growth at the selected growth pressure. Typically the temperature of a growth solution will be between 500 and 750° C., depending on the type of compound semiconductor material being grown, although temperatures above and below this range may be used if appropriate.
Generally it is preferred that the temperature be substantially constant throughout the process, although it is possible in the invention to vary the temperature during and between growth of layers.
Typically the pressure of a growth solution during epitaxial growth will be between atmospheric pressure and a pressure of 10 −4 Torr.
The thickness of an epitaxial layer depends on the length of time that the substrate is in contact with the growth solution. Typically a substrate will be in contact with a growth solution for between 1 second and 3 minutes in order to grow an epitaxial layer of suitable thickness.
The components of the growth solution may be supplied in any suitable form, for instance as pure metal or polycrystalline compounds. They are generally loaded in solid form and melted to form a homogenised solution on heating. For example, to prepare a growth source for InGaAsSb, it is possible to use pure Ga metal mixed with polycrystalline InAs, GaAs and GaSb.
The substrate can be any III-V compound semiconductor wafer, such as gallium arsenide (GaAs), indium phosphide (InP), gallium antimonide (GaSb) or indium arsenide (InAs).
The principle of VP-LPE is to realise supersaturation in the growth solution by changing the growth pressure. Among the various thermodynamical parameters related to the phase diagram, melting point is very sensitive to pressure variation. According to the Clapeyron equation,
ⅆ p ⅆ T = Λ m T ( V mol l - V mol s ) ,
when the pressure p varies, the melting point T will change, which consequently affects the supersaturation of the liquid. Here V mol s is the molar volume of the solid, V mol l is the molar volume of the liquid and Λ m is the molar heat of sublimation.
The thermodynamic basis of LPE growth is the phase diagram that provides information on the composition of the solution and the solid in equilibrium as a function of temperature. Most calculations of III-V compound semiconductor phase diagrams have been based on a regular solution model of the liquid and solid phases. There exist a number of equations that link up the various thermodynamical parameters for the determination of phase diagrams. For example, Jordan and Ilegems (Jordan, A. S., Ilegems, M., J. Phys. Chem. Solids , 36, 329, 1975) showed that the phase diagram of a quaternary with mixing on both sublattices, as in A III x B III 1-x C V y D V 1-y , can be obtained from the following equations:
Δ S AC f ( T AC f - T ) + RT ln 4 x A l x C l xy = M AC l + α AB s ( 1 - x ) 2 + α CD s ( 1 - y ) 2 - α x ( 1 - x ) ( 1 - y ) Δ S AD f ( T AD f - T ) + RT ln 4 x A l x D l x ( 1 - y ) = M AD l + α AB s ( 1 - x ) 2 + α CD s y 2 + α x ( 1 - x ) y
Δ S B C f ( T B C f - T ) + RT ln 4 x B l x C l ( 1 - x ) y = M BC l + α AB s x 2 + α CD s ( 1 - y ) 2 - α x x ( 1 - y ) Δ S BD f ( T BD f - T ) + RT ln 4 x B l x D l ( 1 - x ) ( 1 - y ) = M BD l + α AB s x 2 + α CD s y 2 - α x xy
where
α A B s = y α A C - B C s + ( 1 - y ) y α A D - A D s
α C D s = x α A C - A D s + ( 1 - x ) y α B C - B D s
α x = Δ S A D f ( T A D f - T ) + Δ S B C f ( T B C f - T ) - Δ S A C f ( T A C f - T ) - Δ S B D f ( T B D f - T ) + 1 2 ( α A C 1 + α B D 1 - α B C 1 - α A D 1 )
M A C 1 = α A C 1 { 1 / 2 - x A 1 ( 1 - x C 1 ) - x C 1 ( 1 - x A 1 ) } + ( α A B 1 x B 1 + α A D 1 x D 1 ) ( 2 x A 1 - 1 ) + ( α A B 1 x B 1 + α A D 1 x D 1 ) ( 2 x C 1 - 1 ) + 2 α B D 1 x B 1 x D 1
M A D 1 = α A D 1 { 1 2 - x A 1 ( 1 - x D 1 ) - x D 1 ( 1 - x A 1 ) } + ( α A B 1 x B 1 + α A C 1 x C 1 ) ( 2 x A 1 - 1 ) + ( α B D 1 x B 1 + α C D 1 x C 1 ) ( 2 x D 1 - 1 ) + 2 α B C 1 x B 1 x C 1
M B C 1 = α B C 1 { 1 2 - x B 1 ( 1 - x C 1 ) - x C 1 ( 1 - x B 1 ) } + ( α A B 1 x A 1 + α B D 1 x D 1 ) ( 2 x B 1 - 1 ) + ( α A C 1 x A 1 + α C D 1 x D 1 ) ( 2 x C 1 - 1 ) + 2 α A D 1 x A 1 x D 1
M B D 1 = α B D 1 { 1 2 - x B 1 ( 1 - x D 1 ) - x D 1 ( 1 - x B 1 ) } + ( α A B 1 x A 1 + α B C 1 x C 1 ) ( 2 x B 1 - 1 ) + ( α A D 1 x A 1 + α C D 1 x C 1 ) ( 2 x D 1 - 1 ) + 2 α A C 1 x A 1 x C 1
Here, X A l denotes the mole fraction of component A in the liquid phase, ΔS AB f is the entropy of fusion of compound AB, T AB f is the melting point of AB, R is the gas constant, α AB l is the interaction parameter in the liquid phase for AB, α AB s is the interaction parameter in the solid phase, T is the temperature and x and y are the solid mole fractions.
The phase diagrams for different materials are calculated by solving the above equations involving the interaction parameters and mole fractions simultaneously.
In our research work, we have converted the computation into an optimisation problem. We can form an optimisation function, which can be written as follows for the quaternary materials:
F ( x A l , x B l , x C l ) = { Δ S AC f ( T AC f - T ) + RT ln 4 x A l x C l xy - M AC l - α AB s ( 1 - x ) 2 - α CD s ( 1 - y ) 2 + α x ( 1 - x ) ( 1 - y ) } 2 + { Δ S AD f ( T AD f - T ) + RT ln 4 x A l x D l x ( 1 - y ) - M AD l - α AB s ( 1 - x ) 2 - α CD s y 2 + α x ( 1 - x ) y } 2 + { Δ S BC f ( T BC f - T ) + RT ln 4 x B l x C l ( 1 - x ) y - M BC l - α AB s x 2 - α CD s ( 1 - y ) 2 + α x x ( 1 - y ) } 2
with
x A l +x B l +x C l +x D l =1
The problem is solved by searching for an optimisation solution where the value of F(x A l , x B l , x C l ) is the smallest.
There are a number of methods to solve such a least square minimisation problem, and we have selected the Levenberg-Marquardt Method as it is the most efficient for such iterations.
With a constant temperature in VP-LPE, the supercooling state will be related to the growth pressure. Since pressure is easy to control, the supercooling state can be changed rapidly and precisely. Theoretically, devices with more complicated structures can be grown with VP-LPE.
EXAMPLE 1
The phase diagrams of the quaternary InGaAsSb are calculated based on the thermodynamic parameters of Dolginov (Drakin, A. E., Eliseev, P. G., Sverdlov, B. N., Bochkarev, A. E., Dolginov, L. M., Duzhinina, L. V., Journal of Quantum Electronics, 23, 1089-1094, 1987). To simplify the calculations, we assume that the relation between the melting point and the pressure is given by
T ( p )= T o −30 ×p (0 atm≦ p ≦1 atm)
where T o denotes the melting point at standard atmospheric pressure, T(p) denotes the melting point at pressure p (atm), and the parameter 30 is obtained from growth experiments. Using this simplification, we obtained the phase diagrams of the quaternary with a Ga-rich source.
Taking In 0.1 Ga 0.9 As 0.087 Sb 0.913 as an example of a lattice-matched quaternary to GaSb, we have worked out the phase diagram at 550° C. as a function of the growth pressure. The results are similar to those of InAsSb ternary and are illustrated in FIGS. 4 to 7 .
When the pressure increases, the As and Sb content decreases (FIGS. 6 and 7 ). On the contrary, the In and Ga content increases with an increasing growth pressure (FIGS. 4 and 5 ). This can be explained as less group V ingredients dissolve in the group III solvent when the pressure increases.
All four curves are monotonous. The phase diagram as a function of temperature in normal LPE is complicated and non-monotonous. A monotonous relationship in variable pressure LPE is beneficial to ingredients control in the solid film.
EXAMPLE 2
FIG. 8 is an illustration of an example of an apparatus suitable for carrying out the invention. The refractory furnace boat 11 comprises a melt chamber 12 . The moveable slide 13 is coplanar with the plane of the bottom of the melt chamber 12 . A slot 14 , at the upper surface of the slide 13 is provided. The slot 14 is large enough to accommodate the substrate 15 , with a depth slightly more than the thickness of the substrate. A quantity of growth solution or melt 16 fills part of the melt chamber 12 . The entire apparatus is in a pressure chamber 21 and the pressure of the chamber can be varied.
In FIG. 8 ( a ), with the substrate 15 out of the melt region, the pressure is set such that the solution is supersaturated. The pressure depends on the desired composition of the epitaxial layer. In FIG. 8 ( b ), the substrate 15 comes into contact with the growth solution 16 for a controlled period of time. During this period of growth time, the pressure can be varied in order to realise a compositionally graded layer. In FIG. 8 ( c ), the substrate is moved out of the melt region with the epitaxial layer 17 grown.
It is understood that the variable pressure LPE technique is applicable to other LPE growth techniques, such as the dipping technique.
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The invention provides a method of growing semiconductor epitaxial layers on a substrate comprising the steps of
providing a substrate, providing at least a first growth solution and optionally one or more further growth solutions, and (i) exposing the substrate to the first growth solution, the growth solution being under a supersaturated condition such that a first layer grows on the surface of the substrate; and, (ii) optionally exposing the substrate to one or more further growth solutions, the further growth solutions being under a supersaturated condition such that one or more further layers grow on the surface of the first layer; and (iii) varying the pressure of the system to change the degree of supersaturation of the first growth solution or one or more further growth solutions to affect the growth of the first layer or one or more further layers.
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BACKGROUND OF THE INVENTION
The present invention relates to a process for the densification of a porous structure consisting of filling the voids, gaps or cavities of a porous structure by introducing thereinto an identical or different material from that forming the structure. The filling of the cavities of the structure lead to an increase in the density thereof, which justifies the use of the word "densification".
The invention more particularly applies to the densification of fabrics or felts of a bidirectional or tridirectional nature, which can advantageously be used as a result of their high mechanical strength, their excellent thermal insulation capacity and their good resistance to impacts and abrasions for the production of brake disks.
Hitherto, the densification methods which have been used have consisted of immersing the structure to be densified in a liquid bath of pitch or pyrolyzable resins and then pyrolyzing the pitch or resin so as to rigidify the assembly, or placing the structure to be densified in a gas stream, such as a stream of gaseous hydrocarbons and then raising it to a high temperature, e.g. in such a way as to crack the gaseous hydrocarbons in order to obtain carbon or pyrolytic graphite, which can be deposited in the cavities of the structure. Unfortunately, the time necessary for performing these processes is generally too long, when it is desired to obtain a high density structure.
BRIEF SUMMARY OF THE INVENTION
The invention relates to a novel process for the densification of a porous structure making it possible to obtain a high density structure in a much shorter time than that necessary for the densification carried out according to the prior art processes.
More specifically, the present invention relates to a process for the densification of a porous structure, wherein the structure is immersed in a liquid hydrocarbon and is heated by induction so as to form, by decomposition of the hydrocarbon, carbon or pyrolytic graphite which can be deposited in the pores or cavities of the structure.
This process applies in a non-exclusive manner to the densification of a carbon or graphite porous structure.
According to a preferred embodiment of the process according to the invention, the porous structure immersed in the liquid hydrocarbon is heated to a temperature between 1000° and 1300° C.
According to another preferred embodiment of the process according to the invention, the liquid hydrocarbon is cyclohexane.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail hereinafter relative to non-limitative embodiments and the attached drawings, wherein:
FIG. 1 shows, diagrammatically, a device for performing the process according to the invention.
FIG. 2 depicts curves giving the density d of a densified structure as a function of the time t expressed in hours h; curve a corresponding to a densification according to the invention and curve b to a densification by deposition in the gaseous phase.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the invention, the process consists of immersing a porous structure made e.g. from carbon or graphite in a liquid hydrocarbon, such as for example cyclohexane, and heating it by induction and preferably to a temperature between 1000° and 1300° C. in order to form, by decomposition of the hydrocarbon, pyrolytic graphite or carbon, which is deposited in the cavities or pores of the structure.
FIG. 1 shows a device for performing the process according to the invention. The porous structure 2 to be densified is placed on a rotary mandrel or support 4. This support or mandrel, made for example from graphite is placed in the lower part of the body of the reactor 6, which has a plug 5 provided with an opening through which can slide support 4. Reactor 6 can be heated by means of an induction heating device 8 constituted by coils 10 in which can circulate a high frequency current supplied by a generator 9. The upper part of reactor 6 is sealed by a cover 12, provided with a pipe 14 used for introducing liquid hydrocarbon into the reactor and a pipe 16 used for introducing a neutral gas into the reactor and which is used for expelling the air contained in said reactor.
Furthermore, cover 12 is surmounted by a condenser 18 permitting the separation of the unconsumed hydrocarbon, which is recovered and the neutral gas which is eliminated. The condensation of the different vapours is ensured by a circulation of water in the condenser jacket 19.
This device is also provided with a system making it possible to determine the temperature prevailing in reactor 6, said system being constituted e.g. by thermometer probes 20 located in the reactor body.
A description will now be given of a handling sequence with the device as described hereinbefore. This handling or manipulation firstly consists of placing the structure to be densified 2 on its rotary support 4 and then sealing the upper part of reactor 6 by means of cover 12 surmounted by condenser 18, the reactor then being equipped with its heating system 8. When this has been done, it is possible to fill reactor 6 with liquid hydrocarbon 22 until the porous structure to be densified is completely immersed. The complete installation is then scanned by a stream of inert gas making it possible to expel the air present in the installation. After opening the cooling circuit 18, support 4 can be rotated by means of a motor 24 located outside the reactor. The reactor can then be heated by heating system 8 and is then kept at a particular temperature level for a few minutes. The temperature level is measured by means of probes 20.
The heated liquid hydrocarbon vaporizes and then decomposes into carbon or pyrolytic graphite and hydrogen. The carbon or pyrolytic graphite can then be deposited within the structure to be densified, whereas the hydrogen and the undecomposed hydrocarbon are discharged from the upper part of the reactor. The hydrocarbon vapours are condensed in the condenser 18 provided for this purpose and the hydrogen is expelled to the outside by pipe 26. At the end of about 10 minutes, it is possible to discontinue heating and then allow cooling to take place to ambient temperature. After emptying the reactor by means of a cock 28 located in the lower part of the reactor, followed by the opening of the latter, the densified member can be removed.
By analogy with boiling phenomena of different liquids in which the hot body is immersed, it would appear that different stages for this experiment can be defined. Initially, the liquid hydrocarbon is heated by natural convection and evaporation thereof only takes place on the surface of the liquid. Boiling of the liquid then continues and gas bubbles form level with the porous structure and rise through the liquid mass producing natural circulation streams. At this time, the immersed porous structure is separated from the liquid by a vapour film. It is then that the gas diffuses through the porous structure and carbon or pyrolytic graphite forms.
In view of the fact that the carbon or graphite is initially deposited in contact with the mandrel, a densification gradient is obtained from the interior to the exterior of the structure. As in the prior art processes using deposition in the gaseous phase, the deposition rate of the graphite and the pyrolytic carbon is proportional to the hydrocarbon concentration.
FIG. 2 shows curves giving the density d of a densified structure as a function of time t. Curve a corresponds to densification according to the invention and curve b to densification by deposition in the gaseous phase.
Curve a has been plotted on the basis of a carbon fabric of initial density 0.1 and curve b on the basis of a carbon felt of initial density 0.1.
Comparison of these two densification curves show that the average impregnation speed of the porous structure by cyclohexane is approximately 100 times greater than that obtained by deposition in the gaseous phase. However, it should be noted that fabrics are always more difficult to impregnate than felts.
Moreover, studies have shown that porous structures densified according to the process of the invention have a texture and also physical characteristics identical to those obtained in porous structures densified according to the prior art processes.
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A process is disclosed for the densification of a porous structure. The structure is immersed in a liquid hydrocarbon and is heated by induction so as to form, by decomposition of the hydrocarbon, carbon or pyrolytic graphite which can be deposited in the pores or cavities of the structure. The process may be used for the densification of fabrics or felts for use in pads in disc brakes.
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FIELD OF THE INVENTION
The present invention relates to a device for restraining the hands of an individual such as a criminal. More particularly, the invention is a device for use with standard handcuff bracelets which prevents the individual from using his fingers and thumbs.
BACKGROUND OF THE INVENTION
A recurring problem for law enforcement officials is how to adequately restrain a prisoner during arrest and transport. Normally, law enforcement officials attempt to restrain the criminal by handcuffing his hands together.
As is well known, handcuffs comprise a pair of linked circular bands or bracelets which are selectively lockable about the criminal's wrists. Typically, a chain connects the bands or cuffs.
Handcuffs are effective in preventing a criminal from separating his hands by a distance greater than the length of the chain between the cuffs. The handcuffs thus limit the range of movement of the hands and arms of the criminal. Because a criminal's hands are linked together, the movement of the criminal's arms with respect to his body is also limited. For this reason, handcuffing a criminal's hands behind his back is especially effective.
While handcuffs are effective in limiting a criminal's movement of his hands with respect to one another and of his arms with respect to his body, the handcuffs do not restrain his fingers and thumbs. Thus, occasionally, a handcuffed criminal has grasped a nearby gun or similar item and escaped law enforcement or caused injury.
Others have proposed devices for restraining the hands of individuals. These devices have not been easy to use, are not convenient, or are too complex.
SUMMARY OF THE INVENTION
The present invention is a device for restraining the hands of an individual. In particular, the device comprises a pair of mitts for location over the hands of an individual to prevent the wearer from using his fingers and thumbs. Advantageously, the device of the present invention is useful with standard handcuffs. The mitts of the present invention are useful with a pair of standard handcuffs to handcuff an individual's hands together, and prevent the individual from using his fingers and thumbs.
The mitts comprise sleeves of material having an outer surface, and a closed end and an open end forming an interior pocket. The mitts have a hand-enveloping portion of a durable Cordura™ material and an elastic wristband at the open end. Preferably, extensions of the durable hand-enveloping portion extend across the wristband along the sides of each mitt.
A ring is connected to the extension of each mitt at the wristband section. Each ring is preferably a rectangular link of plastic connected with a loop of material to the mitt. Each ring has an inner dimension sized to allow passage of a handcuff therethrough.
A rib of material encircles the wristband at the open end of each mitt. Preferably, the rib comprises a Cordura™ cord of circular cross-section attached to the wristband.
In use, the mitts are placed over a wearer's hands. A handcuff passes through each ring on each mitt, encircling the wearer's wrists over the outside of the wristband. The handcuffs are closed and locked around the wearer's wrist.
The mitts prevent the wearer from using his fingers or thumbs. Advantageously, the handcuffs prevent the wearer from removing the mitts, and handcuff the wearer's hands together.
The elastic wristband material hugs the wearer's wrists, preventing the wearer from slipping items into the mitts, and making it more difficult for the wearer to pull the mitts off. The rib on each mitt prevents the user from sliding the handcuff over and off the wristband of the mitt in an attempt to remove the mitt from his hand.
Further objects, features, and advantages of the present invention over the prior art will become apparent from the detailed description of the drawings which follows, when considered with the attached figures.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the hand-restraining device of the present invention illustrating two mitts connected by a pair of handcuffs; and
FIG. 2 is a top view of one of the mitts illustrated in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 and 2 illustrate a device 10 for restraining the hands of an individual in accordance with the present invention. In general, the device 10 comprises a first mitt 12 and a second mitt 14 for connection with a pair of handcuffs 16a,b.
Each mitt 12,14 comprises an enclosed sleeve of material sized to envelop a person's hand and a portion of their wrist. Each mitt 12,14 preferably comprises a hand enclosure 18,20, and a wristband 22,24. A rigid plastic ring 58,60 is mounted on an outer surface 26,28 of each mitt 12,14 with a loop 62,64 of material for engagement with the handcuffs 16.
In use, the mitts 12,14 are placed over the wearer's hands in the position shown in FIG. 1. Each handcuff 16a,b is passed through the ring 58,60 and around the outside of the wristband 22,24 of the mitt 12,14 which covers the wrist of the wearer. Each handcuff 16a,b is locked, preventing the wearer from removing the mitts 12,14, and precluding the wearer's use of his fingers and/or thumbs to grasp objects and the like.
Referring again to FIGS. 1 and 2, the device 10 of the present invention will be described in detail. Each mitt 12,14 comprises a sleeve such that the mitt has an inner surface 25,27, an outer surface 26,28, an open end 30,32, and closed end 34,36.
The hand enclosure 18,20 of each mitt 12,14 comprises a pocket of material for enveloping a wearer's hand. To comfortably accommodate the wearer's hands, the mitts 12,14 are preferably elliptical in shape, having a width from a top side 38,40 (corresponding to the "thumb" side of the wearer's hands) to a bottom side 42,44 which is greater than the thickness from a front or outwardly facing surface 46,48 (corresponding to the "top" of a wearer's hands), to a back or inwardly facing surface 50,52 (corresponding to the "palm" of a wearer's hand). For example, the width of the mitts 12,14 may be about 5 to 6 inches, and the thickness may be about 1.5 to 2 inches.
Preferably, two reinforcing extensions 54a,b and 56a,b for supporting the rings 58,60 extend from the hand enclosure 18,20 along the sides of each mitt 12,14 across the wristband 22,24. Each extension 54a,b 56a,b thus coterminates with the wristband 22,24 at the open end 30,32 of the mitt 12,14.
Preferably, the hand enclosure 18,20 and extensions 54a,b 56a,b of each mitt 12,14 are constructed from a durable, fairly slick and semi-rigid fabric or similar material, such as the nylon based fabric material called Cordura™ available from DuPont. This material is preferred because it is fairly rigid and slick, making it difficult for a wearer to grab items through the mitt 12,14. Also, material such as Cordura™ is very durable, reducing the possibility that the wearer will tear or wear a hole in the material of the mitt 12,14, allowing him to use his fingers and thumb. While Cordura™ is the preferred fabric, other materials having similar properties and satisfying the criteria stated above may be useful.
The wristband 22,24 is positioned at the open end 30,32 of each mitt 12,14, extending from the hand enclosure 18,20 of each mitt. Thus, the wristbands 22,24 serve to lengthen the hand enclosure of each mitt 12,14.
Preferably, the wristbands 22,24 comprise an elastic cloth material. This material "clings" to the wearer's wrist, helping keep the mitts 12,14 in place, and reducing the possibility that the wearer can slip something into the mitts 12,14.
A rib, lip or bead 66,68 encircles the wristband 22,24 of each mitt 12,14 at the open end 30,32 thereof. This lip 66,68 preferably comprises a cord of semi-rigid durable material such as Cordura™, and preferably has a circular cross-section. As illustrated in FIG. 2, the lip 66,68 is connected to the wristband 22,24 on the outer surface 26,28 of the mitt 12,14, thus extending outwardly therefrom.
The rings 58,60 are attached to the exterior of the top side 38,40 of each mitt 12,14. Each ring 58,60 preferably comprises a rectangular loop or link of plastic having an interior dimension greater than the outer dimension of the handcuff 16a,b used therewith. When rectangular in shape, the rings 58,60 preferably extend lengthwise outwardly from the mitts 12,14 for engagement with the handcuffs 16a,b.
The rings 58,60 are preferably connected to each mitt 12,14 by a small loop 62,64 of material attached to the wing 54a, 56a located on the top side 38,40 of each mitt.
Use of the restraining device 10 of the present invention is as follows. First, the mitts 12,14 are pulled onto and over an individual's hands. The mitts 12,14 are oriented in such a manner than the side of each mitt having the ring 58,60 thereon corresponds to the "thumb" side of the wearer's hand. The double bar or lock portion of each handcuff 16a,b is placed on the side of the mitt 12,14 opposite the ring, and the free end of the handcuff is passed through the ring 12,14 and secured in the double-bar lock. At this time, each handcuff 16a,b, passes around the wearer's wrist in such a manner to secure the mitts 12,14 over the wearer's hands, but do not cause discomfort or injury.
Advantageously, the device 10 of the present invention reduces the possibility that the wearer can use his fingers and/or thumbs. The mitts 12,14 are useful with a pair of standard handcuffs, thus further restricting the wearer's use of his hands. Moreover, when used with handcuffs, the wearer can not remove the mitts. In particular, the handcuffs 16a,b tightly engage the wearer's wrists, and at the same time pass through the rings 58,60 on the mitts 12,14, preventing the wearer from removing the mitts without removing the handcuffs. The connection of the mitts 12,14 to the handcuffs 16a,b to accomplish these features is also simple and quick.
As stated above, the wristband 22,24 of each mitt 12,14 is preferably constructed of an elastic material so that it hugs the wearer's wrist. The engagement of the elastic wristbands 22,24 with the wearer's wrists also serves to make it difficult for the wearer to remove the mitts 12,14. however.
The wristband 22,24 may be made of other materials. For example, the wristband 22,24 may just be a narrower extension of the hand enclosing portion 18,20. In any case, the wristband 22,24 is preferably a portion of the mitt 12,14 which extends slightly beyond the wearer's hand and over a portion of the wrist, to protect the wearer's wrist from the handcuff. In that instance, it may be desirable to provide a cinch strap, or hook and loop fastener or similar means for constricting the wristband material tightly around the wearer's wrists.
The rib, bead or lip 66,68 on each mitt 12,14 serves to make it more difficult for a wearer to slip the handcuffs 16a,b over and off the wristband portion of each mitt. In particular, when the handcuffs 16a,b are secured around the wearer's wrists, the outwardly extending semi-rigid lips 66,68 act as a barrier to removal of the handcuffs.
The rings 58,60 which connect the handcuffs 16a,b and mitts 12,14 may have any of several shapes, and be constructed of any durable, relatively non-breakable material. For example, the rings 58,60 may comprise steel loops. Preferably, however, and as stated above, the rings 58,60 have an inner dimension close to the outer dimension of the handcuffs to reduce the possibility of the wearer breaking the rings by through movement of the cuffs within the rings.
The loops 62,64 of material which connect the rings 58,60 to the mitts 12,14 may themselves comprise steel, plastic or similar rings which are connected to the mitts 12,14 by sewing, rivets, or similar means. The loops 62,64 are preferably connected to the wings 54a, 56a when the wings 54a, 56a are made of Cordura™ (or similar material) because this material is generally more durable than the elastic material of the wristbands 22,24.
The extensions 54a,b 56a,b are preferably Cordura™ material not only to strengthen the portion of the mitt 12,14 where the rings 58,60 are connected, but to increase the useful life of the mitts. In particular, rubbing of the handcuffs 16a,b against the soft elastic cloth wristband 22,24 may wear the wristbands excessively. The extensions 54a,b 56a,b serve to reduce the wear of the mitts 12,14 at the points where the cuffs most frequently contact the mitts: the areas comprising the intersection of the top and bottom sides 38-42 with the front and back 46-52 of the outer surface 26,28 of the mitts 12,14.
It will be understood that the above described arrangements of apparatus and the method therefrom are merely illustrative of applications of the principles of this invention and many other embodiments and modifications may be made without departing from the spirit and scope of the invention as defined in the claims.
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A hand restraint device for restraining the hands of an individual and preventing them from using their fingers and thumbs is disclosed. The hand restraint device comprises a pair of mitts for connection to a pair of standard handcuffs. The mitts comprise pockets of material with a closed end and open end for enveloping the hands of the wearer. Each mitt includes a durable hand enclosure and elastic wristband. The handcuffs encircle the wearer's wrists, passing through a ring connected to the outside of the wristband of each mitt. A rib is located at the open end of each mitt on the outside of each wristband, preventing the wearer from sliding the mitts from underneath the handcuffs.
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ORIGIN OF THE INVENTION
This invention was made by an employee of the United States Government and may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor. Pursuant to 35 U.S.C. §119, the benefit of priority from provisional application 60/990,673, with a filing date of Nov. 28, 2007, is claimed for this non-provisional application, and the specification thereof is incorporated in its entirety herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to electrospinning. More specifically, the invention is a method of predicting as well as optimizing various parameters for an electrospinning system using a single exemplary test run of the system.
2. Description of the Related Art
Electrospinning is a polymer manufacturing process that has been revived over the past decade in order to produce micro and nano-fibers as well as resulting fiber groups (or mats as they are known) with properties that can be tailored to specific applications by controlling fiber diameter and mat porosity. The individual fibers are formed by applying a high electrostatic field to a polymer solution that carries a charge sufficient to attract the solution to a grounded source. The polymer solution is ejected as a stream from a spinneret. The stream is directed towards a collector where it forms a fiber thereon. Parameters that determine fiber formation include physical system parameters defining the spinneret, the collector, and the distance between the spinneret and collector, as well as material parameters such as polymer solution viscosity, polymer/solvent interaction, surface tension, applied voltage, and the conductivity of the solution.
Typically, only non-woven mats can be produced during this process due to splaying of the fibers and jet instability of the polymer expelled from the spinneret. These non-woven mats are used as scaffolds for tissue engineering, wound dressings, clothing, filters and membranes. While non-woven mats have proven to be useful for a variety of applications, controlling fiber alignment in the mat is a desirable characteristic to expand the applications of electrospun materials. Particularly for the case of tissue engineering scaffolds, the control of fiber distribution, fiber alignment, and porosity of the scaffold are crucial for the success of any scaffold. Current manufacturing techniques are limited by erratic polymer whipping that often produces dense nano-fiber mats, which cannot support cell infiltration or cell alignment.
An improved system for aligning fibers in an electrospinning process was recently disclosed in U.S. patent application Ser. No. 12/131,420, filed Jun. 2, 2008. Briefly, this new system and technique direct a jet of a fiberizable material towards an uncharged collector from a dispensing location that is spaced apart from the collector. While the fiberizable material is directed towards the collector, an elliptical (the term “elliptical” including elliptical and all dipole field-like shapes, including both symmetric and unsymmetric, and including both spherical and ovoid) electric field is generated. The electric field spans between the dispensing location and a control location that is within line-of-sight of the dispensing location such that the electric field impinges upon at least a portion of the collector. The generation of the elliptical electric field and placement of the uncharged collector therein provide for fiber alignment when the fiberizable material is deposited on the collector. However, development of a particular fiber mat design requires a lengthy trial-and-error process to establish the various system parameters.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a method of selecting or predicting a number of system parameters for an electrospinning system.
Another object of the present invention is to provide a method of optimizing system parameters for an electrospinning system without requiring a lengthy trial-and-error process.
Other objects and advantages of the present invention will become more obvious hereinafter in the specification and drawings.
In accordance with the present invention, a method is provided for optimizing electrode parameters for an electrospinning configuration. The system for fabricating an aligned-fiber mat includes: a conductive, semi-conductive or non-conductive collector; an electrically-conductive spinneret having an output facing the collector and maintained in a spaced-apart relationship therewith; an electrode having a tip positioned at a control location that is spaced apart from the collector, with the collector being substantially disposed between the output and tip while they remain in line-of-sight of one another and aligned along a defined x-axis; the output and the tip having substantially the same geometric shape, the application of voltages of opposing polarity to the spinneret and electrode; and the pumping of a fiberizable material through the spinneret. The system is first operated for a fixed amount of time at known values of i) the voltages, ii) a distance between the spinneret output and the electrode tip, iii) length of the spinneret, iv) length of the electrode, v) radius of the spinneret, and vi) radius of the electrode. As a result, a fiber mat is deposited on the collector. The fiber mat has a measured fiber mat width associated therewith. Next, acceleration of the fiberizable material at the spinneret output is modeled to determine values of mass, drag, and surface tension associated with the fiberizable material at the spinneret output. Modeling is repeated until the values are in correspondence with the measured fiber mat width. The model used to determine the values of mass, drag, and surface tension is then applied in an inversion process to generate predicted values of an electric charge at the spinneret output and an electric field between the spinneret and electrode corresponding to a selected fiber mat design. More specifically, the inversion modeling uses the earlier-determined particular width and values for mass, drag, and surface tension to generate the predicted values of electric charge and electric field. The electric charge and field are indicative of design values for i) the voltages, ii) the distance between the spinneret output and electrode tip, iii) length of the spinneret, iv) length of the electrode, v) radius of the spinneret, and vi) radius of the electrode. The design values are used as the system parameters when fabricating the selected fiber mat design.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a system for producing aligned electrospun fibers;
FIG. 2 is a side view of a portion of the system in FIG. 1 taken along line 2-2 thereof and illustrating positions for the fiberizable material dispenser and the electrode in accordance with an embodiment of the system, and
FIG. 3 is a diagrammatic representation of the fiberizable material dispenser, collector, and electrode illustrating various system parameter relationships.
DETAILED DESCRIPTION OF THE INVENTION
Prior to describing the method of the present invention, an exemplary electrospinning system will be described. This electrospinning system is one that can benefit from the novel system parameter optimization scheme of the present invention. The electrospinning system shown and described herein has been previously disclosed in the afore cited U.S. patent application Ser. No. 12/131,420, filed Jun. 2, 2008.
Referring now to the drawings and more particularly to FIG. 1 , the exemplary electrospinning system for fabricating a mat of aligned fibers is shown and is referenced generally by numeral 10 . For simplicity of discussion, system 10 will be described for its use in producing a single-ply mat with aligned single fibers or fiber bundles that are substantially parallel to one another. However, as will be explained further below, the system can also be used to produce a multiple-ply mat where fiber orientation between adjacent plies is different to thereby create a porous multi-ply mat. Such multi-ply porous mats could be used in a variety of industries/applications, as would be understood by one of ordinary skill in the art.
In general, system 10 includes a dispenser 12 capable of discharging a fiberizable material 14 therefrom in jet stream form (as indicated by arrow 14 A) that will be deposited as a single fiber or fiber bundles (not shown) on a collector 16 . Dispenser 12 is typically a spinneret through which fiberizable material 14 is pumped, as is well known in the art of electrospinning. The type and construction of dispenser 12 will dictate whether a single fiber or fiber bundles are deposited on collector 16 . Fiberizable material 14 is any viscous solution that will form a fiber after being discharged from dispenser 12 and deposited on collector 16 . Typically, material 14 includes a polymeric material and can include disparate material fillers mixed therein to give the resulting fiber desired properties. Collector 16 can be a static plate, a wire mesh, a moving-conveyor-type collector, or a rotating drum fabricated in a variety of shapes and configurations, the choice of which is not a limitation of the present invention. For the illustrated example, collector 16 will be rotated about its longitudinal axis 16 A as indicated by rotational arrow 16 B. Collector 16 is maintained in an electrical uncharged state (e.g., floating or coupled to an electric ground potential 18 as illustrated). The fiber deposition surface of collector 16 can be electrically conductive, semi-conductive, or non-conductive.
Dispenser 12 is positioned such that its dispensing aperture 12 A faces collector 16 a short distance therefrom as would be understood in the electrospinning art. For example, if dispenser 12 is a spinneret, aperture 12 A represents the exit opening of the spinneret. In the present invention, the portion of dispenser 12 defining aperture 12 A should be electrically conductive. Typically, dispenser 12 is a “needle electrode.” As is known in the art, a needle electrode is essentially a hollow tube made from an electrically conductive material. A voltage source 20 is coupled to dispenser 12 such that an electric charge is generated at the portion of dispenser 12 defining aperture 12 A.
Positioned near collector 16 and within the line-of-sight of aperture 12 A is an electrode 22 . More specifically, a tip 22 A of electrode 22 is positioned within line-of-sight of aperture 12 A as is readily seen in FIG. 2 where dashed line 24 indicates the line-of-sight communication between aperture 12 A and electrode tip 22 A. A voltage source 26 is coupled to electrode 22 such that an electric charge is generated at electrode tip 22 A. The charge is opposite in polarity to that of the charge on the portion of dispenser 12 defining aperture 12 A. That is, if the charge is positive at aperture 12 A (as indicated), the charge should be negative at electrode tip 22 A (as illustrated) Similarly, if the charge is negative at aperture 12 A, the charge should be positive at electrode tip 22 A. The magnitude of the voltages applied to dispenser 12 and electrode 22 can be the same or different, although they are typically the same.
The opposite-polarity charges at dispenser aperture 12 A and electrode tip 22 A cause an elliptical electric field to be generated therebetween as represented by dashed lines 30 . Typically, aperture 12 A and electrode tip 22 A will be circular, and they can be the same or different in terms of their size. Since aperture 12 A and electrode tip 22 A are in line-of-sight of one another, some portion of electric field 30 will impinge upon the surface of collector 16 . This will be true whether electrode tip 22 A is positioned centrally with respect to collector 16 (as illustrated), or at any position along collector 16 . For purpose of an illustrated example, dispenser 12 is a cylindrical needle electrode while electrode 22 is a cylindrical electrode having the same outer dimensions as dispenser 12 . Further, aperture 12 A and electrode tip 22 A are aligned along an axis referenced by line-of-sight communication line 24 .
In operation, dispenser 12 and electrode 22 are positioned with respect to collector 16 as described above. Opposite-polarity voltages are applied to dispenser 12 and electrode 22 in order to establish electric field 30 with at least a portion of collector 16 being disposed in electric field 30 . Fiberizable material 14 is plumped from dispenser 12 such that a jet stream 14 A thereof is subject to electric field 30 . A pulsed electric field, generated for example by pulsing the voltages applied to dispenser 12 and electrode 22 , may also be used.
As mentioned above, the present invention is a method of predicting and optimizing the various physical system parameters for an electrospinning system such as the one described herein. A diagrammatic representation of dispenser 12 (e.g., a cylindrical needle electrode), collector 16 (e.g., a rotating drum), and electrode 22 (e.g., a cylindrical electrode), is illustrated in FIG. 3 with various system parameters being denoted. It is to be understood that relative sizes of and distances between dispenser 12 , collector 16 , and electrode 22 are not to scale as they are merely sized and positioned to facilitate a description of the present invention. The line-of-sight communication axis 24 forms the x-axis for the relationships discussed below. The y-axis denotes the reference direction for the width of the fiber mat (not shown) that gets deposited on collector 16 during the electrospinning process.
The external dimensions of dispenser 12 and electrode 22 are the same for the following explanation where the length of cylindrical dispenser 12 and cylindrical electrode 22 is “L”, and the distance between dispenser aperture 12 A and electrode tip 22 A is “D”. These parameters are illustrated along the x-axis and are referenced to an origin defined at dispenser aperture 12 A. Points in a spatial region of free-space between dispenser aperture 12 A and electrode tip 22 A are referenced by coordinate (x′,y′) The charge density on dispenser 12 due to an applied voltage is “ρ”, and the charge density on electrode 22 due to an equal and opposite applied voltage is “−ρ”. The external radius of dispenser 12 and electrode 22 is “R”,
Using an electrospinning system as described above, the present invention first requires an exemplary test run of the system in order to generate a sample fiber mat where the width dimension thereof is used in the predicting/optimizing scheme. Briefly and with simultaneous reference to FIGS. 1-3 , system 10 is operated for some short and fixed period of time (e.g., on the order of seconds) with the various system parameters being known. That is, system 10 is set up such that voltage sources 20 and 26 apply equal and opposite voltages to dispenser 12 and electrode 22 , respectively. Further, distance D is known, length L is known (and the same for dispenser 12 and electrode 22 in this example), and the radius R of dispenser 12 and electrode 22 is known (and the same in this example). As a result of this operation, a sample fiber mat (not shown) will be deposited on collector 16 . The width of the fiber mat along the axial length of collector 16 (i.e., perpendicular to axis 24 ) is measured and is designated herein as “y N ”.
In the remaining steps of the present invention, well known electric field/potential relationships (as they apply to electrospinning) and a novel particle acceleration model are used to predict and optimize various system parameters when a particular fiber mat design is to be fabricated. The development of the model will now be explained.
The electric field generated between dispenser aperture 12 A and electrode tip 22 is the negative gradient of the electric potential, given by the well known relationship
E=−∇V (1)
where E is the electric field and V is the electric potential that can be calculated for points in the free-space region between dispenser aperture 12 A and electrode tip 22 A in accordance with
V
(
x
,
y
)
=
1
ɛ
0
(
q
1
r
1
+
q
2
r
2
)
(
2
)
where q 1 is the charge on dispenser 12 for a given applied voltage,
q 2 is the charge on electrode 22 for a given applied voltage,
r 1 is the distance from the charge at dispenser 12 to the location (x,y) in the free-space region,
r 2 is the distance from the charge at electrode 22 to the location (x,y) in the free-space region, and
ɛ o = 8.8541878176 × 10 - 12 C 2 J · m
is the permittivity of free space.
For the exemplary arrangement at some point (x′,y′) in the free-space region,
V
(
x
′
,
y
′
)
=
ρ
ɛ
0
∫
-
L
0
ⅆ
x
(
(
x
′
-
x
)
2
+
y
′2
)
1
/
2
+
-
ρ
∫
D
D
+
L
ⅆ
x
(
(
x
′
-
x
)
2
+
y
′2
)
1
/
2
(
3
)
where the charge density ρ is calculated based upon the required voltage to bring the potential on dispenser 12 and electrode 22 to the operating voltage V O . The charge density is given by
ρ
=
±
V
O
ɛ
0
/
∫
-
L
/
2
L
/
2
ⅆ
x
/
(
x
2
+
R
2
)
1
/
2
(
4
)
In these equations for the exemplary arrangement, D is the distance between dispenser aperture 12 A and electrode tip 22 A, L is the length of dispenser 12 and electrode 22 , R is the radius of dispenser 12 and electrode 22 , and
ɛ o = 8.8541878176 × 10 - 12 C 2 J · m
is the permittivity of free space.
By assuming that the charge q 0 on a droplet of polymer at dispenser aperture 12 A is that required to bring the surface potential to the operating voltage, all parameters needed to calculate the electrostatic force “F” throughout the above-defined free-space region can be defined. The acceleration vector “A” for the polymer droplet can be written in accordance with the well known relationship
A
=
F
m
=
q
0
E
m
(
5
)
where “m” is the mass of the polymer particle.
In addition to the electrostatic forces, the polymer kinetics are dependent upon drag and the surface tension of the polymer as it exits dispenser 12 . In the exemplary system described above, these effects can be modeled as additional forces on the polymer droplet. Drag “μ” is modeled as a force proportional to the square of the velocity “v” of the droplet in the opposite direction of the droplet's velocity vector “v”. Surface tension “σ” is modeled as a force inversely proportional to the cube of the distance “d” between dispenser aperture 12 A and the droplet along the vector “d” from the droplet to dispenser aperture 12 A. Thus, the novel acceleration model applied in the present invention models the kinetics of the polymer during electrospinning as follows
A
i
=
1
m
(
q
0
E
-
μ
v
i
2
v
i
v
i
-
σ
d
i
3
d
i
d
i
)
,
(
6
a
)
v
i
+
1
=
A
i
Δ
t
+
v
i
,
(
6
b
)
d
i
+
1
=
A
i
(
Δ
t
)
2
2
+
v
1
(
Δ
t
)
+
d
i
,
(
6
c
)
d
n
=
x
n
x
+
y
n
y
(
6
d
)
where q 0 is the charge on the droplet exiting dispenser aperture 12 A,
E is an electric field between dispenser 12 A and electrode 22 ,
v i is the velocity of the droplet at an instant (Δt*i) in a fixed amount of system operating time,
v i is the velocity vector at the i-th instant,
d i is a distance from dispenser aperture 12 A to the droplet at the i-th instant,
d i is the distance vector associated with the distance d i ,
x is a unit vector aligned with the x-axis defined by line-of-sight axis 24 ,
y is a unit vector perpendicular to the x-axis,
x n is equal to the distance D, and
y n is equal to the width of the fiber mat deposited on collector 16 during the fixed amount of system operating time.
In accordance with the present invention, the particle acceleration model presented in equations (6a)-(6d) is first used in an iteration process. Specifically, the model is iterated over the amount of time used to create the sample fiber mat in order to generate values for mass m, drag μ, and surface tension σ that will yield, at the n-th time step, a calculated fiber mat width y n that is equal to (or within an acceptable tolerance) of the sample fiber mat width y M . As would be understood by one of ordinary skill in the art, the iteration process begins with some selected initial values for mass, drag, and surface tension.
Following the iteration process, the determined values for mass, drag, and surface tension are used in an inversion application of the particle acceleration model that yields optimized predictions of system parameters. More specifically, the inversion application solves the particle acceleration model using a combination of (i) a value for y n that is set equal to a desired fiber mat width, and (ii) the determined values of mass, drag, and surface tension. Solving the model with these given parameter values yields both the required charge and the electric field. The above-described equations (1)-(4) are then used in a straight-forward fashion to define the operating voltages V O , distance D, length L, and radius R.
The present invention is further described in Carnell, Lisa S.; Wincheski, Russell A.; Siochi, Emilie, J.; Holloway, Nancy M.; and Clark, Robert L., “Electric Field Effects on Fiber Alignment Using an Auxiliary Electrode during Electrospinning,” 2007 Materials Research Society (MRS) Fall Meeting, 29 Nov. 2007, Boston, Mass., the contents of which are hereby incorporated by reference in their entirety.
The advantages of the present invention are numerous. Parameter prediction and optimization for a recently-developed electrospinning technique will enhance the value thereof. The results of a single sample run for the electrospinning system in combination with a novel particle acceleration model will allow system parameters to be defined without time-consuming trial-and-error processing.
Although the invention has been described relative to a specific embodiment thereof, there are numerous variations and modifications that will be readily apparent to those skilled in the art in light of the above teachings. The present invention can be readily extended to electrospinning systems using a dispenser and electrode of differing length and/or radius dimensions. For example, if the lengths are different, the first integral in equation (3) is bounded on one side by −L 1 , and the second integral in equation (3) is bounded on one side by D+L 2 , where L 1 is the length of dispenser 12 and L 2 is the length of electrode 22 . If the radius dimensions are different, equation (4) is calculated twice, i.e., one time to generate a charge density for dispenser 12 using the radius thereof and the potential applied thereto, and a second time to generate a charge density for electrode 22 using the radius thereof and the potentials applied thereto. The “dispenser” charge density would then be used for the first term in equation (3), while the “electrode” charge density would then be used for the second term of equation (3). It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described.
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An electrospinning system using a spinneret and a counter electrode is first operated for a fixed amount of time at known system and operational parameters to generate a fiber mat having a measured fiber mat width associated therewith. Next, acceleration of the fiberizable material at the spinneret is modeled to determine values of mass, drag, and surface tension associated with the fiberizable material at the spinneret output. The model is then applied in an inversion process to generate predicted values of an electric charge at the spinneret output and an electric field between the spinneret and electrode required to fabricate a selected fiber mat design. The electric charge and electric field are indicative of design values for system and operational parameters needed to fabricate the selected fiber mat design.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/543,663, filed on Oct. 5, 2011, and U.S. Provisional Application No. 61/606,031, filed on Mar. 2, 2012, and U.S. Provisional Application No. 61/610,805, filed on Mar. 14, 2012. The disclosure of each of these three provisional applications is hereby incorporated by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to offshore drilling and production platforms. More particularly, it relates to a method and apparatus for drilling a plurality of wells at a single platform (or vessel) location and installing production risers on those wells.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98.
Both tension leg platforms (TLP's) and semi-submersible floating vessels (“semis”) can be used for offshore drilling and production operations.
A tension leg platform (TLP) is a vertically moored floating structure typically used for the offshore production of oil and/or gas, and is particularly suited for water depths greater than about 1000 ft.
The platform is permanently moored by tethers or tendons grouped at each of the structure's corners. A group of tethers is called a tension leg. The tethers have relatively high axial stiffness (low elasticity) such that virtually all vertical motion of the platform is eliminated. This allows the platform to have the production wellheads on deck (connected directly to the subsea wells by rigid risers), instead of on the seafloor. This feature enables less expensive well completions and allows better control over the production from the oil or gas reservoir.
A semi-submersible is a particular type of floating vessel that is supported primarily on large pontoon-like structures that are submerged below the sea surface. The operating decks are elevated perhaps 100 or more feet above the pontoons on large steel columns. This design has the advantage of submerging most of the area of components in contact with the sea thereby minimizing loading from wind, waves and currents. Semi-submersibles can operate in a wide range of water depths, including deep water. The unit may stay on location using dynamic positioning (DP) and/or be anchored by means of catenary mooring lines terminating in piles or anchors in the seafloor. Semi-submersibles can be used for drilling, workover operations, and production platforms, depending on the equipment with which they are equipped. When fitted with a drilling package, they are typically called semi-submersible drilling rigs.
The DeepDraftSemi® vessel offered by SBM Atlantia, Inc. (Houston, Tex.) is a semi-submersible fitted with oil and gas production facilities that is suitable for use in ultra deep water conditions. The unit is designed to optimize vessel motions to accommodate steel catenary risers (SCRs).
BRIEF SUMMARY OF THE INVENTION
A floating, offshore drilling and/or production platform is equipped with a rail-mounted transport system that can be positioned at a plurality of selected positions over the well bay of the vessel. The transport system can move a drilling riser with a drilling riser tensioner system and a blowout preventer from one drilling location to another without removing them from the well bay of the vessel. Using the transport system, the drilling riser is lifted just clear of a first well head and positioned over an adjacent, second well head using guidelines. The transport system may then move the upper end of the drilling riser (together with its attached tensioner and BOP) to a second drilling location. A dummy wellhead may be provided on the seafloor in order to secure the lower end of the drilling riser without removing it from the sea while production risers are being installed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
FIG. 1 is a perspective view of an isolated well bay on an offshore drilling platform according to one particular embodiment of the invention that provides for 27 production riser tensioners and up to nine locations of a moveable drilling riser tensioner and blowout preventer.
FIG. 2 shows the well bay illustrated in FIG. 1 installed in the lower deck (“production deck”) of a TLP.
FIG. 3 shows both a production riser tensioner and surface tree assembly as well as a drilling riser tension joint, drilling riser tensioner and blowout preventer assembly on a transport trolley according to the invention. FIG. 3A is a top view of the two assemblies supported on a topside deck wellbay beam according to the invention. FIG. 3B is a side view of the two assemblies supported on a topside deck wellbay beam according to the invention. FIG. 3C is an end view of the drilling riser tension joint, drilling riser tensioner and blowout preventer assembly on the transport trolley.
FIG. 4 shows various views of an adapter frame in the retracted (drilling) position within a transport trolley according to the invention. FIG. 4A is an isometric view of the adapter frame in the retracted position. FIG. 4B is a top view of the adapter frame in the retracted position. FIG. 4C is an end view of the adapter frame in the retracted position. FIG. 4D is a side view of the adapter frame in the retracted position.
FIG. 5 shows various views of an adapter frame in the extended (transfer) position within a transport trolley according to the invention. FIG. 5A is an isometric view of the adapter frame in the extended position. FIG. 5B is a top view of the adapter frame in the extended position. FIG. 5C is an end view of the adapter frame in the extended position. FIG. 5D is a side view of the adapter frame in the extended position.
FIG. 6 shows various views of a transport trolley according to the invention. FIG. 6A is an isometric view of the transport trolley. FIG. 6B is a top view of the transport trolley. FIG. 6C is an end view of the transport trolley. FIG. 6D is a side view of the transport trolley.
FIG. 7 shows various views of an adaptor frame (or drilling riser support insert) according to the invention. FIG. 7A is an isometric view of the adaptor frame. FIG. 7B is a top view of the adaptor frame. FIG. 7C is an end view of the adaptor frame. FIG. 7D is a side view of the adaptor frame.
FIG. 8 illustrates the sequential steps used in transferring a drilling riser between adjacent wells on the seafloor in a method according to the invention. FIG. 8A is an illustration of Step 1 of the method. FIG. 8B is an illustration of Step 2 of the method. FIG. 8C is an illustration of Step 3 of the method. FIG. 8D is an illustration of Step 4 of the method. FIG. 8E is an illustration of Step 5 of the method.
DETAILED DESCRIPTION OF THE INVENTION
The invention may best be understood by reference to one particular preferred embodiment whose apparatus is illustrated in FIGS. 1-7 and an associated method of use is illustrated in FIG. 8 as a sequence of steps. The drawing figures outline general equipment and methodology for drilling multiple wells from a floating unit, and the installation of production risers, while minimizing or eliminating the need to retrieve the drilling riser when moving between wells.
The system shown is intended for use on a well pattern which is essentially rectangular in shape, but it should be understood that similar methodology could be adapted to well patterns of a more square shape or other patterns.
One particular feature of the system is a transfer trolley, which is suspended from the lower deck (the production deck) of the floating platform. The transfer trolley is set to run down the length of the well pattern. The position of the transfer trolley is held side to side by fixed rails, or similar, which may form part of the deck structure. The end-to-end position of the transfer trolley may be shifted using a rack-and-pinion arrangement with the pinion(s) turned by hydraulic motors or the like. The end-to-end position of the transfer trolley may be controlled by other means—for example by a pair of opposing winches used to translate the transfer trolley.
The transfer trolley may be used to transport the assembled drilling riser together with an associated tensioner and blowout preventer (BOP) between well bay positions.
The production deck (the lower deck) of the floating structure may contain discrete (separate) tensioners 42 for the near-vertical production risers. These tensioners may be arranged in a regular geometric pattern, as shown in FIG. 1 . It should be noted that the spacing of the well bay on the structure may be chosen to be consistent with the physical requirements to fit production tensioners, surface trees, connection jumpers, and other required equipment for drilling, production, work over and so forth. The wells may be spaced on the seafloor to provide access space as required for various seafloor activities related to drilling, production, etc. The seafloor and surface spacing may not necessarily be identical (due to different space requirements) but may be established in a way to minimize the offset angles between corresponding seafloor and surface locations.
Referring in particular to FIGS. 1 and 2 , the TLP includes provision for installation of a total of 27 riser tensioners in a 9-by-3 array of well slots 20 on the rawer deck 82 of a TLP. The drilling riser is deployed only from the central of the three columns, with the ability to reach each of the 27 subsea well head locations from at least one of the nine positions within the central column. For certain well patterns, less than the full 9 central column positions may be needed to reach each of the wells on the seafloor. The central column may initially be open to allow translation of the hanging drilling riser to locations appropriate for reaching the well heads. Production risers in the two outer columns may be installed first, with tensioners 42 and surface trees 40 mounted on the lower deck (production deck) 82 . As additional risers are added, inserts may be placed in the central column to allow installation of production riser tensioners therein. Tree access platforms 16 may be provided in production deck structure 18 . FIG. 1 shows the outer columns with all production risers installed, a single production riser installed at one end of the central column, and the drilling riser 36 near the midpoint of the central column. FIG. 1 also shows a smaller BOP 28 (used for well completion) on a Production Riser Tensioner 42 (connected to production riser tension joint 44 ) in the outer row adjacent to the larger drilling BOP 26 , confirming adequate clearance between the two BOP's.
FIG. 2 shows the production deck 82 of a TLP equipped with a drilling riser transport system according to the invention viewed from the opposite end of the well bay as that shown in FIG. 1 and with the topsides structure (drilling deck) in place. The two winches 22 shown at the near end of the opening in the lower deck 82 are for the drilling riser guidelines 24 . This view also shows the routing of the production 10 , annulus 14 and control jumpers 12 for each of the surface trees. These jumpers are routed outward on the two outer columns of wells. The boxes 84 above the central (open) column represent the tie off locations for the central wells. Note that there is ample clearance for hook up of hard piping to the drilling BOP 26 .
FIG. 3B is a side view of a drilling riser assembly comprising drilling riser tension joint 36 , a drilling riser tensioner system 30 and a high-pressure blowout preventer (BOP) 26 supported in a drilling riser transfer system 32 according to the invention.
As shown in FIG. 3A (a top plan view), the support inserts for both the production tensioners 42 and drilling riser tensioner 30 may rest on brackets 38 extending outward from the main beams 64 along the edges of the opening in the lower deck. The drilling riser 36 may be moved by means of a transporter 32 which fits around the Drilling Riser Transport (DRT) support insert 66 and can lift it clear of the support brackets 38 .
Also shown in the top and side views of FIG. 3 are winches 22 for guide wire ropes 24 . Winches 22 may be constant tension winches Guide wire rope 24 may be routed around sheave 86 and through openings in drilling riser tensioner 30 and hole 62 (see FIG. 6 ) in transport trolley 32 .
As illustrated in FIG. 4 , the transporter 32 may move the drilling riser assembly ( 26 + 30 + 36 in FIG. 3 ) on rails 34 ( FIG. 1 ) by means of a rack-and-pinion drive system, located on the edges of the opening in the lower deck. Racks 70 may be attached to well bay support beams 64 and/or tracks 72 and pinions 68 may be mounted on transport trolley 32 and connected to hydraulic drive motors 52 . The transporter may be supported by Hilman rollers 54 (Hilman Inc., Marlboro, N.J. 07746) resting on horizontal tracks 72 . As shown in FIG. 4 , the drive system of the illustrated embodiment uses four drive motors. In addition, the motion of the transporter may be controlled by guide rollers (not shown) reacting on the sides of the track on one or both sides of the opening in the lower deck.
In FIG. 4 , adaptor frame 66 is shown in the retracted position. The extended position of the adaptor frame 66 is shown in phantom in FIG. 4C and FIG. 4D . When in the retracted position, the adaptor frame 66 is supported by deck support brackets 38 and not (to any significant degree) by transport trolley 32 . It will be appreciated that the retracted position of adaptor frame 66 is that used during drilling operations. When in the retracted position, the reactive force of the drilling riser tensioner system 30 is transmitted to the deck structure 64 via deck support brackets 38 . The supports of transport trolley 32 (e.g., Hillman rollers 54 and support arms 88 ) are not exposed to the dynamic loads of heave compensation imposed by tensioner system 30 .
FIG. 5 is similar to FIG. 4 , but with adaptor frame 66 in the extended position. As shown in FIG. 5 , the DRT support insert 66 may be lifted relative to the transporter 32 by four hydraulic cylinders 60 , two on each side of the insert. The geometric shape of the support insert and the transporter may be such that overlap between the two parts provides guidance as the support insert rises, limiting lateral loads on the hydraulic cylinders.
Extending adapter frame 66 results in lifting the drilling riser assembly sufficiently to clear the wellhead on the seafloor to which is was connected. This permits the drilling riser assembly to be moved horizontally within the well bay without disconnecting either the drilling BOP 26 or the drilling riser tensioner system 30 . Moreover, the drilling riser itself may remain in the sea. In certain embodiments, a dummy wellhead may be provided on the seafloor for landing and securing the lower end of the drilling riser while production risers are run. This can help to prevent collisions between the risers.
FIG. 6 contains four views of a transport trolley 32 according to one embodiment of the invention— FIG. 6A is an isometric view, FIG. 6B is a top plan view, FIG. 6D is a side view and FIG. 6C is an end view. Adapter frame lift cylinders 60 are shown within transport trolley 32 . Also shown are openings 62 for guidelines 24 which may be sized to also permit passage of the remote ROV guide post tops (see FIG. 8 ).
FIG. 7 contains four views of an adapter frame 66 according to one embodiment of the invention— FIG. 7A is an isometric view, FIG. 7B is a top plan view, FIG. 7D is a side view and FIG. 7C is an end view. Adapter frame 66 has a central opening 67 with a perimeter rim 74 which may project into opening 67 . Rim (or flange) 74 may be sized and configured to fit drilling riser tensioner system 30 . Drilling riser tensioner system 30 is supported on rim 74 . Load brackets 80 are sized and configured to engage deck support brackets 38 . Lift extensions 78 are sized and configured to engage adapter frame lift cylinders 60 . In a system according to the invention, the static load of the drilling riser assembly is borne on lift extensions 78 when transport trolley 32 is moved horizontally but the static and dynamic loads are borne by load extensions 80 when the drilling riser is connected and tensioned by tensioner system 30 . As shown in FIG. 7 , load extensions 80 may be reinforced with gussets 90 .
Specific design parameters for one particular preferred embodiment of a drilling riser transport system according to the invention are:
The transporter 32 may be supported by four sets of Hillman rollers 54 . The top of the DRT support insert 66 is level with the top of the support rails when the transporter lift cylinders 60 are retracted. The DRT 30 fits within the inner opening 67 of the support insert 66 , and is supported by a ledge 74 around the perimeter of the opening. Lift of the DRT support insert 66 relative to the transporter 32 is sufficient to clear the well head and its associated guide posts. Maximum load carried by the DRT support insert 66 is carried through the brackets 80 . Static load only is carried by the transporter 32 during lift and movement of the drilling riser. The transporter 32 carries no load when the DRT support insert 66 is resting on the brackets 80 . The transporter may be driven by a rack 70 and pinion 68 system powered by hydraulic drive motors 52 .
As shown in the sequence illustrated in FIG. 8 , the transfer method according to the invention begins at Step 1 ( FIG. 8A ) with the drilling riser and its associated tieback connector attached to a home position wellhead. At Step 2 ( FIG. 8B ), the guidelines are slackened so that the ROV can unlock the upper section of the guideposts (“guide post tops”) and move them to the adjacent wellhead. If not already deployed, the guide arms may be folded down (using the ROV) and the guidelines reattached to the drilling riser by positioning the guidelines in the lower guide arms via gates in the guide arms. In Step 3 ( FIG. 8C ), the tieback is disconnected from the home position wellhead and lifted by extending the adapter frame lift cylinders 60 . This provides sufficient clearance to move the tieback connector from the home position wellhead to the adjacent wellhead by applying a selected amount of tension to the guidelines 24 using guide line winches 22 (which may be constant tension winches). The transporter 32 may concurrently move the drilling riser to the closest available drilling position over the target wellhead. The lower guide arms may be free to swivel around the tie back connector to align and connect with the guidelines and guideposts. The guide arms may be sized such that, in the folded position, they may pass through passageways in the drilling riser tensioner and openings 67 in drilling riser transfer trolley 32 . After full positioning tension is applied to the guidelines thereby realigning the tieback connector over the adjacent well (Step 4 ; FIG. 8D ), the drilling riser may be lowered (Step 5 ; FIG. 8E ) by retracting hydraulic lift cylinders 60 , and the tie back connector landed and locked on the adjacent wellhead.
Although particular embodiments of the present invention have been shown and described, they are not intended to limit what this patent covers. One skilled in the art will understand that various changes and modifications may be made without departing from the scope of the present invention as laterally and equivalently covered by the following claims.
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A floating, offshore drilling and/or production platform is equipped with a rail-mounted transport system that can be positioned at a plurality of selected positions over the well bay of the vessel. The transport system can move a drilling riser with a drilling riser tensioner system and a blowout preventer from one drilling location to another without removing them from the well bay of the vessel. Using the transport system, the drilling riser is lifted just clear of a first well head and positioned over an adjacent, second well head using guidelines. The transport system may then move the upper end of the drilling riser (together with its attached tensioner and BOP) to a second drilling location. A dummy wellhead may be provided on the seafloor in order to secure the lower end of the drilling riser without removing it from the sea while production risers are being installed.
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DESCRIPTION
1. Technical Field
This invention relates generally to an assembly for filling a closed interior chamber and more particularly to an assembly for filling a transmission with a liquid lubricant.
2. Background Art
On earthworking equipment and other vehicles there are often several chambers which must be periodically filled with fluid to a desired level. For example, one chamber may hold engine lubricating oil, another may hold transmission fluid, still another may hold brake fluid, etc. To determine when a particular chamber must have fluid added, it is customary and convenient to utilize a dip stick.
Since there are several chambers which may need filling, there must be a corresponding number of dip sticks. This creates a problem for service personnel of determining which dip stick corresponds to each chamber. Normally, the dip sticks and fluid addition ports are correspondingly labelled. However, such labelling can become obscured due to dirt and/or wear. Hence, labelling alone is not an adequate solution to the problem.
While it is well known to vent chambers such as gasoline tanks and water tanks when they are being filled, an adequate assembly has not been available for accomplishing this with a closed pressure system such as a transmission, particularly through utilizing the filler assembly for this purpose upon disengaging its cap. Yet, it is particularly important to assure that an adequate air vent is present in such a system to normalize transmission pressure since hydraulic lock could occur, particularly when oil viscosity is relatively high as during cold weather, if proper venting has not taken place.
The present invention is directed to overcoming one or more of the problems as set forth above.
DISCLOSURE OF THE INVENTION
In one aspect of the present invention an assembly is provided for adding oil to a closed interior chamber defined by a case. A filler tube structure having input and exit portions has the exit portion thereof in communication with a top portion of the chamber. A dip stick guide tube structure has an interior passage in which a dip stick normally fits. The upper end portion of the guide tube structure is positioned adjacent and generally parallel to the input portion of the filler tube structure. A tubular fitting is provided which has first and second end portions with the first end portion being circumferentially sealed to the upper portion of the guide tube structure and to the input portion of the filler tube structure. The cap is removably attachable in covering relation with the second end portion of the tubular fitting.
When an assembly as set out above is utilized, it is virtually impossible for even an untrained person to utilize the wrong dip stick to determine the lubricant level within a particular system such as a transmission. Also, when the preferred embodiment of the invention is utilized, the occurrence of hydraulic lock when filling the interior chamber is reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates, in side partial view, partially in section, an embodiment of the present invention;
FIG. 2 illustrates a partial view taken along the line II--II of FIG. 1;
FIG. 3 illustrates a view taken along the line III--III of FIG. 2, somewhat enlarged; and
FIG. 4 illustrates, in enlarged view, a portion of an alternate embodiment of the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment of FIGS. 1-3
FIG. 1 shows an assembly 10 for adding a liquid to a closed interior chamber 12 defined by a case 14. The chamber 12 has a top portion 16 and a bottom portion 18. The case 14 would be the case for a transmission (not illustrated), in accordance with the preferred embodiment of the invention. However, it should be realized that the invention is not limited to an assembly 10 for filling only a transmission.
A filler tube structure 20 has an input portion 22 and an exit portion 24. The exit portion 24 is in communication with the top portion 16 of the chamber 12. The input portion 22 is generally above the exit portion 24 so as to provide gravity driven flow. Adverting temporarily to FIG. 3, it will be seen that a bore 26 is formed in a flange 28 which extends generally upwardly from the case 14. The exit portion 24 of the filler tube structure 20 is connected to the bore 26 which then communicates with the top portion 16 of the chamber 12.
A dip stick guide tube structure 30 has an interior passage 32 for receiving a dip stick 34. The dip stick guide tube structure 30 has an upper end portion 36 and a lower end portion 38. The upper end portion 36 is positioned adjacent and generally parallel to the input portion 22 of the filler tube structure 20. Generally, the upper end portion 36 of the guide tube structure 30 is positioned generally above the input portion 22 of the filler tube structure 20. In this manner, when fluid is added to the input portion 22 of the filler tube structure 20, it will generally not flow into the upper end portion 36 of the guide tube structure 30.
A tubular fitting 40, having a first end portion 42 and a second end portion 44, has the first end portion 42 thereof circumferentially sealed to the upper end portion 36 of the guide tube structure 30 and to the input portion 22 of the filler tube structure 20. In the particular embodiment illustrated, a wall 46 is formed across the first end portion 42 of the tubular fitting 40, with the wall 46 having a first hole 48 to which the input portion 22 of the filler tube structure 20 is sealingly attached. The wall 46 also has a second hole 50 to which the upper end portion 36 of the guide tube structure 30 is sealingly attached.
The dip stick 34, as previously mentioned, is adapted to fit in the interior passage 32 of the guide tube structure 30. The dip stick 34 has a lower end 54 and an upper end 56, and a handle 52 is attached adjacent to the upper end 56 and is of a size and construction to fit within the tubular fitting 40. A cap 58, normally of a conventional variety and having conventional pressure release threads to allow release of internal pressure prior to removal and to thereby prevent splattering out of fluid, is removably attachable in a covering, generally sealing, relationship with the second end portion 44 of the tubular fitting 40. The handle 52 of the dip stick 34 is also of a size and construction to be free from interference with the cap 58. In this manner, anyone wishing to add fluid to the chamber 12 and removing the cap 58 will immediately find the handle 52 of the dip stick 34.
In accordance with the preferred embodiment of the invention, a venting structure 60, seen best in FIG. 3, serves for venting air which may become entrapped in the chamber 12 on addition of fluid thereto via the filler tube structure 20. Basically, the venting structure 60 includes a venting passage 62 having one end 64 communicating with the top portion 16 of the chamber 12 and having another end 66 communicating with the interior passage 32 at a location external of the case 14.
The vent passage 62 includes a first portion 68 communicating the top portion 16 of the chamber 12 with a block 70 which is attached, for example by bolts 72 (see FIGS. 1 and 2) to the case 14, and more particularly to the flange 28 adjacent the top portion 16 of the chamber 12. The vent passage 62 also has a second portion 74 which communicates the first portion 68 with the interior passage 32 of the guide tube structure 30. Basically, the first portion 68 is a bore in the flange 28 and the second portion 74 is a passage formed in the block 70.
As will be seen in FIG. 3 the guide tube structure 30, in the embodiment illustrated, includes a first tube 76 which includes the upper end portion 36 and a second tube 78 which includes the lower end portion 38, of the guide tube structure 30. The guide tube structure 30 also includes a first passageway 80 through the case 14, and more particularly through the flange 28, and a second passageway 82 through the block 70 with the first and second passageways 80 and 82 connecting the first tube 76 to the second tube 78.
It should be clear that as fluid is flowed into the filler tube structure 20, air can flow via the portions 68 and 74 of the vent passage 62 to the interior passage 32 of the guide tube structure 30. The air can then flow out of the upper end portion 36 of the guide tube structure 30, thereby preventing hydraulic lock by preventing air from becoming entrapped within the chamber 12.
Embodiment of FIG. 4
Adverting to FIG. 4, there is illustrated therein an alternate embodiment of the present invention. In the alternate embodiment, wherein primed numbers are used to indicate like or substantially like parts, a block 70' is utilized which is of a somewhat different nature than the block 70 of the embodiment of FIGS. 1-3. The block 70' has a second passage portion 74' which communicates a passage portion 68' with the interior 32' of the guide tube structure 30'. The block 70' has a boss 90 attached thereto and generally integral therewith with the boss 90 having a central bore 92. The guide tube structure 30' is connected to the bore 92 and the second passage portion 74' intersects bore 92 leading to the interior 32'.
The embodiment of FIG. 4 is particularly useful in situations wherein the lower end of the guide tube structure 30' measures the oil level in a pan (not illustrated) which sits below the chamber 12. In such a construction, the dip stick guide tube structure 30' cannot conveniently be directly routed through the transmission case. It should be noted that the upper ends of the filler tube structure 20' and the guide tube structure 30' are arranged just as are the upper ends of the filler tube structure 20 and the dip stick tube structure 30 as shown in FIG. 1. Thus, hydraulic lock, on filling, is prevented.
Industrial Applicability
Apparatus as set out above is particularly useful for adding liquid to a closed transmission system of an earthworking vehicle.
When utilizing an apparatus as set out above, the proper dip stick for checking the fluid level in a chamber is immediately available to servicing personnel.
In accordance with the preferred embodiment of the invention, air venting is provided via the interior of the dip stick guide tube during filling of the enclosed chamber. As a result of the air venting, the chance of hydraulic lock developing is eliminated.
Other aspects, objects and advantages of this invention can be obtained from a study of the drawings, the disclosure and the appended claims.
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Service personnel may confuse one dip stick for another in vehicles having a number of fluid reservoirs. When the reservoirs have air entrapped within them during filling, hydraulic lock can occur. Herein, a filler tube structure (20) and a dip stick tube structure (30) have their top ends held within a tubular fitting (40) which is covered by a single cap (58). This eliminates any possible confusion as to the dip stick tube structure (30) which corresponds to a particular reservoir or chamber (12). In the preferred embodiment venting of the chamber (12) to which the fluid is being added is provided via an interior passage (32) of the dip stick tube structure (30), thus preventing hydraulic lock.
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BACKGROUND
The present invention relates to virtual machine images, and more specifically, to methods and systems for administering and maintaining virtual machine images.
A virtual-machine image captures the complete configuration of one or more applications, including the software on which the applications depend, and can run on any physical machine with a compatible virtual-machine monitor. Thus, image repositories, are convenient and reliable ways for a user community to develop and share applications, including deploying them to physical machines, in the “cloud” or otherwise.
While images allow capturing, identifying, and distributing application configurations, a typical Unix distribution distributes software in the form of many interdependent packages, which are developed by thousands of people over the course of decades and stored by servers on the Internet. Administrators use a package manager to install, configure, remove, and upgrade packages.
Package managers may be used to manage the software configurations of millions of physical machines, from large compute clusters to cell phones. Data and images are easy to clone, version, snapshot, and customize; as a result, the repositories may grow to contain many more images than there are physical machines to run them. In the past, package managers only needed to operate on running systems. Designed with that assumption, package managers do not scale well when the number of images exceeds the physical resources available to run them.
BRIEF SUMMARY
According to one embodiment of the present invention, a method for managing a virtual machine image includes receiving a request to change a package configuration of a machine, processing an image action received in the request, wherein the processing the image action received includes, opening the image action with associated action inputs, comparing the opened image action inputs with inputs associated with action instances in a database, determining whether the compared opened image action inputs match the inputs associated with action instances in the database, retrieving from the database, image difference data associated with the image action responsive to determining that the compared opened image action inputs match the inputs associated with action instances in the database, and applying the image difference data to an image to transform the image, determining whether each image action in the request has been processed and processing a second image action responsive to determining that each image action has not been processed.
According to another embodiment of the present invention a system for managing virtual machine images includes a database, and a processor operative to receive a request to change a package configuration of a machine, process an image action received in the request, wherein the processing the image action received includes opening the image action with associated action inputs, comparing the opened image action inputs with inputs associated with action instances in a database, determining whether the compared opened image action inputs match the inputs associated with action instances in the database, retrieving from the database, image difference data associated with the image action responsive to determining that the compared opened image action inputs match the inputs associated with action instances in the database, and applying the image difference data to an image to transform the image, determining whether each image action in the request has been processed, and processing a second image action responsive to determining that each image action has not been processed.
According to yet another embodiment of the present invention a computer readable storage medium having instructions that include receiving a request to change a package configuration of a machine, processing an image action received in the request, wherein the processing the image action received includes, opening the image action with associated action inputs, comparing the opened image action inputs with inputs associated with action instances in a database, determining whether the compared opened image action inputs match the inputs associated with action instances in the database, retrieving from the database, image difference data associated with the image action responsive to determining that the compared opened image action inputs match the inputs associated with action instances in the database, and applying the image difference data to an image to transform the image, determining whether each image action in the request has been processed, and processing a second image action responsive to determining that each image action has not been processed.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with the advantages and the features, refer to the description and to the drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The forgoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 illustrates an exemplary embodiment of a system for managing images.
FIG. 2 illustrates an example of virtual machine images and packages.
FIG. 3 illustrates an exemplary embodiment of a table that may be included in the database of FIG. 1 .
FIGS. 4A-4B illustrates a block diagram of an exemplary method for managing images.
DETAILED DESCRIPTION
Software distributions such as, for example Linux are maintained through a package repository; each release of the distribution corresponds to a set of packages in the repository, which have been tested for compatibility. Each virtual machine image (image) contains a package database that lists the name of each package, an installation state, dependences on other packages, and the files associated with the package.
Package management tools such as, for example, Dpkg download packages from the repository via a network connection and change the installation state of packages on the image. Changes to a package state involve a sequence of small steps, including running scripts that perform a variety of package-specific tasks; for example, the post-upgrade script for a database management system may convert databases from the format used by a prior version of the system to the format used by the new version. Although state-changes are not protected by full transactions, Dpkg attempts to not corrupt the image if a state-change fails; to this goal, Dpkg is coded to allow each step to be rolled back individually on failure.
The Mirage Image Format (MIF) exposes file-sharing among images to the tools that manipulate the images. MIF maps each image file to a content identifier (often, a SHA1 hash) that uniquely identifies the content. A content-addressable store (CAS) holds the actual content. MIF images may be converted to a traditional format for execution on a virtual-machine. Recent versions of Mirage support mounting a MIF image filesystems into the Linux filesystem namespace; the contents of files may be fetched from the CAS only as demanded. However, the fastest way to manipulate a MIF image is to operate on the file-to-identifier map: Mirage provides an operation that, given a filename, returns the file content identifier; and an operation that, given a filename and a new content identifier, replaces the file content with the new identifier content. Operating on content identifiers may be faster than operating on content, because content identifiers are three orders of magnitude smaller than the contents of a file.
The embodiments described below include methods and systems for managing packages in an MIF image file system. In this regard, the embodiments identify similarities in package management operations and image configurations and increase the efficiency of the package management operations.
FIG. 1 illustrates an exemplary embodiment of a system 100 for managing images that includes a processor 102 communicatively linked to a display device 104 , input devices 106 and a memory 108 that may include, for example, a database 110 , and a network connection 112 such as, for example, the Internet.
FIG. 2 illustrates an example of virtual machine images and packages. FIG. 2 includes a virtual machine image (VMI) A 202 and a VMI B 204 . The VMI A 202 includes a Package A and a Package B, while the VMI B 204 includes the Package A, Package B, and a Package C. In the illustrated embodiment, the VMA A 202 represents a beginning state of an image (I 1 ) while the VMA B 204 represents an ending state of an image (I 2 ).
FIG. 3 illustrates an exemplary embodiment of a table that may be included in the database 110 (of FIG. 1 ). The table includes image action (action) entries 302 , action input entries 304 , and a difference between images entries (ΔI) 310 . An action entry 302 may include a description of the action being taken such as, for example, a description of a software update that adds a package to a virtual machine image. For example, referring to FIG. 2 , VMI A 202 may be transformed to be similar to VMI B 204 by adding the Package C of VMI B 204 to VMI A 202 . The action inputs 304 may include, for example, the states or data used by the action to perform the action, or content identifiers of the data used to perform the action. The ΔI 310 entry may include, for example, a data file that describes the differences between the beginning state of the image 202 and the end state of the image 204 .
FIGS. 4A-4B illustrate a block diagram of an exemplary method for populating the table of FIG. 3 , and using the database 110 to manage images. Referring to FIG. 4A , a package management request is received at a package manager in block 401 . The package management request may be sent by a user and may include any variety of management actions such as, for example, installing a package, removing a package, upgrading a package, downgrading a package, or any other type of package manipulation that changes a package configuration of a machine. In block 403 , a first image action is processed. The image action process is described in FIG. 4B .
Referring to FIG. 4B , in block 402 , an image action that includes action inputs is opened. In block 404 , the system 100 compares action inputs of the opened image action with action inputs associated with action instances present in the database 110 (of FIG. 3 ). Block 406 determines if the compared action inputs match. If the action inputs match, the ΔI data file is retrieved from the database 110 in block 408 . In block 410 , the image difference data ΔI is used to transform the image into a resultant image. The transformation may be performed on the data file of the VMI to perform the action, thus by changing the data of a VMI based on the ΔI data i.e., adding, replacing, and/or removing data, the resultant VMI will reflect the application of the desired action. If the inputs do not match (in block 406 ), block 412 performs the action on a VMI. Once the image action is performed, the original VMI data is compared with the resultant VMI data to generate an image difference data file (ΔI) in block 414 . In block 416 , the image difference data file (ΔI) is associated with the image action and image action inputs. The image difference data file (ΔI), the image action, and the image action inputs, are stored in the database 110 in block 418 .
Referring to FIG. 4A , block 405 determines whether each image action has been processed from the package management request. If not, the next received image action is processed in block 407 in a similar manner as discussed above.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof.
The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated
As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon. Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
While the preferred embodiment to the invention had been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described.
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A method for managing a virtual machine image includes receiving a request to change a package configuration of a machine, processing an image action received in the request, wherein the processing the image action received includes, opening the image action with associated action inputs, comparing the opened image action inputs with inputs associated with action instances in a database, determining whether the compared opened image action inputs match the inputs associated with action instances, retrieving from the database, image difference data associated with the image action responsive to determining that the compared opened image action inputs match the inputs associated with action instances in the database, and applying the image difference data to an image to transform the image, determining whether each image action in the request has been processed and processing a second image action responsive to determining that each image action has not been processed.
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BACKGROUND
[0001] The invention relates to a belt drive comprising a circulating belt means, which is driven by at least one drive element and which drives at least one driven element, as well as at least one first tensioning device acting on the belt means in a region of the belt drive, in which this belt means leaves the drive element in the circulating direction and reaches the closest driven element, and at least one second device in a region of the belt drive, in which the belt means reaches the drive element in its circulating direction and leaves the closest driven element.
[0002] Such belt drives are used, for example, for timing and/or accessory drives in internal combustion engines. The traction means, for example, the timing belt, is here driven by a driving gear mounted on a crankshaft of the engine and drives driven gears, which are connected to timing shafts or camshafts of the engine. For limiting transverse vibrations in the timing belt, this belt is led over a guide on its tensioned side running into the driving gear and a force tensioning the belt is applied by a tensioning device to the slack side of the belt running out from the driving gear.
[0003] EP 1 262 685 also shows a belt drive according to the class, in which for limiting transverse vibrations of a timing belt, a force is applied to this belt both on its tensioned side running into the driving gear and also on its slack side running out from the driving gear. The forces are set here by a rotating, adjustable ring body, to which guide rails are attached that act on the timing belt. The tensioning force acting on the timing belt increases or decreases with the degree of rotation of the ring body. The rotation of the ring body itself is generated by a combination of oil pressure and spring force.
[0004] DE 196 16 081 C1 shows a belt drive comprised of belt disks and an endless belt with a device for steadying belt vibrations, in which a guide plate is arranged fixed at a close distance to the belt for reducing belt vibrations in a corresponding critical region.
[0005] Limiting transverse vibrations in belt drives is of great importance with respect to their functionality, service life, and noise output. This applies independent of how many driving and driven gears are actually used for a belt drive. The belt means can involve, for example, a chain or a toothed belt of a timing drive, which synchronizes crankshafts and camshafts with each other, or, for example, also a driving belt, which connects a belt disk of a drive shaft to the belt disk of a driven shaft for some assembly in a driving manner.
[0006] For transverse vibrations that become too large, adjacent components can be damaged, if a toothed belt or a chain temporarily loses positive-fit contact with a driving or also driven element due to transverse vibrations that are too large. Furthermore, unsuitably high mechanical loads for the belt means itself can occur due to excessive transverse vibrations, which lead to a shortened service life of the belt means. In addition, excessive transverse vibrations cause a comparatively high noise generation.
[0007] Finally, synchronization errors between at least two camshafts and/or between these and the crankshaft of an internal combustion engine can occur, when the belt drive is lengthened due to wear and a tensioning device on a belt means strand compensates this by an increased tensioning path. Because this single tensioning device is typically activated by an actuator acted upon by the oil pressure of the internal combustion engine, in particular, at the start of the internal combustion engine, insufficient oil pressure is present in the actuator, so that disadvantageously, tooth jumping is hard to prevent in known belt drives.
[0008] To be noted is also the increasing complexity of accessories for usually only limited space relationships in the region of the belt drive, as well as the necessary flexibility of the belt drive due to the increasing number of different accessories with respect to adaptability to different operating conditions.
SUMMARY
[0009] The invention is based on the objective of creating a belt drive, in which tooth jumping caused by wear-related lengthening of the belt means between the belt means and the driving element or driven element can be prevented reliably and also at least the amplitude of transverse vibrations of the belt means can be reduced.
[0010] The invention is based on the knowledge that through selective improvement of the belt drive layout or belt drive construction, transverse vibrations of the belt means can be reduced and also tooth jumping can be prevented. Here, the important feature is that a special means is provided and arranged on the belt drive for preventing loosening of the belt means due to decreasing force application by the actuator-controlled tensioning device, which would hold back the belt means before the drive element of the belt drive and would lift the belt means from this drive.
[0011] The invention starts from a belt drive, comprising a circulating belt means, which is driven by at least one drive element and which drives at least one driven element, as well as at least one first tensioning device acting on the belt means in a region of the belt drive, in which the belt means leaves the drive element in its circulating direction and reaches the closest driven element, and at least one second device in a region of the belt drive, in which the belt means reaches the drive element in its circulating direction and leaves the closes driven element.
[0012] In this belt drive, according to the invention it is also provided that the second device provided at least once in this drive is constructed for guiding the belt means and at least one third device arranged in the radial direction within the belt drive is provided, which is also suitable for limiting excursions of the belt means.
[0013] Such a belt drive can be a timing drive of an internal combustion engine in the form of a toothed-belt drive or a chain drive, but it can also be constructed as a toothed-belt drive or chain drive for driving auxiliary accessories.
[0014] Through this construction, it is advantageously achieved that a belt means lengthened due to wear past its original installed dimensions cannot lift from the drive element of the belt drive so that it jumps out of the teeth or it cannot be held back in front of this drive element, when the contact force of an allocated tensioning device that can be activated by a pressurized medium is not yet or no longer present due to operation. In addition, with a belt or chain drive built structurally according to the invention, the likelihood and the extent of the appearance of transverse vibrations of the belt means can be reduced.
[0015] The third device arranged in the radial direction within the belt drive is suitable for this purpose and also provided to produce a steering effect on the inside of the belt means not reached by the other devices and, if necessary, is arranged where this appears most relevant to someone skilled in the art for fulfilling this purpose.
[0016] Preferably, it is provided that the third device provided at least once in the belt drive is arranged in the region of the drive element, for example, a crankshaft drive wheel, by means of which, in this usually critical region, an additional avoidance or prevention of undesired vibrations and tooth jumping is advantageously enabled.
[0017] If the third device present at least once in the belt drive is arranged in the region of the drive element, in which the belt means has reached the drive element in its circulating direction or is arranged in the region of the drive element, in which the belt means leaves the drive element in its circulating direction, then a positive effect on the vibrating behavior of the belt means, as well as a given run-in and run-out angle and a given advantageous contact length of the belt means on the drive element, can be realized on these sections of the belt means located in the direct area of the drive element,
[0018] In this connection, it is especially useful if, in the construction of the invention, the third device present at least once in the belt drive is suitable for acting both in the region of the drive element, in which the belt means reaches the drive element in its circulating direction and also in the region of the drive element, in which the belt means leaves the drive element in its circulating direction.
[0019] The third device present at least once in the belt drive here does not necessarily have to be constructed as guide means for the belt means. That is, it does not have to be in constant contact with the belt means, but instead it is absolutely advantageous when this is arranged at a defined distance from the inside of the belt means. In this way, this occurs only for actually appearing undesired transverse vibrations and/or holding back of the belt means in the slack belt strand, which leads, as a whole, to a reduction in friction on this third device.
[0020] In addition, it can be advantageously provided that the third device present at least once in the belt drive is connected mechanically to the first tensioning device present at least once in the belt drive and/or to the second guide device present at least once in the belt drive. In this way, the devices connected to each other can be aligned in common and adjusted easily.
[0021] If at least one of the mentioned devices is advantageously provided with a surface reducing the friction with the belt means, this can lead to further friction reduction and thus an increase in the service life of the belt means.
[0022] Alternatively, according to the invention a belt drive can be created, comprising a circulating belt means, which is driven by at least one drive element and which drives at least one driven element, as well as at least one first tensioning device acting on the belt means in a region of the belt drive, in which the belt means leaves the drive element in its circulating direction and reaches the closest driven element, and at least one second device in a region of the belt drive, in which the belt means reaches the drive element in its circulating direction and leaves the closest driven element.
[0023] According to the invention, it is also provided that the second device present at least once in the belt drive is also constructed for tensioning the belt means, such that this means acts on the belt means with such a force F 1 that is smaller than an opposite force F 2 acting on the second tensioning device in the operation of the belt means. This opposite force F 2 acting on the second tensioning device is applied by the belt means tensioned by the first tensioning device.
[0024] Through this construction, it is achieved that, especially in a standstill phase, in which the first tensioning device operated by pressurized medium does not exert a force tensioning the belt means on the belt means due to the lack of pressure in the pressurized medium, a wear-dependent lengthening of the belt means is compensated in the belt drive, in which this second tensioning device exerts an appropriate tensioning force on the belt means.
[0025] Therefore, tooth jumping as well as associated rotational angle errors or synchronous running errors, for example, on a crankshaft disk or on the camshaft disks of an internal combustion engine, can be reliably prevented. In addition, the appearance likelihood and also the amplitude of transverse vibrations of the belt means are further reduced or even completely avoided.
[0026] In addition, the second tensioning device can have a more compact construction in its structural design than the first tensioning device that can be activated by pressurized medium and is also suitable for guiding the belt means during its operation along its optimum belt path. Because the force F 1 of the second tensioning device acting on the belt means is less than the opposite force F 2 acting on the second tensioning device in the operation of the belt means, the force F 1 of the second tensioning device has no noticeable effect for the operation of the belt means. However, for the lack of pressurized medium supply to the actuator of the first tensioning device, it is in the position to strongly tension the belt means, so that lengthening of the belt means, for example, caused by wear or by counter rotation of the drive element, is compensated, especially when the belt drive is turned off or after the belt drive has been turned off.
[0027] In addition, it can be provided that the force of the second tensioning device acting on the belt means is generated at least partially by a spring force, which allows a structurally simple construction of the device for high reliability. If the spring force is generated by at least one spiral, leaf, or torsion spring, costs can be saved tracing back to common structural elements.
[0028] It is absolutely advantageous for the service life of the belt means if the second tensioning device, which is present at least once in the belt drive and which is acted upon by a spring force or which itself has a spring-elastic construction, is provided with a surface reducing the friction. In this way, the size of the spring can be kept smaller and thus space can be saved or the spring possibly could be completely eliminated.
[0029] The second tensioning device present at least once in the belt drive can have, in an advantageous refinement of the concept of the invention, a guide body that can move in a direction toward the slack belt strand of the belt means or can have a guide body with a deformable construction. By moving the guide body, a very precise adjustment of this body on the belt drive is possible. The use of a deformable guide body leads to an additional force and supports the spring force of the second tensioning device acting on the belt means, by which a spring provided in the structure can be kept smaller.
[0030] In an especially advantageous construction of the invention, it is provided that the first tensioning device present at least once in the belt drive can also be acted upon with a spring force acting on the belt means. In this way, a certain basic tensioning of the belt means on both sides of the drive element is guaranteed, independent of the operating situation of a tensioner of the first tensioning device that can be activated by pressurized medium. Changes in length in the belt means, for example, due to wear or due to counter rotation of the drive element, which can appear, e.g., when a motor is turned off or after the motor has been turned off, can be advantageously compensated.
[0031] It is further advantageous when the first tensioning device that can be activated by pressurized medium and that is present at least once in the belt drive and the second tensioning device present at least once are connected to each other elastically by at least one spring. In this way, this spring generates a force acting on the belt means both on the tightened strand and also on the slack strand, so that too much slack in the belt drive is overcome when the drive machine is turned off or when the pressure supply is stopped for the tensioner of the first tensioning device that can be activated by pressurized medium.
[0032] Similarly, however, it also offers advantages when the first tensioning device that can be activated by pressurized medium and that is present at least once in the belt drive and the second tensioning device present at least once in the belt drive are connected to each other by a linkage mechanism, wherein the linkage mechanism is connected to at least one spring, which generates a force acting constantly on the belt means.
[0033] In a preferred embodiment, it is provided that the guide body of the two tensioning devices are each supported at separate attachment points so that they can pivot, that these guide bodies are connected in articulated ways at other attachment points to a lever-like connection element, that these connection elements are connected to each other so that they can pivot at a connection point, and that at this connection point a spring attaches, such that a basic contact force acts on the belt means through the connection elements and the noted guide bodies.
[0034] In addition, it has been judged to be advantageous when the connection elements and the spring of this belt drive are arranged in the radial direction inside of this drive.
[0035] Through the above structural features, an equal distribution or different distribution of the basic contact force F 1 acting on the belt 8 due to different lever-arm lengths of the connection elements can be achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The invention will be explained in more detail below with reference to the enclosed drawing using a few embodiments. Shown therein are
[0037] FIG. 1 a block diagram of a belt drive according to a first solution according to the invention and
[0038] FIGS. 2 to 9 different schematic diagrams for embodiments of a belt drive according to a second solution according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] The belt drive shown schematically in FIG. 1 can be used in a motor-vehicle engine and features at the bottom a belt disk 9 , which is connected to a not-shown crankshaft and which drives a circulating belt 8 in the counterclockwise direction. The belt 8 also drives two belt disks 10 , which are arranged at the top and which are connected to not-shown camshafts.
[0040] The region of the belt drive, in which the belt 8 leaves the driving belt disk 9 in its circulating direction and reaches the closest belt disk 10 , it designated in general as the slack strand. The region of the belt drive, in which the belt 8 reaches the driving belt disk 9 in its circulating direction and leaves the closest belt disk 10 , is designated in general as the tightened strand.
[0041] As FIG. 1 shows, in the slack strand a first tensioning device 20 is provided, which is comprised of a tensioner 1 that can be activated by pressurized medium in the form of a piston-cylinder arrangement, a guide body 2 hinged to an attachment point 4 so that it can pivot, and a friction-reducing sliding coating 3 deposited on the guide body 2 on the belt side. The tensioner 1 applies a force on the guide body 2 of the first tensioning device 20 with a force that presses and thus tensions the belt 8 running over the sliding coating 3 in this diagram to the right in the radial direction approximately in the direction of the center of the belt drive.
[0042] In the tightened strand, an additional device 21 is provided for guiding the traction means, which is constructed as a belt 8 , and which has a guide body 5 that is mounted at two attachment points 4 and a friction-reducing sliding coating 7 is deposited on this guide body on the belt side. Furthermore, below in the direct area of the belt disk 9 , a guide device 22 , which is suitable for guiding the belt 8 , is provided in the radial direction within the belt drive and above the belt disk 9 .
[0043] This guide device 22 has a guide body 13 , which carries two guide rails that are each provided, in turn, with a sliding coating 14 . Of the two guide rails, one guide rail faces the inside of the slack strand and the other guide rail faces the inside of the belt 8 located in the tightened strand.
[0044] The guide rails are arranged with their sliding coating 14 at a slight distance from the belt 8 , such that an approximately funnel-shaped guide channel 23 , 24 for the belt 8 is formed between the sliding coating 7 of the guide body 5 of the additional device 21 and the sliding coating 14 of the guide body 13 or between the sliding coating 3 of the guide body 2 of the first tensioning device 20 and the sliding coating 14 of the guide body 13 .
[0045] The guide channel 23 prevents, for example, on the slack strand side that a lengthened belt 8 caused by wear can lift so far from the belt disk 9 that the belt jumps from the teeth when tension on the belt 8 falls due to decreasing application of force by the first tensioning device 20 . The other guide channel 24 generates the same effect on the tightened strand side of the driving belt disk 9 , where tooth jumping caused by the belt 8 being held back is prevented. In addition, in this way the production of transverse vibrations in the belt 8 is advantageously prevented or at least advantageously reduced.
[0046] However, the guide rails of the guide device 22 can also be arranged with the sliding coatings 14 such that they are located in constant contact with the belt 8 . It is also possible that the additional guide device 22 located in the radial direction inside the belt drive is arranged at a different position in the radial direction inside of the belt drive, or other guide devices are provided in the radial direction inside the belt drive.
[0047] It is also possible that only one guide device 22 or several guide devices each with only one guiding surface allocated to the belt 8 are arranged in the radial direction inside the belt drive.
[0048] The guide body 13 of the guide device 22 can be connected mechanically in another variation to one of the two other guide bodies 2 or 5 or also to both guide bodies 2 and 5 in a suitable way.
[0049] FIG. 2 likewise shows a belt drive of an internal combustion engine with a circulating traction means constructed as a belt 8 and connecting a driven wheel and at least one drive wheel. In the present case, the drive of the belt disk 9 is transmitted by the belt 8 to the two belt disks 10 . In the slack strand, in turn, a first tensioning device 20 composed of a tensioner 1 that can be activated by pressurized medium and a guide body 2 with a sliding coating 3 is arranged.
[0050] On the tightened strand, there is a second tensioning device 30 with a guide body 35 featuring a sliding coating 7 . The guide body 35 is acted upon by a spring 6 with a force, wherein the spring attachment 11 can be realized on a stationary part, for example, on the housing of the internal combustion engine. In addition, a piston-cylinder arrangement 31 is connected to the guide body 35 and to the housing of the internal combustion engine, such that the guide body 35 of this second tensioning device 30 can be moved away from the belt 8 against the contact force of the spring 6 .
[0051] To enable the movement of the guide body 35 of this second tensioning device 30 , this also features two elongated recesses 51 and 52 , which are aligned in the direction toward the tightened strand of the belt 8 and which are intersected by two attachment points 4 constructed as stay bolts, so that the guide body 35 is arranged so that it can move in the direction toward the belt 8 .
[0052] During operation of the internal combustion engine, a sufficiently large pressurized medium pressure is generated, which is led to the tensioner 1 of the first tensioning device 20 and to the piston-cylinder arrangement 31 of the second tensioning device 30 . Therefore, the first tensioning device 20 presses against the belt 8 in order to tension the belt, while the piston-cylinder arrangement 31 of the second tensioning device 30 is acted upon with oil pressure 12 , such that the guide body 35 lifts from the belt 8 in a friction-reducing way against the force of the spring 6 or contacts the belt 8 at least with low force in a guiding manner on this belt strand.
[0053] If the internal combustion engine is turned off and thus there is no more pressurized medium available for the tensioner 1 or for the piston-cylinder arrangement 31 , then the tensioner 1 of the first tensioning device 20 also cannot tension the belt 8 . Now if the belt 8 becomes longer than its installed dimension due to wear, this leads to a belt 8 suspended in the belt drive that is overall only relatively looser without additional means. Now if the internal combustion engine is started again, undesired tooth jumping can occur on the drive disk 9 and/or on the driven disks 10 , which would lead to phase or rotational angle errors of the shafts in this belt drive.
[0054] Because the piston-cylinder arrangement 31 of the second tensioning device 30 for a deactivated drive motor or for no or insufficient pressurized medium pressure does not generate a counter force overcoming the force of the spring 6 , the spring 6 presses the guide body 35 against the belt 8 just with this spring force F 1 , so that the belt is also tensioned in this operating position and tooth jumping is reliably prevented.
[0055] In contrast, for an activated drive motor, that is, during operation of the belt 8 , sufficient oil pressure 12 for the tensioner 1 that can be activated by pressurized medium is generated, which acts against the spring force F 1 of the spring 6 with a force F 2 on the belt 8 or the second tensioning device 30 arranged in the slack strand, which is greater than the spring force F 1 . Therefore, the guide body 35 is pressed outward until, as FIG. 2 shows, the attachment points 4 constructed as stay bolts are located at the left stop of the recesses 51 , 52 in the guide body 35 of the second tensioning device 30 .
[0056] In contrast to FIG. 2 , FIG. 3 shows a belt drive, in which the guide body 45 of a second tensioning device 40 provided in the slack strand has a deformable construction. For this purpose, in this embodiment the guide body 45 has a two-part construction, wherein this is fixed so that it can pivot on attachment points 4 at the ends of its longitudinal extent. The two individual parts 41 and 42 of the multiple-part guide body 45 are connected to each other so that they can pivot in a middle region of this body at an attachment point 4 ′. A spring 6 , which is fixed in position on the motor housing, for example, with its other end, also engages to this attachment point 4 ′. For this embodiment, the spring force F 1 generated by the spring 6 and acting in the direction toward the belt 8 is also smaller than the force F 2 generated by the first tensioning device 20 and acting on the guide body 45 via the belt 8 in the activated drive motor.
[0057] The belt drive shown in FIG. 4 has, in contrast to the variant according to FIG. 2 , in the tightened strand a second tensioning device 50 , in which the one-part guide body 55 is fixed to two end-side attachment points 4 and in which a spring 6 ′ is arranged between the sliding coating 7 and the guide body 55 . The term sliding coating is understood in this connection not as a coating of a body but instead the body itself, which is in contact with the belt 8 in a spring-loaded manner.
[0058] However, this so-called sliding coating 7 itself (as shown in FIG. 5 ) can also have a spring-elastic, for example, leaf spring-shaped construction, which is supported on the end on a guide body 65 according to the second tensioning device 60 shown there. This guide body 65 is here fixed to the housing also at two attachment points 4 . For the belt drives shown in FIG. 4 or FIG. 5 , the spring force F 1 generated by the spring 6 ′ or the spring-elastic sliding coating 7 itself in the direction toward the belt 8 is also smaller than the force F 2 generated by the tensioner 1 of the first tensioning device 20 that can be activated by pressurized medium and guided by the belt 8 to the guide body 55 or 65 .
[0059] In contrast to the embodiment according to FIG. 2 , FIG. 6 shows a belt drive with a second tensioning device 70 , in which a guide body 75 of this second tensioning device 70 provided on the tightened strand is hinged so that it can pivot via an attachment point 4 only in a lower region pointing toward the drive element 9 . In addition, the two tensioning devices 20 , 70 arranged in the slack strand and tightened strand, respectively, are connected elastically to each other via a spring 6 . Therefore, it is achieved that the belt 8 is acted upon with a basic tension that overcomes belt slack that is too much independent of the pressure supply for the tensioner 1 that can be activated by pressurized medium both in the slack strand and also in the tightened strand.
[0060] For an internal combustion engine during operation, pressurized medium under sufficient operating pressure is generated for the tensioner 1 , so that this tensions a belt 8 compensating for belt slack caused by wear. The spring 6 between the first tensioning device 20 and the second tensioning device 70 also generates in this operating phase a contact force, with which the guide body 75 is pressed against the belt 8 .
[0061] If the pressure supply for the tensioner 1 that can be activated by pressurized medium is interrupted, this definitely leads to a restoring motion of the guide body 2 of the first tensioning device 20 away from the belt 8 , because the spring 6 is pulled along for this restoring movement but with its end fixed to this guide body 2 , the force at least of the guide body 75 of the second tensioning device 70 on the belt 8 remains at least the same size. An undesired large belt slack, as well as tooth jumping in the belt drive, is reliably prevented.
[0062] In FIG. 7 , in a modification to the embodiment according to FIG. 6 , a belt drive is shown, in which a lever-like connection element 15 or 16 is hinged to a corresponding attachment point 4 ″ on the guide bodies 2 and 85 of the two tensioning devices 20 and 80 arranged on the slack strand or tightened strand in their region pointing away from the drive element 9 . These connection elements 15 or 16 are connected to each other in an articulated manner with their other end at a connection point 48 . In turn, a spring 6 , whose spring force acts on the guide body 2 or 5 through the use of the lever-like connection elements 15 or 16 for approximately the same parts, engages at this connection point 48 . This happens in that the belt 8 is acted upon with a basic tensioning force that tensions a slack belt 8 for no compressed-means supply for the tensioner 1 independent of the tensioner 1 that can be activated by pressurized medium both in the slack strand and also in the tightened strand. In the operating behavior, that is, for an activated or deactivated pressure supply for the tensioner 1 , these two tensioning devices 20 and 80 according to FIG. 7 act like the two tensioning devices 20 and 70 according to FIG. 6 .
[0063] In contrast to the embodiment according to FIG. 6 , in the belt drive shown in FIG. 8 , the guide body 2 , 95 of the two tensioning devices 20 and 90 are each acted upon by a spring 6 with a spring force. In this way, it is also achieved that the belt 8 is acted upon with a spring-generated basic tensioning force independent of an activation force of the tensioner 1 that can be activated by pressurized medium both in the slack strand and also in the tightened strand. Here, for a stopped pressurized medium supply for the tensioner 1 , the guide bodies 2 and 95 each press onto the belt 8 via an associated spring 6 , so that tooth jumping of the belt means 8 is prevented, compensating for too much undesired belt slack.
[0064] Deviating from the embodiment according to FIG. 6 , in the belt drive shown in FIG. 9 , the guide bodies 2 and 105 supported so that they can pivot on one side at the attachment points 4 in the two tensioning devices 20 and 100 each act with a spring force on their lower end close to the drive wheel through torsion springs 6 ′ constructed as leg springs. The torsion springs 6 ′ are here supported against stationary spring attachment points 11 ′. In this way, it is also achieved that the belt 8 is acted upon with a basic tensioning force independent of the tensioner 1 that can be activated by pressurized medium both in the slack strand and also in the tightened strand. Belt lengthening caused by wear is compensated in this way and also, finally, rotational angle errors between the shafts rotating in the belt drive are prevented.
[0065] As the embodiments according to FIGS. 6 to 9 make clear, also for these embodiments, during operation of the belt means or when pressure is applied to the tensioner 1 that can be activated by pressurized medium, a force F 1 acts via the second tensioning device 30 , 40 , 50 , 60 , 70 , 80 , 90 , 100 on the belt means 8 , with this force being smaller than the force F 2 that the belt means 8 itself exerts during operation on these second tensioning devices 30 , 40 , 50 , 60 , 70 , 80 , 90 , 100 .
[0066] The second tensioning devices 40 , 50 , 60 , 70 , 80 , 90 , and 100 according to FIGS. 3 to 9 can also be equipped with a piston-cylinder arrangement 31 according to FIG. 2 , which presses such a second tensioning device away from the belt 8 , reducing friction, when during operation of the drive motor, a sufficiently high pressurized medium pressure is provided for the tensioner 1 that can be activated by pressurized medium in the first tensioning device 20 , so that this can reliably tension a non-tensioned belt means 8 that becomes too loose in the belt drive (not shown).
LIST OF REFERENCE SYMBOLS
[0000]
1 Tensioner that can be activated by pressurized medium
2 Guide body of slack strand
3 Sliding coating of guide of slack strand
4 Attachment point
4 ′ Attachment point, hinge point
4 ″ Attachment point
5 Guide body on guide body
6 Spring
6 ′ Torsion spring
7 Sliding coating or surface of guide body
8 Belt, belt means
9 Drive element, belt disk on crankshaft
10 Drive element, belt disk on camshaft
11 Spring attachment
11 ′ Spring attachment
12 Oil pressure
13 Guide body of inner guide device
14 Sliding coating of guide of inner guide device
15 Connection element
16 Connection element
20 First tensioning device
21 Second device, second tensioning device
22 Guide device
23 Guide channel
24 Guide channel
30 Second tensioning device
31 Piston-cylinder arrangement
35 Guide body
40 Second tensioning device
41 Individual part of guide body 40
42 Individual part of guide body 40
45 Guide body
48 Connection point
50 Second tensioning device
51 Recess of guide body
52 Recess of guide body
55 Guide body
60 Second tensioning device
65 Guide body
70 Second tensioning device
75 Guide body
80 Second tensioning device
85 Guide body
90 Second tensioning device
95 Guide body
100 Second tensioning device
105 Guide body
F 1 Force of second tensioning device on belt means
F 2 Force of belt means during its operation on second tensioning device
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A belt drive is provided which includes a circulating belt ( 8 ) which is driven by at least one drive element ( 9 ) and which drives at least one driven element ( 10 ). At least one first tensioning device ( 20 ) acts upon the belt ( 8 ) in the slack strand and at least one second tensioning device acts in the tightened strand. To prevent or reduce jumps and/or transverse oscillations of the belt ( 8 ), the second device ( 21 ) guides the belt ( 8 ) and at least one third device ( 22 ) which is arranged radially inside the belt drive, which is suitable, optionally, limits deviations of the belt ( 8 ). The second device ( 30, 40, 50, 60, 70, 80, 90, 100 ) also tensions the belt ( 8 ) in such a manner that it is subjected to a force (F 1 ) which is smaller than the force (F 2 ) which is oriented counter thereto during the operation of the belt ( 8 ) on the second tensioning device ( 30, 40, 50, 60, 70, 80, 90, 100 ).
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation in part of application Ser. No. 766,889, filed Sep. 27, 1991, and now U.S. Pat. No. 5,158,474.
BACKGROUND OF THE INVENTION
This invention relates to electrical connectors, and in particular to keying structures therefor.
Electrical connectors may be provided with keying structures to permit predetermined pairs of connectors to mate with each other and to prevent the mating of connectors which are not intended to be mated with each other. Keying structures are usually provided on connectors when a plurality of identical connectors are positioned in situ in close proximity to one another so that there is the risk of the wrong connectors being mated therewith. Keying structures do not interfere with the mating of connectors that are intended to be mated with each other but provide interference with the mating of connectors that are not intended to be mated with each other, so as to prevent such mismating.
The keying of connectors is to be distinguished from the polarization of connectors, in that polarization ensures that a first connector which is matable with a second connector is properly oriented relative to the second connector for mating; whereas keying provides a mechanism which permits the mating of connectors which are intended to be mated with each other but prevents the mating of connectors which are not intended to be mated with each other even if they are properly oriented with respect to each other.
U.S. Pat. Nos. 4,822,305 and 4,832,624 disclose keying systems in which a key member is secured to one of the pair of complimentary connectors and is adapted to cooperate with an opposing key member secured in the other connector of the pair.
Each key member is secured in its connector in a selected orientation with respect to its opposing key member so that when the connectors are intended to be mated, extended portions on the key members pass by each other during mating to allow the connectors to mate. If one of the key members is secured in an orientation that is not complimentary to its opposing key member, the extended portions on the key members will engage one another during mating to prevent the connectors from mating. U.S. Pat. No. 4,929,184 disclose a keying system comprising parts which are securable to metal flanges on an electrical connector.
There is disclosed in U.S. Pat. No. 4,934,950 an electrical connector having keying means which are securable in one of a plurality of different angular orientations in a plastic housing.
U.S. Pat. No. 3,491,330 discloses an electrical connector having keying members to each of which a bushing can be locked in one of several possible angular orientations.
According to U.S. Pat. Nos. 3,582,867 and 4,895,535 keying means are securable in one of several possible angularly orientation in a flange of a connector.
U.S. Pat. No. 4,181,391 discloses connectors having keying devices mounted to corresponding flanges of the connectors in one of a plurality of angular orientations. The connectors are securable together by means of jackscrews surrounded by keying structures.
U.S. Pat. No. 4,457,575 discloses a connector having an insulating housing provided with a metal shield. Keying means are formed integrally with the housing forwardly of the shield.
United Kingdom Patent 961,714 discloses a connector having a multi-part keying assembly removably received in a recess in an insulating housing of the connector. The keying assembly includes a rotatable pin having a hexagonal flange at one end and an axial keying spline at the opposite end of the pin.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an electrical connector having a die cast housing , with a keying structure which is of simple unitary construction and which can, if desired, readily be cast with the housing during its manufacture.
According to the present invention, a keyed electrical connector includes a die cast housing having a front face. A keying structure which is an integral part of the housing upstands from the front face. The keying structure comprises a cylindrical protrusion extending to a distal end remote from the front face. The cylindrical protrusion defines an exterior having thereon a radially outwardly extending rib. The rib extends along at least a portion of the exterior surface of the protrusion.
The protrusion of the keying structure can be received in a complementary hollow key on the front face of a mating connector, the rib of the keying structure being received in an axial keying slot in the wall of the hollow key, provided that the rib and the slot have the same angular orientation. The keying structure can, therefore, be provided on the die cast housing with the keying rib so oriented that the connector having the keying structure can only be mated with a predetermined mating connector. The cylindrical protrusion is preferably formed with an axial tapped bore for receiving a jack screw extending through the hollow key, for drawing the connectors into full mating relationship.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of an electrical connector having a die cast housing and keying structures projecting therefrom, according to one embodiment of the present invention;
FIG. 2 is an enlarged, fragmentary, isometric view showing a keying structure of the connector of FIG. 1;
FIG. 3 is a front view of the connector of FIG. 1;
FIG. 4 is a front view of a further embodiment of an electrical connector;
FIG. 5 is a front view of a further embodiment of an electrical connector;
FIG. 6 is a front view of a further embodiment of an electrical connector;
FIG. 7 is a front view of a further embodiment of an electrical connector;
FIG. 8 is a front view of a further embodiment of an electrical connector;
FIG. 9 is an exploded isometric view of a jack screw in combination with a key, for mating with a keying structure of a connector in accordance with the present invention;
FIG. 10 is an isometric view of the key of FIG. 9 and the jack screw when mated with a keying structure of the connector FIGS. 1 to 3;
FIG. 11 is an enlarged isomatic view of a screw lock for securing a connector according to FIGS. 1 to 3,4 or 5 to a mounting panel;
FIG. 12 is a front view of the mounting panel illustrating a connector receiving cut out therein;
FIG. 13 is an isometric view of the connector of FIGS. 1 to 3, secured to the mounting panel by means of a pair of screw locks according to FIG. 11; and
FIG. 14 is an end view of the connector and panel shown in FIG. 13.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 to 3 show a shielded, right-angle keyed electrical connector for surface mounting on a printed circuit board and being constructed according to the teaching of Patent Application No. 853,649 filed Mar. 18, 1992 (15260) and Patent Application No. 853,565 filed Mar. 18, 1992 (15261), the disclosures of which Patent Applications are hereby incorporated herein by reference. The connector 2 which is according to a first embodiment of the invention, comprises a die-cast metal housing 4 receiving upper and lower drawn metal shells 6 and 8, respectively, which in turn receive insulating upper and lower header inserts 10 and 12, respectively, each accommodating two rows of electrical receptacle terminals 14, having solder tails 16 depending below the housing 4 for reception in holes in the printed circuit board. Board locks 18 depend from the housing 4 for reception in further holes in the printed circuit board to secure the connector 2 thereto. The housing 4 has a front face 20 and side walls 22, between which side walls there is secured a rear metal shield 24 covering those parts of the solder tails which project rearwardly from the housing 4. There projects forwardly from the front face 20, on each side of the metal shell 6, a keying structure 26 comprising a circular cross section, tubular, cylindrical protrusion 28 extending normally of the wall 20 to a distal end 30 remote from the face 20; and a keying rib 32 extending axially of the protrusion 28 and projecting radially outwardly from the exterior surface of the protrusion 28. The protrusion 28 has a tapped, axial bore 34 extending therethrough. The rib 32 may extend from the face 20 to the distal end 30 of the protrusion 28, as shown, or the rib 32 may extend only along part of the length of the protrusion 28. Each keying structure 26 is preferably cast integrally with the housing 4, although the structure 26 may be secured to the housing 4, being, for example, threadingly secured to the front face 20. According to the embodiment of FIGS. 1 to 3, each rib 32 projects radially upwardly and vertically. Below each keying structure 26, on a respective side of the metal shell 8, there is formed in the front face 20 of the housing 4, a tapped bore 36 for receiving a screw lock 40 (best seen in FIG. 11) for securing the connector 2 to a mounting panel 38 which is shown in FIGS. 12 to 14. Each screw lock 40 comprises a circular cross section, elongate head 42 having a kerf 44 at one end for receiving a screw driver blade, and at its other end, a screw threaded shank 46 for meshing with the screw thread of a respective bore 36 of the wall 20 of the housing 4. Between the head 42 and the shank 46, the screw lock 40 has a radially projecting collar 48 for engaging the panel 38.
The panel 38 has a central cut-out 50, best seen in FIG. 12, having an upper part 52 dimensioned to receive the metal shell 6 of the connector 2, as well as the keying structures 26 with substantial clearance thereabout. The cut-out 50 has a lower part 54 dimensioned to receive the metal shell 8 of the connector 2. The part 54 of the cut-out, has opposite lateral extensions 56 each dimensioned to receive the shank 46 of a respective screw lock 40 with sufficiently small clearance to allow the collar 48 of the screw lock 40 to engage the front surface of the panel 38. As shown in FIGS. 13 and 14, the connector 2 is mounted to the panel 38 by inserting the metal shells 6 and 8 through the parts 52 and 54 respectively, of the cut-out 50, from the rear of the panel 38, so that the housing 4 engages the rear face of the panel. In order to secure the connector 2 to the panel 38, the shank 46 of each screw lock 40 is screwed into a respective one of the tapped bores 36 in the wall 20 of the housing 4 until the collar 48 of the screw lock 40 engages against the front face of the panel 38.
The connector 2 is formatting with a further connector (only parts of which are shown) constructed according to the teaching of Patent Application No. 766,889 filed Sep. 7, 1991 (15127), the disclosure of which Patent Application is hereby incorporated herein by reference. The further connector comprises a mating part (not shown) containing pin terminals for mating with the terminals 14 of the header insert 10 of the connector 2 and a back shell structure supporting a pair of jack screws 58, one of which is shown in FIGS. 9 and 10 and a key 60 in the form of a keyed insert, associated with each jack screw 58. Each jack screw 58 has a shaft 62, having at one end a head 64 formed with an end kerf 66 for receiving a screw driver blade, the jack screw having at its other end a screw threaded shank 68. Towards the shank 68, the shaft 62 is formed with a radially projecting collar 70, and is provided intermediate to the collar 70 and the shank 68, a short smooth section 72.
Each key 60 comprises a circular cross-section, hollow, forwardly open, keying shaft 74 having a blind, axial keying slot 76 opening into the forward end 78 of the shaft 74. There extends from the rear end wall of the shaft 74 a neck (not shown), which is hollow and has at its rear end, a four sided keying abutment 80 having a central circular opening communicating with the interior of the neck and with the interior of the keying shaft 74. The key 60 can be supported in said back shell structure of the further connector with the keying abutment 80 and thus the keying slot 76 in any selected one of four angular orientations. In the present example, as shown in FIGS. 9 and 10, the keying abutment 80 is so supported, that the keying slot 76 is in a top dead center angular position.
One of the keys 60 is provided on each side of said mating part of the further connector with the forward ends 78 of the shafts 74 projecting forwardly. Said back shell structure comprises a pair of oppositely laterally projecting slotted flanges 82, one such flange being located on each side of said mating part. Each flange 82 engages about the neck of the respective key 60 between its shaft 74 and its keying abutment 80. The threaded shank 68 of each jack screw 58 lies within the hollow keying shaft 74 of the respective key 60, with the smooth section 72 of the jack screw 58 extending through the abutment 80 and the neck and with the collar 70 of the jack screw 58 engaging against the keying abutment 80 of the key 60.
When the connector 2 has been mounted to the panel 38, as described above, the further connector is mated with the connector 2 to mate the pin terminals of said mating part with the receptacle terminals 14 of the header insert 10 of the connector 2. In order so to mate the connectors, the connector 2 and the further connector are so relatively oriented that the protrusion 28 of each keying structure 26 of the connector 2 is axially aligned with a respective key 60 of said further connector. Since the keying ribs 32 and the keying slots 76 of the respective connectors have the same angular orientation, the keying rib 32 of each structure 36 is thereby aligned with the keying slot 76 of the respective key 60. As the connector 2 and the further connector are being mated, the shank 68 of each jack screw 58 enters the tapped bore 34 of the protrusion 28 of the respective keying structure 26. The jack screws 58 are then tightened so that the threads of the shanks 68 thereof mesh with the threads of the respective bores 34, whereby the protrusion 28 of each keying structure 26 is drawn into the hollow keying shaft 74 of the respective key 60 so that the rib 32 of the protrusion 28 is fully received in the keying slot 76 of the key 60 as shown in FIG. 10. The connector 2 and the further connector are thereby drawn into full mated relationship. Where the keying abutments 80 angularly oriented otherwise than according to the present example, the connectors could not be mated as described above.
The header 12 of the connector 2 could be mated with the mating part of a second said further connector having unkeyed inserts for receiving the screw locks 40.
Other embodiments of the present invention will now be described with reference to FIGS. 4 to 8.
FIG. 4 shows connector 2A which is the same as the connector 2 excepting that the keying structures 26 are so angularly oriented that their keying ribs 32 extend horizontally and in opposite directions away from the metal shell 6. It will be appreciated from the foregoing, that the connector 2A can be mated with said further connector only when the keying abutments 80 thereof are so angularly oriented that the slots 76 of the keys 60 face horizontally and in opposite directions. The connector 2B shown in FIG. 5 is the same as the connectors 2 and 2A excepting that the keying ribs 32 project horizontally downwardly, to take account of the case where the slots 76 of the keys 60 of said further connector are correspondingly angularly oriented.
FIGS. 6 to 8 show connectors 2C, 2D and 2E which are the same as the connector 2 excepting that in each case, the connectors 2C to 2E are constructed for mating with two of said further connectors when mounted in stacked relationship. In this case, the connectors 2C to 2E are not panel mounted. The tapped bores 36 for the panel mounting of the connector 2, are replaced, in the embodiments of FIGS. 6 to 8, by keying structures 26', one being disposed on each side of the metal shell 8 for keying with the keys 60 of the lower one of said two further connectors of the stack. In FIGS. 6 to 8, the parts of the structures 26' bear the same reference numerals as the respective structures 26 but with the addition of a ' symbol. As shown in FIG. 6, the keying structures 26' of the connector 2C are angularly oriented in the same way as the keying structures 26 thereof, that is to say with their ribs 32' projecting vertically. As shown in FIG. 7, the keying structures 26' of the connector 2D are differently angularly oriented, by 90 degrees with respect to the keying structures 26, that is to say with their ribs 32/ projecting horizontally and away from the metal shell 8, whereas the keying structures 26/ of the connector 2E are, as shown in FIG. 8, differentially angularly oriented by 180 degrees with respect to the keying structures 26, with their ribs 32/ projecting vertically downwardly, that is to say in the opposite direction to the ribs 32 of the keying structures 26.
It will be appreciated that the keying structures 26 and 26/, as described above, comply with respective possible angular orientations of the keying abutments 80 of the keys 60, which can be adjusted only in 90 degree steps. Nevertheless, as disclosed in said patent application Ser. No. 766,889, the keying abutments 80 could have more than four faces and thus more than four angular orientation. Accordingly, although the angular orientations of the keying structures 26 and 26/, described above, are preferred angular orientations, any required number of different angular orientations of the keying structures would be mathematically possible in dependence upon the number of faces provided on the keying abutments of the further connector or further connectors.
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A keyed electrical connector (2) includes a diecast housing (4) having a front face (20). A keying structure (26) which is an integral part of the housing (4) upstands from the front face (20). The keying structure forms a cylindrical protrusion (28) extending to a distal end (30). The cylindrical protrusions (28) defines an exterior surface having a radially outwardly extending rib (32). The rib (32) extends along at least a portion of the exterior surface of the protrusion (28).
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FIELD OF THE INVENTION
The present invention relates to a process for making alcohol-free aqueous solutions of hydroxylammonium salts, and in particular relates to a novel chemical process for making alcohol-free impurity-free aqueous hydroxylammonium nitrate solutions.
BACKGROUND OF THE INVENTION
Hydroxylammonium nitrate is useful as a reducing agent in re-processing spent nuclear fuel, as an energetic oxidizer salt for use in liquid gun propellants, hybrid rocket motors, solution propellants and as a reagent for preparing various industrial, specialty and pharmaceutical chemicals.
It has previously been reported in the literature that commercially available solutions of hydroxylammonium nitrate may be quite dilute, oftentimes being shipped in inert containers at a maximum concentration of 24 percent.
Various methods for preparing hydroxylammonium nitrate have been proposed over the years. These processes suffer from various drawbacks from a commercial, safety and/or technical perspective.
Several of the known processes for preparing hydroxylammonium nitrate have inadequate product yields, have impurity laden products, and/or present problems in accurately controlling the concentration of the desired salt. For instance, one known electrolytic process for making hydroxylammonium nitrate has the undesirable environmental characteristic of utilizing significant amounts of mercury. As a consequence, the hydroxylammonium nitrate may contain a residual amount of mercury, and extensive mercury contamination can occur if the electrolysis cell should rupture. The process is quite expensive and it has been said that it is difficult to obtain consistent concentrations of the desired product. Further, the process apparently does not produce hydroxylammonium nitrate in sufficient concentration for direct use in making liquid gun propellants, and requires concentrating the hydroxylammonium nitrate solution.
An electrochemical process using a mercury cathode in an electrolysis cell is described in French Patent 2,602,802 (1988).
Earlier efforts involving electrodialysis with hydroxylammonium sulfate or its chloride and nitric acid using an ion exchange membrane to produce hydroxylammonium nitrate are described in French Patent Application 2,243,904 and in Ind. Eng. Chem. Process Des. Dev. 20:361 (1981). In this method, hydroxylammonium nitrate is produced from hydroxylammonium sulfate or hydrochloride by an electrolysis method which uses cation and anion exchange resins and a double decomposition reaction. Four different types of fluids are passed through four chambers of an electrodialysis tank having the chambers in one block but partitioned alternately by cation exchange membranes and anion exchange membranes. The hydroxylammonium nitrate is drawn out of one of the four chambers. The process is complicated, and commercially not very attractive because it requires four units of fluid circulating pipes, direct current power sources, and auxiliary facilities, and productivity is low. Further, the available membrane surface area is limited.
A process for continuously converting a hydroxylammonium salt, such as the sulfate salt, to another hydroxylammonium salt, such as hydroxylammonium nitrate or hydroxylammonium formate, by counter-current liquid extraction, using a so-called cationic solvent is described in French Patent 2,206,270 (1974).
Conversion of hydroxylammonium sulfate into hydroxylammonium nitrate has been proposed using a cation exchange resin. Ind. Eng. Chem Process Des. Dev. 16:220 (1977). In this method, a sulfate is converted into a corresponding nitrate using a cation exchange resin in which the hydroxylammonium ion in the hydroxylammonium sulfate is carried on a cation exchange resin and then eluted with a nitric acid solution. This method is a quite complicated batch process and there is a danger of explosion by the reaction between the cation exchange resin and the nitric acid. Chem. Eng. Nov. 17:271 (1980). The hydroxylammonium nitrate solution produced is extremely dilute.
Hydroxylamine nitrate can be produced by combining NO and H 2 gases in the presence of a platinum catalyst, German Offenlegunschrift 2,100,036, or by hydrogenating nitric acid in the presence of a special palladium catalyst, Dutch patent application 7,009,685. Another process for preparing a hydroxylammonium salt by the catalytic reduction of nitrogen monoxide with hydrogen at elevated temperature in a dilute aqueous solution of a mineral acid and in the presence, in suspension, of a particular supported platinum catalyst is disclosed in Europe 287,952 (1988). The processes for producing hydroxylammonium nitrate wherein nitrous oxide or nitric acid is hydrogenated in the presence of the specified catalyst requires the use of dangerous hydrogen and, in the other case, nitrous oxide. The processes require a special catalyst which must be periodically replaced or regenerated. Catalyst regeneration is complicated and expensive.
The stoichiometric reaction of a boiling saturated barium nitrate solution with hydroxylammonium sulfate yields a dilute solution of hydroxylammonium nitrate. The maximum concentration of hydroxylammonium nitrate obtained is about 20%. However, concerns about product stability often mean the reaction is conducted at lower temperatures which results in a reduced product concentrations on the order of 15%. Further, unless the barium nitrate salt is dissolved prior to admixture with hydroxylammonium sulfate, results are erratic and considerable amounts of barium salt remain unreacted.
Another barium nitrate based process for making hydroxylammonium nitrate is described in U.S. Pat. No. 4,066,736. As the process is described, a hydroxylammonium salt, such as hydroxylammonium sulfate, is slowly added to a well agitated slurry of barium nitrate whereby the hydroxylammonium salt goes into solution and reacts with the dissolved barium salt but does not directly contact the slurried barium nitrate. Effective agitation must be maintained, otherwise direct contact between the slurried barium nitrate and the hydroxylammonium salt occurs whereby the once soluble slurried salt will receive an insoluble barium sulfate coating which causes the reaction to terminate prematurely. The insoluble by-product, barium sulfate, must be separated from the hydroxylammonium nitrate. This may present handling, separation and disposal problems.
Europe 108,294 (I984) describes preparation from solid hydroxylammonium sulfate of alcoholic hydroxylamine solutions, and of oximes, hydroxamic acids and other hydroxylammonium salts via alcoholic hydroxylamine solutions. Among the methods disclosed is one for preparing hydroxylammonium nitrate which involves preparing and stirring a methanolic solution of sodium methoxide and hydroxylamine sulfate in an ice bath, filtering the thus obtained slurry, mixing the clear methanolic filtrate with cake-wash and with concentrated H 2 SO 4 to pH 8.0, filtering thus produced white solid, and adding conc. HNO 3 , while chilling and stirring, to the filtrate whereby hydroxylammonium nitrate in methanolic solution is said to be obtained.
Another dialysis method, which is described in Europe 266,059 (1988), involves providing a dialysis unit comprising a tank divided into chambers by a cation exchange resin, such as styrene and divinyl benzene, placing an aqueous solution of hydroxylamine sulfate and a solution of nitric acid in adjacent chambers, and allowing the hydroxylammonium ions and hydrogen ions to pass through the membrane whereby the nitric acid is converted to the desired hydroxylamine nitrate.
A method for preparing hydroxylamine salts is described in U.S. Pat. No. 4,956,168 in which a slurry of hydroxylamine sulfate in alcohol at a temperature not exceeding 65° C. is prepared, a hydroxylamine-alcohol solution and ammonium sulfate are then prepared by high-shear mixing ammonia with the slurry at ≦65° C., the ammonium sulfate is removed by filtration, the solution is agitated, and nitric acid is admixed under vigorous agitation with the solution at about ≦50° C. and preferably not below 20° C., and the desired hydroxylamine salt is recovered.
Low concentrations of aqueous hydroxylammonium nitrate solutions may pose obstacles in the effective use of hydroxylammonium nitrate in certain applications such as, for instance, a liquid gun propellant and in making pharmaceutical or other specialty chemicals. Accordingly, efforts to find suitable means for concentrating solutions of hydroxylammonium nitrate have been made. However, it has been stated that concentration of solutions containing hydroxylammonium nitrate by techniques which require heating, such as distillation or evaporation, are not desired because decomposition of the product may result.
One effort to provide a suitable process for concentrating dilute aqueous solutions of hydroxylammonium salts, including hydroxylammonium nitrate, is disclosed in U.S. Pat. No. 4,851,125. This processes involves concentrating the hydroxylammonium nitrate salt solution through contact with a membrane having a sorption side and a desorption side, and comprises contacting the dilute salt solution with the sorption side of a membrane to sorb the solvent and permit the solvent to flow through the membrane to the desorption side, and desorbing the solvent from the desorption side of the membrane. This process does not address the underlying problem of providing an economical, environmentally acceptable and technically facile process for manufacturing hydroxylammonium nitrate.
Accordingly, there has been a long standing need for a less capital intensive and facile process for producing hydroxylammonium nitrate solutions sufficiently pure and concentrated for direct use in energetic compositions and in syntheses of pharmaceutical or specialty chemicals.
SUMMARY OF THE INVENTION
The present novel alcohol-free process for preparing high purity concentrated hydroxylammonium nitrate is economical, environmentally acceptable, and technically facile. Neutralizing nitric acid (70% wt. %) with an alcohol-free aqueous hydroxylamine solution having a concentration of at least about 10 wt. % hydroxylamine under low temperatures produces the desired aqueous hydroxylammonium nitrate solution.
Distilling hydroxylamine from an alcohol-free aqueous hydroxylamine solution under low pressure at a temperature less than about 65° C., and neutralizing nitric acid (≦70 wt. %) with the distilled hydroxylamine solution at a temperature not greater than about 30° C. produces an alcohol-free aqueous hydroxylammonium nitrate solution having a sufficiently high concentration and purity for the economic manufacture of liquid gun propellants.
Neutralizing an aqueous hydroxylammonium sulfate solution with at least one alkali or alkaline earth metal oxide or hydroxide, distilling the thus produced hydroxylamine solution under low pressure at a temperature of less than about 65° C., and neutralizing nitric acid (≦70 wt. %) with the distilled hydroxylamine solution at temperatures not greater than 30° C. produces an alcohol-free aqueous hydroxylammonium nitrate solution having a sufficiently high concentration and purity for the economic manufacture of liquid gun propellants.
DETAILED DESCRIPTION OF THE INVENTION
The present process comprises neutralizing nitric acid/water (up to about 70 wt. % HNO 3 ) with an alcohol-free aqueous hydroxylamine solution at low temperatures and recovering hydroxylammonium nitrate (HAN), solid or in alcohol-free aqueous solution form, following the neutralization. Such mercury-free HAN solutions are at least as pure and as concentrated as the HAN solutions now available for the manufacture of liquid gun propellants while being produced at far less cost.
An aqueous alcohol-free hydroxylamine solution is distilled under low pressure conditions (less than about 50 mm Hg) at a temperature of ≦65° C., the hydroxylamine solution is condensed, and the hydroxylamine is added to concentrated nitric acid (≦70 wt. %) at a temperature not greater than about 30° C. whereby an essentially impurity-free and alcohol-free aqueous hydroxylammonium nitrate solution is obtained.
The alcohol-free aqueous hydroxylamine solution can, if desired, be generated by neutralizing hydroxylammonium sulfate ("HAS") with an effective amount of at least one inorganic base selected from the group consisting of alkali metal hydroxides, alkali metal oxides, alkaline earth oxides, and alkaline earth hydroxides. Exemplary hydroxides include, for instance, sodium hydroxide, potassium hydroxide, magnesium hydroxide, and calcium hydroxide. Sodium hydroxide is preferred. Suitable exemplary oxides include, among others, sodium oxide, magnesium oxide, calcium oxide. The thus obtained aqueous hydroxylamine solution is preferably filtered to remove any insolubles, such as alkali metal or alkaline earth metal sulfates. Then the filtered aqueous solution is purified, such as by distillation under reduced pressure at a suitable temperature, such as ≦65° C. to obtain a purified aqueous hydroxylamine solution (16-23 wt. % hydroxylamine). A nitric acid/water solution (≦70 % wt./wt.) is then neutralized with the proper amount of the distilled aqueous hydroxylamine solution whereby an essentially impurity-free alcohol-free aqueous hydroxylammonium nitrate solution is obtained. The impurity-free and alcohol-free aqueous hydroxylammonium nitrate solution is suitable for such demanding uses as liquid gun propellants.
A saturated aqueous hydroxylammonium sulfate solution can be made by methods which are known to those skilled in this art. Suitable concentrations of hydroxylammonium sulfate range from above about 1.25 molar up to about 4-5 molar, although 2.5 molar is preferred. The concentration is selected to insure the maximum amount of the hydroxylammonium sulfate reacts with the inorganic base so as to obtain the desired hydroxylamine and to keep the maximum desired concentration of hydroxylamine in the distillate. The HAS solution may be prepared at any suitable temperature, although pragmatic considerations imply a temperature range of 15° C. to 25° C. An alcohol-free saturated HAS solution at 20° C. will comprise approximately 68.5 grams HAS per 100mls water.
The neutralization of the hydroxylammonium sulfate solution may be conducted at varying temperatures such as, for instance, up to about 60° C., but is preferably conducted at lower temperatures such as up to about 25°-30° C. Useful results have been obtained at 3°-7° C. Decomposition of hydroxylamine is not desired.
The concentration of the alcohol-free aqueous hydroxylamine solution is directly related to the concentration of the aqueous hydroxylammonium nitrate solutions produced by the present processes. Suitable concentrations of hydroxylamine range from 10% to about 50% (wt. % hydroxylamine), and particularly from about 10 wt. % to about 30 wt. %, more particularly from 10 wt. % to 25 wt. %, and most particularly from about 16 wt. % to about 23 wt. %. However, the more concentrated the aqueous hydroxylamine solution, the more concentrated is the hydroxylammonium nitrate solution. To obtain hydroxylammonium nitrate in high purity, the starting materials, such as the hydroxylamine solution, should be substantially impurity-free. In particular, the presence of iron or ions thereof are undesired. The starting materials may be further purified, if, for instance, the hydroxylammonium nitrate end product will be used in a liquid gun propellant. An exemplary commercially available aqueous hydroxylamine solution is said to contain 50% free hydroxylamine in water, 50 ppm max. of sulfate, 1 ppm max of iron, 2 ppm max of lead, 50 ppm ash.
The hydroxylamine solution is distilled under low pressure conditions, i.e. reduced pressure, preferably vacuum conditions at a temperature of not greater than about 65° C., advantageously 40°-60° C. and particularly 40°-50° C. As contemplated herein, low pressure refers to less than about 50 mm Hg, preferably 10-20 mm Hg. The distillation of the aqueous hydroxylamine solution permits production of alcohol-free impurity-free aqueous hydroxylammonium nitrate solutions suitable for the manufacture of storage-stable liquid gun propellants having consistent combustion results.
The nitric acid concentration can be varied across a concentration range, and may be adjusted based on the temperature conditions desired and which prevail during the neutralization step. Suitable nitric acid concentrations (nitric acid/water, wt./wt.) may range from about 20% to about 70%.
The nitric acid neutralization step may be conducted at cryogenic temperatures ranging from slightly above -50° C. up to not greater than about 30° C., and advantageously not greater than about 25° C. The neutralization step may be conducted in the range of -45° C. to +20° C., and may be conducted at less than about +10° C., such as less than about +5° C. The temperature is selected to minimize and, if possible, avoid the formation of undesired by-products and/or the decomposition of hydroxylamine.
During the neutralization step, decomposition of the hydroxylammonium nitrate can be avoided by adding the aqueous hydroxylamine solution to (into) the nitric acid. The addition is preferably conducted such that the solutions are chemically mixed with vigorous agitation. For instance, the alcohol-free aqueous hydroxylamine solution may first be passed through a cooled heat exchanger, and thereafter the nitric acid may be neutralized by controlling the amount of and rate at which the thus cooled alcohol-free aqueous hydroxylamine solution is added to the nitric acid. The hydroxylamine solution may be added to the nitric acid using a mixing tee. The thus obtained neutralization solution is further vigorously agitated using suitable available means, such as a stirred reactor or an inline agitator.
The temperature, nitric acid concentration, and purity of the aqueous hydroxylammonium nitrate solutions appear to be interrelated. It is theorized that there may be a slight interaction between the concentration (wt. %) hydroxylamine added and the concentration (wt. %) nitric acid used. For example, at -4° C., neutralizing 70% nitric acid/water (wt./wt.) with unpurified aqueous hydroxylamine (50 wt. % hydroxylamine from Howard Hall International) resulted in fume-off and generated NO. fumes, whereas at -45° C. neutralizing 60% nitric acid/water (wt./wt.) with the unpurified aqueous hydroxylamine solution (50% hydroxylamine from Howard Hall International) was facilely conducted. However, nitric acid (50 wt. % HNO 3 ) may be neutralized with a purified aqueous hydroxylamine solution (45-48 wt. %) at temperatures of up to about 20° C., with hydroxylamine decomposition occurring at greater than about 30° C. and being complete at about 40° C.
The process is conducted in water. Non-aqueous solvents are undesired. In particular, the process is at least substantially, if not essentially, alcohol-free. The presence of relatively significant amounts of alcohol may result in nitrate ester formation and contamination of the hydroxylammonium nitrate solution. Such contamination may have a deleterious effect on a liquid gun propellant composition. The absence of alcohol also avoids the need to separate the alcohol from the hydroxylamine and hydroxylammonium nitrate. The process also does not require or contemplate the addition of ammonia as such.
The molarity of the hydroxylammonium nitrate solution obtained in accordance with this process embodiment is reasonably predictable from the ratio of hydroxylamine/nitric acid/water used, with a error or about ±0.13 moles/liter hydroxylammonium nitrate/water.
The moles of nitric acid remaining is reasonably predictable from the moles hydroxylamine to moles nitric acid present. Zero percent nitric acid remaining in the hydroxylammonium nitrate solution has been obtained, but is not preferred. The pH of the hydroxylammonium nitrate solution is adjusted to a pH of about 1.0 to about 1.5, and preferably to a pH less than or equal to 1.3, in order to confer the desired stability on such solutions.
Alcohol-free aqueous hydroxylammoniumnitrate solutions are obtainable in accordance with the present invention which are suitable for use in making liquid gun propellants. Such alcohol-free aqueous hydroxylammonium nitrate solutions are sufficiently iron-free for use in such energetic applications. The presence of iron is not desired. The iron content is typically less than about 1 ppm Fe.
Liquid gun propellants comprising energetically effective amounts of hydroxylammonium nitrate and triethanolammonium nitrate in water can be obtained by further concentrating the hydroxylammonium nitrate solutions obtained in accordance with the present invention followed by addition of triethanolamine and nitric acid according to available known procedures.
By way of example, and not limitation, the following examples are given.
EXAMPLES
In the Examples and in Table I, HA means hydroxylamine, HAS means hydroxylammonium sulfate, and HAN means hydroxylammonium nitrate. The mole ratios reported for Examples 2-14 were calculated based on 50 wt. % HA and 70 wt. % HNO 3 . The exact concentration. De-ionized and distilled water was used in the Examples.
EXAMPLE 1
In a round-bottom flask was placed an aqueous hydroxylamine solution (66.36 grams, 50 wt. % HA, commercial grade from Howard Hall International). That solution was distilled with a rotary evaporator under vacuum (25mm Hg) at 57° C. to 60° C. until the flask was dry (about 30 minutes). The recovered solution (64.82 grams) contained hydroxylamine (46.0 wt % HA).
To a half-liter round-bottom flask equipped with a stirrer bar and thermocouple were added conc. HNO 3 (45.0 grams, 70 wt. %) while the flask was kept in an isopropyl alcohol/ice bath (-4° C.). To another flask in an ice/water bath was added a portion of the distilled hydroxylamine solution (35.0 grams, 46.0 wt. % HA). The chilled distilled aqueous hydroxylamine solution was metered, dropwise, to the round-bottom flask containing HNO 3 while stirring. During the neutralization, the temperature in the round-bottom flask rose from -7° C. to about 0° C. when the nitric acid was neutralized. The product solution (79.3 grams) has a pH of 3 To the product solution was added additional conc. HNO 3 (70 wt. % HNO 3 ) to obtain pH 1.3
The product solution contained 59.7 wt. % HAN.
EXAMPLE 2
In a round-bottom flask was placed an aqueous hydroxylamine solution (101.81 grams, 50 wt. % HA, commercial grade from Howard Hall International). That solution was distilled with a rotary evaporator under vacuum (25 mm Hg) at 60° C. until the flask was dry. The recovered solution (101.01 grams) contained hydroxylamine (45.0 wt % HA).
To a conc. nitric acid solution (45.0 grams, 70 wt. % HNO 3 ) was added distilled water (18.0 grams) to obtain a nitric acid solution (63.0 grams, 50 wt. %).
In a 100 mls three-neck round-bottom flask equipped with a thermocouple and magnetic stirrer and cooled in an ice bath at 0° C. was placed a portion of the above-prepared nitric acid (12.6 grams, 50 wt. % HNO 3 ). To another flask was placed a portion of the above-prepared distilled aqueous hydroxylamine solution (7.34 grams, 45 wt. % HA), and the flask and its contents were chilled. To the nitric acid-containing flask was controllably and slowly added the chilled aqueous hydroxylamine solution. The initial nitric acid temperature was 0° C. The hydroxylamine was added at such a rate to attain and maintain the desired target neutralization temperature of about 8°-10° C. The product solution (19.8 grams) has a pH of 4. To the product solution was added additional HNO 3 (50 wt. % HNO 3 ) to obtain pH 1.3.
The product solution contained 48.8 wt. % HAN.
EXAMPLE 3
In a 100 mls. three-neck round-bottom flask equipped with a thermocouple and magnetic stirrer and cooled in an ice bath at 0° C. was placed a portion of the above-prepared nitric acid (12.6 grams, 50 wt. % HNO 3 , Example 2). To another flask was placed a portion of the distilled aqueous hydroxylamine solution (7.34 grams, 45 wt. % HA, Example 2). To the nitric acid-containing flask was controllably and slowly added the chilled aqueous hydroxylamine solution. The initial nitric acid temperature was 2° C. The hydroxylamine was added at such a rate to attain and maintain the desired target neutralization temperature of up to about 20° C. During the neutralization the temperature was maintained between 17°-20° C. The product solution (19.9 grams) had a pH of 3. To the product solution was added additional nitric acid to obtain pH 1.3.
The product solution contained 49.0 wt. % HAN.
EXAMPLE 4
In a 100 mls. three-neck round-bottom flask equipped with a thermocouple and magnetic stirrer and placed in a cool water bath was placed a portion of the above-prepared nitric acid (12.6 grams, 50 wt. % HNO 3 , Example 2). To another flask was placed a portion of the distilled aqueous hydroxylamine solution (7.34 grams, 45 wt. % HA, Example 2). To the nitric acid-containing flask was controllably and slowly added the chilled aqueous hydroxylamine solution. The initial nitric acid temperature was 2° C. The hydroxylamine was added at such a rate to attain and maintain the desired target neutralization temperature of up to about 30° C. During the neutralization the temperature was maintained between 29°-30° C. The product solution (19.62 grams) had a pH of 1.
The product solution contained 48.0 wt. % HAN.
EXAMPLE 5
To water (75 mls) was added hydroxylammonium sulfate (82.0 grams) at a temperature of 22° C. to obtain a saturated aqueous hydroxylammonium sulfate solution. To the thus obtained solution was slowly added sodium hydroxide (80.0 grams 50 wt. % NaOH). The temperature was initially 3° C. but rose to a temperature of 11° C. during the NaOH addition. The solution was cooled to below 5° C. and filtered. The recovered wet solid material (136.1 grams) was set aside. To the cold liquid (98.9 grams) containing hydroxylamine was added ascorbic acid (0.3 grams). The cold liquid was then treated in a rotary evaporator until a residue (14.55 grams) was obtained and a liquid product (80.05 grams) was obtained. The liquid product contained HA (16.0 wt. HA, 0.39 mole HA).
In an isopropyl alcohol/ice bath a 500 ml. round-bottom flask was set up with a magnetic stirring bar and thermocouple. To the round bottom flask was added conc. nitric acid (70% wt./wt., 35.1 grams, 0.39 mole HNO 3 ). To the nitric acid was slowly and controllably added a portion of the purified HA-containing liquid product (80.0 grams, 0.39 mole, 16 wt. % HA, pH 10) at -6° C. The temperature rose to -1° C. After about 2 hours the neutralization was completed. To the neutralization solution was added additional nitric acid to reduce the pH from 4 to 1.3. The thus treated neutralization solution (114.0 grams) was transferred to a 250 ml. Erlenmeyer flask. The neutralization solution contained about 33 wt. % HAN.
EXAMPLE 6
To water (200 mls) was added hydroxylammonium sulfate (82.0 grams) at a temperature of 22° C. to obtain an aqueous hydroxylammonium sulfate solution. To the thus obtained solution was slowly added sodium hydroxide (80.0 grams, 50 wt. % NaOH). The temperature was initially 3° C. but rose to a temperature of 7° C. during the NaOH addition. The solution was cooled to below 5° C. and filtered. The recovered wet solid material was then washed with cold distilled water (50 mls) and added to the filtrate resulting in 288.0 grams of liquid and 113.4 grams of precipitate. To the cold liquid (288.0 grams) containing hydroxylamine was added ascorbic acid (0.3 grams). The cold liquid was then treated in a rotary evaporator until a residue (23.6 grams) was obtained and a liquid product (257.11 grams) was obtained. The liquid product contained HA (10.0 wt. HA, 0.39 mole HA).
A 23.0 wt. % HAN solution is obtained using a portion of the just-prepared HA solution (10 wt. % HA) to neutralize conc. nitric acid (70.2 grams, 70 wt. %) according to the procedure of Example 5.
EXAMPLE 7
To a 500 mls. 3-neck round-bottom flask hydroxylammonium sulfate (82.0 grams, 0.5 mol) and distilled water (200 mls.) were added at 22° C. When the addition was complete, the solution was cooled in an ice bath to about 3° C. To the cooled solution was slowly added sodium hydroxide (80.0 grams, 1.0 mol, 50 wt. % NaOH) while maintaining the reaction temperature between 3°-10° C. When the sodium hydroxide addition was completed, the solution was cooled to less than 5° C. and filtered. The resulting precipitate was washed with 50 mls of cold distilled water and added to the filtrate to obtain a liquid (289.4 grams) and precipitate (115.9 grams). To the thus obtained liquid was added 0.15 gram of ascorbic acid. The thus stabilized liquid was then distilled using a rotary evaporator at about 25 mm Hg at about 57°-60° C. with the condenser column being maintained at less than 0° C. A distilled liquid (263.9 grams) and residue (24.4 grams) were obtained.
Hydroxylamine analysis indicated HA (11.1 wt. %). The hydroxylamine used to neutralize the nitric acid, with a percent yield of 88.6%
EXAMPLE 8
In a 100 mls. three-neck round-bottom flask equipped with a thermocouple and magnetic stirrer and placed in a water bath was placed a portion of the above-prepared nitric acid (12.6 grams, 50 wt. % HNO 3 , Example 2). To another flask was placed a portion of the distilled aqueous hydroxylamine solution (7.34 grams, 45 wt. % HA, Example 2). To the nitric acid-containing flask was controllably and slowly added the chilled aqueous hydroxylamine solution. The initial nitric acid temperature was 23° C. The hydroxylamine was added at such a rate to attain and maintain the desired target neutralization temperature of 30°-40° C. During the neutralization the temperature was maintained between 32°-40° C. Evolution of yellowish colored gas from the neutralization solution was observed. Violent fizzing and bubbling were also observed during the neutralization. The product solution (16.1 grams) has a pH ≦1.
The product solution contained 1.5 wt. % HAN.
EXAMPLES 9-21
Neutralizations were performed by neutralizing varying concentrations of nitric acid in a stirred flask at various low temperatures by controllably adding, dropwise, unpurified aqueous hydroxylamine solution (50% HA, commercial grade, Howard Hall International).
The molar concentrations of hydroxylammonium nitrate and HNO 3 in the hydroxylammonium nitrate solutions produced in accordance with Examples 9-21 were determined from pH titration curves. The equivalence point was determined by plotting a titration curve (mls. titrant versus pH) and the concentration of the desired species was then calculated. The pH determinations were made using an Orion Digital pH meter and, as reagents, 0.2 M n-butylamine, benzoic acid, methanol, and 1% phenolphthalein solution. The general technique and principle are described in Sasse, Analysis of Hydroxylammonium Nitrate-Based Liquid Propellants, Tech. Report No. BRL-TR-3154 (Sept. 1990) and Decker et al, Titrimetric Analyses of HAN-Based Liquid Propellants, Tech. Report (BRL June 1986).
EXAMPLE 22
A neutralization was performed by adding an undistilled aqueous hydroxylamine solution (I.37 grams, 50% HA, commercial grade, from Howard Hall International) dropwise to conc. nitric acid (1.31 grams, 70% HNO 3 ) in a stirred flask set in an ice bath at 4° C. The addition of a drop of hydroxylamine solution resulted in fume-off, generating considerable NO. fumes, with no apparent production of hydroxylammonium nitrate.
TABLE I__________________________________________________________________________ Molar Grams Grams Mol/L Ratio React. HA + Nitric + Moles [HAN] % HA/ Temp. Water Water Nitric In FinalEx Nitric HNO.sub.3 (°C.) Used Used Rem. Soln. pH__________________________________________________________________________ 1 70 1.0 -7 to 0 35.9 45.0 0.00 8.22 1.3* 9 10 1.10 -4 6.34 55.03 0.00 1.57 5.1**10 20 0.90 -4 15.56 82.55 0.43 2.93 1.4**11 20 0.95 -4 8.22 41.28 0.28 3.09 1.5**12 20 1.00 -4 17.32 82.55 0.10 2.93 1.5**13 20 1.00 -4 17.32 82.55 1.26 2.88 2.1**14 20 1.05 -4 9.08 41.28 0.03 2.83 3.9**15 20 1.10 -4 19.02 82.55 0.00 2.83 5.4**16 35 1.00 -4 5.77 15.72 0.13 5.26 1.6**17 45 1.10 -4 19.02 36.69 0.00 6.07 5.2**18 50 1.05 -4 to +2 6.05 11.01 0.05 6.68 2.5**19 50 1.10 -4 to +2 19.02 33.02 0.00 6.58 5.0**20 50 1.05 -46 to -30 6.05 11.01 0.05 6.58 4.3**21 60 1.05 -45 to -35 4.54 6.88 0.08 7.69 2.4**__________________________________________________________________________ *pH adjusted from 3.0 to 1.3 by addition of further HNO.sub.3 **pH of the titrate (alcoholic solution of HAN)
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The present invention pertains to a method for making energetic oxidizer salts and solutions thereof, and in particular relates to processes for making aqueous solutions of hydroxylammonium nitrate in high purity suitable for use in making liquid gun propellants. The present alcohol-free process yields high purity alcohol-free hydroxylammonium nitrate in a simple chemical neutralization reaction by combining an aqueous nitric acid solution 120 to 70 wt. %) with an alcohol-free aqueous hydroxylamine solution at temperatures ranging from about -50° C. to above ambient to produce the desired alcohol-free aqueous hydroxylammonium nitrate solution in a usable concentration and in high purity. The process is economical, environmentally acceptable, and facile.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of and is a continuation-in-part of the following U.S. Nonprovisional Application:
PARENT U.S. NONPROVISIONAL PATENT APPLICATION
Ser. No.
Title
Filing Date
09/861,001
Network Vulnerability Assessment
May 18, 2001
System and Method
The benefit of 35 U.S.C. § 120 is claimed for the above referenced commonly owned application. The contents of the application referenced in the table above is not necessarily identical to the contents of this application.
TECHNICAL FIELD
The present application relates to a system and method for assessing vulnerability of networks or systems to cyber attack.
DESCRIPTION OF THE RELATED ART
As the Internet emerges as an increasingly important medium for conducting commerce, corporate businesses can be being introduced to new levels of opportunity, prosperity . . . and risk. To take full advantage of the opportunities that electronic commerce has to offer, corporations will be increasingly relying on the Internet, Intranets and Extranets to maximize their capabilities. The Internet has become a driving force creating new opportunities for growth through new products and services, enabling greater speed to penetrate global markets, and increasing productivity to facilitate competition. However, embracing the Internet also means undergoing a fundamental shift from an environment where systems and networks have been closed and protected to an environment that can be open, accessible and by its very nature, at risk. The Internet is assumed to be unsecured; the people using the Internet are assumed to be untrustworthy.
The risks come from 30,000 hacker sites that teach any site visitors how to penetrate systems and freely share tools and expertise with anyone who is interested. The tools that are freely available on these sites can be software-packaged electronic attacks that take only minutes to download and require no special knowledge to use, but give the user the ability to attack networks and computers anywhere in the world. In fact, International Data Corporation has estimated that more than 100 million people have the skills to conduct cyber-attacks. Security experts realize that almost every individual online can be now a potential attacker. Currently, people using the tools tend to be individuals, corporations and governments that are using the information provided to steal corporate assets and information, to damage systems or to plant software inside systems or networks.
In addition to the growth of the number of people who can break in, there can be an ongoing explosion in the number of ways to break in. In the year 2000, 1090 new security vulnerabilities were discovered by hackers and security experts and posted on the Internet for anyone to use. Every vulnerability can be a potential way to bypass the security of a particular type of system. Vulnerabilities were discovered for a broad range of systems; and the more popular a system or computer, the more vulnerabilities were found. For example, installing some Microsoft products will actually install many features and functionalities that are not necessarily intended by the computer user, such as a web server, an e-mail server, indexing services, etc. A default install of Microsoft ISS4 would contain over 230 different vulnerabilities.
The pace of discovery in 2000, at an average of more than two new vulnerabilities per day, led to 100% growth in the number of new vulnerabilities from 1999. And well over 2000 new vulnerabilities were discovered in 2001, continuing an extraordinary rate of vulnerability growth. These factors have driven computer break-ins to become a daily news story and have created corporate losses in the hundreds of millions of dollars.
From a testing perspective, vulnerabilities can only be found in devices that are known to exist. Therefore, the ability to see all of the networks and systems that are reachable from the Internet is paramount to accurate security testing.
In response to the increased need for security, corporations have installed Intrusion Detection Systems (IDS) and Firewalls to protect their systems. These security devices attempt to prevent access by potential intruders. A side effect of these devices can be to also block vulnerability assessment software scanners, making them unreliable to the corporations who can be most concerned about security.
Blocking by security devices affects software scanners and all vulnerability assessments that come from a single location in two ways. First, all computers cannot be identified by the scanner. As only computers that are found can be analyzed for vulnerabilities, not all of the access points of the network can be checked for security holes. Secondly, the security device can block access in mid-process of analyzing a computer for vulnerabilities. This can result in only partial discovery of security holes. An administrator can correct all the reported vulnerabilities and believe that the computer is secure, when there remain additional problems that were unreported. Both of these scenarios result in misleading information that can actually increase the risk of corporations.
It is apparent that network vulnerability issues are of strategic importance to businesses and other entities connected to the Internet. The state of the art of network vulnerability testing and reporting test results successfully addresses many issues, but leaves other issues unresolved such as the creation of useful and accessible reporting formats, for example. There are many other unresolved issues, some of which will be explicitly mentioned herein and many of which will be apparent to one of ordinary skill in the art upon review of this application. The present invention successfully addresses those unresolved issues as described, as well as many more that will be apparent to one of ordinary skill in the art.
SUMMARY OF THE INVENTION
To answer the security needs of the market, a preferred embodiment was developed. A preferred embodiment provides real-time network security vulnerability assessment tests, possibly complete with recommended security solutions. External vulnerability assessment tests can emulate hacker methodology in a safe way and enable study of a network for security openings, thereby gaining a true view of risk level without affecting customer operations. This assessment can be performed over the Internet for domestic and worldwide corporations.
A preferred embodiment's physical subsystems combine to form a scalable holistic system that is able to conduct tests for thousands of customers any place in the world. The security skills of experts can be embedded into a preferred embodiment systems and incorporated into the test process to enable the security vulnerability test to be conducted on a continuous basis for multiple customers at the same time. A preferred embodiment can reduce the work time required for security practices of companies from three weeks to less than a day, as well as significantly increase their capacity. This can expand the market for network security testing by allowing small and mid-size companies to be able to afford proactive, continuous electronic risk management.
A preferred embodiment includes a Test Center and one or more Testers. The functionality of the Test Center can be divided into several subsystem components, possibly including a Database, a Command Engine, a Gateway, a Report Generator, an Early Warning Generator, and a Repository Master Copy Tester.
The Database warehouses raw information gathered from the customers systems and networks. The raw information can be refined for the Report Generator to produce different security reports for the customers. Periodically, for example, monthly, information can be collected on the customers for risk management and trending analyses. The reports can be provided in hard copy, encrypted email, or HTML on a CD. The Database interfaces with the Command Engine, the Report Generator and the Early Warning Generator subsystems. Additional functions of the Database and other preferred embodiment subsystem modules can be described in more detail subsequently, herein.
The Command Engine can orchestrate hundreds of thousands of “basic tests” into a security vulnerability attack simulation and iteratively test the customer systems based on information collected. Every basic test can be an autonomous entity that is responsible for only one piece of the entire test conducted by multiple Testers in possibly multiple waves and orchestrated by the Command Engine. Mimicking hacker and security expert thought processes, the attack simulation can be modified automatically based on security obstacles discovered and the type of information collected from the customer's system and networks. Modifications to the testing occur real-time during the test and adjustments can be made to basic tests in response to the new information about the environment. In addition to using the collected data to modify the attack/test strategy, the Command Engine stores the raw test results in the Database for future use. The Command Engine interfaces with the Database and the Gateway.
The Gateway is the “traffic director” that passes test instructions from the Command Engine to the Testers. The Gateway receives from the Command Engine detailed instructions about the different basic tests that need to be conducted at any given time, and it passes the instructions to one or more Testers, in possibly different geographical locations, to be executed. The Gateway can be a single and limited point of interface from the Internet to the Test Center, with a straightforward design that enables it to secure the Test Center from the rest of the Internet. All information collected from the Testers by the Gateway can be passed to the Command Engine.
The Testers can reside on the Internet, in a Web-hosted environment, and can be distributed geographically anyplace in the world. The entire test can be split up into tiny pieces, and it can also originate basic tests from multiple points and therefore be harder to detect and more realistic. The Testers house the arsenals of tools that can be used to conduct hundreds of thousands of hacker and security tests. The Tester can receive from the Gateway, via the Internet, basic test instructions that can be encrypted. The instructions inform the Tester which test to run, how to run it, what to collect from the customer system, etc. Every basic test can be an autonomous entity that can be responsible for only one piece of the entire test that can be conducted by multiple Testers in multiple waves from multiple locations. Each Tester can have many basic tests in operation simultaneously. The information collected by each test about the customer systems is sent to the Gateway and from there to the Database to contribute to creation of a customer's system network configuration.
The Report Generator can use the detailed information collected about a customer's systems to generate reports about the customer's system profile, Internet Address Utilization, publicly offered (i.e., open) services (e.g., web, mail, ftp, etc.), version information of installed services and operating systems, detailed security vulnerabilities, Network Topology Mapping, inventory of Firewall/Filtering Rule sets, publicly available company information such as usernames, email addresses, computer names, etc. The types of reports can be varied to reflect the particular security services purchased by the customer. The report can be created based on the type of information the customer orders and can be delivered by the appropriate method and at the frequency requested.
New vulnerabilities can be announced on a daily basis. So many, in fact, it can be very difficult for the typical network administrator to keep abreast of relevant security news. Bugtraq, a popular mailing list for announcements, has often received over 350 messages a day. Thus, a network administrator using that resource, for example, may need to review a tremendous number of such messages in order to uncover two or three pertinent warnings relevant to his network. Then each machine on his network can need to be investigated in order to determine which can be affected or threatened. After the fix or patch can be installed, each machine can need to be re-examined in order to insure that the vulnerability can be truly fixed. This process can need to be repeated for each mailing list or resource similar to Bugtraq that the administrator can subscribe to.
When a new security vulnerability is announced on a resource like Bugtraq, the information can be added to the Vulnerability Library. Each vulnerability can be known to affect specific types of systems or specific versions of applications. The Vulnerability Library enables each vulnerability to be classified and cataloged. Entries in the Vulnerability Library might include, for example, vulnerability designation, vendor, product, version of product, protocol, vulnerable port, etc. Classification includes designating the severity of the vulnerability, while cataloging includes relating the vulnerability to the affected system(s) and/or application(s). The configuration of the new vulnerability can be compared to the customer's system network configuration compiled in the last test for the customer. If the new vulnerability is found to affect the customer systems or networks then a possibly detailed alert can be sent to the customer. The alert indicates which new vulnerability threatens the customer's network, possibly indicating specifically which machines can be affected and what to do in order to correct the problem. Then, depending on the customer profile, after corrective measures are taken, the administrator can immediately use the system to verify the corrective measures in place or effectiveness of the corrective measures can be verified with the next scheduled security assessment.
Only customers affected by the new security vulnerabilities can receive the alerts. The Early Warning Generator system filters the overload of information to provide accurate, relevant information to network administrators. Additionally, the known configuration of the customer can be updated every time a security vulnerability assessment can be performed, making it more likely that the alerts remain as accurate and relevant as possible.
The above as well as additional objectives, features, and advantages of the present invention will become apparent in the following detailed written description.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of illustrative sample embodiments when read in conjunction with the accompanying drawings, wherein:
FIG. 1 depicts a diagram of an overview of a network vulnerability assessment system, in accordance with a preferred embodiment of the present invention;
FIG. 2 shows a block diagram of a Database logical structure, in accordance with a preferred embodiment of the present invention;
FIG. 3 depicts a block diagram of a Command Engine, in accordance with a preferred embodiment of the present invention;
FIG. 4 depicts a block diagram of a Gateway, in accordance with a preferred embodiment of the present invention.
FIG. 5 depicts a block diagram of a Tester structure, in accordance with a preferred embodiment of the present invention.
FIG. 6 depicts a block diagram of a Report Generator, in accordance with a preferred embodiment of the present invention.
FIG. 7 depicts a block diagram of a Early Warning Generator, in accordance with a preferred embodiment of the present invention.
FIG. 8 depicts a diagram of an overview of a network vulnerability assessment system adapted to update tools using a Repository Master Copy Tester (RMCT), in accordance with a preferred embodiment of the present invention.
FIG. 9 depicts a diagram of an overview of an internationally disposed network vulnerability assessment system adapted to update tools using a RMCT, in accordance with a preferred embodiment of the present invention.
FIG. 10 depicts a diagram of a distributed test, in accordance with a preferred embodiment of the present invention.
FIG. 11 depicts a diagram of a Frontal Assault test, in accordance with a preferred embodiment of the present invention.
FIG. 12 depicts a diagram of a Guerrilla Warfare test, in accordance with a preferred embodiment of the present invention.
FIG. 13 depicts a diagram of a Winds of Time test, in accordance with a preferred embodiment of the present invention.
FIG. 14 depicts a flowchart illustrating dynamic logic in testing, in accordance with a preferred embodiment of the present invention.
FIG. 15 depicts a flowchart illustrating one type of PRIOR ART logic in testing, in accordance with one embodiment of the PRIOR ART.
FIG. 16 a depicts a diagram illustrating results from one method of PRIOR ART testing on a high security network, in accordance with one embodiment of the PRIOR ART.
FIG. 16 b depicts a diagram illustrating results from using a preferred embodiment on a high security network, in accordance with a preferred embodiment of the present invention.
FIG. 17 depicts a diagram of an alternative preferred embodiment in which the functionalities of the database and command engine are performed by the same machine, in accordance with a preferred embodiment of the present invention.
FIG. 18 depicts a diagram of an alternative preferred embodiment in which requests for testing pass through third party portals, in accordance with a preferred embodiment of the present invention.
FIG. 19 depicts a diagram of a geographic overview of a network vulnerability assessment system testing target system with tests originating from different geographic locations in North America, in accordance with a preferred embodiment of the present invention.
FIG. 20 depicts a diagram of a geographic overview of a network vulnerability assessment system testing target system with tests originating from different geographic locations world-wide, in accordance with a preferred embodiment of the present invention.
FIG. 21 depicts a diagram of a logical conception of the relationship between a hacker tool and an application programming interface (API) wrapper, in accordance with a preferred embodiment of the present invention.
FIG. 22 depicts a flow chart of information within a database component of a network vulnerability assessment system, in accordance with a preferred embodiment of the present invention.
FIG. 23 depicts a flow chart of the testing process of a network vulnerability assessment system, in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The numerous innovative teachings of the present application will be described with particular reference to the presently preferred embodiment (by way of example, and not of limitation). Referring now to the drawings, wherein like reference numbers are used to designate like elements throughout the various views, several embodiments of the present invention are further described. The figures are not necessarily drawn to scale, and in some instances the drawings have been exaggerated or simplified for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations of the present invention based on the following examples of possible embodiments of the present invention.
Database Subsystem Functionality
The Database 114 has multiple software modules and storage facilities 200 for performing different functions. The Database warehouses the raw data 214 collected by the Testers' 502 tests 516 from customers systems and networks 1002 and that data can be used by the Report Generator 112 to produce different security reports 2230 for the customers. The raw data 214 contained in the Database 114 can be migrated to any data format desired, for example, by using ODBC to migrate to Oracle or Sybase. The type of data might include, for example, IP addresses, components, functions, etc. The raw data 214 can typically be fragmented and cannot be easily understood until decoded by the Report Generator 110 .
The brand of database 114 is unimportant and the entire schema was designed to port to any database. A preferred embodiment uses Microsoft SQL server, because of availability of the software and experience in developing in SQL Server. Logical overview 200 shows a logical view of Database 114 .
Job Scheduling
The job scheduling module 202 can initiate customer jobs at any time. It uses the customer profile 204 information to tell the Command Engine 116 what services the customer should receive, for example, due to having been purchased, so that the Command Engine 116 can conduct the appropriate range of tests 516 .
Customer Profile
Every customer has a customer profile 204 that can include description of the services the customer will be provided, the range of IP addresses the customer's network 1002 spans, who should receive the monthly reports, company mailing address, etc. The customer profile 204 can be used by the Command Engine 114 to conduct an appropriate set of tests 516 on the customer's systems 1002 . The customer profile 204 can be also used by the Report Generator 110 to generate appropriate reports 2230 and send them to the appropriate destination. Customer Profile information includes that information discussed in this specification which would typically be provided by the Customer, such as IP addresses, services to be provided, etc. In contrast, Customer Network Profile information includes that information which is the result of testing.
Vulnerability Library
The Vulnerability Library 206 catalogs all the vulnerabilities that a preferred embodiment tests for. This library 206 can be used by the Report Generator 110 to tell the customers what security vulnerabilities they have. The data associated with each vulnerability can also indicate the classification of the vulnerability as to its severity. Severity has several aspects, for example, risk of the vulnerability being exploited can be high, medium, or low; skill level to exploit the vulnerability can be high, medium, or low; and the cause of the vulnerability can be vendor (for example, bugs), misconfiguration, or an inherently dangerous service.
Performance Metrics
Different types of performance metrics 208 can be stored for each test. Reasons that the system stores performance metrics 208 include, for example, in order to be able to plan for future scaling of the system and to track the durations and efficiency levels of the tests 516 . Performance metrics 208 allow determination, for example, of when system capacity can be expected to be reached and when more Testers 502 can be expected to be needed added to Tester array 103 to maintain adequate performance capacity.
The ability to perform performance metrics 208 comes from two places: (1) utilizing standard network utilities and methodologies, and (2) analysis of database 114 information. More sources of the ability to perform performance metrics 208 will become available over time. Current performance metrics 208 include, job completion timing, which is (1) time to complete an overall assessment (can be compared with type of assessment as well as size of job); (2) time to complete each Tool Suite 9 e.g., HTTP Suite 2318 ); (3) time to complete each wave of tests 516 ; and (3) time to complete each test 516 . Also, assessment time per IP address/active nodes assessment time per type of service active on the machine. Tester 502 performance metrics 208 include, for example, resources available/used, memory, disk space, and processor. Gateway 118 performances metrics 208 include, for example, resources available/used, memory, disk space, and processor. Other performance metrics 208 include, for example, communication time between Tester 502 and Gateway 118 (latency), communication time between Gateway 118 and Tester 502 (network paths are generally different), and bandwidth available between Tester 502 and Gateway 118 . Future performance metrics might include, Tester 502 usage, by operating system, by Network (Sprint, MCI, etc.), IP address on each Tester 502 ; test 516 effectiveness by operating system, by Network, by Tester 502 ; and Gateway 118 /Distribution of tests across Testers 103 .
Report Elements
Report Elements 210 are used to build reports 2230 . The Report Elements 210 area of the Database 114 can hold these report elements 210 at their smallest resolution. The Report Generator 110 subsystem accesses the report elements 210 to create a customer vulnerability assessment report 2230 . The Report Generator 110 reads the test results of a vulnerability assessment from the Database 114 and can use the test results to organize the Report Elements 210 into a full, customized report 2230 for the customer. All of the raw data 214 as well as the refmed data 216 about a customer network 1002 can be stored in the Database 114 in a normalized secure form which is fragmented and has no meaning until the Report Generator 110 decodes the data and attaches a Report Element 210 to each piece of information. The Report Elements 210 enable the reports 2230 to contain meaningful, de-normalized information and allow the Database 114 to maintain the original data in a manageable format.
Some Report Elements 210 can be the same as, directly based on, or indirectly based on information from Vulnerability Library 206 .
The Report Elements 210 typically compose a very large set of text records which can make up all possible text passages that can eventually appear in a report 2230 .
Customer's Network Profile, Raw Data, and Refined Data
All data collected by the basic tests can be stored in their raw form 214 on an ongoing basis. The data can be used by the Report Generator 110 and by data mining tools. The Report Generator 110 can use this data to provide historical security trending, detailed analysis and current vulnerability assessment reports 2230 . Data mining can provide security trend analysis across varying network sizes and industries. Other data mining opportunities can present themselves as the number of customers grows. The Early Warning Generator 112 can reference the most recent information about a customer network 1002 in order to alert only threatened customers about the newest relevant security vulnerabilities found.
Report 2230 metrics can also be used to classify test results for different market segments and industries to be able to calcify risk boundaries. For example, this would enable an insurer to change insurance rates based on risk metrics indicators.
In addition, the raw information 214 can be used by experienced security consultants to give themselves the same intimate familiarity with the customer's network 1002 that they would normally gain during a manual test 516 but without actually having to perform the tests 516 themselves. This can allow security personnel to leverage their time more efficiently while maintaining quality relationships with customers.
Command Engine Subsystem Functionality
Figuratively, the Command Engine 116 is the “brain” that orchestrates all of the “basic tests” 516 into the security vulnerability attack simulation used to test the security of customer systems and networks 1002 . While the Command Engine 116 essentially mimics hackers, the tests 516 themselves should be harmless to the customer. Each basic test 516 can be a minute piece of the entire test that can be launched independently of any other basic test 516 . The attack simulation can be conducted in waves, with each wave of basic tests 516 gathering increasingly fine-grained information. The entire test can be customized to each customer's particular system 1002 through automatic modifications to the waves of basic tests 516 . These modifications occur in real-time during the actual test in response to information collected from the customer's systems and networks 1002 . For example, the information can include security obstacles and system environment information. The Command Engine 116 stores the raw test results 214 in the Database 114 for future use as well as uses the collected data to modify the attack/test strategy. This test process is iterative until all relevant customer data can be collected. Note that there is no reason why the functions of the Command Engine 116 could not be performed by and incorporated into the Database 114 in an alternative embodiment. Such a device, combining Database 114 and Command Engine 116 functions might be called a Command Database 1702 .
Check Schedule
The Check Schedule module 302 polls the Job Scheduling module 202 to determine whether a new test 516 needs to be conducted. The Check Schedule module 302 then passes the customer profile information 204 for the new tests 516 to the Test Logic module 304 .
Test Logic
The following discussion describes a multiple wave entire test. The Test Logic module 304 receives the customer profile information 204 from the Check Schedule module 302 . Based on the customer profile 204 , the Test Logic module 304 determines which basic tests 516 need to be launched in the first wave of testing and from which Testers 502 the basic tests 516 should come. The Test Logic module 304 uses the customer profile 204 to assemble a list of specific tests 516 ; the Test Logic module 304 uses the Resource Management module 308 , which tracks the availability of resources, to assign the tests to specific Testers 502 . As the basic tests 516 are determined, they are passed with instructions to the Tool Initiation Sequencer 312 where all of the tool 514 details and instructions are combined. Each sequence of basic test instructions proceeds from the Tool Sequencer 312 to the Queue 310 as an instruction for a specific Tester 502 to run a specific test 516 . There is no reason why the Resource Management module 308 could not be part of Gateway 118 because such an alternative would be an example of the many alternatives that would not vary substantially from what has been described. Similarly, throughout this specification, descriptions of functionalities being in certain physical and/or logical orientations (e.g., being on certain machines, etc.), should not be considered as limitations, but rather as alternatives, to the extent that other alternatives of physical and/or logical orientations would not cause inoperability.
As the results of the basic tests 516 return 306 , the Test Logic module 304 analyzes the information and, based on the information discovered, determines which basic tests 516 should be performed in the next wave of basic tests 516 . Again, once the appropriate tests 516 have been determined, they are sent to the Tool Initiation Sequencer 312 where they enter the testing cycle.
Each wave of basic tests 516 becomes increasingly specific and fine-grained as more is learned about the environment 1002 being tested. This dynamic iterative process repeats and adapts itself to the customer's security obstacles, system configuration and size. The process ends when all relevant information has been collected about the customer system 1002 .
Tool Management
The Tool Management module 314 manages all relevant information about the tools 514 , possibly including classification 316 , current release version, operating system dependencies, specific location 318 inside the Testers 502 , test variations of tools, and all parameters 320 associated with the test. Because there can be thousands of permutations of testing available for each tool 514 , the Test Logic module and the Initiation Sequencer 312 are data driven processes. The Tool Management 314 , in conjunction with the Test Logic module 304 , and the Initiation Sequencer 312 supplies the necessary detailed instructions to perform the basic tests 516 . Tools 514 can be classified according to operating system or any other criterion or criteria. If a vulnerability becomes apparent for which no tool 514 currently exists, then a new tool 514 can be written in any language and for any operating system that will test for that vulnerability. The new tool 514 might then be referred to as a proprietary tool.
Tool Initiation Sequencer
The Tool Initiation Sequencer 312 works in conjunction with the Test Logic module 304 and the Tool Management module 314 . It receives each sequence of instructions to run a specific basic test 516 from the Test Logic module 304 . This information can be then used to access the Tool Management module 314 where additional information, such as tool location 318 and necessary parameters 320 , can be gathered. The Tool Initiation Sequencer 312 then packages all relevant information in a standardized format. The formatted relevant information includes the detailed instructions that can be put in the Queue 310 to be polled by the Gateway 118 or pushed to the Gateway 118 .
Queue of Test Tools
The Queue 310 is a mechanism that allows the Gateway 118 to poll for pending instructions to pass on to the Testers 502 . The instructions for each basic test 516 can be stored as a separate order, and instructions for basic tests 516 belonging to multiple customer tests can be intermingled in the Queue 310 freely.
Tools Test Output
The results of each basic test 516 are returned from the Testers 502 to the Command Engine's 116 Tool/Test Output module 306 . This module 306 transfers the test results to two locations. The information can be delivered to the Database 114 for future report generation use and recycled through the Test Logic module 304 in order to be available to adapt a subsequent wave of tests 516 .
Resource Management
The Resource Management module 308 manages Tester 502 availability, Internet route availability, basic test 516 tracking, and multiple job tracking for entire tests being performed for multiple customer networks 1002 simultaneously. Tracking the availability of Testers 502 and Internet routes enables the testing to be performed using the most efficient means. Basic test 516 and job test tracking can be used to monitor for load on Testers 502 as well as the timeliness of overall jobs. The information used to manage resources can be gained from the Gateway 118 and from the Testers 502 , via the Gateway 118 .
Resource management information can be provided to the Test Logic module 304 and the Tool Initiation Sequencer 312 . If a Tester 502 becomes unavailable, this information can be taken into account and the Tester 502 is not used until it becomes available again. The same can be true for periods of Internet route unavailability. Current basic tests 516 that relied on the unavailable resources would be re-assigned, and new basic tests 516 would not be assigned to resources that are unavailable.
The Gateway Subsystem Functionality
Functionally, the Gateway 118 can be partly characterized as the “traffic director” of a preferred embodiment. While the Command Engine 116 acts in part as the “brain” that coordinates the use of multiple tests 516 over multiple Testers 502 , it is the Gateway 118 that interprets the instructions and communicates the directions (instructions) to all of the Testers 502 . The Gateway 118 receives from the Command Engine 116 detailed instructions about basic tests 516 that need to be conducted at any given time, and it passes the instructions to appropriate Testers 502 , in appropriate geographical locations, to be executed. The Gateway 118 can be a single and limited point of interface from the Internet to the Test Center 102 , with a straightforward design that enables it to secure the Test Center 102 from the rest of the Internet. All information collected from the Testers 502 by the Gateway 118 can be passed to the Command Engine 116 .
The Gateway 118 receives basic test 516 instructions from the Command Engine Queue 310 and sends these instructions to the appropriate Testers 502 . The instruction sequence consists of two parts. The first part contains instructions to the Gateway 118 indicating which Tester 502 the Gateway 118 should communicate with. The second part of the instructions is relevant to the Tester 502 , and it is the second part of these instructions that are sent to the appropriate Tester 502 .
Prior to delivering the instructions to the Tester 502 , the Gateway 118 verifies the availability of the Tester 502 and encrypts 406 the instruction transmission. In FIG. 4 , encryption 406 uses key management 408 to achieve encryption 410 , but other encryption techniques would not change the spirit of the embodiment. If communication cannot be established with the Tester 502 , then the Gateway 118 runs network diagnostics to determine whether communication can be established. If communication can be established 404 , then the process continues, otherwise, the Gateway 118 sends a message to the Command Engine Resource Management 308 that the Tester 502 is “unavailable”. If the Gateway 118 is able to send 412 test instructions to the Tester 502 , it does so. After the Tester 502 runs its basic test 516 , it sends to the Gateway 118 the results 414 of the basic test 516 from the Tester 502 and relays the information 414 back to the Command Engine 116 . The Gateway 118 , as “traffic director”, enables a set of tests 516 to be conducted by multiple Testers 502 and multiple tests 516 to be run by one Tester 502 all at the same time. This type of security vulnerability assessment is typically hard to detect, appears realistic to the security system, and can reduce the likelihood of the customer security system discovering that it is being penetrated.
An alternative to the test instruction push paradigm that has been described thus far is a test instruction pull paradigm. The pull approach is useful where the customer simply refuses to lower an unassailable defense. The Tester 502 would be placed within the customer's system 1002 , beyond the unassailable defense, and would conduct its tests from that position. Rather than the sending of instructions from the Gateway 118 to the Tester 502 being initiated by the Gateway 118 , the Tester 502 would repeatedly poll the Gateway 118 for instructions. If the Gateway 118 had instructions in its queue 402 ready for that Tester 502 , then those instructions would be transmitted responsively to the poll.
The Tester Subsystem Functionality
Depicted in overview 500 , FIG. 5 , the Testers 502 can reside on the Internet, in a Web-hosted environment, or on customers' networks 1002 , and can be distributed geographically around the world. Not only can the entire test be split up into tiny pieces, but it can also originate each piece from an independent point and is therefore harder to detect and more realistic. Even entire tests conducted monthly on the same customer can come from different Testers 502 located in different geographical areas.
The Testers 502 house the arsenals of tools 514 that can conduct hundreds of thousands of hacker and security tests 516 . The Tester 502 can receive encrypted basic test instructions from the Gateway 118 , via the Internet. The instructions inform the Tester 502 which test 516 to run, how to run it, what to collect from the customer system, etc. Every basic test 516 can be an autonomous entity that can be responsible for only one piece of the entire test that can be conducted by multiple Testers 502 in multiple waves from multiple locations. Each Tester 502 can have many basic tests 516 in operation simultaneously. The information collected by each test 516 about the customer systems 1002 can be sent to the Gateway 118 .
Following is a partial list of hacker tools 514 that a preferred embodiment is adapted to use: (a) CGI-scanners such as whisker, cgichk, mesalla; (b) port scanners—nmap, udpscan, netcat; (c) administrative tools—ping, traceroute, Slayer ICMP; (d) common utilities—samba's nmblookup, smbclient; and (e) Nessus program for assessing a computer's registry.
The Testers 502 are independent entities working in concert, orchestrated by the Command Engine 116 . Because they can be independent entities, they do not need to have the same operating systems 504 . Utilizing various operating systems 504 can be an advantage in security vulnerability assessment, and assists a preferred embodiment in maximizing the strengths of all the platforms. This typically leads to more accurate assessments and more efficient operations.
Following are three examples of actual information returned by tools 514 . The first tool 514 is Nmap port scanner, running in one of its variations:
Starting nmap V.2.53 by fyodor@insecure.org (www.insecure.org/nmap/) Interesting ports on localhost (127.0.0.1): (The 1502 ports scanned but not shown below are in state: closed)
Port State Service
1/tcp
open
tcpmux
11/tcp
open
systat
15/tcp
open
netstat
21/tcp
open
ftp
22/tcp
open
ssh
23/tcp
open
telnet
25/tcp
open
smtp
53/tcp
open
domain
79/tcp
open
finger
80/tcp
open
http
635/tcp
open
unknown
1080/tcp
open
socks
8/tcp
open
squid-http
12345/tcp
open
NetBus
12346/tcp
open
NetBus
31337/tcp
open
Elite
Nmap run completed—1 IP address (1 host up) scanned in 2 seconds.
The second tool 514 is whisker—web cgi script scanner:
-- whisker/v1.4.0+SSL/rainforestpuppy/www.wiretrip.net-- -(Bonus: Parallel support) =_=_=_=_=_= =Host: 127.0.0.1 - Server: Microsoft—IIS/4.0 +200 OK: HEAD/_vti_inf.html +200 OK: HEAD/_private/form_results.txt
The third tool 514 is icmp query for remote time stamp and remote subnet of a computer:
#./icmpquery -t 127.0.0.1 127.0.0.1: 17:17:33 127.0.0.1: OxFFFFFFEO
Inside each Tester 502 can be storehouses, or arsenals, of independent hacker and security tools 514 . These tools 502 can come from any source, ranging from pre-made hacker tools 514 to proprietary tools 514 from a development team. Because the Testers 502 can be NT, Unix, Linux, etc 504 , the tools 514 can be used in their native environment using an application programming interface (API) 512 , described elsewhere in this specification, with no need to rewrite the tools 514 . This usage gives a preferred embodiment an advantage in production. For example, hacker tools 514 that are threatening corporations everywhere can be integrated into a preferred embodiment the same day they are published on the Internet. The API 512 also serves to limit the quality control testing cycle by isolating the new addition as an independent entity that is scrutinized individually. Additionally, because tools 514 can be written in any language for any platform 504 , the development of proprietary tools 514 need not be dependent on a lengthy training cycle and might even be outsourced. This ability is a significant differentiator for a preferred embodiment.
Running the tools 514 from a separate tool server would be possible using a remote mount.
The API 512 handles the things that are common among all the tools 514 that we have on a Tester 502 . Typically each tool wrapper will have commonly named variables that have specifics about the particular tool wrapper. The API 512 will use these variable values to do specific, common functionality, such as “open a file to dump tool results into”. In that example, the wrapper would simply call API::OpenLogFile. At this point the API 512 would be invoked. In that example, the API 512 will look at the values of the variables from the main program that called it. These variables will have the specifics of the particular wrapper. The API 512 will then open a log file in the appropriate directory for the program to write to. For example, the commands:
$Suite =‘http’; $Tool =‘cgiscan’;
would produce something similar to the following:
/var/achilles/http/cgiscan/scanlog/J2334_T4234
Other common functionality can be handled by the API 512 . For example when a tool 514 has completed and its information has been parsed, each wrapper can call the same function that initiates a connection back the Gateway 118 and deposits the parsed info on the Gateway 118 for pickup by the Command Engine 116 . Example: The tool wrapper simply calls the function API::CommitToGateway (filename) and the API 512 is responsible for opening the connection and passing the info back to the Gateway 118 , all with error handling.
Other functionality includes but is not limited to: retrieving information passed to the tool 514 via command line parameters (Job Tracking ID, Tool Tracking ID, Target Host IP Address, etc.); Opening, Closing, and Deleting files; Error/Debug Logging Capability; Character substitution routines; etc.
The system's capacity to conduct more tests for multiple customers at the same time can be increased dramatically by adding more Testers 502 .
Internal Tester
Internal Tester machines 502 are for the vulnerability assessment of an internal network, DMZ, or other areas of the network 1002 . The performance of an internal assessment can give a different view than just performing an external assessment. The resulting information can let an administrator know, if a cyber attacker were to perform an attack and gain access to network 1002 , what other machines, networks or resources the attacker would have access to. In addition, internal assessments can be conducted with administrative privileges thereby facilitating audit of individual workstations for software licensing, weak file permissions, security patch levels, etc.
For the purposes of an internal assessment, several different appliances can be deployed on the customers network 1002 . For example, for traveling consultants, a pre-configured laptop computer loaded with an instance of a Tester 502 might be shipped for deployment. For permanent, continuous assessment installations a dedicated, pre-configured device in either a thin, rack mountable form or desktop style tower might be shipped for deployment. In both cases the device might boot out-of-the-box to a simple, graphical, configuration editor. The editor's interface is a web browser that might point to the active web server on the local loop-back device. Since the web server would be running on the loop-back device, it could only be accessible by the local machine. Some options of local configurations might include, for example: IP Stack configuration, DNS information, default route table, push/pull connection to Test Center 102 , account information, etc. Other options in the local configuration might include for example: IP diagnostics (Ping, Trace Route, etc.), DNS Resolutions, connections speed, hardware performance graphs, etc.
Once local configuration has been completed and the Tester 502 verified to be active on the local network with some form of connectivity to the Internet, the web browser then can switch from the local web to a remote web server of a preferred embodiment. At this point the specifications of the test might be entered. If this were a single assessment, the IP range, Internet domain name, package type and company information might be necessary. For a continuous/permanent installation, other options might include frequency, re-occurrence, etc. Minor updates might be performed via a preferred embodiment upgrade systems. Major upgrades might be initiated for example by the traveling consultant prior to going to the customer's site or, in the case of a permanent installation, remotely initiated during a scheduled down time.
The actual assessment might be similar to the remote assessment, however distributed capabilities would not be needed. Other future, add-on modules might include: registry readers for auditing of software licenses, modules for asserting file permissions, policy management modules, etc.
Defending the Tester
The use of a distributed architecture can mean placing out Testers 502 in hostile environment(s). Safeguards, policies, and methodologies should be in place to ensure the Integrity, Availability, and Confidentiality of the technology of a preferred embodiment.
While the internal mechanisms of the Testers 502 can be complex, the external appearance can be simple by contrast. Each Tester 502 can be assigned one or more IP addresses; however, it could be that only the primary IP address has services actually running on it. These minimal services can be integral to the Tester 502 . The remaining IP addresses would have no services running on them. Having no services running means that there is no opportunity for an external attacker to gain access to the Tester 502 . In addition, there are several processes that are designed to keep the environment clean of unknown or malicious activity.
Each Tester 502 can be pre-configured in-house and designed for remote administration. Therefore, it would typically be that no peripherals (e.g., keyboard, monitor, mouse, floppies, CD-ROM drives, etc.) are enabled while the Tester 502 is in the field. An exception might be an out-of-band, dial-up modem that might feature strong encryption for authentication, logging, and dial-back capabilities to limit unauthorized access. This modem could be used, for example, in emergencies when the operating system is not completing its boot strap and could be audited on a continuous basis. This could limit the need for “remote-hands” (e.g., ISP employees) to have system passwords, and would reduce the likelihood of needing a lengthy on-site trip. Other physical security methods, such as locked computer cases, can be implemented. One example might be a locked case that would, upon unauthorized entry, shock the hardware and render the components useless.
Until the integrity of Tester 502 can be verified by an outside source, it would be the case that no communication with the device will be trusted and the device can be marked as suspect. Confidence in integrity can be improved by several means. First of all, Tester's 502 arsenals of tools 514 , both proprietary and open source, can be contained on encrypted file systems. An encrypted file system can be a “drive” that, while unmounted, appears to be just a large encrypted file. In that case, when the correct password is supplied, the operating system would mount the file as a useable drive. The can prevent for example an unauthorized attacker with physical access to the Tester 502 from simply removing the drive, placing it into another machine and reading the contents. In that case, the only information an attacker might have access to might be the standard build of whatever operating system the Tester 502 happened to be running. If used, passwords can be random, unique to each Tester 502 , and held in the Test Center 102 . They can be changed from time to time, for example, on a bi-weekly basis.
To protect the contents of the operating system itself, the contents can be verified before placing the Tester 502 in operation. For example, using a database of cryptographically calculated checksums the integrity of the system can be verified. Using that methodology, the “last known good” checksum databases can be held offsite and away from the suspected machine. Also, tools to calculate these sums can not stored on the machine because they might then be altered by a malicious attacker to give a false positive of the integrity of the suspected Tester 502 .
Upon boot, the Tester 502 can send a simple alert to the Gateway 118 indicating it is online. The Gateway 118 can then issue a process to verify the integrity of the operating system. The process can connect to the Tester 502 , upload the crypto-libraries and binaries, perform the analysis, and retrieve the results. Then the crypto-database can be compared to the “Last Good” results and either approve or reject the Tester 502 . Upon rejection the administrator on call can be notified for manual inspection. Upon approval, the process can retrieve the file system password and use an encrypted channel to mount the drive. At this point the Tester 502 can be considered an extension of the “Test Center 102 ” and ready to accept jobs. This verification process can also be scheduled for pseudo-random spot checks.
Security typically requires vigilance. Several processes can be in place to improve awareness of malicious activity that is targeting an embodiment of the invention. Port Sentries and Log Sentries can be in place to watch and alert of any suspicious activity and as a host-based intrusion detection system. Port Sentry is a simple, elegant, open source, public domain tool that is designed to alert administrators to unsolicited probes. Port sentry opens up several selected ports and waits for someone to connect. Typical choices of ports to open are services that are typically targeted by malicious attackers (e.g., ftp, sunRPC, Web, etc.). Upon connection, the program can do a variety of different things: drop route of the attacker to /dev/nul; add attacker to explicit deny list of host firewall; display a strong, legal warning; or run a custom retaliatory program. As such a strong response could lead to a denial of service issue with a valid customer, an alternative is to simply use it to log the attempt to the Tester 502 logs. Log sentry is another open source program that can be utilized for consolidation of log activity. It can check the logs every five minutes and email the results to the appropriate internet address.
According to the Information Security Management Handbook 4 th Edition “There is no control over e-mail once it leaves the internal network, e-mail can be read, tampered with and spoofed”. All e-mails from the Tester 502 can be encrypted, for example, with a public key before transport that improves the likelihood that it can only be read by authorized entities.
Any username and password combination is susceptible to compromise, so an alternative is to not use passwords. An option is that only the administrator account has a password and that account can only be logged on locally (and not for example through the Internet) via physical access or the out-of-band modem. In this scenario, all other accounts have no passwords. Access would be controlled by means of public/private key technology that provides identification, authentication, and non-reputability of the user.
To reduce the likelihood that data can be captured, all communication with the Testers 502 can be by way of an encrypted channel. Currently the module for communication can be Secure Shell (SSH 1 ) for example. This could be easily switched to Open SSH, SSH 2 or any other method. SSH provides multiple methods of encryption (DES, 3DES, IDEA, Blowfish) which is useful for locations where export of encryption is legally regulated. In addition, 2048 bit RSA encryption keys can be used for authentication methods. SSH protects against: IP spoofing, where a remote host sends out packets which pretend to come from another, trusted host; a “spoofer” on the local network, who can pretend he is your router to the outside; IP source routing, where a host can pretend that an IP packet comes from another, trusted host; DNS spoofing, when an attacker forges name server records; interception of clear text passwords and other data by intermediate hosts; and manipulation of data by people in control of intermediate hosts.
Self-Checking Process
Prior to accepting instructions to initiate a basic test 516 , Testers 502 can undergo a Self-Checking Process 506 to verify that resources are available to perform the task, that the tool 514 exists in its arsenal, that the correct version of the tool 514 is installed, and that the security integrity of the Tester 502 has not been tampered with. This process 506 can take milliseconds to perform. Tester 502 resources that can be checked include memory usage, processor usage, and disk usage. If the tool 514 does not exist or is not the correct version, then the correct tool 514 and version can be retrieved by the Tester 502 from the RMCT 119 , discussed elsewhere herein. Periodic testing can be conducted to confirm that the RMCT 119 retains its integrity and has not been tampered with.
Target Verification Pre and Post Test
Pre Test Target Verification 508 can used to detect when a Tester 502 cannot reach its targeted customer system 1102 in network 1002 due to Internet routing problems. Internet outages and routing problems can be reported back through the Gateway 118 to the Resource Management module 308 of the Command Engine 116 , and the basic test 516 can be rerouted to another Tester 502 on a different Internet router.
Post Test Target Verification 508 can be used to detect if the Tester 502 has tripped a defensive mechanism that might prevent further tests from gathering information. This can be particularly useful for networks 1002 with a Firewall/Intrusion Detection System combination. If the Tester 502 was able to connect for the pre test target verification 508 , but is unable to connect for the post verification 508 it is often the case that some defensive mechanism has been triggered, and a preferred embodiment therefore typically infers that network defenses have perceived an attack on the network. Information that the defense has been triggered is sent through the Gateway 118 to the Command Engine 116 in order to modify the basic tests 516 . This methodology results in the ability to trip the security defenses, learn about the obstacles in place, and still accurately and successfully complete the security assessment.
Tester 502 is merely illustrative, and could be Tester 120 , for example; in that case, operating system 504 would be Linux and Tester 502 would be located in New York. Of course, there is no reason why one or more additional Testers 502 could be located in New York and have the Linux operating system.
Tools and API
In detail, the API 512 for each tool 514 includes two kinds of components: an API stub 511 and a common API 510 . The API stub 511 is specifically adapted to handle the input(s) and output(s) of its tool 514 . The common API 510 is standard across all tools 514 and performs much of the interfacing between the Instructions and the tools 514 .
As tools 514 can come from many sources—including in-house development, outsourced development, and open-source hacker and security sites—flexibility in incorporating new tools 514 into a testing system is critical for maintaining rapid time to market. The API 512 serves to enable rapid integration time for new tools regardless of the language the tool 512 is written in or the operating system 504 the tool 514 is written for.
The API 512 standardizes the method of interfacing to any tool 514 that can be added to a preferred embodiment by implementing common API 510 . Using the API 512 , each tool 514 can be integrated into a preferred embodiment through the addition of a few lines of code implementing API stub 511 . Integration of a new tool 514 , after quality assurance testing, can be completed within hours. This is a significant differentiator and time to market advantage for a preferred embodiment.
Each tool 514 should be tested before being integrated into a preferred embodiment in order to protect the integrity of a preferred embodiment system. The use of the API 512 to interface between the Gateway 118 and the tool 514 residing on the Tester 502 reduces testing cycles. The API 512 is an important buffer that allows the tools 514 to remain autonomous entities. In a standard software scenario, the entire software system should be rigorously tested after each change to the software, no matter how minute. For a preferred embodiment, however, the API 512 keeps each tool 514 as a separate piece of software that does not affect the rest of a preferred embodiment. The API 512 passes the instructions to the tool 514 , and the API 512 retrieves the results from the tool 502 and passes them back to the Gateway 118 . This methodology effectively reduces testing cycles by isolating each new tool 514 as a quality assurance focal point while maintaining separation between the integrity of each tool 514 and the integrity of a preferred embodiment.
Logical overview 2100 in FIG. 21 shows a logical view of the complimentary functions of tools 514 and the API 512 wrapper. Diagram section 2102 shows a symbolic hacker tool 514 and emphasizes that a command trigger causes the hacker tool 514 to run the diagnostic piece 516 that is executed to gather information, and the information is returned, in this case, to the Gateway 118 . The brackets around the harmful activity that the tool 514 performs indicate that the harmful part of the hacker tool does not damage the system 1102 in network 1002 under test. Diagram section 2104 illustrates the some of the functionality of the API 512 wrapper. Emphasizing that the information filters and command filters are customizable, providing a standard interface 510 across all hacker tools 514 . That is, the interface 510 between the tools 514 and the Command Database 1702 from the Command Database 1702 perspective is a standardized interface. The API 512 interprets the command from the Command Database 1702 via the Gateway 118 , interfaces to the hacker tool 514 using the correct syntax for that particular hacker tool 514 , and receives output from the hacker tool 514 , and translates that output to the Command Database 1702 input to be stored as raw information 214 . It should be noted that in FIG. 21 the network vulnerability assessment system is using a Command Database 1702 which combines the functionality of a Command Engine 116 and a Database 114 .
The API-integration of tools 514 is a big differentiator and time to market advantage for a preferred embodiment. The use of the tools 514 in their native environment and the use of the API 512 often allows a preferred embodiment to be adapted to use a new tool 514 in the same day it is found, for example in the Internet. The API 512 also isolates quality assurance testing to further shorten time to market. While a different approach can require months to adapt new tools 514 , a preferred embodiment adapts to those same tools 514 in hours.
The API 512 can also normalize test results data that can become part of customer/network profile 212 . The test results can be referred to as “denormalized.” In contrast, “normalized” data can be in binary format that is unreadable without proper decoding. Typically, customer network profile 212 would be stored in normalized format.
Report Generator Subsystem Functionality
Depicted in overview 600 of FIG. 6 , the Report Generator 112 uses information collected in the Database 114 about the customer's systems 1002 to generate one or more reports 2230 about the systems profile, ports utilization, security vulnerabilities, etc. The reports 2230 can reflect the profile and frequency of security services specified for provision to each customer. Security trend analyses can be provided to the extent that customer security information is generated and stored periodically. The security vulnerability assessment test can be provided on a monthly, weekly, daily, or other periodic basis and the report can be provided, for example, in hard copy, electronic mail or on a CD. New reports will continuously evolve, without substantially varying a preferred embodiment. As the customer base grows, new data mining and revenue generation opportunities that do not substantially vary from a preferred embodiment can present themselves. A report 2230 might include, for example, a quantitative score for total network 1002 risk that might be useful to an insurance company in packaging risk so that cyber attack insurance can be marketed. A report 2230 could be provided in any desired language. The level of detail in which information would be reported might include, for example, technical level detail, business level detail, and/or corporate level detail. A report 2230 might break down information by test tool 514 , by positive reports 2230 , by network 1002 and/or system 1102 changes. A report 2230 might even anticipate issues that might arise based on provided prospective changes. Reports 2230 , raw data 214 , etc. could be recorded on, for example, CD for the customer. The customer would then be able to use the data to better manage its IS systems, review actual tests, generate work tickets for corrective measures (perhaps automatically), etc. The specific exemplary reports 2230 shown in overview 600 include Vulnerability Report 602 , Services 604 , Network Mapping 606 , and Historical Trends 608 .
In a preferred embodiment, the Report Generator 112 receives customer network profile 212 from the Database 114 which is in a binary format that is generally unreadable except by the Report Generator 112 . The Report Generator 112 then decodes the customer network profile. The Report Generator 112 also receives the customer profile 204 from Database 114 . Based on the customer profile 204 and customer network profile 212 , the Report Generator 112 polls the Database 114 for selected Report Elements 210 . The Report Generator 112 then complies a report 2230 based on the selected Report Elements 210 .
Early Warning Generators Subsystem Functionality
Early Warning Generator subsystem 112 can be used to alert 714 relevant customers to early warnings on a periodic or aperiodic basis that a new security vulnerability 702 can affect their system. The alert 714 tells the customer which vulnerability 702 can affect them, which computers 1102 in their network 1002 are affected, and what to do to reduce or eliminate the exposure.
On a daily basis, for example, when new security vulnerabilities 702 are found by researchers or provided through other channels, a preferred embodiment compares 710 each configuration 704 affected by new vulnerability 702 against each customer's most recent network configuration test result 708 . If the new vulnerability 702 can be found to affect the customer systems 1102 or networks 1002 then an alert 714 would be sent to the customer, for example, via e-mail 712 . The alert 714 can indicate the detail 716 of the new vulnerability 706 , which machines are affected 720 , and/or what to do 718 to correct the problem. Only customers affected by the new security vulnerabilities 702 receive the alerts 714 . This reduces the “noise” of the great number of vulnerabilities 702 that are frequently published, to just those that affect the customer.
Note that the steps of customizing e-mail 712 and notification 714 need not relate to e-mail technology, but can be any method of communicating information.
A customer would also have the option of tagging specific vulnerability alerts 714 to be ignored and therefore not repeated thereafter, for example, where the customer has non-security reasons to not implement corrective measures. Corrective measures that were to be implemented by the customer could be tracked, the responsible technician periodically reminded of the task, a report made upon completion of implementation of corrective measures, the effectiveness of corrective measures could be checked immediately by running a specific test 516 for the specific vulnerability 702 corrected.
Adding New Tools to a Preferred Embodiment
New security vulnerability assessment tools 516 can regularly be added to a preferred embodiment. The methodology of how to do this can be beneficial in managing a customer's security risk on timely basis.
The tools 514 themselves, with their API 512 , can be added to the Tester's RMCT (again, Repository Master Copy Tester) 119 . An RMCT 119 can be a Tester 502 located in the Test Center 102 . These RMCTs 119 can be used by the Testers 502 that can be web-hosted around the world to obtain the proper copy. The name of the tool 514 , its release number, environmental triggers, etc. can be added to the Command Engine's Tool Management module 314 . Each vulnerability 702 that the new tool 514 checks for can be added to the Vulnerability Library 206 . An addition may need to be made to the Database 114 schema so that the raw output 214 of the test is warehoused.
When a new test 516 is conducted, the Command Engine 116 uses the identifiers of the new tools 514 with their corresponding parameters inside the Tool Initiation Sequencer 312 . The tool information is sent through the Gateway 118 to the Testers 502 . The Tester 502 first checks 506 for the existence of the tool 514 instructed to run. If the tool 514 does not exist, it retrieves the install package with the API 512 from the RMCT 119 . If the tool 514 does exist, it can verify that the version of the tool 514 matches with the version in the instruction set it received. If the instruction set version does not match the tool version, the Tester 502 retrieves the update package from the RMCT 119 . In this manner the ability to update multiple Testers 502 around the world is an automated process with minimum work.
The RMCT 119 is part of the Test Center 101 . The RMCT 119 can be protected since it is a device that is enabled to share the tools 514 with other machines. The RMCT 119 can communicate with Testers 502 through the Gateway 118 , but that need not be the case in all embodiments. The RMCT 119 does not operate as a normal Tester 502 . The RMCT's 119 purpose is to provide the updates (including version rollbacks) to the Tester 502 . A possible version control software and communication might be Concurrent Versioning System (CVS) over Secure Shell (SSH). The performed embodiment might actually utilize any type of version control with any type of encryption or other similarly functioned technology. A preferred embodiment has the flexibility to utilize either pushing or pulling technology. Currently, a preferred embodiment includes a single RMCT 119 : CVS is OS neutral as it stores the source code and binary executables for multiple OS's. However, the number of Testers 502 that need to be updated can exceed the ability of a single RMCT 119 . To meet this potential need, the design of the system allows for multiple RMCTs 119 .
VM Ware is a commercial program that enables multiple operating systems to run on the same computer. For example, VM Ware enables NT to run on a Linux box. The user has the ability to toggle back and forth without rebooting. The possibility of using VM Ware, or a similar product, exists to enable different operating systems to be used without the need for separate machines for each type of operating system.
Updating Additional Preferred Embodiment Systems
Preferred embodiment systems sold to customers can be equipped with the capability to receive automatic updates as part of their support services. These updates can include new tools 514 to test for new vulnerabilities 702 and newly researched or discovered vulnerabilities 702 . These preferred embodiment systems can replicate the Early Warning Generator 112 system for their customers through these active updates. In this way all preferred embodiment systems are up-to-date on a frequent basis.
An effective way to manage security risk is to minimize the window of exposure for any new security vulnerability that affects customer systems. A preferred embodiment is a self-updating risk management system that can be virtually always up-to-date.
Overview diagram of an alternative embodiment 1700 depicts a network vulnerability assessment system in which the functionalities of the Command Engine 116 and the Database 114 are combined into one unit shown as Command Database 1702 which issues attack instructions 138 to Gateway 118 resulting in attack command 140 being transmitted to one of the three shown Tester server farms 1704 .
A Preferred Embodiment Attack/Test Methodology
The Command Engine 116 operates as a data-driven process. This means that it can respond to and react to data or information passed to it. Information is passed through the Command Engine 116 as it is gathered from the systems being tested 1002 . Responding to this information, the Command Engine 116 generates new tests 516 that can, in turn, provide additional information. This iterative process continues until testing has been exhausted. This methodology offers extreme flexibility and unlimited possibilities.
This framework was created so that as new methodologies or techniques are discovered they can be implemented easily. The following discussion gives examples of some of the different methodologies used by a preferred embodiment and that underscore the ability to react to the environment it encounters.
Having a distributed, coordinated attack that tests customer systems has several advantages over alternate vulnerability scanning methodologies.
A typical Intrusion Detection System (IDS) has various methodologies to identify cyber attacks. Various responses are possible: blocking further communications from the same IP address, for example.
There are alternatives around the problem of blocking by security devices. For example, the company performing the vulnerability assessment can coordinate with the corporation being tested. A door may need to be opened in the firewall to allow the testing to occur without interference. This situation may be less than ideal from a network administrator's standpoint as it creates a security weakness and consumes valuable time from the administrator. Another option can be to perform the vulnerability assessment on-site from inside the network. Internal vulnerability assessments will not be affected by the security devices. Internal assessments, however, do not indicate which devices are accessible from the Internet and are also limited to the capabilities of the software.
The distributed model can evade defensive security measures such as IDS. By being distributed, the assessment can be broken down into many basic tests 516 and distributed to multiple Testers 502 . Since each machine only carries a minute part of the entire test, it is harder for defensive mechanisms to find a recognizable pattern. Firewalls and Intrusion Detection Systems rely on finding patterns in network traffic that reach a certain threshold of activity. These patterns are called attack signatures. By using the distributed model we are able to make the attack signature random in content, size, IP source, etc. so as to not meet typical predetermined thresholds and evade defenses. Hence this approach is figuratively referred to as “armor piercing”. Additionally, each Tester 502 can actually have multiple source addresses to work with. This means that each Tester 502 is capable of appearing to be a different computer for each source address it has.
Basic tests 516 , originating from various points on the Internet, provide a fairly realistic approach to security testing. Cyber attacks often stem from an inexperienced attacker simply trying out a new tool 514 . The attacker can find a single tool 514 that exploits one specific service and then begin to scan the Internet, randomly choosing networks 1002 to target. Samples of firewall logs from corporations and individuals show this to be a common attack activity.
In addition, each basic test 516 takes up a very small amount of Tester 5 - 2 resources. Because of this, each Tester 502 can perform thousands of basic tests 516 at any given time against multiple networks 1002 simultaneously.
A preferred embodiment is very scalable. The transaction load can be shared by the Testers 502 . As more customers need to be serviced and more tests 516 need to be performed, it is a simple matter of adding more Testers 502 to the production environment. In addition to the test approaches described, Bombardment is an option. In Bombardment, many Testers 502 are used to flood a system 1102 or network 1002 with normal traffic to perform a “stress test” on the system, called a distributed denial of service.
Frontal Assault
Depicted in overview 1100 of FIG. 11 , the Frontal Assault is designed to analyze networks 1002 that have little or no security mechanisms in place. As the name implies, this testing methodology is a straightforward, open attack that makes no attempt to disguise or hide itself. It is the quickest of methodologies available. Typically, a network 1002 with a moderate level of security can detect and block this activity. However, even on networks 1002 that can be protected, the Frontal Assault identifies which devices 1102 are not located behind the security mechanism. Mapping and flagging devices that are not behind security defenses gives a more accurate view of the network 1002 layout and topology. Test instruction 1101 is sent from Gateway 118 to Tester 1106 to launch all tests 516 at system 1102 . Other Testers ( 1108 through 1122 ) are idle during the testing, with respect to system 1102 .
Guerrilla Warfare
Depicted in overview 1200 of FIG. 12 is “Guerrilla Warfare.” If Frontal Assault has been completed and a heightened level of security detected, a new methodology is needed for further probing of systems 1102 in the target network 1002 . The Guerrilla Warfare method deploys randomness and other anti-IDS techniques to keep the target network defenses from identifying the activity. Many systems can detect a full Frontal Assault by pattern recognition.
However, when the methodology is changed to closely mimic the activities of independent random cyber attackers, many defensive systems do not notice the activity. Such attackers choose a single exploit and scan random addresses for that one problem. There are 131,070 ports for TCP & UDP per every computer 1102 on the network 1002 being analyzed. Port tests are be distributed across multiple Testers 502 to distribute the workload and to achieve the results in a practical period of time.
Other features of this methodology include additional anti-IDS methods. For instance, many sites deploy SSL (secure socket layers) on their web server so that when customers transmit sensitive information to the server it can be protected by a layer of encryption. The layer of encryption prevents a malicious eavesdropper from intercepting it. However, a preferred embodiment uses this same protective layer to hide the security testing of a web server from the network Intrusion Detection system.
Test instructions 1202 through 1218 are sent by Gateway 118 to Testers 1106 through 1122 , respectively, generating appropriate tests 516 in accordance with the Guerrilla Warfare methodology.
Winds of Time
Depicted in overview 1300 in FIG. 13 , the “Winds of Time” slows down the pace of an set of tests until it becomes much more difficult for a defensive mechanism sensitive to time periods to detect and protect against it. For example, a network defense can perceive a single source connecting to five ports within two minutes as an attack. Each Tester 502 conducts a basic test 516 and then waits for a period of time before performing another basic test 516 for that customer network 1002 . Basic tests 516 for other customers who are not receiving the Winds of Time method can continue without interruption. Anti-IDS methods similar to those used in the Guerrilla Warfare methodology can be deployed, but their effectiveness is typically magnified when the element of time-delay is added. The Guerrilla and Wind of Time test methodologies can create unlimited test combinations.
Note that when a Tester (one of Testers 1106 through 1122 ) is said to “sleep for X minutes” in FIG. 13 , the particular values for X do not need to be identical. For example, Tester 1108 will not test system 1102 for ten milliseconds, while Tester 1120 will not test system 1102 for five seconds. However, it should be noted that the sleeping Testers 1108 , 1112 , 1116 , and 1120 can be testing other systems during this “sleep” time. Meanwhile, instructions 1302 through 1310 are sent from the Gateway 118 to the Testers 1106 , 1110 , 1114 , 1118 , and 1122 which are testing 516 system 1102 .
Data Driven Logic
Overview 1400 in FIG. 14 illustrates a sample of the attack logic used by a preferred embodiment. Prior to the first “wave” 1410 of basic tests 516 , an initial mapping 1402 records a complete inventory of services running on the target network 1002 . An initial mapping 1402 discloses what systems 1102 are present, what ports are open ( 1404 , 1406 , and 1408 ) what services each system is running, general networking problems, web or e-mail servers, whether the system's IP address is a phone number, etc. Basic network diagnostics might include whether a system can be pinged, whether a network connection fault exists, whether rerouting is successful, etc. For example, regarding ping, some networks have ping shut off at the router level, some at the firewall level, and some at the server level. If ping doesn't work, then attempt can be made to establish a handshake connection to see whether the system responds. If handshake doesn't work, then request confirmation from the system of receipt of a message that was never actually sent because some servers can thereby be caused to give a negative response. If that doesn't work, then send a message confirming reception of a message from the server that was not actually received because some servers can thereby be caused to give a negative response. Tactics like these can generate a significant amount of information about the customer's network of systems 1002 .
Based on that information, found in the initial mapping, the first wave 1410 of tools can be prepared and executed to find general problems. Most services have general problems that affect all versions of that service regardless of the vendor. For example, ftp suffers from anonymous access 1412 , e-mail suffers from unauthorized mail relaying 1414 , web suffers from various sample scripts 1416 , etc. In addition, the first wave 1410 of tools 514 attempts to collect additional information related to the specific vendor that programmed the service. The information collected from the first wave 1410 can be analyzed and used to prepare and execute the next wave of tools 514 . The second wave 1420 looks for security holes that are be related to specific vendors (for example, 1422 , 1424 , 1426 , and 1428 ). In addition to any vendor specific vulnerabilities that are discovered, the second wave attempts to obtain the specific version numbers of the inspected services. Based on the version number, additional tools 514 and tests 516 can be prepared and executed for the third wave 1430 . The third wave 1430 returns additional information like 1432 , 1434 , 1436 , and 1438 .
Software Scanner Logic
Depicted in overview 1500 of PRIOR ART FIG. 15 for comparison purposes, is the typical method of test that is found in vulnerability scanner software. It simply finds open service ports during an initial mapping 1502 and then executes all tests 516 pertaining to the “testing group” (for example, 1512 , 1513 , and 1514 ) in a first (and only) wave 1510 . While it can gather similar vender/version information as it goes, it does not actually incorporate the information into the scan. This type of logic does not adapt its testing method to respond to the environment, making it prone to false positives. A false positive occurs when a vulnerability is said to exist based on testing results, when the vulnerability does not actually exist.
Software scanners can be blocked at the point of customer defense, as shown for example, in FIG. 16 a , in overview 1600 of PRIOR ART FIG. 16 a , where test 1602 finds devices 1604 , 1606 , an 1608 only. A preferred embodiment, by contrast, can penetrate those defenses to accurately locate all devices reachable from the Internet, in the example shown in overview 1600 of FIG. 16 b , where tests 516 find devices 1604 , 1606 , 1608 , and also, beyond defenses 1652 and 1654 , devices 1658 .
Note that there is no reason why an alternative communication medium other than the Internet could not be used by a preferred embodiment. Such would not constitute a substantial variance.
Better Test Methodologies Provide Better Results
A preferred embodiment, through distributed basic tests 516 , is able to accurately map all of the networks 1002 and systems 1102 that are reachable from the Internet. The same distributed basic test methodology, in conjunction with pre- and post-testing, 508 enables a preferred embodiment to continue to evade IDS in order to accurately locate security vulnerabilities accurately on every machine 1102 .
FIGS. 16 a and 16 b illustrate some differences between the capabilities of some PRIOR ART software scanners and a preferred embodiment. Typically, the greater the security measures in place, the greater the difference between these capabilities. The customer network being analyzed in the illustrations can be based on an actual system tested with a preferred embodiment, the network having very strong security defenses in place. The PRIOR ART testing of FIG. 16 a was able to locate only a small portion of the actual network. By contrast, FIG. 16 b depicts the level of discovery a preferred embodiment was able to achieve regarding the same network under test.
FIG. 23 depicts logic flow within the Command Engine. First, the job cue is read, 2302 ; a job tracking sequence number is generated, 2304 ; information in the job tracking table is updated, 2306 ; and initial mapping basic tests are generated, 2308 . The results of the initial mapping is stored in the Database, 2310 . All open ports are catalogued for each node, 2312 , and the results of that cataloguing is stored in the Database, 2314 . Master tools are then simultaneously launched for all ports and protocols that need to be tested, 2312 . The example illustrated shows only one tool suite needing to be launched, that being the HTTP protocol that was found on the open port. Block 2318 represents the launching of the HTTP suite. If the system under test has given no information about itself, then a generic HTTP test is generated, 2322 , and the results are stored in the Database, 2324 . However, if information is available about the systems under test at step 2320 , then vulnerabilities are looked up and the next wave of basic tests planned accordingly, 2326 . Basic tests are generated for each vulnerability, 2328 , and results are stored in the Database from each basic test, 2324 . Each basic test will either return a positive or negative result. For each positive result, determine whether information is available, 2330 . Once all available information has been gathered, the http suite will end, 2332 . So long as additional available information exists, vulnerabilities are looked up, and the next wave of basic tests, as appropriate, are generated based on that available information, 2334 . Basic tests are generated for each vulnerability, 2336 . The results of those basic tests are stored in the Database, 2338 . Then the cycle repeats itself with a determination of whether available information still exists, 2330 . After the master suite is finished, 2332 , metrics are stored, 2340 . The metrics might describe, for example, how long tools were operated, when the tools were executed, when they finished executing, etc. The status of all master tool suites is determined, 2342 , and following the completion of all master tool suites, the reports are generated accordingly, 2346 . The information in the job tracking table is then updated to indicate that the job has been completed and to store any other information that needs to be tracked, 2348 .
Further Discussion of Testing Methodology
In a preferred embodiment, multiples waves of testing occur with each subsequent wave of tests including tests that are more finely grained. That is, each subsequent wave of tests includes tests that are more specifically focused on the system under test based on information obtained as in prior test results. Thereby, the testing methodology is more efficient than a brute force effort to blindly test every part of the system under test for every possible vulnerability, even though many vulnerabilities are logically eliminated from possibly being present by the results of earlier testing.
A preferred embodiment handles two types of testing difficulties. In the first case, testing may be impossible or hindered by physical or network connection difficulties. That is, tester communications fail to reach the system under test. In the second case, tester communications are able to physically reach the system under test, but a logic connection cannot be established. This is typically caused by recognition of the tester as a cyber attacker by an Intrusion Detection System (IDS). Failure at this point is failure to establish the session component of communicable coupling.
The first case is handled by switching to a different tester, perhaps using a different physical connectivity service provider. Successful establishment of a connection by the different tester would indicate a likelihood that the failed connectivity was due to a physical connectivity problem rather than IDS recognition.
The second case is handled by switching to a different IP address and attempting to test again. The different IP address may be on the same tester or a different tester. Successful establishment of a connection using the different IP address with the same tester would indicate a likelihood of IDS of the test from the first IP address.
In a preferred embodiment, testing occurs in successive waves, each wave generating additional information about the system under test, confirming the presence or likely presence of certain vulnerabilities and logically eliminating the possibility of other vulnerabilities. This process does not gather an infinite amount of information about the system under test. Rather, it gathers as much information as is possible based on the tools contained in the arsenal.
In a preferred embodiment, an initial mapping consists of a wave of a few tests of differing protocols directed to each IP address of the system under test. This efficiently determines with high likelihood the accessibility of IP addresses. For example, if a target IP address was tested previously and determined to be active, but in the current initial mapping it is completely unresponsive to a few tests of differing protocols, then that IP address is not tested further during the currently scheduled test. If a target IP address is found to be open, then subsequent testing waves could, for example, extensively test every port of the IP address.
Many preferred embodiments utilize a customer profile in improving the efficiency and effectiveness of testing. In a preferred embodiment, the pre-test customer profile contains customer information, IP addresses, test tool constraints, test methodology restraints, and connectivity bandwidth of connections. Note that in other embodiments, customer profiles could contain more or less information of an extremely wide scope, and that would not depart from the scope of the present invention.
In a preferred embodiment, tests are distributed among testers to optimize speed, connectivity, and cost considerations. Other embodiments have other decision rules, not necessarily distributing for optimization, and not necessarily having the same factors. Examples of distribution considerations include size of the system under test, load on testers from other sources besides tests for the system under test, connectivity performance, cost for bandwidth factors, geographic proximity, known obstacles, etc. Examples of known obstacles include openings given through system defenses, firewall/filter information already known, active IDS information already known, etc. Examples of cost factors include cost per bit, cost per transmission, etc. Examples of connectivity performance include absolute speed, reliability, etc.
Operation of a Preferred Embodiment
The following is a description of an example of one preferred embodiment's operation flow.
Security assessment tests for each customer can be scheduled on a daily, weekly, monthly, quarterly or annual basis. The Job Scheduling module 202 initiates customer tests, at scheduled times, on a continuous basis.
The Check Schedule module 302 in the Command Engine 116 polls the Job Scheduling module 202 to see if a new test needs to be conducted. If a new test job is available, the Check Schedule module 302 sends the customer profile 204 to the Test Logic module 304 . The customer profile 204 informs the Command Engine 116 of the services the customer purchased, the IP addresses that need to be tested, etc. so that the Command Engine 116 can conduct the appropriate set of tests 516 .
Based on the customer profile 204 , the Test Logic module 304 determines which tests 516 needs to be run by the Testers 502 and where the tests 516 should come from. The Test Logic module 304 uses the customer profile 204 to assemble a list of specific tests 516 ; it uses the Resource Management module 308 , which tracks the availability of resources, to assign the tests 516 to specific Testers 502 . This list can be sent to the Tool Initiation Sequencer 312 . The Tool Initiation Sequencer 312 works in conjunction with the Tool Management module 314 to complete the final instructions to be used by the Gateway 118 and the Testers 502 . These final instructions, the instruction sequences, can be placed in the Queue 310 .
The Gateway 118 retrieves 402 the instruction sequences from the Queue 310 . Each instruction sequence consists of two parts. The first part contains instructions to the Gateway 118 and indicates which Tester 502 the Gateway 118 should communicate with. The second part of the instructions is relevant to the Tester 502 , and it is these instructions that are sent to the appropriate Tester 502 .
Each port on each system 1102 is typically tested to find out which ports are open. Typically, there are 65,535 TCP ports and 65,535 UDP ports for a total of 131,070 ports per machine. For example, one hundred thirty tests can be required to determine how many of the ports are open. Certain services are conventionally found on certain ports. For example, web servers are usually found on port 80 . However, a web server may be found on port 81 . By checking protocols on each possible port, a preferred embodiment would discover the web server on port 81 .
Once the test 516 is completed by the Tester 502 , the results are received by the Tool/Test Output module 306 . This module sends the raw results 214 to the Database 114 for storage and sends a copy of the result to the Test Logic module 304 . The Test Logic module 304 analyzes the initial test results and, based on the results received, determines the make-up of the next wave of basic tests 516 to be performed by the Testers 502 . Again, the new list is processed by the Tool Initiation Sequencer 312 and placed in the Queue 310 to be retrieved by the Gateway 118 . This dynamic iterative process repeats and adapts itself to the customer's security obstacles, system configuration and size. Each successive wave of basic tests 516 collects increasingly detailed information about the customer system 1102 . The process ends when all relevant information has been collected about the customer system 1102 .
As tests 516 are being conducted by the system, performance metrics 208 of each test are stored for later use.
The Resource Management module 308 helps the Test Logic 304 and the Tool Initiation modules 312 by tracking the availability of Testers 502 to conduct tests 516 , the tools 514 in use on the Testers 502 , the multiple tests 516 being conducted for a single customer network 1002 and the tests conducted for multiple customer networks 1002 at the same time. This can represent hundreds of thousands of basic tests 516 from multiple geographical locations for one customer network 1002 or several millions of basic tests 516 conducted at the same time if multiple customer networks 1002 are being tested simultaneously.
The Gateway 118 is the “traffic director” that passes the particular basic test instructions from the Command Engine Queue 310 to the appropriate Tester 502 . Each part of a test 516 can be passed as a separate command to the Tester 516 using the instructions generated by the Tool Initiation Sequencer 312 . Before sending the test instructions to the Testers 502 , the Gateway 118 verifies that the Tester's 502 resources are available to be used for the current test 516 . Different parts of an entire test can be conducted by multiple Testers 502 to randomize the points of origin. This type of security vulnerability assessment is typically hard to detect, appears realistic to the security system, and may reduce the likelihood of the customer security system discovering that it is being penetrated. Multiple tests 516 , for multiple customer systems 1102 or a single customer system 1102 , can be run by one Tester 502 simultaneously. Typically, all communication between the Gateway 118 and the Testers 502 is encrypted. As the results of the tests 516 are received by the Gateway 118 from the Testers 502 they are passed to the Command Engine 116 .
The Testers 502 house the arsenals of tools 514 that can conduct hundreds of thousands of hacker and security tests 516 . The Tester 502 receives from the Gateway 118 , via the Internet, encrypted basic test instructions. The instructions inform the Tester 502 which test 516 to run, how to run it, what to collect from the customer system, etc. Every basic test 516 is an autonomous entity that is responsible for only one piece of the entire test that can be conducted by multiple Testers 502 in multiple waves from multiple locations. Each Tester 502 can have many basic tests 516 in operation simultaneously. The information collected in connection with each test 516 about the customer systems 1102 in customer network 1002 is sent to the Gateway 118 .
The API 512 is a standardized shell that holds any code that is unique to the tool (such as parsing instructions), and thus APIs commonly vary among different tools.
Report Generator Subsystem Functionality
The Report Generator 110 uses the information collected in the Database 114 about the customer's systems 1002 to generate a report 2230 about the systems profile, ports utilization, security vulnerabilities, etc. The reports 2230 reflect the profile of security services and reports frequency the customer bought. Security trend analyses can be provided since the scan stores customer security information on a periodic basis. The security vulnerability assessment test can be provided on a monthly, weekly, daily, or other periodic or aperiodic basis specified and the report can be provided in hard copy, electronic mail or on a CD.
FIG. 22 depicts the logic flow at a high level of information flowing through a preferred embodiment during its operation. The domain or URL and IP addresses of the system to be tested are provided in Table 2202 and 2204 combining to make up a job order shown as Table 2206 . Job tracking occurs as described elsewhere in the specification represented by Table 2208 . Tables 2210 , 2212 , and 2214 depict tools being used to test the system under test. Information is provided from those tools following each test and accumulated as represented in Table 2224 in the Database 114 . Additional information about vulnerabilities is gathered from other sources other than through test results as represented by Tables 2222 , 2220 , 2218 and 2216 , which is also fed into Table 2224 . Therefore, Table 2224 should contain information on the vulnerabilities mapped to the IP addresses for that particular job. Tables 2226 and 2228 represent the vulnerability library, and information goes from there to create Report 2230 .
Future reports/reporting capabilities might include, survey details such as additional information that focuses on the results of the initial mapping giving in depth information on the availability and the types of communication available to machines that are accessible from the Internet; additional vulnerability classifications and breakdowns by those classifications; graphical maps of the network; new devices since the previous assessment; differences between assessments: both what is new and what has been fixed since the previous assessment; IT management reports, such as who has been assigned the vulnerability to fix, who fixed the vulnerability, how long has the vulnerability been open and open vulnerabilities by assignment, and breakdown of effectiveness of personal at resolving security issues.
Early Warning Generator Subsystem Functionality
The Early Warning Generator subsystem 112 can be used to alert relevant customers on a daily basis of new security vulnerability that can affect their system 1102 or network 1002 . On a daily basis, when new security vulnerabilities can be provided, a preferred embodiment compares 710 the new vulnerability 702 against the customer's most recent network configuration profile 708 . If the new vulnerability 702 can be found to affect the customer systems 1102 or network 1002 then an alert 714 is sent via e-mail 712 to the customer. The alert 714 indicates the detail of the new vulnerability 702 , which machines are affected, and what to do to correct the problem. Only customers affected by the new security vulnerabilities 702 receive the alerts 714 .
FIG. 18 shows an alternative preferred embodiment in which third-party portals 1804 , 1806 , and 1808 , for example, access the services of the system. Tester 502 contained within logical partition 1802 have been selected to provide services accessible via portals 1804 , 1806 , and 1808 . Tester's 502 outside of logical partition 1802 have not been selected to provide such services. ASP 1814 has been connected as part of the logical system 1802 in order to provide services directly from the set of Tester's 502 contained within logical system 1802 . The Tester's 502 contained within logical system 1802 is driven by Test Center 102 . Requests for testing services are initiated from customer node 1803 through communication connection 1812 . Requests for services can be initiated directly from a customer node 1803 to Test Center 102 ; or through a third-party portal, such as one of portals 1804 , 1806 or 1808 ; or directly to a linked ASP 1814 . The communication link from any particular customer node 1803 is shown by communication link 1812 and can be any communication technology, such as DSL, cable modem, etc. The ASP is linked to logical system 1802 by using logical system 1802 to host itself to deliver services directly to its customers. In response to service requests, Tester's 502 within logical system 1802 are used to deliver tests 516 on the designated IP addresses which make up customer network 1002 . Customer network 1002 can or cannot be connected to the requesting customer node 1803 via possible communication link 1810 . Note that logical system 1802 can alternatively include all Tester's 502 .
Geographic overview diagram 1900 in FIG. 19 depicts a geographically disbursed array of server farms 1704 conducting tests on client network 1002 as orchestrated by Test Center 101 . Similarly, geographic overview 2000 in FIG. 20 shows the testing of customer network 1002 by a geographically disbursed array of Tester farms 1704 .
Communications described as being transmitted via the Internet may be transmitted, in the alternative, via any equivalent transmission technology. Also, there is no reason why the functionalities of the Test Center 101 cannot be combined into a single computing device. Similarly, there is no reason why the functionalities of Test Center 102 cannot be combined into a single computing device. Such combinations, or partial combinations in the same spirit are within the scope of the invention and would not be substantially different from a preferred embodiments. Similarly, in most discussions of exemplary embodiments discussed in this specification, Test Center 101 and Test Center 102 would be interchangeable without affecting the spirit of the embodiment being discussed. A notable exception, for example, would be the discussion of updating tools 514 , in which Test Center 101 is appropriately used because of the need for the functionality of RMCTs 119 . Reports are described in this specification as being in any of a variety of formats. Additional possible formats include .doc, .pdf, html, postscript, .xml, test, hardbound, CD, flash, or any other format for communicating information.
It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to limit the invention to the particular forms and examples disclosed. On the contrary, the invention includes any further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments apparent to those of ordinary skill in the art, without departing from the spirit and scope of this invention, as defined by the following claims. In particular, none of the description in the present application should be read as implying that any particular element, step, or function is an essential element which must be included in the claim scope: THE SCOPE OF PATENTED SUBJECT MATTER IS DEFINED ONLY BY THE ALLOWED CLAIMS. Thus, it is intended that the following claims be interpreted to embrace all such further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments. Moreover, none of these claims are intended to invoke paragraph six of 35 U.S.C. §112 unless a phrase of the particular style “means . . . for” is followed by a participle.
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To answer the security needs of the market, a preferred embodiment was developed. A preferred embodiment provides real-time network security vulnerability assessment tests, possibly complete with recommended security solutions. External vulnerability assessment tests can emulate hacker methodology in a safe way and enable study of a network for security openings, thereby gaining a true view of risk level without affecting customer operations. Because this assessment can be performed over the Internet, both domestic and worldwide corporations benefit. A preferred embodiment's physical subsystems combine to form a scalable holistic system that can be able to conduct tests for thousands of customers any place in the world. The security skills of experts can be embedded into a preferred embodiment systems and automated the test process to enable the security vulnerability test to be conducted on a continuous basis for multiple customers at the same time. A preferred embodiment can reduce the work time required for security practices of companies from three weeks to less than a day, as well as significantly increase their capacity. Component subsystems typically include a Database, Command Engine, Gateway, multiple Testers, Report Generator, and an RMCT.
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CROSS-REFERENCE TO PRIOR APPLICATION
[0001] This is a continuation of U.S. application Ser. No. 11/328,103, filed Jan. 10, 2006, which is a continuation of U.S. application Ser. No. 10/880,503, filed Jul. 1, 2004 (now U.S. Pat. No. 7,035,883). This application relates to and claims priority from Japanese Patent Application No. 2004-116069, filed on Apr. 9, 2004. The entirety of the contents and subject matter of all of the above is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a storage control system and method for controlling the storage of data to the storage device.
[0004] 2. Description of the Related Art
[0005] In a system handling large amount of data, such as database system in a data center, data is managed using a storage control system that is built separately from the host computer. This storage control system is a disk array system, such as a RAID (Redundant Array of Independent/Inexpensive Disks), where many storage devices are enclosed in an array.
[0006] In such a storage control system, backup for copying data recorded in the storage device to another storage device is performed so that the data can be recovered even if the data recorded in the storage device become damaged. In this case, consistency of data must be guaranteed during the copying operation, because if the copied data is updated during the copying operation, a mismatch of data occurs, and the backup becomes meaningless.
[0007] A method for guaranteeing consistency of the backup data is to stop the program, besides the backup program, that access the data. But in case of a system for which high availability is required, programs cannot be stopped for a long time. Therefore it is necessary to provide a system that creates a stored image of the data at the point of the start of backup without interrupting the programs from updating data during backup. Hereafter the stored image of the data at a certain point in time is called “volume copy”, and the method which allows the system to update the data while having the volume copy of a specified point in time is called “volume copy management method”. Creating of a volume copy is called “volume copy acquisition”, and the data which is the target of volume copy acquisition is called “original data”. Stopping the status where the volume copy exists is called “volume copy deletion”.
[0008] One of the volume copy management methods is by duplicating data.
[0009] According to this method, for example, from a normal state where a volume copy is not acquired, a program on the storage control system creates all data on two storage areas (that is, data is duplicated). And the storage control system separates the two storage areas into individual storage areas, provides data existing on one storage area as original data, and provides the data existing on the other storage area as volume copy.
[0010] While the volume copy is acquired and duplication is being stopped (non-mirroring state), the storage control system enables update for the storage area of original data, and records the location of data update if a data update is generated. In the case of volume copy deletion, the storage control system restarts the duplication of the data, and copies the update data, of which content does not match between the two storage areas, from the storage area of the original data to the storage area provided as volume copy. This copying is called “mirror resynchronization”. In the case of volume copy deletion, the update data may be copied from the storage area of the volume copy to the storage area of the original data, which is the opposite of the above procedure, and such copying is called “reverse mirror resynchronization”.
[0011] The method of duplicating data by a program on a computer is shown in U.S. Pat. No. 5,051,887, for example.
[0012] As the storage device, a disk device (e.g. hard disk drive), magnetic tape storage device, or any other form of physical storage device can be used. Disk devices include high reliability high performance disk devices which are expensive but which have high reliability and performance, and low reliability low performance disk devices which are inexpensive but which have a lower reliability and performance than high reliability high performance disk devices. An example of a high reliability high performance device is a disk device having a fiber channel (hereafter “FC disk device”) interface, for which is being standardized by ANSI T 11 . An example of a low reliability low performance disk device is a disk device having an interface which is different from the interface of a high reliability high performance disk device, such as a disk device having an ATA (AT Attachment) interface (hereafter “ATA disk device), for which is being standardized by ANSI T 13 .
[0013] In the case of volume copy acquisition, the user may wish to store the original data in the storage area of the FC disk device (hereafter “FC storage area”), but may also wish to store the volume copy on the storage area of the ATA disk device (hereafter “ATA storage area”) because of the cost difference.
[0014] If the original data on the FC storage area and the volume copy on the ATA storage area are duplicated and used (that is, the FC storage area and the ATA storage area are in a paired status) to meet the above demand, the I/O processing performance (e.g. read or write speed of data) between the storage control system and the host device will drop, for example, when an I/O request (input/output request) is received from the host device to the storage control system and then processed, because the I/O processing performance of the FC disk device becomes equivalent to the ATA disk device. Also the performance of the ATA disk device becomes a bottleneck when the volume copy is acquired or when mirror resynchronization is performed.
[0015] Such problems could occur when the attribute levels of the data write destination storage devices, such as performance or reliability, are apart.
SUMMARY OF THE INVENTION
[0016] With the foregoing in view, it is an object of the present invention to minimize the influence of a storage device with a low attribute level when storage devices with a different attribute level are used. Specifically, to minimize the drop of processing speed when data is synchronized among a high performance storage device and a low performance storage device, for example.
[0017] Other objects of the present invention will be clarified by the description herein below.
[0018] A storage control system according to a first aspect of the present invention comprises a plurality of physical storage devices with a different attribute level, a plurality of logical units provided on the plurality of physical storage devices, and a control device for writing data received from an external device to a logical unit selected from the plurality of logical units. The plurality of logical units further comprises one or more high level logical units provided on a physical storage device with a high attribute level and one or more low level logical units provided on a physical storage device with an attribute level lower than the high attribute level. Each of the plurality of logical units further comprises two or more chunks. The plurality of chunks constituting the plurality of logical units further include a plurality of high level chunks constituting the one or more high level logical units and a plurality of low level chunks constituting the one or more low level logical units. At least one of the plurality of high level chunks and at least one of the plurality of low level chunks are pool chunks that can be used dynamically. When data in a first chunk selected from the plurality of chunks is written to a second chunk, the control device selects either a high level chunk or a low level chunk from the plurality of pool chunks based on the status of use of the plurality of chunks, and writes the data in the first chunk to the selected chunk.
[0019] The first embodiment of the storage control system according to the first aspect of the present invention further comprises a primary volume further comprising one or more of the high level logical units selected from the plurality of logical units, a secondary volume further comprising one or more of the high level logical units and one or more of the low level logical units selected from the plurality of logical units, and a memory. The plurality of chunks include a plurality of pool chunks and a plurality of allocated chunks. The plurality of allocated chunks include a plurality of primary chunks constituting the primary volume, and a plurality of secondary chunks constituting the secondary volume. The plurality of secondary chunks include a plurality of high level secondary chunks constituting the high level logical unit in the secondary volume, and a plurality of low level secondary chunks constituting the low level logical unit in the secondary volume. The memory stores the correspondence of the primary chunk of the plurality of primary chunks to the high level secondary chunk or the low level secondary chunk. The control device corresponds a new secondary chunk having an attribute level different from the secondary chunk, selected from the plurality of pool chunks, to an original secondary chunk that is corresponded to a primary chunk selected from the plurality of primary chunks, and writes the data in the original secondary chunk to the new secondary chunk, based on the status of use of the plurality of chunks and the information stored in the memory.
[0020] The second embodiment of the storage control system according to the first aspect of the present invention is the above mentioned first embodiment, wherein the control device cancels the correspondence of the original secondary chunk and the selected primary chunk after writing the data in the original secondary chunk to the new secondary chunk, and corresponds the new secondary chunk to the selected primary chunk in the memory.
[0021] The third embodiment of the storage control system according to the first aspect of the present invention is the above mentioned first embodiment, wherein the operating condition of the plurality of chunks is a ratio of the high level secondary volume or the low level secondary volume in the storage capacity provided by the secondary volume.
[0022] The fourth embodiment of the storage control system according to the first aspect of the present invention is the above mentioned third embodiment, wherein when a threshold of a high level ratio, that is a ratio that the plurality of high level secondary chunks occupy in the storage capacity provided by the secondary volume, is recorded in the memory, if the high level ratio is more than the threshold of the high level ratio, the control device preferentially corresponds the low level secondary chunk to the selected original secondary chunk. Or when a threshold of a low level ratio, that is a ratio that the plurality of low level secondary chunks occupy in the storage capacity provided by the secondary volume, is recorded in the memory, if the low level ratio is more than the threshold of the low level ratio, the control device preferentially corresponds the high level secondary chunk to the selected original secondary chunk.
[0023] The fifth embodiment of the storage control system according to the first aspect of the present invention is the above mentioned fourth embodiment, wherein when the data update frequency is recorded in the memory for each of the plurality of primary chunks and the low level secondary chunk is preferentially corresponded to the selected primary, the control device preferentially selects the primary chunk of which the data update frequency recorded in the memory is lower, and when the high level secondary chunk is preferentially corresponded to the selected primary chunk, the control device preferentially selects the primary chunk of which the data update frequency is higher.
[0024] In the sixth embodiment of the storage control system according to the first aspect of the present invention, when the threshold of the data update frequency of the first chunk is recorded in the memory, the control device corresponds a high level chunk to the first chunk if the data update frequency is more than the threshold of the data update frequency.
[0025] The seventh embodiment of the storage control system according to the first aspect of the present invention is the above mentioned first embodiment, wherein when the threshold of the data update frequency of the primary chunk is recorded in the memory, the control device records the data update frequency in the memory for each of the plurality of primary chunks, and corresponds a high level chunk to the low level secondary chunk if the data update frequency of the selected primary chunk is more than the threshold of the data update frequency, and if a low level secondary chunk is corresponded to the selected primary chunk.
[0026] In the eighth embodiment of the storage control system according to the first aspect of the present invention, when the threshold of the data update frequency of the first chunk is recorded in the memory, the control device corresponds a low level chunk to the first chunk if the data update frequency is less than the threshold of the data update frequency.
[0027] The ninth embodiment of the storage control system according to the first aspect of the present invention is the above mentioned first embodiment, wherein when the threshold of the data update frequency of the primary chunk is recorded in the memory, the control device records the data update frequency in the memory for each of the plurality of primary chunks, and corresponds a high level chunk to the low level secondary chunk if the data update frequency of the selected primary chunk is more than the threshold of the data update frequency, and if a low level secondary chunk is corresponded to the selected primary chunk.
[0028] The tenth embodiment of the storage control system according to the first aspect of the present invention is the above mentioned first embodiment, wherein when a new primary volume, which is the same as the primary volume, is generated, the control device corresponds a high level chunk selected from the plurality of pool chunks to the low level secondary chunk if it is judged from the memory that the low level secondary chunk is corresponded to at least one of the plurality of primary chunks, writes the data in the low level secondary chunk to the corresponded high level chunk, and sets each of a plurality of high level chunks, comprised of the corresponded high level chunk and one or more high level secondary chunks corresponded to one or more primary chunks of the plurality of primary chunks, in the memory as primary chunks.
[0029] A storage control method according to a second aspect of the present invention is a storage control method for a storage control system comprising a plurality of physical storage devices with a different attribute level, and a plurality of logical units provided on the plurality of physical storage devices. The plurality of logical units further comprises one or more high level logical units provided on a physical storage device with a high attribute level, and one or more low level logical units provided on a physical storage device with an attribute level lower than the high attribute level. Each of the plurality of logical units further comprises two or more chunks. The plurality of chunks constituting the plurality of logical units further comprise a plurality of high level chunks constituting the one or more high level logical units, and a plurality of low level chunks constituting the one or more low level logical units. At least one of the plurality of high level chunks and at least one of the plurality of low level chunks are pool chunks that can be dynamically corresponded. The storage control method comprises steps of selecting either a high level chunk or a low level chunk from the plurality of pool chunks based on the operating condition of the plurality of chunks when data in a first chunk selected from the plurality of chunks is written to a second chunk, and Writing the data in the first chunk to the selected chunk.
[0030] The first embodiment of the storage control method according to the second aspect of the present invention is the storage control system further comprising a primary volume further comprising one or more of the high level logical units selected from the plurality of logical units, and a secondary volume further comprising one or more of the high level logical units and one or more of the low level logical units selected from the plurality of logical units. The plurality of chunks include a plurality of pool chunks and a plurality of allocated chunks. The plurality of allocated chunks include a plurality of primary chunks constituting the primary volume, and a plurality of secondary chunks constituting the secondary volume. The plurality of secondary chunks include a plurality of high level secondary chunks constituting the high level logical unit in the secondary volume, and a plurality of low level secondary chunks constituting the low level logical unit in the secondary volume. The storage control method comprises steps of corresponding a new secondary chunk having an attribute level different from the secondary chunk, selected from the plurality of pool chunks, to an original secondary chunk that is corresponded to a primary chunk selected from the plurality of primary chunks, based on a memory that stores the correspondence of a primary chunk of the plurality of primary chunks and the high level secondary chunk or the low level secondary chunk, and the operating condition of the plurality of chunks, and writing the data in the original secondary chunk to the new secondary chunk.
[0031] The second embodiment of the storage control method according to the second aspect of the present invention is the above mentioned first embodiment, wherein the storage control method further comprises steps of canceling the correspondence of the original secondary chunk and the selected primary chunk after writing the data in the original secondary chunk to the new secondary chunk, and corresponding the new secondary chunk to the selected primary chunk in the memory.
[0032] The third embodiment of the storage control method according to the second aspect of the present invention is the above mentioned first embodiment, wherein the operating condition of the plurality of chunks is a ratio of the high level secondary volume or the low level secondary volume in the storage capacity provided by the secondary volume.
[0033] The fourth embodiment of the storage control method according to the second aspect of the present invention is the storage control method further comprising a step of corresponding a high level chunk to the first chunk if the data update frequency is more than the threshold of the data update frequency when the threshold of the data update frequency of the first chunk is recorded in the memory.
[0034] The fifth embodiment of the storage control method according to the second aspect of the present invention is the above mentioned first embodiment, wherein the storage control method further comprises steps of recording the data update frequency in the memory for each of the plurality of primary chunks when the threshold of the data update frequency of the primary chunk is recorded in the memory, and corresponding a high level chunk to the low level secondary chunk if the data update frequency of the selected primary chunk is more than the threshold of the data update frequency, and if a low level secondary chunk is corresponded to the selected primary chunk.
[0035] The sixth embodiment of the storage control method according to the second aspect of the present invention is the storage control method further comprising a step of corresponding a low level chunk to the first chunk if the data update frequency is less than the threshold of the data update frequency when the threshold of the data update frequency of the first chunk is recorded in the memory.
[0036] The seventh embodiment of the storage control method according to the second aspect of the present invention is the above mentioned first embodiment, wherein the storage control method further comprises steps of recording the data update frequency to each of a plurality of primary chunks when the threshold of the data update frequency of the primary chunk is recorded in the memory, and corresponding a high level chunk to the low level secondary chunk if the data update frequency of the selected primary chunk is more than the threshold of the data update frequency, and if a low level secondary chunk is corresponded to the selected primary chunk.
[0037] The eighth embodiment of the storage control method according to the second aspect of the present invention is the storage method further comprising steps of deciding that the low level secondary chunk is corresponded to at least one of the plurality of primary chunks when a new primary volume, which is the same as the above mentioned primary volume, is generated, corresponding a high level chunk selected from the plurality of pool chunks to the low level secondary chunk, writing data in the low level secondary chunk to the corresponded high level chunk, and setting each of the plurality of high level chunks, comprised of the corresponded high level chunk and one or more high level secondary chunks which are corresponded to each of one or more primary chunks out of the plurality of primary chunks, in the memory as a primary chunk.
[0038] The above mentioned storage control method can be implemented in a single storage control system, for example, or on a network where a plurality of computers are connected. The above mentioned memory may be a single memory, for example, or a plurality of memories. In the case of a plurality of memories, the memories may be distributed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a diagram depicting the concept of an embodiment of the present invention;
[0040] FIG. 2 shows a configuration example of a storage control system according to an embodiment of the present invention;
[0041] FIG. 3 shows a configuration example of the volume copy LU registration table 309 ;
[0042] FIG. 4 shows a configuration example of a volume copy management table;
[0043] FIG. 5 shows a configuration example of a setup value table 307 ;
[0044] FIG. 6 shows a configuration example of a failure handling volume copy management table;
[0045] FIG. 7 shows the processing flow to be executed by the volume copy acquisition program 302 ;
[0046] FIG. 8 shows the processing flow to be executed by the update frequency threshold swap program 303 ;
[0047] FIG. 9 shows the processing flow to be executed by the disk usage ratio swap program 304 ;
[0048] FIG. 10 shows the processing flow to be executed by the failure swap program 305 ;
[0049] FIG. 11 is a diagram depicting the pair setting of the volume copy which is executed in S 1 in FIG. 7 ;
[0050] FIG. 12 are tables for describing the flow of information to be registered in the volume copy management table 308 in the processing flow shown in FIG. 7 ;
[0051] FIG. 13 are tables showing an example of the failure handling volume copy management table 306 before update and after update; and
[0052] FIG. 14 shows a configuration example of the LU management table 911 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] An embodiment of the present invention will now be described with reference to the drawings.
[0054] FIG. 1 is a diagram depicting the concept of the present embodiment. The concept of the present embodiment will be described first with reference to FIG. 1 .
[0055] As FIG. 1 (A) shows, in the present embodiment, a plurality of storage devices, where the attribute level of at least one of reliability and performance is different, coexist. In the plurality of storage devices, one or more fiber channel disk devices (hereafter “FC disk device”) 201 , which are high reliability high performance disk devices, for example, are included as storage devices with a high attribute level. Also as a storage device with a low attribute level, one or more serial ATA disk devices (hereafter “SATA disk device”) 203 , which have a low reliability low performance but which are less expensive than the FC disk device 201 , are included. In the present embodiment, “reliability” refers to durability which can hold data without damage and to probability of failure which may occur, and specifically to MTBF (Mean Time Between Failure). “Performance” refers to the value of the data transfer rate and the speed of response.
[0056] A plurality of logical units (hereafter LU) are disposed on one or more FC disk devices 201 and on one or more SATA disk devices 203 . Each LU is comprised of a plurality of same sized sub-LUs (hereafter called chunks). And hereafter the LU 205 disposed on the FC disk device 201 is called “FC-LU”, and the LU 207 disposed on the SATA disk device 203 is called “SATA-LU”. The chunk constituting the FC-LU 205 is called “FC-chunk”, and the chunk constituting the FC-LU 206 is called “SATA-chunk”. In FIG. 1 , the FC-chunk is indicated by a blank frame, and the SATA-chunk is indicated by a hatched frame.
[0057] In the present embodiment, one virtual LU is comprised of one or more LUs. A virtual LU is also called a “logical volume”. In the present embodiment, a virtual LU is either a primary volume (hereafter PVOL) 204 or a secondary volume (hereafter SVOL) 206 , for example. The PVOL 204 is comprised of one or more FC-LUs 205 . The SVOL 206 , on the other hand, may be comprised of only one or more FC-LUs 205 or only one or more SATA-LUs 207 , or a combination of FC-LU 205 and SATA-LU 207 . Hereafter the FC-LU 205 constituting the PVOL 204 is called the “PVOL-FC-LU 205 ”, and the FC-chunk constituting the PVOL 204 is called the “PVOL-FC-chunk”. The FC-LU 205 constituting the SVOL 206 is called the “SVOL-FC-LU 205 ”, the SATA-LU 207 constituting the SVOL 206 is called the “SVOL-SATA-LU- 207 ”, the FC-chunk constituting the SVOL 206 is called the “SVOL-FC-chunk”, and the SATA-chunk constituting the SVOL 206 is called the “SVOL-SATA-chunk”. The SVOL-FC-chunk and the SVOL-SATA-chunk may commonly be called the “SVOL-chunk”.
[0058] In the present embodiment, the storage control program can perform management by duplicating of PVOL 204 and SVOL 206 , and in this case, when the data from the host device is written to the PVOL 204 , for example, the same data can be written to the SVOL 206 . Specifically, in the storage control system, the PVOL-FC-chunk and the SVOL-FC-chunk or the SVOL-SATA-chunk are duplicated and managed, and when sub-data (one composing element of data) is written to a PVOL-FC-chunk, the same sub-data is also written to the duplicated SVOL-FC-chunk or SVOL-SATA-chunk. Hereafter storing the same data to the PVOL 204 and the SVOL 206 is called “mirroring”, a pair of PVOL 204 and SVOL 206 is called a “volume pair”, and a pair of PVOL-FC-chunk and SVOL-FC-chunk or SVOL-SATA-chunk is called a “chunk pair”.
[0059] In the present embodiment, other than the PVOL-FC-chunk, SVOL-FC-chunk and SVOL-SATA-chunk, a pool chunk group 208 , comprised of a plurality of pool chunks which belong to neither PVOL 204 nor SVOL 206 , exists. The plurality of pool chunks constituting the pool chunk group 208 includes a “pool-FC-chunk” which is an FC-chunk, and a “pool-SATA-chunk” which is an SATA-chunk. The storage control system selects a pool chunk from the pool chunk group 208 , allocates it to an SVOL-chunk, copies the sub-data in the SVOL-chunk to the selected pool chunk, sets the pool chunk as SVOL-chunk, and sets the SVOL-chunk, which is the copy source of the sub-data, as a pool chunk, so as to exchange the pool chunk and SVOL-chunk. Allocation of pool chunks to the SVOL-chunk can be determined depending on variety of policy, for example, the update frequency of sub-data in the PVOL-chunk which is chunk pair partner of the SVOL-chunk.
[0060] Specifically, in the case when the PVOL-FC-chunk “# 2 ” and SVOL-FC-chunk “ 2 ” form a chunk pair, as shown in FIG. 1 (A), for example, if it is detected that the update frequency of the sub-data in the PVOL-FC-chunk “# 2 ” is lower than a predetermined threshold, the storage control system selects a pool SATA-chunk (e.g. # 51 ”) from the pool chunk group 208 , and copies the sub-data B in the SVOL-FC-chunk “# 2 ” to the selected pool SATA-chunk “# 51 ”. And, as shown in FIG. 1 (B), the storage control system sets the pool SATA-chunk “# 51 ” as SVOL-FC-chunk “# 51 ” instead of SVOL-FC chunk “# 2 ”, and sets the SVOL-FC-chunk “# 2 ” as the pool SATA-chunk “# 2 ” instead of the pool SATA-chunk “# 51 ”. In this way, if it is detected that the chunk pair partner of PVOL-FC-chunk, of which update frequency of the sub-data is lower than the predetermined threshold, is the SVOL-FC-chunk, then the chunk pair partner of the PVOL-FC-chunk is switched from the SVOL-FC-chunk to the pool SATA-chunk (after swap, the pool SATA-chunk becomes the SVOL-SATA-chunk).
[0061] Also, in the case when PVOL-FC-chunk “# 8 ” and SVOL-SATA-chunk “# 4 ” form a chunk pair, as shown in FIG. 1 (A), for example, if it is detected that the update frequency of the sub-data in PVOL-FC-chunk “# 8 ” is higher than the predetermined threshold, the storage control system selects the pool FC-chunk (e.g. “# 53 ”) from the pool chunk group 208 , and copies the sub-data H in the SVOL-SATA-chunk “# 4 ” to the selected pool FC-chunk “# 53 ”. And the storage control system sets the pool FC-chunk “# 53 ” as SVOL-FC-chunk “# 53 ” instead of SVOL-SATA-chunk “# 4 ”, and sets the SVOL-SATA-chunk “# 4 ” as the pool SATA-chunk “# 4 ” instead of the pool FC-chunk “# 53 ”. In this way, when it is detected that the chunk pair partner of the PVOL-FC-chunk, of which the update frequency of the sub-data is higher than the predetermined threshold, is the SVOL-SATA chunk, then the chunk pair partner of the PVOL-FC-chunk is switched from the SVOL-SATA-chunk to the pool FC-chunk (after swap, the pool FC-chunk becomes the SVOL-FC-chunk).
[0062] The above is the description on the concept of the present embodiment. In the description herein below, it is assumed that one or more FC-LUs 205 constituting the PVOL 204 and one or more FC-LUs 205 and SATA-LU 207 constituting the SVOL 206 exist in a same storage control system, but these may be distributed in a plurality of systems.
[0063] Now the present embodiment will be described.
[0064] FIG. 2 shows a configuration example of the storage control system according to the present embodiment.
[0065] The storage control system 200 is comprised of one or more fiber channel interface devices (hereafter fiber I/F) 290 A and 290 B (this is not limited to an FC interface device, but may be another interface device). For example, a host device 100 , such as a personal computer, may be connected to the fiber I/F 290 A, and a backup server 400 having a tape device (e.g. magnetic tape recording device) 500 may be connected to the fiber I/F 290 B. The backup server 400 reads data in the SVOL 206 via the fiber I/F 290 B, and writes the data to the tape device 500 . If the data in the SVOL 206 is updated during backup, data consistency is lost, so the storage control system 200 does not allow backup by the backup server 400 during mirroring. A case of when backup is allowed, for example, is allowing a data update from the host device 100 to the PVOL 204 , but not to the SVOL 206 , which is a non-mirroring status.
[0066] The storage control system 200 comprises a management interface (hereafter management I/F) 240 , such as a LAN controller, for example. A management terminal 600 , for managing the storage control system 200 , is connected to the management I/F 240 .
[0067] The storage control system 200 is comprised of a plurality of disk devices 201 and 203 , a disk controller 250 for controlling the plurality of disk devices 201 and 203 , a cache memory 230 for temporarily storing data to be exchanged between an external device (e.g. host device 100 ) and the disk devices 201 and 203 , a CPU 210 for controlling operation of the storage control system 200 , and a control memory 220 for storing a computer program to be read by the CPU 210 and such control information as a table which is referred to by the CPU 210 .
[0068] The plurality of disk devices 201 and 203 include one or more FC disk devices 201 and one or more SATA disk device 203 . The one or more FC disk devices 201 has a plurality of FC-LUs 205 , as mentioned above. Each FC-LU 205 can be a composing element of the PVOL 204 or can be a composing element of the SVOL 206 . The one or more SATA disk devices 203 , on the other hand, has one or more SATA-LUs 207 , as mentioned above. The SATA-LU 207 can be a composing element of the SVOL 206 . In the illustrated example, one FC-LU 205 constitutes the PVOL 204 , and one FC-LU 205 and one SATA-LU 207 constitute the SVOL 206 .
[0069] In the control memory 220 , a basic control program 301 , volume copy acquisition program 302 , update frequency threshold swap program 303 , disk usage ratio swap program 304 , failure swap program 305 , volume copy LU registration table 309 , volume copy management table 308 , setup value table 307 , failure handling volume copy management table 306 and LU management table 911 are stored.
[0070] The basic control program 301 is a computer program for controlling the basic operation of the storage control system 200 . For example, the basic control program 301 reads data from the LU 205 and 206 A or 206 B according to the I/O request from the host device 100 , and sends it to the host device 100 via the cache memory 230 , or stores the data included in the I/O request in the first LU 205 .
[0071] The volume copy acquisition program 302 is a computer program for executing volume copy acquisition.
[0072] The update frequency threshold swap program 303 selects the type of chunk (in other words, either pool FC-chunk or pool SATA-chunk) to be the data swap partner of the SVOL-chunk corresponded to the PVOL-FC chunk, based on whether the update frequency of the PVOL-FC chunk is over the predetermined update frequency threshold.
[0073] The disk usage ratio swap program 304 selects the type of chunk (in other words, either pool FC-chunk or pool SATA-chunk) to be the copy destination of the sub-data of the SVOL-chunk, based on whether the ratio of the SVOL-FC-chunk (or SVOL-SATA-chunk) in the SVOL 206 is over the predetermined ratio.
[0074] The failure swap program 305 switches the SVOL-FC-chunk corresponding to the PVOL-FC-chunk to the PVOL-FC chunk when a failure occurs to the PVOL 204 (e.g. when the FC disk device having the PVOL-FC-LU is damaged). When failure occurs to the PVOL 204 and if the SVOL-SATA-chunk corresponding to the PVOL-FC-chunk exists in the SVOL 207 , the failure swap program 305 moves the sub-data in the SVOL-SATA-chunk to the pool FC-chunk selected from the pool chunk group 208 , and switches the pool FC-chunk to the PVOL-FC-chunk. In this way, when failure occurs to the PVOL 204 , the failure swap program 305 constructs a new PVOL by the SVOL-FC-chunk corresponding to the PVOL-FC-chunk and the pool FC-chunk allocated to the SVOL-SATA-chunk corresponding to the PVOL-FC-chunk.
[0075] Now each table 309 - 306 and 911 , which are stored in the control memory 220 , will be described with reference to FIG. 3 to FIG. 6 .
[0076] FIG. 3 shows a configuration example of the volume copy LU registration table 309 .
[0077] The volume copy LU registration table 309 is a table where the information on a plurality of LUs in the storage control system 200 is registered. Specifically, in the volume copy LU registration table 309 , a pair number, external LU number, internal LU number, LU capacity, disk type, PVOL/SVOL information and access attribute are registered for each of the plurality of LUs.
[0078] The pair number is an identification number of the volume pair.
[0079] The external LU number is an LU number received from an external device, such as a host device. When two or more LUs are provided to the external device as one logical volume, the external LU number becomes a same number for these two or more LUs. In the case of this example, if “ 2 ” is specified from the external device as an LU number, the LU with the internal LU number “ 2 ” and the LU with the internal LU number “ 3 ” are provided to the external device as one SVOL 206 .
[0080] The internal LU number is an LU number which the storage control system 200 recognizes and manages. In this embodiment, the LU with the internal LU number “ 1 ”, for example, is PVOL-FC-LU 205 , and the LU with the internal LU number “ 2 ” is SVOL-FC-LU 205 , and the LU with the internal LU number “ 3 ” is SVOL-SATA-LU 207 .
[0081] The LU capacity is a storage capacity of an LU.
[0082] The disk type is a type of disk device which has the corresponding LU (e.g. interface). Specifically, a disk type indicates either an FC disk device or an SATA disk device.
[0083] PVOL/SVOL information is information to indicate whether the corresponding LU constitutes a PVOL or an SVOL.
[0084] The access attribute is information to indicate what kind of access is enabled to the corresponding LU. For example, “R/W enable” indicates that both read and write are enabled, “R only” indicates that read is enabled but that write is disabled, “W only” indicates that write is enabled but that read is disabled, and “R/W disable”, which is not shown in the drawing, indicates that both read and write are disabled. Various types can be used for the access attribute.
[0085] FIG. 14 shows a configuration example of the LU management table 911 .
[0086] In the LU management table 911 , a plurality of LU information items, corresponding to the plurality of LUs existing in the storage control system 200 respectively, is registered. The LU information includes such LU information elements as the internal LU # (number), LU capacity, disk type, selectability information and pool chunk #. Here the selectability information is information that indicates if the LU can be selected or not when a volume copy pair is being set (“volume copy” is a stored image of data at a certain point of time). The pool chunk # is a number assigned to a chunk for which the kind of chunk and how the chunk will be used is not defined, and which can be dynamically allocated (therefore it is a pool chunk).
[0087] FIG. 4 is a configuration example of a volume copy management table.
[0088] The volume copy management table 308 is a table for managing original data and information on volume copy. The volume copy management table 308 is largely divided into a left column, middle column and right column.
[0089] In the left column, information on PVOL 204 , which stores original data, is registered. Specifically, in the left column, the LU #, chunk # and update frequency, for example, are registered for each chunk constituting the PVOL 204 . The LU # is an internal LU number of an LU which has a corresponding chunk, and is registered as a PVOL. The chunk # is a serial number of the chunk assigned within an LU. For example, the minimum value of a chunk # is 1, and the maximum value of a chunk # is a value of the quotient obtained when the LU capacity of an LU having a corresponding chunk is divided by the chunk size (the quotient is rounded up if a remainder is generated). The update frequency is a number of times when the sub-data stored in the corresponding chunk is updated, and the initial value is 0. The update frequency is incremented or reset by the CPU 210 , for example.
[0090] In the middle column, information on an SVOL 206 for storing the volume copy is registered. Specifically, in the middle column, a disk type, LU # and chunk #, for example, are registered for each chunk constituting an SVOL 206 . The disk type is a type of disk device (e.g. interface type) which has an LU having a corresponding chunk. The LU # is an internal LU number of an LU which has a corresponding chunk, and is registered as an SVOL. The chunk # is a serial number of the chunk assigned within the LU. Each row in this middle column corresponds to each row of the left column. In other words, information on a PVOL-FC-chunk is registered in the rows of the left column, and in each row of the middle column, information on an SVOL-chunk (specifically, either an SVOL-FC-chunk or an SVOL-SATA-chunk) is registered.
[0091] In the right column, information on a swap partner chunk is registered. Here “swap partner chunk” is a chunk to be the swap destination (in other words the shift destination) of the sub-data in the corresponding SVOL-chunk. In this right column, the disk type, LU# and chunk # are registered for each swap partner chunk. As a swap partner chunk, a pool chunk, which has not yet been decided how to be used as a chunk, can be allocated. A blank means that an SVOL-chunk has no swap partner chunk.
[0092] The CPU 210 refers to this volume copy management table 308 , and can identify the following. For example, the CPU 210 can identify that an FC-chunk with LU # “ 2 ” and chunk # “ 1 ” is corresponded to the PVOL-FC-chunk with LU # “ 1 ” and chunk # “ 1 ” as an SVOL chunk. And the CPU 210 can also identify that a pool SATA-chunk with LU # “ 3 ” and chunk # “ 5 ” is corresponded to the SVOL-chunk as the swap partner chunk.
[0093] The above is a configuration example of the volume copy management table 308 . In the volume copy management table 308 , a plurality of SVOL-chunks may be corresponded to one PVOL-FC-chunk, or a plurality of swap partner chunks may be corresponded to one SVOL-chunk.
[0094] FIG. 5 shows a configuration example of the setup value table 307 .
[0095] In the setup value table 307 , information can be input and registered from the management terminal 600 , for example. The chunk size, swap period, update frequency threshold and disk ratio threshold, for example, are registered in the setup value table 307 .
[0096] The chunk size is a value for driving an LU into a certain number of byte units to be chunks. The swap period is a value for indicating the schedule to swap the data stored in an SVOL-chunk with a pool FC-chunk or pool SATA-chunk, based on the update frequency threshold or disk ratio threshold (e.g. “weekly” if this is to be done once every week).
[0097] The update frequency threshold is a threshold for deciding whether the sub-data in an SVOL-chunk corresponding to a PVOL-FC-chunk is stored in a pool chunk. This update frequency threshold is a value to be compared with the number of times sub-data in a PVOL-FC-chunk was updated during the above mentioned swap period (that is, the update frequency recorded in the volume copy management table 308 ) by the write command from an external device.
[0098] The disk ratio threshold is a threshold of the ratio of the storage capacity created by one or more SVOL-FC-chunks (hereafter SVOL-FC storage capacity) in an entire SVOL 206 . Specifically, if the disk ratio threshold is “0.3”, for example, the SVOL-FC storage capacity is 0.3 (that is 30%) in an entire SVOL 206 , which means that the storage capacity created by one or more SVOL-SATA-chunks (hereafter SVOL-SATA storage capacity) is the remaining 0.7 (that is 70%) in an entire SVOL 206 .
[0099] A plurality of setup value tables corresponding to the plurality of pair numbers (that is a plurality of volume pairs) may be provided. In this case, the CPU 210 of the storage control system 200 may perform management referring to the setup value tables corresponding to each pair number. This increases flexibility of management.
[0100] FIG. 6 shows a configuration example of a failure handling volume copy management table.
[0101] The failure handling volume copy management table 306 is a table for managing which FC-chunk, corresponding to each PVOL-FC chunk in a PVOL 204 , is switched to a PVOL-FC-chunk when a failure occurred to the PVOL 204 . The failure handling volume copy management table 306 is largely divided into a left column, middle column and right column, just like the volume copy management table 308 . The left column has the same configuration of the left column of the volume copy management table 308 , except that the update frequency is not registered in this case. The middle column has the same configuration as the middle column of the volume copy management table 308 .
[0102] In the right column, information on the failure handling shift destination chunk is registered. Here “failure handling shift destination chunk” is a chunk selected from the pool chunk group 208 as a shift destination of the sub-data in an SVOL-chunk. In the right column, the disk type, LU # and chunk # are registered for each failure handling shift destination chunk. As FIG. 6 shows, the failure handling shift destination chunk is an FC-chunk in the present embodiment, and the SVOL-chunk corresponded to the failure handling shift destination chunk is an SVOL-SATA chunk. By this, when a failure occurs in a PVOL 204 , and if a copy of the sub-data in the PVOL-FC-chunk exists in the SVOL-SATA-chunk, the sub-data in the SVOL-SATA-chunk is shifted to the FC-chunk corresponded to the SVOL-SATA-chunk (that is, an open chunk on the FC disk device, which is a high reliability high performance disk device). A blank indicates that a failure handling shift destination chunk in an SVOL-chunk is not corresponded.
[0103] The above is the description on each table 309 - 306 and 911 which are stored in the control memory 220 .
[0104] Now the processing flow to be executed in the present embodiment will be described below with reference to the above mentioned tables 309 - 306 and 911 .
[0105] FIG. 7 shows a processing flow to be executed by the volume copy acquisition program 302 which is read by the CPU 210 .
[0106] The volume copy acquisition program 302 sets a pair of volume copy (step S 1 ). In this case, information is registered in the volume copy LU registration table 309 according to the flow shown in FIG. 11 , for example.
[0107] For example, the volume copy acquisition program 302 displays the copy pair setup screen 912 on the display screen of the management terminal 600 . The LU # (internal LU number) of the PVOL-LU constituting the PVOL 204 and the LU # of a plurality of SVOL-LUs (one or more FC-LU and one or more SATA-LU) constituting the SVOL are input in the copy pair setup screen 912 . When PVOL-FC-LU (FC-LU constituting the PVOL 204 ), SVOL-FC-LU (FC-LU constituting the SVOL 206 ) and SVOL-SATA-LU (SATA-LU constituting the SVOL 206 ) are selected from the plurality of LUs not registered in the volume copy LU registration table 309 (in other words, LUs which are selectable in the LU management table 911 ), the respective LU #s are input in this copy pair setup screen 912 , and the volume copy acquisition program 302 writes each LU # which was input to the volume copy LU registration table 309 . The volume copy acquisition program 302 also acquires other LU information elements (e.g. disk type) corresponding to the LU #, which was input, from the LU management table 911 , and writes the acquired LU information elements to the volume copy LU registration table 309 . For example, if the internal LU # “ 1 ” is input as the PVOL-FC-LU, the internal LU # “ 2 ” is input as the SVOL-FC-LU, and the internal LU # “ 3 ” is input as the SVOL-SATA-LU, then in the LU management table 911 , the volume copy acquisition program 302 switches the selectability information corresponding to each internal LU # “ 1 ”-“ 3 ” from selectable to unselectable, and constructs the volume copy LU registration table 309 shown in FIG. 3 .
[0108] Now S 2 and later processing will be described with reference again to FIG. 7 .
[0109] The volume copy acquisition program 302 receives input of the values of the setup value table 307 from the user via the management terminal 600 , for example. When various values (that is chunk size, swap period, update frequency threshold and disk ratio threshold) are input, the volume copy acquisition program 302 registers the values, that were input, in the setup value table 307 (S 2 ).
[0110] Then the volume copy acquisition program 302 registers the PVOL-FC-chunk in the volume copy management table 308 (S 3 ). A specific example of this processing will be described with reference to FIG. 12 (A). For example, the volume copy acquisition program 302 calculates the number of chunks based on the LU capacity and the chunk size registered in the setup value table 307 , for the PVOL-FC-LU which is set in the volume copy LU registration table 309 . And the volume copy acquisition program 302 assigns the chunk # as a serial number to the calculated number of chunks respectively, and registers the assigned chunk # and the LU # of the PVOL-FC-LU thereof in the volume copy LU registration table 309 . The volume copy acquisition program 302 inputs “0” to the update frequency of each PVOL-FC-chunk as an initial value. When data is updated by a write command from an external device, such as the host device 100 , the volume copy acquisition program 302 adds “1” to the update frequency corresponding to the PVOL-FC-chunk for which data was updated.
[0111] Then the volume copy acquisition program 302 registers the SVOL-FC-chunk in the volume copy management table 308 (S 4 ). A specific example of this processing will be described with reference to FIG. 12 (B). For example, the volume copy acquisition program 302 calculates the number of chunks of the PVOL-FC-LU and assigns a chunk # to each chunk in a same method as the case of registering the PVOL-FC-chunk, and registers the assigned chunk # and the LU # of the SVOL-FC-LU thereof in the volume copy LU registration table 309 .
[0112] If an SVOL-chunk was set for all the PVOL-FC-chunks in S 4 (Y in S 5 ), the volume copy acquisition program 302 moves to S 11 without executing the later mentioned operations in S 6 -S 10 .
[0113] When the SVOL-chunk is not set for at least one PVOL-FC-chunk, and the SVOL-FC-chunk remains without being corresponded with the PVOL-FC-chunk in S 4 (N in S 5 and Y in S 6 ), the volume copy acquisition program 302 executes the operation in S 4 for the remaining PVOL-FC-chunk.
[0114] When the SVOL-chunk is not set for at least one PVOL-FC-chunk and SVOL-FC-chunks do not remain (N in S 5 and N in S 6 ) in S 4 , the volume copy acquisition program 302 calculates the number of chunks for SVOL-SATA-LU and assigns a chunk # to each chunk, just like the case of SVOL-FC-LU, and registers the allocated chunk # and LU # in the volume copy LU registration table 309 (S 7 ). FIG. 12 (C) shows an example of this result.
[0115] When the SVOL-chunk is set for all the PVOL-FC-chunks in S 7 (Y in S 8 ), the volume copy acquisition program 302 moves to S 11 without executing the later mentioned operations in S 9 -S 10 .
[0116] When the SVOL-chunk is not set for at least one PVOL-chunk and the SVOL-SATA-chunk remains without being corresponded to the PVOL-FC-chunk in S 7 (N in S 8 and Y in S 9 ), the volume copy acquisition program 302 returns to the beginning of S 7 .
[0117] When the SVOL-chunk is not set for at least one PVOL-FC-chunk and selectable SVOL-SATA-chunk does not remain at S 7 (N in S 8 and N in S 9 ), the volume copy acquisition program 302 outputs a warning, to add an LU to SVOL, on the management terminal 600 , for example (S 10 ), because this means that the number of chunks of SVOL are insufficient.
[0118] If data is stored in PVOL after Y in S 5 and Y in S 8 , the volume copy acquisition program 302 judges the correspondence of the chunk of PVOL and the chunk of SVOL referring to the volume copy management table 308 , and stores the sub-data in the PVOL-FC-chunk and the SVOL-chunk corresponded thereto (S 11 ). Specifically, the volume copy acquisition program 302 duplicates the sub-data registered in the cache memory 230 , stores one sub-data on the cache memory 230 in the PVOL-FC-chunk, and stores the other sub-data on the cache memory 230 in the SVOL-chunk corresponded to that PVOL-FC-chunk.
[0119] After S 11 , the volume copy acquisition program 302 sets the access attribute of each LU constituting the SVOL to R/W enable (enabling both read and write) in the volume copy LU registration table 309 at an arbitrary timing (S 12 ).
[0120] In this processing, data may be written to the PVOL by random write access, or data may be written by sequential write access. In the case of random write access, for example, the volume copy acquisition program 302 receives a corresponding write command for each PVOL-FC-chunk, and stores the sub-data to the PVOL-FC-chunk and the SVOL-chunk corresponded thereto each time one write command is processed. In the case of sequential write access, for example, the volume copy acquisition program 302 receives write commands corresponding to a plurality of PVOL-FC-chunks (e.g. all the PVOL-FC-chunks), and when one write command is processed, sub-data is written to the plurality of PVOL-FC-chunks and the plurality of SVOL-chunks corresponding thereto sequentially from a smaller chunk #.
[0121] FIG. 8 shows the processing flow to be executed by the update frequency threshold swap program 303 which is read by the CPU 210 .
[0122] When the time of the swap period registered in the setup value table 307 comes (S 21 -A), or when the user inputs a data swap instruction via a predetermined terminal (e.g. management terminal 600 or host device 100 ) (S 21 -B), the basic control program 301 starts up the update frequency threshold swap program 303 .
[0123] When it is detected that the volume pair selected from one or more volume pairs (hereafter target volume pair (s)) are in non-mirror status, the update frequency threshold swap program 303 sets the access attribute of each LU constituting the SVOL of the target volume pair to update disable (e.g. R only) in the volume copy LU registration table 309 . When the target volume pair is in mirror status, a warning is output (S 22 ). Whether the target volume pair is non-mirror status or mirror status can be judged by referring to the pair management table 914 (e.g. provided in the control memory 220 ) in which the status information corresponding to each pair number (information to indicate mirror status or non-mirror status) is registered. Mirror status is a status where data is duplicated. In other words, in this status if data is updated in the PVOL, the same updated data is copied to the SVOL (in other words, the SVOL is synchronized with the PVOL). Non-mirror status is a status where duplication is not being done, in other words, in this status even if data is updated in the PVOL, the updated data is not written to the SVOL (in other words, the SVOL is not synchronized with the PVOL).
[0124] The update frequency threshold swap program 303 compares the update frequency of the PVOL-chunk registered in the first row of the volume copy management table 308 and the update frequency threshold registered in the setup value table 307 (S 23 ).
[0125] When it is judged that the update frequency of the PVOL-FC-chunk is the update frequency threshold or more (Y in S 23 ) and the SVOL-chunk of the chunk pair partner of the PVOL-FC-chunk is an FC-chunk based on the judgment according to the volume copy management table 308 (Y in S 24 ) in S 23 , the update frequency threshold swap program 303 advances to the later mentioned S 28 .
[0126] When the update frequency of the PVOL-FC-chunk is the update frequency threshold or more (Y in S 23 ) and the SVOL-chunk corresponding to the PVOL-FC-chunk is not an FC-chunk based on the judgment according to the volume copy management table 308 (N in S 24 ) in S 23 , the update frequency threshold swap program 303 selects a pool FC-chunk from the plurality of pool chunks, and writes the chunk # and LU # of the selected pool FC-chunk to the right column (column of the swap partner chunk) of the volume copy management table 308 with corresponding to the SVOL-chunk which is not the above FC-chunk (that is, SVOL-SATA-chunk) (S 25 ). By this, for the SVOL-SATA-chunk corresponded to the PVOL-FC-chunk of which the update frequency of the sub-data is the update frequency threshold or more, the FC-chunk existing on a high reliability high performance disk device is corresponded as the data swap partner. The chunk # corresponded to the SVOL-SATA-chunk is selected from a plurality of pool chunks, therefore it is a chunk # not registered on the volume copy management table 308 .
[0127] When the update frequency of the PVOL-FC-chunk is less than the update frequency threshold (N in S 23 ) and the SVOL-chunk corresponding to the PVOL-FC-chunk is an SATA-chunk based on the judgment according to the volume copy management table 308 (Y in S 26 ) in S 23 , the update frequency threshold swap program 303 advances to the later mentioned S 28 .
[0128] When the update frequency of the PVOL-FC-chunk is less than the update frequency threshold (N in S 23 ) and the SVOL-chunk corresponding to the PVOL-FC-chunk is not an SATA-chunk (N in S 26 ) based on the judgment according to the volume copy management table 308 in S 23 , the update frequency threshold swap program 303 selects the SATA-chunk from a plurality of pool chunks, and writes the chunk # and LU # of the selected SATA-chunk to the right column (column of the swap partner chunk) of the volume copy management table 308 with corresponding to the SVOL-chunk which is not the above SATA-chunk (that is the SVOL-FC-chunk) (S 27 ). By this, for the SVOL-FC-chunk corresponded to the PVOL-FC-chunk of which the update frequency of the sub-data is less than the update frequency threshold, the SATA-chunk existing on a low reliability low performance but inexpensive disk device is corresponded as the data swap partner.
[0129] In the case of Y in S 24 , Y in S 26 and a chunk existing in the swap destination (that is, a selectable pool chunk does not exist) in S 25 or S 27 (N in S 28 ), the pools of chunks at the swap destination are insufficient, so the update frequency threshold swap program 303 outputs a warning, to have the SVOL add an LU or change the threshold, to the management terminal 600 or host device 100 , for example (S 29 ). The later mentioned processings in S 31 -S 36 may be executed without confirming all the chunks. In this case, processing in S 22 or later may be executed after these processings.
[0130] When the swap destination chunks are sufficient in S 28 (Y in S 28 ), the update frequency threshold swap program 303 judges whether the comparison processing of the update frequency and the update frequency threshold has been completed for all the PVOL-FC-chunks (S 30 ).
[0131] If there is a PVOL-FC-chunk for which comparison processing has not been executed in S 30 (N in S 30 ), the update frequency threshold swap program 303 returns to S 23 , and executes the processings in S 23 -S 28 for the next PVOL-FC-chunk.
[0132] If it is judged that the comparison processing has been completed for all the PVOL-FC-chunks in S 30 (Y in S 30 ), the update frequency threshold swap program 303 judges whether data is being read from the SVOL by backup so as to execute processing to swap data in the corresponding copy destination chunk to the swap destination chunk having the chunk # registered in the volume copy management table 308 (S 31 ).
[0133] When data is being read from the SVOL in S 31 (Y in S 31 ), the update frequency threshold swap program 303 outputs a warning to stop the reading operation, such as backup, or to stop the swap program (S 32 ).
[0134] When data is not being read from the SVOL in S 31 (N in S 31 ), the update frequency threshold swap program 303 sets the access attribute of each LU constituting the SVOL to read disable (e.g. R/W disabled) (S 33 ).
[0135] After S 33 , the update frequency threshold swap program 303 shifts the sub-data in the SVOL-chunk having a chunk # registered in the middle column (SVOL column) to the swap destination chunk corresponded to the SVOL-chunk based on the volume copy management table 308 (S 34 ). When this completes, the update frequency threshold swap program 303 overwrites the content of the swap destination chunk (disk type, LU # and chunk #) on the content of the SVOL-chunk corresponding to the swap destination chunk in the volume copy management table 308 , and deletes the content of the swap destination chunk from the right column (swap partner chunk column) (S 35 ). In this case, the update frequency threshold swap program 303 may register the deleted content of the swap destination chunk (e.g. chunk #) to the LU management table 911 , for example, as a content of a pool chunk.
[0136] After S 35 , the update frequency threshold swap program 303 sets the access attribute of each LU constituting the SVOL to read enable (e.g. R only) (S 36 ). After S 36 , if processing after S 31 had been executed without performing the above comparison processing for all the PVOL-FC-chunks, the update frequency threshold swap program 303 returns to S 3 , as shown by the dotted line.
[0137] After S 36 , the update frequency threshold swap program 303 resets the update frequency of each v on the volume copy management table 308 to the initial value (S 37 ). And the update frequency threshold swap program 303 sets the access attribute of each LU constituting the SVOL to updatable (e.g. R/W enabled) (S 38 ).
[0138] The above is the processing flow to be executed by the update frequency threshold swap program 303 .
[0139] FIG. 9 shows the processing flow to be executed by the disk usage ratio swap program 304 which is read by the CPU 210 .
[0140] When the swap period registered in the setup value table 307 comes (S 41 -A), or when the user inputs a data swap instruction via a predetermined terminal (e.g. management terminal 600 or host device 100 ) (S 41 -B), the basic control program 301 starts up the disk usage ratio swap program 304 .
[0141] The disk usage ratio swap program 304 sets the access attribute of each LU constituting the SVOL of the target volume pair to update disable (e.g. R only) in the volume copy LU registration table 309 with the same method as S 22 in FIG. 8 (S 42 ).
[0142] Then the disk usage ratio swap program 304 sorts a plurality of rows on the volume copy management table 308 in the descending order of data update frequency (S 43 ). Hereafter the number of rows in the volume copy management table 308 is assumed to be n and the row number after the above sorting is i, and the volume copy management table 308 after the above sorting is P (i). The disk usage ratio swap program 304 executes the following S 44 and the later processings in the sequence of lower row number i after the sorting (in other words, starting from the higher data update frequency).
[0143] The disk usage ratio swap program 304 selects one row number i from the plurality of row numbers after the above sorting, and compares the value i/n when the selected row number i is divided by the number of rows n and the disk ratio threshold T registered in the setup value table 307 (S 44 ).
[0144] When i/n is T or more as a result of S 44 , the disk usage ratio swap program 304 judges whether the SVOL-chunk corresponding to the PVOL-FC-chunk with the above selected row number i is an FC-chunk or not (S 45 ). In S 45 , if a positive judgment result is acquired (Y in S 45 ), the disk usage ratio swap program 304 executes the later mentioned processing in S 51 . If a negative judgment result is acquired in S 45 (N in S 45 ), the disk usage ratio swap program 304 selects an FC-chunk from a plurality of pool chunks, and sets the selected FC-chunk in P(i) as a swap partner chunk of the above mentioned corresponded SVOL-chunk (S 46 ). At this time, if a selectable FC-chunk does not exist in the plurality of pool chunks (N in S 49 ), the disk usage ratio swap program 304 outputs a warning, to increase the selectable pool FC-chunks, to the user (S 50 ), and if not executes S 51 (Y in S 49 ).
[0145] When i/n is less than T as a result of S 44 , the disk usage ratio swap program 304 judges whether the SVOL-chunk corresponding to the PVOL-FC-chunk with the above mentioned selected row number i is an SATA-chunk or not (S 47 ). In S 45 , if a positive judgment result is acquired (Y in S 47 ), the disk usage ratio swap program 304 executes the later mentioned processing in S 51 . If a negative judgment result is acquired in S 47 (N in S 47 ), the disk usage ratio swap program 304 selects an SATA-chunk from a plurality of pool chunks, and sets the selected SATA-chunk in P (i) as a swap partner chunk of the above mentioned corresponded SVOL-chunk (S 48 ). At this time, if a selectable SATA-chunk does not exist in the plurality of pool chunks (N in S 49 ), the disk usage ratio swap program 304 outputs a warning, to increase the selectable pool SATA-chunks, to the user (S 50 ), and if not executes S 51 (Y in S 49 ).
[0146] The disk usage ratio swap program 304 executes the above mentioned processings in S 44 -S 48 for all the row numbers i (N in S 51 ), and when this processing is completed for all the row numbers i (Y in S 51 ), the same processing as S 31 -S 38 in FIG. 8 are executed.
[0147] In the above processing flow, if the SVOL-chunk corresponding to the PVOL-FC-chunk is not a chunk with an appropriate attribute level according to the update frequency of the sub-data in the PVOL-FC-chunk, the sub-data in the SVOL-chunk is shifted to another chunk with an appropriate attribute level, and the ratio of the SVOL-FC storage capacity in SVOL 206 (in other words, the ratio of the SVOL-SATA storage capacity) is adjusted to the disk ratio threshold T.
[0148] FIG. 10 shows the processing flow to be executed by the failure swap program 305 which is read by the CPU 210 . In the description below, to make the description simple and clear, the PVOL when failure occurs is called the “original PVOL”, the SVOL when failure occurs is called the “original SVOL”, and the PVOL and SVOL created by the failure swap program are called the “new PVOL” and the “new SVOL” respectively. Also in the description below, it is assumed that a failure occurred to the original PVOL, while the write data received from the host device 100 is being written to the original PVOL.
[0149] When a failure occurs to the original PVOL (S 61 ), the basic control program 301 detects this, and starts up the failure swap program 305 .
[0150] The failure swap program 305 sets the access attribute of each LU constituting the original PVOL where a failure occurred to read disable (e.g. R/W disable) in the volume copy LU registration table 309 (S 62 ). The failure swap program 305 saves the write data from the host device 100 to the original PVOL in the cache memory 230 or in another LU (S 63 ).
[0151] Then the failure swap program 305 selects an FC-chunk out of a plurality of pool chunks, and writes the chunk # and LU # of the selected FC-chunk in the right column of the failure handling management table 306 (failure handling shift destination chunk column) with corresponding to the original SVOL-SATA-chunk (S 64 ). At this time, if there are sufficient allocatable FC-chunks (Y in S 65 ), the failure swap program 305 executes the later mentioned S 67 , and if no allocatable FC-chunk exists in the plurality of pool chunks, the failure swap program 305 outputs a warning to notify that FC-LU is insufficient (N in S 65 and S 66 ).
[0152] In S 67 , the failure swap program 305 shifts the sub-data in the original SVOL-SATA-chunk, having a chunk # registered in the middle column (SVOL column), to the swap destination chunk (FC-chunk) corresponded to that original SVOL-SATA-chunk, based on the failure handling volume copy management table 306 (S 67 ).
[0153] Then the failure swap program 305 overwrites the content (LU # and chunk #) of the swap destination chunk on the content of the original PVOL-FC-chunk corresponding to that swap destination chunk in the failure handling volume copy management table 306 , and deletes the content of the swap destination chunk. For the original PVOL-FC-chunk where no swap destination chunk exists, the failure swap program 305 overwrites the content (LU# and chunk #) of the original SVOL-FC-chunk on the content of the original PVOL-FC-chunk, and deletes the content of that original SVOL-FC-chunk (S 68 ). If failure occurs to the original PVOL by this processing, the original SVOL-chunk is switched to the new PVOL-chunk if the original SVOL-chunk corresponding to the original PVOL-FC-chunk is an FC-chunk. And if the original SVOL-chunk corresponding to the original PVOL-chunk is an SATA-chunk, then an FC-chunk selected from the plurality of pool chunks is corresponded to that SATA-chunk, and the selected FC-chunk is switched to the new PVOL-chunk. As a result, each of the plurality of original PVOL-chunks registered in the left column (original data column) of the failure handling volume copy management table 306 is switched to the original SVOL-FC-chunk or the above mentioned selected FC-chunk, and a new PVOL comprised of the original SVOL-FC-chunk and the above mentioned selected FC-chunk are generated. FIG. 13 (A) shows the status of the failure handling volume copy management table 306 before update, and FIG. 13 (B) shows the status of the table 306 after update.
[0154] By this update processing in S 68 , the plurality of FC-chunks out of the original SVOL-chunks are all switched to new PVOL-FC-chunks, so new SVOL-chunks for this amount of chunks are required. So the failure swap program 305 selects the required number of FC-chunks from the plurality of pool chunks, and registers the selected FC-chunks in the middle column of the failure handling volume copy management table 306 and the volume copy management table 308 as new SVOL-chunks. And the failure swap program 305 copies the data in the FC-chunks, which were original SVOL-chunks, to the new SVOL-chunks (S 69 ).
[0155] Then the failure swap program 305 writes the write data saved in S 63 to the new PVOL. The failure swap program 305 provides the information on the new PVOL (e.g. external LU number and storage capacity) to the host device 100 when a predetermined inquiry command (e.g. inquiry command based on SCSI protocol) from the host device 100 (S 69 ). By this, the host device 100 can recognize the new PVOL.
[0156] The above is the processing flow executed by the failure swap program 305 . In the processing in S 68 , the failure swap program 305 may update the content of the volume copy management table 308 in the same way. The content of the original SVOL-chunk switched to the new PVOL-chunk may be deleted from the failure handling volume copy management table 306 and volume copy management table 308 .
[0157] According to the above mentioned embodiment, each of the plurality of LUs existing on the storage control system 200 is divided into a plurality of chunks. The PVOL is comprised of only FC-chunks, but an SVOL is comprised of both FC-chunks and SATA-chunks. And to each of the plurality of SVOL-chunks, either an FC-chunk or SATA-chunk selected from the plurality of pool chunks is dynamically corresponded. The type of corresponded chunk is switched depending on the status of data write to the PVOL. Specifically, to the SVOL-SATA-chunk corresponding to the PVOL-FC-chunk with a high data update frequency, for example, an FC-chunk existing on a high reliability high performance FC disk device is corresponded, and to an SVOL-FC-chunk corresponding to a PVOL-FC-chunk with a low data update frequency, a SATA-chunk existing on a low reliability low performance but inexpensive SATA disk device is corresponded. By this, the drop in speed of copy processing by a low reliability low performance disk device and an increase in cost can both be addressed.
[0158] According to the above mentioned embodiment, the storage capacity ratio of an SVOL-FC in an SVOL (in other words the SVOL-SATA storage capacity ratio) is automatically adjusted to be a preset disk ratio threshold. Therefore the FC storage capacity ratio in an SVOL becomes the ratio desired by the user, even if the user does not periodically perform complicated settings.
[0159] According to the above mentioned embodiment, the storage capacity ratio of an SVOL-FC is adjusted in the sequence of SVOL-chunks corresponding to the PVOL-FC-chunks with a higher update frequency. By this, the storage capacity ratio of an FC is efficiently adjusted.
[0160] According to the above mentioned embodiment, when a failure occurs to the original PVOL, even if the chunk corresponded to the original PVOL-chunk is an SATA-chunk, the data in the SATA-chunk is shifted to the FC-chunk selected from the plurality of pool chunks, and the FC-chunk is switched to the new PVOL-chunk. By this, the new PVOL-chunk constituting the new PVOL can be an FC-chunk regardless the type of chunk corresponded to the original PVOL-chunk.
[0161] An embodiment of the present invention was described above, but this is just an example in order to describe the present invention, and it is not intended to limit the scope of the present invention to only this embodiment. The present invention can be implemented by various other embodiments. For example, the above embodiment can be applied to a storage device with an attribute level other than reliability or performance. The above embodiment can be applied even when a plurality of LUs are distributed in two or more devices (e.g. a PVOL exists in a storage control system 200 and an SVOL exists in another storage control system). Also in the above embodiment, there are two levels of disk devices, one has high reliability and high performance, and the other has low reliability and low performance, but more levels of disk devices may be used. Also in the present embodiment, a plurality of thresholds may be used for at least one of the update frequency threshold and the disk ratio threshold, for a more refined adjustment. Two types of disk ratio thresholds may be provided for the FC storage capacity ratio and the SATA storage capacity ratio. The data update frequency is a number of times of data updates in a predetermined period, but may simply be an update frequency, regardless the period.
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A disk array system including a plurality of disk drives, including: a plurality of first-type disk drives being used to form a first-type logical unit having a plurality of a first-type of chunks; a plurality of second-type disk drives being used to form a second-type logical unit having a plurality of a second-type of chunks; and a storage controller, if the storage controller copies data stored in a source chunk to a destination chunk, selecting the destination chunk from the first-type of chunks or the second-type of chunks.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a lace provided with a tubular lace body.
[0003] 2. Description of the Related Art
[0004] Conventionally, as to a lace which needs to be pass through a hole for fixation, a lace, where its core is made of a linear material having elasticity such as a rubber, the outer periphery of the core is covered with fiber, and the fiber portion has knobby portions for hooking into holes of a lace-up shoes, thereby being fixed without lacing, is well-known.
[0005] The knobby portions are braided so as to hook the hole after passing through the hole of the lace-up shoes, and can freely vary its diameter depending on the tension put on the lace. Therefore, the lace has a configuration, where a plurality of knobby portions, of which ends are fixed by the rubber of the core, and the core which is inelastic (flexible) and not fixed, are braided and placed. When a tension is put on the core of rubber, the rubber portion extends and the distance between the ends extends, so that the core of the knobby portion becomes flat, and the diameter becomes smaller.
[0006] Moreover, when the tension is not put on the lace, the rubber portion becomes normal length, and the distance between the ends also becomes normal, so that the shape of the knobby portion is restored to be original, and the diameter becomes greater.
[0007] Thus, it is possible to control variation of the diameter of the knobby portion by the tension put on the lace, so that the shoe lace which does not loosen without lacing can be made as described above.
[0008] For example, the Japanese Patent No. 3493002 discloses such lace provided with knobby portions.
RELATED ART DOCUMENTS
Patent Document 1: Japanese Patent No. 3493002
[0009] However, in the above technology, the both ends of the inelastic knobby portion are fixed to the rubber core, so that the rubber portion cannot extends under high tension. The reason is that the knobby portion is braided by the inelastic fiber and the rubber portion is fixed by the inelastic.
[0010] Moreover, the rubber portion corresponding to the core of the knobby portion repeats extension and shrinks in response to the high tension.
SUMMARY OF THE INVENTION
[0011] Therefore, there are a portion that is subjected to heavy stretching force and a portion that is subjected to no stretching force, and when large strain is accumulated at the boundary between the portions subjected to different stretching forces and the strain reaches the limit, the lace ruptures. In order to solve the above problem, we provide a lace provided with tubular lace body of elastic material, comprising knobby portions repeatedly placed at intervals, of which diameter vary depending on tension on the knobby portion in an axial direction.
[0012] According to the present invention mainly having the above configuration, the lace having an economical advantage, which is not easily torn and does not get loose without lacing, can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a diagram showing a portion of a lace of a first embodiment.
[0014] FIG. 2 is a diagram showing that the lace of the first embodiment is under tension in an axial direction.
[0015] FIG. 3 is a diagram showing that the lace of the first embodiment is used for a shoe lace.
[0016] FIG. 4 is a diagram showing that the lace of the first embodiment is used for a lace for trousers.
[0017] FIG. 5 is a flowchart of fixing process by using the lace of the first embodiment.
[0018] FIG. 6 is a perspective view of an entire lace of a second embodiment.
[0019] FIG. 7 is a cross-section view of a lace of a third embodiment.
[0020] FIG. 8 is a cross-section view of a lace of a fourth embodiment.
[0021] FIG. 9 is a cross-section view of a lace of a fifth embodiment.
[0022] FIG. 10 is an enlarged view of a braided portion of a lace body of a sixth embodiment.
[0023] FIG. 11 is a side view of both sides of the lace of the present invention.
[0024] FIG. 12 is a cross-sectional view when the lace of the present invention is configured to be a rubber tube.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Embodiments of the present invention will be described hereinafter. Relationship between Claims and Embodiments is as follows. The first embodiment will mainly describe claim 1 . The second embodiment will mainly describe claim 2 . The third embodiment will mainly describe claim 3 . The fourth embodiment will mainly describe claim 4 . The fifth embodiment will mainly describe claim 5 . The sixth embodiment will mainly describe claim 6 . The present invention is not to be limited to the above embodiments and able to be embodied in various forms without departing from the scope thereof.
First Embodiment
Outline of First Embodiment
[0026] FIG. 1 is a diagram showing a portion of a lace of a first embodiment. As shown in FIG. 1 , the lace of the first embodiment is a lace provided with tubular lace body of elastic material, comprising a knobby portion repeatedly placed at intervals, of which diameter varies depending on tension on the knobby portion in an axial direction. This configuration enables to provide a lace which is not easily torn under high tension which is repeatedly put on the lace body.
[0027] Note that the design of the lace of FIG. 1 continues only in horizontal direction in the elevation view, and FIG. 11 is a side view of both sides of the lace of the present invention.
Configuration of First Embodiment
[0028] As shown in FIG. 1 , a ‘lace’ 0100 of a first embodiment is a lace provided with tubular lace body comprising knobby portions repeatedly placed at intervals. Specifically, the knobby portions are configured by repeated placed ‘cores’ 0101 , and ‘ends’ 0102 . FIG. 2 is a diagram showing that the lace of the first embodiment is under tension in an axial direction. As shown in FIG. 2 , when putting the tension in the axial direction, the diameter of the knobby portion varies, such that the knobby portion shrinks. When removing the tension in the axial direction, the diameter of the knobby portion varies, such that the knobby portion expands.
[0029] The ‘knobby portion’ of the first embodiment is ‘repeatedly placed at intervals’. Therefore a plurality of knobby portions is placed on the lace body. The plurality of knobby portions may be placed only with intervals between the cores, and the interval is not necessary to be regular. Therefore, the knobby portion may be placed at regular intervals or at random, and the interval is design variation. As show in FIGS. 3 and 4 , it is possible to provide laces for various cases such as a case of lacing up shoes or a case of fastening trousers.
[0030] Moreover, as to the knobby portion, ‘diameter varies depending on tension on the knobby portion in an axial direction’. Specifically, as the tension in the axial direction increases, the diameter is reduced, and as the tension in the axial direction decreases, the diameter increases.
[0031] FIG. 5 is a flowchart of fixing process by using the lace of the first embodiment. The process includes the following steps. At the outset, in a step S 0501 , tension on the lace is put in an axial direction, such that the diameter of the knobby portion is reduced. Subsequently, in a step S 0502 , the lace under tension is made to pass through a hole. Subsequently, in a step S 0503 , it is determined whether lace length is suitable for keeping fixed state. If the length is not suitable, the step S 0502 is repeated. If it is determined that the length is suitable, processing shifts to a step S 0504 . Subsequently, in a step S 0504 , the tension put on the lace is reduced, such that the diameter of the knobby portion increases, thereby expanding the knobby portion. Thus, it is possible to keep the state of being fixed only by hooking the knobby portion on the hole without lacing.
[0032] Note that the ‘knobby portion’ of the present invention is a portion having diameter greater than that of a non-knobby portion with no tension in the axial direction. Therefore, the knobby portion is a part of the lace body, and configured by the after-mentioned elastic material similar to the lace body.
[0033] The terms ‘configured by the elastic material’ means that the lace is configured by a material having a property of elasticity. Examples of the elastic material include natural rubber and synthetic rubber. The lace may be configured to be rubber tube as shown in FIG. 12 by singularly using such material, or may be configured by combination of such materials and inelastic materials such as polyester, nylon, acryl or polyurethane. Therefore, according to this configuration where the entire lace body made of elastic material, the entire lace body can extend and shrink under tension in the axial direction, so that distortion is not easily caused on the respective portions of the lace, thereby providing the lace which is not easily torn under high tension which is repeatedly put on the lace body.
Effects of First Embodiment
[0034] According to the lace of the first embodiment having the above configuration, the lace can preserve the knobby portion under high tension, and can be repeatedly used, thereby solving the problem of the conventional technology.
Second Embodiment
Outline of Second Embodiment
[0035] FIG. 6 is a perspective view of an entire lace of a second embodiment. As show in FIG. 6 , the lace of the second embodiment is basically similar to that of the first embodiment, and the elastic material is braided by rubber and less-elastic normal material. This configuration enables extension and shrink in the axial direction without heavy load for the lace.
Functional Configuration of Second Embodiment
[0036] The configuration of the lace of the second embodiment is basically similar to that of the first embodiment as described with reference to FIG. 1 . Hereinafter, description of difference in configuration of the elastic material is mainly provided.
[0037] The ‘rubber-like material’ is a material having elasticity and a thread-like shape, and can well expand under tension in the axial direction. Note that the term ‘rubber-like material’ does not exclude a rubber material, and therefore, includes any type of rubber such as natural rubber and synthetic rubber. The configuration braided by the rubber-like material enables sufficient extension with small tension in the axial direction.
[0038] The ‘less-elastic normal material’ is fiber material with less elasticity in comparison with the rubber-like material. Therefore, the term ‘less-elastic’ is a technical term and means ‘poor in elasticity’ and does not mean ‘not elastic’. Examples of the less-elastic normal material include the polyester, nylon, acryl, and polyurethane. The configuration braided by such normal fiber materials with high line density enables to provide the lace with durability to tear. Moreover, using the normal material, it is possible to form various shape of knobby portions, which are hard to be formed in using only the rubber-like material.
[0039] The rubber-like material and the normal material configure the elastic material of the first embodiment by braiding them with each other. The term ‘braiding’ means general method for braiding the rubber-like material and the normal material in straight lines crossing each other diagonally. This configuration makes it possible to utilize both advantages of the rubber-like material and the normal material. Specifically, the rubber-like material is provided with durability to shrink and tear under strong tension in the axial direction by being braided with the normal material with high durability, and the normal material is provided with elasticity in the axial direction without heavy load by being braided with the rubber-like material.
[0040] Moreover, in the braiding, timing of crossing the materials and amounts of the materials to be used may be appropriately determined. Therefore, the ratio of the rubber-like material and the normal material may be equal, or may be 1:5 or 1:7 where the normal material is more used than the rubber-like material. Here, in order to secure the elasticity sufficient for performance of the lace of the first embodiment, for example, the suitable ratio between the rubber-like material and the normal material is approximately 1:7.
[0000] Hereinafter, a description of forming the knobby portion placed on the lace body of the first embodiment made by braiding the elastic material is provided. As described above, the knobby portion is necessary to be formed, such that the diameter thereof varies depending on tension on the knobby portion in an axial direction, and this function is necessary to be secured even in the braided configuration. Specifically, it is possible to make partial pitch variation in the braiding, for example, a portion of the lace may be loosely braided in comparison with other portions. This makes it possible to make deflection on the knobby portion, such that the knobby portion is more extendable, and to configure the lace body by the rubber-like material and normal material without patch of separately braided materials at the core and the end of the knobby portion.
Effects of Second Embodiment
[0041] According to the lace using the normal material of the second embodiment, in addition to the first embodiment, it is possible to provide laces of various designs, and to provide the lace not only with durability to tear. Moreover, the normal material reduces friction drag with the hole, and provides the lace with smoothness in moving.
Third Embodiment
Outline of Third Embodiment
[0042] FIG. 7 is a cross-section view of a lace of a third embodiment. As show in FIG. 7 , the lace of the third embodiment is basically similar to that of the first embodiment, and further comprises a ‘centrally-placed lace’ 0705 that is centrally placed in a ‘tube’ 0703 configured by tubular structure of the lace body, consists of less-elastic material, configures a core of the knobby portion, and is balled up at a ‘portion corresponding to knobby portion’ 0704 so as to follow a variation of distance between ends of the knobby portion in response to the variation of the diameter of the knobby portion. According to this configuration, it is possible to reduce difficulty in restoring the original state of the knobby portion due to repeated use of the lace.
Configuration of Third Embodiment
[0043] The configuration of the lace of the third embodiment is basically similar to that of the first embodiment as described with reference to FIG. 1 . Hereinafter, description of difference in configuration of the centrally-placed lace is mainly provided.
[0044] The ‘centrally-placed lace’ has a function of following a variation of distance between ends of the knobby portion in response to the variation of the diameter of the knobby portion, and is balled up at the portion corresponding to the knobby portion, thereby configuring the core of the knobby portion. The ‘variation of distance between ends of the knobby portion in response to the variation of the diameter of the knobby portion’ means that the variation of the diameter of the knobby portion is caused by the tension in the axial direction put the lace body, and the distance between ends of the knobby portion varies in response to the variation of the diameter. The ‘function of following’ the variation is, for example, when the distance between ends of the knobby portion is reduced, the after-mentioned balled-up portion of the centrally-placed lace further shrinks, and when the distance between ends of the knobby portion increases, the balled-up portion of the centrally-placed lace extends.
[0045] Here, the balled-up portion of the centrally-placed lace is made at the portion corresponding to the knobby portion. According to this configuration, the elastic material configuring the lace body forms the knobby portion along the portion corresponding to the knobby portion of the centrally-placed lace, so that the portion corresponding to the knobby portion works as the core for forming the knobby portion. Moreover, by internally placing the centrally-placed lace as the core, the knobby portion can preserve the firmness to endure the repeated use. Note that it is necessary to prevent position gap at the portion corresponding to the knobby portion in order to function the centrally-placed lace as the core of the knobby portion. In order to secure the function as the core of the knobby portion, it is required that the centrally-placed lace connects the respective portions corresponding to the knobby portion and has the thread-like form where it is fixed at the ends of the lace.
[0046] Note that since the centrally-placed lace is not necessary to extend or shrink the lace, the centrally-placed lace may be configured by inelastic material, not by elastic material. Therefore, even when putting the tension in the axial direction on the lace body and extending it, the centrally-placed lace does not extend like the rubber-like material. The centrally-placed lace has slightly longer than the lace body, and the ‘balled-up portion’ has, for example, a spirally-twisted form. According to this configuration, it is possible to reduce difficulty in restoring the original state of the knobby portion when the balled-up portion gets entangled in repeated use of the lace.
Effects of Third Embodiment
[0047] According to the lace having the configuration of the third embodiment, in addition to the first embodiment, it is possible to reduce difficulty in restoring the original state of the knobby portion of the lace body due to repeated use of the lace.
Fourth Embodiment
Outline of Fourth Embodiment
[0048] FIG. 8 is a view showing an outline of a lace of a fourth embodiment. As show in FIG. 8 , the lace of the fourth embodiment is basically similar to that of the first embodiment, and the diameter W 1 of the ‘core of the knobby portion’ 0801 of the lace body is 1.5 times or more of the diameter W 2 of the ‘end of the knobby portion’ 0802 of the lace body without tension in the axial direction. According to this feature in the shape of the knobby portion, the lace easily hooks on the hole, and can smoothly move upon adjusting its length.
Configuration of Fourth Embodiment
[0049] The configuration of the lace of the fourth embodiment is basically similar to that of the first embodiment as described with reference to FIG. 1 . Hereinafter, description of difference in diameter of the knobby portion is mainly provided.
[0050] The state ‘without tension in the axial direction’ is a state that tension on the lace does not exist. Under this state, for example as shown in FIG. 3 , the core of the knobby portion has the diameter greater than the ends of the knobby portion, and functions as a fixture by being hooked on the hole. Therefore, for the function of the knobby portion, the diameter of the core of the knobby portion is required to be greater than that of the hole.
[0051] Meanwhile, when the diameter of the core of the knobby portion becomes excessively greater, the balance in the shape of the entire lace is lost, thereby spoiling the appearance of the lace. Moreover, it is necessary to put excessive tension in the axial direction on the lace to reduce the diameter of the core of the knobby portion and level the diameter of the entire lace. It is assumed that the lace is daily used as the fixture by men and women of all ages, it is preferable that the diameter of the core of the knobby portion varies with the minimum tension in the axial direction, such that elders and children who are less powerful can use the lace. Therefore, it is preferable that the knobby portion easily hooks on the hole, and the diameter of the entire lace is easily leveled.
[0052] In this regard, by using the lace of the present invention, where the diameter of the core of the knobby portion on the lace body was 7 mm, and the diameters of the ends were 4 mm, it was possible to reduce the diameter of the core of the knobby portion and to level the lace body without putting heavy tension in the axial direction.
Effects of Fourth Embodiment
[0053] According to the lace having the configuration of the fourth embodiment, in addition to the first embodiment, the lace easily hooks on the hole, and can smoothly move upon adjusting its length.
Fifth Embodiment
Outline of Fifth Embodiment
[0054] FIG. 9 is a view showing an outline of a lace of a fifth embodiment. As show in FIG. 9 , the lace of the fifth embodiment is basically similar to that of the first embodiment, and the diameter W 3 of the ‘core of the knobby portion’ 0901 of the lace body is 1.3 times or less of the diameter W 4 of the ‘end of the knobby portion’ 0902 of the lace body under tension in the axial direction. According to this feature in the shape of the knobby portion, the lace can smoothly passes through the hole.
Configuration of Fifth Embodiment
[0055] The configuration of the lace of the fifth embodiment is basically similar to that of the first embodiment as described with reference to FIG. 1 . Hereinafter, description of difference in diameter of the knobby portion under tension is mainly provided.
[0056] The state ‘under tension in the axial direction’ is a state that tension is put on the lace. In this state, for example as shown in FIG. 2 , the diameter of the core of the knobby portion becomes smaller than that of the state without tension in the axial direction, and the lace can pass thorough the hole without hooking. Therefore, for the function of the knobby portion, the diameter of the core of the knobby portion is required to be sufficiently small for passing through the hole under tension in the axial direction. It is ultimately preferable that the ‘diameter sufficient small for passing through the hole under tension in the axial direction’ is the same as that of the ends of the knobby portion. However, in the lace of the present invention, the elastic material is used for the lace body, and the lace has the tubular shape. Therefore, there is a room inside the tube, and if the diameter of the core of the knobby portion is slightly greater than that of the ends, the knobby portion extends to the room inside the tube upon passing through the hole, hereby passing the hole having the same diameter as that of the ends.
[0057] In this regard, by using the lace of the present invention, where the diameter of the core of the knobby portion on the lace body was 7 mm, and the diameters of the ends were 4 mm, it was possible to make the lace pass through the hole having 4 mm diameter by putting the tension in the axial direction on the lace even in the state that the diameter of the core of the knobby portion was approximately 5 mm.
Effects of Fifth Embodiment
[0058] According to the lace having the configuration of the fifth embodiment, in addition to the first embodiment, the lace can smoothly passes through the hole.
Sixth Embodiment
Outline of Sixth Embodiment
[0059] FIG. 10 is an enlarged view of a braided portion of a lace body of a sixth embodiment. As show in FIG. 9 , the lace of the sixth embodiment is basically similar to that of the first embodiment, and the lace body is braided at 45 degrees angle to the axial direction. According to this feature, the lace can smoothly passes through the hole.
Configuration of Sixth Embodiment
[0060] The configuration of the lace of the sixth embodiment is basically similar to that of the first embodiment as described with reference to FIG. 1 . Hereinafter, description of difference in braiding angle of the lace body is mainly provided.
[0061] As shown in FIG. 10 , the terms ‘the lace body is braided at 45 degrees angle to the axial direction’ mean a state where the rubber-like material and the normal material are braided at approximately 45 degrees angle. As described above, it is preferable that the lace body can pass through the hole without hooking, and degree of the hooking can vary depending not only on the diameter of the knobby portion but also on surface shape of the knobby portion. Specifically, as the surface shape of the knobby portion gets smooth, the lace body can easily pass through the hole. Here, as the braiding angle gets wide, the braiding gets loose, thereby the lace easily hooks on the hole. Meanwhile, as the angle gets narrow, the diameter of the lace body is reduced, the diameter of the knobby portion relatively becomes greater, and it becomes difficult to make the diameter of the knobby portion small and to make the lace pass through the hole unless heavy tension in the axial direction is put on the lace.
[0062] In this regard, by using the lace of the present invention, where the lace body is braided by the rubber-like material and the normal material at approximately 45 degrees angle to the axial direction, it is possible to make the lace smoothly pass through the hole without causing the above problem.
Effects of Sixth Embodiment
[0063] According to the lace having the configuration of the fifth embodiment, in addition to the first embodiment, the lace can smoothly passes through the hole.
DESCRIPTION OF REFERENCE NUMERALS
[0000]
0100 Lace
0101 Core of knobby portion
0102 End of knobby portion
0103 End
0200 Lace
0201 Core of knobby portion
0202 End of knobby portion
0701 Core of knobby portion
0702 End of knobby portion
0703 Tubular portion
0704 Portion corresponding to knobby portion
0705 Centrally-placed lace
1201 Core of knobby portion
1202 End of knobby portion
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In the conventional lace with knobby portions having elastic rubber core, there is difference in degree of stretch between both ends and core of the knobby portion. Therefore, there are a portion that is subjected to heavy stretching force and a portion that is subjected to no stretching force, and when large strain is accumulated at the boundary between the portions subjected to different stretching forces and the strain reaches the limit, the lace ruptures. In order to solve the above problem, we provide a lace provided with tubular lace body of elastic material, comprising knobby portions repeatedly placed at intervals, of which diameter vary depending on tension on the knobby portion in an axial direction.
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GOVERNMENT FUNDING
This invention was made with Government support under Contract Nos. DA 3801 awarded by the National Institute of Drug Abuse. The Government has certain rights in the invention.
RELATED APPLICATION
This application is a continuation of application Ser. No. 08/658,949 filed May 31, 1996, now U.S. Pat. No. 5,688,825, which is incorporated herein by reference in its entirety.
BACKGROUND
Δ 9 -Tetrahydrocannabinol, the pyschoactive marijuana derived cannabinoid, binds to the CB1 receptor in the brain and to the CB2 receptor in the spleen. Compounds which stimulate the CB1 receptor have been shown to induce analgesia and sedation, to cause mood elevation, to control nausea and appetite and to lower intraocular pressure (Mechoulam, Cannabinoids as Therapeutic Agents, CRC Press, Boca Raton, Fla. (1986), Fride and Mechoulam, Eur. J. Pharmacol. 231:313 (1993), Crawley et al., Pharmacol. Biochem. Behav. 46:967 (1993) and Smith et al., J. Pharm. Exp. Therap. 270:219 (1994)). Cannabinoids have also been shown to suppress the immune system (Mechoulam, Cannabinoids as Therapeutic Agents, CRC Press, Boca Raton, Fla. (1986). Thus, compounds which stimulate the CB1 or CB2 receptor, directly or indirectly, are potentially useful in treating glaucoma, preventing tissue rejection in organ transplant patients, controlling nausea in patients undergoing chemotherapy, controlling pain and enhancing the appetite and controlling pain in individuals with AIDS Wasting Syndrome.
Arachidonyl ethanolamide (anandamide) is a naturally-occurring brain constituent that acts as a CB1 and CB2 agonist and exhibits pharmacological activity in mice comparable to cannabinoids (Fride and Mechoulam (1993), Crawley et al. (1993) and Smith et al. (1994)). Anandamide is cleaved in vivo by anandamide amidase. Thus, inhibitors of anandamide amidase have the effect of indirectly stimulating the CB1 and CB2 receptors by increasing in vivo levels of anandamide.
In addition to acting at the CB1 and CB2 receptors, cannabinoids also affect cellular membranes, thereby producing undesirable side effects such as drowsiness, impairment of monoamine oxidase function and impairment of non-receptor mediated brain function. The addictive and psychotropic properties of cannabinoids also limit their therapeutic value. Inhibitors of anandamide amidase are not expected to have the undesired membrane-related side-effects produced by cannabinoids. By providing an alternate mechanism for stimulating the CB1 and CB2 receptor, anandamide inhibitors might not have the addictive and psychotropic properties of cannabinoids. However, present inhibitors of anandamide amidase have disadvantages. For example, phenylmethylsulfonyl fluoride (PMSF) is toxic to cells. Thus, there is a need for new and more potent inhibitors of anandamide amidase which have reduced toxicity towards cells and which do not significantly interact with the CB1 or CB2 receptor at inhibitory concentrations.
SUMMARY OF THE INVENTION
It has now been found that long chain fatty acids and aromatic acid analogs of long chain fatty acids with head groups capable of irreversibly binding to a nucleophilic group at an enzyme active site are potent inhibitors of anandamide amidase. For example, palmitylsulfonyl fluoride was found to increase the level of undegraded anandamide 55-fold at 10 nM in intact neuroblastoma cells (Example 1) and is therefore more than 100 fold more potent than phenylmethylsulfonyl fluoride at inhibiting anandamide amidase. At the same time, the inhibitors disclosed herein have a low affinity for the CB1 receptor (Example 3). For example, the binding affinity of palmitylsulfonyl fluoride for the CB1 receptor is about 10 times lower than anandamide. In addition, it has been found that palmitylsulfonyl fluoride causes some of the same pharmacological effects in rats as do compounds which stimulate the CB1 receptor directly, such as Δ 9 -tetrahydrocannabinol. For example, palmitylsulfonyl fluoride is shown herein to induce analgesia in rats (Example 4). Based on these results, methods of inhibiting anandamide amidase, thereby stimulating the CB1 and CB2 receptors, in an individual or animal are disclosed. Also disclosed are novel compounds which inhibit anandamide amidase.
The present invention is a method of inhibiting anandamide amidase in an individual or animal. The method comprises administering to the individual or animal a therapeutically effective amount of a compound represented by Structural Formula I:
R--X--Y (I)
and physiologically acceptable salts thereof.
R is selected from the group consisting of a methyl group, an aryl group, a substituted aryl group, a heteroaryl group, a substituted heteroaryl group, a heterocyclic group and a substituted heterocyclic group.
X is a straight chain hydrocarbyl group or a substituted straight chain hydrocarbyl group containing from about 4 to about 18 carbon atoms if R is an aryl group, a substituted aryl group, a heteroaryl group, a substituted heteroaryl group, a heterocyclic group or a substituted heterocyclic group.
X is a hydrocarbyl group or a substituted hydrocarbyl group containing from about 10 to about 24 carbon atoms if R is a methyl group.
Y is a moiety capable of irreversibly binding with a nucleophilic group at the active site of an amidase enzyme.
The method and the novel compounds disclosed herein have therapeutic uses. For example, the compounds and methods of the present invention, like cannabinoids, can relieve the pain caused by cancer and the nausea resulting from cancer chemotherapy. They are not expected to have the undesirable membrane-related side-effects associated with cannabinoids. In addition, the methods and compounds disclosed herein are expected to be immunosuppressive and can therefore be used to prevent organ rejection in an individual undergoing an organ transplant. Because the compounds and methods of the present invention enhance the appetite of an individual, they can be used treat patients with AIDS Wasting Syndrome, who are often suffering from malnourishment as a result of appetite loss.
The novel inhibitors of anandamide amidase disclosed herein also have research uses. For example, they can be used to maintain the level of anandamide in vitro to study the effect of ananamide on cells and to maintain the level of anandamide in vivo to study the effect of anandamide on individuals and animals. They can be used to characterize cells, for example to determine if a cell type has cannabimetic or amidase activity. For example, the inhibitors can be used to determine if a cell population expresses anandamide amidase by contacting the cells with an inhibitor and then determining if there is an increase in the concentration of anandamide. The anandamide inhibitors disclosed herein can also be used as in aid in drug design, for example as a control in assays for testing other compounds for their ability to inhibit anandamide amidase and to determine the structure activity requirements of anandamide amidase inhibitors.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a graph showing the effect of palmitylsulfonyl fluoride and phenylmethylsulfonyl fluoride on anandamide levels in neuroblastoma cells (N18TG2).
FIGS. 2A-2E are graphs showing the IC 50 values for the inhibition of anandamide amidase by (A) laurylsulfonyl fluoride; (B) myristylsulfonyl fluoride; (C) palmitylsulfonyl fluoride; (D) stearylsulfonyl fluoride; and (E) arachidylsulfonyl fluoride.
FIG. 3 is a graph showing the log dose-response curves for palmitylsulfonyl fluoride (K i is 350.4), arachidonyl trifluoromethyl (K i is 1325) ketone and arachidonoyl ethanolamide (K i is 70.03) in competition with H 3 !CP-55940 binding to CB1.
FIG. 4 is a graph showing the effect in rats of anandamide, palmitylsulfonyl fluoride and anandamide co-administration of palmitylsulfonyl fluoride on the time taken for a lightly restrained mouse to flick its tail away from radiant heat stimulus ("rat flick" test), measured by the percent maximum possible effect.
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of the present invention is directed to a method of inhibiting anandamide amidase in an individual or animal. The inhibition of anandamide amidase results in increased levels of anandamide in the individual or animal, thereby causing increased stimulation of cannabinoid receptors in the individual or animal, e.g., the CB1 receptor in the brain and the CB2 receptor in the spleen. Thus, the present invention is also a method of stimulating cannabinoid receptors in an individual or animal. It is to be understood that the present invention can also be used to stimulate receptors not yet discovered for which anandamide and/or a cannabinoid acts as an agonist.
"Y" in Structural Formula I is a moiety capable of irreversibly binding with a nucleophilic group at the active site of an amidase enzyme. Thus, Y is capable of forming a stable covalent bond with the nucleophilic group at the active site of an amidase enzyme. Suitable structures for Y therefore do not encompass moieties, such as trifluoromethyl ketones, which are capable of acting as a transition state analog of an amidase enzyme and which bind reversibly to these enzymes. As used herein, an "amidase" is an enzyme involved in the hydrolysis of an amide bond.
A nucleophilic group at the active site of an amidase enzyme is a heteroatom-containing functional group on the side chain of an amino acid found at the enzyme active site and includes the hydroxyl group of serine or threonine, the thiol group of cysteine, the phenol group of tyrosine and the amino group of lysine, ornithine or arginine or the imidazole group of histidine.
Examples of suitable structures for Y include: ##STR1##
R1 is selected from the group consisting of --F and --O(C1 to C4 straight or branched chain alkyl group). R2 is a C1 to C4 straight or branched chain alkyl group.
As used herein, "a straight chain hydrocarbyl group" includes a polyalkylene, i.e., --(CH 2 ) n --. "n" is a positive integer from about 10 to about 24, when R is methyl, and from about 4 to about 18, when R is aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic or substituted heterocyclic. A straight chain hydrocarbyl group also includes two or more polyalkylene groups connected by one or more ether, thioether ether, cis-alkenyl, trans-alkenyl or alkynyl linkage such that the total number of methylene carbon atoms is from about 10 to about 24 when R is methyl and from about 4 to 18 when R is aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic or substituted heterocyclic. Examples include --(CH 2 ) m --O--(CH 2 ) o --, --(CH 2 ) m --S--(CH 2 ) o --, --(CH 2 ) m --CH═CH--(CH 2 ) o --, --(CH 2 ) m --C.tbd.C--(CH 2 ) o --, wherein m and o are each a positive integer such that the sum of m and o is equal to n. Specific examples include where X is --(CH 2 ) 4 -- (cis-CH═CHCH 2 --) 4 --CH 2 CH 2 --, --(CH 2 ) 4 --(cis-CH═CHCH 2 ) 3 --(CH 2 ) 5 -- and where R--X-- is a docosatetraenyl or a homo-γ-linolenyl moiety.
In one aspect of the present invention, R in the compound being administered to inhibit anandamide amidase is methyl and Y is a sulfonyl fluoride or a C1 to C4 straight of branched chain sulfonyl ester. Preferably, Y is a sulfonyl fluoride. Specific examples of sulfonyl fluorides and sulfonyl esters include where R--X-- is archidyl, Δ 8 , Δ 11 , Δ 14 -eicosatrienyl, docosatetraenyl, homo-γ-linolenyl and CH 3 --(CH 2 ) n --, wherein n is 10 (lauryl), 11, 12 (myristyl), 13, 14 (palmityl), 15 or 16 (stearyl).
As used herein, an "aryl" group is a carbocyclic aromatic ring system such as phenyl, 1-naphthyl or 2-naphthyl. A "heteroaryl" group is an aromatic ring system containing one or more heteroatoms such as nitrogen, oxygen or sulfur. Examples of heteroaryl groups include 2-furanyl, 3-furanyl, 2-thienyl, 3-thienyl, 2-pyridinyl, 3-pyridinyl, 4-pyridinyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 3-pyrazolyl, 4-pyrazolyl, 5-pyrazolyl, 2-pyrazinyl, 2-imidazolyl, 4-imidazolyl, 1-pyrrolyl, 2-pyrrolyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 2-thiazolyl, 4-thiazolyl and 5-thiazolyl. "Heteroaryl" groups also include fused polycyclic systems in which one or more monocylic aryl or monocyclic heteroaryl group is fused to another heteroaryl group. Examples include 2-benzothienyl, 3-benzothienyl, 2-benzofuranyl, 3-benzofuranyl, 2-indolyl, 2-quinolinyl and 3-quinolinyl.
As used herein, a "heterocyclic" group is a C5-C8 non-aromatic ring system containing one or more heteroatoms such as oxygen, nitrogen or sulfur. Examples include 2-tetrahydrofuranyl, 3-tetrahydrofuranyl, 2-tetrahyrothiophenyl, 3-tetrahyrothiophenyl, 2-morpholino, 3-morpholino, 4-morpholino, 2-thiomorpholino, 3-thiomorpholino, 4-thiomorpholino, 1-pyrrolidinyl, 2-pyrrolidinyl, 3-pyrrolidinyl, 1-piperazinyl, 2-piperazinyl, 1-piperidinyl, 2-piperidinyl, 3-piperidinyl, 4-piperidinyl and 4-thiazolidinyl.
Suitable substituents on a straight chain hydrocarbyl group include methyl, ethyl, hydroxy, hydroxymethyl, thiol, methoxy, ethoxy and hydroxy. Suitable substituents on an aryl, heteroaryl or heterocyclic group include groups such as lower alkyl, aryl, heteroaryl, (lower alkyl)--O--, (aryl or substituted aryl)--O--, halo, --CO--O(lower alkyl), --CHO, --CO--(lower alkyl), --CO--NH(lower alkyl), --CO--N(lower alkyl) 2 , --NO 2 , --CF 3 , --CN, and (lower alkyl)--S--. A lower alkyl group is a C1 to about C5 straight or branched chain alkyl group.
The present invention also refers to novel compounds which can be used to inhibit anandamide amidase. In one embodiment, the compound has a structure represented by Structural Formula (II): ##STR2## and physiologically acceptable salts thereof. R1 is --F or (C1 to C4 alkyl)O--. R and X are as defined above for Structural Formula (I).
In another embodiment, the novel compound of the present invention has a structure represented by Structural Formula (III): ##STR3## and physiologically acceptable salts thereof.
R' is selected from the group consisting of an aryl group, a substituted aryl group, a heteroaryl group, a substituted heteroaryl group, a heterocyclic group and a substituted heterocyclic group.
R2 is a C1 to C4 straight or branched chain alkyl group.
p is an integer from about 6 to about 18. In another aspect, p is an integer from about 10 to about 18.
A "therapeutically effective amount" of a compound, as used herein, is the quantity of a compound which, when administered to an individual or animal, results in a sufficiently high level of anandamide in the individual or animal to cause a discernable increase or decrease in a cellular activity affected or controlled by cannabinoid receptors. For example, anandamide can stimulate receptor-mediated signal transduction that leads to the inhibition of forskolin-stimulated adenylate cyclase (Vogel et al., J. Neurochem. 61:352 (1993). Anandamide also causes partial inhibition of N-type calcium currents via a pertussis toxin-sensitive G protein pathway, independently of cAMP metabolism (Mackie et al., Mol. Pharmacol. 47:711 (1993)).
A "therapeutically effective amount" of an anandamide inhibitor can also be an amount which results in a sufficiently high level of anandamide in an individual or animal to cause a physiological effect resulting from stimulation of cannabinoid receptors. Physiological effects which result from cannabinoid receptor stimulation include analgesia, decreased nausea resulting from chemotherapy, sedation and increased appetite. Other physiological functions include relieving intraocular pressure in glaucoma patients and suppression of the immune system. Typically, a "therapeutically effective amount" of the compound ranges from about 10 mg/day to about 1000 mg/day.
As used herein, an "individual" refers to a human. An "animal" refers to veterinary animals, such as dogs, cats, horses, and the like, and farm animals, such as cows, pigs, guinea pigs and the like.
The compounds of the present invention can be administered by a variety of known methods, including orally, rectally, or by parenteral routes (e.g., intramuscular, intravenous, subcutaneous, nasal or topical). The form in which the compounds are administered will be determined by the route of administration. Such forms include, but are not limited to capsular and tablet formulations (for oral and rectal administration), liquid formulations (for oral, intravenous, intramuscular or subcutaneous administration) and slow releasing microcarriers (for rectal, intramuscular or intravenous administration). The formulations can also contain a physiologically acceptable vehicle and optional adjuvants, flavorings, colorants and preservatives. Suitable physiologically acceptable vehicles may include saline, sterile water, Ringer's solution, and isotonic sodium chloride solutions. The specific dosage level of active ingredient will depend upon a number of factors, including, for example, biological activity of the particular preparation, age, body weight, sex and general health of the individual being treated.
General methods of preparing the sulfonyl fluorides, the N- (alkyl-sulfonyl)oxy! succinimides and the N-O-diacylhydroxylamines of the present invention are provided in Example 5, Example 6 and Example 7, respectively.
The invention will now be further and specifically described by the following examples.
EXEMPLIFICATION
Example 1--Increased 3 H!Anandamide Levels in Neuroblastoma Cells in the Presence of Palmityl Sulfonyl Fluoride
The assay of the anandamide amidase in intact neuroblastoma cells was performed as described previously (Deutsch, D. G. and S. A. Chin, Biochem. Pharmacol. 46:791-796 (1993)). The experiments were performed with 4×10 6 neuroblastoma cells (N18TG2)/6-cm dish. Experimental cells were incubated in 2 ml of media, consisting of Hams's F-12/Dulbecco's modified Eagle's medium (Life Technologies, Inc.) with penicillin, streptomycin, and gentamicin plus 10% bovine calf serum (HyClone, Logan, Utah), plus the indicated concentration of inhibitor for 20 minutes. All cells were grown at 37° in a humidified atmosphere containing 5% CO 2 in air. 3 H!Anandamide (0.2 μCi of 221 Ci/mmol of 3 H!anandamide) was added and the incubation continued for 1 hour. Control cells contained no inhibitor. At the end of the incubation, the cells were washed once with cell culture media and removed from the plates, after a brief incubation with 2 ml of 0.05% trypsin in 0.53 mM EDTA solution at 37° C. The amounts of 3 H!anandamide, 3 H!phospholipids, and 3 H!arachidonate in the cells and media were quantified by liquid scintillation counting of the silica scraped from the appropriate areas of the plate after quenching the reaction with chloroform methanol (1:1), extraction of the sample from the organic phase, and TLC analysis on channeled silica gel-coated plates, with a solvent system consisting of the organic layer of an ethyl acetate:hexane:acetic acid:water (100:50:20:100) mixture.
The level of 3 H! anandamide found in the neuroblastoma cells incubated with palmitylfsilfonyl fluoride, with phenylmethylsulfonyl fluoride and in control cells is shown in FIG. 1. Nanomolar amounts of palmitylsulfonyl fluoride were sufficient so that over 50% of the radioactivity was found in anandamide, rather than in anandamide cleavage products such as arachidonate. This result indicates that palmitylfsulfonyl fluoride is highly effective at inhibiting anandamide amidase. Concentrations greater than 10 micromolar of phenylmethylsulfonyl fluoride were required to achieve comparable levels of anandamide amidase inhibition. Almost complete degradation of 3 H!anandamide was observed in control cells.
Example 2--Determination of IC 50 Values for Sulfonyl Fluoride Inhibitors of Anandamide Amidase
The assay of the anandamide amidase in vitro was performed as described previously (Deutsch, D. G. and S. A. Chin, Biochem. Pharmacol. 46:791-796 (1993)). The indicated amount of each compound was preincubated in a buffer consisting of 300 μg of crude rat brain homogenate protein, 500 μg/ml fatty acid-free bovine serum albumin, in phosphate-buffered saline in a final volume of 1.0 ml, for 10 minutes at 37° C. Crude rat brain homogenate was obtained by decapitating female adult Sprague-Dawley rats, dissecting the desired tissue and homogenizing in five volumes of ice-cold TE (10 mN Tris-HCl, 1 mM EDTA, pH 7.6). Substrate (27.7 μM anandamide+0.2 μCi of 221 Ci/mmol 3 H!anandamide ( arachidonyl-5,6,8,9,11,12,14,15- 3 H!ethanolamide)) (obtained from the National Institute on Drug Abuse) was then added and the samples incubated for 10 minutes. The reaction was quenched by the addition of chloroform:methanol (1:1) and enzyme activity was analyzed by TLC as described in Example 1.
The results for laurylsulfonyl fluoride, myristylsulfonyl fluoride, palmitylsulfonyl fluoride, stearylsulfonyl fluoride and arachidylsulfonyl fluoride are shown in FIG. 2. All compounds were effective inhibitors of anandamide amidase. All compounds except arachidylsulfonyl fluoride had an IC 50 of less than 10 nM. Arachidylsulfonyl fluoride was an effective inhibitor of anandamide amidase at concentrations less than 100 nM.
Example 3--Palmitylsulfonyl Fluoride Binds Less Efficiently to the CB1 Receptor than Anandamide
For the CBR1 ligand binding determinations, brain membranes were prepared from frozen rat brains according to the procedure published by Devane et al. (Devane, W. A., et al., Mol. Pharmacol. 34:605-613 (1988)). Quantitation of the binding of the fatty acid analogs to CB1 was performed by incubating the analogs at the indicated concentration with 30 μg of membrane protein in a buffer containing 500 pm of the bicyclic cannabinoid analog 3 H!CP-55940, 20 mM Tris-Cl, pH 7.4, 3 mM MgCl 2 , 1 mM Tris-EDTA, and 0.135 mg/ml fatty acid-deficient bovine serum albumin in a final volume of 200 μl in Regisil-treated glass tubes. Specific binding was defined as that which could be displayed by 100 nM desacetyllevonantradol. After 60 minutes at 30° C., the incubation was terminated by the addition of 250 μl of 50 mg/ml bovine serum albumin and the immediate filtration over GF/B filters and washing with ice cold buffer (20 mM Tris-Cl, pH 7.4, 2 mM MgCl 2 ). The filters were treated with 0.1% sodium dodecyl sulfate prior to addition of scintillation mixture and counting in a liquid scintillation counter.
The log dose-response curve for palmitylsulfonyl fluoride, arachidonoyl trifluoromethyl ketone and arachidonoyl ethanolamide in competition with 3 H!CP-55940 binding CB1 is shown in FIG. 3. This figure shows that palmitylsulfonyl fluoride binds to the CB1 receptor with less than 10% the efficiency of arachidonoyl ethanolamide.
Example 4--Palmitylsulfonyl Fluoride Induces Analgesia in Rats
Drug mixture were prepared by mixing with two parts Tween 80 by weight and dispersing into 0.9% w/v aqueous NaCl solution (saline) as described previously for Δ 9 -THC (Pertwee et al., Br. J. Pharmacol. 105:980 (1992)).
Drug mixtures were injected intravenously into male MF1 mice weighing 23-29 grams. Analgesia was measured by means of a "rat flick test" in which the time taken for a lightly restrained mouse to flick it tail away from a radiant heat stimulus was noted. The methods is based on the test described by D'Amour and Smith (D'Amour, F. E., Smith, D. L., J. Pharmacol. Exp. Ther., 72:74-79 (1941)). Mice were subjected to the tail flick at -30 minutes (control latency) and at 12 minutes (test latency). The maximum possible tail flick latency was 10s as mice that did not respond within this time were removed from the apparatus to prevent tissue damage. Analgesia was calculated as percent maximum possible effect by expressing the ratio (test latency-control latency)/(10-s control latency) as a percentage (Compton, D. R., et al., J. Pharmacol. Exp. Ther., 260:201-209 (1992)). Ambient temperature was kept between 20° and 22° C. Values have been expressed as means and limits of error as standard errors. Dunnett's test has been used to calculate the significance of differences between the mean effect of each drug treatment and the mean effect of the vehicle, Tween 80.
The results are shown in FIG. 4. Palmitylsulfonyl fluoride and anandamide co-administered with palmitylsulfonyl fluoride were about 3× more effective at producing analgesia in the mice than anandamide alone and about 13× more effective than the vehicle.
Example 5--Alkylsulfonyl Fluorides
Alkylmagnesium bromide in dry ether was added to a stirred solution of sulfuryl chloride (2-fold excess) in hexane at 0° C. The reaction mixture was stirred for 1 hour at 0° C. and then the ice bath was removed and stirring was continued overnight at room temperature. The solvent was evaporated in vacuo and the product was purified with column chromatography on silica gel to afford the corresponding alkylsulfonyl chloride as white solid.
Alkylsulfonyl chloride was dissolved in acetone and a 10-fold excess of ammonium fluoride was added while stirring at room temperature. The reaction mixture was refluxed for 3 hours. Then it was filtered to remove the insoluble salt, the solvent was evaporated and the product was dried in vacuo. Water was added to hydrolyze any unreacted alkylsulfonyl chloride and the aqueous mixture was extracted with ether. The ethereal extracts were combined, dried, filtered and the solvent was removed in vacuo. The product was purified with column chromatography on silica gel to afford the corresponding alkylsulfonyl fluoride.
Example 6--Alkyl-N- alkyl-sulfonyl)oxy! Succinimides
Stobbe condensation of aldehydes with diethylsuccinate affords the corresponding alkenylsuccinic acid monoethyl esters which are catalytically hydrogenated and subsequently hydrolyzed to give the corresponding alkylsuccinic acids. The acids are mixed with excess of acetic anhydride and refluxed for 1 hour. The excess of acetic anhydride is removed in vacuo. Vacuum distillation affords the pure alkylsuccinic anhydrides.
The pure products are dissolved in dry toluene and brought to reflux. An equimolar amount of (benzyloxy)amine in toluene is added and the mixtures are refluxed for 30 minutes. The hot solutions are filtered through anhydrous sodium sulfate and the solvent is removed on a rotary evaporator. The residues are dissolved in ethyl acetate and washed with 10% sodium bicarbonate twice and then purified with column chromatography on silica gel.
The resulting 3-alkenyl-N-(benzyloxy)succinimides are hydrogenolyzed with 10% Pd--C for 3 hours. The reaction mixtures are then filtered through a Celite pad and the solvent removed in vacuo. The produced 3-alkyl-N-hydroxysuccinimides are then dissolved in dry toluene and treated with dry pyridine and various alkylsulfonyl chlorides. The reactions are stirred overnight at room temperature under nitrogen and then quenched with the addition of 2N HCl. The products are extracted with ethyl acetate (twice), dried over anhydrous MgSO 4 and purified with column chromatography.
Example 7--N--O-diacylhydroxylamines
Methyl esters of various carboxylic acids are treated with excess of hydroxylamine in methanol. Equimolar amounts of KOH and various acid chlorides dissolved in THF are added to aqueous solutions of the hydroxamic acids at 0°-5° C. in order to afford the corresponding N,O-diacylhydroxylamines.
EQUIVALENTS
Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to specific embodiments of the invention described specifically herein. Such equivalents are intended to be encompassed in the scope of the following claims.
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Disclosed is a method of inhibiting anandamide amidase in an individual or animal and novel inhibitors of anandamide amidase. The disclosed method and novel compounds can be used to reduce pain in an individual or animal suffering from pain, reducing nausea in an individual undergoing chemotherapy, for example cancer chemotherapy, suppressing appetite in an individual, reducing intraocular pressure in the eye of an individual or animal suffering from glaucoma and suppressing the immune system in an individual with an organ transplant.
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This is a continuation of application Ser. No. 166,237, filed July 26, 1971, now abandoned; which is a continuation of application Ser. No. 846,830, filed Aug. 1, 1969, and now abandoned.
BACKGROUND OF THE INVENTION
This invention relates broadly to means for securing facing panels to a building. In particular, it relates to the mechanical fastening of hollow core panels to a building structure, with the fastening means being hidden from view.
Hollow core panels are finding increasing use as architectural panels. Often formed of cast concrete or extruded cement, their exposed faces can be textured to resemble bulky stone panels or provided with ribs or other types of surface treatment to give a highly pleasing architectural effect. The benefit of the hollow construction is that it enables the panels to have a desirable bulky appearance and adequate strength without being too heavy to be readily handled and installed.
The main problem to be overcome with such a panel is the difficulty of securely and rapidly attaching it to a building wall so that no fasteners are visible. Since the time required for installation is a major item in the cost of a structure, it is highly important that workmen be able to simply and easily install the panels.
OBJECTS OF THE INVENTION
The main object of the invention is to provide a simple panel securing arrangement which securely holds a hollow panel to a structural wall and which permits rapid installation.
SUMMARY OF THE INVENTION
The foregoing object is met by the fastening arrangement of this invention which comprises a clip that has a cup portion inserted in the cavity of a hollow core panel adjacent the horizontal edge of the panel, and an arm extending from the cup portion which is attached to the structural wall. The cup portion of the clip is formed by two oppositely facing side walls which engage the interior panel wall surfaces forming the cavity, and a bottom wall connecting the ends of the side walls remote from the horizontal edge of the panel. The side walls of the cup portion, at least adjacent the horizontal edge of the panel, are biased toward and into engagement with the interior wall surfaces to hold the panel securely in place.
DESCRIPTION OF DRAWINGS
The nature of the invention will be more fully understood and other objects may become apparent when the following detailed description is considered in connection with the accompanying drawing, wherein:
FIG. 1 is a pictorial representation of a fastening clip of the invention and a partial pictorial representation of an illustrative panel with which the clip can be used;
FIG. 2 is a sectional view of the clip of FIG. 1 shown as having aligned holes for receiving a fastener;
FIG. 3 is a partial cross-sectional view of a panel held in place by a clip;
FIG. 4 is a sectional view of a modified clip; and
FIG. 5 is a view similar to that of FIG. 3, but showing a further modified arrangement.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a clip 10 is shown adjacent a hollow core panel 12 having faces 14 and 16 connected by webs 18. The panel is illustrated as an extruded cementitious panel, although obviously the panel can take other specific shapes and be formed by other methods. The clip 10 is for the purpose of engaging the hollow core portion of the panel, without being visible in the final installation, and securing it to the face of a structural wall.
As shown in FIG. 2, the clip is comprised of an integral strip bent across its width at several locations to form a cup-like configuration 20 and an upper lateral extension 22. Forming the cup-like configuration are side walls 24 and 26 connected at their lower extremities by bottom wall 28. Extending laterally from the upper extremity of side wall 24 is arm 30, and overlying arm 30 is arm 32 which extends laterally from the upper extremity of the far side wall 26, both of which arms together form the extension 22. The side walls 24 and 26 converge slightly toward the bottom wall 28 to permit the cup portion to be readily inserted into the cavity of a hollow core panel. If desired, apertures may be formed in the arms forming the extension 22 for receiving a bolt or other fastener. The dotted lines at 34 in arm 32 indicate a slot and the dotted lines at 36 indicate a circular aperture. When apertures are provided the slot is necessary for alignment purposes because the arms slide relative to each other when the cup portion of the clip is inserted into a hollow panel the inside thickness of which is slightly less than the width of the upper extremity of the cup portion 20. The arm 30 in such case moves toward the left and the arm 32 moves toward the right, when viewed as in FIG. 2.
FIG. 3 shows the clip 10 attached to a structural wall 38 by bolt 40 and holding the panel 12 in place against the wall. The cup portion of the clip is fitted in the hollow core of the panel, the inside width of which is slightly less than the width of the upper or widest part of the cup portion, resulting in a force fit. This tapered clip construction simplifies the insertion of the clip into the hollow core of the panel, the narrower leading edge of the cup portion guiding the movement of the clip, and provides a secure connection between the panel and the structural wall. The force fit does not permit relative sideward movement between the panel and the installed clip.
A modified clip 42, shown in FIG. 4, has an arm 44 and a cup portion 46 but does not have an arm corresponding to arm 32 of clip 10. With this arrangement the clip performs the same function as clip 10 but is less costly due to the absence of a second lateral arm. This would not be used where maximum holding power is required because the construction is not as sturdy as the clip 10. As illustrated, arm 44 does not have an aperture for receiving a fastener. In such case a rivet or other propelled fastener would be used to pierce both the clip arm and the structural wall. It should be understood that a solid arm or lateral extension can also be provided with the embodiment of clip 10.
Another embodiment is shown in FIG. 5 wherein the panel 48 extends above the structural wall 50. The clip 52 is similar to the clip 42 of FIG. 4, but the arm 54 of the clip is comprised of three sections. Section 56 extends from the cup portion in the usual manner and is connected to the parallel, displaced section 58 by section 60 which extends from the far extremity of section 56 to the near extremity of section 58 at generally right angles to both.
The clip can be formed of any suitable strong material which permits the tapered wall construction of the cup section to be forced inwardly to assume a parallel wall construction and thus exert an outward biasing force tending to move the walls back to their original tapered or converging position. An example is an 18 gauge steel strip bent at suitable locations to form the configurations shown in the drawing. It should be understood that the clip can be inserted either at the top or bottom of the hollow panel, whichever is most convenient, depending upon the construction of the structural wall.
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A portion of a clip fits into the cavity of a hollow core panel and another portion is attached to a structural wall. The portion inside the cavity has normally tapered opposed walls which are straightened, upon insertion into the cavity, to form parallel walls engaging the interior panel surfaces forming the cavity, thus providing a secure fit.
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BACKGROUND
1. Field of the Invention
The present invention relates generally to the manufacture of melt-spun polymeric filaments. More particularly, it relates to the manufacture of polyester filaments by a process involving the use of an improved spinnerette. The improved spinnerette has groups of orifices with specifically defined unequal dimensions from group to group, rather than similar dimensions. It also relates to the improved filamentary product thereby obtained, particularly at high extrusion rates of molten polymer through the pack containing the spinnerette.
2. Prior Art
The manufacture of melt-spun polymeric filaments is extremely old in the art. Typically, a molten polymer (such as polyester, polyamide and polyolefin) is extruded downwardly through a plurality of orifices in the spinnerette to form molten filaments. The extruded filaments are simultaneously cooled in a quench zone and stretched (by yarn haul-off means such as a yarn winder) into finer filaments having at least some molecular orientation (expressed as birefringence, Δn).
High variability of molecular orientation of the melt-spun filaments is also well-known to affect deleteriously downstream processes and/or the properties of downstream products made therefrom, such as drawn yarns. It is also well known that high productivity processes (e.g., involving the extrusion of several hundred pounds of molten polymer each hour through a single spinnerette) tend to result in the production of filaments having higher birefringence variability than filaments made at lower extrusion rates. There is thus a problem in maintaining the quality of the melt-spun yarn when production rates are increased. U.S. Pat. No. 4,332,764 (Brayford and Cardell) discloses one method of reducing birefringence variability in polyester filaments melt-spun at several hundred pounds per hour.
All prior art relating to the melt-spinning of polyester polymer into filaments has apparently involved the use of spinnerettes in which the corresponding dimensions of the individual orifices within the spinnerette have been essentially equal within machinable tolerance limits. This is perhaps not surprising since (i) high birefringence variability is often associated with high denier variability; and (ii) variations between orifices causes denier variability.
Two major classes of prior art relative to the invention claimed hereinafter are discussed below. The first class of prior art relates primarily to theories and mathematical models that have been advanced. The second class of prior art relates primarily to concrete experimental data from the patent literature.
Within the first class of prior art, many attempts have been made to understand the science of melt-spinning polyester polymer. One recent comprehensive publication in the subject area is "Model of Steady-State Melt Spinning at Intermediate Take-Up Speeds" by Dr. H. H. George, published in April 1982 by "Polymer Engineering and Science". Dr. George also gave an oral presentation in Hawaii in 1979 on a related topic. Another publication of interest is "Fundamentals of Fibre Formation" by Andrzej Ziabicki, published by John Wiley & Sons in 1976. Pages 149-248 relate to melt-spinning. An older publication of interest is "Studies on Melt-Spinning. II. Steady State and Transient Solutions of Fundamental Equations Compared with Experimental Results" by Susumu Kase and Tatsuki Matsuo, found in the "Journal of Applied Polymer Science", Volume 11 at pages 251-287 (1967). While all the foregoing publications are valuable contributions to developing a qualitative understanding of the science of melt-spinning polyester polymer, it is believed not unfair to state they still fall far short of enabling a research worker to predict how to further reduce birefringence variability in high productivity processes such as that disclosed in the Brayford and Cardell patent. This is so for reasons including the following. Firstly, all the models are based upon a large number of simplifying assumptions. Secondly, a very large number of interdependent variables are involved in the various mathematical formulae and, as a result, the models tend to have value in predicting qualitative trends under single filament steady state conditions, rather than quantitative trends under multifilament transient conditions. Nonetheless, at least two aspects of the theories developed in the foregoing publications are at least of interest to the instant invention. In particular, firstly, it is well known that increasing the diameter of a circular orifice in a melt-spinning process involving the extrusion of a single filament, without introducing any other changes to independent variables, thereby decreases the extrusion velocity of the filament from the spinnerette; reduces the pressure drop across the orifice; reduces the extrusion temperature; has no effect on take-up speed or take-up denier; increases the final tension of the filament at take-up; and increases the final birefringence of the filament. Secondly, some models suggest that there is a correlation at each and every point in the spinning threadline between the birefringence and the stress at the same point, expressed in grams per denier. Further, George suggests that the foregoing correlation is, in fact, unique. In which case, George's equations lend themselves to predicting what compensatory changes might be made in a pair of groups of filaments when the first group of filaments is subjected to different quench conditions from the second group of filaments. Nevertheless, the fact remains, that the prior art does not show any extrusion of molten polyester polymer through a spinnerette having orifices of differing dimensions within the single spinnerette. Further, the equations of the published prior art cannot be used to accurately predict the actual changes in filament denier that occur as a result of so-doing. Even less, therefore, can they be used to predict the resultant compensatory effects in birefringence. In addition, the prior art teaches that high transverse air quench rates across a single filament result in the filament having asymmetric birefringence across the filament in the direction of quench gas flow. There is, inevitably, a tendency for asymmetric birefringence to occur at the very high cross flow quench rates required when spinning molten polyester at very high throughputs. Accordingly, the foregoing models are, at best, believed to be a guide post concerning the nature of experiments that might perhaps be performed in order to reduce the birefringence variability of polyester melt-spun filaments.
Within the second class of prior art defined above, several patents discussed below are, at least, of interest to the present invention.
Firstly, U.S. Pat. No. 4,248,581 (Harrison) also addresses the problem of obtaining filaments with uniform physical properties in high throughput, high filament density melt-spinning processes. The patent points out that the prior art recognizes that uniform, turbulence-free quenching of filaments is an important factor in the production of filaments having uniform physical properties, a prerequisite to acceptable performance of fibers in subsequent processes. It also points out that this is difficult to achieve in the cross-flow quench system, typically linked to a high throughput and high filament density melt-spinning process, as the traverse path of the quenching fluid causes it to contact first one side of the filament bundle and then pass therethrough. Those filaments most remote (downstream) from the entry of the quench fluid are cooled or solidified by a quench flow which has been pre-heated, made more turbulent and substantially diminished (via a downward moving boundary layer) by the obstruction presented by filaments closer to and previously contacted by the quench fluid. As a consequence, the cooling rate of the filaments is progressively slower as quench fluid passes through the filament bundle. The patent further points out that the ideal solution to quench irregularity would be to increase the spacing of spinnerette orifices, resulting in increased distance between filaments for quenching. However, there are practical restraints to the increase in orifice spacing in a spinnerette of given diameter and orifice count. The patent then points out that the prior art has attempted to solve quench irregularity by rearranging the positions of the spinnerette orifices within the spinnerette plate. For example, it discusses the use of "V" patterns, concentric circles, crescent formations, rectangular grids, and irregular arrangements whereby the spinnerette orifices are staggered so that each one is located in the quench flow path without obstruction. It also discusses the use of spinnerette orifices arranged in parallel rows, such that the orifices in a given row are equally spaced and the distance between adjacent rows is less than the distance between the orifices in each row. The invention disclosed in the '581 patent also relates to a spinnerette in which the orifices are arranged in a specific configuration. Nowhere does the patent remotely suggest the possibility of varying the dimensions from orifice to orifice within the spinnerette in order to improve the uniformity of the final product.
Secondly, U.S. Pat. No. 4,104,015 (Meyer) also addresses the problem of filament non-uniformity. In particular, the patent points out (at column 1, beginning at line 23) that one of the most significant factors contributing to filament non-uniformity during the melt-spinning process is the fact that the temperature of the molten polymer passing through the orifices positioned near the center of the spinnerette is higher as compared to the temperature of the molten polymer passing through the orifices positioned near the edge of the spinnerette. The higher the temperature of the polymer, the lower the viscosity; and the lower the viscosity the faster the polymer under a given pressure passes through an orifice of the spinnerette. Therefore, because of the temperature differential across the face of the spinnerette, the flow rate of the molten polymer through the orifices of the spinnerette varies, and this results in filament (denier) non-uniformity. Although attempts have been made to reduce the temperature differential across the face of the spinnerette and thus improve the uniformity of the filaments, non-uniformity is still a problem. The invention of the '015 patent essentially amounts to the use of an improved bridge plate in which the position of the orifices are adjusted to adjust the pressure above each spinnerette orifice. Thereby the temperature non-uniformity is compensated. It should also be noted that Applicants' assignee commercially used in secret in the 1960's a process involving a somewhat different solution. In particular, in the spinning of nylon 6,6 polymer, observed temperature differentials across the face of the spinnerette were in part compensated for by enlarging the orifices in the cooler portion of the spinnerette. The inventors of the instant invention were unaware of that old work at the time that they conceived their invention and initially reduced it to practice. Further, it should be noted that the work on nylon 6,6 involved enlarging the orifices remote from the quench source (in contrast to the instant invention that is described hereinafter). Further, it should be noted that the work on nylon 6,6 involved the production of continuous filament yarn from relatively small packs at relatively low polymer throughputs per square inch of spinnerette face (in contrast to the invention described hereinafter in which high polymer throughputs per square inch of spinnerette face are used).
Thirdly, U.S. Pat. No. 2,766,479 (Henning) is of interest in that FIG. 3 discloses a plate having orifices of different size therein. The patent relates to the extrusion of cellular plastics upon filamentary conductors. It is pointed out that in order to prevent premature gas expansion within the confines of the extruder, it is important that the temperatures within the extruder and the dye should be accurately regulated, and that the rate of extrusion and the linear speed of the conductive core be adjusted suitably. This may be accomplished by creating a back pressure within the extruder to prevent premature expansion of the gas therein. The plate shown in Henning's FIG. 3 merely relates to such a plate that creates back pressure against the extruder screw and is positioned upstream of the extrusion dye.
Fourthly, U.S. Pat. No. 3,628,930 (Harris) also discloses a baffle plate upstream of the spinnerette, apparently in order to control melt pressure above the spinnerette orifices, which spinnerette orifices appear to be of uniform size.
Fifthly, U.S. Pat. No. 2,030,972 (Dreyfus) discloses in FIG. 2 a spinnerette which at first sight might appear to have larger orifices 16 in the outer ring than orifices 17 in the inner ring. The text of the patent, however, does not confirm this. Indeed, it is pointed out "the size of the orifices is much exaggerated" (page 2, column 2, lines 5-6).
Sixthly, U.S. Pat. No. 3,457,342 (Parr et al) discloses a plate upstream of a spinnerette in which the orifices 15 are smaller in size than the orifices 14 (see FIGS. 2 and 3, in particular). However, the extrusion orifices 3 all appear to have similar dimensions.
Seventhly, U.S. Pat. No. 3,375,548 (Kido et al) discloses in FIG. 1 a pack for producing conjugated filaments in which the spinning orifices 14 are fed with polymer from two other upstream orifices 21 and 22, which orifices 21 and 22 apparently may differ in size. However, there appears to be no suggestion that spinnerette orifices 14 should have different dimensions from each other.
Eighthly, several U.S. patents originally thought to be of interest are believed to be less pertinent than the aforementioned prior art. They are U.S. Pat. Nos. 4,123,208 (Klaver et al); 3,867,082 (Lambertus et al); and 3,311,688 (Schuller).
Ninthly, some patents relate to filamentary products deliberately made with mixed filament deniers. For example, U.S. Pat. No. 3,965,664 (Goetti et al) relates to a spun yarn made from a mix of staple fibers, in which the mix is formed from staple fibers of at least three different titers. The patent further teaches generally that the synthetic plastic fibers may, for instance, be of the type extruded from orifices of different size or different cross-section (at column 3, lines 17-19). There is, however, no specific exemplification thereof. Even less is there any recognition of criticality concerning the location of the larger orifices relative to the location of the smaller orifices.
Tenthly, Russian Pat. No. 419,485 is understood to disclose that the packing density of glass fibers is increased by having a mix of widely different deniers; and that such a product can be made by using a spinnerette having a mixture of orifice sizes. However, glass is not a polymeric orientatable material.
In sum, nowhere does the prior art disclose or suggest the invention claimed hereinafter.
SUMMARY OF THE INVENTION
In contrast to the forementioned prior art, it has now been surprisingly discovered that spinnerettes having so-called "graduated orifice sizes" (GOS) have in fact significant utility in manufacturing melt-spun filaments with good birefringence uniformity at high polymer extrusion rates. The invention involves extruding polymer at an average mass-flow rate through a first group of orifices (defined by specific location in the spinnerette), that is more than the average mass-flow rate of polymer through a second group of orifices (also defined by specific location in the spinnerette).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevation view of prior art apparatus and process for melt-spinning polyester filaments with reduced birefringence variability (as shown in U.S. Pat. No. 4,332,764).
FIGS. 2A and 2B are, respectively, a front elevation view in cross-section, and a plan view, of a prior art melt-spinning pack (as shown in U.S. application Ser. No. 06/281,739, filed July 9, 1981, and now U.S. Pat. No. 4,405,548.
FIGS. 3 and 4 are charts derived from prior art and depict how the properties of a single melt-spun polyester filament (filament dpf and filament birefringence) depend upon the values of parameters in melt-spinning processes.
FIG. 5 is a theoretical chart showing how, under certain assumptions, the variability of spun yarn birefringence of filaments melt-spun from a practical nine row spinnerette of the invention (proposed in Table 1) might be lower than that from a prior art spinnerette.
FIG. 6A is a plan view of a spinnerette of the prior art.
FIG. 6B is an elevation view in Section 6B6B of FIG. 6A.
FIG. 6C is an enlargement of Zone Z of FIG. 6A, wherein all orifices of the spinnerette have the same diameter.
FIG. 6D is an enlarged front elevation view in cross-section of a single spinnerette orifice of length, L, and diameter, D.
FIG. 7A is a graph showing the combined values of filament birefringence variability and filament dpf, and contrasting the prior art to the invention.
FIG. 7B is a graph showing the combined values of filament elongation variability and filament dpf, and contrasting the prior art to the invention.
FIG. 8A is a graph showing the dependence of filament birefringence variability upon quench flow rate, for both the prior art and the invention.
FIG. 8B is a graph showing the dependence of filament elongation variability upon quench flow rate, for both the prior art and the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the invention are best understood if, in addition to examples of the invention, a discussion is included as to how the invention was made and comparative examples are included.
The invention arose out of an attempt to (1) better understand the science of melt-spinning poly(ethylene terephthalate) polymer through a large number of closely spaced spinnerette orifices (a typical prerequisite for high productivity processes); and (2) use these findings to further improve quality and/or productivity of such processes, including processes of the type shown semi-schematically in FIG. 1.
For example, an attempt was made to understand why the typical birefringence variability of yarn melt-spun from a spinnerette having 2,250 orifices arranged in nine circular rows was significantly higher than the corresponding birefringence variability of yarn melt-spun from a spinnerette having 1,904 orifices arranged in seven circular rows. Thermocouple measurements of quench air during the melt-spinning showed that the temperature of the air rose significantly as it passed through the filaments. For example, with the nine row spinnerette, the air temperature close to the spinnerette typically rose from 32° C. to 120° C. in travelling a distance of less than 1 inch as it passed radially outwards between the filaments. Computer modeling of the inside and outside rows of filaments was performed using the model developed by Dr. George discussed above. That analysis revealed that changes in the quench air temperature and velocity could result in a considerable birefringence bias across the bundle. At the same time, however, the computer (steady state) model predicted a theoretical birefringence variability that was, in fact, significantly lower than the observed birefringence variability (which reflects transient and steady state conditions). According to the computer model (so-called Spin 1 model) the average birefringence would vary from 5.79×10 -3 for the inside row of filaments to 4.77×10 -3 for the outside row of filaments in a specific melt-spinning process involving the extrusion of 170 lbs. of polymer per hour through a 2,250 orifice spinnerette and collecting the yarn at 3,000 feet/minute. The question was then posed as to whether this bias of birefringence could be corrected or compensated by introducing a countervailing birefringence effect at the spinnerette. It was concluded that theoretically such a counter bias might be obtained by varying either the spinnerette (polymer) temperature from inside to outside the pack, or the orifice dimensions from inside to outside the pack.
Firstly, it was noted that that the through-pack quench design as shown in FIG. 1 afforded the opportunity to place a heater inside the pack and create a radial temperature gradient. Computer modeling using the Spin 1 program suggested that it would make sense, at least theoretically, to attempt to increase the temperature of the polymer melt-spun through the inner ring of orifices by 9° C. relative to the temperature of the polymer melt-spun through the outermost ring of orifices. However, practically, it was then appreciated that the heating effect would probably not penetrate far enough into the flowing polymer to affect more than the inside one or two rows of filaments. Also, it would be difficult to control the temperature profile from pack position to pack position, and with time for any given pack position. In effect, in order to achieve the desired temperature profile, it would be necessary to redesign the whole polymer delivery system and include a number of separately controllable heating units.
Attention was therefore turned to the secondly proposed possible approach of varying the orifice dimensions across the spinnerette, notwithstanding the inherent inflexibility built into such a technique. It was concluded that the simplest way of performing an experiment would be to enlarge some orifices of a pre-existing spinnerette having 2,250 orifice capillaries of length 0.012 inch and diameter 0.009 inch. Inevitably, such enlargement of diameter also resulted in marginal increase of capillary length because of the pre-existing counterbore (see FIG. 6D). However, this was a secondary effect. The first step was then to determine spun dpf as a function of orifice dimensions. FIG. 3 shows a graph of calculated spun dpf for circular capillary orifices having different diameters (D inches) and different lengths (L inches), for poly(ethylene terephthalate) polymer having an intrinsic viscosity of 0.62 deciliters/gram, melt-spun at a temperature of 295° C. and a pressure drop of 386 psi across the orifice capillary, quenched in radial outflow manner by air fed at a temperature of 32° C. and at a rate of 350 SCFM, and wound up at a speed of 3,000 feet/minute. From the foregoing dpf values and the Spin 1 program, the corresponding values of birefringence were calculated as shown in FIG. 4. From FIG. 4 it was concluded that the diameter of the orifices of the inside row should be enlarged to 0.010 inches in order to reduce the birefringence from 5.79 to 4.77. Note also that the projected dpf simultaneously increased from 5.6 to 8.8. At that point in time it was not known what to do with the intermediate rows between the innermost and outermost rows, since it was not known how the quench variation affected the birefringence profile. Accordingly, it was assumed (as a first approximation) that the birefringence varied linearly between the innermost row (row 1) and the outermost row (row 9), as shown in Table 1 below.
TABLE 1__________________________________________________________________________PROFILES OF BIREFRINGENCE AND ORIFICE DIAMETERROW NO. 1 2 3 4 5 6 7 8 9__________________________________________________________________________Assumed Prior 5.79 5.66 5.54 5.41 5.28 5.15 5.02 4.90 4.77Art Δn × 10.sup.3Ideal Dia. of .0100 .0098 .0097 .0096 .0094 .0093 .0092 .0091 .0090Orifices (in.)Practical Dia. .0100 .0100 .0100 .0095 .0095 .0095 .0090 .0090 .0090of Orifices(in.)Corrected 4.77 4.64 4.52 4.93 4.80 4.67 5.02 4.90 4.77Δn × 10.sup.3__________________________________________________________________________
From FIG. 4, the "ideal orifice size" was then determined for each of the intermediate rows 2 thru 8, which would reduce the birefringence of the filaments of each row to 4.77×10 -3 . It was further recognized that it is not feasible to have a different diameter for the orifices of each row of orifices, on account of practical tolerance limitations. Accordingly, the Table 1 above also includes "practical orifice size" profile, which consists of three different orifice sizes across the spinnerette. Also shown in the table is the theoretical corrected birefringence profile when the practical orifice size distribution is used. Both the uncorrected and corrected birefringence profiles are shown in FIG. 5. Accordingly, theoretically, the birefringence CV could be reduced from 6.4 percent to 3.2 percent (assuming no short term variability along the threadline due to transient conditions).
Thereafter, a 2,250 orifice spinnerette was modified according to the "practical orifice size" profile as shown in Table 1 above. A first trial was then performed with a graduated orifice size (GOS) spinnerette in which the inside three rows of orifices had a diameter enlarged to 0.010 inches, the middle three rows enlarged to 0.0095 inches, and the outside three rows remained at 0.009 inches. Use of the spinnerette resulted in spun yarn with very good birefringence uniformity and very good elongation uniformity. In general, there is a reasonable correlation between birefringence variability and elongation variability. In particular, the birefringence CV's were in the 4-5% range for yarn collected at 3,000 feet/minute. As expected, the different orifice sizes resulted in a higher dpf variability.
In a second trial, the GOS spinnerette was compared to a standard 2250 orifice spinnerette. Hot weather and inadequate quench air cooling caused the spun yarn variability to be higher than expected. However, the GOS spinnerette produced spun yarn with lower birefringence CV and lower elongation CV than the standard spinnerette used under corresponding conditions. An improved quench air cooling system was then installed to ensure adequate control of the quench inlet temperature. Because of the problems encountered in quench temperature control, it was not then clear whether the GOS spun yarn had the same birefringence level as melt-spun yarn made with a standard spinnerette. It was important, however, that this should be determined because it would have a profound effect on the ease with which this technique could be implemented in a pre-existing production plant. Clearly, the GOS product would be mergeable with the standard product only if its birefringence were the same as that of the standard product.
During the course of the foregoing trials, experiments were performed to determine the birefringence variability of yarn melt-spun under a wide range of process conditions. In particular, the effect of the following variables was determined: yarn collection speed over the range 3,000 feet/minute to 7,000 feet/minute; air quench flow rate over the range 175 SCFM to 350 SCFM; closest position of the quench unit source to the spinnerette (quench spacing) over the range 1 inch to 3 inches; and different methods of applying the spin finish with the melt-spun filaments. Essentially, the only problem found with the GOS spinnerette was that it overcompensated for the pre-existing birefringence bias at speeds around 7,000 feet/minute. Accordingly, the specific spinnerette used in the trials appeared to have significant utility only in the speed range from, say, 1,500 feet/minute to 5,000 feet/minute. As a result of the work already done, however, it is believed that there would be no problem in designing the spinnerette that would be effective over the speed range of from 5,000 feet/minute to 10,000 feet/minute. At speeds in excess of 10,000 feet/minute, however, when the melt-spun yarn tends to be crystalline in addition to being partially oriented, somewhat different computer models are required because of the formation of crystallites. It would be expected, however, that GOS spinnerettes might also have utility under those conditions.
Comparative examples and examples of the invention are given below.
EXAMPLES 1-31 AND COMPARATIVE EXAMPLES C13-C31
In all the Examples 1-31 and in all the corresponding Comparative Examples C13-C31, the following processing conditions were used. Melt-spun polyester filaments were made essentially according to the process shown semi-schematically in elevation in FIG. 1 (which is also FIG. 1 of U.S. Pat. No. 4,332,764). The processes used an annular melt-spinning pack similar in principle to that shown in FIGS. 2A and 2B (and which correspond to FIGS. 1 and 2 respectively of U.S. Pat. No. 3,307,216). The polymer was extruded through spinnerettes that conformed to FIGS. 6A-6C. Each spinnerette had 2,250 orifices arranged in nine circular concentric staggered rows. The average spacing between orifices was 0.075 inches.
The sole intended difference between the processing conditions between, say, Example 25 and the corresponding Comparative Example C25, related to the orifice dimensions shown in FIG. 6D (note, however, the dpf spread in Examples 13-16). In particular, in all the Comparative Examples, all of the orifices had capillary diameter ("D" of FIG. 6D) of 0.009±0.0001 inches. In contrast, in all the Examples 1-31, the innermost three rows of orifices had orifices all of which had been enlarged to a capillary diameter D of 0.010±0.0001 inches. Consequently, because of the pre-existing counterbore of 60° immediately upstream of the capillary, the length of the capillary, L, was also increased by about 0.0005×√3 inches to 0.0129±0.001 inches. Likewise, the middle three rows of orifices in Examples 1-31 had orifices enlarged to a capillary diameter, D, of 0.0095±0.0001 inches, and capillary length, L, of 0.012±0.001 inches.
Tables 2A, 2B and 2C below summarize the processing conditions used in the melt-spinning of poly(ethylene terephthalate) polymer having an intrinsic viscosity of about 0.62 deciliters/gram. Further, the quench stick (30 of FIG. 1) had an effective length of 12 inches. And the flow profile of air emerging horizontally and radially from the quench stick was approximately flat in the top six inches decreasingly approximately linearly by two thirds between the midpoint of the stick and the bottom of the stick. It should also be noted that in Examples 10-12, the turning guide 17 of FIG. 1 was freely rotatable by the yarn 15. Whereas in Examples 1-9 and 13-31 turning guide 17 was fixed.
Tables 2A, 2B and 2C also summarize the properties of the melt-spun poly(ethylene terephthalate) yarn obtained.
Some of the product property data shown in Tables 2B and 2C is plotted in graphical form in some of the Figures. In particular, FIGS. 7A and 7B both relate to Examples 13-16 and Comparative Examples C13-C16. FIGS. 8A and 8B both relate to Examples 17-20 and Comparative Examples C17-C20.
Essentially, clearly, use of the process invention claimed hereinafter has resulted in the production of a yarn of melt-spun filaments in which, as compared with the Comparative Examples, the elongation variability and the birefringence variability are both greatly reduced and the denier variability is greatly increased.
TABLE 2A__________________________________________________________________________SPINNING CONDITIONS AND FIBER PROPERTIES (TRIAL 1) BIRE-EXAMPLE WINDUP SPUN DPF FRINGENCE ELONGATIONNO. SPEED (FPM) MEAN ST. DEV. MEAN CV MEAN % CV__________________________________________________________________________1 3000 3.91 0.43 5.80 5.5 361 3.22 3000 4.41 0.61 5.97 5.7 344 4.23 3000 5.44 0.73 5.78 4.3 374 4.24 5000 3.24 0.43 13.8 10.9 252 6.65 5000 3.66 0.36 13.4 6.4 251 5.36 5000 3.96 0.37 14.5 8.4 253 7.47 7000 2.67 0.30 26.2 5.5 174 5.78 7000 2.99 0.44 27.1 11.7 183 6.59 7000 3.34 0.32 29.4 14.6 164 19.910* 3000 3.85 0.46 5.88 6.6 361 5.011* 5000 2.95 0.26 14.7 4.0 243 8.912* 7000 2.66 0.32 27.8 9.3 183 10.3__________________________________________________________________________ *Turning guide was rotating rather than fixed
TABLE 2B__________________________________________________________________________SPINNING CONDITION AND FIBER PROPERTIES (TRIAL 2) BIRE-EXAMPLE QUENCH FINISH SPUN DPF FRINGENCE ELONGATIONNO. FLOW (SCFM) APPLICATOR MEAN STD. DEV. MEAN CV MEAN % CV__________________________________________________________________________13 325 Spray 3.63 0.46 6.04 13.9 352 10.7C13 325 Spray 5.01 0.28 3.89 16.2 390 12.314 325 Spray 4.47 0.52 5.93 8.15 355 6.6C14 325 Spray 6.09 0.36 3.50 12.0 405 10.715 325 Metered 4.51 0.45 6.05 12.1 344 6.5C15 325 Metered 6.21 0.41 3.72 10.7 444 6.916 325 Spray 5.44 0.38 5.41 8.7 378 7.2C16 325 Spray 7.38 0.57 3.50 11.1 455 6.017 175 Spray 6.06 0.71 3.59 16.4 442 3.1C17 175 Spray 6.01 0.40 3.89 8.5 422 9.718 250 Spray 6.02 0.60 3.50 9.2 448 6.4C18 250 Spray 6.03 0.46 3.87 11.4 404 10.319 300 Spray 6.06 0.52 3.70 9.2 419 6.0C19 300 Spray 6.02 0.40 3.98 13.8 423 7.020 350 Spray 6.08 0.63 3.63 8.8 435 5.8C20 350 Spray 6.02 0.32 3.83 12.8 425 17.6__________________________________________________________________________
TABLE 2C__________________________________________________________________________SPINNING CONDITIONS AND FIBER PROPERTIES (TRIAL 3) DOW WINDUP QUENCH BIRE-EXAMPLE TEMP. SPEED SPACING SPUN DPF FRINGENCE ELONGATIONNO. (°C.) (fpm) (in.) MEAN CV MEAN CV MEAN % CV__________________________________________________________________________21 285 4150 1 4.07 8.8 11.2 6.2 294 6.0C21 285 4150 1 4.10 9.1 11.3 7.2 267 6.222 290 4150 1 4.06 8.7 10.5 4.3 298 7.4C22 290 4150 1 4.07 10.4 11.4 6.7 290 6.923 295 4150 1 4.06 10.0 10.2 4.3 302 3.6C23 295 4150 1 4.07 8.6 10.7 6.3 299 5.624 300 4150 1 4.05 12.7 10.4 4.6 300 5.6C24 300 4150 1 4.04 8.1 10.2 4.0 293 6.825 305 4150 1 4.05 14.5 9.8 3.8 318 4.7C25 305 4150 1 4.06 14.0 10.4 8.2 321 5.726 305 6000 1 3.47 9.3 19.5 7.1 224 7.1C26 305 6000 1 3.49 8.6 18.6 3.8 230 4.427 305 5000 1 3.76 8.0 13.9 5.2 278 3.8C27 305 5000 1 3.76 8.5 14.7 6.4 263 7.628 305 3000 1 4.90 10.5 6.1 5.1 369 3.6C28 305 3000 1 4.91 10.3 6.1 7.1 373 4.129 305 4150 1 4.06 11.6 10.1 4.7 305 5.8C29 305 4150 1 4.05 8.6 10.4 7.6 314 5.130 305 4150 2 4.05 11.5 8.6 7.2 332 6.8C30 305 4150 2 4.06 6.7 9.1 7.7 331 4.731 305 4150 3 4.06 17.2 7.8 13.1 354 4.3C31 305 4150 3 4.05 10.9 8.4 8.3 350 5.5__________________________________________________________________________
All the foregoing examples of the invention relate to poly(ethylene terephthalate) polymer spun from a single specific spinnerette and single quench system. However, the invention also clearly relates to other melt-spun polymers (such as polyamides and polyolefins); other shapes of orifice (such as non-circular orifices); and other orifice arrangements (such as linear rows of orifices). It seems likely that the best way of practicing the invention for such other systems, would be to parallel the previously described procedures now used with success for melt-spinning polyester polymer through circular orifices.
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A melt-extrusion process is disclosed for reducing the birefringence variability of melt-spun yarn made at high pack throughputs. It involves extruding polymer at an average mass-flow rate through a first group of orifices (defined by specific location in the spinnerette), that is greater than the mass-flow rate of polymer through a second group of orifices (also defined by location in the spinnerette). It is preferred that a spinnerette be used in which the dimensions of the orifices differ from group to group in a defined manner.
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BACKGROUND OF THE INVENTION
The invention relates to an automatic machining system, and particularly to an automatic machining system which accomplishes scribing, punching and drilling in production of machine parts at instructions given from an operating unit, based on indications on a display unit.
Whereas scribing, punching and drilling take place in the preparatory and finishing stages of machining, scribing and punching are usually accomplished by hand, and drilling, with a manually operated drilling machine. Although numerically controlled (NC) drilling machines have also become available over the recent years, manually operated drilling machines have been predominantly used except in achieving particularly complex operations or in working on pieces which require many drilling operations.
However, manually operated drilling machines have shortcomings such as inability to achieve accurate positioning and need for separate positioning operations even in repeated drilling in the same position. The predominant use, as stated above, of manually operated drilling machines in spite of these disadvantages is attributable to the circumstances described below, in addition to the large cost of NC drilling machines.
The usual procedure of giving an operating instruction to an NC system is for the operator or programmer to prepare a punched (paper) tape in accordance with the machining sequence, and have the machine tool read the so prepared paper tape to receive the instruction and machine the workpiece accordingly. However, when a small number of workpieces are to be machined, the intervention of the paper tape results in inconveniences such as the time required for preparation of the tape being longer than the time required for actual machining and the troubles of storing paper tapes and choosing the desired from the group of tapers. Moreover, when a conventional NC drilling machine is used for drilling operations, every time the distance between the drill and the workpiece varies, even though the drilling depth is constant, the distance from the base point has to be calculated and the drill-workpiece distance specified accordingly. Furthermore, although scribing, punching and drilling are more often than not required in the same stage of processing and positioning along the X and Y axes is indispensable for every such operation, there is no machine available at present that can carry out all these operations by itself. A conventional automatic machining system incorporating an NC drilling unit of the aforementioned type is seen in "Planning for numerical control" of MACHINERY and production engineering, pp. 521-529 by Earl J. Donelan, Sept. 8, 1965.
OBJECT OF THE INVENTION
The object of the present invention is to provide an automatic machining system free from the above described shortcomings of conventional systems.
BRIEF DESCRIPTION OF THE INVENTION
The present automatic machining system is comprised of a head unit having a combined scribing/punching tool or drill chuck, a unit to position said tool or drill chuck in the direction of the Z axis and a revolution-driving unit to turn said drill in drilling a workpiece, a sensor subjected to pressure from said tool or drill according to the back component of force which said tool or drill receives from the workpiece when the tip of said tool or drill comes into contact with said workpiece, and generates an electric signal to detect said contact and senses the variation thereof, a travel distance control unit responsive to a detection signal from said sensor for controlling the travel distance of the tool or drill of said head unit in the Z axis direction in accordance with the requirement of the scribing, punching or drilling operation, an X-Y driving unit that moves and positions said head unit in the directions of the X and Y axes to vary the machining position of the head unit, means for securely fixing said workpiece on a work table, a memory unit to memorize various data, an operating unit which selects one of the scribing, punching and drilling functions for said head unit, chooses a working pattern and feeds said memory unit with machining data including the X and Y coordinates for moving said head unit and the external dimensions and drilling depth of the workpiece, a display unit on whose screen the picture varies with the working condition of said operating unit and the machining data fed from said operating unit to said memory unit as well as the operating instruction and the kinds of data such as said X and Y coordinates and the radius to be next given as input to said operating unit, are indicated, a pattern display unit on which the respective working patterns corresponding to the modes of said scribing, punching and drilling, and all the symbols in which the machining data to be fed from the operating unit to said memory unit are to be indicated are displayed in advance and the working pattern selected by the operating unit is separately indicated as express instruction to an operator, and a control unit for controlling each of the above-mentioned means in accordance with said machining data input from said operating unit to the memory unit.
BRIEF DESCRIPTION OF THE FIGURES
The invention will be described in further detail below with reference to the accompanying drawings in which:
FIG. 1 shows an oblique view of the mechanical part of the automatic machining system of the invention;
FIGS. 2A and 2B show sectional views of the head unit equipped with a drill chuck;
FIGS. 3 and 4 show sectional views of the combined scribing/punching tool respectively before and after it is subjected to pressure;
FIG. 5 shows a block diagram of one embodiment of the invention;
FIG. 6 illustrates the functioning of a travel distance control unit;
FIG. 7 consists of a brief diagram of a working pattern and diagrams indicating symbols to be shown on a pattern display unit 69 of FIG. 5;
Each of FIGS. 8, 9, 10 and 11 shows an example of representation on a display unit 65 of FIG. 5; and
FIG. 12 illustrates the control timing relationship between a control unit 67 and each means by way of a signal line 81 of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an oblique view of the mechanical part of the automatic machining system of the invention. The driving position of a head unit 1 in the direction of the X axis is determined by a driving motor 5 and a driving screw 2, guided by guide shafts 3 and 4 of an X-Y driving unit 17. The X-Y driving unit 17 is positioned in the Y axis direction, guided by guide shafts 8 and 9 and corresponding to the motions of a driving motor 10 and a driving screw 7. A workpiece 44 (FIG. 2A) is securely held on a table 15 by X-Y standards 11 and 13 fixed at a right angle with each other of the table 15 and by workpiece holding cursors 12 and 14 which press the workpiece 44 against said standards 11 and 13. Reference number 16 represents the base.
FIGS. 2A and 2B show sectional views of the head unit 1 of FIG. 1, provided with a drill chuck 22.
In FIG. 2A, the drill chuck 22, which is equipped with a drill 21, is supported by bearings 24 and 25 at the lower and upper ends, respectively, of a bearing-supporting inner case 30 and is fastened with a nut 27, and receives transmission of the rotary drive from the motor 26 of a rotary-driving unit 71 through a coupling 29 and a conical hole 19 at the lower end of a revolution shaft 23. Driving of a head body 37 in the Z axis direction (FIG. 1) is achieved by the force originating from a motor 40 which drives transmission screw 42 through a coupling 41. The head 37 is guided by guide shafts 38 and 39. In FIG. 2A, said bearing-supporting inner case 30 and said head body 37 are integrally joined through an intermediate case 31 made of electrically insulating material. Onto said head body 37 is fixed an electrical contact case 33 made of electrically insulating material. The electrical contact 32 is biased into engagement with a piezo-electric element 45 provided on the rotatable shaft 23 by the suitable pressure of a spring 34 and an adjusting screw 35 built into said electrical contact case 33. Said piezo-electric element 45, being fixed to part of said rotatable shaft 23, generates electric signals resulting from forces applied in the Z axis direction (FIG. 1) and undergoes voltage variation caused by the back component of force from said rotatable shaft 23. This voltage variation is sensed by a sensor unit 64 consisting of a level discriminator and other components, and the contact between the workpiece 44 and the drill 21 is thereby detected.
FIG. 2B illustrates an instance in which a microswitch 46 is used in place of the piezo-electric element 45 of FIG. 2A for detection of contact. In FIG. 2B, the bearing-supporting inner case 30 is so fitted that it can slide against the head body 37 for only a short distance, and a weight 49, which is slightly lighter than the combined weight of all the mechanical parts said bearing-supporting inner case 30 is equipped with, is supported by blocks 47 and 47' and a wire 48. Consequently, the inner case 30 travels according to the back component of force the workpiece 44 receives from the drill 21 as a result of the contact between the workpiece 44 and the drill 21. In the absence of said back component of force, the inner case 30 is situated at its bottom-most position, in the Z axis direction (FIG. 1), relative to head body 37. The microswitch 46 for detecting the travel of the inner case 30 relative to said head body 37 is provided at the top of said head body 37, and a contact of the microswitch 46 is connected to said sensor unit 64. If, for instance, the workpiece 44 comes into contact with the drill 21, due to the downward movement of head 37, the back component of force the workpiece 44 receives from the drill 21 will cause said inner case 30 to slightly rise in the Z axis direction (FIG. 1) and press the actuator of said microswitch 46, whose contacts are thereby closed. Since a voltage is applied in advance between the contacts of said microswitch 46, closure of said contacts causes an electric current to flow to said sensor unit 64, and the contact between the workpiece 44 and the drill 21 is thereby detected.
In FIGS. 2A and 2B, a position-finding element 43 (an element generating pulse signals at regular intervals T, e.g., (Magnescale (trade name) manufactured and distributed by Sony Magnescale Co., Ltd.) attached to the head body 37 and the sensor unit 64 are separately connected to a travel distance control unit 63 (FIG. 5).
FIGS. 3 and 4 show sectional views of a combined scribing/punching tool 18 respectively before and after it is subjected to pressure (after punching). This tool 18 consists of: an exterior taper 20, at its top end, which taper fits into the conical hole 19 in the shaft 23 shown in FIG. 2A; a body 51 having an internal tapered portion 56; a needle 50 which, under pressure from a small spring 54, can slide within the body 51 and has a sharply pointed conical tip for scribing and/or punching; a hammer 57 which, under pressure from a large spring 55, can slide within the body 51 and has a hole 59 matching the needle 50, and a stopper member 52 which, when engaged with a notch 58 in the middle of the hammer 57, is kept pressed against the inner wall of the tapered part 56 of the body 51 by a leaf spring 53 and has a hole 60 axially aligned with the needle 50.
In FIG. 5 which shows a block diagram of one embodiment of the invention, an automatic machining system of the invention consists of: a head unit 62 (corresponding to the head unit 1 of FIG. 1); an X-Y driving unit 61 (corresponding to the X-Y driving unit 17 of FIG. 1) which drives and positions, by means of the driving motors 5 and 10 of FIG. 1, said head unit 62 in the X axis and Y axis directions; the sensor unit 64 which detects contact of the tip of said head unit 62 with the workpiece 44; the travel distance control unit 63 including the position-finding element 43 (FIGS. 2A and 2B) which serves to determine the travel distance of said head unit 62 for scribing, punching or drilling after the surface of the workpiece has been sensed by the sensor unit 64; an operating unit 66; a display unit 65; a memory unit 68; a pattern display unit 69; and a control unit 67 which controls various means referred to above in accordance with the machining data fed from said operating unit 66 to said memory unit 68. In FIG. 5, reference number 81 represents signal lines between blocks.
In FIG. 6, which illustrates the functioning of the travel distance control unit 63, letter A refers to the pulse signals occuring at regular intervals T and derived from the position-finding element 43, and letter B represents the detection signal from the sensor unit 64, which sets a flip-flop 631 contained within the travel distance control unit 63. Only when this setting signal coincides with one of said pulse signals A at regular intervals T, does AND gate 634 open to supply the travel distance control datum (pulse) to a counter 632. A travel stop signal represented by letter C is developed by a comparator 633 when travel distance datum D from the control unit 67 and said travel distance control datum from the counter 632 within the control unit 63 are compared by the comparator 633 and found equal to each other. The travel distance control signal (S63-B of FIG. 12), represented by letter E, of the travel distance control unit 63 is the resetting signal (S63-A of FIG. 12) for the flip-flop 631 and the counter 632 of control unit 67.
FIG. 7 shows a group of simplified diagrams each representing a working pattern to be prepared for scribing, punching or drilling as the case may be and to be displayed by the pattern display unit 69 of FIG. 5, and diagrams of symbols to be shown by said pattern display unit 69 to indicate machining data to be fed from said operating unit 66 to the memory unit 68.
Each of FIGS. 8, 9, 10 and 11 shows an example of representation on the display unit 65 of FIG. 5.
FIG. 12 illustrates the control timing relationship between the control unit 67 and each means by way of the signal line 81 of FIG. 5.
The present automatic machining system will be described in further detail below with reference to FIGS. 1 through 12.
First, the operator puts the workpiece 44 of FIG. 2A on the table 15 of FIG. 1, and, while pressing it against the X-Y standards 11 and 13, fastens the workpiece to the table 15 with the cursors 12 and 14. Then, the control unit 67 starts action in accordance with the information stored in advance in the memory unit 68 of FIG. 5, and issues a control signal to give, as the first phase of operation, a representation (FIG. 8) to indicate the choice of operation on the display unit 65 (S65-A of FIG. 12). On the basis of this representation, the type of operation, i.e., scribing, punching or drilling, to be applied to the workpiece 44 is selected by the operating unit 66 (S66-A of FIG. 12). Following this selection, the display unit 65 indicates, as the second phase, a list, in reference numbers and letters, of working patterns prepared at the instruction of the control unit 67 (S65-B of FIG. 12). If punching is selected in the first phase, a representation like FIG. 9 will appear on the display unit 65. Since, for each of the working patterns indicated in reference numbers on this display unit 65 in a list form, a brief diagram and symbols in which required machining data are to be indicated (e.g., D for diameter) are represented in advance on the pattern display unit 69 shown in FIG. 7, the representation on the display unit 65 and the display unit 69 can be contrasted to facilitate the choice by the operating unit 66 of the pattern of machining to be applied to the workpiece 44 (S66-B).
Upon completion of the choice of the required working pattern out of FIG. 7, the display unit 65, as the third phase, changes its representation to a list of symbols in which to indicate machining data (S65-C of FIG. 12) and the pattern display unit 69 distinguishes with lamps the brief diagram of the selected working pattern and the symbols for indication of the machining data from the remaining unselected patterns (S69-A of FIG. 12--If, in said second phase, the working pattern of "equidistance circular arrangement" is selected, the representation on the display unit 65 will look like FIG. 10). Next, as the representation on the display unit 65 (FIG. 10) is compared with the brief diagram of the working pattern and the symbols for indication of the machining data selected from the pattern display unit 69, and the machining data (S66-C) are successively fed from the operating unit 66 to the memory unit 68, the representation on the display unit 65 will eventually look like FIG. 11 (S65-D).
Whereas machining data are inputted to the memory unit 68 for machining in the third phase of the pattern selected in the first two phases, overlapping of another pattern on said working pattern, if desired, can be achieved as the fourth phase by giving an instruction from the operating unit 66 (S66-D) in the same procedure of selection as described with respect to the second phase (S65-E of FIG. 12). Next, as the fifth phase, entry of the machining data into the memory unit 68 (as described with regard to the third phase) for said additional working pattern can be accomplished through the operating unit 66 (S66-E) on the basis of the display unit 65 and the representation on the pattern display unit 69 (S69-B). Selection of the required working pattern or patterns (S65-F) and input to the memory unit 68 of relevant machining data are achieved in this manner.
The machining data input in said three or five phases are stored in the memory unit 68, converted by the control unit 67 into X and Y coordinates corresponding to the working pattern and used for developing action commands from the X-Y driving unit 61. In response to such an action command, the motor 5 (FIG. 1) for driving in the X axis direction and the motor 10 for drivng in the Y axis direction are set in motion (S61-A) to shift the head unit 1 to the initial machining position. Hereupon, in case of drilling, the drill 21 is rotated by the motor 26 (in case of scribing or punching, the motor 26 does not turn), the head body 37 is lowered by the motor 40 for driving in the Z axis direction, the transmission screw 22, etc. (S62-A), and the tip of the drill 21 then comes into contact with the workpiece 44. As illustrated in FIG. 2A, the contact with the workpiece 44 is detected by the sensor unit 64 as the back component of force, which the tip of the drill 21 receives from the workpiece 44, applies pressure on the piezo-electric element 45 provided on the rotatable shaft 23 to generate an electric signal and said signal is transmitted to the sensor unit 64 via the electric contact 32.
On the other hand in FIG. 2B, the contact with the workpiece 44 is detected by the sensor unit 64 as the back component of force, which the tip of the drill 21 receives from the workpiece 44, shifts for a slight distance the bearing-supporting inner case 30 which is provided in the head body 37 and can slide therein, the shift is sensed by the microswitch 46 provided on the head unit 1 and the electric signal from this microswitch 46 is transmitted to the sensor unit 64.
As referred to with letter A in FIG. 6, the position-finding element 43 (FIGS. 2A and 2B) generates pulse signals at regular intervals T. Upon receipt from the sensor unit 64 of a detection signal represented by letter B in FIG. 6, the travel distance control unit 63 generates a travel distance control signal, as represented by letter C, on the basis of the pulse signals from the element 43 at regular intervals T, and begins to control the travel distance of the head body 37 (FIGS. 2A and 2B). More specifically control unit 63, checking the datum on machining depth entered into the memory unit 68 through the operating unit 66, transmits a signal to the control unit 67 when the travel distance of the head unit 1, after making contact with the workpiece 44, reaches the required value (e.g., the drilling depth in the event of a drilling operation). There-upon, the control unit 67 applies a reversing signal to the driving motor 40 (S62-B). The head body 37 accordingly begins to rise, and upon completion of its upward travel the control unit 67 restarts control of the X-Y driving unit 17 until the next machining position is reached (S61-B), and accomplishes control in a manner similar to the aforementioned operations. When all the input machining data have been put into operation in this manner, the head unit 1 stops in the final machining position and the whole series of machining operations is completed.
Next, actions will be separately described for drilling, punching and scribing operations.
First in a drilling operation, as illustrated in FIG. 2A or 2B, the drill chuck 22 is fitted in advance by inserting the tapered portion 20 into the conical hole 19 at the lower end of shaft 23 in head unit 1 shown in FIG. 1. The operating unit 66 is then used to selectively represent the mode of operation as "drilling" on the screen of the display unit 65, and to enter (as described above) and store the machining data in due order in the memory unit 68. Under the control of the control unit 67 in accordance with these data, first the head unit 1 is positioned by the X-Y driving unit 17, and the head body 37 starts to descend, with the motor 26 in motion. Next, when the tip of the drill 21 comes into contact with the workpiece 44, the head body 37 travels in the Z axis direction under the control of the travel distance control unit 63 so that drilling to the required depth is achieved according to the machining data entered into the memory unit 68. After that, the head body 37 is lifted, and the drilling operation is completed.
Next in a punching operation, the combined scribing/punching tool 18 illustrated in FIG. 3 is fitted in advance by inserting tapered portion 20 into the conical hole 19 at the lower end of the rotatable shaft 23 of the head unit 1 shown in FIG. 1. The operating unit 66 is then used to selectively represent the mode of operation as "punching" on the screen of the display unit 65, and the machining data are inputted to the memory unit 68 from the operating unit 66 to position the head unit 1 relative to the X and Y axes in the same manner as for said "drilling" operation. After that, the head body 37 begins to descend, with motor 26 deenergized. Next, as the tip 50a of the needle 50 comes into contact with the workpiece 44, the travel distance, after tip 50a engages workpiece 44, is controlled by the travel distance control unit 63. Thus, even after the tip 50a of the needle 50 has come into contact with the surface of the workpiece 44, the head body 37 continues to travel in the Z axis direction, and the needle 50, subjected to pressure by the small spring, rises within the body 51. During this process, the stopper member 52 provided under the hammer 57 is pressed by the leaf spring 53 against the inner wall of the taper part 56. Since at this time the needle 50 is not aligned with the hole 60 of the stopper pin 52 in axial center, the needle 50 is kept in contact with the bottom of the stopper member 52 when it rises compressing the spring 55 together with the stopper pin 52 and the hammer 57. As it rises, the stopper member 52 is pressed inwards by the effect of the internal tapered part 56, and when the member 52 is raised to a level where the hole 60 of the stopper pin 52 is aligned with the needle 50 in axial center, the needle 50 slides away from the bottom of the stopper member 52 and enters into the hole 60. As a result, the large spring 55 that has been compressed by the hammer 57 to accumulate repulsive energy is suddenly liberated by the alignement of member 52 and the upper end 50b of needle 50, to cause the hammer 57 to strike against the upper end 50b of needle 50 to apply a force suitable for the punching operation. Whereas the distance of travel between the contact with the workpiece 44 and the release of the punching force is predetermined, control for this purpose is accomplished by the travel distance control unit 63. After the punching action, the head body 37 is raised. As the head body 37 rises, the needle 50 move away from the workpiece 44, and simultaneously with the descent of the needle 50 relative to member 52 by the action of the small spring 54, the hammer 57 is lowered by the action of the large spring 55 and the stopper member 52 travels along the inner wall of the taper part 56 until it assumes the position it occupied before the application of pressure is resumed.
Further in a scribing operation, after the operating unit 66 is used as described above to selectively represented the mode of operation as "scribing" on the screen of the display unit 65, the machining data are entered from the operating unit 66 into the memory unit 68, and the head part 1 is positioned relative to the X and Y axes in the same manner as for said "drilling" or "punching" operation. After that, the head body 37 begins descending. Under the control of the travel distance control unit 63, the head body 37 descends for the distance between the position where the tip needle 50a comes into contact with the workpiece 44 and the position where the rising needle 50 reaches the bottom of the stopper member 52, i.e., the distance where the pressure of the small spring 54 alone is applied, and the driving motor 40 stops running. At this time the head body 37 is kept in the position where it has stopped after the descent and the head unit 1 is shifted relative to the X and Y axes by the X-Y driving unit 17 to achieve scribing. After the completion of this scribing operation, the head body 37 ascends. The scribing operation is thus completed.
Incidentally the memory unit 68, display unit 65, operating unit 66 and pattern display unit 69 which comprise the present invention are known components, and since specific configurations of these components themselves have no direct bearing on the essentials of the invention, they are not described in detail herein. Examples in which these known components are used include an AC grinding system referred to a "AN ADAPTIVE CONTROL SYSTEM OF GRINDING PROCESS" by Hideo Inoue et al. in the Proceedings of The International Conference on Production Engineering, Part 1 (pp. 671-676, particularly FIG. 3), a publication issued in 1974.
Next, the invention has the remarkable technical effects described below. Unlike any conventional numerically controlled system which gives operating commands by way of a paper tape, the present invention, dispensing with the use of any paper tape, makes possible direct entry of data from the operating unit 66 into the memory unit 68 on the basis of indications on the display unit 65, and thereby helps save the time otherwise required for preparation of paper tapes. The invention further dispenses with storage of a number of paper tapes and the time required for selection of a relevant one out of the many paper tapes stored. Moreover, scribing, punching and drilling can be achieved irrespective of the height of the surface to be worked on. Therefore in a drilling operation, for instance, it is sufficient to specify only the drilling depth from the surface to be machined, but not the position relative to the base point of the Z axis direction, and the data to be specified can be accordingly simplified. Furthermore, since, in automatic sensing of the surface of the workpiece, detection of the contact of the combined scribing/punching tool 18 or the drill 21 with the workpiece 44 is detected on the basis of the pressure received from the combined scribing/punching tool 18 or the drill 21 according to the back component of force which the combined scribing/punching tool or the drill receives from the workpiece 44, the workpiece 44 can be formed of an electric insulator material as well as an electric conductor material unlike those systems in which the workpiece 44 and the combined scribing/punching tool or the drill are electrically insulated from each other and electric tension is applied to both in advance so that contact between them could be detected by the flow of an electric current from one to the other. It is also possible to store in advance a number of working patterns in the memory unit 68 and machine the workpiece in accordance with a single pattern or a combination of patterns selected from the stored patterns, and data can be readily entered from the operating unit 66 into the memory unit 68 because a brief diagram of each working pattern and relevant data are represented on the pattern display unit 69. Still another significant feature resides in the fact that, since scribing and punching can be accomplished with a common tool and the combined scribing/punching tool and the drill chuck can be readily interchanged, the operating rate of the system can be correspondingly raised.
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An automatic machining system incorporating all the features of a numerically controlled type machine while eliminating the need for paper tapes. The tool receiving head incorporates means for identifying the moment of contact between tool and work piece, avoiding the need for inputting start position data. Motion control and drive means are provided for X, Y and Z head movement. The novel design provides drilling or punching by insertion of the proper tool in a head adapted to receive either tool.
Visual displays provide step by step directions and allow for selection of the machining operation and sequential execution of the machining steps in accordance with inputted data requested by the display.
The punching tool operates automatically simply under control of Z axis movement.
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BACKGROUND OF THE INVENTION
This invention relates to a front and rear wheel steering device for variably controlling the steering angle of rear wheels relative to the steering angle of front wheels.
The present inventors have previously proposed a steering device for a vehicle which steers the rear wheels in relation with the steering of the front wheels according to vehicle speed in copending U.S. patent application Ser. Nos. 822,000, 822,293, 821,998, 822,008, 822,010 and 822,043 which were filed on Jan. 24, 1986, and assigned to the same assignee. According to these devices, rear wheels are generally steered in the same phase relationship or none at all in high speed range and are steered in the opposite phase relationship in low speed range. If desired, the mathematical function of the vehicle speed for the steering angle of the rear wheels can be modified according to the vehicle acceleration or manually, or can even be manually fixed.
As a result, the minimum angle of turning and the inner radius difference of the vehicle are both drastically reduced and the maneuverability of the vehicle, particularly in low speed range, in driving the vehicle into a garage, driving the car through narrow and crooked alleys and making a U-turn, is substantially improved with the additional advantage of improving the dynamic lateral response of the vehicle in high speed range, for instance in changing driving lanes.
Generally speaking, since the driveability of a vehicle depends on the vertical load acting between the tires and the road surface, the friction coefficient of the road surface, the pneumatic pressure of the tires, the kind of the tires and so on, and the relationship of the steering angle and/or the vehicle speed on the yaw rate is generally non-linear, it is extremely difficult to evaluate the driveability of a vehicle in design stage. On the other hand, if the rear wheels are steered in addition to the front wheels, a controllable variable is added to the system and it may be possible to better evaluate or control the driveability of the vehicle by changing the steering angle ratio of the rear wheels relative to the front wheels. Based upon such a recognition of the inventors, a primary object of the present invention is to provide a front and rear wheel steering device for vehicle which can improve the driveability of the vehicle by appropriately controlling the steering angle ratio of the rear wheels relative to the front wheels.
BRIEF SUMMARY OF THE INVENTION
Based upon such a recognition, a primary object of the present invention is to provide a front and rear wheel steering device for vehicle which can improve the controllability of a vehicle.
Another object of the present invention is to provide a device for controlling the driveability of a vehicle in such a manner that the driver can experience a substantially uniform driveability from the vehicle irrespective of the running condition of the vehicle.
According to this invention, such objects are accomplished by providing a front and rear wheel steering device for vehicle for variably controlling the steering angle ratio of rear wheels relative to the steering angle of front wheels in relation with vehicle speed, comprising: a sensor means for detecting the changes in the running condition of a vehicle; and a means for varying the steering angle ratio of the rear wheels relative to the front wheels as a function of the output of the sensor means.
Thus, by detecting the running condition of the vehicle and varying the property of the steering angle ratio function accordingly to produce a desired driveability, the driver can obtain a uniform driveability irrespective of the driving condition of the vehicle and, through accurate prediction of the behavior of the vehicle, the driving of the vehicle may be made less tiring and more comfortable.
The running conditions of the vehicle may include the static or dynamic load acting between the wheels and the road surface, the frictional coefficient between the tires and the road surface, and the vehicle acceleration, among other factors.
According to a certain aspect of the present invention, the steering angle ratio of the rear wheels relative to the front wheels is varied so as to obtain a substantially constant driving response. The driving response may be evaluated in terms of the yaw rate or the lateral acceleration of the vehicle for a certain steering input.
Thereby, the driver can always expect a substantially same driving response for a certain steering input at a certain vehicle speed irrespective of the running condition of the vehicle, and the driveability of the vehicle will be improved.
BRIEF DESCRIPTION OF THE DRAWINGS
Now embodiments of this invention are described in the following with reference to the appended drawings, in which:
FIG. 1 is a perspective view showing the general basic structure of a vehicle provided with a front and rear wheel steering device to which this invention is applied;
FIG. 2 is a functional block diagram of the computer which is mounted to the vehicle;
FIG. 3 is a steering angle ratio property graph of the above mentioned embodiment; and
FIG. 4 is a functional block diagram of the computer which is mounted to the vehicle according to the second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an embodiment of the structure of the front and rear wheel steering device to which this invention is applied. A steering column shaft 2 of a steering wheel 1 is joined into a rack and pinion type gear box 3, and a pair of tie rods 5 are connected to the two ends of a rack shaft 4. To the external ends of the tie rods 5 are connected a pair of knuckle arms 6 which support front wheels 7, respectively, in such a manner that the front wheels 7 can be steered to the direction determined by the steering wheel 1 in the known manner.
As for the rear wheels, a rack and pinion gear type gear box 8 is laterally arranged in the same manner as that for the front wheels, and tie rods 10 are connected to the two ends of the rack shaft 9 of the gear box 8. And the external ends of the tie rods 10 are connected to knuckle arms 11 which in turn support the rear wheels 12. The pinion shaft of the gear box 8 is connected to an output shaft of a motor 13. Thus, the rear wheels 12 are steered by the power from the motor 13.
A pair of displacement sensors 14 and 15, which for instance may be made of potentiometers or differential transformers, are arranged between the casings of the gear boxes 3 and 8 the rack shafts 4 and 9 for the front and the rear wheels, respectively, so that the displacements of the rack shafts 4 and 9 may be detected as quantities representative of the actual steering angles. The outputs of these displacement sensors 14 and 15 are connected to a control device 16. Further, the output of a vehicle speed sensor 17 provided on the non-driven wheels, for instance, and the output of a running condition sensor 18 which may consist of a load sensor for detecting the load on the rear wheels are also connected to the control device 16.
When a load sensor is to be used as the running condition sensor 18, the load may be obtained as a static load which can be obtained either by averaging the deflection of the suspension springs for the rear wheels or by combining the vertical acceleration of the rear part of the vehicle, the vertical velocity of the rear part of the vehicle obtained by integrating the acceleration and the deflection of the suspension springs for the rear wheels.
The control device 16 is internally equipped with a computer 19 (FIG. 2) which controls the rotation of the motor 13 by supplying thereto an appropriate actuation signal corresponding to the vehicle speed based on the signals supplied from the steering angle sensors 14 and 15 for detecting the steering angles of the front and the rear wheels and the vehicle speed sensor 17 for detecting the vehicle speed, by way of an output device 20.
Now the action of the above-described embodiment will be described in the following with reference to FIGS. 2 and 3.
FIG. 2 shows the functional structure of the computer 19. The steering angle of the front wheels detected by the steering angle sensor 14 is supplied to the computer 19 as a front wheel steering angle signal x and the vehicle speed signal detected by the vehicle speed sensor 17 is also supplied to the computer 19 as a certain vehicle speed signal u.
Since the cornering power of the rear wheels is generally dependent on the load of the rear wheels, even when the vehicle speed is the same and the steering angles of the rear and the front wheels are the same, the yaw rate of the vehicle is not necessarily the same. Therefore, the driver must adjust the steering angle accordingly but it imposes a certain burden on the driver. Therefore, according to the present embodiment, the mathematical function which determines the steering angle ratio of the rear wheels is varied according to the change in the load of the rear wheels. To such an end, the running condition signal z from the running condition sensor 18 is supplied to the computer 19.
In a conversion process (a), one of a plurality of mathematical functions f=f 1 , f 2 , . . . stored in the memory (b) is selected according to the running condition signal z, and the target value y 0 of the steering angle of the rear wheels is given in relation with the actual steering angle x obtained from the steering angle sensor 14 for the front wheels as follows:
y.sub.0 =xf(u)
This can be conveniently implemented by a map control in which the value of the function f(u) is determined from a matrix of various values of u and z.
Meanwhile, the detection result of the steering angle sensor 15 for the rear wheels is inputted to the comparison process (c) in the computer 19 as a rear wheel actual steering angle data y m . Based upon the rear wheel actual steering angle data y m and the target value y 0 for the steering angle of the rear wheels, a relative difference delta y=y m -y 0 is obtained in the comparison process (c). This difference delta y is inputted from the computer 19 to the output control device 20 as data corresponding to the correction of the steering angle which is necessary to achieve the necessary steering angle of the rear wheels. The output end of this output control device 20 is connected to the motor 13 and supplies thereto a control signal s corresponding to the difference delta y. And the motor 13 is driven in the direction which accomplishes the steering angle of the rear wheels which corresponds to the current speed and running condition of the vehicle.
Thus, if the mathematical function f representing the steering angle ratio of the rear wheels is as indicated by a curve P in FIG. 3, as the load on the rear wheels increases, the cornering power of the rear wheels increases and the yaw rate accordingly increases. Therefore, according to the present embodiment, if the load on the rear wheels increases, the mathematical function representing the steering angle ratio of the rear wheels is modified, for instance, as indicated by a curve Q shown in FIG. 3 according to the output from the running condition sensor 18, and the absolute value of the steering angle ratio of the rear wheels is reduced. As a result, the driver can always obtain a yaw rate which corresponds to the steering input and the burden on him is reduced by the elimination of the need for him to adjust the steering input according to the changes in the running condition of the vehicle.
In the above described embodiment, a sensor for detecting the load on the rear wheels was used as the running condition sensor 18, but it is also possible, alternatively or additionally, to detect the friction coefficient of the road surface and vary the mathematical function for the steering angle ratio of the rear wheels according to the detected friction coefficient. As methods for detecting the friction coefficient of the road surface, various methods are possible; for instance it is possible to find the friction coefficient by actually dragging an object and measuring its frictional force, by frequency analyzing the sound from the tires, or by projecting light upon the road surface and evaluating the reflection of the light from the road surface.
Generally, the yaw rate or the lateral acceleration of the vehicle for a certain steering input is selected as an object for evaluating the driveability of a vehicle. Therefore, by detecting the yaw rate and so on and controlling the steering angle ratio of the rear wheels according to such detection results, even more accurate control of the driveability of the vehicle becomes possible. FIG. 4 is a functional block diagram of another embodiment of the control device for the front and rear wheel steering device based upon such a recognition.
The outputs x, y m , u and z of the front wheel steering angle sensor 14, the rear wheel steering angle sensor 15 and the vehicle speed sensor 17 and the running condition sensor 19 are inputted to a computation process (a). The memory (b) internally provided in a computer 19 stores a mathematical function w 0 =F(x, y m , u, z) which gives a target yaw rate w 0 of the vehicle for each combination of the front wheel steering angle signal x, the vehicle speed signal u, the running condition signal z and the target rear wheel steering angle y 0 . The target steering angle y 0 of the rear wheels is uniquely determined by the front wheel steering angle signal x, the vehicle speed signal u, and the running condition signal z, but it is desirable to monitor if the control error is within a certain range or not by comparing the target steering angle y 0 of the rear wheels with the output y m from the rear wheel steering angel sensor 15 at all time to ensure control stability.
In the computation process (a), the yaw rate w 0 which is to be considered as the target value is computed according to the detection results from the various sensors, and the increment of the yaw rate delta w=w m -w 0 for a certain increment of the rear wheel steering angle delta y=y m -y 0 , or the sensitivity coefficient ##EQU1## of the yaw rate relative to the changes in the steering angle of the rear wheels is computed in a certain cycle, and the inverse of the sensitivity coefficient ##EQU2## and the target yaw rate w 0 is outputted. Here, w m denotes the actual yaw rate obtained from the yaw rate sensor 21. As a yaw rate sensor 21, a rate gyro, for instance, placed in the center of the vehicle may be used.
The target yaw rate w 0 is converted into the increment delta w by a division process (c) as a ratio between the target yaw rate w 0 computed in the computation process (a) and the actually measured yaw rate w m . Further, in a multiplication process (d), the increment delta w is multiplied to the inverse of the sensitivity coefficient to obtain ##EQU3## and the correction delta y=y m -y 0 required for bringing the measured yaw rate w m close to the target yaw rate w 0 . The output device 20 supplies a drive signal s to the motor 13 to steer the rear wheels 12 by delta y.
In this embodiment, it is also possible to use the lateral acceleration instead of the yaw rate as an object for evaluating the driveability of the vehicle. Further, the variables representing the running condition of the vehicle may include the dynamic load on the rear wheels, the frictional coefficient of the road surface, the vehicle acceleration, but the number of such variables should be reduced insofar as control stability is assured.
In the above described embodiments, there might be a chance that control stability is lost if the change in the running condition of the vehicle is too sudden. Since such an occurrence means that the driving condition is too severe, it is preferable to fix the steering angle ratio function to a stable one and to issue an alarm at the same time so as to warn the driver to ease the driving condition.
In the above-described embodiments, the various processes conducted in the computer 19 are executed by a certain program (software) stored for instance in a storage area of the computer 19, but it is possible to utilize electric circuitry having a similar functionality to perform the same processes.
Further, this invention is not limited by the above-described embodiments, but may also be applied to other front and rear wheel steering devices in which the rear wheels are hydraulically controlled, the front steering angle information is transmitted by hydraulic pressure, or a mechanical structure for varying the steering angle ratio is provided on the rear wheels so that the rear wheels may be steered by rotational force which is mechanically transmitted from the front wheels.
Thus, according to this invention, since the steering angle of the rear wheels is controlled according to the running condition of the vehicle, a constant driveability can be obtained irrespective of the running condition of the vehicle. Therefore, it is possible to obtain a favorable and safe driveability which is not affected by the running condition of the vehicle while maintaining the advantages of a front and rear wheel steering device.
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A front and rear wheel steering device which varies the steering angle ratio of rear wheels relative to the steering angle of front wheels in relation with vehicle speed is utilized to improve the drive response of a vehicle, as well as to improve the maneuverability of the vehicle. By varying the steering angle ratio which is a function of vehicle speed according to the running condition of the vehicle, the interference of the running condition of the vehicle upon the driving response can be reduced. The driving response may be evaluated in terms of yaw rate or lateral acceleration of the vehicle for a certain steering input. The running condition of the vehicle may comprise any combination of vehicle acceleration, friction between tires and the road surface, load acting between front wheels and the road surface, and load acting between rear wheels and the road surface.
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This application is a continuation of application Ser. No. 599,873 filed Apr. 13, 1984, now abandoned.
FIELD OF THE INVENTION
The present invention relates to an improvement in a multiple lead electrical connector assembly for reducing stress on the leads during installation, use and removal of the connector assembly from a mating connector.
BACKGROUND TO THE INVENTION
Connectors for coupling electrical or signal conductor leads to mating connectors are well known. Electrical connectors are provided for connecting removably a plurality of conductor leads for input or output of information to and/or from an information or power source (instrument) to a receiver-user (instrument), through a mating or complementary connector. Often, vibration and other environmental factors cause failures as conductor leads become separated from their respective receptacles in the connector assembly. To reduce the occurrence of such failures, lead protection has been provided by encapsulating the conductors in the connector assembly with a plastic compound, referred to as a potting material. The objection to this procedure for permanently protecting the lead connections is that changing of conductor lead assignments, repairing leads, or replacing leads requires removing the potting material, and usually requires destruction and complete replacement of the connector assembly. Due to the significant steps involved in making such changes of leads, the connected instrument must be withdrawn from its intended task for the extended period necessary for repair either in a service facility or by a skilled technician.
BRIEF SUMMARY OF THE INVENTION
The present invention provides an improvement in an electrical connector assembly for coupling a plurality of conductor leads to a mating connector. Connectors protect conductor leads assigned to pin receivers of connectors, usually by permanent installation. Hence, the leads are not readily removable. In this improved connector assembly, the conductor leads are fixedly retained, yet readily removable for reconfiguration of the leads to a particular pin number, or for replacement if the lead should be damaged, or for replacement if a different connector receptacle is desired.
The improvements of the present invention enable field change or repair of the connector rather than requiring the time consuming return of the instrument to the repair facility. That is, when the connector is used on an instrument, such as test equipment, at a scene or in a laboratory but away from the usual repair facilities, the user may make repairs, or lead re-assignments, or receptable replacements with minimum time loss. The connector assembly includes a backshell of interlocking end and side pieces which may be disassembled upon removal of two attaching members by which the backshell couples the assembly to a complementary connector. After removing the attaching members, the end pieces of the backshell are displaced to release the side pieces. The backshell is then disassembled so that the conductor leads may be removed readily from the receptacle of the connector assembly. After the replacement of the leads, the disassembly steps are reversed to reassemble the connector for further use. Due to the short turn around time, the user can change lead assignments and make repairs or replacements to the conductor leads in the field.
A separator, enclosed within the backshell of the connector assembly, controls the area of conductor lead bending, placing that area outward of the location at which a lead may have been weakened when insulation was removed therefrom, or where the contact is crimped thereto. Further, the separator displaces this flexing area outward of the connector assembly backshell, whereby strain points, possibly affecting the leads and causing damage due to handling or environmental vibration, are displaced from immediately adjacent the connector assembly. By increasing the area over which strain, resulting from flexing and/or bending of conductor leads may occur, the likelihood of breakage of leads is reduced. Also, the separator, by receiving the contacts and leads in holes formed therein, prevents any strands of the leads or wires if broken, possibly due to faulty wire stripping or vibration, from contacting adjacent wire conductors, and causing circuit failure.
In practice, the backshell of the present invention is of a low profile construction permitting the connector assembly to be used in "tight" locations. This low profile overcomes the space limitations created by known backshells used in connector assemblies.
An object of the invention is to provide an improved connector assembly having a backshell capable of assembly and disassembly permitting in the field repair of the connector assembly.
Another object is to provide for the multi-lead connector assembly a lead separator to maintain separation of the leads.
Another improvement of the invention is the provision of a lead separator within a backshell of a connector assembly to displace the flex points of insulator conductor leads beyond the length from which insulation has been removed.
BRIEF DESCRIPTION OF THE DRAWINGS
Further and other objects of the present invention will become more apparent from the description of the accompanying drawings in which like numerals refer to like parts.
In the drawings:
FIG. 1 is a perspective view of a connector assembly of the present invention with the backshell assembled;
FIG. 2 is a cross sectional view of the connector assembly of the invention taken along section line 2--2 of FIG. 1; and
FIG. 3 is an exploded view of the connector assembly and backshell.
DETAILED DESCRIPTION OF THE INVENTION
As shown in the drawings, an improved multiple lead electrical connector assembly 10 is dimensioned for coupling with a complementary connector (not shown). The complementary connector may either be fixed to a base or be arranged on the ends of other wire lead conductors. The dimensions of the connector assembly 10 are determined by the number of insulated wire lead conductors 22. Typical of known connectors of the class shown are Type D connectors, having as few as 9 or as many as 50 pins (plug type or pin receivers (receptacle type) arranged in two or three rows, usually with the pins in one row offset from the pins in another row.
The insulated conductor leads or wires 22 are prepared for insertion into the connector assembly 10 by stripping of some of the insulation from a short length of the insertion end thereof, typically about 3/16th of an inch or 5 millimeters. A contact 24 is attached to the bared wire end, using a tool that crimps the contact tightly onto the conductor. The contacts 24 with the wire 22 attached are thereafter inserted into the connector assembly 10. Too often, stripping of the insulation causes weakening of the wire lead due to partial or complete cutting of one or more strands of the wire. Flexing or bending of the wires at this point are primary causes for wire breakage or other failure in the harsh environment of use of the connector assembly.
A preferred embodiment of the connector assembly 10 includes a conductor lead receiving receptacle 30 of known construction. Such a receptacle has a ledge or rim 32 formed around the perimeter thereof, proximately along the mid-line of the thickness/depth dimension thereof. A plurality of conductor lead receivers 34 are exposed to one side of the receptacle to receive the contacts 24. On the opposite side of the receptacle are a plurality of pin receivers or pins 36 for mating with pins or pin receivers of complementary connectors (not shown) to complete circuits when the connectors are assembled together.
A multi-part backshell 40, configured of interlocking side pieces 44 and end caps 46, forms a housing partially enclosing the receptacle 30. For a given connector size, the side pieces and end pieces may be identical. Portions of the interior of both side pieces 44 are provided with receptacle retainers, such as ledges or the recesses 48, as shown. The retainers are arranged for mating with sections of the rim 32 of the receptacle 30. On the ends of the side pieces 44 are grooves 52, extending the height of these side pieces. Runners 54 of the end cap portions 46 engage in the grooves 52 to clamp the side pieces 44 together to retain the receptacle 30 therebetween.
To enable attaching connector assembly 10 to a mating connector, a lip 56 is formed as a part of each end cap 46. The lip is provided with a hole (not shown) through which can pass an attaching member 60, shown as a screw. The attaching member 60 is designed to pass through a coresponding hole 62 in the rim 32 of the receptacle 30, and into a complementary hole in the mating connector to cause retention together of the coupled connectors. The backshell 40 requires no other fasteners to complete assembly or to retain the integrity of the assembled backshell as a unitary structure. However, a detent 68 is provided on the interior surface of the end cap portions 46 to engage tang-like spacers 69 of the backshell portions 44 to retain the backshell together until assembly with the fasteners.
Internally of the backshell 40, when assembled, a lead separator 70 is positioned, substantially enclosed by backshell portions 44, 46, and the receptacle 30. The separator, formed of yieldable, electrical insulating material, such as silicone rubber, is shown as a block of material. The width of the block is slightly greater than the predetermined spacing between the backshell portions 44, and slightly greater than the width of the receptacle 30, but effectively displaces the point at which conductor leads may flex beyond the area from which insulation has been removed and beyond the backshell. A plurality of holes 72 in the lead separator block are in a pattern to match the pattern of the receivers 34 of the receptacle. To retain the lead separator in the backshell, the side pieces of the backshell are configured at the lead out edge with inwardly extending flanges 76, which terminate with the tang-like spacers 69 to hold apart the inner flange edges. The conductor leads 22 pass into and out of the connector assembly through this space in the backshell.
The assembly procedure for the connector assembly 10 is simply to align and press the side pieces 44 of the backshell 40 firmly against the sides of the lead separator 70 and of the receptacle 30, and to guide the runners 54 of the end cap pieces 46 into the retaining grooves 52 along the ends of the side pieces until the end pieces snap into place as the runners seat in the grooves of the side pieces. Part of the snap action is caused by the detent 68 passing over the outer edges of the inwardly extending tang-like spacer ends 69 of side backshell portions 44. The contacts may be affixed to the conductors before or after the conductors are passed through the separator. However, the contacts are seated in the receptacle prior to assembly of the connector assembly. Thus, the backshell retains the lead separator in position relative to the receptacle with minimum stress being applied on the conductor leads 22 or contacts 24 thereon.
Following assembly of the connector assembly 10, the backshell 40 and receptacle 30 are held together. Thereafter, the fastener members 60 are threaded through the receptacle and into the mating connector to secure the backshell 40 and the receptacle 30 of the connector assembly to the mating connector.
By the construction as shown in this preferred embodiment, the conductor leads can be removed, reassigned and/or repaired in the field with minimum effort and time loss. Further, the connector assembly with the backshell reduces the likelihood of damage to the conductors, upon attachment to, use, and removal from complementary connectors.
The embodiment shown is illustrative of the invention in which modifications and substitutions can be made without departing from the spirit and scope thereof.
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Disclosed is an improved backshell for an electrical connector assembly, which accepts a plurality of conductor leads, the connector assembly including a receptacle for receiving the leads, and for attachment to a complementary connector by removable attaching means, and the backshell having interlocking portions for substantially enclosing a lead separator having holes for guiding individual leads into the receptacle whereby the connector assembly with the backshell can be readily assembled and disassembled, and can be installed on and removed from the complementary connector with minimum stress applied on the leads during installation, use and/or removal.
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BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for treatment of biological tissues of a living body and more particularly to a medical apparatus and method for pulsed electric field treatment induced by a time varying magnetic field.
Heretofore there has been considerable activity in medical research into the use of direct current, alternating current and pulse signals of single and double polarity in the treatment of biological tissues of living bodies. These research activities have included invasive treatments that utilize implanted electrodes as well as non-invasive techniques utilizing capacitively or inductively coupled induced electric fields. That electric fields stimulate biological changes other than nerve action potentials or thermal effects, which effects occur at much higher field intensities, has previously been demonstrated by producing polarity-selective bone growth and resorption.
In accordance with the present invention, non-invasive techniques are utilized to induce a pulsed electric field in the presence of a concomitant magnetic field to stimulate tissue regeneration or resorption in ordered biological structures, such as bone, or to stimulate cellular chemistry modifications of non-ordered biological structures as found in blood or blood serum. The use of induced, rather than conducted, electric fields for stimulation of osteogenesis has been disclosed in the U.S. Pat. No. 3,893,462 issued to Michael P. Manning. Specific waveform induced electric field strength and pulse repetition patterns using a time varying magnetic field for the treatment of living tissue and/or cells has been disclosed in the U.S. Pat. No. 4,105,017 issued to John P. Ryaby. In accordance with the disclosure in each of these United States patents, the particular field patterns utilized have been shown to require treatment times of several hours per day extending over a period of months. Further, the coil currents required to achieve the stated induced electric fields with the waveforms disclosed in these patents require the use of heavy treatment coils to avoid excessive heating and the consumption of excessive amounts of power through dissipation of the magnetic field energy of the coils. This severely restricts the range of electric field strengths and waveform durations available for treatment and further inhibits the portability of the apparatus. Furthermore, the orientation of the magnetic field and the concomitant induced electric field is spatially fixed and therefore cannot provide symmetrical or uniform stimulation of the treated region. As a result, unwanted spurious growths are often observed after the successful treatment of the original fracture area.
A still further drawback of known techniques for noninvasive treatment utilizing induced electric fields is the potential hazard of electric shock inherent with the large energy storage in high voltage capacitors associated with the waveforms and levels of stimulation.
While it has been recognized and established through research and clinical evaluation that a change in an electrical and/or electromechanical environment of a living cell and/or tissue produces a therapeutic effect on growth, repair and maintenance behavior of the tissue and/or cell, there has not been a general acceptance of such techniques within the medical community. The invasive techniques which implanted electrodes had serious side effects that all but eliminated these techniques. Surgically noninvasive direct inductive coupling, on the other hand, has met with some success and is now being seriously considered by the medical profession. However, there still remains objections to the use of direct inductive coupling primarily for the reasons previously discussed, in particular, the power requirement, weight, and shock hazard. The present invention provides for noninvasive induced pulsed electric fields and conmitant magnetic fields that minimize these disadvantages as found in systems heretofore considered by the medical profession.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a method of noninvasive treatment of biological tissue and/or cells wherein a driving current is generated in a coil and, in response thereto, a time changing magnetic field induces a pulsed electric field into a localized treatment area. The improvement of the present invention is to induce a pulsed electric field that produces a waveform having a first pulse in a first direction having a selected value, followed by a second pulse in a second direction having a second value larger than the value of the first pulse and followed by a third pulse in the first direction having a value on the order of the first pulse, and wherein this waveform repeats for a selected number of periods.
More specifically in accordance with the present invention, a pulsed electric field is induced into the biological tissue to be treated by the use of properly positioned coils connected to a switched bipolar current source. The waveform of the pulsed electric field has three identifiable parts including the first pulse in the first direction, a second pulse in the second direction and a third pulse also in the first direction. The magnetic field generated around the coils follows the bipolar current to induce into the treatment area a three-part waveform electric field. Thus, the induced electric field is the time derivative of the driving current with a resulting waveform as previously described.
The present invention utilizes the volt-second product of the individual pulses of the three-part waveform to artificially stimulate healing in cells or tissue of a living body. Specifically, the sum of the volt-second products of the first and third pulses of the waveform equals magnitude of the the volt-second product of the second pulse of the waveform. This is in contrast with heretofore generated waveforms that exbibit only two pulses, one of each polarity, where the first pulse has a small value and long time interval followed by a second pulse having a large value and a short interval or vice versa.
Further in accordance with the present invention, the effective power requirements of a three-pulse waveform are measurably lower than previous systems utilizing a two-pulse waveform. These power requirements are further reduced in the present invention by recycling the energy stored in the magnetic field of the treatment coils between energy storing devices.
In a preferred embodiment of the invention, this switching is accomplished by solid state elements that consume negligible power. When axial symmetry of the induced electric field stimulation is desired, such as in the treatment of a long bone nonfusion, the time changing magnetic field is generated by means of three coils arranged at equal angles around a desired axis of symmetry. These three coils are driven as sequential pairs with fields aiding on each driven pair. The coils are driven in a rotating sequence such that the magnetic field, and as a consequence the orthogonal induced electric field, is rotated through 120 degrees as each sequential pair of coils is driven. This produces a time-averaged symmetry of stimulation.
Also in accordance with the present invention, there is provided apparatus for the non-invasive treatment of biological living tissues and/or cells which apparatus includes a generator of bipolar driving currents. Means responsive to the bipolar driving currents induce a pulsed electric field into a localized treatment area. This means for inducing a pulsed electric field includes means for generating an electric field waveform that has a first pulse in a first direction having a selected value followed by a second pulse in a second direction having a second value larger than the value of the first pulse, and followed by a third pulse in the first direction on the order of the value of the first pulse. Further, there is provided means to couple the energy of the first pulse to generate the second pulse and couple the energy from the second pulse to generate the third pulse and to recover and store this energy for subsequent pulses.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the invention and its advantages will be apparent from the following detailed description taken in conjunction with the accompanying drawings.
Referring to the drawings:
FIG. 1A is a simplified schematic for describing the generation of the induced three-part waveform induced electric field including circuitry for recycling magnetic field energy;
FIG. 1B illustrates the current waveform for generating the three-part waveform of the pulsed electric field as also illustrated;
FIG. 2A is a simplified schematic of a three-coil configuration of the present invention to induce a symmetrical distribution of the electric field into the treatment area;
FIG. 2B is an illustration of one configuration of a three-coil apparatus in accordance with the present invention;
FIG. 2C is an alternate configuration of a three-coil apparatus wherein the induced electric field does not null on the axis and adjacent currents are in an aiding mode;
FIG. 3 is a schematic of a bipolar current drive circuit in accordance with the present invention; and
FIG. 4 is another embodiment of a bipolar current drive circuit using low power CMOS components.
DETAILED DESCRIPTION
Referring to FIG. 1A there is shown a simplified schematic of apparatus for inducing a three-part electric field into a localized treatment area. A high speed rotary switch 10 includes a wiper arm 12 driven in a clockwise direction as shown by the arrow 14. The rotary arm 12 wipes over three contact segments, 16, 18 and 20 to generate a three-pulse induced electric field by means of a treatment coil 22 having an inductance "L". Each of the contact segments 16, 18 and 20 forms a sector of a circle to establish the time duration for each pulse of the generated waveform.
Connected to the contact segments 16 and 20 is one terminal of a power supply 24 and one terminal of a recycling capacitor 26. The second terminals of the power supply 24 and the recycling capacitor 26 are connected to the treatment coil 22 at connection 21. Also connected to the treatment coil 22 at the connection 21 is one terminal of a recycling capacitor 28 which has a second terminal tied to the contact segment 18.
As the wiping arm 12 is rotated in the direction of the arrow 14 it sequentially connects the treatment coil 22 to each of the contact segments 16, 18 or 20. When connected to the contact segments 16 and 20 the treatment coil 22 is tied to the positive terminal of the recycling capacitor 26 and the positive terminal of the power supply 24. With the treatment coil 22 connected to the contact segment 18 the coil is tied to the negative terminal of the recycling capacitor 28. When the wiper arm 12 passes from the contact segment 20, the treatment coil 22 is disconnected from all sources of energy and the induced electric field decays to zero until the wiper arm again rotates to make contact with the segment 16.
During the time interval when the wiper arm 12 is between the end of the contact segment 20 and the beginning of the contact segment 16 the recycling capacitors 26 and 28 maintain a charge as previously established by the power supply 24.
As the wiper arm 12 rotates between the contact segments 16, 18 and 20 a bipolar driving current is generated as illustrated by the idealized waveform 30 of FIG. 1B. This waveform illustrates the flow of current "I" as measured in the treatment coil 22. As the current is illustrated by the waveform 30 flows through the treatment coil 22 an induced voltage V L appears across the coil. The waveform of this induced voltage and that induced in the treated tissue is illustrated by the waveform 32 of FIG. 1B.
As the wiper arm 12 first contacts the segment 16 the flow of current "I" in the treatment coil 22 begins to rise along a linear ramp at a rate dI/dt that is equal to the ratio V L /L. This is illustrated by the waveform segment 30a during the time t 1 which corresponds to the time the coil 22 is connected to the contact segment 16. That is, the length of the contact segment 16 establishes the time interval t 1 . With the treatment coil 22 connected to the contact segment 16 the recycling capacitor 26 is discharged through the coil until the wiper arm moves off of the segment 16. At this time, the current "I" has increased to a value I/2 and the treatment coil 22 is abruptly switched to the recycling capacitor 28 by the wiper arm 12 making contact with the contact segment 18. The current "I" in the treatment coil 22 continues to have a positive value as the recycling capacitor 28 is charged from the energy stored in the coil 22. The coil current continues in a positive direction until the energy that was stored in the magnetic field of the coil has been transferred to the recycling capacitor 28 (neglecting resistance losses). At this point the direction of current flow within the treatment coil 22 reverses to increase in a negative direction by discharging the capacitor 28 until the current reaches a negative peak value of -I/2. This negative peak value is reached when the wiper arm 12 rotates from the contact segment 18 and contacts the segment 20 and takes place during time t 2 . The coil has now been abruptly switched back to the recycling capacitor 26. While the wiper arm 12 was in contact with the contact segment 18 the waveform 30b of FIG. 1B illustrates the current flowing in the treatment coil 22.
As the wiper arm 12 contacts the segment 20 the treatment coil 22 is again reconnected to the recycling capacitor 26. However, the current flow is still in the negative direction but decreasing in magnitude along a linear ramp toward the zero axis. During this time interval t 3 the stored energy of the magnetic field on the coil 22 is recycled to charge the capacitor 26 until the current has returned to zero. The treatment coil 22 is disconnected by the wiper arm 12 leaving the contact segment 20. The time interval while recycling the energy of the magnetic field in the coil 22 into the recycling capacitor 26 is given by the interval t 3 . That is, the time t 3 is established by the amount of time the wiper arm 12 wipes over the contact segment 20. The treatment coil 22 remains disconnected until the wiper arm 12 again makes contact with the contact segment 16 and the sequence repeats generating another section of the current waveform 30.
With reference to the waveform 32 of FIG. 1B, the induced voltage in the treatment coil 22 is the time derivative of the changing coil current I. This induced voltage generates a time changing magnetic field to induce pulsed electric fields into a localized treatment area. The induced pulsed electric field will have a waveform substantially as illustrated in FIG. 1B at 32. That is, there will be a first positive pulse during time t 1 having a selected value as determined by the power suppy 24 and the recycling capacitor 26 and 28 along with speed of rotation of the wiper arm 12. A second pulse will follow the first pulse of the electic field with the second pulse in a negative direction and having a negative value that is larger than the first value as determined by the recycling capacitors 26 and 28 and the length of the contact segment 18 which as mentioned establishes the time t 2 . This second pulse will be followed by a third pulse that will be in the same direction as the first pulse and has a value on the order of the first pulse, again as determined by the components of the circuit illustrated in FIG. 1A. This waveform will repeat each time the wipe arm 12 again re-establishes contact with the contact segment 16.
It is desirable for the induced voltage of the treatment coil 22 to remain substantially constant during each of the time intervals t 1 , t 2 and t 3 . This requires that the corresponding coil current be rising and falling at a uniform rate. A linear current waveform is obtained with an accuracy of plus or minus 5% if the time constant defined by the inductance "L" of the treatment coil 22 and the series circuit resistance "R" as given by the expression T=L/R is 21/2 times greater than the rise or fall time, that is, greater than the time interval t 1 . For this condition and with the ratio t 1 /t 2 =5, the ratio of energy stored in the magnetic field to energy dissipated will be approximately 3.4 thereby providing for substantial recovery of energy from the coil.
In operation, the circuit of FIG. 1A generates a bipolar driving current flowing through the treatment coil 22 to produce a time changing magnetic field. This time changing magnetic field surrounding the treatment coil 22 induces a pulsed electric field into a localized treatment area at which the coil is positioned. The amount of power required to produce a given level of therapeutic effect on living tissue and/or cells has been shown to be on the order of four times lower than a corresponding monopolar circuit of the prior art that generates a two-pulse waveform. Further, the amount of energy consumed during a treatment cycle is reduced by operation of the recycling capacitors 26 and 28. Combined with the use of aluminum rather than copper coil winding, the present invention provides an order-of-magnitude reduction of coil weight for a given volt-seconds of induced electric field compared with prior monopolar drive current configurations.
Referring to FIG. 2A, there is shown a schematic representation of rotating switch implementation for generating rotating induced pulsed electric fields in localized treatment areas. The implementation of FIG. 2A may be utilized in conjunction with any suitable source of coil current which may be the circuit of FIG. 1A. Thus, the implementation of FIG. 2A includes a two segment rotary switch 34 rotating in the direction of the arrow 36. The contact segment 38 of the rotary switch 34 is connected to the wiper arm 12 of FIG. 1A through a slip ring or equivalent (not shown) and the contact segment 40 is connected to the connection 21 also through a slip ring or equivalent (not shown). Thus, the circuit of FIG. 2A replaces the treatment coil (or coils) 22 of FIG. 1A.
In FIG. 2A there is shown treatment coils 42, 44 and 46. Treatment coils 42 and 44 are interconnected to a wiper arm 48, treatment coils 44 and 46 are interconnected to a wiper arm 50 and treatment coils 46 and 42 are interconnected to a wipe arm 52. The contact segments 38 and 40 are configured so that the three treatment coils are excited in pairs.
With a three treatment coil configuration, the contact segment 38 occupies 120 degrees of rotation while the contact segment 40 occupies 240 degrees of rotation. As these segments are rotated in the direction of the arrow 36, two of the three treatment coils will be connected to the wiper arm 12. As illustrated in FIG. 2A, coils 42 and 46 are connected to the wiper arm 12 by means of the wiper arm 52. At the same time, these same two treatment coils are connected to the power supply 24 and the recycling capacitors 26 and 28 at the connection 21. This connection is made by means of the wiper arms 48 and 50, respectively. During this time interval the treatment coil 44 will be shorted and will not be contributing to the induced electric field in the treatment area.
As the contact segments 38 and 40 rotate in the direction of the arrow 36, the next two coils energized in the sequence will be treatment coils 42 and 44. When treatment coils 42 and 44 are energized, then the treatment coil 46 is shorted as the contact segment 40 has rotated to make contact with the wiper arms 50 and 52. To complete the sequence, the treatment coils 44 and 46 are connected in parallel and energized while the coil 42 is shorted as the contact segment 40 is rotated to make contact with the wiper arms 48 and 52. It should be noted that it is not a requirement to short circuit the unused coil in this switching sequence since there is little magnetic flux coupling to the unused coil and it therefore has little effect on the fields of the active coils. The shorting sequence is merely a result of the operation of the rotary switch 34.
Rotation of the switch 34 is timed to occur at a rate no greater than the repetition rate of the coil current drive circuit as shown in FIG. 1A. That is, the wiper arm 12 will rotate through all three contact segments 16, 18 and 20 before the rotary switch 34 connects a subsequent pair of treatment coils to the circuit of FIG. 1A. Preferably, rotation of the wiper arm 12 and the rotary switch 34 is synchronized to avoid drive pulses while the switches are transitioning between segments.
Referring to FIGS. 2B and 2C, these are isometric illustrations of two arrangements of the treatment coils 42, 44 and 46 arranged about a desired treatment axis of symmetry indicated by the center line 54 in FIG. 2B and the center line 56 in FIG. 2C. The coil configuration of FIG. 2B produces a symmetrical rotating induced electric field having a null near the center line 54. In this configuration currents in adjacent coil wires are in the same direction producing aiding magnetic fields. With reference to FIG. 2C the rotating induced electric fields do not null near the center line 56 although the currents in adjacent coil wires are in the same direction. The coil configuration of FIG. 2B will be recognized as approximately a Helmholtz pair while that of FIG. 2C approximates a toroidal coil. The selection of the coil configuration of either FIG. 2B or FIG. 2C will depend upon the application and the treatment area which is usually near the center line. In either case the axis of symmetry is maintained resulting in a symmetrically induced biological effect while maintaining a constant polarity along the axis in applications where the polarity of the high induced electric field relative to the direction of low induced electric field is desirable.
It will be appreciated from the foregoing description that the direction of the induced electric field with respect to the axis of symmetry is independant of the direction of rotation of the rotary switch 34 of FIG. 2A. Thus, the direction of rotation of the electric field is reversible by reversing the direction of rotation of the switch 34. It should also be recognized that while in FIG. 2B and FIG. 2C three coils are illustrated, the number of treatment coils may be varied and increased, for example, to six or more. Providing more treatment coils enables a more finely graduated advance of the rotating field around the axis of symmetry of the treatment area.
Referring now to FIG. 3, there is shown an implementation of a bipolar current drive in accordance with the present invention utilizing field effect transistors as the switching element in place of the rotary switches of FIG. 1A. In the circuit of FIG. 1 the treatment coil 22, the recycling capacitors 26 and 28 and the power supply 24 are the same as those illustrated in FIG. 1A. The function of the rotary switch 10 of FIG. 1A has been replaced by an N-channel field effect transistor (FET) 58 and a P-channel field effect transistor (FET) 60. Basically, the FET 58 replaces the contact segment 16 and the FET 60 replaces the contact segment 18 of FIG. 1A. The FET 58 is switched "on" for a time interval t 1 by means of a drive voltage 62 applied to a gate drive circuit including resistor 64 and 66. Similarly, the FET 60 is switched on for a time interval t 2 by a voltage 68 by means of a gate drive circuit including resistors 70 and 72. It should be noted that the time intervals t 1 and t 2 are the same as illustrated in FIG. 1B.
To protect the FET 58 during operation of the circuit of FIG. 3 a Zener diode is connected between the drain and source terminals of the FET. This protects the FET from excessive transient voltages created by the collapsing field of the treatment coil 22 during switching of the current flow. Similarly, a Zener diode 76 is connected between the drain and source terminals of the FET 60 for protection from excessive transient voltages.
In operation, switching "on" the FET 58 produces a current flow I 1 from the recycling capacitor 26 through the treatment coil 22 increasing at a rate as illustrated by the waveform segment 30a of FIG. 1B. The current flowing through the treatment coil 22 reaches a maximum at the end of the time interval t 1 as controlled by the duration of the drive voltage 62. At this point the FET 58 is turned "off" and the FET 60 is simultaneously turned "on" by means of the applied voltage 68. Current flow through the treatment coil 22 is now illustrated by the waveform segment 30b of FIG. 1B during time interval t 2 . This current is indicated in FIG. 3 by I 2 and flows to the recycling capacitor 28 via diode 76 in its forward direction. Current flows into the capacitor 28 until it reaches the zero axis level and then switches and flows from the capacitor via FET 60 into the treatment coil 22 until the FET 60 is switched "off" at the end of the time interval t 2 . With both the FET 58 and the FET 60 switched "off", stored energy of the magnetic field surrounding the treatment coil 22 generates a current flow through the Zener diode 74 in its forward direction as indicated by the arrow I 3 recharging the recycling capacitor 26. This continues until the magnetic field has completely collapsed and zero current is flowing through the circuit. The time required for the current I 3 to return to a zero value is defined by the time interval t 3 of FIG. 1B.
Because the Zener diode 74 has a small forward voltage drop as a result of the current flow I 3 , a small amount of stored energy will remain in the magnetic field surrounding the treatment coil 22 at the nominal end of the time interval t 3 . This will result in a damped oscillation at a frequency determined by the inductance of the treatment coil 22 and a small stray capacitance associated therewith. To provide critical damping of this oscillation a resistor 78 is connected in parallel with the treatment coil 22.
It will be appreciated that the circuit of FIG. 3 functions in a manner similar to the circuit of FIG. 1A to generate a time changing magnetic field to induce a pulsed electric field into a localized treatment area by means of the treatment coil 22. The waveform of the pulsed electric field will have a first pulse in a positive direction having a selected value. This first pulse will be followed by a second pulse in the negative direction having a second value larger than the value of the first pulse. This second pulse will in turn be followed by a third pulse in the positive direction again having a value on the order of the first pulse. This waveform is illustrated at 32 in FIG. 1B. By means of the treatment coil 22 in the circuit of FIG. 3 there is provided a method and apparatus for noninvasive treatment of biological living tissues and/or cells in a body.
Referring to FIG. 4, there is shown a schematic of an electronic bipolar current drive and energy recovery circuit including timing circuits for generating the drive voltages for FET transistors 58 and 60. In FIG. 4 the circuit of FIG. 3 with reference to the field effect transistors 58 and 60 is repeated. Thus, for the FET 58 there is the gate drive circuit including resistors 64 and 66 and for the FET 60 there is the gate drive circuit including resistors at 70 and 72. Transient high voltage protection provided by Zener diodes 74 and 77 is also included in FIG. 4 connected to the FET 58 and the FET 60, respectively. Also illustrated in FIG. 4 is the treatment coil 22 and the recycling capacitor 28. The recycling capacitor 26 has been replaced by a capacitor network 82 comprising four capacitors in parallel. Also the power supply 24 has been replaced with an external power supply connected to a terminal 80. Parallel with the treatment coil 22 is the resistor 78.
Also illustrated in FIG. 4 is a gas discharge indicating light 84 in series with a resistor 86 ad connected in parallel with the recycling capacitor 28. This light gives an indication that the treatment coil 22 is being energized and is neither open circuited nor short circuited.
To provide the drive voltages to the FET 58 and the FET 60, there is provided an integrated circuit 88 and an integrated circuit 90 which are each dual timers (such as the type 7556). The first half of the integrated circuit 88 (pins 1 through 6) operates as an astable multivibrator that controls the repetition frequency of the drive pulses to FETs 58 and 60. Typically, the pulse repetition frequency will vary between 30 and 120 pulses per second and is adjustable by means of a variable resistor 92.
An output of the astable multivibrator is shown by the waveform 94 and triggers a monostable multivibrator that comprises the second half of the integrated circuit 88 (pins 8 through 13). This monostable multivibrator generates an output as indicated by the waveform 96 that drives the gate of the FET 58. Typically, the pulse width of the waveform 96 varies between 250 and 750 microseconds and is adjustable by means of a variable resistor 98.
In addition to driving the FET 58 the output of the monostable multivibrator is applied to a differentiator circuit including a capacitor 100 and resistors 102 and 104 to generate a trigger pulse (the waveform 106) to trigger a monostable multivibrator comprising the first half of the integrated circuit 90 (pins 1 through 6). This monostable multivibrator generates an output havng the desired pulse width for driving the FET 60. The pulse width is adjusted within the range of 50 to 150 microseconds by means of an adjustable resistor 108. The pulse output of the monostable multivibrator comprising the first half of the integrated circuit 90 as illustrated by the waveform 110 and is applied to an inverter comprising the second half of the integrated circuit. The inverted pulse output of the inverter is indicated by the waveform 112 and is applied to the drive circuit for the FET 60.
Operationally, the circuit of FIG. 4 is similar to the circuit of FIG. 3. The FET 58 and the FET 60 in conjunction with the integrated circuits 88 and 90 operate to produce a time changing magnetic field to induce a pulsed electric field into a localized treatment area by means of the treatment coil (or coils) 22. The three-pulse waveform of this electric field is illustrated in FIG. 1B.
As an alternate embodiment to FIG. 3 the treatment coil (or coils) 22 is replaced by the circuit of FIG. 2A. To be consistent with the FET switching of FIG. 3 the rotary switch 34 may also be replaced with semiconductor switching devices. This modification of FIG. 3 results in a rotation of the electric field by means of the treatment coils 42, 44 and 46 to produce a time-averaged symmetry of stimulation in the treatment area for bone growth and repair.
Similarly, the circuit of FIG. 4 is modified to replace the treatment coil 22 with the circuit of FIG. 2A. Again, semiconductor switching replaces the rotary switch 34 as illustrated in FIG. 2A. The energy-saving features as described with reference to FIG. 1A will also be found in these modifications of FIGS. 3 and 4.
While the present invention has been described with respect to specific details thereof, it should be understood that various changes and modification will be suggested to one skilled in the art to which the invention relates, and it is intended to encompass those changes and modifications which fall within the scope of the appended claims.
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The treatment of biological tissue is effected by a pulsed electric field induced by a time changing magnetic field produced by a magnetic coil or a plurality of magnetic coils. These magnetic coils are arranged in the area of desired treatment and respond to a driving current to induce the pulsed electric field into the localized treatment area. The driving current and concomitant magnetic field generates an electric field waveform that has a first pulse in a positive direction having a selected value followed by a second pulse in a negative direction having a larger value than the first pulse, and in turn followed by a third pulse in the positive direction having a value on the order of the first pulse. The apparatus for applying the driving current includes switching circuitry for energizing the magnetic coils in pairs to induce a symmetrical distribution of the magnetic and electric fields in the treatment area. This achieves time averaged uniformity of the pulse electric field in the tissue for applications such as stimulation of osteogenesis in long bone nonfusions.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a division of application Ser. No. 635,297 filed Nov. 26, 1975, now U.S. Pat. No. 4,006,230 which, in turn is a continuation-in-part of application Ser. No. 504,381, filed Sept. 9, 1974 and now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to antibacterial agents and is particularly concerned with a class of novel cephalosporin derivatives with broad spectrum antibacterial activity, more especially against gram-negative organisms. In particular, the compounds of the invention constitute a series of 7-(α-amino-arylacetamido)-Δ 3 -cephem derivatives having a novel type of acyl group attached to the α-amino group.
British Pat. No. 1,328,340, published Aug. 30, 1973, describes cephalosporins having the above formula wherein X is a direct carbon-carbon link or a methylene group. However, such compounds as are claimed in the present invention are not structurally obvious over these prior art compounds. Additionally, they exhibit superior antibacterial activity relative to the prior art compounds.
SUMMARY OF THE INVENTION
According to the invention, there are provided compounds having the general formula: ##STR2## wherein R 1 represents a phenyl, 2- or 3-thienyl or 2-furyl group, the phenyl and thienyl groups optionally being substituted with one or more moieties chosen from halogen, hydroxyl, lower alkyl, lower alkoxy and trifluoromethyl; R represents a hydroxyl group, and R 2 represents a hydrogen atom or a hydroxy, acetoxy, carbamoyloxy, N-pyridyl, substituted N-pyridyl, azido or heterocyclicthio group, for example, a 4,6-dimethyl pyrimidin-2-ylthio, 4,5-dimethylthiazol-2-ylthio, 1,3,5-triazin-2-ylthio, pyrimidin-2-ylthio, 2-methyl-1,3,4-thiadiazol-5-ylthio, 2-methyl-1,3,4-oxadiazol-5-ylthio or 1-substituted-1,2,3,4-tetrazol-5-ylthio group wherein the 1-substituent represents a lower alkyl, lower alkenyl, cycloalkyl, benzyl or phenyl group, the latter group optionally being substituted with one or more moieties chosen from halogen, lower alkyl and lower alkoxy; or R and R 2 taken together represent an oxygen atom; R 3 represents a sulpho group; or a group of the formula COOR 4' , wherein R 4' represents hydrogen or R 4 wherein R 4 is lower alkyl, 5-indanyl, naphthyl or phenyl group, the phenyl group optionally being substituted with one or more moieties chosen from halogen, lower alkyl, lower alkoxy and trifluoromethyl; or a carbamoyl group of the formula CONR 5 R 6 , wherein R 5 and R 6 each independently represent a hydrogen atom or a lower alkyl or a cycloalkyl group, or together with the nitrogen atom to which they are attached form a saturated heterocyclic group; X represents an oxygen or sulphur atom, a direct carbon-carbon link, or a carbonyl, methylene, hydroxymethylene, sulphinyl or sulphonyl group, or an imino group of the formula --NR 7 --, wherein R 7 represents a hydrogen atom or a lower alkyl, lower alkenyl, or a benzyl group; and alk 1 and alk 2 each independently represent a divalent saturated aliphatic hydrocarbon group containing from 1 to 3 carbon atoms; and the pharmaceutically acceptable salts thereof.
The pharmaceutically acceptable salts of the novel compounds of the invention include non-toxic metallic salts, particularly of lithium, sodium, potassium, calcium and aluminum, ammonium, and substituted ammonium salts, e.g., of trialkylamines, N-ethylpiperidine, procaine, dibenzylamine, N-benzyl-β-phenylethylamine, 1-ephenamine, N,N'-dibenzylethylenediamine, dehydroabietylamine, N,N'-bis-dehydroabietylethylenediamine and other amines previously used to form salts with benzylpenicillin. Compounds of the formula (I) in which R 2 represents an N-pyridyl group, itself positively charged, are internal salts, having the 4-carboxyl group converted to the corresponding carboxy anion, COO - .
In the above-described normal salts, a single cation may accompany the terminal deprotonated carboxyl or sulpho group represented by R 3 , or the deprotonated 4-carboxyl group, or there may be two cations, one accompanying each of the deprotonated groups.
In this specification, by "halogen" is meant fluorine, chlorine, bromine, or iodine and the term "lower" applied to an alkyl, alkoxy or alkenyl group indicates that such a group contains up to 6 carbon atoms. Where a lower alkyl, alkoxy or alkenyl group contains from 3 to 6 carbon atoms, it may be straight or branched chain. A cycloalkyl group may contain from 3 to 6 carbon atoms.
When R 3 in the formula (I) represents a carbamoyl group of the formula CONR 5 R 6 , any saturated heterocyclic group represented by NR 5 R 6 may contain a second nitrogen atom or an oxygen or sulphur atom as a ring atom. A second nitrogen atom preferably carries a lower alkyl or a benzyl group as substituent. Examples of saturated heterocyclic groups embraced by NR 5 R 6 are the pyrrolidino, piperidino, morpholino, thiomorpholino, perhydroazepino, piperazino or perhydrodiazepino groups, the latter two preferably bearing a lower alkyl or a benzyl group on the second nitrogen atom.
The divalent saturated aliphatic hydrocarbon group represented by alk 1 and alk 2 may have the free valencies located on the same or different carbon atoms. Hence, each may be a methylene, ethylene, trimethylene, ethylidene, propylidene, or 1- or 2-methylethylene group.
The cephalosporin derivatives of the present invention are capable of existing in epimeric "D" and "L" forms, and the invention includes the separated D- and L-epimers as well as mixtures thereof.
One preferred group of compounds of formula (I) are those in which
R is a hydroxy group;
R 1 represents a phenyl, 2-thienyl or 2-furyl group, the first two groups optionally being substituted with one or more moieties chosen from halogen, hydroxyl, lower alkyl, lower alkoxy and trifluoromethyl;
R 2 represents a hydrogen atom or an acetoxy, unsubstituted N-pyridyl, substituted N-pyridyl, azido, 2-methyl-1,3,4-thiadiazol-5-ylthio, 2-methyl-1,3,4-oxadiazol-5-ylthio or 1-substituted-1,2,3,4-tetrazol-5-ylthio group wherein the 1-substituent represents a lower alkyl, lower alkenyl, cycloalkyl, benzyl or phenyl group, the latter group optionally being substituted with one or more moieties chosen from halogen, lower alkyl and lower alkoxy;
R 3 is as previously defined for formula (I);
X represents an oxygen or sulphur atom, a direct carbon-carbon link, or a carbonyl, methylene, hydroxymethylene, sulphinyl or sulphonyl group, or an imino group of the formula --NR 7 --, wherein R 7 represents a hydrogen atom or a lower alkyl or a benzyl group; and
alk 1 and alk 2 are as defined for formula (I);
and the pharmaceutically acceptable salts thereof.
More preferably, the invention provides compounds of the formula (I) wherein R is a hydroxy group, R 1 represents a phenyl group optionally substituted with one or more moieties chosen from halogen, hydroxyl, lower alkyl, lower alkoxy and trifluoromethyl; R 2 represents an acetoxy or 1-substituted-1,2,3,4-tetrazol-5-ylthio group wherein the substituent is as defined for formula (I); R 3 represents a carboxyl group or an ester group of the formula --COOR 4 wherein R 4 is as defined for formula (I); X is an oxygen atom; and alk 1 and alk 2 are each a methylene group.
Preferably R 1 is a p-hydroxyphenyl group optionally substituted with one or more moieties chosen from halogen, lower alkyl, lower alkoxy and trifluoromethyl, and most preferably is a p-hydroxphenyl or m-chloro-p-hydroxyphenyl group.
Particularly preferred individual compounds include the following:
7-D-(α-Carboxymethoxyacetamido-phenylacetamido)cephalosporanic acid;
7-D-(α-Carboxymethoxyacetamido-phenylacetamido)-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)-Δ 3 -cephem-4-carboxylic acid;
7-D-(α-Carboxymethoxyacetamido-phenylacetamido)-3-(2-methyl-1,3,4-thiadiazol-5-ylthiomethyl)-Δ 3 -cephem-4-carboxylic acid;
7-D-(α-Carboxymethoxyacetamido-[p-hydroxyophenyl]acetamido)cephalosporanic acid;
7-D-(α-Carboxymethoxyacetamido-[m-chloro-p-hydroxyphenyl]acetamido)-cephalosporanic acid;
7-D-(α-Carboxymethoxyacetamido-[p-hydroxyphenyl]acetamido)-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)-Δ 3 -cephem-4-carboxylic acid;
7-D-(α-Carboxymethoxyacetamido-[m-chloro-p-hydroxyphenyl]acetamido)-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)-Δ 3 -cephem-4-carboxylic acid;
7-D-(α-Carboxymethyl-[N-methyl]aminoacetamido-phenylacetamido)-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)-Δ 3 -cephem-4-carboxylic acid;
7-D-(α-[5-Indanyl]oxycarbonylmethoxyacetamido-phenylacetamidocephalosporanic acid;
7-D-(α-[4-Isopropylphenyl]oxycarbonylmethoxyacetamido-phenylacetamido)cephalosporanic acid;
7-D-(α-[2-Methoxyphenyl]oxycarbonylmethoxyacetamido-phenylacetamido)cephalosporanic acid;
7-D-(α-[2-Methylphenyl]oxycarbonylmethoxyacetamido-phenylacetamido)-cephalosporanic acid; and
7-D-(α-[n-butyl]oxycarbonylmethoxyacetamido-phenylacetamido)cephalosporanic acid.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of the invention may be prepared in a number of ways, including the following:
1. Compounds of the formula (I), in which R 3 represents a carboxyl or sulpho group, R 2 is as already defined other than a hydroxy group, and X is as already defined other than an unsubstituted imino group, --NH--, may be prepared by reacting a 7-(α-aminoarylacetamido)-4-carboxy-Δ 3 -cephem derivative of the formula: ##STR3## with a cyclic anhydride of the formula: ##STR4## respectively, wherein X is defined as above in this method.
Such a reaction may be accomplished by mixing together the reagents, that of the formula (II) optionally as a salt or necessarily as an internal salt in the case where R 2 represents an N-pyridyl group, in a reaction-inert organic solvent medium, e.g. dimethylformamide, methylene dichloride or acetone, optionally containing a tertiary amine base, e.g. triethylamine or pyridine, or an inorganic base, e.g. sodium bicarbonate. Generally, the reaction goes substantially to completion during a period from 1/2 to 12 hours when the mixture is maintained within the temperature range 10°-45° C., preferably with stirring. Isolation of the product is typically achieved by extracting the reaction mixture with an aqueous medium, e.g. water itself or a basic aqueous medium such as saturated aqueous sodium bicarbonate solution, overlayering the separated aqueous medium with a suitable water-immiscible solvent, e.g. ethyl acetate, acidifying the aqueous phase, e.g. by addition of a mineral acid such as hydrochloric acid and shaking with two-phase solution in order to extract the product into the organic phase, and thereafter separating, washing (e.g. with a saline solution), drying (e.g. with anhydrous magnesium or sodium sulphate), filtering and evaporating to dryness the organic phase. If necessary, the product may be purified by a standard recrystallization technique.
In the case of compounds of the formula (I) in which the grouping alk 2 -X-alk 1 represents or embraces a hydrocarbon chain containing 4 or more carbon atoms, the reaction involving a cyclic anhydride of the formula (III) is generally performed using that compound in a polymeric form in view of the frequent difficulty in obtaining it in a monomeric form. An isolation procedure similar to the one described above would frequently afford a product contaminated with a significant quantity of dicarboxylic acid of the formula:
HOOC--alk.sup.2 --X--alk.sup.1 --COOH (V)
and accordingly it is often necessary to perform more than a single acidification-extraction step at different degrees of acidity and investigate the nature of the extracted product at each stage in order to isolate the desired product in an acceptable state of purity.
2. A half-ester of the formula:
R.sup.4 OOC--alk.sup.2 --X--alk.sup.1 --COOH (VI)
wherein X represents any of the hereinbefore specified atoms or groups with the exception of an unsubstituted imino group, --NH--, and which itself may be prepared according to conventional procedures involving reacting the appropriate compound of the formula (III) with a lower alkanol, R 4 OH, or with the sodio derivative of a lower alkanol, phenol, substituted phenol, 5-indanol or naphthol, R 4 ONa, followed by acidification, may be reacted (as such, or after conversion to a reactive derivative thereof, e.g. its acid chloride, an "activated" ester or a mixed anhydride) with a 7-(α-aminoarylacetamido)-4-carboxy-Δ 3 -cephem derivative of the formula (II) other than those in which R 2 is a hydroxyl group to produce a compound of the formula (I) in which R 3 represents an ester group, COOR 4 as hereinbefore defined, and X is defined as above in this method.
If the half-ester is to be reacted as such, this is conveniently effected in the presence of a dehydrating agent, e.g. dicyclohexylcarbodiimide or carbonyldiimidazole. In a typical procedure using carbonyldiimidazole, a solution of the half-ester in a suitable reaction-inert organic solvent, e.g. methylene chloride, is added to a cooled solution of the dehydrating agent in the same solvent, and after evolution of carbon dioxide has ceased the mixture is stirred at room temperature for a short time prior to addition of the Δ 3 -cephem derivative. Reaction may then be allowed to proceed during several hours at room temperature, preferably with continual stirring of the solution. Isolation of the product may be effected by evaporation of the reaction solution in vacuo to dryness, dissolution of the residue in water, extraction of the acidified aqueous solution into a water-immiscible organic solvent, e.g. ethyl acetate, and evaporation of the optionally washed and dried (e.g. with anhydrous magnesium sulphate) organic phase to dryness. The crude product thus produced may be purified, suitably by a standard crystallization technique.
The same reaction may alternatively be performed in aqueous solution using a water-soluble diimide as the dehydrating agent, of which a typical example is 1-(3-dimethylamino-n-propyl)-1-ethylcarbodiimide hydrochloride. In such a case, a mixture of the two reagents and the water-soluble diimide is added to an aqueous solvent, e.g. water itself or aqueous acetone, and the pH of the solution is adjusted to 5-6, e.g. by addition of hydrochloric acid, and maintained within that acidity range for several hours until stabilization, i.e. when no further quantity of mineral acid is required to maintain the acidity range. The product may then be extracted into a water-immiscible organic solvent, e.g. ethyl acetate, after acidifying the aqueous phase further, and isolating by evaporating to dryness the optionally washed and dried organic phase. Purification may then be effected by suitable means.
If it is desired to react the half-ester of the formula (VI) as its acid chloride with the 7-(α-aminoarylacetamido)-4-carboxy-Δ 3 -cephem derivative, the initial conversion to the acid chloride may be effected using a well-known standard technique for such a reaction e.g. by maintaining a solution of the half-ester and a chlorinating agent such as oxalyl chloride or thionyl chloride in a suitable reaction-inert organic solvent such as benzene for several hours, preferably with stirring, at a suitable temperature, and isolating the crude product by evaporation of the reaction solution to dryness. Thereafter, the residue is conveniently reacted directly with the appropriate Δ 3 -cephem derivative, without purification, in a solvent, e.g. aqueous acetone, containing a base of the sort exemplified in Method (1) above. After sufficient reaction time, e.g. several hours, the product is conveniently isolated and purified by extracting it from an acidified aqueous solution into an organic phase, e.g. ethyl acetate, and then following a similar procedure to that described in Method (1) for the isolation and purification of the product.
The half-ester of the formula (VI) may be converted into an "activated" ester prior to reaction with the 7-(α-aminoarylacetamido)-4-carboxy-Δ 3 -cephem derivative using the preferred reagent N-hydroxysuccinimide in the presence of a dehydrating agent such as dicyclohexylcarbodiimide. The "activated" ester product of the formula: ##STR5## is conveniently then reacted with the Δ 3 -cephem derivative in the reaction solution in which it has been formed, without isolation. In a typical procedure, a solution of the half-ester, N-hydroxysuccinimide and dehydrating agent in a reaction-inert organic solvent, e.g. tetrahydrofuran, is stirred for several hours at room temperature, after which the solid N,N'-dicyclohexylurea formed in the reaction may be removed, e.g. by filtration. To the solution containing the "activated" ester is then added a solution of the Δ 3 -cephem derivative, and reaction generally goes substantially to completion in the presence of a tertiary amine or inorganic base, as hereinbefore examplified and preferably with stirring during a period from 1 to 12 hours at room temperature. The solvent may then be removed, e.g. by evaporation in vacuo, and the residue dissolved in water, the aqueous solution then being acidified, extracted with a water-immiscible organic solvent, e.g. ethyl acetate, and the organic phase subjected to a similar procedure to that described in Method (1) for the isolation and purification of the product.
If the half-ester of the formula (VI) is to be converted to a mixed anhydride prior to reaction with the 7-(α-aminoarylacetamido)-4-carboxy-Δ 3 -cephem derivative, the initial conversion is suitably performed using a lower alkyl chloroformate, e.g. ethyl chloroformate. The reaction may suitably be effected by stirring a mixture of the half-ester, lower alkyl chloroformate and an equivalent quantity of a tertiary amine or inorganic base of the kind hereinbefore exemplified in a suitable solvent, e.g. methylene chloride, at a low temperature, e.g. 0° C., for a short time, e.g. 1/2 hour. Reaction with the Δ 3 -cephem derivative may then be effected, without the necessity to isolate the mixed anhydride, by adding a solution of the former in a suitable solvent, e.g. methylene chloride, containing an equivalent quantity of a base of the kind hereinbefore exemplified, to the reaction solution of the mixed anhydride, of the formula:
R.sup.4 OOC--alk.sup.2 --X--alk.sup.1 --CO--O--COOR.sup.8 (VIII)
wherein R 8 represents a lower alkyl group,
and stirring the reaction solution at room temperature for several hours. Isolation and purification of the product may then be effected by removing the reaction solvent, e.g. by evaporation in vacuo, dissolving the residue in water, acidifying the aqueous solution, extracting it with a waterimmiscible organic solvent, e.g. ethyl acetate, and subjecting the organic phase to a similar procedure to that described in Method (1) in the final stages.
3 Compounds of the formula (I) in which R 3 represents a carbamoyl group of the formula CONR 5 R 6 , as hereinbefore defined, R 2 is as already defined other than a hydroxyl group, and X is as already defined other than an unsubstituted imino group, --NH--, may be prepared by reacting a half-amide of the formula:
R.sup.5 R.sup.6 NCO--alk.sup.2 --X--alk.sup.1 --COOH (IX)
optionally after conversion to its acid chloride, an "activated" ester or a mixed anhydride, with a 7-(α-aminoarylacetamido)-4-carboxy-Δ 3 -cephem derivative of the formula (II) other than those in which R 2 is a hydroxyl group. The half-amide of the formula (IX) may itself be prepared by reacting the appropriate amine, NHR 5 R 6 , with a cyclic acid anhydride of the formula (III) according to a conventional procedure.
The reaction between the half-amide or aforementioned derivative thereof and the Δ 3 -cephem derivative, and conversion of the half-amide into the appropriate derivative, where appropriate, prior to reaction with the Δ 3 -cephem derivative, may be achieved according to the analogous procedures given in Method (2), starting from the half-amide instead of the half-ester, and the isolation procedures may also be effected analogously.
4. Compounds of the formula (I) in which R 2 represents an N-pyridyl or azido group or any of the heterocyclic-thio groups specified hereinbefore may be prepared from the corresponding compounds in which R 2 represents an acetoxy group (cephalosporanic acid derivatives) by a displacement reaction with pyridine, sodium azide or the appropriate heterocyclic-thiol.
In the case of R 2 representing an azido or a heterocyclic-thio group, such a reaction may generally be performed by adding one of the latter reagents to a solution of the appropriate cephalosporanic acid derivative in an aqueous buffer solution, e.g. phosphate buffer, at a pH between 6 and 7.5, optionally containing a base, e.g. sodium bicarbonate, and heating the mixture within the temperature range 35°-70° C. for a period from 1 to 12 hours. The product may then be isolated by diluting the reaction mixture with water, overlayering the aqueous medium with a suitable water-immiscible organic solvent, e.g. ethyl acetate, acidifying the aqueous phase, e.g. to pH 2 by addition of sufficient hydrochloric acid, and thereby inducing extraction of the product into the organic phase, especially with shaking in addition, and thereafter separating, washing, e.g. with a saline solution, drying, e.g. with anhydrous magnesium sulphate, filtering and evaporating to dryness the organic phase. Purification of the crude product, if necessary, may be achieved by a standard recrystallization technique or by washing with a suitable solvent, e.g. diethyl ether.
In the case of R 2 representing an N-pyridyl group, the reaction may be performed by adding first pyridine, e.g. in 1 to 3 molar equivalents, and then potassium thiocyanate or iodide, e.g. in 1 to 10 molar equivalents, to a molar equivalent of the cephalosporanic acid derivative dissolved in water containing at least one molar equivalent of a base of the kind hereinbefore exemplified. To the mixture is then added sufficient phosphoric acid until pH 6 is attained, and the whole is suitably heated within the temperature range 25°-70° C. for a period from 6 to 48 hours. The product, either as the thiocyanate or iodide salt, may then be isolated by adjusting the pH of the solution to 2, e.g. by addition of 2N hydrochloric acid, and collecting the resulting precipitate by filtration. The betaine form of the product may be obtained by well-documented standard ion-exchange procedures.
5. Compounds of the formula (I) in which R 3 represents an ester group, COOR 4 , or a carbamoyl group, CONR 5 R 6 , as hereinbefore defined, and X represents an oxygen or sulphur atom, or an imino group, -NR 7 -, as hereinbefore defined, may be prepared by reacting a 7-(α-aminoarylacetamido)-4-carboxy-Δ 3 -cephem derivative of the formula (II) other than those in which R 2 is a hydroxyl group to produce a compound of the formula (I) in which R 3 represents as ester group, COOR 4 , as hereinbefore defined, with a chloroalkanoyl chloride of the formula:
Cl--alk.sup.1 --COCl (X)
and then reacting the product, of the formula: ##STR6## first with sodium iodide to convert it to the corresponding iodo compound and then with, as appropriate, one of the compounds of formulae: ##STR7## wherein R 3 is as defined as above in this method.
The initial reaction may suitably be effected by maintaining the reactants, of which the acid chloride is preferably in slight excess, at a low temperature, e.g. within the range 0° C. to room temperature, in a reaction-inert organic solvent, e.g. chloroform, in the presence of a tertiary amine or inorganic base, as hereinbefore exemplified, for several hours, preferably with stirring. Isolation of the product, of the formula (XI), is suitably accomplished by removing the solvent from the reaction mixture, e.g. by evaporation in vacuo, dissolving the residue in an aqueous medium, e.g. water itself or a basic aqueous medium such as saturated aqueous sodium bicarbonate solution, extracting the subsequently acidified, e.g. to pH 2, aqueous phase with a water-immiscible organic solvent, e.g. ethyl acetate, and thereafter subjecting the organic phase to a similar procedure to that described in Method (1) for the isolation and, if necessary, purification of the product.
Reaction between the compound of the formula (XI) and sodium iodide may conveniently be accomplished by allowing a solution, e.g. acetone, of the two reagents in approximately equimolar proportions to stand in darkness for several hours at room temperature. Thereafter, that solvent may be replaced with a water-immiscible organic solvent, e.g. ethyl acetate, and the solution washed, e.g. with a saline solution, dried, e.g. over anhydrous magnesium sulphate, filtered and evaporated in vacuo to dryness.
The final stage is typically performed by dissolving the iodo compound in a suitable reaction-inert organic solvent, e.g. methylene chloride or dimethylformamide and adding, as appropriate, the sodium alcoholate [formula (XII)], sodium thiolate [formula (XIII)] or amine [formula (XIV)] in a slight excess, e.g. 10%. After stirring the mixture for several hours within the temperature range 20°-80° C., the solvent is removed, e.g. by evaporation in vacuo, and the residue is dissolved in a suitable waterimmiscible organic solvent, e.g. ethyl acetate. The solution may then be washed, e.g. with a saline solution, dried, e.g. over anhydrous magnesium sulphate, filtered and evaporated in vacuo to dryness, thus furnishing the desired product, which may be purified, if necessary, by a standard recrystallization technique or by washing in a suitable solvent, e.g. diethyl ether.
6. Compounds of the formula (I) in which R 3 and X represent any of the hereinbefore specified atoms or groups with the exception of a sulpho group and an unsubstituted imino group, --NH--, respectively, may be prepared by reacting a trimethylsilyl-protected α-aminoarylacetic acid, R 1 CH(NH 2 )CO 2 Si(CH 3 ) 3 , with one of the compounds of formulae: ##STR8## wherein X is defined as above in this method, in each case either as such or having been converted to its acid chloride, an "activated" ester or a mixed anhydride, to produce a compound of the formula: ##STR9## wherein R 3' represents, as appropriate, one of the moieties Ph 2 CHOOC, R 4 OOC and R 5 R 6 NCO, which is subsequently hydrolyzed to the corresponding α-aminoarylacetic acid derivative, of the formula: ##STR10## this then being converted to its functional equivalent as an acylating agent and reacted with a 7-amino-4-carboxy-Δ 3 -cephem derivative of the formula: ##STR11## wherein R 2 is as defined for formula (I) other than hydroxyl to produce a compound of the formula: ##STR12## the latter, when R 3' represents the carbobenzhydryloxy group, Ph 2 CHOOC, finally being acidified to a compound of the formula (I) in which R 3 `represents a carboxyl group.
The starting trimethylsilyl-protected α-amino-arylacetic acid may be prepared from the unprotected compound by reaction with an approximately equivalent quantity of a silylating agent, e.g. trimethylsilyl chloride, in the presence of a tertiary amine base, e.g. triethylamine, in solution in a suitable reaction-inert organic solvent, e.g. methylene chloride. For convenience, to this solution is added directly one of the compounds of the formulae (XV), (VI) and (IX), either as such together with a condensing agent, e.g. dicyclohexylcarbodiimide, or as an acid chloride, "activated" ester or mixed anhydride, prepared according to one of the procedures given in Method (2), and optionally in the reaction medium in which each was formed. The reaction to form the compound of the formula (XVI) may suitably be performed by stirring the mixture at room temperature for several hours, after which the mixture is filtered to remove any solids present, e.g. the dicyclohexylurea formed from dicyclohexylcarbodiimide present as a dehydrating agent either in this reaction or in the reaction to form an activated ester if used. Treatment of the filtrate with mineral acid, e.g. 10% hydrochloric acid, converts the product to a free acid by removing the trimethylsilyl protecting group, and the organic phase may then be washed, e.g. with saline solution, dried, e.g. with anhydrous magnesium sulphate, filtered, and evaporated in vacuo thus affording a compound of the formula (XVII).
Conversion of the latter compound to that of formula (XIX) is preferably achieved by first forming therefrom a mixed anhydride, e.g. with isovaleric or pivalic acid, and then reacting this product with the 7-amino-4-Δ 3 -cephem derivative of the formula (XVIII). The reactions are typically achieved by adding isovaleroyl or pivaloyl chloride, in slight excess, to a solution of the acid in a suitable reaction-inert organic solvent, e.g. tetrahydrofuran, in the presence of a tertiary amine base, e.g. triethylamine, at a low temperature, e.g. -10° C. The mixture is then stirred, e.g. for 1/2hour, to effect the conversion to the mixed anhydride and added to a stirred solution of the 7-amino-4-carboxy-Δ 3 -cephem derivative of the formula (XVIII) in a suitable aqueous solvent, e.g. aqueous tetrahydrofuran. Reaction generally proceeds satisfactorily at room temperature during several hours, after which the product is extracted from the acidified reaction solution into a water-immiscible organic solvent, e.g. ethyl acetate, the organic phase then being washed, e.g. with saline solution, dried, e.g. over anhydrous magnesium sulphate, filtered and evaporated in vacuo. If the product is of the formula (XIX) wherein R 3' represents one of the moieties R 4 OOC and R 5 R 6 NCO, it may be purified, if necessary, by recrystallization or washing in a suitable solvent, e.g. diethyl ether. Otherwise, being a compound of the formula (XIX) wherein R 3' represents a carbobenzhydryloxy group, the latter may be removed by acidification, and the product purified as before. The acidification may be achieved, in a typical case, by adding trifluoroacetic acid (3 volumes) to a solution of the carbobenzhydryloxy derivative in anisole (1 volume) and allowing the mixture to stand at room temperature for several minutes. Isolation and purification of the product is then effected by removing the solvent by evaporation in vacuo, dissolving the residue in ethyl acetate, adding the solution slowly to a large volume of petroleum ether, and collecting the resulting precipitate of the desired product by filtration.
7. All the compounds of the formula (I) in which X represents an unsubstituted imino group, --NH--, may be prepared according to Methods (1), (2), (3) and (6) given hereinbefore, starting in each case from one of the reagents of the formulae (III), (IV), (VI), (IX) and (XV) wherein the moiety X is replaced by --NR 7' --, in which R 7' represents a suitable protecting group for an imino group, e.g. a tertiary-butyloxycarbonyl group. The procedures are performed similarly, and the final products of such procedures, all of the formula (I) wherein X is replaced by --NR 7' --, are subjected to a further reaction entailing the removal of the protecting group by conventional means.
In a typical case, the tertiary-butyloxycarbonyl group may be removed by stirring the appropriate compound in trifluoroacetic acid at 0°-25° C., and the deprotected product may then be isolated and purified by removing the excess acid, e.g. by evaporation in vacuo, and washing the residue in diethyl ether. However, when Method (6) is used to prepare a compound of the formula (I) in which R 3 represents a carboxyl group, the final acidification stage may also deprotect the protected amino group simultaneously, thus avoiding the necessity to perform an additional acidification reaction.
8. Salts of the compounds of the invention may be prepared, if desired, by standard techniques. For example, preparation of the sodium or potassium salt of a compound of the invention may be accomplished by dissolving the compound in a lower alkanol, e.g. methanol, cooling the resulting solution and adding a solution of the appropriate alkali metal acetate in the same solvent to the stirred organic solution. The reaction is in many cases effected by maintaining the reaction mixture for several hours at room temperature, and the salt may then be isolated by concentrating the reaction solution by partial evaporation in vacuo and adding the concentrates to a large volume of a suitable organic solvent, e.g. diethyl ether, thereby precipitating the salt. Purification may then be achieved by washing the salt in a suitable solvent, e.g. diethyl ether, and thereafter drying it, preferably in vacuo.
9. The compounds of the formula (I) in which R 2 is a hydroxy group may be prepared by the hydrolysis of the corresponding cephalosporin in which R 2 is an acetoxy group. Typically, the hydrolysis may be carried out in aqueous media at a pH of from 5 to 8, using a wheat germ esterase or acetyl citrus esterase. The enzyme in aqueous solution is typically added to the sodium salt of the acetoxy-containing cephalosporin in water. The pH is rapidly adjusted to the desired value. The hydrolysis may then be filtered by keeping this mixture at a suitable temperature, preferably between 20° and 45° C., by the addition of aqueous alkali until hydrolysis is complete. Completion of the hydrolysis can be determined by titration with alkali, or by chromatographic assay. The hydrolysis products may be recovered by conventional methods. Typically, the reaction mixture is overlayered with a water-immiscible solvent, e.g. ethyl acetate, the mixture cooled and the pH adjusted to a value of from 1.5 to 4.5. The insoluble protein may be removed by filtration. The separated organic layer may then be underlayered with water and the pH adjusted to a value of from 4.5 to 8.5. The aqueous extract may then be freeze-dried or concentrated in vaco and the resultant sodium salt purified by recrystallization from a water-miscible solvent mixture, preferably a mixture of lower alcohols, e.g. methanol and isopropyl alcohol.
10. The compounds of the formula (I) in which R and R 2 taken together represent an oxygen atom, i.e. cephalosporins containing a lactone grouping, may be prepared by treating the corresponding derivative in which R and R 2 are each hydroxy with a mineral acid, e.g. 2N hydrochloric acid. Typically, the reaction is carried out in aqueous solution containing a water-miscible solvent, e.g. aqueous dioxan at a temperature of preferably from 5° to 50° C. for a period of several hours, e.g. 1/2 hour to 48 hours. The solution may then be concentrated in vacuo, and the precipitated product removed by filtration or centrifugation.
11. Compounds of the formula (I) in which R 2 is a carbamoyloxy group may be prepared by reacting the corresponding cephalosporin in which R 2 is a hydroxy group with a conventional protecting agent so as to protect the carboxyl group in the 4-position of the cephem nucleus, and, if present, the caboxyl group in the 7-side chain, and then reacting with an isocyanate and finally removing the protecting group or groups. A suitable protecting agent is diphenyldiazomethane which may be reacted with the unprotected cephalosporin in an inert solvent, e.g. ethyl acetate, typically at 10° to 45° C. for from 1/2 hour to 48 hours. The resultant mono- or di-ester may then be dissolved in an inert organic solvent, e.g. acetone, and then treated with trichloroacetyl isocyanate at preferably from 0° to 50° C. to give the corresponding 3N-trichloro-acetylcarbamoyloxy-methyl derivative. Treatment of this derivative with acid, e.g. 0.1N HCl, or chromatography on silica gel, gives the mono- or bis- (depending on whether 7-side chain of the starting material contained a free carboxyl group) diphenyl methyl ester of the 3-carbamoyloxymethyl derivative. The ester group or groups may then be removed in a conventional manner, e.g. by the use of trifluoroacetic acid and aniaole at temperatures of up to 50° C.
The in vitro evaluation of the compounds of the invention as antibacterial agents was performed by determining the minimum inhibitory concentration (MIC) of the test compound in a suitable medium at which growth of the particular microorganism failed to occur. In practice, agar (brain/heart infusion agar) plates, each having incorporated therein the test compound at a particular concentration, where inoculated with a standard number of cells of the test microorganism and each plate was then incubated for 24 hours at 37' C. The plates were then observed for the presence or absence of the growth of bacteria and the appropriate MIC value noted. Microorganisms used in such tests and against which the compounds were effective included strains of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes, Proteus vulgaris, Haeophilus influenzae and Enterobacter aerogenes, and Neisseria gonorrhea.
A selection of MIC values of many of the compounds hereinafter exemplified for activities against the various strains of microorganisms indicated is given in the following table:
__________________________________________________________________________ Pseudomonas Klebsiella Enterobacter Proteus Proteus Staphylococcus StreptococcusExample No. Escherichia aeruginosa pneumoniae aerogenes mirabilis vulgaris aureus pyogenesof Compound coli 51A266 52A490 53A009 55A004 57C015 57C060 01A005 02C203__________________________________________________________________________1 3.1 6.2 1.5 3.1 1.5 1.5 6.2 1.54 25 25 6.2 25 3.1 3.1 12.5 3.16 50 12.5 12.5 100 6.2 6.2 25 3.17 50 50 25 50 6.2 6.2 12.5 3.19 25 25 25 100 25 12.5 25 2510 25 12.5 50 6.2 3.1 3.1 25 2513 6.2 6.2 6.2 6.2 3.1 1.5 12.5 3.114 100 25 25 50 6.2 6.2 25 12.515 6.2 6.2 6.2 12.5 3.1 1.5 6.2 1.516 12.5 6.2 12.5 50 6.2 6.2 3.1 0.7817 25 -- 6.2 6.2 6.2 6.2 25 0.7822 1.5 6.2 1.5 1.5 1.5 1.5 6.2 0.823 12.5 -- 1.5 3.1 3.1 3.1 100 3.126 25 25 3.1 25 3.1 3.1 12.5 1.527 25 25 12.5 12.5 6.2 6.2 12.5 6.228 6.2 12.5 12.5 6.2 3.1 3.1 12.5 3.129 25 25 12.5 12.5 6.2 6.2 25 3.130 12.5 12.5 6.2 6.2 3.1 3.1 3.1 0.3931 25 25 12.5 25 12.5 12.5 3.1 1.532 25 6.2 12.5 50 12.5 12.5 3.1 0.3934 12.5 12.5 12.5 25 12.5 6.2 6.2 6.235 12.5 6.2 6.2 12.5 6.2 6.2 6.2 6.236 12.5 6.2 6.2 12.5 6.2 6.2 3.1 6.237 6.2 12.5 6.2 6.2 6.2 100 6.2 3.138 12.5 50 6.2 25 3.1 3.1 6.2 3.139 25 12.5 12.5 12.5 12.5 12.5 12.5 12.540 12.5 25 12.5 12.5 6.2 3.1 25 6.241 6.2 6.2 3.2 6.2 3.1 3.1 6.2 0.442 25 25 12.5 12.5 6.2 6.2 12.5 6.243 12.5 25 6.2 12.5 6.2 6.2 6.2 6.2__________________________________________________________________________
The compounds of the invention can be administered alone but will generally be administered in admixture with a pharmaceutical carrier selected with regard to the intended route of administration and standard pharmaceutical practice. For example, they may be administered orally in the form of tablets containing such excipients as starch or lactose, or in capsules wither alone or in admixture with excipients, or in the form of elixirs or suspensions containing flavoring or coloring agents. They may be injected parenterally, for example, intraveneously, intramuscularly or subcutaneously. For parenteral administration, they are best used in the form of a sterile aqueous solution which may contain other solutes, for example, salts or glucose to make the solution isotonic.
In treatment of bacterial infections in man, the compounds of this invention may be administered orally or parenterally, in accordance with conventional procedures for antibiotic administration, generally in an amount of from about 5 to 200 mg./kg./day and preferably about 5 to 20 mg./kg./day in divided dosage, e.g. three to four times a day. They may be administered in dosage units containing, for example, 125 to 500 mg. of the active ingredient with suitable physiologically acceptable carriers or excipients. The dosage units may be in the form of liquid preparations such as solutions or suspensions or as solids in tablets or capsules.
Thus, according to a yet further aspect, the invention provides a pharmaceutical composition comprising a compound of the formula (I) as previously defined and a pharmaceutically acceptable carrier. The compositions may preferably be in a form of a dosage unit containing from 125 to 500 mg. of the active cephslorporin.
The invention also provides a method of treating animals to cure them of diseases caused by gram-positive or gram-negative bacteria, which comprises administering to the animal an antibacterially effective amount of a compound of the formula (I).
The invention is illustrated by the following Examples.
EXAMPLE 1
A mixture of 7-D-(α-aminophenylacetamido)cephalosporanic acid (cephaloglycin) (228 g., 0.562 mole) and diglycolic anhydride (62.2 g., 0.562 mole) in acetone (3.3 l.) was stirred at room temperature for 11/2 hours. After the removal by filtration of insoluble material, the filtrate was evaporated in vacuo at a temperature below 30° C., and the resultong gummy residue was stirred in a mixture of ethyl acetate (4.4 l.) and water (3.2 l.). The aqueous phase was separated and extracted with ethyl acetate (b 2.2 l.), and the separated organic phase was combined with the initial ethyl acetate solution, the organic solution then being dried over anhydrous magnesium sulphate, filtered and evaporated in vacuo, at a temperature below 30° C., to dryness.
Produced was a semi-solid foam (284.4 g.) which was shown from thin-layer-chromatographic and infra-red and nuclear magnetic resonance spectroscopic evidence to comprise substantially pure 7-D-(α-carboxymethoxyacetamido-phenylacetamido)cephalosporanic acid.
EXAMPLE 2
To a solution of the product of the previous Example in isopropanol (2.8 l.) was added a solution of anhydrous sodium acetate (45.9 g., 0.562 mole) in methanol (460 ml.), whereupon a bulky gelatinous precipitate formed. The suspension was stirred for 5 minutes to induce any further precipitation and then allowed to stand for 1 hour. The solid product was collected by filtration, washed with 1:6 methanol:isopropanol solution and then with isopropanol, and finally dried in vacuo at room temperature for several hours.
Produced was 244 g. of a solid which was shown from thin-layer-chromatographic and nuclear magnetic resonance spectroscopic evidence to comprise substantially pure sodium salt of 7-D-(α-carboxymethoxyacetamido-phenylacetamido)cephalosporanic acid.
EXAMPLES 3 TO 18
The following 7-aminocephalosporanic acid or 7-amino-3-desacetoxy-cephalosporanic acid derivatives were prepared by a similar procedure to that described in Example 1, starting from the appropriate 7-D-(α-aminophenylacetamido)cephalosporanic acid or corresponding 3-desacetoxy compound, and the appropriate cyclic anhydride of the formula (III) or (IV) herein. All the compounds were characterized by means of infra-red and nuclear magnetic resonance spectroscopy.
__________________________________________________________________________ ##STR13##ExampleR.sup.2 P Q alk.sup.1Xalk.sup.2R.sup.3__________________________________________________________________________ 3 H H H CH.sub.2OCH.sub.2COOH 4 OCOCH.sub.3 H H CH.sub.2SCH.sub.2COOH 5 H H H CH.sub.2SCH.sub.2COOH 6 OCOCH.sub.3 H H CH.sub.2 CH.sub.2 COOH 7 OCOCH.sub.3 H H (CH.sub.2).sub.3 COOH 8 H H H (CH.sub.2).sub.3 COOH 9 OCOCH.sub.3 H H CH(CH.sub.3)OCH(CH.sub.3)COOH10 OCOCH.sub.3 H H ##STR14##11 H H H ##STR15##12 2-methyl- H H CH.sub.2OCH.sub.2COOH1,3,4-thia-diazol-5-yl-thio13 OCOCH.sub.3 H H CH.sub.2N(CH.sub.3)CH.sub.2COOH14 OCOCH.sub.3 H H CH.sub.2 CH.sub.2 SO.sub.3 H15 OCOCH.sub.3 H H ##STR16##16 OCOCH.sub.3 H H ##STR17##17 OCOCH.sub.3 HO H CH.sub.2 OCH.sub.2COOH18 OCOCH.sub.3 HO Cl CH.sub.2 OCH.sub.2COOH__________________________________________________________________________
example 19
to a stirred solution of cephaloglycin (2 g., 0.005 mole) in dimethylformamide (25 ml.) was added a solution of adipic anhydride polymer (6.4 g., 0.05 mole) in dimethylformamide (30 ml.), and the mixture was stirred at room temperature for about 16 hours. The resulting solid was then filtered off, and the filtrate, a yellow solution, was poured into petroleum ether (60°-80° C., 500 ml.) with vigorous stirring. From the resulting solid lower layer the solvent was decanted, and the residue was then treated with 10% aqueous sodium bicarbonate solution with stirring. The remaining solid was removed by filtration, and the filtrate was acidified to pH 4.5 by cautious addition of dilute hydrochloric acid, and extracted with ethyl acetate. Evaporation of the organic phase in vacuo to dryness afforded a pale yellow oil which was found from nuclear magnetic resonance spectroscopic evidence to consist principally of adipic acid. The aqueous phase was acidified further to pH 1 and extracted with ethyl acetate, the isolated pale yellow solid (2.1 g.) from evaporation of the organic phase subsequently being shown to also contain a large proportion of acipic acid.
A portion (1.0 g.) of the yellow solid was dissolved in 10% aqueous sodium bicarbonate solution, and the solution was acidified in stages to pH 4.5, 4.0 and 3.3 by addition of the appropriate amount of N hydrochloric acid and extraction with ethyl acetate after each addition. The organic phases were evaporated to dryness at each stage and their contents investigated by nuclear magnetic resonance spectroscopy. It was found that each fraction contained a considerable proportion of adipic acid, and so was discarded. Finally, the aqueous solution was acidified to pH 2.0 and extracted with a mixture of ethyl acetate and chloroform. The separated organic phase was dried over anhydrous magnesium sulphate and evaporated in vacuo to dryness, affording a solid (250 mg.) containing, from nuclear resonance spectroscopic evidence, a trace of adipic acid and a major proportion of 7-D-(α-[5-carboxyvaleramido]phenylacetamido)cephalosporanic acid.
EXAMPLE 20
By a similar procedure to that described in Example 19, 7-D-(α-[5-carboxyvaleramido]phenylacetamido)-3-desacetoxycephalosporanic acid was prepared from 7-D-(α-aminophenylacetamido)-3-desacetoxycephalosporanic acid and adipic anhydride polymer, and characterized by means of infra-red and nuclear magnetic resonance spectroscopy.
EXAMPLE 21
To a mixture of iminodiacetic acid (13.3 g., 0.1 mole) and tertiary-butyloxycarbonyl azide (21.5 g., 0.15 mole) in 1:4 water:dioxane (125 ml.) at 60° C. was added 2N sodium hydroxide solution at the rate required to maintain the solution at pH 10.2. When the pH had stabilized at that value, the reaction mixture was cooled, extracted three times with diethyl ether in order to remove unreacted azide, and cooled to 0° C. Solid citric acid was added to the aqueous solution to bring it to pH 3, followed by sufficient sodium chloride to saturate it. The solution was then extracted three times with ethyl acetate and the combined organic phases were washed with water and dried over anhydrous magnesium sulphate. The white solid (13.0 g.), m.p. 124°-125° C., produced on evaporation of the ethyl acetate solution in vacuo to deyness, was characterized from infra-red and nuclear magnetic resonance spectroscopic evidence as N-(tertiary-butyloxycarbonyl)iminodiacetic acid.
B. A mixture of the product of (A) (2.0 g., 0.0086 mole) and acetic anhydride (25 ml.) was heated over a steam bath for 20 minutes. The resulting purple solution was evaporated in vacuo to an oil, and the latter was decolorized by dissolving it in ethyl acetate, shaking the solution with a little charcoal, removing the latter by filtration and evaporation the filtrate in vacuo, thereby affording a yellow oil. Warming of the latter under high vacuum caused it to crystallize as a pale yellow, hygroscopic solid, m.p. 65° C. The product was identified by infra-red spectroscopy as N-(tertiary-butyloxycarbonyl)iminodiacetic anhydride.
C. By a similar procedure to that described in Example 1, starting from the produce of (B) and cephaloglycin, 7-D-(α-[N-carboxymethyl-N-{tertiary-butyloxycarbonyl.tbd.amino]acetamido-phenylacetamido)cephalosporanic acid was prepared, and characterized by means of infra-red and nuclear magnetic resonance spectroscopy.
D. To the product of (C) (1.5 g.) was added cooled trifluoroacetic acid at 0° C., and the mixture was stirred at room temperature for 45 minutes. The excess trifluoroacetic acid was then removed by evaporation in vacuo, and to the resulting solid residue was added ether. After the residue had been triturated, the clear upper ethereal layer was removed by decantation, and a fresh portion of diethyl ether was added to the suspension and further trituration performed. When the clear upper ethereal layer had been removed, the suspension was evaporated in vacuo to dryness, affording a product which was shown from thin-layer-chromatographic and infra-red and nuclear magnetic resonance spectroscopic evidence to comprise substantially pure 7-D-(α-[carboxymethylaminoacetamido]phenylacetamido)cephalosporanic acid as its trifluoroacetic acid addition salt.
EXAMPLE 22
To a vigorously stirred suspension of the trifluoroacetic acid addition salt of 7-D-(α-amino-phenylacetamido)-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)-Δ 3 -cephem-4-carboxylic acid (1.65 g., 0.0029 mole; prepared as described in British Pat. No. 1,283,811 and U.S. Pat. No. 3,641,021) in dry dimethylformamide (10 ml.) was added diglycolic anhydride (0.34 g., 0.0029 mole). The solid dissolved, affording a light brown solution, and after 30 minutes the solution was added to an equipart aqueous solution comprising saturated sodium chloride and saturated sodium bicarbonate solutions. After the mixed solution had been overlayered with ethyl acetate, sufficient 2N hydrochloric acid was added to bring the aqueous phase to pH 4, and the ethyl acetate phase (containing principally unchanged starting 7-amino-Δ 3 -cephem derivative) was removed from the previously well-shaken two-phase solution. A fresh quantity of ethyl acetate was added to the aqueous solution, and the latter was brought to pH 2 by addition of a further quantity of 2N hydrochloric acid. The two-phase solution was shaken to ensure sufficient extraction, and the ethyl acetate phase was then separated, washed with saturated aqueous sodium chloride solution, dried over anhydrous sodium sulphate, filtered and evaporated in vacuo to dryness, affording a gum.
Trituration of the crude product as a gum in diethyl ether afforded a buff-colored solid, which was collected by filtration and dried for several hours in vacuo. The solid (1.25 g.) was purified by first washing it with diethyl ether and then dissolving as much of it as possible in methanol, removing insoluble material by filtration, dripping the methanolic filtrate into diethyl ether, collecting the resulting precipitate by filtration and finally drying the solid for several hours in vacuo. Produced and characterized as such from infra-red and nuclear magnetic resonance spectroscopy was 7-D-(α-carboxymethoxyacetamido-phenylacetamido)-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)-Δ 3 -cephem-4-carboxylic acid.
EXAMPLES 23 and 24
The following 7-aminocephalosporanic acid derivatives were prepared by a similar procedure to that described in Example 22, starting from the appropriate 7-D-(α-amino-[substituted phenyl]acetamido)-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)-Δ.sup.3 -cephem-4-carboxylic acid and diglycolic anhydride:
______________________________________ ##STR18##Example P Q______________________________________23 HO H24 HO Cl______________________________________
EXAMPLE 25
By a procedure similar to that described in Example 22, starting from the same cephalosporin starting material as Example 22, and N-methyl iminodiacetic acid anhydride, 7-D-(α-carboxymethyl[N-methyl]aminoacetamidophenylacetamido)-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)-Δ 3 -cephem-4-carboxylic acid was prepared, and characterized by means of infra-red and nuclear magnetic resonance spectroscopy.
EXAMPLE 26
A. 5-Indanol (73.8 g., 0.55 mole) was added to a solution of sodium methoxide in methanol (prepared from 11.6 g., 0.5 mole of sodium and 400 ml. of dry methanol), and after the mixture had been allowed to stand at room temperature for 5 minutes the solvent was removed by evaporation in vacuo. The residue was dissolved in dry dimethylformamide (200 ml.) and the solution was evaporated in vacuo to dryness, thereby removing some moisture from the residue. To a solution of the residue in dry dimethylformamide (400 ml.) was added a solution of diglycolic anhydride (58 g., 0.5 ml.) in dry dimethylformamide (60 ml.), after which the mixture, whose temperature had risen to 70° C., was stirred for 3 hours. The solvent was then removed by reduced pressure evaporation to afford a solid, which was distributed between diethyl ether (150 ml.) and 2N hydrochloric acid (50 ml.), the separated ethereal phase then being washed with water (2 × 100 ml.) and extracted with saturated aqueous sodium bicarbonate solution. After the aqueous phase had been washed with diethyl ether (100 ml.), it was acidified with 2N hydrochloric acid and extracted with diethyl ether. The separated ethereal phase was washed with water, dried over anhydrous magnesium sulphate, filtered and evaporated in vacuo to dryness, the resulting solid then being recrystallized from a mixture of chloroform and petroluem ether (b.p 60° -80° C.) to afford 54 g. of mono-5-indanyl diglycolate, m.p. 95° -98° C.
Analysis: Calc'd for C 13 H 14 O 5 : C, 62.39; H, 5.64% Found: C, 62.75; H, 5.80%
B. To a solution of a portion of the product of (A) (5 g., 0.02 mole) in dry benzene (50 ml.) was added oxalyl chloride (5 ml.) followed by one drop of diemthylformamide. When the ensuing evolution of carbon dioxide had ceased, the solution was left to stand at room temperature for an hour. The solvent was removed by evaporation in vacuo, and a solution of the residue in dry benzene was evaporated in vacuo, thereby effecting removal of some moisture from the acid chloride product.
The residue was dissolved in dry acetone (50 ml.), and a portion of this solution (13 ml.) was slowly added to a solution of cephaloglycin (2.0 g., 0.005 mole) in aqueous acetone (45 ml., containing 5 parts water to 4 parts acetone by volume) containing sodium bicarbonate (0.84 g., 0.01 mole). After the solution has been stirred at room temperature for 1 1/2 hours, further quantities of sodium bicarbonate (0.42 g.) and aqueous acetone solution of cephaloglycin (13 ml.) were added, and stirring was continued for a further 2 hours. The solution was then filtered and evaporated in vacuo to dryness, the resulting gum subsequently being partitioned between aqueous and ethyl acetate phases. To the separated aqueous phase was added sufficient 2N hydrochloric acid to bring it to pH 2, and the aqueous solution was then extracted with ethyl acetate. The ethyl acetate phase was washed with water, dried over anhydrous magnesium sulphate, filtered and evaporated in vacuo to dryness, after which the residual solid was washed with dry diethyl ether and dried for several hours in vacuo. Infra-red and nuclear magnetic resonance spectroscopic evidence was consistent with the product (1.3 g.) being 7-D-(α-[5-indanyl]oxycarbonylmethoxyacetamido-phenylacetamido)cephalosporanic acid.
EXAMPLES 27 to 29
This following 7-aminocephalosporanic acid derivatives were prepared by similar procedures to that described in Example 26 from cephaloglycin, oxalyl chloride, and the appropriate half-ester in place of mono-5-indanyl diglycolate. All the compounds were characterized by means of infra-red and nuclear magnetic resonance spectroscopy.
______________________________________ ##STR19##Example R.sup.4______________________________________27 4-isopropylphenyl28 2-methoxyphenyl29 2-methylphenyl______________________________________
EXAMPLE 30
A. A mixture of diglycolic anhydride (27.9 g.) and methanol (6.75 ml.) was heated in a steam bath for two hours, and the resulting clear liquid was then submitted to a reduced pressure distillation, the major quantity of distillate collected (8.5 g.) having a boiling point of 168° -172° C./12 mms mercury pressure and being monomethyl diglycolate.
B. A portion of the product of (A) (l.48 g., 0.01 mole) was dissolved in methylene chloride (5 ml.), and the solution was added to a solution of carbonyldiimidazole (1.62 g., 0.01 mole) in methylene chloride (25 ml.) at 10° C. Evolution of carbon dioxide occurred, after which the solution was stirred at room termperature for 30 minutes and then added to a solution of cephaloglycin (2 g., 0.005 mole) and triethylamine (1.5 g., 0.015 mole) in methylene chloride (100 ml.). The reaction solution was stirred at room temperature for 2 hours and then evaporated in vacuo to dryness, affording a gum.
A solution of the gum in water(50 ml.) was overlayered with ethyl acetate, sufficient 2N hydrochloric acid added to the aqueous phase to bring ot to pH 2, and the two-phase solution shaken vigorously for several minutes to effect sufficient extraction. The ethyl acetate phase was then separated, dried over anhydrous magnesium sulphate, filtered and evaporated in vacuo to afford a gum. The latter was dissolved in methylene chloride (20 ml.), and the solution slowly dripped into dry diethyl ether (400 ml.) with vigorous stirring. After decanting the volume of ether above the sediment and replacing it with a fresh quantity of dry diethyl ether, the solid was collected by filtration and dried in vacuo for several hours. Thin-layer-chromatographic and infra-red and nuclear magnetic resonance spectroscopic evidence was consistent with the product (0.84 g.) being substantially pure 7-D-(α-methoxycarbonylmethoxyacetamido-phenylacetamido)cephalosporanic acid.
EXAMPLE 31
By a similar procedure to that described in Example 30, 7-D-(α-[n-butyl]oxycarbonylmethoxyacetamido-phenylacetamido)cephalosporanic acid was prepared from cephaloglycin, carbonyldiimidazole, diglycolic anhydride and n-butanol in place of methanol. It was characterized by means of infra-red and nuclear magnetic resonance spectroscopy.
EXAMPLE 32
A mixture of cephaloglycin (2 g.) and N,N-diethylcarboxymethoxyacetamide (3.4 g.) was suspended in water (50 ml.) and the pH was adjusted to 7 by addition of 2N sodium hydroxide solution. To the suspension was added 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and pH of the solution was readjusted to 5.8 and kept thereat, by periodic addition of small quantities of 2N hydrochloric acid, for 2 hours, after which time the acidity had stabilized. A sufficient quantity of 2N sodium hydroxide solution was then added to neutralize the solution, and the latter was overlayered with ethyl acetate. Extraction into the organic layer was achieved by acidifying the lower aqueous layer to pH 2 and shaking the two-phase solution.
The organic phase was subsequently separated, washed with water, dried over anhydrous magnesium sulphate, filtered and evaporated in vacuo to dryness, affording a pale yellow solid. This was washed with dry diethyl ether and dried in vacuo for several hours. Produced and characterized as such from infra-red and nuclear magnetic resonance spectroscopy was 2.4 g. of 7-D-(α-[N,N-diethylcarbamoyl]methoxyacetamido-phenylacetamido)cephalosporanic acid.
EXAMPLE 33
To a stirred suspension of 7-D-(α-carboxymethoxyacetamido-phenylacetamido)cephalosporanic acid (1 g., 0.0019 mole; the product of Example 1), in phosphate buffer at pH 7.0 (15 ml.) was added anhydrous sodium bicarbonate (0.35 g.). When all the solid had dissolved, 5-mercapto-1-methyl-1,2,3,4-tetrazole (0.38 g., 0.0024 mole) was added and the mixture was heated in an oil bath at 60° C. for 6 hours.
The solution was then diluted to a volume of 100 ml. with water, overlayered with ethyl acetate and acidified to pH 2.0 with 2N hydrochloric acid. After the two-phase solution had been shaken vigorously for several minutes to effect sufficient extraction, the ethyl acetate phase was separated, washed with saturated aqueous sodium chloride solution, dried with anhydrous magnesium sulphate, filtered and evaporated in vacuo to dryness. The resulting off-white gum was dissolved in a small quantity of methanol, the solution was dripped into dry diethyl ether, and the resulting precipitate collected by filtration was dried for several hours in vacuo. Produced and characterized as such by infra-red and nuclear magnetic resonance spectroscopy was 7-D-(α-carbomethoxyacetamido-phenylacetamido)-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)-Δ 3 -cephem-4-carboxylic acid (0.35 g.). Comparison of its infra-red and nuclear magnetic resonance spectra with those of the product of Example 22 confirmed its identity with the latter.
EXAMPLES 34 to 42
The following 7-amino-3-substituted-cephalosporanic acid derivatives were prepared by similar procedures to that described in Example 33 from 7-D-(α-carboxymethoxyacetamido-phenylacetamido)cephalosporanic acid and the derivative. All the compounds were characterized by means of infra-red and nuclear magnetic resonance spectroscopy.
______________________________________ ##STR20##Example R.sup.2______________________________________34 1-phenyl-1,2,3,4-tetrazol-5-ylthio35 1-(4-methoxyphenyl)-1,2,3,4-tetrazol-5-ylthio36 1-(4-chlorophenyl)-1,2,3,4-tetrazol-5-ylthio37 2-methyl-1,3,4-thiadiazol-5-ylthio38 4,6-dimethylpyrimidin-2-ylthio39 4,5-dimethylthiazol-2-ylthio40 1,3,5-triazin-2-ylthio41 1-benzyl-1,2,3,4-tetrazol-5-ylthio42 pyrimidin-2-ylthio______________________________________
The compound of Example 37 is also the subject of Example 12.
EXAMPLE 43
To a stirred suspension of 7-D-(α-carboxymethoxyacetamido-phenyl-acetamido)cephalosporanic acid (1 g., 0.0019 mole), the product of Example 1) in phosphate buffer at pH 6 (30 ml.) was added anhydrous sodium bicarbonate (0.4 g.). When all the solid had dissolved, sodium azide (0.65 g., 0.01 mole) was added and the mixture was heated in a water bath at 50° C. for 16 hours.
The solution was then diluted to a volume of 100 ml. with water, overlayered with ethyl acetate, and acidified to pH 2 with 2N hydrochloric acid. After the two-phase solution had been shaken vigorously for several minutes to effect sufficient extraction, the ethyl acetate phase was separated, washed with saturated aqueous sodium chloride solution, dried with anhydrous magnesium sulphate, filtered and evaporated in vacuo to dryness. The resulting foam was triturated in diethyl ether to afford an off-white solid (0.52 g.) which was characterized by infra-red and nuclear magnetic resonance spectroscopy as 3-azidomethyl-7-D-(α-carboxymethoxyacetamido-phenylacetamido)-.DELTA. 3 -cephem-4-carboxylic acid.
The following compounds are similarly prepared from the appropriate 7-D-(α-acylaminoarylacetamido)cephalosporanic acid derivatives:
__________________________________________________________________________ ##STR21##R.sup.1 alk.sup.1Xalk.sup.2R.sup.3__________________________________________________________________________4-HOC.sub.6 H.sub.4 CH.sub.2OCH.sub.2COOH4-HOC.sub.6 H.sub.4 CH.sub.2SCH.sub.2COOH4-HOC.sub.6 H.sub.4 CH.sub.2OCH.sub.2CON(C.sub.2 H.sub.5).sub.23-Cl-4-HOC.sub.6 H.sub.3 CH.sub.2 CH.sub.2 SO.sub.3 HC.sub.6 H.sub.5 CH.sub.2SO.sub.2CH.sub.2COOHC.sub.6 H.sub.5 (CH.sub.2).sub.4COOHC.sub.6 H.sub.5 CH.sub.2N(CH.sub.3)CH.sub.2 COOH4-ClC.sub.6 H.sub.4 CH.sub.2OCH.sub.2COOH4-CH.sub.3 C.sub.6 H.sub.4 CH.sub.2N(CH.sub.2 Ph)CH.sub.2COOH4-CF.sub.3 C.sub.6 H.sub.4 CH.sub.2OCH.sub.2COOH2-thienyl CH.sub.2OCH.sub.2COOH2-thienyl CH.sub. 2 CH.sub.2COOH3-thienyl CH.sub.2SCH.sub.2COOH2-furyl CH.sub.2 CH.sub.2SO.sub.3 H__________________________________________________________________________
example 44
the following compounds are prepared from the appropriate 7-D-(α-aminoarylacetamido)cephalosporanic acid, or corresponding 3-desacetoxy compound, or 3-heterocyclic thiomethyl compound.
__________________________________________________________________________ ##STR22##R.sup.1 R.sup.2 alk.sup.1Xalk.sup.2R.sup.3__________________________________________________________________________2-thienyl OCOCH.sub.3 CH.sub.2OCH.sub.2COOH2-thienyl H CH.sub.2OCH.sub.2COOH2-thienyl H CH.sub.2SCH.sub.2COOH2-thienyl H CH.sub.2 CH.sub.2 COOH2-thienyl OCOCH.sub.3 (CH.sub.2).sub.4COOH2-thienyl OCOCH.sub.3 CH.sub.2SOCH.sub.2COOH2-thienyl OCOCH.sub.3 CH.sub.2SO.sub.2 CH.sub.2COOH2-thienyl H CH.sub.2N(CH.sub.3)CH.sub.2COOH2-thienyl H CH.sub.2N(CH.sub.2CHCH.sub.2)CH.sub.2 COOH2-thienyl OCOCH.sub.3 CH.sub.2OCH.sub.2COOCH.sub.32-thienyl H (CH.sub.2).sub.4COOH2-thienyl H CH.sub.2OCH.sub.2COO-5-indanyl2-thienyl OCOCH.sub.3 CH.sub.2OCH.sub. 2COOnaphthyl2-thienyl H CH.sub.2OCH.sub.2CON(CH.sub.3).sub.22-thienyl OCOCH.sub.3 CH.sub.2N(CH.sub.2 Ph)CH.sub.2COOH3-thienyl OCOCH.sub.3 CH.sub.2OCH.sub.2COO-(4-ClC.sub. 6 H.sub.4)3-thienyl OCOCH.sub.3 CH.sub.2SCH.sub.2COOH3-thienyl H (CH.sub.2).sub.3COOH3-thienyl OCOCH.sub.3 CH.sub.2N(CH.sub.3)CH.sub.2 COOH3-thienyl H (CH.sub.2).sub.4COOCH.sub.33-thienyl H CH.sub.2SO.sub.2CH.sub.2COOH3-thienyl H CH.sub.2 CH.sub.2SO.sub.3 H3-thienyl OCOCH.sub.3 CH.sub.2OCH.sub.2COO-(2-CH.sub. 3 OC.sub.6 H.sub.4)2-furyl OCOCH.sub.3 CH.sub.2OCH.sub.2COOH2-furyl OCOCH.sub.3 CH.sub.2 CH.sub.2COOH2-furyl OCOCH.sub.3 CH.sub.2 CH.sub.2SO.sub.3 H2-furyl H CH.sub.2SCH.sub.2COOH2-furyl H CH.sub.2N(CH.sub.2CHCH.sub.2)CH.sub.2COOH2-furyl H CH.sub.2OCH.sub.2COO-(n-C.sub. 4 H.sub.9)2-furyl OCOCH.sub.3 (CH.sub.2).sub.4COOCH.sub.34-ClC.sub.6 H.sub.4 OCOCH.sub.3 CH.sub.2OCH.sub.2COO-(3-CF.sub. 3 C.sub.6 H.sub.4)3-ClC.sub.6 H.sub.4 OCOCH.sub.3 CH.sub.2SCH.sub.2COOH3-IC.sub.6 H.sub.4 H CH.sub.2OCH.sub.2COO-(4-t-C.sub. 4 H.sub.9 C.sub.6 H.sub.4)4-FC.sub.6 H.sub.4 H CH.sub.2 CH.sub.2 SO.sub.3 H3-BrC.sub.6 H.sub.4 OCOCH.sub.3 CH.sub.2N(C.sub.6 H.sub.13)CH.sub.2 COOH3,4-(CH.sub.3 O).sub.2 C.sub.6 H.sub.3 OCOCH.sub.3 CH.sub.2OCH.sub.2COOH4-CH.sub.3 OC.sub.6 H.sub.4 OCOCH.sub.3 (CH.sub.2).sub.4COOH4-CH.sub.3 C.sub.6 H.sub.4 OCOCH.sub.3 CH.sub.2N(CH.sub.2 Ph)CH.sub.2COOH4-CF.sub.3 C.sub.6 H.sub.4 OCOCH.sub.3 CH.sub.2OCH.sub.2COOH4-FC.sub.3 C.sub.6 H.sub.4 H CH.sub.2OCH.sub.2COO-(5-indanyl)3-HOC.sub.6 H.sub.4 OCOCH.sub.3 (CH.sub.2).sub.4COOH4-HOC.sub.6 H.sub.4 OCOCH.sub.3 CH.sub.2SCH.sub.2COOH4-HOC.sub.6 H.sub.4 OCOCH.sub.3 CH.sub.2OCH.sub.2CON(C.sub.2 H.sub.5).sub.23-Cl-4-HOC.sub.6 H.sub.3 OCOCH.sub.3 CH.sub.2 CH.sub.2SO.sub.3 H2-ClC.sub.6 H.sub.4 H CH.sub.2OCH.sub.2CON(C.sub.6 H.sub.13).sub.2C.sub.6 H.sub.5 H CH.sub.2N(n-C.sub.3 H.sub.7)CH.sub.2COOH__________________________________________________________________________
example 45
the following 7-amino-3-substituted cephalosporanic acid derivatives are prepared by similar procedures to that described in Example 33 from appropriate reactants.
__________________________________________________________________________ ##STR23##
__________________________________________________________________________R.sup.1 R.sup.2 alk.sup.1Xalk.sup.2R.sup.3__________________________________________________________________________2-thienyl 1-methyl-1,2,3,4- CH.sub.2COCH.sub.2COOH tetrazol-5-ylthio2-thienyl 2-methyl-1,3,4-thiadi- CH.sub.2COCH.sub.2COOH azol-5-ylthio2-thienyl pyrimidin-2-ylthio CH.sub.2 CH.sub.2COOH2-thienyl 4,5-dimethyl- CH.sub.2 N(CH.sub.3)CH.sub.2COOH thiazol-2-ylthio3-thienyl 1-methyl-1,2,3,4- CH.sub.2OCH.sub.2COOH tetrazol-5-ylthio3-thienyl 1-phenyl-1,2,3,4- CH.sub.2SCH.sub.2COOH tetrazol-5-ylthio3-thienyl 4,6-dimethylpyrimidin- (CH.sub.2).sub.3COOH 2-ylthio3-thienyl 1,3,5-triazin-2-ylthio CH.sub.2OCH.sub.2COOH2-furyl 1-methyl-1,2,3,4- CH.sub.2OCH.sub.2COOH tetrazol-5-ylthio2-furyl 1-(4-chlorophenyl)- CH.sub.2OCH.sub.2COOH 1,2,3,4-tetrazol-5- ylthio2-furyl 1-benzyl-1,2,3,4- CH.sub.2SCH.sub.2COOH tetrazol-5-ylthio2-furyl pyrimidin-2-ylthio CH.sub.2 CH.sub.2SO.sub.3 HC.sub.6 H.sub.5 2-methyl-1,3,4-oxadi- CH.sub.2 CH.sub.2 COOH azol-5-ylthio__________________________________________________________________________
EXAMPLE 46
To 5 g. of 7-D-(α-carboxymethoxyacetamido-phenylacetamido)cephalosporanic acid sodium salt, dissolved in 250 ml. water and adjusted to pH 7 by addition of 2N aqueous hydroxide solution, was added 1.5 g. of a wheat germ esterase (Lipase from Wheat Germ Type 1, Sigma Chemical Co., St. Louis, Mo., U.S.A.) dissolved in 50 ml. water. The pH was continually re-adjusted to 7 by addition of 2N sodium hydroxide and the mixture stirred at room temperature (20° C.) for 5 hours, by which time hydrolysis was found to be complete, as shown by thin-layer-chromatography. The product was recovered by saturating the solution with sodium chloride, contacting with 250 ml. ethyl acetate, adjusting the pH of the aqueous phase to 2 with 2N aqueous hydrochloric acid solution, cooling to 0° C., filtering the 2-phase system through "Hi-Flo", separating the organic layer, washing the latter with brine and then with water, contacting it with 150 ml. water, adjusting the pH of the aqueous layer to 5.5 with 2N sodium hydroxide, separating the aqueous layer and freeze-drying the latter to give 2.5 g. of a buff, fluffy solid. The product was recrystallized from methanol/isopropanol and shown to be 7-D-(α-carboxymethoxyacetamido-phenylacetamide)-3-hydroxymethyl-.DELTA. 3 -cephem-4-carboxylic acid sodium salt, identified by nuclear magnetic resonance and infra-red spectrography and by thin-layer-chromatography.
EXAMPLE 47
The procedure of Example 46 is repeated, but using as starting materials the sodium salts of the cephalosporanic acid derivatives of Examples 4, 6, 7, 9, 10, 13-19 and 21, and those compounds of Example 44 in which R 2 is OCOCH 3 and R 3 is COOH or SO 3 H, thereby yielding the corresponding 3-hydroxymethyl-Δ 3 -cephem-4-carboxylic acids as sodium salts.
EXAMPLE 48
The procedure of Example 46 and 47 is repeated, but using acetyl citrus extracted from orange peel by known methods (Arch. Biochem., 1947, 15, 415) instead of wheat germ esterase, and the same results are achieved.
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Novel antibacterial agents; namely, 7-(α-acylamino-arylacetamido)-cephalosporanic acid derivatives having the formula: ##STR1## wherein R 1 is thienyl, 2-furyl, phenyl, substituted thienyl or substituted phenyl; R is hydroxyl; R 2 is hydrogen, hydroxy, acetoxy, carbamoyloxy, N-pyridyl, azido or heterocyclic thio group; R and R 2 when taken together represent an oxygen atom; R 3 is sulpho or COOR 4' wherein R 4' is hydrogen or R 4 wherein R 4 is lower alkyl, 5-indanyl, naphthyl, phenyl, or substituted phenyl, CONR 5 R 6 , wherein each of R 5 and R 6 is hydrogen, lower alkyl or cycloalkyl; or R 5 and R 6 together with the nitrogen atom to which they are attached form a saturated heterocyclic group; X is oxygen or sulphur, a direct link, carbonyl, methylene, hydroxymethylene, sulphinyl, sulphonyl or an imino group of the formula --NR 7 --, wherein R 7 is hydrogen, lower alkyl, lower alkenyl, or benzyl; and each of alk 1 and alk 2 is a divalent saturated aliphatic hydrocarbon group containing from 1 to 3 carbon atoms; the pharmaceutically acceptable salts thereof, and methods for their preparation.
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FIELD
[0001] This disclosure pertains to microlithography, which is a key technique used in the manufacture of microelectronic devices such as semiconductor integrated circuits, displays, and the like. More specifically, the disclosure pertains to reticles for use in microlithography performed using a charged particle beam such as an electron beam or ion beam, wherein the reticle defines a pattern to be transferred lithographically to a suitable substrate. Even more specifically, the disclosure pertains to determining the pattern to be defined on the reticle.
BACKGROUND
[0002] As the degree of integration of active circuit elements in microelectronic devices has continued to increase, with corresponding decreases in the size of individual active circuit elements in such devices, the resolution limitations of conventional optical microlithography increasingly have become apparent. Consequently, substantial effort is being expended to develop a practical “next generation” microlithography (NGL) technology. One promising candidate NGL technology is microlithography performed using a charged particle beam, which offers prospects of better resolution than optical microlithography for reasons similar to reasons for which electron microscopy yields better image resolution than optical microscopy. Charged-particle-beam (CPB) microlithography can be performed using an electron beam or ion beam. Most effort is being expended to develop a practical electron-beam microlithography apparatus.
[0003] With current CPB microlithography apparatus, it is not possible to transfer-expose an entire pattern or even a large portion thereof in a single exposure “shot” due to various factors such as the aberration and distortion exhibited by conventional CPB optical systems. For this reason, transfer-exposure using a “divided” reticle has been developed. In a divided reticle, the pattern (corresponding in area to one “chip” or “die” on the lithographic substrate) as defined on the reticle is divided, or “segmented,” into a large number of exposure units, usually termed “subfields,” that define respective portions of the pattern. Exposure of the pattern from the reticle occurs subfield-by-subfield, wherein the respective images of the subfields are transferred to respective locations on the substrate such that the individual subfield images are “stitched together” in a contiguous manner to form the desired chip or die on the substrate. Typically, multiple chips are formed on a single substrate. So as to be imprintable with die patterns, the upstream-facing surface of the substrate is coated with a thin film of a substance termed a “resist.”
[0004] A typical manner of dividing the pattern into subfields is shown in FIG. 8. First, as noted above, multiple chips are transfer-exposed onto a “transfer body” or lithographic substrate (usually a semiconductor “wafer,” which is the term used herein). The chip pattern, as transferred, is divided into one or more “stripes,” and each stripe is subdivided into multiple subfields. The respective subfields in each stripe are arranged rectilinearly in multiple rows, each containing multiple respective subfields. The pattern on the reticle, and thus the reticle itself, similarly is divided into stripes and subfields.
[0005] Transfer-exposure performed using a CPB microlithography apparatus and a divided reticle typically is performed in a manner as shown in FIG. 9. First, the reticle and wafer are mounted on respective stages that provide support and controlled movements of the reticle and wafer, respectively, as required for exposure. During exposure, the respective stages position the reticle and wafer such that the optical axis of the CPB optical system intersects the respective centerlines of the selected stripe on the reticle and wafer. Exposure of a stripe is achieved by appropriate lateral deflections of the beam (performed by the CPB optical system), accompanied by respective continuous motions of the stages at respective constant velocities along the respective stripes, to expose the subfields in the selected stripe subfield-by-subfield and row-by-row.
[0006] The respective stage-movement velocities roughly correspond to the “demagnification” (reduction) ratio of the portion of the CPB optical system used to form the images on the wafer. For example, with a demagnification ratio of 1/4, each subfield image formed on the wafer is 1/4 the size of the respective subfield on the reticle; hence, during exposure the wafer stage moves at about 1/4 the velocity of the reticle stage.
[0007] For exposure, the CPB optical system includes an “illumination-optical system” for illuminating the subfields on the reticle and a “projection-optical system” for carrying respective aerial images of the illuminated subfields to the wafer and for resolving the images on the surface of the wafer. The charged particle beam propagating through the illumination-optical system is termed the “illumination beam,” and the charged particle beam propagating through the projection-optical system is termed the “patterned beam” or “imaging beam.”
[0008] Thus, during exposure of a stripe, the illumination beam is deflected laterally in a direction approximately perpendicular to the reticle-stage-movement direction to expose each row subfield-by-subfield. As exposure of a particular row ends, respective stage movements bring the next row into position for exposure, with a corresponding reverse in the deflection direction of the beam to expose the constituent subfields of the new row, and so on to the end of the stripe. Hence, exposure of the stripe progresses in a raster manner, which minimizes time lost between exposures of adjacent rows and thereby increases throughput. As exposure of a particular stripe ends, respective stage movements bring the next stripe into position for exposure.
[0009] The reticle used in the exposure method described above differs substantially in structure from a reticle used for optical microlithography. Whereas a reticle for optical lithography can be exposed in a single “shot” and is self-supporting, the reticle for CPB microlithography is structured to define individual subfields (each defining a respective portion of the pattern) and intervening structural members termed “struts.” The struts extend across the reticle in a lattice manner and separate the subfields one from another. Contiguous with the struts are frame members extending around the circumference of the reticle. The struts and frame provide structural strength and rigidity for the reticle. Each subfield on the reticle includes a respective membrane portion that includes a respective patterned portion and a respective skirt. The patterned portion defines the respective portion of the pattern defined by the reticle. The skirt surrounds the patterned portion. The patterned portion is transmissive to the illumination beam such that, as the illumination beam passes through the patterned portion, the beam acquires an aerial image of the respective pattern elements defined in the patterned portion. The outer edges of the illumination beam fall within the skirt as each subfield is illuminated. The skirt and the struts surrounding the skirt effectively isolate each subfield for individual exposure without crosstalk between adjacent subfields during exposure.
[0010] CPB microlithography is subject to a phenomenon known as the space charge effect (also termed a “Coulomb effect”) caused by mutual electrostatic repulsion of charged particles in the beam. The mutual repulsion causes widening of the beam, with an accompanying drop in pattern-transfer resolution. To reduce the space-charge effect, the beam-acceleration voltage may be increased to increase the velocity of particles in the beam and correspondingly reduce the particle-particle interaction time during propagation from the reticle to the wafer. Hence, increasing the beam-acceleration voltage conventionally is a favored means for increasing pattern-transfer resolution.
[0011] However, increasing the beam-acceleration voltage causes certain problems, notably undesired changes in the profiles of pattern elements as transfer-exposed onto the wafer, especially in peripheral regions of the chip. For example, a higher beam-acceleration voltage can cause undesired increases in pattern linewidth, relative to design-specified values, especially in peripheral regions of the chip, compared to similar exposures using a lower beam-acceleration voltage. As a result, pattern resolution of the overall chip is degraded.
SUMMARY
[0012] In view of the shortcomings of conventional methods as summarized above, the present invention provides, inter alia, improved methods for configuring a pattern on a reticle. The methods result in pattern portions destined to be located on or near peripheral regions of chips being transferred with greater fidelity to design-mandated values, even when transfer-exposed using a charged-particle-beam (CPB) microlithography (“exposure”) apparatus utilizing a high beam-acceleration voltage.
[0013] According to a first aspect of the invention, methods are provided for configuring a reticle pattern to be defined on a reticle used for charged-particle-beam microlithography. An embodiment of such a method comprises the step of identifying an element of the pattern destined for transfer-exposure to a region of a chip formed on a lithographic substrate, wherein the pattern element has an initial configuration. In another step the pattern element as defined on the reticle is reconfigured such that the profile at least partially offsets proximity effects that otherwise would be imparted to the pattern element, if the element were to be transfer-exposed in its initial configuration to the chip, by proximal elements of the pattern transfer-exposed to the same chip and by proximal elements located in an adjacent chip or chips on the substrate. The reconfigured pattern element desirably is defined in one or more subfields of the reticle. “Proximal elements” are elements located within a “proximal range”, as defined herein later below, of a subject pattern element.
[0014] Another embodiment includes the element-identifying step summarized above. A determination is made of a net proximity effect that otherwise would be imparted to the pattern element, if the element were to be transfer-exposed in its initial configuration to the chip, by proximal elements of the pattern transfer-exposed to the same chip and by proximal elements located in one or more adjacent chips on the substrate. The element as defined on the reticle is reconfigured so as to offset the net proximity effect at least partially.
[0015] Yet another embodiment also includes the element-identifying step summarized above. A determination is made of a net proximity effect that otherwise would be imparted to the pattern element, if the element were to be transfer-exposed in its initial configuration to the chip, by at least one proximal element of the pattern transfer-exposed to the same chip and by at least one proximal element located in one or more adjacent chips on the substrate. A calculation is made of a profile change to be made to the pattern element, as defined on the reticle, that would offset the net proximity effect at least partially and cause the pattern element, when transfer-exposed to the substrate, to be substantially similar to a corresponding design-mandated profile for the element. The profile of the pattern element is changed according to the calculated profile change, and the pattern element is defined on the reticle according to the changed profile. This method can include the steps of determining a manner in which the pattern is to be divided, on the reticle, into subfields, and defining the pattern element in at least one subfield.
[0016] According to another aspect of the invention, methods are provided for manufacturing a divided reticle for use in charged-particle-beam microlithography. An embodiment of such a method comprises the step of dividing a pattern, to be defined on the reticle, into subfields each including a respective portion of the pattern. An identification is made of a pattern element destined for transfer-exposure to a region of a chip formed on a lithographic substrate, wherein the pattern element has an initial configuration. The pattern element is reconfigured so as to have a profile, as defined on the reticle, that at least partially offsets a net proximity effect that otherwise would be imparted to the pattern element, if the element were to be transfer-exposed in its initial configuration to the chip, by at least one proximal element of the pattern transfer-exposed to the same chip and by at least one proximal element located in one or more adjacent chips on the substrate. The reconfigured pattern element is defined in at least one subfield, and the reticle is fabricated to include the reconfigured pattern element.
[0017] In another embodiment of this method a pattern, to be defined on the reticle, is divided into subfields each including a respective portion of the pattern. A pattern element destined for transfer-exposure to a region of a chip formed on a lithographic substrate is identified. A determination is made of the net proximity effect that otherwise would be imparted to the pattern element, if the element were to be transfer-exposed in its initial configuration to the chip, by at least one proximal element of the pattern transfer-exposed to the same chip and from proximal elements located in adjacent chips on the substrate. The pattern element is reconfigured to have a profile that at least partially offsets the net proximity effect. The reconfigured pattern element is defined in at least one subfield, and the reticle is fabricated to include the reconfigured pattern element.
[0018] Yet another embodiment of this method includes the pattern-dividing step, the pattern-element-identification step, and the net-proximity-effect-determination step summarized above. A calculation is made of the reconfigured profile of the pattern element, as defined by the reticle, that would offset the net proximity effect at least partially and cause the pattern element, when transfer-exposed to the substrate, to be substantially similar to a corresponding design-mandated profile. The pattern element is reconfigured according to the calculation, the reconfigured pattern element is defined in at least one subfield, and the reticle is fabricated to include the reconfigured pattern element.
[0019] Another aspect of the invention is directed to divided reticles manufactured by any of the method summarized above.
[0020] According to another aspect of the invention, methods are provided for performing a microlithographic exposure using a charged particle beam. In an embodiment of such a method, a divided reticle is provided as summarized above, wherein the reticle defines a pattern divided among multiple subfields. A charged-particle illumination beam is directed subfield-by-subfield through the reticle, to produce a corresponding patterned beam. The patterned beam is directed to a resist-coated lithographic substrate so as to imprint the pattern in multiple chips on the substrate. The step of directing the patterned beam can comprise the step of imprinting the pattern in centrally located chips and in peripherally located chips on the substrate. In such an instance, the method can further comprise the step of reducing variations in the imprinted profile of the pattern element in the peripherally located chips versus in the centrally located chips on the substrate by transfer-exposing portions, of peripheral chips that extend partially off the substrate, of such peripheral chips still remaining on the substrate. With respect to the peripheral chips extending partially off the substrate, transfer-exposure can be made of at least one respective subfield of the portions of such peripheral chips still remaining on the substrate.
[0021] According to yet another aspect of the invention, methods are provided for manufacturing microelectronic devices, wherein the methods include a microlithographic-exposure method as summarized above.
[0022] The foregoing and additional features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
BRIEF EXPLANATION OF THE DRAWINGS
[0023] [0023]FIG. 1 is a schematic plan view of a chip pattern used in an example embodiment.
[0024] [0024]FIG. 2 is a schematic plan view of multiple chips, each configured as shown in FIG. 1, arranged as imprinted on the surface of a lithographic substrate (e.g., semiconductor wafer).
[0025] FIGS. 3 ( a )- 3 ( c ) are plots of cumulative exposure dose on the resist versus linewidth of a pattern element as imprinted on the substrate.
[0026] [0026]FIG. 4 is a schematic plan view of multiple chips, similar to FIG. 2 but also showing the relationship of the chips to the substrate edge.
[0027] [0027]FIG. 5 is a schematic plan view, similar to FIG. 4 but showing partial exposure of chips located in peripheral regions of the substrate and that straddle the substrate edge.
[0028] [0028]FIG. 6 is a flowchart of a representative process for fabricating microelectronic devices, wherein the process includes a microlithography method according to a representative embodiment.
[0029] [0029]FIG. 7 is a flowchart of certain steps in the microlithography method.
[0030] [0030]FIG. 8 is a schematic plan view showing the manner in which chips are divided into exposure units in conventional divided-reticle charged-particle-beam microlithography.
[0031] [0031]FIG. 9 is a schematic oblique view showing certain details of conventional divided-reticle transfer-exposure.
DETAILED DESCRIPTION
[0032] The invention is described below in the context of representative embodiments that are not intended to be limiting in any way. Since the respective figures accompanying the description of the embodiments are schematic, the figures do not provide actual or relative dimensions of the depicted components.
[0033] As a result of a thorough investigation into the causes of deteriorated accuracy of projected pattern elements in peripheral regions of chips, as observed especially whenever charged-particle-beam (CPB) microlithography is performed with a high beam-acceleration voltage, it has been discovered that the actual cause is a “proximity effect” imparted by adjacent chips imprinted on the lithographic substrate (“wafer”).
[0034] Normally, to perform CPB microlithography of a LSI pattern, for example, a first step involves defining the actual pattern. This step includes determining the manner in which the pattern is to be divided, on the reticle, into subfields and the manner in which individual pattern elements are to be configured in the respective subfields on the reticle. Determining how pattern elements are to be defined takes into consideration proximity effects expected to be imparted to the pattern elements when the elements are transfer-exposed onto the wafer.
[0035] A “proximity effect” is a phenomenon that is manifest on the pattern as transfer-exposed onto the wafer, wherein unwanted regions (especially adjacent to pattern elements actually exposed) of the resist become exposed. The phenomenon is caused by: (1) backscattering, into adjacent areas of resist, of charged particles of the beam by atoms and molecules of the resist and by atoms of the substrate on which the beam is incident, and (2) secondary electrons emitted by the resist on which the beam is incident. The backscattered and secondary electrons penetrate into adjacent areas of resist, causing unwanted “exposure” of the adjacent areas. Defining individual pattern elements while taking into account proximity effects involves configuring the pattern elements, to be defined on the reticle, in a manner serving to offset the proximity effect. In other words, at least certain pattern elements are defined on the reticle with respective profiles that are different from actual designed profiles so that, when the pattern elements are projected onto the wafer, the resulting respective images as formed in the resist have profiles that more closely approximate the desired as-designed profiles.
[0036] Hence, determining how pattern elements are to be defined on the reticle is performed with consideration given to a range over which respective proximity effects are significant, and to pattern elements that may be located within the range. Determining this range (termed the “proximal range”) begins with a determination of the “backscattering radius”). The backscattering radius is the width of the Gaussian function corresponding to backscatter of electrons whenever the energy-intensity distribution of the incident beam is approximated by a linear combination of Gaussian functions. This radius is used to describe a distribution of energy intensity of cumulative exposure energy. The energy-intensity distribution is a function indicating the exposure energy received by surrounding points whenever an electron beam is incident at a point. The proximity effects imparted by pattern elements within the backscattering radius cannot be neglected. The proximal range (range over which proximity effects imparted by other pattern elements is significant) typically is wider than the backscattering radius, and is determined by a trade-off of accuracy versus calculation time (i.e., the greater the desired accuracy with which proximity effects are corrected, the longer the time required to calculate the proximity effects and their required corrections). Typically, by way of example, the proximal region extends more than three times the backscattering radius. The calculations result in determinations of the manner and extent to which individual pattern elements, as defined on the reticle, are to be reconfigured. Typically, these calculations are performed using a computer-simulation technique.
[0037] Information relevant to performing these calculations and determining the width of the proximal region is set forth, for example, in U.S. patent application Ser. Nos. 09/704473 and 09/861210, incorporated herein by reference.
[0038] At the relatively low beam-acceleration voltages conventionally used, backscattering radii tend to be small relative to the normal distance between adjacent (neighboring) chips on the wafer. As a result, adjacent chips on the wafer usually did not cause significant proximity effects on pattern elements projected onto peripheral regions of a chip. Hence, determining how pattern elements are to be defined on the reticle conventionally did not include a consideration of proximity effects caused by neighboring chips.
[0039] However, with increases in beam-acceleration voltage, the backscattering radius and hence the proximal range is increased correspondingly. Hence, it has been discovered that a consideration must be given, when configuring pattern elements to be defined on the reticle, to proximity effects imparted to the elements by neighboring chips when the pattern is transfer-exposed from the reticle to the wafer.
[0040] [0040]FIG. 1 schematically depicts, in plan view, an exemplary chip pattern 10 having outer dimensions of 2000 μm×2000 μm. The chip pattern 10 comprises a large L-shaped pattern element 11 , having arm widths of 100 μm, extending along the left edge and bottom edge and a small line 12 , having a width of 70 nm and a length of 50 μm, situated in the upper right corner opposite the L-shaped element 11 . FIG. 2 shows, in plan view, an exemplary arrangement of nine individual chips 13 A- 13 I, each having a chip pattern as shown in FIG. 1, on the surface of a wafer. The chips 13 A- 13 I are spaced 80 μm apart in this example. Generally, the smaller the distance between chips on the wafer, the better in terms of production efficiency, because each wafer yields a correspondingly larger number of chips.
[0041] Attention is directed, in FIG. 2, to the center chip 13 E that is surrounded on all sides by neighboring (adjacent) chips. With respect to the element 12 E extending along the upper right edge, investigations were made of a first situation in which backscatter from neighboring chips 13 B, 13 C, 13 F was ignored, and a second situation in which backscatter from the neighboring chips was considered. Exemplary parameters in the investigations were: a silicon substrate, a beam-acceleration voltage of 125 kV, a backscatter radius of 47.2 μm, a demagnification ratio of 1/4, and a backscatter coefficient of 0.7. In addition, the blur produced by the CPB optical system was 70 nm.
[0042] In the investigation in which backscatter from adjacent chips is ignored, a sufficient distance was assumed to exist between the large L-shaped element 11 E and the small element 12 E in the chip 13 E. Hence, it was assumed that transfer-exposure of the small element 12 E was not influenced by any proximity effect from other pattern elements or chips. Under such conditions the corresponding pattern element as defined on the reticle (for a demagnification ratio of 1/4) had a width of 280 nm. The resulting pattern element 12 E as transfer-exposed onto the chip 13 E (FIG. 3( a )) was defined on the reticle as having a width of 70 nm. Exposure time was established so that the threshold exposure dose for the resist was exceeded in the element 12 E.
[0043] In actuality, in the chip 13 E backscatter is received by the pattern element 12 E from the respective large pattern elements 11 B, 11 C, 11 F proximally located in the neighboring chips 13 B, 13 C, 13 F, respectively. Taking this backscatter into account, the dosage received at the element 12 E on the wafer is increased, as shown in FIG. 3( b ). Consequently, the linewidth of the element 12 E as formed on the wafer is increased by this proximity effect to 70.9 nm (FIG. 3( b )). Hence, in the investigation in which the contribution, to exposure of the pattern element 12 E on the wafer, of backscatter from the large elements 11 B, 11 C, 11 F is taken into account, calculations reveal that the width of the pattern element 12 E as defined on the reticle should be changed slightly to offset this proximity effect. According to the calculations, the linewidth of the pattern element 12 E as defined on the reticle is decreased to 276 nm. Exposure of this element onto the wafer yields a dosage, as received on the wafer, as shown in FIG. 3( c ), in which the linewidth of the pattern element is restored to the desired width of 70 nm.
[0044] With respect to the method described above, it is noted that a complete chip located peripherally (near an edge) of the wafer does not have a full complement of neighboring chips. As a result, whenever a pattern on the reticle is configured under the assumption in which a full set of neighboring chips exist, the reticle may not be configured optimally for exposure of certain chips (especially peripherally located chips). This situation is shown in FIG. 4, in which an edge 15 of the wafer 14 is depicted relative to the chips 13 A- 13 I formed on the wafer. Each of the chips 13 A- 13 I has a respective pattern such as that shown in FIG. 1. Note that the chips 13 D- 13 E and 13 G- 13 H can be made into finished microelectronic devices, but the chips 13 A- 13 C, 13 F and 13 I cannot because each of these chips is missing at least a portion thereof (due to the chips extending partially or fully off the edge 15 of the wafer 14 ). The chips 13 A, 13 B, 13 F, and 13 I extending partially off the wafer edge 15 are said to be “straddling” the wafer edge.
[0045] Conventionally, it is regarded as wasteful to expose any portions of chips such as 13 A, 13 B, 13 C, 13 F, and 13 I. Consequently, exposure of these chips conventionally is not performed so as not to compromise throughput. Rather, exposure conventionally is performed only of the chips 13 D- 13 E and 13 G and 13 H. In FIG. 4, features that conventionally are exposed are shaded more darkly than features that are not.
[0046] However, whenever exposure of the chips 13 A- 13 C, 13 F, 13 I is not performed, exposure of the chips 13 D, 13 E, and 13 H is unaffected by backscatter from the neighboring chips 13 A- 13 C, 13 F, 13 I. But, since the reticle (used to expose all the chips on the wafer) is configured to account for such backscatter, the chips 13 D, 13 E, 13 H as transfer-exposed onto the wafer do not have optimally corrected pattern elements. To prevent this problem, exposure also is performed of portions of the chips 13 A, 13 B, 13 F, and 13 I that straddle the edge 15 of the wafer 14 but nevertheless will not become actual chips. (The chip 13 C is not exposed at all because it is entirely off the wafer 14 where it cannot contribute any backscatter anyway.) By exposing the wafer in this manner, since all the chips actually formed on the wafer are affected substantially equally by backscatter by neighboring chips (or portions of chips). This allows a reticle configured to offset the resulting proximity effects to have an equally curative effect on all the chips. I.e., by exposing portions of the “partial” chips 13 A, 13 B, 13 F, and 13 I, the full chips 13 D, 13 E, 13 H will have patterns that are as design-mandated and as fully corrected as any other chip (e.g., chip 13 G) on the wafer.
[0047] Note that, with respect to the “partial” chips (i.e., chips 13 A, 13 B, 13 F, 13 I), it is unnecessary to expose all the subfields of such chips. Rather, only those subfields of such chips capable of producing backscatter that can reach proximally situated “complete” chips need be exposed. For example, as shown in FIG. 5, in the “partial” chips 13 A, 13 B, 13 F, and 13 I, only subfields situated in the respective regions denoted 16 A, 16 B, 1 F 6 , and 16 I, respectively, are exposed. (In FIG. 5, exposed portions are shaded more darkly than portions that are not exposed.)
[0048] [0048]FIG. 6 is a flow chart of a microelectronic-device manufacturing method that includes a microlithography step performed using a CPB-microlithography method as described herein. The depicted method generally comprises the main steps of wafer production (wafer preparation), reticle production (reticle preparation), wafer processing to form chips, chip dicing and assembly, and inspection of completed chips. Each step usually comprises several sub-steps.
[0049] The wafer-preparation step results in production or preparation of a wafer suitable for use as a lithographic substrate. This step typically involves growth of a monocrystalline silicon ingot, cutting of the ingot into wafers, and polishing the wafers. The reticle-preparation step results in production or preparation of a reticle that defines a desired pattern to be transferred lithographically to the wafer. This step includes performing methods as described below. The wafer-processing step comprises multiple steps resulting in the formation of multiple layers of vertically and horizontally interconnected circuit elements, and is discussed below. The chip dicing and assembly step involves cutting out (dicing) of individual chips from the wafer after completing formation of all the constituent layers of the chips on the wafer, and assembling each individual chip into a respective package with connecting leads and the like. The inspection step involves qualification and reliability testing and inspection of completed devices.
[0050] Among the main steps, wafer processing is key to achieving the smallest feature sizes (critical dimensions), best inter-layer registration, and device performance. In the wafer-processing step, multiple circuit patterns are layered successively atop one another in each die on the wafer, wherein the formation of each layer typically involves multiple sub-steps. Usually, many operative microelectronic devices (chips or dies) are produced on each wafer.
[0051] Typical wafer-processing steps include: (1) Thin-film formation involving formation of a dielectric layer for electrical insulation or a metal layer for connecting wires. The films are produced by CVD, sputtering, or other suitable technique. (2) Oxidation of the thin-film layer or other portion of the wafer surface. (3) Microlithography to form a resist pattern, according to the reticle pattern, for selective processing of the thin film or the substrate itself. (4) Etching (e.g., dry etching) or analogous step to etch the thin film or substrate according to the resist pattern. (5) Doping as required for implantation of dopant ions or impurities into the thin film or substrate according to the resist pattern. Doping can include a thermal treatment to facilitate diffusion of the impurity. (6) Resist stripping to remove the resist from the wafer. (7) Wafer inspection. Wafer processing is repeated as required (typically many times) to fabricate the desired microelectronic devices on the wafer.
[0052] [0052]FIG. 7 is a flow chart of typical steps performed in microlithography, which is a principal step in wafer processing. The microlithography step typically includes: (1) application of resist to the wafer, wherein a suitable resist is coated on the wafer substrate (which can include a circuit element formed in a previous wafer-processing step); (2) exposure step (using a CPB exposure method as described above), to expose the resist with the desired pattern and form a latent image; (3) development step, to develop the exposed resist and obtain an actual pattern in the resist; and (4) optional annealing step, to stabilize the developed pattern in the resist.
[0053] Commonly known technology can be used for any of the steps summarized above, including the microelectronic-device manufacturing process, wafer-processing, and microlithography. Hence, detailed descriptions of these processes are not provided.
[0054] Whereas the invention has been described in connection with multiple representative embodiments and examples, it will be understood that the invention is not limited to those examples. On the contrary, the invention is intended to encompass all modifications, alternatives, and equivalents as may be included within the spirit and scope of the invention, as defined by the appended claims.
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Methods are disclosed for determining a reticle pattern to be defined on a reticle used for charged-particle-beam microlithography performed using a high beam-acceleration voltage. The pattern is determined so at to define pattern elements, destined for transfer-exposure to respective edges of chips, on the reticle in a manner serving to reduce proximity effects in such elements when imprinted on the substrate, whether or not the elements are in peripherally situated chips (located at or near a wafer perimeter) or in chips located centrally on the substrate. On the reticle the profile of such an element is reconfigured as required to reduce proximity effects caused by proximal pattern elements in neighboring chips. To reduce variations in the imprinted profile of such an element in peripherally located chips versus centrally located chips on the substrate, portions of neighboring chips that straddle the substrate edge are imprinted nevertheless. This ensures that the edges of each entire chip imprinted on the substrate experiences the same proximity effect that is offset by the pattern defined by the reticle, regardless of whether the imprinted entire chips are located peripherally or centrally on the substrate.
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[0001] This application is entitled to the benefit of, and incorporates by reference essential subject matter disclosed in PCT Application No. PCT/GB2011/051995 filed on Oct. 14, 2011, which claims priority to Great Britain Application No. 1017461.3 filed Oct. 15, 2010.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] This invention relates to the electric generation of steam for use in domestic irons, steam cleaners, wallpaper strippers and other hand-held steam generating appliances and to various related components.
[0004] 2. Background Information
[0005] Domestic steam irons have been around for a long time. They comprise a sole plate which is flat and intended to contact the item to be ironed and which is normally heated by means of a sheathed electrical resistance heater mounted to or embedded in the upper side of the sole plate. Traditionally, such irons which are designed to produce steam in order to improve ironing have a semi-closed cavity formed on the upper face of the sole plate and into which water is dripped from an on-board reservoir to produce steam which is then allowed to escape onto the clothes by means of a series of apertures formed in the sole plate. These are commonly known as vented steam irons. They are relatively simple and inexpensive to implement which has made them very popular. However, the steam produced is at very low pressure (essentially ambient pressure) and cannot be produced very quickly, making it relatively ineffective.
[0006] At the other end of the market, are professional or semi-professional steam ironing systems in which high pressure steam (e.g. of the order of 3 to 5 bar) is continuously produced in a static base station incorporating a large water reservoir which can then be fed, on demand, to the user's hand-held unit by means of an umbilical cord.
[0007] These are commonly known as pressurized steam generator irons. They deliver a very high performance but are very expensive and tend to account therefore only for a very small proportion of the market.
[0008] More recently there have been proposals, some of which have been commercialized, which seek to bridge the gap between the two extremes outlined above, although these have tended to carry their own drawbacks. For example, it has been proposed to provide a boiler in a base unit, separate from the iron, which is fed by pumping water into it from a reservoir in the base station. The main disadvantage with these arrangements, commonly known as instantaneous steam generator irons, is that there is in fact a significant time lag (of the order of 10 seconds) between the user pressing a button to demand steam and the steam actually being produced and conveyed to the iron. This significantly limits user acceptance, even though higher steam flow rates than vented steam irons can be achieved when the steam is eventually delivered.
[0009] It is an aim of the present invention to provide an improved arrangement for generating steam on demand which can be used in steam irons, and also in other devices employing steam, such as steam cleaners, wallpaper strippers, other steam generating appliances, etc.
SUMMARY OF THE DISCLOSURE
[0010] When viewed from a first aspect the invention provides a pressurized boiler for a steam generator appliance comprising an evaporation chamber, an electric heater in good thermal contact with a wall of the evaporation chamber, a water inlet arranged in a cover of the evaporation chamber separate from said wall, and a pump in fluid communication with the water inlet arranged to supply water to the evaporation chamber through the water inlet.
[0011] Having the water inlet in a separate cover affords a number of advantages. Primarily the water inlet being in a separate component (the cover) isolates the cooler water supply from the hotter heated walls of the evaporation chamber thus avoiding large temperature gradients in the walls of the evaporation chamber, e.g. compared to if the water inlet was supplied through a heated wall of the evaporation chamber. By avoiding large temperature gradients, premature failure of the boiler through cracking of the heated walls may be avoided. In a preferred set of embodiments the boiler comprises heat resistant sealing means, e.g. a heat resistant sealing gasket or O-ring, between the heated wall and the cover of the evaporation chamber.
[0012] As well as acting to thermally isolate the water inlet from the heated walls of the evaporation chamber, providing the water inlet in the cover of the evaporation chamber physically spaces the water inlet from the heated walls. This spacing provides an internal volume within the evaporation chamber between the water inlet and the heated wall in which scale can build up without blocking the water inlet, e.g. as could happen if the water inlet were provided in the heated wall of the evaporation chamber—e.g. at the bottom of the chamber. In a preferred set of embodiments the water inlet is spaced by at least 5 mm from the heated wall of the evaporation chamber, preferably at least 10 mm, more preferably at least 15 mm, e.g. at least 20 mm. Expressed alternatively, the water inlet is spaced by at least 50% of the maximum dimension of the chamber from the heated part of the chamber wall.
[0013] The Applicant has found, counter-intuitively, that at least some steam generators constructed in accordance with the invention can operate efficiently even when a relatively large amount of scale is present within the evaporation chamber, because of the volume in which scale can safely build up, provided by the spacing of the water inlet from the walls of the evaporation chamber. This is convenient in giving a long operating life without the need to provide user access to the interior of the pressurized boiler.
[0014] The cover could be attached to the wall(s) of the evaporation chamber by any suitable means, e.g. screws, bolts, clamps, welding, but in one set of embodiments the cover is attached to wall(s) of the evaporation chamber by peening, e.g. over the external surface of the evaporation chamber wall(s) and cover to seal the cover in place. This can create an improved seal between the cover and the wall(s) of the evaporation chamber because there is no need to provide additional components, e.g. screws, that may be prone to failure through continued use of the boiler and which would eventually result in the steam pressure generated in the evaporation chamber being sufficient to force the cover open.
[0015] In one set of embodiments the heated wall(s) and the cover of the evaporation chamber each comprise a sealing surface between which the heat resistant sealing means is positioned. Preferably the distance between the sealing surface of the heated wall(s) and the sealing surface of the cover is less than the thickness of the sealing means, so that the sealing means is held under compression. This improves the resistance of the sealing means against the steam pressure generated inside the evaporation chamber. Therefore preferably the sealing means comprises a compressible material, e.g. rubber, silicone.
[0016] The sealing surface of the heated wall(s) is generally parallel to the sealing surface of the cover, with the sealing means sandwiched between. The sealing surfaces could be substantially perpendicular to the direction in which the cover is placed on the evaporation chamber, e.g. in the general horizontal plane of the cover if the cover is flat and covering an opening in the top of the evaporation chamber. However it has been found that sealing in this direction is not effective after prolonged use of the boiler. This is because repeated thermal cycling of the boiler eventually causes slight relative movements between the heated walls and the cover. Therefore if the sealing means is in compression between the two sealing surfaces, thereby exerting a force in the direction in which the cover is opened, over time the steam pressure generated during operation acts to force the cover open and allows steam to escape past the sealing means.
[0017] In one set of embodiments the sealing surfaces are substantially parallel to the direction in which the cover is placed on the evaporation chamber. This has the effect that the direction in which the sealing force is being exerted between the sealing means and the sealing surfaces, is perpendicular to the direction in which the cover is opened, so this force is not acting to open the cover. Furthermore, the sealing surfaces and/or the sealing means can be arranged such that there is some tolerance in the fit between the respective parts which allows some degree of movement of the cover relative to the rest of the evaporation chamber without compromising the seal. Also, if the cover is being worked loose from repeated operation, the steam pressure acts to force the sealing means into the path through which steam could escape, thereby preventing steam for escaping and retaining the cover on the boiler, resulting in the life of the boiler, i.e. the number of operational cycles or hours before steam starts to escape past the sealing means being prolonged. The feature of the sealing means being arranged between the sealing surfaces in this direction has been found to result in a significant increase in the life of the boiler.
[0018] The water inlet could be provided at any point in the cover of the evaporation chamber, but in a preferred set of embodiments the water inlet is provided in the center of the cover. In this set of embodiments the water can therefore be made to fall from the water inlet onto a central point on the wall of the evaporation chamber opposite the inlet so that it is evenly distributed across the heated wall which assists the efficient and rapid generation of steam.
[0019] In a preferred set of embodiments the water inlet comprises a nozzle which projects away from the cover and into the evaporation chamber. This helps to separate the water inlet from the steam outlet, where this is also conveniently provided in the cover of the evaporation chamber, and therefore helps to prevent the steam from undesirably entraining drops of water from the water inlet into the outlet steam flow.
[0020] This is novel and inventive in its own right and therefore when viewed from a further aspect the invention provides a pressurized boiler for a steam generator appliance comprising an evaporation chamber, an electric heater in good thermal contact with one or more walls of the evaporation chamber, a nozzle which projects into the evaporation chamber, and a pump in fluid communication with the nozzle arranged to supply water to the evaporation chamber through the nozzle.
[0021] In this aspect of the invention the nozzle may or may not be provided in a separate cover as recited in the first aspect of the invention, e.g. it could alternatively project from a wall or the base of the evaporation chamber. It will be appreciated that this arrangement also helps to separate the water inlet from the heated walls of the evaporation chamber where scale builds up, and therefore prevents scale blocking the water inlet, as has been discussed above.
[0022] In one set of embodiments of either of the foregoing aspects of the invention, the wall of the evaporation chamber comprises a protuberance, preferably located opposite the water inlet, e.g. at the center of the base in a preferred set of embodiments. The protuberance can prevent water collecting in a pool at the bottom of the evaporation chamber and therefore water from the water inlet falling into a standing pool of water. Instead the water falls onto the protuberance, which because of the spacing of the water inlet from the heated wall of the evaporation chamber, results in an impact causing the water to break up into smaller droplets that are projected onto the internal surface of the evaporation chamber, thereby aiding rapid evaporation of the water and hence efficient steam generation. This contrasts, for example, with a water inlet provided at the bottom of an evaporation chamber, as there may then be a tendency for water to collect at the bottom of the evaporation chamber and not be spread over the heated surface.
[0023] This is novel and inventive in its own right and therefore when viewed from a further aspect the invention provides a pressurized boiler for a steam generator appliance comprising an electric heater, an evaporation chamber in good thermal contact with the electric heater, a water inlet, wherein a wall of the evaporation chamber comprises a protuberance located opposite the water inlet.
[0024] The protuberance could take many different forms, e.g. a simple conical, frusto-conical or convex dome - or a more complex shape.
[0025] Preferably the boiler is provided with a pump for delivering water to the water inlet.
[0026] In a preferred set of embodiments of any aspect of the invention the boiler is provided in a portable appliance such as a steam iron, steam cleaner, wallpaper stripper or other hand-held steam generating appliance. Therefore the invention extends to a steam generator appliance comprising a boiler as set out in all aspects of the invention.
[0027] In a preferred set of embodiments the boiler comprises a valve to control the inlet of water through the water inlet into the evaporation chamber. This enables the amount of water admitted into the evaporation chamber to be regulated so that steam can be generated efficiently, i.e. the water flow rate into the evaporation chamber can be optimized for maximum steam generation. For example, if too much water is admitted at once the evaporation chamber will be cooled, preventing steam from being produced rapidly. The provision of a valve also enables water to be admitted after the electric heater is first energized, allowing the evaporation chamber to be pre-heated so that when water is admitted, steam is rapidly produced.
[0028] Although the boiler will typically be thermostatically controlled, it is preferably arranged such that it is allowed to reach a higher operating temperature when there is no water flow, e.g. when the pump is off or the aforementioned valve is closed, than when water is flowing. This means that the boiler can store additional thermal energy in its thermal mass, further reducing the time to produce the first shot of steam after the valve is opened because the water can then be heated more rapidly.
[0029] The water for supplying the boiler may be provided in a number of ways. In a set of preferred embodiments the boiler is provided in a portable appliance also including a reservoir. In a set of embodiments, the reservoir is pressurized. This could for example be achieved by means of a compressed air chamber or the reservoir could be elastically charged.
[0030] Where a pump is provided, there may be provided means to delay operation of the pump until the boiler has reached a predetermined operating temperature. A temperature sensitive control means may be arranged to provide an electrical connection to the pump only when it is detected that the operating temperature has been reached. Alternatively a timer could be programmed to delay the operation of the pump until such time that the boiler is expected to have heated up. It is preferred that the pump and electric heater of the boiler are connected electrically in parallel so that they may be controlled by a common on/off switch. This allows for simple “one button” operation of the appliance, while also ensuring that the boiler is hot enough when water is pumped into it that steam generation starts rapidly. Advantageously the start-up time may be reduced.
[0031] The evaporation chamber could take a variety of forms and shapes, e.g. tubular, cuboid, conical, part-spherical, obloid, pill-box shaped, etc. In a preferred set of embodiments the evaporation chamber has a portion converging away from the inlet. It could, for example, have a U-shaped cross section with vertical or substantially vertical side walls and a concave base (ignoring any protuberance on the base)—i.e. be broadly torpedo shaped. A torpedo shaped evaporation chamber provides a large surface area from which water can be evaporated. It also provides an evaporation chamber with a large volume (for a given surface area) so that it can operate efficiently even with a large build up of scale.
[0032] The heated surface bounding the evaporation chamber (hereinafter referred to as “the evaporation surface”) is preferably provided with one or more protrusions or recesses to increase the surface area thereof. In a set of preferred embodiments, the surface area of the evaporation surface is more than 10% greater than the area of a smooth surface having the dimensions of the mean surface height, preferably more than 50% greater, more preferably more than 75% greater, more preferably more than 100% greater.
[0033] There are many different ways in which the evaporation surface area could be increased e.g. ridges, ribs, dimples, grooves, bumps, etc. In a preferred set of embodiments the evaporation surface comprises a plurality of parallel, e.g. vertically extending, ribs. Vertical features can prevent water from collecting on the evaporation surface, e.g. compared to features which run horizontally. The vertically extending ribs could also extend across the base of the evaporation chamber, e.g. extending radially outward from the center of the base and then vertically up the walls. As will be appreciated, vertical features are more easily provided in the manufacturing procedure in the embodiments with an evaporation chamber with substantially vertical side walls.
[0034] The vertical ribs could comprise alternating convex and concave features, and in a preferred set of embodiments the radius of curvature of these features is between 1 and 3 mm Preferably there are 24 or fewer vertical ribs arranged around the evaporation chamber, e.g. 22. This arrangement of alternating convex and concave features helps to maximize the area of the evaporation surface whilst giving good performance and manufacturability.
[0035] In a preferred set of embodiments the evaporation chamber is die cast, preferably from aluminum Aluminum is suitable for die casting, is relatively cheap, has a relatively high specific heat capacity and is suitable for treating with a hydrophilic coating. The electric heater could surround the evaporation chamber, e.g. be attached to its outer surface. However, in a preferred set of embodiments the electric heater is embedded in the walls of the evaporation chamber, e.g. by die casting the evaporation chamber around the electric heater. This maximizes the heat transfer from the electric heater to the evaporation surface and minimizes thermal losses.
[0036] The electric heater could comprise any suitable heater, e.g. a thick film heating element attached to the outer surface of the evaporation chamber, but in a preferred set of embodiments the electric heater comprises a sheathed heating element. Preferably the sheathed heating element is embedded in the walls of the die cast evaporation chamber as mentioned above. The sheathed heating element could follow any suitable path around the walls of the evaporation chamber, but in a preferred set of embodiments the sheathed heating element follows a spiral or helical path.
[0037] In a preferred set of embodiments, the mass of the boiler is less than 0.6 kg and is arranged such that during operation the temperature gradient between the electric heater and the heated surface of the evaporation chamber is less than 60° C./mm. Such an arrangement has been found to give a boiler which gives a desirably fast start-up time but without the risk, appreciated by the Applicant, of premature cracking of the boiler which might occur if the mass of the boiler were simply reduced to give a low start-up time. In fact in some preferred embodiments of the invention the mass of the boiler is greater than the skilled person would otherwise have specified in order to meet the thermal gradient criterion specified above to avoid cracking. Having a boiler with a relatively large mass is also advantageous when the boiler is provided in a cordless appliance as this provides a prolonged period over which steam can be generated owing to the relatively large thermal capacity of the boiler.
[0038] Such an arrangement is novel and inventive in its own right and thus when viewed from a further aspect the invention provides a pressurized boiler for a steam generator appliance comprising an electric heater, an evaporation chamber in good thermal contact with the electric heater, wherein the evaporation chamber has a mass less than 0.6 kg, and during operation is arranged such that the temperature gradient between the electric heater and the heated surface of the evaporation chamber is less than 60° C./mm.
[0039] In a typical embodiment, the temperature of the wetted evaporation chamber surface during operation is 120° C. and the temperature at the surface of the heating element is 270° C. The Applicant has found that if the temperature gradient is less than 60° C./mm, preferably less than 50° C./mm, preferably less than 40° C./mm, premature cracking will not occur. It will be appreciated that the arrangement described in the first aspect of the invention with the water inlet provided in the cover of the evaporation chamber, helps to reduce this temperature gradient as it isolates the cooler water supply from the hotter heating element and heated walls of the evaporation chamber, as has been discussed above.
[0040] In a preferred set of embodiments, the distance between the heating element and the evaporation surface is greater than 3 mm, preferably greater than 4 mm.
[0041] The temperature gradient across the wall of the evaporation chamber is also affected by the shape of the chamber and configuration of the heating element, e.g. the separation between adjacent loops of a spiral sheathed heating element. If the loops are too close together, then this will result in too high a temperature gradient owing to the proximity of the heat energy sources.
[0042] It will appreciated that the previously recited features for the previous aspects of the invention are not exclusive to any particular aspect and can be incorporated in any combination with any aspect of the invention.
[0043] In an exemplary set of embodiments the normal operating temperature is greater than 160° C. Preferably the evaporation surface is hydrophilic, at least at its normal operating temperature. This might be a natural characteristic of the material used for the evaporation surface, it might be achieved or enhanced by a suitable surface treatment and/or it might be achieved or enhanced by a suitable heat resistant coating material. Where the evaporation surface is made hydrophilic by a surface treatment or coating the treated or coated surface should be hydrophilic at a temperature at which the Leidenfrost effect would otherwise occur on the untreated or uncoated surface.
[0044] The evaporation chamber may of course have more than one evaporation surface. This might be the case as a result of the distribution of the heating element, the provision of multiple heating elements, or simply by the close thermal connection between a surface which is directly heated and another surface.
[0045] In a set of preferred embodiments the boiler is configured to produce pressurized heated steam. In some preferred embodiments the boiler has a temperature of between 100 and 500° C., more preferably between 105 and 380° C. Preferably the internal steam pressure generated within the boiler should not be greater than that of the water pressure entering it, else water will be prevented from entering the device, resulting in a subsequent drop in steam flow rate and unwanted fluctuation in steam output. Steam may simply be allowed to leave the boiler once it has passed through the evaporation chamber. In a preferred set of embodiments the steam outlet is provided in separate cover—e.g. on an upper part of the evaporation chamber, which in one set of embodiments will be adjacent the water inlet. Providing the steam outlet in an upper part of the evaporation chamber helps to prevent scale particles clogging the steam outlet.
[0046] However, in a set of preferred embodiments the boiler comprises means for collecting the steam. This allows it, for example, to be channeled into one or more pipes for delivering it to the steam outlet(s) of an appliance on which the boiler is provided. The means for collecting steam may comprise means for trapping unevaporated droplets of water. For example this might be a protruding outlet tube encouraging steam channeled by the walls of the chamber to undergo a change of direction leading to expulsion of entrained droplets.
[0047] In one set of embodiments the boiler is divided into the evaporation chamber and a steam collection space. In a set of embodiments the boiler is divided by an intermediate member provided in the evaporation chamber of the boiler. Preferably the intermediate member provides one of the surfaces defining the evaporation chamber. In one set of embodiments the intermediate member comprises a mesh. This mesh retains scale particles within the evaporation chamber, i.e. prevents them from passing into the steam collection space and into the steam outlet where they could create a blockage, and it also reduces the risk of water droplets, e.g. entrained from the water inlet into the steam, from passing into the steam outlet. Water droplets in the steam outlet are to be avoided because they may form steam bubbles which can become trapped and then cause spitting, or generally drops of water will pass into the steam outlet, which is undesired when dry steam is preferred.
[0048] In the embodiments in which an intermediate member is provided to separate the evaporation chamber from the steam collection space, preferably the water inlet projects through the intermediate member into the evaporation chamber. It will be appreciated that this arrangement is particularly suited to the aspect and embodiments of the invention in which the water inlet comprises a nozzle which projects into the evaporation chamber. As well as providing an unrestricted path for water entering the evaporation chamber, i.e. the water not having to pass through the intermediate member, having the water inlet passing through the steam collection space pre-heats the water before it enters the evaporation chamber.
[0049] A boiler in accordance with the aspect of the invention set out above may usefully be used for the continuous generation of steam. However, it is particularly beneficial for appliances where steam is required “on demand”. An important factor in achieving this effect is to supply water to the boiler under pressure and thus a particularly preferred set of embodiments has a boiler of the kind described above, or indeed one which only has some of the features set out in an appliance comprising means for supplying pressurized water to the water inlet of the boiler. As previously mentioned, such an appliance could, for example comprise an electric iron, a steam cleaner, wallpaper stripper or any other steam generating appliance. The means for pressurizing water could be any suitable means such as an elastically charged store or a pressurized reservoir upstream of the evaporation chamber. The pressure of the water supply is preferably greater than 0.5 bar, e.g. more than 1 bar and might be up to 3 bar or more.
[0050] Where the boiler is to be used to produce steam “on demand” it is beneficial, in order to minimize the initial delay between filling it with water and producing steam, that when it does not contain water, it is allowed to increase in temperature and therefore store thermal energy which can be used to heat the initial charge of water to boiling as rapidly as possible. In a set of preferred embodiments, the useable energy which the boiler is adapted to store, that is the amount of heat energy available to generate steam, is more than 20 kilojoules, more preferably greater than 35 kilojoules and more preferably greater than 50 kilojoules.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] Certain preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
[0052] FIG. 1 is a perspective view of a boiler in accordance with an embodiment of the invention;
[0053] FIG. 2 is an exploded view of the boiler of FIG. 1 ;
[0054] FIG. 3 is a vertical cross section through the boiler of FIGS. 1 and 2 ; and
[0055] FIGS. 4 a and 4 b are enlarged portions of the sealing region of FIG. 3 for two different embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0056] FIG. 1 shows the external appearance of a boiler 1 for a steam generator embodying the invention comprising a lower body member 70 which is of die-cast aluminum and an upper cover member 72 , also of die-cast aluminum.
[0057] In the upper left hand region of the boiler 1 there can be seen a water inlet 50 and the two ends of a sheathed electrical resistance heating element 60 . Projecting electrical terminals 62 , 64 (known in the art as cold tails pins) are provided to enable electrical connection to the element 60 . A high temperature regulator 66 is provided against a flange 68 on the lower body member 70 of the boiler. Also. on the lower body member 70 of the boiler can be seen a number of apertures 56 which extend through the wall of the lower body member 70 to expose the sheathed heating element 60 . The purpose of these apertures 56 is to allow positioning of the heating element 60 in the die-cast tool when die-casting the lower body member 70 . A steam outlet 54 is visible in the top right hand part of FIG. 1 .
[0058] With particular reference now to FIG. 2 (in which the high temperature regulator 66 has been removed for clarity), it can be seen that the main section of the boiler is made up of four main parts: the lower body member 70 and upper body (cover) member 72 , both of which are made of die-cast aluminum but could equally be made of another non-ferrous metal or other suitable material; a disc shaped mesh layer 76 , e.g. of stainless steel, and a heat-resistant seal 74 . When assembled, the upper and lower body members 70 , 72 are clamped together by suitable means and this retains the disc shaped mesh layer 76 and heat-resistant seal 74 between them.
[0059] It will be seen that inside, the lower body member 70 defines a generally torpedo shaped evaporation chamber 78 . The inner wall of this evaporation chamber 78 is formed with a series of vertical ribs 75 , and a small protuberance 58 in the center of the base (see FIG. 3 ), the purposes of which will be explained later.
[0060] FIG. 3 shows a cross-section through the assembled boiler 1 . This Figure shows that the lower body member 70 has much thicker walls than the cover member 72 since they accommodate an embedded heating element 60 . This is cast into the lower body member 70 during manufacture. The element is approximately helical so that it wraps around the conical cavity formed by the lower body member 70 . This ensures an even heat distribution across the lower wall of the evaporation chamber 78 .
[0061] In the upper portion of the evaporation chamber 78 is the disc shaped mesh layer 76 which separates the evaporation chamber 78 below the mesh layer 76 from a steam collection space 80 above the mesh layer 76 . A downwardly projecting spout 77 , which projects through the center of the mesh layer 76 , fluidly communicates with the water inlet 50 via a conduit 79 . At the top of the steam collection space 80 there is the steam outlet 54 formed by a passageway 86 through the cover member 72 .
[0062] The internal heat transfer surfaces—that is the walls of the chamber 78 —may be coated with a functional heat resilient surface coating that enhances the transfer of heat into the water. Such a coating can improve the speed of heat absorbed by the water particularly at operating temperatures above 160° C. and below 380° C. The coating can be applied in a single coat. To ensure its durability it may however be necessary subsequently to cure it at an elevated temperature. The method of application need not be complicated and can be accomplished without sophisticated equipment—e.g. via spray, brush, roller or any other suitable method. However other methods can be employed such as electrolytic, electrostatic, plasma, thermal spray, vacuum deposition, spin coated, sol gel process, evaporation and others.
[0063] The functional coating may provide a hydrophilic surface and substantially increase the available heat transfer surface area of the evaporation space by giving the coated surfaces thereof a microstructure. A micro-surface and partially sub-surface structure is imparted by the coating as it creates a surface matrix and micro-textured surface. Additionally the coating is thermally shock resilient, adheres strongly to the internal surfaces and preferably inhibits corrosion.
[0064] It will be seen that the internal configuration of the boiler has heat transfer surfaces that are configured to operate at different scales through use e.g. of the functional coating which operates to improve thermal transfer efficiencies at dimensions between the nano and micro scales. The surface to which the coating is applied is configured to impart a texture to the coating operating between a micro and macro scales.
[0065] The vertically ribbed surface structure 75 on the other hand operates to enhance heat transfer at a macro scale. Therefore the evaporation space operates as a complex heat transfer surface/matrix with additional complex heat transfer surface/matrix interactions at the micro and nano scale provided by the functional coating.
[0066] The sealing region between the lower and upper body members 70 , 72 for two different embodiments is shown in FIGS. 4 a and 4 b , which corresponds to an enlarged view of the upper right hand portion of FIG. 3 , around the steam outlet 54 . In FIG. 4 a the heat-resistant seal 74 is held compressed between a horizontal sealing surface 90 on the upper body member 72 and a parallel horizontal sealing surface 92 on the lower body member 70 to create a tight seal between the lower and upper body members 70 , 72 . In FIG. 4 b the heat-resistant seal 74 is held compressed between a vertical sealing surface 94 on the upper body member 72 and a parallel vertical sealing surface 96 on the lower body member 70 .
[0067] Operation of the steam generator will now be described with reference to the Figures. Electrical power is supplied to the sheathed resistance heating element 60 which is embedded in the lower body member 70 of the boiler. This is controlled by a separate high temperature regulator 66 which allows the boiler to reach a high temperature e.g. between 160° C. and 380° C. Although not shown, one or more indicator lights or other form of indication might be provided to a user to indicate that the boiler has reached its predetermined temperature.
[0068] Water is pumped from a reservoir by a pump (neither of which is shown), optionally via a valve (also not shown). The water first enters the boiler 1 by means of the inlet 50 and passes through a conduit 79 in the cover member 72 . As the water passes through this conduit 79 , it is preheated so that when it enters the evaporation chamber, its temperature is raised significantly above ambient (but below boiling). The water enters the evaporation chamber 78 by means of spout 77 which projects through the center of the mesh layer 76 and impacts against the protuberance 58 with a pressure greater than if it merely had dripped under gravity. The water therefore rebounds off the protuberance 58 in small droplets onto the heated walls of the evaporation chamber 78 . This impact spreads the water across a large surface area (which is further enhanced by the vertical ribs on the walls) which allows a relatively large quantity of water to be evaporated into steam from a relatively small boiler volume.
[0069] The spacing of the water inlet spout 77 from the base of the evaporation chamber 78 , combined with the near vertical walls provide a relatively large volume in which scale can build up without blocking the water inlet spout 77 or preventing efficient steam generation in the evaporation chamber 78 .
[0070] The steam which is produced escapes from the evaporation chamber 78 through the mesh layer 76 clamped between the upper and lower members 70 , 72 of the boiler and into the steam collection space 80 . The mesh layer 76 helps to trap any small remaining droplets of water entrained in the steam as well as any scale particles. Any droplets of water trapped by the mesh layer 76 are evaporated. The pressure of this steam forces it out of the passageway 86 in the top of the steam collection space 80 . The steam exiting the evaporation chamber 78 is pressurized. The steam passes through the passageway 86 to the steam outlet 54 and from there into the appliance (not shown) to be used as required. The rate at which steam is generated can be varied by altering the flow rate of water into the evaporation chamber 78 , e.g. by controlling a valve (not shown) on the water inlet 50 .
[0071] In a particular example of the steam generator described above, the lower member 70 had a mass of 0.516 Kg and was made from aluminum having a specific heat capacity of 0.91 J/(g-K). The heating element 60 had a power of 1800 W and its operating temperature is 270° C. The minimum thickness of the evaporation chamber wall 78 between the element 60 and the nearest valley between ribs 75 was 3 mm. The temperature of the wetted evaporation surface 78 was 120° C. The thermal gradient across the surface was therefore (270-120° C.)/3 mm=50° C./mm. The start-up time for the heater was approximately 60 seconds. No premature cracking of the boiler was observed through accelerated lifetime testing.
[0072] It will be appreciated that in the sealing arrangement in FIG. 4 a , internal steam pressure in the chamber which tends to separate the upper body member 72 from the lower body member 70 will tend to reduce the compressive force on the seal 74 and thereby increase the risk of leakage. However in the arrangement shown in FIG. 4 b , vertical movement of the upper body member 72 relative to the lower body member 70 will not reduce the compressive force on the seal 74 . Indeed any build up of steam pressure passing between the upper and lower body members serves to further compress and hence maintain the seal. This arrangement has therefore been found to have a significantly longer life before leakage occurs.
[0073] Thus it will be seen by those skilled in the art that the embodiment of various aspects of the invention described above provides an extremely effective steam generator boiler which offers the performance of a high steam pressure but which can be produced at a significantly lower cost than traditional pressurized steam generators—e.g. as found in professional ironing systems.
[0074] Whilst the invention has been described in terms of one specific embodiment, many aspects and features of the invention might be applied to many different types of steam generators, in appliances such as irons, wallpaper strippers and other hand-held steam generating appliances. Features mentioned in connection with the embodiments described in detail above or indeed with any other embodiments mentioned herein may be applied equally to any other embodiment and the applicant specifically envisages such combinations of features. Any feature of the invention should therefore be considered as independently applicable and not limited in its application to this specific embodiment in which it is mentioned, except where otherwise indicated.
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A pressurised boiler ( 1 ) for a steam generator appliance comprises an evaporation chamber ( 78 ), an electric heater ( 60 ) in good thermal contact with a wall ( 70 ) of the evaporation chamber ( 78 ), a water inlet ( 77 ) arranged in a cover ( 72 ) of the evaporation chamber ( 78 ) separate from said wall ( 70 ), and a pump in fluid communication with the water inlet ( 77 ) arranged to supply water to the evaporation chamber ( 78 ) through the water inlet ( 77 ).
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/385,039, filed on Mar. 10, 2003 (now U.S. Pat. No. 7,039,771). This application also relates to the subject matter of U.S. patent application Ser. No. 10/384,992, filed on Mar. 10, 2003 (now U.S. Pat. No. 7,492,545); U.S. patent application Ser. No. 10/385,022, filed on Mar. 10, 2003 (now U.S. Pat. No. 7,080,188); U.S. patent application Ser. No. 10/384,991, filed on Mar. 10, 2003 (now U.S. Pat. No. 7,457,903); U.S. patent application Ser. No. 10/385,042, filed on Mar. 10, 2003 (now U.S. Pat. No. 7,099,963); U.S. patent application Ser. No. 10/385,405, filed on Mar. 10, 2003 (now U.S. Pat. No. 7,064,915); and U.S. patent application Ser. No. 10/385,056, filed on Mar. 10, 2003 (now U.S. Pat. No. 7,219,182). The disclosures of the above applications are incorporated herein by reference.
FIELD
The present invention relates generally to storage systems, and more particularly to disk drive servo controllers.
BACKGROUND
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Conventional computer systems typically include several functional components. These components may include a central processing unit (CPU), main memory, input/output (“I/O”) devices, and disk drives. In conventional systems, the main memory is coupled to the CPU via a system bus or a local memory bus. The main memory is used to provide the CPU access to data and/or program information that is stored in main memory at execution time. Typically, the main memory is composed of random access memory (RAM) circuits. A computer system with the CPU and main memory is often referred to as a host system.
The main memory is typically smaller than disk drives and may be volatile. Programming data is often stored on the disk drive and read into main memory as needed. The disk drives are coupled to the host system via a disk controller that handles complex details of interfacing the disk drives to the host system. Communications between the host system and the disk controller is usually provided using one of a variety of standard I/O bus interfaces.
Typically, a disk drive includes one or more magnetic disks. Each disk (or platter) typically has a number of concentric rings or tracks (platter) on which data is stored. The tracks themselves may be divided into sectors, which are the smallest accessible data units. A positioning head above the appropriate track accesses a sector. An index pulse typically identifies the first sector of a track. The start of each sector is identified with a sector pulse. Typically, the disk drive waits until a desired sector rotates beneath the head before proceeding with a read or write operation. Data is accessed serially, one bit at a time and typically, each disk has its own read/write head.
FIG. 1 shows a disk drive system 100 with platters 101 A and 101 B, an actuator 102 and read/write head 103 . Typically, multiple platters/read and write heads are used. Platters 101 A- 101 B have assigned tracks for storing system information, servo data and user data.
The disk drive is connected to the disk controller that performs numerous functions, for example, converting digital data to analog head signals, disk formatting, error checking and fixing, logical to physical address mapping and data buffering. To perform the various functions for transferring data, the disk controller includes numerous components.
To access data from a disk drive (or to write data), the host system must know where to read (or write data to) the data from the disk drive. A driver typically performs this task. Once the disk drive address is known, the address is translated to cylinder, head and sector based on platter geometry and sent to the disk controller. Logic on the hard disk looks at the number of cylinders requested. Servo controller firmware instructs motor control hardware to move read/write heads 103 to the appropriate track. When the head is in the correct position, it reads the data from the correct track.
Typically, read and write head 103 has a write core for writing data in a data region, and a read core for magnetically detecting the data written in the data region of a track and a servo pattern recorded on a servo region.
A servo system 104 detects the position of head 103 on platter 101 A according to a phase of a servo pattern detected by the read core of head 103 . Servo system 104 then moves head 103 to the target position.
Servo system 104 servo-controls head 103 while receiving feedback for a detected position obtained from a servo pattern so that any positional error between the detected position and the target position is negated.
Typically, a servo controller in system 104 communicates with various serial port programmable devices coupled via a serial port interface. The serial port interface enables transmission of commands and configuration data. One such device is shown in FIG. 3 , as the “read channel device 303 ”. An example of such a product is “88C7500 Integrated Read channel” device sold by Marvell Semiconductor Inc®.
There is no standard for these various serial port devices to communicate with the servo controller. For example, length of address and length of data fields may vary from one device to the next. Hence, a single serial port connection is not typically used for plural devices having different protocols. Conventional techniques require a separate controller for each device. This is commercially undesirable because it adds costs and extra logic on a chip.
Therefore, what is desired is an efficient system that allows an embedded disk controller to communicate with plural devices through a single serial port controller interface.
SUMMARY
A servo controller for a disk drive controller comprises a storage device that stores communication information for a plurality of devices. A serial port controller located on the servo controller communicates with the storage device, receives a request to communicate with one of the plurality of devices, and allows communication between at least one processor and the one of the plurality of devices according to the stored communication information and the request, wherein each of the plurality of devices uses a different protocol.
In other features of the invention, the storage device includes at least one register. Logic that enables the plurality of devices to receive at least one of a write request and a read request. The serial port controller arbitrates between a plurality of the requests to communicate. The serial port controller communicates with at least one client device and receives the plurality of the requests to communicate from the at least one client device. The communication information includes at least one of address information, write data information, and read data information. The serial port controller outputs an enabling signal to the one of the plurality of devices according to the communication information and the request. A routing device communicates with the serial port controller, the storage device, and the plurality of devices and allows data to flow at least one of to and from the plurality of devices. At least one of the serial port controller and the storage device are located on one of an integrated circuit (IC) and a system on a chip (SOC) with the servo controller.
A method for communicating with serial port devices with a servo controller for a disk drive controller comprises storing communication information for a plurality of devices in a storage device, communicating with the storage device at serial port controller located on the servo controller, receiving a request to communicate with one of the plurality of devices at the serial port controller, and allowing communication between at least one processor and the one of the plurality of devices according to the stored communication information and the request, wherein each of the plurality of devices uses a different protocol.
In other features of the invention, the storage device includes at least one register. The method further comprises enabling the plurality of devices to receive at least one of a write request and a read request. The serial port controller arbitrates between a plurality of the requests to communicate. The serial port controller communicates with at least one client device and receives the plurality of the requests to communicate from the at least one client device. The communication information includes at least one of address information, write data information, and read data information. The serial port controller outputs an enabling signal to the one of the plurality of devices according to the communication information and the request. The method further comprises communicating with the serial port controller, the storage device, and the plurality of devices with a routing device, and allowing data to flow at least one of to and from the plurality of devices with the routing device.
A servo controller for a disk drive controller comprises storage means for storing communication information for a plurality of devices and serial port control means located on the servo controller for communicating with the storage means, for receiving a request to communicate with one of the plurality of devices, and for allowing communication between at least one processor and the one of the plurality of devices according to the stored communication information and the request, wherein each of the plurality of devices uses a different protocol.
In other features of the invention, the storage means includes at least one register. The servo controller further comprises logic means for enabling the plurality of devices to receive at least one of a write request and a read request. The serial port controller arbitrates between a plurality of the requests to communicate. The serial port control means communicates with at least one client device and receives the plurality of the requests to communicate from the at least one client device. The communication information includes at least one of address information, write data information, and read data information. The serial port control means outputs an enabling signal to the one of the plurality of devices according to the communication information and the request. The servo controller further comprises routing means for communicating with the serial port control means, the storage means, and the plurality of devices and for allowing data to flow at least one of to and from the plurality of devices. At least one of the serial port control means and the storage means are located on one of an integrated circuit (IC) and a system on a chip (SOC) with the servo controller.
In still other features, the systems and methods described above are implemented by a computer program executed by one or more processors. The computer program can reside on a computer readable medium such as but not limited to memory, non-volatile data storage and/or other suitable tangible storage mediums.
Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing features and other features of the present invention will now be described. In the drawings, the same components have the same reference numerals. The illustrated embodiment is intended to illustrate, but not to limit the invention. The drawings include the following Figures:
FIG. 1 shows a block diagram of a disk drive;
FIG. 2 is a block diagram of an embedded disk controller system, according to one aspect of the present invention;
FIG. 3 is a block diagram showing the various components of the FIG. 3 system and a two-platter, four-head disk drive, according to one aspect of the present invention;
FIG. 4 is a block diagram of a servo controller, according to one aspect of the present invention;
FIG. 5 is a schematic of a serial port controller, according to one aspect of the present invention;
FIGS. 6A and 6B provides examples of timing diagrams as used by the serial port controller of FIG. 5 during a write and read phase, respectively, according to one aspect of the present invention; and
FIG. 7 is a flow diagram of executable steps for a state machine used by the serial port controller, according to one aspect of the present invention.
DRAWINGS
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
DETAILED DESCRIPTION
The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the term module, circuit and/or device refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure.
To facilitate an understanding of the preferred embodiment, the general architecture and operation of an embedded disk controller will be described initially. The specific architecture and operation of the preferred embodiment will then be described.
FIG. 2 shows a block diagram of an embedded disk controller system 200 according to one aspect of the present invention. System 200 may be an application specific integrated circuit (“ASIC”).
System 200 includes a microprocessor (“MP) 201 that performs various functions described below. MP 201 may be a Pentium® Class processor designed and developed by Intel Corporation® or an ARM processor. MP 201 is operationally coupled to various system 200 components via buses 222 and 223 . Bus 222 may be an Advance High performance (AHB) bus as specified by ARM Inc. Bus 223 may an Advance Peripheral Bus (“APB”) as specified by ARM Inc. The specifications for AHB and APB are incorporated herein by reference in their entirety.
System 200 is also provided with a random access memory (RAM) or static RAM (SRAM) 202 that stores programs and instructions, which allows MP 201 to execute computer instructions. MP 201 may execute code instructions (also referred to as “firmware”) out of RAM 202 .
System 200 is also provided with read only memory (ROM) 203 that stores invariant instructions, including basic input/output instructions.
System 200 is also provided with a digital signal processor (“DSP”) 206 that controls and monitors various servo functions through DSP interface module (“DSPIM”) 208 and servo controller interface 210 operationally coupled to a servo controller (“SC”) 211 .
DSPIM 208 interfaces DSP 206 with MP 201 and allows DSP 206 to update a tightly coupled memory module (TCM) 205 (also referred to as “memory module” 205 ) with servo related information. MP 201 can access TCM 205 via DSPIM 208 .
Servo controller interface (“SCI”) 210 includes an APB interface 213 that allows SCI 210 to interface with APB bus 223 and allows SC 211 to interface with MP 201 and DSP 206 .
SCI 210 also includes DSPAHB interface 214 that allows access to DSPAHB bus 209 . SCI 210 is provided with a digital to analog and analog to digital converter 212 that converts data from analog to digital domain and vice-versa. Analog data 220 enters module 212 and leaves as analog data 220 A to a servo device 221 .
SC 211 has a read channel device (RDC) serial port 217 , a motor control (“SVC”) serial port 218 for a “combo” motor controller device, a head integrated circuit (HDIC) serial port 219 and a servo data (“SVD”) interface 216 for communicating with various devices.
FIG. 3 shows a block diagram with disk 100 coupled to system 200 , according to one aspect of the present invention. FIG. 3 shows a read channel device 303 that receives signals from a pre-amplifier 302 (also known as head integrated circuit (HDIC)) coupled to disk 100 . One example of a read channel device 303 is manufactured by Marvell Semiconductor Inc.®, Part Number 88C7500, while pre-amplifier 302 may be a Texas instrument, Part Number SR1790. Pre-amplifier 302 is also operationally coupled to SC 211 . Servo data (“SVD”) 305 is sent to SC 211 .
A motor controller 307 (also referred to as device 307 ), (for example, a motor controller manufactured by Texas Instrument®, Part Number SH6764) sends control signals 308 to control actuator movement using motor 307 A. It is noteworthy that spindle 101 C is controlled by a spindle motor (not shown) for rotating platters 101 A and 101 B. SC 211 sends plural signals to motor controller 307 including clock, data and “enable” signals to motor controller 307 (for example, SV_SEN, SV_SCLK and SV_SDAT).
SC 211 is also operationally coupled to a piezo controller 509 that allows communication with a piezo device (not shown). One such piezo controller is sold by Rolm Electronics®, Part Number BD6801 FV. SC 211 sends clock, data and enable signals to controller 509 (for example, SV_SEN, SV_SCLK and SV_SDAT).
FIG. 4 shows a block diagram of SC 211 , according to one aspect of the present invention.
FIG. 4 shows SC 211 with a serial port controller 404 for controlling various serial ports 405 - 407 .
SC 211 also has a servo-timing controller (“STC”) 401 that automatically adjusts the time base when a head change occurs. Servo controller 211 includes an interrupt controller 411 that can generate an interrupt to DSP 206 and MP 201 . Interrupts may be generated when a servo field is found (or not found) and for other reasons. SC 211 includes a servo monitoring port 412 that monitors various signals to SC 211 .
SC 211 uses a pulse width modulation unit (“PWM”) 413 for supporting control of motor 307 A PWM, and a spindle motor PWM 409 and a piezo PWM 408 .
MP 201 and/or DSP 206 use read channel device 303 for transferring configuration data and operational commands through SC 211 (via read channel serial port interface 406 ).
FIG. 5 shows a block diagram of serial port controller 404 , according to one aspect of the present invention. The example only shows how serial port controller 404 allows communication between system 200 and motor controller 307 and piezo controller 509 . It is noteworthy that the invention is not limited to just these two or any particular number of devices.
Controller 404 includes a state machine 404 A that has access to piezo controller 509 and device 307 information in registers 501 and 503 (that includes controller 509 and 307 protocol information), for MP 201 (referred to as Client 1 in FIG. 5 for illustration purposes only). State machine 404 A can also access controller 509 and device 307 information in registers 502 and 504 for DSP 206 (referred to as Client 2 in FIG. 5 for illustration purposes only). Typically information in registers 501 - 504 includes address fields for each device ( 509 or 307 in this example), length of the data fields and timing control information (for example, if data from a certain device is captured on the rising or falling edge of a clock signal,) and setup and hold time data for the active edge of a clock signal.
Controller 404 also includes various registers, for example, registers 515 - 517 for storing address, write data and read data for controller requested by client 1 , and registers 518 - 520 for storing address, write data and read data for a device requested by client 2 . Information from register 515 - 520 is sent to a router 521 that allows MP 201 or DSP 206 to communicate with controller 509 or device 307 .
Request to Write: The following example shows how MP 201 (or any other component) can write data to a device (in this example, controller 509 or device 307 ). MP 201 sends a request 506 that is received by state machine 404 A. MP 201 then adds the address and data in register 515 and 516 . Based on the information in registers 501 - 504 , state machine 404 A determines the identity of the device to which MP 201 wants to write. State machine 404 A then sets up the device by generating signal 508 or 513 that enables controller 509 or device 307 , respectively. Thereafter, data is written to controller 509 or device 307 .
FIG. 6A provides a timing diagram showing the relationship between signals 513 , 512 and 511 to write data to device 307 . Signal 512 is a serial clock that is used for synchronizing data transfer between a client and the device.
Request to Read: The following example shows how DSP 206 (or any other component) can read data from a device (in this example, controller 509 or device 307 ). A request 507 is received by state machine 404 A from DSP 201 . DSP 201 also provides an address to register 518 . Based on the information in registers 501 and 502 , state machine 404 A determines the identity of the device to read data. State machine 404 A then sets up signal 508 or 513 to read data from controller 509 or device 307 .
FIG. 6B provides a timing diagram showing the relationship between signals 508 , 512 and 511 to read data from controller 509 .
FIG. 7 is a flow diagram showing executable process steps used by state machine 404 A, according to one aspect of the present invention.
In step S 700 , state machine 404 A is in an idle state. When it receives requests from various clients (MP 201 and DSP 206 ), state machine 404 A enters an arbitration mode in step S 701 . One of the clients wins arbitration and is then allowed to communicate to an external device, 509 or device 307 .
In step S 702 , state machine 404 A reads programmed information about a device (for example, controller 509 or device 307 ) from registers 501 - 504 .
In step S 703 , state machine 404 A transmits the appropriate device address to the client who won arbitration in step S 701 .
In step S 704 , state machine 404 A, transmits data via router 521 , to controller 509 or device 307 , for a write mode. Thereafter, the process returns to step S 700 .
In step S 705 , state machine 404 A, collects data via router 521 , from controller 509 or device 307 , for a read mode and the data is sent to register 520 for later recovery by the requesting client. Thereafter, the process returns to step S 700 .
In one aspect of the present invention, the servo controller with a single state machine can communicate with multiple serial port devices, and each device may have a different protocol.
Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.
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A servo controller for a disk drive controller comprising a storage device that stores communication information for a plurality of devices and a serial port controller located on the servo controller that communicates with the storage device, that receives a request to communicate with one of the plurality of devices, and that allows communication between at least one processor and the one of the plurality of devices according to the stored communication information and the request, wherein each of the plurality of devices uses a different protocol.
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FIELD OF THE INVENTION
The present invention pertains to a web-roll changing system, wherein a new, successive web roll is exchanged for an old, used web roll, as the web is being conveyed in a continuous manner. Each new web is spliced to the old web as the old web feed roll becomes spent. More particularly, the invention features a web transition and feeding system for webs that have a backing which is stripped therefrom, as each web is unwound, with the backing being stored simultaneously on a separate mandrel as each web is fed to a web conveyor.
BACKGROUND OF THE INVENTION
Web feeding and changing assemblies are well known in the art, as typically illustrated by U.S. Pat. Nos. 3,944,151 (issued to LEE et al on Mar. 16, 1976); 5,354,006 (issued to RODER on Oct. 11, 1994); 5,253,819 (issued to BUTLER, Jr., on Oct. 19, 1993); and 5,356,496 (issued to LINCOLN et al on Oct. 18, 1994).
These conventional web-transition assemblies typically exchange a new web of material for a used web, while the old web material is still being conveyed. In this way, the webs are changed "on the fly". A common mechanism for accomplishing this web transition is known in the art as a "bump splicer". The new, unused web comprises an adhesive surface that attaches to the old web through their "bumping" together, as they are simultaneously being conveyed. Thereafter, the web material trailing from the preceding, "old" web is severed at the splice; thus is the transition in the continuous, web-conveying process accomplished.
Exchanging an old web for a new web is a fairly common procedure. However, this procedure represents a long-standing problem, particularly when the web materials comprise backing. Backing material from each web poses a particularly vexatious problem in accomplishing the transition from one web roll to another, since two layers on each web roll must be handled. Not only must each backing be unwound and stored as each web is advanced, but they must also somehow be positioned out of the splicing, or bump zone, so that they do not interfere with the splice mechanism. Despite the profusion of mechanisms and assemblies for changing web materials on the fly, the splicing of a web with a backing was only recently accomplished, as illustrated in U.S. Pat. No. 5,692,698, assigned to a common assignee.
This invention accomplishes the bump splicing of a web with a backing in a more facile, and advantageous manner than its predecessor system. The bump splice mechanism of this invention is less complicated than the revolving turrets of the aforementioned patent. The mechanism of the invention comprises simplified work stations that have movable threading assemblies. The threading of the web can be accomplished at a distance from the exhausting web, thus providing a threading system that is more reliable, convenient, and safer.
Another advantage of the current inventive system resides in its ability to provide for threading the backing material either clockwise or counterclockwise from the web supply roll.
Still a further advantage of the current invention is that the fresh web can be attached to the exhausting web in two different modes: either when the exhausting web is at rest, or when the exhausting web is moving.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a web feeding system for exchanging a first, used web roll for a second, fresh web roll, so that web material is continuously conveyed along a web-conveying feed path. Each web of the first and second web rolls comprises a backing. The web feeding system comprises a first work station having a first movable threading assembly for allowing the first web roll to unwind and feed the first web to the feed path. A second work station comprises a second movable threading station for allowing the second web roll to unwind and feed the second web to the feed path. The second threading assembly allows the second web roll to unwind so that the second web may be spliced to the first web. A bump splicing, vacuum roll disposed on the first work station adheres the first web comprising an adhesive section, to that of the exhausting, second web as it is running out. Each work station also comprises a cutter to sever the trailing edge of either web after a splice has been achieved. The transition assembly comprises a first backing storage mandrel immediately adjacent the first movable threading assembly for storing a first backing material that unwinds from the first web roll onto the first movable threading assembly. The system also comprises a second backing storage mandrel immediately adjacent the second movable threading assembly for storing a second backing material that unwinds from the second web roll, as it unwinds upon the second movable threading assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent detailed description, in which:
FIG. 1 illustrates a side view of the web splicing system of this invention, having movable web splicing assemblies, each of which is shown in its respective web splicing/feeding position, and with one of the assemblies shown in a phantom threading position. First and second take-up mandrels are shown storing the interleaf materials being unwound from the unwinding web supply rolls;
FIG. 2 depicts a slightly enlarged side view of the web splicing system shown in FIG. 1, with one of the movable splicing assemblies in its threading position adjacent an operator;
FIG. 3 shows a greatly enlarged side view of the movable assembly depicted in FIG. 2, as it is being threaded by the operator of the web splicing system;
FIG. 4 illustrates an enlarged view of the web splicing assemblies shown in FIG. 1, disposed at their splicing/feeding positions, with a new replacement web having been threaded on the right assembly; and
FIG. 5 shows a greatly enlarged view of the web splicing assemblies depicted in FIG. 4, which enlarged view provides greater structural details of the feed and threading rolls.
For purposes of brevity and clarity, like elements and components will bear the same numerical designations throughout the FIGURES.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Generally speaking, the invention features a web feeding and transition system for exchanging a first, used, web roll for a second, fresh, web roll, so that web material is continuously fed and conveyed along a web-conveying feed path. Each of the first and second webs comprises a backing or separate, interleaved web. The backing of each web roll is stored on a mandrel adjacent its respective web supply roll, as each web roll unwinds.
Now referring to FIG. 1, the web splicing system 10 of this invention is shown. The splicing system 10 consists of two work stations 11 and 13, respectively. The web splicing system 10 is shown prior to splicing a new web supply roll 12 to an expiring web supply roll 12a rotatively mounted on a mandrel 14 at work station 13. The new supply roll 12 has been delivered to the work station 11 by a crane 15.
The replacement supply roll 12 has been mounted on rotatable mandrel 16, as shown. Each work station 11 and 13, respectively, comprises respective movable threading assemblies 17 and 18. Each of the threading assemblies 17 and 18, respectively, is movable between a web splicing/feeding position "A", where it is adjacent the other assembly, as shown in FIG. 1, and a web threading position "B", at an extended location at the end of respective work stations 11 and 13. Assembly 17 is shown in phantom at position "B". The movement of assembly 17 to its "B" position can be better observed in FIGS. 2 and 3.
Each assembly 17 and 18 has two juxtaposed threading rolls 19 and 20, better seen with reference to FIGS. 3 and 4. The juxtaposed threading rolls 19 and 20 allow the web to be snaked between them, thus creating web tension therebetween. The juxtaposed threading rolls 19 and 20 are rotatably fixed to their respective movable assembly 17 and 18.
Respective vacuum rolls 24 and 24a have a series of air holes disposed therein (FIG. 5), for drawing a vacuum upon the leading edge of a replacement web. The vacuum rolls are rotatively secured to each respective assembly 17 and 18. Each vacuum roll 24 and 24a is respectively disposed adjacent the two juxtaposed threading rolls 19 and 20. The vacuum roll 24 of the movable threading assembly 17 is pivotally operative (arrow 27) between a splicing position "D" and a non-splicing position "C", as illustrated in FIG. 4, by virtue of being pivotally mounted upon crank arm 25, connected to, and powered by, a pneumatic piston 26 that moves inferior crank 25a.
The inferior crank arm 25a is pivotally secured to larger crank arm 25 about pivot point 29, so that they both pivot under the influence of pneumatic piston 26. The bigger crank arm 25 supports the vacuum roll 24 for pivotable movement (arrow 27) about pivot point 29 and for rotation (arrow 28) about the support shaft 30 to which it is rotatively secured. The pivoting of the vacuum roll 24 is such that it is caused to move between its respective splicing and non-splicing positions "D" and "C", as will be further explained hereinafter.
A pneumatic piston 34 is also connected to a web clamp 33 disposed adjacent the first juxtaposed threading roll 19 of each of the respective movable assemblies 17 and 18. The pneumatically controlled clamps 34 of each assembly are movable between a web clamping position adjacent each first juxtaposed roll 19 and a non-clamping position at a non-extended position with respect to said respective first juxtaposed roll 19, as illustrated by arrows 35. The vacuum roll 24 of the second movable assembly 18 is positioned in place. The pneumatic piston of this assembly operates and connects only to the web clamp 34 disposed adjacent the first juxtaposed threading roll 19. A pneumatically controlled cutting knife 37 is disposed between the vacuum roll 24 and second juxtaposed threading roll 20 of each assembly 17 and 18, as shown in FIGS. 4 and 5.
Referring again to FIGS. 1 and 2, interleaf take-up rolls 62 and 62a are shown mounted upon mandrels 64 and 66, on respective work stations 11 and 13. Respective interleaf sheets 67 and 67a are wound upon their respective mandrels 64 and 66 in either a clockwise or a counterclockwise direction, depending on the way the main supply rolls 12 and 12a are threaded into their respective movable threading assemblies 17 and 18.
OPERATION OF THE SPLICING SYSTEM
The splicing system 10 operates so that a second web supply roll 12a (FIG. 1), that is about to become exhausted, is threaded through the second assembly 18 disposed at its splicing position "A". The old web 36 is movably threaded around the juxtaposed threading rolls 19 and 20, respectively, and the vacuum roll 24, the vacuum of which is inoperative in free flow. The web is freely flowable about all three threading rolls 19, 20, and 24, respectively. The pneumatic piston 34 controlling the clamp for the first juxtaposed threading roll 19 is nominally in its non-extended position. As the second web 36 is about to become exhausted, the operator 40 of the splicing system 10 mounts a new web supply roll 12 upon the mandrel 16 located at the first work station 11. After the new supply roll is rotatively secured upon the mandrel 16, the operator 40 withdraws (arrow 39, FIGS. 2 and 3) the first assembly 17 from its web splicing/feeding position "A" to its web threading position "B" located adjacent the operator 40. The operator 40 then proceeds to thread the new supply web about the three threading rolls 19, 20, and 24, respectively. The leading edge 42 of the new, replacement web 36a (FIG. 3) is positioned about the vacuum roll 24, as illustrated. The vacuum roll 24 is actuated to draw its vacuum through perforations 44 in the surface 45 of the vacuum roll 24, as shown in FIG. 5.
Referring again to FIG. 3, the leading edge 42 of the web 36a is pressure adhered to the vacuum roll 24. The pneumatic piston 34 is actuated to move the web clamp 33 into adjacent contact with the first juxtaposed threading roll 19. The interdisposed new web 36a is held firmly to the first juxtaposed threading roll 19. This prevents the new web 36a from tending to slip backwardly and withdraw into the new supply roll 12. The new web 36a being firmly threaded within the first assembly 17, the operator 40 pushes a button 47 (FIG. 3) disposed on top of a control panel (not shown) that moves (arrow 50) the first assembly 17 into its splicing/feeding position "A".
When the first assembly 17 moves (arrow 50) into the splicing/feeding position "A", as illustrated in FIG. 4, the pneumatic piston 26 of the assembly 17 actuates and causes the crank arms 25a and 25 to move the vacuum roll 24 and its respective web 36a into contact with the old web 36 disposed on the second vacuum roll 24. At the same time, the first clamp 33 is moved to its non-extended position, thus releasing the new web 36a for movement about the first juxtaposed threading roll 19. The leading edge 42 of the new web 36a has an adhesive surface 54 that adheres to the old, second web 36, when the two vacuum rolls 24 come into contact at point "D". The new web 36a is therefore spliced to the old web 36. Simultaneously therewith, the second cutting blade 37 is pneumatically actuated, thus severing the old web 36 from its respective supply roll 12a, thus completing the splicing operation.
When the new web 36a becomes exhausted, a new, second web supply roll 12a is mounted upon the second work station 13 and the second movable assembly 18 is withdrawn from the splicing/feeding position "A". After threading the new, second web onto the second assembly 18, in a manner similar to that previously described for the first assembly 17, the operator 40 pushes a button 47 at the second work station 13 to actuate the splice sequence once again. The crank arm 25 of the first assembly 17 causes the first vacuum roll 24 to contact the second vacuum roll 24a, thus causing contact of the old, first web, with the new, second web. The second clamp 33 is caused to move to its non-extended position, thus freeing the second, new web 36a for movement with respect to the first juxtaposed roll 19 of the second assembly 18. The vacuum is released on the second vacuum roll 24a. The first cutting knife 37 then cuts the first, old web 36a, thus completing the splice, as before.
An accumulator device, or "dancer" 55 (FIG. 1) is located downstream from the first and second work stations 11 and 13, respectively, along the web feed path 57, in order to maintain the proper tension in the moving web during the splice. The splicing system of this invention is configured to allow for the splice when the web is either stationary or moving. The timing of each component during the splicing sequence can comprise simple electronic relay or delay mechanisms.
Referring again to FIGS. 1 and 2, the interleaf sheets 67 and 67a are wound upon their respective mandrels 64 and 66, forming interleaf rolls 62 and 62a, respectively, when the main supply rolls 12 and 12a are threaded into movable threading assemblies 17 and 18, respectively. As aforementioned, the interleaf sheets 67 and 67a can be wound either clockwise or counterclockwise, depending on the threading direction of the main webs.
Referring again to FIG. 5, the vacuum roll 24 of movable assembly 17 comprises an outer elastomeric cover 52 for providing a shock resilient surface. The elastomeric material of cover 52 can be rubber, neoprene, etc. The shock resilient surface could be part of vacuum roll 24a, instead of vacuum roll 24. However, one shock resilient surface is required between the two vacuum rolls 24 and 24a, in order to provide a quiet and smooth contact when vacuum roll 24 moves (arrow 27) from position "C" to contact position "D".
The end section of the replacement web is covered with an adhesive strip from the leading edge 42 of the web 36a to the area below the cutting knife apparatus 37. A protective tear-off strip exposes the sticky adhesive so that, when the two vacuum rolls 24 and 24a come into contact, the two respective webs 36a and 36 bond together, thus completing the splice.
Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.
Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims.
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The present invention features a web feeding and transition system for exchanging a first, used, web roll for a second, fresh, web roll, so that web material is conveyed along a web-conveying feed path. Each web of the first and second web rolls includes a backing or a separate, interleaved web. The web assembly has a first work station having a mounting for allowing the first web roll to unwind and feed the first web to the feed path. A second work station has a mounting adjacent the first mounting for allowing the second web roll to unwind so that the second web may be spliced to the first web. A "bump splicing" vacuum roll disposed upon the first work station causes an adhesive section of the fresh web to contact an end portion of the exhausting web, as the web roll runs out.
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RELATED APPLICATIONS
[0001] The present application is a continuation of co-pending U.S. provisional patent application Ser. No. 14/743,053 filed on Jun. 18, 2015, which in turn is a continuation-in-part of U.S. Provisional Patent Application Ser. No. 62/013,690 filed on Jun. 18, 2014.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to the construction of subterranean wells. More particularly, the present invention relates to methods and constructions for centering a casing within a well, particularly an oil or gas well.
[0003] A well is a subterranean boring from the Earth's surface that is designed to find and acquire liquids or gases. Wells for acquiring oil are termed “oil wells”. A well that is designed to produce mainly gas is called a “gas well”. Typically, wells are created by drilling a bore, typically 5 inches to 40 inches (12 cm to 1 meter) in diameter, into the earth with a drilling rig that rotates a drill string with an attached bit. After the hole is drilled, sections of steel pipe, commonly referred to as “casings” and which are slightly smaller in diameter than the borehole, are dropped “downhole” into the bore for obtaining the sought after liquid or gas.
[0004] The difference in diameter of the wellbore and the casing creates an annular space. When completing oil and gas wells, it is often important to seal the annular space with cement. This cement is pumped down into the annular space, often flushing out drilling mud. Once the annular space is filled with cement, the cement is allowed to harden to seal the well. To properly seal the well, the casing should be positioned so that it is in the middle or center of the annular space. The casing and cement provide structural integrity to the newly drilled wellbore and provide isolation of potentially dangerous high pressure zones. Thus, centralizing a casing inside the annular space is paramount and critical to achieve a reliable seal, and thus good zonal isolation. With the advent of deeper wells and horizontal drilling, centralizing the casing has become more important and more difficult to accomplish.
[0005] A traditional method to centralize a casing is to attach centralizers to the casing prior to its insertion into the annular space. Most traditional centralizers have tabs, wings or bows that exert force against the inside of the wellbore to keep the casing somewhat centralized. The centralizers are commonly secured at intervals along a casing string to radially offset the casing string from the wall of a borehole in which the casing string is positioned. Centralizers ideally center the casing string within the borehole to provide a generally continuous annulus between the casing string and the interior wall of the borehole. This positioning of the casing string within a borehole promotes uniform and continuous distribution of cement slurry around the casing string. Uniform cement slurry distribution results in a cement liner that reinforces the casing string, isolates the casing from corrosive formation fluids, prevents unwanted fluid flow between penetrated geologic formations, and provides axial strength.
[0006] A bow spring centralizer is the most common type of centralizer. It employs flexible bow springs to provide offset between the casing and wellbore sidewall. Bow spring centralizers typically include a pair of axially-spaced and generally aligned tubular collars that are coupled by multiple bow springs. The bow springs expand outwardly from the collars to engage the borehole sidewall to center a pipe received axially through the collars. Configured in this manner, the bow springs provide stand-off from the borehole, and flex inwardly as they encounter borehole obstructions, such as tight spots or protrusions into the borehole, as the casing string is installed into the borehole. Elasticity allows the bow springs to spring back to substantially their original shape after passing an obstruction to maintain the desired stand-off between the casing string and the borehole. Examples of such bow springs are disclosed in U.S. Pat. No. 4,545,436 and Great Britain Patent No. 2242457 which both disclose casing centralizers having a plurality of bow springs which are connected to first and second collars. The collars surround the well casing, and one or both of the collars slide longitudinally upon the pipe when the bow spring is deformed upon engaging the wellbore sidewall.
[0007] The use of bow spring centralizers presents a number of disadvantages and their installation is problematic. To achieve the desired centralization, bow centralizers are designed so that, prior to installation the bow springs extend beyond the inside diameter (“ID”) of the wellbore. The larger diameter of said bow springs requires them to be retracted from the force of pushing it down inside the casing or wellbore. This causes kinetic friction when slid down the hole (requiring running force) and also static friction when engaging restrictions or obstructions (requiring starting force). This friction is a primary reason that their use is discouraged. Further, the radial configuration of the bow springs causes the spring force of one bow spring to be counteracted by the bow springs on the opposite side of the casing. This results in a restoring force that diminishes as the casing approaches center, making better centralization require greater and greater spring forces. Furthermore, increased spring forces also increases running and starting resistance. Therefore, a balance is sought between the needed forces to centralize the casing and the increased resistance that these spring forces create.
[0008] An additional disadvantage of bow spring centralizers is that the bow springs obstruct the pumping of cement downhole. After being positioned downhole, the bow springs project radially outward from the casing like spokes to engage the wellbore's cylindrical wall. These bow springs can block the proper downward flow of the cement slurry or can create voids in the annular cement structure.
[0009] Various attempts have been made to develop centralizers that overcome some of these problems. U.S. Pat. No. 6,871,706 discloses a centralizer that requires the bending of a retaining portion of the collar material into a plurality of aligned openings, each to receive one end of each bow spring. This requires that the coupling operation be performed in a manufacturing facility using a press. The collars of the centralizer are cut with a large recess adjacent to each set of aligned openings to accommodate passage of a bow spring that is secured to the interior wall of the collar. Unfortunately, the recess substantially decreases the mechanical integrity of the collar due to the removal of a large portion of the collar wall to accommodate the bow springs.
[0010] U.S. Patent Publication 20120279725 and U.S. Pat. No. 7,857,063 describe centralizers that have a minimal radial expansion prior and during the casing's transportation downhole. Only after the casing is in place are the centralizer tabs expanded radially outward. This reduces the amount of friction that the casing string encounters as it is dropped downhole. Furthermore, the tabs extend laterally relative to the pipe's central axis in a manner that minimizes the obstruction to the flow of cement as it is poured downhole. Unfortunately, these centralizers are not suitable for traditional metal well casings that provide minimal radial expansion. Instead, the centralizers are useful only for centralizing tubular members capable of substantial expansion so as to force the centralizer tabs to engage the borehole wall.
[0011] Thus, there is a significant need for an improved casing centralizer that provides reduced friction as the centralizer is transported downhole.
[0012] There is a also a need for an improved casing centralizer that provides increased centralizing force for maintaining a casing in the center of a wellbore.
[0013] Still there is an additional need for an improved casing centralizer that provides minimal impedance to the flow of cement as cement is pumped downhole in the annular space between the casing string and the wellbore wall.
[0014] In addition, there is a need for an improved centralizer that provides reduced manufacturing and installation costs, and provides an improved ease of running the casing string downhole into the wellbore.
SUMMARY OF THE INVENTION
[0015] The present invention addresses the aforementioned disadvantages by providing an improved centralizer for centralizing a pipe downhole in a well. The term “pipe” is intended to be interpreted in the traditional sense as a cylindrical structure having an exterior wall and a central conduit. Furthermore, the term “pipe” is intended to include traditional well casings, casing strings, and casing couplers which connect casings to form a casing string. Moreover, the centralizer of the present invention may be integrated into the pipe so as to include the pipe's cylindrical exterior sidewall and central conduit which defines the pipe's longitudinal axis. Alternatively, the centralizer may include a structure for affixing the centralizer to a pipe, such as for affixing to a pipe immediately prior to the pipe being transported downhole into a well.
[0016] The centralizer of the present invention includes a pair of end collars. Each end collar is tubular and has a center hole for receiving a pipe. The end collars' tubular structure forms a longitudinal axis, and the end collars are positioned to receive a pipe coaxial to the longitudinal axis. The end collars are spaced longitudinally from one another and at least one end collar is capable of sliding telescopically and axially relative to the pipe. In alternative embodiments, both end collars are sized to freely rotate and slide longitudinally upon the pipe. Preferably, the end collars' inside diameter is only slightly larger than the outside diameter of the casing or pipe to be centralized, and it is permissible for one of the end collars to have an inside diameter substantially the same as the outside diameter of the pipe so as to form a press-fit engagement. Mechanical fasteners such as circular bands may be affixed to the exterior of the well pipe so as to prevent the centralizer from sliding from its desired location.
[0017] The centralizer further includes a plurality of longitudinally extending bow springs. The bow springs are elastic members which store mechanical energy so as to exert a resisting force when its shape is changed. Each bow spring has first and second ends wherein a bow spring's first end is affixed to a first end collar, and a bow spring's second end is affixed to a second end collar. The bow springs are arcuate so as to bow outwardly at their middle so as to form a radially extending arch capable of pushing against the inner wall of a wellbore. The bow springs are preferably positioned circumferentially and equally about the end collars so as to centralize a pipe within a wellbore and so as to form a substantially uniform annular space between the pipe and wellbore sidewall. Preferably, the bow springs are made of spring steel. As would be understood by those skilled in the art, radial compression of the bow springs causes the end collars to move longitudinally away from one another. When the source of the compression, such as the wellbore sidewall, is removed, the mechanical energy stored within the bow springs will cause the bow springs to expand radially, and cause the end collars to contract longitudinally.
[0018] The centralizer of the present invention also includes one or more center collars. Like the end collars, the center collar has a tubular structure having a center hole sized to slidably receive the pipe. The center collar is positioned coaxial to the pipe and intermediate to the first and second end collars. Preferably the center collar is capable of rotating about the pipe and sliding longitudinally relative to the pipe. However, where the end collars are capable of sliding longitudinally relative to the pipe, it is permissible for the centralizer's center collar to be affixed to the pipe.
[0019] The centralizer of the present invention includes a linkage assembly that forces the bow springs to move radially and in unison. The linkage assembly includes a plurality of linkage arms wherein each arm has a first end and a second end. Each linkage arm's first end attaches to a center collar and each linkage arm's second end attaches to a bow spring member so that the linkage arms extend radially like spokes from the exterior of the pipe to a bow spring. Each linkage arm extends radially and at least partially longitudinally so that when a bow spring is compressed, the linkage arms can be compressed as well while forcing the center collar to move longitudinally. Preferably, the linkage arms are formed of the same material, such as spring steel, that forms the collars and bow springs.
[0020] In a preferred embodiment, the linkage arms are constructed to bias outwardly in the manner of springs by storing mechanical energy to provide additional force causing the bow springs to be forced radially outward. In alternative embodiments, the leverage arms are affixed to the center collar and respective bow springs by hinges or the like so that the leverage arms do not store mechanical energy and do not function as springs. In either embodiment, spring or hinged, the compression of one or more bow springs radially inward causes the linkage assembly (comprised of the linkage arms) to force the center collars in the longitudinal direction. As would be understood by those skilled in the art, inward compression of a single bow spring causes the corresponding linkage arm to force the center collar in the longitudinal direction, which in turn causes the remaining linkage arms to force the remaining bow springs radially inward.
[0021] The centralizer may be constructed so that the bow springs curve outward so that their at-rest curvature would extend beyond the inside diameter of the intended wellbore so that the bow springs engage and are slightly compressed as the well pipe and centralizer are deposited downhole. However, to reduce running force (frictional resistance between the centralizer and wellbore) the centralizer may be constructed to force the bow springs radially inward to reduce the outer diameter of the bow springs, and to store mechanical energy in the bow springs. Various constructions may be employed. For example, the end collars may be forced longitudinally outward and locked in an extended position utilizing bolts or pins, or other projections, which extend outwardly from the well pipe. Longitudinal extension of the respective end collars causes the bow springs to compress radially inward, which in turn causes the center collar to move longitudinally from its at-rest position.
[0022] In alternative embodiments, the pipe may include locking rings which affix to the pipe for engaging both end collars so to maintain the end collars longitudinally apart. Still additional constructions can be developed by those skilled in the art so as to maintain the end collars in an extended position, with the bow springs compressed radially inward, while still enabling the end collars to extend still longitudinally further.
[0023] In additional embodiments, the centralizer includes spacers which affix to the exterior of the pipe for forcing the linkage arms and bow springs radially inward. In a first embodiment, a spacer is positioned between an end collar and center collar so as to move the center collar longitudinally from its at-rest position. The movement of the center collar causes the linkage arms to be forced radially inward, which in turn causes the bow springs to be forced radially inward. In still an alternative embodiment, the centralizer includes two sets of center collars, and two sets of linkage arms. As the bow springs are compressed, a first center collar moves longitudinally in a first direction, while the second collar moves longitudinally in an opposite direction. To radially retract the bow springs, a preferred centralizer includes a spacer which is positioned between the two center collars so as to move the center collars longitudinally away from one another, which in turn causes the linkage arms and bow springs to move radially inward into a compressed condition.
[0024] Preferably, for each of these embodiments, the bow springs have been forced radially inward to a diameter less than the diameter of the wellbore so as to reduce the running force of the well casing as it is deposited downhole. Advantageously, each of the bow springs have been compressed to store mechanical energy so as to exert an increased restoring force when compressed further by the wellbore diameter decreasing to smaller than the diameter of the centralizer bow springs.
[0025] In still additional embodiments, the end collars and one or more center collars are hinged so as to include at least a first hinge so as to allow the centralizer to open in a clamshell member so as to clamp upon a well pipe. Preferably, each collar includes two diametrically opposed hinges which can open and close by a longitudinally extending set pin. Advantageously, set pins can be removed from one side of the centralizer so as to allow the centralizer to open in a clamshell manner so as to affix to a pipe. Thereafter, the pins can be reinserted so as to affix the centralizer to a well pipe.
[0026] Advantageously, the centralizer has a minimal cross section prior to being transported downhole so as to reduce the friction that the casing encounters as it is transported downhole.
[0027] In addition, the centralizer's center collars and linkage assemblies cause all of the bow springs to act in unison. The collaboration of the bow spring motion creates a compounded spring force that improves centralization. Moreover, the centralizer with bow springs operating in unison prevents a single bow spring from bowing inwardly, without the remaining bow springs moving inward, which would decentralize the well casing.
[0028] Also advantageously, the angle, length, and position of the linkage arms can be varied to provide the bow springs with the desired radial force.
[0029] These and other more specific objects and advantages of the invention will be apparent to those skilled in the art from the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a perspective view of a centralizer including two center collars and hinged linkage arms;
[0031] FIG. 2 is a perspective view illustrating the centralizer shown in FIG. 1 wherein the bow springs have been forced radially inward and the center collars have been moved longitudinally outward;
[0032] FIG. 3 is a perspective view of a centralizer including a single center collar and wherein the end collars and center collar are hinged to allow the centralizer to open in a clamshell manner;
[0033] FIG. 4 is a perspective view illustrating the centralizer shown in FIG. 3 wherein the bow springs have been forced radially inward and the center collar has moved longitudinally upward;
[0034] FIG. 5 is a perspective view illustrating the centralizer shown in FIGS. 3 and 4 wherein a first set of locking pins has been removed so as to allow the centralizer to hinge open to accept the pipe;
[0035] FIG. 6 is a perspective cut-away view of a wellbore including a pipe casing and centralizers as illustrated in FIG. 1 ;
[0036] FIG. 7A is a perspective view illustrating a centralizer shown in FIG. 1 affixed to a well pipe prior to selection and insertion of a spacer;
[0037] FIG. 7B is a perspective view illustrating the centralizer and pipe casing of FIG. 7A wherein the centralizer includes a spacer for forcing center collars longitudinally apart;
[0038] FIG. 8A is a perspective view illustrating a centralizer and well casing including flexible straps for pulling center collars apart;
[0039] FIG. 8B is a perspective view illustrating a centralizer and well casing of FIG. 8A wherein the center collars have been forced longitudinally apart and locked in place utilizing flexible straps;
[0040] FIG. 9A is a perspective view of an additional embodiment of a centralizer wherein the linkage assemblies' linkage arms bias outwardly in the manner of leaf springs;
[0041] FIG. 9B is a perspective view illustrating the centralizer shown in FIG. 9A and illustrating the center collar's linkage arm providing additional force to move the bow springs radially outward;
[0042] FIG. 10A is a perspective view illustrating a centralizer and well casing prior to selection of a spacer in the form of a ring;
[0043] FIG. 10B is a perspective view illustrating the centralizer and well casing shown in FIG. 10A wherein a spacer of medium thickness has been selected;
[0044] FIG. 11A is a perspective view of a centralizer and well casing prior to affixing locking rings to a pipe to force the end collars longitudinally outward;
[0045] FIG. 11B is a perspective view illustrating the centralizer and well casing shown in FIG. 11A wherein the locking rings have been affixed to the well pipe in a manner that caused the end collars to be forced longitudinally apart, and caused the bow springs and linkage assemblies to be forced radially inward, and caused the center collars to move longitudinally apart;
[0046] FIG. 12A is a perspective view illustrating a centralizer and well casing prior to insertion of longitudinal spacers between center collars; and
[0047] FIG. 12B is a perspective view illustrating the centralizer and well casing shown in FIG. 12A wherein longitudinal spacers have been positioned between center collars so as to force the center collars longitudinally apart.
DETAILED DESCRIPTION OF THE INVENTION
[0048] While the present invention is susceptible of embodiment in various forms, as shown in the drawings, hereinafter will be described the presently preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the invention, and it is not intended to limit the invention to the specific embodiments illustrated.
[0049] With reference to FIGS. 1-12B , the present invention is a centralizer 1 for centralizing a pipe 3 , also referred to as a casing or well casing, within a wellbore 5 . The centralizer 1 includes two tubular end collars 9 , each having a center hole 11 sized to receive a pipe 3 . (See FIGS. 6-8 and 10-12 ). The end collars 9 are spaced longitudinally relative to one another and are positioned coaxial to the pipe 3 . At least one end collar 9 is capable of sliding longitudinally relative to the pipe 3 .
[0050] The end collars 9 are connected by a plurality of bow springs 17 . Each bow spring 17 includes a first end 19 affixed to a first end collar 9 and a second end 21 affixed to a second end collar 9 . The bow springs bow outwardly at their middle 23 so as to form a leaf spring type construction wherein radial inward compression of the bow spring's middle 23 causes the diameter of the bow springs, and in turn the centralizer, to reduce. This, in turn, causes the bow springs to extend longitudinally to force the end collars longitudinally away from each other. As illustrated in the figures, a preferred centralizer 1 has four bow springs 17 positioned equally circumferentially around the centralizer's central longitudinal axis so as to be positioned at 90° spacing to one another.
[0051] The centralizer 1 also includes at least one center collar 43 . The centralizer's center collar 43 is constructed in a similar manner as the end collar 9 so as to have a center hole 45 for coaxially receiving the pipe 3 . The center collar 43 is positioned and aligned so as to be intermediate the end collars 9 with the center collar's hole 45 coaxial to the end collars 9 .
[0052] Further, the centralizer includes a linkage assembly including linkage arms 31 which structurally connect the centralizer's center collar 43 to the bow springs 17 . Each linkage arm 31 has a first end 33 which affixes to the center collar 43 , and each linkage arm 31 includes a second end 35 which affixes to the bow spring 17 , preferably at approximately the bow spring's middle 23 . As illustrated in FIGS. 1-8B and 10A-12B , the linkage arms 31 may be connected to the bow springs 17 and center collar 43 utilizing hinges 37 which allow the linkage arms to freely pivot where they connect to the bow spring and center collar. Alternatively, as illustrated in FIGS. 9A and 9B , the centralizer may be constructed so that the linkage arms 31 do not freely pivot where they connect to the bow spring and center collar. Instead, for this embodiment, the linkage arms 31 function as springs storing mechanical energy providing additional force against the bow spring's middle 23 .
[0053] Advantageously, the centralizer of the present invention can be constructed in a wide variety of manners. For example, as illustrated in FIGS. 3, 4, 9A and 9B , a preferred centralizer 1 includes only a single center collar 43 connected to the bow springs 17 by a single set of linkage arms 31 . Alternatively, as illustrated in FIGS. 1, 2, 6-8B and 10A-12B , the centralizer 1 may include two center collars 43 , and two sets of linkage arms 31 for connecting to the bow springs 17 . Preferably, the first and second sets of linkage arms are constructed to extend laterally, and longitudinally in opposite directions (not parallel), so that the center collars 43 move longitudinally in opposite directions when the bow springs 17 are compressed radially inward. (See FIGS. 6, 7B, 8B and 10B ).
[0054] Preferably, the centralizer 1 is constructed so that the bow springs 17 relaxed state causes the bow springs' outer diameter 23 to be larger than the wellbore, diameter within which it is placed. However, to reduce the running force of the well casing as it is deposited downhole, it is preferred that the centralizer include one of various mechanisms for displacing the bow springs' radially inward so as to have a diameter smaller than the average diameter of the wellbore. In a first embodiment illustrated in FIGS. 7A, 7B, 10A, 10B, 12A and 12B , the centralizer includes a spacer which forces the two center collars 43 axially apart, which in turn causes the linkage arms 31 to pull the bow springs 17 radially inward. For example, in a first embodiment illustrated in FIGS. 7A and 7B , the spacer may be an arcuate structure 51 abc having different sizes. A person using the centralizer downhole may select a smaller spacer 51 a wherein one wants to decrease the diameter of the bow springs slightly, but still maintain a substantially large diameter. Alternative spacers 51 b or 51 c could be selected to increase the longitudinal space 49 between the center collars 43 by selecting larger spacers such as 51 b or 51 c. For example, FIG. 7B illustrates the centralizer 1 of the present invention affixed to a pipe including an intermediate spacer 51 b for longitudinally separating the center collars 43 . FIGS. 10A and 10B illustrate an alternative spacer 54 abc wherein the spacer is constructed in the form of a ring. A ring of desired thickness, such as a thin ring 54 a or a thick ring 54 c, is positioned between the center collars 43 prior to insertion of the pipe 3 . For example, FIG. 10B illustrates a centralizer and pipe assembly incorporating a spacer 54 b having a medium thickness which forces the bow springs radially inward a greater distance than the small spacer 54 a, but more than the larger spacer 54 c. As would be understood by those skilled in the art, the spacer can take various forms, such as simple longitudinal rods 53 , as illustrated in FIGS. 12A and 12B .
[0055] The bow springs may be forced radially inward utilizing still additional constructions. For example, FIGS. 8A and 8B illustrate a centralizer 1 including a plurality of flexible straps 55 and pins 57 which function as “tension members” so as to pull center collars 43 towards adjacent end collars 9 . In still alternative embodiments, the pipe may be constructed to include mechanical structures, such as projections, which lock the end collars into longitudinally extended positions so as to force the bow springs radially inward. The projections may be simple pins or bolts (not shown) affixed to the pipe's sidewall, which are positioned to maintain the end collars in an extended position. Alternatively, as illustrated in FIG. 11A and 11B , the pipe 3 may include fixed or adjustable ring-like structures 61 which affix to the pipe so as to maintain the end collars 9 in a longitudinally extended condition. Though not shown in the figures, the pipe may include projections, such as pins, bolts, or rings which engage both center collars, or a single center collar and end collar, so as to force the bow springs 17 radially inward.
[0056] In still additional embodiments of the invention illustrated in FIGS. 3-5 , the end collars 9 and center collar 43 include a hinge 13 to allow a centralizer to open in a clamshell member so as to receive a pipe, and thereafter be closed for affixing the centralizer 1 to a pipe 3 . In a preferred embodiment illustrated in FIGS. 3-5 , each end collar 9 and center collar 43 includes two diametrically opposed hinges which can open or close by removal of a longitudinally extending set pin 15 . Removing one side of the set pins 15 enables the centralizer 1 to open or close in a clamshell member. Meanwhile, removal of all set pins permits the centralizer 1 to be separated in half. Removal of either one side of the pins or both sides of the pins permits the centralizer to be affixed to a pipe. Thereafter, the pins 15 can be reinserted into the hinges 13 so as to affix the centralizer 1 to the pipe 3 .
[0057] While several particular forms of the invention have been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. Therefore, it is not intended that the invention be limited to the specific embodiments illustrated. I described my invention in such terms as to enable a person skilled in the art to understand the invention, recreate the invention and practice it, and having presently identified the presently preferred embodiments thereof, I claim:
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A centralizer for centralizing a pipe is provided which collaborates the spring force of its bow springs. The centralizer includes a pair of end collars, and at least one center collar. Each of the collars has a center hole for coaxially receiving a pipe. In addition, the centralizer includes a plurality of longitudinally extending and arcuate bow springs having ends which affix to the end collars. The centralizer includes linkage arms which connect the center collar to the bow springs. The linkage arms may provide additional outward spring force against the bow springs. Preferably, the centralizer includes a mechanism for forcing the bow springs radially inward from their at rest position.
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[0001] If an Application Data Sheet (“ADS”) has been filed on the filing date of this application, it is incorporated by reference herein. Any applications claimed on the ADS for priority under 35 U.S.C. §§119, 120, 121, or 365(c), and any and all parent, grandparent, great-grandparent, etc., applications of such applications, are also incorporated by reference, including any priority claims made in those applications and any material incorporated by reference, to the extent such subject matter is not inconsistent herewith.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0002] The present application claims the benefit of the earliest available effective filing date(s) from the following listed application(s) (the “Priority Applications”), if any, listed below (e.g., claims earliest available priority dates for other than provisional patent applications or claims benefits under 35 U.S.C. §119(e) for provisional patent applications, for any and all parent, grandparent, great-grandparent, etc., applications of the Priority Application(s)).
PRIORITY APPLICATIONS
[0003] U.S. patent application Ser. No. 13/483,970 entitled “Bicycle Bag,” filed on May 30, 2012, and U.S. Provisional Patent Application Ser. No. 61/492,183 entitled “Bicycle Bag,” filed on Jun. 1, 2011.
RELATED APPLICATIONS
[0004] If the listings of applications provided herein are inconsistent with the listings provided via an ADS, it is the intent of the Applicants to claim priority to each application that appears in the Priority Applications section of the ADS and to each application that appears in the Priority Applications section of this application.
[0005] All subject matter of the Priority Applications and the Related Applications and of any and all parent, grandparent, great-grandparent, etc., applications of the Priority Applications and the Related Applications, including any priority claims, is incorporated herein by reference to the extent such subject matter is not inconsistent herewith.
TECHNICAL FIELD
[0006] This disclosure relates to a bicycle bag and, in particular, to a bicycle bag that provides protection from the elements while the bike with bicycle bag are on a rack, and that can be used with a large variety of different bicycle and rack types.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Additional aspects and advantages will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings, in which:
[0008] FIG. 1A depicts an exemplary tray-type bicycle rack;
[0009] FIG. 1B depicts another exemplary tray-type bicycle rack;
[0010] FIG. 1C depicts an exemplary post-type bicycle rack;
[0011] FIG. 1D depicts an exemplary fork-type bicycle rack;
[0012] FIG. 2 depicts one embodiment of a bicycle bag; and
[0013] FIG. 3 depicts another embodiment of a bicycle bag.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0014] When a bicycle is secured to a rack the bicycle can become dirty or damaged due to exposure to the elements, road debris, vandalism, theft, and the like. As used herein a “rack” refers to any mechanism for securing a bicycle including, but not limited to: a vehicle rack configured to secure one or more bicycles to a vehicle for transport, a storage rack to storing a bicycle, a parking rack for bicycle storage, or the like. Bicycle covers or (bicycle “bags”) can be used to reduce this exposure. However, most existing bicycle bags do not provide sufficient protection. Moreover, bicycle bags that attempt to provide additional protection by covering the bicycle while in transit are often incompatible with certain vehicle rack systems, making their use dangerous and impractical. Moreover, these bags can be incompatible with certain bicycle types or frame configurations and/or may prevent bicycles from being “packed together” for transport. In some cases, when a bicycle is mounted on a vehicle rack, the bicycle (or bicycle bag) may obscure portions of the lighting system of the vehicle, such as the brake lights, turn signals, backup lights, and the like.
[0015] The bicycle bag disclosed herein addresses these and other shortcomings. The disclosed bicycle bag provides full coverage for a bicycle while on a rack. As used herein “full coverage” refers to a bicycle being fully enclosed by a bag, such that the bicycle is protected from outside elements, such as moisture, road debris, or the like. Accordingly, “full coverage” refers to a bicycle being fully enclosed within material of the bicycle bag, with no portions of the bicycle protruding therefrom. In some embodiments, the bicycle bag includes resealable openings configured to allow the bicycle bag to be used with a large variety of different rack types. The openings may be adapted such that the bicycle is protected whether or not the openings are in use. The disclosed bicycle bag may include pockets adapted to receive a lighting system, which may be used when the bicycle bag obscures the lighting system of the vehicle.
[0016] Various embodiments of a bicycle bag are disclosed herein. The disclosed bicycle bags provide advantages over existing bags. The features described with respect to the various embodiments may be combined in any suitable fashion.
[0017] The bicycle bag disclosed herein may be configured to allow a bicycle enclosed therein to be secured to a plurality of different rack types and/or securing mechanisms, which may include, but are not limited to: a tray-type rack, a post-type rack, a fork rack, bicycle straps, J-hooks, arm clamps, or the like.
[0018] FIG. 1A depicts an exemplary tray-type bicycle rack 170 . The rack 170 may comprise a J-bar to secure a wheel of a bicycle and one or more wheel trays. The one or more wheel trays may comprise respective straps for securing bicycle wheels thereto. FIG. 1B depicts another exemplary tray-type rack. The wheel tray of the rack 172 may comprise one or more wheel straps for securing a bicycle to the tray. The rack 172 may comprise a stabilizer bar configured to secure a bicycle in an upright position. The arm clamp may be configured to releasably secure one or more frame members of a bicycle (e.g., the downtube of a bicycle). As shown in FIG. 1B , the arm clamp may be configured to secure a bicycle in an upright position on the rack 172 . FIG. 1C depicts an exemplary post-type rack 174 . The rack 174 comprises one or more posts to which a bicycle frame may be secured. The one or more posts may comprise respective straps for securing a bicycle thereto. FIG. 1D depicts an exemplary fork-type rack 176 . The rack 176 may comprise a wheel tray having one or more straps to secure a bicycle wheel thereto. The rack 176 may further comprise a fork receptacle for securing a bicycle frame.
[0019] FIG. 2 depicts one embodiment of a bicycle bag 200 configured to allow a bicycle enclosed therein to be secured to a plurality of different rack types. The bicycle bag 200 may be constructed of any suitable material including, but not limited to: canvas, Kevlar®, neoprene, nylon, polyester, plastic, rigid plastic, metal, or the like, and/or combinations of different materials. The bag 200 (or portions thereof) may be formed from materials that are resistant to the elements. For example, the bag 200 may be formed from materials that provide protection from moisture (e.g., water proofing), provide ballistic protection from high-velocity road debris, are tamper resistant (e.g., include structural members, such as Kevlar® or metallic filaments or fibers, that resist cutting or tearing), or the like. In some embodiments, portions of the bag 200 (and/or the openings 203 and 204 therein) may be formed from flexible materials capable of adapting to different bicycle 201 and/or rack configurations. For example, the materials forming the opening 203 and/or resealable closure 243 thereof (discussed below) may be capable of expanding and/or deforming to adapt to different rack and/or bicycle 201 types. The flexible portions may be configured to allow the bag 200 to enclose bicycles 101 of different sizes and/or types.
[0020] As illustrated in FIG. 2 , bottom portions 211 and 212 of the bag 200 may be configured to generally conform to the shape of a bicycle 201 disposed therein. For example, the portion 211 may be configured to conform to the curvature of the front wheel 221 and the portion 212 may be configured to conform to the curvature of the rear wheel 222 . The portions 211 and 212 may be configured to allow the bag 200 to be used with bicycle racks that secure the bicycle 201 using curved wheel trays, such as the tray-type bicycle racks 170 , 172 , and/or 176 . The curvature of the bottom portions 211 and 212 of the bag 200 , allows a bicycle 201 disposed within the bag 200 to be secured by such a rack by, inter alia, securing the wheels 221 and 222 of the bicycle 201 within curved wheel trays of the rack.
[0021] The bag 200 may further comprise one or more resealable openings 204 in the wheel portions 211 and/or 212 . The openings 204 may be configured to allow a strap (or other securing mechanism) to pass through the bag 200 to secure one or more of the wheels 221 and/or 222 to, inter alia, a tray of a tray-type rack. The openings 204 may allow a securing mechanism to pass through the bag 200 and bicycle wheel 221 / 222 when the bicycle 201 is in the bicycle bag 200 . The openings 204 may comprise respective resealable closures 224 , which allow the bicycle 201 to be placed within the bag 200 and/or removed from the bag 200 (e.g., by disengaging the resealable closures 224 of the openings 204 ). The resealable closure 224 may comprise any suitable mechanism including, but not limited to: VELCRO®, a zipper, fastening straps, buttons, or the like. The resealable closure 224 may be configured to protect the bicycle 201 from the elements (e.g., moisture, debris, etc.). The openings 204 (and resealable closures 224 ) may be configured to avoid impinging on structural elements (e.g., spokes) of the bicycle 201 . Accordingly, in alternative embodiments, the openings may be narrowed and/or oriented vertically (along the radius of the wheels 221 and/or 222 ) so that the openings 204 may accept a securing member of a rack, while minimizing the chance of the openings impinging on wheel spokes or other components of the bicycle 201 . In some embodiments, the openings 204 may not be resealable, but may comprise one or more gaskets, flaps, elastics, or the like, that are configured to protect the interior portion of the bag 200 from the elements.
[0022] The bag 200 may further comprise resealable openings 205 disposed near the top portions 213 and 214 of the bag 200 . The resealable openings 205 may comprise respective resealable closures (not shown) configured to selectively open and/or seal the openings 205 . The openings 205 may be used to secure the bicycle 201 (and bag 200 ) to an upper portion of a rack (e.g., an over the wheel rack). As depicted in FIG. 2 , the openings 205 may be configured to prevent impinging on the structural components of the bicycle 201 (e.g., the wheels 221 , 222 and/or the spokes thereof).
[0023] In some embodiments, the bag 200 comprises a resealable opening 203 disposed near the center of the bag 200 . The opening 203 may be configured to create an opening within a diamond portion 203 of the bicycle 201 frame (under a top-tube of and/or above a down tube of the bicycle 201 ). The resealable opening 203 may be configured to allow the bicycle 201 to be secured to a post-type rack (e.g., a rack that secures a frame of the bicycle 201 to one or more posts or the like, such as the bicycle rack 174 ). For example, the opening 203 may be configured to provide for passing one or more posts of a post-type rack through the bicycle 201 within the bicycle bag 200 , such that the bicycle 201 may be secured thereto.
[0024] The opening 203 may be opened by disengaging the resealable closure 243 , which allows the bicycle 201 to be placed within the bag 200 and/or removed from the bag 200 . The resealable closure 243 may comprise any suitable mechanism including, but not limited to: VELCRO®, a zipper, fastening straps, buttons, or the like. The resealable closure 243 may be configured to prevent the elements (e.g., moisture, debris, etc.), from entering the interior of the bag 200 . The resealable closure 243 may be disengaged (e.g., opened) to allow the bicycle 201 to be placed within the bag 200 (or removed therefrom). The resealable closure 243 may re-sealed when the bag 200 is used for transport. In some embodiments, the opening 204 may not be resealable, and may comprise one or more gaskets, flaps, elastics, or the like, to protect the interior of the bag 200 from the elements.
[0025] In some embodiments, a top portions 213 and 214 of the bag 200 are configured to conform to the top portion of each wheel 221 and 222 . The top portions 213 and 214 allow the bicycle 201 (within the bag 200 ) to be secured to a “J-shaped” rack that secures the bicycle 201 using one or more “over-the wheel” J-shaped members, such as the bicycle rack 172 of FIG. 1A . Similarly, the portions 213 and 214 may allow the bicycle 201 and bag 200 to be secured to conventional shaped bicycle parking racks.
[0026] Although a particular set of resealable openings 203 , 204 , and/or 205 are depicted herein, one of skill in the art would recognize that the bag 200 could be adapted to include additional openings configured to allow the bag 200 to be used with different rack types and/or different bicycle 201 configurations. Accordingly, the disclosure should not be read as limited to any particular set of openings. For example, in some embodiments, the bag 200 may include one or more openings (not shown) or tabs (not shown), which may be used to secure or lock the bag 200 to a rack (or other structure).
[0027] In some embodiments, the bag 200 comprises one or more pockets 230 . The pockets 230 may be integrated into the bag 200 itself and/or may be removably attached thereto. The pockets 230 may be configured to receive tail lights 232 . The tail lights 232 may comprise any suitable lighting mechanism including, but not limited to: brake lights, turn signals, backup lighting, etc. The tail lights may be secured within the pockets 230 without the need for special brackets or other mechanisms. Accordingly, in some embodiments, the pockets 230 include a securing member 234 or flaps adapted to secure a tail light 232 therein (e.g., a zipper closure, VELCRO®, or the like). An exterior facing portion of the pockets 230 may be formed from a transparent material to allow light from the tail lights 232 to emit therefrom.
[0028] The bag 200 may provide an electrical connection between the pockets 230 and an exterior portion of the bag 200 . For example, the bag 200 may include an electrical connection 236 configured to receive an electrical connection from a vehicle, such as a trailer hitch electrical connection or the like. The electrical connection 236 may be disposed on a lower portion of the bag 200 to be proximate to a hitch electrical connection of a vehicle. The electrical connection 236 may be electrically coupled to each of the one or more pockets 230 . Accordingly, each of the two or more pockets 230 may include an electrical connection (not shown) in electrical communication with the electrical connection 236 . The electrical coupling may be implemented using conductors embedded within material of the bag 200 , conductors in the interior of the bag 200 , conductors along the exterior of the bag 200 , or the like. In some embodiments, the bag 200 may also comprise an electrical coupling output (not shown) to connect two or more of the bags 200 electrically in serial.
[0029] The bag 200 may comprise a resealable closure (not shown) along a bottom portion of the bag 200 . The resealable closure may be selectively opened to allow a bicycle 201 to be placed within the bag 200 and/or removed therefrom. The resealable closure may comprise any suitable mechanism including, but not limited to: Velcro®, a zipper, buttons, or the like. The resealable closure may be configured to protect the bicycle 201 from the elements when closed. Accordingly, the resealable closure may be waterproof and/or tamper resistant. In some embodiments, the resealable closure may include a locking mechanism to prevent the resealable closure from being opened. Alternatively, or in addition, the bag 200 may comprise a resealable closure along the top portion of the bag 200 . The top-portion resealable closure may allow a bicycle 201 to be placed within (or removed) from the top portion of the bag 200 .
[0030] The bag 200 may further comprise a portion 250 configured to allow the pedals and/or crank of the bicycle 201 to rotate therein. The pedals and/or crank may rotate within an arc 252 within the bag 200 . Accordingly, the portion 250 may comprise a sufficient interior volume to accommodate various bicycle pedal and/or crank configurations. The rotation 252 of the pedals and/or crank may facilitate arranging two or more bicycles next to one another on a rack. For example, the pedals of the two or more bicycles may interfere with one another when oriented side-by-side in a rack. The rotation 252 of the bicycle 201 pedals and/or crank may allow the pedals to offset one another, allowing the bicycles to be placed in closer proximity.
[0031] As discussed above, the bag 200 may be formed from a material configured to provide protection from the elements while the bicycle 201 is transported on a vehicle. Accordingly, the bag 200 may be formed from waterproof material and/or material that provides ballistic protection (e.g., protection from high-velocity road debris).
[0032] FIG. 3 illustrates other aspects of a bicycle bag as disclosed herein. The bicycle bag 300 comprises a resealable opening 315 running along a top rear portion and bottom of the bag 300 . The resealable opening 315 may be configured to receive a bicycle into an interior portion of the bag 300 . As described above, portions of the bag 300 may be formed from deformable and/or flexible material, such as spandex, neoprene, or the like. In the FIG. 300 example, a handlebar compartment 360 , a top-tube portion 361 , and a seat portion 362 of the bag may be formed from a deformable material, which may allow the bag 300 to accommodate bicycles of different sizes and/or configurations. For example, the handlebar compartment 360 of the bag may be configured to receive handlebars of varying widths and/or heights. Similarly, the top tube portion 361 may be deformable to accommodate bicycles of varying lengths, and the seat portion 362 may be deformable to accommodate bicycles of varying height. The bicycle bag 300 may be provided in different sizes and/or configurations. For example, the bag 300 may be provided in small, medium, and/or large sizes to accommodate a large range of bicycles sizes (e.g., frame sizes from 40 to 64 cm). Similarly, the bag 300 may be provided with different handlebar compartment 360 types, including, but not limited to: a road bike compartment configured to receive road bike handlebars, a mountain bike compartment configured to receive wider mountain bike handle bars, and/or a cruiser compartment configured to receive wide bar types. In some embodiments, the handle bar compartment 360 may be removable and/or modular, such that the bag 300 may switch between road, mountain, and/or cruiser handler bar compartments. Alternatively, or in addition, the handle compartment 360 may comprise one or more straps, expansion sleeves, or the like, to allow a user to change the configuration of the handlebar compartment 300 (and/or other portions of the bag 300 ) to accommodate a particular size and/or style of bicycle.
[0033] As shown in FIG. 3 , the opening 103 may be provided in a diamond shape to fit a wide variety of post-type racks. The opening 203 may be resealable, as described above. The bag 300 may further comprise a seat-tube opening 306 configured to allow a rack to secure a seat tube of a bicycle within the bag 300 . A down-tube opening 307 may be configured to allow a rack to secure a down tube of a bicycle within the bag 300 . In some embodiments, the opening 204 may be configured to allow a fork of the bicycle to protrude from the bag 300 , such that the fork may be secured to a fork-type rack (e.g., rack 176 ).
[0034] As described above, bottom portions 211 and 212 of the wheel compartments 281 and 282 may be configured to conform to a contour of the wheels of the bicycle. Accordingly, the wheel compartments 281 and/or 282 may be configured to allow the wheels of the bicycle to be secured to a tray-type rack and/or be secured using a wheel slot or clamp (or similar mechanism). As shown in FIG. 3 , the wheel compartment 281 may be configured to allow a front portion 283 A and/or rear portion 284 A of the front wheel to be secured to a tray and/or wheel slot or clamp. The wheel compartment 282 may be configured to allow a front portion 283 B and/or read portion 284 B of the rear wheel to be secured to a tray and/or wheel slot or clamp. In addition, the openings 204 may be used to secure the front and/or rear wheels to various rack types, as described above.
[0035] Top portions 213 and 214 of the wheel compartments 281 and 282 may conform to top portions of the bicycle wheels. As such, the wheel compartments 281 and/or 282 may be configured to allow the bicycle to be secured to an over-the-wheel rack, a J-hook, or similar mechanism. The bag 300 may further comprise pockets 230 to receive lighting, a crank compartment 250 configured to allow a bicycle crank and/or pedals to rotate within the bag 300 , as described above.
[0036] It will be understood by those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles presented herein. For example, any suitable combination of various embodiments, or the features thereof, is contemplated.
[0037] Any methods disclosed herein comprise one or more steps or actions for performing the described method. The method steps and/or actions may be interchanged with one another. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order and/or use of specific steps and/or actions may be modified.
[0038] Reference throughout this specification to “an embodiment” or “the embodiment” means that a particular feature, structure or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the quoted phrases, or variations thereof, as recited throughout this specification are not necessarily all referring to the same embodiment.
[0039] Similarly, it should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than those expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment.
[0040] The claims following this Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims. Recitation in the claims of the term “first” with respect to a feature or element does not necessarily imply the existence of a second or additional such feature or element. Elements specifically recited in means-plus-function format, if any, are intended to be construed in accordance with 35 U.S.C. §112 ¶6.
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A bicycle bag protects a bicycle while the bicycle is secured to a rack, such as a vehicle bicycle rack. The bicycle bag includes resealable openings configured to allow the bicycle (and bag) to be securely attached to a wide variety of different rack types. Additionally, because there is risk of obscuring the tail lights of a vehicle for rear-mount racks when a bicycle bag is on the bike and the bike on the rack, the bicycle bag includes pockets designed to support a tail-light system that can be connected to the vehicle to provide additional lighting and safety.
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FIELD OF THE INVENTION
[0001] The invention generally relates to sewage treatment apparatus and, more particularly, to sewage treatment apparatus for use on vessels, such as marine vessels.
BACKGROUND OF THE INVENTION
[0002] Sewage or waste water treatment plants are generally known. It is also known to provide such apparatus on marine vessels. In marine applications, the capacity of the treatment plant is typically sized according to the number of persons carried by the vessel, whereby, for example, sewage treatment plants on passenger ships and freighters are of a totally different size category.
[0003] In the following both the terms sewage and waste water are used. These terms comprise waste from sanitary installations, such as toilets, urinals, wash basins, hospitals, and sick bays, as well as kitchens, food stuff treatment facilities, and the like. Other terms used in this connection are black water and grey water, as are generally understood in the art.
[0004] A typical apparatus for sewage treatment comprises as basic components an aeration chamber, a settling chamber, and a disinfection chamber for the sewage. In the aeration chamber the organic components of the sewage are transformed by means of bacteria into carbon dioxide and water. The air necessary for the process is usually produced by blowers. From the aeration chamber, the treated waste water is led to the settling chamber, from where the separated sediment is returned back to the aeration chamber for further disintegration. From the settling chamber, the cleared water is led to the disinfection chamber, where disinfection is carried out either chemically and/or by UV-light or UV-radiation. From the disinfection chamber, the cleaned water can be emptied into the sea, a receiving facility on land, such as a sewer network, or into a storage container at some other location aboard the vessel.
[0005] In known waste water treatment plants intended for use on ships, the aeration chamber, settling chamber, and disinfection chamber form a separate entity, wherein short transfer connections are installed between the chambers, and whereby the fluid is arranged to flow from one chamber to another by way of overflow. The treatment plant is usually preceded by a collecting container which has the function of guaranteeing a stable load for the treatment plant at all hours of the day. A storage container is often arranged after the treatment plant and clearly separated from the same, having the function of storing the waste water cleaned aboard the vessel at times when it cannot be discharged into the sea due, for example, to different regulations, such as into a harbor basin when the vessel is in a harbor.
[0006] In known apparatus the storage container is always a container situated apart form the treatment plant and often arranged at the bottom of the hull, whereas the treatment plant is placed in the machine room, and therefore the transfer connections from the treatment plant to the storage container are long, thereby increasing the possibility of leaks in the connecting piping. Furthermore, in conventional apparatus, each system needs its own pumping station and level metering system, including control automation.
SUMMARY OF THE INVENTION
[0007] In view of the foregoing, an apparatus for the treatment of sewage is described herein which provides for an efficient and multifunctional sewage treatment process by simple means, while avoiding the aforementioned disadvantages.
[0008] In this regard, the sewage treatment plant and the storage container intended for use on a ship are provided, as much as possible, as an integrated structure, whereby the means necessary for the transfer connections and the control of the same can be minimized and whereby an efficient as possible interaction can be achieved between the different components of the apparatus. Accordingly, the aeration chamber, the settling chamber, the disinfection chamber, and the storage container are integrated in the same structure, whereby at least the level metering system, the pumping station, and the control center can be combined into one unit, i.e. having the process and its control monitored from a central arrangement. The disinfection chamber and the storage container can be arranged as separate units and provided with surface level sensors connected to a control center. This provides for a controlled temporary storage stage when direct discharge of treated waste is not possible.
[0009] The storage container can also be arranged directly as a fixed part of the structure of the treatment plant, whereby the disinfection chamber, for example, may be expanded from being only a disinfection chamber into a multifunctional combined disinfection chamber-storage container. The combined control of this arrangement may advantageously be provided with surface level sensors connected to a control center.
[0010] At the aeration stage preferably two (i.e. a first and a second) aeration chambers are used in order to optimize the aeration stage.
[0011] To provide for alternative ways of treating sewage, the first aeration chamber and the storage container may be provided with sewage supply pipes connected to the source of sewage. This means, for example, that the sewage treatment process may also temporarily be by-passed, such as during annual maintenance, whereby the sewage can be collected directly in the storage container, from where the sewage can be returned to the aeration chamber for treatment to be carried out later. The treatment process can thus be finished after annual maintenance or some other interruption.
[0012] It has also shown to be advantageous that the sewage supply pipes connected to the first aeration chamber and the storage container be further connected to an ejector device when the apparatus is employed in connection with a vacuum waste system.
[0013] The above mentioned arrangements further provide for both the aeration chamber and the storage container to function directly as a collecting container for sewage.
[0014] The disinfection chamber and the storage container may be advantageously provided with a common pump means connected to the control center in order to further centralize the arrangement.
[0015] The disinfection chamber may be advantageously provided with a disinfection system comprising a disinfectant container and a dosage pump connected to the control center as noted above.
[0016] The integrated structure of the device according to the invention provides for connecting all the operating means to the central control center.
[0017] Other features and advantages are inherent in the embodiments claimed and disclosed, or will become apparent to those skilled in the art from the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 is a partially schematic side elevation view showing one embodiment of a system in accordance with the teachings of the present invention, in which a disinfection chamber and a storage container are arranged as separate units;
[0019] [0019]FIG. 2 is a partially schematic side elevation view showing another embodiment of a system in which a disinfection chamber and a storage container are arranged as an integrated unit;
[0020] [0020]FIG. 3 is a partially schematic side elevation view showing a further embodiment of a system in which a disinfection chamber and a storage container are arranged as separate units; and
[0021] [0021]FIG. 4 is a partially schematic side elevation view showing a yet another embodiment of a system in which a disinfection chamber and a storage container are arranged as an integrated unit.
DETAILED DESCRIPTION
[0022] A first embodiment of a sewage or waste water treatment plant is shown in FIG. 1 having a first aeration chamber 1 and a second aeration chamber 2 . Next to the second aeration chamber 2 is arranged a settling chamber 3 , in the immediate vicinity of which is arranged a disinfection chamber 4 a , which is provided with a lower first surface level sensor 5 and an upper second surface level sensor 6 . The apparatus further comprises a disinfection system, whereby dosage of disinfectant takes place from a disinfectant container 8 by means of a dosage pump 9 . The function of the surface level sensors and the dosage of disinfectant are controlled by a control center 10 .
[0023] A storage container 4 b is integrated into the treatment plant, wherein it nonetheless forms a separate unit. The waste water is transferred from the disinfection chamber 4 a to the storage container 4 b through a pipe connection 13 , 16 . The storage container 4 b is provided with a third surface level sensor 7 for monitoring the storage stage, which will be discussed below in more detail.
[0024] Untreated waste water is arranged to be supplied from a source of sewage 20 either to the first aeration chamber 1 through a supply pipe 21 or to the storage container 4 b through a supply pipe 22 . Treated waste water is discharged by a pump 14 from the storage container 4 b into the sea or a storage facility on land, e.g. a sewer network (not shown). The waste water can also be returned through a pipe connection 19 , 25 to the first aeration chamber 1 .
[0025] In normal operation, the shut-off valve 23 is open and the shut-off valve 24 is closed, so that untreated waste water is supplied from the source of sewage 20 through the pipe 21 to the first aeration chamber 1 . The waste water is subsequently transferred by way of overflow (shown by arrows) to the second aeration chamber 2 and further to the settling chamber 3 , from where any undissolved particles may be returned to the first aeration chamber 1 through a pump 11 and a pipe 12 for renewed treatment. From the surface of the settling chamber 3 the waste water is transferred by way of overflow (shown by arrow) to the disinfection chamber 4 a.
[0026] If the water can be discharged from the treatment plant directly e.g. into the sea or other receiving facility, i.e. no temporary storage is required, the actual disinfection process is controlled by the lower first surface level sensor 5 and the upper second surface level sensor 6 . The central control center 10 also controls the supply of disinfectant from the disinfectant container 8 to the disinfection chamber 4 a by the pump 9 by means of signals given by the surface level sensors 5 , 6 . The discharge of cleaned waste water from the disinfection chamber 4 a is carried out in a controlled manner through the discharge pipe 13 and the pump 14 to a discharge pipe 30 , whereby shut-off valves 17 and 31 are open and shut-off valves 15 , 18 , and 26 are closed. The disinfection chamber 4 a is usually of a smaller size (as schematically indicated in FIG. 1) and suitably sized for the disinfection process. Discharge from the disinfection chamber 4 a is generally initiated by a signal from the upper second surface level sensor 6 .
[0027] If the situation requires waste water to be stored for a certain time (e.g. when the ship is in the harbor), the waste water is led through the pipe connection 13 , 16 to the storage container 4 b , where the surface level of the collected waste water is controlled by a third surface level sensor 7 . In this case shut-off valve 15 is open and shut-off valves 26 , 31 are closed. This provides for a temporary storage stage as mentioned above, whereby the storage container 4 b may be sized according to an estimated need. The filling and discharge of the storage container 4 b is thus generally monitored by the third surface level sensor 7 , which also is connected to the control center 10 .
[0028] Waste water can also, when necessary, be returned from the storage container 4 b to the first aeration chamber 1 through the pump 14 and the return pipe 19 , which through a pipe connection 25 is connected to the sewage supply pipe 21 . In this case shut-off valves 18 , 26 , and 31 are open and shut-off valves 15 and 17 are closed.
[0029] If it is desirable to by-pass the waste water treatment process, e.g. for maintenance or other reasons, waste water can be led from the source of waste water 20 through the supply pipe 22 directly to the storage container 4 b . In this case the waste water can at a later stage be led from the storage container 4 b to the first aeration chamber 1 as described in the above paragraph.
[0030] Waste water can also be led untreated from the storage container 4 b directly into the sea or other receiving facility, e.g. a sewer network (not shown). Discharge into the discharge pipe 30 is carried out by the pump 14 , whereby shutoff valves 17 , 26 , and 31 are open and shut-off valves 15 and 18 are closed.
[0031] An alternative embodiment of a sewage or waste water treatment plant is shown in FIG. 2 having a first aeration chamber 1 and a second aeration chamber 2 . Beside the second aeration chamber 2 is arranged a settling chamber 3 , in the immediate vicinity of which is arranged a disinfection chamber 4 , which at the same time functions as a storage container. The integrated or combined disinfection chamber-storage container 4 is provided with three surface level sensors, a lower first surface level sensor 5 , an upper second surface level sensor 6 and a high third surface level sensor 7 . The apparatus further comprises a disinfection system, whereby dosage of disinfectant takes place from a disinfectant container 8 by means of a dosage pump 9 .
[0032] The function of the surface level sensors and the dosage of disinfectant are controlled by the control center 10 . The first and second surface level sensors 5 and 6 are employed primarily for the disinfection stage and the third surface level sensor 7 primarily for the storage stage, which will be discussed more in detail below.
[0033] Waste water is arranged to be supplied from a source of waste water 20 either to the first aeration chamber 1 through a supply pipe 21 or to the combined disinfection chamber-storage container 4 through a supply pipe 22 .
[0034] Treated waste water is discharged by a pump 14 from the combined disinfection chamber-storage container 4 into the sea or a storage facility on land, e.g. a sewer network (not shown). Waste water can also be returned through a pipe connection 19 , 25 to the first aeration chamber 1 .
[0035] During normal operation, the shut-off valve 23 is open and the shut-off valve 24 is closed, so that waste water flows from the source of sewage 20 through the pipe 21 to the first aeration chamber 1 . The waste water is transferred by way of overflow (shown by arrows) to the second aeration chamber 2 and further to the settling chamber 3 , from where any undissolved particles may be returned to the first aeration chamber 1 through a pump 11 and a pipe 12 for renewed treatment. From the surface of the settling chamber 3 , waste water is transferred by way of overflow (shown by arrow) to the combined disinfection chamber-storage container 4 .
[0036] If the water can be discharged directly from the treatment plant (e.g., into the sea) and therefore no temporary storage is required, the actual disinfection process is controlled by the two lower sensors (i.e., the lower first surface level sensor 5 and the upper second surface level sensor 6 ). The control center 10 also controls the supply of disinfectant from the disinfectant container 8 to the lower part of the combined disinfection chamber-storage container 4 by the pump 9 by means of signals given by the surface level sensors 5 , 6 . The discharge of cleaned waste water from the combined disinfection chamber-storage container 4 is carried out in a controlled manner by the pump 14 , whereby shut-off valve 17 is open and shut-off valve 18 is closed. In this case the disinfection process takes place in the lower part of the combined disinfection chamber-storage container 4 . Discharge is generally initiated by a signal from the upper second surface level sensor 6 .
[0037] If the situation requires that waste water has to be stored for a certain time, the function of the second surface level sensor 6 is by-passed and the storage stage is controlled by the high third surface level sensor 7 . The above mentioned disinfection process can also be carried out in this connection. This advantageously provides for temporary storage of waste water within the combined chamber or container. The filling and discharge of the combined disinfection chamber-storage container 4 is thus generally monitored by the high third surface level sensor 7 , which is connected to the central control center 10 .
[0038] The waste water can also, when necessary, be returned from the combined disinfection chamber-storage container 4 to the first aeration chamber 1 through the pump 14 and the return pipe 19 , which through a pipe connection 25 is connected to the sewage supply pipe 21 . In this case shut-off valve 18 is open and shut-off valve 17 is closed. When waste water is returned to the aeration chamber in this manner, chemical disinfectant should not be added to the combined disinfection chamber-storage container, in order to secure the process. If disinfectant has been added, the waste water is returned in small portions. Control is carried out by the control center 10 .
[0039] If it is desirable to by-pass the waste water treatment process, e.g. for maintenance or other reasons, waste water can be led from the source of waste water 20 through the supply pipe 22 directly to the combined disinfection chamber-storage container 4 . In this case the waste water can at a later stage be led from the combined disinfection chamber-storage container 4 to the first aeration chamber 1 as described in the above paragraph.
[0040] Waste water can also be led untreated from the combined disinfection chamber-storage container 4 directly into the sea or a receiving facility on land, such as a sewer network (not shown), if so desired. Discharge into the discharge pipe 30 is carried out by the pump 14 , whereby shut-off valve 17 is open and shutoff valve 18 is closed.
[0041] A further embodiment of a sewage or waste water treatment plant is shown in FIG. 3 which substantially corresponds to the apparatus described in connection with FIG. 1. In this apparatus, however, the first aeration chamber 1 also functions as a collecting container for sewage or waste water. When necessary, such as during maintenance of the aeration chamber 1 , the storage container 4 b can directly function as a collecting container for sewage. These arrangements can also be implemented in connection with the embodiment shown in FIG. 1.
[0042] Next to the second aeration chamber 2 is arranged a settling chamber 3 , in the immediate vicinity of which is arranged a disinfection chamber 4 a , which is provided with a lower first surface level sensor 5 and an upper second surface level sensor 6 . The apparatus further comprises a disinfection system, whereby dosage of disinfectant takes place from a disinfectant container 8 by means of a dosage pump 9 . The function of the surface level sensors and the dosage of disinfectant are controlled by a control center 10 .
[0043] The storage container 4 a is integrated into the treatment plant, wherein it nonetheless forms a separate unit. Waste water is transferred from the disinfection chamber 4 a to the storage container 4 b through a pipe connection 13 , 45 . The storage container 4 b is provided with a third surface level sensor 7 for monitoring the storing stage, which will be discussed below in more detail.
[0044] The waste water is arranged to be supplied from a source of sewage 20 by an ejector device 40 either to the first aeration chamber 1 through a supply pipe 42 or to the storage container 4 b through a supply pipe 43 . The ejector device 40 generates underpressure by means of the ejector pump 41 in the direction of the source of sewage 20 through a suction pipe connection 44 , whereby waste water is transferred to the integrated or combined collecting container-aeration chamber 1 by way of the flow generated by the ejector pump 41 . The function of the ejector device is not described in more detail in this connection since such devices are known to a person skilled in the art.
[0045] The treated waste water is discharged by a pump 14 from the storage container 4 b into the sea or a storage facility on land, such as a sewer network (not shown). The waste water can also be returned through a pipe connection 45 to the first aeration chamber 1 .
[0046] During operation, shut-off valve 46 is closed so that waste water is supplied from the source of sewage 20 through the pipe 42 (by means of the pressure differential and the flow generated by the ejector device 40 and the ejector pump 41 ) to the first aeration chamber 1 . Waste water is transferred by way of overflow (shown by arrows) to the second aeration chamber 2 and further to the settling chamber 3 , from where any undissolved particles may be returned to the first aeration chamber 1 through a pump 11 and a pipe 12 for renewed treatment. From the surface of the settling chamber 3 , waste water is transferred by way of overflow (shown by arrow) to the disinfection chamber 4 a.
[0047] If the water can be discharged from the treatment plant directly, such as into the sea or other receiving facility, no temporary storing stage is required and the actual disinfection process is controlled by the lower first surface level sensor 5 and the upper second surface level sensor 6 . The central control center 10 also controls the supply of disinfectant from the disinfectant container 8 to the disinfection chamber 4 a by the pump 9 by means of signals given by the surface level sensors 5 , 6 . The discharge of cleaned waste water from the disinfection chamber 4 a is carried out in a controlled manner through the discharge pipe 13 and the pump 14 to a discharge pipe 30 , whereby shut-off valves 17 and 32 are open and shut-off valves 15 , 26 and 31 closed.
[0048] The disinfection chamber 4 a is usually of a smaller size (as schematically indicated in FIG. 3) suitable for the disinfection process. Discharge from the disinfection chamber 4 a is generally initiated by a signal from the upper second surface level sensor 6 .
[0049] If the situation requires that waste water has to be stored for a certain time, such as when the ship is in the harbor, the waste water is led through the pipe connection 13 , 16 to the storage container 4 b , where the surface level of the collected waste water is controlled by a third surface level sensor 7 . In this case shut-off valves 15 and 32 are open and shut-off valves 26 , 31 and 17 are closed. This provides for a temporary storage stage as mentioned above, whereby the storage container 4 b usually is sized according to an estimated need. The filling and discharge of the storage container 4 b is thus generally monitored by the third surface level sensor 7 , which also is connected to the central control center 10 .
[0050] Waste water can also be returned from the storage container 4 b for renewed treatment to the first aeration chamber 1 through a circulation pipe 45 , the ejector pump 41 and the supply pipe 42 . In this case shut-off valves 26 and 31 are open and shut-off valves 32 and 46 closed.
[0051] If it is desirable to by-pass the waste water treatment process, such as for maintenance or other reasons, the waste water can be led from the source of waste water 20 through the ejector device 40 and the supply pipe 43 directly to the storage container 4 i b. In this case the waste water can at a later stage be led from the storage container 4 b to the first aeration chamber 1 as described in the above paragraph.
[0052] Waste water can also be led untreated either from the combined collecting container-aeration chamber 1 or the storage container 4 b directly into the sea or a receiving facility on land, such as a sewer network (not shown).
[0053] From the combined collecting container-aeration chamber 1 , discharge is carried out into the discharge pipe 30 by the pump 14 , whereby shut-off valves 33 , 31 , 32 , and 17 are open and shut-off valves 15 and 26 are closed. From the storage container 4 b discharge is carried out by the pump 14 , whereby shut-off valves 17 , 26 , and 32 are open and shut-off valves 15 and 31 are closed.
[0054] Yet another embodiment of a sewage or waste water treatment plant is shown in FIG. 4 that substantially corresponds to the embodiment of FIG. 2. In this embodiment, however, the first aeration chamber 1 also functions as a collecting container for sewage or waste water. When necessary, such as during maintenance of the aeration chamber 1 , the combined disinfection chamber-storage container 4 can directly function as a collecting container for sewage. These arrangements can also be implemented in connection with the embodiment shown in FIG. 2.
[0055] Next to the second aeration chamber 2 is arranged a settling chamber 3 , in the immediate vicinity of which is arranged a disinfection chamber 4 , which at the same time functions as a storage container. The integrated or combined disinfection chamber-storage container 4 is provided with three surface level sensors, a lower first surface level sensor 5 , an upper second surface level sensor 6 and a high third surface level sensor 7 . The apparatus further comprises a disinfection system, whereby dosage of disinfectant takes place from a disinfectant container 8 by means of a dosage pump 9 .
[0056] The function of the surface level sensors and the dosage of disinfectant are controlled by the control center 10 . The first and second surface level sensors 5 and 6 are employed primarily for the disinfection stage and the third surface level sensor 7 primarily for the storage stage, which will be discussed more in detail below.
[0057] Waste water is arranged to be supplied from a source of sewage 20 by an ejector device 40 either to the first aeration chamber 1 through a supply pipe 42 or to the combined disinfection chamber-storage container 4 through a supply pipe 43 . The ejector device 40 generates underpressure by means of the ejector pump 41 in the direction of the source of sewage 20 through a suction pipe connection 44 , whereby waste water is transferred to the integrated or combined collecting container-aeration chamber 1 by way of the flow generated by the ejector pump 41 . The function of the ejector device is not described in more detail in this connection since such devices are known to a person skilled in the art.
[0058] The treated waste water is discharged by a pump 14 from the combined disinfection chamber-storage container 4 into the sea, a harbor basin, or a storage facility on land, such as a sewer network (not shown). The waste water can also be returned through a pipe connection 45 to the first aeration chamber 1 .
[0059] In operation, waste water is supplied from the source of sewage 20 through the pipe 42 by means of the pressure differential and the flow generated by the ejector device 40 and the ejector pump 41 , shut-off valve 46 closed, to the first aeration chamber 1 . Waste water is transferred by way of overflow (shown by arrows) to the second aeration chamber 2 and further to the settling chamber 3 , from where any undissolved particles may be returned to the first aeration chamber 1 through a pump 11 and a pipe 12 for renewed treatment. From the surface of the settling chamber 3 , waste water is transferred by way of overflow (shown by arrow) to the combined disinfection chamber-storage container 4 .
[0060] If the water can be directly discharged from the treatment plant, such as into the sea or other receiving facility, the actual disinfection process is controlled by the lower first surface level sensor 5 and the upper second surface level sensor 6 . The control center 10 also controls the supply of disinfectant from the disinfectant container 8 to the combined disinfection chamber-storage container 4 by the pump 9 by means of signals given by the surface level sensors 5 , 6 . The discharge of cleaned waste water from the combined disinfection chamber-storage container 4 is carried out in a controlled manner by the pump 14 to a discharge pipe 30 , whereby shut-off valves 32 and 34 are open and shut-off valve 31 is closed. In this case, the disinfection process takes place in the lower part of the combined disinfection chamber-storage container 4 . Discharge is generally initiated by a signal from the upper second surface level sensor 6 .
[0061] If the situation requires that waste water has to be stored for a certain time, the function of the second surface level sensor 6 is by-passed and the storage stage is controlled by the high third surface level sensor 7 . The above mentioned disinfection process can be carried out also in this connection. This advantageously provides for temporary storage within the combined chamber or container, as mentioned above. The filling and discharge of the combined disinfection chamber-storage container 4 is thus generally monitored by the high third surface level sensor 7 , which is connected to the central control center 10 .
[0062] The waste water can also, when necessary, be returned from the combined disinfection chamber-storage container 4 for renewed treatment to the first aeration chamber 1 through a circulation pipe 45 , the ejector pump 41 , and the supply pipe 42 . In this case shut-off valves 34 and 31 are open and shut-off valves 32 and 46 closed.
[0063] If it is desirable to by-pass the waste water treatment process, such as for maintenance or other reasons, the waste water can be led from the source of waste water 20 through the ejector device 40 and the supply pipe 43 directly to the combined disinfection chamber-storage container 4 . In this case, the waste water can at a later stage be led from the combined disinfection chamber-storage container 4 to the first aeration chamber 1 as described in the above paragraph. Waste water can also be led untreated either from the combined collecting container-aeration chamber 1 or from the combined disinfection chamber-storage container 4 directly into the sea or a receiving facility on land, such as a sewer network (not shown).
[0064] From the combined collecting container-aeration chamber 1 , discharge is carried out into the discharge pipe 30 by the pump 14 , whereby shut-off valves 33 , 31 , and 32 are open and shut-off valve 34 is closed. From the combined disinfection chamber-storage container 4 , discharge is carried out by the pump 14 , whereby shut-off valves 34 and 32 are open and shut-off valve 31 is closed.
[0065] The shut-off valves in the above described examples are advantageously motor actuated, whereby their control is connectable to the central control center 10 , to which also the function of the other components and operating means of the apparatus can be connected.
[0066] The integrated arrangement is also well exemplified in the above embodiments by, for example, the multifunctional pump 14 , which is controlled by the central control center 10 . The disinfection system may as an alternative also comprise an arrangement for UV-light or UV-radiation. It is also clear that the apparatus may function with only one aeration chamber as an alternative to the two chambers indicated in the above embodiments.
[0067] The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications would be obvious to those skilled in the art.
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Apparatus for treatment of sewage on vessels. The apparatus includes at least a first aeration chamber, a settling chamber, a disinfection chamber, and a storage container. In order to provide a multifunctional and efficient apparatus, the aeration chamber, the settling chamber, the disinfection chamber, and the storage container are integrated into the same structure.
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The present application is a continuation of U.S. application Ser. No. 09/066,964, filed Apr. 27, 1998, now U.S. Pat. No. 6,079,506 which is incorporated in its entirety by reference.
BACKGROUND OF THE INVENTION
The present invention relates generally to underground boring tool guidance and, more particularly, to a remote walk over locator/controller configured for determining the underground location of a boring tool and for remotely issuing control commands to a drill rig which is operating the boring tool.
Installing underground utility cable using a steerable boring tool is well known in the art. Various examples are described in U.S. Pat. Nos. 5,155,442, 5,337,002, 5,444,382 and 5,633,589 as issued to Mercer et al (collectively referred to herein as the Mercer Patents), all of which are incorporated herein by reference. An example of the prior art Mercer technique is best illustrated in FIG. 1 herein which corresponds to FIG. 2 in the Mercer Patents. For purposes of clarity, the reference numerals used in the Mercer Patents have been retained herein for like components.
As seen in FIG. 1, an overall boring machine 24 is positioned within a starting pit 22 and includes a length of drill pipe 10 , the front end of which is connected to the back end of a steerable boring head or tool 28 . As described in the Mercer Patents, the boring tool includes a transmitter for emitting a dipole magnetic field 12 which radiates in front of, behind and around the boring tool, as illustrated in part in FIG. 1. A first operator 20 positioned at the starting pit 22 is responsible for operating the boring machine 24 ; that is, he or she causes the machine to let out the drill pipe, causing it to push the boring tool forward. At the same time, operator 20 is responsible for steering the boring tool through the ground. A second locator/monitor operator 26 is responsible for locating boring tool 28 using a locator or receiver 36 . The boring tool is shown in FIG. 1 being guided beneath an obstacle 30 . The locator/monitor operator 26 holds locator 36 and uses it to locate a surface position above tool head 28 . Once operator 26 finds this position, the locator 36 is used to determine the depth of tool head 28 . Using the particular locator of the present invention, operator 26 can also determine roll orientation and other information such as yaw and pitch. This information is passed on to operator 20 who then may use it to steer the boring tool to its target. Unfortunately, this arrangement requires at least two operators in order to manage the drilling operation, as will be discussed further.
Still referring to FIG. 1, current operation of horizontal directional drilling (HDD) with a walkover locating system requires a minimum of two skilled operators to perform the drilling operation. As described, one operator runs the drill rig and the other operator tracks the progress of the boring tool and determines the commands necessary to keep the drill on a planned course. In the past, communication between the two operators has been accomplished using walkie-talkies. Sometimes hand signals are used on the shorter drill runs. However, in either instance, there is often confusion. Because an operating drill rig is typically quite noisy, the rig noise can make it difficult, if not impossible, to hear the voice communications provided via walkie-talkie. Moreover, both the walkie-talkie and the hand signals are awkward since the operator of the drill rig at many times has both of his hands engaged in operation of the drill rig. Confused steering direction can result in the drill being misdirected, sometimes with disastrous results.
The present invention provides a highly advantageous boring tool control arrangement in which an operator uses a walk-over locator unit that is configured for remotely issuing control commands to a drill rig. In this way, problems associated with reliable communications between two operators are eliminated. In addition, other advantages are provided, as will be described hereinafter.
SUMMARY OF THE INVENTION
As will be described in more detail hereinafter, there is disclosed herein a locator/control arrangement for locating and controlling underground movement of a boring tool which is operated from a drill rig. An associated method is also disclosed. The boring tool includes means for emitting a locating signal. In accordance with the present invention, the locator/control arrangement includes a portable device for generating certain information about the position of the boring tool in response to and using the locating signal. In addition to this means for generating certain information about the position of the boring tool, the portable device also includes means for generating command signals in view of this certain information and for transmitting the command signals to the drill rig. Means located at the drill rig then receives the command signals whereby the command signals can be used to control the boring tool.
In accordance with one aspect of the present invention, the means located at the drill rig for receiving the command signals may include means for indicating the command signals to a drill rig operator.
In accordance with another aspect of the present invention, the means located at the drill rig for receiving the command signals may include means for automatically executing the command signals at the drill rig in a way which eliminates the need for a drill rig operator.
In accordance with still another aspect of the present invention, drill rig monitoring means may be provided for monitoring particular operational parameters of the drill rig. In response to the particular operational parameters, certain data may be generated which may include a warning that one of the parameters has violated an acceptable operating value for that parameter. In one feature, the certain data regarding the operational parameters may be displayed at the drill rig. In another feature, the certain data regarding the operational parameters may be displayed on the portable device. The latter feature is highly advantageous in embodiments of the invention which contemplate elimination of the need for a drill rig operator.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be understood by reference to the following detailed description taken in conjunction with the drawings, in which:
FIG. 1 is a partially broken away elevational and perspective view of a boring operation described in the previously recited Mercer Patents.
FIG. 2 is an elevational view of a boring operation being performed in accordance with the present invention in which a portable locator/controller is used.
FIG. 3 is a diagrammatic perspective view of the portable locator/controller which is used in the boring operation of FIG. 2, shown here to illustrate details of its construction.
FIG. 4 is a partial block diagram illustrating details relating to the configuration and operation of the portable locator/controller of FIG. 3 .
FIG. 5 is a partial block diagram illustrating details relating to the configuration and operation of one arrangement of components located at the drill rig for receiving command signals transmitted from the portable locator/controller of the present invention.
FIG. 6 is a partial block diagram illustrating details relating to the configuration and operation of another arrangement of components located at the drill rig for receiving command signals transmitted from the portable locator/controller and for, thereafter, executing the commands signals so as to eliminate the need for a drill rig operator.
DETAILED DESCRIPTION OF THE INVENTION
Turning again to the drawings, attention is immediately directed to FIG. 2 which illustrates a horizontal boring operation being performed using a boring/drilling system generally indicated by the reference numeral 70 . The drilling operation is performed in a region of ground 72 including a boulder 74 . The surface of the ground is indicated by reference numeral 76 .
System 70 includes a drill rig 78 having a carriage 80 received for movement along the length of an opposing pair of rails 82 which are, in turn, mounted on a frame 84 . A conventional arrangement (not shown) is provided for moving carriage 80 along rails 82 . During drilling, carriage 80 pushes a drill string 86 into the ground and, further, is configured for rotating the drill string while pushing, as will be described. The drill string is made up of a series of individual drill string sections or pipes 88 , each of which includes a suitable length such as, for example, ten feet. Therefore, during drilling, sections 88 must be added to the drill string as it is extended or removed from the drill string as it is retracted. In this regard, drill rig 78 may be configured for automatically adding or removing the drill string sections as needed during the drilling operation. Underground bending of the drill string sections enables steering, but has been exaggerated for illustrative purposes.
Still referring to FIG. 2, a boring tool 90 includes an asymmetric face 92 and is attached to the end of drill string 86 . Steering of the boring tool is accomplished by orienting face 92 of the boring tool (using the drill string) such that the boring tool is deflected in the desired direction. Boring tool 90 includes a mono-axial antenna such as a dipole antenna 94 which is driven by a transmitter 96 so that a magnetic locating signal 98 is emanated from antenna 94 . Power may be supplied to transmitter 96 from a set of batteries 100 via a power supply 102 . A control console 104 is provided for use in controlling and/or monitoring the drill rig. The control console includes a drill rig telemetry transceiver 106 connected with a telemetry receiving antenna 108 , a display screen 110 , an input device such as a keyboard 112 , a processor 114 , and a plurality of control levers 116 which, for example, hydraulically control movement of carriage 80 along with other relevant functions of drill rig operation.
Still referring to FIG. 2, in accordance with the present invention, drilling system 70 includes a portable locator/controller 140 held by an operator 141 . With exceptions to be noted, locator 140 may be essentially identical to locator 36 , as described in the Mercer Patents.
Turning to FIG. 3 in conjunction with FIG. 2, the same reference numerals used to describe locator 36 in the Mercer Patents have been used to designate corresponding components in locator/controller 140 . In order to understand and appreciate the present invention, the only particular components of locator 36 that form part of locator 140 and that are important to note here are the antenna receiver arrangement comprised of orthogonal antennas 122 and 124 and associated processing circuitry for measuring and suitably processing the field intensity at each antenna and roll/pitch antenna 126 and associated processing circuitry 128 for measuring the pitch and roll of the boring tool. Inasmuch as the Mercer patents fully describe the process by which locator 140 is used to find the position of boring tool 90 , the reader is referred to the patents for a detailed description of the locating method.
Referring to FIGS. 2-4, in accordance with the present invention, locator/controller 140 includes a CPU 144 , interfaced with a remote telemetry transceiver 146 , a joystick 148 and a display 150 . Remote transceiver 146 is configured for two-way communication with drill rig transceiver 106 via an antenna 152 . Joystick 148 is positioned in a convenient location for actuation by operator 141 . In accordance with one highly advantageous feature of the present invention, operator 141 is able to remotely issue control commands to drill rig 78 by actuating joystick 148 . Commands which may be issued to the drill rig by the operator include, but are not limited to (1) roll orientation for steering direction purposes, (2) “advance” and (3) “retract.” It should be appreciated that the ability to issue these commands from locator/controller 140 , in essence, provides for complete boring tool locating and control capability from locator/controller 140 . A locator/controller command is implemented using CPU 144 to read operator actuations of the joystick, interpret these actuations to establish the operator's intended command, and then transfer the command to remote transceiver 146 for transmission to the command drill rig telemetry transceiver 106 at the drill rig, as will be described immediately hereinafter.
Still referring FIGS. 2-4, control commands are entered by using display 150 in conjunction with joystick 148 . Display 150 includes an enhanced roll orientation/steering display 154 having a clock face 156 which shows clock positions 1 through 12. These clock positions represent the possible steering directions in which boring tool 90 may be set to travel. That is, the axis of the boring tool is assumed to extend through a center position 158 of the clock display and perpendicular to the plane of the figure. The desired roll orientation is established by moving joystick 148 either to the left or right. As the joystick is moved, a desired roll orientation pointer 160 incrementally and sequentially moves between the clock positions. For instance, if the desired roll pointer was initially located at the 12 o'clock position (not shown), the locator/controller operator may begin moving it to the 3 o'clock position by moving and holding the joystick to the right. CPU 144 detects the position of the joystick and incrementally moves the desired roll pointer to the 1 o'clock, then 2 o'clock, and finally the 3 o'clock position. At this point, the operator releases the joystick. Of course, at the 3 o'clock position, the command established is to steer the boring tool to the right. Similarly, the 6 o'clock position corresponds to steering downward, the 9 o'clock position corresponds to steering to the left and the 12 o'clock position corresponds to steering upward. As mentioned previously, steering is accomplished by setting face 92 of the boring tool in an appropriate position in accordance with the desired roll of the boring tool. With regard to boring tool steering, it is to be understood that boring tool steering has been implemented using concepts other than that of roll orientation and that the present invention is readily adaptable to any steering method either used in the prior art or to be developed.
Having established a desired steering direction, operator 141 monitors an actual roll orientation indicator 162 . As described in the Mercer patents, roll orientation may be measured within the boring tool by a roll sensor (not shown). The measured roll orientation may then be encoded or impressed upon locating signal 90 and received by locator/controller 140 using antenna 126 . This information is input to CPU 144 as part of the “Locator Signal Data” indicated in FIG. 4 . CPU 144 then causes the measured/actual roll orientation to be displayed by actual roll orientation indicator 162 . In the present example, operator 141 can see that the actual roll orientation is at the 2 o'clock position. Once the desired roll orientation matches the actual roll orientation, the operator will issue an advance command by moving joystick 148 forward. Advancement or retraction commands for the boring tool can only be maintained by continuously holding the joystick in the fore or aft positions. That is, a stop command is issued when joystick 148 is returned to its center position. If the locating receiver were accidentally dropped, the joystick would be released and drilling would be halted. This auto-stop feature will be further described in conjunction with a description of components which are located at the drill rig.
Still referring to FIGS. 2-4, a drill string status display 164 indicates whether the drill rig is pushing on the drill string, retracting it or applying no force at all. Information for presentation of drill string status display 164 along with other information to be described is transmitted from transceiver 106 at the drill rig and to transceiver 146 in the locator/controller. Once the boring tool is headed in a direction which is along a desired path, operator 141 can command the boring tool to proceed straight. As previously described, for straight drilling, the drill string rotates. In the present example, after having turned the boring tool sufficiently to the right, the operator may issue a drill straight command by moving joystick 148 to the left and, thereafter, immediately back to the right. These actuations are monitored by CPU 144 . In this regard, it should be appreciated that CPU 144 may respond to any suitable and recognizable gesture for purposes of issuance of the drill straight command or, for that matter, CPU 144 may respond to other gestures to be associated with other desired commands. In response to recognition of the drill straight gesture, CPU 144 issues a command to be transmitted to the drill rig which causes the drill string to rotate during advancement. At the same time, CPU 144 extinguishes desired roll orientation indicator 160 and actual roll orientation indicator 162 . In place of the roll orientation indicators, a straight ahead indication 170 is presented at the center of the clock display which rotates in a direction indicated by an arrow 172 . It is noted that the straight ahead indication is not displayed in the presence of steering operations which utilize the desired or actual roll orientation indicators. Alternatively, in order to initiate straight drilling, the locator/controller operator may move the joystick to the left. In response, CPU 144 will sequentially move desired roll indicator 160 from the 3 o'clock position, to the 2 o'clock position and back to the 1 o'clock position. Thereafter, the desired roll indicator is extinguished and straight ahead indication 170 is provided. Should the operator continue to hold the joystick to the left, the 12 o'clock desired roll orientation (i.e., steer upward) would next be presented.
In addition to the features already described, display 150 on the locator/controller of the present invention may include a drill rig status display 174 which presents certain information transmitted via telemetry from the drill rig to the locator/controller. The drill rig status display and its purpose will be described at an appropriate point below. For the moment, it should be appreciated that commands transmitted to drill rig 78 from locator/controller 140 may be utilized in several different ways at the drill rig, as will be described immediately hereinafter.
Attention is now directed to FIGS. 2 and 5. FIG. 5 illustrates a first arrangement of components which are located at the drill rig in accordance with the present invention. As described, two-way communications are established by the telemetry link formed between transceiver 106 at the drill rig and transceiver 146 at locator/controller 140 . In this first component arrangement, display 110 at the drill rig displays the aforedescribed commands issued from locator/controller 140 such that a drill rig stationed operator (not shown) may perform the commands. Display 110 , therefore, is essentially identical to display 150 on the locator/controller except that additional indications are shown. Specifically, a push or forward indication 180 , a stop indication 182 and a reverse or retract indication 184 are provided. It is now appropriate to note that implementation of the aforedescribed auto-stop feature should be accomplished in a fail-safe manner. In addition to issuing a stop indication when joystick 148 is returned to its center position, the drill rig may require periodic updates and if the updates were not timely, stop indication 182 may be displayed automatically. Such updates would account for loss of the telemetry link between the locator/controller and the drill rig.
Still referring to FIGS. 2 and 5, the forward, stop and retract command indications eliminate the need for other forms of communication between the drill rig operator and the locator/controller operator such as the walkie-talkies which were typically used in the prior art. At the same time, it should be appreciated that each time a new command is issued from the locator/controller, an audible signal may be provided to the drill rig operator such that the new command does not go unnoticed. Of course, the drill rig operator must also respond to roll commands according to roll orientation display 154 by setting the roll of the boring tool to the desired setting. In this regard, it should be mentioned that a second arrangement (not shown) of components at the drill rig may be implemented with a transmitter at the locator/controller in place of transceiver 152 and a receiver at the drill rig in place of transceiver 106 so as to establish a one-way telemetry link from the boring tool to the drill rig. However, in this instance, features such as operations status display 174 and drill string status display 164 cannot be provided at the locator/controller.
It should be appreciated that the first and second component arrangements described with regard to FIG. 5 contemplate that the drill rig operator may perform tasks including adding or removing drill pipe sections 88 from the drill string and monitoring certain operational aspects of the operation of the drill rig. For example, the drill rig operator should insure that drilling mud (not shown) is continuously supplied to the boring tool so that the boring tool does not overheat whereby the electronics packaged housed therein would be damaged. Drilling mud may be monitored by the drill rig operator using a pressure gauge or a flow gauge. As another example, the drill rig operator may monitor the push force being applied to the drill string by the drill rig. In the past, push force was monitored by “feel” (i.e., reaction of the drill rig upon pushing). However, push force may be directly measured, for instance, using a pressure or force gauge. If push force becomes excessive as a result of encountering an underground obstacle, the boring tool or drill string may be damaged. As a final example, the drill rig operator may monitor any parameters impressed upon locating signal 98 such as, for instance, boring tool temperature, battery status, roll, pitch and proximity to an underground utility. In this latter regard, the reader is referred to U.S. Pat. No. 5,757,190 entitled A SYSTEM INCLUDING AN ARRANGEMENT FOR TRACKING THE POSITIONAL RELATIONSHIP BETWEEN A BORING TOOL AND ONE OR MORE BURIED LINES AND METHOD which is incorporated herein by reference.
Referring to FIG. 5, another feature may be incorporated in the first and second component arrangements which is not requirement, but which nonetheless is highly advantageous with regard to drill rig status monitoring performed by the drill rig operator. Specifically, a rig monitor section 190 may be included for monitoring the aforementioned operational parameters such as drilling mud, push force and any other parameters of interest. As previously described, proper monitoring of these parameters is critical since catastrophic equipment failures or damage to underground utilities can occur when these parameters are out of range. In accordance with this feature, processor 114 receives the status of the various parameters being monitored by the rig monitor section and may provide for visual and/or aural indications of each parameter. Visual display occurs on operations status display 174 . The display may provide real time indications of the status of each parameter such as “OK”, as shown for drilling mud and push force, or an actual reading may be shown as indicated for the “Boring Tool Temperature”. Of course, visual warnings in place of “OK” may be provided such as, for example, when excessive push force is detected. Audio warning may be provided by an alarm 192 in the event that threshold limits of any of the monitored parameters are violated. In fact, the audio alarm may vary in character depending upon the particular warning being provided. It should be mentioned that with the two-way telemetry link between the drill rig and locator/controller according to the aforedescribed first component arrangement, displays 164 and 174 may advantageously form part of overall display 150 on locator/controller 140 , as shown in FIG. 4 . However, such operational status displays on the locator/controller are considered as optional in this instance since the relevant parameters may be monitored by the drill rig operator. The full advantages of rig monitor section 190 and associated operations status display 174 will come to light in conjunction with a description of a fully automated arrangement to be described immediately hereinafter.
Referring to FIGS. 2 and 6, in accordance with a third, fully automated arrangement of the present invention, a drill rig control module 200 is provided at drill rig 78 . Drill rig control module 200 is interfaced with processor 114 . In response to commands received from locator/controller 140 , processor 114 provides command signals to the drill rig control module. The latter is, in turn, interfaced with drill rig controls 116 such that all required functions may be actuated by the drill rig control module. Any suitable type of actuator (not shown) may be utilized for actuation of the drill rig controls. In fact, manual levers may be eliminated altogether in favor of actuators. Moreover, the actuators may be distributed on the drill rig to the positions at which they interface with the drill rig mechanism. For reasons which will become apparent, this third arrangement requires two-way telemetry between the drill rig and locator/controller such that drill string status display 164 and operations status display 174 are provided as part of display 150 on the locator/controller. At the same time, these status displays are optional on display 110 at the drill rig.
Still referring to FIGS. 2 and 6, in accordance with the present invention, using locator/controller 140 , operator 141 is able to issue control commands which are executed by the arrangement of FIG. 6 at the drill rig. Concurrent with locating and controlling the boring tool, operator 141 is able to monitor the status of the drill rig using display 150 on the locator/controller. In this regard, display 174 on the locator/controller also apprises the operator of automated drill rod loading or unloading with indications such as, for example, “Adding Drill Pipe.” In this manner, the operator is informed of reasons for normal delays associated with drill string operations. Since push force applied by the drill rig to the drill string is a quite critical parameter, the present invention contemplates a feature (not shown) in which push force is measured at the drill rig and, thereafter, used to provide push force feedback to the operator via joystick 148 for ease in monitoring this critical parameter. The present invention contemplates that this force feedback feature may be implemented by one of ordinary skill in the art in view of the teaching provided herein. Still other parameters may be monitored at the drill rig and transmitted to locator/controller 140 . In fact, virtually anything computed or measured at the drill rig may be transmitted to the locator/controller. For example, locator/controller 140 may display (not shown) deviation from a desired path. Path deviation data may be obtained, for example, as set forth in U.S. Pat. No. 5,698,981 entitled BORING TECHNIQUE which is incorporated herein by reference. Alternatively, path deviation data may be obtained by using a magnetometer (not shown) positioned in the boring tool in combination with measuring extension of the drill string. With data concerning the actual path taken by the boring tool, the actual path can be examined for conformance with minimum bend radius requirements including those of the drill string or those of the utility line which, ultimately, is to be pulled through the completed bore. That is, the drill string or utility line can be bent too sharply and may, consequently, suffer damage. If minimum bend radius requirements for either the drill string or utility are about to be violated, an appropriate warning may be transmitted to locator/controller 140 . It should be appreciated that with the addition of the drill rig control module, complete remote operation capability has been provided. In and by itself, it is submitted that integrated locating capability and remote control of a boring tool has not been seen heretofore and is highly advantageous. When coupled with remote drill rig status monitoring capability, the present invention provides remarkable advantages over prior art horizontal directional drilling systems.
The advantages of the fully automated embodiment of the present invention essentially eliminate the need for a skilled drill rig operator. In this regard, it should be appreciated that the operator of a walkover locator is, in most cases, knowledgeable with respect to all aspects of drill rig operations. That is, most walkover locator operators have been trained as drill rig operators and then advance to the position of operating walkover locating devices. Therefore, such walkover locator operators are well versed in drill rig operation and welcome the capabilities provided by the present invention.
It should be understood that an arrangement for remotely controlling and tracking an underground boring tool may be embodied in many other specific forms and produced by other methods without departing from the spirit or scope of the present invention. Therefore, the present examples are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.
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A locating and control arrangement forms part of a drilling apparatus which also includes a boring tool that emits a locating signal. The locating and control arrangement is used for locating and controlling underground movement of a boring tool which is operated from a drill rig. The locating and control arrangement includes a portable device for generating certain information about the position of the boring tool in response to the locating signal. The portable device includes a command arrangement forming one portion of the locating and control arrangement for generating at least one movement command such that maintaining the movement command requires a continuous interaction between the portable device and a user, and for transmitting the movement command to the drill rig. A receiving arrangement forms another portion of the locating and control arrangement, located at the drill rig, for receiving the movement command for use in controlling the boring tool responsive to the movement command.
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FIELD OF THE INVENTION
This invention relates to scaffold supports and in particular supports which suspend the scaffold from the roof of a building.
DESCRIPTION OF THE PRIOR ART
When working on roofs in the process of repairing shingling or applying other roofing, it is necessary that the workman be supported in a safe and convenient manner. It has been common in the past to use various forms of scaffold supported on brackets, mounted on ladders, or mounted on the ground. If the scaffold is directly supported from the ground it is evident that substantial construction may be required to raise the scaffold high enough to provide access to the roof. Much time and effort may be expended in building the scaffold to the proper height which adds to the cost and time consumed in the construction or repair of buildings.
It has been proposed in the past to avoid this to some degree by supporting the scaffold from the roof. Typical of a roof supported scaffold is the scaffold shown in U.S. Pat. No. 1,558,425. This scaffold is supported by means of brackets spiked to the roof with the scaffold support pinned onto the brackets to adapt to various roof pitches. While providing a firm and convenient support for the workman while working on the roof, it is evident that the scaffold does not permit access to the whole of the edge of the roof since the mounting brackets and the attachment of the support structure interferes with the surface of the roof near the edge.
An alternative arrangement is shown in U.S. Pat. No. 3,158,223 issued Nov. 24, 1964 which shows a scaffold supported from the roof in which the supports are not attached to the roof but merely maintain their position by their frictional engagement with the roof.
A somewhat similar arrangement is shown in U.S. Pat. No. 4,074,792 which once again is suspended from the roof by members which do not actually fasten to the roof but are merely held in position by their frictional engagement or extended prongs.
These latter patents show inventions which permit access to the edge of the roof but obstruct continued operation and hence are not useful in shingling since the frictional engaging pads interfere with the process of shingling. Also, since there is no positive connection of the pads and the roof, the support is uncertain particularly in the case of steep pitch roofs.
It is desirable to design a roof supported scaffold support which is light and easily portable which permits access and work over the whole of the roof surface without interfering with the shingling process and that provides adequate safety for the workman.
SUMMARY OF THE INVENTION
In accordance with the present invention, a scaffold support bracket is supported from a cleat which is positively but removably secured to the roof in such a manner that shingling or other roofing may be applied over the cleat and yet the cleat may be subsequently removed without damaging the roof surface. The bracket is supported from a point outside the edge of the roof so that the support point does not interfere with the roofing process and the structure of the bracket is such as to provide mounting for additional scaffold planks which provide safety during the continuing roofing process. In addition, the scaffold brackets are sufficiently light and disassembable that they easily may be handled by one man and installed individually, thus minimizing the time required for set-up prior to commencement of roof installation.
A clearer understanding of the invention may be had from a consideration following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of scaffold brackets in their installed position on a building including an enlarged view of a roof cleat.
FIG. 2 is an isometric view of a scaffold bracket in greater detail.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 there is shown a building having a roof 1 ending in a fascia board 2 and a soffit 3 which joins the bottom edge of the fascia 2 to the wall 4 of the building. Mounted on the fascia board 2 is an eaves trough 5. A number of cleats 6, all identical, are fastened to the roof 1 by means of roofing nails. Details of the cleat 6 are shown enlarged. The cleat 6 ends in a hook, as described in more detail subsequently. The scaffold bracket 7, shown in more detail in FIG. 2, consists of an upright member 8 joined at right angles to horizontal member 9. An adjustable extension leg 10 fits within the horizontal member 9 and is adjustable in a manner shown in more detail in FIG. 2. The leg 10 bears against the wall 4 maintaining the upright member 8 perpendicular. A safety rail 11 is provided and supported by safety rail uprights 12 mounted at the outer ends of the horizontal member 9. The scaffold bracket is connected to the hook on the roof cleat 6 by the scaffold bracket angle member 13 which ends in a pin 22 which engages the hook on the cleat 6. In use, a plank 15 is laid across the horizontal members 9 of two or more scaffold brackets and the workman may then stand on the plank and proceed with the normal roofing operation. The shingles, or whatever other material being laid on the roof, may pass completely over the roof cleat 6 which in no way interfere with the roofing process.
After the roofing has proceeded to such a stage that the workman can no longer work conveniently while standing on plank 15, a further plank 14 may be placed between adjacent angle members 13 to provide a foot hold and safety member for the workman while working above the edge of the roof.
Turning now to FIG. 2, it will be seen that the vertical member 8 consists of an upper portion designated 8 and a lower portion designated 8' which fits within the upper portion and is adjustably located relative to portion 8 by means of a locking pin 16 which passes through both members. A plurality of holes in member 8' permit the adjustable location. In a similar manner, extension leg 10 is positioned relative to horizontal member 8 by means of one or more pins 17 which pass through holes in the extension leg 10. The end of the extension leg 10 is provided with a pad 26 distributing the force over an area of the wall 4. A gusset plate 18 joins vertical member 8' to horizontal member 9 to provide the necessary support. At the outer end of horizontal member 9 is mounted a nipple 19 into which the safety rail upright 12 can be slipped, the safety rail upright 12 being a rod with an eye at the top, designated 20. The safety rail 11, which may be a piece of standard pipe, passes through the eye 20 of adjacent scaffold bracket safety rail uprights. The angle support member 13 terminated in a pin 22 which, as has been previously indicated, engages the hook on the end of the cleat 6. A gusset plate 21 fastens the angle member 13 to the upright member 8 to provide the necessary strength. A cleat 23 is welded to the angle member 13, the cleat being of a suitable form to support a plank and a stop 24 is also welded to the angle member spaced from the cleat a sufficient distance to permit a plank to be inserted and held in place. The spacing of the cleat 23 and the stop 24 will depend upon the dimension of the plank intended to be inserted at this point.
As will be seen in the enlarged view in FIG. 1, the roof cleat 6 consists of a fastening plate 27 having nail slots 28 connected by means of a hinge 29 to the hooked end plate 30. An anvil pin 31 is welded onto the fastening plate 27 and onto the portion of the hinge 29 which is fixed to the fastening plate. In the unenlarged view, the fastening plate, rather than having nail slots, is provided with nail holes of a keyhole shape. The upper portion of the holes are sufficient to permit the passage of the shaft of the nail but not the head of the nail. The lower portions are sufficiently large to permit the head of the nail to pass through.
OPERATION
In operation, the workman nails a series of roof cleats 6 to the edge of the roof 1 in such a location that the hinge 29 falls right at the edge of the roof and the hooked end 30 of the cleat hangs straight down against the fascia board 2. With the vertical upright 8 at its desired length, the workman then hooks the pin 5 into the hook at the end of the end plate 30 and adjusts the leg 10 so that the upright 8 is vertical. With a number of scaffold brackets installed in this manner, planks 15 may be laid between members 9 of the adjacent brackets. Safety rail uprights 12 may be inserted in the nipples 19 and suitable safety rail 11 threaded through the eyes 20 at the tops of the uprights. The scaffold is now in position and may be used by the roofer.
In the case of a shingled roof, the first strip of material may now be laid along the edge continuously, proceeding along the scaffold from one end of the roof to the other without interference from the scaffold itself. Roofing may then proceed, covering the roof cleats. After the roof has proceeded to such a stage that it is no longer conveniently accessible from the plank 15, it is possible to adjust the uprights 8 to raise the plank 15 to permit the roofer to reach further up the roof. After a sufficient surface has been laid, the roofer may then proceed onto the roof and work further up.
While working further up on the roof, plank 14 is laid across the angle members 13 held in position by cleat 23 and stop 24 thus providing a safety ledge in case the roofer, while working, slips and slides down towards the edge of the roof.
After the roof is complete, planks 14 can be removed, planks 15 and the safety rail 11 removed. The individual scaffold brackets 7 may now be lifted out of the roof cleats 6 and lowered to the ground. The roof cleats 6 may now be removed by striking the anvil pin 31 which drives the fastening plate 27 up the roof as the hooked plate 30 pivots permitting the fastening plate 27 to move and be driven up as far as it will go. The fastening plate releases from the nails and nail heads either pass through the openings in the bottom of the nail holes or out through the open end of the slots 28 depending on the formation of the roof cleats being used. The anvil pin 31 ensures that the blow struck by the workman in removing the fastening plate is transmitted to the fastening plate and he does not instead strike the hinge and damage the roof cleat. After removal of the roof cleat is complete, no further work is necessary since the cleat has in no way interfered with the installation of the roof.
While no dimensions have been provided, it will be evident to those skilled in the art that the dimensions desirable are those which provide the necessary clearance. For example, the angle and length of the angle member 13 must be such as to provide clearance of normal eaves trough and the end of the pin 22, therefore, should be about 14 centimeters from the upright member 8. The angle of the angle member 13 should be such that the plank 14 is substantially perpendicular to the average pitch of roof. The dimensions of the vertical and horizontal members 8 and 9 should be sufficient to bear the necessary weight of the workman and his materials but should not be so heavy as to make the scaffold support 7 awkward to handle by a single workman. Square steel tubing of about 4 centimeters has been found to be satisfactory for all the members both the vertical and angle members. Naturally, the telescoping members such as extension leg 10 and the vertical member 8' will have to be of somewhat lesser dimension. Pin 22 may be about 2 centimeters in diameter and about 12 centimeters long. The hook at the end of hook plate 30 will be suitably dimensioned to receive pin 22 and preferably the upper outer end of the hook is bent slightly inwardly to permit the pin 22 to snap into place, but not so much as to cause difficulty in installing and removing the pin from the hook.
While specific construction of the various components has been shown, it is evident that many variations may be made within the scope of the invention. It is important, however, in the design and installation of the roof cleat that the hinge 29 is located at the edge of the roof and the hook plate 30 hangs vertically down lying against the fascia board 2. This arrangement ensures that the weight supported by the scaffold bracket applied downward at the hook produces a mechanical couple with the force applied to the wall balanced by an equal pull on the roof cleat fastening plate 27. The pull is therefore primarily parallel to the roof and produces minimal forces tending to pry or lift the cleat off the roof. In other words, the nails holding the cleat to the roof are subject primarily to sheer force and minimal axial pull which minimizes the possibility of the cleat loosening from the roof while in use.
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A scaffold bracket for suspensing scaffolding from a pitched roof in such a manner as to permit roofing up to the edge of the roof without interference, the scaffolding bracket being of such a structure as to permit easy adjustment and installation and subsequent removal, the point of support for the scaffold bracket lying outside the surface of the roof during use.
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STATEMENT OF GOVERNMENT INTEREST IN INVENTION
This invention was made with the United States Government support under the NIST ATP program, award number 70NANB4H3035, awarded by the National Institute of Standards and Technology (NIST). The United States Government has certain rights in the invention.
TECHNICAL FIELD
The present invention relates to large mode area optical fibers and, more particularly, to a large mode area optical fiber exhibiting a refractive index profile particularly designed to minimize the effects of bend-induced reductions in the fiber's effective area.
BACKGROUND OF THE INVENTION
In the field of optical fiber-based communication, there is an increasing interest in the use of large mode area fibers, particularly associated with the fabrication of fiber-based optical amplifiers and the like, since large mode area fibers are known to overcome various nonlinear impairments, such as Raman and Brillouin scattering. The use of large mode area fibers, however, has been found to increase the presence of other fiber-related sensitivities such as macrobend losses, inter-mode coupling and sensitivities to nonuniformities in the fiber's refractive index profile.
There have been at least two different approaches in the prior art to minimize bend-induced losses in optical fiber. In one approach, essentially a mechanical approach, rod-like fibers are utilized that are extremely bend resistant. By forcing the fibers to remain essentially linear, the bend-induced loss can be significantly reduced. However, in most “field” applications of such fibers, there is a need to bend, even spool, such fibers. Therefore, restricting the physical ability of the fiber to bend is considered to be an impractical solution. The other approach is associated with determining a priori a fixed bend loss by defining the specific “spooling” to be used, and then always utilizing the fiber in accordance with the specified spooling radius (and number of turns). Again, this approach is considered to limit the various applications of large area fibers, as well as limit modifications in the field implementations and variations in the use of such fibers.
While these and other designs take into account the bend-induced losses of the fiber mode, the issue of bend-induced distortion remains neglected—specifically, distortion that includes bend-induced reduced effective area. In previous conventional applications using more conventional core dimensions, such mode distortions had minimal impact. However, in large mode fiber applications, the presence of bend-induced mode distortions generates a significant reduction in effective area.
Thus, a need remains in the art for providing a large mode area fiber whose effective area is not seriously distorted as the fiber is subjected to bending in various applications.
SUMMARY OF THE INVENTION
The need remaining in the prior art is addressed by the present invention, which relates to large mode area optical fibers and, more particularly, to a large mode area optical fiber exhibiting a refractive index profile particularly designed to minimize the effects of bend-induced reductions in the fiber's effective area.
In accordance with the present invention, the refractive index profile characteristics of a large mode area optical fiber are based upon both the conventional bend-induced loss parameters, as well as bend-induced distortions impacting the fiber's effective area. The refractive index profile of a large mode area fiber in accordance with the present invention will essentially compensate for bend-induced distortions that will be “seen” by signals as they propagate along the large mode area fiber.
In a manner similar to signal “pre-distortion”, the refractive index profile for a large mode area optical fiber of the present invention is particularly defined in a “pre-bend” fashion such that upon the fiber being bent, the equivalent index profile will have the desired “flat” and “broad” guiding region. It is an aspect of the present invention that the ability to provide the refractive index profile “pre-distortion” may be used with a variety of different types of fibers, including fiber-based amplifiers, photonic bandgap fibers, birefringent fibers, and the like.
In one embodiment of the present invention, a large mode area optical fiber is formed to exhibit an essentially parabolic refractive index profile, where any bending of the fiber functions to merely shift the index profile in a manner such that its parabolic shape is maintained. As a result, the characteristics of the fiber become relatively invariant to bending-related changes.
In an alternative embodiment, a raised-cone refractive index profile has been found to yield a relatively large guiding region with a flat index peak even when the fiber is bent.
Other and further aspects and embodiments of the present invention will become apparent during the course of the following discussion and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings,
FIG. 1 illustrates an exemplary section of large mode area fiber, including a certain “bend” in the fiber shape;
FIG. 2 contains a pair of graphs illustrating the refractive index of the fiber of FIG. 1 , FIG. 2( a ) illustrating the refractive index of a conventional “straight” fiber, and FIG. 2( b ) illustrating the equivalent refractive index of a fiber that is bent as shown in FIG. 1 ;
FIG. 3 illustrates the calculated mode fields as a function of fiber core diameter and bend radius;
FIG. 4 contains a pair of schematic intensity and index plots, with FIG. 4( a ) illustrating the intensity and refractive index profile plots for a “straight” fiber and FIG. 4( b ) illustrating the intensity and refractive index profile plots for a “bent” fiber;
FIG. 5 is a graph of changes in a fiber's effective area as a function of bend radius;
FIG. 6 contains a pair of refractive index profiles, with FIG. 6( a ) illustrating an “ideal” as-fabricated profile associated with a fiber that can then be bent to exhibit the “ideal” flat and broad profile as shown in FIG. 6( b );
FIG. 7 is a graph of a parabolic-shaped refractive index profile fiber, where FIG. 7( a ) illustrates the profile associated with a “straight” fiber and FIG. 7( b ) illustrates the profile associated with a “bent” fiber;
FIG. 8 contains simulation results confirming the stability of the exemplary parabolic profile bend-resistant fiber of the present invention;
FIG. 9 is a plot of an exemplary piecewise-constant arrangement for the parabolic profile fiber of the present invention;
FIG. 10 is a plot of effective area as a function of bend radius for the fiber of FIG. 9 ;
FIG. 11 contains a plot of loss ratio as a function of effective area for the bend-resistant fiber of the present invention;
FIG. 12 is a plot, for the sake of comparison, of an incorrect performance comparison that results from neglecting bend-induced changes in effective area;
FIG. 13 is a plot of the raised-cone refractive index profile of an alternative embodiment of the present invention;
FIG. 14 contains contour plots of the index profile for the “raised-cone” profile for both a straight fiber and a bent fiber; and
FIG. 15 is a plot of effective area vs. bend radius that compares a conventional step-index core fiber to the raised-cone profile for a bend-invariant fiber of the present invention.
DETAILED DESCRIPTION
FIG. 1 illustrates an exemplary section 10 of a large core diameter optical fiber that has been bent to exhibit a defined bend radius. As shown, bent fiber 10 is defined as having a bend radius R bend , with the x-y orientation as shown. The bending of a large core diameter optical fiber, as mentioned above, has been found to introduce distortion in the form of reduced effective area. In particular, the equivalent index model of bent fiber 10 can be determined and then analyzed to account for the different path lengths “seen” by a propagating optical signal at different transverse positions x as it travels around the bend of radius R bend as follows:
ⅆ ( length ) ⅆ ( angle ) = R bend + x ,
where path lengths are adjusted by defining the equivalent index profile n eq 2 ,
n eq 2 ( x , y ) = n 2 ( x , y ) ( 1 + 2 x R bend ) ,
which is considered to be a modified version of the nominal refractive index profile (n 2 ) of the optical fiber material. FIG. 2 illustrates the impact of a bend on the refractive index of fiber, with FIG. 2( a ) showing the refractive index profile for an essentially “straight” section of fiber, and FIG. 2( b ) showing the refractive index profile for a fiber as bent in FIG. 1 . As shown, the equivalent refractive index is shifted upward along a slope defined by the following relation:
Δ
n
=
nx
R
bend
.
The calculated mode fields for exemplary fiber and bend dimensions, as shown in FIG. 3 , illustrate the impact of bending for prior art fibers, one with a moderately large core area (30 μm)—in the top two images; and one fiber with an extremely large core area (50 μm)—in the bottom two images. In each case, the image on the left illustrates the fundamental mode intensity for a “straight” fiber section, and the image on the right illustrates the fundamental mode intensity for a fiber with a 7.5 cm bend radius. For the purpose of illustration, a large mode area fiber with a step-index core shape was used to create these images. Without the use of the bend compensating refractive index profile of the present invention, it is clear that the mode intensity profile of each fiber is perturbed as a result of the bending, with the perturbation being greater for the larger core area fiber. This perturbation will thus result in distortion of an optical signal propagating through the bent optical fiber. The present invention, by virtue of “pre-compensating” the fiber's index profile, will compensate for this distortion and provide a relatively flat “equivalent profile” for the large mode area fiber.
The mode distortion in a bent fiber can best be understood by reference to the intensity and index plots of FIG. 4 , where FIG. 4( a ) illustrates the intensity and refractive index profile plots for a “straight” fiber and FIG. 4( b ) illustrates the intensity and refractive index profile plots for a bent fiber. In the bent fiber, it is clearly shown that the mode intensity plot is distorted, having a more asymmetric and sharply-peaked index. Referring to the refractive index plot of FIG. 4( a ), the straight fiber is shown as able to support a fundamental mode (with an effective index as indicated by reference letter A), as well as a number of higher order modes (HOMs), illustrated by reference letters B and C in the refractive index profile. These modes are shown as being well-confined over the relatively broad transverse region x 1 . In contrast, the refractive index plot of FIG. 4( b ) illustrates that for the case of a bent fiber (conventional fiber), the fiber is able to support a few modes (modes A and B, in this case), and these fewer modes are confined in a narrower guiding region of core X 2 . Confinement is now provided by a fairly narrow, low index trench X 3 . Beyond the trench, on the right-hand side, will be a relatively high index outer cladding region, so that the modes are able to evanescently tunnel out into the cladding, as shown by the arrow in the graph of FIG. 4( b ).
A key parameter affected by bending a large mode area optical fiber is its “effective area”. FIG. 5 illustrates the effective area A eff as a function of bend radius R bend for the same two fibers as analyzed above. In particular, the dashed lines represent the effective areas of the “straight” fibers, and the associated curves illustrate the change in effective area resulting from introducing a bend into the fiber. The curves clearly show that the modes of the larger core area (50 μm) fiber have greatly reduced the effective area for any reasonable bend radius (as indicated by the double-ended arrows between the curve and the dashed line.
The equivalent index model defined above leads to the conclusion that the effect of a bend in a fiber (particularly a large area fiber) can be likened to adding a constant index gradient to the profile of the fiber material itself (assuming low contrast). The tighter the bend, the larger the gradient and the resulting bend-induced distortion will be. As mentioned above, however, conventional optical systems and fiber designs do not take this effect into account. Rather, the prior art has concentrated on various methods to limit/control the amount of bend-induced losses. In accordance with the present invention, however, it is proposed to configure a large core area fiber's refractive index profile to account for both bend-induced losses and bend-induced distortion. Indeed, it has been found that the refractive index profile may be configured (referred to hereinafter as the “as-fabricated” profile) so as to increase the effective area “seen” by an optical signal when the fiber is bent.
FIG. 6 illustrates this basic premise of the present invention, where FIG. 6( b ) contains a refractive index profile plot (refractive index as a function of distance from the center of the core) as desired for most applications (that is, a relatively large and flat region where an optical signal may propagate with experiencing little or no distortion). FIG. 6( a ) shows an “as-fabricated” refractive index profile that is required to provide the resultant “equivalent” index profile of FIG. 6( b ), once the fiber is bent. Although the profile as shown in FIG. 6( a ) would ideally provide the desired profile, it is relatively difficult to replicate in reasonable fashion in most optical fiber manufacturing processes.
Accordingly, a variety of optical fiber “as-fabricated” profiles are proposed that are manufacturable while also providing the pre-compensated aspects that result in flattening the profile once the fiber is bent. As mentioned above, an advantage of the refractive index treatment of the present invention is that it is applicable to virtually any type of optical fiber (large area fiber). Fiber amplifiers, in particular and as will be addressed in further detail below, are considered as one class of fiber types that are particularly well-suited for the use of such pre-compensation. The inventive technique is equally applicable however, to various other types of fibers including, but not limited to, birefringent fiber, photonic bandgap fibers (including air holes or solid-filled holes extending along the longitudinal axis) and fibers including “features” such as UV-sensitized areas or grating features. One particular embodiment of the present invention utilizes a parabolic refractive index profile as the “as-fabricated” profile, where the parabolic profile will be essentially invariant under the addition of a constant gradient (i.e., as the fiber is bent). A parabolic refractive index profile can be defined as:
n ( x, y )= n core −( n core −n clad )( x 2 +y 2 )/ R core 2 .,
which thus defines the profile as being invariant under the addition of a constant gradient. It is then automatically pre-compensated for virtually any bend radius, as long as the associated boundary effects remain relatively small. This property is illustrated in FIG. 7 , which illustrates in FIG. 7( a ) a parabolic-shaped refractive index profile. A truncated version of the profile is illustrated by the darker line in FIG. 7( a ), where for the truncated profile n(x,y)=n core for r>R core . By mathematically completing the square:
n ( x , y ) + B x = n core - Δ n R core 2 ( x 2 + y 2 ) + B x = n core - Δ n R core 2 [ ( x - x d ) 2 + y 2 ] + C ,
where Δn=n core −n clad . Thus, the addition of the bend-induced term Bx is equivalent to a displacement x d , where
x d = B R core 2 2 Δ n ,
and the addition of a constant index shift, C, is defined by:
C
=
x
d
2
R
core
2
Δ
n
.
Such a transformation yields almost no change in mode size or shape as the fiber is bent, as seen by comparing the profile illustrated in FIG. 7( a ) to the profile in FIG. 7( b ). Moreover, a truncated parabolic profile fiber will exhibit some additional immunity to bend-induced reduction of effective area, and will then have better resistance to nonlinear impairments. Bend-induced distortion and displacement of the guided light may also have an important change in the overlap between the light and the gain medium. Pre-compensation of the bend-induced distortion can then have the added benefit of improving the gain overlap seen by the amplified signal. As shown, the parabolic index function is naturally invariant (but translated) under the influence of bending, so that mode fields are largely free of bend-induced distortion, asymmetry, and contraction. As a result of this understanding, it has been found in accordance with this embodiment of the present invention that the effective area can be significantly reduced in a “bent” fiber as compared to modes of the same fiber without a bend. This result is extremely important in the context of a fiber amplifier, since most of the fiber is bent (spooled) when deployed in the field. By pre-compensating the refractive index profile in accordance with the present invention, the overlap between the desired (signal) modes of a propagating signal and the gain medium can be improved, while also reducing the overlap between the undesirable (“noise”) modes and the gain medium. Indeed, a fiber amplifier of the present invention may be formed in a manner similar to conventional fiber amplifiers, using a rare-earth doped core region (a rare earth element such as, for example, erbium, ytterbium and the like). Indeed, the core dopant may be confined to a portion of the core so as to further improve the overlap between the desired signal mode and the gain region, further improving the amplifier's efficiency. Mode-mixing features may also be provided within the fiber amplifier to provide efficient absorption of the pump light within the gain medium. In some cases, a low index outer cladding layer may be formed around the defined cladding region so as to allow for the pump signal to be guided along the cladding region.
FIG. 8 contains simulation results that confirm the stability of the parabolic refractive index profile fiber of this particular embodiment of the present invention. FIG. 8( a ) illustrates the mode field profile for a “straight” fiber with a parabolic profile, and FIG. 8( b ) illustrates the mode field profile for a fiber having a bend radius of 7.5 cm. Comparing these results to the plots shown in FIG. 3 for conventional index-profiled fibers, it is clear that the use of a parabolic index profile results in much less distortion. Even for a fairly tight bend, the mode shows essentially no distortion or contraction.
In a particular configuration of this embodiment of the present invention, the parabolic shape of the refractive index profile may be achieved through piece-wise linear approximation of a number of separate steps, each with a slightly different index. FIG. 9 contains a refractive index profile of such a piecewise-constant index embodiment. The simulated effective area (A eff ) of this fiber is illustrated as the darker curve in FIG. 10 , plotted as a function of bend radius. It is clearly shown that the use of a parabolic index profile results in holding the effective area essentially constant over a bend radius ranging from less than 8 cm to at least 20 cm. For the sake of comparison, the changes in effective area for the 30 μm core prior art fiber (curve II) and 50 μm core prior art fiber (curve III) are also shown in FIG. 10 . It is obvious that the prior art fibers are much more affected by bending of the fiber.
FIG. 11 contains a plot of loss ratio as a function of effective area for the parabolic profile fiber of this embodiment present invention (curve I), as compared to plots for the standard step-index-core fiber as shown in FIG. 2 , and a conventional photonic crystal fiber (formed as a microstructured optical fiber). This plot allows for a comparison of the tradeoff between effective area and higher order modes, where the “best performance” is obtained upwards along the plot (indicating performance as single mode) and to the right (larger mode area). As shown, the parabolic profile fiber of the present invention provides improved performance over prior art fibers according to the measure. For the sake of comparison, FIG. 12 contains the same plot, where bend-induced changes in mode area have been neglected. By ignoring the bend-induced reduction of mode area, it is clear that this plot completely overlooks the potentially important advantages of the parabolic design. This plot further substantiates the need for performing experiments and understanding results based on a “bent” fiber section, particularly in applications where large core area fibers are used.
FIG. 13 contains a refractive index “as fabricated” profile for another embodiment of the present invention, in this case a “raised-cone” index profile, that also results in providing a relatively flat index profile once the fiber is bent. As with the parabolic profile, the raised-cone index profile can be formed as a piecewise approximation with a finite number of constant-index layers. In particular, the index profile for the raised-cone embodiment can be defined as follows:
n ( x , y ) = n core - Ar ( for r < R core ) ; and = n clad ( for r > R core ) ,
where r is defined as the radial distance from the center of the core.
In this case, if the gradient of the cone matches the bend-induced gradient, the resulting equivalent index profile will have a broad and flat guiding region. FIG. 14 illustrates the contour plots of the index profiles for this fiber, with FIG. 14( a ) illustrating the contour plot for a “straight” fiber section and FIG. 14( b ) illustrating the contour plot for a “bent” fiber section. Referring to FIG. 14( b ), it is clear that this particular raised-cone profile results in providing a large-area guiding region with a flat index peak when the fiber is bent.
FIG. 15 is a plot of effective area as a function of bending radius, comparing a step-index fiber of the prior art (dotted curve) with a raised-cone bend-invariant fiber formed in accordance with the present invention (solid curve). It is seen that for bends tighter than about 12 cm, the raised-cone profile yields a larger effective area. Thus, by forming a large mode area fiber with a raised-cone profile, the problems with reduced effective area found in the prior art are eliminated.
In summary, the inventive concept is directed defining an “as-fabricated” refractive index profile that essentially compensates for the bend-induced gradient that will be “seen” by guided light within a bent optical fiber. The “as-fabricated” refractive index profile can, in general terms, be defined as a “conventional” profile, with the bend-induced gradient subtracted from the conventional profile.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. In particular, various other refractive index profile arrangements can be used to “pre-distort” the index profile to take the gradient associated with fiber bending into account. Thus it is intended that the present invention cover the modifications and variations of this invention, provided they come within the scope of claims appended hereto, and their equivalents.
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An optical fiber that exhibits reduced mode distortions as the fiber is bent is formed by properly defining its refractive index profile during fabrication. The as-fabricated profile is defined as a “pre-distorted” profile that takes into account the gradient introduced by bending the fiber. A parabolic index profile is one exemplary bend-resistant profile that exhibits a quadratic form. A raised-cone index is another profile that may be used as the “as-fabricated” profile. In any properly configured form, factors such as bend loss and mode distortion are significantly reduced, since the profile undergoes a shift of essentially constant gradient as a bend is introduced. The resultant effective area of the inventive fiber is substantially improved over state-of-the-art fiber that is subjected to bending during installation. The as-fabricated profile may be incorporated into various types of fibers (birefringent, photonic bandgap, etc.), and is particularly well-suited for use in a fiber amplifier arrangement.
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FIELD OF THE INVENTION
This invention relates to the separation and removal of water from a gas-water mixture using a liquid desiccant, as well as the removal of water from the liquid desiccant such that the liquid desiccant can be reused.
DESCRIPTION OF THE RELATED ART
Natural gas, refinery gas, carbon dioxide, hydrogen, synthesis gas, gas from an oil production facility and other industrial gases are often used in circumstances that require the water in these gases to be removed. Water may be removed, for example, to prevent the formation of hydrates in downstream processes and pipelines, meet dew point specifications for the sale of the gas, and to prevent corrosion associated with wet gas.
There are two general categories of gas dehydration systems; solid desiccant and liquid desiccant. Liquid desiccant systems are relatively simple to operate and easy to maintain. Unfortunately, the liquid desiccant systems are typically unable to produce gases with extremely low levels of moisture. Solid desiccant systems are often used to provide gas with very low levels of moisture, however these plants can be more complex and expensive to operate than liquid desiccant systems. Thus, there is a continuing need for a relatively simple liquid desiccant gas dehydration system that produces gas with the low moisture content normally associated with solid desiccant systems.
Hygroscopic liquids such as triethylene glycol, diethylene glycol and tetraethylene glycol are commonly used liquid desiccants. In the typical liquid desiccant system, a substantially dry glycol such as one of the those listed above is introduced to the top of a contactor. The liquid desiccant flows downward through the contactor while at the same time, wet gas is introduced at the bottom of the contactor. When the liquid desiccant and gas contact each other, the liquid desiccant absorbs water from the gas. Water-rich liquid desiccant is removed from the bottom of the contactor, while dry gas leaves the top of the contactor. Water absorbed by the liquid desiccant is removed by the application of heat and the liquid desiccant is thus regenerated and reused. The dryness of the gas, expressed as its "dew point" depends on several factors, including the water content of the dry liquid desiccant, the number of theoretical stages in the contactor, and the liquid desiccant and gas flow rates. The dew point of the dry gas leaving the contactor decreases as the water content of the dry liquid desiccant entering the contactor decreases. To produce a dry gas with a very low dew point, it is essential that the dry liquid desiccant entering the contactor have an extremely low moisture content.
The regeneration of wet liquid desiccant is typically accomplished by heating it in order to vaporize the water it has absorbed from the wet gas. The concentration of water in a regenerated liquid desiccant depends in part on the regeneration temperature and pressure. Theoretically, it is possible to produce liquid desiccant with very low levels of water by subjecting the liquid desiccant to high temperatures. However, as the regeneration temperature approaches the boiling point of pure liquid desiccant, the liquid desiccant thermally decomposes. To avoid this problem, thermal regeneration of liquid desiccants is usually limited to temperatures below the thermal decomposition point of the liquid desiccant. This results in a relatively high concentration of water in the regenerated liquid desiccant. The higher concentration of water in the liquid desiccant produces dry gas with a higher than desirable dew point. To date, attempts to deal with the problem of producing low dew point gas with a liquid desiccant system have met with limited success.
In one process, described in U.S. Pat. No. 3,105,748, an aliquot of dried natural gas is heated to 325° F. to 365° F. in a gas-fired heater. The gas is passed through wet glycol maintained at the same temperature. This gas strips water from the glycol and produces a regenerated glycol with a lower concentration of water than can be obtained with heat alone at the indicated regeneration temperature. The stripping gas is then either vented or flared. This practice, however, has the undesirable effects of wasting gas and polluting the atmosphere. Moreover, the hot glycol may also contain toxic components such as benzene and toluene, absorbed from the gas that is dried in the process. When stripping gas is applied to the wet glycol, these toxic components are purged in a manner that does not permit their condensation at ambient conditions. While it is possible to compress the stripping gas in order to reuse the gas and facilitate the condensation of its toxic components, this is a high maintenance and high cost solution.
In another process, described in U.S. Pat. No. 3,349,544, an azeotroping agent is introduced below the surface of the liquid desiccant in a regeneration zone. The regeneration zone is maintained at a temperature above the vaporization temperature of the azeotroping agent. A vaporized mixture of water and azeotroping agent is condensed and the water is separated from the azeotrope. The azeotroping agent is then recycled. The azeotroping agent acts as a moisture carrier, allowing the regeneration zone to be operated at a lower partial pressure of water vapor. This produces drier liquid desiccant without subjecting the liquid desiccant to excessively high regeneration temperatures. While this azeotroping agent process produces a regenerated liquid desiccant with a lower moisture content than can be achieved in a conventional liquid desiccant process, the moisture content of the liquid desiccant cannot be reduced below the equilibrium concentration dictated by the partial pressure of water in the regeneration zone.
In an improvement over the process described in U.S. Pat. No. 3,349,544, presented in U.S. Pat. No. 4,005,997, the recovered azeotroping agent is vaporized, superheated to the regeneration temperature and fed to an isothermal stripper in counter current contact with semi-lean hot liquid desiccant produced from the liquid desiccant regenerator. The additional stripping action at the regeneration temperature improves the performance of the azeotroping agent, removing more water than the process described in U.S. Pat. No. 3,349,544. Again, the azeotroping agent is no more than a moisture carrier that further improves the regeneration with additional stripping action. The moisture content of the liquid desiccant cannot be reduced below the equilibrium water content dictated by the operating temperature and pressure.
SUMMARY OF THE INVENTION
This invention is directed to an improved liquid desiccant dehydration of gases wherein the regeneration of wet liquid desiccant to very low levels of moisture enables the process to produce dry gas with extremely low dew points. The invention accomplishes this by stripping partially dehydrated liquid desiccant with a dried stripping agent or "solvent."
One aspect of the invention is to produce a liquid desiccant with a very low moisture content. When this low moisture liquid desiccant is used to dry gas, the moisture content of the dried gas is 0.1 ppm or lower, a level suitable for cryogenic processing.
Another aspect of the invention concerns reducing the moisture content of the solvent used as a stripping agent during the regeneration of the liquid desiccant such that the regenerated liquid desiccant has a moisture content of 10 ppm and lower. This is accomplished by drying the solvent in a solid-liquid contactor containing commercially available solid desiccant such as silica gel, aluminum gel, alumina or molecular sieves.
Additional features of the present invention include the recovery of light hydrocarbons removed from the wet gas for use as solvent, and the separation and removal of noncondensable gases and lighter components from the liquid desiccant.
The liquid desiccant of the invention is a hygroscopic liquid. Representative liquid desiccants are well known in the art and include polyols alone or in a mixture. Typical polyols include liquid compounds such as ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, glycerol, trimethyol propane, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripopylene glycol, tetrapropylene glycol, and mixtures thereof. These glycols contain from 2 to 12 carbon atoms.
Polyol compounds which are normally solid, but which are substantially soluble in anhydrous liquid polyols or liquid hydroxyl amines, may also be used as liquid desiccants. Typical of these solid polyol compounds are erythritol, sorbitol, pentaerythritol and low molecular weight sugars. Typical hydroxyl amines include alkanolamines such as monoethanol amine, diethanol amine, triethanol amine, iso-propanol amine, including mono, di, and tri, isopropanol amine or diglycolamine. The alkanolamines can contain from 2 to 9 carbon atoms.
A stripping agent is employed to regenerate the liquid desiccant to a higher purity. The stripping agent also acts as a solvent that absorbs hydrocarbons that were removed from the wet gas in the contactor by the liquid desiccant. The solvent can be a liquid hydrocarbon, either aliphatic or aromatic, or mixtures thereof, which is substantially insoluble in the liquid desiccant and in water, and which has a boiling temperature between from about 40° C. and about 160° C. A non-hydrocarbon could also be used as a solvent. The non-hydrocarbon solvent would have a boiling range of about 80° C. to about 100° C. for 90% of the mixture with an end point not greater than about 130° C. The specific gravity of the non-hydrocarbon solvent would need to be between about 0.7 to about 0.9 to permit economical solvent-water separation. The solvent will also consist of hydrocarbons removed from the gas that is dried in the contactor. Preferably, the solubility of the solvent in the liquid desiccant should not exceed about 5 percent.
Liquid aliphatic hydrocarbons may include alkanes, cycloalkanes, alkenes, and cycloalkenes with normal boiling points in the range of about 40° C. to about 160° C. Representative aliphatic hydrocarbons include the straight and branched chain monoalkenes and alkanes having from 6 to 10 carbon atoms and mixtures thereof. Representative aromatic hydrocarbons include benzene, toluene, xylene, ethyl benzene, and the like. Representative mixtures of aliphatic and/or aromatic hydrocarbons include petroleum fractions in the desired boiling range such as naphtha and natural gasoline, which can include in the mixture hydrocarbons with number of carbon atoms as low as 3, and as high as 15.
In practicing the invention, substantially dry liquid desiccant is introduced to the top of a contacting zone and wet gas is introduced at the bottom of the contacting zone. The liquid desiccant flows down countercurrent to the gas flow and absorbs water from the gas. The dry gas leaving the contacting zone is suitable for use in applications demanding extremely low dew point gas. The wet liquid desiccant leaving the contacting zone is regenerated for reuse in the contacting zone. The wet liquid desiccant is initially heated and then flashed to remove substantially all dissolved hydrocarbons in the wet liquid desiccant.
The flashed wet liquid desiccant is introduced to a first stripping zone where it is heated and also stripped by vaporized solvent received from the overhead of a second stripping zone, described below. The heat can be provided by a conventional heat exchanger, a direct fired heater, a conventional stripper reboiler or any of the other systems well known to those with skill in the art. The overhead of the first stripping zone contains water, solvent, and light components. The bottoms of the first stripping zone contains partially dehydrated liquid desiccant.
The partially dehydrated liquid desiccant bottoms from the first stripping zone is introduced into a second stripping zone where its water is stripped by dried, vaporized solvent. The overhead of the second stripping zone, which contains vaporized solvent and water removed from the partially dehydrated liquid desiccant, is fed to the first stripping zone, where it acts as a stripping agent.
Solvent, water and other light products from the overhead of the first stripping zone are cooled and decanted in one or more separators. Solvent is recovered from the separator and dried to a very low moisture content in a conventional solid-liquid contacting zone that contains commercially available solid desiccant. The solid desiccant could be silica gel, aluminum gel, alumina or molecular sieves. Two desiccant beds are typically employed. One bed would be on-stream, absorbing water from the solvent, while the other bed is being regenerated and cooled. The solid desiccant is regenerated by passing a heated gas through it. The moist hot vapor stream exiting the regenerating bed can be cooled, condensing the water to facilitate its removal. The regeneration can be accomplished with any hot superheated gas. Readily available gas suitable for regeneration would include dry gas leaving the contactor or vaporized solvent.
Once dried, the solvent is vaporized and used as a stripping agent in the second stripping zone. The use of extremely dry solvent as the stripping agent in the second stripping zone produces a liquid desiccant leaving the second stripping zone with a very low moisture content. When this low moisture content liquid desiccant is used in the contacting zone, it produces dry gas with dew points significantly lower than what can be achieved in the conventional liquid desiccant dehydrators found in the prior art.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic representation of a gas dehydration system according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 represents the preferred embodiment of the present invention. Contacting zone 10 is a conventional gas-liquid contacting column. An inlet 11 for the wet gas is located in the contacting zone below the contacting device, (typically trays or packing). Dried gas is removed from outlet 13. Dry liquid desiccant enters the contacting zone 10 from inlet line 15. Wet liquid desiccant is removed from contactor 10 via line 17.
Wet liquid desiccant flows via line 17 to heat exchanger 20 where it is heated to between about 100° C. and 180° C. by indirect heat exchange with substantially dry liquid desiccant delivered to heat exchanger 20 via line 21. The heated wet liquid desiccant flows via line 19 to flash drum 30 wherein substantially all dissolved hydrocarbons removed from the wet gas by the dry liquid desiccant are flash separated from the wet liquid desiccant.
Flashed gas leaves flash drum 30 and flows via line 31 to cooler 32 where hydrocarbons, water and any liquid desiccant present in the vapor stream are condensed. The cooled stream from cooler 32 flows through line 33 to flash gas separator 34 wherein any noncondensed light ends are separated and vented from the system via line 35. This gas may be flared, utilized as a fuel source or otherwise recovered.
Liquid from flash gas separator 34 which contains hydrocarbons, water and liquid desiccant, leaves flash gas separator 34 via line 37 and joins the flashed wet liquid desiccant flowing from line 39. The combined wet liquid desiccant stream flows through line 41 to first stripping zone 40 wherein the wet liquid desiccant is subjected to heating by reboiler 42 and the stripping by stripping agent received from the overhead of second stripping zone 44, via line 46.
The combined wet liquid desiccant stream from line 41 is heated to about 150° C. to about 205° C. in reboiler 42. The heating of the wet liquid desiccant and the action of the stripping agent remove from about 50% to about 95% of the water originally contained in the combined wet liquid desiccant stream. Vapor from first stripping zone 40 which is at a temperature of about 85° C. to about 100° C., is conveyed via line 45 to condenser 60, where it is partially condensed and cooled to a temperature of about 0° C. to about 40° C. From condenser 60 the cooled stream flows via line 61 to three-phase separator 62. The small amount of vapor that does not condense in condenser 60 may be routed from separator 62 via line 63 to a flare or other system that can accommodate this gas. Condensed water from separator 62 is discharged via line 65 to a conventional water treatment facility. Solvent accumulated in separator 62 exits via line 67 and is routed to pump 70. The solvent is discharged from pump 70 via line 71 and is directed via line 74 to solid desiccant drying bed 75 of the solid desiccant dryer and if necessary, via line 72 as described below. The solid desiccant dryer is comprised of solid desiccant drying bed 75 and solid desiccant bed 76. Solid desiccant drying bed 75 is depicted in drying mode and solid desiccant bed 76 is depicted in regeneration mode. When solid desiccant drying bed 75 is in drying mode, the solvent discharged from pump 70 via line 71 is directed to line 73 to solid desiccant drying bed 76.
In solid desiccant dryer 75 the solvent is dried from an equilibrium water content of about 100 ppm to about 2000 ppm (depending on solvent composition and relevant water retention in hydrocarbon phase) down to about 10 ppm to almost zero ppm. The dried solvent exits solid desiccant drying bed 75 via line 77 and is then heated and vaporized in liquid desiccant cross exchanger 90. When solid desiccant drying bed 76 is in regeneration mode, the dried solvent exits solid desiccant drying bed 76 via line 78 and is then heated and vaporized in liquid desiccant cross exchanger 90. The vaporized solvent may be further superheated in optional superheater 89 before entering the second stripping zone 44 via line 91.
A portion of superheated solvent vapor is diverted from line 91 to line 92 and is used to dry the desiccant in solid desiccant drying bed 76, which is in regeneration mode. Moist superheated solvent vapor leaves solid desiccant dryer bed 76 via line 95 and is conveyed to line 45 via line 98.
Once the moisture in solid desiccant bed 76 is removed by the superheated solvent, the flow of superheated solvent to solid desiccant dryer bed 76 is terminated and solid desiccant drying bed 76 is placed in cooling mode. A portion of dried gas is diverted from line 13 and conveyed via line 14 and then line 94 to solid desiccant dryer bed 76. Dry gas flows through solid desiccant dryer bed 76, cooling the desiccant and then leaves solid desiccant dryer bed 76 via line 95 and is transported via line 97 to a gas flare for disposal. Once the cooling mode is completed for solid desiccant drying bed 76, it can then be placed in drying mode. When solid desiccant drying bed 75 is in regeneration mode and solid desiccant drying bed 76 is in drying mode, a portion of dried gas is diverted from line 13 and conveyed via line 14 and then to line 93 to solid desiccant drying bed 75. Dry gas in this configuration flows through solid desiccant drying bed 76 and upon exiting the bed, flows through line 96 and is transported via line 97 to a gas flare for disposal. Solid desiccant dryer beds 75 and 76 alternate between drying, cooling mode and regeneration mode automatically, every eight hours, or a longer cycle, as solvent drying conditions require.
Hot, partially regenerated liquid desiccant flows from reboiler 42 via line 43 to second stripping zone 44, a conventional stripping column. In second stripping zone 44, substantially all the remaining water in the liquid desiccant is removed by the stripping action of the stripping agent, dry vaporized solvent.. The stripped water and stripping agent leave second stripping zone 44 via line 46 and are delivered to reboiler 42. Liquid desiccant that is substantially dry leaves second stripping zone 44 from outlet line 47 and flows to surge vessel 48. Dry liquid desiccant leaves surge vessel 48 via line 49 and supplies heat for vaporizing the solvent in liquid desiccant cross exchanger 90. The partially cooled dry liquid desiccant leaving cross heater 90 is transported via line 21 to heat exchanger 20. In heat exchanger 20, the partially cooled dry liquid desiccant is further cooled by indirect heat exchange with wet liquid desiccant. The partially cooled dry liquid desiccant is then pumped by liquid desiccant pump 50 to heat exchanger, 51 for further cooling before entering contacting zone 10 via line 15 as described above.
Solvent will be produced if the wet gas stream has adequate amounts of suitable components, such as light hydrocarbons, that are absorbed by the liquid desiccant in contactor 10. This compensates for various solvent circulation losses. If excess solvent is thus produced, it is diverted from the discharge of pump 70 through discharge line 72 to storage or other uses. If the solvent obtained from the wet gas is insufficient to compensate for various solvent circulation losses, fresh solvent is added to the system.
EXAMPLE 1
A wet liquid desiccant solution of aqueous triethylene glycol (TEG) containing approximately 3.5% water was fed at the rate of 5.2 m 3 /hr to a regeneration system as depicted by the apparatus in FIG. 1 including a reboiler 42 placed between a first stripper 40 and a second stripper 44. The first stripper and the second stripper contained respectively 1.8 m meters and 3.0 m meters of 1-inch pall ring packing. The reboiler was operated at 204° C., resulting in a continuous stream of semi-regenerated TEG being fed to the top of the second stripper at 204° C. and contacted with solvent vapors. The solvent vapors were superheated to 227° C. to supply the heat for vaporizing water from the TEG. The solvent flow rate, measured as a liquid after it is pumped by the solvent pump, was maintained at approximately 1.8 m 3 /hr. The overhead vapor from the first stripper was cooled in a water cooled exchanger to 38° C. wherein substantially all water vapor and solvent were condensed. The condensed solvent was separated from the water, dried in the solid bed dryer, and reused. At steady state conditions, the recycled solvent contained less than 1 ppm of water by weight, and the dry liquid desiccant contained less than 10 ppm of water by weight. The regenerated liquid desiccant contained 99.999 wt % TEG. This purity of TEG is capable of reducing the moisture content of the gas exiting the absorber to about 0.1 ppm. The water content of the wet inlet gas varied from 100 to 21 ppm at a contactor pressure of 90 Bar and a contactor temperature of 4° C.
EXAMPLE 2
Example 2 was performed under the same operating conditions as Example 1, with the exception that the condensates from the first stripper overhead were subcooled to 10° C. using a refrigerant at 5° C. At steady state conditions, the solvent in the first stripper overhead contained 92 ppm water by weight. The solvent dryer eliminated virtually all the remaining water in the solvent. The dry liquid desiccant produced by stripping with this solvent contained 12 ppm water by weight and 99.999+ wt % TEG. This dry liquid desiccant can be used to dry a wet industrial gas to a dew point of -80° C. or lower.
EXAMPLE 3
Under the same operating conditions of Example 1, natural gasoline was used as the solvent. The solvent flow rate was maintained at 0.3 liter per liter of wet liquid desiccant. At the steady state conditions, the dry liquid desiccant contained 26 ppm of water by weight. The natural gasoline used as solvent was a debutanized natural gas condensate, consisting of hydrocarbons in the range of C 5 to C 12 . The resultant dried liquid desiccant produced by stripping with dried natural gasoline solvent, was 99.998+ wt % TEG.
EXAMPLE 4
A wet liquid desiccant solution of aqueous diethylene glycol (DEG) containing 5%. water was fed at the rate of 2 liters per hour to an apparatus similar to that described in Example 1. The reboiler was operated at 175° C. and the circulation rate of solvent at 200° C. was maintained at 0.3 liter per liter of wet liquid desiccant. The resulting partially regenerated liquid desiccant leaving the first stripper contained 200 ppm of water by weight. After the partially regenerated liquid desiccant was stripped with dried vaporized solvent, the dry liquid desiccant contained less than 40 ppm of water by weight. The resultant dry liquid desiccant contained 99.99+ wt % DEG.
EXAMPLE 5
A dry liquid desiccant comprised of TEG obtained from the process described in Example 1 was fed to a glycol contactor 10 as depicted in FIG. 1 at the rate of 5.2 m 3 /hr. A wet natural gas saturated with water at 4° C. to 20° C. and 1350 psig to 1800 psig was fed to the bottom of the contactor at the rate of 7.08×10 6 SCMD. The contactor was packed with 20 feet of structured packing. The contactor diameter was 2133 mm.
The dry gas removed from the top of the contactor contained less than 0.1 ppm by weight of water with an equivalent dew point of -85° C. at the operating pressure. The wet liquid desiccant removed from the bottom of the contactor was heated to 150° C. before feeding the flash tank. The flash drum pressure was controlled to 50 psig. The flash gas from the flash drum was cooled to 25° C. in an air cooled exchanger. A sample of the condensate from the exchanger was collected in a solvent-water separator over a period of 24 hours. Analysis indicated that the resultant condensate thus recovered contained hydrocarbons in the C 3 to C 13 range, suitable for use as the solvent in the liquid desiccant regeneration.
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A gas drying method is disclosed in which gas streams are dehydrated to low dew points by contacting the wet gas with a dry liquid desiccant, with the liquid desiccant regenerated by heating it and stripping it with a stripping agent that is dried with solid desiccant.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to collapsible trailer hitches of the type used to retain highway cargo trailers on railway cars or ship decks. The invention specifically relates to pivot mounts for attaching the collapsible hitch to a deck or support surface.
2. Description of the Prior Art
Fifth wheel hitch assemblies used to support cargo trailers hauled on railway cars maintain the trailers positioned on the cars by attachment to the kingpin of the trailer. These support assemblies are collapsible to enable the assembly to retract away from the trailer onto the deck of the railway car so a tractor equipped with a fifth wheel can engage the kingpin and remove the trailer from the railway car. Due to the need for collapsibility these support assemblies are pivotally mounted to the deck or support surface of the railway car by pivot mounts rigidly attached to the railway car. These mounts are subjected to severe force loadings, particularly during abrupt accelerations and decelerations of the railway car while the support assembly is supporting a heavily laden cargo trailer. Past efforts to strengthen the pivot mountings for the support struts have included the need to rigidly attach gussets from the inner sides of the box sill members of the railway car to the pivot mountings as well as to the outside of the box sill members. The need to attach gussets to the inner surfaces of the box sill members and the pivot mountings entails undesirably complicated and costly construction to enable the pivot mountings to transfer strut loadings from the support struts through the pivot mounts to the box sill members without damage to, or failure of, the pivot mountings.
U.S. Pat. No. 3,653,621 shows an angle shaped member which serves as a connective member between the components of a pivot bracket or mount.
SUMMARY OF THE INVENTION
In the field of flat railroad car mounted hitches, a principal purpose of the invention is to provide a reinforcement in the form of an inverted U shaped beam between the pivot mounts of the hitch, whereby the box rigidly attaches the lugs, end members, and base member of a hitch pivot mount structure together.
A further object is to provide a three walled torque box or beam in position and configure it to engage and rigidly maintain components of a strut pivot mount for the fifth wheel support assembly of a railway car in a relationship sufficiently strong to enable the pivot mount to be rigidly affixed to the center sill of a railway car by placement of gussets or the like only between the external or outside surfaces of the box sill members and the pivot mounts or by rigidly attaching the pivot mount directly to the deck of the car without the need to form a direct connection between the box sill members and the pivot mount by going through the deck.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view of a typical fifth wheel cargo trailer support assembly pivotally mounted on a railway car;
FIG. 2 is a top section view of FIG. 1 as indicated by the section line 2--2;
FIG. 3 is a partial cutaway side view of vertical strut pivot mount shown in FIGS. 1 and 2;
FIG. 4 is an enlarged partially cutaway view of the front or vertical strut pivot mount shown in FIG. 2;
FIG. 5 is an enlarged partial cutaway view of the rear or diagonal strut pivot mount shown in FIG. 2; and
FIG. 6 is a partially cutaway side view of the pivot mount shown in FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an elevation view of a typical collapsible cargo trailer fifth wheel hitch assembly 2 pivotally mounted on the deck or support surface 3 of a railway car (not shown). Assembly 2 is comprised of a fifth wheel 4, a front or vertical support strut 5 and a diagonal and collapsible rear support strut 6.
As shown, fifth wheel assembly 2 is pivotally attached adjacent an upper end 7 of support strut 5 by appropriate means such as a pivot pin 8.
An upper end 9 of rear or diagonal strut 6 is pivotally engaged with support strut 5 by a pivot pin 10.
Rigidly affixed to the deck 3 of the railway car is a front or vertical strut pivot mount assembly 11 and a rear or diagonal strut pivot mount assembly 12. Adjacent its lower end 13 strut 5 is pivotally engaged with front pivot mount 11 by pivot pin 14. Similarly, lower end 15 of diagonal strut 6 is pivotally engaged with rear pivot mount 12 by a pivot pin 16.
As shown, pivot mount assemblies 11 and 12 are constructed on a base means, such as support plates 17 and 18, respectively. However, as will be readily understood by those skilled in the art of cargo trailer transport by rail, the pivot mount base means may be the deck or top surface of the railway car.
Also, as will be readily understood by those skilled in the art of cargo trailer transport by rail, the top surface 19 of fifth wheel 4 is adapted to engage the underside support surface of a cargo trailer (not shown) and lockingly receive a kingpin (not shown) on the trailer to maintain the fifth wheel and trailer engaged. Diagonal strut 6 is collapsible intermediate pivot pins 10 and 16 to enable the fifth wheel 4 and vertical strut 5 to rotate about pivot pin 14 and collapse or retract onto surface 3. Typically, diagonal strut 6 is provided with resilient shock absorption means to dampen mechanical shock loads transferred from the railway car through the hitch to the trailer and its cargo.
FIG. 2 shows a top sectioned view of FIG. 1 in which the front mount 11 and rear mount 12 are shown mounted on base means or plates 17 and 18 and the plates are rigidly affixed to the deck 3 of a railway car. As shown, mounts 11 and 12 are preferably mounted astraddle the primary longitudinal support members of the railway car, such as members 20 which form the center sill of the railway car.
FIGS. 3 and 4 show an enlarged cutaway side view and a partial cutaway top view, respectively, of the structure of front or vertical strut pivot mount 11.
Referring to FIG. 4 pivot mount 11 is comprised of a first end member 21 and a second end member 22. As shown, end members 21 and 22 are positioned parallel to each other, spaced from each other and rigidly attached such as by welding, as indicated, to support plate 17.
A first lug member 23 and a second lug member 24 are positioned between end members 21 and 22. First lug member 23 is positioned adjacent, parallel to and in a spaced relationship from first end member 21 and second lug member 24 is positioned adjacent, parallel to and in a spaced relationship to second end member 22. The space 25 between first end member 21 and first lug member 23 and the space 26 between second end member 22 and second lug member 24 are provided to receive an end of a support strut, such as strut 5. As shown lug member 23 and 24 are rigidly affixed to plate 17 by appropriate means, such as welding, as indicated.
A pair of aligned pivot pin receiving openings or aperture means 27 and 28 are provided in each end member, lug member set to receive a pivot pin for pivotally connecting the strut legs of strut 5 to the pivot mount 11.
A three walled formed torque box or beam 29 is positioned transverse and substantially normal to said end members. Box 29, as shown, has first end 30 abutting against and rigidly affixed, such as by welding, to first end member 21 and a second end 31, abutting against and rigidly affixed to end member 22.
Referring to FIG. 3 it will be seen that box 29 is comprised of a first vertically oriented wall 32 having a lower terminal end 33 and an upper end 34 connected with a second horizontally oriented wall 35 and a third vertically oriented wall 36 having an upper end 37 connected with horizontal wall 35 and a lower terminal end 38. The lower terminal ends 33 and 38 of the vertical walls define an open side of box 29. Each of the lower ends of the vertical walls abut and are rigidly secured, such as by welding, to a rigid base means, such as plate 17 to form a torque box structure therewith.
As shown in FIGS. 3 and 4 two slots or openings 39 and 40 are provided in wall 36. Each slot 39 and 40 is aligned to receive a portion of a lug member 23 and 24, respectively. The lug members are rigidly secured to the edges defining the slots 39 and 40 whereby the components of pivot mount 11 are secured together as a strong and rigid assembly.
FIGS. 5 and 6 show an enlarged partially cutaway top view and side view, respectively, of rear or diagonal strut pivot mount 12.
As shown, pivot mount 12 is similar in structure to pivot mount 11.
Pivot mount 12 has two end members 41 and 42, two lug members 43 and 44 and a torque box or beam 45 connected to the end and lug members substantially as described above for pivot mount 11.
Two differences between pivot mount 11 and pivot mount 12 are that the terminal ends 46 and 47 of lug members 43 and 44, respectively, abut against the first vertical wall 48 of beam 45 and each of the end member, lug member sets 41, 43 and 42, 44 are provided with two sets 49, 50 and 51, 52 of aligned pivot pin receiving openings. The provision of two sets of pivot pin openings enable the lower end 15 of diagonal strut 5 to be selectively positioned to receive two types of trailers having different dimensions between the kingpin and the front of the trailer.
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Pivot mounts for enabling pivotal attachment of support struts of a fifth wheel hitch assembly to the deck of a raiway car are provided with a fabricated inverted U shaped torque box or beam fixed transversely between upright pivot mount plates of the center sill mounted hitch on the railway car for structural strength and rigidity. Due to the torque box the mount is sufficiently rigid to preclude the need to attach the pivot mount to the inside of the box sill of a railway car.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to magnetic tape recording apparatuses and methods, magnetic tape reading apparatuses and methods, recording media used therewith, and magnetic tape formats. In particular, the present invention relates to a magnetic tape recording apparatus and method for recording high definition (HD) video data on a magnetic tape, a magnetic tape reading apparatus and method for reading HD video data from a magnetic tape, a magnetic tape format for use in the magnetic tape recording apparatus and method and the magnetic tape reading apparatus and method, and a recording medium used therewith.
2. Description of the Related Art
Along with an advanced compression technique, video data can be compressed and recorded on a magnetic tape according to a digital video (DV) system. A format therefor is defined as a DV format for consumer digital videocassette recorders.
FIG. 1 shows the configuration of one track of the DV format, which relates to the present invention. In the DV format, video data is recorded after being converted by twenty-four-to-twenty-five (24–25) conversion. The numbers of bits, shown in FIG. 1 , indicate values obtained after the 24–25 conversion is performed.
An area of a magnetic tape which corresponds to a winding angle of 174 degrees is used as one substantial track portion. Outside the one track portion, an overwrite margin having a length of 1250 bits is formed. The overwrite margin prevents data from remaining after erasure.
When a rotary head is rotated while synchronizing with a frequency of 60×1000/1001, the one track portion has a length of 134975 bits. When the rotary head is rotated while synchronizing with a frequency of 60 Hz, the one track portion has a length of 134850 bits.
In the one track portion, an insert and track information (ITI) sector, an audio sector, a video sector, and a subcode sector are sequentially arranged in the trace direction (the left-to-right direction in FIG. 1 ) of the rotary head. A gap G 1 is formed between the ITI sector and the audio sector, a gap G 2 is formed between the audio sector and the video sector, and a gap G 3 is formed between the video sector and the subcode sector.
The ITI sector has a length of 3600 bits, and includes a 1400-bit preamble, and a start sync area (SSA) and a track information area (TIA) which have a length of 1920 bits. In the SSA, a bit string (sync number) necessary for detecting the position of the TIA is provided. In the TIA, information representing the consumer DV format, information representing an SP mode or an LP mode, information representing the pattern of a pilot signal in one frame, etc., are recorded. The TIA is followed by a 280-bit postamble.
The gap G 1 has a length of 625 bits.
The audio sector has a length of 11550 bits. Its first 400 bits are used as a preamble, and its last 500 bits are used as a postamble. The intermediate 10650 bits are used as data (audio data).
The gap G 2 has a length of 700 bits.
The video sector has a length of 113225 bits. Its first 400 bits are used as a preamble, and its last 925 bits are used as a postamble. The intermediate 111900 bits are used as data (video data).
The gap G 3 has a length of 1550 bits.
The subcode sector has a length of 3725 bits when the rotary head is rotated at a frequency of 60×1000/1001 Hz, and has a length-of 3600 bits when the rotary head is rotated at a frequency of 60 Hz. Its first 1200 bits are used as a preamble. In the former case, the last 1325 bits are used as a postamble, and in the latter case, the last 1200 bits are used as a postamble. The intermediate 1200 bits are used as data (subcode).
As described above, in the DV format, a so-called “overhead” is long because the ITI sector, the audio sector, the video sector, and the subcode sector not only have the gaps G 1 to G 3 thereamong, but also each have a preamble and a postamble, so that a sufficient data-recording rate cannot be obtained.
As a result, in the DV format, a video rate of, at most, approximately 24 Mbps can be ensured which corresponds to MP@HL in the MPEG system although a bit rate of approximately 25 Mbps is required for recording, for example, HD video data. Accordingly, in the DV format, standard definition (SD) video data can be recorded, but HD video data cannot be compressed by MP@HL, MP@H-14, etc., for recording.
SUMMARY OF THE INVENTION
Accordingly, the present invention is made in view of the foregoing circumstances, and it is an object of the present invention to provide a magnetic tape recording apparatus and method for recording HD video data on a magnetic tape, a magnetic tape reading apparatus and method for reading HD video data from a magnetic tape, a magnetic tape format for use in the magnetic tape recording apparatus and method and the magnetic tape reading apparatus and method, and a recording medium used therewith.
To this end, according to an aspect of the present invention, the foregoing object is achieved through provision of a magnetic tape recording apparatus for recording digital data on a magnetic tape by using a rotary head. The magnetic tape recording apparatus includes a first acquisition unit for acquiring a first group of data including video data, audio data, or search data, a second acquisition unit for acquiring a second group of data including subcode data related to the first group of data, a synthesizing unit for synthesizing data by combining the first group of data and the second group of data so that both groups of data are continuous on the tracks of the magnetic tape without being separated, and a supply unit for supplying the synthesized data to the rotary head so that the synthesized data is recorded on the magnetic tape.
Preferably, the first acquisition unit acquires high definition video data as the video data. The first acquisition unit may further include a compression unit for compressing the high definition video data acquired by the first acquisition unit. The synthesizing unit may perform combination processing on the high definition video data compressed by the compression unit.
The compression unit may compress the high definition video data by using MP@HL or MP@H-14 in the MPEG system.
The magnetic tape recording apparatus may further include a third acquisition unit for acquiring compressed standard definition video data. The high definition video data acquired by the first acquisition unit may include identification information for identifying the high definition video data as the standard definition video data. The synthesizing unit may select either the high definition video data compressed by the compression unit or the standard definition video data acquired by the acquisition unit in order to perform combination processing on the selected video data.
According to another aspect of the present invention, the foregoing object is achieved through provision of a magnetic tape recording method for recording digital data on a magnetic tape by using a rotary head. The magnetic tape recording method includes a first acquisition step for acquiring a first group of data including video data, audio data, or search data, a second acquisition step for acquiring a second group of data including subcode data related to the first group of data, a synthesizing step for synthesizing data by combining the first group of data and the second group of data so that both groups of data are continuous on the tracks of the magnetic tape without being separated, and a supply step for supplying the synthesized data to the rotary head so that the synthesized data is recorded on the magnetic tape.
According to a further aspect of the present invention, the foregoing object is achieved through provision of a computer-readable recording medium containing a program for controlling a magnetic tape recording apparatus which records digital data on a magnetic tape by using a rotary head. The program includes a first acquisition step for acquiring a first group of data including video data, audio data, or search data, a second acquisition step for acquiring a second group of data including subcode data related to the first group of data, a synthesizing step for synthesizing data by combining the first group of data and the second group of data so that both groups of data are continuous on the tracks of the magnetic tape without being separated, and a supply step for supplying the synthesized data to the rotary head so that the synthesized data is recorded on the magnetic tape.
According to a more aspect of the present invention, the foregoing object is achieved through provision of a format for use in a magnetic tape having digital data recorded by a rotary head, in which a first group of data including video data, audio data, or search data, and a second group of data including subcode data related to the first group of data are continuously recorded on the tracks of the magnetic tape without being separated.
According to another aspect of the present invention, the foregoing object is achieved through provision of a magnetic tape reading apparatus including a rotary head for reading a magnetic tape on which a first group of data including compressed high definition or standard definition video data, audio data, and search data, and a second group of data including subcode data related to the first group of data are continuously recorded on the tracks of the magnetic tape without being separated, a first decompression unit: for, among the data read from the magnetic tape by the rotary head, decompressing the compressed high definition video data, a second decompression unit for, among the data read from the magnetic tape by the rotary head, decompressing the compressed standard definition video data, a detection unit for, from the data read from the magnetic tape by the rotary head, detecting identification information for identifying either the high definition video data or the standard definition video data, and a selection unit for selectively controlling, based on the result of detection by the detection unit, one of the first decompression unit and the second decompression unit to process the data read from the magnetic tape by the rotary head.
Preferably, the first decompression unit decompresses the high definition video data by using MP@HL or MP@H-14 in the MPEG system, and the second decompression unit decompresses the standard definition video data by using the digital visual format.
According to another aspect of the present invention, the foregoing object is achieved through provision of a magnetic tape reading method for a magnetic tape reading apparatus for reading, by a rotary head, a magnetic tape on which a first group of data including compressed high definition or standard definition video data, audio data, and search data, and a second group of data including subcode data related to the first group of data are continuously recorded on the tracks of the magnetic tape without being separated. The magnetic tape reading method includes a first decompression step for, among the data read from the magnetic tape by the rotary head, decompressing the compressed high definition video data, a second decompression step for, among the data read from the magnetic tape by the rotary head, decompressing the compressed standard definition video data, a detection step for, from the data read from the magnetic tape by the rotary head, detecting identification information for identifying either the high definition video data or the standard definition video data, and a selection step for selectively controlling, based on the result of detection by the detection step, one of the first decompression step and the second decompression step to process the data read from the magnetic tape by the rotary head.
According to another aspect of the present invention, the foregoing object is achieved through provision of a computer-readable recording medium containing a program for controlling a magnetic tape reading apparatus which uses a rotary head to read a magnetic tape on which a first group of data including compressed high definition or standard definition video data, audio data, and search data, and a second group of data including subcode data related to the first group of data are continuously recorded on the tracks of the magnetic tape without being separated. The program includes a first decompression step for, among the data read from the magnetic tape by the rotary head, decompressing the compressed high definition video data, a second decompression step for, among the data read from the magnetic tape by the rotary head, decompressing the compressed standard definition video data, a detection step for, from the data read from the magnetic tape by the rotary head, detecting identification information for identifying either the high definition video data or the standard definition video data, and a selection step for selectively controlling, based on the result of detection by the detection step, one of the first decompression step and the second decompression step to process the data read from the magnetic tape by the rotary head.
In a magnetic tape recording apparatus and method, and a recording medium used therewith which are in accordance with the present invention, a first group of data and a second group of data are combined to synthesize data so that both groups of data are continuous on the tracks of a magnetic tape without being separated, and the synthesized data is supplied to a rotary head, and is recorded on the magnetic tape.
In a magnetic tape format of the present invention, a first group of data and a second group of data are recorded so as to be continuous on the tracks of a magnetic tape without being separated.
In a magnetic tape reading apparatus and method, and a recording medium used therewith which are in accordance with the present invention, based on the result of detection of identification information that identifies either HD video data or SD video data, processing that decompresses data read from a magnetic tape is selected.
According to the present invention, by synthesizing data in which a first group of data and a second group of data are combined so that both groups of data are continuous on the tracks of a magnetic tape without being separated, and supplying the synthesized data to a rotary head, large amount data, such as HD video signal data, can be recorded on the magnetic tape in digital form.
According to the present invention, a first group of data and a second group of data are recorded on the tracks of a magnetic tape so that both groups of data are continuous without being separated, whereby a magnetic tape that contains large amount data such as HD video signal data is realized.
According to the present invention, by detecting identification information for identifying either HD video data and SD video data, and processing data read from a magnetic tape in accordance with the result of the detection, not only SD video data but also HD video data can be securely read.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a track sector according to the DV format;
FIG. 2 is a block diagram showing an example of a recording system in a magnetic tape recording/reading apparatus to which the present invention is applied;
FIG. 3 is an illustration of the track format of the magnetic tape shown in FIG. 2 ;
FIG. 4 is a graph illustrating a tracking pilot signal recorded on the tracks shown in FIG. 3 ;
FIG. 5 is a graph illustrating a tracking pilot signal recorded on the tracks shown in FIG. 3 ;
FIG. 6 is a graph illustrating a tracking pilot signal recorded on the tracks shown in FIG. 3 ;
FIG. 7 is an illustration of an arrangement of sectors in each of the tracks shown in FIG. 3 ;
FIG. 8 is an illustration of the patterns of the preamble and postamble shown in FIG. 7 ;
FIG. 9 is an illustration of the configuration of the main sector shown in FIG. 7 ;
FIG. 10 is an illustration of the configuration of the subcode sector shown in FIG. 7 ;
FIG. 11 is a block diagram showing an example of a recording system in the magnetic tape recording/reading apparatus to which the present invention is applied;
FIG. 12 is a block diagram showing another example of the recording system in the magnetic tape recording/reading apparatus to which the present invention is applied;
FIG. 13 is an illustration of another example of the recording system in the magnetic tape recording/reading apparatus to which the present invention is applied; and
FIG. 14 is an illustration of the configuration of the TIA.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2 shows an example of a recording system in a magnetic tape recording/reading apparatus to which the present invention is applied. In the magnetic tape recording/reading apparatus, a video data compressor 1 compresses an input HD video signal by the MPEG system such as MP@HL or MP@H-14. An audio data compressor 2 compresses an audio signal corresponding to the HD video signal by, for example, audio compression in the MPEG system. System data including auxiliary (AUX) data and subcode data is input from a controller 13 to a terminal 3 .
A switch 4 is activated by the controller 13 so that an output from the video data compressor 1 , an output from the audio data compressor 2 , or the system data from the terminal 3 is selected with predetermined timing and is supplied to an error-detecting/correcting-code-and-ID adder 5 . The error-detecting/correcting-code-and-ID adder 5 adds an error detecting or correcting code or an identification (ID) to the input data. The error-detecting/correcting-code-and-ID adder 5 also processes the input data so that interleaving among sixteen tracks is performed, and outputs the processed data to the 24–25 converter 6 . The 24–25 converter 6 converts input 24-bit-unit data into 25-bit-unit data by adding one redundant bit to the input data so that a tracking pilot-signal component strongly appears.
A synchronization (sync) generator 7 generates sync data, and preamble and postamble data. The sync data, and preamble and postamble data are added to main data (shown in FIG. 9 ) and a subcode (shown in FIG. 10 ), which are described later.
Under control of the controller 13 , a switch 8 selects either of the output of the 24–25 converter 6 and the output of the sync generator 7 , and outputs the selected output to a modulator 9 . The modulator 9 randomizes the data input via the switch 8 in order to prevent the sequential appearance of ones and zeroes. The modulator 9 also modulates the input data by a method which is adapted for recording on the magnetic tape 21 and which is identical to that used in the DV format, and supplies the modulated data to a parallel/serial converter 10 .
The parallel/serial converter 10 converts the input data from parallel form into serial form. An amplifier 11 amplifies data from the parallel/serial converter 10 , and supplies the amplified data to a rotary head 12 that is provided on a rotary drum (not shown) so that the data is recorded on the magnetic tape 21 .
FIG. 3 shows the format of tracks formed on the magnetic tape 21 by the rotary head 12 . The rotary head 12 traces the magnetic tape 21 from the bottom right to the top left in FIG. 3 . This forms tracks that are inclined to the longitudinal direction of the magnetic tape 21 . The magnetic tape 21 travels from the right to the left in FIG. 3 .
The type of each track is one of the types, F 0 , F 1 , and F 2 in accordance with the type of a tracking-control pilot signal that is recorded on the track. The tracks are formed in the order of F 0 , F 1 , F 0 , F 2 , F 0 , F 1 , F 0 , and F 2 .
On the track F 0 , no pilot signal having either frequency f 1 or f 2 is recorded, as shown in FIG. 4 . Conversely, on the track F 1 , a pilot signal having frequency f 1 is recorded, as shown in FIG. 5 , and on the track F 2 , a pilot signal having frequency f 2 is recorded, as shown in FIG. 6 .
Frequencies f 1 and f 2 are set at 1/90 and 1/60 of a channel bit recording frequency, respectively.
As shown in FIG. 4 , the notches of frequencies f 1 and f 2 each have a depth of 9 dB. In the cases of the tracks F 1 and F 2 , the carrier-to-noise (CNR) of frequency f 1 or f 2 is greater than 16 dB and less than 19 dB, as shown in FIGS. 5 and 6 . The depth of the notch of frequency f 1 or f 2 is greater than 3 dB.
A track pattern having the above-described frequency characteristics is similar to that in the DV format. Accordingly, magnetic tapes, rotary heads, driving systems, demodulation systems, and control systems in consumer video tape recorders can be directly used also in this embodiment.
A tape speed and a track pitch are recorded similarly to those in the DV format.
FIG. 7 shows an example of an arrangement of sectors in each track. In FIG. 7 , the number of bits in each sector is indicated by a length obtained after performing the 24–25 conversion. One track has a length of 134975 bits when the rotary head 12 is rotated at a frequency of 60×1000/1001 Hz, and has a length of 134850 bits when the rotary head 12 is rotated at a frequency of 60 Hz. The length of one track corresponds to a winding angle of 174 degrees at which the magnetic tape 21 is wound. After the one track, a 1250-bit overwrite margin is formed. The overwrite margin prevents data from remaining after erasure.
In FIG. 7 , the rotary head 12 traces the magnetic tape 21 from the left to the right. At the top, a 1800-bit preamble is positioned. In this preamble, clock-generating data having the pattern A and pattern B shown in FIG. 8 are recorded in combination. Patterns A-and B are reverse to each other such that zeroes and ones are reversed. By appropriately combining patterns A and B, the tracking patterns of the tracks F 0 , F 1 , and F 2 shown in FIGS. 4 to 6 can be formed. The run pattern in FIG. 8 indicates a pattern obtained after the 24–25 converter 6 ( FIG. 2 ) performs the 24–25 conversion.
In FIG. 7 , next to the 1800-bit preamble, a main sector having a length of 130425 bits is positioned. The configuration of the main sector is shown in FIG. 9 .
As shown in FIG. 9 , the main sector consists of 141 sync blocks. Each sync block has a length of 888 bits (111bytes).
Among the 141 sync blocks, first 123 sync blocks consists of a 16-bit sync (data), a 24-bit ID, an 8-bit sync block (SB) header, 760-bit main data, and an 80-bit parity C 1 . The sync is generated by the sync generator 7 . The ID is added by the error-detecting/correcting-code-and-ID adder 5 . The SB header includes identification information for identifying the main data as a type of data among audio data, video data, video data for searching, transport stream data, AUX data, etc. The SB header data is supplied as a type of system data from the terminal 3 to the controller 13 .
When the main data is video data, it is supplied from the video data compressor 1 . When the main data is audio data, it is supplied from the audio data compressor 2 . When the main data is AUX data, it is supplied from the controller 13 via the terminal 3 .
For each sync block, based on the ID, the SB header, and the main data, the parity C 1 is calculated and is added by the error-detecting/correcting-code-and-ID adder 5 .
Among the 141 sync blocks, 18 sync blocks each consist of the sync, the ID, and the parities C 2 and C 1 . The parity C 2 is found by vertically calculating the SB header or the main data. This calculation is performed by the error-detecting/correcting-code-and-ID adder 5 .
The total data amount of the main sector is 888 bits×141 sync blocks=125208 bits, and the total data amount obtained after performing the 24–25 conversion is 130425 bits. In this case, when the rotary head 12 is rotated while synchronizing with a frequency of 60 Hz, if one frame consists of ten tracks, a substantial maximum data rate is, on average, 760 bits×123 sync blocks×10 tracks×30 Hz=28.044 Mbps. This bit rate is sufficient for recording HD video data according to MP@HL or MP@H-14, compressed audio data, AUX data, and video data for searching.
Next to the main sector, a 1250-bit subcode sector is positioned. The configuration of the subcode sector is shown in FIG. 10 .
The subcode sector for one track consists of ten subcode sync blocks. Each subcode sync block consists of a sync, an ID, subcode data, and a parity.
At the top of each subcode sync block in the subcode sector having 1250 bits (a length obtained after performing the 24–25 conversion), the sync, which has a length of 16 bits, is positioned, and the ID, which has a length of 24 bits, follows in which the lengths are values before performing the 24–25 conversion. The sync is added by the sync generator 7 , and the ID is added by the error-detecting/correcting-code-and-ID adder 5 .
Next to the ID, 40-bit subcode data is positioned. The subcode data is supplied from the controller 13 via the terminal 3 , and includes, for example, a track number and a time code number. After the subcode data, a 40-bit parity is added. The parity is added by the error-detecting/correcting-code-and-ID adder 5 .
After the 24–25 conversion is performed, each subcode sync block that has 120 bits before the 24–25 conversion is performed has 125 (=120×25/40) bits.
The subcode sector is followed by a postamble. This postamble is also recorded by combining the patterns A and B in FIG. 8 . The length of the postamble is 1500 bits when the rotary head 12 is rotated while synchronizing with a frequency of 60×1000/1001 Hz, and is 1375 bits when the rotary head 12 is rotated while synchronizing with a frequency of 60 Hz.
Next, the operation of the a magnetic tape recording/reading apparatus shown in FIG. 2 is described below.
The HD video signal is input to and compressed by the video data compressor 1 using, for example, MP@HL or MP@H-14, with video data for searching (thumbnail video data). The audio data is input to and compressed by the audio data compressor 2 . The controller 13 supplies system data such as subcode data, AUX data, and a header to the terminal 3 .
Under control of the controller 13 , the switch 4 acquires, with predetermined timing, the video data (including the video data for searching) from the video data compressor 1 , the audio data from the audio data compressor 2 , or the system data from terminal 3 , and outputs them to the error-detecting/correcting-code-and-ID adder 5 , whereby they are combined.
The error-detecting/correcting-code-and-ID adder 5 adds a 24-bit ID to each sync block ( FIG. 9 ) of the main sector. For each sync block, the parity C 1 ( FIG. 9 ) is calculated and added, and instead of the SB header and the main data, the parity C 2 is added to the last 18 sync blocks among the 141 sync blocks.
As shown in FIG. 10 , the error-detecting/correctingcode-and-ID adder 5 adds the 24-bit ID to each subcode sync block of the subcode sector. Also, in the error-detecting/correcting-code-and-ID adder 5 , a 40-bit parity is calculated and added.
The error-detecting/correcting-code-and-ID adder 5 holds data corresponding to sixteen tracks, and interleaves the data among the sixteen tracks.
The 24–25 converter 6 converts the input data in 24-bit units into data in 25-bit units. By performing the 24–25 conversion, tracking pilot signal components including the frequencies f 1 and f 2 strongly appear.
The sync generator 7 adds a 16-bit sync to each sync block of the main sector, as shown in FIG. 9 . The sync generator 7 adds a 16-bit sync to each subcode sync block, as shown in FIG. 10 . The sync generator 7 generates the run pattern ( FIG. 8 ) for the preamble or postamble.
The above-described data addition (combination) is more specifically performed such that the controller 13 controls the switch 8 to perform switching so that data output from the sync generator 7 and data output from the 24–25 converter 6 are appropriately selected and supplied to the modulator 9 .
In the modulator 9 , the input data is randomized and modulated by a method adapted for the DV format, and the modulated data is output to the parallel/serial converter 10 . The parallel/serial converter 10 converts the input data from serial form into parallel form, and supplies the converted data to the rotary head 12 via the amplifier 11 . The human resources 12 records the supplied data on the magnetic tape 21 .
FIG. 11 shows an example of a reading system for reading the data recorded on the magnetic tape 21 .
The data recorded on the magnetic tape 21 is read and output to an amplifier 41 by the rotary head 12 . In the amplifier 41 , the input signal is amplified and supplied to an analog-to-digital (A/D) converter 42 . In the A/D converter 42 , the input signal is converted from analog form to digital form. The digital signal is supplied to a demodulator 43 . The demodulator 43 derandomizes the supplied data correspondingly to the randomizing in the modulator 9 , and demodulates the supplied data correspondingly to the modulation method used in the modulator 9 .
In the sync detector 44 , from the data modulated by the demodulator 43 , the sync of each sync block in the main sector shown in FIG. 9 , and the sync of each sync block in the subcode sector shown in FIG. 10 are detected and supplied to the error-correcting-code-and-ID detector 46 . A twenty-five-to-twenty-four (25–24) converter 45 converts; data supplied from the demodulator 43 from 25-bit-unit data to 24-bit-unit data so that the 25–24 conversion corresponds to the conversion by the 24–25 converter 6 . The 25–24 converter 45 outputs the converted data to an error-correcting-code-and-ID detector 46 .
The error-correcting-code-and-ID detector 46 performs, based on the sync from the sync detector 44 , error correction, ID detection, and deinterleaving. Under control of the controller 13 , a switch 47 outputs, among the data output from the error-correcting-code-and-ID detector 46 , video data (including video data for searching) to a video data decompressor 48 , outputs audio data to an audio data decompressor 49 , and outputs system data that includes subcode data and AUX data to the controller 13 via a terminal 50 .
In the video data decompressor 48 , the input video data is decompressed and digital-to-analog-converted, and the converted data is output as an analog video signal. In the audio data decompressor 49 , the input audio data is decompressed and digital-to-analog-converted, and the converted data is output as an analog audio signal.
Next, the operation of the reading system is described below.
The data recorded on the magnetic tape 21 is read by the rotary head 12 , and is amplified by the amplifier 41 . The amplified data is supplied to the A/D converter 42 . The data is converted into digital data by the A/D converter 42 . The digital data is input to the demodulator 43 , and is derandomized and demodulated using a method corresponding to the randomizing and demodulation by the modulator 9 shown in FIG. 2 .
An output from the A/D converter 42 is supplied to a servo circuit (not shown). The servo circuit performs tracking control by reading the data of pattern A and the data of pattern B ( FIG. 8 ), which are recorded in the preamble and the postamble, and generating a tracking pilot signal.
The 25–24 converter 45 converts the data demodulated by the demodulated by the demodulator 43 from 25-bit-unit data to 24-bit-unit data, and outputs the converted data to the error-correcting-code-and-ID detector 46 .
The sync detector 44 detects the main sector ( FIG. 9 ) or the sync of the subcode sector ( FIG. 10 ) from the data output from the demodulator 43 , and supplies them to the error-correcting-code-and-ID detector 46 . The error-correcting-code-and-ID detector 46 stores sixteen track data and performs deinterleaving, and performs error correction using the parities C 1 and C 2 in the main sector shown in FIG. 9 . Also, the error-correcting-code-and-ID detector 46 detects the SB header of the main sector, and determines the type of data included in each sync block, among plural types of data such as audio data, video data, AUX data, and video data for searching.
The error-correcting-code-and-ID detector 46 uses the parity in the subcode sync block ( FIG. 10 ) to perform error-correction processing on subcode data. The error-correcting-code-and-ID detector 46 also detects each ID, and determines the type of the subcode data corresponding to the detected ID. Accordingly, it is determined that the subcode data represents a track number or that the subcode data represents a time code number.
Based on the SB header detected by the error-correcting-code-and-ID detector 46 , the switch 47 supplies the video data and the video data for searching to the video data decompressor 48 . The video data decompressor 48 decompresses the input data by using a method corresponding to the compression method in the video data compressor 1 shown in FIG. 2 , and outputs the decompressed data as a video signal.
The switch 47 outputs the audio data to the audio data decompressor 49 . The audio data decompressor 49 decompresses the input audio data by using a method corresponding to the compression method in the audio data compressor 2 shown in FIG. 2 , and outputs the decompressed data as an audio signal.
The switch 47 also outputs data output from the error-correcting-code-and-ID detector 46 , such as AUX data and subcode, from the terminal 50 to the controller 13 .
FIG. 12 shows a second example of the recording system. In the second example, similarly to the case shown in FIG. 2 , an HD video signal and a corresponding audio signal (HD audio signal), and system data (HD system data) can be recorded on the magnetic tape 21 by using the MPEG system. In addition, in the consumer DV format as in the conventional recording, an SD video signal, an SD audio signal, and SD system data can be recorded.
Specifically, the second example, ( FIG. 12 ) includes, an MPEG recording-signal processor 61 that includes a video data compressor 1 , an audio data compressor 2 , a terminal 3 , a switch 4 , and an error-detecting/correcting-code-and-ID adder 5 as shown in FIG. 2 , and a (consumer) DV recording-signal processor 62 . Under control of a controller 13 , a switch 63 selects either one of an output from the MPEG recording-signal processor 61 and an output from the DV recording-signal processor 62 , and supplies the selected one to a 24–25 converter 6 .
The second example ( FIG. 12 ) also includes an insert and track information (ITI) generator 64 . The ITI generator 64 generates data of the ITI sector as shown in FIG. 1 , and supplies the data to a switch 8 . The switch 8 selects one of an output from the 24–25 converter 6 , an output from a sync generator 7 , and an output from the ITI generator 64 , and outputs the selected one to a modulator 9 . The other points in configuration are identical to those in the case shown in FIG. 2 .
In other words, in the second example, similarly to the case shown in FIG. 2 , an HD recording signal and a corresponding HD audio signal, and HD system data are recorded on the magnetic tape 21 . The operation of the second example is omitted since it is identical to that in the case shown in FIG. 2 . In addition, the DV recording-signal processor 62 performs DV-format signal processing on an input SD signal and a corresponding SD audio signal, and SD system data.
The data output from the DV recording-signal processor 62 is supplied to the 24–25 converter 6 via the switch 63 , and is converted from a 24-bit-unit from to a 25-bit-unit form. The switch 8 selects, with predetermined timing, one of an output from the 24–25 converter 6 , a sync, a preamble or a postamble that is output from the sync generator 64 , and data (the data of the ITI sector shown in FIG. 1 ) output from the ITI generator 64 , and outputs the selected one to the modulator 9 . The modulator 9 modulates the input data, and outputs the modulated data to a parallel/serial converter 10 for conversion from parallel form to serial form. The serial data output from the parallel/serial converter 10 is amplified by an amplifier 11 , and the amplified data is recorded on the magnetic tape 21 by a rotary head 12 .
As described above, on the magnetic tape 21 , the data is recorded on a DV format track as shown in FIG. 1 .
The error-detecting/correcting-code-and-ID adder 5 (as shown in FIG. 2 ) of the MPEG recording-signal processor 61 records, in the ID of the main sector ( FIG. 9 ) and in the ID of the subcode sector ( FIG. 10 ), identification information indicating that the presently recorded data is data compressed by the MPEG system.
As the DV recording-signal processor 62 , the 24–25 converter 6 , the ITI generator 64 , the switch 8 , the modulator 9 , the parallel/serial converter 10 , the amplifier 11 , and the rotary head 12 (shown in FIG. 12 ), those used in a conventional consumer DV system can be used without being changed. Among these components, the 24–25 converter 6 , the switch 8 , the modulator 9 , the parallel/serial converter 10 , the amplifier 11 , and the rotary head 12 can be used in common in cases in which the SD video signal is recorded and in which the HD video signal is recorded.
FIG. 13 shows an example of a reading system corresponding to the recording system shown in FIG. 12 . In this example, an ID detector 81 detects the ID of the main sector ( FIG. 9 ) or the ID of the subcode sector ( FIG. 10 ), and recognizes that data which is being read is HD video signal data compressed using the MPEG system. The ID detector 81 also detects APT 2 , APT 1 , and APT 0 that are recorded in the TIA of the ITI sector shown in FIG. 1 . As shown in FIG. 14 , the values of APT 2 , APT 1 , and APT 0 are “000” in the consumer digital videocassette recorder. Accordingly, these values make it possible to recognize that data which is being read is SD video signal data according to the consumer DV system.
Based on the recognition result, when HD video signal data is being read, the ID detector 81 switches the switch 82 to be connected to an MPEG-recording-signal processor 83 , and allows a 25–24 converter 45 to supply its output to the MPEG-recording-signal processor 83 . When SD video signal data is being read, the ID detector 81 switches the switch 82 to be connected to a consumer-DV-read-signal processor 84 , and allows the 25–24 converter 45 to supply its output to the consumer-DV-read-signal processor 84 .
The MPEG-recording-signal processor 83 includes the sync generator 44 , the error-correcting-code-and-ID detector 46 , the switch 47 , the video data decompressor 48 , the audio data compressor 49 , and the terminal 50 , which are shown in FIG. 11 .
The other points in configuration are identical to those in the case shown in FIG. 11 .
In other words, in the reading system shown in FIG. 13 , based on the data output from the demodulator 43 , the ID detector 81 determines whether the read data is MPEG data (HD video signal data) or consumer DV data (SD video signal data). If the read data is MPEG data, the data output from the 25–24 converter 45 is supplied via the switch 82 to and processed in the MPEG-recording-signal processor 83 . The processing in this case is similar to that in the case shown in FIG. 11 .
Conversely, if the ID detector 81 has determined that the data output from the demodulator 43 is consumer-DV-format data, the ID detector 81 switches the switch 82 so that the output from the 25–24 converter 45 is supplied to the DV-read-signal processor 84 . The DV-read-signal processor 84 performs DV-format decompression processing on the input data, and outputs the processed data as an SD video signal, an SD audio signal, and SD system data.
Among the components shown in FIG. 13 , the rotary head 12 , the amplifier 41 , the A/D converter 42 , the demodulator 43 , and the 25–24 converter 45 can be used-in common in cases in which an SD signal is read and in which an HD video signal is read.
Although the above-described successive processing can be executed by hardware, it may be executed by software. In a case in which software is used to execute the above-described successive processing, programs constituting the software are installed from recording media in a computer that is built into dedicated hardware, or in, for example, a general-purpose personal computer in which various functions can be executed by installing various programs therein.
As shown in FIGS. 2 , and 11 to 13 , the recording media include package media composed of a magnetic disk 31 (including a floppy disk), an optical disk 32 (including a compact-disk read-only memory and a digital versatile disk), a magneto-optical disk 33 (including a Mini-Disk), and a semiconductor memory 34 , which are distributed separately from the magnetic tape recording/reading apparatus in order to provide the user with programs and which contain the programs. The recording media also include a program-recorded read-only memory or a hard disk that is provided to the user in a form in which it is built into the magnetic tape recording/reading apparatus.
In this Specification, steps that describe each program recorded in the recording media specifically include time-sequential processes that are executed in the order given, and include processes that are executed separately or in parallel although the processes are not sequentially executed.
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A magnetic tape recording apparatus uses a rotary head to record digital data on a magnetic tape. The magnetic tape recording apparatus includes a first acquisition unit for acquiring a first group of data including video data, audio data, or search data, a second acquisition unit for acquiring a second group of data including subcode data related to the first group of data, a synthesizing unit for synthesizing data by combining the first group of data and the second group of data so that both groups of data are continuous on the tracks of the magnetic tape without being separated, and a supply unit for supplying the synthesized data to the rotary head so that the synthesized data is recorded on the magnetic tape.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims the priority based on Japanese Patent Applications No. 2007-162216 filed on Jun. 20, 2007 and No. 2008-133804 filed on May 22, 2008, the disclosures of which are hereby incorporated by reference in its entirety.
BACKGROUND
1. Technical Field
The present invention relates to a fluid ejection device for ejecting a fluid, and particularly to a structure by which fluid-containing packs containing fluid for ejection are positioned within the fluid ejection device.
2. Related Art
Printers of ink jet format, which eject drops of ink onto thin sheets of a recording medium such as paper or plastic in order to record text or images thereon, are a representative type of fluid ejection device. Other types of fluid ejection devices include those adapted for use in display production systems employed in the production of liquid crystal displays, plasma displays, organic EL (Electro Luminescence) displays, field emission displays (FED), and the like, and used for ejecting various types of liquid materials to form coloring material, electrodes, etc. in the pixel regions or electrode regions.
A typical fluid ejection device is equipped with a carriage on which rides an ejection head for ejecting fluid onto an ejection target; the location for fluid ejection onto the ejection target is adjusted by moving either the carriage or the recording medium, or both. Where a fluid ejection device employs a system in which a container portion containing fluid for ejection is positioned apart from the carriage (known as an off-carriage system) it will be possible to reduce the load associated with driving the carriage. Patent Citation JP 2005-47258 A discloses such a printer of off-carriage type in which an ink cartridge containing ink packs is inserted into the printer unit.
SUMMARY
However, in the past, sufficient consideration was not given to a design able to accommodate fluid containers of larger capacity. For example, there were problems such as the difficulty of ensuring sufficient space within the unit between the fluid containers and other structures; and damage to other structures inside the unit due to operator error when installing the fluid container within the unit.
In view of the issues discussed above, it is an object of the invention to provide a fluid ejection device able to accommodate larger capacity fluid containers.
An advantage of some aspects of the invention is intended to address this issue at least in part, and can be reduced to practice as described below.
A fluid ejection device according to an aspect of the invention is a fluid ejection device ejecting a fluid, the fluid ejection device includes: a fluid container; a fluid ejection unit; a delivery needle; a guard cover; and a guide. The fluid container includes a container portion and a withdrawal portion. The container portion contains a fluid for ejection, and the withdrawal portion allows withdrawal of the fluid contained in the container portion. The fluid ejection unit ejects a fluid onto an ejection target. The delivery needle provides a flow passage which communicates with the fluid ejection unit. The guard cover projects over the delivery needle. The guide mates with the fluid container, and then slidably guides the withdrawal portion toward a locking position where the delivery needle sticks through the withdrawal portion. According to the above-mentioned fluid ejection device, since the guard cover is disposed projecting out so as to cover the delivery needle, it is possible to prevent accidental damage to the delivery needle during securing of the fluid container to the container case.
A method of manufacturing according to an aspect of the invention is a method of manufacturing a fluid ejection device including a fluid ejection unit that ejects a fluid onto an ejection target, a delivery needle that provides a flow passage which communicates with the fluid ejection unit, and a guard cover that projects over the delivery needle, the method comprising: providing a fluid container that includes a container portion and a withdrawal portion, wherein the container portion contains a fluid for ejection, and the withdrawal portion allows withdrawal of the fluid contained in the container portion; mating the fluid container with a guide that extends approximately aligned with a center axis of the delivery needle; and sliding the fluid container mated with the guide toward a locking position where the delivery needle sticks through the withdrawal portion away from the guard cover. According to the above-mentioned method, since the fluid container is mated with the guide at a location away from the guard cover disposed projecting so as to cover the delivery needle, and the fluid container can then be subsequently slid into the locking position and secured, it is possible to prevent damage to the delivery needle during securing of the fluid container to the container case.
The invention is not limited to being embodied as a fluid ejection device, and may be reduced to practice as a method for manufacture thereof, or other mode having a structure for accommodating fluid-containing packs. The invention should not be construed as limited to the embodiments set forth hereinabove, and naturally various modifications such as the following may be made herein without departing from the scope of the invention.
These and other objects, features, aspects, and advantages of the invention will become more apparent from the following detailed description of the preferred embodiments with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with reference to the accompanying drawings in which:
FIG. 1 is an illustration depicting in simplified form a configuration of a printer;
FIG. 2 is a sectional view depicting in simplified form the configuration of the printer with the upper chassis unit closed;
FIG. 3 is a sectional view depicting in simplified form the configuration of the printer with the upper chassis unit open;
FIG. 4 is a top view showing the interior of the upper chassis unit;
FIG. 5 is an illustration depicting fastening of holders carrying ink packs within the upper chassis unit;
FIG. 6 is an illustration depicting an ink pack prior to connection with the ink delivery section, viewed in A-A cross section in FIG. 4 ;
FIG. 7 is an illustration depicting an ink pack connected with the ink delivery section, viewed in A-A cross section in FIG. 4 ;
FIG. 8 is an illustration depicting a configuration of a printing mechanism section of a printer;
FIG. 9 is a flowchart depicting a method of manufacturing the printer;
FIG. 10 is a top view showing the interior of the upper chassis unit; and
FIG. 11 is a sectional view depicting in simplified form the configuration of a printer, shown with the upper chassis unit closed;
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A better understanding of the constitution and advantages of the invention set forth above will be provided through the following description of the invention embodied in a fluid ejection device. In the embodiment, a printer of ink-jet type will be described as an example representative of a picture recording device, as one embodiment of a fluid ejection device.
A. Embodiment
FIG. 1 is an illustration depicting in simplified form the design of a printer 10 . The printer 10 is a printer of ink-jet type which records text and images by ejecting ink drops onto a recording medium, namely, printer paper 900 . The printer 10 includes a main chassis unit 20 which houses a printing mechanism section 50 constituting the fluid ejecting portion for ejecting ink drops onto the printer paper 900 ; the main chassis unit 20 houses a paper feed tray 12 for loading into the interior of the main chassis unit 20 the printer paper 900 which is to be supplied to the printing mechanism section 50 , as well as a paper output tray 14 for guiding out from the main chassis unit 20 the printer paper 90 which has been discharged from the printing mechanism section 50 . The specifics of the design of the printing mechanism section 50 will be discussed later.
Also housed in the main chassis unit 20 is a controller section 40 for controlling the various parts of the printer 10 . In the embodiment, the controller section 40 includes ASICs (Application Specific Integrated Circuits) furnished with hardware such as a central processing unit (CPU), read only memory (ROM), and random access memory (RAM). Software for accomplishing the various functions of the printer 10 is installed in the controller section 40 .
On the upper face of the main chassis unit 20 is installed an upper chassis unit 30 which constitutes the container case for accommodating a plurality of ink packs 310 which constitute the container portions respectively containing liquid inks of different colors. The upper chassis unit 30 is pivotably attached to the main chassis unit 20 so as to open and close about a rotation shaft 350 .
In the embodiment, the ink packs 310 take the form of flat bag portions of generally rectangular shape made of pliable sheeting and having generally elliptical cross section; a pack aperture 60 serving as the withdrawal opening from which ink may be withdrawn is provided on one of the short sides. The specific design of the pack aperture 60 will be discussed later. In the embodiment, the plurality of ink packs 310 are held stacked on an incline with one long side thereof upraised. In the embodiment, the upper chassis unit 30 accommodates four ink packs 310 for individual inks of the four colors black, cyan, magenta, and yellow. In an alternative embodiment, in a printer adapted to carry out printing with light cyan and light magenta in addition to these four colors for a total of six colors, the upper chassis unit 30 could be designed to accommodate six ink packs 310 for individual inks of six colors including the additional light cyan and light magenta.
The upper chassis unit 30 which constitutes the ink delivery unit for the printing mechanism section 50 has an ink delivery section 330 which connects to the ink packs 310 so as to enable ink to be dispensed from them. A delivery tube 340 which defines a fluid passage allowing the ink dispensed from the ink packs 310 to flow down to the printing mechanism section 50 connects with the ink delivery section 330 . The delivery tube 340 can be fabricated of material having gas barrier properties, for example, a thermoplastic elastomer such as an olefin or styrene.
FIG. 2 is a sectional view depicting in simplified form the configuration of the printer 10 with the upper chassis unit 30 closed. FIG. 3 is a sectional view depicting in simplified form the configuration of the printer 10 with the upper chassis unit 30 open. FIG. 4 is a top view showing the interior of the upper chassis unit 30 . The upper chassis unit 30 has a lower housing 360 which constitutes the inside lower face of the upper chassis unit 30 ; and an upper housing 370 which constitutes the inside top wall of the upper chassis unit 30 . Inside the lower housing 360 are disposed a plurality of holder guides 362 constituted in sections of the inside lower face defined by the lower housing 360 , and extending approximately parallel to the rotation shaft 350 and spaced at approximately equal intervals apart from one another. As shown in FIG. 3 , in the embodiment, the upper part of the printing mechanism section 50 housed within the main chassis unit 20 will lie exposed by opening the upper chassis unit 30 .
As shown in FIG. 2 , a plurality of holders 380 on which the ink packs 310 rest are provided as liquid containers within the upper chassis unit 30 . The holders 380 have inclined panels 381 which are inclined with respect to the holder guides 362 . The ink packs 310 are arranged resting against the upper faces of the inclined panels 381 of the holders 380 , with one side face of the flat bag which makes up the ink pack 310 in contact therewith. In the embodiment, the ink packs 310 are attached with double-sided tape on at least a portion of the face thereof contacting the inclined panel 381 of the holder 380 . In the lower section of the inclined panel 381 of the holder 380 there is formed a base section 382 which is fittable within the holder guide 362 . After the base section 382 has been fitted into the holder guide 362 , the holder 380 will be secured fastened to the lower housing 360 by fastening screws 388 , 389 which constitute the fastening components. The plurality of holders 380 are positioned in a row staggered along the inside lower face of the lower housing 360 , with the inclined panel 381 of one holder 380 overlapping the top of the ink pack 310 which rests on another holder situated adjacently in the direction of incline of the inclined panels 381 . As depicted in FIGS. 2 and 3 , the inclined panels 381 of the holders 380 are inclined with respect to the holder guides 362 of the lower housing 360 , by an angle of incline θh enabling them to remain in contact with the ink packs 310 from below in the direction of gravity as the upper chassis unit 30 moves from the closed position to the open position. In the embodiment, the allowable rotation angle θc for opening and closing of the upper chassis unit 30 about the rotation shaft 350 is approximately 45 degrees, whereas the angle of incline θh of the inclined panels 381 with respect to the holder guides 362 is approximately 40 degrees.
As shown in FIG. 2 , on the back face of the inclined panel 381 of each holder 380 is pendently disposed a back face reinforcing rib 384 having a tabular contour which extends along the ink pack 310 resting on the adjacent holder 380 . On the inside lower face of the lower housing 360 is disposed a holder reinforcing rib 364 of tabular contours which rises up to meet the bottom of the inclined panel 381 of the holder 380 situated at the end in the direction of incline of the inclined panels 381 in the row of holders 380 . In the embodiment, the upper part of the holder reinforcing rib 364 abuts the back face of the inclined panel 381 of this holder 380 . On the inside top wall of the upper chassis unit 30 is pendently disposed an end portion reinforcing rib 374 having a tabular contour which extends towards the upside of the ink pack 310 resting on the holder 380 situated at the end opposite from the direction of incline of the inclined panels 381 in the row of holders 380 . On the inside top wall of the upper chassis unit 30 is also pendently disposed a medial reinforcing rib of tabular contours which extends along the upside of the ink pack 310 resting on the holder 380 , along a zone sandwiched between two of the holders 380 . Also disposed on the inside top wall of the upper chassis unit 30 is a mating portion 373 which mates with the upper edge portion 383 of the inclined panel 381 of a holder 380 .
As shown in FIG. 4 , the ink delivery section 330 has a guard cover 332 disposed covering the upside of the connector portions with the pack apertures 60 of the ink packs 310 . The guard cover 332 has openings 333 to permit insertion of a tool for tightening fastening screws 388 which fasten the holders 380 to the lower housing 360 .
FIG. 5 is an illustration depicting fastening of holders 380 carrying ink packs 310 within the upper chassis unit 30 . In each of the holders 380 , a through hole 386 adapted for passage and engagement of a fastening screw 388 is formed at a location adjacent to the pack aperture 60 of the ink pack 310 , and a through hole 387 adapted for passage and engagement of a fastening screw 388 is formed at a location adjacent to the opposite end from the pack aperture 60 of the ink pack 310 . In the lower housing of the upper chassis unit 30 , at fastening locations where the holders 380 carrying the ink packs 310 are to be fastened, there are formed screw holes 368 for threadably engaging the fastening screws 388 passed through the through holes 386 of the holders 380 , as well as screw holes 369 for threadably engaging the fastening screws 389 passed through the through holes 387 of the holders 380 .
During the process of fastening the holders 380 carrying the ink packs 310 in the interior of the upper chassis unit 30 , first, the base portion 382 of the holder 360 carrying the ink pack 310 is fitted from above into one of the holder guides 362 of the lower housing 360 . Then, the holder 380 is slid along the holder guide towards a delivery needle 320 until the delivery needle 320 is threaded through the aperture of the ink pack 310 . The holder 380 is then fastened to the lower housing 360 with the fastening screws 388 , 389 .
FIG. 6 is an illustration depicting an ink pack 310 prior to connection with the ink delivery section 330 , viewed in A-A cross section in FIG. 4 . FIG. 7 is an illustration depicting an ink pack 310 connected with the ink delivery section 330 , viewed in A-A cross section in FIG. 4 . The delivery needles 320 , each of which has a hollow flow passage 322 communicating with the delivery tube 340 , are provided to the ink delivery section 330 . A first end of the delivery needle 320 has a tip 324 of tapered shape. A delivery channel 326 which communicates with the hollow flow passage 322 is formed in the tip 324 of the delivery needle 320 . The delivery channel 326 is formed from the tip of the delivery needle 320 to a side wall 321 which extends generally along the center axis of the delivery needle 320 . As shown in FIG. 7 , the delivery channel 326 of the delivery needle 320 is defined by a vertical face 326 a which extends generally along the center axis of the delivery needle 320 , and a lateral face 326 b which intersects the center axis of the delivery needle 320 . In the embodiment, the delivery channel 326 of the delivery needle 320 is formed with a cross shape (“+ (plus)” shape) having its intersection point at the center axis of the delivery needle 320 . In the embodiment, the delivery needle 320 is a resin component which has been integrally molded with the ink delivery section 330 using a mold.
The pack aperture 60 provided to each of the ink packs 310 is provided with a delivery aperture portion 610 having formed therein a delivery aperture 612 which communicates with the interior of the ink pack 310 . A cylindrical gasket 640 having a through hole 642 which mates intimately with the delivery needle 320 threaded through the delivery aperture 612 is disposed at the inlet of the delivery aperture 612 . The gasket 640 installed in the delivery aperture 612 is forced into the delivery aperture 612 by a cap 620 which fits onto the delivery aperture portion 610 .
A valve body 630 having a sealing face 634 that intimately attaches to the gasket 640 is housed within the delivery aperture 612 . The valve body 630 housed within the delivery aperture 612 is urged towards the gasket 640 from the interior of the delivery aperture 612 by a coil spring 650 which constitutes a resilient member, and seals off the through hole 642 of the gasket 640 . The valve body 630 is provided with a plurality of guides 638 disposed contacting the inside wall of the delivery aperture 612 generally along the center axis of the delivery aperture 612 ; between the plurality of guides 638 are defined offset faces 636 which are offset from the inside face of the delivery aperture 612 . A mating face 632 adapted to mate with the tip 324 of the delivery needle 320 is formed on the valve body 630 on the side thereof which abuts the gasket 640 .
As shown in FIG. 7 , when the delivery needle 320 is threaded through the through-hole 642 of the gasket 640 , with the tip 324 of the delivery needle 320 mated with the mating face 632 of the valve body 630 , the valve body 630 will be pushed inward towards the ink pack 310 within the delivery aperture 612 . During this process, since the delivery channel 326 of the delivery needle 320 has been formed so as to extend from the tip 324 to the side wall 321 and beyond the mating face 632 of the valve body 630 , the channel will now communicate with the delivery aperture 612 . The interior of the ink pack 310 will thereby be placed in communication with the hollow flow passage 322 of the delivery needle 320 , via the offset faces 636 of the valve body 630 and the delivery channel 326 of the delivery needle 320 .
FIG. 8 is an illustration depicting a configuration of the printing mechanism section 50 of the printer 10 . The printing mechanism section 50 has a platen 530 of rectangular shape disposed in a printing area where ejection of ink drops onto the printer paper 900 will be carried out. The printer paper 900 is transported over the platen 530 by a paper feed mechanism (not shown). The printing mechanism section 50 also has a carriage 80 which is connected to the delivery tube 340 and which carries an ejection head 810 . The carriage 80 is moveably supported in the lengthwise direction of the platen 530 along a guide rod 520 , and is driven via a timing belt 512 by a carriage motor 510 which constitutes the carriage driving section. The carriage 80 thereby undergoes reciprocating motion in the lengthwise direction over the platen 530 . In the interior of the main chassis unit 20 , a home position where the carriage 80 waits in standby is provided in a nonprinting area away to one side of the printing area where the platen 530 is located. A maintenance mechanism section 70 for maintenance of the carriage 80 is disposed at this home position.
FIG. 9 is a flowchart depicting a method of manufacturing the printer 10 . When installing the ink packs 310 in the printer 10 , first, the ink-filled ink packs 310 are positioned on the inclined panels 381 of the holders 380 (Step S 110 ). The holders 380 carrying the ink packs 310 are then fitted into the holder guides 362 of the lower housing 360 , and the holders 380 are fastened to the lower housing 360 with the fastening screws 388 , 389 so that the plurality of holders 380 are arranged on the lower housing 360 (Step S 120 ). Subsequently, the lower housing in which the plurality of holders 380 have been arranged is sealed with the upper housing 370 , whereby the plurality of ink packs 310 are housed in the interior of the main chassis unit 30 (Step S 130 ).
According to the printer 10 of the embodiment described above, since the guard cover 332 is disposed projecting out over the delivery needle 320 , it is possible to prevent accidental damage to the delivery needle 320 when the holder 380 carrying the ink pack 310 is secured to the lower housing 360 . Additionally, by working through the openings 333 provided in the guard cover 332 the fastening screws 388 can be passed through the through holes 386 of the holders 380 and fastened into the screw holes 386 of the lower housing 360 , and thus while preventing accidental damage to the delivery needle 320 when the holder 380 carrying the ink pack 310 is secured to the lower housing 360 , the holder 380 can be secured to the lower housing 360 in the vicinity of connection between the delivery needle 320 and the pack aperture 60 .
Moreover, because by opening the upper chassis unit 30 it is possible to access parts of the main chassis unit 20 which are normally covered by the upper chassis unit 30 , the degree of freedom in positioning of the ink packs 310 can be improved. Moreover, because the upper chassis unit 30 is pivotably attached to the main chassis unit 20 allowing the top part of the printing mechanism section 50 to be opened or closed, the upper chassis unit 30 which houses the ink packs 310 can be utilized as the cover for the printing mechanism section 60 ; and by opening the upper chassis unit 30 it will be possible to easily perform maintenance on the printing mechanism section 50 housed within the main chassis unit 20 .
Moreover, because the individual ink packs 310 respectively rest on the inclined panels 381 of the holders 380 , the plurality of ink packs 310 can be stacked and accommodated efficiently, while preventing the weight of ink packs 310 from bearing on neighboring ink packs 310 . Additionally, because the ink packs 310 are retained from below as the upper chassis unit 30 moves from the closed state to the open state, the ink packs 310 can be prevented from pushing with excessive force against neighboring holders 380 due to gravity.
Furthermore, by disposing the holder reinforcing rib 364 on the lower housing 360 , the holder 380 can be reinforced with respect to force acting in the direction of incline of the inclined panels 381 . Moreover, by disposing the end portion reinforcing rib 374 on the upper housing 370 , it will be possible to avoid excessive deformation of the ink pack 310 carried on the holder 380 which is situated at the end opposite the direction of incline of the inclined panels 381 . Additionally, by disposing the medial reinforcing rib 376 on the upper housing 370 , it will be possible to avoid excessive deformation at the upside of an ink pack 310 unsupported by the back face of the inclined panel 381 of the adjacent holder. Furthermore, because the upper edge portion 383 of the inclined panel 381 of the holder 380 mates with the mating portion 373 disposed on the upper housing 370 , it is possible to prevent the holder 380 from experiencing excessive deformation.
B. Alternative Embodiments
The foregoing description of the invention based on certain preferred embodiments should not be construed as limiting of the invention, and various modifications will of course be possible without departing from the scope of the invention. For example, the upper chassis unit 30 need not be pivotably attached to the main chassis unit 20 , and the upper chassis unit 30 may instead by slidably attached to the main chassis unit 20 . With this design, the ink packs 310 can be housed in a more stable condition within the upper chassis unit 30 .
Another possible orientation of the holders 380 on the lower housing 360 is that depicted in FIG. 10 wherein the holders 380 are arranged generally along the direction of the axis of the rotation shaft 350 . According to the embodiment illustrated in FIG. 10 , because the individual ink packs 310 held in the upper chassis unit 30 are maintained at generally identical height as the upper chassis unit 30 moves from the closed state to the open state, generally identical pressure head can be maintained in the inks contained in the individual ink packs 310 . The ejection quality of the ink ejected from the ejection head 810 can be improved thereby. Alternatively, the holders 380 may be positioned with the direction of incline of the inclined panels 381 oriented towards the rotation shaft 350 as depicted in FIG. 11 . According to the embodiment illustrated in FIG. 11 , with the upper chassis unit 30 in the opened state the ink packs 310 rest in a more stable condition on the inclined panels 381 of the holders 380 , as compared with the arrangement of the holders 380 depicted in FIGS. 2 and 3 in which the inclined panels 381 incline in the direction opposite from the rotation shaft 350 .
The fluid targeted by the fluid ejection device of the invention is not limited to liquids such as the ink mentioned above, and various fluids such as metal pastes, powders, or liquid crystals may be targeted as well. The ink-jet recording device equipped with an ink-jet recording head for picture recording purposes like that described above is but one representative example of an fluid ejection device; the invention is not limited to recording devices of ink-jet type, and has potential implementation in printers or other picture recording devices; in coloring matter ejection devices employed in manufacture of color filters for liquid crystal displays and the like; in electrode material devices employed in formation of electrodes in organic EL (Electro Luminescence) displays or FED (Field Emission Displays); in liquid ejection devices for ejection of liquids containing bioorganic substances used in biochip manufacture; or in specimen ejection devices for precision pipette applications.
According to the aspect of the invention, the fluid ejection device may further comprise: a container case that houses the fluid-containing pack; and a fastening member that fastens the fluid container at the locking position to the container case, wherein: the fluid container includes a mating portion that mates with the fastening member in proximity to the withdrawal portion; and the guard cover includes a through-hole portion that locates corresponding to the mating portion of the fluid container at the locking position. According to the above-mentioned fluid ejection device, since the guard cover is disposed projecting so as to cover the delivery needle, while preventing accidental damage to the delivery needle during securing of the fluid container to the container case, the fluid container can be secured to the container case in the vicinity of connection between the delivery needle and the withdrawal opening.
According to the aspect of the invention, the fluid container may be a plurality of fluid containers; the fluid container may include a holder that inclines and holds the container portion; and the plurality of fluid containers may be arranged spaced apart with a part of one fluid container overlapping a holder of another fluid container. According to the above-mentioned fluid ejection device, the individual fluid containers are positioned at an incline, thereby allowing a plurality of fluid containers to be stacked and accommodated efficiently.
According to the aspect of the invention, the fluid ejection device may further comprise: a container case that houses the fluid-containing pack; and a main chassis case that houses the fluid ejection unit, wherein the container case is pivotably attached to the main chassis case and openable by rotation about a rotation shaft. According to the above-mentioned fluid ejection device, by opening the container case it will be possible to access the parts of the main chassis unit which are normally covered by the container case, thereby improving the degree of freedom in positioning of the fluid containers.
According to the aspect of the invention, the fluid container may incline by an angle which affords hold against the container portion from below in a direction of gravity as the container case moves from a closed position to a open position. According to the above-mentioned fluid ejection device, because the container portions of the fluid containers are retained from below as the container case moves from the closed state to the open state, the fluid container portions can be prevented from pushing with excessive force against other adjacent structures.
According to the aspect of the invention, the fluid container may be a plurality of fluid containers; and each of the withdrawal portions of the plurality of fluid containers may be arranged approximately along an axis of the rotation shaft. According to the above-mentioned fluid ejection device, as the container case moves from the closed state to the open state the individual fluid containers retained in the container case will be positioned at approximately identical height, thereby maintaining approximately identical pressure head of the fluid contained in the individual fluid containers. The fluid ejection quality can be improved thereby.
Although the invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the invention being limited only by the terms of the appended claims.
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A fluid ejection device ejecting a fluid, the fluid ejection device includes: a fluid container; a fluid ejection unit; a delivery needle; a guard cover; and a guide. The fluid container includes a container portion and a withdrawal portion. The container portion contains a fluid for ejection, and the withdrawal portion allows withdrawal of the fluid contained in the container portion. The fluid ejection unit ejects a fluid onto an ejection target. The delivery needle provides a flow passage which communicates with the fluid ejection unit. The guard cover projects over the delivery needle. The guide mates with the fluid container, and then slidably guides the withdrawal portion toward a locking position where the delivery needle sticks through the withdrawal portion.
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This application is a continuation in part of U.S. Ser. No. 09/090,046, filed Jun. 3, 1998, now U.S. Pat. No. 6,001,813, and is a continuation in part of U.S. Ser. No. 09/090,274, filed Jun. 3, 1998, now U.S. Pat. No. 6,001,814; both of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The serine proteases are a class of enzymes, which includes elastase, chymotrypsin, cathepsin G, trypsin and thrombin. These proteases have in common a catalytic triad consisting of Serine-195, Histidine-57 and Aspartic acid-102(chymotrypsin numbering system). Human neutrophil elastase (HNE) is a proteolytic enzyme secreted by polymorphonuclear leukocytes (PMNs) in response to a variety of inflammatory stimuli. This release of HNE and its extracellular proteolytic activity are highly regulated and are normal, beneficial functions of PMNs. The degradative capacity of HNE, under normal circumstances, is modulated by relatively high plasma concentrations of α 1 -proteinase inhibitor (α-PI). However, stimulated PMNs produce a burst of active oxygen metabolites, some of which (hypochlorous acid for example) are capable of oxidizing a critical methionine residue in α-PI. Oxidized α-PI has been shown to have limited potency as an HNE inhibitor and it has been proposed that alteration of this protease/antiprotease balance permits HNE to perform its degradative functions in localized and controlled environments.
Despite this balance of protease/antiprotease activity, there are several human disease states in which a breakdown of this control mechanism is implicated in the pathogenesis of the condition. Improper modulation of HNE activity has been suggested as a contributing factor in adult respiratory distress syndrome, septic shock and multiple organ failure. A series of studies also have indicated the involvement of PMNs and neutrophil elastase in myocardial ischemia-reperfusion injury. Humans with below-normal levels of α 1 -PI have an increased probability of developing emphysema. HNE-mediated processes are implicated in other conditions such as arthritis, periodontal disease, glomerulonephritis, dermatitis, psoriasis, cystic fibrosis, chronic bronchitis, atherosclerosis, Alzheimer's disease, organ transplantation, corneal ulcers, and invasion behavior of malignant tumors.
There is a need for effective inhibitors of HNE as therapeutic and as prophylactic agents for the treatment and/or prevention of elastase-mediated problems.
SUMMARY OF THE INVENTION
In one embodiment, the present invention provides compounds of formula I
wherein X and Y are independently O or N;
R 1 is alkyl α,α-dialkylalkylaryl or α,α-dialkylalkyl fused aryl-cycloalkyl wherein the cycloalkyl group is optionally substituted with two or more O atoms;
R 2 and R 3 are independently H or alkyl; or together form a ring consisting of 3-5 carbons in which one or more carbon atoms of the ring can optionally be replaced with heteroatoms selected from O, S or N wherein N is optionally substituted with H or alkyl, preferably one of R 2 and R 3 is H and the other is iso-propyl; and
R 4 is alkyloxycarbonyl.
Preferably, compounds of the present invention comprise a 1,3,4 oxadiazole ring (i.e., X is N; Y is O).
In one preferred embodiment of the invention, R 1 is alkyl, such as tert-butyl. In another embodiment, R 1 is α,α-dialkylalkylaryl, such as an α,α-dimethylbenzyl group. In still another preferred embodiment, R 1 is α,α-dialkylalkyl fused aryl-cycloalkyl wherein the cycloalkyl group is substituted with two O atoms, such as an α,α-dimethyl-(3,4-methylenedioxy)benzyl group. In yet another preferred embodiment, R 2 and R 3 are independently alkyl, such as isopropyl, or H. Preferably, R 2 is isopropyl and R 3 is H.
In another embodiment, the present invention provides compounds of formula II:
wherein X and Y are independently O or N;
R 1 , R 2 , and R 3 are as above;
R′ 2 and R′ 3 are independently H or alkyl; or together form a ring consisting of 3-5 carbon atoms in which one or more carbon atoms of the ring can optionally be replaced by heteroatoms selected from O, S or N, wherein N is optionally substituted with H or alkyl;
A is a direct bond, —NH— or —OC(O)—NH—;
R 4 is H or halo; and
R 5 is H, alkyl or arylalkyl; or
a pharmaceutically acceptable salt thereof.
Preferably, compounds of this embodiment of the present invention comprise a 1,3,4 oxadiazole ring (i.e., X is N; Y is O).
In one preferred embodiment of the invention, R 1 is alkyl, such as tert-butyl. In another embodiment, R 1 is α,α-dialkylalkyl fused aryl-cycloalkyl wherein the cycloalkyl group is substituted with two O atoms, such as an α,α-dimethyl-(3,4-methylenedioxy)benzyl group. In yet another embodiment, R 1 is α,α-dialkylalkylaryl, such as an α,α-dimethylbenzyl group. In still another preferred embodiment, R 2 and R 3 are independently alkyl, such as isopropyl, or H. In a more preferred embodiment, R 2 is isopropyl, R 3 is H, and R 2 ′ and R 3 ′ are both H. Where R 4 is halo, R 4 may be Cl, F, I or Br, although preferably it is F.
As used herein, the term “optionally substituted” means, when substituted, mono to fully substituted.
As used herein, the term “independently” means that the substituents may be the same or different.
As used herein, the term “alkyl” means C 1 -C 15 , and preferably C 1 -C 8 . It will be understood that the alkyl group may be linear or branched.
As used herein, the term “α,α-dialkylalkylaryl” means that the alkyl groups are substituted at the α-positions to the oxadiazole ring or to the aryl group or both. One such example is an α,α-dialkylbenzyl, wherein the α-substituents are preferably methyl, ethyl or propyl. A specific example is α,α-dimethylbenzyl. The term “α,α-dialkylalkyl fused arylcycloalkyl” is defined to mean that the alkyl groups are substituted at the α-positions to the oxadiazole ring or to the aryl group, and a cycloalkyl is fused to the aryl ring. One such example of an “α,α-dialkylalkyl fused aryl-cycloalkyl” is an α,α-dialkyl-3,4-methylenedioxybenzyl group, wherein the α-substituents are preferably methyl, ethyl or propyl; preferably they are methyl. A specific example includes the α, α-dimethyl-3,4-methylenedioxybenzyl group.
As used herein, the term alkyloxycarbonyl means alkyl—O—C(O)— wherein the meaning of alkyl is defined above. One such example of an alkyloxycarbonyl is methyloxycarbonyl and is defined by the formula CH 3 —O—C(O)—.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of the synthetic scheme for the Boc protected amino alcohol intermediates used in the invention.
FIG. 2 is a schematic representation of the synthetic scheme for the compounds of one embodiment of the invention.
FIG. 3 is a schematic representation of the synthetic scheme for the compounds of another embodiment of the invention.
DETAILED DESCRIPTION
The compounds of the present invention have been found to be potent inhibitors of the serine protease human neutrophil elastase (HNE). They are reversible inhibitors that presumably form a transition state intermediate with the active site serine residue. The compounds are characterized by their low molecular weights, high selectivity with respect to HNE and stability regarding physiological conditions. Therefore, the compounds can be implemented to prevent, alleviate and/or otherwise treat diseases, which are mediated by the degradative effects associated with the presence of HNE. Their usage is of particular importance as they relate to various human treatment in vivo but may also be used as a diagnostic tool in vitro.
The present invention provides, but is not limited to, specific embodiments set forth in the Examples as well as those set forth below.
The nomenclature for the embodiments is as follows (although embodiments disclosed indicate the stereochemistry of the 2-methylpropyl group as having the (S)-configuration, it will be understood that both the enantiomerically pure (R) and racemic (R,S) configurations are within the scope of the invention):
EXAMPLE 1
Methyloxycarbonyl-L-valyl-N-[1-(2-[5-(tert-butyl)-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]-L-prolinamide.
EXAMPLE 2
Methyloxycarbonyl-L-valyl-N-[1-(2-[5-(α,α-dimethylbenzyl)-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]-L-prolinamide.
EXAMPLE 3
Methyloxycarbonyl-L-valyl-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]-L-prolinamide.
EXAMPLE 4
2-[6-Oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[P-(2-[5-tert-butyl 1,3,4-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]acetamide.
EXAMPLE 5
2-[5-Benzyloxycarbonylamino-6-oxo-2-(4-fluorophenyl) 1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]acetamide.
EXAMPLE 6
2-[5-Amino-6-oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl]acetamide.
EXAMPLE 7
2-[5-Benzyloxycarbonylamino-6-oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]acetamide.
EXAMPLE 8
2-[5-Amino-6-oxo-2-phenyl-1,6dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl]acetamide.
EXAMPLE 9
2-[6-Oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl]acetamide.
EXAMPLE 10
2-[6-Oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl -3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl]acetamide.
EXAMPLE 11
2-[6-Oxo-2-(4-fluorophenyl)-1,6-dihydro-l-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl]acetamide.
EXAMPLE 12
2-[6-Oxo-2-phenyl-1,6-dihydro4-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl]acetamide.
EXAMPLE 13
2-[5-Methyloxycarbonylamino-6-oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(tert-butyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl]acetamide.
The compounds of the present invention are not limited to use for inhibition of human elastase. Elastase is a member of the class of enzymes known as serine proteases. This enzyme class also includes, for example, chymotrypsin, cathepsin G, trypsin and thrombin. These proteases have in common a catalytic triad consisting of Serine-195, Histidine-57 and Aspartic acid-102 (chymotrypsin numbering system). The precise hydrogen bond network that exists between these amino acid residues allows the Serine-195 hydroxyl to form a tetrahedral intermediate with the carbonyl of an amide substrate. The decomposition of this intermediate results in the release of a free amine and the acylated enzyme. In a subsequent step, this newly formed ester is hydrolyzed to give the native enzyme and the carboxylic acid. It is this carboxyl component that helps characterize the specificity for the enzyme. In the example in which the carboxyl component is a peptide, the alpha-substituent of the amino acid is predominately responsible for the specificity toward the enzyme. Utilizing the accepted nomenclature by Schechter and Berger ( Biochem. Biophy. Res. Commun ., 27:157 (1967) and Biochem. Biophys. Res. Commun ., 32:898 (1968)), the amino acid residues in the substrate that undergo the cleavage are defined as P 1 . . . P n toward the N-terminus and P 1 ′ . . . P n ′ toward the C-terminus. Therefore, the scissile bond is between the P 1 and the P 1 ′ residue of the peptide subunits. A similar nomenclature is utilized for the amino acid residues of the enzyme that make up the binding pockets accormmodating the subunits of the substrate, where the binding pocket for the enzyme is designated by S 1 . . . S n instead of P 1 . . . P n as for the substrate.
The characteristics for the P 1 residue defining serine proteinase specificity is well established. The proteinases may be segregated into three subclasses: elastases, chymases and tryptases based on these differences in the P 1 residues. The elastases prefer small aliphatic moieties such as valine whereas the chymases and tryptases prefer large aromatic hydrophobic and positively charged residues respectively.
One additional proteinase that does not fall into one of these categories is propyl endopeptidase. The P 1 residue defining the specificity is a proline. This enzyme has been implicated in the progression of memory loss in Alzheimer's patients. Inhibitors consisting of α-keto heterocycles have recently been shown to inhibit propyl endopeptidase (Tsutsumi et al., J. Med. Chem ., 37, 3492-3502 (1994)). By way of extension, α-keto heterocycles as defined herein allow for an increased binding in P′ region of the enzyme.
TABLE 1
P 1 Characteristics for Proteinase Specificity
Proteinase Class
Representative Enzyme
P 1 Characteristic
Elastases
Human Neutrophil Elastase
small aliphatic residues
Chymases
alpha-Chymotrypsin,
aromatic or large
Cathepsin G
hydrophobic residues
Tryptases
Thrombin, Trypsin,
positively charged
Urokinase, Plasma
residues
Kallikrein, Plasminogen
Activator, Plasmin
Other
Prolyl Endopeptidase
proline
Since the P 1 residue predominately defmes the specificity of the substrate, the present invention relates to P 1 -P n ′ modifications, specifically, certain alpha-substituted keto-heterocycles composed of 1,2,4 oxadiazoles and 1,3,4-oxadiazoles. By altering the alpha-substituent to the ketone and, to some extent, the substituent on the heterocycle, the specificity of these compounds can be directed toward the desired proteinase (e.g., small aliphatic groups for elastase).
The efficacy of the compounds for the treatment of various diseases can be determined by scientific methods, which are known in the art. The following are noted as examples for HNE mediated conditions:
for acute respiratory distress syndrome, the method according to human neutrophil elastase (HNE) model ( AARD , 141:227-677 (1990)); the endotoxin induced acute lung injury model in minipigs ( AARD , 142:782-788 (1990)); or the method according to human polymorphonuclear elastase-induced lung hemorrhage model in hamsters (European Patent Publication No. 0769498) may be used;
in ischemia/reperfusion, the method according to the canine model of reperfusion injury ( J. Clin. Invest ., 81: 624-629 (1988)) may be used. The compounds of the present invention, salts thereof, and their intermediates can be prepared or manufactured as described herein or by various processes known to be present in the chemical art (see e.g., WO 96/16080).
Alternatively, the compounds of the present invention may be prepared as described in FIGS. 1, 2 and 3 . FIG. 1 relates to the synthesis of the Boc protected amino alcohol intermediates used in the invention. FIGS. 2 and 3 show the use of the intermediates for the synthesis compounds of the invention.
The 2-substituted 1,3,4-oxadiazoles (3) may be prepared via formation of methyl esters from the corresponding acids (1) utilizing, for example, thionyl chloride and methanol, followed by treatment with hydrazine in a suitable solvent to yield hydrazonic acids (2). Alternatively, esters can be prepared by methods known to one skilled in the art or those methods described in Comprehensive Organic Transformations (R. Larock, VCH Publishers 1989, 966-972). Reaction of (2) with triethyl orthoformate or trimethyl orthoformate and TsOH gives the requisite 2-substituted 1,3,4-oxadiazoles (3).
Intermediate (3′) can be formed utilizing standard conditions (e.g., butyllithium. or other known alkyl lithium reagents, at low temperature in a polar aprotic solvent, and further, if desired, reacting with MgBr·OEt 2 ) and subsequently added to aldehyde (4) to give alcohol (5).
The aldehyde (4) may be prepared via any of three methods as described in FIG. 1 . One method reduces the intermediate that is formed between Boc-Val-OH and iso-propylchloroformate with sodium borohydride to give Boc-Valinol (12). In a subsequent step, the Boc-Valinol is oxidized with SO 3 -Py in DMSO to give aldehyde (4). Another such method takes the Weinreb amide (13) that is prepared from Boc-Val-OH (11) and reduces it to the aldehyde using diisobutylaluminum hydride (DIBAL). Alternatively, one may generate the ester (14) of the amino acid followed by reduction with DIBAL to afford aldehyde (4).
As shown in FIGS. 2 and 3, deprotection of amine (5) using hydrochloric acid in dioxane gives the amino hydrochloride (6), which is then coupled to the desired acid (7) or (7′) by methods available to one skilled in the art to give intermediate (8) or (8′). Oxidation using the Swerm Oxidation, Dess-Martin's Periodinane or other methods as described in Oxidation in Organic Chemistry (M. Hudlicky, ACS Monograph 186 (1990)) yields the desired ketone (9) or (9′).
Where a compound is substituted at the 5 position of the pyrimidinone group with a benzyloxycarbonylamino group, a deprotection step can be conducted as described in FIG. 3 . This step requires removal of the protecting group from the amine and may be carried out by a number of methods. For example, one may utilize aluminum chloride, anisole and nitromethane in a suitable solvent such as dichloromethane to give the 5-amino compound (10′). Other methods of deprotection available in the art may also be used.
Although the compounds described herein may be administered as pure chemicals, it is preferable to present the active ingredient as a pharmaceutical composition. The invention thus further provides the use of a pharmaceutical composition comprising one or more compounds together with one or more pharmaceutically acceptable carriers thereof and, optionally, other therapeutic and/or prophylactic ingredients. The carrier(s) must be ‘acceptable’ in the sense of being compatible with the other ingredients of the composition and not deleterious to the recipient thereof.
Pharmaceutical compositions include those suitable for oral or parenteral (including intramuscular, subcutaneous and intravenous) administration. The compositions may, where appropriate, be conveniently presented in discrete unit dosage forms and may be prepared by any of the methods well known in the art of pharmacy. Such methods include the step of bringing into association the active compound with liquid carriers, solid matrices, semi-solid carriers, finely divided solid carriers or combination thereof, and then, if necessary, shaping the product into the desired delivery system.
Pharmaceutical compositions suitable for oral administration may be presented as discrete unit dosage forms such as hard or soft gelatin capsules, cachets or tablets each containing a predetermined amount of the active ingredient; as a powder or as granules; as a solution, a suspension or as an emulsion. The active ingredient may also be presented as a bolus, electuary or paste. Tablets and capsules for oral administration may contain conventional excipients such as binding agents, fillers, lubricants, disintegrants, or wetting agents. The tablets may be coated according to methods well known in the art, e.g., with enteric coatings.
Oral liquid preparations may be in the form of, for example, aqueous or oily suspension, solutions, emulsions, syrups or elixirs, or may be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations may contain conventional additives such as suspending agents, emulsifying agents, non-aqueous vehicles (which may include edible oils), or preservatives.
The compounds may also be formulated for parenteral administration (e.g., by injection, for example, bolus injection or continuous infusion) and may be presented in unit dose form in ampules, pre-filled syringes, small bolus infusion containers or in multi-dose containers with an added preservative. The compositions may take such forms as suspensions, solutions, or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilizing and/or dispersing agents. Alternatively, the active ingredient may be in powder form, obtained by aseptic isolation of sterile solid or by lyophilization from solution, for constitution with a suitable vehicle, e.g., sterile, pyrogen-free water, before use.
For topical administration to the epidermis, the compounds may be formulated as ointments, creams or lotions, or as the active ingredient of a transdermal patch. Suitable transdermal delivery systems are disclosed, for example, in Fisher et al. (U.S. Pat. No. 4,788,603) or Bawas et al. (U.S. Pat. No. 4,931,279, 4,668,504 and 4,713,224). Ointments and creams may, for example, be formulated with an aqueous or oily base with the addition of suitable thickening and/or gelling agents. Lotions may be formulated with an aqueous or oily base and will in general also contain one or more emulsifing agents, stabilizing agents, dispersing agents, suspending agents, thickening agents, or coloring agents. The active ingredient can also be delivered via iontophoresis, e.g., as disclosed in U.S. Pat. Nos. 4,140,122, 4,383,529, or 4,051,842.
Compositions suitable for topical administration in the mouth include unit dosage forms such as lozenges comprising active ingredient in a flavored base, usually sucrose and acacia or tragacanth; pastilles comprising the active ingredient in an inert base such as gelatin and glycerin or sucrose and acacia; mucoadherent gels, and mouthwashes comprising the active ingredient in a suitable liquid carrier.
When desired, the above-described compositions can be adapted to provide sustained release of the active ingredient employed, e.g., by combination thereof with certain hydrophilic polymer matrices, e.g., comprising natural gels, synthetic polymer gels or mixtures thereof.
The pharmaceutical compositions according to the invention may also contain other adjuvants such as flavorings, coloring, antimicrobial agents, or preservatives.
It will be further appreciated that the amount of the compound, or an active salt or derivative thereof, required for use in treatment will vary not only with the particular salt selected but also with the route of administration, the nature of the condition being treated and the age and condition of the patient and will be ultimately at the discretion of the attendant physician or clinician.
In general, however, a suitable dose will be in the range of from about 0.5 to about 100 mg/kg/day, e.g., from about 1 to about 75 mg/kg of body weight per day, such as 3 to about 50 mg per kilogram body weight of the recipient per day, preferably in the range of 6 to 90 mg/kg/day, most preferably in the range of 15 to 60 mg/kg/day.
The compound is conveniently administered in unit dosage form, for example, containing 0.5 to 1000 mg, conveniently 5 to 750 mg, and most conveniently, 10 to 500 mg of active ingredient per unit dosage form.
Ideally, the active ingredient should be administered to achieve peak plasma concentrations of the active compound of from about 0.5 to about 75 μM, more preferably, about 1 to 50 μM, and most preferably, about 2 to about 30 μM. This may be achieved, for example, by the intravenous injection of a 0.05 to 5% solution of the active ingredient, optionally in saline, or orally administered as a bolus containing about 0.5-500 mg of the active ingredient. Desirable blood levels may be maintained by continuous infusion to provide about 0.01-5.0 mg/kg/hr or by intermittent infusions containing about 0.4-15 mg/kg of the active ingredient(s).
The desired dose may be conveniently presented in a single dose or as divided doses administered at appropriate intervals, for example, as two, three, four or more sub-doses per day. The sub-dose itself may be further divided, e.g., into a number of discrete loosely spaced administrations, such as multiple inhalations from an insufflator or by application of a plurality of drops into the eye.
While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims.
The following examples are given to illustrate the invention and are not intended to be inclusive in any manner.
EXAMPLES
The compounds of the present invention, salts thereof, and their intermediates can be prepared or manufactured as described herein or by various processes known to be present in the chemical art. By way of an example, the final step in the process defined here, is an oxidation of a 2° alcohol to a ketone. As described here, this transformation from an alcohol to ketone was preformed using dimethylsulfoxide and oxalyl chloride followed by base, which is known as the Swern oxidation. However, modifications of the Swern oxidation are known in the art and are acceptable in this present invention. It is known that alternative electrophilic molecules can be substituted for oxalyl chloride such as dicyclohexylcarbodiimide, acetic anhydride, trifluoroacetic anhydride or sulfur trioxide (Mancuso et al., Synthesis 165 (1981)). Alternatively, other oxidative methods can be used such as N-chlorosuccinimide (NCS) followed by base as described by the inventors in U.S. Pat. No. 5,618,792 or periodinane such as the Dess-Martin reagent. Still other methods may also be appropriate as described in Oxidation in Organic Chemistry (M. Hudlicky, ACS Monograph 186 (1990)).
Besides the methods described below, other methods can be used for making substituted oxadiazole nonpeptides. U.S. Pat. No. 5,807,829, incorporated herein by reference, teaches some other methods for making substituted oxadiazole nonpeptides.
The skilled artisan will understand that where a particular enantiomer is mentioned, the mirror-image enantiomer or a mixture of enantiomers can be used.
Symbols have the standard meanings as familiar to one skilled in the art, by way of example the following have been used: ml (milliliters), g (grams), TLC (thin layer chromatography), R f (the ratio of the distance moved by a compound to the distance that the solvent front moved during the same time on a TLC plate), 1 H NMR (proton nuclear magnetic resonance), DMSO-d6 (deuterodimethylsulfoxide) and CDCl 3 (deuterochloroform).
Example 1
Methyloxycarbonyl-L-valyl-N-[1-(2-[5-(tert-butyl)-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]-L-prolinamide.
The secondary alcohol, methyloxycarbonyl-L-valyl-N-[1-(2-[5-(tert-butyl)-oxadiazolyl] hydroxymethyl)-2-(S)-methylpropyl]-L-prolinamide, was oxidized using one of the methods known to one skilled in the art, such as, the Swem Oxidation. The intermediate methyloxycarbonyl-L-valyl-N-[1-(2-[5-(tert-butyl)-oxadiazolyl] hydroxymethyl)-2-(S)-methylpropyl]-L-prolinamide was prepared as follows:
A. tert-Butylcarbohydrazonic Acid
The mixture of methyl trimethylacetate (230 ml) and hydrazine monohydrate (170 ml) was refluxed for 24 hours. The reaction was cooled to room temperature, and concentrated under reduced pressure. The residue was azeotroped with toluene several times, dissolved in a saturated aqueous solution of sodium chloride, and extracted with chloroform (4×). The extract was dried over anhydrous sodium sulfate, and concentrated under reduced pressure to give tert-butylcarbohydrazonic acid (176 g) having the following physical data.
TLC: R f =0.59, chloroform: methanol (10:1).
1 H NMR (DMSO-d 6 ): δ 68.78 (1H, brs), 4.15 (2H, brs), 1.08 (9H, s).
B. 2-tert-Butyl-1,3,4-oxadiazole
The mixture consisting of tert-butylcarbohydrazonic acid (176 g), trimethyl orthoformate (250 ml) and p-toluenesulfonic acid monohydrate (4.3 g) was heated and methanol removed by distillation at a temperature ranging from 90° C. to 110° C. Trimethyl orthoformate was removed (50° C./43 mm Hg) and the residue was distilled at 120° C./23 mm Hg to give 2-tert-Butyl-1,3,4-oxadiazole (131 g) having the following physical data.
TLC: R f =0.68, chloroform: methanol (10:1).
1 H NMR (DMSO-d 6 ): δ 9.12(1H, s), 1.3 6 (9H, s).
C. 1-[2-(5-tert-Butyl)-1,3,4-oxadiazolyl]-2-(S)-(tert-butoxycarbonylamino)-3-methylbutan-1-ol
To a solution of 2-tert-Butyl-1,3,4-oxadiazole (62.1 g) in tetrahydrofuran (1650 ml) was added n-butyllithium in hexane (1.6 M, 307.8 ml) dropwise at −78° C. under an atmosphere of argon. The mixture was stirred for 40 min at −78° C., magnesium bromide diethyl etherate (127.2 g) was added, and the resulting mixture was allowed to warm to −45° C. After 1.5 hours, a solution of 2-(S)-[N-(tert-butoxycarbonyl)amino]-3-methylbutanal (90 g) in tetrahydrofuran (60 ml) was added dropwise at -45° C. and allowed to warm to −15° C. The reaction mixture was quenched by addition of a saturated aqueous solution of ammonium chloride, and extracted with ethyl acetate. The extract was washed with water (×3) and a saturated aqueous solution of sodium chloride, dried over anhydrous sodium sulfate and concentrated. The residue was purified by column chromatography on silica gel (Merck 7734) (ethyl acetate:hexane=1:20 to 1:1) to give 1-[2-(5-tert-butyl)-1,3,4-oxadiazolyl]-2-(S)-(tert-butoxycarbonylamino)-3-methylbutan-1-ol (78.6 g) having the following physical data.
TLC: R f =0.42, hexane:ethyl acetate (1:1).
1 H NMR (CDCl 3 ): δ 5.16-4.90 (2H, m), 4.67 (1H, m), 4.23 (1H, m), 3.90 (1H, m), 3.66 (1H, m), 1.98 (1H, m), 1.42, 1.41 and 1.36 (total 18H, each s), 1.13-0.90 (6H, m).
D. 1-[2-(5-tert-Butyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol Hydrochloride
To a solution of 1-[2-(5-tert-butyl)-1,3,4-oxadiazolyl]-2-(S)-(tert-butoxycarbonylamino)-3-methylbutan-1-ol (76.3 g) in dioxane (200 ml) was added 4N hydrochloric acid in dioxane solution (1000 ml) at 0° C. The reaction mixture was concentrated under reduced pressure. The residue was solidified with diethyl ether. The solid was azeotroped with benzene several times to give 1-[2-(5-tert-butyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol hydrochloride (66.1 g) having the following physical data.
TLC: R f =0.30, chloroform:methanol (10:1);
1 H NMR (CDCl 3 ): δ 8.50-8.10 (2H, br), 7.10-6.80 (1H, br), 5.55-5.35 (1H, m), 3.95-3.60 (2H, m), 2.10 (1H, m), 1.41 (9H, s), 1.20-1.00 (6H, m).
E. Methyloxycarbonyl-L-valyl-N-[1-(2-[5-(tert-butyl)-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]-L-prolinamide
Prepared using methyloxycarbonyl-L-Val-Pro-OH and 1-[2-(5-tert-Butyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol hydrochloride and a coupling method known to one skilled in the art.
The product had the following physical data.
TLC: R f =0.58, ethyl acetate.
1 H NMR: (200 MHz, CDCl 3 ), δ 7.53 (brd., J=6.2 Hz, 1H, NH), δ 5.45-5.29 (m 2H, NH, and α CH of P 1 Val), δ 4.79-4.62 (m, 1H, α CH of Pro), 4.32 (m, 1H, α CH of P 3 -Val), 3.83-3.51 (m, 2H, NCH 2 of Pro), 3.68 (s, 3H, CH 3 O), 2.55-1.80 (m, 6H, CHs of iso-Pr, and CH 2 CH 2 of Pro), 1.47 (s, 9H, CH 3 s of t-Bu), 1.16-0.86 (m, 12H, CH 3 s of iso-Pr).
Example 2
Methyloxycarbonyl-L-valyl-N-[1-(2-[5-(α,α-dimethylbenzyl)-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]-L-prolinamide
The compound was prepared by oxidizing methyloxycarbonyl-L-valyl-N-[1-(2-[5-(α,α-dimethylbenzyl)-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]-L-prolinamide using a procedure known to one skilled in the art, such as, the Swern Oxidation.
The intermediate, methyloxycarbonyl-L-valyl-N-[1-(2-[5-(α,α-dimethylbenzyl)-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]-L-prolinamide, was prepared using methyloxycarbonyl-L-Val-Pro-OH and 1-[2-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol hydrochloride and a coupling method know to one skilled in the art. The intermediate 1-[2-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol hydrochloride was prepared using a similar procedure as described in Example 1 except methyl phenylisobutyrate was used instead of methyl trimethylacetate.
The product had the following physical data.
TLC: R f =0.64, ethyl acetate.
1 H NMR (200 MHz, CDCl 3 ): 7.84 and 7.49 (each brd., J=7.6 Hz, totally 1H, NH), 7.40-7.20 (m, 5H aromatic Hs), 5.46-5.29 (m, 2H, NH and α CH of P 1 Val), 4.77-4.60 (m, 1H, α CH of Pro), 4.40-4.25 (m, 1H α CH of P 3 Val), 3.84-3.55 (m, 2H, NCH 2 of Pro), 3.68 (s, 3H, CH 3 O), 2.55-1.76 (m, 6H, CHs of iso-Pr and CH 2 CH 2 of Pro), 1.88 (s, 6H, hetC(CH 3 ) 2 Ph), 1.12-0.82 (m, 12H, CH 3 s of iso-Pr).
Example 3
Methyloxycarbonyl-L-valyl-N-[1-(2-[5-(α,α-dimethyl-3,4-methylene-dioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]-L-prolinamide
The compound was prepared by oxidizing methyloxycarbonyl-L-valyl-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]-L-prolinamide using a procedure know to one skilled in the art, such as, the Swern Oxidation.
The intermediate, methyloxycarbonyl-L-valyl-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]-L-prolinade, was prepared using methyloxycarbonyl-L-Val-Pro-OH and 1-[2-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-ol hydrochloride and a coupling method know to one skilled in the art. The intermediate 1-[2-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol hydrochloride was prepared using a similar procedure as described in Example 1 except methyl 3,4-methylenedioxyphenylisobutyrate was used instead of methyl trimethylacetate.
The product had the following physical data.
TLC: R f =0.63, ethyl acetate.
1 H NMR (200 MHz, CDCl 3 ): 7.49 (d, J=6.4 Hz, 1H, NH), 6.85-6.73 (m, 3H, aromatic Hs), 5.95 (s, 2H, OCH 2 O), 5.46-5.28 (m, 1H α CH of Pro), 4.30 (m, 1H, α CH of P 3 -Val), 3.84-3.54 (m, 2H, NCH 2 of Pro), 3.68 (s, 3H, CH 3 O), 2.55-1.78 Pr, and CH 2 CH 2 of Pro), 1.83 (s, 6H, HetC(CH 3 )2Ph), 1.11-0.85 (m, 12H, CH 3 s of iso-Pr).
Example 4
2-[6-Oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-tert-butyl-1,3,4-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]acetamide
To a solution of oxalyl chloride (5.80 ml) in dichloromethane (160 ml) was slowly added dropwise a solution of dimethylsulfoxide (9.44 ml) in dichloromethane (16 ml) at −78° C. under an atmosphere of argon. The mixture was stirred for 30 min at 78° C. To the mixture was added dropwise a solution of 2-[6-Oxo-2-(4-fluorophenyl)-1,6-dihydro-pyrimidinyl]-N-[1-(2-[5-tert-butyl-1,3,4-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]acetamide (15.2g) in dichloromethane (160 ml) at −78° C. The mixture was stirred for 2 hours at −78° C. To the resulting solution was added triethylamine (97.2 ml) dropwise at −78° C. The reaction mixture was warmed up to room temperature, and stirred for 34 hours at the same temperature. The reaction mixture was acidified by addition of 2N aqueous solution of hydrochloric acid, and extracted with dichloromethane. The extract was washed with 2N aqueous solution of hydrochloric acid, water and a saturated aqueous solution of sodium chloride, dried over anhydrous sodium sulfate, and concentrated. The residue was purified by column chromatography on silica gel using a gradient elution of 66 to 100% ethyl acetate/hexane to give 2-[6-oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-tert-butyl-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]acetamide (10.92 g) having the following physical data.
TLC: R f =0.63, chloroform:methanol (10:1).
1 H NMR (CDCl 3 ): δ 8.00(1H, d, J=6.5 Hz), 7.64 (2H, dd, J=8.6, 5.4 Hz), 7.17 (2H, t, J=8.6 Hz), 6.95 (IH, brd, J=8.4 Hz), 6.50 (IH, d, J=6.5 Hz), 5.43 (IH, dd, J=8.4, 4.8 Hz), 4.63 and 4.58 (each 1H, each d, J=15.4 Hz), 2.53 (IH, m), 1.48 (9H, s), 1.09 (3H, d, J=6.8 Hz), 0.90 (3H, d, J=6.8 Hz). The intermediate 2-[6-Oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-tert-butyl-1,3,4-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]acetamide was prepared as follows:
A. tert-Butylcarbohydrazonic acid t-Butylcarbohydrazonic acid was prepared as described above. TLC: R f =0.59, chloroform:methanol (10:1). 1 H NMR (DMSO-d 6 ): δ 8.78 (1 H, brs), 4.15 (2H, brs), 1.08 (9H, s).
B. 2-tert-Butyl 1,3,4-oxadiazole t-tert-Butyl 1,3,4-oxadizole was prepared as described above.
C. 1-[2-(5-tert-Butyl)-1,3,4-oxadiazolyl]-2-(S)-(tert-butoxycarbonylamino)-3-methylbutan-1-ol
To a solution of 2-tert-Butyl-1,3,4-oxadiazole (62.1 g) in tetrahydrofuran (1650 ml) was added n-butyllithium in hexane (1.6 M, 307.8 ml) dropwise at −78° C. under an atmosphere of argon. The mixture was stirred for 40 min at −78° C., magnesium bromide diethyl etherate (127.2 g) was added, and the resulting mixture was allowed to warm to −45° C. After 1.5 hours, a solution of 2-(S)-[N-(tert-butoxycarbonyl)amino]-3-methylbutanal (90 g) in tetrahydrofuran (60 ml) was added dropwise at −45° C. and allowed to warm to −15° C. The reaction mixture was quenched by addition of a saturated aqueous solution of ammonium chloride, and extracted with ethyl acetate. The extract was washed with water (×3) and a saturated aqueous solution of sodium chloride, dried over anhydrous sodium sulfate and concentrated. The residue was purified by column chromatography on silica gel (Merck 7734) (ethyl acetate:hexane=1:20→1:1) to give 1-[2-(5-tert-butyl)-1,3,4-oxadiazolyl]-2-(S)-(tert-butoxycarbonylamino)-3-methylbutan-1-ol (78.6 g) having the following physical data.
TLC: R f =0.42, hexane:ethyl acetate (1:1).
1 H NMR (CDCl 3 ): δ 5.16-4.90 (2H, m), 4.67 (1H, m), 4.23 (1H, m), 3.90 (1H, m), 3.66 (1H, m), 1.98 (1H, m), 1.42, 1.41 and 1.36 (total 18H, each s), 1.13-0.90 (6H, m).
D. 1-[2-(5-tert-Butyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol Hydrochloride
To a solution of 1-[2-(5-tert-butyl)-1,3,4-oxadiazolyl]-2-(S)-(tert-butoxycarbonylamino)-3-methylbutan-1-ol (76.3 g) in dioxane (200 ml) was added 4N hydrochloric acid in dioxane solution (1000 ml) at 0° C. The reaction mixture was concentrated under reduced pressure. The residue was solidified with diethyl ether. The solid was azeotroped with benzene several times to give 1-[2-(5-tert-butyl)-1,3,4-oxadiazolyl]-2-(S)-ainino-3-methylbutan-1-ol hydrochloride (66.1 g) having the following physical data.
TLC: R f =0.30, chloroform:methanol (10:1);
1 H NMR (CDCl 3 ): δ 8.50-8.10 (2H, br), 7.10-6.80 (1 H, br), 5.55-5.35 (1H, m), 3.95-3.60 (2H, m), 2.10 (1H, m), 1.41 (9H, s), 1.20-1.00 (6H, m).
E. 2-[6-Oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrinidinyl]-N-[1-(2-[5-tert-butyl-1,3,4-oxadiazol]hydroxymethyl-)2-(S)-methylpropyl]acetamide
To a solution of 1-[2-(5-tert-butyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol hydrochloride (10.76 g), [6-oxo-2-(4flurophenyl)-1,6-dihydro-1-pyrimidinyl]acetic acid (8.63 g) and 1-hydroxybenzotriazole (5.85 g) in dimethylformamide (100 ml) was added 1-ethyl-3-[3-(dimethylamino) propyl]carbodiimide (7.33 g) at 0° C. To the resulting mixture was added 4-methylmorpholine (4.21 ml) at the same temperature. The reaction mixture was stirred for 17 hours at room temperature. The reaction was quenched by addition of water, extracted with ethyl acetate (×3). The extract was washed with aqueous 10% citric acid solution, a saturated aqueous solution of sodium hydrogencarbonate, water and a saturated aqueous solution of sodium chloride. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure to 2-[6-oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrnmidinyl]-N-[1-(2-[5-tertbutyl 1,3,4-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]acetarnide (14.6 g) having the following physical data.
TLC: R f =0.40, chloroform:methanol (10:1);
1 H NMR (DMSO-d 6 ): δ 8.00 and 7.94 (each 1H, each d, J=6.6 Hz), 7.71 and 7.55 (each 2H, each m), 7.19 and 7.18 (each 2H, each J=6.6 Hz), 6.43 and 6.3 8 (each 1H, each d, J=6.6 Hz), 5.13 (1H, d, J=2.2 Hz), 5.05 (1H, d, J=4.4 Hz), 4.54 (2H, s), 4.43 (2H, m), 4.31 (1H, m), 4.04 (1H, m), 2.20-1.52 (1H, m), 1.41 and 1.37 (each 9H, each s), 1.08, 1.00, 0.94 and 0.92 (each 3H, each d, J=6.6 Hz).
Example 5
2-[5-Benzyloxycarbonylamino-6-oxo-2-(4-fluorophenyl)-1,6-dihydro-l-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]acetamide
The compound was prepared using a similar oxidative procedure as described in Example 1 utilizing 2-[5-benzyloxycarbonylamino-6-oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]acetamide for the 2° alcohol. The title compound, 2-[5-benzyloxycarbonylamino-6-oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]acetamide, gave the following physical data.
TLC: R f =0.66, chloroformn:methanol (10:1);
1 H NMR (CDCl 3 ): δ 8.76 (1H, brs), 7.63-7.52 (2H, m), 7.49 (1H, brs), 7.38 (5H, brs), 7.13 (2H, t, J=8.6 Hz), 6.82-6.74 (3H, m), 6.71 (1H, brd, J=8.6 Hz), 5.94 (2H, s), 5.42 (1H, dd, J=8.6, 5.0 Hz), 5.22 (2H, s), 4.58 (2H, brs), 2.50 (1H, m), 1.83 (6H, s), 1.05 and 0.86 (each 3H, each d, J=7.0 Hz).
The intermediate 2-[5-benzyloxycarbonylamino-6-oxo-2-(4-fluorophenyl)-1,6-dihydro-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]acetamide was prepared in an analoguous manner as described in Example 1 E using [5-benzyloxycarbonylamino-6-oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]acetic acid and 1-[2(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol hydrochloride. The intermediate 1-[2-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol hydrochloride was prepared using a similar procedure as described in Example 1 D. The heterocyclic intermediate 2-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazole gave the following physical data.
TLC: R f =0.69, chloroform:methanol (10:1).
1 H NMR (CDCl 3 ): δ 8.30 (1H, s), 6.78(1H, brs), 6.74(2H, brs), 5.94 (2H, s), 1.81 (6H, s).
Example 6
2-[5Amino-6-oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl]acetamide
To 2-[5-(benzyloxycarbonylamino)-6-oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]acetamide (1.42 g) was added 30% hydrobromic acid in acetic acid solution (50 ml). The reaction mixture was stirred for 1 hour at room temperature. The reaction mixture was quenched by addition of ice water, extracted with ethyl acetate (×2). The combined extracts were washed with water (×2) and a saturated aqueous solution of sodium chloride. The organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel using a gradient elution of 50 to 100% ethyl acetate/hexane to give 2-[5-amino-6-oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl]acetamide (457 mg) having the following physical data.
TLC: R f =0.39, ethyl acetate.
1 H NMR (CDCl 3 ): δ 7.53 (2H, dd, J=8.8, 5.3 Hz), 7.48 (1H, s), 7.06 (2H, t, J=8.8 Hz), 6.90 (1H, brd, J=8.4 Hz), 6.84-6.70 (3H, m), 5.95 (2H, s), 5.43 (1H, dd, J=8.4, 4.8 Hz), 4.63 and 4.54 (each 1H Abq, J=15.0 Hz), 4.05 ((2H, brs), 2.51 (1H, m), 1.84 (6H, s), 1.06 and 0.87 (each 3H, each d, J=7.0 Hz).
Example 7
2-[5-Benzyloxycarbonylamino-6-oxo-2-pheny-1-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl]acetamide
The compound was prepared using a similar oxidative procedure as described in Example 1 utilizing 2-[5-benzyloxycarbonylamino-6-oxo-2-phenyl-1,6-dihydro4-pyrimidinyl]-N-[1-(2-[-5(α,α-dimethyl-3,4methylenedioxybenzyl)-1,3,4-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyljacetamide for the 2° alcohol. The title compound, 2-[5-benzyloxycarbonylamino-6-oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl]acemide gave the following physical data.
TLC: R f =0.34, hexane:ethyl acetate (1:1).
1 H NMR (CDCl 3 ): δ 8.78 1H, brs), 7.60-7.30 (1H, m), 6.78 (3H, m), 6.68 (1H, d, J=8.8 Hz), 5.94 (2H, s), 5.42 (1H, dd, J=8.8, 4.8 Hz), 5.23 (2H, s), 4.65 and 4.57 (2H, Abq, J=15.0 Hz), 2.49 (IH, m), 1.83 (6H, s), 1.04 (3H, d, J=6.0 Hz), 0.84 (3H, d, J=5.8 Hz).
The intermediate 2-[5-benzyloxycarbonylamino-6-oxo-2phenyl-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]acetamide was prepared in an analogous manner as described in Example 1 E using 5-benzyloxycarbonylamino-6-oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]acetic acid and 1-[2-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol hydrochloride. The intermediate 1-[2-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol hydrochloride was prepared using a similar procedure as described in Example 1 D. The heterocyclic intermediate 2-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazole gave the following physical data.
TLC: R f =0.69, chloroform: methanol (10:1).
1 H NMR (CDCl 3 ): δ 8.30 (1H, s), 6.78(1H, brs), 6.74(2H, brs), 5.94 (2H, s), 1.81 (6H, s).
Example 8
2-[5-Amino-6-oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl]acetamide
The compound was prepared using a similar procedure as described in Example 3 utilizing 2-[5-benzyloxycarbonylamino-6-oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,αdimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]acetamide. The title compound 2-[5-Amino-6-oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]acetamide gave the following physical data.
TLC: R f =0.40, ethyl acetate.
1 H NMR (CDCl 3 ): δ 7.59-7.34 (5H, m), 7.50 (1H, s), 6.86 (1H, d, J=8.2 Hz), 6.86-6.72 (3H, m), 5.95 (2H, s), 5.43 (1H, dd, J=8.2 and 4.8 Hz), 4.66 1H, d, J=15.4 Hz), 4.56 (2H, f, J=15.4 hz), 4.05 (2h, brs), 2.62-2.36 (1H, m), 1.84 (6H, s), 1.05(3H, d, J=7.0 Hz), 0.85 (3H, d, J=7.0 Hz).
Example 9
2-[6-oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl] acetamide
TLC: R f =0.46, ethyl acetate.
1 H NMR (CDCl 3 ): δ 8.01 (1H, d, J=6.6 Hz), 7.65-7.35 (5H, m), 6.87 (1H, d, J=8.6,Hz), 6.85-6.70 (3H, m), 6.49 (1H, d, J=6.6 Hz), 5.95 (2H, s), 5.42 (1H, dd, J=8.6 and 5.0 Hz), 4.67 (1H, d, J=15.2 Hz), 4.54 (1H, d, J=15.2 Hz), 2.63-2.37 (1H, m), 1.84 (6H, s), 1.05 (3H, d, J=6.8 Hz), 0.85 (3H, d, J=6.8 Hz)
Example 10
2-[6-oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl] acetamide
TLC: R f =0.43, ethyl acetate.
1 H NMR (CDCl 3 ): δ 7.99 (1H, d, J=6.6 Hz), 7.63 (2h, dd, J=8.6, 5.2 Hz), 7.14 (2H, t, J=8.6 Hz), 6.93 (1H, brd, J=8.6 Hz), 6.84-6.70 (3H, m), 6.49 (1H, d, J=6.6 Hz), 5.95 (2H, s), 5.41 (1H, dd, J=8.6, 5.0 Hz), 4.64 and 4.53 (each 1H, Abq, J=I 5.0 Hz), 2.50 (1H, m), 1.84 (6H, s), 1.06 and 0.87 (each 3H, each d, J=7.0 Hz).
Example 11
2-[6-oxo-2-(4-fluorophenyl-)1,6-dihydro4-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)methylpropyl]acetamide
The compound was prepared using a similar oxidative procedure as described in Example 1 utilizing 2-[6-oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]acetamide for the 2° alcohol. The title compound, 2-[6-oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethylbenryl)-1,3,4-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]acetamide, gave the following physical data.
TLC: R f =0.42, ethyl acetate.
1 H NMR (CDC 13): δ 7.99 (1H, d, J=6.5 Hz), 7.62 (2H, m), 7.40-7.20 (5H, m), 7.14 (2H, t, J=8.8 Hz), 6.89 (1H, brd, J=8.6 Hz), 6.49 (1H, d, J=6.5 Hz), 5.42 (1H, dd, J=8.6, 5.0 Hz), 4.61 and 4.54 (each 1H, each d, J=15.0 Hz), 2.50 (1H, m), 1.88 (6H, s), 1.06 and 0.86 (each 3H, each d, J=6.71 Hz).
The intermediate 2-[6-oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]acetamide was prepared in an analoguous manner as described in Example 1 E using [6-oxo-2-(4-fluoropheny-1)1,6-dihydro-1-pyrimidinyl]acetic acid and 1-[2-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol hydrochloride. The intermediate 1-[2-(α,α-dimethyl-3,4-methylenedioxybenzyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol hydrocloride was prepared using a similar procedure as described in Example 1 D. The heterocyclic intermediate 2-(α,α-dimethylbenyl)-1,3,4-oxadiazole gave the following physical data.
TLC: R f =0.43, ethyl acetate:hexane (1:2).
1 H NMR (CDCl 3 ): δ 8.31 (1H, s), 7.40-7.14 (5H, m), 1.86 (6H, s).
Example 12
2-[6-oxo-2-phenyl-1,6-dihydro-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)-methylpropyl]acetamide
The compound was prepared using a similar oxidative procedure as described in Example 4 utilizing 2-[6-oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]acetamide for the 2° alcohol. The title compound, 2-[6-oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]carbonyl)-2-(S)-methylpropyl]atetamide, gave the following physical data.
TLC: R f =0.44, ethyl acetate.
1 H NMR (CDCl 3 ): δ 8.02 (1H, d, J=6.5 Hz), 7.64-7.24 (10H, m), 6.82 (1H, brd, J=8.4 Hz), 6.50 (1H, d, J=6.5 Hz), 5.44 (1H, dd, J=8.4, 4.8 Hz), 4.63 and 4.56 (each 1H, each d, J=15.4 Hz), 2.50 (1H, m), 1.89 (6H, s), 1.06 and 0.86 (each 3H, each d, J=6.8 Hz).
The intermediate 2-[6-oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]hydroxymethyl)-2-(S)-methylpropyl]acetamide was prepared in an analoguous manner as described in Example 1 E using [6-oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]acetic acid and 1-[2-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]-2-(S)-amino-3-methylbutan-1-ol hydrochloride.
Example 13
2-[5-Methyloxycarbonylamino-6-oxo-2-phenyl-1,6-dihydro4-pyrirnidinyl]-N-[1 -(2-[5-(tert-butyl)-1,3,4-oxadiazolyl]carbonyl)-2-(R,S)methylpropyl]acetamide.
Prepared by a procedure analogous to that of Example 7. The product had the following physical data.
TLC: R f =0.57methanol:chloroform, 1:10.
1 H NMR (200 MHz, CDCl 3 ): 8.78 (brs, 1H, H of pyrimidinone), 7.62-7.40 (m, 6H, NH and aromatic Hs), 6.73 (brd, J=8.4 Hz, 1H, CONH), 5.45 (dd, J=8.4, 5.0 Hz, 1H, α CH of Val), 4.67 and 4.61 (each d, J=15.0 Hz, each 1H, CH 2 of Gly), 3.81 (s, 3H, CH 3 O), 2.512 (m, 1H, CH of iso-Pr), 1.48 (s, 9H, CH 3 s of t-Bu), 1.07 and 0.88 (each d, J=6.8 Hz, each 3H, CH3s of iso-Pr).
Example 14
In Vitro Inhibition of Elastase
The following protocol was used to determine inhibitory activity of compounds described herein. The elastase used in the protocol was derived from human sputum (HSE). A mother solution of the HSE enzyme was prepared from commercially available HSE (875 U/mg protein, SE-563, Elastin Product Co., Inc, Missouri, USA) by diluting with saline to 1,000 U/ml, which was flirdier diluted to 2 U/ml at 0° C. prior to use.
A solution was prepared by mixing 100 μl 0.2 M HEPES-NaOH buffer (pH 8.0), 40 μl 2.5 M NaCl, 20 μl 1% polyethyleneglycol 6000, 8 μl distilled water, 10 μl of a DMSO solution of inhibitor and 2 μl solution of N-methoxysuccinyl-Ala-Ala-Pro-Val-p-nitroaniline (SEQ ID NO:1)(at concentrations of 100, 200 and 400 μM). The solution was incubated for 10 minutes at 37° C. To this was added an enzyme solution of HSE (elastase derived from human sputum). The resulting mixture was subjected to the following rate assay.
Optical density (SPECTRA MAX 250, Molecular Devices) at 405 nm due to p-nitroaniline generated by the enzyme reaction was measured at 37° C. in order to measure the reaction rate during the period that the production rate of p-nitroaniline remains linear. The rate, mO.D./min., was measured for 10 minutes at 30 second intervals immediately after the addition of the enzyme solution. IC 50 values were determined by log-logit method and converted to K I values by Dixson plot method. The compounds are presented in Table 2 g the inhibition activity (K I values, nM) against HNE.
TABLE 2
Biological Activity
Example
Name
K I (nM)
1
Methyloxycarbonyl-L-valyl-N-[1-(2-[5-(tert-butyl)-
3.0
1,3,4-oxadiazolyl]carbonyl)-2-(S)-methyl-propyl]-
L-prolinamide
2
Methyloxycarbonyl-L-valyl-N-[1-(2-[5-
1.32
(α,αdimethylbenzyl)oxadiazolyl]carbonyl)-2-(S)-
methylpropyl]-L-prolinamide.
3
Methyloxycarbonyl-L-valyl-N-[1-(2-[5-(α,α-di-
0.24
methyl-3,4-methylenedioxybenzyl)-1,3,4-oxadia-
zolyl]carbonyl)-2-(S)-methylpropyl]-L-prolinamide.
4
2-[6-Oxo-2-(4-fluorophenyl)-1,6-dihydro-1-
44.4
pyrimidinyl]-N-[1-(2-[5-tert-butyl-1,3,4-oxadiazol-
yllcarbonyl-2-(R,S)-methylpropyl]acetamide
6
2-[5-Amino-6-Oxo-2-(4-fluorophenyl)-1,6-dihydro-
0.51
1-pyrimidinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-
methylenedioxybenzyl)-1,3,4-oxadiazolyl]carbonyl-
2-(R,S)-methylpropyl]acetamide
8
2-[5-Amino-6-Oxo-2-phenyl-1,6-dihydro-1-pyri-
1.06
midinyl]-N-[1-(2-[5-α,α-dimethyl-3,4-methylene-
dioxybenzyl)-1,3,4-oxadiazolyl]carbonyl-2-(R,S)-
methylpropyl]acetamide
9
2-[6-Oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]-N-
0.34
[1-(2-[5(α,α-dimethyl-3,4-methylenedioxybenzyl)-
1,3,4-oxadiazolyl]carbonyl-2-(R,S)-methyl-
propyl]acetamide
10
2-[6-Oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimi-
1.53
dinyl]-N-[1-(2-[5-(α,α-dimethyl-3,4-methylene-
dioxybenzyl)-1,3,4-oxadiazolyl]carbonyl-2-(R,S)-
methylpropyl]acetamide
11
2-[6-Oxo-2-(4-fluorophenyl)-1,6-dihydro-1-pyrimi-
5.34
dinyl]-N-[1-(2-[5-(α,α-dimethylbenzyl)-1,3,4-
oxadiazolyl]carbonyl)-2-(R,S)-methylpropy-
flacetamide
12
2-[6-Oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl]-N-
1.83
[1 -(2-[5-(α,α-dimethylbenzyl)-1,3,4-oxadiazolyl]
carbonyl)-2-(R,S)-methylpropyl]acetamide
Example 15
Ex vivo inhibition of elastase
Sixty (60) minutes after the oral administration of an inhibitor with an appropriate vehicle, a blood sample (0.9 ml) is collected through the abdominal aorta by a syringe containing 0.1 ml of a 3.8% sodium citrate solution.
The blood sample is processed as follows: 60 μl of (final 0.1-1 mg/ml) a suspended solution of opsonized zymosan in Hank's buffer is added to the preincubated whole blood (540 μl) for 5 minutes at 37 ° C., and the resulting mixture is incubated for 30 minutes at the same temperature. The reaction is terminated by immersing the test tube into ice water. The reaction mixture is then centrifuged at 3,000 rpm for 10 minutes at 4° C. Twenty (20) μl of each of the resulting supernatant (the Sample) is measured for elastase activity.
The mixture consisting of the following components is incubated for 24 hours at 37° C., and then optical density is measured at 405 nm:
0.2 M tris-HCI buffer (pH 8.0)
100 μl
2.5 M NaCl
40 μl
Distilled water
36 μl
50 mM solution of a substrate (*)
4 μl
The Sample
20 μl
*N-Methylsuccinyl-Ala-Ala-Pro-Val-p-nitroaniline (SEQ ID NO: 1)
A test sample mixed with 1-methyl-2-pyrrolidone instead of the substrate is regarded as Substrate (−). A test sample mixed with saline instead of the Sample is regarded as Blank. The remaining elastase activity in the Sample is calculated according to the following:
optical density of Substrate (+)−(optical density of Substrate (−)+optical density of Blank)
as a total production of p-nitroaniline over 24 hours based on a standard curve for the amount of p-nitroaniline.
An average activity is calculated based on the test sample of 5-6 animals. An agent at 3, 10 or 30 mg/kg is orally given by a forced administration to a 24 hour fasted animal at 60 minutes before the blood sampling. Optical density is measured by SPECTRA MAX 250 (Molecular Devices).
Some representative results are given in Table 3.
TABLE 3
Representative Results of Ex-Vivo Studies
Percent Inhibition at Indicated Dosage
Example
3 mg/kg
10 mg/kg
30 mg/kg
2
7%
9%
62%
3
44%
69%
99%
1
1
4
PRT
Artificial Sequence
Sequence is a known commercially available
substrate for elastases.
1
Ala Ala Pro Val
|
The present invention relates to certain substituted oxadiazole peptoids and nonpeptoids useful as inhibitors of serine proteases, especially human neutophil elastase (HNE). Compounds of the present invention are useful for the treatment or amelioration of symptoms of adult respiratory distress syndrome, septic shock, and multiple organ failure. Processes mediated by HNE are also implicated in conditions such as arthritis, periodontal disease, glomerulonephritis, and cystic fibrosis.
| 2
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to logging instrumentation for oil field wells, and more particularly to methods and instruments that can communicate topside over a standard, non-insulated slickline from substantial exploration depths.
[0003] 2. Description of the Prior Art
[0004] The oil-field industry uses two basic types of logging methods to explore oil and gas wells, e.g., slickline and wireline. Dropping a series of sensing tools, such as porosity tools, gamma tools, pipe-collar detectors, etc. Getting the info out of the hole.
[0005] Wireline has a large-diameter cable that mechanically supports the hanging instrument. A wireline truck on the surface is required in support, and such is large and expensive. A data cable supplies power and provides a communication connection down the well to the instrument. But wireline data cable is very difficult to use in high-pressure wells because of its large diameters. The pressure on the well will work across the entire diameter at the top seals, so at high pressures only thin monofilaments are practical to seal.
[0006] Slickline techniques are used. But they are not real-time, and data is recorded in memory that is later read-out on the surface. Battery power only. Solid wire ⅛ inch to 60/1000 inch, e.g., like piano-wire. Tool string can weigh 200 pounds, and such weigh may not be enough to pull the whole down given the well. Only the cable depth is provided. If the logging discovered something interesting, the whole procedure must be repeated.
[0007] Slickline logging tools have been developed in recent years to enable data collection in deep oil and gas wells. The well casing is completed by setting pipe and grouting it in place with cement. The cement seals the annulus between the soil and the outside diameter of the pipe. The top of the pipe is threaded and a blow-out preventer is screwed on. Such closing valve and a second pipe provide a sealable standpipe. The standpipe is long enough to accommodate a logging tool with a top sub attached to the slickline cable. The cable exits a lubricator through a sealing gland that enables the slick line to enter the sealed standpipe under pressure. When the gate valve is fully opened, the logging tool descends into the well casing, maintaining a seal with the slick line as the hoist lowers the logging tool into the holes.
[0008] Conventional slickline logging tools are designed with internal recording memory to log data during descent and ascent in the hole. After returning from the well, recorded digital data is read out on the surface and chart recordings are used to display the data for analysis.
[0009] What is needed is a data communication system that can support real-time data transmissions of oil-field logging instrumentation over conventional non-insulated solid-wire slicklines.
SUMMARY OF THE PRESENT INVENTION
[0010] Briefly, a slickline data transmission system embodiment of the present invention comprises radio frequency couplers at each end of a slickline that communicate with associated transceivers using radio FSK carriers. The down-the-hole data transmission system interfaces to standard toolstrings and communicates readings and data up to the surface equipment. Duplex repeaters are strategically positioned at intervals along very long slicklines. Commands can be issued and sent down to the toolstring as is commonly done in wireline systems.
[0011] An advantage of the present invention is that a data transmission system is provided that supports real-time communication with a down-the-hole toolstring on a conventional non-insulated solid-wire slickline.
[0012] A further advantage of the present invention is that a data transmission system is provided that interfaces directly to a slickline toolstring.
[0013] A still further advantage of the present invention is that a system is provided that saves rigging up and rigging down time on location.
[0014] Another advantage of the present invention is that a data transmission system is provided that supports perforating capability over a slickline used in real-time communication.
[0015] These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment which is illustrated in the various drawing figures.
IN THE DRAWINGS
[0016] FIG. 1 is a diagram of a slickline data logging system embodiment of the present invention;
[0017] FIG. 2 is a functional block diagram of a data transmission system embodiment of the present invention;
[0018] FIG. 3 is a side view diagram of a slickline attachment embodiment of the present invention; and
[0019] FIG. 4 is a perspective view diagram of a DTS embodiment of the present invention to fit within a one-inch diameter tubing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] FIG. 1 represents a slickline data logging system, and is referred to herein by the general reference numeral 100 . The system 100 is used in an oil-field at a well. A slickline 102 , resembling a piano wire 0.060 to 0.125 inches in diameter is used to support a down-the-hole instrument package. The slickline feeds down from the surface through a standpipe 104 connected to a drillhole casing 106 . These are secured in a concrete setting 108 . Industry standard slickline wires are made of stainless steel and are not insulated. It may be advantageous in embodiments of the present invention to use slicklines with metal oxide or polymer film insulating coatings to provide for electrical insulation and better signal transmission down hole. In any event, to be a commercial success, embodiments of the present invention are retrofittable to existing conventional equipment.
[0021] Very high pressures can exist within drillhole casing 106 , and so greased packing glands 110 and 112 are used to seal the slickline 102 against the pressure inside the standpipe 104 . Typically, these packing glands 110 and 112 are split plugs that can be clamped around the slickline and stuffed inside the standpipe 104 with special slickline grease. Each packing gland 110 and 112 is about one foot long, has a 0.050 inch clearance, and each can seal a pressure differential of 1500 PSI. Sealing 15,000 PSI will therefore require ten such packing glands. An air bladder 114 is inflated inside standpipe 104 to retain the packing glands 110 and 112 .
[0022] A valve 114 is used as a blow-out preventer and can be used to close down and seal around slickline 102 . If necessary, it can cut through slickline 102 and close off completely. But doing so would jettison the down-the-hole instrument package and be very costly.
[0023] The down-the-hole instrument package is mechanically hoisted by a sucker rod 116 connection with an adapter 118 to a data transmission system (DTS) 120 and a toolstring 122 . The toolstring uses industry standard time division multiple access (TDMA) pulse communication formats and interfaces to report data and to respond to commands. For example, it uses the interface standard with the Scientific Data Warrior System.
[0024] According to company information published at, http://www.scientificdata.com/products.htm, the Warrior Well Logging System comprises a tool interface and power supply panel, a computer, a printer and optional depth, line speed, line weight panel, and perforating power supply. The software supports cased hole logging tools from a wide selection of tool manufacturers. The tool interface panel contains circuits to interface to cased hole tools, both analog and digital. The depth encoder and line weight interfaces are built into the panel, as is the down hole tool power supply. All functions are digitally controlled from the software, with the power supply having a manual control mode. The panel incorporates data acquisition functions primary DSP based, that interface to a host computer through the industry standard Universal Serial Bus (USB). A seven port USB hub is also incorporated inside the panel allowing a single cable connection to the host computer. The computer runs Windows 98, ME, 2000, or XP, with a USB port. A second monitor may be attached to provide a hoistman's or client's display. The system supports thermal well log plotters and color printers. A depth, line speed and line weight panel provides 12-VDC powered, independent depth measurement. It connects to the host computer through the USB and is synchronized from the host depth or the host depth may be read from the depth panel. An optional perforating power supply is available. The software provides all the usual well logging functions and supports tools from a wide selection of manufacturers.
[0025] Embodiments of the present invention provide an inductively coupled radio communication link between a surface data logger and the down-the-hole logging tool. For example, a coupler 124 allows a surface instrumentation 126 to communicate over a radio frequency shift keyed (FSK) carrier with the DTS 120 . A software programmable digital modem inside the DTS 120 provides for signal and format translations compatible with toolstring 122 .
[0026] The standpipe 104 can comprise a non-metallic chamber storing multiple radio repeaters. These can be snapped on the slickline at various intervals when needed to ensure high signal-to-noise ratio during descent of the logging tool into the well. The coupler 124 is a loop antenna and can be axially or longitudinally wound with or without a ferrite core. The best choice between cores and windings depends on the particular installation and the nature of the well being instrumented. A surface instrument 126 provides for user readout of data being transmitted by the toolstring 122 . It can further provide for issuing commands to the toolstring 122 , e.g., to operate a perforating device.
[0027] Extremely long slickline applications may require the inclusion of a duplex repeater 128 . A simple repeater receives on an F 1 frequency, stores the demodulated data, and retransmits it again on the same F 1 frequency. A more elaborate repeater can communicate on a first frequency F 1 with the surface instrumentation 126 , while simultaneously translating and communicating with the DTS 120 on a second frequency F 2 . Multiple repeaters 128 may be used at intervals for even longer slicklines or where the attenuation losses warrant.
[0028] FIG. 2 represents a data transmission system (DTS) embodiment of the present invention, and is referred to herein by the general reference numeral 200 . The DTS 200 here is similar to the one shown in FIG. 1 but includes the toolstring. DTS 200 comprises a protective housing 202 that is lowered into a borehole on the end of a slickline 204 . A pigtail section of the slickline extends inside and is inductively coupled to by a loop antenna 206 . Its distal end is grounded to the casing.
[0029] Experiments conducted have tested various antenna configurations including longitudinal winding, axial winding, air core, ferrite core, coaxial, and side-by-side arrangements. Prototypes have used loop antennas with 3-ohm input impedances. The antenna resonance is trimmed at the factory with a tuner 208 to get a purely resistive impedance at the operating frequency of radio. Other frequencies could be used, especially if there is noise on this particular channel. A simplex system is shown here, but a full-duplex system with different transmit and receive frequencies could also be used.
[0030] A receive/transmit (Rx/Tx) switch 210 accepts amplified transmission signals from a class-L amplifier 212 . During receive mode, it steers signals received down the slickline 204 to a modem 214 . A tuning capacitor is placed in parallel during receive, and in series during transmit. The class-L amplifier 212 can be implemented as is described in U.S. patent application Ser. No. 10/046,793, filed Nov. 15, 2002, and Ser. No. 11/062,241, filed Feb. 22, 2005, by two of the present inventors, I. BAUSOV and L. STOLARCZYK.
[0031] An isolated ground and power distribution 216 is provided by a DC/DC isolator 218 from a toolstring battery 220 . The power isolation, and DC signal isolation provided by an opto-isolator 222 are needed to be able to induce signals on the pigtail slickline 204 . Otherwise, the FSK signals would be shorted out to case 202 .
[0032] Modem 214 is fully programmable and completely under software control. Digital signal processing (DSP) techniques are used to input and output a very flexible range of signal formats, carriers, and modulations. Here, in this embodiment, the modem 214 interfaces with radio FSK transmissions on slickline 204 and translates the modulation format to suit the industry standard toolstring TDMA communications with a toolstring instrumentation 224 . Such toolstring instrumentation is conventional, and so is not described further herein.
[0033] In one embodiment, modem 214 is programmed to look for quiet channel frequencies on the slickline and to then use those quiet channels for subsequent communication sessions. Other embodiments may be addressable. Modem 214 may also adopt code division multiple access (CDMA) modulation communication formats in particularly noisy and attenuated applications. The CDMA communication common to the global positioning system (GPS) is one example of how to receive exceedingly faint signals.
[0034] Embodiments of the present invention enable slickline toolstring instrumentation 224 to operate in a real-time mode, as do conventional wireline toolstrings. Essentially, this means the surface can communicate with the toolstring while down-the-hole.
[0035] FIG. 3 illustrates a slickline instrument attachment 300 that allows an internal antenna to couple signals to the distal end of a slickline. Attachment 300 comprises a slickline 302 that is locked onto with a brass wedge 303 inside a wire rope socket (sucker rod) 304 . An isolator 305 screws onto the bottom of rope socket 304 and electrically isolates the bottom part with an insulator washer 306 and an insulated bolt 307 . Bolt 307 is in electrical contact with slickline 302 , but its bottom half is isolated from but still carries the weight of an adapter 308 . A pigtail 309 contacts bolt 307 , e.g., with a spring-loaded pin, and terminates at a distal end inside an instrument housing 310 . A loop antenna 312 is coupled to the pigtail 309 to induce and receive signals in the rest of slickline 302 .
[0036] High pressure wells are also associated with high temperatures. So the construction of the DTS 200 ( FIG. 2 ) must include materials and techniques that will allow the electronics to operate properly. A metal chassis is used as a foundation to which are attached several printed circuit boards (PCB's). Polyethylene ketone (PEK), mica, and other high temperature insulation materials are used to electrically isolate the PCB's from the metal chassis. This allows ground and power distribution 216 to float relative to the chassis and protective housing 202 .
[0037] In extreme high temperature applications, the semiconductors used to implement the various electronics modules will need to be selected types, e.g., military types. The chassis and its PCB's may also need to be enclosed in a protective and insulative Dewar flask.
[0038] FIG. 4 represents a DTS 400 that has been implemented to fit within a one-inch tube. A metal chassis 402 has mounted to it several individual PCB's 404 - 411 . These PCB's implement the functional blocks illustrated in FIG. 3 , and can further include modules for navigation, power control, etc. A navigation module would be useful in generating a dead reckoning position solution. The power control module would be useful to turn off other functions that will not be needed until later.
[0039] Although the present invention has been described in terms of the presently preferred embodiments, it is to be understood that the disclosure is not to be interpreted as limiting. Various alterations and modifications will no doubt become apparent to those skilled in the art after having read the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all alterations and modifications as fall within the true spirit and scope of the invention.
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A slickline data transmission system for a high pressure oil-field well comprises inductive couplers at opposite ends of a slickline in order to establish real-time radio communication between down-the-hole logging toolstrings and supervisory control and data acquisition equipment on the surface. A frequency shift keyed (FSK) carrier centered around radio is used to send data up to the surface and commands back down to the toolstring. The toolstring itself can be a conventional one with a TDMA interface originally intended to be memory-dumped when the toolstring is returned to the surface.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to improved environmental design of work surfaces utilized for desk work and more particularly of a desk top work support device for sustained combination reading and writing tasks.
2. Description of the Prior Art
Sustained close visually-centered tasks such as reading and writing separately and in combination result in certain interactions between the work support mechanisms, the body support mechanisms, and the human organism. To understand these relationships a dynamic/adaptive concept of posture and vision is necessary as developed by Harmon, Darell Boyd, Notes on a dynamic theory of vision, 3d revision, Austin, Texas, The Author, 1958; The coordinated classroom; Grand Rapids, Mich. American Seating Co. 1951, and articulated further by Moran, Walter J., The design of a basic home study unit, Term paper for Environmental Design 801, Madison, University of Wisconsin, 1969. This concept states, briefly, that the body tends to grow or adapt along lines of stress. The body and especially the torso will reflexively position itself so that an object to be viewed is essentially perpendicular to the observer's line of sight. For a close visual or eye motor task as might be ordinarily performed when using a flat desk and a chair, a person must hunch over the table to obtain adequate visual contact. The short term effects of this hunching are a sacrifice of comfort and premature fatigue and/or restlessness. The longer term effects are the result of postural accomodations which typically exceed the normal limits of human adaptation and lead to a series of problems, important among which are the inability to characteristically stand erect, concomitant vision problems, and finally a progression of osteo arthritis of the neck and/or lower back.
These conditions can be minimized or perhaps even prevented by adequate work environment design. For sustained combination reading and writing tasks such an adequate work environment design includes a secondary work support member for predominantly reading tasks placed in relative close proximity, typically about 16 inches, to the user at an inclination of approximatey 70° with the horizontal, a primary work support surface for predominantly writing tasks placed at approximately 20° with the horizontal, and a geometric relationship between the secondary work support member and the primary work support surface to allow note taking during reading tasks.
In addition, I have found that when it is necessary to engage in sustained combination reading and writing tasks it is desirable that the secondary work support member should be movable to a second position more distant from the user wherein the secondary work support member will support reference materials for secondary or occasional reading but will not interfere with unrestricted use of the primary work surface. However, if the primary work surface and secondary work support member are properly lighted, movement of the secondary work support member would frequently cause lighting problems unless the inclination of the support member is adjusted.
The use of an inclined work surface is well known, as in the drafting table art. The use of raised work holders is also well known, as in work stands for holding copy in connection with typing tasks, and in music stands for holding music for musicians. Although limited attempts have been made to combine a book support or similar work holder with a desk, none have satisfactorily provided a combination of inclined primary work surface and secondary work support member which is both movable and provides a desirable change of inclination between forward reading positions and rearward secondary reference positions.
It is believed that my invention disclosed herein satisfies the conditions necessary for an adequate work environment relating to work surfaces in a manner that is heretofore unknown in the industry.
SUMMARY OF THE INVENTION
My new and improved desk top work support device includes a base having an inclined primary work surface upon which is pivotally mounted a secondary work support member that pivots to translate the position of the secondary work support member from a forward position directly over the primary work support surface to a rearward position substantially rearwardly displaced from the forward position. At the same time, the pivoting means changes the angle of the work support member with respect to the primary work surface.
The pivoting means comprises a pivotally connected four bar linkage which is a variation from the configuration of a parallelogram. With the top and bottom links unequal in length, the inclination of the secondary work support member which is connected to the top link changes as it is pivoted by the pivoting means from a preset forward to a preset rearward position. The preset forward position of the secondary work support member provides the user with a close reading surface which may preferably be inclined at approximately 70° to the horizontal. When the length of the top link is somewhat greater than the bottom link, the linkage provides the secondary work support member with a preset rearward position presenting a reading surface for secondary reference purposes which is inclined at approximately 50° to the horizontal, and which at the same time allows the operator full access to the inclined primary work surface for his writing task. Additionally, the operator's ability to select preset secondary work positions at said preferred inclinations of 70° and 50° eliminates glare problems when a light source is placed in a position which is optimum for illuminating the work surfaces, without requiring separate adjustment of the inclination of the support member by the operator at each separate position.
It is an object of the present invention to provide a desk top work support device of improved environmental design.
It is a further object of the present invention to provide a primary work surface and a rotatable secondary work support member to be used for sustained reading and/or writing tasks, separately or in combination.
An additional object of the present invention is to provide a desk top work support device which is highly portable and that can be used on any flat surface.
Other objects, features and advantages of my invention will be apparent from the following detailed description of the drawings wherein a preferred embodiment of the invention has been selected for exemplification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing my improved desk top work support device placed on a desk top.
FIG. 2 is a side view of my work support device showing preset forward and rearward positions of the secondary work support member in full and dotted lines, respectively, and having a knob portion cut away for purposes of illustration.
FIG. 3 is a section view taken along section line 3--3 of FIG. 2, in which one secondary work support holder is shown in a stored position.
FIG. 4 is a section view taken along section line 4--4 of FIG. 1.
FIG. 5 is an enlarged partial section view taken along section line 5--5 of FIG. 2, in which the secondary work support bar is only partially shown.
FIGS. 6 and 7 are side views showing an operator seated in front of schematically illustrated secondary work holders in the respective preferred forward and rearward positions provided by my improved desk top work support device.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more particularly to the drawings, wherein like numerals refer to like parts throughout the several views, FIG. 1 illustrates a preferred embodiment of my desk top work support device, generally represented by reference number 10, which is shown portably mounted on a desk top. The illustrated work support device 10 has a base 14 which supports an inclined primary work surface 12. A conventional thin fixed or removable drawing surface 11 may preferably be retained on the inclined work surface 12 by a front lip 13 which projects upwardly along the lower edge of the surface 12.
As best shown in FIG. 4 the primary work surface 12 is preferably supported at an angle C of approximately 20° with the horizontal by the base 14, which includes side rails 14a having rotatable rear legs 15. As best shown in FIGS. 3 and 4, the base 14 also includes a slotted rear storage bar 32 attached to and extending between the side rails 14a, which prevents further rearward rotation of the rear legs 15.
The primary work surface 12 is attached to the top surface of the side rails 14a by any conventional means such as gluing, bolting, clamping, or by my preferred use of attachment screws (not shown). Similarly, the slotted rear storage bar 32 can be secured to the inner side surfaces of the side rails 14a by any suitable means, such as attachment screws 41, shown in FIG. 2. The rotatable rear legs 15 can be attached by any conventional means that will allow the legs to rotate more than 90°. The rear legs 15 in the preferred embodiment can then be rotated upwardly adjacent the side rails 14a for convenient storage or transit as shown by the dotted lines in FIG. 4. For added stability and to prevent scratching the surface upon which the desk top work support device is placed, rubber feet 43 have been attached to the bottom surface of the side rails 14a and the rear legs 15.
A secondary work support member 16 suitable for holding books and other reference materials is pivotally mounted above the primary work surface 12 on a linkage represented generally by reference number 17. As best shown by FIGS. 3 and 4 the secondary work support member 16 is preferably of two parts, having a secondary work support bar 16a and an L-shaped secondary work support holder represented generally by reference number 34. As best shown by FIG. 2, the L-shaped secondary work support holder 34 has an upright plate 36, a lower arm 35, retaining arms 31 rotatably mounted on the front edge of the lower arm 35, and an extended lower section 37 which projects below the junction of the upright plate 36 and the lower arm 35. In FIG. 2, the knob 29 has been partially broken away for illustrative purposes.
As shown in FIG. 3 the secondary work support holders 34 can be slideably engaged in the slots 33 of the slotted rear storage bar 32 beneath the primary work surface 12 in a storage position. Only one secondary work support holder 34 is shown in such a storage position in FIG. 3 to better illustrate the structure and use of the slots 33. FIG. 4 illustrates that the secondary work support holders 34 are prevented from being withdrawn from the slots 33 by the secondary work support bar 16a when it is pivoted to its preset rearward position, as will be more fully described below. This storage and "locking" feature in conjunction with the folding of the rear legs 15 makes the illustrated preferred embodiment a compact and highly portable unit.
As best shown in FIG. 4, the secondary work support bar 16a has a J-shaped cross-section with a short front portion 16b and a longer rear portion 16c which in part define a longitudinal slot 16d. FIG. 2 shows the work support bar 16a removably engaging the work support holder 34 in the following manner. The extended lower section 37 is engaged within the longitudinal slot 16d. The rearside of the upright plate 36 bears against the longer support bar rear portion 16c. The lower portion of the front side of the upright plate 36 bears against the support bar front portion 16b. It is to be understood that the angular orientation of the slot 16d and the gravitational force on the inclined plate 36 assures retention of the work support holder 34 within the support bar 16a.
The secondary work support bar 16a is connected to the top link 21 of the subsequently described linkage 17 in rotatably adjustable relation. The preferred adjustable connection is shown in FIG. 5, and consists of a threaded shaft 24 attached to a short link 25, which is in turn attached to the end of the work support bar 16a by conventional means such as the illustrated attachment screws 40. The threaded shaft 24 passes through a spacer washer 28, a bevelled washer 27, and the top link 21 intermediate the ends thereof. A threaded nut 26 is rotatably positioned over the threaded shaft 24 and is integrally connected to a knob 29, which facilitates tightening and loosening of the threaded nut 26 to permit selective adjustment of the angular inclination of the work surface secondary work support bar 16a on the linkage 17.
The linkage 17 previously referred to preferably comprises a forward link 18, a rearward link 19, a bottom link 20, and a top link 21. The bottom link 20 is fixedly secured to the base 14 at the side rails 14a by conventional means such as the attachment screws 42 shown in FIG. 2. The linkage 17 has a preset forward position in which the secondary work support bar 16a extends across the primary work surface 12 near the mid-point thereof as shown in full lines in FIG. 2, and a preset rearward position in which the secondary work support bar 16a is located rearwardly from the primary work surface 12 to allow the operator full access to the primary work surface for writing tasks while supporting a reading surface for secondary reference purposes as represented in dotted lines in FIG. 2. It is also seen that the linkage 17 extends forwardly from the fixedly secured bottom link 20 while in its illustrated forward position, and extends rearwardly from link 20 when in its illustrated rearward position.
The preset forward and rearward positions are determined by the particular means used to limit the pivotal motion of the linkage 17. It is understood, for example, that such limiting means could be provided by placement of pins (not shown) on the side rails 14a. In the preferred embodiment, the top link 21 is connected to the inside surfaces of the forward and rearward links, as shown, and the illustrated forward and rearward positions are established when the threaded nut 26 which extends outwardly from the top link 21 engages the facing side edges 18a and 19a of the forward and rearward links, respectively, to prevent further pivotal rotation of the linkage 17. As shown in dotted lines in FIG. 4, the preset forward position preferably results in a clearance space between the secondary work support bar 16a and the primary work surface 12 adequate for placement of the writing surface 11 and the working papers.
The top link 21 is slightly longer than the bottom link 20 so that the linkage 17 is not a perfect parallelogram. As a result thereof, the angle of the top link 21 with respect to the horizontal decreases approximately 20° as the work support bar 16a is pivoted through a much larger angle such as 145° from its forward position to its rearward position. It is to be understood that the angle of the top link with respect to the horizontal can be decreased or increased as it pivots from its preset forward to rearward positions, depending on whether the top link 21 is longer or shorter than the bottom link 20, respectively.
FIGS. 6 and 7 schematically illustrate the use of the work surfaces of my invention in relation to an optimum light source. FIG. 6 shows that when the primary work surface 12 is positioned at an inclination C equal to approximately 20° and the secondary work support holder 34 is positioned in its forward position at an inclination A equal to 70°, both angles with respect to the horizontal, the operator will not be distracted by direct reflection of light from either surface. FIG. 7 illustrates that when the secondary work holder has been pivoted to its preset rearward position at an inclination B equal to 50° with respect to the horizontal, the operator will again not be distracted by direct reflection of the light.
In accordance with the preceding description, the secondary work support bar 16a of my preferred embodiment is preferably adjustably connected to the top link 21 of linkage 17 so that the secondary work support holder 34 supported by the bar 16a is positioned at angles of 70° and 50° with respect to the horizontal when in the preset forward and rearward positions, respectively, as shown in FIG. 2. The foregoing describes the preferred inclinations for my device. However, the advantages of my device may be particularly obtained with a primary work surface inclination of from approximately 10° to 30°, and with a difference of inclination of the secondary work support member between its forward and rearward positions of up to approximately 30°, the range of 10° to 30° being most useful.
The preferred frictional connecting means used in the linkage 17 is shown in FIG. 5 to have a rivet 30 passing through holes in the end of the connected links which is expanded against a concave washer 27a to flatten the washer 27a against the adjacent link causing friction between the rivet, the washer and the links. Such friction enables an operator to rotate the linkage 17 to a stable position anywhere between the preset forward position and the preset rearward position in response to personal, job or lighting requirements.
It is to be understood that my desk top work support device 10 can be constructed of any suitable known materials. It is to be further understood that my invention is not confined to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modified forms, and equivalents thereof, as come within the scope of the following claims.
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A desk top work support device having a base with an inclined primary work surface, and having a secondary work support member positioned above the primary work surface. The secondary work support member is pivotally mounted on the base to provide a preset forward position for close reading, and a preset rearward position for secondary reference tasks wherein the secondary work support member does not interfere with access to the primary work surface. The pivoting linkage provides different inclinations for the secondary work support member with respect to the primary work surface in said forward and rearward positions to permit optimum utilization of remote light sources. The secondary work support member has a support bar, and removable work holders which may be slidably engaged within the base and are retained therein by the secondary work support bar when it is in its rearward position.
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TECHNICAL FIELD
[0001] The present invention relates to a device for coupling a heat exchanger such as an evaporator to an expansion valve, in particular for a vehicle.
STATE OF THE ART
[0002] An evaporator is known, intended for an air conditioning device of the interior of a vehicle, that comprises a bundle formed from a stack of plates allowing for a heat exchange between a flow of air passing through the bundle and a refrigerant circulating in the bundle. The bundle is arranged between two end plates. This type of evaporator is described in the document FR-A1-2 026 437 from the applicant and is well known to those skilled in the art.
[0003] One of the end plates of the evaporator comprises two ports respectively for the refrigerant to enter into the evaporator and for this fluid to exit.
[0004] It is also known practice to link the evaporator to an expansion valve via a coupling device which is generally formed by a metal block. The expansion valve comprises fluid inlet and outlet ports intended to be linked by internal passages of the coupling device respectively to outlet and inlet ports of the evaporator. The axes of the inlet and outlet ports of the expansion valve are parallel and extend in a plane passing substantially through a bulb of the expansion valve.
[0005] In use the bundle of he evaporator is generally arranged vertically and the inlet and outlet ports of the evaporator then emerge horizontally.
[0006] In the case where the expansion valve is positioned horizontally and the center distance of the ports of the evaporator is substantially identical to that of the ports of the expansion valve, that does not pose any design problems regarding the coupling device because its internal fluid passages can be rectilinear, which is relatively simple to produce. The document EPA2-1 515 104 describes a coupling of this type.
[0007] However, to optimize the operation of the bulb of the expansion valve, it is preferable for it to be in a high position, which means positioning the expansion valve such that the abovementioned plane of its ports is in a vertical position or slightly inclined relative to the vertical. This nevertheless poses a design problem regarding the coupling device. In effect, although one of the passages of the device could be substantially rectilinear to couple aligned ports of the evaporator and of the expansion valve, the other passage is more complex to produce because it has to include one orifice aligned with the port of the evaporator, another orifice aligned with the port of the expansion valve, and a duct linking these orifices. A first solution for producing this duct would be to orient it in an inclined manner and to produce it by drilling into the body inside the block of the device during a machining operation. This would however be complex to implement and would entail overdimensioning the block because or the bends to be formed.
[0008] The aim of the present invention is notably to provide a simple, effective and economical solution to this problem.
SUMMARY OF THE INVENTION
[0009] The invention proposes a device for coupling a heat exchanger, such as an evaporator, to an expansion valve, in particular for a vehicle, said exchanger and said expansion valve being provided with fluid inlet/outlet ports, at least one of the ports of the expansion valve not being aligned with one of the ports of the exchanger, said device comprising a first part, intended to be joined and fixed to the exchanger and/or the evaporator, said first part being suitable for defining, with at least one neighboring part, a first fluid passage intended to couple said non-aligned ports, said neighboring part being chosen from second part of said device, said exchanger and/or said expansion valve.
[0010] The invention makes it possible to simplify the production of the coupling device, in particular when the expansion valve is not positioned horizontally, that is to say that at least one of its ports is not aligned with a port of the exchanger. According to the invention, the duct is in fact formed by making a number of parts cooperate with one another, in particular an parts such as the exchanger and/or the expansion valve. The formation of the duct in the part or parts of the coupling device is thus simplified compared to the production by drilling of a bent passage in the body of a single block.
[0011] According to an advantageous embodiment of the invention, said first part is intended to be pressed flat onto the exchanger and comprises through holes intended to cooperate respectively with the ports of the exchanger. Said second part is intended to be pressed flat onto the first part and comprises two through holes intended to cooperate respectively with the ports of the expansion valve. The holes of the parts are further in fluidic communication to define said first passage as well as a second passage intended to couple the other ports of the exchanger and of the evaporator.
[0012] It is in fact easy to form through holes in parts, for example by machining, or to form parts directly with holes, for example from casting. The parts of the device are preferably metal, and for example made of aluminum and/or aluminum alloys.
[0013] In the present application, the concept of “through holes” should be understood to mean holes which pass through a part, that is to say whose ends emerge on opposite faces of the part, these passages extending preferably in a direction intended to be substantially parallel to the axes of the ports of the exchanger and/or of the expansion valve.
[0014] The parts are stacked and fixed together and to the exchanger, for example by brazing. In the assembled position, the holes of the parts define the passages coupling the ports of the exchanger to the ports of the expansion valve. The fact that the first part is pressed flat and fixed onto the exchanger, and for example onto an end plate of this exchanger, makes it possible to close the first passage in a seal-tight manner, on the side of the exchanger. The fact that the second part is pressed flat and fixed onto the first part makes it possible to close the first passage in a seal-tight manner, on the side of said second part. Furthermore, the holes of said parts are linked in seal-tight manner to one another and with the ports of the exchanger and of the expansion valve.
[0015] In a preferred embodiment of the invention, the holes of the first part are formed respectively by an opening or slit of elongate form, defining, with said exchanger and/or said second part, said first passage, and by an orifice, defining said second passage.
[0016] At least a part of the slit can have an incurved form about en axis of the orifice of the first part. This incurved part can have a radius of curvature, taken substantially at the middle of the slit, which is substantially equal to a center distance between the holes of the second part. This makes it possible to allow the adjustment of the angular position of the second part with respect to the first, about the axis of the orifice of the first part. The angular range over which the incurved part of the slit extends corresponds substantially the angular range of adjustment of position of the second part with respect to the first. This also makes it possible to provide a single reference (called standard part) for said first part, this reference being able to be associated with a number of different references for the second part, the references of the second part being able to differ from one another by the positions of their holes.
[0017] The slit can comprise a rectilinear part of which one end is linked to the incurved part of the slit and of which the opposite end is intended to cooperate with a port of the exchanger.
[0018] One of the holes of the second part can emerge in the incurved part of the slit of the first part.
[0019] The first part can be formed by a plate or a sheet.
[0020] In the case where a sheet is used, the latter can be stamped, the sheet comprising at least two indented zones at the bottom of which the holes are formed, for example by drilling.
[0021] The second part can be formed by a metal block, and its holes can be formed by orifices.
[0022] Said device will be able to comprise tubular bushings into which some of the holes of the second part emerge.
[0023] Some of these tubular bushings can protrude on a face of the second part, which is situated on the side opposite the first part, and which intended to be inserted into the ports of the expansion valve. These bushings simplify the assembly and the positioning of the expansion valve on the coupling device.
[0024] Others of these tubular bushings can protrude on a face of the second part, which is situated on the side of the first part, and which are intended to be inserted into the holes of this first part. These bushings simplify the assembly and the positioning of the parts on one another.
[0025] The present invention relates also to an assembly comprising a heat exchanger such as an evaporator, an expansion valve, and a coupling device as described above.
[0026] The present invention relates also to a method tor assembling a device as described above, in which the part or parts are pressed flat and fixed onto one another and/or between said exchanger and said expansion valve, for example by brazing, depending on the desired angular position of the expansion valve.
[0027] Advantageously, the second part is positioned in relation to the first part such that one of the holes of the second part is substantially aligned on the axis of a corresponding hole of the first part, the second part being positioned angularly in relation to the first part about the abovementioned alignment axis, to obtain the orientation desired for the expansion valve.
DESCRIPTION OF THE FIGURES
[0028] The invention will be better understood and other details, features and advantages of the invention will become apparent on reading the following description given as a nonlimiting example and by referring to the attached drawings, in which:
[0029] FIG. 1 is a partially exploded perspective schematic view of an assembly comprising on evaporator, an expansion valve and a device for coupling the evaporator to the expansion valve, according to the invention;
[0030] FIG. 2 is a view on a larger scale of the expansion valve and of the coupling device of FIG. 1 ; and
[0031] FIGS. 3 to 6 are views similar to those of FIG. 2 and representing variant embodiments of the invention.
DETAILED DESCRIPTION
[0032] Reference is first of all made to FIG. 1 which represents an exchanger 10 of the evaporator type, notably for an air conditioning device of the interior of a motor vehicle. This exchanger 10 comprises, for example, a stack of exchange plates 12 arranged between two end plates 14 , 16 .
[0033] The plates will be able to be grouped in pairs to form a tube allowing a flow of refrigerant between the plates of a some pair of plates. Between two neighboring tubes, said exchanger will be able to comprise separators making it possible to increase the exchange surface area with a flow of air passing through the exchanger by passing between the tubes. Said plates comprise, at at least one of their ends, connection means, such as added-on stamped parts or flanges, forming manifolds making it possible to pass the refrigerant from one pair of plates to the other and emerging at at least one 16 of said end plates.
[0034] This latter comprises a fluid inlet port 18 in the exchanger and a fluid outlet port 20 of the exchanger, communicating here with said manifolds. As can be seen in FIG. 1 , in the position (vertical) of use of the exchanger, the axes of the ports 18 , 20 which are parallel extend in a horizontal plane P 1 .
[0035] The ports 18 , 20 of the exchanger 10 are linked to ports 22 , 24 of an expansion valve 26 via a coupling device 28 according to the invention.
[0036] In the case represented in FIG. 2 , the expansion valve 26 is in the vertical position and the axes of its ports 22 , 24 are parallel to one another and to the axes of the ports 18 , 20 , and extend in a vertical plane P 2 which passes through a bulb 30 of the expansion valve, which is here in a high position.
[0037] The part 22 of the expansion valve 26 is aligned on the port 20 of the exchanger 10 and the port 24 of the expansion valve 26 is not aligned on the port 10 of the exchanger.
[0038] The coupling device 20 according to the invention ensures the fluidic communication between the ports 20 and 22 , on the one hand, and the ports 18 and 24 , on the other hand, and here comprises an assembly or stack of two parts 30 , 32 .
[0039] A first part 30 of the device 28 is pressed flat against the and plate 16 and comprises two through holes 34 , 36 fluidically linking to the ports 18 , 20 of the exchanger. This part 30 is here formed by a plate of small thickness (for example between 1 and 10 mm) with substantially rectangular outline. The passage of the holes 34 , 36 is here produced in a direction parallel to the ports 1 B- 24 .
[0040] The hole 34 is formed by a cylindrical orifice aligned on the axis of the port 20 of the exchanger. The hole 36 is formed by a substantially L-shaped slit of elongate form. This slit comprises a first rectilinear and vertical 38 , the top end of which is situated facing the port 18 of the exchanger, is in the plane P 1 , and serves to fluidically link with this port. The rectilinear part 38 is linked by its bottom and to the top end of an incurved part 40 of the slit, the bottom and of which is situated substantially facing the port 24 of the expansion valve, and is in the plane P 2 . The part 40 is incurved about an axis A which is the axis of the hole 34 and of the port over an angular range of approximately 45° in the example represented. The radius of curvature R of this incurred part 40 is measured between the axis A and the middle of the slit.
[0041] When the part 30 is applied and fixed, for example by brazing, onto the end plate 16 , the ports 18 , 20 are in fluidic communication with the top and of the hole 36 and with the hole 34 , respectively. The end plate 16 blocks the rest of the hole 36 in a seal-tight manner, on the side of the exchanger.
[0042] The second part 32 of the device is pressed flat against the first part 30 and comprises two through holes 42 , 44 fluidically linking to the ports 2 , 24 of the expansion valve. This part 32 is here formed by a substantially parallelepipedal metal block that has, for example, a thickness of between approximately 5 and 20 mm. The passage of the holes 42 , 44 is here produced in a direction parallel to the ports 18 - 24 . The holes 42 , 44 are each formed by a cylindrical orifice. The orifice 42 is aligned on the axis A, that is to say on the hole 34 of the first plate 30 and on the ports 20 and 22 . The orifice 44 is aligned on the axis B of the port 24 of the expansion valve and is facing the bottom end of the incurved part 40 of the hole 36 of the first part 30 . The center distance between the holes 42 , 44 is substantially equal to the abovementioned radius R. The hole 42 thus ensures the fluidic communication between the hole 34 and the port 22 , and the hole 44 ensures the fluidic communication between the hole 36 and the port 24 .
[0043] The part 32 comprises, on its face oriented toward the expansion valve 26 , two protruding cylindrical bushings 46 , which surround the corresponding ends of the holes 42 , 44 . These bushings 46 are intended to be inserted into the ports 22 , 24 of the expansion valve 26 , to facilitate the positioning and mounting thereof.
[0044] The part 32 further comprises, on this same face, two tapped holes 48 which are intended to receive fixing screws (not represented) for the expansion valve 26 , the expansion valve comprising two orifices 50 for the passage of these screws.
[0045] When the part 32 is applied and fixed, for example by brazing, onto the part 30 , the holes 34 and 42 are in fluidic communication and the hole 44 is in fluidic communication with the hole 36 by its bottom end, the rest of this hole 36 being blocked in a seal-tight manner by the covering of the plate 30 by the plate 32 .
[0046] The slit 36 of the part 30 , closed laterally here by the end plate 16 of the exchanger and by the neighboring part 32 , thus defines a duct for the fluid between the two non-aligned ports 18 , 24 . By combining a number of parts together, a passage is therefore formed between said ports without having to involve complex machining or casting operations generally associated with the bulk production of bent ducts.
[0047] The expansion valve is mounted on the plate 32 by inserting the bushings 46 of this plate 32 into the ports 32 , 24 of the expansion valve, then the above-mentioned screws are mounted in the orifices 50 and screwed into the holes 40 to join together the assembly.
[0048] The arrows f 1 to f 9 represent the path of the fluid from the outlet port 20 of the exchanger to the inlet port 22 of the expansion valve, by passing through the holes 34 , 42 of the device and from the outlet port 24 of the expansion valve to the inlet 18 of the exchanger, by passing through the holes 44 , 36 of the device. As a variant, this path could be reversed.
[0049] In the exemplary embodiment of FIGS. 1 and 2 , the expansion valve 20 is in the vertical position. In the variants represented in FIGS. 3 and 4 , it is in the inclined position. In these variants, the part 30 is identical to that described previously and thus constitutes a standard part that can be used for a number of embodiments of the invention.
[0050] In the variant of FIG. 3 , the part 32 ′ differs from the part 32 described above through the position of its hole 44 which is intended, in the assembled position, to be facing the top end of the inclined part of the hole 36 of the part 30 . In this case, the plane P 2 of orientation of the expansion valve in which the axes of the holes 42 , 44 of the part 32 ′ extend, is inclined, here by an angle of approximately 45′. In the assembly position, the peripheral edges of the parts 30 , 32 ′ are substantially aligned with one another.
[0051] The embodiments of FIGS. 2 and 3 show that a number of different parts 32 , 32 ′ references can be associated with a single reference of a so-called standard part 30 .
[0052] In the variant of FIG. 4 , the part 32 is identical to the part 32 of FIGS. 1 and 2 but is positioned differently in relation to the part 30 . The part 32 has undergone a rotation of 45° about the axis A such that its hole 44 is facing the top end of the inclined part of the hole 36 of the part 30 .
[0053] The embodiments of FIGS. 2 and 4 show that two standard parts 30 , 32 can be used to produce a coupling of the exchanger to an expansion valve having any orientation, so long as the second part 32 laterally closes the hole 36 .
[0054] FIGS. 5 and 6 represent other variant embodiments of the coupling device according to the invention, in which the first part 130 , 130 ′ is formed by a stamped sheet, which has a substantially rectangular outline.
[0055] The part 130 of FIG. 5 comprises two zones 152 , 154 indented by stamping. The bottoms of these zones 152 , 154 are substantially flat and extend in a plane parallel to and at a distance from the plane of the sheet. The first hole 134 is formed in the bottom of the first zone 152 and has a substantially circular outline. The second hole 136 is L-shaped comparable to the shape of the abovementioned hole 36 , and is formed in the bottom of the second zone which is also generally L-shaped.
[0056] The holes 134 , 136 can be formed during the stamping operation or thereafter.
[0057] The second part 132 of FIG. 5 differs from the part of FIG. 2 essentially in that it further comprises, on its face oriented toward the first part 130 , two protruding cylindrical bushings 155 which surround the corresponding ends of the holes 142 , 144 of the part 132 . The bushings 156 are intended to be inserted into the holes 134 , 136 of the first part 130 , to facilitate the positioning and mounting thereof. The bushing 156 of the hole 142 is intended to be inserted into the hole 14 , and the bushing 156 of the hole 144 is intended to be inserted into the bottom end of the incurved part of the hole 136 , such that the expansion valve, intended to be fixed onto the part 132 has a vertical position.
[0058] For that, the hole 134 has a diameter slightly greater than the outer diameter of the bushing 156 of the hole 142 , and the bottom end of the incurved part of the hole 136 has a transverse dimension slightly greater than the outer diameter of the bushing 156 of the hole 144 .
[0059] The second part 132 is configured to laterally close the hole 136 .
[0060] The part 130 ′ of FIG. 6 differs from the part 130 of FIG. 5 that the hole 136 ′ formed in the bottom of the zone 154 has a circular outline and is situated at the level of the top and of the incurved part of the hole 136 of FIG. 5 . This hole 136 ′ has a diameter slightly greater than that of the bushing 156 . The part 132 of FIG. 6 is identical to that of FIG. 5 , except that it will be able to have a reduced extension because its function is no longer to laterally close the duct linking the port 18 to the orifice 136 ′, said duct being here laterally closed by the bottom of the stamped part, on the side of said second part 132 .
[0061] The parts 130 , 132 and 130 ′, 132 can also be fixed together and to the exchanger by brazing, notably when brazing the different parts of the exchanger.
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The invention relates to a device ( 28 ) for coupling a heat exchanger, such as an evaporator ( 10 ), to an expansion valve ( 26 ), in particular for a vehicle, said exchanger and said expansion valve being provided with ports ( 18, 20, 22, 24 ) for the inlet/outlet of fluid, at least one ( 24 ) of the ports of the expansion valve not being aligned with one ( 18 ) of the ports of the exchanger, said device including a first part ( 30 ), intended for being assembled and seemed to the exchanger and/or the evaporator, said first part ( 30 ) being capable of defining, with at least one adjacent part, at least one first fluid passage intended for connecting said non-aligned ports ( 18, 24 ), said adjacent part being selected among a second part ( 32 ) of said device, said exchanger and/or said expansion valve.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of removing impurities from wet process phosphoric acid. More particularly, the present invention relates to a process of precipitating aluminum, magnesium, iron and other cationic impurities from wet process phosphoric acid.
2. Description of the Prior Art
Wet process phosphoric acid is made by reacting phosphate rock with sulfuric acid. Phosphate rock is principally composed of fluoroapatite, but large amounts of contaminating substances are always present. These include silica and metal values such as iron, aluminum and magnesium along with smaller amounts of trace impurities. During the reaction with sulfuric acid, gypsum is precipitated and removed by filtration. After filtration of gypsum, many solubilized impurities remain in the acid. Because the quality of phosphate rock is declining as the better grades of the mineral are mined, the impurity levels in the wet process acid obtained from mined phosphate rock have been steadily increasing.
The presence of impurities in wet process phosphoric acid results in a variety of problems for those who manufacture ammonium phosphate fertilizers. One problem is that the presence of impurities dilutes the nitrogen and P 2 O 5 contents of the fertilizer ingredients thus resulting in a lower grade. Impurities also precipitate from the phosphoric acid and settle during storage thereby resulting in slime accumulation in storage tanks and other apparatus resulting in reprocessing and equipment cleaning costs, effective reduction in storage capacity, production loss, the clogging of liquid fertilizer application equipment, particularly spray nozzle orifices through which the fertilizer is applied, and precipitates which tie up phosphate in a form that is unavailable to plants (i.e., citrate insoluble form).
Because of the desirability of removing impurities from wet process acid, a number of different impurity removal methods have been developed. One such method is solvent extraction, of which there are a number of variations. Solvent extraction involves the extraction of either phosphoric acid or impurities from wet process phosphoric acid using an organic extractant, while leaving other components behind in the aqueous solution. Significant disadvantages of solvent extraction are the high capital and operating costs and the fact that organic solvents must be handled.
Another type of impurity removal process is concentration/clarification of wet process phosphoric acid. In the first step of this process, wet process acid is concentrated to about 54% P 2 O 5 and some of the impurities are allowed to precipitate. However, there are several major disadvantages to the process, namely, high energy consumption, difficulties in concentrating the acid from low quality phosphate rock, the cost of clarification equipment and the inability to reduce impurity concentrations to acceptably low levels.
Another general method of removing metal impurities from wet process acid involves ammoniation of wet process acid. Metal impurities normally found in phosphate rock include minerals containing magnesium, aluminum, iron and others.
U.S. Pat. No. 4,136,199 discloses a method for removing metal ion impurities from wet process phosphoric acid by treating waste pond water from a wet process phosphoric acid plant with lime or limestone to obtain a sludge high in calcium fluoride which, when added to wet process acid, causes the precipitation of solids containing fluorine and metal ions such as magnesium and aluminum.
U.S. Pat. No. 4,500,502 discloses a method of preparing a purified ammoniated phosphoric acid composition by reacting wet process phosphoric acid containing magnesium, aluminum and fluorine impurities with ammonium ions, including ammonia, in order to precipitate complex metal salts containing magnesium, aluminum and fluorine. Unfortunately the complex metal salts also contain valuable phosphates which are lost.
U.S. Pat. No. 4,299,804 discloses a method of removing magnesium and aluminum impurities from wet process phosphoric acid. The disclosed process maintains the Al/Mg mole ratio within the range of 1.1-2.0 and the F/Al ratio within the range of 3.5-7 by adding aluminum ion donating compounds (such as alum) and fluoride ion donating compounds (such as hydrofluoric acid) which are reacted with wet process acid to precipitate crystalline compounds containing magnesium, aluminum and fluorine (MgAl 2 F 8 ).
U.S. Pat. No. 4,493,820 discloses a typical concentration/clarification process.
U.S. Pat. No. 4,435,372 discloses the removal of aluminum, magnesium and fluoride ion impurities from wet process phosphoric acid by hydrolizing and recycling the off-gas scrubber solutions in the presence of a ferric iron catalyst.
U.S. Pat. No. 4,325,327 discloses a two-stage ammoniation process involving the precipitation of solids in the pH regions of 1.5-2.5 and 4-5. The solids are filterable and thus easily separated from the monoammonium phosphate solutions.
SUMMARY OF THE INVENTION
Accordingly, it is an important object of the present invention to provide a process by which impurities, especially metal cationic impurities such as aluminum, magnesium and iron, present in wet process phosphoric acid can be substantially removed by precipitation while at the same time maintaining a high P 2 O 5 concentration.
It is another important object of the present invention to provide an ammoniated liquid phosphate fertilizer that can be stored for extended periods of time without encountering solid precipitation problems.
These and other important objects of the present invention are attained by a method of removing aluminum, magnesium, iron and other impurities from wet process phosphoric acid comprising partially ammoniating wet process phosphoric acid having a P 2 O 5 concentration within the range of about 17-54%, reacting the acid with a fluoride ion donating compound to precipitate compounds containing said impurities, thereby producing a partially ammoniated phosphoric acid of reduced impurities content. The impurity-containing compounds precipitated in connection with the present invention include: (i) aluminum- and magnesium-containing ralstonite; and (ii) ammonium fluorosilicate or magnesium fluorosilicate; which precipitated compounds can be easily separated from the acid. The purified acid comprises an excellent feed for producing monoammonium or diammonium phosphate.
While specific preferred embodiments of the invention have been selected for description hereinbelow, it will be appreciated by those skilled in the art that a wide variety of modifications and variations of the invention can be made without departing from the scope of the invention, as defined in the appended claims.
DETAILED DESCRIPTION
The method of the present invention is effective for removing aluminum, magnesium, iron and other impurities from wet process phosphoric acid, having a P 2 O 5 concentration of from about 17 to 54% by causing precipitates of ralstonite and fluorosilicates to form. Normally, the phosphoric acid will have a P 2 O 5 concentration of from about 17% to 45%. Briefly, the method comprises the combined treatment of (i) partially ammoniating the wet process acid and (ii) adding a fluoride ion donating compound.
The method of the present invention is particularly useful in connection with processes in which wet process phosphoric acid is ammoniated and granulated to produce monoammonium or diammonium phosphate. Typically when making an ammoniated phosphate fertilizer, a mixture of wet process phosphoric acid, having a P 2 O 5 content of about 40-55%, and a scrubber liquor (also a wet process phosphoric acid stream) is reacted in a preneutralizer with ammonia to form a slurry having an N/P mole ratio between about 1.35 to 1.55. The slurry then is further ammoniated in a drum granulator to produce granular diammonium phosphate. Scrubber liquor is produced when dilute wet phosphoric acid (about 18%-30% P 2 O 5 ) is used to scrub ammonia vapors emanating from the granulator and the preneutralizer. The N/P mole ratio of the scrubber liquor often ranges from about 0.3 to about 1.6, typically about 0.4.
According to one embodiment of the present invention, a soluble fluoride ion donating compound capable of releasing free fluoride ions, such as ammonium fluoride, is added to the scrubber liquor. The scrubber liquor constitutes a partially ammoniated wet process phosphoric acid stream. Ammonium fluoride should be added in an amount of up to about 3.0 wt. %, preferably about 1.5 wt. %, based on the total weight of the scrubber liquor. If other fluoride ion donating compounds are used, the fluoride should be added in an amount up to about 1.5 wt. % as F. If necessary, additional ammonia can be added to the scrubber liquid to increase its N/P ratio to at least about 0.2.
Seed crystals of ralstonite, which assist in the precipitation of ralstonite, also may be added at this time.
The mixture is then sent to a settling tank where the mixture is allowed to sit preferably for up to about 8 hours. This allows the ralstonite crystals, as well as the fluorosilicate crystals to form and settle to the bottom of the tank. The mixture can then be sent to any number of known separation apparatus including filtering devices, centrifuges, decanters and the like in order to separate the precipitated ralstonite and fluorosilicates from the purified acid. The purified acid then can be used for manufacturing diammonium phosphate or monoammonium phosphate.
As examples of fluoride ion donating compounds there can be mentioned any compound which freely donates fluoride ions when in solution. For example, NH 4 F, HF, NaF, and NaHF 2 , NH 4 HF 2 , and KF may all be used as fluoride ion donating compounds. Of these, ammonium fluoride and hydrofluoric acid ar preferred since these compounds add no undesirable metal ion impurities (such as sodium and potassium) to the wet process acid. Compounds such as fluosilicic acid and fluorosilicate salts cannot be used in the present invention since these compounds do not freely dissociate when in solution.
The wet process acid may be ammoniated in any number of ways, including sparging with ammonia gas or by the addition of hydrous ammonia to the wet process acid. The amount of ammonia added to the acid is preferably calculated to give a N/P mole ratio in the range of about 0.2-1.0. In the case when the fluoride ion donating compound contains nitrogen (such as ammonium fluoride) the N/P mole ratio should be within this range after both partial ammoniation and the addition of the fluoride ion donating compound. Preferably, the N/P mole ratio is within the range of about 0.2-0.3.
When using ammonium fluoride, the amount added to the wet process acid may be in concentrations up to about 3.0 wt. %, preferably about 1.5 wt. %, based upon the total weight of the acid. If other fluoride donating compounds are used, the total added fluoride should be in an amount of up to about 1.5% wt. % as fluoride. The amount of fluoride ion donating compound added to the wet process acid should be determined based upon the concentrations of magnesium and aluminum impurities in the acid. Thus, in cases where the acid contains very low magnesium and aluminum impurities, only small amounts of the fluoride ion donating compound need be added.
The end product of the ammoniation of wet process phosphoric acid is typically an ammonium phosphate fertilizer. Fertilizers are typically graded depending upon their nitrogen, phosphorus and potassium contents. The ammoniation of phosphoric acid produces a N,P grade fertilizer. Thus, the use of ammonium fluoride as the fluoride ion donating compound is preferable from the standpoint that it contributes to the overall nitrogen content of the fertilizer product.
In the processes of the present invention, three separate species of compounds may be precipitated. The first is ralstonite which is a class of compounds in the cryolite family having the general formula:
(NH.sub.4)AlMgF.sub.y-z (OH).sub.z.xH.sub.2 O
wherein y typically equals 6, z typically equals 1, and x typically equals 0-1.
The second class of compounds precipitated by the processes of the present invention comprise fluorosilicates of the general formula:
(M).sub.q SiF.sub.6
wherein M is a cation such as ammonium, magnesium, calcium, etc. and q is 1 or 2.
A third class of precipitates comprises aluminum and iron-containing compounds having the general formula
(Fe,Al).sub.3 (K,NH.sub.4)H.sub.8 (PO.sub.4).sub.6.6H.sub.2 O
While this third class of precipitates is desirable from the standpoint of removing iron impurities from the acid, it is undesirable from the standpoint that some phosphate values are lost. Unfortunately, the art has yet to devise any means of precipitating iron without also precipitating some phosphate values. However, the processes of the present invention precipitate much less phosphate values than the prior art processes which tended to lose phosphate values in the removal of magnesium and aluminium impurities, as well as in the removal of iron impurities.
The advantages of the present invention will become more apparent from the examples appearing hereinafter.
EXAMPLES 1-4
In Examples 1-4, 450 g of 27% acid was placed in a teflon coated stainless steel beaker with a teflon stir bar. A loose-fitting plexiglas cap having holes for a teflon coated thermometer was placed on the beaker. The beaker was also fitted with a gas sparger (the sparger was made from teflon tubing with 16-20 1.5" long razor blade slashes near one end and was plugged with solid teflon). The contents of the beaker were heated to 75° C. while stirring vigorously on a Corning PC-351 hot plate stirrer, after which time the quantity of NH 4 F indicated in Table 1 was quickly added to each sample. The beaker was heated to 85° C. and ammonia was sparged over a 22 minute period. Subsequently, the slurry was aged with slow stirring at 75° C., removed from the heat and its viscosity measured at 75° C. with a Thomas viscosimeter. The slurry was centrifuged at 600+ g for 40 minutes. The supernatant was collected and weighed and the solids were washed with acetone, centrifuged twice, and then washed again with acetone, filtered and dried. The chemical analyses for the four examples are presented in Table 1.
TABLE 1__________________________________________________________________________Supernatant Liquid Chemical Analyses N/P Wt % AgingExample Mole NH.sub.4 F Time % P.sub.2 O.sub.5No. Ratio Added (min.) % NH.sub.4 % Al % Fe % Mg % F % P.sub.2 O.sub.5 (% Al + % Fe + %__________________________________________________________________________ Mg)Untreated -- -- -- 0.069 0.495 0.89 0.275 2.15 26.7 16.08Acid1 0.3 3.0 60 3.22 0.17 0.80 0.0842 2.1 26.8 25.422 0.3 1.5 60 3.28 0.17 0.82 0.0804 2.1 26.8 25.043 0.3 1.5 240 3.23 0.080 0.12 0.0376 2.1 26.5 111.534 0.5 1.5 240 4.63 0.099 0.0433 0.0461 2.0 26.2 139.09__________________________________________________________________________
The SO 4 content was 1.6% for the untreated acid, was 1.7% for Examples 1 and 2 and was 1.8% in Examples 3 and 4. The acid of Example 2 was seeded with 0.6677 g of the solids recovered from Example 1 prior to the addition of ammonium fluoride. Ammoniation and fluoride additive levels for Example 3 were similar to those of Example 2, but the aging time was increased to four hours and 1.02 g of solids recovered in Example 1 solids were used for seeding. Example 4 was similar to Example 3 but the N/P mole ratio achieved by ammoniation was increased from 0.3 to 0.5.
X-ray diffraction analysis for the solids collected from Example 1 revealed significant amounts of ralstonite, Fe 3 (K,NH 4 )H 8 (PO 4 ) 6 .6H 2 O), ammonium fluorosilicate and potassium fluorosilicate.
Increasing the aging time from one hour to four hours decreases the final magnesium and aluminum content of the liquid phase acid by over 50% and the final iron content by 85%. Increasing the N/P mole ratio to 0.5 at a four hour aging time increased the magnesium and aluminum contents slightly, while reducing the iron content by an additional two-thirds.
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A method of removing aluminum, magnesium, iron and other impurities from wet process phosphoric acid is provided. The method comprises partially ammoniating the acid and reacting the acid with a fluoride ion donating compound to precipitate aluminum- and magnesium-containing ralstonite and ammonium fluorosilicate which can be easily separated from the acid thereby producing a partially ammoniated wet process phosphoric acid of reduced impurities content.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to knife operating devices for sewing machines. More particularly, the invention unifies a needle operating means and a knife operating means into one system, to, thereby, omit the assembling of a separate device for the operation of the knife and to, thus, simplify the structure of the sewing machine.
2. Prior Art
Generally, a sewing machine provided with a knife has a knife operating means in addition to a needle operating means. These needle operating means and knife operating means are formed of racks and links of separate systems connected with respective pulley shafts.
Therefore, the sewing machine having a knife mechanism is complicated in the structure; is troublesome to maintain and service, is large in the volume and is disadvantageous to make small. Also, there are a large number of component parts in making such a machine, and is, therefore, very high in cost and difficulty in manufacture.
In view of such problems as are mentioned above of a sewing machine provided with a knife, the present inventors have invented a novel concrete means for solving various problems caused in relation to such sewing machine by combining a knife operating means with a needle operating means so as to be made one system.
OBJECTS OF THE INVENTION
An object of the present invention is to assemble a knife operating mechanism into a needle operating mechanism so that the needle operating mechanism and knife operating mechanism are one system, the structure of the sewing machine having the knife operating mechanism being simplified and the machine being smaller.
Another object of the present invention is to apply an approximately linear motion mechanism utilized in the operation of a needle to the operation of a knife.
A further object of the present invention is to inhibit unnecessary vibrations produced by the weight and the structure of the operating means in the part operated by the unified operating mechanism and particularly in the part for carrying the knife so that the sewing machine operation may be smooth.
A still further object of the present invention is to provide a structure for reducing as much as possible the stress which is given by the knife carrying part subjected to a large cutting stress to the knife operating mechanism unified with the needle operating mechanism.
These objects can be attained with the device of the present invention. Various embodiments of the device attaining these objects are shown in the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an elevation view of an embodiment wherein a needle stub guiding bar and a guiding bar guiding a part for carrying a knife are used so that the part for carrying the knife may be driven integrally with the needle stub through the needle stub by being connected with the needle stub through a connecting rod;
FIG. 2 is a side view of the same;
FIG. 3 is a sectioned plan view on line A--A in FIG. 1;
FIG. 4 is an elevational view of an embodiment wherein only a needle stub guiding bar is used as a guiding bar so that a part for carrying a knife may be driven integrally with the needle stub through the needle stub by being connected with the needle stub through a connecting rod and the part for carrying the knife may be guided with a guiding piece;
FIG. 5 is a side view of the same;
FIG. 6 is a sectioned plan view on line B--B in FIG. 4;
FIG. 7 is an elevational view of an embodiment wherein a needle stub guiding bar and a guiding bar guiding a part for carrying a knife are used so that the part for carrying the knife may be driven in a position in which the stress moment is smaller than in the needle stub by being connected with a rocking arm in a part nearer to the force point than the needle stub.
FIG. 8 is a side view of the same;
FIG. 9 is a sectioned plan view on line C--C in FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The mechanism common to the three kinds of embodiments shown in the above drawing of the present invention is of a needle stub 2 and a knife holder 3 which is a part for carrying a knife as connected directly or indirectly with a link-shaped rocking arm 1 of a so-called Scott Russell's type so that the knife holder 3 may be rocked vertically and reciprocally by a driving means of one system together with the needle stub 2.
As in FIG. 1, a rocking arm 1 is connected at the rear end with a link 4 through a pin 5 and the link 4 is pivoted at the other end to a proper place of a machine frame through a pin 6. The rocking arm 1 is connected in the middle part with a driving rod 7 through a pin 8 and the driving rod 7 is carried at the other end with a driving shaft 9 making a half rotation. With the half-rotating operation of the driving shaft 9, the driving rod 7 will reciprocally rotate from the position shown by the solid line to the position shown by the two-dot chain line so that the rocking arm 1 may also reciprocally move from the position shown by the solid line to the position shown by the two-dot chain line. Thus, the rocking arm 1 rocks vertically and reciprocally and makes, at the front end, a so-called approximately linear motion. This motion at the front end of this rocking arm 1 describes a very microscopically curved-shaped locus which can be considered to be a linear motion for a needle driving device for a sewing machine and is generally used as such.
This rocking arm 1 is forked at the front end and a needle stub 2 which can move up and down, as guided by a needle stub guiding bar 10, is pivoted in the fork through a pin 11.
The needle stub guiding bar 10 is fixed at the upper end to a sewing machine frame 12 with a nut 13 and suspended so as to intersect with the rocking arm 1. The bar 10 is inserted through a guiding hole 14 so that the needle stub 2 may move up and down along the needle stub guiding bar 10. Further, a needle receiving hole 15 is provided on the lower surface of the needle stub 2 and a needle 16 is inserted into said needle receiving hole 15 and is fixed with a set screw 17.
A guiding bar 18 for a knife holder is arranged in parallel with the needle stub guiding bar 10 and is fixed with a nut 19 so as to be suspended. This guiding bar 18 is of the same length as of the needle stub guiding bar 10 and is suspended outside the front side of the rocking arm 1.
Various other means of guiding this knife holder than the here described guiding bar can be adopted. A knife holder 3 is guided movably up and down by the guiding bar 18 inserted into a guiding hole 20 made in the knife holder 3 and is fitted with an L-shaped knife stand 23 so as to be adjustable in the sidewise direction with a set screw 21 screwed on the front side and a slot 22 passing it.
In the drawings, 24 is a knife fitted to the knife stand and 25 is a lower knife provided in the part of a needle plate so as to correspond to the knife 24. The structure of the knife stand 23 is shown particularly in FIG. 3.
In FIG. 3, the knife stand 23 is fixed by screwing a set screw 21 into the knife holder 3 through a slot 22 made in the knife stand 23 and has on the side a receiving groove for receiving and stabilizing the knife 24. The knife 24 is fitted in the receiving groove and is pressed and held with a knife pressing piece 27 pressed against the knife stand 23 with a fastening screw 26.
As in FIGS. 1 and 2, such knife holder 3 is pivoted and engaged with the end part of the pin 11 pivoting the needle stub 2 to the rocking arm 1 in the front part of a connecting rod 28 extended in the sidewise upper direction. This manner can be definitely observed mostly in FIG. 2.
It should further be noted that the knife holder 3 can be projected on the side opposite the side on which the needle of the needle stub is provided without the need for the connecting rod 28. When so projected the knife holder 3 can be fixed on the front side by means such as a pin.
In the embodiment shown in FIGS. 4 and 6, there is only one guiding bar and a guiding piece is used for the guide for the knife holder.
That is to say, as in FIG. 4, a needle stub 2 is pivoted with a pin 11 at the front end of a rocking arm 1 and is guided in the same manner as in the above described embodiment by a needle stub guiding bar 10.
The needle stub 2 is projected on the side opposite the part holding a needle 16 so as to be a knife holder 3. This knife holder 3 is formed to be substantially integral with the needle stub 2 and may be substantially of such form as is shown in FIG. 4. A knife holder made of a member different from a needle stub 2 can be closely fixed to the needle stub 2.
A knife stand 23 is fixed on the front side of the knife holder 3 with a slot 22 made in it and a set screw 21 inserted through the slot. Needless to say, the knife stand 23 can be adjusted sidewise in the fitting position with the slot 22.
As in FIGS. 5 and 6, a knife 24 is fixed to this knife stand 23 with a knife pressing piece 27 and fastening screw 26 in the same manner as in the above described embodiment.
The end surface of the knife holder in the projected part on the side opposite the side on which the needle 16 is fitted of the needle stub 2 is made at right angles with the respective surfaces on the front side and back side. Both the back side and the end surface are very smoothly finished.
The knife holder 3, which is integral with the needle stub 2, is securely supported and guided with a guiding piece 30. The guide piece 30 is substantially L-shaped for the above mentioned back side and end surface and vertically has a long receiving surface 29. The receiving surface 29 is smoothly finished. The guiding piece 30 is fixed to an L-shaped fitting piece 31 fixed to a sewing machine frame 12. The fitting piece 31 has slots 32 and is fixed with set screws 33 passed through the slots 33 so as to be adjustable sidewise. The guiding piece is also fixed with the slot 32 and set screw 33 so as to be adjustable forward and rearward in the position in the same manner.
Thus, the guiding piece 30 securely receives the needle stub 2 and knife holder 3 and guides them in their moving direction. Thereby the knife 24 integral with the needle stub 2 is well supported and guided and irregular vibrations by the stress produced in the case of cutting cloth are inhibited by the guiding piece 30.
In FIGS. 7 to 9, there is shown an embodiment wherein a needle stub guiding bar 10 and a knife holder guiding bar 18 are used and a knife holder 3 is connected with a rocking arm 1 separate from a needle stub so that the stress of cutting cloth on the knife is not greatly translated to the rocking arm 1.
To achieve this, the rocking arm 1 is forked to be long enough at the front end, the needle stub guiding bar 10 fixed to the machine frame 12 is suspended and held in the fork. The same needle stub 2 as described with reference to the embodiment shown in FIG. 1 is pivoted with a pin 11. The needle stub 2 is guided by the needle stub guiding bar 10. The other formations are also the same as is shown in FIG. 1 and, therefore, the detailed explanation shall be omitted.
As seen in FIGS. 8 and 9, the knife holder guiding bar 18 is suspended and fixed to the machine frame 12 so as to intersect with the outside of the front side of the forked front end of the rocking arm 1.
As in FIG. 9, the knife holder 3 is guided by the guiding bar 18 and holds a knife 24 in the same manner as in the embodiment of FIG. 1. Therefore, the detailed explanation of this point shall also be omitted.
As in FIGS. 8 and 9, the knife holder 3 is provided with a bracket pin 35 to project so as to intersect with the rocking arm 1 on its lower side.
On the other hand, as in FIG. 7, a pin 36 for a link is provided across the above mentioned forked part in the front part of the rocking arm 1. A link 37 is pivoted to this pin 36 and is connected with the above mentioned bracket pin 35. This connecting manner is clearly shown in FIG. 7.
In this embodiment, the knife holder 3 is linked with the rocking arm 1 in a part nearer to the force point of the rocking arm than the needle stub. Therefore, the knife holder 3 is moved up and down together with the needle stub 2 by the rocking arm 1 but the stress of cutting cloth on the knife 24 is reduced by reducing the moment of the force. Further, the link connecting part describes a locus which is largely curved by the part near the rotary pivotal point of the rocking arm. However, the knife holder 3 is allowed, by the link 37, to make a linear motion according to the knife holder guiding bar 18. Thus, the link 37 absorbs vibrations relative to the rocking arm 1 of the knife holder 3. The stress on the knife holder 3 is reduced effectively and, therefore, the operation of the machine becomes smooth.
When the knife holder 3 is connected with the rocking arm 1 in the part nearer to the force point than the needle stub 2, the rotary curvature radius of said connecting part of said rocking arm will become smaller and therefore it is difficult to linearly drive the knife holder.
Thus, the rotary curve motion of the rocking arm must be absorbed by using such means as the above described link 37. It is further contemplated, that the link could be replaced by a link system wherein the knife holder is connected with the rocking arm through a groove formed in the direction intersecting at right angles with the direction of the vertical motion of the knife holder with a connecting piece movable in the width of the groove fitted therein. However, in the simplicity of the formation, the above mentioned link system is the best.
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A knife operating device for sewing machines includes a needle stub pivotally mounted to the front part of a rocking arm. The rocking arm intersects with a needle stub guiding bar and is pivotally mounted and its rear end. A knife holder is, also, connected to the rocking arm and is guided so as to be movable with the needle stub.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of copending International Application No. PCT/EP01/14629, filed Dec. 12, 2001, which designated the United States and was not published in English.
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a household machine for washing or drying laundry, having a drawer disposed in the top region and being intended for accommodating detergents or condensate, and having a three-dimensional grip plate that is fastened on the front of the drawer and contains a grip hollow on its front side, it being possible to reach, through the grip hollow, a catch that is disposed in the rear cavity of the grip plate, is retained in the latching position by a spring and in the locked position grips, by way of a catch edge, behind a latching edge on the housing.
Such household machines are common and widely available. Attempts have been made to fit locking devices on such machines to avoid unauthorized individuals using the machines at all or, in the case of washing machines, using the drawer of a detergent-dispensing device. The main group of individuals targeted is constituted, in particular, by children, for which reason such devices are generally also referred to as childproof locks.
All previous proposals for such childproof locks, however, are unsatisfactory in some way. For example, German Published, Non-Prosecuted Patent Application DE 31 01 745 A1 discloses a childproof lock of the generic type for a detergent drawer that is unsatisfactory because, on one hand, it is too easy to open and, on the other hand, it is too complicated to deactivate altogether.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a household machine for washing or drying laundry that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that configures the lock such that it cannot be opened easily by children but can be deactivated altogether by adults of average intelligence without any complicated manipulations being required.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a household laundry machine for at least one of washing and drying laundry, including a machine housing having a front side having a surface, an operating panel defining a recess with a frame, the operating panel being disposed approximately flush with the surface of the front side, and a latching edge disposed on the frame of the recess and defining a catch edge, and a drawer slidably disposed in the recess for accommodating detergents or condensate therein, the drawer having an insertion direction and a removal direction, a front, a bias device, a three-dimensional grip plate fastened at the front, the grip plate having a front side defining a grip hollow, a latching position, and a rear cavity, a catch disposed in the rear cavity and having an unlocked position and a locked position, the bias device retaining the catch in the locked position, the catch gripping behind the catch edge with respect to the insertion direction in the locked position, an arresting device having an arresting slide moveably disposed into and out from an arresting position, the arresting device retaining the catch out of the locked position when the arresting slide is in the arresting position, during operation of the machine the grip plate being inserted in the recess and the catch interacting with the latching edge to hold the grip plate in the recess, and the grip hollow permitting access by a user for actuating the catch from outside the drawer.
With the objects of the invention in view, in a household laundry machine for at least one of washing and drying laundry, the machine having a housing with a front side having a surface, an operating panel defining a recess with a frame, the operating panel being disposed approximately flush with the surface of the front side, and a latching edge disposed on the frame of the recess and defining a catch edge, there is also provided a detergent holder including a drawer slidably disposed in the recess for accommodating detergents or condensate therein, the drawer having an insertion direction and a removal direction, a front, a bias device, a three-dimensional grip plate fastened at the front, the grip plate having a front side defining a grip hollow, a latching position, and a rear cavity, a catch disposed in the rear cavity and having an unlocked position and a locked position, the bias device retaining the catch in the locked position, the catch adapted to grip behind the catch edge with respect to the insertion direction in the locked position, an arresting device having an arresting slide moveably disposed into and out from an arresting position, the arresting device retaining the catch out of the locked position when the arresting slide is in the arresting position, the grip plate adapted to being inserted in the recess during operation of the machine, the catch adapted to interact with the latching edge to hold the grip plate in the recess, and the grip hollow permitting access by a user for actuating the catch from outside the drawer.
With the objects of the invention in view, there is also provided a household laundry machine for at least one of washing and drying laundry, including a machine housing defining a recess and having a latching edge disposed in the recess, and a drawer slidably disposed in the recess for accommodating detergents or condensate therein, the drawer having a bias device, a three-dimensional grip plate being inserted in the recess during operation of the machine and having a front side defining a grip hollow, a latching position, and a body defining a rear cavity, a catch disposed in the rear cavity and having an unlocked position and a locked position, the bias device retaining the catch in the locked position, the catch gripping the latching edge in the locked position and preventing the drawer from being removed from the recess, the catch interacting with the latching edge to hold the grip plate in the recess when the grip plate is inserted in the recess, an arresting device moveably disposed into and out from an arresting position, the arresting device retaining the catch out of the locked position when the arresting device is in the arresting position, and the grip hollow permitting access by a user for actuating the catch from outside the drawer.
According to the invention, during operation of the machine, the grip plate is inserted in a recess of an operating panel, which is disposed at least more or less flush with the surface of the front side of the machine, and a latching edge that interacts with the catch is provided on the frame of the recess, and the catch can be retained outside the latching position by an arresting device if an arresting slide of the arresting device is located in an arresting position. By virtue of the configuration according to the invention of a plurality of elements that are in functional connection with one another, it is no longer readily possible for children to open a way of blocking access to the detergent drawer. On the other hand, it is possible for operators of average intelligence to deactivate the arresting device altogether without any significant effort and without the aid of tools. Preferably, the bias device is a spring.
In accordance with another feature of the invention, the catch is connected firmly to a handle that projects through to the front side of the grip plate.
In accordance with a further feature of the invention, a handle is firmly connected to the catch and the handle projects away from the catch.
In accordance with an added feature of the invention, the catch has an integral handle projecting away from the catch for providing access by the user to the handle through the grip hollow.
The handle, which is disposed for easy gripping, facilitates the operations both of opening the latching device of the drawer once in each case and of permanently deactivating the arresting device.
In accordance with an additional feature of the invention, in a form of the measure according to the invention that is straightforward to configure in terms of its design, the catch engages, by way of a retaining latching element, in a mating catch on the arresting slide if the catch is located in the non-latching position and the arresting slide is located in the arresting position. The configuration of the childproof lock, thus, manages with a maximum of three additional components—catch, spring, and arresting slide.
In accordance with a concomitant feature of the invention, in which the bias device is a constituent part of the catch, which is of plastic, a part of the catch that is supported on an abutment of the grip plate is configured to be elastic along its length. As such, it is possible to dispense with yet a further component, namely with the spring, which is, then, replaced by that part of the catch that is elastic along its length. It is, then, only necessary to have two additional parts, which are straightforward to configure and to fit, for the purpose of realizing the object.
Other features that are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a household machine for washing or drying laundry, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view from the front of a washing machine according to the invention with the detergent drawer in a pulled out position;
FIG. 2 is a perspective and partially cut-away view from the front of the pulled-out detergent drawer according to the invention with its grip shell freed from the covering plate and the handle being visible;
FIG. 3 is a perspective and partially hidden view from the front of the pulled-out detergent drawer of FIG. 2 with the covering plate in front of the grip shell and the catch with handle, the arresting slide and the spring being indicated by dashed lines;
FIG. 4 is an elevational view of the drawer of FIGS. 2 and 3 from the rear with the fitted components;
FIG. 5 is a fragmentary, perspective view of the front of the machine according to the invention with the cavity for the detergent drawer having a latching edge on the frame;
FIG. 6 is an enlarged side elevational view of the arresting slide of FIGS. 2 , 3 , and 4 ; and
FIG. 7 is a perspective and partially cut-away view from the front of the pulled-out detergent drawer according to the invention with its grip shell freed from the covering plate and the handle projecting through a front side.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a washing machine having, above a front filling opening 1 , an operating panel 2 , alongside which the recess for a detergent drawer 3 , only indicated schematically here, is disposed. At the front, the detergent drawer 3 has a screening plate 4 , which is usually adapted, in terms of shape and design, to the operating panel 2 and is often also referred to as a grip plate. Provided at an easy-to-grip location of the grip plate 4 is a grip hollow 5 , which is set back some way behind the front so that an operator can place his/her fingers therein. Positioned in front of the top region of the grip hollow 5 is a covering plate 6 , to allow, finally, the operator's fingers to grip behind the plate 6 in order to pull out the detergent drawer 3 by the grip plate 4 and/or the covering plate 6 .
FIG. 2 shows the detergent drawer 3 , once again in a schematic illustration, on an enlarged scale and removed from the recess. Moreover, in such a case, the covering plate has been removed from in front of the grip hollow 5 to make visible a handle 7 that is otherwise concealed behind the covering plate 6 (FIG. 1 ). The handle 7 can be actuated in a laterally displaceable manner and, in the process, actuate a catch 8 mounted behind the grip plate 4 (FIG. 5 ), as will be explained in more detail at a later stage in the text. As can be seen from FIG. 5 where the detergent drawer 3 has been completely removed, it is possible for the catch 8 in a right-hand position, with the detergent drawer 3 pushed in to the full extent, to grip behind a latching edge 9 of a latch 14 and, thus, to arrest the detergent drawer 3 in the retracted position. Then, unauthorized individuals cannot access the detergent drawer 3 , i.e., the childproof lock is active.
So that the catch 8 can be retained in this or in a non-arresting position, an arresting slide 10 is disposed behind the grip plate 4 (FIG. 3 ), the function of the arresting slide, together with the rest of the functions of the catch 8 as well, being explained with reference to FIGS. 4 and 6 .
FIG. 4 shows the grip plate 4 from behind. The grip hollow is formed by a shell 11 , which is shown from the rear, is open at the top and above the opening of which the handle 7 for the catch 8 is visible. The catch 8 is mounted on both sides in slot-shaped recesses 12 ( FIG. 6 ) of box-shaped slide guides 13 . To improve clarity, a number of components, such as the slide guides 13 , have only been depicted in FIGS. 4 and 6 by thick lines, rather than double lines, on account of their thin wall thicknesses. The catch 8 projects out a little way on the side of the border of the grip plate 4 that is on the left in FIG. 4 (on the right-hand side as seen from the front of the drawer). Located on the left of FIG. 4 is a latch 14 , disposed in the frame of the recess, with the latching edge 9 , behind which the projecting part of the catch 8 can spring when it is pushed in the direction of the latch 14 by the force of the spring 15 , which is clamped in between an arm 16 of the catch 8 and an abutment 17 on the grip plate 4 .
Over its considerable length, the catch 8 is guided, on one hand, by a top boundary 18 of the grip hollow 5 and, on the other hand, by the abutment 17 and a further guide tab 19 fastened on the grip plate 4 . As a result, any transverse forces that may be introduced through the handle 7 cannot bend the catch 8 .
To the right of the right-hand slide guide 13 as shown in FIG. 4 , the arresting slide 10 is mounted such that it can be displaced in the direction of arrow 30 by its grip tab 20 and is guided longitudinally by bearing parts 21 of the grip plate 4 . The arrows on the arresting slide 10 and on the catch 8 , depending on whether they have been filled in or not, indicate the direction in which the respective element has to be pushed in order to be moved into the locking or arresting position. A filled-in arrow indicates the locking or arresting position, and an empty or hollow arrow indicates the free position.
At its right-hand end, which passes through a through-passage 22 in the arresting slide 10 , the catch 8 has a notch 23 , which interacts with a lug 24 in the arresting slide 10 if the catch 8 has been pushed into this position and the lug 24 , by virtue of the arresting slide 10 being moved upward, has passed into the notch 23 . In such a position, the catch 8 is retained counter to the force of the spring 15 and is, then, no longer able to grip behind the latching edge 9 . As a result, the detergent drawer 3 can be pushed freely in and out.
To activate the childproof lock, the arresting slide 10 , thus, has to be pulled into the bottom position again, with the result that the lug 24 disengages from the notch 23 of the catch 8 and the catch 8 springs into the locking position again by virtue of its spring 15 . In such a case, it projects, by way of its end that is on the left-hand side of FIG. 4 , beyond the outer edge of the grip plate 4 , is pushed back briefly into the grip plate 4 , counter to the spring pressure, by way of a run-on surface on the latch 14 when the detergent drawer 3 is pushed into the recess, and, then, springs behind the latching edge 9 of the latch 14 . As a result, the detergent drawer 3 is locked in the closed position.
For the purpose of opening the detergent drawer 3 once in each case, it is sufficient for an individual in the know to unlock the catch 8 from the latching edge 9 promptly before executing the pulling movement. Once the handle 7 is released, the catch 8 immediately springs back again into the spring-actuated locking position and it is automatically locked again when the detergent drawer 3 is next pushed in.
If the childproof locking is to be eliminated again on a permanent basis, then the catch 8 has to be arrested in the unlocked position upon actuation of the handle 7 . This takes place by transferring, with the catch 8 secured, the arresting slide 10 into the top, arresting position. As a result, the lug 24 is pushed into the notch 23 of the catch.
When the catch 8 is released, this notch 23 , then, secures the catch 8 , counter to its spring force, in the permanently unlocked position.
The spring 15 may be configured, as is shown here, as a helical compression spring made of steel. In contrast, it may also be produced as a tension spring and/or from some other material. A possible variant for the spring would include integrally connecting the spring to the plastic catch 8 . In such a case, the plastic, in order to be provided with resilient properties at the same location, would be configured in meandering fashion or to be similarly elastic along its length.
FIG. 7 shows the detergent drawer 3 , once again in a schematic illustration, on an enlarged scale and removed from the recess. Moreover, in such a case, the covering plate has been removed from in front of the grip hollow 5 to make visible a handle 7 that projects through to the front side of the grip plate. The handle 7 can be actuated in a laterally displaceable manner and, in the process, actuate a catch 8 mounted behind the grip plate 4 (FIG. 5 ).
The invention has been described above in respect of a detergent drawer for a washing machine. The same motivation for protecting children is also present in the case of condensate vessels that, in a manner similar to a detergent drawer, have a grip plate in the area alongside the operating panel of a laundry dryer. The invention can be used in the same, or a similar, way in this case.
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Usually disposed in the top region of a household laundry machine is a drawer that is intended for accommodating detergents or condensate and is connected to a three-dimensional grip plate at the front. During operation of the machine, the grip plate is inserted in a recess of an operating panel, which is disposed at least more or less flush with the surface of the front side of the machine. For childproof locking, a latching edge is provided on the frame of the recess, and a catch, which is retained in the latching position by a spring, is disposed in the rear cavity of the grip plate. By virtue of an arresting device, the catch can be retained outside the latching position if an arresting slide is located in an arresting position.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of copending International Application No. PCT/DE99/02526, filed Aug 12, 1999, which designated the United States.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0002] The invention lies in the field of semiconductor technology and relates to a method for monitoring a semiconductor fabrication process for processing a substrate.
[0003] A multiplicity of fabrication processes are used in fabricating and processing semiconductor substrates to form integrated semiconductor circuits therein. Deposition processes and etching processes for patterning layers that are applied on a substrate are mentioned as examples. These fabrication processes must be monitored, in principle, since, because of their complexity, unnoticed disturbances or poorly adapted process conditions can lead to defectively fabricated semiconductor circuits. To be able to efficiently carry out this monitoring, there is generally a desire to characterize the fabrication process through real-time analysis of specific measurement quantities that are determined during the fabrication process to thereby be able to make a regulating intervention, if appropriate.
[0004] Possible methods for monitoring fabrication processes are disclosed, for example, in U.S. Pat. No. 5,877,032, which describes a method for determining the end point of a plasma etching process, in which the detected optical emission of the plasma is used for determining the end point. The background to this approach is the fact that, during etching processes, a layer situated on a substrate is etched through and the underlying substrate is uncovered in the process. The interaction between the etching gas and the uncovered substrate can be demonstrated spectroscopically as a change in the emission spectrum of the plasma. In accordance with U.S. Pat. No. 5,877,032, this change is compared with a multiplicity of predetermined reference curves and the end point of the plasma etching process is inferred from the comparison.
[0005] U.S. Pat. No. 5,739,051 likewise discloses a method for determining the end point of a plasma etching process, in which the optical emission of the plasma is likewise used for determining the end point. Emission lines that are characteristic of the interaction between the etching gas and the substrate are used for the assessment.
[0006] However, very often it is difficult to extract the measurement quantity that is characteristic of the etching process from the multiplicity of available spectra or else from other measurement quantities. Therefore, U.S. Pat. No. 5,658,423 proposes a method based on so-called principal component analysis, in which the temporal development of the entire emission spectrum from about 240 to 600 nanometers is used for the end point analysis. Using principal component analysis, the volume of data obtained is reduced to a few so-called base patterns and the temporal development thereof is used for detecting the end point. As a result of this, the detection of the end point is no longer based on the assessment of a single emission wavelength, but on the change in the entire available spectrum. In principle, however, this approach also requires that reference values be provided for comparison with the currently measured measurement quantities.
[0007] In U.S. Pat. No. 5,737,496, an attempt is made to avoid the last-mentioned problem, in particular, by using a neural network. The neural network is trained using a multiplicity of determined measurement quantities, so that it can subsequently be used for decision-making with regard to the end point identification. It has been shown, however, that neural networks often learn incorrect signals and patterns, so that an incorrect interpretation can occur. Erroneous training of the neural network arises, for example, through a change in the emission spectra because of aging phenomena of the sensors or because of chamber contamination that occurs. Therefore, U.S. Pat. No. 5,864,773 proposes a so-called virtual sensor system, in which these changes are taken into account before the measurement quantities are actually assessed. As a result, the intention is to produce a virtual sensor that is free of chamber-specific or process-specific fault effects. Since it is necessary to have recourse to the operating personnel's experiences in this case, too, unexpectedly occurring faults and changes cannot automatically be taken into account.
SUMMARY OF THE INVENTION
[0008] It is accordingly an object of the invention to provide a method for monitoring a semiconductor fabrication process for processing a substrate which overcomes the above-mentioned disadvantages of the prior art methods of this general type.
[0009] In particular, it is an object of the invention to provide a method for monitoring a semiconductor fabrication process for processing a substrate which enables the fabrication process to be monitored reliably and in a manner that is, as far as possible, free from faults. Even more particularly, the method serves for determining the end point of the fabrication process.
[0010] With the foregoing and other objects in view there is provided, in accordance with the invention, a method for monitoring a plasma process that includes steps of:
[0011] using a first model to determine an end point of a first plasma process that is performed in a plasma;
[0012] defining the first model with an algorithm, with a termination criterion, and with at least one predetermined measurement quantity that can be determined during the first plasma process and that is based on an intensity of at least one predetermined emission wavelength of the plasma;
[0013] configuring the algorithm such that when the algorithm is applied to the predetermined measurement quantity that is determined, the algorithm provides a decision quantity which, upon comparison with the termination criterion, serves for determining the end point of the first plasma process;
[0014] performing the first plasma process by using a plasma-excited gas in a plasma chamber, by introducing a substrate, which will be treated, into the plasma chamber, and by allowing the substrate to interact with the plasma-excited gas in the plasma chamber;
[0015] during the first plasma process, determining the predetermined measurement quantity for the first model to thereby obtain a measured quantity;
[0016] applying the algorithm of the first model to the measured quantity and determining the decision quantity;
[0017] comparing the decision quantity with the termination criterion prescribed by the first model and terminating the first plasma process when the termination criterion is met;
[0018] using a second model for comparatively determining the end point of the first plasma process;
[0019] defining the second model with an algorithm, with a termination criterion, and with at least one predetermined measurement quantity that can be determined during the first plasma process and that is based on an intensity of at least one predetermined emission wavelength of the plasma;
[0020] using an additional monitoring function for continuously assessing the first model and the second model;
[0021] if the end point that was determined with the second model has a higher significance than the end point that was determined with the first model, then using the second model to determine an end point of a second plasma process succeeding the first plasma process;
[0022] measuring intensities of a plurality of emission wavelengths of the plasma during the first plasma process;
[0023] using the intensities of the plurality of the emission wavelengths as measurement quantities and continuously storing the measurement quantities in a data processing system;
[0024] also using the data processing system for identifying the end point of the first plasma etching process;
[0025] performing the first plasma process as a plasma etching process and providing the plasma-excited gas as a dry etching gas that etches at least parts of the substrate;
[0026] providing the substrate with an insulating layer; and
[0027] etching contact holes using the plasma etching process.
[0028] In accordance with an added feature of the invention, the method includes: using the second model during the second plasma process; performing the second plasma process in a plasma; using a third model for comparatively determining the end point of the second plasma process; defining the third model with an algorithm, with a termination criterion, and with at least one predetermined measurement quantity that can be determined during the second plasma process and that is based on an intensity of at least one predetermined emission wavelength of the plasma of the second plasma process; and if the end point that was determined with the third model has a higher significance than the end point that was determined with the second model, then using third model for determining an end point of third plasma processes.
[0029] In accordance with an additional feature of the invention, the method includes: determining a significance of the end point that was determined with the first model and determining a significance of the end point that was determined with the second model by comparing a temporal development of the measurement quantity based on the predetermined emission wavelength of the first model with a temporal development of the measurement quantity based on the predetermined emission wavelength of the second model.
[0030] In accordance with another feature of the invention, the method includes: determining a significance of the end point that was determined with the first model and determining a significance of the end point that was determined with the second model by comparing the decision quantity that was determined by the algorithm of the first model with a decision quantity that is determined by the algorithm of the second model.
[0031] In accordance with a further feature of the invention, the method includes: comparing the decision quantity that was determined by the algorithm of the first model with the termination criteria of the first model to obtain a first result; comparing the decision quantity that was determined by the algorithm of the second model with the termination criteria of the second model to obtain a second result; and determining the significance of the end point that was determined with the first model and determining the significance of the end point that was determined with the second model by comparing the first result with the second result.
[0032] In accordance with a further added feature of the invention, the method includes: basing the measurement quantity of the first model and the measurement quantity of the second model on a common emission wavelength; and determining a measure of contamination of the plasma chamber by comparing the measurement quantity of the first model and the measurement quantity of the second model.
[0033] In accordance with a further additional feature of the invention, the method includes making the insulation layer from silicon oxide.
[0034] In accordance with yet an added feature of the invention, the method includes etching the contact holes to have different depths in the insulation layer.
[0035] In accordance with yet an additional feature of the invention, the method includes: using a rotating plasma during the first plasma process; and using a rotating plasma during the second plasma process.
[0036] In accordance with an added feature of the invention, the method includes obtaining the measured quantity by forming a mean value over a predetermined period of time.
[0037] In accordance with an additional feature of the invention, the method includes: using a rotating plasma during the first plasma process; and setting the predetermined period of time to correspond to at least one circulation period of the rotating plasma.
[0038] In accordance with another feature of the invention, the method includes: using the algorithm of the first model to determine a position of a local maximum, a local gradient, or a point of inflection of a curve representing a temporal development of the measurement quantity of the first model to thereby yield the decision quantity; and using the algorithm of the second model to determine a position of a local maximum, a local gradient, or a point of inflection of a curve representing a temporal development of the measurement quantity of the second model to thereby yield a decision quantity.
[0039] In accordance with a further feature of the invention, the first model differs from the second model at least in terms of the predetermined measurement quantity of the first model or the predetermined algorithm of the first model.
[0040] In accordance with a further added feature of the invention, the method includes using stored measurement quantities from preceding fabrication processes for determining a significance of the first model and of the second model.
[0041] The invention provides a method for monitoring a fabrication process for processing a substrate in a semiconductor fabrication, which has the steps of:
[0042] prescribing a first model for determining the end point of the fabrication process; the first model being defined by an algorithm, by at least one predetermined measurement quantity which can be determined during the fabrication process, and by a termination criterion; the algorithm, when applied to the measurement quantity determined, yields a decision quantity which, upon comparison with the termination criterion, serves for determining the end point of the fabrication process;
[0043] carrying out the fabrication process in a chamber suitable for this purpose; and introducing a substrate to be treated into the chamber and processing the substrate in the chamber;
[0044] determining the measurement quantity that is predetermined by the first model during the fabrication process;
[0045] applying the algorithm of the first model to the measurement quantity that is determined and determining the decision quantity;
[0046] comparing the decision quantity with the termination criterion that is prescribed by the first model; and ending the fabrication process when the criterion is met;
[0047] using a second model for comparatively determining the end point of the fabrication process; the second model being likewise defined by an algorithm, by at least one predetermined measurement quantity that can be determined during the fabrication process, and by a termination criterion; the second model being used for determining the end point of a further fabrication process that succeeds the fabrication process, provided that the end point is determined by the second model with a higher significance than with the first model.
[0048] In the method according to the invention, first a first model is prescribed. In this case, this model is determined, in particular, by an algorithm, by the selection of at least one predetermined measurement quantity that can be determined during the fabrication process, and by a termination criterion. The measurement quantity may be, for example, the intensity of the optical emission of the plasma at a wavelength that is predetermined by the model, the pressure, the temperature and other quantities that can be determined during the fabrication process. The measurement quantity is preferably determined using a sensor that is provided on the chamber and the measurement quantity is fed to a data processing system.
[0049] The algorithm prescribed by the model is applied to the measurement quantity that is determined during the fabrication process and in this case yields a decision quantity. The predetermined algorithm is generally assigned a termination criterion that is characteristic of the algorithm, which termination criterion is compared with the determined decision quantity. The end point of the fabrication process is determined from this comparison.
[0050] Since the meaningfulness of the measurement quantity or the decision quantity that is determined from the measurement quantity by the algorithm can be impaired because of chamber contaminants, the invention proposes using a second model for comparatively determining the end point of this fabrication process. The second model is likewise defined by an algorithm, by at least one predetermined measurement quantity that can be determined during the fabrication process, and by a termination criterion. The first and second models generally differ at least with regard to the measurement quantity selected or with regard to the algorithm used. However, it is also possible for the second model to use a different measurement quantity and a different algorithm than the first model.
[0051] The second model is then likewise used for determining the end point of the fabrication process. The significance of the meaningfulness of the two models are compared with one another. This can be done, for example, by directly comparing the significance of the respective decision quantities of the first and second models with one another. Another possibility is to access the determined measurement quantities with regard to their meaningfulness when the respective algorithms are used. Thus, the intention is, for example, to check whether the measurement quantities are excessively noisy or whether other events occurring during the measurement unfavorably alter the measurement quantities.
[0052] If the first and second models differ only with regard to the predetermined measurement quantity, the significance of the two models can be assessed, for example, by directly comparing the two measurement quantities. If the two measurement quantities used represent different emission wavelengths, then it is possible, for example, to use the magnitude of the signal swing when reaching the end point as a measure for determining the significance.
[0053] In order to minimize the uncertainties that occur in the prior art in the prediction of the measurement quantities that currently will be measured, according to the invention, first the first model is still used to determine the end point, but the second model is used for a subsequent fabrication process, provided that the second model determines the end point with a higher significance. This enables reliable determination of the end point over many fabrication processes while taking account of changes that occur in the measurement quantities because of chamber contamination, drift of sensors, and also because of changes that stem from different fabrication processes that are carried out in the same chamber. As a result, it is possible, for example, to use the chamber for longer without interim costly cleaning, or to carry out different fabrication processes in one chamber in a targeted manner so that changes because of these different fabrication processes, in part, mutually compensate for one another. This can be observed, for example, when etching processes using different etching gases are carried out in one and the same chamber such that the contamination of one etching process is at least partly removed by the etching gases of the other etching process.
[0054] A higher significance in the determination of the end point is manifested e.g. in the decision quantity, upon comparison with the termination criterion, leading to a clearer result than in the case of another model. Another possibility for determining the significance consists in comparing the curve profiles of the measurement quantities of the individual models and assigning a higher significance to that measurement quantity and hence to that assigned model whose curve profile is the most similar to a predetermined mode curve.
[0055] However, it is also within the scope of the invention for a plurality of models to be used simultaneously for determining the end point, and for the model with the greatest meaningfulness to be used. One essential advantage of the invention consists in using measurement quantities independently of their correlation with process specifics. Thus, by way of example, in the case of an emission spectrum of a plasma, only a few emission lines are characteristic of the interaction between the etching gas and the substrate. It is customary, therefore, for precisely these lines to be selected for end point determination. If these lines can no longer be used for assessing the end point because of chamber contamination, the chamber has hitherto had to be cleaned. Consequently, the preselected lines could only be used under “good” process conditions.
[0056] Using the inventive method, it is now possible to select further emission lines that are not even characteristic or not very characteristic of the interaction between the etching gas and the substrate, provided that they yield a useable and reliable end point signal when the algorithms prescribed by the models are used. Thus, in principle, all measurement quantities are available and can be used for determining the end point. In this case, the individual measurement quantities that are available can be tested during the fabrication process and can be processed with the algorithms in order to ascertain whether a suitable end point signal can be generated from them.
[0057] If the second model is used for determining the end point in a subsequent fabrication process, furthermore a third model is used for comparatively determining the end point and the third model is used, if appropriate, provided that it determines the end point with a higher significance.
[0058] Preferably, the measurement quantities determined are stored and are thus also available for comparative checking. Using these stored measurement quantities, the individual algorithms of the models can be tested and the decision quantities formed in the process can be compared with regard to their meaningfulness. From this comparison it is then possible to determine in each case the “best” measurement quantity and the “best” model for determining the end point for further fabrication processes.
[0059] In contrast to the previously known methods, the inventive method thus contains an additional monitoring function that serves for assessing the models. This ensures that a reliable model for end point identification is always provided for the respective fabrication process. This model takes account of the fabrication-specific changes that have occurred previously. As a result, therefore, by selecting the respectively suitable model, despite the occurrence of chamber contamination and other generally undesirable changes, the end point of the fabrication process is determined reliably and with the smallest possible fluctuations. The uncertainties that usually occur in comparing measurement quantities with fixedly predetermined reference values are precluded to the greatest possible extent when using the inventive method.
[0060] Suitable algorithms for determining the decision quantity from the measurement quantities determined are, for example, the determination of a local maximum, the local or temporal gradient or the point of inflection of the temporal development of the measurement quantity. The measurement quantities can be stored, for example, in a manner dependent on their temporal development and are thus available for the testing of the algorithms.
[0061] However, it is also possible to use a multiplicity of measurement quantities and to apply the algorithm to them. If appropriate, data reduction is effected at the same time. If the measurement quantities represent the emission spectrum of a plasma in a predetermined wavelength range, the so-called principal component analysis can also be used as an algorithm. The analysis determines base patterns representing the spectrum and also the temporal development thereof. In particular the temporal development of individual base patterns can be used as a decision quantity.
[0062] The invention furthermore proposes a method for monitoring a plasma process for processing a substrate in semiconductor fabrication having the steps of:
[0063] using a first model for determining the end point of the plasma process; the first model being defined by an algorithm, by at least one predetermined measurement quantity that can be determined during the plasma process and that is based on the intensity of at least one predetermined emission wavelength of the plasma, and by a termination criterion; the algorithm, when applied to the measurement quantity determined, yields a decision quantity which, upon comparison with the termination criterion, serves for determining the end point of the plasma process;
[0064] carrying out the plasma process using a plasma-excited gas in a plasma chamber; a substrate to be treated is introduced into the plasma chamber and interacts there with the plasma-excited gas;
[0065] determining the measurement quantity predetermined by the first model during the plasma process;
[0066] applying the algorithm of the first model to the measurement quantity determined, and determining the decision quantity;
[0067] comparing the decision quantity with the termination criterion prescribed by the first model; the plasma process being terminated when the termination criterion is met;
[0068] using a second model for comparatively determining the end point of the plasma process, which is likewise defined by an algorithm, by at least one predetermined measurement quantity that can be determined during the plasma process and that is based on the intensity of at least one predetermined emission wavelength of the plasma, and by a termination criterion; the second model being used for determining the end point of a further plasma process succeeding the plasma process, provided that the end point was determined by the second model with higher significance than with the first model.
[0069] In plasma processes, in particular, there is a need to reliably determine the end point since undesirable incipient etching of the substrate can otherwise occur. This arises, for example, in so-called plasma etching processes in which a plasma-excited gas (dry etching gas) interacts with the substrate. The substrate is usually covered with a masking layer (photomask), so that only the uncovered regions of the substrate come into contact with the dry etching gas and the substrate is actually only etched there. However, layers located deeper in the substrate should not be attacked by the dry etching gas, so that the etching process must be stopped when the substrate is etched through and the layers are reached.
[0070] A suitable measurement quantity in plasma etching processes is, in particular, the emission spectrum of the plasma, since a multiplicity of emission wavelengths are available here.
[0071] The inventive method is preferably used when etching contact holes into an insulation layer that is situated on the substrate. In this case, the insulation layer is preferably composed of silicon oxide. In the course of etching contact holes in the insulation layer, it is possible at the same time, or else afterward, to produce further structures in the insulation layer, which are finally filled with a conductive material, for example. It is thus possible to fabricate e.g. wiring planes in an integrated semiconductor circuit using so-called demasking technology.
[0072] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0073] Although the invention is illustrated and described herein as embodied in a method for monitoring a fabrication process for processing a substrate in semiconductor fabrication, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0074] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0075] [0075]FIG. 1 shows individual method steps for determining the end point of a plasma process;
[0076] [0076]FIG. 2 shows the selection of a suitable model for determining the end point;
[0077] [0077]FIGS. 3 a and 3 b show an insulation layer on a substrate with contact holes of different depths that will be introduced therein;
[0078] [0078]FIG. 4 shows the normalized spectrum of an oxide etching process at different points in time;
[0079] [0079]Fig. 5 shows the temporal profile of an emission line of the oxide etching process;
[0080] [0080]FIG. 6 shows a selected emission line of the oxide etching process that can be used for determining the end point;
[0081] [0081]FIG. 7 shows a changed emission line because of chamber contaminants;
[0082] [0082]FIG. 8 shows the determination of the end point from the changed emission line by using another algorithm;
[0083] [0083]FIG. 9 shows the fluctuations of determined end points in comparison with the fluctuations in the case of a fixedly predetermined model; and
[0084] [0084]FIG. 10 shows a plasma etching chamber for carrying out the inventive method.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0085] Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown the basic sequence of the inventive method. First, a substrate that will be processed is introduced into a plasma chamber. This plasma chamber usually has a substrate carrier and devices for generating the plasma are arranged above this substrate carrier. After introducing the substrate in the plasma chamber, the plasma is ignited in the plasma chamber and the reaction gases used are introduced. Using a sensor, for example, a multichannel spectrometer, the emission of the plasma is then continuously detected in a selected wavelength range, lying between 200 and 900 nm for example. In this case, a sampling rate of a different magnitude is chosen depending on the expected changes. To limit the volume of the data obtained, it is expedient, for example, to choose a sampling rate of 1 per second.
[0086] From the multiplicity of intensities determined, after the first model has been prescribed, an intensity at a predetermined wavelength is selected and is used as the measurement quantity. In parallel with this, for comparatively assessing the plasma process, it is possible to use a second model that is associated with a different emission wavelength that is used as the measurement quantity. Thus, in the present case, the intensity of the optical emission is measured at two different wavelengths and the measurement quantity of the respective models is determined from these.
[0087] The two models can be compared by directly comparing the respective measurement quantities. A possible decision criterion here is e.g. the magnitude of the signal swing or the degree of relative change of the measurement quantities. The decision quantity is subsequently formed from the determined measurement quantities by applying the respectively predetermined algorithm. By way of example, the algorithm can include the determination of the local maxima of the temporal development of the measurement quantity, the formation of the derivative, and the determination of the point of inflection. The decision quantities determined differ depending on the algorithm used. If the algorithm that is used determines the local maxima, the decision quantity specifies e.g. the position and the size of the local maximum. When a derivative algorithm is used, the magnitude of the temporal gradient of the measurement quantity, i.e. the degree to which it changes, is determined.
[0088] However, decision quantities based on different algorithms can be compared with one another only to a limited extent, so that a statement with regard to the significance of the end point identification can only be obtained by directly comparing the decision quantity with its assigned termination criterion. If the termination criterion demands e.g. a minimum height and a minimum width of the local maximum, then the significance of this end point identification can be specified, for example, by specifying the relative height of the local maximum with respect to the minimum height.
[0089] In contrast to using the local maximum, when using the temporal gradient of the measurement quantity, the termination criterion can demand that the temporal gradient have a minimum value over a predetermined period of time. Here, too, this requirement serves for preventing incorrect interpretations.
[0090] At the same time, by comparing the decision quantity with the termination criterion, it is possible to determine the extent to which the result obtained is significant. This may be manifested, for example, in a direct comparison of the decision quantity with the threshold value that is prescribed by the termination criterion (for example, the magnitude of the local gradient). Therefore, it possible for the significance of the statement that is determined with the respective model to be directly compared with one another with regard to the end point. Even if this comparison does not necessarily lead to using the model with the highest significance in the present plasma process, the statement can nonetheless be used to state which model will to be used in a subsequent plasma process. In the present exemplary embodiment, the first model is still used in the plasma process, even if the second model has determined the end point with a higher significance. However, in a subsequent plasma process, the second model is then used for determining the end point.
[0091] An advantage of this approach is the determination of the end point with little fluctuation, so that the etching processes can be effected essentially with the same time duration. However, if longer etching times result because of contamination, they are taken into account by the second model since the second model is associated with, for example, a different emission wavelength in which the changes are manifested in a manner such that they can be registered.
[0092] The model selection will be consolidated below using FIG. 2. In principle, it is possible to prescribe more than just two models for end point determination. It is expedient first to use a single model for the end point identification of the respective current plasma process. The other models are then used for comparatively determining the end point. In this case, it is also possible to use data records of previous plasma processes for model assessment, in order thus to find out which model is the most robust with respect to process changes. The model assessment can either be effected in parallel with the end point identification of the first model or can follow after the end of the plasma process. Consequently, the invention provides, in addition to monitoring the plasma process and determining the end point, a further monitoring to the effect that the models used for end point determination are continuously tested with regard to their suitability. This ensures that work is always effected with reliable models.
[0093] The invention will be consolidated below using a concrete exemplary embodiment. To that end, reference is made to FIGS. 3 a and 3 b, which show a semiconductor substrate 100 on which a silicon oxide layer 105 is situated. Together these form the substrate to be processed. A further layer 115 , which represents a conductive structure, for example, is buried in the silicon oxide layer 105 . This conductive structure may be an interconnect of a metallization plane.
[0094] In order to define contact holes, an etching mask 110 is applied to the silicon oxide layer 105 . In this case, there is a first opening 120 in the etching mask 110 above the further layer 115 , whereas a second opening 125 is laterally offset with respect to the further layer 115 .
[0095] The substrate prepared in this way is transferred into a plasma etching chamber and is exposed to a plasma-excited, fluorine-containing etching gas. An etching gas mixture including CF 4 , CHF 3 and argon is used as the etching gas, and the homogeneity of the plasma is improved by a magnetic field of about 60 gauss. The plasma itself is generated and maintained by a capacitively applied RF voltage (AC). The power used for this purpose is about 1000 watts. The pressure in the plasma etching chamber is about 150 mtorr, the flows, specified in sscm, being about 170 for argon, about 18 for CF 4 and about 85 for CHF 3 . The etching process was carried out on a so-called MxP+ etching installation from Applied Materials™. There was fitted to the latter, at a window, a multichannel spectrometer from Hamamatsu™ bearing the type designation C7460 for detecting the optical emission of the plasma. The spectrometer has 1024 channels distributed uniformly between a wavelength range from 200 to 950 nm. A maximum sampling rate of 50 per second can be achieved with the spectrometer used.
[0096] The spectrometer is connected to a data processing system that continuously records, evaluates and stores the registered spectra. Furthermore, the data processing system is also used for identifying the end point of the plasma etching process. The basic construction of such an etching chamber in conjunction with the spectrometer and the data processing system is shown in FIG. 10. The substrate 200 is situated in the plasma etching chamber 205 , below an etching gas inlet device 210 . Coils 215 are situated laterally with respect to the etching gas inlet device 210 . These coils 215 are for homogenizing the plasma and are arranged in rotary fashion, if appropriate. The magnetic field rotation made possible as a result improves the homogenization of the plasma. The multichannel spectrometer 225 is arranged on the outer wall of the plasma etching chamber 205 in the region of a window 220 . The multichannel spectrometer 225 is linked to a data processing system 230 via a data line. Using the etching gas described above, contact holes are subsequently etched into the silicon oxide layer 105 . These contact holes reach as far as the further layer 115 in the region of the first opening 120 of the etching mask 110 and as far as the semiconductor substrate 100 in the region of the second opening 125 of the etching mask 110 . Two contact holes of different depth are thus produced. Monitoring the plasma etching process as described below serves, in particular, for identifying when the silicon oxide layer 105 is completely etched through so that the etching process can then be terminated.
[0097] At least one of the 1024 available emission wavelengths is selected for monitoring the plasma etching process. In FIG. 4, for that purpose the spectrum between 500 and 950 nm during a so-called oxide PAD etching is shown and the relative normalized intensity changes of the wavelengths between the main etch (layer 105 shown in FIG. 3) and the over etch (after removal of the layer 105 ) are plotted. The “upper” curve corresponds to the normalization with regard to the main etch curve and the “lower” one with regard to the over etch curve. These are identical, except for the sign, in the case of patterning without topology (i.e. the etching depth is the same at all points on the substrate). The y-axis shows the percentage change in the wavelength intensities between the main etch and the over etch. FIG. 4 illustrates that the maximum change for this process is at 918 nm. The profile of this wavelength (918 nm) is illustrated in FIG. 5. This example demonstrates how the “best” wavelength can be found by comparing the main etch and the over etch curves.
[0098] The over etch is usually understood to be a prolongation of the determined etching time (main etch, i.e. the time for etching through the silicon oxide layer) in order to compensate for possible fluctuations in the etching rate over the substrate.
[0099] It can clearly be seen in FIG. 4 that a maximum change in the signal swing is recorded at about 918 nm.
[0100] The temporal profile of the emission wavelength at 918 nm is illustrated in FIG. 5. Here, too, it can be seen that a great fall in the intensity occurs, which can be used for detecting the end point.
[0101] However, a different line, namely the so-called CN line at 378 nm, was used for end point identification during the etching of the contact hole in the silicon oxide layer 105 . This line is shown in FIG. 6. Two local maxima are clearly discernible. The first maximum is associated with the shallower contact hole and the second maximum is associated with the deeper contact hole in the silicon oxide layer 105 . The maxima, i.e. the change in the intensity of the CN line, can be attributed to an interaction between the etching gas and the respectively uncovered materials that are situated at the bottom of the contact holes. The end point of the plasma etching process can be determined in particular from the position of the second maximum. Preferably, after the end point has been reached, the etching process is additionally continued by a fixedly predetermined time (over etch) in order to compensate for fluctuations in the local etching rate. These fluctuations are manifested, for example, in relatively wide and flat maxima. The above-mentioned fluctuations arise, for example, as a result of a locally varying thickness of the silicon oxide layer 105 or as a result of non-uniform distribution and feeding of the etching gas. It can thus happen that the etching advances more quickly in the central region of the substrate than in the edge region. These fluctuations mean that the interaction between the etching gas and the uncovered material occurs at different points in time and thus leads to a relatively weakly pronounced maximum. In order, however, to ensure that the silicon oxide layer is reliably etched through in all of the contact holes that are being formed, after the detection of the maximum, the plasma etching process is continued for the predetermined time duration. The predetermined time duration is preferably determined in a manner dependent on the width of the local maximum.
[0102] Accordingly, in the present exemplary embodiment, the determination of the position of the second maximum serves for determining the end point. To that end, an algorithm that determines the position of local maxima is applied to the measured intensity of the emission at 387 nm. This algorithm yields the position and the width of the determined maxima as a decision quantity. These details are compared with a termination criterion that demands a minimum height and a minimum width of the local maxima. This is intended to prevent fluctuations in the determination of the measurement quantity, which can likewise be manifested in local maxima, from leading to an incorrect interpretation. The termination criterion can be defined e.g. such that the height and width of the local maxima correspond to at least twice the height and width of the fluctuations that are expected. If appropriate, the measured intensity can also be subjected to mean value formation to reduce the fluctuations.
[0103] The selection of the emission line at 387 nm, the algorithm for determining the local maximum and the predetermined termination criterion together form the first model. Further models are tested in parallel with the identification of the end point by the first model. The further models differ from the model used either with regard to the selection of the emission line used used or with regard to the algorithm used. The models, i.e. the significance of the identification of the end point, are continuously compared with one another in order to select the best model in each case for subsequent etching processes. In the present exemplary embodiment, the significance of the model can be determined, for example, by calculating the relative difference between the height of the determined maximum and the height prescribed by the termination criterion.
[0104] Contamination of the chamber or of the window at which the spectrometer is arranged can result in a change in the measured pattern of the intensity at the predetermined emission wavelength. This is illustrated in FIG. 7, which likewise shows the CN line at 387 nm, but after a multiplicity of plasma etching processes. In the meantime, the local maxima are no longer discernible for this line. Using the first model, which works with the algorithm for identifying the local maxima, would therefore no longer enable identification of the end point. For this reason, it is necessary to change the model. Since further models have already been tested, during previous plasma etching processes, with regard to their suitability for end point identification, it is now possible to have recourse to a further model that works at the same wavelength, but with a different algorithm. In the present case, the points of inflection of the curve illustrated in FIG. 7 are determined for that purpose, their position serving as a measure of the identification of the end point. To that end, the derivative of the curve is calculated. This is illustrated in an unsmoothed and in a smoothed form in FIG. 8. From the smoothed curve, in particular, a suitable end point signal can be generated either by using a further derivative or by using an algorithm for determining local maxima. It is known from the previous comparative assessments of this model with the model originally employed that the local minimum of the smoothed curve illustrated in FIG. 8 is good for determining the position of the end point. This minimum is therefore used for detecting the end point.
[0105] An essential advantage of the inventive method is that the end points are determined with relatively small fluctuations despite changed process conditions. This is illustrated in FIG. 9, in which the open boxes denote the fluctuation range of the end points determined with a fixedly prescribed model. In this case, 80% of the end points determined lie within the open boxes. The diamond specifies the mean value. The maximum fluctuations are identified by error bars. In this case, the boxes each represent at least one batch.
[0106] In contrast thereto, significantly less fluctuation in the end point identification can be expected by continuously adapting the model for end point identification. This can be seen from the filled boxes, in which, on the one hand, the mean values are relatively constant, and on the other hand, the fluctuations have only a relatively small value. Moreover, it is evident that the actual end points are generally distinctly earlier than those that are determined with the fixedly prescribed model. In this case, the graphical derivative of the curve profile of a predetermined emission wavelength was used as the fixedly prescribed model.
[0107] The algorithms of the models that are used according to the invention can be classified into at least two categories. In the first category, threshold-value analysis of the curve profile of emission wavelengths is carried out, e.g. testing for absolute or relative changes in the expected end point interval is effected or the curve profile is compared with a predetermined model profile. A distance dimension, which represents the decision quantity, can then be determined from the comparison. If this distance dimension exceeds a threshold value that is predetermined by the termination criterion, the end point is deemed to be identified. It goes without saying that it is also possible to compare the currently determined measurement curve with a plurality of model profiles to be able to combat a drift in the measurement curve. The end point is then determined when the measurement curve that is currently being measured reaches a predetermined section in the model profile associated with it. Equally, graphical derivatives can be associated with the threshold-value analysis. By contrast, threshold-value-free analyses form the second category, is characterized, for example, by the identification of zero crossings, maxima, and points of inflection.
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The invention relates to a method for monitoring a production process, whereby several models are used for detecting a finish point. The results of the model are subsequently compared with one another and the best model therefrom is used in other production processes to detect a finish point. The inventive method provides the advantage that process changes resulting from chamber contaminations or sensor drift are compensated for by selecting the best model, thereby ensuring reliable finish point detection even in case of unfavorable process conditions.
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FIELD OF THE INVENTION
The invention relates to a loose flange for connecting pipes at opposite pipe ends each provided with a collar, having an annular flange body which has a plurality of circumferentially distributed outer through-passage openings for fastening means.
The invention also relates to a method of producing a loose flange for a pipe connection, which has a plurality of circumferentially arranged outer through-passage openings.
BACKGROUND OF THE INVENTION
It is known, for the sealing connection of pipes, to use annular flanges with distributed through-passage openings in the region of pipe ends. The flanges are positioned as loose flanges in each case on an encircling collar of the pipe end and braced by means of bolts, guided through the circumferentially distributed through-passage openings, in conjunction with nuts positioned at free ends of said bolts, with the result that a fixed and sealing connection is produced between the ends of the two pipes. In this case, the loose flanges each butt against a pipe end on a side of the collar of the pipe end which is directed away from the opposite pipe ends.
Since the axial bracing forces prevail in the radially outward direction from the collars, it may be the case that the loose flanges move towards one another in an outer region and are thus deformed on a permanent basis. The flanges then have an undesired thrustoconical shaping. During the bracing of such a pipeline flange connection by the tightening of the bolts, the seal and the collars are compressed, the flanges are inverted and the screws are expanded.
In particular when loose flanges are used in pipelines made of polymer material, creep of the force-carrying elements, the collars, the seal and the loose flanges in particular, cannot be avoided, with the result that the sealing forces decrease. The clamping bolts or clamping screws, with their small amount of expansion, usually cannot compensate for the creep of the polymer-material parts. Although it would be possible for axially elastic loose flanges to compensate for the creep, such a desirably pliable flange would have the basic disadvantage mentioned above that, in the case of mechanical loading, the flange, in accordance with its low axial rigidity, would deform axially to a pronounced extent and/or be inverted. The effect of the associated conical deformation of the flanges is thereby intensified, which would result in the bearing surfaces for the screws tilting and thus in the screws being subjected to undesired eccentric loading.
SUMMARY OF THE INVENTION
It is thus an object of the present invention to develop a loose flange for a pipe connection so as to ensure defined axial resilient rigidity and deformability without the screw-bearing surfaces being inclined disadvantageously and the screws being subjected to eccentric loading as a result.
In order to achieve this object, the loose flange according to the invention, in conjunction with the preamble of Patent Claim 1, is characterized in that the flange body has an inner ring section and an outer ring section, a radially inner side of the inner ring section having, at least in certain regions, a circumferentially running groove of a predetermined depth.
The particular advantage of the loose flange according to the invention is that defined axial rigidity is ensured by the provision of a groove in an inner ring section of the flange body. The groove allows specific elastic deformability of the loose flange in a radially inner region of the same. The axial rigidity of the loose flange decreases from an outer region to an inner region of the same, with the result that an additional fastening means, namely a clamping bolt with a head or a screw, is always retained with predetermined surface-area abutment against the loose flange.
It is advantageously possible to prevent undesired “dishing” of the flange body or tilting of the outer ring section as a result of an excessively large tightening torque. Non-uniform bearing of the ends of the fastening means, in particular of a nut and of a screw head, on radial surfaces of the flange body may thus be reliably avoided.
According to a preferred embodiment of the loose flange, the groove is of V-shaped design and runs continuously in the circumferential direction. The contour of the groove-forming oblique surfaces may be of planar or curved design here. The shape of the groove depends on the desired deformation characteristics of the inner ring section. The shape of the groove depends on the geometry of the loose flange and/or on the predetermined desired clamping force of the flange connection.
In conjunction with a radial surface for the flange parts of the flange body which is directed towards the collar, the groove is shaped such that, with the flange being subjected to nominal loading, the establishing inversion or tilting of the outer ring section is compensated for, the radial surface of the flange body butting against the collar over its surface area, with a relatively low level of surface pressure being formed in the process.
According to a development of the loose flange, circumferentially distributed and radially inwardly projecting protuberances are arranged on an inner side of the inner ring section, said protuberances retaining the loose flange with clamping action at the pipe end. It is thus possible for the loose flange to be fixed on the pipe for installation purposes.
According to a development of the loose flange, on a side located opposite the oblique surface, the flange parts have radial surfaces with a prism-like surface structure which, when clamping screws are tightened, deform and level out such that when the predetermined tightening torque of the clamping screws is reached, the washers have reached their definitive position and it is no longer possible for them to be lowered any further. It is thus possible to see when the predetermined tightening torque of each screw has been reached by the position of the respective washer. Furthermore, the visibly deformed geometry gives an indication of prior use.
According to a development of the loose flange, circumferentially distributed clamping noses are arranged on an inner side of the outer through-passage openings, with the result that clamping screws are retained with clamping action in the through-passage openings. This facilitates, in particular, the vertical installation of the flange connection. These clamping noses, and also the protuberances on the inner side of the inner ring section, preferably consist of an elastic material, namely polymer material. If the loose flanges themselves are produced from polymer material, then the protuberances and/or clamping noses may simply be integrally formed thereon.
It is also an object of the present invention to specify a method of producing a loose flange for a pipe connection, with the result that a flange body with a clamping-force capacity which is stable over a long period of time is provided in a manner which is straightforward in production terms.
In order to achieve this object, the method according to the invention, in conjunction with the preamble of Patent Claim 18, is characterized in that two identical annular flange parts are formed separately by injection moulding or casting, with a radially inwardly oriented flattened portion being formed in the process, and in that, in a second step, the flange parts are connected to one another in an outer ring section, with a groove produced by the mutually facing flattened portions being formed in the process.
The particular advantage of the method according to the invention is the simplicity of production. Preferably identical flange halves are formed separately and then welded to one another with surface-area abutment of radial surfaces of an outer region section. The flange parts or flange halves are thus of straightforward geometrical shape, with the result that they can be produced with a relatively high throughput.
According to a preferred embodiment of the method according to the invention, the shaped parts are produced from a polymer material by injection moulding, it being possible for the fixed connection between the same to be easily produced by welding.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention are explained in more detail hereinbelow with reference to the drawings, in which:
FIG. 1 shows a plan view of a first flange part,
FIG. 2 shows a cross section through the first flange part along line II—II in FIG. 1,
FIG. 3 shows a plan view of a second flange part,
FIG. 4 shows a cross section through a flange body, formed by the first and second flange parts, along line II—II in FIG. 1,
FIG. 5 shows an enlarged part of a detail from FIG. 4,
FIG. 6 a shows a cross section of part of a flange body, provided with a sensor device, in a relieved position, and
FIG. 6 b shows a cross section of part of the flange body according to FIG. 6 a in a clamping position.
DETAILED DESCRIPTION OF THE INVENTION
The loose flange described hereinbelow serves for connecting pipe ends (not illustrated) each with a collar which butt against one another over their surface area directly or in a state in which they are separated by a seal. Each collar is assigned an annular loose flange, the internal diameter of the loose flange being smaller than the external diameter of the collar. The two loose flanges are aligned coaxially with one another and are braced in the axial direction by fastening means.
FIG. 1 illustrates a first flange part 1 , which is joined together with a second flange part 2 , illustrated in FIG. 3, to form a flange body 3 . The flange body 3 is of annular design and serves as a loose flange for butting against the collar. A central through-passage opening 4 has a diameter which is greater than the diameter of the pipes which are to be connected, on the one hand, and is smaller than the external diameter of the collar, on the other hand. The flange body 3 has circumferentially distributed outer through-passage openings 5 into which it is possible to fit in each case one bolt (not illustrated) with a head as fastening means. The bolts are fitted through the outer through-passage openings 5 of a first flange body 3 and are of such a length that the free end of the bolt engages through the corresponding through-passage opening 5 of the identical second flange body 3 . Thereafter, the bolt may be brought into engagement with a nut at the free shank end, with the result that the flange bodies positioned on the collars in each case can be braced in relation to one another.
The flange body 3 has an outer ring section 7 and an inner ring section 8 , the outer through-passage openings 5 being arranged essentially in the outer ring section 7 . The flange parts 1 and 2 are fixed to one another in the outer ring section 7 . In the inner ring section 8 , which is adjacent in the radially inward direction, the flange parts 1 and 2 are designed to be spaced apart from one another in a relieved starting position, with the circumferentially running groove 9 being formed in the process. The groove 9 is of cross-sectionally V-shaped design and extends continuously in the circumferential direction on an inner side 10 of the flange body 3 .
Alternatively, it is also possible for the groove 9 to be of interrupted design, the groove being arranged at least in a circle cutout of the flange body 3 in which there are no outer through-passage openings 5 .
By virtue of the groove 9 , the flange parts 1 , 2 each form, in the inner ring section 8 , an oblique surface 11 which is of elastically deformable design. The groove 9 is a rotationally symmetrical design and has a foot section 12 which runs along a root circle 6 , the root circle 6 intersecting the outer through-passage openings 5 . Alternatively, it is also possible for the root circle 6 to have a smaller radius, with the result that it is spaced apart radially from the outer through-passage openings 5 . The size of the radius of the root circle 6 depends on the material property of the flange body 3 and/or the desired resilience of the oblique surface 11 . As the radius of the root circle 6 increases, the resilience of the oblique surface 11 decreases, which reduces the prestressing-force compensation for setting the flange connection.
The invention advantageously makes it possible, by virtue of the depth of the groove 9 , the thickness of the flange body 3 and the material properties thereof being predetermined, to set a predefined clamping force for the oblique surface 11 , the oblique surface 11 compensating for a considerable amount of the clamping-force losses once it has been compressed in a clamping position of the flange body 3 in a spring-like manner when the flange connection is set.
The root circle 6 , at the same time, forms a pivoting axis or a pivoting circle about which the oblique surface 11 can be pivoted. The groove 9 has an opening angle a which is located in a range of between 2° and 20°. The groove 9 preferably has an opening angle of 8°. A diameter d F of the root circle 6 is smaller than a hole-circle diameter d M of the flange parts 1 , 2 and/or of the flange body 3 . The diameter d F is preferably designed to be smaller, by the diameter of the outer through-passage opening 5 , than the diameter d M .
The flange parts 1 , 2 are of the same thickness, with the result that the flange body 3 is of essentially symmetrical design in relation to a centre plane ME.
According to the invention, it is also possible for the groove 9 to be used for signalling a predetermined clamping position of the flange body 3 . The width and the depth of the groove 9 may be coordinated with a predetermined tightening torque, by means of which the bolt is intended to be brought into engagement with the nut. The envisaged clamping position of the flange body 3 is signalled to the fitter in that border edges 13 of the opposite oblique surface 11 come into direct abutment.
A further criterion which may be used alternatively or in addition for determining when the envisaged clamping position is reached is constituted by the fact that an outer radial surface 14 of the oblique surface 11 has a prism-like surface structure 16 in certain regions, preferably in the region of a recess 15 for the screw head and/or the nut. The envisaged clamping position is reached in that, following abutment of the screw head and/or of the nut against the recess 15 , which widens the outer through-passage opening 5 on the end side, and application of a clamping force, the prism-like elevations 16 are deformed plastically such that a planar radial surface 14 is formed. The now-reached clamping position corresponds to the predetermined tightening torque of the bolt.
The surface structure 16 may be of uniform or irregular design. The essential factor is that the resulting recesses, on average, fill a volume which corresponds to the volume of the rest of the radial regions 17 of the recess 15 . The prism-like surface structure 16 is preferably assigned to a radially inwardly oriented radial region 17 of the recess 15 .
The outer radial surfaces 14 are designed such that they diverge in the radially inwardly oriented direction in the initial state, with the result that, following engagement of the clamping bolt and displacement of the same into the clamping position, the head and the nut butt directly, with coaxial orientation, against the radial surfaces 14 .
In order to facilitate overhead installation, the outer through-passage openings 5 have, in an edge region in each case, circumferentially offset clamping noses 18 , on which the bolt is retained with clamping action following insertion into the through-passage opening 5 .
In order to detect a decreasing clamping force once the flange connection has been set, one embodiment of the loose flange provides a sensor device 19 , which has a pressure sensor 20 which is mounted in a mount 21 which projects essentially axially from an outer radial surface 14 of the oblique surfaces 11 . The mount 21 is preferably integrally formed on the radial surface 14 of the oblique surfaces 11 . The oblique surface 11 , containing the mount 21 , has a through-passage bore 22 through which a sensor bolt 23 , which is connected integrally to the opposite oblique surfaces 11 , can engage. Depending on the opening angle of the oblique surface 11 , the pressure sensor 20 is actuated with abutment of the end surface of the sensor bolt 23 . If the clamping force of the flange body 3 decreases, which is associated with a spreading action of the oblique surface 11 , the sensor bolt 23 is displaced to an extent. If the changing extent exceeds a predetermined desired length outside the tolerance range, this triggers a signal, in the pressure sensor 20 , which, following evaluation in an evaluation unit (not illustrated), serves for signalling a residual sealing force outside the tolerance range.
In order to produce the flange body 3 , the flange parts 1 and 2 are produced separately from polymer material by injection moulding. The flange parts 1 , 2 may consist of a thermoplastic or a preferably glass-fibre-reinforced thermoset polymer material. Alternatively, it is also possible for the flange parts 1 and 2 to consist of metal, in particular sheet metal.
In a following step, the two flange parts 1 and 2 are fixed to one another in the outer ring section 7 by welding. For centred positioning of the flange parts 1 , 2 and/or for aligned arrangement of the outer through-passage openings 5 of the same, the flange parts 1 , 2 have axially running centring bolts 24 and centring bores 25 in the inner ring section 8 .
In order to form the later groove 9 , the flange parts 1 , 2 each have flattened portions 26 in an inner ring section 8 . Since the flange parts 1 , 2 are of identical design, they may be produced using a single tool. This reduces the production costs and increases the throughput.
In order to facilitate overhead installation, the inner side 10 of the inner ring section 8 has circumferentially distributed protuberances 27 , which project radially inwards and serve for securing the flange body 3 with clamping action at a pipe end.
Alternatively, it is also possible for the flange body 3 to be produced in one piece.
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A loose flange for connecting pipes, the flange having radially inwardly oriented and elastically deformable oblique surfaces. The clamping force capacity of the loose flange is improved as a result. A method for producing the loose flange is also disclosed.
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BACKGROUND OF THE INVENTION
The present invention relates to a novel material for use as a cushion insock or in a cushion insole, which material has compression stiffness, resilience and energy absorption characteristics to provide foot comfort in conventional or sports footwear.
It has been demonstrated in a number of studies, for example as reported by T. A. McMahon and P. R. Greene in J. Biomechanics, 1986, Volume 12, pp 893-904, and by D. J. Pratt, P. H. Rees and C. Rogers, Prosthetics and Orthotics International, 1986, 10, pp 453-45 that compression stiffness and energy absorption characteristics are important in sports shoe design, in particular for designing a good running shoe. Although for a sports shoe the sole unit offers most scope for applying these principles, extra benefit can be derived from the use of an insole or insock having specifically designed compression stiffness and energy absorption characteristics. The use of insocks and insoles having specific compression stiffness and energy absorption characteristics is also desirable in conventional, non-sports footwear, where the sole unit offers less scope for modifying these characteristics.
It has been proposed to provide polymer foam-based insocks and insoles with specific compression stiffness and energy absorption characteristics but these foam-based insocks and insoles have the disadvantages that their moisture-permeability and heat-transmission and moisture-transmission properties are less advantageous than those of conventional non-woven insole and insock materials.
OBJECT OF THE INVENTION
It is an object of the present invention to provide a material for cushion insocks and for use in cushion insoles, in which the above disadvantages are reduced or substantially obviated.
SUMMARY OF THE INVENTION
The present invention provides a material for cushion insoles and insocks comprising a non-woven low-density felt having a thickness of between 3 and 10 mm, said felt being manufactured from fibres and being impregnated with a resilient rubbery impregnant, wherein the fibres have a decitex of between 5 and 17 and a staple length of between 30 and 80 mm, and the density of the impregnated felt is in the order of 0.08 to 0.20 g/cm 3 (80-200 kg/m 3 ).
One suitable material according to the invention comprises a non-woven felt made from fibres having a decitex of at least 5 decitex, in particular fibres having a decitex of 6.7. In general, it is found that the thickness of fibre which can be used depends upon the required thickness of the finished insock or insole. The thicker the final product, the thicker the fibres to be used. For example, for a felt of a finished thickness of 3 mm, which is considered to be a minimum thickness at which the advantageous properties of the material are obtained, the fibres used should have a thickness of 5 decitex. However, for a felt of 4 mm, the fibres used should have a decitex of at least 6, preferably 6.7. For a felt with a finished thickness of 6 mm, fibres used in the production of the felt are preferably polyester fibres, which may contain up to about 10% by weight of bicomponent fibres, for example bicomponent fibres with a higher melting polyester core and a lower melting polyester sheath. The incorporation of bicomponent fibres in the felt makes the felt suitable for fusion bonding, which increases the extension stability and resilience of the final product.
The felt for use according to the invention is a low-density felt. By the term "low-density" is meant a felt which prior to impregnation has a density of less than 0.lg/cm 3 (100kg/m 3 ), preferably in the range 0.075 to 0.085g/cm 3 (75-80kg/m 3 ).
The impregnant used in the material according to the invention may conveniently be a blend of nitrile and PVC latices cross-linked with a cross-linking agent such as melamine-formaldehyde or sulphur; alternatively a polychloroprene latex or polyurethane latex may be used. Cross-linked nitrile/PVC impregnants are preferred, both from cost reasons and because of their heat-sensitivity is more satisfactory. The cross-linked nitrile PVC impregnant is suitably used at a dry impregnant-to-fibre ratio by weight of at least 0.5 to 1.
Where the material according to the invention is to be used as an insole material, it may be necessary to provide it with an integral backing which provides adequate stiffness in, in particular, the forepart of the shoe. Such an integral backing is suitably provided by back coating the impregnated material with a stiffening impregnant such as a styrene/butadiene latex containing approxiatly 60% of styrene. Where back coating is used to provide an integral backing the stiffening impregnant should be chosen to ensure that satisfactory bonding can be obtained during lasting with a hot melt lasting adhesive.
When the material according to the invention is used as an insole material, it is, because of the characteristics which are required from it, rather thicker than conventional insole materials which do not have these characteristics. Depending on the particular style or type of shoe being manufactured, it may be necessary to make slight modifications to conventional shoe-making procedures in order to avoid any difficulties due to this increased thickness. For example in conventional shoe-making techniques the insole is cold-pressed, using a substantial press, to give the forepart some shaping prior to lasting. The insole is then attached to the last, usually with a single insole tack. One problem which may arise if the shoe-making technique is not suitably modified, in particular in the manufacture of ladies' shoes, where the last has a curved bottom, is that during lasting the lasting wipers may catch on the edge of the insole and cause creasing. This problem can be overcome in a number of ways. The preferred way is to press the insole with slight heating, prior to lasting, to give the insole an initial curvature. Alternatively, additional insole tacks may be used to attach the insole to the last, or the edges of the insole may be skived prior to lasting.
For many applications the material according to the invention may be used in a shoe without further surface treatment. In some cases, the slightly fluffy felt-like texture of the insole may be desirable, or the shoemaker may wish, in particular for ladies' shoes where the heel is to be attached by heel nails, to cover the backpart of the insole with an insock to hide the nails so that the surface finish of the insole itself is not important. For applications where a smooth surface is required, the material according to the invention may optionally be provided with a surface finish derived from a fine fibre/bicomponent fibre layer. Such a surface finish is obtained by laying on top of the coarse fibre felt a surface layer comprising a fleece which is a blend of a fine fibre and a fusible fibre, needling the two layers together so that substantially none of the coarser fibres protrude through the surface layer, and heating the material in a heated press to a temperature above the melting point of the fusible fibre. An insole material having such a surface finish is described and claimed in U.S. application Ser. No. 07/513829 filed 24th April 1990 (thus incorporated herein by reference).
It is also possible, by use of an appropriate impregnant, for example an impregnant containing glycerol, to make the material RF (radio frequency) lossy, and thus suitable for cutting and welding using RF techniques. If the fabric and impregnant composition are suitably chosen to allow RF cutting and to provide a surface finish, then this surface finish can be made, during cutting, to extend over the cut edge to provide an edge finish. The provision of an edge finish is particularly desirable in the manufacture of sandal platforms.
Insole or insock materials for use in different type of shoes, for example running shoes or casual shoes, may be required to have different physical properties. It is a feature of the materials according to the present invention that the compression-stiffness, energy-absorption and resilience characteristics can readily be changed by choosing different fibre blends, making base felts of different density, and/or by varying the nature of the impregnant or the binder to fibre ratio at which it is used. For example, an increase in felt weight and density, or an increase in impregnant-to-fibre ratio, will increase the compression-resistance of a particular material.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Selected materials according to the invention will now be described with reference to the following Examples.
EXAMPLE 1
A base felt was prepared from 100% Hoechst Trevira 290, a polyester staple fibre having a staple length of 60 mm and a density of 6.7 decitex. The base felt is a 450 grams per square meter felt, needled to a gauge of 5.5 mm±0.25 mm.
The felt was impregnated with an impregnant having the following composition:
______________________________________ Parts per 100, wet weight______________________________________Bayer Perbunan Butadiene - Acrylonitrile 52.0Latex 2890 (Acrylonitrile content 28%)BASF Lutofan LA951 PVC Copolymer 2.0Latex70% dispersion of EEC International 15.0Queensfil 240 Calcium Carbinate FillerBIP Beetle 338 Melamine Formaldehyde Resin 0.6Alloid Colloids Viscalex HV30 (Acrylic 3.1Copolymer)Bayer Coagulant WS (Organopolysiloxane) 0.8DOW Corning DB 110 A Antifoam Emulsion 0.1Pigmet 0.4Water 26.0 100.0______________________________________
The impregnants had a solids content of approximately 35%.
The felt was impregnated to give a 1:1 dry impregnant-to-fibre ratio, i.e. a pick-up of 450 grams/sq. meter of dry impregnant. The impregnated felt was dried at a temperature rising to 140° C. to provide adequate melamine-formaldehyde cross-linking. The final gauge of the material was 4.5 mm, and the final density 0.17 g/cm (170 kg/m 3 ).
The impregnated felt was then back-coated, to a coating weight of 200 grams per square meter (dry), using a blade or rotary screen coater, using the following formulation:
______________________________________ Parts per 100, wet weight______________________________________Doverstrand Revinex 2023 styrene-butadiene 73.0latex, (styrene content 80%)EEC International Speswhite Clay filler 23.0(60% solids)Scott Bader Texicryl 13/302 Carboxylated 4.0Acrylic Thickening Agent 100.0______________________________________
The back-coating formulation had a solids content of about 53%. The back-coated material was dried in a hot-air drier.
The material according to this example had a compression modulus of 85 lbs per square inch (0.586 MPa), corresponding to a McMahon-Green "track stiffness" of 20,000 lb per ft (615 kN/m). This material was therefore suitable for use in running shoes.
EXAMPLE 2
For shoes other than running shoes, such as casual or more conventional footwear, a material of lower compression modulus, for example 60 to 70 lbs per squear inch (0.414-0.483 MPa), providing more cushioned comfort may be more suitable.
A material having a compression modulus in the range 60 to 70 lbs per square inch (0.414-083 MPa) was produced by repeating the method of Example 1, using the same felt, impregnant formulation and back-coating method, with the variation that the dry impregnant-to-fibre ratio was reduced to 0.75:1, giving a final density of the 1 impregnated felt of 0.15g/cm 3 (150kg/m 3 ). The following names referred to in the foregoing are Registered Trade Marks: TREVIRA, PERBUNAN, QUEENSFIL, BEETLE, VISCALEX, REVINEX, TEXICRYL, LUTOFAN, SPESWHITE
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A cushion insole/insock material having a compression stiffness, resilience and energy absorption to provide comfort in conventional or sports footware. The material is a non-woven, low density felt made from fibres and imrpegnated with a rubbery impregnant.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority from U.S. Provisional Application No. 60/781,349 filed on Mar. 9, 2006.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to residential and commercial security systems, and more particularly to an intrusion detection in an IP connected security system.
[0004] 2. Discussion of the Prior Art
[0005] Many modern residential and commercial security systems are connected to a central monitoring station via the internet or an intranet. The advantages of such a setup are many. The use of internet protocol (IP) packetized data for transmitting status and updates to and from the security system allows for routine updates to the system. Also, fully digital sensors can be added incrementally to the system without compromising the existing infrastructure. Operators can also match many wired and wireless components onto the system without compromising the integrity of the system.
[0006] However, with the advantages of a IP-connected security system are a host of disadvantages. Some of those disadvantages stem from having a security system occupy a node on the Internet. In order to receive and transmit IP packets, the security system will have an IP address and a gateway router associated with the address. It is fairly easy to find an IP address and attack the IP address using a variety of attacks to shut down the IP address. These attacks can be engineered by criminals hoping to compromise the security system, disgruntled employees, hackers and competitors. As security systems expand to take on more duties (including surveillance, facility access control, etc.), the disabling of a security system by an Internet attack can have dire consequences. Furthermore, since IP attacks at security system IP addresses can frequently go unnoticed at the facility, the attacks can pose even bigger threats to security systems which protect the physical premises.
SUMMARY OF THE INVENTION
[0007] The present invention provides a device and method for detecting and responding to an IP intrusion in a security system. An intrusion detection device is coupled to primary and secondary communication devices of a security system so that when a Internet attack is detected, communication between the security system and a central monitoring station occurs over the secondary communication device rather than the primary communication device. The invention preserves communication between the security system and the central monitoring station even when a denial of service type attack is occurring so that physical premise security is uncompromised.
[0008] In one aspect the invention is a security system comprising: a control panel; sensors electrically coupled to said control panel; a primary communication device for transmitting and receiving data; a secondary communication device for transmitting and receiving data; and an intrusion detection device coupled to said control panel, wherein said intrusion detection device, upon detection of an intrusion, switches communication to said secondary communication device.
[0009] In another aspect, the invention is a method of detecting intrusions to a security system, said security system including a control panel; sensors electrically coupled to said control panel; a primary communication device coupled to said control panel for transmitting and receiving data; a secondary communication device for transmitting and receiving data; and an intrusion detection device coupled to said control panel, said method comprising the steps of: at the intrusion detection device, detecting an intrusion attempt; raising a local alert on said control panel; and switching communication to said second communication device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing objects and advantages of the present invention for intrusion detection in a IP connected security system may be more readily understood by one skilled in the art with reference being had to the following detailed description of several embodiments thereof, taken in conjunction with the accompanying drawings in which:
[0011] FIG. 1 is a schematic diagram of a prior art security system;
[0012] FIG. 2 is a schematic diagram of a security system in accordance with one embodiment of the invention; and
[0013] FIG. 3 is a flowchart diagram of the steps taken at the security system to detect intrusions.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with these embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention may be practiced without those specific details. In other instances, well known methods, procedures, components and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention.
[0015] Referring to FIG. 1 , there is shown a schematic diagram of a typical residential or commercial security system 100 . Security system 100 may include a control panel 110 which may use proprietary buses and separate wiring and cables within a building to communicate with a variety of sensors 125 and 127 . The sensors 125 , 127 may be, for example, radio frequency motion sensors, cameras, alarm reporting devices, or the like, which generally report intrusions or sense emergencies in the building to the control panel. The control panel 110 typically houses a display means for displaying the status of the various sensors and for alerting local facility managers and residents if a physical security breach or emergency has occurred. The control panel also may contain means for resetting sensors and running diagnostics on the sensors.
[0016] The control panel is coupled to IP communication device 115 which connects the security system to a central monitoring station 150 . It will be understood that the IP communication device may be hubs, switches or routers which enable communication through messages compliant with Internet Protocol. The IP communication device 115 communicates to the central monitoring station 150 through the Internet 120 . The central monitoring station 150 may maintain contact with the control panel 110 so that the status of the system is kept up to date at the central monitoring station.
[0017] The security system 100 has a secondary communication device 125 for providing communication to the central monitoring station 150 when the primary method of communication is unavailable. Such secondary communication device 125 may be, for example, a GSM dialer configured to communicate wirelessly to the central monitoring station. Such back-up communication equipment 125 may be a telephone modem configured for communicating with the central monitoring station 150 through plain old telephone service (POTS) lines. Although the back-up communication equipment 125 is illustrated as a separate component, it may be integrated within the control panel 110 .
[0018] Generally, concurrent with the rise in connectivity among diverse computer networks and the corresponding increase in dependence on networked information systems, there has been a dramatic increase in the need for robust security to enforce restrictions on access to and prevent intrusion on security systems. The topology of the interconnected networks has also grown increasingly complex, and often involves open networks such as the internet or the extranet that expose security systems to increased threats of attack. No single solution has yet been proposed that addresses the current needs for intrusion detection and response for a security system. Additionally, the intrusion detection and response of a security system must be cognizant of the special needs of a security system.
[0019] For instance, a security system at a residential or commercial facility may not be monitored by facility personnel on a regular basis. Since most of the control panel data is transmitted and received at a central monitoring station, facility personnel may not actively manage the control panel, instead, only paying heed when a local alarm or alert is raised by the security system. Further, unlike when a website is attacked by a coordinated Internet attacks and the operator of the website chooses just to disable the website until the attack is ended, an Internet attack at a security system may be part of a coordinated attack in conjunction with a physical attack on the facility. Therefore, it is especially important that communication with the central monitoring station is maintained during an Internet attack.
[0020] The present invention contemplates an intrusion detection device which monitors Internet traffic and, if certain conditions are met, disables the primary connection to the central monitoring station so that secondary communication is established.
[0021] Methods used by intruders to gain unauthorized access to computer networks evolve in sophistication in lock step with advances in security technology. It is typical, however, that successful attacks on network systems often begin by attacking the security subsystems in place on the target network that are responsible for detecting common intrusion signatures, disabling those systems and destroying evidence of the intrusion. Such attacks include a “denial-of-service” attack, which is an attack on a computer system or network that causes a loss of service to users, typically the loss of network connectivity and services by consuming the bandwidth of the victim network or overloading the computational resources of the victim system. A “smurf” attack is a “denial-of-service” attack, which uses spoofed broadcast IP messages to flood a target system. A “banana” attack involves redirecting outgoing messages from the network back onto the network, preventing outside access, as well as flooding the client with the sent packets.
[0022] Attempts to gain unauthorized access to computer networks capitalize on inherent loopholes in a network's security topology. It is known, for example, that weaknesses in individual security components are often sought out and successfully exploited. The rapid introduction of new technology exacerbates the problem, creating or exposing additional weaknesses that may not become known even after a breach in security has already occurred. Some currently available intrusion tools allow an intruder to evade detection by intrusion detection systems.
[0023] Referring now to FIG. 2 , there is shown a schematic diagram of a security system 200 in accordance with one embodiment of the invention. Security system 200 includes a control panel 210 , which uses proprietary buses and separate wiring and cables within a building to communicate with a variety of sensors 225 and 227 . The sensors 225 , 227 may be, for example, radio frequency motion sensors, cameras, alarm reporting devices, or the like, which generally report intrusions or sense emergencies in the building to the control panel. The control panel 210 houses a display means (not shown) for displaying the status of the various sensors and for alerting local facility managers and residents if a physical security breach or emergency has occurred. The control panel also may contain means for resetting sensors and running diagnostics on the sensors.
[0024] The control panel is coupled to an intrusion detection device 240 , which is further coupled to IP communication device 215 . The IP communication device may be hubs, switches or routers, which enable communication through messages compliant with Internet Protocol. In one embodiment, the IP communication device 215 is a gateway router for directing data traffic onto and from the Internet. The IP communication device 215 communicates to the central monitoring station 150 through the Internet 220 . The central monitoring station 250 may maintain contact with the control panel 210 so that the status of the system is kept up to date at the central monitoring station.
[0025] The security system 200 includes a secondary communication device 225 for providing communication to the central monitoring station 250 when the primary method of communication is unavailable. The secondary communication device is also coupled to the intrusion detection device 240 . Such secondary communication device 225 may be, for example, a GSM dialer configured to communicate wirelessly to the central monitoring station. Such back-up communication equipment 225 may be a telephone modem configured for communicating with the central monitoring station 250 through POTS lines. Although the back-up communication equipment 225 is illustrated as a separate component, it may be integrated within the control panel 210 .
[0026] The intrusion detection device 240 may include a firewall for controlling access to the security system. The firewall is configurable and serves to control access by hosts on the Internet to resources on the network. This protects the security system from intruders outside the firewall by essentially filtering out packets of information transmitted over the Internet. The intrusion detection device 240 further includes a packet sensor, which reads packets passing through the firewall, and looks for inherent signatures of an Internet attack.
[0027] Preferably, the intrusion detection device is embedded in the control panel as a software package and implemented on computers comprising at least a master system and the security subsystem. In another embodiment, the intrusion detection device is implemented in firmware and loaded into a processing unit associated with the control panel. This allows for updates by the central monitoring station as signatures for new types of attacks are discovered.
[0028] During operation, the intrusion detection device 240 monitors the message activity at the security system. All outgoing and incoming message packets are examined at the intrusion detection device. The intrusion detection device examines individual packets and gathers data related to the originating IP address of each message. If, for instance, bursts of data messages from one specific IP address are directed to the security system, a denial-of-service type attack may be occurring. In another instance, if the burst of data traffic is outside the statistical range of normal data traffic for the security system, a denial-of-service attack from spoofed IP addresses may be occurring.
[0029] A host of factors related to the security system, including vulnerability, visibility of the target, data traffic capacity, time of day, and other factors may figure into how the intrusion detection device handles anomalous data message activity at the security system. These factors can be coded into the software or firmware implementation of the intrusion detection device so that trigger levels for raising an alarm or alert can be modified.
[0030] Referring now to FIG. 3 , there is shown the steps involved in a method of intrusion detection for a security system. In step 310 , an intrusion attempt is detected at the intrusion detection device. For instance, if the intrusion detection device detects a certain data traffic over a predefined trigger number, the intrusion detection device logs the event as an intrusion attempt. In step 320 , the intrusion detection device raises a local alert at the control panel. The control panel has a display means, which alerts local facility personnel of an intrusion attempt. This may be accomplished by means of a warning displayed on the display means of the control panel. In step 330 , the intrusion detection device enables the secondary communication device for communications to and from the central monitoring station. The intrusion detection device may also disable the primary communication device so that data message traffic over the primary communication device is ignored.
[0031] The preferred embodiment of the present invention, a monitored voltage inverter for a security system, is thus described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the below claims.
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An intrusion detection device and method in an IP connected security system is disclosed. An intrusion detection device is coupled to primary and secondary communication devices of a security system so that when a Internet attack is detected, communication between the security system and a central monitoring station occurs over the secondary communication device rather than the primary communication device. The invention preserves communication between the security system and the central monitoring station even when a denial of service type attack is occurring so that physical premise security is uncompromised.
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BACKGROUND OF THE INVENTION
As more businesses and government entities increasingly rely on computer networks to conduct their operations and store relevant data, security of these networks has become increasingly important. The need for increased security is emphasized when these networks are connected to non-secure networks such as the Internet. The preservation of important data and the ability to retrieve the data in the aftermath of a security breach has become the focus of Information Technology (IT) practitioners, particularly in the area of Incident Response (IR).
When a security breach occurs Incident Response Teams (IRTs) often respond, analyzing available information to determine the scope and risk associated with the breach. In order to accomplish this task they must collection information from IT assets, such as detection systems, firewalls, and computer systems. They must also collect data directly from potentially compromised assets to identify the methods employed by an attacker to accomplish the breach.
When attackers compromise an asset such as a computer system, they may install malicious software designed to damage a system, evade detection, or perform surveillance. In all cases these malicious programs (“malware”) alter the normal state of the compromised system, making collection of accurate information about the system (which is something necessary for performing meaningful IR) very difficult for response personnel. Malware can alter the state of a computer system to make it appear a compromise has not occurred. Only through detailed inspection of multiple aspects of a running system can a responder hope to effectively identify and confirm a compromise.
In order to account for malware on a compromised system and collect accurate information that may aid in responding to an incident, forensic techniques may be employed to derive system information through direct examination of the contents of a computer system's memory. By employing software that analyzes the information, structures, and anomalies present in system memory, the ability of an attacker to camouflage its activities is greatly reduced. These approaches are collectively referred to as memory forensics. These techniques differ from traditional computer forensics in that the focus is in discerning the live state of a computer system through review of memory rather than looking at the “dead” state of a system through examination of the contents of storage media, such as hard drives.
The field of memory forensics is relatively new in the digital forensics arena, especially when compared to techniques in practice for the analysis of storage media. As such, many problems remain unsolved and new methods for memory analysis are being developed constantly. Existing methods face numerous challenges, such as the rapid change of modern operating systems, the variety of operating systems present in the marketplace today, and the fact that most information associated with live system state for a computer system is not a common topic of information sharing, particularly for proprietary operating system vendors. As such, the practice of memory forensics is relegated to a highly specialized cadre of computer and security researchers with advanced degrees and many years of experience in the field. A strong need exists in the industry to provide capabilities that utilize memory forensic techniques in such a way as to make their benefits accessible to IT professionals in various enterprise and organizational environments. In particular, a need exists to be able to accurately identify various elements within a computer system, including characteristics such as operating system type and version, memory management configuration, and virtual machine state of the computer system.
SUMMARY OF THE INVENTION
In response to this need, the present application describes a method and system for utilizing memory forensic techniques to identify an operating system, its memory utilization configuration, and virtual machine state.
In an embodiment, a plurality of values representing data contained within a memory of a computer system can be accessed, those valued can be searched for a first identifying characteristic that indicates an operating system and, upon finding the first identifying characteristic, searched for a second characteristic that indicates an operating system. The distance within the memory of the computer system can be analyzed between the first identifying characteristic and the second identifying characteristic, leading to a determination, from the distance, of a type and a version of an operating system loaded into the computer system's memory.
In another embodiment, a plurality of values representing data contained within a memory of a computer system can be accessed, those valued can be searched for a first one or more identifying characteristics that indicate a system structure used for memory management. The addresses in the memory corresponding to the values of the one or more identifying characteristics can then be determined and the structure of addresses to identify one or more methods for memory management in use within the computer system can be analyzed.
In another embodiment, a plurality of values representing data contained within a memory of a computer system can be accessed and those values can be searched for one or more identifying characteristics that indicate a virtual system. Processes corresponding to those characteristics can then be analyzed to determine if the process is running on at least one of computer hardware and a virtual environment
In yet a further embodiment, all three methods outlined can be used to provide a set of memory forensic features that can provide valuable forensic information to Incident Response Teams without requiring them to have the same level of knowledge as experts currently developing techniques in the memory forensics field.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 . depicts the basic functional areas of a real computer system.
FIG. 2 . depicts a series of computer systems running as virtual machines inside of a virtual environment on a real computer system.
FIG. 3 . depicts how malicious software may run in a computer system, and the types of information stored within memory and on storage devices within a computer system.
FIG. 4 . depicts an embodiment that uses specific characteristics of the structure of an operating system to identify its core process within the memory of a running computer system and identify the type and version of the running operating system.
FIG. 5 . depicts a flowchart that explains the detailed steps used by one embodiment of the invention to identify the type and version of an operating system by examining the contents of system memory of a computer system.
FIG. 6 . depicts how management of system memory is performed on a computer system that does not have Physical Address Extensions (PAE) enabled.
FIG. 7 . depicts how management of system memory is performed on a computer system that does have PAE enabled.
FIG. 8 . depicts how memory addresses are specified in systems with and without PAE enabled.
FIG. 9 . depicts a flowchart describing how one embodiment of the invention examines structures in the memory of a computer system to determine whether PAE is enabled or disabled.
FIG. 10 . depicts a flowchart describing how to use an examination of the contents of a computer system's memory to determine if core operating system processes found within memory are running on real physical hardware, or within a virtual machine.
DETAILED DESCRIPTION
The present application describes methods and systems for forensic identification of operating system type and version, memory management configuration, and virtual machine status on a computer system. Various embodiments can be used together. In one embodiment, software can execute on a computer system to be examined. In another embodiment, software can execute on another system not under examination but take as input a file containing the entire contents of system memory from a computer system of interest that is under examination.
Various embodiments can work with a real system or a virtual machine. A real system is compromised of an operating system running directly on a single instance of computer hardware. A virtual machine is a bounded software environment (a virtual environment) that emulates an additional layer of computer hardware and runs on actual computer hardware. A virtual machine can allow various computer software applications to be run within this software-emulated-hardware environment. One virtual environment may in turn run several virtual machine inside of it, effectively emulating multiple hardware platforms. This technique has many benefits in IT environments and is a common practice in modern enterprises. When examining a computer system during the course of an incident response, it is important be able to determine if virtual machines are running in a virtual environment on a real system in order to guide interpretation of results from conducting forensic analysis.
The process of memory forensics involves either contemporaneously examining the active running state of a computer system by reviewing its memory or capturing the running state of a computer system into a persistent representation (such as a file stored on a disk), which is then reviewed at a later time. In either case the examiner must understand the structures stored in the memory of the computer system in order to extract relevant data. A great deal of information may be derived from this data, including but not limited to information about the programs running on the computer system, data being accessed or manipulated by the computer system, and communications information (e.g., network connections, data being transferred, remote parties attempting to connect to the computer system).
The information stored in a computer system's memory varies widely based on the type and version of operating system being executed, features enabled or disabled within the operating system, and the configuration of the execution environment (such as hardware). Determining this information is critical to being able to conduct successful memory forensics on memory data from a computer system.
The analysis can further be complicated if the computer system is running as a virtual machine. FIG. 1 outlines the components of a real system (i.e., physical machine), while FIG. 2 depicts a virtual environment comprising one or more virtual machines. Note that in each figure a real system is present (real system 100 and real system 200 respectively). In the real system depicted in FIG. 1 , the operating system 140 can execute directly in the hardware environment, interacting with subsystems such as memory 110 , storage 130 , and other hardware and peripherals 120 .
Within the virtual environment 250 in FIG. 2 , operating system 262 can execute on a virtual interface emulated by virtual machine 260 and operating system 272 can execute on a virtual interface emulated by virtual machine 270 . Virtual machine 260 and virtual machine 270 can be provided by virtual environment 250 , which can be running on an operating system 210 . Operating system 210 can be running on real system 200 . It is, therefore, extremely important to be able to determine if data obtained from system memory is from a real system or a virtual machine system within a virtual environment.
Forensic examination of a computer system may need to be undertaken for a number of reasons. Memory forensic techniques, in particular, are used in situations where understanding the live, running state of a computer system is critical to accomplishing the task at hand (including incident response). Modern attackers often use malicious software, or malware, that may only be examined or understood when it is observed executing in the memory of a computer system. FIG. 3 depicts how malicious software 320 may inject itself into a computer environment and subvert actions of the operating system 310 by interfering with how it interacts with its execution environment (e.g., the physical hardware or virtual environment it is running in). Various embodiments utilize techniques that allow a forensic examiner to determine characteristics of a computer system by observing the contents of memory rather than directly interrogating the environment itself. This is important because on a compromised system, malicious software 310 can be programmed to interfere with direct interrogation methods by substituting or altering responses to queries. For example, malicious software could be programmed to obscure the presence of another program running on the system or a file stored on a disk.
In an embodiment, the contents of memory as depicted in FIG. 4 can be read so that the operating system type and version (within either computer system memory or a file containing the contents of memory from a computer system) can be identified. In this particular case, system memory 400 can be scanned from its lowest address to its highest address and searched for an identifier that indicates the presence of the structures representing the core process of a computer system. In an embodiment that can operate on computer systems running an operating system such as the operating system sold under the trademark MICROSOFT WINDOWS®, system memory 400 can be scanned for the process name System 410 , which is the word “System” stored as 8-bit byte sequences according to the American Standard Code for Information Interchange (ASCII) followed by ten empty values (e.g., hexadecimal value 0x00). System memory 400 can then be scanned for a specific byte pattern 420 that indicates the beginning of another structure used by the operating system called the Dispatch Header. The address in memory where the system process name 410 is stored as well as the beginning of the dispatch header 420 can be determined and the distance in bytes between them measured. The result can then be compared to a table of information that identifies which operating system types and versions map to this distance; if a match is found then the Dispatch Header/System process distance information and corresponding operating system and version identifier can be output in a format readable either by an end user or another computer program.
FIG. 5 is a flow chart 500 that depicts an embodiment that can include software executing on a computer system where memory is to be analyzed, or executing on another system taking the contents of a target computer system's memory as input. In an embodiment, a pointer can be initialized in a step 502 to the beginning of memory and memory can be read in a step 504 (where memory is either active memory or contents of memory provided as an input) to look for a sequence of bytes indicating the System process name. If a matching sequence is found in a step 506 , then memory can be scanned in a step 510 in reverse from where the System process identifier was located looking for a byte sequence indicating the presence of the Dispatch Header. If the sequence is found in a step 512 the distance between Dispatch Header and System Process identifier can be calculated in a step 516 , and the result examined in a step to see if it matches values for known operating systems and versions. Because an environment may contain multiple execution environments (e.g., a real environment with multiple virtual environments as depicted in FIG. 2 ) the scan may iterate in a step 520 through the rest of memory until all potential instances of the System process have been identified and the end of memory contents reached in a step 524 .
Understanding the methods used to manage memory in a computer system is critical to determining the context of data observed during memory forensic operations. Memory contents and methods for interpretation will differ according to the memory management method in force. Memory management dictates the specific methods used by the computer system to allocate, reference, and utilize memory for the programs that execute in its environment. Methods utilized for memory management may differ according to hardware specification, operating system, operating system version, and system configuration. If these inputs are either provided directly from a computer system or otherwise available (e.g., in a file), memory management structures may be directly examined to determine the memory management methods and configuration in place on the computer system being examined.
In an embodiment, the memory management configuration of the computer system can be determined once the operating system type and version have been identified. For example, a determination can be made whether the computer system has enabled Physical Address Extensions (PAE). PAE is a method used in computer systems that allows a computer system that uses a 32-bit computer processor to utilize and access system memory configurations of greater than four gigabytes (32 bits allows a computer to represent a number between 0 and 4294967295; if PAE were not utilized a 32-bit computer system would only be able to use 4294967296 bytes of memory within the system).
FIG. 6 is a logical block diagram that depicts how a computer system may interpret memory addresses when PAE is not enabled. System Process Information 600 can contain a pointer to Page Directory 610 . Page Directory 610 can be used as a starting point for interpreting memory addresses in order to find information stored at a given address. Addresses are typically represented as virtual addresses—that is, they must be interpreted in order to access the information they reference. A virtual address 602 , for example, can be broken into several different fields, each used in combination with Page Directory 610 to identify where information is stored in physical memory 618 .
FIG. 7 is a logical block diagram that depicts how memory addresses can be interpreted when PAE is enabled. In this instance, an additional level of indirection is added—in the place of Page Directory 610 shown in FIG. 6 , a series of Page Directory Pointers 712 can be utilized to point to four different Page Directories 716 . As demonstrated by FIG. 6 and FIG. 7 , understanding the memory management configuration significantly alters how the contents of memory should be interpreted, and is therefore critical when performing memory forensics.
Systems with PAE enabled use 24 bits to specify a memory address within a Page Directory Entry, as opposed to systems that do not have PAE enabled, which only use 20 bits. FIG. 8 depicts the differences between non-PAE addresses 800 and PAE addresses 810 . Non-PAE entries utilize only 32 bits for addressing (20 bits for address, 12 bits for flags, 800), while PAE entries utilize 64 bits (28 bits reserved, 24 bits for address, and 12 bits for flags, 810). Reserved bits are always set to zero. This means that for PAE entries the first 32 bits of the entry will set at a maximum 4 bits, 810 , which sets bounds on values for PAE address entries. In an embodiment, the entries in the Page Directory can be examined and a determination can be made if any portions of the entries exceed the values possible using 4 bits within a 32-bit block. If these values are exceeded, a conclusion can be reached that PAE is not enabled.
FIG. 9 is a flowchart that depicts the process 900 of determining if a system is running with PAE enabled or PAE disabled. Software is run on a system with memory to be examined or the contents of system memory are provided as an input. Memory values are read in a step 902 , and the Page Directory identified and examined in a step 904 . If any values are identified in the Page Directory that exceed the limits implied by having 28 bits reserved for a PAE configuration, then the determination is made that the system does not have PAE enabled in a step 914 , else the determination is made that the system does have PAE enabled in a step 912 .
When a System process is identified as depicted in FIG. 4 , it is possible to determine if it corresponds to an operating system running on real hardware, or an operating system running in a virtual environment as depicted in FIG. 2 . In an embodiment, this determination can be made as depicted in the process 1000 depicted in the flowchart in FIG. 10 . Memory within the computer system can be scanned and the System process can be identified as depicted in FIG. 4 . The Page Directory can be identified in a step 1002 (as discussed with reference to FIG. 6 and FIG. 7 ), and a determination can be made if PAE is enabled ( FIG. 9 ). A global virtual address consistently provided by the operating system within the System process structure (e.g., an address that always has the same value, irrespective of how or where the operating system is running) can then be utilized in a step 1004 in conjunction with the Page Directory to translate the global virtual address and access its contents. To translate this address, the Page Directory can be examined in a step 1006 , and the entry for the global virtual address can be validated (e.g., by verifying flags values are valid and that any address or reserved bits do not exceed maximum values as described in FIG. 9 ). The Page Directory Entry then can be followed in a step to a Page Table Entry, and the same validation is performed on the Page Table Entry in a step 1008 . If the operation succeeds (that is, the Page Directory Entry and Page Table Entry are valid and a Physical Memory location is successfully accessed), then a determination can be made in a step 1010 that the System process identified is running in a real environment. If the operation fails, then a determination can be made in a step 1012 that the System process is executing within a virtual environment.
As these and other variations and combinations of the features discussed above can be utilized without departing from the present invention as defined by the claims, the foregoing description of the preferred embodiment should be taken by way of illustration rather than by way of limitation of the invention set forth in the claims.
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A system and method for employing memory forensic techniques to determine operating system type, memory management configuration, and virtual machine status on a running computer system. The techniques apply advanced techniques in a fashion to make them usable and accessible by Information Technology professionals that may not necessarily be versed in the specifics of memory forensic methodologies and theory.
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BACKGROUND OF THE INVENTION
This invention relates to the removal of soil from fabric in a gaseous environment, and, more particularly, to the utilization of acoustic energy to improve the dislodging of soil from the fabric and to prevent its redeposition onto the fabric.
The dry cleaning of fabrics is currently performed commercially using organic solvents such as perchloroethylene or petroleum derivatives. These solvents pose a health hazard, are smog-producing, and/or are flammable. As an alternative, U.S. Pat. No. 5,467,492 discloses a dry-cleaning process that uses liquid carbon dioxide as a cleaning medium. This process allows the fabric to be cleaned without the use of undesirable chemicals. One of the disadvantages of this liquid carbon dioxide process is that it must be performed within a pressure system, and thus has associated high capital costs.
In an alternative approach, U.S. Pat. No. 5,651,276 describes an apparatus and method to expel soils from fabric using gas jets in an ambient-pressure environment, without immersion of the fabric in a liquid cleaning medium. In this approach, mechanical agitation is provided by a jet of pressurized gas directed at the soiled fabric. The agitation of the fabric, by the mechanical agitation of the pressurized gas and by other coordinated sources of mechanical agitation such as tumbling, loosens and expels particulate soil from the fabric. The soil is entrained in the gas flow and subsequently filtered from the gas flow. The use of gas jet cleaning resolves the health and environmental concerns posed by conventional solvents. An additional benefit is that its use reduces secondary waste streams associated with processes that employ conventional solvents.
These agitation-based processes for cleaning fabric without immersion in water and without the use of environmentally undesirable chemicals have been demonstrated to be operable. Nevertheless, there is a desire to improve their cleaning effectiveness and efficiency. The present invention provides such an improvement.
SUMMARY OF THE INVENTION
The present invention provides an improvement to the mechanical agitation process for cleaning fabric such as garments. The modified process has an increased effectiveness and efficiency in removing soil from the fabric, and preventing its redeposition on the fabric. The process remains environmentally friendly, inasmuch as no noxious or dangerous chemicals are used, and waste streams are small. The present approach is compatible with the use of other techniques for enhancing the cleaning process. The process is a “dry cleaning” process, and the fabric is not immersed in any liquid cleaning medium during the actual cleaning procedure. The cleaned fabric is dry as it is taken from the cleaning apparatus.
In accordance with the invention, a method for cleaning fabric comprises the steps of providing a piece of fabric having soil therein, providing a source of acoustic energy, and cleaning the piece of fabric in a gaseous environment wherein the piece of fabric is not immersed in a liquid cleaning medium. The step of cleaning includes the steps of subjecting the piece of fabric to acoustic energy emitted from the source of acoustic energy, and, simultaneously, mechanically agitating the piece of fabric. The piece of fabric is preferably mechanically agitated by a jet of a soil-dislodging gas and/or by tumbling. All or a part of the piece of fabric may be treated with a mobilizing chemical that loosens the soil.
The frequency of the acoustic energy may be either in an audible range or at a high acoustic frequency. Typically, the acoustic energy has a frequency of from about 1 hertz up to about 1 megahertz (10 6 hertz). This acoustic energy is preferably provided by an acoustic device which converts an electrical input signal into an acoustic output signal. There is typically an electrical source which provides the electrical input signal to the acoustic device. The electrical source may include a controllable function generator which provides the electrical input signal to the acoustic device.
Simultaneously with the subjecting of the fabric to the acoustic energy, it is mechanically agitated by any operable approach. Examples of operable mechanical agitation techniques include gas jet agitation and tumbling agitation. In the first case, the jet of the soil-dislodging gas loosens soil that adheres to the fibers of the fabric, both by direct impingement and by causing flexure in the fabric that frees the soil from the fabric. In the second case, tumbling as in a cylindrical drum causes the fabric to flex, having somewhat the same effect. The acoustic energy creates sympathetic vibrations in the fibers, which aid in and accelerate this loosening and dislodging of the soil from the fabric at the same time that it is mechanically agitated.
The fabric may be treated with safe, environmentally benign chemicals to improve the dislodging process. Such chemicals may serve to loosen particulate soil, or to cause non-particulate soil to become particulated. The chemicals may be generally acting chemicals that are used to treat the entire fabric, or “spotting” chemicals that act on specific types of soil. Such chemicals may be applied either before or during the cleaning operation. Other chemicals such as odorants and anti-static compounds may be introduced during or after the cleaning operation. The chemicals are selected to be environmentally friendly and non-toxic.
This method of the invention is a gaseous approach, accomplished without the immersion of the fabric in a liquid cleaning medium while it is subjected to the acoustic energy. This feature is important, inasmuch as the fabric is dry and ready for use immediately after cleaning is complete. The present approach may therefore be considered a dry-cleaning process, as distinct from a washing process wherein the fabric is immersed in a bath of a liquid cleaning medium, as in conventional tub washing of fabric in water. In the present approach, the fabric may be contacted with a liquid or even immersed in a liquid prior to the step of subjecting the fabric to acoustic energy, but it may not be immersed in a liquid during and simultaneously with the step of subjecting the fabric to acoustic energy.
The present approach provides a technique for dry-cleaning fabrics. The approach has enhanced effectiveness as compared with conventional techniques, and as compared with prior gas jet cleaning techniques. The acoustic energy vibrates the fabric to aid in the dislodging of soil from the fabric, and that same vibration aids in preventing redeposition of the soil back onto the fabric before the soil may be removed from the system, as by filtering. Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. The scope of the invention is not, however, limited to this preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block flow diagram of an approach for practicing the present invention;
FIG. 2 is a diagrammatic view of an apparatus for practicing the present invention; and
FIG. 3 schematically illustrates the dislodging mechanism of soil from fabric.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 depicts a preferred approach for practicing the fabric cleaning method of the invention. A piece of fabric is provided, numeral 10 . The fabric may be of any operable type, including both woven and nonwoven fibers. The fabric may be of a wide variety of weights and thread densities. Typically, the greater the weight and the greater the thread density, the greater the agitation required, and in a preferred case the higher the pressure drop across the gas jet nozzles utilized in a subsequent step. The fabric has soil adhered to the fibers of the fabric. As used herein, “soil” includes both particulate and non-particulate material.
The fabric may optionally be pretreated, numeral 12 , as for example with a pretreatment chemical that loosens the particulate soil and/or a chemical that causes a non-particulate soil to become particulated. Either of these types of chemicals may be a generally acting chemical or a chemical that acts on specific types of soil (i.e., a “spotting” compound), and such chemicals are known for other applications. A colorless sulfonated dye site blocker such as those disclosed in U.S. Pat. Nos. 4,501,591; 4,592,940; 4,908,149; and 4,699,812 may be used to dislodge and particulate a specific stain. Examples of chemicals that loosen and particulate the soil are aliphatic sulfonic acid cleaning compounds, both alkyl and alkenyl, in the preferred range of C8-C24, as disclosed in U.S. Pat. No. 4,699,812. These chemicals are selected to be consistent with other features of the process, specifically safety, biodegradability, and environmental acceptability. The particulating chemicals are often furnished as liquids, but they are used only to moisten the fabric and not as a general cleaning medium as in a conventional water-immersion washing machine.
Another example of a chemical that may be applied to the fabric in the pretreatment step 12 is a foaming agent. Foaming agents are known for use in other applications. A preferred foaming agent is sodium lauroyl sarcosinate, marketed as Secosyl by Stephan Co. When a foaming agent is used, the foaming agent aids in floating the loosened soil to the surface of the fabric.
Yet another chemical agent which may be applied to the fabric in pretreatment step 12 alters the vibrational behavior of the fabric when subjected to an acoustic beam. Such a chemical agent may alter the effective weight, density, or size of the fibers of the fabric, so that they vibrate differently than untreated fibers. Care is taken so that such a chemical agent does not adversely affect the removal of soil from the fabric. Chemical agents that alter the vibrational characteristics of the fabric but do not prevent removal of soil typically deposit on the fibers of the fabric and change their mass and thence their vibrational characteristics. The pretreatment chemicals discussed above for use in step 12 may have this effect. Other chemical agents that alter the vibrational characteristics of fabric include antistatic agents and odorants. Examples of operable anti-static compounds include, but are not limited to, alcohol ethoxylates, alkylene glycol, or glycol esters. Examples of odorants include, but are not limited to, perfumes, and essential natural or synthetic oils.
A cleaning apparatus is provided, numeral 14 . FIG. 2 illustrates a preferred form of a cleaning apparatus 30 , although other operable types of cleaning apparatus may also be used. The apparatus 30 includes a contacting chamber 32 with a perforated basket 36 therein. At least a portion of the wall of the contacting chamber 32 desirably includes a filter 32 a. The perforated basket 36 is electrically grounded by a ground 39 . The contacting chamber 32 and the perforated basket 36 are preferably cylindrical in cross section with a cylindrical axis 37 (extending out of the plane of the illustration). The perforated basket 36 is smaller in cylindrical diameter than the contacting chamber 32 .
The piece of fabric 35 which is to be agitated is placed into an interior 38 of the perforated basket 36 . There may also be provided a cabinet that encloses the contacting chamber 32 , and an exterior door in the cabinet to allow access to the interior 38 of the perforated basket 36 . Because the cleaning requires the use of ultrasonic energy within the cabinet, the walls of the cabinet and door may be insulated to prevent the acoustic energy from leaking to the exterior. Noise cancellation devices may also be used to acoustically insulate the cabinet.
The cleaning apparatus is provided with at least one device to mechanically agitate the fabric. The preferred apparatus 30 is provided with one or more sources of tumbling mechanical agitation, gas jet mechanical agitation, another approach to achieve mechanical agitation, and/or a combination of such mechanical agitation techniques. Two preferred techniques for mechanically agitating the fabric, tumbling and gas jet, are described in relation to the single preferred apparatus 30 , but the invention is not so limited.
To achieve tumbling agitation, where provided, the perforated basket 36 is mounted on a rotational support for rotation about the cylindrical axis 37 and provided with a rotation drive motor to drive such rotation. The apparatus may also be provided with paddles 34 that project inwardly from the perforated basket 36 to contact the piece of fabric 35 within the perforated basket 36 during the cleaning operation. The rotation of the perforated basket 36 about the axis 37 and the contacting of the fabric 35 within the perforated basket 36 by the paddles 34 are included within the term “tumbling” as one approach to mechanically agitating the fabric. When such a rotational capability is provided, during the cleaning step of the present invention the perforated basket 36 may optionally be locked into a fixed position when the gas jets function, or the perforated basket 36 may be rotated while the gas jets function.
To achieve gas jet mechanical agitation, where provided, there is positioned between an inner surface 40 of the contacting chamber 32 and an outer surface 42 of the perforated basket 36 at least one, and preferably several, gas jet manifolds 44 . In the preferred cylindrical design, the gas jet manifolds 44 extend parallel to the cylindrical axis 37 . The manifolds 44 may be affixed to the outer surface 42 of the perforated basket 36 , affixed to the inner surface 40 of the contacting chamber 32 , or separately supported. Preferably, the manifolds 44 (or individual gas jets) are affixed to the inner surface 40 of the contacting chamber 32 , or separately supported. A number of gas jet nozzles 46 are provided in each manifold, with the gas flows from the nozzles 46 directed inwardly into the interior 38 of the perforated basket 36 through the perforations. The manifolds 44 and gas jet nozzles 46 are positioned to promote reversible garment agitation to prevent garment roping, tangling, and strangling during cleaning. Rotation of the perforated basket 36 can also aid in this effort. During the cleaning operation, the soil-dislodging gas flows through the manifolds 44 , through the nozzles 46 , and into the interior 38 of the perforated basket 36 to contact the fabric 35 .
Preferably, at least one injector 48 is also provided and directed inwardly into the interior 38 of the perforated basket 36 through the perforations. As with the manifolds 44 , it is preferred that the injectors 48 are affixed to the inner surface 40 of the contacting chamber 32 , with the flows from the injectors 48 directed through perforations in the perforated basket 36 . Any additives, such as treatment chemicals of the same type as the pretreatment chemicals described above or of other types, that are contacted to the fabric during the cleaning step may be introduced through the injectors 48 . Such additives may instead be entrained into the soil-dislodging gas and introduced through the nozzles 46 .
The soil-dislodging gas is pressurized by a compressor 50 (or supplied from a pressurized gas bottle or condensed gas source, not shown) and supplied to the manifolds 44 through a first piping system 52 . The first piping system 52 includes manually operated or processor-controlled valves 54 to distribute the gas flow and, optionally, a filter 56 to filter the incoming gas and a heater 58 to heat the incoming gas to a desired temperature. The soil-dislodging gas is pressurized by the compressor 50 , flows through the first piping system 52 to the manifolds 44 , is introduced into the interior 38 of the perforated basket 36 through the nozzles 46 , and flows out of the contacting chamber 32 through an exit pipe 60 (after passing through the filter 32 a, if provided). A particulate filter 62 removes the particulate from the gas flowing in the exit pipe 60 , so that it is not released into the air and the environment.
Any operable soil dislodging gas may be used. Examples include air, nitrogen, oxygen, carbon dioxide, water, nitrogen oxide, carbon monoxide, chlorine, bromine, iodine, nitrous oxide, and sulfur dioxide, and mixtures thereof. Nitrogen, oxygen, or carbon dioxide, and their mixtures, are preferred. Air, which is principally a mixture of nitrogen and oxygen, is most preferred. The soil-dislodging gas is pressurized to an operable pressure, preferably from about 30 to about 300 pounds per square inch. However, the remainder of the interior 38 of the perforated basket 36 remains at atmospheric pressure, so that no pressure chamber is used.
Additives such as treatment chemicals, anti-static compounds, and/or odorizing compounds are supplied to the injectors 48 from additive sources 64 through a second piping system 66 . As noted, these additives may have the additional effect of changing the acoustic vibrational characteristics of the fabric. The second piping system 66 includes manually operated or processor-controlled valves 68 to select the types and amounts of the additives, a mixer 70 as necessary, and manually operated or processor-controlled valves 72 to distribute the additives to the injectors 48 and/or to the manifolds 44 as desired. Any additives that are not reacted with the fabric 35 in the interior 38 of the perforated basket 36 leave the contacting chamber 32 through the exit pipe 60 and are entrapped in the exit filter 62 .
The apparatus 30 further includes a source of acoustic energy 80 . The source of acoustic energy preferably includes at least one acoustic device 82 which converts an electrical input signal into an acoustic output signal. The acoustic device 82 is positioned such that the acoustic signal is directed into the interior 38 of the perforated basket 36 , into the volume occupied by fabric 35 during the cleaning operation. Preferably, the acoustic device 82 is affixed to the inner surface 40 of the contacting chamber 32 , or separately supported. There may be multiple acoustic devices 82 positioned at various locations around the perforated basket 36 .
The nature of the acoustic device 82 depends upon the frequency of the acoustic energy to be produced. As used herein, “acoustic” includes audible, ultrasonic, and megasonic energy having a frequency ranging from about 1 hertz to about 1 megahertz. (The terms “audible”, “ultrasonic”, and “megasonic” are sometimes defined as having numerical ranges slightly different from those set forth herein, but for the purposes of the present application the terms are defined as set forth next.) For example, if the frequency of the acoustic energy is in the audible range of from about 20 hertz to about 20 kilohertz (20,000 hertz), the acoustic device 82 would typically be a loudspeaker device 82 a in which a coil drives a membrane. If the frequency of the acoustic energy is higher, in the ultrasonic range of from about 20 kilohertz up to about 150 kilohertz or the megasonic range of from about 150 kilohertz up to about 1 megahertz (10 6 hertz), the acoustic device 82 would typically be a transducer 82 b such as a piezoelectric transducer. However, any other operable acoustic device may be used. Such acoustic devices are well known for use in other applications. Both types of acoustic devices 82 a and 82 b may be supplied for use in a single apparatus 30 , so that acoustic energy of a wide range may be directed into the interior 38 of the perforated basket 36 . If several types of acoustic devices 82 are provided in a single apparatus 30 , they may be operated individually or at the same time, according to the requirements for optimally cleaning the fabric. Any of the acoustic devices 82 may be operated at a single frequency, a range of frequencies, or a number of discrete frequencies, or swept over a range of frequencies.
The electrical input signal to the acoustic device 82 is provided by an electrical source. The electrical source typically includes an appropriate driver 84 , which provides an electrical signal of a selected amplitude and frequency. The driver 84 is selected according to the nature of the acoustic device 82 , and there could be multiple drivers 84 . The shape and frequency of the electrical signal of the driver 84 are typically defined by a function generator 86 that is also a part of the electrical source. The function generator 86 is controllable to select the shape and frequency of the signal of the driver 84 , by a command controller 88 portion of the electrical source. The command controller 88 also typically controls the driver 84 as to the amplitude and on/off functions. The command controller 88 may be set manually and/or may include a microprocessor or other type of automated controller. A typical power level for the acoustic device would be 50 watts or larger, but the required power depends upon the size of the perforated basket 36 and the total mass of the fabric being processed.
Returning to FIG. 1, the fabric 35 is placed into the interior 38 of the perforated basket 36 of the apparatus 30 , numeral 16 . The apparatus 30 is then started, and cleaning is performed, numeral 18 . The cleaning step 18 includes at least operation of the gas jets 46 (numeral 20 ) and/or the tumbling (numeral 24 ), and additionally the source of acoustic energy 80 (numeral 22 ). That is, the cleaning step includes one or more types of mechanical agitation and additionally acoustic excitation. The cleaning step 18 may also optionally include the addition of chemical treatments, such as the treatment chemicals, odorants, vibration-altering, and/or antistatic compounds discussed above, numeral 26 .
The duration of the cleaning step 20 depends upon the nature of the apparatus used, the nature and extent of the soiling, and the size of the load of fabric being processed. Typically for a normal load of fabric in the apparatus 30 , the cleaning time is from about 30 seconds to about 5 minutes. This exposure time is considerably shorter than required for conventional dry cleaning or wet washing, and the fabric leaves the processing dry and fresh smelling.
FIG. 3 schematically illustrates the mechanism of the cleaning process of step 18 . In this preferred approach, the fabric 36 is contacted by a gas jet 90 from the nozzle 46 and at the same time tumbled, as represented by arrow 92 , although alternatively only one of these mechanical agitation effects would be employed. The mechanical agitation is produced by a source of agitation other than the acoustic device 82 . These mechanical agitation effects impart a macroscopic movement to the fibers of the fabric, which serve to dislodge soil from the fibers. The acoustic device 82 directs an acoustic beam 94 at the fabric 35 . The acoustic beam 94 induces localized sympathetic transverse (i.e., bending and flexing) and longitudinal (i.e., stretching) vibrations along the length of the fibers of the fabric, as indicated at numeral 96 . The combination of these mechanical and acoustic movements of the fibers of the fabric is more effective at dislodging soil from the fabric, and preventing its redeposition on the fabric, than the action of either the gas jet 90 acting alone, the tumbling 92 acting alone, or the combination of the gas jet and the tumbling acting together.
The soil-dislodging effects of the source of acoustic energy 80 may be optimized by adjusting the amplitude and the frequency of the acoustic beam 94 , through controlling the driver 84 in the manner discussed above. In some situations, an optimum acoustic beam 94 may be known. In other situations, the best cleaning may be obtained by sweeping the acoustic beam 94 through a wide range of frequencies and amplitudes, thereby possibly necessitating the use of multiple acoustic devices 82 if no one type of device is capable of operating over the desired range of frequencies and amplitudes.
In all cases, the cleaning is necessarily accomplished without immersing the fabric in a liquid cleaning medium during the period when it is subjected to the acoustic beam. The present approach is distinct in respect to the absence of immersion of the fabric in any liquid cleaning medium and also the mechanism of the cleaning action by the acoustic energy. When a fabric in a liquid medium is subjected to an acoustic beam, there is a cavitation action that affects the fabric. In the present approach, the gaseous medium is of too low a density to cavitate in an acoustic beam, and instead the acoustic beam operates directly on the fabric to accomplish a sympathetic vibration.
Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.
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A soiled piece of fabric is cleaned by mechanical agitation while the fabric is simultaneously subjected to acoustic energy in a gaseous environment wherein the piece of fabric is not immersed in a liquid cleaning medium. Mechanical agitation may be by gas jet action and/or by tumbling. The acoustic energy vibrates the fibers of the fabric to enhance the cleaning action. The piece of fabric may be chemically treated to mobilize the soil.
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[0001] The present application is a continuation of pending U.S. patent application Ser. No. 14/230,259, filed on Mar. 31, 2014, which is a continuation of U.S. patent application Ser. No. 13/763,965, filed on Feb. 11, 2013, now U.S. Pat. No. 8,732,244, which is a continuation of U.S. patent application Ser. No. 13/466,209, filed on May 8, 2012, now U.S. Pat. No. 8,402,091, which is a continuation of U.S. patent application Ser. No. 11/787,562, filed on Apr. 16, 2007, now U.S. Pat. No. 8,200,756, the disclosures of which are incorporated herein by their entireties.
FIELD OF THE INVENTION
[0002] The present invention relates to phone conferencing, multimedia conferencing, online conferencing, collaboration software, real-time collaboration applications, and more specifically to a virtual private meeting room.
BACKGROUND OF THE INVENTION
[0003] A need often arises for people to meet and share information, exchange data or documents, discuss topics, or collaborate in preparing various documents. It may not be desirable, or possible, for all of the participants in a meeting to be in the same physical location at the same time, in which case meeting objectives may be achieved using communication equipment or networks, and tools such as software tools for facilitating remote collaboration in a multimedia collaboration session.
[0004] It can be useful for such a session to include a variety of media types that include the participants' voices, video images, shared documents, text messages, drawings, computer screen images, etc.
[0005] Several systems exist for teleconferencing or telecollaboration; in several such systems session information disappears a certain time after the session ends. For instance, a meeting participant that wants to see material presented during a previous session may not be able to find it several weeks after the session ended.
[0006] Some systems require a conference ID for each sessions, and some require a distinct Conference ID and or user ID for sessions conducted using different types of media, for example if a user connects to a session via a telephone and via a computer. Some systems don't allow a user to be connected simultaneously from several devices, for instance both from a telephone and from a computer. In many systems the audio portion is managed on phones in a phone conference in parallel to a data collaboration session on a different system—in this case each of the sessions has a different conference ID or entry code.
[0007] Another drawback of some prior art systems is that they allocate resources in advance and not only when a session actually starts. For instance some systems allocate telephony ports in advance, sometimes a long time ahead. If the session does not start as planed the allocated resources are released.
[0008] Therefore, it would be beneficial to provide improved systems and methods for collaboration, which for example can overcome the illustrative drawbacks of existing collaboration tools mentioned or provide new functionality to users.
SUMMARY OF THE INVENTION
[0009] An aspect of an embodiment of the invention, relates to a system and method for conducting multi-user conferences, wherein each user can participate in the conference with multiple devices (e.g. telephones and computers) and multiple types of communication, for example audio, video, text. In an exemplary embodiment of the invention, each user is provided with a unique ID to identify the user when connecting via any available device and/or by any method of communication and associate all of the user's devices to the same meeting. A user that can initiate a conference is associated with a virtual private meeting room, which defines a virtual meeting place for multiple users to connect to and participate in a meeting when the virtual meeting room is activated. Optionally, the proceedings of the meeting are recorded and stored in a database associated with the virtual meeting room for future access by the participants of the meeting. Optionally, the proceedings include among other things the list of participants in the meeting, the time each participant joined the meeting, a voice recording of the conversation in the meeting, a recording of any data transferred during the meeting, for example videos, files, text, and pictures.
[0010] In an exemplary embodiment of the invention, the data recorded from the proceedings of a conference is persistent and remains available after the conference is over. In some embodiments of the invention, the meeting room owner may edit the recorded data. Alternatively, the recorded data may not be edited but can be deleted by the meeting room owner.
[0011] In an exemplary embodiment of the invention, when a user contacts a server with one or more devices, each device may be identified to the server by the unique user ID so that the server can join the device to a common conference. In some embodiments of the invention, a conference initiator schedules a conference by defining a virtual meeting room for conducting the conference, a time for the conference and a list of user's, which are identified by their user IDs that may participate in the conference.
[0012] In some embodiments of the invention, the user dynamically activates his meeting room, by accessing it and providing his credentials.
[0013] There is thus provided in accordance with an exemplary embodiment of the invention a method of providing a multi-media conference meeting, the method comprising:
(a) providing each of a plurality of users with a unique user id; (b) associating with each user, that is permitted to initiate a conference meeting, a persistent virtual private meeting room; (c) establishing a conference session, in response to an activation act by a meeting initiator, said session is associated with the meeting initiator's persistent virtual private meeting room; (d) when a session is active, establishing communications via a plurality of network connections and/or phone connections between users that are logged in/dialed in to the conferencing session.
[0018] In some embodiments of the invention, the user is a meeting initiator; said session is associated with the meeting initiator's virtual private meeting room.
[0019] In some embodiments of the invention, a unique user id is a unique number or unique string or a combination thereof; a unique user id is a unique telephone number or a unique email address or a combination thereof; or the user is allocated more than one user id.
[0020] In some embodiments of the invention, communication is established between the user's client software and at least one server that enable collaboration among the users of a conference session.
[0021] In some embodiments of the invention, the user can be connected to a conference session simultaneously from a plurality of devices.
[0022] In some embodiments of the invention, the user has the same unique user id for connecting from different devices.
[0023] In some other embodiments of the invention, the user selects the type of content to receive on a particular device.
[0024] In yet other embodiments of the invention, the user can be connected to a session, simultaneously from a remote computer and from a phone or from a handheld or wireless device having telephony capabilities.
[0025] In some embodiments of the invention, the user has the same unique user id for connecting to a session from a phone and from a computer.
[0026] In other embodiments of the invention, the user connects to different conference sessions using the same unique user id.
[0027] In some embodiments of the invention, the virtual private meeting room owned by the meeting initiator of a conference session stores log information of the session or by the user initiating a conference session, stores content provided or presented during the session or by the user initiating a conference session, stores content provided or presented during sessions initiated by said user.
[0028] In some embodiments of the invention, the content includes any combination of text files, text messages, slides, multi-media files, shared documents, video clips, music, participants' voices and drawings.
[0029] In some embodiments of the invention, communication is established when the conference session is active and wherein establishing communication comprises dynamic allocation and release of resources.
[0030] In other embodiments of the invention, allocation of resources occurs when the user joins an active session; release of resources occurs when a user leaves an active session; allocation or release of resources is based on at least one optimization criteria; and allocation or release of telephony ports is carried out when a phone connects to a when a session that is active.
[0031] There is also provided in accordance with an exemplary embodiment of the invention a computer-readable medium having computer-executable set of instructions for performing steps for providing a multi-media conference meeting, the set of instructions comprising (a) providing each of a plurality of users with a unique user id; (b) associating with each unique user id a virtual private meeting room; (c) establishing a conference session, in response to an activation act by the user that is a meeting initiator, said session is associated with the meeting initiator's persistent virtual private meeting room; and (d) after establishing a conference session, establishing communications via a plurality of network connections between users that are logged in to the conferencing session.
[0032] There is also provided in accordance with an exemplary embodiment of the invention a system for providing a conferencing or collaboration session, comprising a) at least one management and control software; b) at least one computer server c) at least one storage device d) at least one persistent database e) a plurality of communication devices; the system (a) providing each of a plurality of users with a unique user id; (b) associating with each user id a virtual private meeting room; (c) establishing a conference session, in response to an activation act by a user that is a meeting initiator, said session is associated with the meeting initiator's persistent virtual private meeting room; and (d) after establishing a conference session, establishing communications via a plurality of network connections between users that are logged in to the conferencing session.
[0033] In the above exemplary embodiments of the present invention the virtual private meeting room is preferably persistent and resources for the conference session are dynamically allocated.
BRIEF DESCRIPTION OF THE FIGURES
[0034] The present invention will be understood and better appreciated from the following detailed description taken in conjunction with the drawings. Identical structures, elements or parts, which appear in more than one figure, are generally labeled with the same or similar number in all the figures in which they appear, wherein:
[0035] FIG. 1 is a schematic illustration of a conferencing system providing multi-media conferencing services, in accordance with an exemplary embodiment of the invention;
[0036] FIG. 2 is a flow chart of a process for providing or participating in a conference session, in accordance with an exemplary embodiment of the invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0037] The invention generally relates to a system, methods, and software for providing multi-media conferencing or collaboration.
[0038] For clarity of the description, a non-limiting example of a multi-media conferencing service system is described as an exemplary embodiment of the invention.
[0039] FIG. 1 is a schematic illustration of a conferencing system 190 providing multi-media conferencing services. Various elements shown in FIG. 1 cooperate to provide communication services among users, including telephony, multi-party conferencing and collaborative communications. By way of example, conferencing services are supported by a service provider, which supplies a conferencing management application 101 that operates with an interactive voice response (IVR) system 103 and an Distributed Internet Protocol (IP) conference bridge 105 which is comprised of multiple distributed servers as described in detail in U.S. patent application Ser. No. 11/509,253 titled A SOFTWARE BRIDGE FOR MULTI-MEDIA TELECONFERENCING AND TELECOLLABORATION, filed 24 Aug. 2006, the contents of which is incorporated herein by reference. Optionally, IVR system 103 controls directing of telephone connections into conferences. Likewise, Web Server 201 directs PC client connections into conferences. All aspects of each of the conferences are managed by a distributed IP conference bridge 105 . Thus, a conference based upon elements, which use all the devices will be managed by system 190 as a single session.
[0040] In an exemplary embodiment of the invention, conference management application 101 processes requests to schedule a conference for a certain date and time as well as ad hoc activation of conferences by users accessing their own meeting rooms. Conference management application 101 allows logging of events pertaining to a conference session and recording of the control of the session as well as the content of the session. Optionally, session control includes logging of events, such as for example, start time, stop time, logon and logoff times of each participant, along with indexing markers or annotations inserted during the session by a presenter or participants. In an exemplary embodiment of the invention, the recording process, includes recording video, audio, textual messaging conversations, presentations and collaborative work as well as data items, such as documents or images, which are introduced by participants in the course of the meeting.
[0041] The conference management application 101 controls a database 111 , wherein session information and data is preferably stored. Database 111 may be replaced by a number of different databases interconnected and located in various locations and managed by conference management application 101 . Additionally, conference management application 101 performs various management functions for controlling conferencing services, such as identifying the participants of the conference, authenticating participants that attempt to access or activate conferences and redirecting of participates to dynamically allocated resources in conference bridge 105 .
[0042] A communications network 117 provides communications among the processes and sub-systems of the network service provider. Network 117 can include multiple interconnected networks, with connectivity, for example, to the Internet or other public data networks. The network 117 , in an exemplary embodiment, is a data transport network, such as an Internet Protocol (IP) based network, an Asynchronous Transfer Mode (ATM) network, a frame relay network, or a combination thereof. The network 117 interfaces with telephony systems, such as a Public Switched Telephone Network (PSTN) 119 and a Private Branch Exchange (PBX) 121 , via an IP gateway 125 or 127 .
[0043] The gateway 125 provides an interface between the network 117 and the PSTN 119 . The gateway 125 allows a party using a conventional phone such as telephone 124 or a wireless phone 126 to dial into the distributed IP Conference bridge 105 . IP Phones such as SIP Phone 141 can connect to the IP conferencing system directly through the IP network without an IP Gateway. It is noted that the SIP phone 141 can be implemented as a stand-alone device or as a software client, for example on a personal computer.
[0044] Similarly, the gateway 127 couples the network 117 to a private branch exchange (PBX) 121 , which supports one or more PBX telephones 122 . In this example, the PBX 121 resides at the user's site. The PBX 121 is often of proprietary design and function, but presents a standard signaling and trunk interface in order to be connected to conventional telephone networks. Gateway 127 enables telephone 122 to participate in conferences through the network 117 .
[0045] In an exemplary embodiment of the invention, personal computers 137 , 139 and voice over IP phones (e.g. SIP phone 141 ) are connected to network 117 . Optionally, personal computers 137 , 139 may require the use of a software client (not shown) to enable the transfer of data from the client stations to system 190 .
[0046] In an exemplary embodiment of the invention each of a plurality of users is provided by system 190 with a unique user ID. Optionally the user ID is provided by management application 101 . The unique user ID is a unique number or a unique string or a combination thereof. The unique user ID can be a unique telephone number or a unique email address or a combination thereof. The unique user ID serves the user to connect from multiple devices to a conference session, for instance from telephone 122 and from computer 137 and be recognized as a single user controlling multiple devices in a concurrent session. Optionally these connections are established simultaneously, although some devices may be used simultaneously and some may be used sequentially as the need arises during the conversation. The unique user ID also serves the user for connecting to different sessions that occur at different times. In some exemplary embodiments of the present invention, the need to recognize a user using more than a single device arises when users would use one device to transfer audio signal from and to the conference and another device to transfer data from and to the conference. Such exemplary situation arises when a user does not have a microphone connected to his computer, for example, or when the user's computer lacks a sound card, or if the user's computer is connected to a low band connection which will not effectively convey both data and voice information from and to the conference.
[0047] In some embodiments of the invention, a user is allocated more than one user ID, for example one to identify the user as he/she logs onto system 190 and a second user ID to identify a meeting room for the user (as described below). Optionally, one user ID may be a function of the other, for example the second user ID may be the first unique user ID with an additional number appended to it or removed from it. The unique user ID is used for example to allow the user to log in to schedule events or respond to invitations to schedule events, or to allow system 190 to link between conversations conducted by the user with more than one device (e.g. PC and telephone). In contrast the meeting room ID may be given by the user to others in order to allow them to enter his meeting room to conduct meetings.
[0048] In some embodiments of the invention, the unique ID comprises a unique number or a string of characters which is allocated by system 190 or selected by the user and verified for uniqueness by system 190 . Its some embodiments of the invention, the unique user ID may be a telephone number or an email of the user.
[0049] In an exemplary embodiment of the invention, a virtual private meeting room is associated with each unique user id. All information associated with a conference session or meeting, such as information presented during the meeting, is associated with the virtual private meeting room of the meeting initiator. Optionally, the information comprises the session log information of the participants, content provided or presented during the session, wherein content includes any combination of text files, text messages, slides, multi-media files, shared documents, video clips, music, participants' voices and drawings.
[0050] In an exemplary embodiment of the invention, the information associated with the virtual private meeting room is saved in database 111 and is stored indefinitely. Therefore, the virtual private meeting room is considered persistent, since information associated with previous conference sessions can be accessed at any time in the future after a conference was conducted. To maintain persistency of the conference files and data, each conference file or data is associated with a User ID and is stored such that each such user whose ID is associated with said file or data may later access or retrieve the files and data associated with his ID. Data stored in the database 111 can include data associated with each conference, such as the names of the participants, the location of each participants, information about each participant, the time the conference begun and ended, the materials used, the messages exchanged, the documents sent to participants, notes made by any of the participants, a recording of the conference, meta data associated with the conference to include statistical data, data associated with a number of conferences, for example a series of interrelated conferences, meta data associated with a number of conferences, including statistical data, usage times, talk times, the number of documents exchanged, the bandwidth taken and the like.
[0051] In an exemplary embodiment of the invention a user initiates a conference meeting by accessing management application 101 . Accessing can be from a client software, for instance from a web browser (e.g. accessing a web page that is designed to let the user schedule a meeting) or from Microsoft outlook (e.g. using the calendar to schedule meetings) or from a specially designed client software. The process of initiating a meeting comprises providing a meeting name or meeting subject, providing a date and time and duration of the meeting, providing a list of participants, wherein each participant is identified by a unique user ID, and optionally providing additional information. Alternatively a user can activate a meeting in an “Ad hoc” manner by connecting to system 190 , provide his meeting room ID, and initiator password. Once the user has “opened” his/her meeting room other users can be notified to join the conference session.
[0052] In an exemplary embodiment of the invention, a user can join a conference by logging into system 190 and requesting to enter a specific meeting room, or system 190 may be set to automatically “pull” the user into concurrent conferences which requested his/her participation as soon as they login.
[0053] FIG. 2 is a flowchart 200 of a process for providing or participating in a conference session, in accordance with an exemplary embodiment of the invention. In an exemplary embodiment of the invention, a user connects ( 205 ) to system 190 with a PC (e.g. personal computer 137 ) or a telephone (e.g. telephone 122 , 124 ) or any other communication device. Optionally, the user may provide a meeting room ID of the conference in which the user is interested to participate ( 210 ) and the ID is preferably validated ( 215 ). Optionally, system 190 determines ( 220 ) if the meeting room for accommodating the conference is a valid meeting room that was defined in system 190 . If the meeting room ID is not valid system 190 will indicate that an error ( 230 ) has occurred and deny service or allow the user to reenter the meeting room D. If the meeting room ID is a valid ID, system 190 determines if the meeting room is activated ( 225 ) to allow users to enter and participate in a conference. If the meeting room has been activated for a conference the user enters ( 280 ) the meeting room and joins the conference, wherein the user may participate by viewing the conference material and contribute to the conference. However if the meeting room is not activated system 190 determines ( 235 ) if the user is the owner of the meeting room and can then initiate a conference. If the user is not the owner of the meeting room the user will enter ( 260 ) into a waiting state, wherein system 190 will periodically query ( 270 ) the status of the meeting room and if it becomes available allow the user to enter ( 280 ). When the user enters the meeting room his device (PC or phone or other communication device) is automatically redirected to an allocated server in the distributed IP conference bridge ( 282 ). In case of phone the phone is redirected from the IVR to the distributed conference bridge, and in the case of a PC client application the client application receives a list of available server and establishes an IP connected to the one of the servers. The system may also dynamically allocated additional conference servers to serve this conference in case resources on one of the servers participating in this conference are exhausted.
[0054] If the user is the owner of the meeting room the user will be authenticated by providing ( 240 ) the owner password, which will be validated ( 245 ) in database 111 by system 190 . Other known or later developed authentication methods can also be applied by those skilled in the art. Optionally, after verifying that the user is the owner of the meeting room, system 190 will activate ( 250 ) a conference using the meeting room. In this phase Management system 101 dynamically allocates resources on one or more servers in the distributed conference bridge 105 to the conference ( 252 ) and the user enters the meeting room ( 280 ) as is described above.
[0055] In an exemplary embodiment of the invention, once a user has activated a meeting room, the user may provide IDs of users or groups of users that are allowed to join the conference or open the conference to any user that is interested in joining. In some embodiments of the invention, the list of users that are allowed to participate in the conference is provided when scheduling the conference.
[0056] In some embodiments of the invention, users cannot enter the meeting room if the meeting room owner is not logged in. Alternatively, users that were invited to a scheduled conference may enter the meeting room and begin the conference even without participation of the owner of the meeting room.
[0057] In some embodiments of the invention, if the owner logs out the meeting room is closed down and any active conference is ended. Optionally, users that participated in the conference may have access to the records that were created by the conference and stored on database 111 .
[0058] In some embodiments of the invention, the owner of the meeting room is the first presenter and the other participants are not provided with privileges allowing such participants to change documents or upload documents or make notations on a shared document. In other alternative embodiments of the present invention each user, whether owner of the meeting room or not is provided with privileges with respect to presenting, changing or editing documents, making notations and the like. Such privileges can be provided prior to the conference based on predetermined user preferences or owner preferences.
[0059] In some embodiments, the system and methods of the invention provide a client-server infrastructure capable of supporting multimedia conferencing activities in a virtual private meeting room. The client-server infrastructure supports data persistence, so that data files associated with the virtual private room can be stored for subsequent access.
[0060] In a preferred embodiment of the present invention, the meeting room resources are allocated by the system 190 only once the conference session is activated. The resources will be typically dynamically allocated such that available resources such as hard disk space, band width, processor time and like resources are provided to the activated meeting room according to the number of participants which joined effectively. Thus, even if a conference is scheduled for hundreds of users and only a handful or users eventually join the conference, such conference (event) resources are limited to the number of participants that actually joined. In practice, once a participant joins the conference the system 190 will review its available resources and allocate additional resources which are necessary to maintain an efficient conference. System 190 is provided with predetermined definitions of which resources are required to obtain a the level of service expected from the conference, such as what is the amount disk space, band width, processor time necessary, and the like. Optimization criteria may be used to enhance the quality of service provided during the event. Such can include the expected bandwidth available to each participant, the quality of video or audio provided to each participant, the distance between each of the servers and each of the participants, the location where conference materials are stored, the availability of storage for each participant, and the like. For better quality of service additional resources will be required, though these are allocated, as noted above, on the basis of participants effectively joining the conference. The resources may also be allocated and released based on the optimization criteria. Thus, in one exemplary embodiment of the invention, if to provide better video or audio quality additional resources are to be allocated, and if such resources are available, such resources will be allocated when a particular participant joins or is of need of such resources.
[0061] In some embodiments of the present invention resource allocated to an event are releases back to system 190 when a user leaves an active session. Such resources may be reallocated to other on going events.
[0062] In some embodiments of the present invention telephone ports are allocated to an event only when a telephone connects to a session, if such session is active. Such allocation is efficient since persons wishing to connect to an event will not be allocated a port until such time when the even is active and the participants can begin the conference. Until such time, the waiting participants are put on hold thus releasing some of the telephony ports for the use of other participants in other on going “live” events.
[0063] The present invention has been described using non-limiting detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. It should be understood that features described with respect to one embodiment may be used with other embodiments and that not all embodiments of the invention have all of the features shown in a particular figure or described with respect to one of the embodiments. It is noted that some of the above described embodiments may describe the best mode contemplated by the inventors and therefore include structure, acts or details of structures and acts that may not be essential to the invention and which are described as examples.
[0064] While the above description has focused on methods, it is meant to also encompass apparatus for carrying out the invention. The apparatus may be a system comprising of hardware and software. The apparatus may be a system, such as, programmed computers or a network appliance. The apparatus may include various computer readable media having suitable software thereon, for example, diskettes and computer and/or flash RAM.
[0065] Structure and acts described herein are replaceable by equivalents, which perform the same function, even if the structure or acts are different, as known in the art. Therefore, only the elements and limitations as used in the claims limit the scope of the invention. When used in the following claims, the terms “comprise”, “include”, “have” and their conjugates mean “including but not limited to”.
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A conference session is established. Different unique identifications and persistent dedicated virtual private network conference rooms are assigned to different recipients. A conference session using one of the persistent dedicated virtual private network conference rooms assigned to a recipient is established using a communication device with a processor and memory and in response to an instruction from the recipient assigned the persistent dedicated virtual private network conference room. A network resource is allocated to the conference session established, based on a participant in the conference session logging in to the conference session using one of the unique identifications.
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The present application is based on and claims the benefit of U.S. provisional patent application Ser. No. 60/553,392, filed Mar. 16, 2004, the content of which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and method for driving nails into an object. In particular, the present invention relates to an apparatus and method for rapidly driving nails with a hydraulic system and a pneumatic system.
An item commonly used to transport goods that requires its component parts to be nailed together is a wooden pallet. Wooden pallets began being used in industry in the 1930s. Wooden pallets came into widespread use by the United States Navy during World War II to move large amounts of goods in a short period of time with forklifts. Since World War II the use of wooden pallets has steadily increased every year.
It is estimated that currently there are about 1.5 billion pallets used in the United States alone. There is an estimated construction of 700 million new pallets each year while an additional 700 million wood pallets are being annually repaired.
To keep up with the high demand, wooden pallets are being mass-produced with automated pallet making machines. The automatic pallet making machines typically include nail guns that are mounted on a frame and are aligned with stringers used to make the pallet. A majority of the mass produced pallets are built on automated machines using hydraulic nailing guns. On these machines, the relative motion between the nail gun and the material being nailed stops while the nail is driven into the material. One limiting factor in the production of wooden pallets is the average speed of the material relative to the nail gun. The relative motion between the material and the nail gun is a limiting factor because the material stops while the nail is driven.
Additionally, the speed at which a nail is driven by a hydraulic system requires the material be stationary while the nail is driven. The additional time required to drive the nail into the material also has made the hydraulic system a limiting factor in the mass production of pallets.
SUMMARY OF THE INVENTION
The present invention includes an apparatus for nailing a plurality of cross members to an underlying stringer in which the stringer and the plurality of cross member are positioned on a support. A carriage moves in a continuous motion without stopping over the plurality of cross members until the plurality cross members are nailed to the stringer. At least one nailing gun is secured to the carriage for driving nails in to the cross members and the underlying stringer to secure the cross members to the stringer. A hydraulic accumulator is mounted on the carriage and is in hydraulic communication with the at least one nailing gun for supplying hydraulic fluid under pressure to provide a force to the nailing gun for nailing the cross member to the stringer.
The at least one nailing gun may also be pivotally secured to the carriage for driving nails into the cross members and the underlying stringer wherein the nailing gun pivots with respect to the carriage while driving a nail into the cross member and the underlying stringer thereby permitting the carriage to move without stopping.
The apparatus may also include the at least one nail gun having a chuck portion which contacts the wood during the nailing operation and is pneumatically driven to the wood and wherein a hydraulic cylinder actuates the nail driving mechanism moving it through the wood chuck to drive nails into the cross members and the underlying stringer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of the nail gun of the present invention.
FIG. 2 is a perspective view of an automatic pallet-making machine employing the nail gun of the present invention.
FIG. 3 is a side sectional view of the nail gun of the present invention mounted to a frame.
FIG. 4 is a side view of the nail gun of the present invention mounted to a frame.
FIG. 5 is a schematic view of the control system for the nail gun of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention includes a nailing carriage that moves in a continuous fashion for nailing cross members to underlying stringers. By continuous motion is meant that the carriage does not stop while nailing. Such a carriage does not require carriage brakes as prior art devices, and also requires a relatively inexpensive electric motor with a variable frequency drive to power the movement of the nailing carriage. Prior art devices required expensive servo motors or carriage brakes in conjunction with a hydraulic motor drive to stop the carriage when the nails are being driven. The nailing carriage of the present invention moves approximately an average of 5.5 inches per second when compared to prior art devices which move approximately an average of 3 inches per second due to the stoppage that has to occur when the nailing guns drive nails into the cross members and into the underlying stringers.
Some of the elements that permit continuous motion of the nailing carriage of the present invention include a high speed nailing chuck having a pneumatic cylinder with a 1 inch bore that drives the chuck body of the nailing chuck down to the wood. Another aspect of the continuously moving the nailing carriage of the present invention is a hydraulic accumulator mounted on the nailing carriage in close proximity to the hydraulic nailing chuck cylinder thereby reducing hydraulic head losses. Reducing hydraulic head losses creates higher flow and reduces nail driving times. Furthermore, the nail chuck of the present invention pivots with respect to the frame allowing relative motion between the moving nailing carriage and the stationary cross members while nails are being driven.
A nail gun of the present invention is generally illustrated at 10 in FIG. 1 . The nail gun 10 includes a nail chuck 12 and a hydraulic cylinder 14 and is designed to be mounted to a machine that secures at least two components together with a nail 16 .
One such machine is an automated pallet making machine 20 illustrated in FIG. 2 . Throughout the application, the nail gun 10 of the present invention will be referenced in association with the automated pallet making machine 20 and the production of pallets 22 . However, the nail gun 10 can also be used in other applications besides the production of pallets. Additionally, the nail gun 10 does not have to be secured to a machine used to mass-produce goods, but rather the nail gun 10 can be mounted to any object that securely retains the nail gun 10 .
The exemplary automatic pallet-making machine 20 includes three nail guns 10 that are aligned with three stringers 24 of the pallet 22 . The number of nail guns 10 employed by the automatic pallet-making machine 20 varies with corresponding number of the stringers 24 used to construct the pallet 22 .
Referring to FIGS. 1 , 2 and 3 , nails 16 are fed into the nail chuck 12 through a singulating system 30 . The singulating system 30 properly aligns the nails 16 such that a head 17 of one nail 16 is proximate a pointed end of another nail. The singulating system 30 includes a vibrating bin 32 that holds a quantity of nails 16 . The aligned nails 16 exit the bin 32 through a valve 33 controlled by a programmable logic controller (PLC) 50 as illustrated in FIG. 4 .
Referring to FIGS. 1 , 2 , 3 and 4 , the nails 16 are fed into the nail chuck 14 through a second valve 35 also controlled by the PLC 50 and enter a tube 34 that feeds the nails 16 to the nail chuck 12 . Because the nail chuck 12 and the hydraulic cylinder 14 move to drive the nails 16 into an object, the tube 34 feeding the nails 16 to the nail chuck 14 preferably is flexible and made of a vinyl or a PVC material.
The nail 16 is retained in a selected position within the nail chuck 14 by a pair of opposing spring-loaded nail keepers 40 (one of which is shown). Preferably, a circular spring 42 is positioned about and biases the pair of nail keepers 40 together such that the nail 16 is retained in the selected position therebetween.
The nail 16 is driven into an object with a hydraulic system 46 acting upon the hydraulic cylinder 14 in combination with a pneumatic system 48 acting upon the nail chuck 12 . Preferably, the pneumatic system 48 and the hydraulic system 46 are controlled by the PLC 50 such that the PLC 50 simultaneously activates both the pneumatic system 48 to force the nail chuck 12 into contact with a cross board 23 and the hydraulic system 46 forces a hydraulic ram 52 into the nail 16 which drives the nail 16 into the cross board 23 and stringer 24 . An exemplary PLC is series 9030 controller manufactured by GE Fanuc located at 2500 Austin Drive, Charlottesville, Va. 22911.
The pneumatic system 48 , which is more responsive than the hydraulic system 46 , positions the nail chuck 12 proximate the cross board 23 while the hydraulic system 46 begins driving the nail 16 toward the cross board 23 and the stringer 24 . With the nail chuck 12 manipulated into a position adjacent the cross board 23 by the pneumatic system 48 , the hydraulic system 46 forces the hydraulic ram 52 from the hydraulic cylinder 16 to drive the nail 16 into the stringer 24 and the cross board 23 . The combination of the pneumatic system 48 cooperating with the hydraulic system 46 reduces the cycle time between nails 16 being driven as compared to a hydraulic system both manipulating the nail chuck 12 into position and driving the nail 16 into the pallet 22 .
Referring to FIG. 1 , the nail chuck 12 is positioned within through bores 58 , 62 of upper and lower linear motion bearings 56 , 60 , respectively that slidably guide the movement of the nail chuck 12 toward and away from the pallet 22 . The preferred linear bearing are Oilite AA-2001-11 manufactured by Beamer Precision, Inc. located at 230 New York Drive, Fort Wash., Pa. 19034-0980.
The upper linear motion bearing 58 includes a nozzle 64 through which pressurized gas is forced into a chamber 66 defined by a shoulder 68 extending from the linear bearing and contacting an outer surface 13 of the nail chuck 12 and a ring 70 extending from the outer surface 13 of the nail chuck 12 and forming a seal with a surface defining the through bore 58 within the upper linear bearing 56 . The PLC 50 controls a valve 72 to begin flow of the pressurized gas into the chamber 66 as illustrated in FIG. 4 . As pressure is built up in the chamber 66 by the compressed gas, the nail chuck 12 is forced towards the cross board 23 . Preferably, the compressed gas is compressed air.
While the nail chuck 12 is being forced proximate the cross board 23 with the pneumatic system 48 , the PLC 50 sends a signal to a control valve 74 that directs high pressure hydraulic fluid from an accumulator 37 mounted on the carriage 21 into an upper port 76 of a hydraulic cylinder 14 which forces a ram 52 of the hydraulic cylinder 14 towards the nail 16 . A drive pin 78 that is coupled to the ram 52 by a threaded retaining nut 80 engages the head 17 of the nail 16 and drives the nail 16 into the cross board 23 and the stringer 22 . Since the hydraulic accumulator is mounted on the carriage 21 it is in close proximity to the hydraulic cylinder. The close proximity of the hydraulic accumulator 37 to the hydraulic cylinder 14 minimizes the length of the hydraulic lines 39 reducing hydraulic head losses, creating faster flow of hydraulic fluid thereby resulting in fast nail driving. The close proximity of the hydraulic accumulator 37 to the hydraulic cylinder 14 by mounting on the carriage 21 results in nails driven in approximately 100 milliseconds or less for a typical pallet nail approximately 2.5 inches long when compared to prior art devices such as a Champion nailing carriage produced by Viking Engineering and Development Company which drives nails in approximately 180 milliseconds. The present invention, close proximity of the accumulator to the hydraulic nailing valves that control the nail chuck reduces hydraulic pressure losses about 300 pounds per square inch when compared to prior art systems such as a Champion nailing carriage in which the accumulator is not located on the nailing carriage.
The hydraulic system 46 is pressurized with a hydraulic pump 82 . The hydraulic system 46 includes a hydraulic fluid accumulator 84 positioned near the control valves 74 . The pump 82 is connected to the accumulator 84 and the valves 74 with a hydraulic pressure line 86 . The hydraulic accumulator 84 provides the necessary high pressure hydraulic fluid to the hydraulic system 46 to actuate as many hydraulic cylinders 16 of the nail guns 10 as necessary during a cycle. Preferably, the hydraulic accumulator 84 and the hydraulic valves 74 are positioned proximate the hydraulic cylinders 16 of the nail guns 10 to minimize pressure drop in the hydraulic system 46 such that the cycle time for driving the nails 16 is minimized.
Once the nail 16 is driven into the cross board 23 and the stringer 24 , the controller 50 sends another signal to the hydraulic valves 74 to redirect the high-pressure hydraulic fluid to a lower port 77 of the hydraulic cylinder 16 such that the hydraulic ram 52 is retracted back into the cylinder 14 . As the hydraulic ram 52 is retracted back into the cylinder 14 , the nail chuck 12 , which is coupled to the hydraulic ram 52 with a threaded cap 88 that threadably engages the nail chuck 12 , is also retracted from the cross board 23 by the engagement of the threaded cap 88 with the threaded nut 80 .
With the nail chuck 12 retracted from the cross board 23 , an electric motor 90 coupled to a frame 21 that retains the nail gun 10 , moves the frame 21 along with the nail gun 10 in the direction of arrow 25 to another selected position, as illustrated in FIG. 3 with an encoder or high speed counter within the PLC 50 as illustrated in FIG. 5 . The PLC 50 sends a signal to the electric motor 90 to move the frame 21 to a selected location where a nail 16 is to be driven into the cross board 23 . With the frame in the selected position, a brake 91 engages the motor 90 and retains the frame in the selected position.
The speed at which nails 16 driven into the cross board 23 and the stringer 24 is increased because of the pneumatic system 48 cooperation with the hydraulic system 46 in driving the chuck 12 into contact with the cross board 23 . The PLC 50 also has an interface 57 which allows the control parameters to be adjusted.
With the frame 21 in the selected position, the valve 35 is opened by the PLC 50 to deliver another nail 16 to the nail chuck 12 through the flexible tube 34 through a port 94 that is angled into the chuck 12 . A nut 96 threadably engages the port 94 and frictionally retains the tube 34 to the port 94 . The angle of the port 94 allows the nail 16 to slide into the chuck 12 and between the nail grippers 40 . The port 94 is secured to the chuck 12 with a holder 98 that is bolted to the chuck 12 .
Referring to FIG. 1 , the nail chuck 12 also includes adjusting mechanisms for adjusting a depth of the head 17 of the nail 16 into the cross board 23 . The depth of the head 17 of the nail 16 can be adjusted such that the head 17 is above the cross board 23 , even with the cross board 23 , or countersunk into the cross board 23 .
The depth of the nail head 17 is adjusted by manipulating the threaded nut 80 that retains the driving pin 78 to the hydraulic ram 52 . The depth of the nail head 17 is adjusted such that an end 81 of the threaded nut contacts a shoulder 102 of a bore 100 of the chuck 12 thereby limiting the stroke of the hydraulic ram 52 . By limiting the stroke of the hydraulic ram 52 , the distance that the nail 16 can be driven is also limited or extended depending upon whether the end 81 is closer to the hydraulic ram 52 or farther from the hydraulic ram 52 , respectively.
The depth of the nail head 17 can also be adjusted by manipulating a nose 104 that threadably engages a threaded outer surface 106 of the chuck 12 . The nose 104 is rotated on the chuck 12 to threadably engage the chuck 12 and move the nose 104 to a selected position such that an end 105 of the nose 104 extends from the chuck 12 . One skilled in the art will recognize that by manipulating the distance that the end 105 of the nose 104 is from the chuck 12 , the depth of the nail head 17 can be adjusted because of the limited range of the hydraulic ram 52 . With the end 106 of the nose 104 proximate the nail chuck 12 the nail head 17 can be driven further into the cross board 23 than if the end 105 of the nose 104 is farther away from the nail chuck 12 . With the nose 104 in a selected position, a locking nut 108 threadably engaged with the chuck 12 is positioned to frictionally engage the nose 104 and retain the nose 104 in the selected position.
Referring to FIGS. 3 , 4 and 5 , the nail gun 10 is pivotally mounted at pivot point 27 to the movable frame 21 of the automatic pallet making machine 20 with brackets 110 that engage plates 112 that are secured to opposite sides of the linear bearings 56 , 60 and the hydraulic cylinder 14 . Bolts 113 are positioned between through bores in the brackets 110 aligned with a through bore in each plate 112 such that the nail gun 10 pivots about the bolts 113 .
The nail chuck 12 is retained proximate the frame 21 with a spring 114 that is mounted to the frame 21 and the plates 112 . The spring 114 biases the nail chuck 14 toward the frame 21 such that the nose 104 is within a known proximity of a desired location. The speed at which the pallet 22 is manufactured is increased by the nail chuck being driven by the hydraulic system 46 assisted by the pneumatic system 38 .
Additionally, the speed at which a pallet 22 is manufactured is also increased by the pivotal attachment of the nail gun 10 to the frame 21 which allows nails 16 to be driven into the cross-boards 23 and the stringers 24 while the frame 21 with nail guns 10 is moving. With the nail gun 10 engaging the pallet 22 , the nail gun 10 moves with respect to the pallet 22 by pivoting about the bolts 113 and with the chuck 12 rotating back in the direction of arrow 29 . As the nail gun 10 disengages from the cross-board 23 the spring 114 returns the nail gun 10 to an upright position with respect to the frame 21 .
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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An apparatus nails a plurality of cross members to an underlying stringer to produce a pallet. The carriage moves in a continuous motion without stopping over the cross members until the cross members are nailed to the stringer. The carriage includes at least one nailing gun for driving nails and a hydraulic accumulator mounted on the carriage in hydraulic communication with the at least one nailing gun for supplying hydraulic fluid to provide a force to the nailing gun to nail the cross members to the stringer. The nailing gun may be pivotally secured to the carriage wherein the nailing gun pivots with respect to the carriage while driving a nail into the cross member and the underlying stringer. The nail gun is also positioned into a nail driving position pneumatically and when in the nail driving position the hydraulic cylinder is actuated to drive the nail into the cross member.
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FIELD OF INVENTION
The present invention relates to cable bolt structures, related components and method for use in underground mines, such being useful in achieving ground control as to mine roof strata disposed above a particular mine opening.
DESCRIPTION OF PRIOR ART AND BRIEF HISTORY OF CABLE BOLT SUPPORTS
Incorporated by way of reference herein is the inventors' prior filed patent application entitled: CABLE BOLT STRUCTURE AND RELATED COMPONENTS, application Ser. No. 08/332,266 filed 31 Oct. 1994. This application is presently on pending status. Also fully incorporated by way of reference are Seegmiller U.S. Pat. Nos. 5,015,125 and 5,215,411. Other patent literature which is tangentially related include Gillespie U.S. Pat. Nos. 5,230,589 and 5,259,703. All of the above patent literature, including additional literature recited in the inventors' pending patent application above referenced, include other references and teach in rather substantial detail the prior art, and problem situations addressed thereby. The patents of the co-inventor herein, Seegmiller U.S. Pat. Nos. 5,015,125 and 5,215,411, teach what the co-inventor describes as a pressure bubble technique. This is to say, a tubular member is positioned in a selected borehole of mine roof strata and is provided with a reaction plate or bearing plate that abuts the mine roof surface about the borehole. In both the prior and the present applications of the co-inventors herein, a take-up torquing nut is threaded upon the tubular member and directly abuts the bearing plate utilized. Cable bolt structure is disposed in the borehole and is anchored at its remote end within the upper reaches of the hole.
In the present invention the cable bolt structure includes a cable length having a friction-bubble-producing enlargement at or near the proximate end thereof. The cable bolt of course is disposed through the tubular member and the enlargement is initially seated, preferably in a friction fit, for preinstallation purposes, in a counterbore area supplied the bore of the tubular member at its proximate end. In dynamic operation, such enlargement coacts in an interference fit with the primary bore of the tubular member so as to radially expand in its elastic range the tubular member at the section thereof directly contacting and/or proximate the enlargement. The takeup torquing nut is turned so as to provide an initial preload of perhaps one to two tons tension relative to the cable bolt.
In active mode, as the mine strata settles and the mine roof surfaces dilates, the cross-sectional enlargement of the cable bolt, relatively speaking, progresses upwardly relative to the tubular member; or, looking at it from a reverse point of view, and what actually occurs, the descending tubular member experiences a relative movement, i. e. relative to the enlargement, so that a controlled resistance feature is present as between the cable bolt at its enlargement and the radially elastically expanded tubular member supplied.
Particular attention is called to a primary feature in the present invention wherein the enlarged portion of the cable bolt finds its genesis in the provision of either a cylindrical gripping member disposed about and secured to the cable length of the cable bolt or, alternatively, one or more elongated cylindrical members such as roll pins which are situated on the king wire of the cable length interior of the cable strands. Whether roll pins or their equivalent are employed, or whether simply a circular gripping member is used, it is requisite that the surface hardness of these elements be at least of the order of the surface hardness of the cable strands. Thus, what is not wanted is any appreciable plastic deformation of the cylindrical members or roll pins. Any possible scarring by the cable strands of the roll pins or cylindrical member should be held to a minimum. Therefore, the surface hardness of the roll pins or their equivalence, or the cylindrical member, should be held to to a point not less than minus 15 percent of the surface hardness of the cable strands of the cable bolt. When such a condition exists, then the roll pins are fully functional in holding outwardly the cable strands so that these will frictionally engage and indeed radially elastically expand the tubular member proximate that portion thereof which the enlargement engages. It is this elastic expansion of the tubular member that produces the radial, elastic, contractive or compressive forces needed to generate heightened force normals for producing the resistance loading desired. Thus, in such an arrangement, a dynamic resistances offered by the invention achieves tensile loading of from perhaps 23 to even 40 tons. This is a substantial resistance, and one which is needed for appropriate mine roof ground control. Further, this resistance loading is dynamic in operation in that further dilation of the mine roof will maintain or perhaps even increase the resistance loading of the cable bolt.
None of the prior art as known to the applicants teach the concept of producing a circumferential, essentially cylindrical sectional enlargement of a cable bolt wherein there is essentially no plastic deformation experienced as to elements of the cable bolt wherein the requisite radial elastic expansion of the tubular member is nullified.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
In the present invention, a cable bolt installation is provided a selected mine roof borehole produced in mine roof strata. A cable bolt structure is provided a cable length having a proximate end and also a remote end constructed for anchoring within the essentially upper reaches of the borehole. Epoxy anchoring, point anchors, etc., provide the essential end-anchoring of the cable length. Proximate the proximate end of the cable length is structure providing a circumferential enlargement as contributed by one or more cylindrical elements. Such elements are disposed either over the king wire and interior of the cable strands, or over the cable length proper. An elongated tubular member is disposed over the cable and is provided with a reaction plate, either secured to or slipped over the end of the cable bolt. The tubular member is preferably exteriorly threaded, and a torquing nut is threaded thereon and abuts the reaction plate, the latter being designed to thrust against the mine roof surface surrounding the applicable borehole. A tension pre-load, of the cable bolt, of perhaps 1-2 tons is produced by torquing the nut against the reaction plate.
The interior bore of the tubular member receives the cable bolt and reacts with its circumferential enlargement, operating in essentially the elastic range of the tubular member, in offering a controlled resistance to tubular member travel relative to said cable bolt. To facilitate assembly, it is desire that there be a proximate counterbore or bore enlargement, relative to the proximate end of the tubular member, and that its junction with the bore proper be a conically tapered portion. It is preferred that, initially, the enlarged portion of the cable bolt be in friction-fit relationship relative to the enlarged bore portion; subsequently, the nut is tightened for an initial desired preload. As the mine roof strata tends to settle, the mine roof surface dilates so as to urge the tubular member downwardly. The latter's coaction with the enlargement of the cable bolt produces a circumferential, at least partially elastic enlargement of the tubular member at that portion thereof which is transversely proximate such enlargement. This creates a moving pressure bubble, as between the tubular member and the enlargement, for increasing travel constraint of the enlargement area, thereby offering resistance to mine roof strata settling.
As to the circumferential enlargement of the cable bolt, this is produced either through the inclusion of one or more cylindrical members, disposed on the king wire of the cable length, or an internally serrated cylindrical member position upon the cable length and constructed to grip the cable length in an increasing manner as the pressure bubble is produced. The method inherent in the invention, broadly stated, is to supply cable bolt anchoring structure in a mine roof, wherein dilation of the roof, as produced through settling of roof strata, is constrained through controlled descent as is regulated through the generation of a pressure bubble, i.e. by the radial elastic pressure, exerted circumferentially about a cylindrically enlarged portion of the cable bolt of the structure, by a tubular member expanded elastically thereabout and secured relative to a mine roof reaction plate, as by torquing nut structure or otherwise.
OBJECTS
Accordingly, the principal object of the present invention is to provide new and improved cable bolt structure and related components.
A further object of the invention is to provide a cable bolt installation having a cable bolt constructed in such manner that the same has an enlargement capable of producing an elastic radial expansion within a tubular member employed, whereby to rely upon the radial compression of such tubular member against the periphery of the cable bolt enlargement to produce a dynamic-control resistance relative to relative motion between the cable bolt and the tubular member employed.
A further object is to provide an improved cable bolt structure wherein the cable length constituting a principal portion of the structure includes a king wire, multiple strands wrapped about said king wire, and one or more hardened cylindrical elements disposed along said king wire for expanding outwardly the strands immediately adjacent the cylinders, thereby permitting said strands to coact in interference fit relationship with a tubular member so as to radially expand the tubular member in its elastic range, this for producing the compressive forces needed to supply the dynamic frictional resistance characteristic desired relative to the cable bolt and its tubular member.
An additional object is to provide a cable bolt member having an enlargement taking the form of a cylindrical member that grips the peripheral strands of the bolt length, a side wall of the cylindrical member being slit to provide for structural circumferential compression without chancing plastic deformation of such cylindrical member.
A further object is to provide a method for achieving ground control in mine roof strata, this by supplying a dynamic resistance characteristic which in effect is spring-loaded by virtue of the elastic expansion of a supplied tubular member relative to the enlargement of the cable bolt with which the later cooperates.
BRIEF DESCRIPTION OF DRAWINGS
The present invention together with objects and advantages thereof may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view, partially broken away and sectioned for convenience of illustration, of the ground control structure constructed in accordance with the basic principles of the present invention.
FIG. 2 is similar to FIG. 1 but illustrates an alternate structure, for achieving a cable bolt enlargement section, relative to that structure seen in FIG. 1.
FIG. 3A illustrates in perspective the combination of a cable length with a roll pin type of cylindrical element to be disposed over the king wire or central wire of such cable length.
FIG. 3B is similar to FIG. 3A but illustrates that the strands are temporarily unwound so as to provide access to the king wire for a preferable press fit of one or more cylindrical members such as roll pins which are urged together to a desired intermediate point along the king wire within the cable length proper.
FIG. 3C illustrates the structure of FIG. 3B wherein the outer strands are rewound so as to encase, by the helical strands of the cable, the hardened metal enlargements or roll pins within the cable length.
FIGS. 4A and 4B are similar to FIGS. 3A-3C excepting that, in the case of these present figures, an external cylindrical member is disposed about the cable length.
FIG. 5 illustrates an installation wherein a bearing plate is secured to a central tubular member disposed in the mine roof borehole, the cable bolt this time including an external peripheral cylindrical member as seen in FIG. 4B.
FIG. 6 illustrates the condition wherein the structure of FIG. 1, for example, is installed and the mine roof strata settles so as to produce a relative downward movement, i.e., to the left in FIG. 6, of the tubular member so that the enlarged area of the cable bolt advances relatively speaking, upwardly through the upper portion of the tubular member.
FIG. 7 is similar to FIG. 6 but illustrates the pressure bubble being created as between the cylindrical member shown and the radially expanded inner wall of the tubular member of the installation.
For convenience of illustration and understanding, the transverse dimensions of the structural features relating to the tubular member and cable bolt transverse enlargement comprising the pressure bubble are shown in greatly enlarged scale.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 1 mine roof strata 10 has a vertical borehole 11 which passes through mine roof surface 12. Disposed in the borehole is tubular member 13, the same having a plurality of external threads 14 as indicated. The interior bore 15 of the threaded tubular member has an interior chamfered shoulder area 16 which is conically shaped and which joins an enlarged counter bore area 17.
Positioned within bore 15 is a cable length 18 comprised of a king wire 19 and a series of strands 20 helically wound thereabout. Of importance in the invention is the inclusion of one or more cylindrical members 21 and 22 which are pressed end-to-end over the king wire and about which the strands 20 are rewound. More will be said about this later. At this juncture it is important to note that the cable length 18 has an upper end 23 that is anchored by epoxy 23A (see FIG. 6) or otherwise into the upper reaches of borehole 11. The end of extremity 23 may include any one several types of structures, e.g. as common to the art, for aiding in the epoxy securement and anchoring of the cable length within the bore hole.
Cable bolt 24 may be thought of as including the cable length 18 and the cylindrical members 21 and 22, while the cable bolt structure 25 may be considered as including cable bolt 24, plus tubular member 13 and torquing nut 26. Torquing nut 26 will include, of course, an interiorly threaded nut body 27 and a forward hemispherical, self-centering head portion 28. This allows for self-centering of the nut and associated structure relative to aperture 29 in the bearing plate or reaction plate 30, positioned about the bore hole and abutting the mine roof surface at 31.
In FIG. 3A it is seen that cable length 18 is about to receive cylindrical member 22. The latter may take the form of a hardened roll pin having a surface hardness of the order of not less than that of the strands 20, minus 15%, of the cable length. In FIG. 3A cylindrical member 22 takes the form of a roll pin having a sidewall slot 33 and a long tapered end portion at 32. In FIG. 3B the makeup of the cable bolt comprehends temporarily unwinding the strands 20 so that the cylindrical elements 21 and 22 can be pressed on to the king wire 19. The leading, conically tapered edge 32 of member 22 aids in reducing the likelihood of cable failure. In any event, once the tubular cylindrical members are in place, being installed end-to-end, then the cable strands 20 are rewound so that the cable bolt achieves the structural integrity as seen in FIG. 3C. The greater the pressure bubble effect desired, the greater the over-all length to be selected, whether unitary or segmented, of the the cylindrical element(s) 21, 22.
In installation the borehole is first generated and the cable bolt is thrust therein and spun by means of a tool gripping the lower end of cable length 18. An epoxy or other agent 23A (see FIG. 6) is employed for securing the upper end 23 within the upper reaches of the bore hole. The bearing plate 30, having aperture 29 is inserted over cable bolt 24 and externally threaded tubular member 13 freely passes through aperture 29, with torquing nut 26 being threaded thereon.
For most installations it will be preferred that tubular member 13 will be pre-installed over the cable bolt 24. The interior counter bore area 17 is preferably dimensioned to receive the cable bolt 24, with the included cylindrical members 21 and 22 in a friction fit, for temporary holding purposes. In any event, and once the upper end of the cable bolt at 23 is securely anchored within the borehole, through upward thrusting and spinning of the cable bolt in a conventional manner, a tool will be employed to tighten nut 26 so as to supply to the cable length a tension preload of perhaps from 1 to 2 tons.
In operation, the settling of the mine roof strata 10 above mine roof surface 31 will produce a dilation of such surface a downward direction, thereby causing the bearing plate 30 and also the nut 26 and tubular member 13 assembly likewise to move incrementally downwardly. This causes the enlargement portion 34, see FIG. 3C, as produced by the inclusion of cylindrical members 21 and 22, to advance from the press-fit area within the counterbore of the threaded tubular member upwardly into the primarily bore area. This operation acts to expand radially the metal tubular member 13 proximate the area of members 21 and 22. Such radial expansion is at least primarily within the elastic range of the material of the tubular member so that such action generates, by the tubular member 13, a radial, inward, elastic compression force, serving to enhance the frictional, elastically compressive holding power of the tubular member relative to the cable bolt. Further dilation of the mine roof surface will produce a further riding up, relatively speaking, of the enlargement portion of the cable bolt with respect to tubular member 13. Accordingly the pressure bubble that is produced advances upwardly, relatively speaking, as to cable bolt 24. Again, pressure bubble is defined as the frictional resistance generated through the coaction by and between the cable bolt, with it enlarged portion as previously described, and the elastically expanded material of tubular member 13. Such a friction generating bubble travels upwardly, relatively speaking, in accordance with the downward settling of mine roof strata.
At this juncture it is important to note that cylindrical members 21 and 22, preferable comprising roll pins, will generally be case hardened and approach the surface hardness characteristics of tool steel. What is not wanted is any significant plastic deformation of members 21 and 22. Rather, these should preserve the outward integrity of the strands such that the strands 20, such that the latter are useful to urge outwardly the sidewall of the tubular member 13 to produce the elastic compressive forces as previously mentioned. Therefore, the surface hardness of the members should be not less than 15 percent the surface hardness of the strands 20.
The structure in FIG. 2 is similar to that seen in FIG. 1 with the exception that this time, in lieu of the inclusions of the cylindrical members 21 and 22 one the king wire, a new cylindrical member 35 is employed which is pressed over the cable length in the manner seen in FIG. 2. Cylindrical member 35 is preferably case hardened and includes a sidewall slot 36 and also a tapered forward leading edge 37. For ease of installation, the cylindrical member 35, gripping the cable length, is lightly frictionally seated within counterbore area 17 such that the forward tapered edge or end 37 engages frusto-conically formed section 16 of the bore area of tubular member 13. Nut 26 is disposed in place as indicated and torqued for desired pre-load. The settling of mine roof strata will produce a downward movement of tubular member 13 relative to the cable bolt so that, relatively speaking, cylindrical member 35 as clamped on the cable travels upwardly into the bore area of tubular member 13. This advance passed the area 16 produces, again, a pressure bubble or elastic expansion of the tubular member 13 at that region which is proximate to cylindrical member 35.
Whether the structure in FIG. 1 or FIG. 2 be used, it has been observed that resistant pressures of the order of 28 to 40 tons can be generated, thus producing a controlled settling of mine roof strata through tensioned integrity of the cable bolt installation prior to approaching the ultimate failure point of the cable.
FIGS. 4A and 4B amplify upon the assembly of cylindrical member 35 and cable length 18. For fabricating cylindrical member 35, a threaded nipple can be supplied to provide gripping serrations 38. The nipple us turned down to proper, interference-fit size, and wall slot 36 is produced as well as forward tapered portion 38. The unit is then case hardened to a point approaching the characteristics of tool steel, i.e. by heating with a rosebut acetylene torch to 900 degrees F. and then quenching in a bath of oil, and made ready for installation on a selected cable length. The threads 38 serve as serrations to grip against the strands of the cable length, providing a non-slip junction, and which gripping action is enhanced through the pressure bubble effect above recited.
For pre-load and adjustment purposes, it is very much desired that a threaded tubular member be used in conjunction with the torquing nut 26 as seen in FIGS. 1 and 2. It is possible, however, for the installation to be used as seen in FIG. 5, wherein tubular member 13A is now secured to bearing plate 30A by welding or otherwise, with the enlargement, see 35, being used with cable length 18 in the manner as previously described. Of course, a nut or other attachment means can be employed to secure the bearing plate 30A with respect to tubular member 13A.
FIG. 6 illustrates the generation of the pressure bubble 34A relative to the enlargement 34 of the cable bolt.
FIG. 7 illustrates the generation of a similar pressure bubble 34A relative to the cable bolt enlargement as occasioned by the inclusion of member 35, see FIG. 5.
Inherent in the invention as shown and described is a method for controlling the dilation of a mine roof, as produced through settling of strata thereabove, comprising the steps of:
(1) providing a borehole;
(2) anchoring a cable bolt at its remote end within said bore hole;
(3) providing an elongated, cylindrical enlargement of said cable bolt at its proximate end;
(4) providing an elongated, exteriorly threaded metal tubular member of radially elastic expansion characteristics, said metal tubular member receiving said cable bolt at said cylindrical enlargement in a tube-expansion interference fit;
(5) providing for said tubular member a reaction plate and also a torquing nut, threaded upon said tubular member and backing said reaction plate,
(6) preloading said cable bolt through tightening said torquing nut against said reaction plate, and
(7) creating a controlled, travel resistant pressure bubble as between said cable bolt and said tubular member, whereby to retard in a controlled resistive manner the descent of said tubular member relative to said cable bolt in response to dilation of said mine roof as occasioned through strata settling.
While particular embodiments of the present invention have been shown and described it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the essential aspects of the invention and, therefore, the aim in the appended claims is to cover such changes and modifications as fall within the true spirit and scope of the invention.
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Cable bolt structure, related components and method for achieving desired ground control of mine roof strata in a dynamic manner; a sustained transverse enlargement, of particular design, of a portion of the cable bolt employed coacts with a tubular member to elastically expand the latter, whereby to generate a heightened frictional resistance as between the cable bolt and such tubular member, for achieving desired strata control.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/209,460, filed Jun. 5, 2000 (Attorney Docket No. 87711.104700) and U.S. Provisional Patent Application Ser. No. 60/270,919, filed Feb. 22, 2001 (Attorney Docket No. 87711.128400).
FIELD OF INVENTION
[0002] This invention relates generally to real-time systems for location determination, and more specifically to real-time telephony systems for location and zone determination.
DEFINITIONS
[0003] Geocoding, also called “forward geocoding”, is the assignment of a geographic latitude and longitude or other geographic coordinates to an identified location, zone, or address.
[0004] “Reverse geocoding” is the determination of an identifier for a location, zone, or address using a geographic latitude and longitude or other geographic coordinates.
[0005] “Point-in-polygon processing” refers to the execution of software to determine whether or not a given point lies within the boundary, on the boundary, or outside of a given closed polygon.
[0006] “Polygon-in-polygon processing” refers to the execution of software to determine whether or not a given closed polygon: 1) lies within the boundary of a second given closed polygon, 2) lies outside of the second given closed polygon, 3) overlaps the second given closed polygon. Subcases exist when the two polygons are in contact at points or along edges.
[0007] CBB—Campus-Based Billing
[0008] GLSB—Geographic Location Services Broker
[0009] HLR—Home Location Register
[0010] LBB—Location-Based Billing
[0011] LMP—Location Management Platform
[0012] MBR—Minimum Bounding Rectangle
[0013] MER—Minimum Enclosing Rectangle (synonym for MBR)
[0014] MPC—Mobile Positioning Center
[0015] MSC—Mobile Switching Center
[0016] PDE—Position Detection Equipment
[0017] PSAP—Public Safety Answering Point
[0018] SCP—Service Control Point
[0019] VLR—Visitor Location Register
DISCUSSION OF PRIOR ART
[0020] The operation of wireless communication systems entails the translation of latitude and longitude information (“lat-long”) into specific physical, geographic, and administrative terms. In a first example, telephone calls must be billed according to the caller's location or zone. Such a location or zone must be quickly and accurately determined from a lat-long during call setup or closure. In a second example, wireless callers may need to know what landmark is near them, for purposes of navigation. In these and other applications, the process of mapping a given lat-long to some division of territory or some known landmark must be done quickly, accurately, and at relatively low cost.
[0021] While the problem appears straightforward, a simple database system for determining a landmark or zone from a latitude and longitude can turn out to be very large and slow in response. The granularity of the map is a major factor in sizing such a database. The U.S. federally-mandated E911 initiative will require location resolution to approximately 100 meters. If the provider of services wishes to determine a location on a continent to within 100 meters, a map of a 5000 by 5000 kilometer area would require the classification of 2.5 billion separate areas.
[0022] A second major factor in the database sizing is the irregularity of shape of the zones being used. Normally a zone is defined as a polygon, which requires the identification of all the vertices of the polygon. If a zone requires 100 vertices for its definition, each vertex must be stored in the database in some form as part of the zone. In the continental example, zones of about 10 by 10 kilometers would require listing about 25 million vertices.
[0023] Another critical problem is the determination of whether or not a given point lies within a given polygon on a map. This problem is soluble but computationally difficult, requiring significant time for a computed solution. The time required can exceed the time available during a call.
[0024] Underlying all of these problems are the general problems of availability, stability, and reliability of the system solving them. Any solution to the problems of database size and performance must meet stringent telephony system requirements in these areas.
[0025] Forward geocoding is the translation of a named address, location or zone into a latitude and longitude. Reverse geocoding is the opposite process. U.S. Pat. No. 5,991,739 (Cupps et al.) teaches the use of forward geocoding to determine an appropriate franchise zone in an Internet commerce application. U.S. Pat. No. 5 5,978,747 (Craport et al.), which also uses forward geocoding, uses polygon-in-polygon processing and a plurality measure to decide whether or not one region is inside another. U.S. Pat. No. 5,961,572 (Craport et al.), which also uses forward geocoding, uses point-in-polygon processing and a plurality measure to decide whether or not a point is inside a region. U.S. Pat. No. 5,796,634 (Craport et al.), which also uses forward geocoding, uses point-in-polygon processing and a plurality measure to decide whether or not a region associated with a point is inside another region. None of the Cupps and Craport patents address any requirement for response times consistent with telephone call processing. All of these patents teach the use of forward geocoding, that is, the translation of a given address or named location to a latitude and longitude or other coordinate system. None of them teach the use of reverse geocoding, which translates from latitude and longitude into a named address, location or zone. None of them provides any means of determining rapidly how a location's latitude and longitude translate to the everyday referents, such as geographic zones, landmarks, street addresses, road names or buildings, which people and automated processes use to convey different kinds of meaning.
[0026] To summarize, the problems faced in determining location or zone from a latitude and longitude require fast, accurate, inexpensive and reliable methods and equipment. Such solutions are not currently available.
SUMMARY
[0027] The invention accomplishes the rapid translation of geographic latitude and longitude into any of a number of application-specific location designations or location classifications. These designations and classifications include street address, nearest intersection, PSAP (Public Safety Answering Point) zone, telephone rate zone, franchise zone, or other geographic, administrative, governmental or commercial division of territory. The speed of translation meets call-setup requirements for call-processing applications such as PSAP determination, and meets caller response expectations for caller queries such as the location of the nearest commercial establishment of a given type. To complete its translation process in a timely manner, the invention uses a memory-stored spatial database to eliminate mass-storage accesses during operations, a spatial indexing scheme such as an R-tree over the spatial database to locate a caller within a specific rectangular area, and an optimized set of point-in-polygon algorithms to narrow the caller's location to a specific zone identified in the database. Additional validation processing is supplied to verify intersections or street addresses returned for a given latitude and longitude. Automatic conversion of latitude-longitude into coordinates in different map projection systems is provided.
[0028] The invention's memory-stored database is built in a compact and optimized form from a persistent spatial database as required. The compact R-tree spatial indexing of the memory-stored database allows for substantially unlimited scalability of database size without degradation of response time. The invention insures maximum performance of its database retrievals by isolating the retrieval process from all updating and maintenance processes. Hot update of the in-memory database can be provided without degradation of response time.
DESCRIPTION OF DRAWINGS
[0029] [0029]FIG. 1 shows the determination of a franchise zone for a mobile telephone call.
[0030] [0030]FIG. 2 a shows the initial stage of location determination (GLSB) for a caller in a neighborhood.
[0031] [0031]FIG. 2 b shows the stage of street address reverse geocoding for a caller in a neighborhood.
[0032] [0032]FIG. 2 c shows the stage of street address forward geocoding for a caller in a neighborhood.
[0033] [0033]FIG. 3 a shows geographic areas, and a point to be located, in the nest of minimum enclosing rectangles (MERs) as defined in an R-tree index.
[0034] [0034]FIG. 3 b shows geographic areas, and a point to be located, in the lowest level of minimum enclosing rectangles (MERs) as defined in an R-tree index.
[0035] [0035]FIG. 3 c shows the structure of the R-tree index for the MERs and geographic areas in FIGS. 4 a and 4 b.
[0036] [0036]FIG. 4 a shows a detailed subset of the geographic areas in FIGS. 4 a and 4 b, and a point to be located among the areas using point-in-polygon processing.
[0037] [0037]FIG. 4 b shows an expanded and highlighted set of the geographic areas in FIG. 4 a, and a point to be located among them using point-in-polygon processing.
DETAILED DESCRIPTION OF INVENTION
[0038] Applications
[0039] The invention's applications are a suite of computer programs that operate as a Location Management Platform program, or LMP, in a wireless telephony system. The invention provides multiple services, including E911 service, location-based call billing, 411 franchise zone location, and GLSB, or the Geographic Location Services Broker, for determining accurate street addresses.
[0040] The E911 Application
[0041] The first application is E911, for emergency services. E911 service is mandated by the FCC to determine the caller's location and send out emergency services to that location. In Phase 1 of the mandate, the location must be specified in terms of the cell of origin, or in effect the area around the cell tower where the call originated. In Phase 2, the location must be specified within 250 feet.
[0042] When a caller makes an E911 call, one approach is to have the network communicate with the cellphone through three or more cell towers. Position determining equipment, or PDE, uses the inputs from the towers to triangulate to determine the originating position of the call. Some cellphones carry a global positioning system (GPS) unit inside the phone. Such phones use three or more satellites to triangulate the call's originating position. Often a combination of tower and GPS sources will be used to satisfy the E911 mandates. The PDE resolves its inputs into a location expressed as a latitude and longitude, or lat-long, for the call's originating point.
[0043] In a matter of milliseconds, the call is routed through several different components within the network. An HLR, or home location register, determines the caller's home telephone number. A VLR, or variable location register, processes roaming callers by assigning a temporary telephone number to the calling phone. An SCP, or service control point, manages call routing and billing. An MPC, or mobile positioning center, determines the originating position of the call.
[0044] The SCP communicates with the MPC to retrieve the position information and forward it to the E911 dispatcher. The invention is a module integrated with the MPC information, and is called a Location Management Platform, or LMP. During the interval of milliseconds allotted to call processing during call setup, the invention determines what public safety answering point, or PSAP, should be notified on the caller's behalf. The invention's ability to determine the correct PSAP within a few milliseconds makes the invention commercially and statutorily acceptable in support of the E911 application.
[0045] The LBB and CBB Applications
[0046] A second application is location-based billing, or LBB, for mobile telephone service. Using the same PDE inputs as for the E911 application, the invention determines the rate zone for the calling point. This allows cellular service providers to organize customized billing zones for its customers, such as a circle of ten-kilometer radius around a customer's home and another such circle around the same customer's place of work. Calls from within either area would be billable at a lower rate than calls from outside both areas.
[0047] The same method is usable for irregularly-shaped areas such as college campuses. In this context the application is called campus-based billing (CBB). Students on campus using the invention's capabilities can make calls on that campus with reduced rates. The sole difference between LBB/CBB and E911 is the use of telephone rate zones instead of PSAP areas. The response time requirement of less than one second still applies, since the rate determination is made as a part of call setup. In either case, the ability to offer location-and campus-based billing enhances the attractiveness and capabilities of a wireless or cellular phone service provider's offerings.
[0048] The 411 Application
[0049] A third application is the selection of franchise zones to assist a mobile caller. This application extends the 411 Directory Assistance application to select a specific commercial establishment for a caller without requiring the caller to contact Directory Assistance and receive inadequate information or no information at all. In this application, a commercial firm with franchise locations defines the zone of call dispatching for each franchise in an area. A call to a common number for that firm is then routed to a franchise based on the originating point of the call.
[0050] See FIG. 1 for an example. A coffee-shop chain such as Starbuck's might have a large shop franchise 401 on a major city street 450 , and a smaller shop franchise 402 within a shopping mall 410 not far away. In this situation, the chain wishes to direct callers outside the mall to shop 401 , and callers inside the mall to shop 402 . The chain establishes a franchise zone 401 z for shop 401 , and a franchise zone 402 z, nested inside zone 401 z, for shop 402 . A caller specifies a general number for Starbuck's. If the caller is inside zone 401 z but outside zone 402 z, the invention routes the call to shop 401 . If the caller is inside zone 402 z, the invention routes the call to shop 402 . As before, the response time requirement of less than one second still applies, since the franchise selection is made as a part of call setup.
[0051] To summarize these three applications: the invention assumes a mobile call that includes positioning data such as latitude and longitude to give point or polygon coordinates for the call's point of origin. For the E911 and 411 applications, the invention enables connection of such a call to a service provider selected geographically for calls made from that point or polygon. The caller enters a general number, not the number of any one area, and then the invention and the call-handling equipment connect the caller to the number of the appropriate geographical service provider. For the LBB or CBB call, the caller's location serves to identify a rate class within which the call is to be billed. Using the invention's capabilities for call setup, many more such applications are possible.
[0052] The GLSB Application
[0053] The invention's fourth application, Geographic Location Services Brokering, or GLSB, provides a World Wide Web-related caller service instead of a call setup service. Many commercial establishments using the World Wide Web for commerce have no ready access to latitude and longitude data, and no convenient way to use it. Instead, they rely on a caller's use of address information to determine a ZIP code, a city block, or other location information useful to the Website. For a mobile caller, however, such address information is not available on a reliable basis.
[0054] When the mobile caller is equipped with a Web-enabled wireless phone, having the address nearest the phone itself is especially advantageous. The Web-enabled wireless phone can be used to access Websites, displaying information formatted to fit the phone's handheld display. A caller can access a hotel, restaurant, auto rental or other commercial Website, enter the phone's location on a Web page form displayed by the site, and transmit the caller's current address to the Website as data. The Website then looks up the provided address to determine which zone it falls in, and returns the location of the appropriate facility nearest to the caller, along with information concerning that facility. The invention provides this capability through the GLSB, in effect, enabling the wireless Web to operate with location information.
[0055] A simple example of the GLSB application is its use to determine a nearest address, access a hotel-chain Website, enter the nearest address on the hotel chain's form displayed by the Web browser, and get back the address of the nearest hotel from that chain, together with directions. The invention's contribution to this process is the furnishing of the street address nearest to the point of origin of the call.
[0056] The invention determines the nearest street address using the following process. First, the PDE passes the latitude and longitude to the invention. The invention uses the latitude and longitude to look up a set of zones in a spatial database containing address information. Each zone found contains a range of streets and street intersection coordinates for an area.
[0057] [0057]FIG. 2 a shows an example of a residential neighborhood, with caller location 550 , streets 511 , 512 , 513 , and houses 560 having house numbers 560 n between streets 514 and 515 . Using point-in-polygon processing, the invention selects area 501 z containing caller location 550 , and having vertex coordinates such as 501 p and 501 q. As shown in FIG. 2 b, the invention applies well-known coordinate geometry rules to determine the street 512 closest to the point of the call. Based on the distance of the point of the call from the two nearest street intersections of the street selected, the invention retrieves the coordinates of the two intersections. The invention assumes linear distribution of addresses 521 and 522 for the left and right sides of the street respectively, selects the right or left set based on the single-axis nearness of location 550 to reference points 501 p and 501 q, and interpolates a candidate street address 561 c for the caller's location. This completes the reverse geocoding step: determining a trial street address from a latitude and longitude. FIG. 2 b shows that the candidate building number 1215 was selected.
[0058] To validate the candidate address, the invention then uses the spatial database's address information to try to find the address calculated. See FIG. 2 c. The spatial database does not contain latitudes and longitudes for all addresses, so an estimation process must be used. If the candidate address is found exactly as estimated, the invention furnishes the address to the caller for use with the Web features of the phone. In the example, the candidate address was not found. In this case, the invention compares the candidate address to all addresses retrieved from the database to try to find the closest match. In this case, the nearest actual building number to 1215 is found at building 561 n. The building number there is 1217 , and the invention selects for the address location of the caller.
[0059] The invention adjusts house or building numbers to match most closely what exists on the street, adds directionals if appropriate, and corrects spelling of the street name. The resulting address is then furnished to the caller for use with the Web features of the phone. In effect, the invention has reverse-geocoded the supplied latitude and longitude to get a candidate address, and then forward-geocoded an actual address to develop a match for the caller.
[0060] With its multiple accesses to the database, the GLSB application is designed to complete its processing and return results to the caller within several seconds of receiving the request for address determination. This matches well the level of expected Web browser response time, and is therefore within reasonable caller expectation.
[0061] An alternative embodiment of the GLSB application makes the address determination whenever the caller requests an address form fill-in on a Web phone, and posts the address information directly into the browser form. The advent of XML, the extended markup language now in wide use on the World Wide Web, facilitates such automatic transfers of data.
[0062] Additional embodiments of the GLSB application embed the entire process of interpreting and forwarding location information in the underlying protocols of the wireless phone system. Under both IS-41 and GSM standards, current wireless systems continually exchange information between phone and cell tower concerning the phone's location, primarily so that a mobile station can determine when it has crossed from one registration area to another, and change its registration. This process is event-driven, by the receipt of a new serving MSC (Mobile Switching Center) identifier by the mobile station. In the additional embodiments, the mobile station is enhanced to poll the LMP periodically to obtain interpreted location information as described for GLSB. The interpreted location information is then passed to the active MSC for use and distribution. The incorporation of already-interpreted location information in this continual process makes the Web-enabled wireless phone a tool for unprecedented access to services and connections with other Web users.
[0063] Here is an example of such an embodiment. A commercial firm maintains a security perimeter around a facility, with guards stationed at known points and moving along planned tours of watch. Using Web-based wireless phones, any guard or supervisor can maintain up-to-the-second awareness of the position and status of any other guard.
[0064] Following the same model, a social example enables a group engaged in a common search or exploration of an area to maintain constant contact without calls. This is especially useful in a search-and-rescue scenario, when individuals must fan out through a wide area to locate a victim or a desired object. It is also especially useful in forest fire-fighting, where team coordination often consumes the time and attention of fire fighters. The use of a Web-based system to identify continuously the whereabouts of all members of the team allows the front-line team members to devote all their attention to their work. A coordinator or dispatcher can use a wireless Web phone to locate each team member, call team members to direct movement, and direct resources accurately to members who urgently need them in isolated places. The use of a good geographic database in fighting a forest fire would allow a dispatcher, for example, to examine the phone's display, see the marks corresponding to individuals and teams of workers, and call a fire fighter to say, “There's a team on the ridge above you, about 50 yards straight up the incline. Work toward them.”
[0065] Performance
[0066] The speed of the invention arises out of its coordinated use of high-performance software and hardware techniques to convert the latitude and longitude sent by the PDE into the correct PSAP code, rate zone, or other classification. These techniques include the use of a high-performance spatial index, optimized point-in-polygon and polygon-in-polygon processing, a spatial database stored in high-speed computer memory, and the use of isolation levels in the database to prevent conflicts between fast database retrievals and processor-intensive database maintenance tasks.
[0067] The Spatial Index
[0068] The first technique is the use of a spatial database with a spatial index, to enable high-speed lookups of data based on latitude and longitude, and even elevation if provided. The spatial database is made up of an index tree and a set of leaf nodes on that tree which contain the data classified by the index. The index tree is in the form of an R-tree, well-known to those skilled in the art of spatial database software.
[0069] The R-tree is defined in the software literature. See R-Trees: A Dynamic Index Structure for Spatial Searching, by Antonin Guttman, published in ACM SIGMOD 1984. Briefly, the R-tree is a height-balanced index tree structure similar to a B-tree (also widely known in software literature), made up of index nodes and leaf nodes. Index records are grouped in the nodes of the tree. Each node in the R-tree contains a set of from 2 to 50 index records. In the R-tree's index nodes, each index record contains two coordinate pairs representing opposite comers of what is called a Minimum Enclosing Rectangle, or MER, for a geographic area. The MER is the smallest rectangle, aligned with the coordinate system used in the index, which will enclose (circumscribe) a given geographic area. The geographic area identified in an index entry of the R-tree is the MER containing all of the MERs in the nodes below that node. In the R-tree's leaf nodes, each index record contains a pointer to a polygon definition of a known geographic area such as a ZIP code or an area code.
[0070] R-trees are not restricted to two-dimensional spatial definitions. Through the use of three-dimensional coordinates in each index entry, an R-tree may define a minimum enclosing rectangular parallelepiped, defining the limits of a three-dimensional form. This concept generalizes to N dimensions. Consequently the invention's R-tree may optionally store limited geographic elevation data to discriminate between calls originating at different elevations at the same latitude and longitude. An example of such a call would originate in a high-rise building. Assuming that the PDE can provide the necessary coordinates, the invention can return elevation (or floor) data as well as zone or geographic location.
[0071] The advantages of R-trees are well-known in the art. Given a pair of coordinates, such as latitude and longitude, an R-tree can return a set of candidate geographic areas with very few probes of the index. Since the invention's index is stored in main memory, the cost of each such probe is on the order of microseconds. This cost does not contribute significantly to the invention's response time delay.
[0072] The spatial database index may also take a form derived from the R-tree, such as an R+ tree, an R* tree, a Hilbert R-tree, or an X-tree, all of which represent variations on the basic R-tree structure. The R-tree's characteristics are sufficient for definition of the invention, but different embodiments of the invention may use any similar index forms such as one or more of those listed above. Each method has its own advantages, which can be applied as appropriate. R+ trees offer reduced overlap of minimum enclosing rectangles. R* (R-star) trees offer improved storage (memory) utilization and robustness in processing poor data distributions. Hilbert R-trees offer further improved storage (memory) utilization. X-trees offer improved performance in processing higher-dimensional data. The following references detail the differences among these forms: Guttman A.: ‘R-trees: A Dynamic Index Structure for Spatial Searching’, Proc. ACM SIGMOD Int. Conf. on Management of Data, Boston, Mass., 1984, pp. 47-57; Sellis T., Roussopoulos N., Faloutsos C.: ‘The R+-Tree: A Dynamic Index for Multi-Dimensional ‘Objects’, Proc. 13th Int. Conf on Very Large Databases, Brighton, England, 1987, pp 507-518; C. Faloutsos and S. Roseman: ‘Fractals for secondary key retrieval.’ Eighth ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems (PODS), pages 247-252, March 1989; N. Beckmann, H. -P. Kriegel, R. Schneider, and B. Seeger: ‘The r*-tree: an efficient and robust access method for points and rectangles.’ ACM SIGMOD, pages 322-331, May 1990; Ibrahim Kamel and Christos Faloutsos: ‘Hilbert r-tree: an improved r-tree using fractals’ pp 500-509, Proc. 20th Int. Conf. on Very Large Databases, Santiago, Chile, 1994; and Stefan Berchtold, Daniel A. Keim, and Hans-Peter Krieger: ‘The X-tree: An Index Structure for High-Dimensional Data’ Proc. 22nd Int. Conf. on Very Large Databases, Brighton, England, 1996, pp 406-415.
[0073] To give an overview of the spatial indexing process with an R-tree, the input area's MER is determined at the outset. Then the incoming area's MER is compared to the MERs in the index, and a set of candidate geographic areas are found wherever the input MER overlaps with an MER in the index. Comparing one MER to another is a simple set of numeric operations on the four corners of each MER. If there is no overlap, then there is no possible crossing, and the invention immediately returns a negative result. If there is overlap of the incoming MER and a database MER, the algorithm checks the overlapping area to see if it is smaller than either of the MERs involved. If the overlapped area is smaller, the algorithm restricts the area of analysis to the overlapped area only. Next, the invention's point-in-polygon or polygon-in-polygon processing determines the relationship between the actual incoming area and the relevant portions of the geographic areas defined in the spatial database. If an intersection with a contour from the database does fall between adjacent points defined for the input, then a crossing has been found, and the input area overlaps with the area found in the database.
[0074] Here is a detailed example of R-tree spatial index processing. See FIG. 3 a, which is adapted from the original Guttman paper. The minimum enclosing rectangles are shown as rectangles which overlap and nest within each other. The geographic zones are shown as the irregular polygonal shapes inside the lowest-level rectangles. The root record of the R-tree index contains the largest MERs 201 and 202 , each one containing a set of smaller MERs. MER 201 contains MERs 211 , 212 and 213 . MER 202 contains MERs 214 and 215 . In turn, MER 211 contains MERs 221 , 222 and 223 , each of which contains only a geographic zone. MERs 224 , 225 , 226 , 227 , 228 , 229 , 230 , 301 , 302 , and 303 also contain only geographic zones. A single area may have separate parts, as in MER 230 .
[0075] In FIG. 3 a, a point 310 is shown as the input point for which the geographic zone is to be found. To determine the geographic zone for point 310 , the lookup process begins at the root of the R-tree with MERs 201 and 202 . By comparing the coordinates for points 201 p and 201 q to those for point 310 , the process determines that point 310 is within MER 201 . Likewise, by comparing the coordinates for points 202 p and 202 q to those for point 310 , the process determines that point 310 is within MER 202 as well. The process then descends to the next level of the index tree, in which all MERs within the MER 201 branch and all MERs within the MER 202 branch are stored. Checking MERs in these two branches of the index tree results in finding that point 310 appears only in MER 212 . The process then descends to the next level of the index tree to retrieve only the MERs in MER 212 , namely MERs 224 , 301 , 302 and 303 . Point 310 is found to be within all four. Since all of these MERs contain only geographical areas defined as polygons, the process shifts from the index selection and retrieval to the point-in-polygon determination.
[0076] In an alternative view of the process, FIG. 3 c diagrams the descent from the root node 51 of the R-tree 50 . Note that nodes 53 , 54 , 56 , 57 , and 58 are not accessed, and no areas are accessed from the leaf nodes except for areas 224 a, 301 a, 302 a, and 303 a.
[0077] The process illustrated is for far fewer nodes overall than any real case. In a real situation, root node 51 would have up to 50 nodes directly beneath it, and the same would hold true for each node at subsequent lower levels of the tree. Even with tens of thousands of nodes, the descent of such a “bushy” tree would normally require very few MER comparisons. If it is assumed that each node contains 30 MERs, only one or two nodes on each level of the index tree would be accessed. An R-tree index supporting a seven-million-polygon spatial database with 30 MERs per node would require five levels of index, so that in general the MERs in about ten nodes would require comparison with the input point.
[0078] The advantages of the R-tree become even more evident once the MER screening has eliminated most of the database's geographical areas from the screening process. So far, the example process has required only rapid point-MER comparisons for MERs 201 , 202 , 211 , 212 , 213 , 214 , and 215 . Lengthier point-in-polygon processing is required only for geographic areas 224 a, 301 a, 302 a, and 303 a within MER 212 . See FIG. 3 b, which shows the same areas as in FIG. 3 a, with the higher-level MERs removed, and the geographic areas identified. The R-tree's leaf nodes contain the detailed polygon data for shapes within the MERs. In a real-world database, only a handful of geographic areas would require point-in-polygon processing, just as in the example.
[0079] Point-in-Polygon and Polygon-in-Polygon Processing
[0080] The second technique used to make the invention work faster is optimized point-in-polygon or polygon-in-polygon processing. This processing determines the relationship between an incoming latitude and longitude or area, and one or more specific, defined, geographic areas in the spatial database. In the polygon-in-polygon case, the input is not a single point, but an area, defined as a polygon of points.
[0081] For the point-in-polygon processing, see FIG. 4 a. The method used by the invention is an application of Jordan's Theorem, which states that a closed contour in a Euclidean plane divides the plane into two separate areas (call them an “outside” and an “inside”). A point can be determined to be inside or outside of a closed contour by 1) extending a line (ray) straight out from the point past the outermost reach of the contour, 2) counting the crossings the extending line makes with the contour, 3) calling all points with an odd number of such crossings “inside” the contour, and 4) calling all points with an even number of such crossings “outside” the contour. In the present example, point 310 is in the MER box 301 for area 301 a. Extend a horizontal line 320 from point 310 to either left or right. Define box B p , essentially a narrow neighborhood to either side of the horizontal line 320 , to restrict the number of points of the area contour which must be compared versus line 320 . Box B p defines edge segments I p1A , I p1B , I p2A , I p2B , and I p2C , each containing a small number of polygon points for the areas in question. To find whether point 310 is inside or outside area 301 a, count intersections 311 , 312 of line 320 with the edge segments I p1A and I p1B of area 301 a, going to the left only. Counting stops once the edge of MER 301 has been passed (clearly, no further points of area 301 a can exist beyond this point). If the count is even, point 310 is outside area 301 a. If the count is odd, point 310 is inside area 301 a. Here the count is even, so point 310 is outside area 301 a.
[0082] With area 303 a, I p2A doesn't intersect both sides of box B p , so it is not counted as crossing line 320 . I p2B and I p2C do intersect line 320 , giving an even value (2) for the intersection count, and therefore showing point 310 to be outside area 303 a. With area 302 a, I p1B and I p2B both intersect with line 320 , and I p2A is again ignored, but only one direction (left or right) is considered from point 310 . Whether the direction chosen is left or right, the count proves to be 1 (odd), showing that point 310 is inside area 302 a.
[0083] Area 224 a, which is too large to include in FIG. 4 a, is also listed under MER 224 , which is in MER 212 . See FIG. 4 b, which shows the four areas, 301 , 302 , 303 and 224 , all of which require point-in-polygon analysis for point 310 . By the same process as for areas 301 , 302 , and 303 , point 310 is shown to be outside area 224 a.
[0084] Note that there is no need to extend line 320 beyond the candidate MERs in either direction. This treatment, as it operates in the invention, covers both point-in-polygon and polygon-in-polygon, and treats all boundary cases correctly. Special cases, such as how to define a crossing when a ray touches a contour in one point that may be a vertex or a point of tangency, require some additional processing, but do not substantially change the impact of the method used. Boundary points are special cases, each requiring definition of rules to ensure consistent behavior of the algorithm. The processing performed is topologically correct.
[0085] The polygon-in-polygon case treats adjacent points from the input polygon one by one, and uses point-in-polygon processing to determine whether the adjacent points are both inside, both outside, or straddling the contour of the area being compared to the input.
[0086] The Memory-Stored Database
[0087] The third technique used in the invention for fast response times is the storage and management of the entire spatial index in high-speed memory, to remove all mass storage access overhead from the lookup process. The spatial database itself is stored on mass storage devices as a relational (and spatial) database, using a commercial database management system (DBMS). The direct use of a commercial DBMS presents two problems which the invention overcomes.
[0088] The first DBMS problem is access time. The spatial database is stored and maintained by the DBMS on disk-type mass storage. Retrieval of index and data records from mass storage is time-consuming, and requires constant attention to database tuning to insure the optimum access time. The invention solves this problem by the use of a transformation program which converts the disk-stored form of the database into a more compact, memory-stored form which requires no disk-access software operation. This form of the database is loaded onto a single system. From there it provides immediate memory access to all spatial index nodes and records, and to all spatial data required. Any and all network latency inherent in many DBMSs is eliminated. In this way the tens to hundreds of milliseconds required to retrieve one node shrink to tens to hundreds of microseconds, a thousandfold increase in speed.
[0089] The invention preserves and amplifies this speed advantage by implementing the processing of spatial predicates in its queries against the memory-stored data. Spatial predicates are language constructs designed for querying spatial databases to determine the relationships between geometric shapes. A typical set of spatial predicates in OpenGIS SQL are:
Equals Returns a value of 1 for TRUE, 0 for FALSE, and −1 for (g1, g2) UNKNOWN. TRUE if g1 and g2 are equal. Disjoint Returns a value of 1 for TRUE, 0 for FALSE, and −1 for (g1, g2) UNKNOWN. TRUE if the intersection of g1 and g2 is empty. Touches Returns a value of 1 for TRUE, 0 for FALSE, and −1 for (g1, g2) UNKNOWN. TRUE if the only points in common between g1 and g2 lie in the union of the boundaries of g1 and g2. Within Returns a value of 1 for TRUE, 0 for FALSE, and −1 for (g1, g2) UNKNOWN. TRUE if g1 is completely contained in g2. Overlaps Returns a value of 1 for TRUE, 0 for FALSE, and −1 for (g1, g2) UNKNOWN. TRUE if the intersection of g1 and g2 results in a value of the same dimension as g1 and g2 that is different from both g1 and g2. Crosses Returns a value of 1 for TRUE, 0 for FALSE, and −1 for (g1, g2) UNKNOWN. TRUE if the intersection of g1 and g2 results in a value whose dimension is less than the maximum dimension of g1 and g2 and the intersection value includes points interior to both g1 and g2, and the intersection value is not equal to either g1 or g2. Intersects Returns a value of 1 for TRUE, 0 for FALSE, and −1 for (g1, g2) UNKNOWN. This is a convenience predicate: TRUE if the intersection of g1 and g2 is not empty. Intersects(g1, g2) implies Not (Disjoint(g1, g2 )) Contains Returns a value of 1 for TRUE, 0 for FALSE, and −1 for (g1, g2) UNKNOWN. This is a convenience predicate: TRUE if g2 is completely contained in g1. Contains(g1, g2) implies Within(g2 , g1)
[0090] The second DBMS problem is the negative effect on retrieval performance which occurs whenever the database is undergoing extensive updating or backup. Even with the best of tuning, database maintenance consumes a major part of a system's processing resources. If retrievals for location determination happen to occur during database updating, they can suffer significant delays. The DBMS cure for this is to add more retrieval processing resources, which significantly increases the cost of the system. The invention avoids this problem by isolating the retrieval process to its own memory-stored form of the spatial database, while DBMS maintenance goes on in the disk-stored form of the database. The DBMS processing overhead for database maintenance is therefore isolated to parts of the system not involved in the online retrieval process.
[0091] The net result of these database improvements is sub-second response time for its queries during operation.
[0092] Database Isolation Levels
[0093] The fourth technique used in the invention to sustain fast response times is the use of isolation levels in the spatial database to allow high-speed retrieval of information from the spatial database to continue unaffected while sections of that database are undergoing updating. At intervals, the memory-stored form of the database must be updated. The invention accomplishes this without significant performance penalty on retrievals by 1) isolating a segment of the index tree with that segment's underlying data being updated, 2) creating a new version of just the updated portion of the tree and data, and 3) switching the retrievals to the new version of that portion at one time. The space used by the old version can then be freed for further use in updating. Since this can be done for subtrees of the database, the entire database need not be fully replicated in memory in both an old and a new version. In this manner the invention avoids penalizing the retrieval process during updating.
[0094] Scalability
[0095] Out of the combination of all these performance-related innovations, the invention derives an added major advantage in its architecture: it is scalable to support the use of any size of spatial database using latitude, longitude and limited elevation. The compaction of the spatial database into its index nodes and leaf nodes in memory strips out all DBMS-required overhead information. The use of MERs and R-tree design also reduce the incremental database space requirements dramatically. These factors allow the disk-stored DBMS level of the database to be nearly any size desired, while the growth rate of the memory-stored level remains relatively small. Only the information essential to the retrieval operation is stored in memory, in a compact form.
[0096] As the database size scales up, R-tree spatial indexing sustains high performance. Even when the database size requires the addition of a tier of index records, the memory-based traversal of the added tier of records adds very little cost to the overall access.
[0097] For example, see Table 1 below, titled R-Tree Space Calculations. These calculations show that a database of seven million two-dimensional geographical areas of a maximum size of 100 kilometers each, stored as 100-point polygons with an R-tree index, can be stored in full in about two gigabytes of memory. Simple, well-known compression techniques are applied in this estimate, and reduce the overall size significantly, thereby allowing the storage and retrieval of larger numbers of more-complex shapes in the same range of memory. Further use of compression, such as an assumed coordinate baseline on a smaller-than-global scale, can reduce the memory need still more. Main memory sizes in the 2-gigabyte range are easily configured in current computer systems.
TABLE 1 Index # of Index Node Nodes at R-Tree Space Calculations Level Level Number of data recs (leaf nodes) Maximum index records per node Bytes per R-tree index MER* Bytes per R-tree index pointer Bytes per R-tree index node (ovhd) Bytes per R-tree leaf node (ovhd) Index node occupancy Mean polygon points per area Overall area scale (km) 1 2 3 4 5 6 7 8 9 Total 233334 7778 260 9 0 0 0 0 0 241382 Index records per node 30 Bytes per R-tree index node 496 Number of index nodes 241382 Index node space 119725472 114.18 MB Bytes per leaf node 269 (from compression calculations in Table 2) Leaf node space 1883000000 1795.77 MB Total Database Space 2002725472 1909.95 MB (Leaves and Index)
[0098] If multiple sets of zone and location information are required for the same geographic area, the invention's system can be “layered”, installing one system for each distinct class of areas and data content. For example, given a state or province, one system would contain the spatial data and index for PSAPs, and another system would contain the spatial data and index for rate zones and similar information. Such splitting allows wider system coverage than if all spatial index and data content of all types had to be stored in a single system.
[0099] Conclusions, Ramifications, and Scope of Invention
[0100] From the above descriptions, figures and narratives, the invention's advantages in supplying spatial area and location identifiers from latitude and longitude inputs should be clear. The invention is easily scalable to databases encompassing continental and global areas without significant impact on system architecture, and without significant degradation of response time. The use of memory-based spatial-index software technology takes advantage of the technology curve of growing memory sizes and capacities and increased memory speeds, thereby amplifying the invention's scalability and insuring its continued high performance. The isolation of the memory-stored database from its relational source database protects the performance of the invention while maintaining its flexibility in handling diverse sources of data and varying database management requirements.
[0101] Although the description, operation and illustrative material above contain many specificities, these specificities should not be construed as limiting the scope of the invention but as merely providing illustrations and examples of some of the preferred embodiments of this invention.
[0102] Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given above.
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An apparatus and method for rapid translation of geographic latitude and longitude into any of a number of application-specific location designations or location classifications, including street address, nearest intersection, PSAP (Public Safety Answering Point) zone, telephone rate zone, franchise zone, or other geographic, administrative, governmental or commercial division of territory. The speed of translation meets call-setup requirements for call-processing applications such as PSAP determination, and meets caller response expectations for caller queries such as the location of the nearest commercial establishment of a given type. To complete its translation process in a timely manner, a memory-stored spatial database is used to eliminate mass-storage accesses during operation, a spatial indexing scheme such as an R-tree over the spatial database is used to locate a caller within a specific rectangular area, and an optimized set of point-in-polygon algorithms is used to narrow the caller's location to a specific zone identified in the database. Additional validation processing is supplied to verify intersections or street addresses returned for a given latitude and longitude. Automatic conversion of latitude-longitude into coordinates in different map projection systems is provided.
The memory-stored database is built in a compact and optimized form from a relational spatial database as required. The R-tree spatial indexing of the memory-stored database allows for substantially unlimited scalability of database size without degradation of response time. Maximum performance for database retrievals is assured by isolating the retrieval process from all updating and maintenance processes. Hot update of the in-memory database is provided without degradation of response time.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a regular National application claiming priority from Provisional Application, U.S. application Ser. No. 60/045,947 filed May 8, 1997.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for treating cerebral vasospasm and/or cerebral ischemia using iron chelators. More particularly, the present invention relates to a method for treating cerebral vasospasm by administering to a patient an iron chelator which is able to cross the blood-brain barrier.
2. Description of Related Art
Although there are several postulated mechanisms for cerebral vasospasm, there is evidence supporting oxyhemoglobin as the principal spasmogen. Furthermore, recent experiments indicate that the binding properties of iron as a catalytic transitional metal play an important role early in the reaction cascade.
During erythrocyte lysis, free iron is released and accumulates in the cerebrospinal fluid (CSF) in the absence of iron binding proteins (e.g., transferrin. Additionally, oxyhemoglobin is released and auto-oxidizes to form methemoglobin and superoxide radicals. Free iron interacts with superoxides in the Fenton reaction and leads to the formation of hydroxyl radicals. Hydroxyl radicals are extremely reactive and initiate several cascade reactions, including lipid peroxidation, that can lead to cellular injury. (Kassell et al, J Neurosurg 73:18-36, 1990)
Limiting the amount of iron available to catalyze the Fenton reaction results in decreased free radical formation. (Al Refaie et al, Blood 80:593-599, 1992) It has been demonstrated that iron chelation with deferoxamine is effective in attenuating vasospasm. (Comair et al, Neurosurgery 32:58-65, 1993; Kontoghiorghes, Indian J Pediatr 60(4):485-507, 1993) Deferoxamine, a chelator of intra- and extracellular iron, is cytoprotective in several models of tissue injury and has been shown to protect against cerebral vasospasm in vivo. (Comair et al, Neurosurgery 32:58-65, 1993; Hamilton et al, Brit J Haem 86:851-857, 1994; Kontoghiorghes et al, Indian J Pediatr 60(4):485-507, 1993) However, although deferoxamine is effective as an iron chelator, it is relatively hydrophilic and thus does not readily cross lipid bilayers. Such hydrophilic compounds are therefore not as effective for treating cerebral vasospasm, because they cannot cross the blood-brain barrier.
Cerebral ischemia, commonly stroke, is one of the largest causes of morbidity and mortality in the United States. In this medical crisis, brain tissue is deprived of blood. In such a situation, the generation of harmful superoxide radicals may be responsible for a significant amount of damage to brain tissue. Effective suppression of these harmful radicals may protect against at least some of the nerve cell damage encountered in stroke patients.
Therefore, in view of the aforementioned deficiencies attendant with prior art methods of treating cerebral vasospasm and cerebral ischemia, it should be apparent that there still exists a need in the art for method for such treatment.
SUMMARY OF THE INVENTION
Accordingly, one object of this invention is to provide a novel material and pharmaceutical composition for treatment of cerebral vasopasm and cerebral ischemia.
With the foregoing and other objects, advantages and features of the invention that will become hereinafter apparent, the nature of the invention may be more clearly understood by reference to the following detailed description of the preferred embodiments of the invention and to the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 is a graphical representation of the mean values of cross-sectional area values of the basilar artery lumen showing the effect of deferiprone on cerebral vasospasm in rabbits.
FIG. 2 depicts representative arterial cross-sections from each of the study groups.
DETAILED DESCRIPTION
The present inventors have now found that iron chelators which are hydrophobic in nature, are able to cross the blood-brain barrier (BBB) and are effective at inhibiting cerebral vasospasm. The issue of BBB penetration is a complex one. Theoretical measurements include the delta-delta value, a measure of the differential solubility in octane and octanol. For simplicity, the lipid-water partition coefficient is employed in this application. A preferred hydrophobic chelator for use in accordance with the present invention is deferiprone. Deferiprone, in contrast to deferoxamine, is highly lipophilic. A variety of similar compounds, developed for other purposes, are known. 21-aminosteriods, such as those set forth in U.S. Pat. No. 4,975,537, may be used in this invention. Deferiprone, (1,2-dimethyl-3-hydroxypyrid-4-one) has a lipid-water partition coefficient 21 times greater than deferoxamine. In general, a chelator effective in this invention should have a lipid-water partition coefficient at least 10 times that of deferoxamine.
The preferred iron chelating compounds to be used in accordance with the method of this invention, as active agents in the pharmaceutical compositions of this invention, are substituted hydroxypyridines. Deferiprone (1,2-dimethyl-3-hydroxypyrid-4-one) has the structure ##STR1## In general, the methyl groups of deferiprone may be substituted for with bulky alkyl groups, particularly to improve lipophilicty. Accordingly, preferred compounds for use in this invention as active agents in the pharmaceutical compositions for administration to those in need of treatment for cerebral vasospasm or cerebral ischemia are compounds of the formula ##STR2## where R 1 and R 2 are independently linear or branched alkyls of 1-12 carbon atoms, preferably 1-6 carbon atoms, or hydrogen, with the proviso that at least one of R 1 and R 2 is not hydrogen. Particularly preferred compounds are those wherein both R 1 and R 2 are alkyl compounds, with further preference being had for substituents such as t-butyl groups. In a preferred embodiment, R 1 is methyl and R 2 is t-butyl.
As used herein, the phrase "pharmaceutically acceptable" refers to molecular entities and compositions that are physiologically tolerable and do not typically produce an allergic or similar untoward reaction, such as gastric upset, dizziness and the like, when administered to a human.
The phrase "therapeutically effective amount" is used herein to mean an amount sufficient to prevent, and preferably reduce a feature or pathology attendant with cerebral vasospasm, such as for example, cross-sectional area of the basilar artery and corrugation of the internal elastic lamina, or to suppress formation of tissue damaging free radicals. Clinical cerebral vasospasm is typically detected functionally as it causes delayed ischemia neurologic deficits (DINDS). It can also be detected by angiography or Doppler measurement of blood velocities.
The active agent of the invention may be prepared in pharmaceutical compositions, with a suitable carrier and at a strength effective for administration by various means to a patient experiencing an adverse medical condition associated with cerebral vasospasm for the treatment thereof. A variety of administrative techniques may be utilized, among them, oral administration, parenteral techniques such as subcutaneous, intravenous and intraperitoneal injections, catheterizations and the like. Average quantities of the iron chelator may vary and in particular should be based upon the recommendations and prescription of a qualified physician or veterinarian.
The preparation of therapeutic compositions which contain active ingredients is well understood in the art. Typically, such compositions are prepared as oral consumables or injectables, either as liquid solutions or suspensions, however, solid forms suitable for solution in, or suspension in, liquid prior to injection can also be prepared. The preparation can also be emulsified. The active therapeutic ingredient is often mixed with excipients which are pharmaceutically acceptable and compatible with the active ingredient. Suitable excipients are, for example, water, saline, dextrose, glycerol, ethanol, or the like and combinations thereof. In addition, if desired, the composition can contain minor amounts of auxiliary substances such as wetting or emulsifying agents, pH buffering agents which enhance the effectiveness of the active ingredient.
The iron chelators can be formulated into the therapeutic composition as neutralized pharmaceutically acceptable salt forms. Pharmaceutically acceptable salts include the acid addition salts and which are formed with inorganic acids such as, for example, hydrochloric or phosphoric acids, or such organic acids as acetic, oxalic, tartaric, mandelic, and the like. Salts formed from the free carboxyl groups can also be derived from inorganic bases such as, for example, sodium, potassium, ammonium, calcium, or ferric hydroxides, and such organic bases as isopropylamine, trimethylamine, 2-ethylamino ethanol, histidine, procaine, and the like.
The therapeutic compositions are conventionally administered intravenously, as by injection of a unit dose, for example. The term "unit dose" when used in reference to a therapeutic composition of the present invention refers to physically discrete units suitable as unitary dosage for humans, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect in association with the required diluent; i.e., carrier, or vehicle. Suitable ranges for a unit dose are 30 to 300 mg/kg, preferably 100 to 200 mg/kg, and more preferably 150 to 200 mg/kg.
The compositions are administered in a manner compatible with the dosage formulation, and in a therapeutically effective amount. The quantity to be administered depends on the subject to be treated, capacity of the subject's immune system to utilize the active ingredient, and degree of iron chelation desired. Precise amounts of active ingredient required to be administered depend on the judgment of the practitioner and are peculiar to each individual. Suitable regimes for initial administration and booster shots are also variable, but are typified by an initial administration followed by repeated doses at one or more hour intervals by a subsequent injection or other administration. Alternatively, continuous intravenous infusion sufficient to maintain concentrations of ten nanomolar to 100 micromolar in the blood are contemplated.
The therapeutic compositions may further include an effective amount of the iron chelator, and one or more of the following active ingredients: an antibiotic, a steroid.
The substituted pyridone deferiprone is an iron chelator that has a partition coefficient 21 times that of deferoxamine. Recent work shows that the cellular uptake of deferiprone is significantly higher than that of deferoxamine. (Berdoukas et al, Lancet 341:1088, 1993) Other studies have shown that deferiprone, unlike deferoxamine, is able to chelate transferrin-derived endosomal iron. (Gale et al, Res Comun Chem Pathol Pharmacol Vol. 73, No. 3, September 1991) Deferiprone's ability to dramatically decrease lipid peroxidation, hydroxyl radical production, and free radical-mediated cell damage has been well documented. (Kamiyama et al, Neurol Med Chir 21:201-209, 1981). A recent paper has also demonstrated that deferiprone can penetrate into both ventricular CSF and cortical brain tissue less than seven minutes after systemic administration. (Asano et al, Wilkins RH (ed) 190-201, 1980)
Additionally, in a clinical setting, deferiprone may act as a neuroprotective agent since oxygen free-radical production has been causally linked to ischemic-mediated neuronal destruction.(Sasaki et al, J Neurosurg 54:357-365, 1981). This assertion is supported by recently published work showing that deferiprone is effective in reducing ischemic damage to canine spinal cord following experimental arterial occlusion.(Reuter et al, J Thorac Cardiovasc Surg 109(5):1017-1019, 1995) In addition, deferiprone may be effective in decreasing the infarct volume in a rat model of temporary focal cerebral ischemic. Accordingly, treatment of both cerebral vasospasm and cerebral ischemia are contemplated within the scope of this invention. As there are no known significant side-effects to the short term administration of the preferred substituted pyridones of this invention, routine "protective" doses of the pharmaceutical compositions may be administered whenever strokes are suspected to have occurred.
Although not intending to be bound by theory, the following lines of evidence support the hypothesis that the protective effect of deferiprone results from the iron-binding capacity of the compound and from the prevention of free radical production: 1) deferiprone's effect is not mediated by a direct vasodilatory action on vessel tone since administration of the compound to non-SAH rabbits (Group 4 in this study) did not produce a change in vessel size; 2) deferiprone's ability to dramatically decrease lipid peroxidation, hydroxyl radical production, and free radical-mediated cell damage has already been established (e.g. Morel et al.), and 3) deferiprone's well-characterized binding properties are very similar to those of deferoxamine and the 21-aminosteroids which have been extensively studied in cerebral vasospasm.(Comair et al, Neurosurgery 32:58-65, 1993; Harada et al, J Neurosurg 77:763-767, 1992; Morel et al, Free Radic Biol Med 13:499-508, 1992; Sano et al, Neurol Res 2:253-272, 1980, Vollmer et al, Neurosurgery 28:27-32, 1991)
Preferred substituted pyridones such as deferiprone are attractive candidates for clinical therapy because of this rapid absorption, high lipid solubility, low incidence of serious side effects, and documented ability to chelate iron and prevent the production of free-radical species. The present findings provide a clear indication that this iron chelator can be of benefit for the treatment of cerebral vasospasm following SAH.
Deferiprone and related compounds have been shown to be safe for administration in humans, with few side effects. (Fassos et al, Clin Pharmacol Ther 55:70-75, 1994; Hider et al, U.K. Patent GB-2118176; Harada et al, J Neurosurg 77:763-767, 1992; Harada et al, J Neurosurg 77:763-767, 1992; Agarwal et al, Br J Haematol 82:460-466, 1992; Kontoghiorghes et al, Ann N Y Acad Sci 34:339-350, 1992) Deferiprone, unlike deferoxamine, has been shown to rapidly penetrate the intracellular environment and to chelate endosomal stores of iron.
Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified.
EXAMPLES
Twenty-eight male New Zealand White rabbits were assigned to one of four groups (Table 1). Rabbits in the subarachnoid hemorrhage (SAH) groups were sacrificed 48 hours after they were subjected to SAH. Group 1 (Control) was not subjected to SAH or administered any treatment (n=8). Group 2 (SAH+placebo) was subjected to SAH and given an oral placebo (n=8). Group 3 (SAH+deferiprone) was subjected to SAH and given oral administration of deferiprone (n=8) while Group 4 (deferiprone only) was not subjected to SAH but was given deferiprone (n=4).
TABLE 1______________________________________ADMINISTRATION SCHEDULE* 0 8 16 24 32 40 48 Observation Period hrs hrs hrs hrs hrs hrs hrs______________________________________Group 1 (Control) F Group 2 (SAH + Placebo) SAH P P P P P F Group 3 (SAH + Deferiprone) SAH D D D D D F Group 4 (Deferiprone Only) D D D D D F______________________________________ *SAH = induction of subarachnoid hemorrhage P = administration of placebo D = administration of 100 mg/kg deferiprone F = sacrifice by perfusionfixation
The techniques utilized for SAH, perfusion-fixation, embedding, and morphometry were performed as described previously (Takahashi et al, Neurosurgery 32(2):281-288, 1993), and are described below.
Deferiprone was synthesized as described previously. (Gale et al, Res Comun Chem Pathol Pharmacol Vol. 73, No. 3, September 1991) An aqueous suspension of 3-hydroxy-2-methyl-pyrone, maltol, (Aldrich Chemical Co., Milwaukee, Wis., 50 gm, 396 nmol) and NH 2 CH 3 (Aldrich Chemical Co., Milwaukee, Wis., 3 eq, 92 ml, 1.18 mol, 12.88 M) in distilled, degassed H 2 O was heated under reflux for 12 hours. The solution was allowed to cool to room temperature. The excess methyl amine was removed under reduced pressure and the brown mixture was carefully concentrated to a volume of approximately 200 ml. Reagent grade acetone (50 ml) was added to this brown suspension and the solid recovered by filtration. The solid was washed with 1200 ml of acetone and briefly allowed to dry. To this crude solid was added 2 g of Norite and 2 g of Celite 545 (fisher Scientific, Pittsburgh, Pa.) and the crude solid was dissolved in a minimal amount of hot water. The Celite/Norite matrix was removed from the solution by filtration. The pure crystalline compound was recovered by filtration to give 29.8 g (54%) of the title compound. All recovery and transfer procedures were performed with a porcelain spatula rather than stainless steel equipment due to the potent iron chelating property of 1,2-dimethyl-3-hydroxypyrid-4-one. Analytically pure 1,2-dimethyl-3-hydroxypyrid-4-one was obtained by a single recrystallization from H 2 O. Other alkyl-substituted pyridones can be prepared by similar measures.
Analytical Data: R f 0.25 (1:1, EtOAC:Pet. Ether); m.p. 269-70° C. uncorrected; 1 H NMR (H 2 O, 300 MHZ) 2.35 (s,3H, vinylic --CH 3 ), 3.71 (s, 3H, N--CH 3 ), 6.49 (d, 1H, vinylic H@C6, J=7.1 Hz), 7.98 (d, 1H, vinylic H@C51, J=7.1 Hz); 13 C NMR (H 2 O, 75 MHZ) 12.25, 42.61, 112.49, 139.38, 142.99, 153.6)
The administration schedule for each of the four experimental groups during the 48 hour study period is shown in Table 1. Deferiprone (100 mg/kg) in gel capsules was administered to Groups 3 and 4 every 8 hours per os. Dosing began 8 hours after SAH in Group 3, and 8 hours after initial observation in Group 4. The last dose was administered at hour 40 of the study period (i.e. 8 hours prior to sacrifice) for a total of 5 doses. Experimental animals in Group 2 (SAH+placebo) were dosed with empty gel capsules using the same administration schedule.
Animals in Groups 2 and 3 were anesthetized with an intramuscular injection of a mixture of ketamine (40 mg/kg) and xylazine (8 mg/kg) and endotracheally intubated. The central ear artery was cannulated to obtain 5 cc of autologous arterial blood. A 23 gauge butterfly needle was inserted percutaneously into the cisterna magna and the 5 cc of autologous blood was injected over a 10 second period. The animals were then positioned with their heads down for 20 minutes to facilitate the settling of blood in the basal cisterns. The animals were monitored closely for respiratory distress and were immediately placed on a ventilator. They remained on the ventilator until spontaneous respiration resumed. The animals were extubated and returned to their cages when fully awake. The animals were given free access to food and water over the next 48 hours and were observed closely for poor feeding or any possible neurological deficits.
Animals were anesthetized at the 48 th hour of the study period as described above; they were then intubated, ventilated and paralyzed with pancuronium bromide (0.3 mg/kg). The central ear artery was cannulated for recording arterial pressure via an arterial line transducer. Arterial blood gas tensions were measured and ventilation parameters adjusted accordingly to maintain arterial pO 2 and pCO within the physiological range. After satisfactory respiratory parameters under anesthesia were established, the thorax was opened and a cannula was placed in the aorta via the left ventricle. The right atrial appendage was opened and the descending thoracic aorta was clamped. The vascular system was perfused with 300 ml of Hanks' balanced salt solution (Sigma Chemical Co., St. Louis, Mo.) (pH 7.4 at 37° C.) followed by 500 ml of 1% paraformaldehyde and 1.5% glutaraldehyde fixative in Hanks' balanced salt solution (pH 7.4 at 37° C.). Perfusion was performed at a pressure of 75 mm Hg in all groups. After perfusion-fixation, the brainstem was removed, placed in the same fixative solution, and stored at 4° C. overnight. Animals that showed incomplete subarachnoid clot, or had residual blood in the vasculature suggesting an inadequate perfusion were excluded from the study at this point.
After fixation, the basilar artery was removed from the brainstem and the proximal third of the vessel was cut into segments 2 mm in length. The tissue samples were washed several times in 0.1 mol/L phosphate buffer, postfixed in 1% osmium tetroxide in 0.1 mol/L phosphate buffer (pH 7.4) for 1 hour at room temperature, and then washed again in phosphate buffer. The tissue was dehydrated through a series of graded ethyl alcohol solutions followed by propylene oxide. The samples were placed into a 1:1 mixture of propylene oxide and epoxy resin overnight, and then flat embedded the next day in 100% epoxy resin and allowed to polymerize at 60° C. for 48 hours. Cross-sections of the basilar artery (0.5 μm thick) were cut on a Reichert Ultracut E ultramicrotome (Vienna, Austria), mounted on glass slides, and stained with toluidine blue for light microscopy.
Morphometric measurements of three randomly selected arterial cross-sections from each animal were performed using the Image 1 Analysis System (Universal Imaging, West Chester, Pa.). Basilar artery cross-sectional area of the basilar artery lumen was measured by an investigator blinded to the treatment groups of the individual arteries. Three measurements were taken from randomly selected cross-sections of each basilar artery. The luminal area for each basilar artery was obtained by averaging these 3 measurements.
A Kruskal-Wallis one-way ANOVA was performed on the entire data set which showed a significance of 0.0048. Direct comparison of treatment groups was performed using a one-tailed Mann-Whitney U test.
One animal from Group 4 (deferiprone only) was found to have residual blood in the cerebral vasculature following perfusion-fixation and was excluded from the study. No animals in any of the treatment groups were observed to have any neurological deficits or to be feeding poorly.
Cross-sectional area values are shown in Table 2 and a graphical representation of the mean values of each group is presented in FIG. 1. Subarachnoid hemorrhage elicited a reduction in vascular area of 54% in the placebo-treated animals (Group 2). In contrast, the reduction in cross-sectional area in animals treated with deferiprone was only 24%; this represents a statistically significant attenuation of the vasospastic response observed in Group 2. It is also noteworthy that although the cross-sectional area of vessels in the SAH+deferiprone group (Group 3) animals was less than that for control animals, this difference did not achieve statistical significance. Finally, the values obtained for animals treated with deferiprone but not subjected to SAH (Group 4) did not differ from the untreated control animals (Group 1).
TABLE 2______________________________________CROSS-SECTIONAL AREA OF BASILAR ARTERIES Group 1: Group 2: Group 3: Group 4: Control SAH + Placebo SAH + Deferiprone Deferiprone Only______________________________________2.832 2.017 1.830 3.100 3.134 0.866 2.818 3.303 3.210 0.808 0.739 2.070 2.918 0.666 2.217 2.542 0.904 2.124 2.181 2.699 1.370 3.166 0.917 2.749 1.746 1.130 2.817 2.72 ± 0.19*# 1.25 ± 0.25# 2.08 ± 0.26 2.82 ±______________________________________ 0.38 All values are expressed in units of 10.sup.5 μm.sup.2. *P < 0.005 compared to Group 2. #P < 0.05 compared to Group 3.
FIG. 2 depicts representative arterial cross-sections from each of the study groups. Vasospasm was evident in Group 2 (SAH+placebo) (FIG. 2B) in which characteristic corrugation of the internal elastic lamina (IEL) was observed. Group 1 (Control) (FIG. 2A) and Group 4 (deferiprone only) did not demonstrate any evidence of vasospasm on histological evaluation. Animals in Group 3 (SAH+deferiprone) (FIG. 2C) showed a variable amount of corrugation of the IEL; in all instances, this corrugation was qualitatively less than that observed in Group 2 (SAH+placebo).
The dosage of deferiprone used in this study was approximately one tenth of the LD50 dosage reported in the literature but was roughly twice the dosage administered to most of the human subjects receiving long-term deferiprone.(Agarwal et al, Br J Haematol 82:460-466, 1992; Berdoukas et al, Lancet 341:1088, 1993; Kontoghiorghes et al, Indian J Pediatr 60(4):485-507, 1993; Kontoghiorghes et al, Clin Pharm Ther 34:255-261, 1990; Tondury et al, Br J Haematol 76:550-553, 1990) Since cerebral vasospasm typically occurs between days 3-21 after SAH with a peak at day 10, deferiprone could be safely administered prophylactically in the clinical setting following the onset of SAH or suspected cerebral ischemia without encountering any of the side effects associated with long-term deferiprone usage.(Kassell et al, J Neurosurg 73:18-36, 1990)
Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention as set forth herein.
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The invention relates to methods for treating cerebral vasospasm induced by hemorrhage or cerebral ischemia, by treating patients with a therapeutically effective amount of a lipophilic iron chelator.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application No. 60/273,181, filed on Mar. 1, 2001.
FIELD OF THE INVENTION
The present invention relates to the field of CXC chemokine receptor antagonists.
BACKGROUND OF THE INVENTION
The CXC chemokines that possess the receptor-signaling glutamic acid-leucine-arginine (ELR) motif (e.g., CXCL1/GROα, CXCL8/IL-8; ref. 1) are important to the influx of inflammatory cells that mediates much of the pathology in multiple settings, including ischemia-reperfusion injury (ref. 2, 3), endotoxemia-induced acute respiratory distress syndrome (ARDS; ref. 4), arthritis, and immune complex-type glomerulonephritis (ref. 5). For instance, inappropriately released hydrolytic enzymes and reactive oxygen species from activated neutrophils initiate and/or perpetuate the pathologic processes. On the other hand, during most bacterial infections this chemokine response represents a critical first line of defense, but even here ELR + CXC chemokine responses can, via their abilities to activate inflammatory cells displaying the CXCR1 and CXCR2 receptors, exacerbate the pathology. For example, during experimental ‘cecal puncture and ligation’ sepsis, neutralization of MIP-2 reduces mouse mortality from 85 to 38% (ref. 6). Infect. Immun. 65:3847–3851). And experimental treatments that eliminate circulating neutrophils ameliorate the pathology of pneumonic mannheimiosis (ref. 7), wherein CXCL8 expression in the airways variably effects the neutrophil chemoattraction (ref. 8, 9). Despite the critical importance of these chemokine responses in many settings, wayward inflammatory cell responses are sufficiently damaging that the development of therapeutic tools with which we can block ELR + chemokines has become a research priority (ref. 10).
The ‘ELR’ chemokines chemoattract and activate inflammatory cells via their CXCR1 and CXCR2 receptors (ref. 1, 11). The CXCR1 is specific for CXCL8 and CXCL6/granulocyte chemotactic protein-2 (GCP-2), while the CXCR2 binds CXCL8 with high affinity, but also macrophage inflammatory protein-2 (MIP-2), CXCL1, CXCL5/ENA-78, and CXCL6 with somewhat lower affinities (see, for example, ref. 10). CXCL8 signaling in cell lines transfected with the human CXCR1 or CXCR2 induces equipotent chemotactic responses (ref. 13, 14), and while neutrophil cytosolic free Ca ++ changes and cellular degranulation in response to CXCL8 are also mediated by both receptors, the respiratory burst and activation of phospholipase D reportedly depend exclusively on the CXCR1 (ref.16). On the other hand, it has been reported that a non-peptide antagonist of the CXCR2, but not the CXCR1, antagonizes CXCL8-mediated neutrophil chemotaxis, but not cellular activation (ref. 17). Finally, there is abundant evidence that chemokines are most often redundantly expressed during inflammatory responses (see, for example, ref. 8). But, despite active research in the field, no CXC chemokine antagonists are known in the prior art that are effective in suppressing adverse inflammatory cell activity induced by either ELR-CXC chemokine receptor.
SUMMARY OF THE INVENTION
Compositions of the present invention include novel ELR-CXC chemokine antagonist proteins that are capable of binding to CXCR1 or CXCR2 receptors in mammalian inflammatory cells. These include antagonists that are capable of high-affinity binding, wherein “high-affinity” refers to the antagonist's affinity for the receptor being at least about one order of magnitude greater than that of the wild-type chemokine agonist. The novel antagonist proteins also include those that are substantially equivalent (that is, those that contain amino acid substitutions, additions and deletions that do not delete the CXCR1 and CXCR2 binding functions) to a wild-type bovine CXCL8 protein (illustrated herein as the amino acid sequence of SEQ ID NO:2) and also bear a truncation of the first two amino acid residues along with substitutions of Lys11 with Arg and Gly31 with Pro. Analogues of this CXCL (3-74) K11R/G31P are also included, namely CXCL (3-74) K11R/G31P/P32G and CXCL (3-74) K11R/T12S/H13F/G31P. In addition, compounds having a three dimensional structure resulting in high affinity binding to CXCR1 or CXCR2 receptors in mammalian inflammatory cells.
Other compositions of the invention are novel polynucleotides and polypeptides relating to these proteins. One such novel polynucleotide is the nucleotide sequence identified herein as SEQ ID NO:4, while one such novel polypeptide is the amino acid sequence identified herein as SEQ ID NO:1. Further, the invention includes vectors comprising the novel polynucleotides, and expression vectors comprising the novel polynucleotides operatively associated with regulatory sequences controlling expression of the polynucleotides. Similarly, gene fusions comprising affinity handles and the novel polynucleotides are included in the invention, as are the resultant vectors and expression vectors containing such gene fusions.
The invention also includes hosts genetically engineered to contain the novel polynucleotides as well as hosts genetically engineered to contain the novel polynucleotides operatively associated with regulatory sequences, that is, associated with regulatory sequences in such a fashion that the regulatory sequences control expression of the novel polynucleotides. Also included are hosts containing gene fusions, either associated with regulatory sequences in such a fashion that the regulatory sequences control the expression of the gene fusions, or in the absence of such regulatory sequences. These hosts may be viruses or cells, wherein the latter include without limitation bacteria, yeast, protozoa, fungi, algae, plant cells, and animal cells and higher organisms derived therefrom.
The invention additionally comprises uses of the novel polypeptides in treating CXC chemokine-mediated pathologies involving the CXCR1 or CXCR2 receptors in mammals. Likewise, the invention includes methods of treating ELR-CXC chemokine-mediated pathologies involving the CXCR1 or CXCR2 receptors, comprising administering to the afflicted mammal an effective amount of one of the novel polypeptides. Pharmaceutical compositions comprising a biologically-active amount of one of the novel polypeptides are also included in the invention.
Finally, methods of producing and purifying the novel polypeptides are also included in the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 . The G31 P analogue of CXCL8 (3-74) K11R is a potent inhibitor of CXCL8-binding to peripheral blood neutrophils. Bovine peripheral blood neutrophils (87–93% purity) were (upper panel) exposed at 4° C. for 2 h to CXCL8 (3-74) K11R analogues (10 ng/ml) or medium (med) alone, then washed and similarly incubated with biotinylated CXCL8 ( biot CXCL8; 1000 ng/ml or 129 nM). These levels of CXCL8 approximate those found in the lung tissues of animals with pneumonic pasteurellosis (ref. 8, 9). The levels of biot CXCL8 binding to the cells were determined using ELISA technology. The depicted amino acid substitutions within CXCL8 (3-74) K11R included: G31P; P32G; T12S/H13P/G31P; and T12S/H13P/G31P/P32G. The G31P, but not the P32G, analogue was a highly effective antagonist of CXCL8 binding to the cells. With both the G31P and P32G analogues, additional substitutions of T12S and H13F reduced their CXCL8 antagonist activities (lower panel). Neutrophils were exposed simultaneously for 45 min at 4° C. to varying concentrations of CXCL8 (3-74) K11R/G31P or unlabeled CXCL8 and 20 pM 125 I-CXCL8. This level of 125 I-CXCL8 was chosen as nearly saturating for the cell's high affinity CXCL8 receptors (data not shown). The levels of cell-associated 125 I-CXCL8 were assessed using a counter. The data clearly indicate that CXCL8 (3-74) K11R/G31P had a substantially higher affinity for the neutrophils than CXCL8.
FIG. 2 . CXCL8 (3-74) K11R/G31P is not an agonist of neutrophil chemoattraction responses or β-glucuronidase release. CXCL8 and the G31P, P32G, or combined G31P/P32G analogues of CXCL8 (3-74) K11R were tested for their neutrophil agonist activities, using freshly purified bovine peripheral blood neutrophils. (upper panel) The chemotactic responses to each protein were tested in 30 min microchemotaxis assays and the results expressed as the mean (+/− SEM) number of cells/40× objective microscope field, as outlined in the methods section. Both the G31P and G31P/P32G analogues displayed little discernable chemotactic activity, while the P32G analogue stimulated substantial responses at 100 ng/ml. (lower panel) The neutrophils were exposed to varying doses of each analogue for 30 min, then the cellular secretion products were assayed for β-glucuronidase using the chromogenic substrate p-nitrophenyl—βD-glucuronide, as presented in the methods section. The total cellular stores of β-glucuronidase were determined from aliquots of cells lysed with Triton-X-100. The enzyme release with each treatment is expressed as the percent of the total cellular stores. None of the analogues had substantial agonist activity, although CXCL8 itself did induce significant enzyme release. The positive control treatment with phorbol-12,13-myristate acetate and calcium ionophore A23187 induced 42+/−6% enzyme release.
FIG. 3 CXCL8 (3-74) K11R-G31P is a highly effective antagonist ELR-CXC chemokine-medicated neutrophil chemoattraction. The ability of CXCL8 (3-74) K11R/G31P to block chemotactic responses of bovine neutrophils to several ELR-CXC chemokines was measured using 20 min microchemotaxis assays. (left panel) The cells were simultaneously exposed to CXCL8 (1 μg/ml) and varying concentrations of the analogue. The number of cells that responded to the CXCL8 was assessed by direct counting of the chemotaxis assay membranes, as in FIG. 2 . CXCL8 (3-74) K11R/G31P was a highly effective competitive inhibitor of the cell's responses to CXCL8. (middle panel) Dose-response curves for chemoattraction of bovine neutrophils by human CXCL1, CXCL5, or CXCL8. Each chemokine displayed a biphasic activity pattern, with maxima at 1–10 ng/ml and at 1 μg/ml. (right panel) The ability of CXCL8 (3-74) K11R/G31P to block the cell's responses to 1 ng/ml of human CXCL5 or CXCL1 or 10 ng/ml of human CXCL8 was assessed as above. CXCL8 (3-74) K11R/G31P effectively antagonized each ELR-CXC chemokine, with complete inhibition being achieved with from 3–20 nM CXCL8 (3-74) K11R/G31P.
FIG. 4 . CXCL8 (3-74) K11R-G31P blocks the activities of CXCL8 and non-CXCL8 chemoattractants expressed within pneumonic airways or in endotoxin-induced mastitis. The effects of monoclonal anti-IL8 antibody 8B6 or CXCL8 (3-74) K11R-G31P on neutrophil responses to the chemoattractants expressed within the airways of animals with pneumonic pasteurellosis or in the mammary cisterns of cattle with endotoxin-induced mastitis were assessed as in FIG. 3 . (A) Diluted (1:10) bronchoalveolar lavage fluids (BALF) from lesional lung lobes of pneumonic cattle (PNEUMONIA) or teat cistern lavage fluids from cattle with mastitis (MASTITIS) were tested as is (none) or after treatment with either anti-CXCL8 MAb 8B6 (5 μg/ml) or CXCL8 (3-74) K11R/G31P (G31P; 1 or 10 ng/ml) for their chemotactic activities compared to medium alone. With both samples, the Mab 8B6 antibodies by themselves neutralized 74% of the chemotactic activities in the samples, while CXCL8 (3-74) K11R/G31P reduced the responses by 93–97%. (B) In order to confirm these results using an alternate strategy, we next absorbed lesional BAL fluids with monoclonal antibody 8B6-immunoaffinity matrices, removing >99% of their content of CXCL8, then tested both their residual chemotactic activities and the ability of CXCL8 (3-74) K11R/G31P to antagonize these residual non-CXCL8 chemotactic activities. There was a dose-dependent inhibition of the total and residual chemotactic activities in the samples, indicating that both CXCL8 and non-CXCL8 chemoattractants are expressed in these lesions.
FIG. 5 . CXCL8 (3-74) K11R-G31P can ablate endotoxin-induced inflammatory responses in vivo. Two week-old Holstein calves were tested for their neutrophilic inflammatory responses to intradermal endotoxin (1 μg/site) challenge before and at various time after intravenous (i.v.), subcutaneous (subcutan.), or intramuscular (i.m.) injection of CXCL8 (3-74) K11R-G31P (75 μg/kg). Fifteen hour endotoxin reaction site biopsies were obtained at 0, 16, 48 and 72 h post-treatment and processed for histopathologic assessment of the neutrophil response, as determined by counting the numbers of neutrophils in nine 40× objective microscope fields per section. (left panel) Photomicrographs of the tissue responses to endotoxin challenge around blood vessels within the reticular dermis prior to (0 h) and 48 h post-treatment. Large numbers of neutrophils accumulated around the vasculature within the reticular dermis in the pre-, but not post-treatment tissues. (B) Graphic presentation of the neutrophil responses to endotoxin challenge either before (0 h) or after (16, 48, 72 h) CXCL8 (3-74) K11R-G31P delivery by each route. ** or ***=p 0.01 or 0.001, respectively, relative to the internal control pretreatment responses.
FIG. 6 Eosinophils purified from the blood of atopic asthmatic or atopic non-asthmatic donors (left panels) or a subject with a hypereosinophilia (right panel) were assessed for their responses to recombinant human CXCL8, CXCL5, or CCL11, in the presence or absence of the indicated doses of recombinant bovine CXCL8 (3-74) K11R/G31P (G31P). Low doses of G31P were able to block the responses of these cells to each of the CXCR1 and CXCR2 ligands, but had no effect on the eosinophil's responses to the unrelated CCR3 ligand CCL11/eotaxin.
FIG. 7 Neutrophils from the peripheral blood of a healthy donor were tested for their responses to recombinant human CXCL8 or CXCL5 in the presence or absence of bovine CXCL8 (3-74) K11R/G31P (G31P; 10 ng/ml). G31P blocked the neutrophil's responses to both ligands.
DETAILED DESCRIPTION OF THE INVENTION
(The following abbreviations are used throughout this disclosure: ARDS, acute respiratory distress syndrome; BALF, bronchoalveolar lavage fluid(s); BHR, Bolton-Hunter Reagent; CXCR1, CXCR2, CXCL8 receptors A, B, respectively; ELR, glutamic acid-lysine-arginine motif; CXCL1, growth-related oncogenealpha; CXCL4, platelet factor-4; CXCL5, epithelial-derived neutrophil activator-78; CXCL6, granulocyte chemotactic protein-2; CXCL8, interleukin-8; fMLP, formyl methionyl-leucylproline bacterial tripeptide; IPTG, isopropyl-thio-D-galactopyranoside; MIP-2, macrophage inflammatory protein-2; PMSF, phenylmethylsulfonyl fluoride; TMB, tetramethylbenzidine.)
When amino terminal truncation of bovine CXCL8 is combined with a lysine to arginine substitution at amino acid 11 (i.e., CXCL8 (3-74) K11R), dramatic increases in CXCR1 and CXCR2 receptor affinity are evident, such that CXCL8 (3-74) K11R competitively inhibits the binding of multiple ligands to both receptors (ref. 24). Further truncation into the receptor-signaling ELR motif (e.g., amino acids 4–6 of human CXCL8) of some CXC chemokines can transform them into mild (CXCL8 (6-72) ) to moderate (CXCL1 (8-73) ) receptor antagonists (ref. 15, 25). As disclosed herein, the introduction into bovine CXCL8 (3-74) K11R of a second amino acid substitution, glycine 31 to a proline residue (i.e., CXCL8 (3-74) K11R/G31P), renders this CXCL8 analogue a very high affinity antagonist of bovine and human ELR-CXC chemokine responses. It fully antagonizes the entire array of ELR-CXC chemokines expressed within bacterial or endotoxin-induced inflammatory foci and blocks endotoxin-induced inflammation in vivo.
Although the following discussion deals primarily with bovine neutrophils, other mammalian (including human) inflammatory cells also display CXCR1 and CXCR2 receptors (see, for example, ref. 52) and so are vulnerable to inhibition by CXCL8 (3-74) K11R/G31P. Accordingly, the present invention has broad applicability to mammalian ELR-CXC chemokine-mediated pathologies.
In an alternate embodiment of the invention, it is envisioned that compounds having the same three dimensional structure at the binding site may be used as antagonists. Three dimensional analysis of chemical structure is used to determine the structure of active sites, including binding sites for chemokines. Chemical leads with high throughput screening have been used to generate and chemically optimize a selective antagonist of the CXCR2 (ref. 17). A similar approach was also used to generate a CCR3 antagonist (ref. 56).
Wells et al (ref. 57), has employed nuclear magnetic resonance spectroscopy (NMR) to detail the three dimensional structure of ligands for CXCR, including both ELR and non-ELR CXC chemokines. With their NMR information, Wells et al generated multiple substitutions within the receptor binding sites of multiple chemokines, such that they could substantially alter the ligands' receptor specificities.
Material and Methods
Reagents & supplies. The following reagents were purchased commercially: glutathione-Sepharose, the expression vector pGEX-2T, Sephadex G-25 (Amersham-Pharmacia-Biotech, Baie d'Urfé, PQ), Bolton-Hunter reagent, a protein biotinylation kit (Pierce Scientific, Rockford, Ill.), the sequencing vector pBluescript II KS, Pfu Turbo™ DNA polymerase (Stratagene, La Jolla, Calif.), a site-directed mutagenesis kit (QuickChange™; Boerhinger-Mannheim Canada, Laval, PQ), aprotinin, benzene, calcium ionophore A23187, chloramine T, cytochalasin B, dimethylformamide, endotoxin ( Escherichia coli lipopolysaccharide, serotype 0127B8), isopropyl-thio-D-galactopyranoside (IPTG), leupeptin, p-nitrophenyl-β-D-glucuronide, mineral oil, silicon oil, tetramethylbenzidine (TMB), phenylmethylsulfonyl fluoride (PMSF), phorbol-12,13-myristate acetate (PMA), and Triton X-100 (Sigma Chemical Co, Mississauga, ON), a Diff-Quick staining kit (American Scientific Products, McGaw Pk, Ill.), human CXCL1, CXCL5, and CXCL8 (R & D Systems Inc, Minneapolis, Minn.), horse radish peroxidase (HRP)-conjugated anti-rabbit Ig (Zymed, South San Francisco, Calif.), DMEM, HBSS (Gibco, Grand Island, N.Y.), HRP-streptavidin (Vector Labs, Burlingame, Calif.), ABTS enzyme substrate (Kirkegaard & Perry Labs, Gaithersburg, Md.), bovine serum albumin (BSA), and Lymphocyte Separation Medium (ICN Pharmaceuticals, Aurora, Ill.).
Generation of CXCL8.sub. (3-74) K11R analogues. The high affinity CXCR1/CXCR2 ligand CXCL8.sub. (3-74) K11R, and its T12S/H13F analogue were generated in accordance with the methods described in Li and Gordon (ref. 24). The Gly31Pro (G31P), Pro32Gly (P32G), and G31P/P32G analogues of these proteins were similarly generated by site-directed mutagenesis using PCR with the appropriate forward and reverse oligonucleotide primers (Table 1). The products from each reaction were digested with DpnI, ligated into the vector pGEX-2T, transfected into HB101 cells, and their sequences verified commercially (Plant Biotechnology Institute, Saskatoon). Briefly, the recombinant bacteria were lysed in the presence of a protease inhibitor cocktail (2 mM PMSF, 2 μg/ml aprotinin, and 2 μg/ml leupeptin) and the recombinant fusion proteins in the supernatants purified by affinity chromatography, using glutathione-Sepharose beads in accordance with the methods of Caswell et al. (ref. 26). The CXCL8 (3-74) K11R analogues were cleaved from the GST fusion proteins by thrombin digestion, dialysed against phosphate buffered saline (PBS), run through commercial endotoxin-removal columns, and then characterized by polyacrylamide gel electrophoresis (PAGE) and Western blotting with a goat anti-bovine CXCL8 antibody (provided by Dr. M. Morsey). Each purified analogue had a molecular mass of 8 kDa, was specifically recognized by the anti-CXCL8 antibody in the Western blotting, and had a relative purity of 96%, as determined by densitometric analysis of the PAGE gels.
Labeling of the recombinant proteins. We used biot CXCL8 for the initial surveys of analogue binding to neutrophils and 125 I-CXCL8 for the later stage assays of relative receptor affinity. CXCL8 was biotinylated and the levels of biotin substitution determined using a commercial kit, as noted in Li and Gordon (ref. 24). The biot CXCL8 was substituted with 2.15 moles of biotin per mole of CXCL8. CXCL8 was radiolabeled with 125 I using the Bolton-Hunter Reagent (BHR) method, as noted in detail (ref. 24). The labeled protein was separated from the unincorporated 125 I-BHR by chromatography on Sephadex G50, and the labeled CXCL8 characterized for its relative affinity for neutrophils and the time required to achieve binding equilibrium, as noted in Li and Gordon (ref. 24). CXCL8 (3-74) K11R analogue binding assays. Cells (85–93% neutrophils) were purified from the blood of cattle in accordance with the Caswell method (ref. 26). In preliminary experiments, we determined that none of our analogues affected the viability of neutrophils, as determined by trypan blue dye exclusion. For the broad analogue surveys, neutrophils in HBSS/0.5% BSA were incubated for 2 h at 4° C. with the analogue, washed in cold DMEM, and then incubated for another 2 h at 4° C. with biot CXCL8 (1000 ng/ml). The cell-associated biotin was detected by incubating the washed cells with alkaline phosphatase-conjugated streptavidin (1:700 dilution) and then with ABTS enzyme substrate. The OD 405 of the samples was determined using an ELISA plate reader. Medium-treated neutrophils routinely bound sufficient .sup.biotCXCL8 to generate an OD 405 of 0.5–0.6.
For the in-depth studies with CXCL8 (3-74) K11R/G31P, we used 125 I-CXCL8 in binding inhibition assays with unlabeled CXCL8 or CXCL8 (3-74) K11R/G31P. In preliminary experiments we determined that the binding equilibrium time of neutrophils for 125 I-CXCL8 was 45 min and that 20 pM 125 I-CXCL8 just saturated the cell's high affinity receptors. Thus, in our assays, 10 6 purified neutrophils were incubated for 45 min on ice with 20 pM 125 I-CXCL8 and varying concentrations of unlabeled competitor ligand. The cells were then sedimented through 6% mineral oil in silicon oil and the levels of cell-associated radio-ligand determined using a counter. The non-specific binding of 125 ICXCL8 to the cells was assessed in each assay by including a 200-fold molar excess of unlabeled ligand in a set of samples. This value was used to calculate the percent specific binding (ref. 27).
Neutrophil β-glucuronidase release assay. The neutrophil β-glucuronidase assay has been reported in detail (ref. 24). Briefly, cytochalasin B-treated neutrophils were incubated for 30 min with the CXCL8 analogues, then their secretion products assayed colorimetrically for the enzyme. β-Glucuronidase release was expressed as the percent of the total cellular content, determined by lysing medium-treated cells with 0.2% (v/v) Triton X- 100. Neutrophil challenge with the positive control stimulus PMA (50 ng/ml) and A23187 (1 μg/ml) induced 42+/−6% release of the total cellular β-glucuronidase stores. Samples from inflammatory lesions. We obtained bronchoalveolar lavage fluids (BALF) from the lungs of cattle (n=4) with diagnosed clinical fibrinopurulent pneumonic mannheimiosis (ref. 8), as well as teat cistern wash fluids from cattle (n=4) with experimental endotoxin-induced mastitis (ref. 28). In preliminary dose-response experiments we determined that 5 μg of endotoxin induced a strong (70–80% maximal) mammary neutrophil response. Thus, in the reported experiments mastitis was induced by infusion of 5 μg of endotoxin or carrier medium alone (saline; 3 ml volumes) into the teat cisterns of nonlactating Holstein dairy cows, and 15 h later the infiltrates were recovered from the cisterns by lavage with 30 ml HBSS. The cells from the BALF and teat cistern wash fluids were sedimented by centrifugation and differential counts performed. Untreated and CXCL8-depleted (below) wash fluids were assessed for their chemokine content by ELISA (CXCL8 only) and chemotaxis assays.
Neutrophil chemotaxis assays. Microchemotaxis assays were run in duplicate modified Boyden microchemotaxis chambers using polyvinylpyrrolidone-free 5 μm pore-size polycarbonate filters, in accordance with known methods (ref. 26, 29). For each sample, the numbers of cells that had migrated into the membranes over 20–30 min were enumerated by direct counting of at least nine 40.times. objective fields, and the results expressed as the mean number of cells/40× field (+/− SEM). The chemoattractants included bovine or human CXCL8, human CXCL5 and CXCL1, pneumonic mannheimiosis BALF and mastitis lavage fluids (diluted 1:10–1:80 in HBSS), while the antagonists comprised mouse anti-ovine CXCL8 antibody 8M6 (generously provided by Dr. P. Wood, CSIRO, Australia) or the CXCL8 (3-74) K11R analogues. In some assays we preincubated the samples with the antibodies (5 μg/ml) for 60 min on ice (ref. 30). In others we generated CXCL8-specific immunoaffinity matrices with the 8M6 antibodies and protein-A-Sepharose beads and used these in excess to absorb the samples (ref. 8, 31); the extent of CXCL8 depletion was confirmed by ELISA of the treated samples. For assays with the recombinant antagonists, the inhibitors were mixed directly with the samples immediately prior to testing.
CXCL8 ELISA. For our ELISA, MAb 8M6 was used as the capture antibody, rabbit antiovine CXCL8 antiserum (also from P. Wood, CSIRO) as the secondary antibody, and HRPconjugated anti-rabbit Ig, and TMB as the detection system, as noted in Caswell et al. (ref. 8). Serial dilutions of each sample were assayed in triplicate, and each assay included a recombinant bovine CXCL8 standard curve.
CXCL8 (3-74) K11R/G31P blockade of endotoxin responses in vivo. We used a sequential series of 15 h skin tests to test the ability of CXCL8 (3-73) K11R/G31P to block endotoxininduced inflammatory responses in vivo. For each test, we challenged 2 week-old healthy Holstein cows intradermally with 1 μg endotoxin in 100 μl saline, then 15 h later took 6 mm punch biopsies under local anaesthesia (lidocaine) and processed these for histopathology (ref. 31). Following the first (internal positive control) test, we injected each animal subcutaneously, intramuscularly, or intravenously with CXCL8 (3-74) K11R/G31P (75 μg/kg) in saline, then challenged them again with endotoxin, as above. The animals were challenged a total of 4 times with endotoxin, such that 15 h reaction site biopsies were obtained at 0, 16, 48, and 72 h post-treatment. The biopsies were processed by routine methods to 6 .mu. paraffin sections, stained with Giemsa solution, and examined in a blinded fashion at 400− magnification (ref. 31, 32). The mean numbers of neutrophils per 40× objective microscope field were determined at three different depths within the skin, the papillary (superficial), intermediate, and reticular (deep) dermis.
Statistical analyses. Multi-group data were analyzed by ANOVA and post-hoc Fisher protected Least Significant Difference (PLSD) testing, while two-group comparisons were made using the students t-test (two-tailed). The results are expressed as the mean +/− SEM.
Results
CXCL8 (3-74) K11R/G31P competitively inhibits CXCL8 binding to neutrophils. We surveyed the ability of each CXCL8 (3-74) K11R analogue to bind to the CXCL8 receptors on neutrophils, and thereby compete with CXCL8 as a ligand. In our initial surveys, we employed biot CXCL8 binding inhibition assays, incubating the cells with the analogues (10 ng/ml) for 2 h at 4° C. prior to exposure to biot CXCL8 (1 μg/ml). This level of CXCL8 approximates those found in the lung tissues of sheep with experimental pneumonic mannheimiosis (ref. 33). We found that CXCL8 (3-74) K11R/G31P was a potent antagonist of CXCL8 binding in this assay ( FIG. 1 ), such that 10 ng/ml of CXCL8 (3-74) K11R/G31P blocked 95% of subsequent biot CXCL8 binding to the cells. When tested at this dose, CXCL8 (3-74) K11R/P32G blocked only 48% of CXCL8 binding, while unlabeled CXCL8 itself competitively inhibited 30% of biot CXCL8 binding. Introduction into CXCL8 (3-74) K11R/G31P or CXCL8 (3-74) K11R/P32G of additional amino acid substitutions at Thr12 and His13 substantially reduced the antagonist activities of the analogues ( FIG. 1 ). This data clearly suggests that pre-incubation of neutrophils with CXCL8 (3-74) K11R/G31P strongly down-regulates subsequent binding of CXCL8.
In order to more finely map the ability of CXCL8 (3-74) K11R/G31 to inhibit the binding of CXCL8, in our next set of experiments we simultaneously exposed the cells to 125 ICXCL8 and varying doses of CXCL8 (3-74) K11R/G31P or unlabeled CXCL8. We found that CXCL8 (3-74) K11R/G31P was about two orders of magnitude more effective than wildtype CXCL8 in inhibiting the binding of 20 pM 125 I-CXCL8 to the cells ( FIG. 1 ). The concentration for inhibiting 50% of labelled ligand binding (IC 50 ) was 120 pM for unlabelled CXCL8, and 4 pM for CXCL8 (3-74) K11R/G31P. This data suggests that CXCL8 (3-74) K11R/G31P is a very potent competitive inhibitor of CXCL8 binding to neutrophils.
CXCL8 (3-74) K11R/G31P does not display neutrophil agonist activities. While CXCL8 (3-74) K11R/G31P was certainly a high affinity ligand for the neutrophil CXCL8 receptors, it would equally well do so as an agonist or an antagonist. Thus our next experiments addressed the potential agonist activities of the CXCL8 (3-74) K11R analogues we generated, as measured by their abilities to chemoattract these cells or induce release of the neutrophil granule hydrolytic enzyme β-glucuronidase in vitro ( FIG. 2 ). We found that even at 100 ng/ml, CXCL8 (3-74) K11R/G31P was a poor chemoattractant, inducing 13.9+/−4% or 5.4+/−2% of the responses induced by 1 or 100 ng/ml CXCL8 (p<0.001), respectively. At 100 ng/ml, the CXCL8 (3-73) K11R/P32G analogue induced a response that was fairly substantial (38.3+/−2% of the CXCL8 response), while the combined CXCL8 (3-74) K11R/G31P/P32G analogue also was not an effective chemoattractant. When we assessed their abilities to induce -glucuronidase release, we found that none of the CXCL8 (3-74) K11R analogues was as effective as CXCL8 in inducing mediator release. Indeed, we found only background release with any of them at 10 ng/ml, and at 100 ng/ml only CXCL8 (3-74) K11R/G31P/P32G induced significant neutrophil responses ( FIG. 2 ). Given the combined CXCL8 competitive inhibition and neutrophil agonist data, from this point on we focused our attention on CXCL8 (3-74) K11R/G31P.
CXCL8 (3-74) K11R/G31P blocks neutrophil chemotactic responses to both CXCR1 and CXCR2 ligands. The most pathogenic effect of inappropriate ELR + chemokine expression is the attraction of inflammatory cells into tissues. Thus, we next assessed the impact of CXCL8 (3-74) K11R/G31P on the chemotactic responses of neutrophils to high doses of CXCL8 ( FIG. 3 ). As predicted from our in vivo observations in sheep and cattle (ref. 33), 1 μg/ml (129 nM) CXCL8 was very strongly chemoattractive, but even very low doses of CXCL8 (3-74) K11R/G31P ameliorated this response. The addition of 12.9 pM CXCL8 (3-74) K11R/G31P reduced the chemotactic response of the cells by 33%. The IC 50 for CXCL8 (3-74) K11R/G31P under these conditions was 0.11 nM, while complete blocking of this CXCL8 response was achieved with 10 nM CXCL8 (3-74) K11R/G31P.
When we tested the efficacy of CXCL8 (3-74) K11R/G31P in blocking responses to more subtle bovine CXCL8 challenges, we also extended the study to assess the ability of CXCL8 (3-74) K11R/G31P to block neutrophil responses to human CXCL8 as well as to the human CXCR2-specific ligands CXCL1 and CXCL5. Each of these is expressed in the affected tissues of pancreatitis (ref. 34) or ARDS (ref. 3) patients at 1–10 ng/ml. We found that bovine neutrophils were responsive to 1 ng/ml hCXCL1 or hCXCL5, and similarly responsive to 10 ng/ml hCXCL8 ( FIG. 3 ), so we employed these doses to test the effects of CXCL8 (3-74) K11R/G31P on neutrophil responses of these ligands. The neutrophil responses to hCXCL1 and hCXCL5 were reduced to 50% by 0.26 and 0.06 nM CXCL8 (3-74) K11R/G31P, respectively, while their responses to hCXCL8 were 50% reduced by 0.04 nM CXCL8 (3-74) K11R/G31P ( FIG. 3 ). This data indicates that CXCL8 (3-74) K11R/G31P can antagonize the actions of multiple members of the ELR-CXC subfamily of chemokines.
CXCL8 (3-74) K11R/G31P is an effective in vitro antagonist of the neutrophil chemokines expressed in bacterial pneumonia or mastitis lesions. We wished to test the extent to which our antagonist could block the array of neutrophil chemoattractants expressed within complex inflammatory environments in vivo. Thus, we chose two diseases in which chemokine-driven neutrophil activation contributes importantly to the progression of the pathology, mastitis and pneumonic mannheimiosis. We utilized an endotoxin model of mastitis (ref. 35), in which we infused 5 μg of endotoxin/teat cistern and 15 h later lavaged each cistern. Neutrophils comprised 82 and 6%, respectively, of the cells from endotoxin and saline-control cisterns, with the bulk of the remaining cells comprising macrophages. The diluted (1:10) wash fluids induced strong in vitro neutrophil chemotactic responses, and the addition of anti-CXCL8 antibodies to the samples maximally reduced these by 73+/−8% ( FIG. 4A ), relative to the medium control. On the other hand, the addition of 1 ng/ml of CXCL8 (3-74) K11R/G31P to the samples reduced their chemotactic activity by 97+/−3%.
Neutrophils also comprised 93+/−12% of the cells recovered from the BALF of cattle with advanced pneumonic mannheimiosis. When tested in vitro, these samples too were strongly chemotactic for neutrophils, and the addition of anti-CXCL8 antibodies maximally reduced their neutrophil chemotactic activities by 73+/−5% ( FIG. 4A ). Treatment of these BALF samples with 1 or 10 ng/ml of CXCL8 (3-74) K11R/G31P reduced the neutrophil responses by 75+/−9 or 93+/−9%, respectively, relative to the medium controls. This data suggests that CXCL8 (3-74) K11R/G31P blocks the actions of CXCL8 and non-CXCL8 chemoattractants in these samples.
In order to confirm these observations using an alternate strategy, we next depleted bacterial pneumonia BALF samples of CXCL8 using immunoaffinity matrices, then assessed the efficacy of CXCL8 (3-74) K11R/G31P in blocking the residual neutrophil chemotactic activities in the samples ( FIG. 4B ). The untreated lesional BALF samples contained 3,215+/−275 pg/ml CXCL8, while the immunoaffmity-absorbed BALF contained 24+/−17 pg/ml CXCL8. In this series of experiments the neutrophil response to the CXCL8-depleted BALF samples was 65.4+/−4% of their responses to the unabsorbed samples. It is known that CXCL8 can contribute as little as 15% of the neutrophil chemotactic activities in pneumonic mannheimiosis BALF obtained from an array of clinical cases (ref. 9). Whereas the CXCL8 depletion treatments were 99% effective in removing CXCL8, there remained in these samples substantial amounts of neutrophil chemotactic activities, and the addition of 1 ng/ml CXCL8 (3-74) K11R/G31P fully abrogated their cumulative effects ( FIG. 4B ). This data unequivocally confirmed that CXCL8 (3-74) K11R/G31P also antagonizes the spectrum of non-IL-8 chemoattractants expressed in these samples.
CXCL8 (3-74) K11R/G31P is highly efficacious in blocking endotoxin-induced neutrophilic inflammation in vivo. In our last experiments, we assessed the ability of CXCL8 (3-74) K11R/G31P to block endotoxin-induced inflammatory responses in the skin of cattle, as well as the time-frames over which it was effective. The animals were challenged intradermally with 1 μg bacterial endotoxin 15 h before (internal positive control response), or at three different times after, intravenous, subcutaneous or intramuscular injection of CXCL8 (3-74) K11R/G31P (75 μg/kg). Thus, punch biopsies of 15 h endotoxin reaction sites were taken 15 min before treatment and at 16, 48 and 72 h after injection of the antagonist into each animal, and the numbers of infiltrating neutrophils were determined in a blinded fashion for the papillary (superficial), intermediate and reticular dermis of each biopsy. Prior to the antagonist treatments, strong neutrophilic inflammatory responses were evident at the endotoxin challenge sites in each animal ( FIG. 5 ). Within the biopsies, the responses in the papillary dermis were mild in all animals (data not shown) and became progressively more marked with increasing skin depth, such that maximal inflammation (neutrophil infiltration) was observed around the blood vessels in the reticular dermis ( FIG. 5A ). Following the CXCL8 (3-74) K11R/G31P treatments, the inflammatory responses observed within the 16 h biopsies were 88–93% suppressed, while those in the 48 h biopsies were 57% (intravenous) to 97% (intradermal) suppressed, relative to their respective pretreatment responses. By 72 h post-treatment the effects of the intravenously administered antagonist had worn off, while the endotoxin responses in the intradermally and subcutaneously treated cattle were still 60% suppressed. This data clearly indicates that CXCL8 (3-74) K11R/G31P is a highly effective antagonist of endotoxin-induced inflammatory responses in vivo, that these effects can last for 2–3 days, and that the route of delivery markedly affects the pharmacokinetics of this novel antagonist.
We have found that G31 antagonizes also the chemotactic effects of the human ELR-CXC chemokines CXCL8/IL-8 and CXCL5/ENA-78 on human neutrophils. Thus, the chemotactic activities of 0.1 to 500 ng/ml of either CXCL8 ( FIG. 6 , left panel) or CXCL5/ENA-78 ( FIG. 6 , right panel) were essentially completely blocked by the addition of 10 ng/ml of our antagonist to the chemotaxis assays. Similarly, G31P blocked the chemotactic effects of CXCL8 for CXCR1/CXCR2-positive eosinophils. We and others have found that eosinophils from atopic or asthmatic subjects express both ELR-CXC chemokine receptors, and are responsive to CXCL8 ( FIG. 7 , left panel). The chemotactic effects of 100 ng/ml CXCL8, but not the CCR3 ligand CCL11/eotaxin, on purified peripheral blood eosinophils of an mildly atopic, non-asthmatic donor (‰99% purity) were completely abrogated by the addition of 10 ng/ml G31P to the chemotaxis assays ( FIG. 7 , middle panel). When tested against purified eosinophils from a hypereosinophilic patient ( FIG. 7 , right panel), G31P was neutralized the responses of these cells to either CXCL8/IL-8 or CXCL5/ENA-78.
This data clearly indicates that bovine G31P is an effective antagonist of the bovine ELR-CXC chemokines expressed in vivo in response to endotoxin challenge, but also can fully antagonize neutrophil and eosinophil ELR-CXC chemokine receptor responses to CXCL8 and CXCL5, known ligands for both the CXCR1 and CXCR2.
TABLE 1
PCR primers employed for the generation of each
CXCL8 analogue.
CXCL8 (3–74)
K11R
upstream primer
downstream primer
ANALOGUE
(5′–3′ orientation)
(5′–3′ orientation)
T12S/H13F
CA GAA CTT CGA TGC
G AA AGG TGT GGA
CAG TGC ATA AGA TCA
AAA TGA TCT TAT GCA
TTT TCC ACA CCT TTC
CTG GCA TCG AAG TTC
C
TG
G31P
GAG AGT TAT TGA GAG
GAT TTC TGA ATT TTC
TCC GCC ACA CTG TGA
ACA GTG TGG CGG ACT
AAA TTC AGA AAT C
CTC AAT AAC TCT C
P32G
GAG AGT TAT TGA GAG
GAT TTC TGA ATT TTC
TGG GGG ACA CTG TGA
ACA GTG TCC CCC ACT
AAA TTC AGA AAT C
CTC AAT AAC TCT C
G31P/P32G
GAG AGT TAT TGA GAG
GAT TTC TGA ATT TTC
TCC GGG ACA CTG TGA
CAC GTG TCC CGG ACT
AAA TTC AGA AAT C
CTC AAT AAC TCT C
DISCUSSION
We demonstrated herein that CXCL8 (3-74) K11R/G31P is a high affinity antagonist of multiple ELR-CXC chemokines. In vitro, this antagonist effectively blocked all of the neutrophil chemotactic activities expressed in mild to intense inflammatory lesions within two mucosal compartments (lungs, mammary glands), and up to 97% blocked endotoxin-induced inflammatory responses in vivo. We identified CXCL8 as a major chemoattractant in the pneumonia and mastitis samples, but also demonstrated that 35% of the activity in the bacterial pneumonia samples was due to non-CXCL8 chemoattractants that were also effectively antagonized by CXCL8 (3-74) K11R/G31P. Based on studies of inflammatory responses in rodents (ref. 18, 19), cattle (ref. 8), and humans (ref. 3), it is clear that these samples could contain numerous ELR + CXC chemokines (e.g., CXCL5, and CXCL8) to which CXCL8 (3-74) K11R/G31P has an antagonistic effect.
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28. Waller, K. P. 1997. Modulation of endotoxin-induced inflammation in the bovine teat using antagonists/inhibitors to leukotrienes, platelet activating factor and interleukin 1 beta. Vet. Immunol. Immunopathol. 57:239–251.
29. Cairns, C. M., J. R. Gordon, F. Li, M. E. Baca-Estrada, T. N. Moyana, and J. Xiang. 2001. Lymphotactin expression by engineered myeloma tumor cells drives tumor regression. Mediation by CD4+ and CD8+ T cells and neutrophils expressing XCR1 receptors. J. Immunol. 167:57–65.
30. Gordon, J. R. 2000. TGFb and TNFa secretion by mast cells stimulated via the FceRI activates fibroblasts for high level production of monocyte chemoattractant protein-1. Cell Immunol. 201:42–49.
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32. Gordon, J. R. 2000. Monocyte chemoattractant protein-1 (MCP-1) expression during cutaneous allergic responses in mice is mast cell-dependent and largely mediates monocyte recruitment. J. Allergy Clin. Immunol. 106:110–116.
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35. Persson, K., I. Larsson, and C. Hallen Sandgren. 1993. Effects of certain inflammatory mediators on bovine neutrophil migration in vivo and in vitro. Vet. Immunol. Immunopathol. 37:99–112.
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45. Jones, S. A., B. Dewald, I. Clark Lewis, and M. Baggiolini. 1997. Chemokine antagonists that discriminate between interleukin-8 receptors. Selective blockers of CXCR2. J. Biol. Chem. 272:16166–16169.
46. Hang, L., B. Frendeus, G. Godaly, and C. Svanborg. 2000. Interleukin-8 receptor knockout mice have subepithelial neutrophil entrapment and renal scarring following acute pyelonephritis. J. Infect. Dis. 182:1738–1748.
47. Saurer, L., P. Reber, T. Schaffner, M. W. Buchler, C. Buri, A. Kappeler, A. Walz, H. Friess, and C. Mueller. 2000. Differential expression of chemokines in normal pancreas and in chronic pancreatitis. Gastroenterol. 118:356–367.
48. Szekanecz, Z., R. M. Strieter, S. L. Kunkel, and A. E. Koch. 1998. Chemokines in rheumatoid arthritis. Springer Semin. Immunopathol. 20:115–132.
49. MacDermott, R. P. 1999. Chemokines in the inflammatory bowel diseases. J .Clin. Immunol. 19:266–272.
50. Damas, J. K., L. Gullestad, T. Ueland, N. O. Solum, S. Simonsen, S. S. Froland, and P. Aukrust. 2000. CXC-chemokines, a new group of cytokines in congestive heart failure—possible role of platelets and monocytes. Cardiovasc. Res. 45:428–436.
51. Morsey, M., Y. Popowych, J. Kowalski, G. Gerlach, D. Godson, M. Campos, and L. Babiuk. 1996. Molecular cloning and expression of bovine interleukin-8. Microbial Pathogen. 20:203–212.
52. Benson, M., I. L. Strannegard, G. Wennergren, and O. Strannegard. 1999. Interleukin-5 and interleukin-8 in relation to eosinophils and neutrophils in nasal fluids from school children with seasonal allergic rhinitis. Pediatr. Allergy Immunol. 10:178–185.
53. Hauser, U., M. Wagenmann, C. Rudack, and C. Bachert. 1997. Specific immunotherapy suppresses IL-8-levels in nasal secretions: A possible explanation for the inhibition of eosinophil migration. Allergol. 20:184–191.
54. Sehmi, R., O. Cromwell, A. J. Wardlaw, R. Moqbel, and A. B. Kay. 1993. Interleukin-8 is a chemoattractant for eosinophils purified from subjects with a blood eosinophilia but not from normal healthy subjects. Clin. Exp. Allergy 23:1027–1036.
55. Ulfinan, L. H., D. P. Joosten, J. A. van der Linden, J. W. Lammers, J. J. Zwaginga, and L. Koenderman. 2001. IL-8 induces a transient arrest of rolling eosinophils on human endothelial cells. J. Immunol. 166:588–595.
56. White JR, Lee JM, Dede K, Imburgia CS, Jurewicz AJ, Chan G, Fornwald JA, Dhanak D, Christmann LT, Darcy MG, Widdowson KL, Foley JJ, Schmidt DB, Sarau HM. 2000. Identification of potent, selective non-peptide CC chemokin receptor-3 antagonist that inhibits eotaxin-, eotaxin-2-, and monocyte chemotactic protein-4-induced eosinophil migration. J. Biol Chem. 275(47):36626-31.
57. Wells TN, Power CA, Lusti-Narasimhan M, Hoogewerf AJ, Cooke RM, Chung CW, Peitsch MC, Proudfoot AE. 1996. Selectivity and antagonism of chemokine receptors. J Leukoc Biol. 59(1):53-60.
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The present invention provides novel nucleic acids, novel polypeptide sequences encoded by these nucleic acids, methods for production thereof, and uses thereof, for a novel ELR-CXC chemokine receptor antagonist.
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This application is a Divisional Application of prior U.S. application Ser. No. 09/729,071 filed on Dec. 4, 2000 now U.S. Pat. No. 6,503,569.
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a novel composition and process for applying a styrenic based adhesive, cement, coating, or paint to thermoplastic polymer surfaces, particularly to toy articles formed of elastomeric materials. Because the coating composition uses naturally occurring terpene solvents, it is safe for use as a coating or paint for toy articles which can be safely used by children.
BACKGROUND OF THE INVENTION
Children's toys and dolls, in particular, have a history dating back into antiquity. Generally, the technology surrounding the manufacture of dolls centers on creation of an attractive doll face, miniturized application of conventional clothes, manufacture of a doll body using plush or other sculptural techniques, and the simulation of the hair with sculptural elements, fibers, or other techniques. In the case of doll faces, the doll maker has a wide panoply of possible constructions and manufacturing techniques at his disposal. Traditional techniques involve the use of plaster-like or hard plastics material to cast a doll face. In time, however, soft rubber materials such as styrene-butadiene rubber (SBR) and styrene-butadiene-styrene block copolymer (Kraton) elastomers have come to replace plaster and hard plastics in the production of doll heads because of their realistic look and feel.
The soft rubber doll faces include all the normal features of a human figure simulated by the doll including the entire head, including well formed lips, teeth, cheeks, nose, chin, ears, and forehead. After the injection molding of an elastomeric doll face, it is finished by applying a dye or other similar material to give the face a natural skin color. Parts of the facial skin are often given a contrasting reddish color to improve the attractiveness of the face, as by using an air brush may be used to apply a patch of rosy hue to the cheeks.
Regardless of the type of paint used on a toy doll article, it has remained imperative that such materials be safe for young children. Safety requirements have evolved through the years as safety concerns have grown. Generally, safety requirements mandate that any material compositions used in a toy be odorless, nonirritating to the skin or eyes or the like, and be nontoxic if ingested. Additional requirements have been expected of materials used to coat or paint toy articles in that they must be non-peeling, requiring that the coating or paint tenaciously adhere to the toy item to avoid flaking or peeling and possible consumption by a child user. Accordingly, such paints should be resistant to oxidation and flaking, particularly as applied to elastomeric rubber surfaces of soft doll faces. And further the paint should be able to withstand the stretching and other physical abuse of a child so that the appearance of the painted surface is maintained. And above all the paint or coating composition must avoid the use of undesirable volatile organic solvents the residual presence of which can be dangerous due to the toxic effect of certain aromatic and chlorinated hydrocarbon solvents.
In view of the environmental, health and safety concerns in the use of organic solvents, less controversial solvents such as water or mineral spirits have been used to provide toy paint or coating compositions. The mineral spirits is less toxic and considered generally safe in coating applications for toys and, of course, water is completely safe and non odiferous as a coating solvent for any coating applications. However both solvents evaporate relatively slowly over a long period of time which detracts from the overall effectiveness of these coating compositions. For example, when applying a water based latex emulsion paint to a soft elastomeric item, a slower evaporation time delays set up of the paint coating composition and inhibits complete bonding between the joined surfaces of the applied coat and the article. As a result of an extended drying period, non-uniform and unstable coatings result leaving these coating vulnerable to use factors which generate peeling and splitting among other negative consequnces.
As indicated above, the class of the styrenic elastomeric materials commonly used to mold doll faces and other toy articles are A-B-A type block polymers such as styrene-butadiene-butylene copolymer-styrene or styrene-butadiene-styrene, manufactured by Shell and sold under the trademark Kraton. The molded polymeric doll faces tend to be dull and unattractive and so are finished by application of a skin coating or paint to provide a good facial appearance to this facial piece. It has now been found that an elastomeric adhesive coating comprising a styrene based resin and a terpene solvent has particular advantages in forming tenaciously bonded adhesive coatings on styrenic resin molded items.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a resin coating composition particulary useful for toy article applications comprising a styrenic copolymer and a terpene solvent. The terpenes are naturally occuring, biodegradable compounds characterized by a very low level release of organic vapor and, accordingly, they are considered safe as solvents for coating or paint applications for toy items. The terpene solvents have also been found particularly effective in solubilizing styrenic copolymers and enhancing the bonding of the copolymers to form adhesive coatings on resinous substrate surfaces. Therefore compositions made in accordance with the present invention are completely non-toxic, environmentally and child safe, and result in an overall superior coating or paint product.
Of particular significance, styrenic copolymer/terpene coating compositions made in accordance with the present invention preliminarily dry in a rapid manner to provide a strong bond with polymeric substrate surfaces thereby engendering consequent use durability to the applied coat or film. The terpene solvent has been found capable of completely solubilizing styrene based resins, styrenic copolymers, pigments or other additives to provide a coating composition having a relatively high solids content up to 20% by weight of the total composition. Therefore while the resinous coating compositions made in accordance with the present invention can be viscous, they can be formulated to be poured and applied by hand, brush or other manipulative means for uniform coating application at ambient temperatures, while comprising a sufficient percentage of solids to avoid shrinkage following evaporation of the solvent.
The discovery of the present invention is that one may formulate a superior adhesive, cement, coating or paint composition by combining a styrenic copolymer and a terpene solvent in certain amounts to form a coating composition of completely unexpected character when applied to elastomeric substrate surfaces. While the coating composition is effective with any thermoplastic resin surface, the instant compositions are especially effective as a coating or adhesive for styrene based elastomers, those copolymers with a linear A-B-A configuration in which A is a polystyrene endblock. It is believed that the terpene solvent is particularly effective in solubilizing the styrene-based copolymer molecules of the substrate surface thereby takifying the elastomeric surface to generate a miscible interface with the applied coat resulting in an amalgam like bonding upon drying. The terpene solvent has been particularly effective with styrene based elastomeric copolymer surfaces having unsaturated block segments such as styrene-ethylene-butylene-styrene (SEBS) surfaces. Consequently the resulting coating is characterized by an exceptional durability, elongation and flexibility. Because the coating compositon employs certain naturally occuring terpene solvents, they are safe for use as paints for children's toys and are particularly useful in applications to the soft elastomeric materials used in doll facial structures where the paint coatings are expected to withstand the rigorous and hostile environment of child use.
The present invention is more particularly directed to a protective or adhesive coating for elastomeric substrates comprising from about 0.1% to 20% by weight of a styrenic copolymer resin and from 80% up to 99.9 weight % of a terpene solvent. A preferred protective or ornamental paint coating composition comprises from about 0.5% to 5% of a styrenic resin selected from the group of styrene butadiene rubber (SBR), styrene-butadiene-styrene (S-B-S), and styrene-ethylene-butylene styrene SEBS elastomeric block copolymers and from 95 to 99.5 wt. % of a terpene solvent. The preferred terpene solvents in the instant coating compositions include a monoterpene or sesquiterpene. This coating composition is found very effective in application to styrenic surface subtrates and particularly, styrene-ethylene-butylene-styrene elastomeric copolymer surfaces. An application of the subject protective or adhesive coating include the steps of (i) providing an elastomeric resin substrate; (ii) applying a composition comprising from about 0.1% to 20.0% by weight of a styrenic copolymer resin and from 80.0% to 99.9 wt. % of a terpene solvent to the elastomeric substrate; and (iii) curing the applied composition to form a layer on the elastomeric substrate.
In yet another embodiment, the instant composition can be formulated as an adhsive or cement to act as a glue when applied to a styrenic elastomeric substrate. A cement, glue, or adhesive compositon comprises from about 5% to 10.0 wt % of the styrenic resin and from 90% to 95 wt % of the terpene solvent. The application of this glue composition include the steps of (i) providing an elastomeric resin substrate surface; (ii) contacting the surface with an effective amount of a composition comprising from about 5% to 10.0% by weight of a styrenic copolymer resin and from 90.0 to 95 wt. % of a terpene solvent; and (iii) curing the applied composition to form an adhesive layer on the elastomeric substrate. Any curing steps in the application of the coating compositions include any means (e.g. heating) for evaporating the terpene solvent or otherwise hardening an applied coating or film of the instant formulation to form a hardened or solid layer on a substrate surface.
The coatings and adhesive compositions herein are characterized by viscosities approaching that of ordinary paint or the more viscous glue formulations. A dried coat of the instant formulations have elongation values and adhesion characteristics conforming to the quality and safety standards necessary for application to toy products. In addition, these coatings or adhesives have ultimate tensile values of greater than about 500 psi indicating that toughness is not being sacrificed to flexibility. It is important that coatings or adhesives used for application to toy articles, such as a soft elastomeric doll facial element, have high tensile strength so that the coated or painted article have child use durability especially as to stretchability. The instant coating and adhesive compositions have flexibility at both ambient and cold temperatures.
Paint application equipment constrains good application of coatings with viscosities that are greater than average paint and surface coating formulations and accordingly the viscosity of the instant compositions for a paint or film coating application have to be controlled by keeping a proper ratio of styrenic resin to terpene solvent. Stringing, nozzle clogging, and inconsistent or poor coating application occurs at high viscosities. A combination of high percent elongation, high adhesion, and low modulus in the instant compositions are shown to have good correlation with excellent lay flat characteristics in a finish coated elastomeric article. The resultant properties of the instant coating and adhesive compositions make them ideally suited for toy paint applications especially where good lay flat character is required.
DETAILED DESCRIPTION OF THE INVENTION
The present composition is the combination of two key ingredients, the styrene based copolymer and the terpene solvent, which synergistically provide for the desirable properties of the instant invention recited above. The instant styrenic based coating composition is characterized by the presence of a terpene solvent that is capable of solubilizing resinous components, particularly styrenic copolymers, to provide a uniform composition for application to elastomeric at ambient temperatures. Terpene compounds that are suitable for this purpose include but are not limited to monoterpenes and sesquiterpene; the monoterpenes include pinashe, both the alpha and beta isomers; gamma terpinene; delta-3-carene; limonene, both the l and d isomers; methadiene; and dipentene (the racemic mixture of the isomers of optically active limonene). A sesquiterpene compound used in the present invention is the general name for the compound having the formula C 15 H 24 . Examples of the sesquiterpene compound include cadinenes, caryophyllene, copaene, alpha-farnesene, humulene, longifolene, thujopsene and ylangene.
Preferred monoterpene and sesquiterpene solvents include d-limonene, l-limonene, dl-limonene, dipentene, terpineol, sesquiterpene, natural extracts such as lemon oil and orange oil containing the above-mentioned terpenes or mixtures thereof. Limonene is a natural product found in various ethereal oils such as oils of lemon, orange, caraway, dill and bergamot and which possesses a citrus-like odor and is found in commercial quantities in citrus fruits. Dipentene is found in large quantities in pine trees and has a distinct pine scent. Among all the listed terpenes, limonene in all forms is preferably used because it has a pleasant mild citrus scent, is color free and is found to enhance the coloring of paint coatings. Optimum coating composition results have been achieved with the isomer d-limonene. Terpene solvents in the practice of the present invention are available commercially from Arizona Chemical Company of Panama City, Fla. under the trademark ACINTENE “LS” series. The terpene may be combined or blended with other safe solvents, such as mineral spirits, to lower the overall solvent emmision or scent character of the composition and to facilitate early set up or curing following application of the coating or adhesive composition. Additionally, any other additive may be used to render the particular terpene satisfactory for use in a particular application. For example, deoderizing or perfuming agents can be used to temper the scent of odiferous terpenes such as pine scented dipentene and render the terpene as usable for toy coating application.
The total amount of solvent provided in the subject coating and adhesive compositions will vary depending on the character of the composition prepared, but will generally range from about 80.0% to 99.9 wt %, but preferably from about 90 to 99 wt % in the case of an adhesive or coating application contemplated herein. For application of a lay flat coating the terpene solvent is preferably present in an amount of from 95% to 99% by weight and as an adhesive or cement application the solvent is present in amounts of from 90.0% to 95% by weight of the total composition. The remainder of the composition comprises a styrenic resinous component in amounts ranging form about 0.1% to 20.0% by weight and preferably ranging from about 1% to 10.0% by weight of the total styrenic resin/terpene solvent composition. As indicated above, optional fillers, gellants, surfactants, pigments, dyes, perfuming agents and other additives may be included.
The resinous component of the present composition is a styrene based thermoplastic elastomer which include blends prepared by the copolymerization of one or more conjugated dienes, such as butadiene, isoprene, and chloroprene with styrene. Useful blends in the preparation of the instant coating and adhesive compositions include styrene butadiene rubber (SBR) and styrene-butadiene-styrene block copolymer. Styrene-based thermoplastic elastomers comprise blocks of hard segments, e.g., polystyrene, and blocks of soft segments, e.g., polyisoprene, polybutadiene, poly(ethylene-propylene), poly(ethylene-butylene), and polypropylene. Thus, useful styrene-based elastomers may comprise, for example, blocks of polystyrene and blocks of polyisoprene, or blocks of polystyrene and blocks of polybutadiene, of blocks of polystyrene and blocks of poly(ethylene-butylene). Examples of styrene based thermoelastic elastomers useful in the present composition, include styrene-ethylene-butylene-styrene block coplymers (e.g. KRATON G-1650, G-1651, G-1652, and G-1657) and styrene-ethylene-propylene block copolymers (e.g. KRATON G-1701, G-1702 and G-1762X), all commercially available from Shell Chemical Company. Combinations of these block copolymers can also be included. Styrene-ethylene-butylene-styrene (SEBS) copolymers are particularly effective because they have superior physical properties manifested in the coatings of the present invention, including durability in that it can withstand prolonged wear and tear in the form of impact resistence and flexibility. Again, the amount of thermoplastic elastomer useful in the present coating and adhesive compositions to achieve the desired characteristics is from about 0.1% to 20 wt % based on the total weight of the styrenic copolymer/terpene solvent composition. The compositional weights recited herein are based on the resin/solvent composition and inclusion of any additives will accordingly affect the overall compositional weight but the ratio of styrenic resin to terpene solvent will remain the same as initially formulated; that is, a 5% by weight styrenic resin in 95 wt % d-limonene will remain in the same ration to one another even with the addition of dye or pigment.
It is to be emphasized that the purview of the compositional invention herein is the combination of a styrene based thermoplastic polymer and a terpene solvent in certain amounts for adhesion or paint application to elastomeric substrate surfaces. As indicated above, especially effective elastomers are styrene-ethylene-butylene-styrene (SEBS) copolymers which are solvated very effectively with a terpene such as d-limonene, the compatibility between the polymer and terpene solvent being speculated as being due to the mutual unsaturation in the terpene and the ethylene-butylene segment of the styrenic polymer. The particular compatibility of the terpene and and the SEBS polymer in the coating composition follows on through application to a solid molded or otherwise formed SEBS substrate surface, which acts as an optimal substrate surface for application of the SEBS/terpene (d-limonene) adhesive or paint coating composition. Accordingly, the most preferred embodiment of this invention is an application of an SEBS/terpene coating to a solid molded SEBS substrate surface.
The instant coating may be applied as a paint and accordingly the composition would contain a pigment, dye, or colorant in amounts of up to 3% by weight in addition to the thermoplastic elastomeric resin and terpene solvent. The pigment used herein is not particularly limited and various inorganic or organic pigments can be employed. Concrete examples of pigments and colorants are: synthetic organic colorants sold as the T-series by the Day Glow Corporation of South Gate City, Calif. Other pigments which can be used include sodium aluminum sulpho silicate sold as MR 582 by the Cleveland Pigment Corp. of Cleveland, Ohio; polyamide condensates with organic dyes with less than 2% phthalocyanine; and tetra-chloro-zincate sold by the Day Glow Corporation.
In reinforcement of the additives mentioned above, compositions made in accordance with the present invention may additionally employ gelling and thickening agents such as ethylene glycol and clay mixtures to provide the desired texture and body for ease of application of the instant coating compositions. In certain coating applications, fillers and stabilizers such as organic and inorganic fibers, sand, talc and mixtures thereof may also be included as part of the coating composition. Compositions of the present invention can be applied by any means such as with a brush, a cloth, or a spray applicator. The surface of a polymeric substrate surface should be clean and dry before application of the instant coating. Once applied the compositions should be allowed a period of at least 30 minutes to allow curing of the composition by drying of the terpene solvent.
Having generally described the present invention, the following examples are set for the below to further demonstrate compositions embodying the present invention. The compositions of the present invention are prepared by adding the specified amount of styrenic resin to the stated amount of terpene solvent under agitaiton. Specified amounts of other ingredients are added where indicated. In the following Example 1, the applied paint composition is subjected to an Eraser Abrasion Test, a Surface Coating Adhesion (Tape Pull) Test, and Stretch Tests to determine the adhesion and stretch characteristics of the present styrenic copolymer/terpene coating composition. These tests are carried out employing standard Quality and Safety Operating Procedures of the Assignee of the present application, Mattel, Inc.
EXAMPLE 1
4 percent by weight of a styrene-ethylene-butylene-styrene (SEBS) copolymer elatomer known as Kraton 1651 is dissolved in a 96 percent by weight of the terpene d-Limonene in a flask. After complete disolution of the styrenic elastomer the viscosity of the solution being slighly greater than water. 1% by weight of a red pigment was added to the paint coating solution with stirring continued until dispersion of the pigment and generation of a red color to the coating (paint) composition. A molded soft elastomeric doll face comprised of a solid molded SEBS elastomeric copolymer was provided and the paint composition applied to the cheek and lip areas of the molded doll face. The rubbery painted doll facial item was allowed to dry for one hour. Thereafter the soft painted rubbery painted doll face was subjected to 1600% Elongation Test and an Eraser Abrasion Test. The tests revealed that the paint coating did not split, peel, or abrade under the tests. The surface bonding between the applied coating and the surface substrate was so strong and uniform so as cause complete adhesion between the styrenic coating and the rubbery elastomeric substrate surface.
EXAMPLE 2
95 percent by weight of the same styrenic thermoplastic elastomer of Example 1 (Kraton 1651) was dissolved in a 4 percent by weight volume of the terpene d-Limonene in a wide mouth beaker. After complete disolution of the styrenic thermoplastic elastomer with difficult stirring the viscosity of the solution was approximate that of a thick glue. Thereafter a rubbery styrenic copolymer substrate surface is provided and a dab of the viscous elastomeric terpene solution is applied to the rubber surface and as separate piece of rubbery material patched onto the dabbed viscous area. After drying for an hour the patched rubber item was found glued tenaciously to the thermoplastic elastomeric substrate surface. Attempts at removal of the patch results in damage to the elastomeric substrate surface.
The adhesive and coating compositions of the present invention possess unique combinations of properties, including both a high degree of elastic durability under suddenly applied stresses, and a high degree of plasticity when the stress is applied more slowly. The miscible character of the styrenic polymer/terpene composition when applied to a molded polystyrene endblocked polymer substrate surface causes an anneal like bonding with that substrate surface so as to form a physically indistinguishable layer with that surface. Accordingly the well bonded compositional layer reacts to the physical stresses applied to the body of the substrate in exactly the same manner as the underlying substrate. Therefore the coating will stretch, strain, and impact as its substrate underlayer and shoe no splitting or peeling. Other properties include excellent stability throughout a very wide temperature range. Most importantly, the applied coatings of these novel compositions are nontoxic and, therefore, coated toy items are safe for use by children of all ages.
Having thus described the principals of the invention, together with illustrative embodiments thereof, it is to be understood that although specific terms are employed, they are used in a generic and descriptive sense and not for the purpose of limitation, the scope of the invention being set forth in the following claims.
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The invention is directed to resin coating, adhesive, and cement compositions comprising styrenic copolymers and a terpene solvent. The compositions are particulary useful for toy article applications because of the use of safe, naturally occuring terpene solvents. These compositions form high adhesion bonding with molded elastomeric styrene copolymer surface substrates. The invention is also directed to a method of applying the instant coatings to substrate surfaces.
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[0001] The present application is a Divisional of U.S. patent application Ser. No. 10/850,514 filed May 21, 2004 which claims the benefit of U.S. Provisional Application Ser. No. 60/546,694, filed Feb. 20, 2004, which applications are incorporated herein in their entirely by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to concealment of pocket pistols, and in particular to altering the profile of a pocket pistol to both alter the outline of a pistol carried in a pocket, and to stabilize the attitude of the pistol in the pocket.
[0003] Off duty and plain clothes law enforcement officers generally carry concealed weapons, and are in some instances required to carry such weapons. When an officer carries a pocket pistol, the outline of the piston may be observable, and either alert a criminal, or create concern among bystanders. Various articles have been developed to address these issues, but none have provided an adequate solution.
[0004] U.S. Pat. No. 4,387,523 for “Wallet Holster for a Semi Automatic Weapon,” describes a wallet shaped holster for providing concealment. Although the wallet holster alters the outline of the pistol, the feel of the grips is lost, and access to the safety, magazine, magazine release, etc. may be reduced.
[0005] U.S. Pat. No. 4,466,537 for “Concealable Holster,” describes a holster similar to the holster of the '523 patent, but is larger and somewhat cumbersome, in addition to having the same disadvantages as the '523 patent.
[0006] U.S. Pat. No. 4,741,465 for “Concealment Pocket Holster,’ and U.S. Pat. No. 3,720,013 for “Handgun Concealing Pouch,” describe pouches for carrying revolvers, which pouches alter the profile to provide concealment. Such pouches further restrict access to safeties, magazines, magazine releases, etc., and are not suitable for pistols.
[0007] Further, pocket pistols are not well suited for aiming with standard sights. An ideal solution is the addition of a laser site such as taught in U.S. Pat. No. 5,581,898 for “Modular Sighting Laser for a Firearm.” Unfortunately, the laser sight described in the '898 patent does not substantially alter the profile of a pistol carried in a pocket, and it interferes with the use of another device used to provide concealment.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention addresses the above and other needs by providing a pistol which is concealed and stabilized by filling in an area below the barrel and in front of the grip with a spacer. The result is a rectangular shape similar to a wallet, which shape conceals the presence of the pistol when carried in a pocket (i.e., de-prints the pistol shape), and stabilizes the pistol in the pocket. The spacer according to the present invention may be attached to a trigger guard, to a portion of the pistol frame beneath the forward end of the barrel, or be integrated with the pistol grips, creating the rectangular shape. The spacer may further include a laser aiming device. In one embodiment, the spacer securely grasps a curved portion of the trigger guard and includes a contoured rear surface which is urged against a lower leading edge of the grip, thus firmly establishing a position for the spacer relative to the pistol.
[0009] In accordance with one aspect of the invention, there is provided a pistol concealment device for a pistol having a barrel assembly, a hand grip, and a trigger guard. The pistol has a first distance extending horizontally from a front of the hand grip to a forward end of the barrel assembly, and a second distance extending vertically from an underside of the barrel assembly to a bottom of the hand grip. The concealment device comprising a spacer and a means for attaching the spacer to the pistol. The spacer has a length approximately equal to the first distance, a height approximately equal to the second distance, and a recessed corner. The recessed corner is positioned around to the trigger to allow access for a trigger finger to pull the trigger. Attachment of the spacer to the pistol results in a substantially rectangular profile.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0010] The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:
[0011] FIG. 1A is front view of a prior art pistol.
[0012] FIG. 1B is a side view of the prior art pistol.
[0013] FIG. 1C is a rear view of the prior art pistol.
[0014] FIG. 1D is a side view of a slide of the prior art pistol.
[0015] FIG. 1E is a side view of a frame of the prior art pistol.
[0016] FIG. 2A shows how the prior art pistol is likely to rest in a pocket.
[0017] FIG. 2B shows how the outline of the prior art pistols appears on the outside of the pocket.
[0018] FIG. 3A is front view of a pistol including a spacer according to the present invention.
[0019] FIG. 3B is side view of the pistol including the spacer according to the present invention.
[0020] FIG. 3C shows how the pistol including the spacer is likely to rest in a pocket.
[0021] FIG. 3D shows how the pistol including the spacer appears on the outside of the pocket.
[0022] FIG. 4A is a front view of the spacer.
[0023] FIG. 4B is a side view of the spacer.
[0024] FIG. 4C is a rear view of the spacer.
[0025] FIG. 4D is a top view of the spacer.
[0026] FIG. 5 is a cross-sectional view of the spacer taken along line 5 - 5 of FIG. 4A .
[0027] FIG. 6A is a front view of the pistol with a second embodiment of the spacer.
[0028] FIG. 6B is a side view of the pistol with the second embodiment of the spacer.
[0029] FIG. 7A is a rear view of the pistol with a third embodiment of the spacer.
[0030] FIG. 7B is a side view of the pistol with the third embodiment of the spacer.
[0031] FIG. 8 describes a method of manufacturing the spacer.
[0032] Corresponding reference characters indicate corresponding components throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0033] The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims.
[0034] A typical prior art pistol 10 is shown in FIG. 1A in front view, and in FIG. 1B is side view. The pistol 10 includes a frame 14 , barrel assembly comprising a barrel 11 and a slide 12 , a grip 20 , a trigger guard 16 , a trigger 18 , and a magazine release 22 . The pistol 10 has a horizontal distance D 2 between the grip 20 and the front of the pistol, and a distance D 2 ′ which is the overall length of the pistol 10 . The pistol 10 has a vertical distance D 1 between the bottom of the barrel assembly and the bottom of grip portion 20 , and a distance D 1 ′ which is the overall height of the pistol 10 . The trigger guard has a width W 1 and a thickness T 1 . The grip portion 20 has a grip front surface 21 . A rear view of the pistol 10 is shown in FIG. 1C . Grips 20 a and 20 b are attached to a grip frame 52 of the frame 14 by grip screws 44 .
[0035] The slide 12 only is shown in side view in FIG. 1D , and the frame 14 only is shown in side view in FIG. 1E . The frame 14 includes the grip frame 52 having grip screw holes 45 .
[0036] Law enforcement officers often carry prior art small pistols (sometimes called pocket pistols) similar to the pistol 10 when off duty, or when in plain clothes. The some cases, it is convenient to carry the pistol 10 in a pocket 24 as shown in FIG. 2A . Unfortunately, the pistol 10 may rest in the position shown in FIG. 2A . making quick access to the pistol 10 difficult. Further, a clear outline 10 ′ may be readily apparent as shown in FIG. 2B , which may cause alarm among those who are unaware that the carrier is a law enforcement officer, or may disclose the presence of the pistol to a criminal.
[0037] A pistol 10 with a spacer 26 according to the present invention is shown in FIG. 3A in front view, and in FIG. 3B in side view. The spacer 26 preferably is constructed of two sides 26 a and 26 b . A laser aiming device 28 may be included in the spacer 26 , and an actuator (or switch) 30 (preferably an electrical switch) is included in the spacer 26 for controlling the laser aiming device 28 . The spacer 26 may be assembled using at least one screw 32 , and preferably two screws 32 . The screws 32 preferable engage nuts held in shaped recesses in the opposite side of the device 26 .
[0038] The spacer 26 fills in the area under the barrel assembly and in front of the grip to create a substantially rectangular outline, that is, there are some small variations due to, for example, the shape of the rear of the pistol 10 , but the overall shape is rectangular. The spacer 26 and the pistol 10 combination defines a trigger opening 33 a overlapping the interior of the trigger guard 16 , allowing a trigger finger to access to the trigger 18 , and a second opening 33 b below the trigger guard 16 allowing at least one finger to grasp the grip portion 20 .
[0039] The pistol 10 with the spacer 26 attached is shown in the pocket 24 in FIG. 3C . Because of the rectangular shape, the pistol 10 with spacer 26 remains in a predictable upright position, and is easily drawn from the pocket 24 if needed. An outline 10 ″ of the pistol 10 with the spacer 26 attached in shown in FIG. 3D , which outline 10 ″ resembles a wallet.
[0040] A front view of the spacer 26 is shown in FIG. 4A , and a side view of the spacer 26 is shown in FIG. 4B . The spacer 26 has a height H and a length L. The height H is approximately equal to the distance D 1 and the length L is substantially equal to the distance D 2 (see FIGS. 1A and 1B ). A recessed corner is shown generally at 19 . The recessed corner 19 is positioned and of sufficient size to provide access for a trigger finger to the trigger 18 when the spacer 26 is attached to the pistol 10 .
[0041] A rear view of the spacer 26 is shown in FIG. 4C , and a top view of the spacer 26 is shown in FIG. 4D . A trigger guard slot 34 is provided in the spacer 26 to allow the spacer to enclose a portion of the trigger guard 16 (see FIG. 1B ), thereby attaching the spacer 26 to the pistol 10 . The trigger guard slot 34 has a width W 2 sized to provide a firm fit to the trigger guard 16 width W 1 (see FIG. 1A ). A contoured surface 35 cooperates with the grip front surface 21 (see FIG. 1B ) to position the spacer 26 on the pistol 10 , wherein assembling the spacer 16 over the trigger guard 16 causes the contoured surface 35 to be urged against the grip front surface 21 . The spacer has a face 27 and a base 25 .
[0042] A cross-sectional view of the spacer 26 taken along line 5 - 5 of FIG. 4A is shown in FIG. 5 . The trigger guard slot 34 is shown to curve down and to the rear substantially matching a curved portion of the trigger guard 16 . The trigger guard slot 34 has a thickness T 2 sufficient to allow the spacer 16 to be assembled over the trigger guard 16 . A laser cavity 29 is provided for positioning the laser aiming device 28 in the spacer 26 . A battery cavity 39 is provided for a battery 38 for powering the laser aiming device 28 . A switch cavity 31 is provided for a switch 30 for turning the laser aiming device 28 on. The switch cavity 31 is located in a portion of the spacer 26 proximal to the grip 20 (see FIG. 1B ) and on a rear surface of the second opening 33 b (see FIG. 3B ). Wires 36 a and 36 b electrically connect the laser aiming device 28 to the battery 38 , through the switch 30 . The wires 36 a , 36 b are preferably thin flat wires, and are preferably bonded to an interior surface of one of the sides 26 a , 26 b.
[0043] Another embodiment of the present invention including horizontal frame rails 41 in front of and above the trigger guard, cooperating with corresponding spacer rails 42 to attach a second spacer 40 to the pistol 10 , is shown in front view in FIG. 6A and in side view in FIG. 6B . One of the screws 32 may be located near the rails 42 , thereby applying gripping force to the cooperation of the rails 41 , 42 .
[0044] Yet another embodiment of the present invention including a spacer 48 having integral grips 50 a and 50 b is shown in FIG. 7A , wherein the spacer 48 is preferably attached to the frame using the grip screw holes 45 (see FIG. 1E ).
[0045] A method for manufacturing a spacer 26 is described in FIG. 8 . A starting set of pistol dimensions are obtained at step 100 . A prototype of the spacer is made based on the starting set of pistol dimensions at step 102 . The prototype device is compared to the pistol at step 104 . If the prototype spacer is not a good fit to the pistol, the dimensions are adjusted if necessary at step 106 . The prototype is modified, or a new prototype is made, based on the adjusted dimensions at step 108 , and the comparison is repeated at 104 . If the prototype spacer is a good fit to the pistol, the prototype dimensions are used to manufacture the spacers 26 at step 110 .
[0046] In a preferred method, the comparison step 104 includes testing the aim of the laser aiming device 28 , and adjusting the dimensions to adjust the aim of the laser aiming device 28 . The laser cavity 28 (see FIG. 5 ) is preferably formed to sight-in the laser aiming device 28 such that at a distance of approximately 21 feet, a laser beam from the laser aiming device 28 will designate a bullet impact point. A preferred method also includes modifying the dimensions by modifying CNC machine code.
[0047] The method described in FIG. 8 is preferred for small to medium production levels. In the case of very high volume production, for example, when the space is included as part of a production pistol, other methods may be preferred, for example, injection molding.
[0048] The spacer 26 may be manufactured to mount to a variety of pistols, for example, the Baretta® Tomcat pistol, the Kel-Tec Inc. model P-32 and P-3AT pistols, the North American Arms® Inc. Guardian .380 pistol, the L. W. Seecamp Company Seecamp 32 pistol, the Rohrbaugh R-9 pistol, and many other pocket pistols. Various embodiments of the present invention are contemplated for these and other pistols, the various embodiments being adapted to individual pistol designs and/or dimensions, and any spacer providing a substantially rectangular profile when attached below the barrel assembly and in front of the grip, is intended to come within the scope of the present invention.
[0049] While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.
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A pistol is concealed and stabilized by filling in an area below the barrel and in front of the grip with a spacer. The result is a rectangular shape similar to a wallet, which shape conceals the presence of the pistol when carried in a pocket (i.e., de-prints the pistol shape), and stabilizes the pistol in the pocket. The spacer may be attached to a trigger guard, to a portion of the pistol frame beneath the forward end of the barrel, or be integrated with the pistol grips, creating the rectangular shape. The spacer may further include a laser aiming device. In one embodiment, the spacer securely grasps a curved portion of the trigger guard and includes a contoured rear surface which is urged against a lower leading edge of the grip, thus firmly establishing a position for the device relative to the pistol.
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CROSS REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims benefit of U.S. Pat. No. 6,889,680 which issued on May 10, 2005, which in turn claimed priority to U.S. Provisional Patent Application No. 60/372,273 filed Apr. 12, 2002, both of which are incorporated herein by reference in its entirety.
FIELD OF INVENTION
[0002] This invention relates to paintball loaders and, more particularly, to a detection system for controlling ball feed in a paintball loader.
BACKGROUND
[0003] Popularity and developments in the paintball industry have led to the demand for increased performance from paintball guns. Paintball gun users usually partake in paintball war games. A paintball war game is generally played between two teams of players that try to capture the opposing team's flag. Each flag is located at the team's home base. Such a game is played on a large field with opposing home bases at each end. The players are each armed with a paintball gun that shoots paintballs. Paintballs are gelatin-covered spherical capsules filled with paint.
[0004] During the game, the players of each team advance toward the opposing team's base in an to attempt to steal the opposing team's flag. The players must do so without first being eliminated from the game by being hit by a paintball shot by an opponent's gun. When a player is hit by a paintball the gelatin capsule ruptures and the paint is splashed onto the player. As a result the player is “marked” and is out of the game.
[0005] These war games have increased in popularity and sophistication resulting in more elaborate equipment. One such improvement is the use of semi-automatic and automatic paintball guns which allow for rapid firing of paintballs. As a result of the increased firing speed, a need has developed for increased storage capacity of paintballs in the paintball loaders that are mounted to the gun. Also, users demand faster feed rates as the guns continue to develop.
[0006] Paintball loaders typically include a housing that sits on an upper portion of a paintball gun and which is designed to hold a large quantity of paintballs. There is an outlet tube at the bottom of the housing through which the paintballs drop by the force of gravity. The paintballs pass into an inlet tube located in the upper portion of the gun.
[0007] In use, paintballs fall sequentially through the outlet tube into the inlet of the gun. The inlet tube directs each paintball into the firing chamber of the gun where the paintball is propelled outwardly from the gun by compressed air. Because existing paintball loaders rely on the force of gravity to feed the paintballs to the gun, they function properly to supply paintballs only if the gun and the loader are held in a substantially upright position. If, during a game, a player is forced to hold the gun sideways or upside down, the loader will not function properly.
[0008] Furthermore, it is not uncommon that, while feeding paintballs to the gun, the paintballs jam in the gun. In order to correct the problem, the player may shake the gun or strike the loader in order to dislodge the jammed paintball. This obviously places the player at risk during the game since the player is distracted by the need to adjust the equipment.
[0009] Currently there are on the market paintball loaders that utilize an optical sensor mounted within the loaders to detect the absence of a paintball in the infeed tube of a paintball gun. When the sensor detects that there is no paintball in the infeed tube of the paintball gun, a motor is activated which causes a paddle to force a paintball into the paintball gun. Other conventional paintball loaders utilize agitators having sound sensors to sense a gun firing event. In response to the sound of the gun firing, an electrical signal is sent to activate an agitator which moves a paintball into the feed tube.
[0010] While recent feed systems are an improvement over the prior feeders, the current feed systems are complicated and costly to manufacture. Such systems may also lead to jamming.
[0011] There is, therefore, a need for a feed mechanism for a feed system that simply and reliably feeds paintballs to a paintball gun at a high rate, while at the same time prevents or reduces the likelihood of paintball jams. There is also a need for a paintball loader which controls the feed motor so as to prolong battery life and reduce undesirable noise.
SUMMARY
[0012] In one aspect, the present invention is a ball feed mechanism for use in a paintball loader. The ball feed mechanism includes a feeder for feeding paintballs. The feeder may be a drive cone, paddle wheel, or indexing belt, which has protrusions, recesses or paddles that convey or impel balls toward a feed neck. The feed mechanism also preferably includes a drive shaft which is concentric with the feeder. The feeder mounts on the drive shaft and is free to rotate about the drive shaft before engaging mechanical stops. The feeder is coupled to the drive shaft through a spring. The spring is configured to store potential energy which is used to rotate the feeder and, thus, drive the balls toward the feed neck. An electric motor is used to rotate the drive shaft to wind or compress the spring.
[0013] In operation the spring is normally compressed so that the spring energy is always available to impel balls toward the feed neck as required. The motor is energized as needed to restore the spring energy (e.g., through compression of the spring). Other resilient members, such as elastomers, may be used in place of the spring.
[0014] The feed mechanism includes an indexing mechanism which includes a sensor, for example, to determine the degree of tension or winding of the spring. In one embodiment, the indexing mechanism accomplishes this by using the sensors to detect rotational movement of the feeder and a drive mechanism (which includes the drive shaft). A controller is in communication with the sensors and determines the relative position of the feed mechanism to the drive mechanism for determining whether the spring requires winding. The relative position of the feeder and drive mechanism can be correlated with the degree of compression/tension of the spring. If the controller determines that the spring requires winding, a motor is activated, causing the drive mechanism to rotate. This, in turn, causes the spring to wind.
[0015] The feed mechanism may alternately include a tensionometer or a strain gauge in communication with a controller. These devices are used to determine the state of deflection of the spring. If the controller determines that additional deflection of the spring is required, the controller will actuate a motor which rotates the drive mechanism and the spindle. The rotation of the spindle, in turn, causes the spring to compress or tension.
[0016] The foregoing and other features of the invention and advantages of the present invention will become more apparent in light of the following detailed description of the preferred embodiments, as illustrated in the accompanying figures. As will be realized, the invention is capable of modifications in various respects, all without departing from the invention. Accordingly, the drawings and the description are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWING(S)
[0017] The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. In the drawings:
[0018] FIG. 1 is a side elevation view of a rapid feed paintball loader constructed in accordance with the teachings of the present invention and operatively attached to a representative paintball gun illustrated in phantom;
[0019] FIG. 2 is an exploded upper isometric view of one embodiment of the loader according to the present invention;
[0020] FIG. 3 is an exploded lower isometric view of the embodiment of the loader shown in FIG. 2 ;
[0021] FIG. 4 is a lower isometric view of the embodiment of the loader shown in FIG. 3 ;
[0022] FIG. 5 is an exploded upper isometric view of a second embodiment of the loader according to the present invention;
[0023] FIG. 6 is a side view of the loader of FIG. 5 ;
[0024] FIG. 7 is a top view of an alternate feeder according to the present invention;
[0025] FIG. 8 is a top view of yet another feeder according to the present invention;
[0026] FIG. 9 is a schematic of a controller according to the present invention; and
[0027] FIG. 10 illustrates a pulley mechanism for driving the drive shaft in accordance with an alternate embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Referring now to the drawings wherein like numerals indicate like elements throughout, FIG. 1 is a side elevation view of paintball loader 40 in accordance with the present invention and operatively attached to a representative paintball gun 20 , illustrated in phantom. The paintball gun 20 , includes a main body 22 , a compressed gas cylinder 24 , a front handgrip 26 , a barrel 28 , and a rear handgrip 30 . The paintball gun 20 also includes an inlet tube 32 , leading to a firing chamber (not shown) in the interior of the main body and a trigger 34 . The front handgrip 26 preferably extends downwardly from the barrel 28 and provides a grip. The compressed gas cylinder 24 is typically secured to a rear portion of the paintball gun 20 . The compressed gas cylinder normally contains CO 2 , NO 2 or air, although other gases may also be used.
[0029] In using the paintball gun 20 , trigger 34 is squeezed, thereby actuating the compressed gas cylinder to release controlled bursts of compressed gas. The bursts of gas are used to eject paintballs outwardly through the barrel 28 . The paintballs are continually fed by the paintball loader 40 through the inlet tube of the firing chamber. The paintball gun depicted in FIG. 1 is an automatic paintball gun, however the gun may also be semi-automatic.
[0030] The paintball loader 40 comprises a paintball container 42 having a container wall 44 forming an interior area 46 . The container has an upper portion 48 and a lower portion 50 . An exit tube 52 leads from the lower portion of the container to an outlet opening 54 . The exit tube is positioned on top of the inlet tube 32 of the paintball gun 20 . A feed mechanism 100 (shown in FIG. 2 ) is used to drive or urge the paintballs toward the exit tube and into the inlet tube 32 .
[0031] FIG. 2 is an exploded isometric view of one embodiment of the feed mechanism 100 according to the present invention. While a preferred feed mechanism 100 is shown, various other components may be substituted therefore for driving paintballs into the paintball gun 20 . The feed mechanism 100 includes a feeder 102 which drives or otherwise conveys paintballs into the exit tube 52 , and a drive mechanism 500 .
[0032] A variety of feeders 102 can be used in the present invention, including an feeder, drive cone, paddle wheel, carrier or other device which can direct or otherwise urge paintballs from the loader into the exit tube 52 . One preferred feeder 102 is shown in the figures and includes a housing 103 with a plurality of fins 104 which preferably extend in a radial direction from the housing 103 . While the fins 104 are shown as being straight, other shapes can be used as will be discussed below. The feeder 102 also preferably includes flanges 105 that extend between adjacent fins 104 . As should be apparent from the drawings, the housing, fins and flanges can be made as a single injection molded part. While fins are shown, the feeder may include recesses within which the paintballs sit as they are shuttled toward the exit tube.
[0033] A cylindrical opening 106 is formed in the center of the housing 103 for receiving a fastener 130 . The fastener 130 is used to engage or mount the feeder 102 to a drive shaft or spindle 108 of the drive mechanism 500 . More particularly, the fastener 130 extends through the opening 106 and threads into a hole formed in the top of the drive shaft 108 .
[0034] Referring now to FIG. 3 , the bottom of the feeder 102 is shown in more detail. The housing 103 includes a first flange 124 which is attached to and projects downward from the housing 103 . In the illustrated embodiment, the first flange 124 is formed integral with the housing 103 . The first flange 124 is designed to engage with a first end of a spring 116 as will be better understood hereafter.
[0035] As shown in FIGS. 3 and 4 , the drive mechanism 500 includes a spring housing 112 which is disposed about the drive shaft 108 and is positioned so as to be below the feeder 102 . The spring housing 112 includes an outer wall 113 and a bottom wall 115 . An inner wall 117 is formed about a central opening 119 . The drive shaft 108 is designed to pass through the central opening 119 and engage with the spring housing 112 such that rotation of the drive shaft 108 produces concomitant rotation of the spring housing 112 . In the illustrated embodiment, a portion of the drive shaft 108 is shown non-cylindrical in shape and the opening 119 is formed with a mating non-cylindrical shape. A spring clip 132 or similar fastener is preferably used to restrain vertical movement of the spring housing 112 on the drive shaft 108 . This is more clearly illustrated in FIG. 4 which shows the spring housing 112 mounted to the drive shaft 108 .
[0036] A second flange 120 is attached to or, more preferably, formed integral with the spring housing 112 . The second flange 120 is configured to engage with a send end of the spring 116 .
[0037] The inner wall 117 and outer wall 113 define a spring chamber 114 within the spring housing 112 . A spring or other biasing member 116 is located within the spring chamber 114 . Although a spring is shown in the figures, it should be readily apparent that other biasing members, such as elastomers, could instead be used. The spring 116 is preferably a torsion spring. A first leg 150 on the first end of the spring 116 is adapted to engage with the first flange 124 on the feeder 102 . A second leg 152 on the second end of the spring is adapted to engage with the second flange 120 on the spring housing 112 . As such, the spring 116 is mounted so as to bias the feeder 102 against rotation relative to the spring housing 112 . In other words, rotation of the spring housing 112 relative to the feeder 102 produces deflection or winding of the spring 116 . When the spring is rotated in the direction which produces winding of the spring, the rotation creates a restoring force (potential energy) in the spring which attempts to counter-rotate the spring housing 112 relative to the feeder 102 . As should be readily apparent, if the feeder 102 is unrestrained, rotation of the spring housing will produce concomitant rotation of the feeder 102 . It is only when there is something which inhibits rotation of the feeder 102 (such as paint balls already in the exit tube) that the spring housing 112 will wind the spring 116 .
[0038] FIG. 4 illustrates the assembled feeder 102 , spring housing 112 , and the drive shaft 108 . The drive shaft 108 projects downward from the spring housing 112 and is adapted to engage with a drive member or gear that is part of the drive mechanism 500 .
[0039] Extending downward from the lower surface of the feeder 102 is at least one and, more preferably, a plurality of spaced apart upper indexing teeth 160 . The upper indexing teeth 160 are preferably spaced in a circular pattern about the bottom of the feeder 102 . As will be discussed below, the upper indexing teeth 160 are used in combination with a sensor to determine the rotational position of the feeder 102 . The indexing teeth 160 are preferably formed integral with or attached to the feeder 102 . While indexing teeth are shown in the illustrated embodiment, other indexing members, such as reflectors, markers, recesses, etc, may be used.
[0040] Referring back to FIGS. 2 and 3 , one embodiment of the drive member 508 is shown. In this embodiment, the drive member 508 is a drive gear includes a plurality of spaced apart gear teeth 503 formed about the periphery of the drive gear 508 . The teeth 503 of the drive gear 508 are adapted to engage with mating teeth on a second gear connected to a motor 99 . While the drive member 508 in the illustrated embodiment is a gear, other types of conventional drive members can be used to produce controlled rotation, such as a pulley mechanism or stepper motor. A pulley mechanism is shown in FIG. 10 . The pulley 508 is engaged to the motor through a belt 99 .
[0041] The drive member 508 also includes at least one and, more preferably, a plurality of lower indexing members 510 formed on the drive gear 508 and preferably on its lower surface. As with the upper indexing teeth 160 , the lower indexing members 510 are used to determine the position of the drive gear 508 and, thus, the spring housing 112 . While the indexing members are shown as protrusions in the illustrated embodiment, other indexing members, such as teeth, reflectors, markers, recesses, etc, may be used.
[0042] The feed mechanism 100 also includes a first indexing sensor positioned below and preferably adjacent to the lower surface of the feeder 102 . The first indexing sensor 504 is located so as to be able to detect or otherwise sense the upper indexing teeth 160 . More particularly, as the feeder 102 rotates around its central axis, the sensor 504 detects the upper indexing teeth 160 as they pass the sensor. The number of passing teeth 160 that is sensed (e.g., over a prescribed period) is used to determine the rotational motion of the feeder 102 . As should be readily apparent, the more upper indexing teeth 160 that are formed on the feeder 102 , the more accurate the position of the feeder 102 can be determined. A signal is sent from the sensor indicative of the sensed number of passing teeth. Alternatively, the sensor 504 may be a ratcheting mechanism that supplies the controller with a signal after the ratchet has rotated a predetermined number of times or amount.
[0043] A second indexing sensor 506 is mounted adjacent to the drive gear 508 so as to be able to detect the passing of the lower indexing members 510 . The rotational motion of the drive gear 508 and, thus, the spring housing 112 , is determined by counting the number of passing lower indexing members 510 . A signal is sent from the sensor indicative of the sensed number of passing teeth. While the illustrated embodiment depicts the sensor and indexing members as being mounted to the drive gear, it should be readily understood that the sensor can be mounted so as to detect rotational motion of the drive shaft.
[0044] Referring to FIG. 9 , the first indexing sensor 504 and second indexing sensor 506 are in communication with a controller 900 , such as a computer or microprocessor (not shown). The controller 900 determines the position of the feeder 102 relative to the drive gear 508 and evaluates whether the spring 116 requires tensioning (winding) or deflection. If the controller 900 determines that the spring 116 requires tensioning, the controller will actuate a motor 950 which is engaged with the drive gear 508 to rotate the drive gear 508 a desired amount. The engagement is preferably through a drive system 960 , such as a gear that meshes with the teeth 503 on the drive gear 508 . Rotation of the drive gear 508 , in turn, rotates the drive shaft 108 and, thus, the spring housing 112 . The rotation of the spring housing 112 relative to the feeder 102 causes the spring 116 to wind, preferably until the second flange 120 meets the first flange 124 .
[0045] During operation, as the feeder 102 advances the paint balls into the gun, the first sensor 504 counts the number of upper indexing teeth 160 that have passed and provides a signal to the controller. The second sensor 506 , likewise, counts the number of lower indexing members 510 that have passed and provides a signal indicative thereof to the controller. It is envisioned that, during firing, the drive gear 508 may not necessarily be moving. Instead, only after the controller 900 detects that the positional location of the feeder 102 relative to the drive gear 508 correlates to a spring that needs “rewinding” would the controller 900 send a signal to the motor 950 to rotate the drive gear 508 . For example, the system may be set such that only after half of the paintballs are dispensed that can be held by the feeder is the motor activated to rotate the drive gear 508 .
[0046] Alternately, the controller 900 can continuously monitor the movement of the feeder 102 and the drive gear 508 . Any movement of the feeder 102 relative to the drive gear 508 can result in the motor rotating the drive gear 508 to rewind the spring. Thus, the gun will always be set to feed the maximum number of balls possible using the feeder.
[0047] The controller 900 may also be programmed to rotate the drive gear 508 a prescribed distance to wind the spring, thus preventing overwinding. The lower indexing members 510 can be tracked through the second sensor 506 to stop the rotation of the drive gear 508 when desired. For example, the controller may be programmed to tension the spring a sufficient amount to feed 10 paintballs into the gun before needing to be rewound. Upon firing of the gun, tension of the spring will feed the 10
[0048] paintballs into the exit tube. The controller determines the number of balls to be fed from the data provided by the first indexing sensor 504 .
[0049] Alternatively, the present invention may utilize only one sensor to detect the movement of the feeder. A motor, such as a stepper motor, can be used to incrementally wind the spring for every detected movement of the feeder. For example, if the spring has a tension sufficient to feed 10 paintballs, for every ball that the sensor detects as being fed by the feeder, the motor will wind the spring by 1/10th of the complete rotation.
[0050] The controller may be used to detect whether there are any paintballs in the exit tube. If the controller 900 determines that there are no paintballs in the tube, that would indicate that the spring is in an unwound condition. Thus, the controller 900 would activate the motor 950 and rewind the spring.
[0051] An alternate embodiment of the sensor mechanism is shown in FIG. 5 . In this embodiment, the first sensor includes a first emitter 602 and a first receiver 604 . The first emitter 602 provides a beam that is reflected by reflectors placed around the periphery of the underside of feed cone 102 . The reflected signal is detected by receiver 604 . Although depicted separately for clarity, the emitter 602 and receiver 604 may be housed in the same unit. The beam may be an infrared (IR) beam. Likewise a second emitter 606 and a second receiver 608 are provided in lieu of second indexing sensor 506 . The second emitter 606 provides a beam that is reflected by reflectors placed around the periphery of the top or underside of drive gear 508 . The reflected beam is detected by second receiver 608 . The emitter 606 and receiver 608 may be housed in the same unit, or mounted separate as shown. The first and second emitters/receivers are in communication with the controller 900 . FIG. 6 illustrates the assembled unit of FIG. 5 .
[0052] The sensing mechanism may instead include a tensionometer or strain gauge 93 (shown in phantom in FIG. 2 ) to determine the tension of the spring. The strain gauge would be in communication with the controller. If the tension in the spring falls below a preselected limit, the controller will actuate the motor which rotates the drive mechanism that in turn rotates the spindle, thereby tensioning the spring.
[0053] Referring to FIGS. 7 and 8 , alternate feeder arrangements are shown. More particularly, FIG. 7 illustrates a feeder 200 which includes two fins 202 . The fins are spaced 180 degrees apart, thus permitting a plurality of balls 206 to be located between adjacent fins 202 . FIG. 8 illustrates a feeder with a plurality of curved fins 302 , each one designed to cup an individual paintball 206 . Those skilled in the art would be readily capable of substituting alternate design configurations for the feeder in order to effect sufficient feeding of the desired number of paint balls.
[0054] The present invention provides a novel system for feeding paintballs from a container. The use of a two sensors permits controlled feeding which is not possible with conventional feeders. The controller in the present invention can be adjusted to minimize use of the motor, thereby conserving battery power. The controller can also be used to accurately track the amount of balls dispensed.
[0055] Furthermore, the controller in the present invention can also be controlled so as to vary the tension and pressure applied to the ball supply. The feed mechanism can include a user input mechanism, such as a dial or pushbuttons, which permits the user to adjust when the drive mechanism re-winds the spring.
[0056] While the potential energy caused by the spring has been described as resulting from winding the spring, it should be readily apparent that a compression spring can be used, in which case the winding of the spring should be understood to refer to a compression of the spring to build up a restoring force or potential energy.
[0057] The present invention may be embodied in other specific forms without departing from the spirit thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention.
[0058] Although preferred embodiments of the sensors have been described and shown in the drawings, those skilled in the art will understand how features from the two embodiments may be combined and interchanged.
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The present invention is directed to a ball feed mechanism for use in a paintball loader. The ball feed mechanism includes a feeder which conveys or impels balls toward a feed neck, and a drive member which is concentric with the feeder. The feeder is coupled to the drive member through a spring. The spring is configured to store potential energy which is used to rotate the feeder and, thus, drive the balls toward the feed neck. An electric motor is used to rotate the drive member to wind the spring. The feed mechanism includes sensors which detect the motion of the feeder and the drive member. A controller determines the spring tension based on the relative motion of the feeder and drive member, and actuates a motor when necessary.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 61/074,170 filed on Jun. 20, 2008, the entire contents of which is expressly incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The invention relates generally to the field of carts, and more specifically, to mobile computer carts and mobile carts used for medication storage and delivery.
BACKGROUND OF THE INVENTION
[0003] With the implementation of strict HIPAA (Health Insurance Portability and Accountability) and JCOAH (Joint Commissions on Accreditation of Healthcare Organizations) requirements at most hospitals, the proper tracking and storage of medications is critical. Unfortunately, however, the healthcare market has not established process standards, and many hospitals have implemented processes that are unrealistic or impossible to enforce, and may also be quite costly to implement.
[0004] For example, some hospitals use very large bulk storage or centrally located medication storage systems, such as the PICIS system, which require a nurse to use small plastic bags for each patient's medications. A nurse may need to make several trips back and forth each day to the medication storage system with the patient's chart to get each patient's medication. At the other end of the spectrum, it is not uncommon to have the nursing staff sign out the medication for several patients at once and place the medications in their pockets as they make their way from one patient room to another. While this may save time for the nurse, there is the possibility of delivering the wrong medication to the patient.
[0005] There is a need then, for a mobile, secure medication storage and delivery cart to simplify the process of beside medication delivery for multiple patients at once. Ideally, such a cart would have a secure compartment with auto-closing and auto-locking features, and a secure means for unlocking the compartment. In addition, these carts are typically used by many different people over the course of a day or a week, and it is thus important that these carts have certain ergonomic features. For example, it is desirable for the user to be able to adjust the height of the cart to place the work surfaces and secure compartment or drawer and computer keyboard and mouse at a convenient and comfortable position. In addition, a medication storage and delivery cart would need a small footprint to accommodate bedside delivery of medications.
[0006] Ergonomic features are also important for mobile computer carts, including those used by the health care market. Many hospitals have converted to paperless processes, which may result in the use of mobile computers for entering and retrieving data. The overall weight of a mobile computer cart, particularly those equipped with a power supply, is an issue for health care administrators. With an average weight of 150 pounds, pushing a mobile cart can be tiring and cumbersome, particularly for smaller users. Many hospitals have reported back issues from users who are required to push a mobile cart all day as part of their job responsibilities.
[0007] In the past, mobile carts have been equipped with four swivel casters, which permit the user to maneuver the cart around corners, or push it out of the way if necessary, but makes the cart difficult to steer. In particular, the momentum of the cart may be a problem if the cart is moved quickly, as the cart may become difficult to stop or turn. In addition, the carts are difficult to push in a straight line, as the four swivel casters may cause the cart to move slightly from side to side as it is pushed, especially if the floors are uneven.
[0008] The maneuverability of a mobile cart can be improved by making two of the four casters ridged or non-swiveling. In this configuration, the mobile cart operates much like a shopping cart, and the user steers the cart by controlling the front end. This is not ideal, however, because it is still difficult to turn tight corners, and nearly impossible to pivot in place.
[0009] There is a need in the art, then, for a mobile cart that is easy to maneuver; a cart that can turn effortlessly and quickly, without a concern that the momentum of the cart will lead the cart astray. In addition, there is a need for a mobile cart that will move in a straight line when pushed, and will self-adjust so that the wheels stay in contact with the floor.
SUMMARY OF THE INVENTION
[0010] The invention provides a mobile cart, and in particular a mobile cart that may be used to carry a computer, monitor or display, a shelf or tray, and/or a secure medication storage compartment. The invention also provides a multi-wheeled base, which may include one or more swiveling wheels and one or more non-swiveling, self-leveling wheels. The mobile cart is also height-adjustable.
[0011] When used as a bedside medication cart, the mobile cart of the invention provides an organized approach to medication storage and delivery. The mobile cart of the invention includes an auto-closing and auto-locking medication storage compartment that can be accessed through an electronic password, or manually via a standard key-operated lock. The mobile cart may also include a computer, monitor or display, or a shelf or tray in addition to, or in place of, the medication storage compartment.
[0012] The wheeled base may include two or four swiveling, lockable, caster wheels, and may also include one or two non-swiveling, self-leveling wheels, which improve the maneuverability of the cart by making it easier to steer and stop. The self-leveling wheels also serve to keep the cart wheels on the floor.
[0013] In preferred embodiments, the invention provides a mobile cart, comprising a rolling base section, an intermediate section that accomplishes a variable length under user control, and an upper working section supported by the intermediate section and comprising a secure storage compartment comprising a normally-locked lid that, when unlocked, must be held open by a user, and when released automatically returns to the closed position and locked state.
[0014] In an aspect, the upper working section further comprises an electrically-operated, normally-locked locking mechanism for the lid. In an additional aspect, the locking mechanism is unlocked under computer control. In yet another aspect, the locking mechanism comprises a solenoid. In another aspect, the secure storage compartment further comprises one or more damped cylinders to allow the lid to close gently.
[0015] In an aspect, the secure storage compartment comprises a plurality of removable containers. In an additional aspect, the intermediate section comprises an adjustable post. In yet another aspect, the base section comprises a plurality of swiveling wheels and at least one non-swiveling wheel. In a further aspect, the base section is generally rectangular in shape, and one swiveling wheel is located proximate each of the corners of the base section.
[0016] In an aspect, the at least one non-swiveling wheel is located on one side of the base section, between two of the swiveling wheels. In another aspect, the at least one non-swiveling wheel is self-leveling. In a further aspect, the cart further comprises a spring assembly removably coupled to the at least one non-swiveling wheel, to accomplish a self-leveling function.
[0017] In additional preferred embodiments, the invention provides a cart comprising a base section having a generally rectangular shape and a bottom, a top, a front, a back, and two opposing sides, and comprising four swiveling wheels mounted to the bottom of the base section proximate each of the four corners of the base section and two non-swiveling wheels mounted to the bottom of the base section, proximate the centers of the sides of the base section, and two non-swiveling wheels mounted to the bottom of the base section, each non-swiveling wheel located between two of the swiveling wheels; an intermediate section comprising an adjustable post; and an upper working section supported by the intermediate section.
[0018] In an aspect, the upper working section further comprises a locking compartment. In another aspect, the upper working section comprises a secure storage compartment comprising a normally-locked lid that, when unlocked, must be held open by a user, and when released automatically returns to the closed position and locked state. In yet another aspect, the upper working section further comprises an electrically-operated, normally-locked locking mechanism for the lid. In an additional aspect, the locking mechanism is unlocked under computer control.
[0019] In additional preferred embodiments, the invention provides a cart comprising a base section having a generally rectangular shape and a bottom, a top, a front, a back, and two opposing sides, and comprising four swiveling wheels mounted to the bottom of the base section proximate each of the four corners of the base section and two non-swiveling wheels mounted to the bottom of the base section, proximate the centers of the sides of the base section, two non-swiveling wheels mounted to the bottom of the base section, each non-swiveling wheel located between two of the swiveling wheels, and a spring assembly removably coupled to the each non-swiveling wheel, to accomplish a self-leveling function; an intermediate section that accomplishes a variable length, under user control; and an upper working section supported by the intermediate section and comprising a secure storage compartment comprising a normally-locked lid that, when unlocked, must be held open by a user, and when released automatically returns to the closed position and locked state, where the locking mechanism is under computer control, and one or more damped cylinders to allow the lid to close gently.
[0020] In an aspect, the upper working section further comprises an electrically-operated locking mechanism. In another aspect, the locking mechanism is unlocked under computer control.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
[0022] FIG. 1 is a perspective view of an embodiment of the inventive rolling cart in the lowest position;
[0023] FIG. 2 is an exploded view of portions of the upper section of the cart of FIG. 1 , including the compartment body of the secure medication storage compartment;
[0024] FIG. 3 shows the top for the secure medication storage compartment of FIGS. 1 and 2 ;
[0025] FIG. 4 is a more detailed view of the compartment body of FIG. 2 ;
[0026] FIG. 5 shows the medication tray of the secure medication storage compartment of FIGS. 1-4 ;
[0027] FIGS. 6A-6C are perspective, front and end views, respectively, of portions of the locking assembly for the secure medication storage compartment of FIGS. 1-5 ;
[0028] FIG. 7 is a perspective view of the upper working section of the cart of FIGS. 1-6 , with the top in the open position;
[0029] FIG. 8 is a view of an alternative embodiment of the rolling base section of the cart of FIG. 1 ;
[0030] FIG. 9 is a rear view of the rolling base section of FIG. 8 ;
[0031] FIG. 10 is a perspective view of the base frame of the base section of FIG. 8 ;
[0032] FIG. 11 is a perspective view of the base frame of FIG. 10 , with the addition of swiveling casters;
[0033] FIG. 12 is a perspective view of the bottom of the base section of FIG. 8 , showing the swiveling casters and the non-swiveling, self-leveling wheels;
[0034] FIG. 13 is a perspective view of the base section of FIG. 8 , showing the covers for the non-swiveling wheels;
[0035] FIG. 14 is an exploded view of the left side non-swiveling wheel assembly of the base section of FIG. 8 ; and
[0036] FIG. 15 is an exploded view of the right side non-swiveling wheel assembly of the base section of FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
[0037] A preferred embodiment of the bedside medication delivery cart of the invention is shown in FIGS. 1-7 . Cart 200 , as shown in FIG. 1 , comprises rolling base section 220 , upper working section 210 , and intermediate section 230 . Intermediate section 230 comprises a length-adjustable upwardly-extending post 232 . Base section 220 and intermediate section 230 can take different forms than shown, as long as they allow the cart 200 to be rolled, and the height of the upper working section 210 to be adjusted, either manually or otherwise. In one embodiment, and as shown in FIG. 1 , base section 220 includes four locking swiveling casters 222 . In alternate embodiments, as shown in FIGS. 8-15 and described below, base section 220 may also include one or two non-swiveling, self-leveling wheels to allow the cart to move in a straight line when pushed, and adjust to different floor conditions.
[0038] With further reference to FIG. 1 , in a preferred embodiment, upper working section 210 includes keyboard support 271 and keyboard 270 , and one or two retractable mouse trays 272 . This arrangement allows user input to a computer (not shown) that is typically carried by the cart, for example by a bracket coupled to upper working section 230 . Computer display 260 is also provided. Upper working section 210 further includes secure medication storage compartment 250 having a compartment body 10 , the construction and functionality of which is further described below. Front projecting handle 50 and rear projecting handle 60 are included to allow the user to easily roll the cart. In alternate embodiments, the mobile cart of the invention may not include a secure medication storage compartment, and upper working section 210 may comprise one or more trays or shelves, and/or may support a monitor or display or computer.
[0039] One of the functional aims of intermediate section 230 is to allow the user to relatively easily move the upper working section 210 between the lowest and highest positions, and any location between the two, and maintain the upper working section 210 at the selected height. The post 232 is designed such that the user can accomplish this by squeezing and holding a front release lever (not shown) that is located near the center of front handle 50 . The operation of the height adjustment can be accomplished in various manners, but does not form part of the invention and so will not be further described herein. In alternate embodiments, intermediate section 230 may have a fixed position and a fixed height.
[0040] Secure medication storage compartment 250 allows medical personnel to securely store and easily transport medications for several patients from room to room. As shown in FIG. 5 , the medications are stored in open-top removable containers or bins 110 . In this embodiment, ten bins 110 fit into medication tray body 104 of medication tray 100 . Bins are not required, and, when used, there is no set quantity or configuration of bins that can be used in the inventive cart.
[0041] With reference to FIGS. 1 , 2 , 3 , and 5 compartment body 10 of storage compartment 250 has front panel 14 and openings 16 a and 16 b for damped cylinders 120 a and 120 b, respectively, which allow hinged top 20 to close gently. When top 20 is open, it must be held open by the user to remain open, and will return automatically to the closed and locked position when released. When top 20 is released, it pivots about a rear hinge (not shown) that is coupled to rear flange 26 and impacts cylinders 120 a and 120 b, which then slowly compress under the weight of the top so that the last portion of the top's closing motion is damped. With reference to FIG. 2 , compartment body 10 may also include an opening 12 that may be used for cable storage, and a power cord catch 70 that may be used to hold the plug end of a power cord when the on-board power supply or battery is not being recharged. With reference to FIG. 4 , an opening encircled by a grommet, preferably plastic, 29 may be provided for routing cables into upper working section 210 .
[0042] Top 20 is automatically locked when it moves from the open position shown in FIG. 7 to the closed position shown in FIG. 1 . With reference to FIGS. 2 , 6 A, 6 B and 6 C, this is accomplished with a normally-locked locking assembly that is carried by bracket 30 which is coupled to front panel 14 . The locking assembly comprises movable catch 36 that sits underneath top fixed locking catch 22 , shown in FIG. 3 , when the top is locked. Catch 22 is coupled to top 20 through mounting holes 24 . Top 20 is unlocked so that it can be manually lifted to expose tray 100 , as follows.
[0043] With reference to FIGS. 6A , 6 B and 6 C, electrically operated solenoid 31 has two stable positions, corresponding to the locked and unlocked states of the top 20 . Solenoid 31 pushes actuator 32 , which pivots arm 33 about pivot points 34 and 39 . This causes catch 36 to move laterally within slot 38 , to release catch 36 from being directly below fixed catch 22 . Top 20 can then be lifted. Also shown in FIGS. 6A , 6 B and 6 C is bushing 35 , which is used to help dampen the sound of arm 33 when it snaps back to the locked position.
[0044] With reference to FIG. 4 , manual locking control is provided by standard key-operated lock 19 with a projection that engages with catch 36 . This allows access or locking should the computer control malfunction. Manual control may be limited to supervisors, so that the computer can accurately monitor the solenoid operation and thus the user-actuated locking/unlocking actions. Also shown in FIG. 4 are spring bumpers 18 a and 18 b, preferably made of steel, which maintain tension on medication tray body 104 .
[0045] In one embodiment, the compartment unlocking operation of solenoid 31 is controlled by the computer that is carried by the cart. A user would be assigned a unique access code to allow solenoid control. The computer could be enabled to track access and unlocking actions by all users, as part of a medication control procedure. Solenoid 31 is driven through a pulse of DC voltage provided over a USB cable from the computer carried by the cart. Once the access code is entered by the user, the pulse is delivered. This pulls the solenoid shut, which unlocks the top cover. After a preset amount of time (which can potentially be selected by the user or whoever sets up the system), which may be from 5 seconds to 5 minutes, another pulse is automatically delivered, which locks the top, if and when it is closed. As shown in FIGS. 6A , 6 B and 6 C, PC board 37 contains the circuitry and connections for cables that drive solenoid 31 . PC board 40 contains status indicating LEDs that indicate battery charge status. Board 40 mounts into enclosure 10 .
[0046] In a preferred embodiment, and as shown in FIGS. 8-15 , the mobile cart of the invention may include a base section with four swiveling casters and one or two non-swiveling, self-leveling wheels. With reference to FIGS. 8 and 9 , base section 800 includes four omni-directional, locking swiveling casters or wheels 810 . Swiveling casters or wheels 810 are preferably four inches in diameter, although alternate configurations, including but not limited to three-inch, six-inch and eight-inch diameter casters are contemplated. Base section 800 also includes cover sections 820 a and 820 b, although in an alternate embodiment, cover sections 820 a and 820 b may be combined into a single unit.
[0047] With reference to FIGS. 10 and 11 , base section 800 comprises a supporting base frame 805 . In a preferred embodiment, base frame 805 is generally rectangular, having a top, a bottom, a front, a back, and two opposing sides. Base frame 805 may also includes brackets 815 for supporting a battery power source carried on the cart.
[0048] FIG. 12 is a bottom view of base section 800 , showing the four omni-directional, locking swiveling casters 810 , the left side non-swiveling wheel assembly 841 , the right side non-swiveling wheel assembly 842 , and the wheel covers 840 . The swiveling casters 810 are rotatably mounted to the bottom of base frame 805 , proximate each of the four corners of the generally rectangular base frame 805 . The non-swiveling wheel assemblies 841 and 842 are also mounted to the bottom of base frame 805 , proximate the centers of each of the sides of the base frame 805 . In an alternate embodiment, base section 800 may include only one non-swiveling wheel assembly, located proximate the center of one of the sides of base frame 805 .
[0049] As shown in FIG. 13 , a spring assembly 850 is used to exert a slight downward pressure on each of the non-swiveling wheel assemblies 841 and 842 , to keep the wheels in contact with the surface of the floor. In a preferred embodiment, each spring assembly 850 comprises a bushing 851 , a spring 852 , a retainer 853 and a screw 854 . Spring 852 is preferably a compression spring, and pushes down on the front end of wheel assemblies 841 and 842 , while the rear end of the wheel assemblies pivots, to keep the wheel assemblies 841 and 842 on the floor.
[0050] With reference to FIGS. 14 and 15 , each wheel assembly 841 and 842 comprises a wheel 843 mounted on a bushing 844 . Left side wheel assembly 841 further includes two plate brackets 861 and 863 , and right side wheel assembly 842 further includes two plate brackets 862 and 864 .
[0051] The claims should not be read as limited to the described order or elements unless stated to that effect. Therefore, all embodiments that come within the scope and spirit of the following claims and equivalents thereto are claimed as the invention.
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A mobile cart that may be used to carry a computer and/or a secure medication storage compartment. The mobile cart includes a multi-wheeled base, which may include two or more omni-directional, locking swivel casters and one or more non-swiveling, self-leveling wheels. The mobile cart is also height-adjustable. When used as a bedside medication cart, the mobile cart includes an auto-closing and auto-locking medication storage compartment that can be accessed through an electronic password, or manually via a standard key-operated lock. The mobile cart may also include a computer in addition to, or in place of, the medication storage compartment.
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This is a continuation-in-part of U.S. Ser. No.: 10/444,559, now U.S. Pat. No. 6,827,873, filed May 23, 2003 (Granted Dec. 7, 2004) which is a continuation of U.S. Ser. No.: 10/260,808, now U.S. Pat. No. 6,582,622, filed Sep. 30, 2002 (Granted Jun. 24, 2003), which is a continuation-in-part of U.S. Ser. No.: 10/212,319, now U.S. Pat. No. 6,596,188, filed Aug. 5, 2002 (Granted Jul. 22, 2003), and a continuation-in-part of U.S. Ser. No.: 10/212,318, now U.S. Pat. No. 6,599,440, filed Aug. 5, 2002 (Granted Jul. 29, 2003), which both are a continuation-in-part of application U.S. Ser. No. 09/971,163 now U.S. Pat. No. 6,440,325 and U.S. Ser. No. 09/971,165 now U.S. Pat. No. 6,436,310 both filed on Oct. 4, 2001 (Granted Aug. 27, 2002 and Aug. 20, 2002, respectively), which are both a continuation-in-part of U.S. Ser. No. 09/755,587, now U.S. Pat. No. 6,299,793, filed Jan. 5, 2001 (Granted Oct. 9, 2001), which is a continuation-in-part application of U.S. Ser. No. 09/224,906 filed on Jan. 4, 1999, now abandoned and U.S. Ser. No.: 60/070,636 filed Jan. 7, 1998, the entirety of each of the above applications which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The current state of the art for coping with snow and ice on roads usually involves applying a deicer material such as a salt to the road surface. Sometimes antiskid materials such as sand or other aggregates such as gravel are added with or without a salt.
The use of salt and compositions having high concentrations of salt, cause an undesirable corrosive effect on vehicles, the road surface, and the environment with respect to the run off of water containing salt which contaminates the surrounding land and water.
Considering the above problems associated with salt formulations, there has been a continuing need for a deicing composition or formulation which can be easily applied to effectively melt snow and ice yet which reduces the corrosion and environmental contamination referred to above. In response to the above problems associated with the use of road salt, the prior art has looked to alternative formulations which are less corrosive and more environmentally friendly.
U.S. Pat. No. 5,922,240 (Johnson et al.) relates to a deicing composition comprising brewers' condensed solubles produced, for example, as by-products from a commercial beer brewing process, which by-products are biodegradable. The invention also relates to the use of a deicing composition to reduce the buildup of snow and ice on road, bridges and other outdoor surfaces.
U.S. Pat. No. 5,635,101 (Janke et al.) relates to a deicing composition containing a by-product of a wet milling process of shelled corn. Corn kernels are steeped or soaked in a hot solution containing small amounts of sulfurous acid. The corn kernels are separated from the steep water and the corn steepwater solubles are used in the production of a deicing composition.
U.S. Pat. No. 4,676,918 (Toth et al.) relates to a deicing composition which comprises a mixture containing at least one component selected from a number of chlorides or urea and an admixture of waste concentrate of alcohol distilling that has a dry substance content of from 200 to 750 g/kg and from 10% to 80% by weight of water.
U.S. Pat. No. 6,299,793 (Hartley et al.) utilizes a concentration of low molecular weight carbohydrates to produce a synergistic effect on the freezing point and ice/snow melting characteristics of chloride containing liquid deicers.
In some cases, the above described formulations appear to have low viscosities and poor adhering characteristics and when applied to salt and sand piles, the material will run off and not remain in its intended location on and in the salt/sand pile. Formulations exhibiting this problem also exhibited a tendency to run off when applied directly to roadway surfaces.
To improve quality and performance, and to meet current mandated standards, there has been a continuing need for a source of deicing formulations which exhibit improved performance with respect to their use and application and which also exhibit reduced metal corrosion, spalling of concrete, toxicity and address environmental concerns.
It is therefore an object of the present invention to provide a deicing formulation which exhibits improved performance standards which overcome the prior art problems described above.
It is a further object of the present invention to provide a deicing formulation which exhibits an improved viscosity profile.
It is another object of the present invention to provide a deicing formulation which exhibits increased stickiness when applied to salt piles and roadway surfaces and the like.
It is a further object of the present invention to provide a deicing formulation which provides consistent physical and chemical properties, thereby assuring consistent quality and performance.
It is another object of the present invention to provide an economical, highly effective deicing formulation which can be efficiently and effectively applied to salt piles and roadway surfaces and the like.
SUMMARY OF THE INVENTION
The present invention relates to deicer formulations and comprises an aqueous solution containing any one of a number of agricultural residuals and a freezing point depressant such as a chloride salt. Suitable agricultural materials include brewers condensed solubles (BCS), distillers condensed solubles (DCS), and condensed corn steep liquor (CCSL). A preferred formulation utilizes a carbohydrate in a carefully controlled molecular weight range of about 180–1500 (more preferably 180–1000) in place of the agricultural residuals described above. It has been discovered that a preferred viscosity profile and the desired stickiness of these formulations for optimum application in use can be obtained by the addition of small, but critical amount of lignosulfonate. It has been found that lignosulfonate in a range of about 5 to 10% by weight is sufficient to impart the desired degree of stickiness. The improvement in viscosity and stickiness is obtained without changing the deicing properties of these formulations. The addition of the lignosulfonate provides the desired viscosity control and stickiness without the addition of significant amounts of viscosity modifiers such as high molecular weight carbohydrate and cellulose derivatives.
The deicer formulation of the present invention also functions to prevent the cementing together of sand, sand/salt, salt, aggregates, aggregates/salt etc when stored in piles. Ice crystals act as cement/adhesive and cause the formation of large masses of very hard, rock like substances. It becomes very difficult to break down these masses into a small size so that the normal application onto roads can be achieved. These problems are largely overcome by spraying the salt pile with the liquid deicer in an amount sufficient to form a liquid coating of the surface of the salt particles.
DETAILED DESCRIPTION OF THE INVENTION
Lignosulfonate is a metallic sulfonate salt made from the lignin of sulfite pulp-mill liquors, having a molecular weight range of about 1000–20,000.
In the present invention the lignosulfonate may be in the form of ammonium lignosulfonate, sodium lignosulfontate, and the mixed salt sodium/ammonium lignosulfonate.
In the development of the present invention, four fully formulated deicer solutions were investigated. Three formulations included various corn syrups while the fourth included distillers condensed solubles (DCS). The formulations appeared to have low viscosities and poor adhering characteristics and when applied to salt and sand piles, the material will run off and not remain in its intended location on and in the salt/sand pile. The objective was to evaluate the use of a number of additives to one of the formulations (DCS) to thicken the solution and lessen run off without changing the deicing properties of the formulations.
Known weights of the selected powdered or liquid thickeners were added to 10 ml samples of the DCS formulation. The solutions were mixed using a vortex mixer to fully dissolve the materials. The mixing in most cases caused the formation of foam that required 24 hours in some cases to dissipate.
The samples were evaluated at room temperature for signs of an increase in thickness by inverting the tubes and observing the time required for the liquid coating to run off the walls of the container. When increased thickness was suspected, the solution was again evaluated by comparing the time required for the treated liquid to run off a microscope slide dipped in the solution to the time required for the same untreated solution to run off a dipped microscope slide. Some test solutions were placed at 5 and −20° C. to further evaluate increases in thickness as temperature decreases.
In addition, stickiness and slipperiness was assessed by dipping a microscope slide in the treated test solution and touching the wet area with a gloved finger and pulling away slowly. Stickiness was observed by looking for a film of the liquid to pull away from the slide and the glove, and then break. Slipperiness was checked when gel globules were present in the test solutions by holding the wet microscope slide between the thumb and fore finger and rubbing them back and forth and comparing the result with the original formulation without added thickener.
The following six additives were tested with two Spanish DCS and one BCS compositions under the conditions outlined above and in various concentrations and with the results set forth below.
Xanthan Gum. ADM Industrial Dispersible Xanthan Gum, product code 174960 lot 02XG127 was added to the three test solutions at concentrations of 0.2, 0.4 and 1.0% by weight, respectively. Initially the material floats on the surface of the solution and requires vigorous mixing using a vortex mixer to dissolve the material. Mixing causes the formation of significant amounts of foam that requires 24 hours to disperse before the effect of the gum addition can be evaluated. The addition of the gum did increase the viscosity of the solutions however gelatinous globules formed that did not dissolve. The gel globules would randomly deposit on the surface while the remainder of the liquid would run off. The gel on the surface increased the surface slipperiness without increasing wither the viscosity or the stickiness.
Maltodextrin and Corn Syrups. ADM Maltodextrin Clintose CR5 Lot M02070140, CR10 lot M02071260, Clintose CR24 corn syrup solids lot M01121320 and CASCO product 01400 corn syrup solids were each separately added to the three test solutions at concentrations of 0.5, 1, 5 and 10% by weight, respectively. All of the materials dissolved without problems, however the initial foam prevented assessment for 24 hours after addition. No visible increase in viscosity or stickiness was observed at room temperature when compared to the original formulations. All solutions showed an increase in both viscosity and stickiness at 5 and −20° C. when compared to room temperature.
Ammonium Lignosulfonate Liquid. The Ammonium Lignosulfonate liquid was added to the test solutions at concentrations of 0.5, 1, 5, and 10% by weight, respectively. The material dissolved in the test solutions without problems, however the vortex mixing caused the formation of significant foam. Once the initial foam dissipated shaking the solutions did not cause excessive foam formation. All test samples with both the 5 and 10% addition of ammonium lignosulfonate at room temperature showed a visible increase in both viscosity and stickiness. The viscosity and stickiness increased as the temperature decreases. At 5 and −20° C. good surface coatings were observed.
The table below list a grouping of suitable lignosulfonates which may be used in the deicer formulations of the present invention.
TABLE 1
Source Tembec Inc.
Type
Total
Viscosity (cps)
Reference No.
of lignosulfonate
Solids (%)
at 25° C. (77° F.)
A02
Ammonium
47.0
200 to 1200
S01
Sodium
46.0
Less than 1000
S05
Sodium
48.5
Less than 400
S07
Sodium
48.5
Less than 300
SA02
Sodium/Ammonium
48.0
Less than 700
The following four deicer solutions (Examples 1–4) were tested as outlined above, and the results tabulated below. For Examples 1–3 stickiness was tested at 68° F. and −4° F. with no additive component.
EXAMPLE 1
Corn Syrup 42/43 DE solids 16.14% parts by weight.
Magnesium chloride solids (anhydrous) 21.42% parts by weight.
Water 62.44% parts by weight.
Stickiness Rating at 20° C. (68° F.) Poor.
Stickiness Rating at −20° C. (−4° F.) Good.
EXAMPLE 2
High Fructose Corn Syrup 42 DE Solids 14.20% parts by weight.
Magnesium chloride solids (anhydrous) 21.42 parts by weight.
Water 64.38% parts by weight.
Stickiness Rating at 20° C. (68° F.) Poor
Stickiness Rating at −20° C. (−4° F.) Good
EXAMPLE 3
Corn Syrup 42 DE Solids 7.32% parts by weight.
Magnesium chloride (anhydrous ) 26.87% parts by weight.
Water 65.81% parts by weight.
Stickiness Rating at 20° C. (68° F.) Poor.
Stickiness Rating at −20° C. (−4° F.) Poor to Fair.
EXAMPLE 4
This is the basic formulation for the testing of various additives.
Distillers Condensed Solubles Solids 22.50% parts by weight.
Magnesium Chloride (anhydrous) 15.30% parts by weight.
Water 62.20% parts by weight.
Stickiness Rating Results
As set forth in Table II, various additives were added to Example 4 and the Stickiness Ratings determined at different additive concentrations and temperatures.
TABLE II
%
Addi-
tive
by
Stickiness Rating
Additive
weight
20° C./68° F.
5° C./41° F.
−20° C./−4° F.
Control: No
Nil
Poor
Poor
Poor
additive
Xanthan Gum
0.2
Poor
Poor
Poor
0.4
Poor
Poor
Poor
1.0
Poor
Poor
Poor
Maltodextrin
0.5
Poor
Fair
Fair
CR5 (ADM)
1.5
Poor
Fair
Fair
5.0
Poor
Fair
Fair
10.0
Poor
Fair
Fair
Maltodextrin
0.5
Poor
Fair
Fair
CR10 (ADM)
1.0
Poor
Fair
Fair
5.0
Poor
Fair
Fair
10.0
Poor
Fair
Fair
Corn Syrup
0.5
Poor
Fair
Fair
CR24 (ADM)
1.0
Poor
Fair
Fair
5.0
Poor
Fair
Fair
10.0
Poor
Fair
Fair
Corn Syrup
0.5
Poor
Fair
Fair
01400
1.0
Poor
Fair
Fair
(Casco)
5.0
Poor
Fair
Fair
10.0
Poor
Fair
Fair
Ammonium
0.5
Fair
Fair
Fair
Lignosulfonate
1.0
Fair
Fair
Fair
Solution
5.0
Good
Very Good
Very Good
(Tembec)
10.0
Good
Very Good
Very Good
The ammonium lignosulfonate liquid was analyzed for selected metals and the results are presented in Table III. The phosphorus concentration is low (68, 71 ppm) and the other metals are in small concentrations which would be acceptable in meeting deicer solution specifications.
TABLE III
Metal
Mg/mL (ppm)
Aluminum
9, 9
Boron
2, 2
Beryllium
<0.02, <0.02
Calcium
796, 812
Cadmium
<0.2, <02
Cobalt
<0.1, <0.1
Chromium
<0.4, <0.4
Copper
<0.5, <0.5
Iron
11, 12
Phosphorus
68, 71
Potassium
601, 564
Magnesium
146, 150
Manganese
49, 50
Molybdenum
<0.5, <0.5
Sodium
886, 907
Nickel
<0.2, <0.3
Lead
<0.7, <0.7
Silicon
14, 5
Titanium
<0.1, <0.1
Vanadium
<0.2, <0.2
Zinc
6, 6
From the above testing it was discovered that the addition of between about 5 and 10% Ammonium Lignosulfonate liquid provides the required visible increase in viscosity and stickiness at room temperature without adding any significant metals or phosphorus. The material also meets the cost requirements at the concentrations added and provides a solution to the thickening problem.
The Xanthan Gum thickeners show a visible increase in viscosity and stickiness but are considered unsuitable because of the formation of the gel globules that result in an undesirable increase in slipperiness.
The Maltodextrin and corn Syrup Solids did not visibly increase the viscosity or stickiness at 10% and concentration greater than that are not considered cost effective.
With respect to foaming, xanthan gum exhibited serious foaming problems followed by maltodextrin and corn syrup, with the least foaming problems associated with the ammonium lignosulfonate.
While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims.
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A deicing formulation which exhibits improved viscosity and stickiness for application to surfaces which includes at least one of BCS, DCS, CSSL or a low molecular weight carbohydrate fraction with a chloride salt, and an effective amount of a lignosulfonate to provide for improved viscosity and stickiness.
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BACKGROUND
1. Field
The invention relates generally to boot soles and fins for boot soles.
2. Related Art
A user can couple a known flipper to each foot of the user. These known flippers have fins, and when the user kicks in water, for example, the fins can facilitate generating propulsion in the water.
Many known flippers have foot pockets for receiving a foot of a user, but these foot pockets are generally integral to the fin and available only in a small number of standard sizes because, for example, manufacturing and distribution costs of entire flippers with a large variety of foot sizes and shapes would be prohibitive. Therefore, when a user selects a flipper, a user must also select a single foot pocket size of the flipper, often from among a small number of available sizes. Therefore, these foot pockets often do not comfortably fit a foot of a user, and space between the foot and an inside wall of the foot pocket can receive water, disadvantageously adding to drag of the flipper in water and limiting the control of the user over the flipper. Other known flippers include alternatives to foot pockets, but such known alternatives may still require a user to choose from small number of standard sizes because, for example, of potentially high manufacturing and distribution costs for a large variety of foot sizes.
SUMMARY
According to one illustrative embodiment, there is provided a boot sole system for guiding a fin, the system comprising: at least one toe sole body connectable to the fin and comprising first and second stop surfaces; a posterior sole body comprising third and fourth stop surfaces; and a transverse hinge for hingedly connecting the at least one toe sole body to the posterior sole body to permit longitudinal deflection of the at least one toe sole body relative to the posterior sole body in a first deflection direction and in a second deflection direction opposite the first deflection direction. The first, second, third, and fourth stop surfaces are positioned such that when the transverse hinge connects the at least one toe sole body to the posterior sole body: the first and third stop surfaces abut each other in response to longitudinal deflection of the at least one toe sole body relative to the posterior sole body in the first deflection direction to restrict longitudinal deflection of the at least one toe sole body relative to the posterior sole body in the first deflection direction; and the second and fourth stop surfaces abut each other in response to longitudinal deflection of the at least one toe sole body relative to the posterior sole body in the second deflection direction to restrict longitudinal deflection of the at least one toe sole body relative to the posterior sole body in the second deflection direction.
According to another illustrative embodiment, there is provided a fin comprising a toe sole body hingedly connectable to a posterior sole body of a boot, wherein the toe sole body comprises first and second stop surfaces, and wherein: the first stop surface is positioned to abut a third stop surface on the posterior sole body in response to longitudinal deflection of the toe sole body relative to the posterior sole body in a first deflection direction, when the toe sole body is connected to the posterior sole body, to restrict longitudinal deflection of the toe sole body relative to the posterior sole body in the first deflection direction; and the second stop surface is positioned to abut a fourth stop surface on the posterior sole body in response to longitudinal deflection of the toe sole body relative to the posterior sole body in a second deflection direction opposite the first deflection direction, when the toe sole body is connected to the posterior sole body, to restrict longitudinal deflection of the toe sole body relative to the posterior sole body in the second deflection direction.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded bottom perspective view of a boot system according to one illustrative embodiment;
FIG. 2 is a bottom perspective view of a posterior sole body of the boot system of FIG. 1 ;
FIG. 3 is a bottom perspective view of a toe sole body of the boot system of FIG. 1 ;
FIG. 4 is an elevation view of the posterior sole body of FIG. 2 and the toe sole body of FIG. 3 illustrating a maximum longitudinal deflection of the toe sole body of FIG. 3 relative to the posterior sole body of FIG. 2 in a first deflection direction;
FIG. 5 is an elevation view of the posterior sole body of FIG. 2 and the toe sole body of FIG. 3 illustrating a maximum longitudinal deflection of the toe sole body of FIG. 3 relative to the posterior sole body of FIG. 2 in a second deflection direction;
FIG. 6 is a bottom view of the posterior sole body of FIG. 2 and the toe sole body of FIG. 3 ;
FIG. 7 is a bottom view of a boot system according to another illustrative embodiment;
FIG. 8 is an elevation view of the boot system of FIG. 7 ;
FIG. 9 is a bottom view of a boot system according to another illustrative embodiment;
FIG. 10 is an elevation view of the boot system of FIG. 9 ;
FIG. 11 is an exploded bottom view of a frame of the boot system of FIG. 1 and fin elements of a fin;
FIG. 12 is a bottom view of the frame and the fin of FIG. 11 ;
FIG. 13 is a bottom view of the frame of FIG. 11 when folded along a longitudinal hinge of the frame of FIG. 11 ;
FIG. 14 is an elevation view of the frame and the fin of FIG. 11 ;
FIG. 15 is a cross-sectional view of the boot system of FIG. 1 and the fin of FIG. 11 ;
FIG. 16 is a bottom view of a frame and a fin according to another illustrative embodiment;
FIG. 17 is an exploded bottom view of a boot sole system according to another illustrative embodiment;
FIG. 18 is an assembled bottom view of the boot sole system of FIG. 17 ;
FIG. 19 is a top perspective view of a boot system according to another illustrative embodiment;
FIG. 20 is a bottom perspective view of a toe sole body of the boot system of FIG. 19 ;
FIG. 21 is a top perspective view of a frame of the boot system of FIG. 19 ;
FIG. 22 is a top perspective view of a boot system according to another illustrative embodiment;
FIG. 23 is a partial cross-sectional view of the boot system of FIG. 22 , taken along the line XXIII-XXIII in FIG. 22 ; and
FIG. 24 is a top perspective view of a boot system according to another illustrative embodiment.
DETAILED DESCRIPTION
Referring to FIG. 1 , a boot system according to one illustrative embodiment is shown generally at 100 . The boot system 100 includes a boot 102 , a posterior sole body 104 , a toe sole body 106 , and a frame (or “Y-frame”) 108 .
When a user wearing the boot system 100 walks on a surface, a bottom side shown generally at 110 generally faces downward and therefore generally contacts the surface. In general, a “bottom” side herein refers to a side that faces downward and generally contacts a surface when a user walks on the surface. However, when swimming or diving in water, a user generally faces downward, and therefore a “bottom” side herein refers to a side that generally faces upward when in use during swimming or diving in water. A drawing of a “bottom view” herein generally refers to a view of such a “bottom” side, and therefore a “bottom view” herein generally refers to a view from above when in use in water.
The boot 102 includes a boot sole 112 on the bottom side 110 of the boot 102 , and as described further below, the boot sole 112 in various embodiments may be bonded to the posterior sole body 104 and to the toe sole body 106 to form an integral boot sole including the posterior sole body 104 and the toe sole body 106 .
Referring to FIG. 2 , the posterior sole body 104 extends between a heel end shown generally at 114 and a midsole end shown generally at 116 and opposite the heel end 114 . The posterior sole body 104 also has a bottom side shown generally at 118 and a top side shown generally at 120 . As indicated above, the bottom side 118 generally faces downward and generally contacts a surface when a user walks on the surface, but the bottom side 118 generally faces upward when in use during swimming or diving in water for example. The posterior sole body 104 is relatively rigid, and in various embodiments may include one of, or a combination of more than one of, carbon fibre, relatively rigid thermoplastic material, and metal. The posterior sole body 104 on the top side 120 may define a mesh grid pattern (not shown) to facilitate adhesion to and bonding with the bottom side 110 of the boot sole 112 (shown in FIG. 1 ).
At the midsole end 116 , the posterior sole body 104 includes generally cylindrical pivot holders 122 and 124 . The pivot holder 122 defines axial through-openings 126 and 128 and the pivot holder 124 defines axial through-openings 130 and 132 . The through-openings 126 , 128 , 130 , and 132 are sized and aligned along a generally transverse axis 134 to receive a pivot 136 (shown in FIG. 1 ) along the generally transverse axis 134 . Also at the midsole end 116 , the posterior sole body 104 defines stop surfaces 138 , 140 , 142 , and 144 on the bottom side 118 and stop surfaces 146 and 148 on the top side 120 . The stop surfaces 138 , 140 , 142 , and 144 are generally coplanar in a plane extending from the generally transverse axis 134 towards the bottom side 118 , and the stop surfaces 146 and 148 are generally coplanar in a plane extending from the generally transverse axis 134 towards the top side 120 .
The pivot holder 122 defines an opening shown generally at 150 at the midsole end 116 , and the pivot holder 124 defines an opening shown generally at 152 at the midsole end 116 . The openings 150 and 152 may receive respective projections on the toe sole body 106 (shown in FIG. 1 ) for hingedly connecting the toe sole body 106 to the posterior sole body 104 as described further below.
The posterior sole body 104 includes projections 154 , 156 , 158 , 160 , 162 , 164 , 166 , and 168 projecting towards the bottom side 118 , with a generally transverse gap 170 between the projections 154 , 156 , 158 , and 160 , a generally transverse gap 172 between the projections 158 , 160 , 162 , and 164 , and a generally transverse gap 174 between the projections 162 , 164 , 166 , and 168 . The generally transverse gaps 170 , 172 , and 174 are spaced apart from each other longitudinally, namely in a direction extending from the heel end 114 to the midsole end 116 .
Referring to FIG. 3 , the toe sole body 106 extends between a midsole end shown generally at 176 and a toe end shown generally at 178 and opposite the midsole end 176 . The toe sole body 106 also has a bottom side shown generally at 180 and a top side shown generally at 182 . As indicated above, the bottom side 180 generally faces downward and generally contacts a surface when a user walks on the surface, but the bottom side 180 generally faces upward when in use during swimming or diving in water for example. The toe sole body 106 is relatively rigid, and in various embodiments may include one of, or a combination of more than one of, carbon fibre, relatively rigid thermoplastic material, and metal. The toe sole body 106 on the top side 182 may define a mesh grid pattern (not shown) to facilitate adhesion to and bonding with the bottom side 110 of the boot sole 112 (shown in FIG. 1 ).
On the bottom side 180 and towards the toe end 178 , the toe sole body 106 defines a generally planar abutment surface 184 and generally curved abutment surfaces 186 and 188 (shown in FIG. 1 ) extending away from the generally planar abutment surface 184 towards the bottom side 180 . The abutment surfaces 184 , 186 , and 188 abut corresponding surfaces of the frame 108 and define a receptacle shown generally at 190 for receiving a portion of the frame 108 as described further below.
Facing the midsole end 176 , the toe sole body 106 defines a generally semi-cylindrical recess shown generally at 192 and a generally semi-cylindrical recess shown generally at 194 . A projection 196 projects into the recess 192 towards the midsole end 176 , and a projection 198 projects into the recess 194 towards the midsole end 176 . The projection 196 defines a transverse through-opening 200 , and the projection 198 defines a transverse through-opening 202 . The through-openings 200 and 202 are aligned along a generally transverse axis 204 and are sized to receive the pivot 136 (shown in FIG. 1 ). Also at the midsole end 176 , the toe sole body 106 defines stop surfaces 206 and 208 on the bottom side 180 and stop surfaces 210 and 212 on the top side 182 . The stop surfaces 206 and 208 are generally coplanar in a plane extending from the generally transverse axis 204 towards the bottom side 180 , and the stop surfaces 210 and 212 are generally coplanar in a plane extending from the generally transverse axis 204 towards the top side 182 .
Referring to FIGS. 1, 2, and 3 , the recesses 192 and 194 are sized to receive respective portions of the pivot holders 122 and 124 respectively, and the projections 196 and 198 are sized to be received in the openings 150 and 152 respectively when the recesses 192 and 194 receive the respective portions of the pivot holders 122 and 124 such that the generally transverse axes 134 and 204 coincide to permit the through-openings 200 and 202 to receive the pivot 136 along the generally transverse axis 134 . The pivot 136 thus functions as a transverse hinge for hingedly connecting the midsole end 176 of the toe sole body 106 to the midsole end 116 of the posterior sole body 104 . Further, the stop surfaces 138 , 140 , 142 , 144 , 146 , 148 , 206 , 208 , 210 , and 212 are positioned such that when the recesses 192 and 194 receive the respective portions of the pivot holders 122 and 124 and when the through-openings 126 , 128 , 130 , 132 , 200 , and 202 receive the pivot 136 , the toe sole body 106 may pivot about the pivot 136 to deflect longitudinally relative to the posterior sole body 104 in a first deflection direction 214 (shown in FIGS. 4 and 5 ) and in a second deflection direction 216 opposite the first deflection direction 214 .
Referring to FIGS. 2, 3, and 4 , in response to longitudinal deflection of the toe sole body 106 relative to the posterior sole body 104 in the first deflection direction 214 , the stop surfaces 138 and 140 abut the stop surface 206 and the stop surfaces 142 and 144 abut the stop surface 208 to restrict longitudinal deflection of the toe sole body 106 relative to the posterior sole body 104 in the first deflection direction 214 . Also, referring to FIGS. 2, 3, and 5 , in response to longitudinal deflection of the toe sole body 106 relative to the posterior sole body 104 in the second deflection direction 216 , the stop surfaces 146 and 148 abut the stop surfaces 210 and 212 respectively to restrict longitudinal deflection of the toe sole body 106 relative to the posterior sole body 104 in the second deflection direction 216 . The stop surfaces 138 , 140 , 142 , 144 , 146 , 148 , 206 , 208 , 210 , and 212 thus define a maximum longitudinal deflection range 218 between a maximum longitudinal deflection of the toe sole body 106 relative to the posterior sole body 104 in the first deflection direction 214 (shown in FIG. 4 ) and a maximum longitudinal deflection of the toe sole body 106 relative to the posterior sole body 104 in the second deflection direction 216 (shown in FIG. 5 ).
Referring back to FIG. 3 , on the bottom side 180 and towards the toe end 178 , the toe sole body 106 defines laterally opposite receptacles 220 and 222 for receiving and retaining respective portions of a resilient body, such as an elastomeric body 224 shown in FIG. 6 for example. The laterally opposite receptacles 220 and 222 may more generally be referred to as resilient body connectors. Referring to FIGS. 3 and 6 , the receptacles 220 and 222 include respective relatively wide portions for receiving relatively wide end portions of the elastomeric body 224 , and the receptacles 220 and 222 include respective relatively narrow portions adjacent the respective relatively wide portions for retaining the relatively wide end portions of the elastomeric body 224 . Further, the receptacles 220 and 222 are open at respective opposite sides of the toe sole body 106 to receive respective end portions 226 and 228 of the elastomeric body 224 as shown in FIG. 6 .
Referring to FIG. 6 , a middle portion shown generally at 230 of the elastomeric body 224 is received in the generally transverse gap 172 , and may alternatively be received in the generally transverse gap 170 or in the generally transverse gap 174 . Because the generally transverse gaps 170 , 172 , and 174 are spaced apart from each other longitudinally, moving the middle portion 230 of the elastomeric body 224 to different ones of the generally transverse gaps 170 , 172 , and 174 may vary a tension of the elastomeric body 224 , and varying the tension of the elastomeric body 224 may adjust a tendency of the toe sole body 106 to deflect longitudinally relative to the posterior sole body 104 . Moving the middle portion 230 of the elastomeric body 224 to different ones of the generally transverse gaps 170 , 172 , and 174 may thus vary a flexibility of a boot sole including the posterior sole body 104 and the toe sole body 106 , which may be desirable in some swimming or diving applications for example. Also, flexibility of such a boot sole may be varied by varying a material of the elastomeric body 224 . The generally transverse gaps 170 , 172 , and 174 may more generally be referred to as resilient body connectors defined by the posterior sole body 104 .
Referring to FIGS. 7 and 8 , a boot system according to another illustrative embodiment includes a boot 232 including a boot sole integrally formed with the posterior sole body 104 and the toe sole body 106 . An elastomeric body 234 extends from the sole body 106 to the posterior sole body 104 as shown in FIG. 6 , except that the elastomeric body 234 includes a heel strap 236 sized to extend laterally around a heel region of the boot 232 and attach to a heel strap attachment 238 near a heel end of the boot 232 for attaching the heel strap 236 to the boot 232 . Attaching the heel strap 236 to the heel strap attachment 238 may vary a tension of the elastomeric body 234 to vary a flexibility of the boot sole as described above. In some embodiments, the heel strap attachment 238 may permit the heel strap 236 to be attached to the boot 232 in a plurality of positions, and attaching the heel strap 236 to the boot 232 in different ones of the plurality of positions may vary the tension of the elastomeric body 234 to vary the flexibility of the boot sole as described above.
Referring to FIGS. 9 and 10 , a boot system according to another illustrative embodiment includes a boot 240 including a boot sole integrally formed with the posterior sole body 104 and the toe sole body 106 . An elastomeric body 242 extends from the sole body 106 to the posterior sole body 104 as shown in FIG. 6 , except that the elastomeric body 242 includes a heel strap 244 sized to extend under a heel region of the boot 240 on a bottom side of the boot 240 and attach to a heel strap attachment 246 near a heel end of the boot 240 for attaching the heel strap 244 to the boot 240 . Attaching the heel strap 244 to the heel strap attachment 246 may vary a tension of the elastomeric body 242 to vary a flexibility of the boot sole as described above. In some embodiments, the heel strap attachment 246 may permit the heel strap 244 to be attached to the boot 240 in a plurality of positions, and attaching the heel strap 244 to the boot 240 in different ones of the plurality of positions may vary the tension of the elastomeric body 242 to vary the flexibility of the boot sole as described above.
Referring to FIG. 11 , the frame 108 includes first and second laterally opposite frame elements 248 and 250 and a longitudinal hinge 252 hingedly connecting the first and second laterally opposite frame elements 248 and 250 . The first laterally opposite frame element 248 defines through-openings 252 and 254 for connecting the first laterally opposite frame element 248 to a fin element 256 , and the second laterally opposite frame element 250 defines through-openings 258 and 260 for connecting the second laterally opposite frame element 250 to a fin element 262 . The fin element 256 includes a hinge element 264 defining through-openings 266 and 268 ; a fastener (not shown) may pass through the through-openings 252 and 266 and another fastener (not shown) may pass through the through-openings 254 and 268 to connect the first laterally opposite frame element 248 to the fin element 256 . Also, the fin element 262 includes a hinge element 270 defining through-openings 272 and 274 ; a fastener (not shown) may pass through the through-openings 258 and 272 and another fastener (not shown) may pass through the through-openings 260 and 274 to connect the second laterally opposite frame element 250 to the fin element 262 . However, alternative embodiments may include different fins which may be attached to the frame 108 in different ways.
Referring to FIG. 12 , when the first laterally opposite frame element 248 is connected to the fin element 256 and the second laterally opposite frame element 250 is connected to the fin element 262 , the fin elements 256 and 262 form a fin shown generally at 276 . The fin 276 is thus connectable to the frame 108 . In alternative embodiments, the fin may be permanently connected to the frame, but nevertheless such a fin may be referred to as “connectable” to the frame. In general, “connectable” herein may refer to a permanent connection or to a selectable connection.
The fin 276 has a proximal end shown generally at 278 and a distal end shown generally at 280 and opposite the proximal end 278 . Further, the hinge element 264 has a hinge axis 282 and the hinge element 270 has a hinge axis 284 . The hinge axis 282 extends away from a central longitudinal axis 286 of the fin 276 and towards the distal end 280 at an acute angle 288 , and the hinge axis 284 extends away from the central longitudinal axis 286 of the fin 276 and towards the distal end 280 at an acute angle 290 . The fin 276 may therefore spread apart in response to lateral deflection of the fin 276 relative to the frame 108 similarly to various fins described and illustrated in U.S. patent application Ser. No. 13/639,446, originally published as WO 2011/123950 A1. The entire contents of U.S. patent application Ser. No. 13/639,446 are incorporated by reference herein. As indicated above, alternative embodiments may include different fins which may include fins similar to those described in and illustrated in WO 2011/123950 A1 or still other fins.
Referring to FIGS. 11, 12, and 13 , the frame 108 includes a connector 292 for connecting the frame 108 to the pivot 136 (shown in FIGS. 1 and 4 to 6 ). The connector 292 includes a generally planar flange 294 fastened to the first laterally opposite frame element 248 but not fastened to the second laterally opposite frame element 250 . Therefore, when the first and second laterally opposite frame elements 248 and 250 are extended apart from each other around the longitudinal hinge 252 (as shown in FIGS. 11 and 12 ), the second laterally opposite frame element 250 abuts the generally planar flange 294 and the generally planar flange 294 prevents further rotation of the second laterally opposite frame element 250 around the longitudinal hinge 252 , thus maintaining the first and second laterally opposite frame elements 248 and 250 generally coplanar. However, the second laterally opposite frame element 250 may be pivoted around the longitudinal hinge 252 away from the generally planar flange 294 and towards the first laterally opposite frame element 248 , effectively permitting the frame 108 to be folded around the longitudinal hinge 252 . Folding the frame 108 around the longitudinal hinge 252 may reduce space consumed by the frame 108 , and reduced space may be desirable in some applications such as storing or transporting the frame 108 for example.
Referring to FIGS. 14 and 15 , the connector 292 defines a receptacle shown generally at 296 and sized to receive a portion of the pivot 136 to connect the frame 108 to the pivot 136 . As shown in FIG. 1 , the pivot 136 includes a threaded end shown generally at 298 , and the through-opening 126 defines complementary threads (not shown) to hold the pivot 136 in the through-openings 126 , 128 , 130 , 132 , 200 , and 202 (shown in FIGS. 2 and 3 ) when the generally transverse axes 134 and 204 coincide (shown in FIGS. 2 and 3 ). The pivot 136 is thus removable from the posterior sole body 104 and from the toe sole body 106 by removing the threaded end 298 from the complementary threads of the through-opening 126 . In alternative embodiments, the pivot 136 may be held by a friction fit instead of by threads. When the pivot 136 thus removed, the frame 108 may be positioned with a portion of the connector 292 between the pivot holders 122 and 124 (shown in FIG. 2 ), and the receptacle 296 is configured to receive the pivot 136 when the frame 108 is thus positioned, as shown in FIG. 15 . The receptacle 296 defines a retaining surface 300 in the receptacle 296 that abuts the pivot 136 when the receptacle 296 receives the pivot 136 as shown in FIG. 15 to retain the connector 292 and thus the frame 108 to the pivot 136 . The frame 108 is thus removably connectable to the posterior sole body 104 at the pivot 136 .
As indicated above, the generally planar flange 294 prevents rotation of the second laterally opposite frame element 250 around the longitudinal hinge 252 beyond the generally planar flange 294 . Further, in FIG. 15 , the first and second laterally opposite frame elements 248 and 250 abut the generally planar abutment surface 184 , and the generally planar abutment surface 184 thus prevents rotation of the second laterally opposite frame element 250 around the longitudinal hinge 252 away from the generally planar flange 294 . Therefore, as shown in FIG. 15 , when the first and second laterally opposite frame elements 248 and 250 abut the generally planar abutment surface 184 , the generally planar abutment surface 184 and the generally planar flange 294 maintain the first and second laterally opposite frame elements 248 and 250 generally coplanar.
The connector 292 also defines a stop 302 having a stop surface 304 . Referring to FIG. 15 , in response to longitudinal deflection of the frame 108 relative to the posterior sole body 104 in the first deflection direction 214 , the stop surface 304 abuts a stop surface 306 (also shown in FIG. 2 ) on the posterior sole body 104 to restrict longitudinal deflection of the frame 108 relative to the posterior sole body 104 in the first deflection direction 214 .
Therefore, both the toe sole body 106 and the frame 108 are connected to the pivot 136 and may pivot about the pivot 136 for longitudinal deflection relative to the posterior sole body 104 in the first deflection direction 214 and in the second deflection direction 216 .
In operation, when a foot of a user (not shown) is received in the boot 102 , the pivot 136 may be proximate metatarsophalangeal joints (or simply toe joints) of the user. In other words, one or both of the toe sole body 106 and the frame 108 may deflect longitudinally with the toes of the user. Therefore, the frame 108 may also be referred to as a “toe sole body” and the toe sole body 106 and the frame 108 may collectively be referred to as “at least one toe sole body” connectable to a fin (the fin 276 shown in FIG. 12 in the embodiment shown) because at least one of the at least one toe sole body (the frame 108 in the embodiment shown) is connectable to the fin.
Although the pivot 136 is referred to herein as a transverse hinge, the pivot 136 (and other transverse hinges described herein) do not necessarily extend perpendicular to any longitudinal axis. Rather, in the embodiment shown in FIG. 15 for example, the pivot 136 may extend under metatarsophalangeal joints of a user, which may follow a curve that is not perpendicular to any longitudinal axis. More generally, transverse hinges described herein may extend transversely at various angles that may be desired in various embodiments but that are not necessarily perpendicular to any longitudinal axis. Although the transverse hinge in the embodiment shown is the pivot 136 , transverse hinges in other embodiments may include other hinges, such as thermoplastic hinges for example.
Referring to FIGS. 1 and 15 , because the first and second laterally opposite frame elements 248 and 250 abut the generally planar abutment surface 184 , and because the generally planar abutment surface 184 is on the toe sole body 106 that may be below (or “inferior to”) toes of a user as shown in FIG. 15 , the first and second laterally opposite frame elements 248 and 250 may extend laterally from below (or “inferior to”) toes of the user rather than from in front of (or “anterior to”) the toes of the user. In such embodiments, an overall length of the boot system 100 and the fin 276 (shown in FIG. 12 ) may be shorter when compared to some other fins that do not include structure below (or “inferior to”) toes of a user and instead include more structure and spacing in front of (or “anterior to”) the toes of the user. Such reduced overall length may be advantageous in some applications where compactness of a fin may be desirable. Further, reduced overall length may improve a mechanical advantage of a user's leg and reduce strain on the user's leg because when the fin is closer to the user's hip, knee, ankle, and toe joints, less force is required to move the fin by a given angle about such joints.
In the embodiment shown in FIG. 15 , the toe sole body 106 and the frame 108 do not necessarily move together, and for example when a user wearing the boot 102 kicks downward (which would be upward in FIG. 15 if the user is facing down while swimming or diving), then the frame 108 may be deflected longitudinally relative to the posterior sole body 104 in the first deflection direction 214 without necessarily longitudinally deflecting the toe sole body 106 in the first deflection direction 214 to the same extent as the frame 108 or at all. However, in alternative embodiments such as those shown in FIGS. 17 to 24 for example, the frame may be fastened to the toe sole body such that the frame and the toe sole body move together, generally with longitudinal deflection relative to the posterior sole body in substantially similar angles. Also, although the toe sole body 106 and the frame 108 are separate bodies in the embodiment shown, alternative embodiments may include a single toe sole body connectable to a fin and hingedly connectable to a posterior sole body.
Further, the at least one toe sole body (the toe sole body 106 and the frame 108 in the embodiment shown) collectively include at least one stop surface (one or more of the stop surfaces 206 , 208 , and 304 in the embodiment shown) to restrict longitudinal deflection of the toe sole body 106 relative to the posterior sole body 104 in the first deflection direction 214 and at least one stop surface (one or more of the stop surfaces 210 and 212 in the embodiment shown) to restrict longitudinal deflection of the toe sole body 106 relative to the posterior sole body 104 in the second deflection direction 216 , and thus the at least one toe sole body in the embodiment shown includes a stop surface to restrict longitudinal deflection of the toe sole body 106 relative to the posterior sole body 104 in the first deflection direction 214 and a stop surface to restrict longitudinal deflection of the toe sole body 106 relative to the posterior sole body 104 in the second deflection direction 216 . In alternative embodiments, one or more of at least one toe sole body may include a stop surface to restrict longitudinal deflection relative to a posterior sole body in a first deflection direction and a stop surface to restrict longitudinal deflection relative to the posterior sole body in a second deflection direction opposite the first deflection direction, and such stop surfaces may be on the same toe sole body or on different toe sole bodies in various embodiments.
As shown in FIG. 5 , stop surfaces in the embodiment shown restrict longitudinal deflection of the of the toe sole body 106 relative to the posterior sole body 104 to a maximum longitudinal deflection range 218 . In some embodiments, the maximum longitudinal deflection range 218 may be within a normal range for bending of metatarsophalangeal joints. In some embodiments, the maximum longitudinal deflection range 218 may range from a position where toes are fully extended forward (or anterior) to a maximum normal superior (that is, towards the head of the user) bending. For example, a maximum normal superior bending of metatarsophalangeal joints may be about 30° to about 80°, and therefore in some embodiments, the maximum longitudinal deflection range 218 may range from a position where toes are fully extended forward (or anterior) to, for example, about 30°, about 35°, about 40°, about 45°, about 50°, about 55°, about 60°, about 65°, about 70°, about 75°, or about 80° superior (that is, towards the head of the user) to the position where toes are fully extended.
In general, the pivot 136 and other transverse hinges such as those described herein may in some embodiments improve a connection between a user's foot and a fin attached to the user's foot when compared to other boot bindings systems. For example, a user of the boot system 100 may sense movement of a fin by sensing movement of the user's toes, which may enhance the user's experience by enhancing the user's awareness of fin movement. Also, the user may control movement of the fin by controlling movement of the user's toes. Still further, allowing movement of the user's toes may permit more natural body movement that may avoid cramps and other potential disadvantages of other boot bindings systems that may not permit such foot movement.
In many applications such as swimming and diving for example, a user faces downward in water. Further, many swimmers and divers have stronger downward kicks (that is, kicks downward when facing downward in water, or kicks that involve straightening or extending the leg at one or more of the hip, knee, ankle, and toe joints) when compared to their upward kicks (that is, kicks upward when facing downward in water, or kicks that involve flexing the leg at one or more of the hip, knee, ankle, and toe joints). In the embodiment shown, when a user kicks downward in such an orientation, resistance in surrounding water generally causes the fin 276 , the frame 108 , and the toe sole body 106 to deflect upward, or longitudinally relative to the posterior sole body 104 in the first deflection direction 214 .
Therefore, as indicated above, in embodiments where the maximum longitudinal deflection in the first deflection direction 214 is a position where toes are fully extended forward (or anterior), then a downward kick (in an orientation where the user is facing downwards) in such embodiments will tend to deflect the fin 276 , the frame 108 , and the toe sole body 106 longitudinally relative to the posterior sole body 104 in the first deflection direction 214 to the maximum longitudinal deflection in the first deflection direction 214 , thereby extending the fin 276 away from the leg.
When the fin 276 is extended away from the leg, the effective surface area of the fin 276 against incident water is increased by orienting the fin 276 generally perpendicular to a direction of motion of the fin 276 . Increasing effectiveness of the fin 276 during the downward kick may be desirable where the downward kick is relatively stronger than the upward kick.
Also, in embodiments where the maximum longitudinal deflection range 218 ranges to maximum normal superior bending of metatarsophalangeal joints (such as about 30° to about 80° for example), then an upward kick (in an orientation where the user is facing downwards) causes the fin 276 , the frame 108 , and the toe sole body 106 to deflect longitudinally relative to the posterior sole body 104 in the second deflection direction 216 , thereby angling the fin towards the user's leg and reducing effective surface area of the fin 276 against incident water by orienting the fin 276 generally closer to parallel to a direction of motion of the fin 276 during the relatively weaker upward kick. Therefore, the longitudinal deflection range 218 in various embodiments may allow a fin such as the fin 276 to deflect longitudinally relative to a user's foot to increase and decrease effective surface area of the fin 276 during a kick cycle to increase effectiveness of the relatively stronger downward stroke while facilitating the relatively weaker upward stroke by reducing resistance during the upward stroke.
Further, in embodiments where the longitudinal deflection range 218 is limited by a maximum longitudinal deflection in the second deflection direction 216 corresponding to a maximum normal superior bending of metatarsophalangeal joints (such as about 30° to about 80° for example), the longitudinal deflection range 218 may in some such embodiments prevent damage to metatarsophalangeal joints, or bones or other tissue surrounding the metatarsophalangeal joints, that could result from bending the metatarsophalangeal joints beyond normal bending. For example, when a user jumps out of a boat or off of a dock and into water feet-first, fins attached to the user's feet will naturally be deflected upward in response to resistance in the water surrounding the fin, and forcefully under the user's body weight and speed of motion. However, the longitudinal deflection range 218 in some embodiments may prevent such damage that could result from such forceful upward deflection of the fin 276 , in the embodiment shown because the stop surfaces 146 and 148 abut the stop surfaces 210 and 212 respectively to restrict longitudinal deflection of the toe sole body 106 relative to the posterior sole body 104 in the second deflection direction 216 .
In the embodiment shown, the toe sole body 106 and the frame 108 both directly connect to the pivot 136 . However, in alternative embodiments, only one of the toe sole body 106 and the frame 108 may be connected directly to the pivot 136 . For example, in some embodiments, the frame 108 may not connect directly to the pivot 136 , but may connect instead to the toe sole body 106 . However, in such embodiments, the frame 108 may still be referred to as connected to the pivot 136 because the frame 108 is indirectly connected to the pivot 136 through the toe sole body 106 .
Referring to FIG. 16 , a frame 308 according to another illustrative embodiment is substantially the same as the frame 108 described above, but includes an actuator 310 in communication with one or more gears (not shown) that, when rotated, vary an angle 312 between a central longitudinal axis 314 of a fin connected to the frame 308 and a transverse axis 316 of a receptacle of the frame 308 for receiving a transverse pivot. For example, in some embodiments, a connector (similar to the connector 292 described above) of the frame 308 may be pivotally coupled to first and second laterally opposite frame elements (similar to the first and second laterally opposite frame elements 248 and 250 described above) of the frame 308 and the actuator 310 may be in communication with a pinion (not shown) on the connector of the frame 308 and in geared engagement with a static rack (not shown) on one of the first and second laterally opposite frame elements of the frame 308 such that rotation of the pinion causes the connector of the frame 308 to move along the rack, thereby pivoting the connector of the frame 308 relative to the first and second laterally opposite frame elements of the frame 308 and changing the angle 312 . In other embodiments where the connector of the frame 308 is pivotally coupled to the first and second laterally opposite frame elements of the frame 308 , the actuator 310 may be in communication with a worm (not shown) on the connector of the frame 308 and in geared engagement with a static worm gear (not shown) on one of the first and second laterally opposite frame elements of the frame 308 such that rotation of the worm causes the worm move along the static worm gear, thereby pivoting the connector of the frame 308 relative to the first and second laterally opposite frame elements of the frame 308 and changing the angle 312 . Adjusting the angle 312 may, for example, compensate for “pigeon-toed” or “bowlegged” foot orientations of some users, and more generally may allow users to vary angles between feet of the user and fins attached to the feet of the user.
Referring to FIGS. 17 and 18 , a toe sole body 318 according to another illustrative embodiment is substantially the same as the toe sole body 106 described above, but defines a threaded opening 320 for receiving a threaded fastener 322 . The threaded fastener 322 may also be received in a through-opening 324 of a retainer 326 such that the threaded fastener 322 retains the retainer 326 against first and second laterally opposite frame elements 328 and 330 of a frame 332 that is substantially the same as the frame 108 , and such that the retainer 326 retains the first and second laterally opposite frame elements 328 and 330 against a generally planar abutment surface 334 (similar to the generally planar abutment surface 184 shown in FIGS. 1, 3, and 15 ) to maintain the first and second laterally opposite frame elements 328 and 330 generally coplanar as described above with reference to FIG. 15 . As indicated above, the frame 332 may thus be fastened to the toe sole body 318 such that the frame 332 and the toe sole body 318 move together, generally with longitudinal deflection relative to the posterior sole body in substantially similar angles.
Referring to FIG. 19 , a boot system according to another illustrative embodiment includes a toe sole body 336 and a frame 338 . The toe sole body 336 is substantially the same as the toe sole body 106 described above, but defines a recess shown generally at 340 on a top side shown generally at 342 of the toe sole body 336 . Referring to FIGS. 19, 20, and 21 , the recess is complementary to a projection 344 on a top side shown generally at 346 of the frame 338 . When the projection 344 contacts a surface 348 of the recess 340 , the surface 348 holds an upper surface 350 of the frame 338 against a lower surface 352 of the toe sole body 336 . A user wearing the boot of FIG. 19 may thus “step in” to the frame 338 and fasten the frame 338 , and thus a fin (not shown) connected to the frame 338 , to the toe sole body 336 and thus to the boot. The surface 348 of the recess 340 and the lower surface 352 of the toe sole body 336 thus cooperate with the projection 344 and the upper surface 350 of the frame 338 to couple the frame 338 to the toe sole body 336 when the projection 344 is received in the recess 340 as shown in FIG. 19 . As indicated above, the frame 338 may thus be fastened to the toe sole body 336 such that the frame 338 and the toe sole body 336 move together, generally with longitudinal deflection relative to the posterior sole body in substantially similar angles. The frame 338 also includes a resilient body 354 , which may be used as a heel strap positioned behind a heel end of the boot shown in FIG. 19 to hold the projection 344 in the recess 340 and more generally to hold the frame 338 (and any fin, not shown, that may be attached to the frame 338 ) in connection with the toe sole body 336 for longitudinal deflection of the frame 338 together with the toe sole body 336 relative to a posterior sole body of the boot system of FIG. 19 .
Referring to FIG. 22 , a boot system according to another illustrative embodiment includes a toe sole body 356 and a frame 358 . The toe sole body 356 and the frame 358 are substantially the same as the toe sole body 336 and the frame 338 respectively, except that the frame 358 does not include a heel strap and instead the toe sole body 356 and the frame 358 may be connected and disconnected by actuation of an actuator 360 , which in the embodiment shown extends over a top of the boot shown in FIG. 22 when the actuator 360 is in a position (as shown in FIG. 22 ) in which the frame 358 is connected to the toe sole body 356 . The actuator 360 may therefore be referred to as an “instep lever” by reference to the position of the actuator 360 when the frame 358 is connected to the toe sole body 356 . The frame 358 may be disconnected from the toe sole body 356 by pivoting the actuator 360 such that the actuator 360 moves away from the boot shown in FIG. 22 . Further, a user wearing the boot of FIG. 22 may “step in” to the frame 358 and fasten the frame 358 , and thus a fin (not shown) connected to the frame 358 , to the toe sole body 356 and thus to the boot.
Referring to FIGS. 22 and 23 , the actuator 360 is rotationally coupled to a pivot 362 , which in the embodiment shown includes a connection region rectangular in cross-section and having a width 364 in a first radial direction and a width 366 in a second radial direction different from (and perpendicular to in the embodiment shown) the first radial direction. The width 366 is greater than the width 364 . The frame 358 includes a connector 367 defining a receptacle shown generally at 368 open at an opening shown generally at 370 . The opening 370 has a height 371 greater than the width 364 but less than the width 366 such that the opening 370 may receive the connection region of the pivot 362 when the pivot 362 is oriented with the width 364 passing through the opening 370 . The pivot 362 may then be rotated (by actuation of the actuator 360 ) such that the width 366 is blocked from passing through the opening 370 , and the connector 367 is thus connected to the connection region of the pivot 362 . The pivot 362 may further be rotated (by actuation of the actuator 360 ) such that the width 364 may pass through the opening 370 , and the connector 367 is thus disconnected to the connection region of the pivot 362 . Alternative embodiments may include different ways of connecting to a connector such as the connector 367 . For example, in an alternative embodiment, actuation of the actuator 360 may translate a pivot in an axial direction relative to the pivot in and out of a receptacle such as the receptacle 368 .
Referring to FIG. 24 , a boot system according to another illustrative embodiment includes a toe sole body 372 and a frame 374 . The toe sole body 372 and the frame 374 are substantially the same as the toe sole body 356 and the frame 358 respectively, except that the actuator 376 of the toe sole body 372 extends over a toe of the boot of FIG. 24 when the actuator 376 is in a position (as shown in FIG. 24 ) in which the frame 374 is connected to the toe sole body 372 . The actuator 376 may therefore be referred to as a “toe lever” by reference to the position of the actuator 376 when the frame 374 is connected to the toe sole body 372 . The frame 374 may be disconnected from the toe sole body 372 by pivoting the actuator 376 such that the actuator 376 moves away from the toe region of the boot shown in FIG. 24 . Again, a user wearing the boot of FIG. 24 may “step in” to the frame 374 and fasten the frame 374 , and thus a fin (not shown) connected to the frame 374 , to the toe sole body 372 and thus to the boot.
In general, the sole bodies described herein (such as the posterior sole bodies and the toe sole bodies described herein for example) may be molded into or otherwise formed in boot soles (such as the boot sole 112 shown in FIG. 1 for example) to form integral boot soles connectable to frames that are in turn connectable to fins such as those described herein for example. Such sole bodies may be standardized and manufactured in one or in a small number of sizes, thereby possibly reducing manufacturing costs when compared to other boot binding systems, while boots (such as the boot 102 shown in FIG. 1 for example) may be manufactured by a number of manufactures in a large number of varieties that may vary by foot size and shape, by material, by ankle support, and in many other ways. Further, fins (such as the fin 276 shown in FIG. 12 for example) may also vary in many ways, such as in length, in width, in shape, in material, and in flexibility, for example. Nevertheless, such various boots and various fins may be interchangeable where the boots include standardized sole bodies (such as the posterior sole bodies and the toe sole bodies described herein for example) and where the fins are connectable to standardized frames (such as the frames described herein for example) connectable to such standardized sole bodies. Therefore, a user may interchange a variety of boots and a variety of fins to form combinations of particular boots and particular fins to suit particular purposes (for example, a boot suitable for cold water combined with a fin suitable for spear fishing, or a boot suitable for warm water combined with a fin suitable for snorkeling) without requiring entire flipper apparatuses to embody the desired features of both the boot and the fin.
Although specific embodiments have been described and illustrated, such embodiments should be considered illustrative only and not as limiting the invention as construed according to the accompanying claims.
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In one illustrative embodiment, there is provided a boot sole system for guiding a fin, the system comprising: at least one toe sole body connectable to the fin and comprising first and second stop surfaces; a posterior sole body comprising third and fourth stop surfaces; and a transverse hinge for hingedly connecting the at least one toe sole body to the posterior sole body to permit longitudinal deflection of the at least one toe sole body relative to the posterior sole body in a first deflection direction and in a second deflection direction opposite the first deflection direction. The first, second, third, and fourth stop surfaces are positioned to restrict longitudinal deflection of the at least one toe sole body relative to the posterior sole body in the first deflection direction and in the second deflection direction. Fins are also disclosed.
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RELATED APPLICATIONS
The present application is a Continuation-in-part of U.S. Ser. No. 08/733,035, filed Oct. 16, 1996 now abandoned.
FIELD OF THE INVENTION
The present invention relates to skin cleansing bar compositions preferably formed by cast melt method. These bars are extremely mild, foam well and provide consumer-desired sensory properties.
BACKGROUND
Personal washing bars are constantly moving toward milder formulations that ultimately will provide some enhanced skin care, for example, minimizing levels of skin irritation and enhancing moisturization. It is desirable to have a bar composition that carries a significant amount of emollient oily liquid that provides positive sensory cues to many consumers. To properly process such a bar composition, cast-melt is the preferred technique.
It is a challenge to find an economical bulk chemical which can function as a bar filler/binder that enhances skin mildness or moisturization, promotes bar lather performance and facilitates bar processing. For example, solid polyalkylene glycols (e.g., polyethylene glycols (PEG) having molecular weight above 2000) are effective bar structurants and they do not defoam. However, in comparison to a PEG having a lower molecular weight, they provide much less oily skin feel which signals moisturization to many consumers, and they are less readily miscible with long chain fatty acid soaps that are used as gelling agents in the subject invention. Solid fatty acids, on the other hand, can effectively structure bar but tend to defoam. Paraffin waxes defoam if included in a bar at relatively high levels (i.e., greater than 25% wt. total composition), especially in the presence of hydrophobic emollient oils.
In the subject invention, applicants have formulated relatively high levels of low molecular weight polyalkylene glycols (e.g., polyethylene glycol having molecular weight of 300 to below 1500, preferably about 350 to 1450, more preferably 350 to 1400, more preferably 350 to 1300) in a synthetic detergent bar using the cast melt technology. In-vivo and in-vitro data showed that, only at high levels of addition (polyethylene glycol to anionic weight ratio at 1:1 and above) do these low MW PEGs significantly mitigate the irritation potential of commonly used anionic surfactants. Unlike solid PEGs with molecular weight greater than 1500, the low molecular weight PEGs are more readily miscible with long chain fatty acid soaps that are the gelling agents of this invention, and therefore are a significant component of the immobilized liquid fraction of these bars. It is this liquid fraction that readily dissolves upon use providing the benefits of enhanced skin feel, mildness and lather. As an additional benefit, the low molecular weight PEGs enhance desired lather properties to a skin cleanser.
Thus using high levels of these relatively low molecular weight materials, applicants were able to obtain bars which simultaneously (1) provided desired user and processing properties (2) lathered well and (3) were less irritating.
The use of polyalkylene glycol (e.g., polyethylene glycol) in personal washing bar compositions is not itself new.
U.S. Pat. No. 3,312,627, to D. Hooker, for example, teaches a bar composition containing 30-70% polyethylene glycol (PEG) as bar structurant for a nonionic formulation basically free of anionic detergents. The PEG used in this invention has a molecular weight above 4000 Dalton, which is significantly higher than the MW claimed for the PEGs applied in the subject invention (less than 1500, preferably greater than 300 to about 1450 and below). In contrast to the subject invention, the referred patent used significantly higher level of high MW PEG in total bar composition. Further, the PEG/anionic surfactant ratio is not important in this patent since it refers to a primarily nonionic formulation.
World Patent Application No. 93/07245 to F. Moran, B. O'Briain and D. Moran (assigned to NEPHIN) teaches a shampoo bar composition containing 12-20% synthetic detergents and 70-80% PEGs with molecular weight between 5000 and 10,000. An embodiment of the invention includes a softening PEG with molecular weight between 100 and 800 (preferably 1-8% wt. total composition). In contrast to the subject invention, the referred patent application used a significant level (70-80%) of high MW PEGs in total bar composition. The referred patent used significantly less amount of low MW PEG than used in the subject invention.
In applicant's copending U.S. Ser. No. 08/594,363, Continuation of U.S. Ser. No. 08/213,287, entitled "Synthetic Detergent Bar and Manufacture Thereof", to J. Chambers et al., there is taught a bar containing 10-60% synthetic surfactants and 10-60% PEG as structurant. The PEG used has a range of melting temperatures between 40° C. and 100° C., and a range of molecular weight between 1500 and 10,000. This molecular weight makes PEG a solid at room temperature. The PEG molecular weight used is above that claimed (less than 1500, preferably about greater than 300 to about 1450 and below) by the subject invention. Also the referred patent application does not teach PEG/anionic ratio of at least 1:1 that is relevant to the mildness enhancement, a criticality of the subject invention.
U.S. Pat. No. 5,520,840 to M. Massaro et al. teaches a skin cleansing bar composition containing 10-60% of synthetic surfactant, 10-60% water soluble structurant (e.g., PEG) with having a range of melting points between 40° C. and 100° C., and 1-25% water soluble starch such as maltodextrin. Again, the molecular weight of the PEGs used (i.e., above 1500) is above that claimed for the subject invention. Also the referred patent application does not teach a PEG/anionic ratio of at least 1:1 that is relevant to the mildness enhancement, a criticality of the subject invention.
U.S. Pat. No. 2,287,484 to Lundberg teaches a bar made by a closed die molding technique which comprises 35-70% of anionic synthetic surfactant and 22-50% fatty acid. The bar also may contain up to 10% ethylene and di-ethylene glycols as additives. As found by the subject invention, the ethylene and di-ethylene glycols are not as effective as low MW PEGs (MW above 300) in reducing the skin irritation of anionic surfactants. Also the referred patent does not teach a PEG/anionic surfactant weight ratio of at least 1:1 that is relevant to the mildness enhancement, a criticality of the subject invention.
Applicants' copending application Ser. No. 08/662,394, filed Jun. 12, 1996 teaches a mild bar composition containing 10-60% synthetic detergents, 10-50% high molecular weight PEG with melting point above 40° C. and 0.1 to 10% low molecular weight PEG (melting point below 40° C.) as processing aid. The application claims the use of relatively low levels of low MW PEG as a lubricant to aid the extrusion process. This is significantly different from the art of the subject invention, which formulated relatively high levels of low MW PEG (e.g., >10% wt. total composition) into a bar as a moisturizer. Also the referred patent application did not specify the PEG/anionic surfactant weight ratio, which is a criticality of the subject invention to achieve superior skin mildness.
U.S. Pat. Nos. 5,262,079 and 5,227,086 to M. Kacher, J. Taneri, D. Quiram, D. Schmidt and M. Evans teach a framed cleansing bar composition containing 5-50% of a mixture of free and neutralized monocarboxylic acid, 15-65% synthetic anionic and nonionic bar firmness aid and 15-55% water. The bar firmness aid consists of 5-50% synthetic surfactants and 0-40% polyethylene glycol or polypropylene glycol with MW ranging from approximately 44 to 10,000 Dalton. The referred patents do not teach or suggest use of PEGS with MW between 400 and 1500 with specific PEG/anionic surfactant weight ratios to achieve both enhanced cast-melt processibility and mildness enhancement. Further, to obtain the desired bar user properties (i.e., mush and hardness) the applicants of the subject invention include only 2-10% wt. water in the bar compositions claimed, which is significantly below the 15-55% water claimed by the referred patents.
Finally, applicants are concurrently filing an application entitled "Pourable Cast Melt Bar Compositions Comprising Low Levels of Water and Minimum Ratios of Polyol to Water". The subject invention is made by the same cast melt methodology. However, the related application is not directed to specific compositions wherein high levels of polyalkylene glycol with molecular weight between 400 and 1,500 are used and ratio of polyalkylene glycol to anionic surfactant is at least 1:1.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to bar compositions in which alkylene glycols (e.g., polyethylene glycols) of very specific molecular weight range (high enough molecular weight to mitigate harshness effect of anionic, but low enough MW to provide the desired sensory profile and facilitate the cast-melt processing) are used and ratio of alkylene glycol to anionic is maintained at least 1:1 and higher. Such compositions are mild, foam well and provide consumer desired sensory profiles.
More specifically, the invention comprises:
(1) 2 to 35%, preferably 10 to 30% by wt. total composition synthetic anionic surfactant;
(2) 0 to 20% by wt. total composition surfactant selected from the group consisting of amphoteric, zwitterionic nonionic and mixtures thereof; preferably amphoteric and zwitterionic surfactants comprise 2 to 15% by wt. total composition;
(3) 10% by 70% by wt. total composition of a polyalkylene glycol or mixture of polyalkylene glycol compounds having MW greater than 300 to less than about 1500, preferably grater than 300 to about 1450 and below, more preferably 350 to 1400, more preferably above about 400 to about 1300 and below. Especially preferred embodiments have MW of about 1000 and below;
the weight ratio of the polyalkylene glycol to the anionic surfactant being at least 1:1, preferably 2:1 and greater;
(4) about 0% to 35% by wt. of solid structuring aids and fillers selected from the group consisting of (i) polyalkylene glycols having MW of 2500 to 10,000 and MP of about 55° to 65° C.; (ii) preferably straight chain, preferably saturated C 8 to C 24 free fatty acids; (iii) preferably straight chain, preferably saturated C 8 to C 20 alkanols; (iv) water soluble starches (e.g., maltodextrin);
(5) about 1% to 20% by wt. gelling agent; and
(6) about 2% to 10% by wt. water.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a graph showing that polyethylene glycol with molecular weight of 400 and above significantly reduce the amount of zein dissolved by acyl isethionate (i.e., is less harsh) when weight ratio of PEG to isethionate is above 1:1, preferably above 2:1.
FIG. 2 shows that, at molecular weight below 400, PEGs or other water soluble nonionic monomer (e.g. ethylene glycol, propylene glycol) do not reduce the amount of zein dissolved by isethionate.
FIG. 3 shows that at molecular weight below 400, PEGs or other water soluble nonionic monomer do not reduce the amount of zein dissolved by sodium lauryl ether.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to compositions in which alkylene glycols within a very specific molecular weight range (high enough to mitigate harshness effect of anionic surfactant, but low enough MW to provide consumer-desired sensory profile and facilitate the cast-melt processing) are used at a minimum ratio of alkylene glycol to anionic to provide compositions which are (1) mild, (2) maintain good foam profile and (3) provide both consumer-desired sensory profiles (i.e., due to lower molecular weight) and processing benefits.
More specifically, the composition comprises:
(1) 2 to 35%, preferably 10 to 30% by wt. total composition synthetic anionic surfactant;
(2) 0 to 20% by wt. total composition surfactant selected from the group consisting of amphoteric, zwitterionic nonionic and mixtures thereof; preferably amphoteric and zwitterionic surfactants comprise 2 to 15% by wt. total composition;
(3) 10% by 70% by wt. total composition of a polyalkylene glycol or mixture of polyalkylene glycol compounds having MW greater than 300 to less than 1500, preferably greater than 300 to about 1450 and below, more preferably 350 to 1400, more preferably above about 400 to about 1300 and below. Especially preferred embodiments have MW of about 1000 and below;
the weight ratio of the polyalkylene glycol to the anionic surfactant being at least 1:1, preferably 2:1 and greater;
(4) about 0% to 35% by wt. of solid structuring aids and fillers selected from the group consisting of (i) polyalkylene glycols having MW of 2500 to 10,000 and MP of about 55° to 65° C.; (ii) preferably straight chain, preferably saturated C 8 to C 24 free fatty acids; (iii) preferably straight chain, preferably saturated C 8 to C 20 alkanols; (iv) water soluble starches (e.g., maltodextrin);
(5) Further, because the high levels of low MW polyalkylene glycol are in the form of liquid or paste, about 1% to 20% by weight total composition gelling agents, as described more specifically below, are used to enhance bar integrity; and
(6) about 2% to 10% by weight total composition water.
Synthetic Non Soap Surfactant
The surfactant system of the invention will generally comprise at least one anionic surfactant as well as an optional second surfactant which is selected from the group consisting of amphoteric/zwitterionic surfactant, nonionic or mixtures thereof. Preferably, the composition comprises an anionic or anionic surfactant and an amphoteric/zwitterionic.
The anionic surfactant which may be used may be aliphatic sulfonates, such as a primary alkane (e.g., C 8 -C 22 ) sulfonate, primary alkane (e.g., C 8 -C 22 ) disulfonate, C 8 -C 22 alkene sulfonate, C 8 -C 22 hydroxyalkane sulfonate or alkyl glyceryl ether sulfonate (AGS); or aromatic sulfonates such as alkyl benzene sulfonate.
The anionic may also be an alkyl sulfate (e.g., C 12 -C 18 alkyl sulfate) or alkyl ether sulfate (including alkyl glyceryl ether sulfates). Among the alkyl ether sulfates are those having the formula:
RO(CH.sub.2 CH.sub.2 O).sub.n SO.sub.3 M
wherein R is an alkyl or alkenyl having 8 to 18 carbons, preferably 12 to 18 carbons, n has an average value of greater than 1.0, preferably greater than 3; and M is a solubilizing cation such as sodium, potassium, ammonium or substituted ammonium. Ammonium and sodium laurel ether sulfates are preferred.
The anionic may also be alkyl sulfosuccinates (including mono and dialkyl, e.g., C 6 -C 22 sulfosuccinates); alkyl and acyl taurates, alkyl and acyl sarcosinates, sulfoacetates, C 8 -C 22 alkyl phosphates and phosphates, alkyl phosphate esters and alkoxyl alkyl phosphate esters, acyl lactates, C 8 -C 22 monoalkyl succinates and maleates, sulphoacetates, alkyl glucosides and acyl isethionates.
Sulfosuccinates may be monoalkyl sulfosuccinates having the formula:
R.sup.1 O.sub.2 CCH.sub.2 CH(SO.sub.3 M)CO.sub.2 M; and
amide-MEA sulfosuccinates of the formula
R.sup.1 CONHCH.sub.2 CH.sub.2 O.sub.2 CCH.sub.2 CH(SO.sub.3 M)CO.sub.2 M
wherein R 1 ranges from C 8 -C 22 alkyl and M is a solubilizing cation.
Sarcosinates are generally indicated by the formula
RCON(CH.sub.3)CH.sub.2 CO.sub.2 M,
wherein R ranges from C 8 -C 20 alkyl and M is a solubilizing cation.
Taurates are generally identified by formula
R.sup.2 CONR.sup.3 CH.sub.2 CH.sub.2 SO.sub.3 M
wherein R 2 ranges from C 8 -C 20 alkyl, R 3 ranges from C 1 -C 4 alkyl and M is a solubilizing cation.
Particularly preferred are the C 8 -C 18 acyl isethionates. These esters are prepared by reaction between alkali metal isethionate with mixed aliphatic fatty acids having from 6 to 18 carbon atoms and an iodine value of less than 20. At least 75% of the mixed fatty acids have from 12 to 18 carbon atoms and up to 25% have from 6 to 10 carbon atoms.
Acyl isethionates, when present, will generally range from about 10% to about 35% by weight of the total bar composition. Preferably, this component is present from about 10% to about 30%.
The acyl isethionate may be an alkoxylated isethionate such as is described in Ilardi et al., U.S. Pat. No. 5,393,466, hereby incorporated by reference. This compound has the general formula ##STR1## wherein R is an alkyl group having 8 to 18 carbons, m is an integer from 1 to 4, X and Y are hydrogen or an alkyl group having 1 to 4 carbons and M + is a monovalent cation such as, for example, sodium, potassium or ammonium.
In general the anionic component will comprise from about 2 to 35% of the bar composition, preferably 10 to 30%.
Amphoteric detergents which may be used in this invention include at least one acid group. This may be a carboxylic or a sulphonic acid group. They include quaternary nitrogen and therefore are quaternary amido acids. They should generally include an alkyl or alkenyl group of 7 to 18 carbon atoms. They will usually comply with an overall structural formula: ##STR2##
where R 1 is alkyl or alkenyl of 7 to 18 carbon atoms;
R 2 and R 3 are each independently alkyl, hydroxyalkyl or carboxyalkyl of 1 to 3 carbon atoms;
n is 2 to 4;
m is 0 to 1;
x is alkylene of 1 to 3 carbon atoms optionally substituted with hydroxyl, and
y is --CO 2 -- or --SO 3 --
Suitable amphoteric detergents within the above general formula include simple betaines of formula: ##STR3##
and amido betaines of formula: ##STR4##
where m is 2 or 3.
In both formulae R 1 is alkyl or alkenyl of 7 to 18 carbons; and R 2 and R 3 are independently alkyl, hydroxyalkyl or carboxylalkyl of 1 to 3 carbons. R 1 may in particular be a mixture of C 12 and C 14 alkyl groups derived from coconut so that at least half, preferably at least three quarters of the groups R 1 have 10 to 14 carbon atoms. R 2 and R 3 are preferably methyl.
A further possibility is that the amphoteric detergent is a sulphobetaine of formula ##STR5##
where m is 2 or 3, or variants of these in which --(CH 2 ) 3 SO 3 - is replaced by ##STR6##
In these formulae R 1 , R 2 and R 3 are as discussed for the amido betaine.
Amphoteric, if present, generally comprises 2% to 15% of the bar composition.
Other surfactants (i.e., nonionics, cationics) may also be optionally used although these generally would not comprise more than 0.01 to 10% b wt. of the bar composition.
Nonionic surfactants include in particular the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example, aliphatic alcohols, acids, amides or alkyl phenols with alkylene oxides, especially ethylene oxide either alone or with propylene oxide. Specific nonionic detergent compounds are alkyl (C 6 -C 22 ) phenols-ethylene oxide condensates, the condensation products of aliphatic (C 8 -C 18 ) primary or secondary linear or branched alcohols with ethylene oxide, and products made by condensation of ethylene oxide with the reaction products of propylene oxide and ethylenediamine. Other so-called nonionic detergent compounds include long chain tertiary amine oxides, long chain tertiary phosphine oxides and dialkyl sulphoxides.
The nonionic may also be a sugar amide, such as a polysaccharide amide. Specifically, the surfactant may be one of the lactobionamides described in U.S. Pat. No. 5,389,279 to Au et al. which is hereby incorporated by reference and polyhydroxyamides such as described in U.S. Pat. No. 5,312,954 to Letton et al., hereby incorporated into the subject application by reference.
Examples of cationic detergents are the quaternary ammonium compounds such as alkyldimethylammonium halogenides.
Other surfactants which may be used are described in U.S. Pat. No. 3,723,325 to Parran Jr. and "Surface Active Agents and Detergents" (Volume I & II) by Schwartz, Perry & Berch, both of which are also incorporated into the subject application by reference.
Polyalkylene Glycol
A second required component of the invention is polyalkylene glycol or mixture of polyalkylene glycols wherein the polyalkylene glycol is, for example, a polyethylene or polypropylene glycol. The polyalkylene glycols must have a MW of between greater than 300, preferably greater than about 350 and 1500 Dalton.
This MW range is important because at MW below the minimum 300 range, the PEG in bar does not significantly reduce the skin irritation potential caused by anionic surfactants (see Example 2, FIG. 2 and 3); and at MW above 1500, the PEG molecule is not as readily miscible with long chain fatty acid soaps, which are used as gelling agents. Also at MW above 1500, the PEG does not provide as much oily skin feel as a PEG with a lower molecular weight.
It is another important aspect of the invention that ratio of alkylene glycol to anionic is at least 1:1 and preferably 2:1 and greater. Again, at ratio below 1:1, the mildness is not readily felt (see Example 1, FIG. 1).
Generally, this compound or mixture of compounds will comprise 10% to 70% by wt. of the bar compositions.
Gelling Agent
A gelling agent is required in the compositions of the invention. While not wishing to be bound by theory, such component is believed required because the higher levels of low MW polyalkylene glycol required by the invention are in the form of liquid or paste. The gelling agent is believed needed to enhance bar integrity.
Examples of gelling agents include, but are not limited to:
(i) neutralized C 8 to C 25 carboxylic acid (soap), preferably neutralized C 8 to C 25 monocarboxylic acid (straight chain, saturated soap);
(ii) paraffin waxes, polyethylene waxes, petrolatum, greases, jellies, fumed silica and/or aluminosilicates, urea, and clay;
Examples of waxes which may be used include Paraffin Wax distributed by Whittaker, Clark & Daniels, Inc. and Luwax from BASF, and MULTIWAX Microcrytalline WAX from Witco. A preferred wax is glyceryl stearate.
Generally, the gelling agent will comprise 1 to 20% by wt. total composition.
Bar Moisture Level
Finally, bars of the invention use low levels of water, i.e., 2% to less than 10% by wt., preferably 2% to 8%, more preferably 3% to 7% by weight total composition. Water levels are kept purposefully in such a range to ensure homogenous, pumpable melts which, upon cooling, form rigid solids. Excess water will result in poor mixing, low viscosities and phase separation in the melt and unacceptably soft solids and mushiness when cooled.
Optional Structuring Aids and Fillers
Another optional component of the invention is the use of solid structuring aids and fillers, i.e., to maintain bar structural integrity. Examples of such structuring aids include, but are not limited to the following:
polyalkylene glycols having MW of 2500 to 10,000 and MP of about 40° C. to 65° C.; C 8 to C 20 alkanols, preferably straight chain, preferably saturated C 14 to C 8 alkanols; C 8 to C 25 fatty acids, preferably straight chain, preferably saturated C 14 to C 22 fatty acids; and water soluble starches, such as maltodextrin.
The structuring aids and fillers generally comprise 0% to 35% by weight of the bar composition, preferably 10% to 25% by weight.
Other Optional Ingredients
Other components which may be used in the bars of the invention are as follows:
Bars of the invention also generally incorporate 0 to 30% by wt., preferably 1 to 25% of a benefit agent in the bar composition.
The benefit agent "composition" of the subject invention may be a single benefit agent component or it may be a benefit agent compound added via a carrier. Further the benefit agent composition may be a mixture of two or more compounds one or all of which may have a beneficial aspect. In addition, the benefit agent itself may act as a carrier for other components one may wish to add to the bar composition.
The benefit agent can be an "emollient oil" by which is meant a substance which softens the skin (stratum corneum) by increasing into water content and keeping it soft by retarding decrease of water content.
Preferred emollients include:
(a) silicone oils, gums and modifications thereof such as linear and cyclic polydimethylsiloxanes; amino, alkyl alkylaryl and aryl silicone oils;
(b) fats and oils including natural fats and oils such as jojoba, soybean, rice bran, avocado, almond, olive, sesame, persic, castor, coconut, mink oils; cacao fat; beef tallow, lard; hardened oils obtained by hydrogenating the aforementioned oils; and synthetic mono, di and triglycerides such as myristic acid glyceride and 2-ethylhexanoic acid glyceride;
(c) waxes such as carnauba, spermaceti, beeswax, lanolin and derivatives thereof;
(d) hydrophobic plant extracts;
(e) hydrocarbons such as liquid paraffins, vaseline, microcrystalline wax, ceresin, squalene, pristan and mineral oil;
(f) higher fatty acids such as lauric, myristic, palmitic, stearic, behenic, oleic, linoleic, linolenic, lanolic, isostearic and poly unsaturated fatty acids (PUFA);
(g) higher alcohols such as lauryl, cetyl, stearyl, oleyl, behenyl, cholesterol and 2-hexydecanol alcohol;
(h) esters such as cetyl octanoate, myristyl lactate, cetyl lactate, isopropyl myristate, myristyl myristate, isopropyl palmitate, isopropyl adipate, butyl stearate, decyl oleate, cholesterol isostearate, glycerol monostearate, glycerol distearate, glycerol tristearate, alkyl lactate, alkyl citrate and alkyl tartrate;
(i) essential oils such as mentha, jasmine, camphor, white cedar, bitter orange peel, ryu, turpentine, cinnamon, bergamot, citrus unshiu, calamus, pine, lavender, bay, clove, hiba, eucalyptus, lemon, starflower, thyme, peppermint, rose, sage, menthol, cineole, eugenol, citral, citronelle, borneol, linalool, geraniol, evening primrose, camphor, thymol, spirantol, penene, limonene and terpenoid oils;
(j) lipids such as cholesterol, ceramides, sucrose esters and pseudo-ceramides as described in European Patent Specification No. 556,957;
(k) vitamins such as vitamin A and E, and vitamin alkyl esters, including those vitamin C alkyl esters;
(l) sunscreens such as octyl methoxyl cinnamate (Parsol MCX) and butyl methoxy benzoylmethane (Parsol 1789);
(m) phospholipids; and
(n) mixtures of any of the foregoing components.
A particularly preferred benefit agent is silicone, preferably silicones having viscosity greater than about 10,000 centipoise. The silicone may be a gum and/or it may be a mixture of silicones. One example is polydimethylsiloxane having viscosity of about 60,000 centistokes.
All percentages mentioned above are intended to be by wt. unless otherwise indicated.
The following examples are meant for illustrative purposes only and are not intended to limit the claims in any way.
EXAMPLES
Methodology
Mildness Assessments
Zein dissolution test was used to preliminarily screen the irritation potential of the formulations studies. In an 8 oz. jar, 30 mLs of an aqueous dispersion of a formulation were prepared. The dispersion sat in a 45° C. bath until fully dissolved. Upon equilibration at room temperature, 1.5 gms of zein powder were added to each solution with rapid stirring for one hour. The solutions were then transferred to centrifuge tubes and centrifuged for 30 minutes at approximately 3,000 rpms. The undissolved zein was isolated, rinsed and allowed to dry in a 60° C. vacuum oven to a constant weight. The percent zein solubilized, which is proportional to irritation potential, was determined gravimetrically.
Formulation Processing (Cast-melt)
Bars were prepared by a cast melt process. First, the components were mixed together at 80-120° C. in a 500 ml beaker, and the water level was adjusted to approximately 10-15 wt. %. The batch was covered to prevent moisture loss and was mixed for about 15 minutes. Then the cover was removed, and the mixture was allowed to dry. The moisture content of the samples taken at different times during the drying stage and was determined by Karl Fisher titration with a turbo titrator. At the final moisture level (˜5%), the mixture in the beaker (in the form of a free-flow liquid) was dropped into bar molds and was allowed to be cooled at room temperature for four hours. Upon solidification, the mixture was casted in the bar mold into a bar.
Example 1
The Impact of PEG (MW>300)/Anionic Ratio on Anionic Surfactant--Protein Interaction
In the zein dissolution testing (FIG. 1), PEGs with molecular weight at 400 and above were found to significantly reduce the amount of zein protein dissolved by sodium acyl isethionate when the PEG to the anionic surfactant weight ratio was above 1:1, preferably above 2:1. Below this 1:1 PEG/anionic ratio, the benefit of zein-reduction by PEG was insignificant. These results show that, only at relatively high levels of addition, PEGs having molecular weight above 300 Dalton, preferably above about 350, function as skin moisturizer to reduce the surfactant skin interaction that leads to skin irritation.
Example 2
The Lack of Mildness Enhancement of PEG (MW≦300) on Anionic Surfactants
At and below molecular weight 300, PEGs and the presented water soluble nonionic monomers (i.e., ethylene glycol, propylene glycol, sorbitol, and glyceryl) do not significantly reduce the amount of zein protein dissolved by sodium acyl isethionate (FIG. 2) and sodium laurylether (3 EO) sulfate (FIG. 3). Therefore, there is a cut-off PEG molecular weight (around 300), below which PEG and those water soluble monomers are ineffective in reducing the surfactant protein interaction that may lead to skin irritation.
Example 3
Bar Formulations
The bar formulations 1-5 in Table 1 use anionic sodium acyl isethionate and sodium laurylether (3 EO) sulfate and amphoteric cocoamidopropyl betaine as the major detergents. Novel to the art, these bar compositions contain relatively high levels of low MW PEGs (MW between 400-1500) as moisturizer. PEG 1450 and PEG1000 in these ultra-mild bars (Formulation No. 1 to No. 4) promote rich and creamy lather.
In order to enhance the liquidish, non-occlusive type of moisturizing sensory cues, PEG 400 (having MW and melting temperature even lower than those of PEG 1450 and PEG 1000), is preferably used in Bar formulation No. 5
TABLE 1______________________________________Bar compositions containing relatively high levels of low MW PEGS. FORMULATIONS No. 1 No. 2 No. 3 No. 4 No. 5COMPOSITIONS Wt. % Wt. % Wt. % Wt. % Wt. %______________________________________Sodium Acyl Isethionate 15.0 15.0 8.0 10.0 20.0Sodium Laurylether 0.0 0.0 2.0 3.0 ?(3EO) SulfateCocoamidopropyl 10.0 10.0 15.0 12.0 5.0BetaineSodium Stearate 12.0 15.0 15.0 9.0 12.0PEG 1450 35.5 18.5 40.0 30.0 ?PEG 1000 0.0 0.0 0.0 12.0 ?PEG 8000 15.0 29.0 5.0 7.0 12.0Fatty Acid 4.0 4.0 9.5 4.5 10.0Paraffin Wax 3.0 3.0 0.0 7.0 5.0Water 5.5 5.5 5.5 5.5 4.0______________________________________
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The present invention relates to skin cleansing bar composition in which polyalkylene glycols of very specific molecular weights are used to define compositions which are mild, foam well and provide consumer-desired sensory profiles. A significant amount of these specific PEGs must be incorporated into the bar to deliver these desired effects. To properly process such a bar composition, the cast-melt method is the preferred technique.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to coding information, and more particularly, to a method and apparatus for coding information having improved information density. The present invention further relates to producing a modulated signal from the coded information, producing a recording medium from the coded information, and the recording medium itself. The present invention still further relates to a method and apparatus for decoding coded information, and decoding coded information from a modulated signal and/or a recording medium.
[0003] 2. Description of the Background Art
[0004] When data is transmitted through a transmission line or recorded onto a recording medium such as a magnetic disc, an optical disc or a magneto-optical disc, the data is modulated into code matching the transmission line or the recording medium prior to the transmission or recording.
[0005] Run length limited codes, generically designated as (d, k) codes, have been widely and successfully applied in modern magnetic and optical recording systems. Such codes, and means for implementing such codes are described by K. A. Schouhamer Immink in the book entitled “Codes for Mass Data Storage Systems” (ISBN 90-74249-23-X , 1999). Run length limited codes are extensions of earlier non return to zero recording codes, where binary recorded “zeros” are represented by no (magnetic flux) change in the recording medium, while binary “ones” are represented by transitions from one direction of recorded flux to the opposite direction.
[0006] In a (d, k) code, the above recording rules are maintained with the additional constraints that at least d “zeros” are recorded between consecutive “ones”, and no more than k “zeros” are recorded between consecutive “ones”. The first constraint arises to obviate intersymbol interference occurring because of pulse crowding of the reproduced transitions when a series of “ones” are contiguously recorded. The second constraint arises to ensure recovering a clock from the reproduced data by “locking” a phase locked loop to the reproduced transitions. If there is too long an unbroken string of contiguous “zeros” with no interspersed “ones”, the clock regenerating phase-locked-loop will fall out of synchronism. In, for example, a (2,7) code there is at least two “zeros” between recorded “ones”, and there are no more than seven recorded contiguous “zeros” between recorded “ones”.
[0007] The series of encoded bits is converted, via a modulo-2 integration operation, to a corresponding modulated signal formed by bit cells having a high or low signal value. A “one” bit is represented in the modulated signal by a change from a high to a low signal value or vice versa, and a “zero” bit is represented by the lack of change in the modulated signal.
[0008] The information conveying efficiency of such codes is typically expressed as a rate, which is the quotient of the number of bits (m) in the information word to the number of bits (n) in the code word (i.e., m/n). The theoretical maximum rate of a code, given values of d and k, is called the Shannon capacity. FIG. 1 tabulates the Shannon capacity C(d,k) for d=2 versus k. As shown, for a (2,7) code, the Shannon capacity, C(2,7), has a value of 0.5174. This means that a (2,7) code cannot have a rate larger than 0.5174. The practical implementation of codes requires that the rate be a rational fraction, and to date the above (2,7) code has a rate ½. This rate of ½ is slightly less than the Shannon capacity of 0.5174, and the code is therefore a highly efficient one. To achieve the ½ rate, 1 unconstrained data bit is mapped into 2 constrained encoded bits.
[0009] (2,7) codes having a rate of ½ and means for implementing associated encoders and decoders are known in the art. U.S. Pat. No. 4,115,768 entitled “Sequential Encoding and Decoding of Variable Word Length, Fixed Rate Data Codes”, issued in the names of Eggenberger and Hodges, discloses an encoder whose output sequences satisfy the imposed runlength constraints.
[0010] However, a demand exists for even more efficient codes so that, for example, the information density on a recording medium or over a transmission line can be increased.
SUMMARY OF THE INVENTION
[0011] In the converting method and apparatus according to the present invention, m-bit information words are converted into n-bit code words at a rate greater than ½. Consequently, the same amount of information can be recorded in less space, and information density increased.
[0012] In the present invention, n-bit code words are divided into a first type, a second type and a third type, and into coding states of a first kind, a second kind and a third kind such that an m-bit information word is converted into an n-bit code word of the first, second or third kind if the previous m-bit information word was converted into an n-bit code word of the first type and is converted into an n-bit code word of the first or third kind, if the previous m-bit information word was converted into an n-bit code word of the second type and is converted into an n-bit code word of the first kind, if the previous m-bit information word was converted into an n-bit code word of the third type. Further, sets of code words belonging to the different coding states do not contain any code words in common. In one embodiment, n-bit code words of the first type end in “00”, n-bit code words of the second type end in “10”, n-bit code words of the third type end in “01”, n-bit code words belonging to the states of the first kind start with “00”, n-bit code words belonging to the states of the second kind start with “00”, “01” or “10”, and n-bit code words belonging to the states of the third kind start with “00” or “01”. Furthermore, in the embodiments according to the present invention, the n-bit code words satisfy a dk-constraint to (2,k) such that a minimum of 2 zeros and a maximum of k zeros falls between consecutive ones.
[0013] In other embodiments of the present invention, the coding device and method according to the present invention are employed to record information on a recording medium and create a recording medium according to the present invention.
[0014] In still other embodiments of the present invention, the coding device and method according to the present invention are further employed to transmit information.
[0015] In the decoding method and apparatus according to the present invention, n-bit code words created according to the coding method and apparatus are decoded into m-bit information words. The decoding involves determining the state of a next n-bit code word, and based on the state determination, the current n-bit code word is converted into an m-bit information word.
[0016] In other embodiments of the present invention, the decoding device and method according to the present invention are employed to reproduce information from a recording medium.
[0017] In still other embodiments of the present invention, the decoding device and method according to the present invention are employed to receive information transmitted over a medium.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, wherein like reference numerals designate corresponding parts in the various drawings, and wherein:
[0019] [0019]FIG. 1 tabulates the Shannon capacity C(d,k) for d=2 versus k;
[0020] [0020]FIG. 2 shows an example of how the code words in the various subgroups are allocated into the various states in the first embodiment;
[0021] [0021]FIG. 3 shows an embodiment for a coding device according to the invention;
[0022] FIGS. 4 A- 4 B show a complete translation table according to the first embodiment for converting 6-bit information words into 11-bit code words;
[0023] [0023]FIG. 5 illustrates the conversion of a series of information words into a series of code words using the translation table of FIGS. 4 A- 4 B;
[0024] [0024]FIG. 6 illustrates an embodiment of a recording device according to the present invention;
[0025] [0025]FIG. 7 illustrates a recording medium and modulated signal according to the present invention;
[0026] [0026]FIG. 8 illustrates a transmission device according to the present invention;
[0027] [0027]FIG. 9 illustrates a decoding device according to the present to invention;
[0028] [0028]FIG. 10 illustrates a reproducing device according to the present invention;
[0029] [0029]FIG. 11 illustrates a receiving device according to the present invention;
[0030] [0030]FIG. 12 shows an example of how the code words in the various subgroups are allocated in to the various states in the second embodiment;
[0031] FIGS. 13 A- 13 B show the beginning portion of a translation table according to the second embodiment for converting 11-bit information words into 20-bit code words;
[0032] [0032]FIG. 14 shows an example of how the code words in the various subgroups are allocated into the various states in the third embodiment;
[0033] FIGS. 15 A- 15 B show a translation table according to the third embodiment for converting 6- bit information words into 11-bit code words;
[0034] [0034]FIG. 16 shows an example of how the code words in the various subgroups are allocated into the various states in the fourth embodiment;
[0035] FIGS. 17 A- 17 D show a translation table according to the fourth embodiment for converting 7 -bit information words into 13 -bit code words.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] The general coding method according to the present invention will be described followed by a specific first embodiment of the coding method. Next, the general decoding method according to the present invention will be described in the context of the first embodiment. The various apparatuses according to the present invention will then be described. Specifically, the coding device, recording device, transmission device, decoding device, reproducing device and receiving device according to the present invention will be described. Afterwards, additional coding embodiments according to the present invention will be described.
CODING METHOD
[0037] According to the present invention, an m-bit information word is converted into an n-bit code word such that the rate of m/n is greater than ½. The code words are divided into first, second and third types wherein the first type includes code words ending with “00”, the second type includes code words ending with “10” and the third type includes code words ending with “01”. As a result, the code words of the first type are divided into three subgroups E 0000 , E 1000 and E 0100 , code words of the second type are divided into three subgroups E 0010 , E 1010 and E 0110 , and the code words of the third type are divided into three subgroups E 0001 , E 1001 and E 0101 . Code word subgroup E 0000 includes code words that start with “00” and end with “00”, code word subgroup E 1000 includes code words that start with “10” and end with “00”, code word subgroup E 0100 includes code words that start with “01” and end with “00”. Code word subgroup E 0010 includes code words that start with “00” and end with “10”, code word subgroup E 1010 includes code words that start with “10” and end with “10”, code word subgroup E 0110 includes code words that start with “01” and end with “10”. Code word subgroup E 0001 includes code words that start with “00” and end with “01”, code word subgroup E 1001 includes code words that start with “10” and end with “01”, code word subgroup E 0101 includes code words that start with “01” and end with “01”.
[0038] The code words are also divided into at least one state of a first kind, at least one state of a second kind, and at least one state of a third kind. States of the first kind include code words that only start with “00” and states of the second kind include code words that start with one of the “00”, “01” and “10”, and states of the third kind include code words that start with either “00” or “01”.
[0039] Further, sets of code words belonging to the different coding states do not contain any code words in common. In other words, different states can not include the same code word.
CODING METHOD ACCORDING TO A FIRST EMBODIMENT
[0040] In a first preferred embodiment of the present invention, 6-bit information words are converted into 11-bit code words. The code words satisfy a (2,k) constraint, an d are divided into 4(r 1 ) states of the first kind, 3(r 2 ) states of the second kind, and 2(r 3 ) states of the third kind (total of r=r 1 +r 2 +r 3 =9 states). In order to reduce the k-constraint, a code word, namely, “0000000000000” is barred from the encoding tables.
[0041] To perform encoding, each 11-bit code word in each state is associated with a coding state direction. The state direction indicates the next state from which to select a code word in the encoding process. The state directions are assigned to code words such that code words that end with a “00” (i.e. code words in subgroups E 0000 , E 1000 and E 0100 ) have associated state directions that indicate any of the r=9 states, while code words that end with a “10” (i.e., code words in subgroups E 0010 , E 1010 and E 0110 ) have associated state directions that only indicate one of the states of the first kind or the third kind. Furthermore, code words that end with a “01” (i.e., code words in subgroups E 0001 , E 1001 and E 0101 ) have associated state directions that only indicate one of the states of the first kind. This ensures that the d=2 constraint will be satisfied.
[0042] Furthermore, while, as explained in more detail below, the same code word can be assigned to different information words in the same state, different states cannot include the same code word. In particular code words in subgroups E 0000 , E 1000 and E 0100 can be assigned 9 times to different information words within one state, while code words in subgroups E 0010 , E 1010 and E 0110 can be assigned 6 times to different information words within one state. Furthermore, code words in subgroups E 0001 , E 1001 and E 0101 can be assigned 4 times to different information words within one state. As there are 18 code words in subgroup E 0000 , 13 code words in subgroup E 1000 and 9 code words in subgroup E 0100 , there are 360 (9*(18+13+9)) “code word—state direction” combinations for code words of the first type. There are 9 code words in subgroup E 0010 , 6 code words in subgroup E 1010 and 4 code words in subgroup E 0110 , so that there are 114 (6*(9+6+4)) “code word—state direction” combinations for code words of the second type. There are 11 code words in subgroup E 0001 , 9 code words in subgroup E 1001 and 6 code words in subgroup E 0101 , so that there are 104 (4*(11+9+6) “code word—state direction” combinations for code words of the third type. In total 360+114+104=578 “code word—state direction” combinations exist.
[0043] For m-bit information words, there are a total of 2 m possible information words. So, for 6-bit information words, 2 6 =64 information words exist. Because there are nine states in this encoding embodiment, 9 times 64=576 of the “code word—state direction” combinations are needed. This leaves 578-576=2 remaining combinations.
[0044] The available code words in the various subgroups are distributed over the states of the first, the second and third kind in compliance with the restrictions discussed above. FIG. 2 shows an example of how the code words in the various subgroups are allocated in this embodiment to the various states. As shown in FIG. 2, in this example, states 1 , 2 , 3 and 4 are states of the first kind, and states 5 , 6 and 7 are states of the second kind, and states 8 and 9 are states of the third kind. Taking the subgroup E 0000 of size 18 as an example, subgroup E 0000 has 6 code words in states 1 and 4 code word in each of states 2 , 3 and 4 . And, taking state 1 as an example, in state 1 the number of “code word—state direction” combinations is 9×6+6×1+4×1=64, which means that 6-bit information words can be assigned. Remember, each code word of the first type can be assigned any one of the nine different states as a state directions, and therefore used nine times within a state; while each code word of the second type can only be assigned one of the six states of the first kind and the third kind as a state direction because of the d=2 restriction, and therefore used six times within a state. Furthermore, each code word of the third type can only be assigned one of the four states of the first kind as a state direction because of the d=2 restriction, and therefore used four times within a state.
[0045] It can be verified that from any of the r=9 coding states shown in FIG. 2 there at least 64 information words that can be assigned to code words, which is enough to accommodate 6-bit information words. In the manner described above any random series of 6-bit information words can be uniquely converted to a series of code words.
[0046] FIGS. 4 A- 4 B show a complete translation table according to this embodiment for converting 6-bit information words into 11-bit code words. Included in the translation table of FIGS. 4 A- 4 B are the state direction assigned to each code word. Specifically, in FIGS. 4 A- 4 B, the first column shows the decimal notation of the information words. The second, fourth, sixth, eighth, tenth, twelfth, fourteenth, sixteenth, and eighteenth columns show the code words (also referred to in the art as channel bits) assigned to the information words in states 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 and 9 , respectively. The third, fifth, seventh, ninth, eleventh, thirteenth, fifteenth, seventeenth and nineteenth columns show by way of the respective digits 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 and 9 , the state direction of the associated code words in the second, fourth, sixth, eighth, tenth, twelfth, fourteenth, sixteenth, and eighteenth columns, respectively.
[0047] The conversion of a series of information words into a series of code words will be further explained with reference to FIG. 5. The first column of FIG. 5 shows from top to bottom a series of successive 6-bit information words, and the second column shows in parenthesis the decimal values of these information words. The third column “state” is the coding state that is to be used for the conversion of the information word. The “state” is laid down when the preceding code word was delivered (i.e., the state direction of the preceding code word). The fourth column “code words” includes the code words assigned to the information words according to the translation table of FIGS. 4 A-B. The fifth column “next state” is the state direction associated with the code word in the fourth column and is also determined according to the translation table of FIGS. 4 A-B.
[0048] The first word from the series of information words shown in the first column of FIG. 5 has a word value of “1” in decimal notation. Let us assume that the coding state is state 1 (S 1 ) when the conversion of the series of information words is initiated. Therefore the first word is translated into code word “00000000100” according to the state 1 set of code words from the translation table. At the same time the next state becomes state 2 (S 2 ) because the state direction assigned to code word “00000000100” representing decimal value 1 in state 1 is state 2 . This means that the next information word (decimal value “3”) is going to be translated using the code words in state 2 . Consequently, the next information word, having a decimal value of “3”, is translated into code word “00001000100”. Similar to the manner described above, the information words having the decimal values “5”, “12” and “19” are converted.
Decoding Method
[0049] Hereinafter, decoding of n-bit code words (in this example 11-bit words) received from a recording medium will be further explained with reference to FIGS. 4 A- 4 B. For the purposes of description, assume that the word values of a series of successive code words received from, for example, a recording medium are “00000001000”, “00010010000”, “10000100100”. From the translation table of FIGS. 4 A- 4 B, it is found that the first code word “00000001000” is assigned to the information words “9”, “10”, “11”, “12”, “13”, “14”, “15”, “16”, and “17” and state directions 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 and 9 , respectively. The next code word value is “00010010000”, and belongs to the set of code words in state 3 . This means that the first code word “00000001000” had a state direction of 3. The first code word “00000001000” with a state direction of 3 represents the information word having a decimal value of “11”. Therefore, it is determined that the first code word represents information word “00000001000” having a decimal value of “11”.
[0050] Furthermore, the third code word “10000100100” is a member of state 6 . Therefore, it is determined in the same manner as above that the second code word “00010010000” represents the information word having the decimal value “14”. In the same manner other code words can be decoded. It is noted that both the current code word and the next code words are observed to decode the current code word into a unique information word.
Coding Device
[0051] [0051]FIG. 3 shows an embodiment for a coding device 124 according to the invention. The coding device 124 converts m-bit information words into n-bit code words, where the number of different coding states r is represented by s bits. For example, when the number of coding states r=9, s equals 4. As shown, the coding device 124 includes a converter 50 for converting (m+s) binary input signals to (n+s) binary output signals. In a preferred embodiment, the converter 50 includes a read only memory (ROM) storing a translation table according to at least one embodiment of the present invention and address circuitry for addressing the translation table based on the m+s binary input signals. However, instead of a ROM, the converter 50 can include a combinatorial logic circuit producing the same results as the translation table according to at least one embodiment of the present invention.
[0052] From the inputs of the converter 50 , m inputs are connected to a first bus 51 for receiving m-bit information words. From the outputs of the converter 50 , n outputs are connected to a second bus 52 for delivering n-bit code words. Furthermore, s inputs are connected to an s-bit third bus 53 for receiving a state word that indicates the instantaneous coding state. The state word is delivered by a buffer memory 54 including, for example, s flip-flops. The buffer memory 54 has s inputs connected to a fourth bus 55 for receiving a state direction to be loaded into the buffer memory 54 as the state word. For delivering the state directions to be loaded in the buffer memory 54 , the s outputs of the converter 50 are used.
[0053] The second bus 52 is connected to the parallel inputs of a parallel-to-serial converter 56 , which converts the code words received over the second bus 52 to a serial bit string. A signal line 57 supplies the serial bit string to a modulator circuit 58 , which converts the bit string into a modulated signal. The modulated signal is then delivered over a line 60 . The modulator circuit 58 is any well-known circuit for converting binary data into a modulated signal such as a modula- 2 integrator.
[0054] For the purposes of synchronizing the operation of the coding device, the coding device includes a clock generating circuit (not shown) of a customary type for generating clock signals for controlling timing of, for example, the parallel/serial converter 58 and the loading of the buffer memory 54 .
[0055] In operation, the converter 50 receives m-bit information words and an s-bit state word from the first bus 51 and the third bus 53 , respectively. The s-bit state word indicates the state in the translation table to use in converting the m-bit information word. Accordingly, based on the value of the m-bit information word, the n-bit code word is determined from the code words in the state identified by the s-bit state word. Also, the state direction associated with the n-bit code word is determined. The state direction, namely, the value thereof is converted into an s-bit binary word; or alternatively, the state directions are stored in the translation table as s-bit binary words. The converter 50 outputs the n-bit code word on the second bus 52 , and outputs the s-bit state direction on fourth bus 55 . The buffer memory 54 stores the s-bit state direction as a state word, and supplies the s-bit state word to the converter 50 over the third bus 53 in synchronization with the receipt of the next m-bit information word by the converter 50 . This synchronization is produced based on the clock signals discussed above in any well-known manner.
[0056] The n-bit code words on the second bus 52 are converted to serial data by the parallel/serial converter 56 , and then the serial data is converted into a modulated signal by the modulator 58 .
[0057] The modulated signal may then undergo further processing for recordation or transmission.
Recording Device
[0058] [0058]FIG. 6 shows a recording device for recording information that includes the coding device 124 according to the present invention as shown in FIG. 3. As shown in FIG. 6, m-bit information is converted into a modulated signal through the coding device 124 . The modulated signal produced by the coding device 124 is delivered to a control circuit 123 . The control circuit 123 may be any conventional control circuit for controlling an optical pick-up or laser diode 122 in response to the modulated signal applied to the control circuit 123 so that a pattern of marks corresponding to the modulated signal are recorded on the recording medium 110 .
[0059] [0059]FIG. 7 shows by way of example, a recording medium 110 according to the invention. The recording medium 110 shown is a read-only memory (ROM) type optical disc. However, the recording medium 110 of the present invention is not limited to a ROM type optical disk, but could be any type of optical disk such as a write-once read-many (WORM) optical disk, random accessible memory (RAM) optical disk, etc. Further, the recording medium 110 is not limited to being an optical disk, but could be any type of recording medium such as a magnetic disk, a magneto-optical disk, a memory card, magnetic tape, etc.
[0060] As shown in FIG. 7, the recording medium 110 according to one embodiment of the present invention includes information patterns arranged in tracks 111 . Specifically, FIG. 7 shows an enlarged view of a track 111 along a direction 114 of the track 111 . As shown, the track 111 includes pit regions 112 and non-pit regions 113 . Generally, the pit and non-pit regions 112 and 113 represent constant signal regions of the modulated signal 115 (zeros in the code words) and the transitions between pit and non-pit regions represent logic state transitions in the modulated signal 115 (ones in the code words).
[0061] As discussed above, the recording medium 110 may be obtained by first generating the modulated signal and then recording the modulated signal on the recording medium 110 . Alternatively, if the recording medium is an optical disc, the recording medium 110 can also be obtained with well-known mastering and replica techniques.
Transmission Device
[0062] [0062]FIG. 8 shows a transmission device for transmitting information that includes the coding device 124 according to the present invention as shown in FIG. 3. As shown in FIG. 8, m-bit information words are converted into a modulated signal through the coding device 124 . A transmitter 150 then further processes the modulated signal, to convert the modulated signal into a form for transmission depending on the communication system to which the transmitter belongs, and transmits the converted modulated signal over a transmission medium such as air (or space), optical fiber, cable, a conductor, etc.
Decoding Device
[0063] [0063]FIG. 9 illustrates a decoder according to the present invention. The decoder performs the reverse process of the converter of FIG. 3 and converts n-bit code words of the present invention into m-bit information words. As shown, the decoder 100 includes a first look-up table (LUT) 102 and a second LUT 104 . The first and second LUTs 102 and 104 store the translation table used to create the n-bit code words being decoded. Where K refers to time, the first LUT 102 receives the (K+1)th n-bit code word and the second LUT 104 receives the output of the first LUT 102 and the Kth n-bit code word. Accordingly, the decoder 100 operates as a sliding block decoder. At every block time instant the decoder 100 decodes one n-bit code word into one m-bit information word and proceeds with the next n-bit code word in the serial data (also referred to as the channel bit stream).
[0064] In operation, the first LUT 102 determines the state of the (K+1)th code word from the stored translation table, and outputs the state to the second LUT 104 . So the output of the first LUT 102 is a binary number in the range of 1, 2, . . . , r (where r denotes the number of states in the translation table). The second LUT 104 determines the possible m-bit information words associated with Kth code word from the Kth code word using the stored translation table, and then determines the specific one of the possible m-bit information words being represented by the n-bit code word using the state information from the first LUT 102 and the stored translation table.
[0065] For the purposes of further explanation only, assume the n-bit code words are 11-bit code words produced using the translation table of FIGS. 4 A- 4 B. Then, referring to FIG. 5, if the (K+1)th 11-bit code word is “00001000100” the first LUT 102 determines the state as state 2 . Furthermore, if the Kth 11-bit code word is “00000000100”, then the second LUT 104 determines that the Kth 11-bit code word represents one of the 6-bit information words having a decimal value of 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9. And, because the next state or state direction of state 2 is supplied by the first LUT 102 , the second LUT 104 determines that the Kth 11-bit code word represents the 6-bit information word having a decimal value of 1 because the 11-bit code word “00000000100” associated with a state direction of 2 represents the 6-bit information word having a decimal value of 1.
Reproducing Device
[0066] [0066]FIG. 10 illustrates a reproducing device that includes the decoder 100 according to the present invention as shown in FIG. 9. As shown, the reading device includes an optical pick-up 122 of a conventional type for reading a recording medium 110 according to the invention. The recording medium 110 may be any type of recording medium such as discussed previously. The optical pickup 122 produces an analog read signal modulated according to the information pattern on the recording medium 110 . A detection circuit 125 converts this read signal in conventional fashion into a binary signal of the form acceptable to the decoder 100 . The decoder 100 decodes the binary signal to obtain the m-bit information words.
Receiving Device
[0067] [0067]FIG. 11 illustrates a receiving device that includes the decoder 100 according to the present invention as shown in FIG. 9. As shown, the receiving device includes a receiver 160 for receiving a signal transmitted over a medium such as air (or space), optical fiber, cable, a conductor, etc. The receiver 160 converts the received signal into a binary signal of the form acceptable to the decoder 100 . The decoder 100 decodes the binary signal to obtain the m-bit information words.
Coding Method According to a Second Embodiment
[0068] [0068]FIGS. 12 and 13A- 13 B illustrate another embodiment of the present invention. According to this embodiment, the greater than ½ rate is achieved by converting 11-bit information words into 20 -bit code words; wherein the number of coding states r equals 9, and 4 of the coding states are coding states of the first kind and 3 of the coding states are coding states of the second kind and 2 of the coding states are coding state of the third kind. Also, the code words satisfy a (2,k) constraint. FIG. 12 corresponds to FIG. 2 of the first embodiment, and illustrates the division of code words among the states in this second embodiment.
[0069] As described above, code words that end with a “00”, i.e. code words in subgroups E 0000 , E 1000 , and E 0100 , are allowed to enter any of the r=9 states, while code words that end with a “10” i.e. code words in subgroups E 0010 , E 1010 and E 0110 , may only enter the states of the first kind or third kind (State 1 to State 4 or State 8 to State 9 ). Furthermore, code words that end with a “01” i.e. code words in subgroups E 0001 , E 1001 and E 0101 , may only enter the states of the first kind (State 1 to State 4 ).
[0070] Therefore, code words in subgroups E 0000 , E 1000 and E 0100 can be assigned 9 times to different information words, while code words in subgroups E 0010 , E 1010 and E 0110 can be assigned 6 times to different information words, and code words in subgroups E 0001 , E 1001 and E 0101 can be assigned 4 times to different information words. Referring to FIG. 12, subgroup E 0000 has 152 code words in state 1 , and the subgroup E 0010 has 65 code words in state 1 , and the subgroups E 0001 has 70 code words in state 1 . So the number of “code words—state direction” combinations is (9×152)+(6×65)+(4×75)=2,058, which means that 11-bit information words (2 11 =2,048) can be assigned. It can be verified that from any of the r=9 coding states there at least 2,048 information words that can be assigned to code words, which is enough to accommodate 11-bit information words.
[0071] FIGS. 13 A- 13 B illustrate the beginning portion of the translation table for this second embodiment in the same fashion that FIGS. 4 A- 4 B illustrated the translation table for the first embodiment.
Coding Method According to a Third Embodiment
[0072] [0072]FIGS. 14 and 15A- 15 B illustrate another embodiment of the present invention. According to this embodiment, the greater than {fraction (1/2)} rate is achieved by converting 6-bit information words into 11-bit code words; wherein the number of coding states r equals 9, and 4 of the coding states are coding states of the first kind and 3 of the coding states are coding states of the second kind and 2 of the coding states are coding state of the third kind, similar to those of the first embodiment. Also, the code words satisfy a (2,k) constraint. FIG. 14 corresponds to FIG. 2 of the first embodiment, and illustrates the division of code words among the states in this third embodiment. It can be verified that from any of the r=9 coding states there at least 64 information words that can be assigned to code words, which is enough to accommodate 6-bit information words.
[0073] FIGS. 15 A- 15 B illustrate a translation table for this third embodiment in the same fashion that FIGS. 4 A- 4 B illustrated the translation table for the first embodiment.
Coding Method According to a Fourth Embodiment
[0074] [0074]FIGS. 16 and 17A- 17 D illustrate another embodiment of the present invention. According to this embodiment, the greater than ½ rate is achieved by converting 7-bit information words into 13-bit code words; wherein the number of coding states r equals 9, and 4 of the coding states are coding states of the first kind and 3 of the coding states are coding states of the second kind and 2 of the coding states are coding state of the third kind, similar to those of the first embodiment. Also, the code words satisfy a (2,k) constraint. FIG. 16 corresponds to FIG. 2 of the first embodiment, and illustrates the division of code words among the states in this fourth embodiment. It can be verified that from any of the r=9 coding states there at least 128 information words that can be assigned to code words, which is enough to accommodate 7-bit information words.
[0075] FIGS. 17 A- 17 D illustrate a translation table for this fourth embodiment in the same fashion that FIGS. 4 A- 4 B illustrated the translation table for the first embodiment.
[0076] 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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A coding device and method in which m-bit information words are converted into n-bit code words such that the coding rate m/n is greater than ½. The coding device and method are also employed to record information on a recording medium and to transmit information. In the decoding method and apparatus, n-bit code words are decoded into m-bit information words. The decoding involves determining the state of a next n-bit code word, and based on the state determination, the current n-bit code word is converted into an m-bit information word. The decoding device and method are employed to reproduce information from a recording medium, and to receive information transmitted over a medium.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of co-pending provisional application No. 61/056,000 filed May 25, 2008.
FIELD OF INVENTION
[0002] This invention relates to pattern analysis. This invention relates particularly to methods and devices for detecting and analyzing energy fields emitted by organisms.
BACKGROUND
[0003] All live organisms emit energy fields, referred to herein as vital fields, which are characterized by the organic processes that produce or modify them. There is a significant amount of skepticism surrounding vital fields because no known scientific instruments can detect them. The inability to detect, measure, and describe the energy in a vital field is a problem that inhibits human understanding of biological interactions with the environment.
[0004] A wave in an energy field is considered to comprise four components—electric, magnetic, gravitational and temporal. The electric, magnetic, and gravitational components are orthogonal to each other. In an electromagnetic wave, the gravitational and temporal components have a static value, and the electric and magnetic components vary inversely. In this context, a static temporal component equates to time moving forward at a constant rate. In contrast, a vital wave is theorized to contain static electric and magnetic components and dynamic temporal and gravitational components. Such a wave is essentially a longitudinal or compression wave in the space-time fabric. Because vital waves do not have a dynamic magnetic component, they do not induce a current in a conductor. Most known devices rely on such induction and is therefore unable to reliably detect the presence of vital waves or measure or describe them scientifically.
[0005] Kirlian photography, discovered in the early 20th century, can be considered one of the earliest means of analyzing vital fields. Kirlian photography works by driving a photographic plate at high voltage, with a biological specimen resting on the plate. The resulting image left on the film is consistent with the corona discharge pattern of the specimen. Live specimens tend to show a shimmering coronal effect, whereas dead specimens and inanimate objects exhibit a more uniform pattern. The difference is attributed to the live specimen having at least one vital field. It should be noted, however, that Kirlian photography as an indication of vital fields has been met with skepticism, with the results explained away as errors in the experimental process.
[0006] Most vital field detection devices to date have been either a variation of Kirlian high-voltage equipment or low voltage electric field sensors. One device, used to detect pathogens in an organism, places the organism in an electrical field and detects an aura signature of pathogens energized by the field. Another device uses a passive detector that characterizes pulses of charge transfer called charge density pulses through conductive plates placed near the palms of the hands. The decay envelope of the detected pulse train may provide information useful for analysis of the body's chakra regions. However, the data is extracted from a pulse train that does not achieve a steady state, and so the data that can be obtained is limited. Further, the data describing the electric component of present waves would not completely describe the temporogravitational wave because its electric component is static.
[0007] Some detectors, such as electrocardiographs and electroencephalographs, analyze alternating current waveforms detected by electrodes placed on the skin of the test subject. One known device uses contacts on the palms and fingers to detect the physiological signals of the human body supposedly associated with auras. Other detectors introduce an electric current into the electrodes, such as with a galvanic skin response and others, which measure the organism's interaction with the introduced current through physical contact between the organism and the detector. Still other devices use capacitance to measure the interaction, but must be placed extremely close to the organism to be effective. Contact and capacitance based devices suffer significant problems with artifacts caused by the proximity.
[0008] One device capable of detecting the static magnetic component of a wave is the Superconducting Quantum Interference device, or “SQUID.” SQUIDS are highly sensitive, extremely expensive magnetometers. However, SQUIDS only detect the presence of strong waves. A typical vital field generated by an organism has weak vital waves that SQUIDS cannot detect. Further, SQUIDS do not detect the spectral information needed analyze a vital field.
[0009] A detection device that is inexpensive, reliable, and capable of detecting vital fields is needed. Therefore, it is an object of the present invention to reliably detect and analyze vital fields. It is a further object that the vital fields be detected with a device that is relatively inexpensive compared to known devices. It is another object of the invention that the device and method of detection reduces unwanted artifacts by not contacting the organism.
SUMMARY OF THE INVENTION
[0010] The present device is placed in a vital field such that the vital waves in the vital field are conducted into a detector having an avalanche diode and an avalanche initiator. The avalanche diode is preferably an avalanche photodiode (“APD”). The APD is reverse biased and the bias voltage is supplied by a voltage source. The avalanche initiator impacts the avalanche diode with sufficient energy to generate seed electrons for the electron avalanche process. The energy provided by the avalanche initiator to the avalanche diode may be continuous or pulsed. The avalanche initiator is preferably an optical energy source, and most preferably a silicon vertical cavity surface emitting laser (“VCSEL”), but may be a high-electronvolt generator if the avalanche diode is not a photodiode. Preferably, the vital waves are conducted into the active region of the APD through a focusing horn to concentrate the energy.
[0011] Control circuitry provides a first control signal at a first sampling frequency to the detector. The first control signal is chosen to undersample the vital waves from the vital field, which have very high frequency. The first control signal modulates the gain of the avalanche diode. The avalanche initiator provides sufficient energy to the avalanche diode to create free electrons that start the avalanche process. During the period of increased gain, the vital waves from the vital field cause a detectable interference with the electric field in the active region of the avalanche diode, producing a first mixed signal including a first beat frequency that is the difference between the frequency of the vital waves and a high harmonic of the first sampling frequency.
[0012] The first mixed signal is conducted to signal processing circuitry, which filters the signal and applies Fourier transforms. Extraction of the beat frequency from the first mixed signal indicates that the vital waves are present. Then, the control circuitry is adjusted to produce a second control signal and the detection process repeats, producing a second mixed signal with a second beat frequency. The signal processing circuitry uses the first and second beat frequencies to determine the frequency of the vital waves from the vital field. The results of the signal processing are then displayed on a screen. Both the control circuitry and the signal processing circuitry include components that work to limit noise and other artifacts generated during the detection process.
[0013] Through continued use of the device, a reference database is developed to associate vital fields with the organisms, organs, organic material, metaphysical changes, or conditions presumed to generate the vital fields.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic diagram of the present device.
[0015] FIG. 2 is a circuit diagram of the preferred embodiment of the present device.
[0016] FIG. 3 is a circuit diagram of an alternate embodiment of the present device.
DETAILED DESCRIPTION OF THE INVENTION
[0017] FIG. 1 illustrates the present invention, which is a device 10 for detecting and analyzing vital fields. The device 10 is placed in the path of vital waves 19 that are present in the vital field to be detected. The detection process is initiated through a user interface 14 , such as by pressing a button or a designated part of a touch screen that indicates to control circuitry 11 that the process should begin. The control circuitry 11 then generates, as described in detail below, a first control signal having a first sampling frequency, and sends the first control signal to a detector 12 . The control circuitry 11 may also send the first control signal to signal processing circuitry 13 for use in a frequency converter as described below.
[0018] To achieve the desirably high sensitivity of the device 10 , the detector 12 may be substantially enclosed by electromagnetic shielding 15 . The shielding 15 protects the internal components of the detector 12 from unwanted interference by light and other electromagnetic waves. The shielding 15 may be a Faraday cage or other shielding structure. If light-sensitive components are not used, the shielding 15 may be a mesh of conducting material, but preferably the shielding 15 fully encloses the detector's 12 internal components, except that a small opening may be left in the shielding to allow the vital waves 19 to pass into the detector 12 . In the preferred embodiment, this opening is covered by an opaque dielectric material (not shown) that blocks light but allows the vital waves 19 to pass. The dielectric material may be any electrical insulator, including insulating tape such as vinyl, plastic, or polyester tape. Preferably, the dielectric material is black polyester tape.
[0019] The internal components of the detector 12 include an avalanche diode 16 and an avalanche initiator 17 that cooperate to control the parameters of an electron avalanche. The electron avalanche amplifies the signal passing through the avalanche diode 16 by a multiplication factor, known as the gain, which is inversely proportional to the difference between the avalanche diode's 16 breakdown voltage and the voltage applied to the avalanche diode 16 . The vital waves 19 entering the device are detectable at a high gain. The device 10 is therefore configured to drive the gain as high as possible. The gain is limited by the intrinsic resistance of the avalanche diode 16 but preferably the peak gain is at least 20,000 and most preferably about 50,000. The avalanche diode 16 may be any avalanche diode that can achieve this gain range and that has device geometry that allows the vital waves 19 to propagate substantially parallel to the electron avalanche, including a standard avalanche diode, a modified Zener diode, or an APD. The diode may use any suitable semiconducting material, including silicon, germanium, and InGaAs, and may be doped to increase the gain range. The diode may alternatively propagate the signal through an air avalanche, but a semiconducting material is preferable because it will have a much lower impedance than air. Preferably, the avalanche diode 16 is a doped silicon APD. The avalanche diode 16 is reverse biased and a constant voltage is applied to the cathode of the avalanche diode 16 to keep the avalanche diode 16 biased in its linear region. Then, the avalanche diode 16 is modulated to its peak gain as described below.
[0020] The avalanche initiator 17 emits energy that impacts the semiconducting material of the avalanche diode 16 , causing impact ionization and creating seed electrons for the electron avalanche. The appropriate avalanche initiator 17 will depend on the type of avalanche diode 16 used. In the preferred embodiment, the avalanche initiator 17 is an optoelectronic device with low residual intensity noise and sufficient energy to cause impact ionization in the preferred APD. Suitable devices include lasers such as a VCSEL or fiber laser, and light-emitting diodes such as a resonant cavity light-emitting diode (“RCLED”). The avalanche initiator 17 is most preferably a silicon VCSEL. Alternatively, the electron avalanche may be initiated by voltage alone, such as in a standard avalanche diode, and the avalanche initiator 17 may be a generator functioning as a device electrode and capable of applying enough electronvolts to the avalanche diode 16 to prompt impact ionization. Such an avalanche diode 16 may be doped to allow electron avalanche initiation by voltage alone.
[0021] The first control signal is directed to the avalanche diode 16 , where it causes the application of a low voltage to the cathode as described below. This low voltage brings the total voltage at the cathode up to within, preferably, several millivolts of the breakdown voltage of the avalanche diode 16 . The applied voltage significantly raises the operating gain of the avalanche diode 16 as it approaches the breakdown voltage of the avalanche diode 16 . The period of high operating gain is referred to as the high gain period. The low voltage is preferably modulated such that it varies from 0 to between 5 and 10 volts on a sine wave having the first sampling frequency. In the preferred embodiment, the high gain period lasts for between 20 and 50 picoseconds, during which the operating gain is increased from a factor of around 70 to a peak factor of more than 25,000. In the alternate embodiment described below, where a logic level pulse of low voltage is applied to the avalanche diode 16 , the high gain period lasts for as much as 10 nanoseconds, and typically between five and 10 nanoseconds.
[0022] In the preferred embodiment, described in detail below and in FIG. 2 , the avalanche initiator 17 constantly emits energy, most of which impacts the avalanche diode 16 . The amount of energy provided to the avalanche diode 16 is adjustable in order to generate approximately a desired number of seed electrons for the electron avalanche. Preferably, a low average number of seed electrons are generated, and most preferably the impact ionization produces an average of five seed electrons during the high-gain period of the avalanche diode 16 .
[0023] In an alternate embodiment, described in detail below and in FIG. 3 , the first control signal is synchronized to provide a current pulse to the avalanche initiator 17 during the high-gain period of the avalanche diode 16 . The current pulse causes the avalanche initiator 17 to pulse at the first sampling frequency. Each pulse of the avalanche initiator 17 causes an electron avalanche to propagate through the active region of the avalanche diode 16 .
[0024] In either described embodiment, the avalanche propagates so quickly, typically within about 100 picoseconds, that the first sampling frequency is retained in the resulting amplified signal that is emitted from the anode of the avalanche diode 16 . The resulting signal is called the first mixed signal, as described below.
[0025] The vital waves 19 pass into the detector 12 and are incident on the avalanche diode 16 . Preferably, a focusing horn 18 is used to concentrate the vital waves 19 into the active region of the avalanche diode 16 where the electron avalanche process takes place. The focusing horn 18 is made of a conductive material, preferably metal, that will reflect the vital waves 19 due to their static electric component. Suitable metals include brass, copper, and aluminum, but most preferably the focusing horn 18 is brass. The focusing horn 18 is soldered to the shielding 15 to prevent light leaks, and the dielectric material is used to cover the end of the focusing horn 18 inside the detector 12 .
[0026] An electron avalanche requires the presence of a strong electric field in the active region of the avalanche diode 16 . This field is static, assuming no interference and a constant applied voltage, and it has a known strength that is dependent on the intrinsic breakdown voltage of the avalanche diode 16 used. However, the incident vital waves 19 also have a static electric component, which interferes with the electric field in the active region and may advance or retard the avalanche process. In the case where the vital waves 19 have extremely high frequencies, of at least 30 gigahertz and further into the terahertz range, undersampling may be used to determine the frequency. The signal propagated through the avalanche diode 16 has sufficient harmonic content that heterodyning occurs between the vital waves 19 and a high harmonic of the first sampling frequency. As a result, the first mixed signal, carried out of the avalanche diode 16 by the amplified current, contains a first beat frequency that is the difference between the frequency of the vital waves 19 and a high harmonic of the first sampling frequency.
[0027] The first mixed signal is then processed by signal processing circuitry 13 . As described below, the first mixed signal undergoes filtration, optional frequency conversion, and Fourier transformation to extract the desired frequency data. During or after this processing, the control circuitry generates a second control signal having a second sampling frequency and sends it to the detector 12 , resulting in a second mixed signal having a second beat frequency. The second mixed signal is also processed by signal processing circuitry 13 . The second beat frequency is subtracted from the first beat frequency to obtain the beat frequency shift.
[0028] The harmonic with which the vital waves 19 were heterodyned is determined by dividing the sampling frequency shift by the beat frequency shift. The harmonic number of the first sampling frequency then allows calculation of the observed frequency imparted by the vital waves 19 . The detection process may be repeated with additional sampling frequencies to reduce uncertainties if multiple vital wave 19 frequencies are present.
[0029] The spectral data of the detection process may be formatted and displayed on a screen in the user interface 14 . Further, the spectral data may be compared to records in a reference database to determine if it matches information gathered on known vital fields. In this manner, if it has been determined that certain data previously gathered by the device 10 correlates to, for example, the presence of a blood disease or its precursors, the results of the detection process may be compared to the previously collected data to determine if the scanned person has the same disease or its precursors. Reference databases may be generated for specific plants and animals, and may be used to detect vital fields associated with bodily states and conditions, the presence or absence of diseases, and aspects of other body energies such as chakra or qi.
[0030] Referring to FIG. 2 , the preferred embodiment of the device 10 utilizes a silicon APD 21 . These devices are capable of a very high operating gain, which corresponds to desirably high sensitivity in detecting the weak vital waves in a vital field. However, APDs are also susceptible to significant noise due to their sensitivity. Therefore, the preferred embodiment of the present device endeavors to minimize noise in the circuit using components that filter unwanted signals and maintain low impedance on sensitive elements.
[0031] When the detection process is initiated, a master clock oscillator 28 supplies the master clock frequency to a signal source 55 , which produces the first control signal at the first sampling frequency. The master clock oscillator 28 is preferably a voltage controlled crystal oscillator, allowing the frequency to be controlled by a digital-to-analog converter 29 . Alternatively, the master clock oscillator 28 may be a frequency synthesizer. The signal source 55 is a frequency synthesizer. The signal source 55 sends the first control signal into the detector 12 .
[0032] Within the detector 12 , a pulse buffer 25 provides a low impedance drive for the APD 21 bias modulation. The pulse buffer 25 is a transistor amplifier, either discrete or part of an integrated circuit, and is preferably a GaAs monolithic microwave integrated circuit (“MMIC”). Alternatively, a MMIC using a different semiconducting material, or a CMOS inverter, may be used. A pulse inductor 53 performs impedance matching to maximize power transfer to the APD 21 . The pulse capacitor 22 and high-stop capacitor 23 present low impedance on the cathode of the APD 21 . The pulse capacitor 22 also couples a periodic low voltage onto the APD 21 bias. In a typical embodiment, the low voltage modulates in a sine wave having the first sampling frequency and a maximum amplitude of between five and 10 volts, which will sum with a constant high voltage bias to raise the applied voltage to just below the breakdown voltage of the APD 21 . During this modulation, the avalanche gain will peak at over 25,000 for about 35 picoseconds. The voltage source 35 supplies the high voltage bias to the APD 21 . The voltage level is controlled by an external computer processor. The voltage is adjusted to give a fixed current through the bias resistor 36 . The bias resistor 36 also forms a low pass noise filter with the pulse capacitor 22 . The pulse capacitor 22 coupling, low pass filtration, and low impedance together reduce noise contributed by the APD 21 dark current or light leakage in the vicinity of the APD 21 . Modulation of the APD 21 gain also eliminates any potential problems with sensitivity reduction due to the APD 21 gain-bandwidth product, because ejected electrons are more quickly replenished in the active region during periods of low gain. Noise from the dark current, caused by impurities in the APD 21 , is further reduced by keeping the active region of the APD 21 very small.
[0033] The VCSEL 30 has low noise but may be susceptible to temperature or manufacture variation that affects the consistency of emitted light. Therefore, an automatic level control circuit (“ALC”) 51 provides an adjustable current to the VCSEL 30 . The current from the ALC 51 causes the VCSEL 30 to emit a substantially constant amount of light, most of which impacts the APD 21 . Some of the light hits a monitor diode 52 , preferably a PIN diode, that detects the amount of light being emitted and signals the ALC 51 to adjust the current if the amount is outside the range needed to generate the desired average number of seed electrons by impact ionization of the semiconducting material in the APD 21 . In an alternate embodiment using an RCLED as the avalanche initiator 17 , an ALC 51 and monitor diode 52 may not be needed due to the RCLED being much less sensitive to temperature than a VCSEL.
[0034] The fewer the number of seed electrons, the higher the possible avalanche gain and hence, the sensitivity. However, with a sufficiently small number of seed electrons, the quantized nature of electron charge introduces quantization noise which limits the sensitivity. Preferably, at least five seed electrons are generated by an optical pulse, and most preferably exactly five. The signal is multiplied exponentially due to the nature of the electron avalanche process, and this effect is magnified by modulating the high-gain period of the APD 21 . Modulation at the first sample frequency creates harmonics that are beyond the harmonic content of the first control signal.
[0035] Because the APD 21 is biased in the linear region, the avalanche gain is limited by the intrinsic impedance of the APD 21 , including any parasitic reactance associated with the APD 21 . The APD 21 must see a short circuit at high frequencies, particularly between 2 and 3 gigahertz, to minimize this intrinsic impedance and also to eliminate frequencies that are contributed to the mixed signal by the APD 21 geometry. The short circuit is provided by a short-circuit lowpass filter 33 , which has a cutoff frequency of half the first sampling frequency. The short-circuit lowpass filter 33 therefore suppresses the first sampling frequency, preventing overload of the signal processing circuitry. In the preferred embodiment, the short-circuit lowpass filter 33 is a lumped element filter. The baseband DC amplifier 34 and baseband AC amplifier 54 both present a suitable terminating impedance for the short-circuit lowpass filter 33 and set the baseband noise floor after the APD 21 . The baseband DC amplifier 34 is DC coupled and is used if the first mixed signal has a low enough frequency to be passed through an analog-to-digital converter (“ADC”) 47 . The baseband AC amplifier 54 is AC coupled and filters out the DC portion of the first mixed signal if a frequency conversion is needed.
[0036] The first mixed signal, now a baseband signal, may be routed through a frequency converter 50 . This is not a necessary step, but it can provide a more practical realization by allowing a sampling frequency that is much higher than the ADC 47 sampling rate. Because most signals of interest are undersampled, doubling the sampling frequency will produce about a 3 decibel improvement in signal to noise ratio. Within the frequency converter 50 , the first intermediate frequency mixer 40 provides frequency conversion to a first intermediate frequency (“IF”) by mixing the first mixed signal with a signal generated by the first local oscillator 43 . The first local oscillator 43 is preferably a frequency synthesizer that is in phase lock with the master clock oscillator 28 . Preferably, the IF is 916.36 megahertz to allow the use of an inexpensive inline surface acoustic wave (“SAW”) filter for the first IF filter 41 . The first IF filter 41 then provides image rejection in the down-converted signal to improve the performance of a second IF mixer 56 . The second IF mixer 56 converts the first mixed signal to a frequency of 10.7 megahertz to allow the use of a ceramic filter as a second IF filter 57 , which provides high quality noise filtering of the signal. The sampling mixer 42 mixes the IF with a signal from a second local oscillator 44 to convert the first mixed signal down to a suitable range for the ADC 47 sampling rate. The second local oscillator 44 is preferably a frequency divider that takes the master clock signal as an input. The switch 38 is used to bypass the frequency converter 50 . Anti-alias lowpass filter 39 provides anti-aliasing filtering of the baseband first mixed signal when the frequency converter 50 is bypassed.
[0037] With a master clock of 44 megahertz, the second local oscillator 44 signal is 11 megahertz, the first sample frequency is 905.66 megahertz, and the baseband first mixed signal ranges from 0 to 452.83 megahertz. These frequencies are chosen to allow the use of low cost ceramic and SAW filters. Additionally, a sampling frequency at or near 1 gigahertz allows the use of smaller Fourier transforms during signal processing. The smaller transforms account for both random variation in detected frequencies and frequency drift in the signal source 55 . The frequency converter 50 loss is corrected by a converter amplifier 45 . Any out of band noise from the converter amplifier 45 is removed by a converter lowpass filter 46 .
[0038] The baseband signal is digitized by ADC 47 . A Fourier transform computer 48 computes a large fast Fourier transform (“FFT”) to detect the desired signals, such as the first beat frequency, within the baseband signal. After the detection process is run a second time to acquire a second beat frequency, the computer 48 calculates the input frequency. The FFT results are processed and displayed on the screen 49 .
[0039] Referring to FIG. 3 , an alternate embodiment of the device 10 utilizes a silicon APD 21 and a silicon VCSEL 30 . When the detection process is initiated, the master clock oscillator 28 supplies the master clock frequency to a clock frequency divider 27 , which produces the first sampling frequency. The clock frequency divider 27 supplies the first sampling frequency to an asynchronous state machine (“ASM”) 26 that generates a narrow pulse on one edge of the incoming waveform. The ASM 26 is preferably a gate and inverter, generating a first control signal having the first sampling frequency and a pulse length of several nanoseconds. The first control signal is sent into the detector 12 .
[0040] Within the detector 12 , the pulse buffer 25 provides a low impedance drive for the APD 21 bias pulsing. A pulse resistor 24 forms a low pass filter with high-stop capacitor 23 to limit the rate of APD 21 bias change. The pulse capacitor 22 and high-stop capacitor 23 present low impedance on the cathode of the APD 21 . The pulse capacitor 22 also couples a periodic low voltage onto the APD 21 bias. In a typical embodiment, the logic level pulse has a maximum voltage of about 2V, which will raise the biased voltage to just below the breakdown voltage of the APD 21 and raise the avalanche gain from 70 to about 20,000 for several nanoseconds. The voltage source 35 supplies the high voltage bias to the APD 21 . The voltage level is controlled by an external computer processor. The voltage is adjusted to give a fixed current through the bias resistor 36 . The bias resistor 36 also forms a low pass noise filter with the pulse capacitor 22 .
[0041] The time delay circuit 32 produces a time delay to align an optical pulse with the APD 21 high gain period. The time delay circuit 32 is a logic device or a resistor-capacitor circuit chosen to cause the desired delay while retaining the incoming signal frequency. A pulse generator 31 , preferably a regenerative switch, provides a current pulse to the VCSEL 30 on the rising edge of the first control signal. Alternatively, the pulse generator 31 may be a step recovery diode. The pulse generator 31 produces a pulse that is sufficient to cause the VCSEL 30 to emit a very short pulse of light. The duration of the light pulse is made as short as possible while emitting sufficient energy to generate approximately the preferred number of seed electrons in the APD 21 , as described below. For a VCSEL with 3 gigahertz bandwidth, the pulse is preferably in the range of 50-100 picoseconds. The pulse may be even shorter if a fiber laser is used.
[0042] The short circuit of high APD 21 frequencies is provided by short-circuit lowpass filter 33 , which has a cutoff frequency of half the first sampling frequency. In the present embodiment, short-circuit lowpass filter 33 is a lumped element filter. The baseband amplifier 34 presents a suitable terminating impedance for the short-circuit lowpass filter 33 , and sets the baseband noise floor after the APD 21 .
[0043] The first mixed signal, now a baseband signal, may be routed through a frequency converter 50 . Within the frequency converter 50 , intermediate frequency mixer 40 provides frequency conversion to the IF by mixing the first mixed signal with a signal generated by the first local oscillator 43 . In the present embodiment, the first local oscillator 43 is a direct digital frequency synthesizer that tunes from 11.0 to 17.8 megahertz. Preferably, the IF is 10.7 megahertz to allow the use of inexpensive ceramic filters for the first IF filter 41 . In the present embodiment, the first IF filter 41 is a ceramic filter that provides high quality noise filtering of the down-converted signal. The sampling mixer 42 mixes the IF with a signal from a second local oscillator 44 to convert the first mixed signal down to a suitable range for the ADC 47 sampling rate. The second local oscillator 44 is preferably a frequency divider that takes the master clock signal as an input. Switches 37 and 38 are used to bypass the frequency converter 50 at low frequencies if desired. Anti-alias lowpass filter 39 provides anti-aliasing filtering of the baseband first mixed signal when the frequency converter 50 is bypassed.
[0044] With a master clock of 44 megahertz, the second local oscillator 44 signal is 11 megahertz, the first sample frequency is 14.66 megahertz, and the baseband first mixed signal ranges from 0 to 7.33 megahertz. These frequencies are chosen to allow the use of low cost ceramic filters, and the use of low cost CMOS analog switches for frequency mixing. The frequency converter 50 loss is corrected by a converter amplifier 45 . Any out of band noise from the converter amplifier 45 is removed by a converter lowpass filter 46 .
[0045] The baseband signal is digitized by ADC 47 . A Fourier transform computer 48 computes a large fast Fourier transform (“FFT”) to detect the desired signals, such as the first beat frequency, within the baseband signal. After the detection process is run a second time to acquire a second beat frequency, the computer 48 calculates the input frequency. The FFT results are processed and displayed on the screen 49 .
[0046] While there has been illustrated and described what is at present considered to be the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made and equivalents may be substituted for elements thereof without departing from the true scope of the invention. Therefore, it is intended that this invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
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A device and method of detecting and analyzing a vital field places an avalanche diode in the path of vital waves in the vital field. The vital waves interfere with the electron avalanche process in the avalanche diode. Control circuitry and an avalanche initiator cause electron avalanches at a known sampling frequency. The interference from the vital waves produces a beat frequency that is output from the avalanche diode. By adjusting the sampling rate by a known amount, a second beat frequency is produced and the beat frequency shift is used to determine the input frequency of the vital waves. The vital waves are very weak and produce frequencies into the terahertz range, so that the input frequency is undersampled by the device. Further, high sensitivity is required and a circuit design is implemented to maximize sensitivity while minimizing noise and other interference that is common to avalanche diode operation.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The following applications, filed on even date, herewith, are incorporated by reference: Ser. No. 08/970,230, "Echo Canceller Employing Dual-H Architecture Having Improved Coefficient Transfer"; Ser. No. 08/971,116, "Echo Canceller Employing Dual-H Architecture Having Improved Double-Talk Detection"; Ser. No. 08/970,228, "Echo Canceller Employing Dual-H Architecture Having Improved Non-Linear Echo Path Detection"; Ser. No. 08/970,639, "Echo Canceller Employing Dual-H Architecture Having Improved Non-Linear Processor"; Ser. No. 08/970,229, "Echo Canceller Employing Dual-H Architecture Having Split Adaptive Gain Settings."
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
Long distance telephone facilities usually comprise four-wire transmission circuits between switching offices in different local exchange areas, and two-wire circuits within each area connecting individual subscribers with the switching office. A call between subscribers in different exchange areas is carried over a two-wire circuit in each of the areas and a four-wire circuit between the areas, with conversion of speech energy between the two and four-wire circuits being effected by hybrid circuits. Ideally, the hybrid circuit input ports perfectly match the impedances of the two and four-wire circuits, and its balanced network impedance perfectly matches the impedance of the two-wire circuit. In this manner, the signals transmitted from one exchange area to the other will not be reflected or returned to the one area as echo. Unfortunately, due to impedance differences which inherently exist between different two and four-wire circuits, and because impedances must be matched at each frequency in the voice band, it is virtually impossible for a given hybrid circuit to perfectly match the impedances of any particular two and four-wire transmission circuit. Echo is, therefore, characteristically part of a long distance telephone system.
Although undesirable, echo is tolerable in a telephone system so long as the time delay in the echo path is relatively short, for example, shorter than about 40 milliseconds. However, longer echo delays can be distracting or utterly confusing to a far end speaker, and to reduce the same to a tolerable level an echo canceller may be used toward each end of the path to cancel echo which otherwise would return to the far end speaker. As is known, echo cancellers monitor the signals on the receive channel of a four-wire circuit and generate estimates of the actual echoes expected to return over the transmit channel. The echo estimates are then applied to a subtractor circuit in the transmit channel to remove or at least reduce the actual echo.
In simplest form, generation of an echo estimate comprises obtaining individual samples of the signal on the receive channel, convolving the samples with the impulse response of the system and then subtracting, at the appropriate time, the resulting products or echo estimates from the actual echo on the transmit channel. In actual practice generation of an echo estimate is not nearly so straightforward.
Transmission circuits, except those which are purely resistive, exhibit an impulse response which has amplitude and phase dispersive characteristics that are frequency dependent, since phase shift and amplitude attenuation vary with frequency. To this end, a suitable known technique for generating an echo estimate contemplates manipulating representations of a plurality of samples of signals which cause the echo and samples of impulse responses of the system through a convolution process to obtain an echo estimate which reasonably represents the actual echo expected on the echo path. One such system is illustrated in FIG. 1.
In the system illustrated in FIG. 1, a far end signal x from a remote telephone system is received locally at line 10. As a result of the previously noted imperfections in the local system, a portion of the signal x is echoed back to the remote site at line 15 along with the signal v from the local telephone system. The echo response is illustrated here as a signal s corresponding to the following equation:
s=h*x
where h is the impulse response of the echo characteristics. As such, the signal sent from the near end to the far end, absent echo cancellation, is the signal y, which is the sum of the telephone signal v and the echo signal s. This signal is illustrated as y at line 15 of FIG. 1.
To reduce and/or eliminate the echo signal component s from the signal y, the system of FIG. 1 uses an echo canceller having an impulse response filter h that is the estimate of the impulse echo response h. As such, a further signal s representing an estimate of echo signal s is generated by the echo canceller in accordance with the following equation:
s=h*x
The echo canceller subtracts the echo estimate signal s from the signal y to generate a signal e at line 20 that is returned to the far end telephone system. The signal e thus corresponds to the following equation:
e=s+v-s≈v
As such, the signal returned to the far end station is dominated by the signal v of the near end telephone system. As the echo impulse response h more closely correlates to the actual echo response h, then s-bar more closely approximates s and thus the magnitude of the echo signal component s on the signal e is more substantially reduced.
The echo impulse response model h may be replaced by an adaptive digital filter having an impulse response h. Generally, the tap coefficients for such an adaptive response filter are found using a technique known as Normalized Least Mean Squares adaptation.
Although such an adaptive echo canceller architecture provides the echo canceller with the ability to readily adapt to changes in the echo path response h, it is highly susceptible to generating sub-optimal echo cancellation responses in the presence of "double talk" (a condition that occurs when both the speaker at the far end and the speaker at the near end are speaking concurrently as determined from the viewpoint of the echo canceller).
To reduce this sensitivity to double-talk conditions, it has been suggested to use both a non-adaptive response and an adaptive response filter in a single echo canceller. One such echo canceller is described in U.S. Pat. No. 3,787,645, issued to Ochiai et al on Jan. 22, 1974. Such an echo canceller is now commonly referred to as a dual-H echo canceller.
Although the dual-H echo canceller architecture of the '645 patent provides substantial improvements over the use of a single filter response architecture, the '645 patent is deficient in many respects and lacks certain teachings for optimizing the use of such a dual-H architecture in a practical echo canceller system. For example, the present inventors have recognize that the adaptation gain used to adapt the tap coefficients of the adaptive filter may need to be altered based on certain detected conditions. These conditions include conditions such as double-talk, non-linear echo response paths, high background noise conditions, etc.. The present inventors have recognized the problems associated with the foregoing dual-H architecture and have provided solutions to such conditions.
BRIEF SUMMARY OF THE INVENTION
An echo canceller circuit for use in an echo canceller system is set forth that provides sensitive double-talk detection. The echo canceller circuit comprises a second digital filter having adaptive tap coefficients to simulate an echo response occurring during the call. The adaptive tap coefficients of the second digital filter are updated over the duration of the call using a Least Mean Squares process having an adaptive gain a. A channel condition detector is used to detect channel conditions during the call. The channel condition detector is responsive to detected channel conditions for changing the adaptive gain a during the call. For example, the channel condition detector may detect the presence of a double-talk condition and set the adaptive gain a to zero. Similarly, the channel condition detector may detect the occurrence of a high background noise condition and set the adaptive gain a to a level less than 1 that is dependent on the detected level of the background noise. Other similar channel conditions and corresponding adaptive gain settings may likewise be utilized.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a block diagram of a conventional canceller.
FIG. 2 is a schematic block diagram of an echo canceller that operates in accordance with one embodiment of the present invention.
FIG. 3 is a flow chart illustrating one manner of carrying out coefficient transfers wherein the transfer conditions may be used to implement double-talk detection in accordance with one embodiment of the present invention.
FIG. 4 is a flow chart illustrating a further manner of carrying out coefficient wherein the transfer conditions may be used to implement the double-talk detection an accordance with one embodiment of the present invention.
FIG. 5 illustrates an exemplary solution surface for the adaptive filter whereby the desired result is achieved at the solution matching the echo response of the channel.
FIG. 6 illustrates one manner of checking for various echo canceller conditions and responding to these conditions using a change in the adaptive gain setting of the adaptive filter of the echo canceller.
FIG. 7 illustrates one manner of implementing an echo canceller system employing the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 illustrates one embodiment of a dual-h echo canceller suitable for use in implementing the present invention. As illustrated, the echo canceller, shown generally at 25, includes both a non-adaptive filter h and an adaptive filter h to model the echo response h .Each of the filters h and h are preferably implemented as digital finite impulse response (FIR) filters comprising a plurality of taps each having a corresponding tap coefficient. The duration of each of the FIR filters should be sufficient to cover the duration of the echo response of the channel in which the echo canceller 25 is disposed.
The output of the non-adaptive filter h is available at the line 30 while the output of the adaptive filter h is available at line 35. Each of the signals at lines 30 and 35 are subtracted from the signal-plus-echo signal of line 40 to generate echo compensated signals at lines 50 and 55, respectively. A switch 45, preferably a software switch, may be used to selectively provide either the output signal at the line 50 or the output signal at line 55 to the echo canceller output at line 60.
A transfer controller 65 is used to transfer the tap coefficients of filter h to replace the tap coefficients of filter h. As illustrated, the transfer controller 65 is connected to receive a number of system input signals. Of particular importance with respect to the present invention, the transfer controller 65 receives the signal-plus-echo response y and each of the echo canceller signals e and e at lines 50 and 55, respectively. The transfer controller 65 is preferably implemented in the software of one or more digital signal processors used to implement the echo canceller 25.
As noted above, the art is substantially deficient of teachings with respect to the manner in which and conditions under which a transfer of tap coefficients from h to h is to occur. The present inventors have implemented a new process and, as such, a new echo canceller in which tap coefficient transfers are only made by the transfer controller 65 when selected criterion are met. The resulting echo canceller 25 has substantial advantages with respect to reduced double-talk sensitivity and increased double-talk detection capability. Further, it ensures a monotonic improvement in the estimates h.
The foregoing system uses a parameter known as echo-return-loss-enhancement (ERLE) to measure and keep track of system performance. Two ERLE parameter values are used in the determination as to whether the transfer controller 65 transfers the tap coefficients from h to h. The first parameter, E, is defined in the following manner: ##EQU1##
Similarly, the parameter E is defined as follows: ##EQU2## Each of the values E and E may also be averaged over a predetermined number of samples to arrive at averaged E and E values used in the system for the transfer determinations.
FIG. 3 illustrates one manner of implementing the echo canceller 25 using the parameters E and E to control tap coefficients transfers between filter h to h. As illustrated, the echo canceller 25 provides a default h set of coefficients at step 80 during the initial portions of the call. After the tap coefficients values for h have been set, a measure of E is made at step 85 to measure the performance of the tap coefficient values of filter h.
After the initialization sequence of steps 80 and 85, or concurrent therewith, the echo canceller 25 begins and continues to adapt the coefficients of h to more adequately match the echo response h of the overall system. As noted in FIG. 3, this operation occurs at step 90. Preferably, the adaptation is made using a Normalized Least Mean Squares method, although other adaptive methods may also be used (e.g., LMS and RLS).
After a period of time has elapsed, preferably, a predetermined minimum period of time, the echo canceller 25 makes a measure of E at step 95. Preferably, this measurement is an averaged measurement. At step 100, the echo canceller 25 compares the value of E with the value of E. If the value of E is greater than the value of E, the tap coefficients of filter h are transferred to replace the tap coefficients of filter h at step 105. If this criterion is not met, however, the echo canceller 25 will continue to adapt the coefficients of the adaptive filter h at step 90, periodically measure the value of E at step 95, and make the comparison of step 100 until the condition is met.
If the echo canceller 25 finds that E is greater than E, the above-noted transfer takes place. Additionally, the echo canceller 25 stores the value of E as a value E max . This operation is depicted as step 110 of the FIG. 3. The value of E max is thus the maximum value of ERLE that occurs over the duration of the call and at which a transfer has taken place. This further value is used thereafter, in addition to the E and E comparison, to control whether the tap coefficients of h are transferred by the transfer controller 65 to replace the tap coefficients of h. This further process is illustrated that steps 115, 120, and 125 of FIG. 3. In each instance, the tap coefficient transfer only occurs when both of the following two conditions are met: 1) E is greater than the current E, and 2) E is greater than any previous value of E used during the course of the call. (E is greater than E max ). Each time that both criteria are met, the transfer controller 65 of echo canceller 25 executes the tap coefficient transfer and replaces the previous E max value with the current E value for future comparison.
Requiring that E is greater than any E value used over the course of the call before the coefficient transfer takes place has two beneficial and desirable effects. First, each transfer is likely to replace the prior tap coefficients of filter h with a better estimate of the echo path response. Second, this transfer requirement increases the double-talk protection of the echo canceller system. Although it is possible to have positive ERLE E during double-talk, the probability that E is greater than E max during double-talk decreases as the value of E max increases. Thus an undesirable coefficient transfer during double-talk becomes increasingly unlikely as the value of E max increases throughout the duration of the call.
The echo canceller 25 may impose both an upper boundary and a lower boundary on the value of E max . For example, E max may have a lower bounded value of 6 dB and an upper bounded value of 24 dB. The purpose of the lower bound is to prevent normal transfers during double-talk conditions. It has been shown in simulations using speech inputs that during double-talk, a value of greater than 6 dB ERLE was a very low probability event. The upper bound on E max is used to prevent a spuriously high measurement from setting E max to a value at which further transfers become impossible.
The value of E max should be set to, for example, the lower bound value at the beginning of each call. Failure to do so will prevent tap coefficient transfers on a new call until the echo cancellation response of the echo canceller 25 on the new call surpasses the quality of the response existing at the end of the prior call. However, this criterion may never be met during the subsequent call thereby causing the echo canceller 25 to operate using sub-optimal tap coefficients values. Resetting the E max value to a lower value increases the likelihood that a tap coefficient transfer will take place and, thereby, assists in ensuring that the h filter uses tap coefficients for echo cancellation that more closely correspond to the echo path response of the new call.
One manner of implementing the E max value change is illustrated in the echo canceller operations flow-chart of FIG. 4. When all transfer conditions are met except E greater than E max , and this condition persists for a predetermined duration of time, the echo canceller 25 will reset the E max value to, for example, the lower bound value. In the exemplary operations shown in FIG. 4, the echo canceller 25 determines whether E is greater than the lower bound of E max at step 140 and less than the value of E max at step 145. If both of these condition remain true for a predetermined period of time as determined at step 150, and all other transfer criterion have been met, the echo canceller 25 resets the E max value to a lower value, for example, the lower bound of the E max value, at step 155. This lowering of the E max value increases the likelihood of a subsequent tap coefficient transfer.
Choosing values for the lower and upper bound of E max other than 6 dB and 24 dB, respectively, is also possible in the present system. Choosing a lower bound of E max smaller than 6 dB provides for a relatively prompt tap coefficient transfer after a reset operation or a new call, but sacrifices some double-talk protection. A value greater than 6 dB, however, inhibits tap coefficient transfer for a longer period of time, but increases the double-talk immunity of the echo canceller. Similarly, varying the value of the predetermined wait time T before which E max is reset may also be used to tweak echo canceller performance. A shorter predetermined wait time T produces faster reconvergence transfers, but may sacrifice some double-talk immunity. The opposite is true for larger predetermined wait time values.
A further modification of the foregoing echo canceller system relates to the value stored as E max at the instant of tap coefficient transfer. Instead of setting E max equal to the E value at the transfer instant, E max may be set to a value equal to the value of E minus a constant value (e.g., one, three, or 6 dB). At no time, however, should the E max value be set to a value that is below the lower bound value for E max . Additionally, a further condition may be imposed in that a new softened E max is not less than the prior value of E max . The foregoing "softening" of the E max value increases the number of transfers that occur and, further, provides more decision-making weight to the condition of E being larger than E. Further details with respect to the operation of the echo canceller coefficient transfer process are set forth and the co-pending patent application titled "ECHO CANCELLER HAVING THE IMPROVED TAP COEFFICIENT TRANSFER", filed on even date herewith.
Preferably, the adaptive filter h uses a Normalized Least Mean Square (NLMS) adaptation process to update its tap coefficients. In accordance with the process, coefficients are adapted at each time n for each tap m=0, 1, . . . , N-1 in accordance with the following equation: ##EQU3## where h n (m) is the m th tap of the echo canceller, x n is the far-end signal at time n, e n is the adaptation error of time n, and a n is the adaptation gain at time n.
The foregoing adaptation process will converge in the mean-square sense to the correct solution the echo path response h if 0<a n <2. Fastest convergence occurs when a=1. However, for 0<a≦1, the speed of convergence to h is traded-off against steady-state performance.
FIG. 5 is provided to conceptualize the effect of the adaptation gain on the filter response. The graph of FIG. 5 includes an error performance surface 185 defined to be the mean square error between h and h, to be a N=3 dimensional bowl. Each point in the bowl corresponds to the mean-square error for each corresponding h (of length N). The bottom of the bowl is the h which produces the least mean-square error, i.e. h. The NLMS process iteratively moves the h towards h at the bottom of the performance surface as shown by arrow 190. When a=1, h moves to the bottom of the bowl most quickly, but once the bottom is reached, the adaptation process continues to bounce h around the true h bottom of the bowl, i.e. E[h]=h but h≠h. If a small a is used, then the steady-state error is smaller (h will remain closer to h), but h requires a longer time to descend to the bottom of the bowl, as each step is smaller.
In some cases, as the present inventors have recognized, the performance surface will temporarily change. In such situations, it becomes desirable to suppress the h from following these changes. This presents a challenge to choose the best a for each scenario.
FIG. 6 illustrates operation of the echo canceller 25 in response to various detected scenarios. It will be recognized that the sequence of detecting the various conditions that is set forth in FIG. 6 is merely illustrative and may be significantly varied. Further, it will be recognized that the detection and response to each scenario may be performed concurrently with other echo canceller processes. Still further, it will be recognized that certain detected scenarios and their corresponding responses may be omitted.
In the embodiment of FIG. 6, the echo canceller 25 entertains whether or not a double-talk condition exists at step 200. Double talk, as noted above, is defined as the situation when both far-end and near-end talkers speak at the same time during a call. In such a scenario, the adaptive error signal is so severely corrupted by the near-end speaker that it is rendered useless. As such, if a double-talk condition is detected, the echo canceller 25 responds by freezing the adaptation process at step 205, i.e., set a=0, until the double talk ceases.
There are several methods that the echo canceller 25 can use for detecting a double-talk condition. One is to compare the power of the near-end signal to the far-end signal. If the near-end power comes close enough to the far-end power ("close enough" can be determined by the system designer, e.g. within 0 or 6 or 10 dB), then double talk can be declared. Another method is to compare the point-by-point magnitudes of the near-end and far-end signals. This search can compare the current |x| with the current |y| the current |x| with the last several |y| the current |y| with the last several |x|, etc. In each case, the max |x| and |y| over the searched regions are compared. If ##EQU4## where max |x| indicates the maximum |x| over the search region (|y| is similarly defined), then a double-talk condition is declared.
A still further manner of detecting a double-talk condition is set forth in Ser. No. 08/971,116, titled "Echo Canceller Employing Dual-H Architecture Having Improved Double-Talk Detection", the teachings of which are hereby incorporated by reference. As set forth in that patent application, a double-talk condition is declared based on certain monitored filter performance parameters.
It may be possible to further condition the double-talk declaration with other measurements. For example, the current Echo Return Loss (ERL) may be used to set the Double Talk Threshold noted above herein. The short-term power of either the far-end, the near-end, or both, may also be monitored to ensure that they are larger than some absolute threshold (e.g. -5 OdBm or -4 OdBm). In this manner, a double-talk condition is not needlessly declared when neither end is speaking.
Once a double-talk condition is declared, it may be desirable to maintain the double-talk declaration for a set period time after the double talk condition is met. Examples might be 32, 64, or 96 msec. After the double-talk condition ceases to exist, the adaptive gain value may be returned to the value that existed prior to the detection of the double-talk condition, or to a predetermined return value.
At step 210, the echo canceller 25 determines whether a high background noise condition is present. A low level of constant background noise can enter from the near-end, for example, if the near-end caller is in an automobile or an airport. Its effects are in some ways similar to that of double-talk, as the near-end double-talk corrupts the adaptive error signal. The difference is that, unlike double talk, near-end background noise is frequently constant, thus setting a=0 until the noise ends is not particularly advantageous. Also background noise is usually of lower power than double-talk. As such, it corrupts the adaptation process but does not render the resulting adaptation coefficients unusable.
As illustrated at step 215, it is desirable to choose a gain 0<a<1, i.e. lower the gain from its fastest value of 1 when a high background noise condition is present. While this will slow the adaptation time, the steady state performance increases since the effects of noise-induced perturbations will be reduced. In other words, the tap variance noise is reduced by lowering the adaptation gain a.
Preferably, the background noise is measured as a long-term measurement of the power of when the far-end is silent. As this measurement increases, a decreases. One schedule for setting the adaptive gain a as a function of background noise level is set forth below.
______________________________________Background Noise (dBm) a______________________________________ > -48 .125> -54 ≧ -48 .25> -60 ≧ -54 .5< -60 1______________________________________
It will be readily recognized that there are other schedules that would work as well, the foregoing schedule being illustrative.
A further condition in which the adaptive gain may be altered from an otherwise usual gain value occurs when the adaptive filter h is confronted with a far-end signal that is narrow band, i.e. comprised of a few sinusoids. In such a scenario, there are an infinite number of equally optimal solutions that the LMS adaptation scheme can find. Thus it is quite unlikely that the resulting cancellation solution h will properly identify (i.e. mirror) the channel echo response h. Such a situation is referred to as under-exciting the channel, in that the signal only provides information about the channel response at a few frequencies. The echo canceller 25 attempts to determine the existence of this condition that step 220.
Consider a situation where the far-end signal varies between periods in which a narrow band signal is transmitted and wide band signal is transmitted. During the wide band signal periods, the h filter should adapt to reflect the impulse response of the channel. However, when the narrow band signal transmission period begins, the h filter will readapt to focus on canceling the echo path distortion only at the frequencies present in the narrow band signal. Optimizing a solution at just a few frequencies is likely to give a different solution than was found during transmission of the wide band signal. As a result, any worthwhile adaptation channel information gained during wide band transmission periods is lost and the h filter requires another period of adaptation once the wide band signal returns.
When the far-end signal is narrow band, the adaptation can and should be slowed considerably, which should discourage the tendency of the coefficients to diverge. Specifically, when a narrow band signal is detected, a may be upper-bounded by either 0.25 or 0.125. This operation is illustrated at step 225.
Narrow band signal detection may be implemented using a fourth order predictive filter. Preferably, this filter is implemented in software executed by one or more digital signal processors used in the echo canceller system 25. If it is able to achieve a prediction gain of at least 3 to 6 dB (user defined) over the h filter, then it is assumed that the received signal is a narrow band signal.
An amplitude threshold for the far-end signal is also preferably employed in determining the existence of a narrow band signal. If the far-end power is greater than -40 dBm, the current far-end sample is sent to the fourth order predictive filter, which determines whether or not the far-end signal is narrow band. If the far-end power is less than -40 dBm, the predictive filter is re-initialized to zero.
A further scenario in which it is desirable to alter the gain of the adaptive filter h is when the echo path response is non-linear. The presence of non-linearities in the echo path encourages constant minor changes in the coefficients h in order to find short-term optimal cancellation solutions. The detection of non-linearity of the echo path response preferably proceeds in the manner set forth in Ser. No. 08/970,228, titled "Echo Canceller Employing Dual-H Architecture Having Improved Non-Linear Echo Path Detection"filed on even date herewith. The presence of a non-linear echo path is determined that step 230.
In a non-linear echo path scenario, it is desirable to choose the adaptive gain constant a large enough that h can track these short-term best solutions. However, choosing a=1 may be suboptimal in most non-linear scenarios. This is due to the fact that the gain is too large and, thus, short-term solutions are "overshot" by the aggressive adaptation effort. Accordingly, as shown at step 235, choosing a gain lower than 1 is preferable. Choosing a=0.25 was found to be the best trade off between tracking and overshooting short term optimal solutions. The gain constant a may be further reduced if large background noise is measured, as discussed above.
A still further scenario in which the adaptive gain may be varied relates to the convergence period of the adaptive filter h. As noted above, a large gain constant a is desired during convergence periods while a smaller a is desired in steady state conditions after the filter has converged. In other words, there seems little lost and perhaps some potential gain to reduce a after an initial period of convergence is completed. This appears to be especially valuable if the long-term performance is found to be substandard.
In view of the foregoing, the echo canceller 25 may implement a reduced gain mode in which an upper bound for the gain constant a is set at a lower value than I (e.g., at either 0.25 or 0.125). This mode is detected at step 240 and is entered at step 245 if the ERLE remains below a predetermined threshold value (e.g., either 6 dB or 3 dB) after a predetermined period of adaptation. The adaptation time is preferably selected as a value between 100 to 300 msec. This amount of time will generally prevent the echo canceller 25 from entering the reduced gain mode during convergence periods.
As will be readily recognized, the echo canceller of the present invention may be implemented in a wide range of manners. Preferably, the echo canceller system is implemented using one or more digital signal processors to carry out the filter and transfer operations. Digital-to-analog conversions of various signals are carried out in accordance with known techniques for use by the digital signal processors.
FIG. 7, illustrates one embodiment of an echo canceller system, shown generally at 700, that maybe used to cancel echoes in multi-channel communication transmissions. As illustrated, the system 700 includes an input 705 that is connected to receive a multi-channel communications data, such as a T1 transmission. A central controller 710 deinterleaves the various channels of the transmission and provides them to respective convolution processors 715 over a data bus 720. It is within the convolution processors 715 that a majority of the foregoing operations take place. Each convolution processor 715 is designed to process at least one channel of the transmission at line 730. After each convolution processor 715 has processed its respective channel(s), the resulting data is placed on the data bus 720. The central controller 710 multiplexes the data into the proper multichannel format (e.g., T1) for retransmission at line 735. User interface 740 is provided to set various user programmable parameters of the system.
Numerous modifications may be made to the foregoing system without departing from the basic teachings thereof. Although the present invention has been described in substantial detail with reference to one or more specific embodiments, those of skill in the art will recognize that changes may be made thereto without departing from the scope and spirit of the invention as set forth in the appended claims.
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An echo canceller circuit for use in an echo canceller system is set forth that provides sensitive double-talk detection. The echo canceller circuit comprises a second digital filter having adaptive tap coefficients to simulate an echo response occurring during the call. The adaptive tap coefficients of the second digital filter are updated over the duration of the call using a Least Mean Squares process having an adaptive gain a. A channel condition detector is used to detect channel conditions during the call. The channel condition detector is responsive to detected channel conditions for changing the adaptive gain a during the call. For example, the channel condition detector may detect the presence of a double-talk condition and set the adaptive gain a to zero. Similarly, the channel condition detector may detect the occurrence of a high background noise condition and set the adaptive gain a to a level less than 1 that is dependent on the detected level of the background noise. Other similar channel conditions and corresponding adaptive gain settings may likewise be utilized.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is continuing application of U.S. Patent Publication Number 2014/0232040, published on Aug. 21, 2014, which is a divisional application of U.S. Patent Publication Number 2012/0175813, published on Jul. 12, 2012, the entirety of both are hereby incorporated by reference.
BACKGROUND
[0002] Embodiments of the present invention relate generally to a shoe customization system and a method of using a shoe customization system.
[0003] Multiple systems for varying the size and shape of platens used to print designs on articles of clothing have been proposed. Jennings (U.S. Pat. No. 4,901,638) discloses a method and apparatus for silk screen printing the tops and fronts of completed painter's caps. The apparatus includes: a platen sized and shaped to receive T-shirt fronts; a platen sized and shaped to receive T-shirt sleeves; a platen sized and shaped to receive the tops of painter's caps; and a platen sized and shaped to receive the fronts of painter's caps. While Jennings discloses platens sized and shaped to receive various articles of clothing, these platens are not sized and shaped to receive assembled shoes. Similarly, the platens are not sized and shaped to receive multiple articles of clothing on a single platen. Thus, a drawback to the proposed system of Jennings is that a single platen cannot be used for printing two articles of clothing at the same time. Furthermore, the size of the platens proposed by Jennings cannot be adjusted.
[0004] Olsen (U.S. Pat. No. 2,291,832) discloses a method and apparatus for coating a fabric upper of an unassembled shoe with cement. The apparatus includes two rectangular platens hinged together. The platens are used to coat an upper of an unassembled shoe with cement. A drawback to the apparatus proposed by Olsen is that it does not include a platen sized and shaped to receive a pair of shoes. Furthermore, the size of the platens proposed by Olsen cannot be adjusted.
[0005] Systems for decorating the bottoms of assembled shoes have been proposed. Mussells (U.S. Pat. No. 224,030) discloses a shank channeling, creasing, and coloring machine. The machine includes four shoe-supports, which hold assembled shoes as they are creased, colored, or stamped. The shoe-supports are attached to the plate by pins and so that they may be readily replaced with shoe-supports having other shapes or sizes. A drawback to the system proposed by Mussells is that the shoe-supports are not sized and shaped to individually receive a pair of assembled shoes. Furthermore, size of the shoe-supports is not adjustable.
SUMMARY
[0006] A shoe customization system and a method of using the same are disclosed. In one aspect, the shoe customization system may include a heat press device having a flat press surface, a first curved edge, a second curved edge opposite the first curved edge, and a first connecting edge connecting the first curved edge to the second curved edge. A first shoe receiving portion may be configured to receive a shoe. The first shoe receiving portion may be bounded by part of the first curved edge, part of the second curved edge, and the first connecting edge. A second shoe receiving portion may be configured to receive a shoe. The second shoe receiving portion may be disposed opposite the first shoe receiving portion.
[0007] In another aspect, the shoe customization system may include a heat press device having a flat press surface, a first edge, a second edge opposite the first edge, a third edge connecting the first edge to the second edge, and a fourth edge opposite the third edge. The distance between the third edge and the fourth edge may taper from the first edge to the second edge. The heat press device may further include a first shoe receiving portion configured to receive a shoe. The first shoe receiving portion may be bounded by part of the first edge, part of the second edge, and the third edge.
[0008] In another aspect, the shoe customization system may include a heat press machine having a first quick connect mechanism and a heat press device configured to be connected to the heat press machine. The heat press device may include a flat press surface, a first edge, a second edge opposite the first edge, and a third edge connecting the first edge to the second edge. The heat press device may further include a first shoe receiving portion configured to receive a shoe. The first shoe receiving portion may be bounded by part of the first edge, part of the second edge, and the third edge. The heat press device may further include a second quick connect mechanism configured to connect to the first quick connect mechanism.
[0009] In another aspect, a method of customizing a shoe may include loading a first shoe on a first shoe receiving portion of a heat press device, loading a second shoe on a second shoe receiving portion of the heat press device, connecting the heat press device to a heat press machine, placing a design on top of the first shoe and the second shoe, and pressing a heat plate of the heat press machine on top of the first shoe and the second shoe.
[0010] Other systems, methods, features and advantages of the invention will be, or will become, apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description and this summary, be within the scope of the invention, and be protected by the following claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views.
[0012] FIG. 1 is an exemplary embodiment of two platens disposed on a heat press machine;
[0013] FIG. 2 is a top view of a platen from FIG. 1 ;
[0014] FIG. 3 is an perspective view of the top of the platen from FIG. 2 ;
[0015] FIG. 4 is a bottom view of the platen from FIG. 2 ;
[0016] FIG. 5 is a perspective view of the bottom of the platen from FIG. 2 ;
[0017] FIG. 6 is the press machine from FIG. 1 with a platen removed to expose a quick connect plate;
[0018] FIG. 7 is the press machine from FIG. 1 with shoes loaded on a platen and a design to be printed on the shoes.
[0019] FIG. 8 is the press machine from FIG. 7 with the design overlying the shoes.
[0020] FIG. 9 is the press machine from FIG. 7 with the heat press plate pressing down on the shoes.
[0021] FIG. 10 is the press machine from FIG. 7 after the shoes have been printed on.
[0022] FIG. 11 is an exemplary embodiment of multiple platens having different sizes.
[0023] FIG. 12 is a view of the platens from FIG. 11 stacked.
DETAILED DESCRIPTION
[0024] FIG. 1 shows an exemplary embodiment of two heat press platens disposed on a heat press machine 100 . Heat press machine 100 comprises a base 102 and a top heat plate 104 connected to base 102 by an arm 106 having a handle 108 . A first platen 110 may be connected to base at one end and a second platen 112 may be connected to base 102 at the opposite end. As discussed in detail below, first and second platens 110 , 112 may have the same components and may be interchangeable. Arm 106 may be connected to base 102 so that it slides top heat plate 104 from a first position overlying first platen 110 to a second position overlying second platen 112 . Top heat plate 104 may be vertically displaced by pulling handle 108 forward about a pivot point 114 . The operation of using heat press machine 100 and platens to print on shoes will be discussed with reference to FIGS. 7-10 below. Heat press machine 100 is merely exemplary. First and second platens 110 , 112 may be used with any other similar type of heat press machine. For example, first and second platens 110 , 112 may be used interchangeably on a heat press machine that receives one platen at a time.
[0025] FIG. 2 is a top view of platen 110 and FIG. 3 is a perspective view of the top of platen 110 . Platen may be formed with a first edge 216 , a second edge 218 opposite first edge 216 , a third edge 220 , and a fourth edge 222 opposite third edge 220 . First edge 216 and second edge 218 may be curved in the same direction. Third edge 220 and fourth edge 222 may be straight. The width of platen 110 defined by third edge 220 and fourth edge 222 may be tapered from first edge 216 to second edge 218 . A first protrusion 224 may extend from first edge 216 and a second protrusion 226 may extend from second edge 218 . As described in detail with reference to FIGS. 4 and 5 below, first protrusion 224 and second protrusion 226 may provide slots for connecting platen 110 to heat press machine 100 .
[0026] Platen 110 may be made of metal or any other material suitable for heat pressing. A pad 228 may be shaped to cover a flat press surface of platen 110 to provide padding beneath the shoe material being printed on. Pad 228 may be made of silicone or any other material capable of providing padding while withstanding high heat and pressure. Pad may include adhesive backing or adhesive may be applied to pad 228 or platen 110 for attachment. In some embodiments, pad 228 may be omitted.
[0027] Platen 110 may include a first shoe receiving portion 230 and a second shoe receiving portion 232 . Platen 110 may be symmetrical about longitudinal axis 234 such that first shoe receiving portion 230 and second shoe receiving portion 232 may be mirror images of one another. Thus, when a pair of shoes is loaded on platen 110 , the shoes may be mirror images of one another. This positioning allows a single print, including mirror images of the same design, to be applied to two shoes at the same time. First shoe receiving portion 230 may be bounded by part of first edge 216 , part of second edge 218 , and third edge 220 . Second shoe receiving portion may be bounded by part of first edge 216 , part of second edge 218 , and fourth edge 222 .
[0028] FIG. 2 shows a first pair of shoe outlines 236 , a second pair of shoe outlines 238 , and a third pair of shoe outlines 240 to demonstrate how a pair of shoes may be arranged on first shoe receiving portion 230 and second shoe receiving portion 232 . First pair of shoe outlines 236 , second pair of shoe outlines 238 , and third pair of shoe outlines 240 each represents a different shoe size demonstrating how a single platen may accommodate a range of shoe sizes. A first piston spring tensioner and a second piston spring tensioner may be provided to further aid in accommodating a range of shoe sizes. First piston spring tensioner may include a first piston head 242 and a first rod 244 . First piston spring tensioner may further include a first coil spring 246 disposed around first rod 244 . Second piston spring tensioner may include a second piston head 248 and a second rod 250 . Second piston spring tensioner may further include a second coil spring 252 disposed around second rod 250 . More details of first and second spring tensioners are discussed with reference to FIGS. 4 and 5 below.
[0029] As shown in FIG. 2 , a pair of print surface outlines 254 reveal where the print may appear on the shoes loaded on platen 110 , as well as where top heat plate 104 may contact first shoe receiving portion 230 and second shoe receiving portion 232 . The shape of first shoe receiving portion 230 and second shoe receiving portion 232 allows a large portion of a pair of shoes to be flattened by top heat plate 104 , and thus printed on. Platen 110 may be tapered along the longitudinal axis 243 to minimize the print paper size while centering the print surfaces of the shoes (indicated by print surface outlines 254 ) beneath top heat plate 104 . The print size may be reduced because the tapering minimizes the space between the two shoes being printed on, as demonstrated by the position of first pair of shoe outlines 236 , second pair of shoe outlines 238 , and third pair of shoe outlines 240 . Tapering may also position the print surfaces of the shoes (indicated by print surface outlines 254 ) so that the print surfaces may lie beneath the center of top heat plate 104 during heat pressing. Positioning the shoes beneath the center of top heat plate 104 may improve heat transfer and pressure during heat pressing. Additionally, this positioning may limit temperature loss experienced at the edges of top heat plate 104 . As a result of tapering, the size of platen 110 may be minimized.
[0030] The shape of platen 110 may allow left and right shoes to be interchangeably received on platen 110 to print on both lateral and medial sides of a pair of shoes. For example, first shoe receiving portion 230 may receive a right shoe and second shoe receiving portion 232 may receive a left shoe, as indicated by first pair of shoe outlines 236 , second pair of shoe outlines 238 , and third pair of shoe outlines 240 , to print on the lateral sides of a pair of shoes. Then, the left shoe may be moved to the first shoe receiving portion 230 and the right shoe may be moved to the second shoe receiving portion 232 to print on the medial sides of the pair of shoes.
[0031] FIG. 4 is a bottom view of platen 110 and FIG. 5 is a perspective view of the bottom of platen 110 . As mentioned above, platen 110 includes first and second piston spring tensioners. First rod 244 of first piston spring tensioner may be connected to platen 110 by a first bracket 456 and a second bracket 458 . First coil spring 246 may be disposed around first rod 244 between second bracket 458 and first piston head 242 . Second rod 250 may be connected to platen 110 by a third bracket 460 and a fourth bracket 462 . Second coil spring 252 may be disposed around second rod 250 between fourth bracket 462 and second piston head 248 . As shown by the placement of first pair of shoe outlines 236 , second pair of shoe outlines 238 , and third pair of shoe outlines 240 in FIG. 2 , first piston head 242 and second piston head 248 may rest against a toe of shoes. First coil springs 246 may bias first piston head 242 and second coil spring 252 may bias second piston heads 248 against the toe of shoes to create longitudinal tension in the shoes. This tension may enhance the flattening of shoes against platen 110 to facilitate even printing on the shoes. The spring-biasing of first and second piston spring tensioners may also improve the adjustability of platen by aiding the platen in receiving a range of shoe sizes. In some embodiments, first coil spring 246 and second coil spring 252 may be replaced by other mechanisms for biasing first piston head 242 and second piston head 248 against the toes of shoes. In some embodiments, piston spring tensioners may be omitted.
[0032] The bottom of platen 110 may include quick connect mechanisms for quickly connecting platen to base. For example, as shown in FIGS. 4 and 5 , the quick connect mechanisms may include a first T-slot, a second T-slot, and a shallow hole 464 disposed along longitudinal axis 234 . In some embodiments, the quick connect mechanisms may include a single T-slot and a shallow hole. In some embodiments, the quick connect mechanisms may include a plurality of shallow holes. In some embodiments, the quick connect mechanisms may include different types of mechanisms configured to connect with various types of heat press machines.
[0033] The first T-slot may be formed by a first circular hole 466 and a first slot 468 . The second T-slot may be formed by a second circular hole 470 and a second slot 472 . Shallow hole 464 may be shallower than first and/or second T-slots. In some embodiments, shallow hole 464 may be at the same depth as the first and/or second T-slots. In some embodiments, shallow hole 464 may include a hole having a depth that is deeper than the first and/or second T-Slots.
[0034] FIG. 6 shows press machine 100 from FIG. 1 with platen 110 removed to expose a quick connect plate 674 . Quick connect plate 674 may include quick connect mechanisms complimentary to the quick connect mechanisms of platen 110 . The quick connect plate 674 may include a first circular head 676 , a second circular head 678 , and a retractable button 680 . First circular head 676 and second circular heads 678 may be connected to quick connect plate 674 by a first neck 682 and a second neck 684 , respectively.
[0035] To connect platen 110 to quick connect plate 674 as shown in FIG. 1 , platen 110 may be placed on top of quick connect plate 674 so that first circular hole 468 and second circular hole 470 line up with first circular head 676 and second circular head 678 , respectively. When first circular head 676 and second circular head 678 are inserted into first circular hole 468 and second circular hole 470 , platen 110 may be pushed along longitudinal axis 234 so that first neck 682 slides within first slot 468 and second neck 684 slides within second slot 472 until retractable button 680 may be inserted into shallow hole 464 . In this position, first slot 468 and second slot 472 and retractable button 680 may prevent platen from moving in a direction transverse to longitudinal axis 234 . Retractable button 680 may further prevent platen 110 from moving along longitudinal axis 234 .
[0036] Quick connect plate 674 may further include a knob 686 for releasing retractable button 686 from shallow hole 464 . To disconnect platen 110 , knob 686 may be pulled down to withdraw retractable button 686 from within shallow hole 464 as platen 110 may be pushed along longitudinal axis 234 until first circular hole 468 and second circular hole 470 line up with first circular head 676 and second circular head 678 , respectively. Then, platen 110 may be lifted and removed from press machine 100 .
[0037] The quick connect mechanisms on platen 110 may allow platen 110 to be quickly interchanged with another platen. Thus, platen 110 may be replaced with a platen of a different size and/or platen 110 may be replaced with a preloaded platen. For example, while a first pair of shoes loaded on platen 110 may be being printed on, a second platen may be loaded with second pair of shoes. Then, when printing on the first pair of shoes is complete, platen 110 may be quickly replaced with the second platen. And as the second pair of shoes is being printed on the second platen, platen 110 may be loaded with a third pair of shoes.
[0038] The quick connect mechanisms shown in FIGS. 4-6 are merely exemplary embodiments. In some embodiments, the size, shape, and location of the quick connect mechanisms may be altered. In other embodiments, different types of quick connect mechanisms may be provided for connection between platen 110 and quick connect plate 674 . For example, platen 110 may be used with another type of press machine. In this situation, the quick connect mechanisms provided on platen 110 may be altered to correspond with the quick connect mechanism provided on the press machine that platen 110 is being used with.
[0039] FIGS. 7-9 demonstrate a method of using press machine 100 and platen 110 to print on a pair of shoes. FIG. 7 is an isometric view of a right shoe 788 mounted on first shoe receiving portion 230 and a left shoe 790 mounted on second shoe receiving portion 232 . As discussed above with reference to FIGS. 2, 4, and 5 , first piston head 242 and second piston head 248 may press against the toes of right shoe 788 and left shoe 790 to create longitudinal tension in right shoe 788 and left shoe 790 . The tension may enhance the flattening of the lateral sides of right shoe 788 and left shoe 790 against the flat press surface of platen 110 . The shoes may be mounted on platen 110 before platen 110 is mounted on quick connect plate 674 , as discussed above with reference to FIGS. 4-6 . Alternatively, platen 110 may be connected to press machine 100 before loading right shoe 788 and left shoe 790 onto platen 110 .
[0040] FIG. 7 further shows a piece of transfer paper 892 with an argyle design 894 to be printed on right shoe 788 and left shoe 790 . Argyle design 894 may be printed in dye sublimation ink on a piece of sublimation transfer paper. In some embodiments, any other known type of ink and/or transfer paper may be used. Argyle design 894 may be replaced with any design.
[0041] FIG. 8 shows transfer paper 892 placed over right shoe 788 and left shoe 790 . Argyle design 894 may be positioned over right shoe 788 and left shoe 790 where argyle design 894 is to be printed. Then, top heat plate 104 may be slid from first end of base 102 to second end of base 102 so that it may be positioned over argyle design 894 and platen 110 . As shown in FIG. 9 , while top heat plate 104 is positioned over argyle design 894 and platen 110 , handle 108 may be pulled forward so that top heat plate 104 may be lowered onto argyle design 894 . Top heat plate 104 may be heated and may press argyle design 894 down against right shoe 788 and left shoe 790 , thus printing argyle design 894 onto right shoe 788 and left shoe 790 .
[0042] FIG. 10 shows right shoe 788 and left shoe 790 after argyle design 894 is printed on lateral sides of right shoe 788 and left shoe 790 . To print on the medial sides of right shoe 788 and left shoe 790 , right shoe 788 may be moved to second shoe receiving portion 232 and left shoe 790 may be moved to first shoe receiving portion 230 . Then, the above-described method of using press machine 100 and platen 110 to print on a pair of shoes may be performed.
[0043] FIG. 11 shows exemplary embodiments of platens in different sizes such that each platen may accommodate a range of shoe sizes. A small platen 1200 may accommodate sizes 4 through 6 , a medium platen 1202 may accommodate sizes 7 through 9 , and a large platen 1204 may accommodate sizes 10 through 13 . While a single platen may accommodate a wide range of shoe sizes, a more precise fit can be achieved by providing multiple platens each sized to accommodate a small range of shoe sizes. In some embodiments, a single platen may be used to accommodate all shoes sizes. In other embodiments, more sizes of platens may be used to provide a more precise fit for each shoe size. For example, each individual platen may be sized to accommodate a single shoe size. In another example, the platens may be sized as shown in the exemplary embodiment of FIG. 11 and a fourth platen may be provided to accommodate sizes 14 - 16 .
[0044] Small platen 1200 , medium platen 1202 , and large platen 1204 may have the same components as platen 110 shown in FIGS. 1-5 and 6-11 . As shown in FIG. 11 , small platen 1200 may have a first protrusion 1206 , a second protrusion 1208 , a first piston spring tensioner, and a second piston spring tensioner. The first piston spring tensioner may include a first piston head 1210 and a first rod 1212 . The first piston spring tensioner may further include a first coil spring 1214 disposed around first rod 1212 . The second piston spring tensioner may include a second piston head 1216 and a second rod 1218 . The second piston spring tensioner may further include a second coil spring 1220 disposed around second rod 1218 .
[0045] Medium platen 1202 may have a first protrusion 1222 , a second protrusion 1224 , a first piston spring tensioner, and a second piston spring tensioner. The first piston spring tensioner may include a first piston head 1226 and a first rod 1228 . The first piston spring tensioner may further include a first coil spring 1230 disposed around first rod 1228 . The second piston spring tensioner may include a second piston head 1232 and a second rod 1234 . The second piston spring tensioner may further include a second coil spring 1236 disposed around second rod 1234 .
[0046] Large platen 1204 may have a first protrusion 1238 , a second protrusion 1240 , a first piston spring tensioner, and a second piston spring tensioner. The first piston spring tensioner may include a first piston head 1242 and a first rod 1244 . The first piston spring tensioner may further include a first coil spring 1246 disposed around first rod 1244 . The second piston spring tensioner may include a second piston head 1248 and a second rod 1250 . The second piston spring tensioner may further include a second coil spring 1252 disposed around second rod 1250 .
[0047] As shown in FIG. 11 , in addition to small platen 1200 , medium platen 1202 , and large platen 1204 differing in size, the components of small platen 1200 , medium platen 1202 , and large platen 1204 may also differ in size. The sizes of the components may differ to further aid in accommodating a range of shoe sizes. For example, as the platens increase in size to accommodate larger shoe sizes, the piston heads may also increase in size. Small platen 1200 may include small piston heads, medium platen 1202 may include medium piston heads, and large piston 1204 may include large piston heads. Similarly, the length of rods may correspond with the size of the platens. For example, small platen 1200 may have a short rod, medium platen 1202 may have a medium rod, and large platen 1204 may have a long rod.
[0048] The first and second protrusions of small platen 1200 , medium platen 1202 , and large platen 1204 may be sized to position the shallow hole and the first circular hole in a location corresponding with the first circular head and the retractable button of the quick connect plate, as discussed with reference to FIGS. 4-6 above. In some embodiments, the size and shape of the protrusions may vary depending on the type of quick connect mechanisms provided on the platen and the press machine. In some embodiments, the protrusions may be eliminated entirely and the quick connect mechanisms may be provided in another location of the platens.
[0049] FIG. 12 shows small platen 1200 , medium platen 1202 , and large platen 1204 stacked. The piston spring tensioners of small platen 1200 , medium platen 1202 , and large platen 1204 have been removed in this view. Small platen 1200 is shown with a first print surface outline 1254 for a size 4 shoe. Medium platen 1202 is shown with a second print surface outline 1256 for a size 9 shoe. Large platen 1204 is shown with a third print surface outline 1258 for a size 13 shoe. Similar to platen 110 shown in FIGS. 1-5 , small platen 1200 may have a first edge 1260 and a second edge 1262 , medium platen 1202 may have a first edge 1264 and a second edge 1266 , and large platen 1204 may have a first edge 1268 and a second edge 1270 . In FIG. 12 , small platen 1200 , medium platen 1202 , and large platen 1204 are stacked with first edges aligned to show how the different sizes of platens and shoe prints compare. While the sizes of small platen 1200 , medium platen 1202 , and large platen 1204 differ, the general shape of the platens may remain the same.
[0050] While various embodiments of the invention have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.
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Heat press platens for a shoe customization/decoration system and a method of using the same are disclosed. The platens may be quickly interchanged to allow the same equipment to be used to dye shoes of different sizes. The platens individually accommodate a pair of assembled shoes and are shaped to: reduce print sizes, maintain symmetry and flatness of the shoe, and accommodate a range of shoe sizes. The size and shape of the platens enable one shoe to be fitted on one side of a platen and another shoe to be fitted on the opposite side. The platens position the shoes so that they are mirror images of each other. This positioning allows a single print, including mirror images of the same design, to be applied to two shoes at the same time.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a non-provisional application and claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 62/181,161, filed Jun. 17, 2015, which is incorporated herein in its entirety by reference.
BACKGROUND
[0002] Field of the Invention
[0003] The present invention relates generally to providing pressurized infusion of liquids and, more particularly, is directed to providing a stable and pressurized flow of irrigation fluid to the eye during surgery utilizing a secondary set of fluidics lines.
[0004] Description of the Background
[0005] Certain surgical procedures, such as phacoemulsification surgery, have been successfully employed in the treatment of certain ocular problems, such as cataracts. Phacoemulsification surgery utilizes a small corneal incision to insert the tip of at least one phacoemulsification handheld surgical implement, or handpiece, through the corneal incision. The handpiece includes a needle which is ultrasonically driven once placed within the incision to emulsify the eye lens, or to break the cataract into small pieces. The broken cataract pieces or emulsified eye lens may subsequently be removed using the same handpiece, or another handpiece, in a controlled manner. The surgeon may then insert a lens implant into the eye through the incision. The incision is allowed to heal, and the result for the patient is typically significantly improved eyesight.
[0006] As may be appreciated, the flow of fluid to and from a patient through a fluid infusion or extraction system, and thus the control of fluids and fluid pressure through the phacoemulsification handpiece, is critical to the procedure performed. Different medically recognized techniques have been utilized to control the fluid flow during the lens removal portion of the surgery. Among these, one popular technique is a simultaneous combination of phacoemulsification, irrigation and aspiration using a single handpiece. This method includes making the incision, inserting the handheld surgical implement to emulsify the cataract or eye lens, and, simultaneously with this emulsification, having the handpiece provide a fluid for irrigation of the emulsified lens and a vacuum for aspiration of the emulsified lens and inserted fluids.
[0007] Currently available phacoemulsification systems, such as those mentioned above, typically include a variable speed peristaltic pump and/or vacuum pump, a vacuum sensor, an adjustable source of ultrasonic power, and a programmable microprocessor with operator-selected presets for controlling aspiration rate, vacuum and ultrasonic power levels. The phacoemulsification handpiece is interconnected with a control console by an electric cable for powering and controlling a piezoelectric transducer that drives the action of the handpiece. Tubing provides irrigation fluid to the eye through the handpiece and enables withdrawal of aspiration fluid from an eye through the handpiece.
[0008] Generally, irrigation and aspiration are employed by the surgeon using the device to remove unwanted tissue and maintain pressure within the eye. Moreover, the use of, and particularly the pressurization of, the irrigation fluid is critical and may, for example, prevent the collapse of the eye during the removal of the emulsified lens. Irrigation fluid pressure is also used to protect the eye from the heat generated by the ultrasonic cutting needle and may suspend fragments created during the surgery in fluid for more easy removal through aspiration.
[0009] Irrigation fluid pressure has been conventionally handled in two ways. The first method to increase irrigation fluid pressure has relied upon the height of the fluid source. Conventional IV poles may be adjusted in height to create the desired pressure head using gravity-feed principles. The second method includes the use of an infusion pump either directly pumping the fluid typically in the form of a peristaltic pump used in-line with an irrigation delivery line or by pressurizing the fluid container thus increasing higher atmosphere above the fluid resulting in higher infusion pressure and flow to the surgical site.
[0010] Furthermore, alone or in conjunction with the methods discussed above, the fluid pressure within the fluid source may be adjusted by compression which may be internal and/or external to the fluid source. For example, an IV bag may be physically compressed by at least two opposed plates which may exert a force on the bag sufficient to provide for a fluid pressure above a simple gravity feed. The compression of the fluid may be dynamic to allow for a consistent and/or specific pressure as the volume of fluid decreases in the IV bag. Pressure may also be provided internal to the fluid source by the introduction of a higher pressure, such as using an inert gas, for example.
[0011] Although each of the foregoing methods produces pressurized irrigation fluid at the surgical site, each suffers from difficulties in maintaining a constant pressure. For example, infusion pumps must be deployed with a dynamic pressure-sensing control loop to prevent over or under pressurizing the anterior chamber, and may further require venting to control unwanted pressures. Solving these issues may require the use of a special drip spike, a mechanical pressurization compartment, or an over-bag, to control atmospheric pressure. Such solutions add costs and complications to the surgical set-up and to the maintenance of the surgical equipment.
[0012] Further, it is typical that the smaller the incision made during surgery, the greater the pressure needed to properly irrigate the surgical site, and gravity-feed systems may not produce the desired amount of pressure due at least to limitations on the height which may be achieved by physically raising the source of irrigation liquid. Typically, the irrigation source is affixed to a movable IV pole which is raised to increase the pressure head. Of course, limitations as to the maximum height of the IV pole and/or the height of overhead objects, such as lights or a ceiling, for example, may limit the amount of achievable height.
[0013] Moreover, in the aforementioned configurations combining phacoemulsification, irrigation and aspiration, the handpiece may be configured to provide a fluid for irrigation of an emulsified lens and a vacuum for aspiration of the emulsified lens and inserted fluids. In such configurations fluidics lines are typically switched from phacoemulsification to irrigation and aspiration. While the configuration provides advantages for the surgical procedure, the switching of fluidics lines unnecessarily slows down the procedure and creates the potential for fluid to drain accidentally. Furthermore, the switching of lines has the tendency to introduce fluctuations of intra-ocular pressure.
[0014] Thus, there is a need for a system and method that provides improved pressurized delivery of irrigation fluid to a surgical site.
SUMMARY OF THE INVENTION
[0015] The present disclosure is directed to a system and a method of providing pressurized fluid to the eye. The system and method may include at least one constant pressure source and at least one height adjustable irrigation fluid source to provide a stable pressurized fluid flow.
[0016] In one embodiment, a secondary set of fluidics lines are provided to allow phacoemulsification, irrigation and aspiration handpieces to be primed and ready for surgery simultaneously. A tertiary peristaltic pump and an additional fluid reservoir may be provided to pressurize a balanced salt solution (BSS) bag. The system software, tangibly embodied in hardware, would allow a surgeon to select a desired inter-ocular pressure and would then control the pumps and valves to achieve and maintain the selected pressure.
[0017] Accordingly, the disclosure provides a system and method that provides improved pressurized delivery of irrigation fluid to a surgical site.
DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate disclosed embodiments and/or aspects and, together with the description, serve to explain the principles of the invention, the scope of which is determined by the claims.
[0019] In the drawings:
[0020] FIG. 1 schematically illustrates an eye treatment system in which a cassette couples an eye treatment probe with an eye treatment console, along with a method for use of the system for treating the eye of a patient;
[0021] FIG. 2 schematically illustrates a dual mode cassette having a surgical fluid pathway network for use in the system of FIG. 1 ;
[0022] FIG. 3 schematically illustrates a single mode displacement-based aspiration cassette having a surgical fluid pathway network for use in the system of FIG. 1 ;
[0023] FIG. 4 illustrates a block diagram of a pressurized infusion pack under one exemplary embodiment; and
[0024] FIG. 5 illustrates an exemplary interface for the pressurized infusion pack of FIG. 4 under one embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0025] It is to be understood that the FIG.s and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for the purpose of clarity, many other elements found in typical surgical, and particularly optical surgical, apparatuses, systems, and methods. Those of ordinary skill in the art may recognize that other elements and/or steps are desirable and/or required in implementing the present invention. However, because such elements and steps are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements and steps is not provided herein. The disclosure herein is directed to all such variations and modifications to the disclosed elements and methods known to those skilled in the art.
[0026] Referring to FIG. 1 , a system 10 for treating an eye E of a patient P generally includes an eye treatment probe handpiece 12 coupled to a console 14 by a cassette 16 mounted on the console. Handpiece 12 generally includes a handle for manually manipulating and supporting an insertable probe tip. The probe tip has a distal end which is insertable into the eye, with one or more lumens in the probe tip allowing irrigation fluid to flow from the console 14 and/or cassette 16 into the eye. Aspiration fluid may also be withdrawn through a lumen of the probe tip, with the console 14 and cassette 16 generally including a vacuum aspiration source, a positive displacement aspiration pump, or both to help withdraw and control a flow of surgical fluids into and out of eye E. As the surgical fluids may include biological materials that should not be transferred between patients, cassette 16 will often comprise a disposable (or alternatively, sterilizable) structure, with the surgical fluids being fed through flexible conduits 18 of the cassette that avoid direct contact in between those fluids and the components of console 14 .
[0027] When a distal end of the probe tip of handpiece 12 is inserted into an eye E (for example) for removal of a lens of a patient with cataracts, an electrical conductor (not shown) may supply energy from console 14 to an ultrasound transmitter of the handpiece. Alternatively, the handpiece 12 may be configured as an I/A or vitrectomy handpiece. Also, the ultrasonic transmitter may be replaced by other means for emulsifying a lens, such as a high energy laser beam. The ultrasound energy from handpiece 12 helps to fragment the tissue of the lens, which can then be drawn into a port of the tip by aspiration flow. So as to balance the volume of material removed by the aspiration flow, an irrigation flow through handpiece 12 (or a separate probe structure) may also be provided, with both the aspiration and irrigations flows being controlled by console 14 .
[0028] So as to avoid cross-contamination between patients without incurring excessive expenditures for each procedure, cassette 16 and its flexible conduit 18 may be disposable. Alternatively, the flexible conduit or tubing may be disposable, with the cassette body and/or other structures of the cassette being sterilizable. Regardless, the disposable components of the cassette are typically configured for use with a single patient, and may not be suitable for sterilization. The cassette will interface with reusable (and often quite expensive) components of console 14 , including peristaltic pump rollers, a Venturi or other vacuum source, a controller 40 , and the like.
[0029] Controller 40 may include an embedded microcontroller and/or many of the components of a personal computer, such as a processor, a data bus, a memory, input and/or output devices (including a touch screen user interface 42 ), and the like. Controller 40 will often include both hardware and software, with the software typically comprising machine readable code or programming instructions for implementing one, some, or all of the methods described herein. The code may be embodied by a tangible media such as a memory, a magnetic recording media, an optical recording media, or the like. Controller 40 may have (or be coupled to) a recording media reader, or the code may be transmitted to controller 40 by a network connection such as an internet, an intranet, an Ethernet™, a wireless network, or the like. Along with programming code, controller 40 may include stored data for implementing the methods described herein, and may generate and/or store data that records parameters corresponding to the treatment of one or more patients. Many components of console 14 may be found in or modified from known commercial phacoemulsification systems from Abbott Medical Optics Inc. of Santa Ana, Calif.; Alcon Manufacturing, Ltd. of Ft. Worth, Tex., Bausch and Lomb of Rochester, N.Y., and other suppliers.
[0030] Referring now to FIGS. 1 and 2 , components of the aspiration and irrigation fluid flow networks of system 10 are described in more detail with respect to a dual mode or dual pump cassette 16 A that enables both displacement-based and vacuum-based aspiration modes. FIG. 2 generally highlights the surgical aspiration and irrigation fluid control elements included within the cassette 16 A, with the irrigation components often being relatively straightforward. An irrigation source 46 of the console optionally provides irrigation fluid pressure control by relying at least in part on a gravity pressure head that varies with a height of an irrigation fluid bag or the like. An irrigation on/off pinch valve 48 may generally include a short segment of a flexible conduit of cassette 16 A, which can be engaged and actuated by an actuator of the console 14 , e.g. with a surface of the cassette body often being disposed opposite the actuator to facilitate closure of the conduit lumen. Alternative irrigation flow systems may include positive displacement pumps, alternative fluid pressurization drive systems, fluid pressure or flow modulating valves, and/or the like. In certain embodiments, irrigation fluid is alternatively or additionally provided to a separate handpiece (not shown).
[0031] The aspiration flow network 50 generally provides an aspiration flow path 52 that can couple an aspiration port in the tip of handpiece 12 to either a peristaltic pump 54 and/or to a fluid container or holding tank 56 . Fluid aspirated through the handpiece 12 may be contained in the holding tank 56 regardless of whether the aspiration flow is induced by peristaltic pump 54 or the vacuum applied to the holding tank 56 . When valve 58 is closed and peristaltic pump 54 is in operation, pumping of the aspiration flow may generally be directed by the peristaltic pump 54 , independent of the pressure in the holding tank 56 . Conversely, when peristaltic pump 54 is off, flow through the peristaltic pump may be halted by pinching of the elastomeric tubing arc of the peristaltic pump by one or more of the individual rollers of the peristaltic pump rotor. Hence, any aspiration fluid drawn into the aspiration network when peristaltic pump 54 is off will typically be affected by opening of a valve 58 , which may be a selector control valve so that the aspiration port of the probe is in fluid communication with the holding tank. Regardless, the pressure within tank 56 may be maintained at a controlled vacuum level, often at a fixed vacuum level, by a vacuum system 45 of the console. The vacuum system 45 may comprise a Venturi pump 47 , a rotary vane pump, a vacuum source, or the like, and a vent valve 44 . Aspiration flow fluid held into holding tank 56 may be removed by a peristaltic drain pump 60 and directed to a disposal fluid collection bag 62 . Vacuum pressure at the surgical handpiece may be maintained within a desired range through control of the fluid level in the holding tank.
[0032] In more detail, the operation of aspiration flow network 50 can be understood by first considering the flow when valve 58 is closed. In this mode, peristaltic pump 54 draws fluid directly from handpiece 12 , with a positive displacement peristaltic pump flow rate being controlled by the system controller 40 (see FIG. 1 ). To determine the appropriate flow rate, the level of vacuum within the aspiration flow network may be identified in part with reference to a vacuum sensor 64 disposed along the aspiration flow network 50 between peristaltic pump 54 and handpiece 12 . This allows the system to detect and adjust for temporary occlusions of the handpiece and the like. While the aspiration material flows through holding tank 56 and eventually into collection bag 62 , the holding tank pressure may have little or no effect on the flow rate in this mode.
[0033] When peristaltic pump 54 is not in operation, rotation of the peristaltic pump is inhibited and the rotors of the peristaltic pump pinch the arcuate resilient tubing of the probe so as to block aspiration flow. Material may then be drawn into the aspiration port of handpiece 12 by opening selector valve 58 and engagement or operation of the vacuum system 45 . When valve 58 is open, the aspiration port draws fluid therein based on the vacuum in the holding tank 56 Aspiration network 50 of the dual mode cassette 16 A allows system 10 to operate in either peristaltic or vacuum-based pumping modes.
[0034] When only displacement-based pumping will be used for a particular procedure, an alternative cassette may be employed in the console 14 , with the alternative cassette lacking a holding tank 56 , selector valve 58 , and the like. Referring now to FIGS. 1 and 3 , components of a single mode cassette 16 B are described, the single mode cassette enabling only the displacement-based aspiration mode. Within the single mode cassette, peristaltic pump 54 draws fluid directly from handpiece 12 , with a positive displacement peristaltic pump flow rate being controlled by the system controller 40 (see FIG. 1 ). To determine the appropriate flow rate, the level of vacuum within the aspiration flow network may be identified in part with reference to a vacuum sensor 64 disposed along the aspiration flow network 50 between peristaltic pump 54 and handpiece 12 . The aspiration material flows directly into collection bag 62 . Alternatively, a single mode cassette may also be provided that only enables vacuum-based aspiration.
[0035] As a dual mode cassette may be somewhat more complex, a single mode cassette may be both simpler and less expensive. Therefore, the present invention may avoid complexity and provide cost savings by enabling the use of a less expensive single mode cassette when only a single aspiration mode is needed during a procedure on a particular patient.
[0036] Turning now to FIGS. 4 and 5 , an exemplary pressurized infusion pack 500 and console interface 600 with left/right pack capture clamps 610 - 611 , is illustrated, comprising a first peristaltic line 502 , a second peristaltic line 514 and a tertiary peristaltic line 501 , wherein each may interface with pumps 502 A, 514 A and 501 A respectively located on console interface 600 as shown in FIG. 5 . Pump 502 A may comprise a peristaltic pump that mates with peristaltic line 502 , and may serve as a primary means of moving fluid through the system and a prospective patient's eye in the event that the system is being used in peristaltic mode or Venturi mode.
[0037] An initial fluid intake line (from a balanced salt solution (BSS) source) may be provided to line 501 , which would contact a roller head 501 A as shown in FIG. 5 . The line and the roller head may be configured to be the driving force for creating fluid pressure. Line 514 may be configured as the last section of an aspiration line, which would mate with peristaltic pump 514 A, which may act as a drain pump to remove fluid from Venturi reservoir 513 when fluid level within the tank is too high.
[0038] Phacoemulsification aspiration line 505 , and irrigation and aspiration (I/A) and vitrectomy line 506 are configured to enter strain gauge 503 via pinch valve receptor 504 , where the aspiration lines may comprise used BSS fluid. In an embodiment, pinch valves 504 A and 504 B, located on console interface 600 as shown in FIG. 6 , may be received on either side of strain gauge 503 . Depending on the surgical mode being utilized, one of the two pinch valves, for example 504 A, may be energized to prevent fluid flow from an inactive line. Strain gauge 503 may be coupled to mating surface 503 A of FIG. 5 in order to measure a vacuum present in the aspiration lines. Combined aspiration fluid may be transferred as shown in FIG. 4 to Venturi tank reservoir 513 . Fluid level in Venturi tank 513 may be monitored via LEDs 513 A or other suitable visual indicia.
[0039] Pressurized infusion tank 507 may be configured to store pressurized fluid, where strain gauge 508 and mating surface 508 A may allow strain gauge 508 to measure pressure inside the pressurized infusion tank 507 . Fluid level in pressurized infusion tank 507 may be monitored via LEDs 507 A or other suitable visible indicia. Irrigation from pressure infusion tank 507 is provided via phacoemulsification irrigation line 511 , and I/A and vitrectomy irrigation line 512 as shown in FIG. 4 . Pinch valve receptors 509 - 510 , for receiving pinch valves 509 A and 510 A, located on console interface 600 as shown in FIG. 6 , may be energized to cut off fluid supply from inactive lines.
[0040] Accordingly, pressurized infusion pack 500 may be configured to provide three methods of introducing fluid to the surgical area: peristaltic, Venturi and pressurized infusion. In the cases of Venturi and peristaltic, the pack may operate in a manner similar to that described above, except that pressurized infusion pack 500 may utilize peristaltic pump 501 , which may be configured in the center of the fluidics panel. In one embodiment, at least one roller head associated with peristaltic pump 501 may be temporarily disengaged from the fluid line to provide more control over the pressure within the line.
[0041] For pressurized infusion, infusion tank 507 , arranged above Venturi tank reservoir 513 , is configured to build pressure, where the system would make use of tertiary peristaltic roller from 501 to push fluid from the fluid source into tank 507 . The fluid may be held inside tank 507 utilizing pinch valves 509 A, 510 A on the outgoing irrigation lines 511 , 512 . When sufficient pressure and fluid volume is present, at least one of pinch valves 509 , 510 may be released to allow fluid to move through the lines at a user's desired pressure.
[0042] As mentioned above, pressure may be measured (+mmHg) utilizing strain gauge 508 which may be configured to be inside tank 507 . The system may additionally utilize measurements from strain gauge 503 (−mmHg) to ensure that pressure within an eye has not become too high or too low.
[0043] One of the advantages of the disclosed configuration is that having two sets of fluidics tubing may allow end users to simultaneously prime a phacoemulsification handpiece and an I/A handpiece, such that they may be prepared for use in surgery simultaneously. One skilled in the art would recognize that this advantageously saves users time and potential frustration from changing lure fittings at least once during a procedure.
[0044] In one embodiment, lures and tubing of one fluidics tubing set may be configured for the phacoemulsification handpiece, while the other set would be configured for the irrigation and aspiration handpiece. The tubing may advantageously be color coded for ease of use. During surgery, only one set of lines would be active at one time under one embodiment. When a user selects phacoemulsification, the pinch valves would operate as normal for the phacoemulsification fluidics lines, while the pinch valves for the I/A fluidics lines would energize and prevent any flow from those lines. Similarly, when a user selects the I/A handpiece (or vitrectomy), the pinch valves for those modes would act as normal while pinch valves for the phacoemulsification fluidics energize to prevent further flow.
[0045] Those of ordinary skill in the art may recognize that many modifications and variations of the herein disclosed systems and methods may be implemented without departing from the spirit or scope of the invention. Thus, it is intended that the present invention covers such modifications and variations provided they come within the scope the appended claims and their equivalents.
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Apparatus, system and method for providing pressurized infusion of liquids and, more particularly, providing a stable and pressurized flow of fluid to the eye during surgery. Aspiration fluid may be received via an aspiration line at a first peristaltic pump, where aspiration fluid is transferred to a Venturi tank reservoir coupled to a second peristaltic pump. Fluid from a fluid source is provided via a third peristaltic pump to a pressurized infusion tank. A determination is made if the pressure in the pressurized infusion tank is at a predetermined level, where fluid may be transferred from the pressurized infusion tank to an irrigation line when pressure in the pressurized infusion tank is determined to be at the predetermined level. Alternate activation of a plurality of aspiration and irrigation lines are also provided.
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This is a continuation application of application Ser. No. 834,369 filed Feb. 28, 1986 now abandoned.
BACKGROUND OF THE INVENTION
1. Technical Field Of The Invention
This invention relates generally to dough testing devices and methods. In particular, this invention relates to an apparatus and method for testing dough qualities and characteristics in a reliable and repeatable manner.
Dough testing equipment using burst testing is generally known in the mechanical arts.
2. Background Art
A particular apparatus for burst testing of doughs is, for example, the Chopin Alveographe. This device is a mechanical dough testing apparatus used for determining quality of wheats and of flours. It also tests the rheological characteristics of dough. The principle of this device is based upon bi-axial stretching of a dough sample, which under pressure expands into a large volume bubble having a very thin wall. This type of stretching emulates the deformation of the dough under the influence of gaseous pressure of biological origin, such as carbonic fermentation using yeast, or chemical origin, employing chemical yeasts.
In such an alveographe, the internal bubble pressure is recorded, that is, the air or other fluid pressure existing inside the bubble. The volume of the bubble is also measured. A particular dough, employing particular flours, can be tested according to this device, and the test results after repeated test measurements of the dough result in a close correllation between the measurements obtained and the baking results of such a dough. Therefore, this prior art device is useful in evaluating particular wheat varieties for use in dough, for evaluating particular doughs and formulations of doughs, and for testing the quality of a particular flour.
Due to inherent testing errors in the Alveograph, the measured variables for each dough sample can vary even for a highly uniform batch of dough samples. Furthermore, a large number of tests must generally be conducted in order to determine a "true" value for the dough characteristics being measured by this device, employing a statistical analysis. Such statistical analysis includes a determination of standard deviation of the measured values about some average value. Thus, the smaller the standard deviation, the greater the likelihood that the average value about which the standard deviation occurs is the true value of the variable being measured.
U.S. Pat. No. 3,160,002 to Lovette shows an automatic burst tester. This particular burst tester has graphical output as seen in FIGS. 1 and 3. An air supply as seen in FIG. 4 is used to provide the bursting pressure.
In U.S. Pat. No. 4,272,824 to Lewinger et al., a batch of ingredients is mixed in a receptacle, the mixed batch is then divided into equal portions, and weight is measured. A control device is shown for adjusting a portion of the mixed batch to be transferred, including a dividing means.
U.S. Pat. No. 2,673,463 to Kimball et al., teaches a device for determining the consistency of materials. This is particularly with reference to the mixing of dough, wherein a sample dough is made, and kneaded until an adequate consistency is reached. This patent takes note that the hygroscopic propeties of flour may vary from sack to sack, and that other controls and testing devices may be somewhat inaccurate, and that human errors also occur. A power graph is employed in this invention to aid in providing repeatable test results.
U.S. Pat. No. 2,275,341 to Braybender relates to a device for testing dough. In this device, as seen in FIG. 4, a curve is made representing the resistence to extension of the dough with respect to the extensibility of the dough. The dough is tested until it reaches a breaking point. Here, a dough sample is ruptured by an arm of a machine.
A variety of patents relating to dough testing include U.S. Pat. Nos. 1,591,360; 1,468,900; and 2,281,182. These patents are each by Chopin. Also, a French Patent to Chopin No. 733,686 relates to such testing equipment for determining properties of materials. All of these references are deemed relevant to Alveograph.
SUMMARY OF THE INVENTION
By the present invention, the variability of test results in burst-testing type of apparatus is greatly reduced and the standard deviation of test results of a single mixed batch of dough is reduced as compared to the prior art testing devices, thereby increasing significantly the reliability of the test results obtained.
The present invention employs, preferably, a Chopin Alveograph for burst-testing of dough samples. The dough samples are first made by mixing the desired ingredients thoroughly and then extruding them through a slot onto a shelf having a coating of polytetrofluorethylene, which coating is known by a commercial name as Teflon®.
The extruded dough sample is then placed upon a flat surface having upstanding sidewalls of a predetermined height, the flat surface also being coated with polytetrafluorethylene, also known commercially as Teflon®. A roller is used having arms which span the upstanding sidewalls of the support tray, so that the roller extends below the predetermined height of the sidewalls such as that during a rolling operation, a dough sample placed beneath the roller will eventually be rolled to a very uniform thickness, which thickness does not vary significantly from one dough sample to another, except at the edge portions thereof. The roller surface itself is preferably coated with polytetrafluorethylene, which is known by a commercial name as Teflon®.
Once the dough has been rolled to a predetermined thickness by the roller, a circular cutter is used to cut out disc-shaped pieces of dough from the rolled dough sample. The cutter edges and surfaces also are coated by polytetraflouroethylene. Preferably, five pieces of disc-shaped dough are cut, to provide a sufficient number of samples to ensure a reliable set of test results. The disc-shaped dough pieces are then placed upon resting trays, which resting trays are then placed into a chamber maintained at a predetermined temperature and humidity for a length of time sufficient for the dough to reach uniform conditions. The resting trays also are preferably coated with polytetrafluorethylene, the coating material having a commercial name of Teflon®.
After the predetermined "resting" period has elapsed, each sample is in turn placed in the burst-testing portion of the apparatus. Here, air is introduced quickly initially, and then added slowly and steadily to stretch the sample disk. During this time, the air pressure inside the forming dough bubble is measured as a function of time, and also measured is the extension of the dough sample in terms of its changed surface area. At the bursting point of the dough sample, which bursts after expanding balloon-like into a semi-spherical membrane, the pressure suddenly drops to atmospheric pressure and the test ends. Doughs such as used for animal biscuits and the like burst more quickly and are less extensible than are doughs used, for example, for breads.
The testing is repeated until all of the dough samples have been tested. The properties of the dough are then calculated from the test measurements, and the values are averaged over all of the samples to determine the dough qualities of the dough batch.
Heretofore, it was assumed in the prior art that substantially all of the variability of the test results was due to the inherent limitations of the dough samples themselves and to the testing procedures. Heretofore also, no polytetrafluorethylene coatings were used for the various components which contact the surface of the dough samples, as such were not necessary and since such were not believed heretofore to be relevant to the test results. By the present invention, an unexpected results occurs, namely that the reliability of the test results has been significantly increased. The statistical variability of the test results, defined as the standard deviation divided by the mean, is reduced by approximately one-half.
Further details and advantages of the present invention appear from the following description of a preferred embodiment shown schematically in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a front view of an apparatus according the present invention;
FIG. 2 is a perspective view showing a roller and rolling tray usable with the present invention;
FIG. 3 is a top elevational view of a dough sheet with a circular cut-out formed therein;
FIG. 4 is a front elevational view of the dough cut-outs lying upon a resting tray in a cabinet;
FIG. 5 is view illustrating a dough cut-out being tested;
FIG. 6 shows a set of curve results obtained from the testing operation, including test results from a plurality of samples;
FIG. 7 is a block diagram showing the method employed according to the present invention; and
FIG. 8 is a side elevational view of dough being extruded onto a shelf.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a front elevational view of an Alveographe used in a preferred embodiment of the present invention. The apparatus 1 includes a dough mixer and extruder 2 having a motor and control system 3, which is linked to the mixer 2 by the shaft 17. The apparatus 1 includes a power supply 4 for supplying power to all of the operating components as illustrated in FIG. 1. The apparatus 1 includes the dough testing station 5 having an upstanding dough sample support 8.
The apparatus 1 includes a cabinet 6 having doors 9, 10. Each door has a knob 53. A humidity controller 11 and a temperature controller 12 are optionally provided to control humidity and temperature inside of the cabinet 6. The cabinet 6 is used for receiving samples of dough "resting", to permit the dough to come to a uniform temperature and humidity. An air pressure indicating output (not shown in the Figures) connects the test stand 5 with the graphical output device 7. The graphical output device 7 includes a cylindrical column 14 supporting a sheet of graph paper 13. A vertical post 15 movably supports a pen 16, the height of the pen 16 being dependent upon the air pressure supplied to the dough sample being stretched and ultimately burst. The cylinder 14 is adapted to rotate and does rotate so that during the upward and downward travel of the pen 16, rotation of the cylinder 14 brings different regions of the graph paper into contact with the pen 16. The upward and downward movement of the pen 16 is indicated by the double headed arrow in FIG. 1. The rotational movement of the cylinder 14 is indicated by the curved arrow R as seen in FIG. 1.
As seen in FIG. 1, a pair of headed members 21, 21 are connected to a support shelf 19. A receiving tray 20 is mountable adjacent to a slot 52 formed in the mixing chamber 2. The receiving tray 20 has an upper surface 18 which is composed of polytetrafluoroethylene according to the present invention.
The operation and nature of the Alveographe equipment is well-known in the food industry and a French book on the subject by Marcel Chopin, among many other references illustrating use and nature of this type of test equipment, is entitled Cinquante Annees de Recherches Relatives Aux Bles et a Leur Utilisation Industrielle, published in March of 1973 in Boulogne.
FIG. 8 is illustrative of the positioning of the receiving tray 20 atop the shelf 19, the tray 20 being retained snuggly against the shelf 19 by the heads of the numbers 21, 21. The top of the shelf 20 is adjacent and co-planar with the lower most edge of the slot 52 through which an extrudate 30 passes. The extrudate 30 is preferably a dough which has been mixed and blended inside of the mixer 2 until extrusion is desired.
A sheet 24, 25 is shown in FIG. 2. Prismatic rectangular bars 22, 23 are spaced in parallel relationship across the interior portion 25 of the cookie sheet 24. A rough sample would be rolled between prismatic rectangular bars 22, 23 by a rolling pin 26 having handles 27, 28. The thickness of each of the rectangular prismatic bars 22, 23 determines the thickness to which a dough sample 29 can be rolled. In a preferred embodiment, the cookie sheet 24 is formed of aluminum and has a Teflon® coating. Nonetheless, any material for the cookie sheet 24 may be used, and any shape of cookie sheet 24 may be used. The rectangular prismatic bars 22, 23 may also be of any material, including wood, iron, steel, plastic, or the like, so long as they are strong enough to withstand breaking of substantial deformation during the rolling operation by roller 26.
The sheet 24, 25 shown in FIG. 2 is, according to the present invention, coated with a coating of polytetrafluorethylene. The material known as polytetrafluoroethylene is commercially available under the name Teflon®. Other coatings are also known employing such a non-stick surface or a low friction surface. The outer surface of the roller 26 is likewise coated, according to the present invention, with a coating of the material polytetrafluorethylene. This material is known commercially as Teflon®, among other commercial names. The extrudate 30 as shown in FIG. 8 is cut by a spatula or the like and placed above the tray 25, where the roller 26 is operated so as to reduce the thickness of the extrudate 30 to a generally uniform thickness, except around the edges of the extrudate 30. This is accomplished due to the predetermined thicknesses of the bars 22, 23 which cause a predetermined thickness to exist in the central regions of the extrudate dough 30.
Once the extrudate dough 30 has been rolled to a generally uniform thickness, a plurality of generally disk-shaped samples are cut into the dough, as seen in FIG. 3. The cutter is preferably any type of generally sharp-edges round cutter, such as a cookie-cutter or other circular, generally sharp-edged, object. The cutter, according to the present invention, also has a coating along its surfaces of polytetrafluorethylene. This material is known commercially as Teflon®. Once the plurality of disk-shaped test samples 31 are cut, they are removed gently with a spatula, or alternatively the surrounding extrudate dough sheet 30 can be peeled off the sheet leaving the test disks 31 remaining lying upon the surface 25. An ordinary spatula or other article can be used to transfer the test disks 31 to a resting tray 40.
A resting tray 40 is shown in FIG. 4. This resting tray 40 preferably has an uppermost surface 41 composed of a coating of polytetrafluorethylene. The material forming the coating 41 is commercially available under the name Teflon®. The test disks 31, 31 visible in FIG. 4 are seen resting atop the tray 40. The tray 40 is shown in FIG. 4 as being placed within the cabinet 6, having a resting chamber 61. The doors of the cabinets 6 are then closed, and the test disks 31 are permitted to reach an equilibrium temperature over a predetermined period of time, for example 15 minutes. After the test disks 31 have "rested" for a sufficient amount of time, they are then tested by being expanded under air pressure until bursting. This operation is as seen in FIG. 5.
In FIG. 5, the uppermost portion of the sample support block 8 is seen, with the lowermost portion being broken away. Here, the test disk 31 has been expanded by air pressure into a relatively thin membrane having a semi-spherical shape which is growing with a velocity W as indicated in the arrows in FIG. 5. During the entire time of expansion of the test sample 31, the air pressure within the support 8 is continuously measured and plotted with respect to time. Furthermore, the total amount of extension of the sample 31 is determined, either by direct measure, observation, or by theoretical calculations based upon the air pressure of the stand 8. This information is used to compute the extensibility of the sample 31 as well as to determine its maximum extension at bursting. This simulates the expansion of bubbles in materials such as breads and the like.
This is particularly useful for testing various strains of wheat, batches of flour, new recipes, or for comparing various combinations of ingredients. For example, doughs having a low amount of extensibility would include animal biscuits, crackers, and doughs for crusts. Dough having a high degree of extensibility, as measurable by the present test apparatus and method include bread doughs, cake doughs, and any other doughs in which expansion is highly desirable.
Tests results are indicated in FIG. 6, for a sample run of five tests. A horizontal reference line 80 and vertical reference line 81 have been drawn in. A plurality of curves, 82, each having a peak 83, result from the same mixed batch of dough each curve resulting from a different sample disk taken from that same sample of mixed dough. If the vertical reference line 81 is generally representative of the mean, the variability of the bursting points, indicated as generally vertical lines 84, indicate the bursting of each sample. Thus, a sample of dough having individual test disk which bursts at a relatively high degree of extension, may not be indicative of the quality of flour, or the dough sample used, and therefore, a large number of tests are highly desirable in order to ensure statistical accuracy when using the test results to compare one batch of dough against another batch of dough, or one flour versus other flours.
By the present invention, the variability of the test results is greatly reduced, and more closely approximates the "true" test results which would be achieved by running a far higher number of tests upon substantially identical doughs. This advantageous result, which occurs entirely due to the use of the coating material polytetrafluorethylene used upon the surfaces described, is unexpected since the coating material is not used at the point of testing itself, namely the stand 8. Therefore, it is unexpected that the use of the material polytetrafluorethylene would be of any value in conducting such tests. Such coatings were not heretofor employed in the dough testing art for burst testing.
An example of the effect of the coating of polytetrafluorethylene of the extrusion plate 20 the roller 26, the templates (not shown but described hereinabove), and resting chamber plate 40, are shown with respect to the Alveographe values. Here, the symbol P is a unit of pressure which is convertible into millimeters of mercury. This represents the pressure differential over atmospheric pressure during the test. The symbol L represents a link along the graph from the initial point at which air pressure is applied into the test sample, until the burst point or vertical line 84 is seen in FIG. 6. The symbol W represents the area under the curve formed for each sample in FIG. 6, which is indicative of the work applied to the four in extending it, and therefore is indicative of the strength of the flour or dough used. Extensibility is highly desirable in dough, as discussed above, and is indicative itself of the a higher degree of protein bonding, as well as of disulphide bonds.
The symbol X indicates the average or mean value of each of the above-described variables, which are summarized at the bottom of the table discussed hereinunder. The symbol S.D. is the standard variation of the various test samples about the mean. The symbol C.V. represents the coefficient of variation of the test samples about the mean. This is especially important in such testing, since a single batch of dough is expected to have a "true" value about which all of the other test results may vary. The coefficient of variation is a statistical variable well-known in the mathematical and statistical arts and sciences, and is readily calculated from the tabular value shown in Table 1 hereinunder. The left-hand columns represent the prior art test results and values, and the three right-hand columns represent the values taken during tests in accordance with the present invention, with coatings applied to the described surfaces.
TABLE 1______________________________________ Present InventionPrior Art With CoatingsP L W P L W______________________________________ 57 92 185 56 75 160 56 77 160 55 86 180 57 76 160 56 88 165 56 93 180 57 85 175 61 83 185 56 85 170 59 69 155 57 80 165 57 80 165 59 81 175 59 75 160 57 83 160 56 85 175 58 83 170X 57.6 81.1 169.4 56.8 82.9 170S.D. 1.64 7.5 11.2 1.13 3.6 5.8C.V. 2.8 9.24 6.61 1.99 4.38 3.41______________________________________
As can be seen from Table 1, the coefficient of variation (C.V.) for each of the values P, L, and W, is virtually halved with the present invention having coatings on the described surfaces, as compared to the prior art wherein such coatings are not present. This Table 1 represents actual test results taken under laboratory conditions with the same doughs and same flours being used for comparison with one another.
FIG. 7 is a block diagram illustrating the method of the present invention. At step 101, the dough ingredients are mixed and blended. At step 102, the mixed dough is extruded onto a sheet coated with polytetrafluorethylene. At step 103, the extruded dough is cut into an appropriate sample size with the edge of a spatula.
At step 104, the dough sample which has been extruded is rolled to a predetermined thickness, using a roller and a support tray coated with polytetrafluorethylene. Test disks are cut out from the rolled dough, using a cutter having surfaces coated with polytetrafluorethylene, at the block 105.
At step 106, the test disks are placed upon a resting tray, which is also coated with polytetrafluorethylene. The test disks are permitted to rest for a predetermined period of time as seen at step 107. At step 107, the resting tray rests within a chamber which preferably permits the test disks to reach a predetermined uniform temperature and any other desired stable conditions, for a predetermined period of time.
At step 109, each test disk is tested by employing air pressure and an Alveographe device to extend the dough biaxially to form a bubble-shaped structure which eventually bursts. During the entire testing procedure, the pressure of the air employed is carefully measured with respect to time, and a curve is made showing the air pressure and bursting points at which time the pressure drops to zero.
At step 109, the bursting test is repeated for N sample disks and after a desired number of sample disks have been tested from the same dough batch, a statistical analysis is performed to determine the dough extensibility, and other quantities associated with the particular dough sample employed.
The success of the present invention is not completely understood since as discussed in the above, there is no direct use of the coating of polytetrafluoroethylene in the actual bursting or test support portion 8. However, it is theoretically possible that the use of the coating of polytetraflouroethylene prevents minor surface defects from forming during the initial extrusion period, rolling period, cutting period, and resting periods, during which, to the naked eye, no such defects would be apparent. Also, alternatively, it is possible that the dough samples undergo some geometric or other changes during the above-described operations, some of which changes are inhibited slightly by the presence of the non-coated materials in the prior, but which changes are permitted to occur more repeatably by the apparatus according to the present invention. Nonetheless, the present invention is not dependent upon any particular theory of its operation, but relies upon the fact that it actually works and is used to dramatically and significantly reduce the variability of test results, and thereby increase the reliability of such test results. As seen from the sample tests shown in Table 1, the test results at the mean values X are very close between the prior art testing procedure and the procedure according to the present invention.
While a preferred embodiment has been shown and described, the scope of the present invention is not limited thereto, but is described by the following claims.
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An apparatus and method improves the reliability and reduces the variability of test results using a Alveographe testing appartus for dough. Dough samples are prepared and the qualities of the flour and/or doughs used are measurable by biaxially stretching dough samples until they burst employing air pressure for the biaxial deformation. The reliability and reduced variability of test results is achieved by using a low-friction coating on the surfaces of the tools and equipment used to prepare the dough samples. The standard deviation is thereby reduced by approximately one-half. In particular, the low friction coating used is polytetrafluorethylene.
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BACKGROUND OF THE INVENTION
This application is a continuation-in-part of Ser. No. 328,968 filed Dec. 9, 1981 and currently pending application Ser. No. 433,585 filed Oct. 12, 1982, both now abandoned.
This invention relates to sealing compositions for container closures, e.g. covers, crowns and caps and more particularly for sealants prepared from plastisols having a mass of hollow discrete microspheres incorporated therein.
The term "void volume" refers to the proportion or percentage of a gasket which is devoid of gasket forming material. A typical foamed gasket made from a plastisol may have a void volume as low as about 5 percent or as high as about 75 percent.
The void volume of gaskets prepared from a plastisol composition may suffer from a lack of uniformity due to changes in processing temperature, changes in amount of chemical blowing agent, or variations in film weight, closure weight, closure metal, or temperature distribution across the fluxing oven. Non-uniformity in the void volume of gaskets is undesirable from a commercial standpoint because it frequently causes variations in seal quality, seal appearance, removal torques when the gasket is employed on screw cap bottles and product quality. Therefore, maintaining a uniform void volume in the gasket is essential to good sealability and seal quality.
Several U.S. patents disclose plastisols containing a mass of hollow discrete spheres incorporated therein; however, none of these patents, which will be discussed hereinafter, disclose plastisols which are eminently suitable for container sealing compositions.
U.S. Pat. No. 3,409,567 discloses a vulcanizable composition for forming gaskets in closure elements for containers comprised of a rubber latex, a vulcanizing agent for the rubber, an ammonium soap, zinc soap, zinc oxide, a non-ionic surfactant which is a condensation product of an alkylene oxide and a member selected from a long chain fatty alchol, acid or amine, and a filler. The patent further discloses that a porous layer may be obtained by incorporating microballoons, but this in generally less desirable than a solid layer, except for certain applications such as in providing sealing gaskets for drums.
U.S. Pat. No. 4,005,033 discloses a sealant formulation comprising an acrylic latex or a vinyl acrylic latex and hollow, resilient expandable thermoplastic resinous microspheres formed from an expandable copolymer of vinylidene chloride and acrylonitrile.
U.S. Pat. No. 3,247,158 discloses a vinyl plastisol composition containing as a filler a mass of hollow discrete spheres of synthetic, fused, water-insoluble alkali metal silicate-based glass.
U.S. Pat. No. 3,230,184 discloses a polyester resin molding composition containing as a filler a mass of hollow discrete spheres of synthetic, fused, water-insoluble alkali metal silicate-based glass.
U.S. Pat. No. 4,107,134 discloses a low density resin composition comprising a polybutadiene having an average molecular weight by number lower than 100,000, and inorganic or organic hollow spheres included in the resin.
U.S. Pat. No. 4,100,114 discloses a rigid polyurethane foam composition containing 5 to 20% by weight of hollow-spherical silica balloons and 0.2 to 2% by weight of an organosilane compound.
Typically, in industrial applications sealing compositions are mixed at one location and shipped to a second location where the gaskets are manufactured. Even when mixing and gasket manufacture occur in the same plant, a period of time elapses between mixing of the sealing composition and production of the gaskets therefrom. The maximum time which can elapse between mixing the sealing composition and manufacturing a gasket without redistribution of the components of the sealing composition is referred to as "the shelf life" of the sealing composition.
Increasing the shelf life of the sealing compositions is extremely important since reachievement of uniformity of distribution of the components of the sealing composition is, at best, difficult once separation occurs. After separation has occured the most effective way to redistribute the components uniformly has been with a vacuum system. These vacuum systems are not only expensive but are generally not available at the manufacturing site. This long standing problem of redistribution is related to the shelf life of the sealing composition. If the shelf life of the sealing composition is lengthened, the need to redistribute the components is diminished.
One way to increase the shelf life is to increase viscosity; however, this is an impractical alternative because the fluid application machinery used in the industry dictates use of gasketing material with relative low viscosity. The inventors herein have discovered a method of increasing the shelf life of a sealing composition while maintaining a workable viscosity which is acceptable in the industry. That is, it has been discovered that the stability of the sealing composition can be improved within the narrow range of viscosities necessary to produce sealing gaskets from sealing compositions using fluid application machinery current being used.
Further, the inventors herein have discovered that the improved sealing compositions of the present invention can be formed into sealing gaskets which have uniform void volume. That is, it is surprising that the hollow spheres within the gasketing composition of the present invention remained almost totally uncrushed when the composition was forced through small diameter lining nozzles and into closures. Further, it was surprising that the sealing performance of gaskets wherein the voids are produced entirely by rigid hollow microspheres are equivalent or superior to gaskets having conventional flexible air voids.
Therefore, it is an advantage of this invention to provide sealing gaskets for container closures which exhibit a uniform void volume and do so independently of gasket manufacturing conditions.
It is another advantage to manufacture a sealing gasket composition which can be stored for a prolonged period, called "prolonged aging", without undergoing excessive viscosity increases or undesirable separation of components at room temperature. Prolonged aging as used herein means that a composition has a shelf life of more than two and one half weeks.
It is a further advantage to provide a sealing gasket composition which will allow covers, crowns and caps to be processed at a lower temperature, thus yielding a substantial energy saving and reducing the likelihood of heat degradation of the plastisol composition.
It has been discovered that sealing gaskets having the foregoing desirable characteristics can be prepared by employing a liquid plastisol base which incorporates a mass of hollow discrete microspheres. Resins which are suitable for the liquid plastisols of this invention are characterized as being prepared by emulsion (dispersion), suspension or mass polymerization. Hollow microspheres which are suitable for the liquid plastisols are characterized as being formed from water-insoluble alkali metal silicate based glass, polystyrene resins, phenolic resins or polyvinylidene chloride acrylonitrile resins and as having an alkalinity below about 0.5 milliequivalents per gram. It has also been discovered that in certain cases separation inhibitors such as colloidal silica, aluminum stearate waxes or bentonite clay can be added to the formulation to improve the stability of the plastisols.
SUMMARY OF THE INVENTION
This invention involves a sealing composition for container closures, such as covers, crown and caps. The composition is a plastisol which comprises a resin, a plasticizer, and hollow discrete microspheres incorporated therein. The fluid composition exhibits increased shelf life and a low degree of separation of the spheres from the plastisol. In addition, the gaskets formed from the sealing compositions exhibit uniform void volume which is necessary for promoting good seal quality.
DETAILED DESCRIPTION
The preferred microspheres of this invention can be characterized as being hollow discrete spheres of synthetic, water-insoluble alkali metal silicate-based glass. Non-glass spheres such as polystyrene and phenolic types may also be used. The spheres of this invention have solid walls of approximately uniform density and smooth surfaces. The spheres should have a diameter within the range of from about 1 to about 300 microns and preferably from about 10 to about 150 microns. Within the preferred range the average sphere diameter will usually be from about 15 to about 80 microns.
The wall thickness can be expressed as a percentage of the diameter of the microspheres and will be from about 0.1 to about 20 percent thereof, preferably from about 0.5 to about 5 percent of the diameter of particles having a diameter of 15 to 100 microns.
The preferred hollow microspheres used in the composition of this invention can be made from an alkali metal silicate which has the formula
(Me.sub.2 O).sub.x :(SiO.sub.2).sub.y.
Various alkali metal silicates within the range where x is 1, y is 0.5 to 5 and Me is an alkali metal such as sodium, potassium, or lithium are satisfactory. Suitable alkali metal silicates include Na 2 O(SiO 2 ) 3 .22. A silicate insolubilizing agent must be added to render the hollow spheres more resistant to moisture. Suitable insolubilizing agents are oxides of metal and metalloids such as, for example, the oxides of zinc, aluminum, iron, boron, and magnesium. The negative radicals such as borates and aluminates are preferred. These are the preferred insolubilizing materials because they reduce the alkalinity of the hollow microspheres.
The hollow discrete microspheres to be employed are generally selected on the basis of the viscosity desired for the plastisol composition. For Brookfield Viscosities measured at 60 rpm, viscosities range from about 3,000 to about 5,000 cps at room temperature, the preferred hollow glass spheres have diameters ranging from about 10 to about 60 microns. For Brookfield Viscosities measured at 60 rpm, viscosities range from about 15,000 to 70,000 cps at room temperature, the preferred hollow glass spheres have diameters ranging from about 10 to 150 microns.
TABLE I__________________________________________________________________________ Average Particle Strength Alkalinity Average Wall Density (Pressure for 10% (milliequivalents Diameter ThicknessManufacture Brand (g/cc) Collapse psi)* per gram)** (microns) (microns)__________________________________________________________________________Emerson & Cuming, Canton, MA FTF15 0.30 1500 0.5 or less 15 0.73M Company, St. Paul, MN C15/250 0.15 250 0.5 or less 70 0.5-23M Company, St. Paul, MN B23/500 0.23 500 0.5 or less 70 0.5-23M Company, St. Paul, MN E22-X 0.22 750 0.5 or less 30 0.5-23M Company, St. Paul, MN C37/3700 0.37 3700 0.5 or less 70 0.5-2Arco, Philadelphia, PA Dylite 0.30 -- 0.5 or less Expandable (Polystyrene)Union Carbide, NY, NY B50-0840 0.25-0.35 -- 0.5 or less 5-130*** (Phenolic)__________________________________________________________________________ *ASTM D 310272 (using glycerol in place of water). These nominal values may vary by ± 20%. **ASTM D 3100 ***Range of Particle size Microballoons having a low alkalinity, herein defined as about 0.5 milliequivalents per gram or less, are preferred and may be used with or without addition of separation inhibitors as those items are generally understood. Microballoons having a high alkalinity, herein defined as more than about 0.5 milliequivalents per gram, may be used in this invention but only in combination with certain separation inhibitors.
The properties of the hollow discrete spheres which are suitable for the present invention are set forth in Table I.
Selection of the proper type of resin was found to be important to the stability of the sealing composition of the present invention. It was found that at least about 70% (percent by weight) of the resin should be prepared by emulsion (dispersion) polymerization. More preferably at least about 75% should be prepared by the emulsion method and most preferably 100% of the resin should be prepared by the emulsion method. A maximum of about 30% of the resin should be prepared by suspension of mass polymerization or a combination thereof. A preferred dispersion resin to be employed in forming the sealing composition of the present invention is one with an ASTM designation of D6-42. Other suitable dispersion resins are those having ASTM designations of D4-43, D3-67, D6-33, D4-95, D5-94, and D3-54.
It has been found that addition of surfactants to the dispersion (emulsion) resins after they are prepared increases separation.
The plasticizers which can be used in conjunction with resins are basically of two different types, the solvating and non-solvating types. The solvating types tend to swell the resin and permit a more rapid fusion. The non-solvating types do not cause swelling and tend to cause slower fusion, but serve to render the plastisol more viscosity stable at room temperature. Any plasticizer conventionally employed in plastisol technology may be employed in this invention. Representative plasticizers include the phthalate esters such as butyl phenyl phthalate, di-2-ethylhexyl phthalate, dibutoxyethyl phthalate, capryl phthalate, octyl decyl phthalate, di-2-ethylhexyl tetrahydrophthalate, dicyclohexyl phthalate; the adipates such as butyl cellosolve adipate, dioctyl adipate, and di-2-ethylhexyl adipate which yield good low temperature properties; the phosphates which impart good flame resistance such as octyl diphenyl phosphate, triisooctyl phosphate, triocytl phosphate, tricresyl phosphate, tributoxyethyl phosphate, cresyl diphenyl phosphate; the sebacates such as dioctyl sebacate; and the epoxy plastizers which impart viscosity stability, good migration resistance and superior heat stability, such as an epoxidized unsaturated oil. Other conventionally used plasticizers such as butyl phthalate, butyl glycolate and tetraethylene glycol diisohexoate may also be employed.
Certain separation inhibitors may be added to the plastisol of the present invention to improve the shelf life of the sealing composition of the present invention. The purpose of a separation inhibitor is to retard the separation of the hollow discrete spheres from the plastisol. Separation of the hollow spheres from the plastisol is normally a problem because many end users do not have facilities for mixing and deaerating. Generally, low density microspheres will rise to the top of the plastisol composition. The inventors herein found that addition of a separation inhibitor was effective when 100% of the resin had been formed by the dispersion method. In such cases, separation of microballoons having either high or low alkalinity was inhibited. Further, it was discovered that suitable separation inhibitors for plastisol compositions having a viscosity below 15,000 cps include microcrystalline waxes, hydrogenated castor oil, bentonite, and aluminum stearate and that suitable separation inhibitors for plastisol compositions having a viscosity above 15,000 cps include fumed silica, bentonite, and waxes.
About 0.1 to about 10 parts by weight separation inhibitor per 100 parts by weight resin may be employed. The finished plastisol will contain from about 50 to about 150 parts by weight of plasticizer per 100 parts by weight of resin, depending upon the particular plasticizer, the particular resin, and the particular properties desired in the final product. At least about 70% of the resin should be formed by dispersion polymerization. The hollow discrete spheres should be used in an amount from about 5 parts to about 100 parts by volume per 100 parts by weight of resin. The amount of the hollow spheres depends upon the density of the microspheres and the final desired void volume.
The method of formulating a plastisol containing the discrete spheres is in accordance with convention. A preferred method involves the use of a shear type mixer having a cooling jacket to prevent excessive buildup of heat which might cause premature gellation of the plastisol.
In the preferred method, a portion of the plasticizer is added to the mixing apparatus first. Any compounding ingredients are generally dispersed in plasticizer and then added to the plasticizer in the mixing apparatus. Next, the resin is added slowly with agitation. Plasticizer is added as required to keep the mixture fluid. Generally, the remaining plasticizer is added when the plastisol is homogeneous.
At this point, the hollow microspheres are added to the plastisol. Although the microspheres can be added prior to this point, it is preferred to add them after the plastisol is formed in order to minimize breaking the hollow microspheres during mixing.
After the hollow microspheres have been added to the plastisol, the dispersion is mixed until smooth. A mixing time of the order of ten minutes is generally satisfactory. The resulting mixture is then dearated.
After the sealing composition has been prepared, it can be used to prepare sealing gaskets in accordance with conventional technology. A desirable method for preparing sealing gaskets is disclosed in U.S. Pat. No. 3,563,936. This method involves the steps of:
(1) Dispensing a fixed amount of the plastisol into a bottle cap or crown or a can end.
(2) Contacting the plastisol with a hot mold to form it into a fluxed gasket and/or passing the whole through an oven at a 300°-450° F. for 20-500 seconds.
The following specific examples are illustrative but not limitative of our invention, it being understood that similar improved results are obtainable with other combinations of components equivalent to those set forth in the examples. All such variations which do not depart from the basic concept of the invention and composition disclosed above are intended to come within the scope of the appended claims.
EXAMPLES 1-8
Approximately two-third of the specified amount of plasticizer was introduced initially to a low shear mixer, e.g. a paddle or Hobart mixer. This was followed by introduction of the specified additives. Next the resin was added slowly, and the resulting mixture was stirred until smooth. The remaining plasticizer was then added. Finally, the hollow glass micropheres were added with slow agitation to prevent their rupture. When the resulting mixture was smooth, it was deaerated.
Table II demonstrates the effect that the method of polymerization of the resin component of the plastisol has upon separation of the hollow glass microspheres after prolonged aging. Within two and one half weeks all of the formulations shown in Table 2 had separated except for formulation 2. The plastisol composition of formulation 2 was allowed to stand up to four months after preparation and still had not separated.
Table II shows that separation of the hollow glass spheres from the plastisol composition after prolonged aging at room temperature occurs when the resin component employed in the plastisol composition contains too high of a percentage of non-dispersion type resin. The resin component should contain at least about 70 phr (70 percent) of dispersion resin. It is preferred that at least about 75 phr (75 percent) of dispersion resin be employed. The sealing composition of Example 2 which contained 100% dispersion resin was stable after prolonged aging. The sealing compositions of Examples 4-8 which did not contain more than 70% dispersion resin separated after prolonged aging.
TABLE II__________________________________________________________________________Effects of Resin Types Upon Separation of Hollow Glass Spheres 1 2 3 4 5 6 7 8__________________________________________________________________________Resin, phrD6-42, homopolymer (dispersion) 100 100 60 60 60 70 60 65D3-54, copolymer (dispersion) -- -- 40 -- -- -- -- --GP3-86200, mass polymerized -- -- -- 40 40 -- -- --GP1-87000, mass polymerized -- -- -- -- -- 30 -- --GP3-17240, mass polymerized -- -- -- -- -- -- 40 --GP3-86200, suspension -- -- -- -- -- -- -- 35Plasticizer, phrDioctyl Phthalate 65 68 78 75 69 78 78 68Heat Stabilizers, phrCalcium-zinc stearate -- -- 1 -- -- 1 1 --Zinc stearate -- -- 1.5 -- -- 1.5 1.5 --Separation Inhibitors, phrWax, 127-130° F. melt pt -- -- 3 -- -- -- -- --Wax, 112-122° F. melt pt -- -- -- -- -- 3 3 --Cab-0-sil M-5 -- -- 0.2 -- -- 0.2 0.2 --Hollow Glass Sphere, phrEmerson & Cuming IG25 (high alk) 14 -- 14 14 -- 14 14 --3M C15/250 (low alk) -- 6 -- -- 6 -- -- 6Viscosity, Brookfield cps @ 60 rpmInitial, room temperature 5,200 5,720 10,000 5,100 3,650 4,770 10,000 3,600Initial, 110° F. -- -- 1,780 -- -- 1,720 1,810 --Separation after 21/2 weeksroom temperature yes no yes yes yes yes yes yes__________________________________________________________________________
EXAMPLE 9-14
The compositions of Examples 9-14 were prepared in the same manner as that employed in Examples 1-8. The composition of Example 9 is the same as the composition of Example 1. The composition of Example 11 is the same as the composition of Example 2.
Table III demonstrates the effect of the composition of hollow sphere upon (1) separation of the spheres from the plastisol composition and (2) molding characteristics of the plastisol composition. Table III also shows the effect of alkalinity of the glass hollow spheres upon these characteristics. The compositions containing low alkalinity ceramic micropheres separatd even though a separation inhibitor was included, whereas the compositions using low alkaline phenolic or polystyrene microspheres did not separate. The composition of Example 9 (same as Example 1) separated although it was composed of 100% dispersion resin, whereas the composition of Example 11 (same as Example 2) was also comprised of 100% dispersion but did not separate. Low alkaline microspheres were used in Example 11 whereas microspheres having high alkalinity were used in Example 9.
TABLE III__________________________________________________________________________Effects of Alkalinity and Material of Construction of HollowSpheres on Separation and Molding Characteristics 9(1) 10 11(2) 12 13 14__________________________________________________________________________Resin, phrD6-42, homopolymer 100 100 100 100 100 100Plasticizer, phrDioctyl Phthalate 65 131 68 78 81 70Heat Stabilizers, phrCalcium-zinc stearate -- 1.2 -- 1 1 --Zinc octoate -- -- -- 2 -- 2Zinc stearate -- 1.8 -- 1.5 1.5 --Separation Inhibitors, phrWax, paraffinic (127-130° F. melt pt) - -- 3 -- 3 --Petrolatum -- -- -- 3 -- 3Hollow Microsphere, phrEmerson & Cuming IG 25 14 -- -- -- -- --Emerson & Cuming Fillite FA-A -- 8 -- -- -- --3M C15/250 -- -- 6 -- -- --3M E 22-X -- -- -- 15 -- --Union Carbide BJO-0840 -- -- -- -- 11 --Arco, 270-P -- -- -- -- -- 5Hollow SphereMaterial glass ceramic glass glass phenolic polystyreneAlkalinity high low low low low lowDensity 0.24 0.7 0.15 0.22 0.2 0.3Separation after 2-5 weeks yes yes no no no noMolding characteristics good poor good good fair poor__________________________________________________________________________
EXAMPLES 15-22
Table IV demonstrates the effect of separation inhibitors and surfactants on minimizing separation of the hollow glass microspheres from the plastisol composition after prolonged aging. The compositions of Examples 15-22 were prepared by the same procedure as that employed in the compositions of Examples 1-8. The compositions were allowed to stand two months after preparation.
The sealing composition of Example 22 which includes no separation inhibitors includes a 100% dispersion resin and high alkaline microspheres separated within 2 months. In the compositions of 15-21 certain separation inhibitors were added to improve stability. Examples 15, 18, and 19 show that additions of certain inhibitors at certain levels improved stability. Examples 21 and 22 demonstrate that certain added surfactants actually decrease stability.
TABLE IV__________________________________________________________________________Effects of Additives on Minimizing the Separation of High Alkaline ofHollow Glass Spheres 15 16 17 18 19 20 21 22__________________________________________________________________________Resin, phrD6-42, homopolymer (dispersion) 100 100 100 100 100 100 -- 100D1-22, homopolymer (dispersion) -- -- -- -- -- -- 100 --Plasticizer, phrDioctyl Phthalate 78 80 80 80 80 66 60 80Heat Stabilizers, phrCalcium-zinc stearate 0.8 0.8 0.8 1 1 1 -- 1Zinc stearate 1.2 1.2 1.2 1.5 1.5 1.5 -- 1.5Zinc octoate -- -- -- -- -- -- 2.5 --Separation Inhibitors and Surfactants, phrCab-O-Sil M-5 0.2 -- -- -- -- -- -- --Wax, paraffinic (127-130° F. melt pt) 2 -- -- -- -- -- -- --Surfactant, sodium dioctyl sulfosuccinate -- 2 -- -- -- -- -- --Surfactant, paraffinic sulfonate K30, Mobay Chemical -- -- 1.2 -- -- -- -- --Thickener, aluminum stearate -- -- -- 5 -- -- -- --Thickener, Bentone 34 from NL Industries -- -- -- -- 2 -- -- --Surfactant, BYK I, Mallinckrodt -- -- -- -- -- -- -- --Petrolatum -- -- -- -- -- 5 3 --Surfactant, Tween 60, Atlas Chemical -- -- -- -- -- 5 2 --Hollow Glass Sphere, phrEmerson & Cuming FA-A (high alk) -- -- -- -- 13.6 -- -- --Emerson & Cuming IG 25 (high alk) 14 14 14 14 -- 14 -- 14BM E22X (Low alk) -- -- -- -- -- -- 14.7 --Separation within two months no yes yes slight no yes yes yes__________________________________________________________________________
EXAMPLES 23-29
Table V demonstrates the effect of alkalinity of the hollow glass spheres upon the viscosity stability of the sealing composition. These compositions were prepared by means of the method employed in Examples 1-8. In each of the compositions of Example 23-29, the system labelled (a) contains high alkaline microspheres and that labelled (b) contains low alkaline microspheres. The composition of Example 23(a) is the same as that of Example 1 and the composition of Example 23(b) is the same as that of Example 2. A relative viscosity increase of 1 is equal to 100% change in viscosity and an increase of 2 is equal to a change of 200% in viscosity. Comparison of each of the composition of example (a) with its comparable example (b) shows that those compositions using high alkaline microspheres undergo a greater change in viscosity than a comparable system using low alkaline microspheres.
TABLE V__________________________________________________________________________Effects of Various Resins and Alkalinity of Hollow Glass Spheres onViscosity Stability 23 24 25 26 27 28 29__________________________________________________________________________Paste Resin*, phrD6-42 100 -- -- -- -- -- --D7 -- 100 -- -- -- -- --D4-33 -- -- 100 -- -- -- --D5-94 -- -- -- 100 -- -- --D5-23 -- -- -- -- 100 -- --D5-32 -- -- -- -- -- 100 --D5-94 -- -- -- -- -- -- 100Plasticizer, phr (a) (b) (a) (b) (a) (b) (a) (b) (a) (b) (a) (b) (a) (b)Dioctyl Phthalate 65 68 75 69 69 65 77 77 68 65 79 76 69 71Hollow Glass Sphere, phr***Emerson & Cuming IG 25 14 -- 14 -- 14 -- 14 -- 14 -- 14 -- 14 --3M C15/250 -- 6 -- 6 -- 6 -- 6 -- 6 -- 6 -- 6Alkalinity high low high low high low high low high low high low high lowRelative Viscosity Increase**High alkalinity (2.4 ave.) 2.3 2.2 3.7 3.1 2.8 1.0 1.4Low alkalinity (1.2 ave.) 1.3 1.1 1.5 1.4 2.2 0.9 0.3__________________________________________________________________________ *This classification is according to ASTM D 1755 **This is the relative increase in the Brookfield viscosity as measured a 60 rpm and room temperature upon aging three weeks at ambient temperature ***The void volume ranged from 19-25 percent.
From the relative viscosity increase shown in Table V, it can be inferred that the alkalinity of the hollow microspheres affects the viscosity stability of the plastisol. If the alkalinity of the hollow spheres is relatively low, i.e., equal to or less than about 0.5 milliequivalents/gram, the viscosity of the plastisol does not increase unacceptably upon aging. If the alkalinity of the hollow glass microspheres is relatively high, i.e. greater than about 0.5 milliequivalents/gram, the viscosity increases unacceptably upon aging. Thus, to improve the shelf life of the plastisol composition it is preferable to employ hollow glass spheres having low alkalinity.
Table V shows, however, that even when low alkaline microspheres are used not all dispersion resins produce sealing compositions which have equally satisfactory viscosity from a stability point of view.
EXAMPLES 30-33
Table VI demonstrates the effect of size and density of the hollow glass microspheres upon the degree of separation of the spheres from the plastisol composition. The compositions were prepared according to the method used in Examples 1-8.
TABLE VI______________________________________ Effects Of Size Of Hollow Glass Spheres UponSeparation In Plastisols 30 31 32 33______________________________________Resin, phrD6-42, homopolymer 100 100 100 100Plasticizer, phrDioctyl Phthalate 78 78 78 60Dioctyl Adipate -- -- -- 20Heat Stabilizer, phrCalcium-zinc stearate 1 1 1 1Zinc stearate 1.5 1.5 1.5 --Separation Inhibitor, phrParaffin wax, (127-130° F. 3 3 3 --melt pt)Paraffin wax, (117-127° F. -- -- -- 6melt pt)Hollow Glass Sphere, phrEmerson & Cuming IG25 21 -- -- --(high alk)3M C15-250 (low alk) -- 10 -- --3M E22-X (low alk) -- -- 14.7 --Emerson & Cuming FTF15 -- -- -- 43.2low alkBrookfield Viscosity, (60 rpm/ 1170 1590 1710 ˜9000110° F.) cpsDiameter (microns), approxi- 80 80 40 15matelyDensity (g/ml) 0.23 0.15 0.22 0.30Separation upon prolonged very slight none noneaging slight______________________________________
As the diameter of the hollow glass spheres decreases and as the density increases, the degree of separation of the spheres from the plastisol also decreases. This relationship can be explained by Stokes Law which holds that the separation rate is directly proportional to the product of (1) the difference in density between the microspheres and the plastisol medium, and (2) the square of the radius of the microspheres, and is inversely proportional to the viscosity of the plastisol.
EXAMPLES 34-36
Table VII demonstrates the sealing performance of the gaskets made from the plastisols which have the hollow microspheres incorporated therein. The sealing compositions which were used to make the gaskets of Examples 34 and 35 were prepared in the same manner as the compositions in Examples 1-8.
Gaskets were prepared by dispensing approximately 140 mg of the sealing composition into a standard bottle crown which then was placed in a heated platen and immediately contacted with a hot die for 2.2 seconds.
The sample gaskets Examples 34 and 35 prepared by the foregoing method were compared with the gasket of Example 36 which was prepared from commercial plastisol gasket composition, CP 3133, from Chemical Products Corporation. This composition contains a chemical blowing agent but no microspheres. The comparisons were made by means of the Stack Test and the Abuse Angle Test.
The Stack Test comprised the following steps:
Ten bottles containing dilute sulfuric acid were capped with the gasketed crowns. Three of the bottles were used as unstacked controls. Immediately prior to capping, a sodium bicarbonate tablet was added to each of the bottles. The tablet generated 3.0 gas volumes of carbon dioxide upon contact with the acidic liquid. Next the packs were pasteurized at 140° F. for 20 minutes and then a 100 pound load was applied to the top of each crowned bottle. After one week, the bottles were unstacked, cooled to 60±5°, shaken for 15 seconds, and then the pressure was measured. The pressure was converted to gas volume using standard tables.
The Abuse Angle Test comprised the following steps:
Ten bottles containing dilute sulfuric acid were capped with the gasketed crowns. Immediately prior to capping, a sodium bicarbonate tablet was added to each of the bottles. This tablet generated a 3.0 gas volume of carbon dioxide upon contact with the acidic liquid. The sample bottles remained standing for 24 hours at room temperature before being tested. The test consisted of dropping the bottle down at 70° incline onto its crown from distances of 1, 2 and 3 inches. The sample bottle was dropped four times at each height with a 90° rotation between drops. The numerical rating for each drop was the drop distance in inches. The overall rating for each sample was the sum of the individual drop ratings up to the point at which the bottle first began to leak. Scores can range from zero to a maximum score of 24. [Maximum score of 24 is the sum of the following: 4 drops×1 inch plus a 4 drops×2 inches plus 4 drops×3 inches.]
TABLE VII______________________________________Sealing Performance of Gaskets Made FromPlastisol Containing Hollow Glass Spheres 34 35 36______________________________________Resin, phrD6-42, homopolymer 100 100 --Plasticizer, phrDioctyl Phthalate 78 68 --Heat Stabilizer, phrCalcium-zinc stearate 0.8 1 --Zinc stearate 1.2 1.5 --Separation Inhibitor, phrCab-O-Sil M5, phr 0.1 0.3 --Wax, (127-130° F. melt pt) 2 2 --Titanium dioxide -- 0.8 --Chemical Blowing Agent No No YesHollow Glass Sphere, phrEmerson & Cuming IG 25 (high alk) 14 -- --3M C15/250 (low alk) -- 5.8 --Stack Test (% gas volume lost) 0% 0% 0%Abuse Angle Test 24 24 23Abuse Angle Test (% of maximum) 100% 100% 97%______________________________________
From Table VII it can be seen that sealing performance of gaskets which have their voids produced entirely by rigid hollow microspheres are equivalent or superior to gaskets having conventional flexible air voids.
EXAMPLES 37-38
Table VIII demonstrates the effect of flux temperature on the void volume of the fluxed plastisol derived from the composition of the present invention. The compositions of Examples 37 and 38 were prepared in the same manner as those employed in Examples 1-8. The composition of Example 37 contains a chemical blowing agent; the composition of Example 38 contains hollow glass microspheres.
The compositions were comprised as follows:
______________________________________ 37 38______________________________________Resin, phr 100 100D6-42Plasticizer, phr 65 65Dioctyl PhthalateHeat Stabilizer, phr 2 2Calcium-zinc stearateSeparation Inhibitor, phr 10 10Wax; MicrocrystallineMelt pt 140-145° F.Chemical blowing agent, phr 3.3 --AzodicarbonamideHollow glass sphere, phr -- 13.63M C15/250 (low alk)______________________________________
The plastisol formulations were fluxed in standard 11/4 inch crowns for 37 seconds in a Dewey and Almy Baby Hurricane, Forced Draft Oven.
From the results of Table VIII it can be seen that the presence of hollow glass spheres in the plastisol composition brings about uniformity in the void volume of the fluxed sealing material over a wide range of fluxing temperature. When a chemical blowing agent is used there is a greater variation in the void volume of the plastisol fluxed over a range of temperatures. As noted previously, uniformity in void volume utlimately results in an improved seal.
TABLE VIII______________________________________Effects of Flux Temperature on the Void Volume of Plastisols Example (#): 37 38Source of Chemical Blowing HollowVoids: Agent MicrospheresFlux Temperature Void Volumes(°F.) (percent)______________________________________300 -1.0 ± 0.6 24.8 ± 0.0325 -1.9 ± 0.8 24.5 ± 0.3350 -0.9 ± 0.3 24.4 ± 0.6375 2.4 ± 3.2 25.1 ± 0.2400 3.2 ± 3.1 24.9 ± 0.2425 32.0 ± 5.1 25.2 ± 0.2450 50.1 ± 5.4 25.4 ± 0.2______________________________________
Table IX demonstrates the effect of film weight on the void volume of the fluxed plastisol derived from the composition of the present invention. The composition of Example 37 contains a chemical blowing agent, the composition of Example 38 contains hollow microspheres.
Table IX shows that the composition containing the hollow microspheres has a uniform void volume over a wide range of film weights over a wide range of fluxing temperatures. The composition containing the chemical blowing agent has a large variation of void volume for different film weights even at the same fluxing temperature.
TABLE IX______________________________________Effects of Film Weight and Temperature on theVoid Volume of PlastisolsFluxTem-pera-Example 37 Example 38ture Chemical Hollow(°F.)Blowing Agent Microspheres______________________________________375 Weight (Milligrams) 175 194 347 131 230 288Void Volume (%) 5.7 2.1 -0.6 24.8 25.2 25.2400 Weight (Milligrams) 309 388 432 133 200 213Void Volume (%) 6.6 0.5 2.4 24.7 25.0 25.1425 Weight (Milligrams) 212 216 318 196 211 269Void Volume (%) 37.2 31.6 27.1 25.0 25.2 25.3450 Weight (Milligrams) 180 263 296 172 175 180Void Volume (%) 56.4 46.7 47.3 25.6 25.3 25.4______________________________________
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A container sealing composition made from a plastisol having a mass of hollow discrete microspheres incorporated therein. The composition is characterized by having increased shelf life, as manifested in reduced separation of the hollow discrete microspheres from the plastisol, and improved viscosity stability. The container sealing composition also exhibits uniform void volume which is essential for good sealability and seal quality.
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BACKGROUND OF THE INVENTION
This invention relates to an improved photoconductive film of electrophotographic photoconductors used for printers and copying machines which employ electrophotographic processes. More specifically, this invention relates to constituent materials of the photoconductive film.
Conventional photosensitive materials of the electrophotographic photoconductor (hereinafter simply referred to as a "photoconductor" used for the printers, facsimile machines, digital copying machines and analog copying machines) employed in electrophotographic processes include inorganic photoconductive materials such as selenium, selenium alloys deposited by vacuum deposition zinc oxide and cadmium sulfide dispersed into resin binder, organic photoconductive materials such as poly-N-vinylcarbazole, poly(vinyl anthracene), phthalocyanine compounds and bisazo compounds dispersed into resin binder or deposited by vacuum deposition.
It is required that the photoconductor retain surface charges in the dark, generate electric charges in response to the received light, and transport electric charges in response to the received light. The photoconductor may be classified into either the mono-layered-type, that exhibits the above described functions using one single photoconductive film, or the so-called laminate-type, that consists of one layer mainly for charge generation and another layer for charge retention in the dark and for charge transport in response to the received light. The electrophotographic techniques for image formation using the aforementioned types of photoconductors include the Carlson's process. The Carlson's process for image formation includes charging of the photoconductor by corona discharge in the dark, formation of electrostatic latent images of the letters and figures in a manuscript on the charged surface of the photoconductor, development of the electrostatic latent images with toner, and fixing of the developed toner images on a paper or other such carriers. The photoconductor is used again after charge removal, residual toner removal and optical charge removal.
Various image formation steps are employed in the Carlson's process. The corotron method or the scorotron method that uses metal wire and the contact charging method that uses the charging brush or charging roller are used for charging the photoconductor. The two-component development method, nonmagnetic-single-component development method, and magnetic-single-component development method may be used in the development step.
Recently, organic photoconductors have been developed by virtue of the flexibility, thermal stability and ease of film formation thereof. U.S. Pat. No. 3,484,237 discloses a photoconductor that includes poly-N-vinyl carbazole and 2,4,7-trinitrofluorenone. Japanese Unexamined Laid Open Patent Application No. S47-37543 discloses a photoconductor that includes an organic pigment as the main component thereof. Japanese Unexamined Laid Open Patent Application No. S47-10785 discloses a photoconductor that includes an eutectic complex consisting of a dye and resin as the main component thereof. At present, the function-separation-type organic photoconductors, which include a charge generation layer and a charge transport layer, are mainly used. The charge generation layer comprises metal-free phthalocyanine, metal phthalocyanine such as titanyl phthalocyanine or azo compound and a resin binder. The charge transport layer contains a hydrazone compound, styryl compound, diamine compound or butadiene compound and a resin binder.
Although the organic photoconductive materials have many advantages over inorganic photoconductive materials, the conventional organic photoconductive materials do not exhibit all the properties required of an electrophotographic photoconductor. It is desired to obtain a highly sensitive photoconductor that exhibits little change in the properties thereof after the photoconductor is continuously used in the electrophotographic apparatus for a long time. The aforementioned capability is especially important because of the customer's increasing demand for photoconductors which are durable enough to endure long continuous use in various electrophotographic devices using the foregoing imaging processes. The photosensitivity of the conventional laminate-type photoconductors are insufficient. Practical long use of the conventional laminate-type photoconductors causes charge potential lowering, residual potential rise, sensitivity lowering, and such problems have yet to be solved. Thus, there is a need for a technology that facilitates realizing all the favorable properties for the electrophotographic photoconductor.
In view of the foregoing, it is an object of the invention to provide an electrophotographic photoconductor that is stable enough to endure repeated continuous use for an extended time in practical electrophotographic devices. It is another object of the invention to provide an electrophotographic photoconductor that is fully adaptable to various electrophotographic devices which employ the corotron method or the scorotron method that uses metal wire for charging, which employ the contact charging method that uses the charging brush or charging roller for charging, which employ the two-components-development method, which employ the nonmagnetic-single-component development method and which employ the magnetic-single-component development method.
SUMMARY OF THE INVENTION
It has been found that the foregoing problems are solved by an electrophotographic photoconductor that contains a photoconductive film having at least one compound selected from specific furan derivatives and thiophene derivatives.
According to one embodiment of the invention, there is provided an electrophotographic photoconductor that includes a conductive substrate, a photoconductive film on the conductive substrate, with the photoconductive film including at least one furan derivative or thiophene derivative described by the general formula: ##STR3## where R 1 is a hydrogen atom, halogen atom, substituted or non-substituted alkyl group, alkoxy group, cyano group, substituted or non-substituted heterocyclic group, or substituted or non-substituted aromatic group; R 2 is a hydrogen atom, halogen atom, substituted or non-substituted alkyl group, alkoxy group, cyano group, substituted or non-substituted heterocyclic group, or substituted or non-substituted aromatic group; R 3 is a hydrogen atom, halogen atom, substituted or non-substituted alkyl group, alkoxy group, cyano group, substituted or non-substituted heterocyclic group, or substituted or non-substituted aromatic group; R 4 is a hydrogen atom, halogen atom, substituted or non-substituted alkyl group, alkoxy group, cyano group, substituted or non-substituted heterocyclic group, or substituted or non-substituted aromatic group; R 5 is a hydrogen atom, halogen atom, substituted or non-substituted alkyl group, alkoxy group, cyano group, substituted or non-substituted heterocyclic group, or substituted or non-substituted aromatic group; R 6 is a cyano group, or alkoxycarbonyl group; R 7 is a cyano group, or alkoxycarbonyl group; X is an oxygen atom or sulfur atom; and n is an integer having a value of 0 or 1.
According to another embodiment of the invention, there is provided an electrophotographic photoconductor that includes a conductive substrate, a photoconductive film on the conductive substrate with the photoconductive film including at least one charge transport agent which is a furan derivative or thiophene derivative described by the general formula: ##STR4## where R 8 is a hydrogen atom, halogen atom, substituted or non-substituted alkyl group, alkoxy group, cyano group, substituted or non-substituted heterocyclic group, or substituted or non-substituted aromatic group; R 9 is a hydrogen atom, halogen atom, substituted or non-substituted alkyl group, alkoxy group, cyano group, substituted or non-substituted heterocyclic group, or substituted or non-substituted aromatic group; R 10 is a hydrogen atom, halogen atom, substituted or non-substituted alkyl group, alkoxy group, cyano group, substituted or non-substituted heterocyclic group, or substituted or non-substituted aromatic group; R 11 is a hydrogen atom, halogen atom, substituted or non-substituted alkyl group, alkoxy group, cyano group, substituted or non-substituted heterocyclic group, or substituted or non-substituted aromatic group; R 12 is a hydrogen atom, halogen atom, substituted or non-substituted alkyl group, alkoxy group, cyano group, substituted or non-substituted heterocyclic group, or substituted or non-substituted aromatic group; R 15 is a hydrogen atom, halogen atom, substituted or non-substituted alkyl group, alkoxy group, cyano group, substituted or non-substituted heterocyclic group, or substituted or non-substituted aromatic group; R 16 is a hydrogen atom, halogen atom, substituted or non-substituted alkyl group, alkoxy group, cyano group, substituted or non-substituted heterocyclic group, or substituted or non-substituted aromatic group; R 13 is a cyano group, or alkoxycarbonyl group; R 14 is a cyano group, or alkoxycarbonyl group; and X an oxygen atom or sulfur atom.
The alkyl group and the alkoxy group for the groups R 1 through R 5 in the general formula (I) preferably contain from one to eight carbon atoms.
The alkyl group and the alkoxy group for the groups R 8 through R 12 , R 15 and R 16 in the general formula (II) preferably contain from one to eight carbon atoms.
DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood from the description of a preferred embodiment that follows and from the diagrammatic figures in the drawings.
In the drawings:
FIG. 1 shows a cross section of an electrophotographic photoconductor including a monolayered photoconductive film according to the present invention.
FIG. 2 shows a cross section of a negative-charging laminate-type electrophotographic photoconductor according to the present invention.
FIG. 3 shows a cross section of a positive-charging laminate-type electrophotographic photoconductor according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The furan derivatives and the thiophene derivatives described by the general formulas (I) and (II) have not previously been used in electrophotographic photoconductors. However, it has now been discovered that photoconductors employing the furan derivatives and the thiophene derivatives described by the general formulas (I) and (II) exhibit high sensitivity, and that the electrical potential characteristics and sensitivity characteristics of the photoconductor are not deteriorated by their long term use in various electrophotographic devices. Thus, excellent electrophotographic properties are realized by adding the furan derivatives or the thiophene derivatives as described by the general formula (I) or (II) to the photoconductive film.
While not wishing to be bound by any one theory it is believed that the deterioration of electrophotographic photoconductors (e.g. lowering of charge potential, increase in residual potential, and decrease of sensitivity after repeated use) may be attributed to the formation of carrier trap centers in the photoconductive film due to repeated stresses incurred in the electrophotographic process, such as charging, light exposure, and development. Accordingly, it is believed that the use of an electron-attracting compound or compounds such as the furan and thiophene compounds of general formulas (I) and (II) suppress carrier trap formation. The photoconductive films of this invention containing the furan or thiophene compounds of general formulas (I) and (II) have been found to exhibit excellent electrical potential characteristics and high sensitivity after long term use in various electrophotographic processes.
Examples of the thiophene derivatives and the furan derivatives described by the general formula (I) are described as follows: ##STR5##
Examples of the thiophene derivatives and the furan derivatives described by the general formula (II) are described as follows: ##STR6##
Examples of the charge generation agent used in the present invention include phthalocyanine compounds (III-1) through (III-6), and azo compounds including the derivatives thereof (III-7) through (III-24), as follows: ##STR7##
Various compounds (IV-1) through (IV-12) which may be used in combination with the furan derivatives and the thiophene derivatives described by the general formulas (I) and (II) have the following formulas: ##STR8## The charge transport layer may also include at least one resin binder. Examples of the resin binder for the charge transport layer include various polycarbonate resins (V-1) through (V-7) described as follows: ##STR9## Amine antioxidants, phenolic antioxidants, sulfur-containing antioxidants, phosphite antioxidants, phosphor containing antioxidants and benzopinacol antioxidants (VI-1) through (VI-45) which may be used in the photoconductive film to prevent the photoconductive film from being deteriorated by ozone have the following formulas: ##STR10##
This invention will be explained hereinafter with reference to the accompanied drawing figures which illustrate the photoconductive film of the invention that contains the foregoing compounds.
FIG. 1 is a cross section of an electrophotographic photoconductor including a monolayered photoconductive film according to the present invention. FIG. 2 is a cross section of a negative-charging laminate-type electrophotographic photoconductor according to the present invention. FIG. 3 is a cross section of a positive-charging laminate-type electrophotographic photoconductor according to the present invention. In these figures, the reference numeral 1 designates a conductive substrate, 2 a photoconductive film, 3 a charge generation layer, 4 a charge transport layer, and 5 a cover layer.
The photoconductor shown in FIG. 1 is a so-called monolayered photoconductor that includes a conductive substrate 1 and a photoconductive film 2 on the conductive substrate 1. The photoconductive film 2 includes a charge generation agent and a butadiene derivative charge transport agent dispersed into a binder resin. A cover layer 5 is formed on the photoconductive film 2, if necessary.
The photoconductor shown in FIG. 2 is a so-called laminate-type photoconductor that includes a conductive substrate 1 and a photoconductive film 2 that includes a charge generation layer 3 containing a charge generation agent and a charge transport layer 4 including a butadiene derivative charge transport agent dispersed into a binder resin.
The photoconductor shown in FIG. 3 has another laminate structure in which the order of layer lamination is reversed. In this laminate-type photoconductor, a cover layer 5 is usually formed to protect the charge generation layer 3.
The photoconductor shown in FIG. 1 is manufactured by coating the dispersion liquid, which is prepared by dispersing a charge generation agent into a solution into which a charge transport agent and a binder resin are dissolved, on a conductive substrate. If necessary, a cover layer is formed on the photoconductive film by conventional coating methods.
The photoconductor shown in FIG. 2 is manufactured as follows. The charge generation layer is formed by depositing a charge generation agent by vacuum deposition on the conductive substrate, or by coating and drying a dispersion liquid, which is prepared by dissolving a charge generation agent into a solvent or by dispersing a charge generation agent into a binder resin, on the conductive substrate. Then, the charge transport layer is formed by coating and drying a solution, into which a charge transport agent and a binder resin are dissolved, on the charge generation layer.
The photoconductor shown in FIG. 3 is manufactured as follows. The charge transport layer is formed by coating and drying a solution, into which a charge transport agent and a binder resin are dissolved, on the conductive substrate. Then, the charge generation layer is formed by depositing a charge generation agent by vacuum deposition on the charge transport layer, or by coating and drying a dispersion liquid (which is prepared by dissolving a charge generation agent into a solvent or by dispersing a charge generation agent into a binder resin), on the charge transport layer. Then, a cover layer is formed on the charge generation layer by conventional coating methods.
The conductive substrate 1 functions as an electrode of the photoconductor and sustains the layers of the photoconductor. The conductive substrate 1 may be shaped with a cylindrical tube, a plate or a film. Metals such as aluminum, stainless steel and nickel, or glass or resin (treated to exhibit electrical conduction) are used for the conductive substrate 1. Insulative polymers such as casein, poly(vinyl alcohol), nylon, polyamide, melamine and cellulose, conductive polymers such as polythiophene, polypyrrole and polyaniline or polymers that contains metal oxide powder or low molecular weight compounds used for surface decoration may additionally be used in combination with the conductive substrate.
As explained above, the charge generation layer 3 is formed by depositing a charge generation agent by vacuum deposition, or by coating and drying a dispersion liquid, which is prepared by dissolving a charge generation agent into a solvent or by dispersing a charge generation agent into a binder resin. The charge generation layer 3 generates charges in response to the irradiated light. It is preferable for the charge generation layer 3 to exhibit high charge generation efficiency and high efficiency of the generated charge injection into the charge transport layer 4. It is also preferable for the charge injection efficiency not to depend on the electric field and to be sufficiently high even in the low electric field.
Pigments and dyes such as phthalocyanine (III-1) through (III-6), azo compounds (III-7) through (III-24), their derivatives, metal phthalocyanine such as titanyl phthalocyanine, quinone compounds, indigo compounds, cyanine compounds, squarylium compounds, azulenium compounds and pyrilium compounds, selenium, and selenium compounds may be used for the charge generation agent. An appropriate charge generation agent may be selected to correspond to the wavelength range of the exposure light source used for image formation. The charge generation layer must exhibit a required charge generation performance, as is well known to those skilled in the art. The charge generation performance is determined by the light absorption coefficient and the thickness of the charge generation layer, as is well understood by those skilled in the art. The charge generation layer 3 is formed to be 5 μm or less, preferably 2 μm or less, in thickness. The concentration of the charge generation component in the charge generation layer within the range as is well known to those skilled in the art. The charge generation layer may contain a charge transport agent in addition to the charge generation agent as the main component thereof.
Binder resins which may be used in the charge generation layer include polycarbonate, polyester, polyamide, polyurethane, epoxy resin, poly(vinyl butyral), poly(vinyl acetal), phenoxy resin, silicone resin, acrylic resin, vinyl chloride resin, vinylidene chloride resin, vinyl acetate resin, formaldehyde dimethyl acetal resin, formaldehyde dimethyl acetal resin, cellulose resin, their copolymers, their halides and their cyanoethyl compounds. These binder resins may be used alone or in combination.
The charge transport layer 4 is a coating film containing at least one charge transport agent dispersed in a binder resin. The charge transport agent may be selected from one or more of compounds (IV-1) through (IV-12), in concentrations which are well known to those skilled in the art. The charge transport layer 4 functions in the dark as an insulation layer that retains the charges of the photoconductive film and transports the charges injected from the charge generation layer during light reception. The charge transport layer of the photoconductive film in this invention contains, as an electron attracting compound, the at least one furan derivative or the thiophene derivative described by the foregoing general formula (I) and (II), respectively, in combination with the charge transport agent or agents. Generally, the concentration of the furan derivative or thiophene derivatives in the charge transport layer is between 0.01 and 3 wt. %, preferably between 0.1 and 2 wt. %. The charge transport layer 4 is preferably from 10 to 40 μm in thickness. Various polycarbonate resins (V-1) through (V-7), polystyrene, polyacrylate, polyphenylene etheracryl, polyester, polymetacrylate, and their copolymers may be used as the resin binder for the charge transport layer.
Amine antioxidants, phenolic antioxidants, sulfur-containing antioxidants, phosphite antioxidants and phosphorus containing antioxidants (VI-1) through (VI-45) may be used in the photoconductive film to prevent the photoconductive film from being deteriorated by ozone.
The cover layer 5 retains in the dark the charge caused by the corona discharge and transmits the light to that the photoconductive film is sensitive. It is required for the cover layer 5 to transmit the exposure light to the photoconductive film, to receive the generated charges injected thereto and to neutralize the surface charges. Organic insulative film materials such as polyester and polyamide may be used for the cover layer 5. Inorganic materials such as glass resins and SiO 2 , and materials such as metal and metal oxide which facilitate lowering the electrical resistance may be mixed to the organic insulative film materials. The coating materials are preferably transparent as much as possible in the wavelength region in which the charge generation agent absorbs light at its maximum. The thickness of the cover layer may be set within a range such that repeated use of the photoconductor does not cause adverse effects such as residual potential rise.
The invention will be explained more in detail by way of the examples set forth below. The photoconductors of the examples were of the negative-charging laminate-type. Cylindrical aluminum tubes of 1 mm in thickness, 310 mm in length and 60 mm in outer diameter were cleaned, dried and used for the substrates of the photoconductors of the examples.
EXAMPLE 1 (E1)
Coating liquid for the undercoating film (undercoating liquid) was prepared by dissolving 10 weight parts of alcohol-soluble polyamide copolymer (CM8000 supplied from TORAY INDUSTRIES, INC.) into a solvent mixture of 45 weight parts of methanol and 45 weight parts of methylene chloride. The undercoating film of 0.1 μm in thickness was formed on the aluminum substrate by coating the undercoating liquid on the aluminum substrate by dip-coating and by drying the coating liquid at 90° C. for 30 min.
The coating liquid for the charge generation layer (charge generation coating liquid) was prepared by dispersing 1 weight part of poly (vinyl acetal) resin (S-LEC KS-1 supplied from Sekisui Chemical Co., Ltd.) and 1 weight part of the bisazo compound (III-17) as a charge generation agent into 150 weight parts of methyl ethyl ketone in a ball mill for 48 hr. The charge generation layer of 0.2 μm in thickness was formed by dip-coating the charge generation coating liquid on the undercoating film and by drying the coating liquid at 90° C. for 30 min.
The coating liquid for the charge transport layer (charge transport coating liquid) was prepared by dissolving 50 weight parts of the hydrazone compound (IV-1), 50 weight parts of the hydrazone compound (IV-2), 100 weight parts of the bisphenol A-type-biphenyl polycarbonate copolymer (V-4) (TOUGHZET supplied from IDEMITSU KOSAN CO., LTD.), 5 weight parts of the hindered phenolic compound (VI-2) and 1 weight part of the thiophene derivative (I-1) into 700 weight parts of dichloromethane. The charge transport layer having a thickness of 20 μm was formed by dip-coating the charge transport coating liquid on the charge generation layer and by drying the coating liquid at 90° C. for 30 min. Thus, the photoconductor of this example was prepared.
EXAMPLE 2 (E2)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that the thiophene derivative (I-5) was used in substitute for the thiophene derivative (I-1).
EXAMPLE 3 (E3)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that the thiophene derivative (I-9) was used in substitute for the thiophene derivative (I-1).
EXAMPLE 4 (E4)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that the furan derivative (I-13) was used in substitute for the thiophene derivative (I-1).
EXAMPLE 5 (E5)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that the thiophene derivative (II-1) was used in substitute for the thiophene derivative (I-1).
EXAMPLE 6 (E6)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that the thiophene derivative (II-4) was used in substitute for the thiophene derivative (I-1).
EXAMPLE 7 (E7)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that the thiophene derivative (II-7) was used in substitute for the thiophene derivative (I-1).
EXAMPLE 8 (E8)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that the furan derivative (II-10) was used in substitute for the thiophene derivative (I-1).
EXAMPLE 9 (E9)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that the bisazo compound (III-7) was used in substitute for the charge generation agent of Example 1.
EXAMPLE 10 (E10)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that the bisazo compound (III-24) was used in substitute for the charge generation agent of Example 1.
EXAMPLE 11 (E11)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that 50 weight parts of the hydrazone compound (IV-3) and 50 weight parts of the butadiene compound (IV-4) were used in substitute for the hydrazone compounds (IV-1) and (IV-2) of Example 1.
EXAMPLE 12 (E12)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that 50 weight parts of the diamine compound (IV-10) and 50 weight parts of the distyryl compound (IV-11) were used in substitute for the hydrazone compounds (IV-1) and (IV-2) of Example 1.
EXAMPLE 13 (E13)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that the polycarbonate resin (V-2) was used in substitute for the resin (V-4) of the charge transport layer in Example 1.
EXAMPLE 14 (E14)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that the polycarbonate resin (V-6) was used in substitute for the resin (V-4) of the charge transport layer in Example 1.
EXAMPLE 15 (E15)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that the compound (VI-30) was used as an antioxidant in substitute for the antioxidant (VI-2) of Example 1.
EXAMPLE 16 (E16)
The photoconductor of this example was prepared in the similar manner as the photoconductor of Example 1 except that the compound (VI-37) was used as an antioxidant in substitute for the antioxidant (VI-2) of Example 1.
Comparative Example 1 (C1)
The photoconductor of comparative example 1 was prepared in the similar manner as the photoconductor of Example 1 except that the thiophene derivative of the Example 1 was not contained in the charge transport layer in comparative example 1.
Comparative Example 2 (C2)
The photoconductor of comparative example 2 was prepared in the similar manner as the photoconductor of Example 9 except that the thiophene derivative of Example 9 was not contained in the charge transport layer in comparative example 2.
Comparative Example 3 (C3)
The photoconductor of comparative example 3 was prepared in the similar manner as the photoconductor of Example 11 except that the thiophene derivative of Example 11 was not contained in the charge transport layer in comparative example 3.
Comparative Example 4 (C4)
The photoconductor of comparative example 4 was prepared in the similar manner as the photoconductor of Example 13 except that the thiophene derivative of Example 13 was not contained in the charge transport layer in comparative example 4.
Comparative Example 5 (C5)
The photoconductor of comparative example 5 was prepared in the similar manner as the photoconductor Example 15 except that the thiophene derivative of Example 15 was not contained in the charge transport layer in comparative example 5.
The electrophotographic properties of the photoconductors of the examples and the comparative examples were evaluated in the following way.
The surface potential when the photoconductor surface was negatively charged by corona discharge at -6.0 kV in the dark for 10 min. and surface potential after the photoconductor had been left in the dark for 5 min. from the end of the corona discharge were measured, and the retention rate VK5 of the surface potential 5 min. afterward the corona discharge was obtained. Then, the half decay exposure light quantity E 1/2 (lux.s (seconds)) was obtained by measuring a period of time (sec) until the surface potential had been halved by irradiation of the white light to the photoconductor surface at the illuminance of 2 lux.
The change of the surface potential during continuous use of the photoconductor was evaluated in an analog copying machine provided with the scorotron charging process and two-components developing mechanism. The charging mechanism, exposure mechanism and charge removal mechanism of the analog copying machine were fixed at certain outputs. Each photoconductor was subjected to a running test that prints 50000 sheets of A4-size paper at an ordinary temperature (about 20° C.) and ordinary humidity (about 60% RH) environment. White paper potential Vw and black paper potential Vb were measured at the start and end of the running test, and the potential changes ΔVw and ΔVb were obtained. Table 1 lists the results.
TABLE 1__________________________________________________________________________Furan Charge Running Testor genera- Charge Anti- Initial ChangeSpeci- thio- tion transport Binder oxi- VK5 E1/2 Vw Vb ΔVw ΔVb men phene agent agents resin dant (%) (lux · s) (V) (V) (V)__________________________________________________________________________ (V)E 1 I-1 III-17 IV-1 IV-2 V-4 VI-2 97.0 0.90 -47 -605 5 -2 E 2 I-5 III-17 IV-1 IV-2 V-4 VI-2 98.5 0.92 -45 -603 4 -1 E 3 I-9 III-17 IV-1 IV-2 V-4 VI-2 96.4 1.02 -45 -605 0 -3 E 4 I-13 III-17 IV-1 IV-2 V-4 VI-2 95.5 0.88 -44 -603 5 0 E 5 II-1 III-17 IV-1 IV-2 V-4 VI-2 96.7 0.93 -48 -604 7 -2 E 6 II-4 III-17 IV-1 IV-2 V-4 VI-2 98.0 0.95 -47 -605 4 -3 E 7 II-7 III-17 IV-1 IV-2 V-4 VI-2 97.0 0.90 -45 -607 3 -3 E 8 II-10 III-17 IV-1 IV-2 V-4 VI-2 96.2 0.97 -45 -605 0 -5 E 9 I-1 III-7 IV-1 IV-2 V-4 VI-2 95.8 1.06 -45 -607 5 -3 E 10 I-1 III-24 IV-1 IV-2 V-4 VI-2 96.7 1.03 -45 -605 2 -4 E 11 I-1 III-17 IV-3 IV-4 V-4 VI-2 97.2 0.92 -45 -605 3 -4 E 12 I-1 III-17 IV-10 IV-11 V-4 VI-2 98.0 1.03 -45 -607 5 0 E 13 I-1 III-17 IV-1 IV-2 V-2 VI-2 98.0 0.99 -45 -605 6 -3 E 14 I-1 III-17 IV-1 IV-2 V-6 VI-2 98.0 0.95 -45 -607 2 -5 E 15 I-1 III-17 IV-1 IV-2 V-4 VI-30 98.0 1.05 -45 -605 0 -1 E 16 I-1 III-17 IV-1 IV-2 V-4 VI-37 98.0 0.99 -45 -605 2 -2 C 1 -- III-17 IV-1 IV-2 V-4 VI-2 96.0 0.99 -45 -610 82 -26 C 2 -- III-7 IV-1 IV-2 V-4 VI-2 97.0 0.95 -46 -608 55 -19 C 3 -- III-17 IV-3 IV-4 V-4 VI-2 95.5 1.03 -45 -605 59 -28 C 4 -- III-17 IV-1 IV-2 V-2 VI-2 97.4 1.03 -44 -609 76 -16 C 5 -- III-17 IV-1 IV-2 V-4 VI-30 95.2 1.01 -45 -605 93 -18__________________________________________________________________________
As Table 1 clearly indicates, the comparative photoconductors which do not contain any furan derivative or thiophene derivative in the charge transport layer thereof cause much larger potential changes as compared with the photoconductors of the invention. That is, the comparative photoconductors do not exhibit excellent electrophotographic properties. Comparing the photoconductors of Examples E1, E9 and E10, it has been demonstrated that stable electrophotographic properties were obtained from the photoconductors of this invention using different charge generation agents. Since the favorable effects of the furan derivatives or thiophene derivatives were obtained by Examples E11 and E12 (which include different charge transport agents), by Examples E13 and E14 (which include different resin binders for the charge transport layer), and by Examples E15 and E16 (which include different antioxidants), the furan derivatives and the thiophene derivatives of the invention have been shown as advantageous for various electrophotographic photoconductors.
By containing the furan derivatives or thiophene derivatives in the charge transport layer, the photoconductors for printers, digital copying machines or facsimile devices which contain any of the metal free phthalocyanine and titanyl phthalocyanine compounds (III-1) through (III-6) exhibit similar effects as those of the photoconductors of the foregoing examples which contain the azo compound for use in the analog copying machines.
The photocoductors of this invention, which include any of the furan derivatives or thiophene derivatives in the charge transport layer, exhibit excellent stability against continuous use over a long period of time for various analog copying machines, digital copying machines, printers and facsimile devices which employ the corotron method, whether employing the charging brush, the charging roller or the single-component development method. This is similar to the photoconductors of the foregoing examples which employ the scorotron method and two-component development method.
By containing at least one of the furan derivatives or thiophene derivatives described by the general formulas (I) or (II) in the photoconductive film according to this invention, a highly sensitive electrophotographic photoconductor that is stable enough to endure repeated continuous use for a long time in practical electrophotographic processes is obtained.
From the foregoing, it is readily apparent that new and useful electrophotographic photoconductors have been described and illustrated which fulfill all of the aforestated objectives. It is of course understood that such modifications, alterations and adaptations as will readily occur to those skilled in the art are intended within the scope of the invention.
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An electrophotographic photoconductor comprises:
(a) a conductive substrate; and
(b) a photoconductive film on said conductive substrate, with the photoconductive film comprising at least one charge generation agent, at least one charge transport agent, and at least one furan derivative or thiophene derivative, the furan or thiophene derivative having the general formula: ##STR1## or ##STR2##
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FIELD OF THE INVENTION
[0001] The present invention relates generally to ophthalmic instruments, systems and methods. More specifically, the present invention relates to instruments, systems and methods by which tonometry and pachymetry measurements are conducted.
BACKGROUND OF THE INVENTION
[0002] Goldmann applanation tonometry is a well known technique in the ophthalmic field to measure a patient's intraocular pressure (IOP) which is used as a diagnostic tool for determining eye disorders, such as glaucoma. However, conventional applanation tonometry assumes that each patient has a standard central corneal thickness. Since corneal thickness has a direct impact on the tonometry measurement, the assumption of a standardized corneal thickness means that conventional applanation tonometry can only at best provide a close approximation of the actual IOP from one patient to another.
[0003] Goldmann and Schmidt noted the probable relationship of central corneal thickness (CCT) to intraocular pressure (IOP) measurement when they introduced the applanation tonometer in 1956. Multiple reports have confirmed the correlation between increased CCT and increased measured IOP in adults, and a single published report notes a similar finding in children. The Ocular Hypertension Treatment Study highlighted decreased CCT as a predictive factor for progression to glaucoma and other studies have supported the importance of CCT as a contributor to the risk of glaucomatous progression. In addition, black adults demonstrate thinner corneas than whites, and also show increased risk of visual loss from glaucoma.
[0004] Both under-diagnosis and over-diagnosis of glaucoma can occur as a result of false intraocular pressure readings. Patients with thinner corneas may register normal intraocular pressures when in fact the pressure within the eye may be high, causing damage to the optic nerve. The reverse also is true in that patients with corneas thicker than normal may have high intraocular pressure readings, yet have normal intraocular pressure and still be treated inappropriately for glaucoma. Accurate and reproducible intraocular pressure readings are not only important for diagnosis of glaucoma but for monitoring the effects of drugs, and laser or incisional surgery. The inability of tonometry alone to detect accurately the true intraocular pressure hampers both detection and treatment. The need for accurate IOP measurements regardless of corneal thickness has also become more important in recent years with the popular practice of surgically altering a patient's cornea for purpose of vision correction. More specifically, patients who have undergone photorefractive keratotomy (PRK) or laser in situ keratomileusis (LASIK) procedures have thinner corneas. These surgically thinned corneas may therefore produce inaccurate and/or misleading IOP readings using current methods, which could lead to an inability to detect glaucoma and loss of sight.
[0005] In addition, and perhaps of even more clinical significance is the recent clinical data suggesting that central corneal thickness may be an independent risk factor for glaucomatous damage, even when the IOP has been ‘corrected’ for the measured central corneal thickness. Hence those eyes with thinner than average corneas, seem to be at increased risk for optic nerve damage compared to those with thicker corneas.
[0006] For the reasons noted above, it has recently been accepted practice in the ophthalmic field to determine separately the corneal thickness of a patient (e.g., using an ophthalmic pachymeter such as disclosed in U.S. Pat. No. 5,512,966 to Snook 1 ) in conjunction with conventional applanation tonometry (e.g., using an applanation tonometer such as disclosed in U.S. Pat. Nos. 5,355,884 to Bennett and 4,987,899 to Brown). The tonometer reading is then corrected based on the measured corneal thickness using conventional correction algorithms so as to arrive at a more accurate IOP determination. It has also been proposed in U.S. Pat. No. 6,113,542 to Hyman et al to combine a conventional applanation tonometer with an optical pachymeter having respective separate tonometer and pachymeter probes in a single instrument by which the tonometer signal may be modified using correction algorithms stored in a microprocessor based on the corneal thickness determined previously by the optical pachymeter. A device has also been proposed in U.S. Pat. No. 6,083,161 to O'Donnell, Jr. whereby applanation is done with an ultrasonic transducer which measures the corneal thickness at an exact point of applanation to thereby allow for the simultaneous determination of both applanation pressure and corneal thickness. 1 All cited patents and written publications are expressly incorporated fully hereinto by reference.
[0007] While the techniques employed presently in the art may be satisfactory to improve the accuracy of IOP measurements, there still exists a need for improvement. For example, it would be highly desirable if instruments and methods could be provided which enable ophthalmic tonometry and pachymetry to be conducted simultaneously using a common optical signal path. The importance of a single instrument capable of measuring simultaneously both IOP and central corneal thickness goes beyond convenience. Currently, both of these measurements require that something touch the surface of the anesthetized cornea. While this is an inconvenience to cooperative patients, there are many children and some adults who would greatly benefit by having only one instrumentation of their corneas. Each time an instrument touches the cornea, there is a small disturbance of the surface corneal epithelium, and a topical anesthetic must be placed, which lasts only a few minutes, and which itself can interfere with the blinking response and cause irregularity and even damage to the corneal surface in vulnerable subjects. Therefore, obtaining all needed measurement (i.e., the IOP and central corneal thickness) by a single ‘touch’ to the cornea, poses significant benefit for the patient as well as the eye care provider.
[0008] Also, the current algorithms are empirically derived from the average characteristics of a group of test subjects, and therefore result in only an approximation of the IOP correction needed for varying corneal thickness. A more desirable instrument would separate the influence of each cornea on each IOP measurement by an analytic algorithm.
[0009] It is towards fulfilling such needs that the present invention is directed.
SUMMARY OF THE INVENTION
[0010] Broadly, the present invention is embodied in ophthalmic instruments, systems and methods which enable contact tonometry and optical pachymetry measurements to be conducted simultaneously. According to the present invention, therefore, ophthalmic instruments, systems and methods are provided whereby a patient's intraocular pressure (IOP) and corneal thickness may be determined accurately by a single path optical signal.
[0011] In especially preferred forms, the present invention is embodied in ophthalmic instruments whereby contact tonometry and optical pachymetry measurements are obtained simultaneously (i.e., both measurements are obtained only during a single corneal applanation). Preferably, both the tonometry and pachymetry measurements are obtained optically using a common optical signal path. Alternatively, a tonometer tip associated with a conventional Goldmann contact tonometer employing a pressure sensor to determine applanation pressure may be modified to include optical pachymetry according to the present invention.
[0012] According to one embodiment of the present invention ophthalmic instruments are provided which include an applanation tonometer for determining an intraocular pressure measurement, and an optical pachymeter for determining a corneal thickness measurement. The optical pachymeter and tonometer are integral so as to simultaneously generate respective output signals indicative of the intraocular pressure and corneal thickness measurements in response to a single corneal applanation.
[0013] In other preferred embodiments of the present invention, both the tonometry and pachymetry measurements are obtained optically using a common optical signal path. Such ophthalmic instruments of the present invention will therefore most preferably include a reference surface at a distal end of the instrument, an applanation plate spaced from the reference surface, and a compliant mount for mounting the applanation plate for resilient displacements relative to the reference surface. The instrument most preferably has a housing such that the reference surface is located at a fixed position at one end of the housing, and the applanation plate is mounted to that one end of the housing in coaxial spaced alignment relative to the reference surface by means of the compliant mount. If desired, the housing may have a handle and a substantially orthogonal head piece containing suitable optic mirrors which allow visible light to pass therethrough so that the procedure can be viewed and/or photographed.
[0014] The applanation plate is most preferably circular so that the compliant mount defines an annular mounting region for mounting the applanation plate relative to the reference surface. In this regard, the mounting region is continuous or discontinuous. Preferably, the compliant mount comprises an elastomeric structure, such as an elastomeric O-ring (in which case the annular mounting region is continuous) or a plurality of elastomeric posts circumferentially arranged to define an annular mounting region (in which case the annular mounting region is discontinuous). However, the compliant mount may also be in the form of a plurality of compression springs arranged circumferentially about the applanation plate.
[0015] A preferred system for conducting simultaneous tonometry and pachymetry measurements will include an ophthalmic instrument having a reference surface at a distal end of the instrument, an applanation plate spaced from the reference surface; and a compliant mount for mounting the applanation plate for resilient displacements relative to the reference surface, and an interferometer for optical connection to the instrument. The interferometer will most preferably have a source of light to be supplied to the instrument, and a spectrometer for receiving reflected light from the instrument and generating a signal indicative of a patient's intraocular pressure and corneal thickness. A microprocessor is preferably provided to receive the signal generated by the interferometer and determine a patient's intraocular pressure corrected for the patient's corneal thickness.
[0016] In use, the ophthalmic instrument of this invention may be brought into alignment with a patient's cornea and advanced toward the cornea so as to cause contact between the cornea and the applanation plate thereof. Continued advancement of the ophthalmic instrument relative to the cornea will cause the applanation plate to be displaced resiliently parallel to and toward the reference surface of the instrument while the cornea is progressively “flattened”. Such advancement of the ophthalmic instrument continues until the cornea is flattened or scanned across this surface sufficiently against the applanation plate. A light beam (preferably annular although another shaped beam or multiple beams could be utilized) may thus be directed toward the flattened cornea so that light may be reflected therefrom. A signal may thus be generated from the reflected light which contains data yielding a patient's intraocular pressure and corneal thickness. In such a manner, therefore, a measurement of the patient's intraocular pressure corrected by the patient's corneal thickness may be obtained.
[0017] The measurements and data obtained optically by means of the present invention may also be advantageously used to determine IOP and/or corneal biomechanical properties. For example, the present invention is capable of determining the distance of several points on the cornea from an applanating surface over a range from first corneal contact to full corneal applanation. From such distance data, one can derive factors such as corneal curvature and the applanation area/diameter. Differences of distance to the applanating surface among such points provides a measure of the probes alignment and may thus also be used to drive indicators for the user to assess the quality of the readings. A table with multiple entries of force generated (by the combined effects of IOP and corneal bending) versus applanation diameter can be analyzed to derive an expression of the form F=f 1 (d)+f 2 (d), where F is the measured force and d is the applanation diameter. Function f 1 is of order 1 , and represents the cornea component of force, function f 2 is of order 2 and represents IOP component; the internal coefficients required to generate the best fit to the data points in the table indicate the true correction for the force from cornea (which primarily varies with thickness), and the true IOP. Mathematical transformations known to those skilled in the art can be performed with the data from this technology to generate other expressions, e.g., functions of applanation area rather than diameter, and to apply calibration corrections.
[0018] These and other aspects and advantages will become more apparent after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0019] Reference will hereinafter be made to the accompanying drawings, wherein like reference numerals throughout the various FIGURES denote like structural elements, and wherein;
[0020] FIG. 1 is a schematic cross-sectional view of an ophthalmic instrument which embodies the present invention; lens 22 may be positioned to create a parallel or converging beam, or a focal zone;
[0021] FIGS. 2A to 2 C are schematic rear perspective views of various embodiments that may be employed to compliantly mount the applanation plate;
[0022] FIGS. 3A to 3 C are schematic representations of the manner in which the instrument depicted in FIG. 1 may be employed to conduct simultaneous tonometry and pachymetry in accordance with the present invention;
[0023] FIGS. 4 and 5 are representative exemplary interferogram plots of optical signal amplitude versus distance from the reference surface for the instrument conditions represented by FIGS. 3B and 3C , respectively;
[0024] FIG. 6 is a schematic cross-sectional view of a hand-held ophthalmic instrument which embodies the present invention and allows for visual inspection of the patient's eye; and
[0025] FIG. 7 is a schematic representation of another embodiment of the present invention showing a modified applanation tip of a contact tonometer in schematic cross-section which is modified so as permit optical pachymetry measurements to be obtain simultaneously with contact tonometry measurements.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Accompanying FIG. 1 depicts schematically an ophthalmic instrument 10 that embodies one particularly preferred form of the present invention. In this regard, the instrument 10 is most preferably in the form of a hand-held device having a housing 12 defining an interior space 14 terminating in an optically transparent partially reflecting reference surface 16 . A cylindrical mounting sleeve 17 is slidably fitted over a distal extremity of the housing 12 and carries at a forward end an optically transparent rigid applanation plate 18 . The mounting sleeve 17 thus mounts the applanation plate 18 in coaxially spaced relation to the reference surface 16 . Thus, the reference surface 16 is posteriorly spaced from the applanation plate 18 so as to define a cavity space 19 therebetween.
[0027] The housing 12 includes an annular stop 12 - 1 located proximally of the cylindrical mounting sleeve 17 . A compliant annular mount 20 is thereby positioned between the mounting sleeve 17 and the stop 12 - 1 to allow the applanation plate 18 to be capable of parallel resilient displacements towards and away from the reference surface 16 .
[0028] Since the applanation plate 18 is the forwardmost structure of the instrument 10 , it is thereby adapted to being brought into physical contact with the surface of a patient's cornea C. (see FIGS. 3A-3C ). In order to prevent contamination of the patient's cornea C, it is preferred that a disposable sterile transparent protective cover or “condom” 21 may be provided. The proximal edge of the protective cover 21 may thus be stretched around the stop 12 - 1 which then serves as the cover's retainer. The protective cover 21 may be made of any suitable transparent material such as polyethylene terephthalate (e.g., MYLAR® film), silicone, polyurethane, polyvinyl chloride (PVC) or the like.
[0029] Preferably, the compliant mount 20 is formed of an elastomeric material, such as silicone rubber or the like. Other suitable compliant mounting means may also be envisioned, such as compression springs with mechanical restriction to ensure parallelism in movement of the applanation plate using for example the exterior mounting sleeve 17 depicted in FIG. 1 . Alternatively, the mounting sleeve 17 (and hence the annular stop 12 - 1 and compliant mount 20 ) could be provided internally of the housing 12 . Also, although a cylindrical mounting sleeve 17 has been depicted as being presently preferred, those in this art will recognize that other structurally equivalent mounting assemblies (e.g., multiple piano hinges) could be provided so as to ensure parallelism of the applanation plate 18 and the reference surface 16 during displacements of the former relative to the latter.
[0030] The applanation plate 18 is most preferably an optically transparent material that has, or may be made to have, at least about 5% reflectivity at the light wavelengths of the source. Thin films or coatings may thus be provided on the applanation plate 18 and/or reference surface 16 in accordance with well known optical techniques so as to impart desired reflectivity properties. Single crystal sapphire with thickness between 100 and 200 microns is presently preferred as the material from which the applanation plate 18 is constructed though different glasses, acrylics, or other crystals could be used. The applanation plate 18 is also sufficiently rigid so as to remain planar in response to a wide range of intraocular pressure conditions that may be encountered.
[0031] In especially preferred embodiments, the applanation plate 18 has a circular geometry as depicted in FIGS. 2A-2C . The compliant mount 20 therefore in turn most preferably establishes an annular circumferential mounting region relative to the applanation plate 18 which allows the applanation plate 18 to be resiliently displaced substantially uniformly parallel towards and away from the reference surface 16 (i.e., so that the plane of the applanation plate 18 remains substantially parallel to the reference surface 16 throughout its entire range of displacements). Thus, as shown in FIG. 2A the compliant mount 20 may be in the form of a resilient elastomeric O-ring structure and thereby establish a continuous compliant juncture between the applanation plate 18 and the distal end of the housing 12 . Alternatively, a discontinuous annular mounting region could likewise be provided by means of structurally individual compliant mounts (e.g., by providing the compliant mount in the form of structurally individual resilient elastomeric post elements 20 - 1 and/or structurally individual compression springs 20 - 2 as shown in FIGS. 2B and 2C , respectively). In such a case the number and circumferential spacing of the individual compliant mounts are such that the applanation plate 18 does not skew relative to the reference surface 16 in response to a compression force. The compliant mount 20 (or 20 - 1 , 20 - 2 and the like) therefore allows substantially uniform planar displacement of the applanation plate 18 from a rest or “zero” position towards the relatively stationary reference surface 16 in response to a compressive force. Once the compressive force is removed, the compliant mount 20 has sufficient resiliency to extend the applanation plate 18 to its rest or “zero” position and thus reestablish the rest or “zero” distance between the applanation plate 18 and the reference surface 16 .
[0032] Referring again to FIG. 1 , it can be seen that the proximal end of the housing 12 is provided with a conventional optical connector 22 for connecting the instrument 10 to an interferometer 24 via a conventional optical signal guide. The interferometer 24 could also be provided as an integral component part of the instrument 10 (e.g., by being integral within the housing 12 ). The interferometer 24 most preferably comprises a low coherence light source 26 and a spectrometer 28 each being optically connected to a beam splitter 30 . The light source 26 serves to provide low coherence light to the instrument 10 whereas the spectrometer receives back scattered light from the instrument 10 . The low coherent light source is formed into a circular beam B by internal lens 27 located within the interior space 14 between the proximal and distal ends of the housing 12 . Most preferably, the diameter of beam B is substantially 3.06 mm or larger so as to allow measurements equivalent to conventional Goldmann-type tonometer readings to be taken, though with scanning or multiple beams, the diameters would be smaller.
[0033] The output signal 28 a from the spectrometer 28 is connected to a microprocessor 32 (e.g., a personal computer) by presently preferred means of a conventional USB connection (not shown). Microprocessor 32 stores the algorithms for converting the interferograms data provided by the spectrometer signal 28 a into a corrected IOP measurement. Most preferably, the interferometer 24 embodies the principles disclosed more completely in Izatt et al, “Novel Noncontact Optical Pachymeter”, SPIE Ophthalmic Technologies XV Conference, Photonics West, Jan. 22-23, 2005 and Fercher et al, “Measurement of Intraocular Distances by Backscattering Spectral Interferometry”, Optics Communications 117, 43-48 (1995).
[0034] Accompanying FIGS. 3A through 3C depict schematically the manner by which simultaneous tonometry and pachymetry measurements may be accomplished. Specifically, FIG. 3A depicts the instrument 10 positioned adjacent to, but spaced from, the patient's cornea C at the beginning of the measurement procedure. The instrument is then advanced toward the cornea C (arrow A 1 ) until the applanation plate 18 contacts the cornea C as depicted in FIG. 3B . At this point in the procedure, the patient's cornea begins to flatten under pressure of the applanation plate 18 . Further advancement of the instrument toward the patient's cornea causes further corneal flattening until the flattened cornea occupies the entire area of the circular light beam from the instrument 10 as depicted in FIG. 3C . Due to the compliant mount 18 , the distance between the reference surface 16 and the applanation plate 18 decreases due to intraocular pressure of the patient's eye exerted on the cornea C. Thus, whereas the distance between the reference surface 16 and the applanation plate 18 decreases from distance D 1 upon initial contact with the cornea C as depicted in FIG. 3B to distance D 2 when the cornea C has been completely flattened as depicted in FIG. 3C .
[0035] The interferograms generated by the spectrometer 28 corresponding to the instrument conditions depicted in FIGS. 3B and 3C are shown in FIGS. 4 and 5 , respectively. In this regard, it will be observed in FIG. 4 that, upon initial contact with the cornea C, the interferogram includes a total of four peaks labeled peaks 1 0 through 4 0 from the zero distance position of the reference surface 16 . Specifically, the distance from the zero position to peak 1 0 represents the distance D 1 between the reference surface 16 and the applanation plate 18 . The distance between peaks 1 0 to 2 0 represents the thickness of the applanation plate 18 , while the distance between peaks 2 0 and 3 0 represents the annular separation distance between the applanation plate 18 and the cornea C as measured around the central corneal contact point with the applanation plate 18 (i.e., as measured in a region of the diameter of the beam B). Finally, the distance between peaks 3 0 and 4 0 represents the thickness of the cornea C.
[0036] As the cornea C is flattened, the distance between peaks 2 0 and 3 0 trends toward zero when there is no longer any annular separation distance between the applanation plate 18 and cornea C. As shown in FIG. 5 , peaks 2 0 and 3 0 depicted in FIG. 4 merge into peak 2 1 so that the corneal thickness is measured between peaks 2 1 and 3 1 . The area of the flattened cornea achieved by the instrument condition in FIG. 3C will be known since it will is defined by the diameter of the beam B. At zero annular separation distance between the cornea and the applanation plate 18 , therefore, the difference between distances D 1 and D 2 will be indicative of the pressure force needed to displace the applanation plate 18 toward the reference surface 16 .
[0037] It will be appreciated that the actual distance that the applanation plate 18 is displaced from its normal or rest condition will depend on the particular form and material of the compliant mount 20 which can vary from mount to mount or even with the particular instrument's temperature or age. Thus, for any compliant mount 20 , the actual displacement distance that the applanation plate 18 moves towards the reference surface 16 will be a function of the magnitude of compression force that is exerted against the applanation plate 18 which those skilled in this art may determine empirically by standard calibration testing before each use. Thus, following such empirical determination of the relationship of the displacement distance and the pressure force for a given compliant mount configuration and/or material, the microprocessor 32 may be provided with an algorithm or look-up table. The displacement distance of the applanation plate 18 relative to the reference surface 16 which is determined by the spectrometer 28 may therefore be converted into a pressure force against the applanation plate 18 . This pressure force against the applanation plate 18 will thus correspond to a patient's intraocular pressure condition uncorrected by corneal thickness-that is, an IOP measurement that corresponds to conventional Goldmann-type applanation tonometers. It may be useful to employ an annular beam which is larger than the desired applanation diameter, in which case, peaks 2 0 and 3 0 do not merge to peak 2 1 , but remain separate ( FIGS. 4 and 5 ). The separation of peaks 2 0 and 3 0 is then fixed at a distance that would correspond to having the appropriate applanation diameter, given an average curvature of the cornea. The corneal thickness would then be the distance between peak 2 0 and 4 0 ( FIG. 4 ). Having simultaneously determined the corneal thickness in the manner described previously, the microprocessor 32 may thus output an IOP measurement corrected for such corneal thickness using conventional correction algorithms well known to those skilled in this art. The data could also be used to determine corneal biomechanics and corneal curvature.
[0038] Accompanying FIG. 6 depicts another preferred hand-held instrument 50 which embodies the present invention. Specifically, the instrument 50 includes a handle 52 positioned at an essentially right angle to a headpiece 54 . An optical connector 56 is provided at the lower end of the handle 52 so as to connect with interferometer 24 (see FIG. 1 ). The low coherent light is formed into a circular beam B by means of lenses 60 , 62 positioned within the handle 52 which is thereafter redirected by means of a wavelength selective mirror 64 . The distal end of the headpiece 54 includes a reference surface 16 ′, an applanation plate 18 ′ and an annular compliant mount 20 ′ which are structurally and functionally similar to the reference surface 16 , applanation plate 18 and mount 20 described previously with respect to the embodiment of FIG. 1 . The reflected light of visible wavelengths is thus allowed to pass through the mirror 64 to allow viewing and/or video or photographic recording.
[0039] The embodiments described above employ optical means for simultaneously obtaining both tonometry and pachymetry measurements. However, according to the present invention conventional tonometers could be modified so that optical pachymetry measurements could be obtained simultaneously with conventional tonometry measurements using standard electromechanical pressure sensors. Such an embodiment of the present invention is depicted in accompanying FIG. 7 whereby a tonometer tip 70 having internal prisms 72 , 74 includes an optical fiber 76 embedded within the tip 70 . The optical fiber 76 includes a terminal end 76 - 1 which is coplanar with the applanation surface 70 - 1 of the applanation tip 70 and coaxially disposed relative to the applanation tip's central axis A c . As is in and of itself conventional, the applanation tip 70 is connected operatively to a slit lamp tonometer 78 that may be operated manually by the attending professional using techniques will known to those in the optometry art. A pressure sensor 80 is operatively coupled to the tonometer 78 so as to sense the IOP reading obtained by the tonometer 78 during applanation of the patient's cornea C. The pressure sensor 80 outputs a signal via line 82 indicative of the IOP measurement obtained by the tonometer 78 .
[0040] The optical fiber 76 is coupled operatively to an interferometer 84 having characteristics similar to the interferometer 24 described previously. The interferometer 84 will thus output a signal via line 86 which is indicative of the thickness of the patient's cornea C. Thus, simultaneously with corneal applanation by the applanation surface 70 - 1 and the generation of the tonometry signal 82 , the interferometer 84 will output a pachymetry signal via line 86 . These simultaneously generated tonometry and pachymetry signals 82 , 86 , respectively, are received by microprocessor 90 (e.g., a personal computer) which converts the data signals into a corrected IOP measurement using algorithms according to the techniques described previously.
[0041] It is entirely conceivable that the instruments and systems described fully herein, while being especially suited for the simultaneous measurement of a patient's IOP and corneal thickness, could be employed to determine such measurements separately. Thus, if desired, the instruments and systems described herein could be employed so as to determine separately one of the IOP and corneal thickness if that were deemed desirable. Thus, the microprocessor could be configured to provide a readout of the patient's IOP (e.g., as determined by the displacement distance of the applanation plate 18 , in which case the IOP measurement would be commensurate with conventional Goldmann-type tonometer readings at a full applanation diameter of 3.06 mm) and/or a readout of the patient's corneal thickness. In other words, while it may be very desirable to conduct simultaneous measurements of both IOP and corneal thickness, the instruments and systems are sufficiently flexible to permit separate measurement determinations if desired.
[0042] Therefore, while the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
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Ophthalmic instruments, systems and methods enable tonometry and pachymetry measurements to be conducted simultaneously. As such, a patient's intraocular pressure (IOP) corrected for corneal thickness may be determined accurately by a single corneal applanation. Preferably, the ophthalmic instruments have a reference surface at a distal end of the instrument, an applanation plate spaced from the reference surface, and a compliant mount for mounting the applanation plate for resilient displacements relative to the reference surface. The instrument most preferably has a housing such that the reference surface is located at a fixed position at one end of the housing, and the applanation plate is mounted to that one end of the housing in coaxial spaced alignment relative to the reference surface by means of the compliant mount. If desired, the housing may have a handle and a substantially orthogonal head piece containing suitable optic mirrors which allow visible light to pass therethrough so that the procedure can be viewed and/or photographed.
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BACKGROUND OF THE INVENTION
The invention is directed to a process for the production of sulfur containing organosilicon compounds.
In German Pat. No. 2,141,159 (and related Meyer-Simon U.S. Pat. No. 3,842,111, the entire disclosure of which is hereby incorporated by reference and relied upon), there is described a process for the production of bis(alkoxysilylalkyl)oligosulfides from the corresponding alkoxysilylhalides and alkali metal oligosulfides, preferably in alcoholic solution. Because of the easy hydrolyzability of the alkoxysilyl group this reaction always must be carried out under nearly water-free conditions.
The carrying out of the process is also made more difficult since on the one hand no water-free alkali metal oligosulfides are available and hence they first must be dehydrated by an expensive procedure which is likewise difficult because of its ready hydrolyzability and on the other hand, the production of water-free oligosulfides is associated with the development of unpleasant by-products, e.g. especially hydrogen sulfide.
Analogously this also is true for the process described in German Pat. No. 2,141,160 for the production of bis-(alkoxysilylalkyl)oligosulfides which provides for a reaction of alkoxysilylalkyl-mercaptans with sulfur dihalides or for a process described in German Pat. No. 2,405,758 (and related Pletka U.S. Pat. No. 3,997,581, the entire disclosure of which is hereby incorporated by reference and relied upon) which likewise starts from alkoxysilylalkyl-mercaptans and sulfur, or for a process described in German Pat. No. 2,542,534 (or related Pletka U.S. Pat. No. 4,072,701, the entire disclosure of which is hereby incorporated by reference and relied upon) which starts out from alkoxysilylalkyl-halides, metal or ammonium hydrogen sulfides and sulfur.
According to a process described in German Pat. No. 2,712,866 (and related Buder U.S. Pat. No. 4,129,585, the entire disclosure of which is hereby incorporated by reference and relied upon), there is reacted an alkali metal alcoholate with an alkoxysilylorganylhalide, metal or ammonium hydrogen sulfide and sulfur in the presence of an organic solvent.
However, the production of an alkali metal alcoholate solution requires such a large amount of time that apparently an industrial realization of the process is improbable.
The object of the invention is to develop a process for the production of sulfur containing organosilicon compounds which avoids the development of hydrogen sulfide, and which simultaneously makes possible a time saving production of oligo- and monosulfidic compounds.
SUMMARY OF THE INVENTION
The subject matter of the invention is a process for the production of sulfur containing organosilicon compounds of the formula
Z--Alk--S.sub.x --Alk--Z (1)
in which Z is the group ##STR1## wherein R 1 is a linear or branched alkyl group having 1-5 carbon atoms, a cycloalkyl group having 5-8 carbon atoms, a benzyl group, a phenyl group, or a phenyl group substituted by methyl, ethyl, or chloro,
R 2 is an alkoxy group with a linear or branched carbon chain having 1-5 carbon atoms or a cycloalkoxy group having 5-8 carbon atoms, the phenoxy group, or the benzyloxy group, and
wherein R 1 and R 2 in each case can have the same or different meaning,
Alk is a divalent saturated linear or branched hydrocarbon group having 1-10 carbon atoms, and
x is a number from 1.0 to 6.0 which comprises partially or completely dissolving in an organic solvent a hydrogen sulfide of the formula
MeSH (2)
wherein Me is an alkali metal or an equivalent of an alkaline earth metal or of zinc or ammonium, then treating this dispersion or solution with an alkali metal after the end of the development of H 2 , if x is >1, with the necessary amount of sulfur and directly subsequently further reacting with a compound of the formula
Z--Alk--Hal (3)
wherein Z and Alk are as defined above and Hal is a chlorine or bromine atom, separating the organic product from the halide formed and removing the organic solvent.
The starting materials of formula (3) can be produced according to known processes and are generally available.
As alkali metal there is preferably used potassium or sodium even if Me of formula (2) has a different meaning.
As organic solvent in principle there can be employed all polar materials in which the hydrogen sulfide of formula (2) is at least partially soluble, and which neither reacts with the alkali metal nor with the organic silicon compound of formula (3) to form an undesired by-product. Alcoholotes, which may possibly be formed when employing alcohols do not effect the process of the invention.
Preferably there is employed as organic solvent a linear or branched alcohol having 1-5 carbon atoms such as e.g., methyl, ethyl, propyl, butyl or pentyl alcohol, as well as isopropyl alcohol, sec.butyl alcohol. Also suitable are cycloalkyl alcohols having 5-8 carbon atoms, e.g. cyclopentyl alcohol, cyclohexyl alcohol, cyclooctyl alcohol, phenyl or benzyl alcohol. It is useful in order to, e.g. avoid a transesterification, to employ the alcohol which in each case orresponds to the group R 2 . In a given case, advantageously there can also be used a mixture of these alcohols, e.g. when R 2 has different meanings in a compound.
In carrying out the process of the invention as the compounds of formula (2) there are preferably used sodium, potassium, calcium, or ammonium hydrogen sulfides.
To carry out the reaction of the invention there is advantageously employed the elemental sulfur in finely divided form, for example, as commercial sulfur powder. Also the hydrogen sulfide is preferably employed in powder form to accelerate the reaction.
In the formulae (1) and (3) Alk signifies methylene as well as preferably ethylene, i-propylene, n-propylene, i-butylene, or n-butylene but can also be n-pentylene, 2-methylbutylene, 3-methylbutylene, 1,3-dimethylpropylene, n-hexylene, or n-decylene.
Illustrative compounds within formula (3) are 3-chloropropyltriethoxysilane, 3-bromopropyltriethoxysilane, chloromethyltrimethoxysilane, 2-chloroethyldiethoxyethylsilane, 2-bromoethyltri-i-propoxysilane, 2-chloroethyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyldiethoxymethylsilane, 3-chloropropylcyclohexoxydimethylsilane, 4-bromobutyl-diethoxybenzylsilane, chlorobutyltrimethoxysilane, 5-chloropentyldimethoxyphenylsilane, 3-bromo-i-butyltriethyoxysilane, 3-chloropropyl-dimethoxy-p-ethylphenylsilane, 3-chloropropylethoxymethylethylsilane, 5-n-pentyldiethoxycyclo-pentylsilane, 3-bromopropyldimethoxycyclo-pentoxysilane, 2-chloro-2'-methylethyldiethoxycycloheptoxysilane, 3-bromo-2'-methylpropyldimethoxycylooctylsilane, 3-chloropropyldiethoxy-2'-methoxy-ethoxy-silane, 3-chloroethyldimethylcyclooctysilane, 3-chloropropyldibutozymethylsilane, 3-bromopropylphenyloxydimethoxysilane, 3-chloropropyldi-i-butozy-2'-methylphenysilane, 3-chloro-3'-methyl-propyldimethoxybenzyloxysilane, 3-chloropropyltributoxysilane, 3-chloropropyldiethoxyamysilane, and 3-chloropropyldiethoxy-p-methylphenylsilane.
There can be made as products any of the products within formula (1) mentioned for example in the above-mentioned Meyer-Simon U.S. patent, the Pletka U.S. patents and the Buder U.S. patent.
The reaction between the hydrogen sulfide and the alkali metal already begins spontaneously at room temperature and proceeds quantitatively within the shortest time and with heating of the solution. Suitably to reduce the total reaction time the procedure is carried out at elevated temperature or at a temperature increased to the boiling point of the solvent used, insofar as this is not disadvantageous to the quality of the product or effects the safety of the control of the reaction.
Furthermore it is recommended to carry out the reaction while excluding air and water (moisture) in order to suppress the formation of byproducts or to substantially avoid them. In the phase of development of hydrogen the operation can be under dry protective gas. It can also be suitable to carry out the reaction under reduced pressure; slightly elevated pressure likewise is not excluded.
In contrast to a portion of the precedingly described syntheses for bis(alkoxysilyalkyl)oligosulfides in this procedure of the invention there is no formation of hydrogen sulfide.
In contrast to the process described in German Pat. No. 2,712,866 (and the related Buder U.S. patent) it is emphasized that the process of the invention is carried out with a considerably reduced expenditure of time and even monosulfidic compounds can be produced.
The entire reaction starting, e.g. from sodium hydrogen sulfide and sodium, can be described through the equation
2 Z--Alk--Hal+NaSH+Na+(x-1)S→Z--Alk--S.sub.x --Alk--Z+1/2H.sub.2 +2NaHal
whereby x is 1.0-6.0.
The molar ratio of the reactants also is given in the preceding equation. After the complete combination in the described sequence it is advantageous to employ a post reaction time while the mixture is stirred under reflux. After the end of the reaction, the reaction mixture is cooled, the salt deposited separated off and then the organic solvent removed by distillation, whereby suitably there is employed reduced pressure. The sulfur containing organosilicon compounds formed as end products with the exception of the monosulfide derivatives under ordinary conditions cannot be distilled without decomposition. They are normally collected in the distillation sump and in most cases can be supplied withou purification directly to the desired use. They can be employed as adhesive promoters or reinforcing additives in silicate fillers containing rubber mixtures.
Unless otherwise indicated, all parts and percentages are by weight.
The process can comprise, consist essentially of, or consist of the stated steps with the materials recited.
DETAILED DESCRIPTION
EXAMPLES
The general procedure is fully described in Example 1, additional examples of synthesized sulfur containing organosilicon compounds of formula (1) prepared using the process of the invention together with the amounts employed, the starting materials used, and the analytical data of the product are set forth in tabular form.
EXAMPLE 1
There were present in a 10 liter four neck flask equipped with a KPG stirrer, inner thermometer, reflux condenser, solid respectively liquid dosing apparatus a N 2 gassing apparatus and a waste gas line while simultaneously supplying nitrogen, 4.25 liters of ethanol and then 310 grams (5.25 moles) of about 95% sodium hydrogen sulfide. There were added to the milky solution 115 grams (5.0 moles) of sodium in the form of a piece. This dissolved within 30 minutes with the vigorous development of hydrogen and an increase in temperature up to reflux temperature. To the solution cooled to about 30° C. there were then added all at once, 481 grams (15.0 moles) of sulfur and directly subsequent there was begun the dosing of, in all, 2408 grams, (10.0 moles) of chloropropyltriethoxysilane, whereby the temperature in the sump again increased to reflux temperature. After about 50 minutes the silane component was completely added and then the mixture was stirred for a further 1.5 hours under reflux, then cooled, filtered over a Seitz pressure filter and the salt remaining on the filter washed twice with 200 ml of ethanol. After the ethanol was removed from the filtrate on the rotary evaporator at about 100 mbar pressure and up to a tempeature of 120° C., there remained as a light yellow clear liquid the desired product bis(3-triethoxysilylpropyl)-tetrasulfide in an amount of 2.66 kg (98.7% of theory).
The expected structure can be confirmed by NMR and IR spectroscopy. The index of refraction n D 21 was determined to be 1.4938.
The analytical data read:
______________________________________ % S % C % H % Si______________________________________Found 23.79 40.12 7.86 10.42Theory 23.40 38.80 8.15 10.28______________________________________
Following examples 2-9 were carried out analogously to Example 1. Insofar as it is a matter of a monosulfide derivative after the reaction of the sodium naturally there is carried out no further addition of sulfur but there is immediately begun the dosing of the haloorganylalkysilane to the cooled sulfide solution. Table 1 contains the most important date of Examples 2-9.
The entire disclosure of German priority application No. P 3311340.8 is hereby incorporated by reference.
TABLE 1__________________________________________________________________________ Starting MaterialsExampleSolvent Hydrogen Sulfide Sulfur Alkali Metal SilaneNr. (1) (g) (g) (g) (g)__________________________________________________________________________2 C.sub.2 H.sub.5 OH NaSH Na Cl(CH.sub.2).sub.3 Si(OC.sub.2 H.sub.5).sub .3 (95%)4,1 333 -- 125 27203 C.sub.2 H.sub.5 OH NaSH Na Cl(CH.sub.2).sub.8 Si(OC.sub.2 H.sub.5).sub .3 (95%)4,1 333 -- 125 35054 C.sub.2 H.sub.5 OH NaSH Na Cl(CH.sub.2).sub.3 Si(OC.sub.2 H.sub.5).sub .3 (95%)4,1 311 166,8 115 25365 CH.sub.3 OH NaSH Na Cl(CH.sub.2).sub.3 Si(OC.sub.2 H.sub.3).sub .3 (95%)4,1 310 321 115 19906 CH.sub.3 OH KSH K Cl(CH.sub.2).sub.2 Si(OCH.sub.3).sub.3 (94%)4,1 384 481 196 17077 i-C.sub.3 H.sub.7 OH NaSH Na Br(CH.sub.2).sub.3 Si(OC.sub.3 H.sub.7)(C.s ub.2 H.sub.5).sub.2 (95%)4,1 310 160,3 115 26738 C.sub.2 H.sub.5 OH NaSH Na Cl(CH.sub.2).sub.5 Si(OC.sub.2 H.sub.5).sub .2 (C.sub.6 H.sub.5) (95%)4,1 310 321 115 30109 C.sub.2 H.sub.5 OH 4,1 NaSH (95%) 310 481 Na 115 ##STR2##__________________________________________________________________________ Analytical Data % S % C % H % SiExample Formula Theor. Theor. Theor. Theor.Nr. (g) Found Found Found Found__________________________________________________________________________2 [(C.sub.2 H.sub.5 O).sub.3 Si(CH.sub.2).sub.3 ].sub.2 S 7.24 48.83 9.56 12.69 2463 7.10 48.02 9.87 12.023 [(C.sub.2 H.sub.5 O).sub.3 Si(CH.sub.2).sub.8 ].sub.2 S 5.50 57.68 10.72 9.63 3159 5.32 56.90 10.93 9.274 [(C.sub.2 H.sub.5 O).sub.3 Si(CH.sub.2).sub.3 ].sub.2 S.sub.2 13.50 45.53 8.92 11.83 2401 13.43 44.86 9.22 11.295 [(H.sub.3 CO).sub.3 Si(CH.sub.2).sub.3 ].sub.2 S.sub.3 22.75 34.10 7.15 13.29 2082 21.29 33.46 7.10 12.746 [(H.sub.3 CO).sub.3 Si(CH.sub.2).sub.2 ].sub.2 S.sub.4 30.05 28.15 6.14 13.16 2120 29.06 27.20 6.38 13.857 [(H.sub.5 C.sub.2).sub.2 (H.sub.7 C.sub.3 O) Si(CH.sub.2).sub.3 ].sub.2 S.sub.2 14.61 54.74 10.57 12.80 2175 14.09 53.71 10.42 12.178 [(H.sub.5 C.sub.6)(H.sub.5 C.sub.2 O).sub.2 Si(CH.sub.2).sub.5 ].sub.2 S.sub.3 15.34 57.46 8.04 8.96 3100 14.76 57.00 8.22 8.51 ##STR3## 19.34 18.71 50.72 49.22 6.99 6.86 8.47 8.10__________________________________________________________________________
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The invention is directed to a process for the production of sulfur containing organosilicon compounds by reaction of an oligosulfide obtained in the reaction solution from a hydrogen sulfide an alkali metal and sulfur with a haloalkylsilane.
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The invention relates to a foamable styrenic polymer gel expandable to form a closed-cell, unimodal foam structure with an aqueous blowing agent and a process for making the structure.
BACKGROUND OF THE INVENTION
Due to present environmental concerns over the use of potentially ozone-depleting or flammable blowing agents, it is desirable to make styrenic polymer foam structures with aqueous blowing agents. Such foam structures made with aqueous blowing agents can be seen in U.S. Pat. No. 4,455,272, U.S. Pat. No. 4,559,367, and European Patent Application 89114160.8.
A problem with styrenic polymer foam structures made with aqueous blowing agents is the formation of bimodal cell structures of relatively larger primary foam cells and relatively smaller secondary foam cells. The bimodal cell structure makes machining and fabricating difficult since the smaller secondary cells govern mechanical properties. Easy machinability and fabricability of foam structures is important in decorative, floral, novelty, and craft applications as well as tongue and groove cutting.
It would be desirable to have a closed-cell, styrenic polymer foam structure blown with an aqueous blowing agent that is easy to machine and fabricate. It would be desirable to have such a foam structure with a unimodal or primary cell size distribution.
SUMMARY OF THE INVENTION
According to the present invention, there is a foamable styrenic polymer gel capable of forming a closed-cell, unimodal foam with enhanced machinability and fabricability. The gel comprises in admixture a flowable melt of a styrenic polymer material having greater than 50 percent by weight of styrenic monomeric units and a blowing agent having at least about 1 percent by weight water based upon the total weight of the blowing agent. The styrenic polymer melt has a water solubility sufficient to provide for formation of a styrenic polymer foam structure having a unimodal cell size distribution upon expansion of the gel. The desired level of solubility may be obtained by employing a styrenic polymer material of sufficiently low molecular weight or solubilizing or compatibilizing additives or polymers.
Further according to the present invention, there is a foamable styrenic polymer material as described above except that the blowing agent comprises a quantity of water sufficient to provide for formation of a foam structure having a substantially bimodal cell size distribution and consisting essentially of polystyrene of about 200,000 weight average molecular weight with about 20 weight percent or less of the polystyrene being individual polymer molecules each less than 20,000 molecular weight.
Further according to the present invention, there is a process for making a closed-cell styrenic polymer foam structure having a unimodal cell size distribution. The process comprises: a) heating a styrenic polymer material having greater than 50 percent by weight styrenic monomeric units based upon the total weight of the styrenic polymer material to form a melt polymer material having a water solubility sufficient to provide for formation of a styrenic polymer foam structure having a substantially unimodal cell size distribution; b) incorporating into the melt polymer material at an elevated temperature a blowing agent comprising about 1 percent or more by weight water based upon the total weight of the blowing agent to form a foamable gel; and c) expanding the foamable gel through a die to form a foam structure.
DETAILED DESCRIPTION
The styrenic polymer foamable gel of the present invention forms, upon expansion, a foam structure having a unimodal cell size distribution. Forming a unimodal foam structure from a foamable gel containing certain quantities of an aqueous blowing agent is heretofore unknown because aqueous blowing systems typically cause formation of foam structures with a bimodal cell size distribution.
Unimodal foam structures and bimodal foam structures differ in the configuration of their respective cell size distributions. A unimodal cell size distribution is one in which the cells are of a generally uniform size throughout the foam structures, except for the skin regions in the case of extruded foam. A bimodal cell size distribution is one in which there is one group of relatively larger primary foam cells of generally uniform size and another group of relatively smaller secondary foam cells of generally uniform size ranging in average cell size from about 5 percent to about 50 percent of the average cell size of the primary cells. The secondary cells may be situated within the cell walls or struts of the primary cells, or may be situated outside of or adjacent to the primary cells individually or in groups of two or more. A strut is a juncture of three or more cell walls. The primary cells may be generally dispersed throughout the secondary cells such that the foam structure has a generally heterogeneous dispersion of the two cell types throughout. Additional teachings directed to foam structures with bimodal cell distributions are seen in U.S. Pat. Nos. 4,455,272 and 4,559,367, U.S. Ser. Nos. 07/895,970 filed Jun. 9, 1992 abandoned and 07/896,025 filed Jun. 9, 1992, abandoned and European Patent Application No. 89114160.8, which are incorporated herein by reference.
The prior art is instructive concerning processes for making bimodal foam structures with aqueous blowing agent systems. U.S. Pat. No. 4,559,367 relates a process for making a bimodal foam structure by incorporating finely-divided, water-containing organic vegetable matter into a polymer feedstock, melting the resulting solid mixture, incorporating a volatile foaming agent into the solid mixture melt to form a foamable mixture, and extruding the foamable mixture through a die to form the foam structure. U.S. Pat. No. 4,455,272 relates a process for making a bimodal foam structure by injecting water and a physical blowing agent into a polymer melt and extruding the resulting mixture through a die to form the structure. EPO Application No. 89114160.8 relates a process for making a bimodal foam structure by incorporating into the polymer feedstock a fine, water-absorbing mineral powder, melting the resulting solid mixture, incorporating a volatile foaming agent into the solid mixture melt to form a foamable mixture, and extruding the foamable mixture through a die to form the foam structure.
Though not bound by any particular theory, bimodal cell size distributions are believed to result when foamable gels contain a level of water exceeding the solubility of water in the polymer melt at the extant processing conditions (e.g. temperature, pressure, mechanical agitation, etc.). The excess water manifests itself in the form of secondary cells upon expansion of the foamable gel to a foam structure.
Use of aqueous blowing agent systems comprising about 1 or more weight percent or more water by weight based upon the total weight of the blowing agent typically result in bimodal foam distributions in foam structures made from commercially-available styrenic polymers, particularly polystyrene.
The present invention sets forth a process for making a closed-cell, unimodal foam structure with an aqueous blowing agent system and a foamable gel expandable to form such structure. An important feature of the invention is the formation of a foamable gel having a level of water solubility sufficiently high to enable expansion of the gel to form a unimodal foam structure and avoid formation of a bimodal foam structure. A sufficiently high level of water solubility may be attained by selecting a styrenic polymer material of requisite water solubility or by addition of solubilizing or compatibilizing agents to the styrenic polymer material. Desirably, the polymer material will have a water solubility of about 0.4 parts or more water and more desirably 3 parts or more water by weight per hundred parts by weight polymer melt at 125° C. The 0.4 parts level is approximately the lower limit of solubility in which a conventional polystyrene resin will form the desired unimodal foam structure.
The present foam structure comprises a styrenic polymer material. Suitable styrenic polymer materials include styrenic homopolymers and copolymers of styrenic compounds and copolymerizable ethylenically unsaturated comonomers. The styrenic polymer material may further include minor proportions of non-styrenic polymers. The styrenic polymer material may be comprised solely of one or more styrchic homopolymers, one or more styrenic copolymers, a blend of one or more of each of styrenic homopolymers and copolymers, or blends of any of the foregoing with a non-styrenic polymer. Regardless of composition, the styrenic polymer material comprises greater than 50 and preferably greater than 70 weight percent of styrenic monomeric units. Most preferably, the styrenic polymer material is comprised entirely of styrenic monomeric units. The styrenic polymer material preferably has a weight average molecular weight of 100,000-350,000 according to size exclusion chromatography.
Suitable styrenic polymers include those derived from styrenic compounds such as styrene, alphamethylstyrene, ethylstyrene, vinyl benzene, vinyl toluene, chlorostyrene, and bromostyrene. Minor amounts of monoethylenically unsaturated compounds such as C 1-4 alkyl acids and esters, ionomeric derivatives, and C 2-6 dienes may be copolymerized with styrenic compounds. Examples of copolymerizable compounds include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, itaconic acid, acrylonitrile, maleic anhydride, methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, methyl methacrylate, vinyl acetate, vinyl alcohol, amides, and butadiene. Preferred structures comprise substantially polystyrene (i.e. greater than 80% by weight) and most preferably entirely of polystyrene because polystyrene foam is economical, and is commonly employed as an insulating plastic foam.
A means of attaining a sufficient level of water solubility in the styrenic polymer melt of the foamable gel is to incorporate previously-processed or recycled styrenic polymer into the melt. The lower molecular polymerst oligomers, and inorganic foam processing additives increase the water solubility of the melt over a corresponding melt without the previously-processed or recycled styrenic polymer. The lower molecular weight polymers and oligomers are present in the previously-processed or recycled styrenic polymer because of the process shearing and temperature degradation the previously-processed or recycled styrenic polymer previously underwent.
Another means of attaining a sufficient level of water solubility is to incorporate into the styrenic polymer material melt minor proportions (i.e. less than 15 weight percent) of relatively hydrophilic polymers or copolymers such as polyethylene, polyvinyl acetate, polyacrylonitrile, and C 1-4 polycarboxylic acids and acrylates. The relatively hydrophilic polymers increase the water solubility of the styrenic polymer material melt over a corresponding polymer melt without the hydrophilic polymers.
Another means of attaining a sufficient level of water solubility is to incorporate a solubilizing or compatibilizing agent into the styrenic polymer material melt to increase the water solubility of the melt over a corresponding polymer melt without the agent. The agent would increase water solubility of the melt in the typical foaming temperature range for styrenic polymers of between 110°-135° C. The agents are at least partly soluble in both the melt and water. Representative solubilizing or compatibilizing agents include the following:
saturated and unsaturated aliphatic or aromatic alcohols having the formula
R--OH
wherein R is a linear or cyclic alkyl or alkenyl group having 1-10 carbon atoms;
ketones having the formula ##STR1## wherein R and R' are aliphatic or aromatic groups of 1-10 carbon atoms; carboxylic acids having the formula
R--COOH
wherein R is an H (hydrogen atom) or an aliphatic or aromatic group of 1-10 carbon atoms;
esters having the formula
R--COO--R'
wherein R and R' are an H or aliphatic or aromatic groups of 1-10 carbon atoms;
aldehydes having the formula ##STR2## wherein R is an aliphatic or aromatic group of 1-10 carbon atoms; aliphatic and aromatic amines having the formula
R--NH.sub.2
wherein R is an aliphatic or aromatic group of 1-10 carbon atoms; and
ethers having the formula
R--O--R'
wherein R and R' are aliphatic or aromatic groups of 1-10 carbon atoms.
The unimodal structure may contain additional additives such as pigments, fillers, antioxidants, extrusion aids, nucleating agents, stabilizing agents, antistatic agents, fire retardants, acid scavengers, or the like.
The foam component of the unimodal foam structure preferably has density of about 16 to about 80 kilograms per cubic meter. The foam component further preferably has an average cell size of about 0.05 to about 2.4 millimeters.
The unimodal foam structure is generally formed by melting and mixing the styrenic polymer itself or with other polymers if present to form a plastic melt, incorporating a blowing agent into the plastic melt to form a foamable gel, and extruding the foamable gel through a die to form the foamed structure. During melting and mixing, the polymers are heated to a temperature at or above the glass transition temperature or at or above the melting point of the polymer. Melting and mixing of polymers and any additives is accomplished by any means known in the art such as with an extruder, mixer, or blender. Likewise the blowing agent, including water, is incorporated or blended into the plastic melt by any of the same above-described means. The blowing agent is blended with the plastic melt at an elevated pressure sufficient to prevent substantial expansion of the resulting plastic gel or loss of generally homogeneous dispersion of the blowing agent within the gel. The blowing agent is incorporated into the melt in a weight proportion of between about 1 to about 30 parts and preferably from 3 to 15 parts per hundred parts of the polymer to be expanded. The foam gel is preferably passed through a cooler or cooling zone to lower the gel temperature to an optimum foaming temperature. For polystyrene, typical optimum foaming temperatures range from 110° C. to 135° C. The cooled gel is then passed through the die into a zone of lower or reduced pressure to form the foam structure. The zone of lower pressure is at a pressure lower than that in which the foamable gel is maintained prior to extrusion through the die. The lower pressure may be super atmospheric or subatmospheric (vacuum), but is preferably at an atmospheric level.
Water preferably comprises about 1 weight percent or more and more preferably about 3 weight percent or more of the blowing agent based upon the total weight of the blowing agent. Water may be incorporated into the polymer melt or polymer feedstock in the form of a water-carrying or water-generating solid, a liquid, or a vapor or gas. Incorporation of water in the form of a liquid or vapor is preferred.
The level of water in the blowing agent sufficient to provide the unimodal foam structure may alternately be characterized relative to the level necessary to provide a bimodal foam structure comprised of polystyrene commonly employed commercially to make foam structures. A commonly-employed polystyrene consists essentially of polystyrene of about 200,000 weight average molecular weight with about 20 weight percent or less of the polystyrene being of individual polymer molecules each less than about 20,000 molecular weight as determined by size exclusion chromatography. The molecular weight of about 20,000 corresponds approximately to the lower threshold of entanglement molecular weight for the polystyrene. A maximum fraction of low molecular weight molecules is specified to better characterize the polystyrene since the low molecular weight fractions of the polystyrene substantially determine its extent of water solubility. The commonly-employed polystyrene is described as consisting essentially of polystyrene since it refers to a certain reference polystyrene irrespective of other polymers or agents which may impact the water solubility of the reference (commonly-employed) polystyrene. The foamable gel of the present invention may comprise a level of water sufficient in a reference foamable gel of the reference (commonly-employed) polystyrene to form a bimodal foam structure of the reference polystyrene. The present foam gel nonetheless comprises a styrenic polymer material having a water solubility sufficient to result in a foam structure of a substantially unimodal cell size distribution.
The styrenic polymer material of the present foamable gel is not limited in any way to the reference (commonly-employed) polystyrene referred to above. As stated previously, the styrenic polymer material may vary in weight average molecular weight from 100,000 to 350,000. The reference to the commonly-employed resin is made so that the water content of the blowing agent and the water solubility of the melt material may be described functionally without referring to specific quantities or proportions of water.
Blowing agents which may be utilized in combination with water include inorganic agents, organic blowing agents and chemical blowing agents. Suitable inorganic blowing agents include carbon dioxide, nitrogen, argon, water, air, nitrogen, and helium. Organic blowing agents include aliphatic hydrocarbons having 1-9 carbon atoms and fully and partially halogenated aliphatic hydrocarbons having 1-4 carbon atoms. Aliphatic hydrocarbons include methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, and the like. Fully and partially halogenated aliphatic hydrocarbons include fluorocarbons, chlorocarbons, and chlorofluorocarbons. Examples of fluorocarbons include methyl fluoride, perfluoromethane, ethyl fluoride, 1,1-difluoroethane, 1,1,1-trifluoroethane (HFC-143a), 1,1,1,2-tetrafluoroethane (HFC-134a), pentafluoroethane, difluoromethane, perfluoroethane, 2,2-difluoropropane, 1,1,1-trifluoropropane, perfluoropropane, dichloropropane, difluoropropane, perfluorobutane, perfluorocyclobutane. Partially halogenated chlorocarbons and chlorofluorocarbons for use in this invention include methyl chloride, methylene chloride, ethyl chloride, 1,1,1-trichloroethane, 1,1-dichloro-1-fluoroethane (HCFC-114b), 1-chloro-1,1-difluoroethane (HCFC-142b), 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) and 1-chloro-1,2,2,2-tetrafluoroethane (HCFC-124). Fully halogenated chlorofluorocarbons include trichloromonofluoromethane (CFC-11), dichlorodifluoromethane (CFC-12), trichlorotrifluoroethane (CFC-113), 1,1,1-trifluoroethane, pentafluoroethane, dichlorotetrafluoroethane (CFC-114), chloroheptafluoropropane, and dichlorohexafluoropropane. Chemical blowing agents include azodicarbonamide, azodiisobutyro-nitrile, benzenesulfonhydrazide, 4,4-oxybenzene sulfonyl-semicarbazide, p-toluene sulfonyl semi-carbazide, barium azodicarboxylate, N,N'-dimethyl-N,N'-dinitrosoterephthalamide, and trihydrazino triazine.
Preferred blowing agents are those using a combination of water and an inorganic blowing agent such as nitrogen, carbon dioxide, krypton, or argon. A most preferred blowing agent comprises water and carbon dioxide. The blowing agent comprises an amount of water sufficient to form the bimodal structure. The blowing agent preferably comprises from about 1 to about 80 weight percent water, more preferably from about 3 to about 80 weight percent water, and most preferably between about 5 and about 60 weight percent water based upon the total weight of the blowing agent.
The unimodal foam structure is preferably closed-cell, and has a closed-cell content of at least 90 percent according to ASTM D2856-87.
Though the preferred process for making the present structure is an extrusion process, it is understood that the above structure may be formed by expansion of beads, which may be molded at the time of expansion to form structures of various shapes. Insulating panels formed from molded, expandable beads are commonly referred to as bead board.
The unimodal foam structure may be used to insulate various surfaces by applying to the surface an insulating panel fashioned from the present structure. Such panels may be used in any conventional insulating application such as roofing, buildings, refrigerators, etc.
The unimodal foam structure may also be formed into a variety of plurality of discrete foamed particles for conventional loose-fill cushioning and packaging applications.
The following are examples to illustrate various aspects of the present invention, and are not to be construed as limiting. All percentages and parts are by weight unless otherwise noted.
EXAMPLES
Example 1
Foam structures were made with an apparatus comprising a single-screw extruder, mixers, a cooler, and a die in series. General Purpose Polystyrene (200,000 weight average molecular weight by size exclusion chromotography) (The Dow Chemical Company) was fed to the extruder with 30 percent by weight recycle polystyrene of 150,000 weight average molecular weight according to size exclusion chromatography. 0.05 parts per hundred magnesium oxide, 0.05 parts per hundred calcium stearate, and 1.0 parts per hundred hexabromocyclododecane by weight were added to the polystyrene in the extruder. 1.5 parts per hundred water and 4 parts per hundred carbon dioxide mixture was added to the polymer melt in the mixer to form a foamable gel. The foamable gel was cooled to 125° C. and extruded through the die and expanded between substantially parallel forming plates. The die pressure was 1100 pounds per square inch (psig). The foam structure had a unimodal cell size distribution with a relatively large average cell size of 0.2 millimeter (mm) and a density of 2.1 pounds per cubic foot (pcf). The machinability of the foam structure was excellent as determined by the router test.
Example 2
Styrenic polymer foam structures were made using the same formulation and the apparatus of Example 1 except that the blowing agent comprised 2.0 pph water and 2.0 pph carbon dioxide. The foam had a unimodal cell size distribution of 1.7 mm and a density of 2.0 pcf. The machinability of these foam structures was good as determined by the router test.
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Disclosed is a foamable styrenic polymer gel containing an aqueous blowing agent capable of forming a closed-cell, unimodal foam structure. The gel composes in admixture the flowable melt of a polymer composition having greater than 50 percent by weight of a styrenic polymer and a blowing agent having about 1 percent or more by weight water based upon the total weight of the blowing agent. The styrenic polymer has a degree of water solubility sufficient to ensure formation of a unimodal foam structure instead of a bimodal foam structure. The unimodal cell size distribution provides desirable fabricability and machinability characteristics for the foam structure.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to equipment and methods for testing of rock drills before each deployment for use to determine whether they are in good functional condition or in need of service or repair.
BACKGROUND OF THE INVENTION
[0002] Stoper and jack-leg drills are two types of rock drills commonly used in mining operations. These pieces of equipment are deployed to different areas of a mine site as their use is required. As with all equipment, it is desirable to minimize down time in which the rock drill is not available for use. In mining, a particular rock drill will sometimes be deployed from an area at which it is normally stored to a particular location in the mine or use by an operator, only for the operator to discover that the rock drill is not functioning properly. Time is wasted as the defective unit must be transported back out of the mine for repair and a replacement rock drill is deployed in its place.
[0003] Accordingly there is a desire for rock drill testing equipment and methods that facilitate testing of rock drills before their deployment into a mine in order to first establish that the equipment is in good working order, and not in urgent need of service or repair.
SUMMARY OF THE INVENTION
[0004] According to a first aspect of the invention there is provided a rock drill testing apparatus comprising:
[0005] a base structure;
[0006] a displaceable structure spaced from the base structure and movable toward and away from the base structure along a linear axis;
[0007] a fluid pumping mechanism mounted to a respective one of the base and displaceable structures, the fluid pumping mechanism thereof being operable by driven rotation of an input shaft thereof extending parallel to the linear axis, the input shaft being rotatable about the linear axis relative to the base and displaceable structures and being engagable by a drill component of a rock drill at an end of the input shaft nearest an opposite one of the base and displacement structures;
[0008] a fluid passage communicating with an outlet of the pumping mechanism;
[0009] a flow control mechanism operably installed on the fluid passage at a distance therealong from the outlet of the fluid pumping mechanism to close and then open the fluid passage with the fluid pumping mechanism running to first cause a buildup of pressure in the fluid passage when closed and then relieve the buildup of pressure in the fluid passage when opened; and
[0010] an indicator mechanism associated with the fluid passage and operable to provide an indication of a status of the buildup of pressure in the flow passage under operation of the fluid pumping mechanism with the fluid passage closed.
[0011] Preferably the fluid pumping mechanism comprises a hydraulic pump and the fluid passage is also communicating with an inlet of the fluid pumping mechanism.
[0012] Preferably the fluid passage comprises a fluid conduit that communicates with the inlet and outlet of the fluid pumping mechanism and a hydraulic fluid reservoir connected inline with the fluid conduit at a position therealong between the flow control mechanism and the inlet of the fluid pumping mechanism.
[0013] Preferably the hydraulic fluid reservoir is mounted on the respective one of the base and displaceable structures on which the hydraulic pump is mounted.
[0014] Preferably the flow control mechanism comprises a pressure relief valve installed on the fluid passage to open the fluid passage only after the pressure buildup therein exceeds a given level.
[0015] Preferably there are provided displacement resisting devices associated with the displaceable structure to resist movement thereof away from the base structure. Preferably the displacement resisting devices are configurable to allow adjustment of resistance to movement of the displaceable structure away from the base structure.
[0016] Preferably the displaceable structure disposed over the base structure and is movable upward and downward away from and toward the base structure.
[0017] Preferably the displacement resisting devices comprises weights carried with the displaceable structure and suspended at a position downward therefrom. Preferably the weights are selectively disconnectable from the displaceable structure to facilitate swapping of different weights for one another on the apparatus.
[0018] Preferably the weights have guide features thereon cooperable with stationary guide members projecting away from the base structure toward the displaceable structure to guide motion of the weights along the guide members during lifting and lowering of the displaceable structure away from and toward the base structure.
[0019] Preferably the guide features comprise collars fixed to the weights and closing around the guide members
[0020] Preferably there are provided stops defined on the guide members for engagement thereagainst by the guide features on the weights under lifting of the displaceable structure away from the base structure by a given distance to prevent movement of the guide features passed upper ends of the guide members.
[0021] Preferably the weights comprise metal plates.
[0022] Preferably the guide members comprise outer tubular members fixed to the base structure and projecting upward therefrom parallel to the linear axis and inner members fixed to and projecting downward from the displaceable structure are slidably received in the guide members to limit movement of the displaceable structure to movement along the linear axis.
[0023] Preferably the indicator mechanism comprises a pressure gauge operably installed on the fluid passage between the outlet of the fluid pumping mechanism and the flow control mechanism.
[0024] Preferably the fluid pumping mechanism is carried on the displaceable structure on a side thereof opposite the base structure and the input shaft projects through the displaceable structure.
[0025] Preferably movement of the displaceable structure is guided by a pair of parallel telescopic supports projecting from the base structure to the movable structure, the telescopic supports comprising stationary sections fixed to the base structure adjacent opposite sides thereof and movable sections slidable relative to the stationary sections toward and away from the base structure, and the displaceable structure comprising a cross member fixed to and extending between the movable sections of the parallel telescopic supports for movement with the movable sections toward and away from the base structure.
[0026] Preferably the stationary sections of the telescopic supports comprise tubular members in which the movable sections of the telescopic supports are slidably disposed.
[0027] Preferably the pumping mechanism is mounted to the displaceable structure.
[0028] According to a second aspect of the invention there is provided a rock drill testing apparatus comprising:
[0029] a base structure;
[0030] a displaceable structure positioned over the base structure at a distance upward therefrom and lowerable and liftable toward and away from the base structure along a linear axis;
[0031] a rotatable element mounted to a respective one of the base and displaceable structures and extending parallel to the linear axis, the rotatable element being rotatable about the linear axis relative to the base and displaceable structures against a source of rotation resistance and being engagable by a drill component of a rock drill at an end of the rotatable element nearest an opposite one of the base and displacement structures; and
[0032] weights carried with the displaceable structure and suspended at positions downward therefrom to resist lifting of the displaceable structure away from the base structure.
[0033] According to a third aspect of the invention there is provided a rock drill testing method comprising:
[0034] positioning a rock drill between a base surface and a displaceable load movable toward and away from the base surface;
[0035] with the rock drill remaining between the base surface and the displaceable load, performing a leg test and a drill test, the leg test comprising attempting to extend a telescopic leg component of the rock drill against the load to move the load away from the base surface and the drill test comprising using a drill component of the rock drill as a drive source for a fluid pumping mechanism to attempt to pump fluid into a closed fluid passage and buildup a pressure level therein; and
[0036] deeming the rock drill either (a) suitable for use if the rock drill passes both the leg test and the drill test by successfully moving the load away from the base surface in the leg test and successfully building up the pressure level in the drill test, or (b) unsuitable for use if the rock drill fails one or both of the leg test and the drill test.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] In the accompanying drawings, which illustrate an exemplary embodiment of the present invention:
[0038] FIG. 1 is a front elevational view of a rock drill test apparatus according to the present invention.
[0039] FIG. 2 is a side elevational view of the rock drill test apparatus.
[0040] FIG. 3 is a front elevational view of a hanger bracket of the rock drill test apparatus.
[0041] FIG. 4 is a side elevational view of a weight of the rock drill test apparatus.
[0042] FIGS. 5A and 5B are overhead plan and front elevational view of a hydraulic pump mounting bracket of the rock drill test apparatus.
[0043] FIGS. 6A and 6B are overhead plan and front elevational views of a hydraulic pump mounting spacer of the rock drill test apparatus.
[0044] FIG. 7 is a front elevational view of a hydraulic reservoir mounting bracket of the rock drill test apparatus.
[0045] FIG. 8 is a side elevational view of a pressure relief valve mounting bracket of the rock drill test apparatus.
[0046] FIGS. 9A and 9B are side elevational and overhead plan views of a weight guiding bracket of the rock drill test apparatus
DETAILED DESCRIPTION
[0047] FIGS. 1 and 2 show an apparatus 10 for testing both the pneumatically expanding and contracting leg component and pneumatically rotating drill component of a rock drill, whether a stopper drill or jack-leg drill. The testing apparatus 10 of the illustrated embodiment is configured as an upright stand having a horizontally oriented base frame 12 , a pair of parallel telescopic support leg assemblies 14 projecting vertically upward from the base at opposite sides thereof and a horizontally oriented cross member 16 extending between the support leg assemblies 14 at the movable upper ends thereof opposite the base frame 12 . A hydraulic pump 18 is mounted atop the cross member 16 and has its internal drive shaft coupled with a rod 20 that projects vertically downward through the cross member 16 at a central position between the support leg assemblies 14 to form an extension of the pump drive shaft so that the rod and driveshaft are rotatable together and collectively form an input shaft assembly that is rotatable to drive the pump. For testing of a rock drill, the bottom base end of the rock drill's air leg is placed atop the base frame 12 of the test apparatus 10 , or the ground therebeneath, and the chuck of the rock drill's drilling end is locked onto the rod 20 . Expansion of the air leg with the rock drill in this vertically position in the test stand acts to lift the weight of the cross member 16 and the components carried therewith to verify the functionality of the air leg, and driving of the drill component of the rock drill drives the hydraulic pump to build up a pressure in a hydraulic conduit connected to the pump to confirm the rotational functionality of the rock drill.
Structure
[0048] The structure of the illustrated testing apparatus 10 is described in further detail as follows.
[0049] The base frame 12 features a pair of feet 22 each disposed immediately beneath a respective one of the telescopic leg assemblies 14 and each formed by a length of rectangular steel tubing extending horizontally in a direction normal to the vertical plane at which the two parallel support legs 14 lie. A central member 24 of the base frame 12 extends horizontally between the two feet 22 at the plane of the support legs 14 , closing off a planar rectangular area bound between the two support legs 14 the cross member 16 and the central frame member 24 . Each support leg assembly 14 features a stationary section 26 defined by another length of rectangular steel tubing fixed at its lower end to the respective foot 22 at a central position therealong to project vertically upward from the horizontal base frame 12 . The upper end of the stationary tube 26 is left open and a respective cross-sectionally smaller piece of steel rectangular tubing fixed at its upper end to the cross member depends downward into the stationary tube 26 through the open upper end thereof to define a movable section 28 of the respective leg assembly 14 slidably disposed within the stationary section to give the leg assembly a telescopic configuration. Triangular vertically oriented gusset plates 55 are fixed between the central frame member 24 and the stationary sections 26 to better support the leg assemblies 14 .
[0050] The telescopically assembled linear sections 26 , 28 of the leg assemblies 14 allow the cross member 16 to move relative to the base frame 12 , but substantially limit this motion of the cross member 16 to vertical displacement along a linear vertical axis A normal to the horizontal plane of the base frame 12 . The displaceable cross bar 16 of the illustrated embodiment is defined by a piece of rectangular steel tubing of the same dimension as that of the movable inner sections 28 of the leg assemblies 14 , this cross bar being fixed to and crossing the upper ends of the inner leg sections 28 so as to extend laterally outward past the two leg assemblies on opposite sides of the base frame 12 . At these shoulder-like end portions 16 a of the cross member 16 projecting outward past the respective leg assemblies 14 , hanger brackets 30 are fixed to and project a short distance downward from the bottom surface of the cross member 16 . In the illustrated embodiment, each of the two hanger brackets is defined by a small metal plate 30 a fixed to the cross member 16 at an upper end, for example by welding, and having a single round hole 30 b passing normally therethrough near a bottom end of plate furthest from the cross member 16 , as shown in FIG. 3 . A shackle 32 passes through the hole of each hanger bracket 30 and a vertically hanging steel cable 34 passes through the opening of the shackle 32 and then folds back over itself to define an upper end of the cable connected to the shackle and hanger bracket, the cable being secured to itself by cable clamps 36 to define this looped upper end. A likewise looped bottom end of the cable formed by another portion of the cable where it is folded back over itself and secured by additional cable clamps 38 carries a weight 40 . As shown in FIG. 4 , the weight of the illustrated embodiment is provided by a generally rectangular steel plate 40 a having an integral lug 40 b projecting vertically upward from a top horizontal edge of the otherwise rectangular weight. A round hole 40 c passing normally through the flat lug 40 b has another shackle 44 passed through it, which in turn has the looped bottom end of the cable 34 passed through it to form the connection between the cable and the weight 40 .
[0051] Each weight 40 is provided with a guide bracket 42 projecting from the inwardly directed face of the weight facing toward the weight on the opposite side of the stand. The guide bracket 42 cooperates with the plate structure of the weight to define a rectangular collar that closes about the stationary lower section 26 of the respective leg assembly adjacent the weight 40 . With reference to FIG. 9 , the guide bracket 42 of the illustrated embodiment is a flat bar having been bent at right angles at four points along its width to take on a winged U-shape with straight flat sections and right angle corners. The resulting guide bracket 42 has two spaced-apart coplanar foot sections 42 a at opposite ends, two parallel leg sections 42 b projecting at right angles from the adjacent inner ends of the foot sections 42 a and a central section 42 c parallel to the foot sections to perpendicularly interconnect the leg sections 42 b at ends thereof opposite the foot sections. The central and leg sections 42 b, 42 c define a squared-off U-shape, and the foot sections define wings of this U. Each foot section 42 a has a round through hole 42 d passing normally therethrough to receive a respective one of two threaded studs 40 d projecting normally from the inwardly directed face of the respective weight 40 at symmetrical positions horizontally across a central vertical axis 40 e of the weight's plate structure. The U-shape of the guide bracket 42 has its feet 42 a placed against the inner face of the weight from the side of the respective leg assembly 14 opposite the weight to slide the holes 42 d of the guide bracket 42 over the studs 40 d of the weight for tightening of nuts 44 onto the studs from the side of the feet 42 a opposite the face of the weight to fasten the guide bracket onto the weight. As a result, the stationary lower section 26 of the telescopic support leg assembly 14 is disposed within a rectangular area bound by the three sides of U-shaped portion of the guide bracket 42 and the inner face of the weight.
[0052] Referring to FIG. 1 , lifting of the cross member 16 away from the base frame 12 acts to also lift the inner sections 28 of the telescopic support legs 14 and the weights suspended from the cross member by the hanger brackets 30 and cables 34 . The guide brackets 42 on the weights 40 slide along the stationary lower sections 26 of the support leg assemblies 14 to guide the weights during this lifting and subsequent lowering so that the weights follow linear paths parallel to those of the displacement of the cross member 16 and inner movable sections 28 of the support legs 14 . The stationary lower sections 26 of the telescopic leg assemblies 14 thus not only define guides to establish the linear motion path of the cross member and attached inner leg sections 28 , but also define guides to establish parallel paths of motion for the weights. A small rectangular plate 46 fixed to the stationary lower section 26 of each telescopic leg assembly 14 projects horizontally inward therefrom a short distance toward the opposite leg assembly to form a stop that limits upward sliding of the guide brackets 42 on the weights to prevent sliding of the guide brackets 42 , and the bottom ends of the movable inner sections 28 disposed at an elevation below the guide brackets 42 , from sliding upwardly past the stops and off the top ends of the stationary lower sections 26 of the leg assemblies 14 .
[0053] At a central position along the cross member 16 , a vertical hole passes therethrough along the central axis A between the support leg assemblies 14 . Two flanged roller bearings 48 a, 48 b are mounted on the cross member, one on the upward facing side thereof to define an upper roller bearing 48 a and one of the downward facing side of the cross member to define a lower roller bearing 48 b. The central opening through each of these two roller bearings 48 , 48 b is concentrically aligned with the vertical hole through the cross member 16 . In the illustrated embodiment, the two roller bearings are the same and have their flanges bolted to the cross member 16 by bolts passing through the flanges of both bearings and the cross member therebetween. A thrust bearing 50 is mounted to the lower roller bearing 48 b at a position immediately therebeaneath. The rod 20 is made of drill steel and passes vertically upward form its bottom end through the thrust bearing 50 , lower roller bearing 48 b, cross member 16 and upper roller bearing 48 a. At its top end, the rod 20 is fixed to a mechanical coupling 52 that couples the rod 20 to the drive shaft of the hydraulic pump 18 .
[0054] A pump mounting bracket 54 installed on the cross member 16 supports the hydraulic pump 18 at a distance above the cross member 16 . The pump mounting bracket of the illustrated embodiment, shown in isolation in FIG. 5 , is formed by a flat steel bar bent into a shape somewhat similar to that of the guide brackets 42 , but on a larger scale. The installed pump mounting bracket 54 features two coplanar horizontal feet 54 a disposed on opposite sides of the rotational rod and bearing assembly at the center of the cross member 16 , a pair of legs 54 b projecting convergingly upward from adjacent inner ends of the feet 54 a nearest the rod 20 and a central section 54 c horizontally interconnecting the top ends of the converging legs 54 b at a position over the connection of the mechanical coupling 52 to the rod 20 . A pair of round steel cylindrical spacers 56 , one of which is shown in isolation in FIG. 6 , each feature a bore 56 a passing vertically therethrough along the longitudinal axis of the spacer's cylindrical shape. Each spacer is disposed between the top surface of the cross member 16 and the bottom surface of a respective foot 54 a of the pump mounting bracket 54 . A bolt passes vertically through the cross member 16 , the bore 56 a of the spacer 56 and a through hole 54 d in the respective foot 54 a of the pump mounting bracket and is fitted with a mating nut to clamp these elements together and secure the pump mounting bracket 54 in place atop the cross member 16 . The drive shaft of the pump 18 , or part of the mechanical coupling 52 fixed thereto, passes vertically through a central through hole 54 e in the central section 54 c in the pump mounting bracket. Four mounting holes 54 f near the four corners of the central section 54 c of the pump mounting bracket 54 are provided to receive fasteners to facilitate mounting of the housing of the pump 18 to the top surface of the pump mounting bracket's central section 54 c.
[0055] A reservoir 58 containing hydraulic fluid is also mounted atop the cross member 16 using a bracket. The reservoir mounting bracket 60 of the illustrated embodiment, shown in isolation in FIG. 7 , is a flat steel bar bent into three linearly extending sections disposed at right angles to one another to create two legs 60 a fixed to the cross member, for example by welding, to project vertically upward from the top surface of thereof and a central section 60 b extending horizontally between the upper ends of these legs. The hydraulic fluid reservoir 58 is fixed atop the central section 60 b of the reservoir mounting bracket 60 and includes an oil filler tube 58 a projecting vertically upward from within the reservoir. A first section of flexible tubing 62 is connected to the reservoir at one end in sealed fluid communication with the reservoir's interior through a port in a wall of the reservoir and is coupled to the pump 18 at the opposite end in sealed fluid communication with an inlet 18 a of the hydraulic pump 18 . A second section of flexible tubing 64 is connected in sealed fluid communication with an outlet 18 b of the hydraulic pump at one end and with in an inlet side of a pressure gauge 66 at an opposite end. A third section of tubing 67 is connected in sealed fluid communication with an outlet of the pressure gauge 66 at one end and with in an inlet side of a pressure relief valve 68 at an opposite end. A final fourth section of tubing 70 is connected in sealed fluid communication with an outlet of the pressure relief valve 68 at one end and with an inlet port of the reservoir 58 at the opposite end. The tubing sections thus define a fluid flow passage that connects the inlet and outlet of the pump and by way of a conduit having an inline installation thereon of a pressure gauge, pressure relief valve and fluid reservoir, in this order, from the pump outlet to the pump inlet. In the illustrated embodiment, the reservoir and pressure relief valve are carried adjacent opposite ends of the cross member 16 on opposite sides of the centrally mounted pump, and the pressure relief valve 68 is mounted on top of the cross member using a valve supporting bracket 69 , shown in isolation in FIG. 8 , formed by a vertically projecting plate having fastener holes 69 a and being fixed to the top surface of the cross member 16 , for example by welding.
[0056] Although not readily visible in the drawings, the test stand apparatus may have rubber pads of ¼-inch thickness placed between each foot of the pump mounting bracket and the respective spacer, between each spacer and the cross member and between the pump housing and the central section of the pump mounting bracket to provide vibratory isolation between the pump and the cross member during operation of the pump.
Operation
[0057] The use of the illustrated testing apparatus 10 is described in further detail as follows.
[0058] The air leg of a stoper or jack-leg type rock drill is stood vertically between the parallel support leg assemblies 14 of to engage the base end of the air leg with the central frame member 24 or the ground on which the base frame 12 is disposed. For example, a stoper drill with a pointed tip of its air leg's piston rod may engage the central frame member 24 by inserting the pointed tip into a vertical hole passing through the central frame member's 24 , or at least through the horizontal top wall of the tubular structure of the illustrated central frame member 24 , at the central vertical axis A of the test stand apparatus, as generally indicated at 72 in FIG. 1 . The claw-like foot of a jack-leg drill may instead be placed over the central frame member 24 to instead seat upon the ground on opposite sides thereof. The frame assembly or the ground on which it is disposed to support the test stand apparatus thus forms a stationary horizontal base structure against which air leg may push when telescopically expanded under pneumatic actuation.
[0059] The stand is built sufficiently tall so that the cross member 16 is high enough to accommodate the length of the rock drills to be tested between the base structure and the bottom end of the rod 20 when the cross member is in its lowest position, which may correspond to the movable sections 28 of the support legs 14 sitting atop the feet 22 of the base frame 12 , the cross member 16 sitting atop the top ends of the stationary sections 26 of the support legs 14 , or engagement of some other stop-defining configuration denoting the fully retracted position in which the cross member is nearest the base structure. The drill chuck of the rock drill is opened, the air-leg is telescoped to expand a short distance to position the rod 20 within the drill chuck, and the chuck is subsequently closed around the rod 20 of the test stand for gripping thereof in the same manner as it would engage a rock drill bit when prepared for use of the drill at a mining site. With the air leg and drill component of the rock drill coupled to a suitable source of compressed air in its normal manner, the rock drill is now considered installed in the test stand apparatus and ready for testing.
[0060] The stand enables testing of both the air leg and the drill component of the rock drill simultaneously, or separately but without requiring any removal of the rock drill or reconfiguration of any aspect of the rock drill's installation within the test stand.
[0061] In a leg test or lift test, the air leg control is used to introduce compressed air to force the expansion of the air leg and accordingly displace the drill component at the top of the air leg upward, this acts to lift the cross member 16 and all components of the apparatus mounted thereon and carried therewith. The mass of the weights 40 supported from the cross member 16 are selected so that the overall mass of the cross member and components carried therewith is low enough so that the drills being tested should be able lift this mass through operation of the air leg pneumatic controls in the expansion driving manner when the drill is in good operating condition, but sufficiently high so that a rock drill air leg not in such good operation condition, but rather being in need of service or repair would not lift the cross member and components carried therewith. Using a shackle at one or both of the connections between each cable and the cross member and respective weight allows easy removal and installation of weights on the apparatus to allow changing of the lift-resisting weight to enable testing of rock drills with different air leg specifications and capabilities.
[0062] In a drill test or torque test, the drill component is driven to drive rotation of the rod 20 , which in turn drives operation of the hydraulic pump 18 via the driveshaft thereof. This draws hydraulic fluid from the reservoir through the pump, forcing it onward past the pressure gauge into the normally closed pressure relief valve. With this valve mechanism closed, the pumping of fluid from the pump against this closure of the conduit builds up the pressure within the portion of the conduit between the pump and the relief valve. Once this pressure buildup exceeds the threshold pressure value of the relief valve, the valve opens to allow the pressurized fluid to continue onward through the remainder of the conduit back to the reservoir 58 . An operator of the test apparatus can confirm that the drill's torque is driving the pump sufficiently to reach this threshold pressure value in the closed section of the conduit by monitoring the pressure gauge. As shown in FIG. 2 , the pressure gauge can be obliquely angled downward for easy viewing by the user from below. If no pressure buildup and subsequent relief is occurring, then the drill is not sufficiently driving the pump. Like with the mass selected to resist the lifting action on the test stand by the air leg, the threshold or actuating value of the relief valve is selected on the basis that driving of the pump with a properly operating drill will be capable of exceeding the this pressure value in the conduit, but a drill in need of repair would not reach the threshold pressure value. Use of an adjustable pressure relief valve allows this value to be changed to accommodate testing of rock drills with different drill specifications and rotational capabilities.
[0063] The testing apparatus can be calibrated once by determining the load lifting and rotational capabilities of a particular type of drill, or of different drills having similar capabilities or ratings, and then used repeatedly to test multiple drills of the same type or ability. The individual tests require no taking of measurements and no comparison of performance values against the known performance characteristics of a properly functioning drill of the same type. The operator of the test stand merely needs to visually confirm the lifting of the cross member and visually confirm the fluctuating pressure in the fluid passage under the opening and subsequent re-closing of the relief valve. Failure of the rock drill to upwardly displace the cross member in the leg test indicates repair of the air leg component of the rock drill is likely required, and accordingly the rock drill should not be dispensed for use in a mine. In the same manner, failure of the rock drill to build up sufficient pressure to actuate the relief valve indicates repair of the drill component of the rock drill is likely required, and accordingly the rock drill should not be dispensed for use in a mine. Acknowledging failure of one or both of the tests prevents an unsuitable rock drill from being sent out for use on the job, and identifying which of the two tests failed provides further information on which of the two components requires repair. Not only is time not wasted on transporting the rock drill into a mine, only to realize it is not functional and have to transport it back out of the mine for repair, but also diagnostic and/or disassembly and reassembly time during repair is minimized since which one(s) of the component require repair has already been identified.
[0064] The present invention can therefore be employed at a mining site, for example at a shop or storage area outside the mine, to quickly and easily test each rock drill before its deployment into the mine to improve productivity by reducing otherwise wasted transport and repair downtime of a rock drill.
Variations
[0065] The particular materials and part configurations described with reference to the illustrated embodiment reflect a prototype construction employed in development of the present invention, and will be appreciated that material types, structure of individual parts and configuration of the parts with one another may be varied without departing from the scope of the present invention. For example, while mild steel plates and bars and steel tubing were used in the prototype, other materials may be employed, for example to reduce the weight of the apparatus to increase portability, provided that the resulting parts are of suitable strength for the end use of the apparatus. Telescopic rail assemblies, as opposed to nesting of a tube or bar within a larger outer tube, may be employed for sliding lifting and lowering of the cross member. It also may be possible to replace the telescopically supported cross member with a displacable structure that slides or rolls along vertical rails projecting away from the base and has its fully retracted position nearest the base defined by stops in the rails at a distance above the base.
[0066] In a further alternate embodiment, the testing apparatus may be laid out horizontally instead of being configured as the vertically extending test stand of the illustrated embodiment. A fixed body structure defining a vertical base surface against which the air leg can push could have a horizontally displaceable structure spaced therefrom, the rock drill being being placeable between the structures to bear against the fixed structure and displace the movable structure away therefrom under expansion of the leg. Telescopic or rail supports could again guide or limit the motion of the displaceable structure to occur in a linear manner. However, the vertical stand construction has the benefit that the weight of the displaceable structure and components carried therewith acts to automatically return it to the retracted position, and also benefits from a smaller footprint (i.e. less occupied surface area/floor space). It will also be appreciated that the pump used to test the torque or rotational performance of the rock drill, and the associated components cooperating the pump, may alternatively be mounted on the stationary base, as opposed to the displaceable structure movable relative thereto.
[0067] The suspended weights of the illustrated embodiment improve safety by keeping a significant portion of the lift-resisting weight lower than if carried directly on the cross member, making the apparatus less top-heavy, and the weight guides prevent the weights from swinging or swaying and potentially injuring the operator or other personnel. However, other test systems or methods in which weights are not suspended below the cross member, including horizontally oriented test apparatuses mentioned above, could still make use of the easy to evaluate torque test using the pumping and pressurization of a fluid as the performance marker. Similarly, vertically oriented stands using the suspended weights may benefit from their advantages without necessarily using a fluid-based torque test if some other source of rotational resistance is instead employed to allow visual confirmation of a rock drill's rotational performance when the rotational resistance is overcome. In the illustrated embodiment, the lifting resistance is adjustable by adding to or reducing the weight carried by the cross member and attached movable sections of the support legs and the rotational resistance is adjustable by changing the threshold pressure value of the relief valve benefits from flexibility and adaptability, but test systems intended for use with only one particular rock drill type may be constructed to have fixed resistances based on the known performance characteristics of a properly functioning drill of that type.
[0068] While the illustrated embodiment uses a pressure gauge to reflect whether the rotational drive of the drill is in good operating condition based on the pressure in the fluid passage, it may be possible to use other indicators. For example, it may be possible to configure the relief valve to perform some function upon reaching the threshold pressure that provides an indication of a successful torque test to the operator. While this could trigger an audible signal, preferably a visual signal or indicator is used due to high noise levels associated with the operation of a rock drill.
[0069] It will also be appreciated that the fluid being pressurized through the rotation of the rock drill need not necessarily be a hydraulic fluid or even a liquid, as an alternative embodiment could alternatively pressurize and subsequently release a gas or combination of gases. For example, one embodiment could use coupling of the rock drill chuck to the driveshaft of an air compressor discharging into a closed conduit or vessel until the pressure buildup exceeds the actuating value of a pressure relief valve installed thereon. The air compressor could draw on ambient air from the environment in which the apparatus is installed and bleed the pressurized air off back into the environment through a suitable discharge after the pressure relief valve is opened.
[0070] Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.
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An apparatus for testing a rock drill has a base structure, a displaceable structure movable toward and away from the base and a fluid pumping mechanism carried on one of the structures to be driven by the rotation of the rock drill. The air leg of the rock drill is deemed either operational or in need of repair based on whether attempted extension of the leg is sufficient move the displaceable structure away from the base. A control mechanism in a fluid passage fed by the pump output is closable so that a pressure builds up in the passage under operation of the pump. Successful of unsuccessful buildup of the pressure to a sufficient level reflecting good rotational operation of the drill reflects whether the drill component is to be deemed operational or in need of repair. Quick and simple testing of both the leg and drill components is facilitated.
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GOVERNMENT RIGHTS
This invention was made with Government support under Contract No.: N66001-11-C-4104 (awarded by Defense Advanced Research Projects Agency (DARPA)). The government has certain rights in this invention.
BACKGROUND
Technical Field
The present invention relates to reliability testing and, more particularly, to isolating and localizing time dependent dielectric breakdown defects.
Description of the Related Art
Time dependent dielectric breakdown (TDDB) in the back-end-of-line (BEOL) in integrated circuits is a significant source of reliability problems as circuit formation technology reaches 22 nm and beyond. As a result, the performance of interconnection is susceptible to technology shrinking, new material (low-k value) features, and process improvement and development. To better understand the effect, leakage current measurement and emission microscopy tests have been conducted separately. Leakage current measurement demonstrates the evolution of dielectric breakdown times. Extrapolation and interpolation on the measurement results then enable the lifetime analysis of the dielectric and the TDDB effect. Light emission tests have also been used, since photon emission is recognized as occurring via energy states generated by dangling bonds and/or impurities at the material interface, which is tightly related to the TDDB progressive development. However, the detailed mechanism of the TDDB effect is still not clear, for that: (1) the progressive development of TDDB effect is not carefully caught on-site; and (2) all prior analysis was conducted off-line and after the experiments, when the TDDB sites on the device under test (DUT) are totally destroyed. This leads to inaccuracy and insufficient for the further failure analysis, including physical failure analysis and scanning electron microscope; and (3) the correlation between electrical leakage current and photon emission is not studied.
SUMMARY
A system for reliability testing includes an electrical measurement device configured to measure an electrical characteristic of a DUT; a camera configured to measure an optical characteristic of the DUT based on the timing of the measurement of the electrical characteristic; and a test system configured to apply a stress to the DUT and to correlate measurements of the electrical characteristic with measurements of the optical characteristic using a processor to determine a time and location of a defect occurrence within the DUT.
These and other features and advantages will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
The disclosure will provide details in the following description of preferred embodiments with reference to the following figures wherein:
FIG. 1 is a pair of graphs that show electrical measurements of a circuit undergoing a time-dependent dielectric breakdown (TDDB);
FIG. 2 is a diagram of an exemplary device under test comparing an image before a TDDB event and an image during the TDDB event;
FIG. 3 is a diagram of a system for performing TDDB reliability tests according to the present principles;
FIG. 4 is a block/flow diagram of a method for integrated electrical and optical testing according to the present principles;
FIG. 5 is a set of graphs showing a correlation between electrical and optical measurements according to the present principles; and
FIG. 6 is a test system to control and analyze TDDB testing according to the present principles.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present principles provide reliability testing that combines both the electrical and emission characteristics of a device under test. Electrical monitoring of the DUT is performed during various types of stress in order to detect TDDB. The present principles provide integration and synchronization of electrical measurements and emission microscopy with an online instantaneous data analysis and further offline data analysis and processing. This provides early detection of TDDB events and also allows precise spatial localization before any real destructive event takes place, so that physical failure analysis can be performed to investigate precursors and root causes that lead to the TDDB event. This is contrasted to previous techniques, whereby emission testing was only performed post-measurement in a failure analysis mode to aid in the localization of the destroyed region of the DUT.
Referring now to FIG. 1 , two graphs are shown that show electrical measurements of a circuit undergoing a TDDB event. Graph 102 has a vertical axis of voltage, measured in volts, and a horizontal time axis measured in hours. The graph 102 shows a linear voltage increase with respect to time. Graph 104 has a similar horizontal time axis, but measures leakage current on its vertical axis in amperes. At time 106 , abnormal leakage current fluctuations begin in the DUT. These fluctuations represent an in-progress TDDB event. Eventually, at time 108 , the DUT has been destroyed by TDDB effects, producing a stable, but much higher, leakage current. The characteristic breakdown pattern shown in graph 104 will not precisely reflect every type of technology, but a similar pattern may be generated for any type of TDDB breakdown event. Noisy behavior, such as that shown in graph 104 after point 106 , is frequently a signature of TDDB events.
It should be noted that the TDDB event may occur at any point on the DUT, such that it is impossible to know from the electrical measurements alone precisely where the breakdown happened. There is no external visual indication to show the breakdown after it has occurred.
Referring now to FIG. 2 , an exemplary DUT 202 is shown at two different points in time. The representation of the DUT 202 is a top-down picture, taken over a period of time to allow accumulation of emission light. At t=5 hours, no emissions are visible at the DUT 202 . However, during the TDDB effect, at t=5.7 hours, a point of light 204 is recorded by the camera indicating the physical location of the breakdown in the DUT 202 .
There are many effects which can cause point emissions such as that shown as 204 . As such, merely providing visual measurements of a DUT 202 does not suffice to determine which points represent TDDB events. However, by integrating electrical measurements and optical measurements, the characteristic breakdown pattern shown in graph 104 can be used to provide timing information for a camera, such that optical emissions 204 can be correlated with known TDDB events.
Referring now to FIG. 3 , a system 300 for performing TDDB reliability tests is shown. A DUT 302 is optically monitored using an appropriate imaging camera 304 . This camera may be any suitable emission microscopy system with a sufficiently high accuracy and resolution to detect the emissions produced by a TDDB event. Any camera 304 will have a determined exposure time needed to detect an emission event. In one embodiment, the camera 304 may detect emissions in near-infra red wavelengths, but it is also contemplated that other tools such as a superconducting quantum interference device (SQUID), thermal cameras, and laser stimulation tools may be employed to localize TDDB sites.
Exposure time for the camera 304 represents a period of integration that determines the time resolution of optical imaging. A camera 304 which integrates over the entire duration of a test will record every emission event, but will not be able to distinguish said events in time. As such, it is advantageous to limit the integration period to a minimal length of time that enables detection. Alternatively, the camera 304 may be used in a “movie” mode, which may capture faster changing events if said events are relatively bright. In each case, a high spatial resolution of images permits a concurrent precise spatial localization of any detected emission to guide subsequent physical failure analyses.
An electrical measurement device 306 monitors electrical properties of the DUT 302 at a known frequency. It is specifically contemplated that the electrical measurement device 306 may be a picometer measuring leakage currents, but this is not intended to be limiting. Any appropriate measurement device may be used to detect characteristic TDDB patterns. The camera 304 and the measurement device 306 provide measurement information to the test system 308 . The test system 308 coordinates measurements from the measurement device 306 with imaging periods in the camera 304 . After every electrical measurement, the test system 308 initiates a new emission test if the camera is idle. The correlation between specific measurements and particular emission tests is stored in a memory in the test system 308 for analysis.
As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing. Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
Referring now to FIG. 4 , a block/flow diagram of a method for integrated electrical and emission testing is shown. Block 402 begins by initializing test parameters. These parameters may include, for example, stress voltage, stress duration, an overall testing time, a camera mode, a camera integration period, an electrical measurement frequency, and early-termination criteria. These parameters may be entered manually at test system 308 or loaded from predetermined configuration files. Reading in a configuration file offers greater flexibility in controlling measurements, allowing one to create highly robust measurement schemes. For example, stress voltage may be specified according to a designated waveform.
Block 403 begins stressing the DUT 302 by applying, e.g., a stress voltage. As noted above, the particular voltage pattern and duration may be set as user parameters, but it is particularly contemplated that the stress voltage may be a linearly increasing function of time. Optionally, the stress test may run for a predetermined period of time, because TDDB events frequently take time before a breakdown occurs. Thus, to save on storage space, it may be advantageous to delay collection of emission data until TDDB events can be more reasonably expected.
Block 404 then begins electrical measurement and optical emission testing. As noted above, electrical testing may include periodically making electrical measurements of the leakage current across the DUT 302 using, e.g., a picometer 306 . After each electrical measurement, block 404 checks the status of camera 304 : if the camera is idle, a new emission test is invoked, but if the camera is busy, block 406 idles until the emission test is finished.
After the emission test completes, block 408 performs analysis on the collected data. In the case of a camera 304 in single image mode, emission information is integrated over a specified duration of time to produce a final image. Data analysis may include, e.g., digital 1-dimensional and 2-dimensional filters, derivatives, 2-dimensional gradients, and correlation functions to detect early signs of a TDDB event. These early signs may include increases in leakage current and the appearance of emission spots. A time stamp is associated with each electrical measurement, and each emission measurement may include a start/stop time. Additional associated information that may be stored with a given measurement includes a time difference from a first measurement and a present stress voltage value.
These analytical operations accomplish several goals. Signatures of early TDDB initiation may be used to adaptively change the emission component of the experiment, such as changing parameters that may include acquisition time, acquisition rate, and single-image vs. movie mode. They may also be used to start or stop acquisition. Signatures in both the optical and electrical realms (or a combination of the two) could be used for early detection of the formation of a TDDB event to modify the stress experiment parameters, for example slowing down the process to highlight particular physical phenomena, or even to stop the stress process before the DUT is destroyed, so that physical failure analysis can identify the precursors of TDDB. Analysis can be used to spatially localize the position of the TDDB defect, before or after a destructive event takes place, for later physical failure analysis. Furthermore, by studying the progression of the TDDB effect from its early formation through the destruction of the structure and beyond, a TDDB event in one spatial location may be observed as being followed by other TDDB events at different locations. The region close to a previously damaged location may be susceptible to additional TDDB events.
If data analysis concludes that some specified termination criterion has been met at block 410 , e.g., if a TDDB event has been detected, processing halts. If not, and if an overall testing time has not yet elapsed at block 412 , processing returns to block 404 and a new set of electrical and emission tests begins. If the overall testing time has elapsed, processing ends.
The data analysis of block 408 includes establishing correlations between electrical measurements and optical emission data. Historical values of electrical measurements may be formatted into an electrical measurement vector. When measuring, for example, leakage current, a leakage current vector is formed at each measurement time instant m that includes all past measurements: I=[I 1 , I 2 , I 3 , . . . , I m ]. Meanwhile, historical values of optical measurements are also formatted into an optical measurement vector: E=[E 1 , E 2 , E 3 , . . . , E n ]. The length of the I and E vectors are usually different, with length(I)≠length(E), so a convolution is used to determine the correlation between them. The correlation between the two vectors is calculated as
Con k = conv ( I , E ) = ∑ j E ( j ) I ( k + 1 - j ) ,
where k=1, . . . , m+n−1 and where the maximum value is regarded as the maximum correlation between the electrical and optical measurements: Corr=max (Con k ). This is only one possible way to correlate the two vectors. Any appropriate correlation may be used to, e.g., find the best time to stop testing to capture the TDDB event.
In the above evaluation of the correlation between electrical and optical measurements, the maximum emission intensity in the chip area is used to compose the emission vector. While this value may be quickly calculated, it is not able to differentiate between locations. For more accuracy, the chip area can be divided into sub-areas or divided into pixels. Then, multiple emission vectors, each representing a different area in the chip image, may be used to correlate with the single electrical measurement vector. The sub-area having the highest emission value is used as the maximum emission intensity.
Referring now to FIG. 5 , graphs showing measurements of leakage current 502 , emission intensity 504 , and the calculated correlation 502 between the two is shown. As can be seen from graph 504 , emission events are detected which are clearly unrelated to the TDDB event shown in graph 502 . The increase in leakage current shown in graph 502 corresponds with a specific emission event in graph 504 , producing a corresponding jump in the calculated correlation shown in graph 506 .
Referring now to FIG. 6 , a more detailed view of testing system 308 is shown. It should first be noted that, although testing system 308 is shown as one unit, its functions may be divided into multiple different devices. This may be advantageous in circumstances where, for example, data analysis might slow the acquisition of data from tests. By implementing such functions on separate hardware, testing efficiency can be increased.
Testing system 308 includes a processor 602 to perform processing related to data analysis and test control, as well as a memory 604 to store measurement and configuration information. The processor 602 and memory 604 are controlled by functional modules which, as described above, may be implemented as hardware, software, or a combination of the two. A configuration module 606 loads in testing parameters, whether inputted manually or by reading a configuration file from memory 604 . Said parameters may include, e.g., stress voltage, stress duration, an overall testing time, a camera mode, a camera integration period, an electrical measurement frequency, and early-termination criteria.
A testing module 608 initiates and controls electrical and emission testing by controlling, e.g., electrical measuring device 306 and camera 304 . The testing module 608 monitors the status of the measuring device 306 and the camera 304 to determine when said devices are active or idle and coordinates the activation of the respective testing cycles. The testing module 608 further collects data from each respective device and stores said data in memory 604 .
A data analysis module 610 accesses data stored in memory 604 and uses processor 602 to analyze the measurements as set forth above. In particular, the data analysis module 610 attempts to correlate electrical and optical measurements to predict and localize TDDB events. The data analysis module 610 may furthermore communicate with configuration module 606 and testing module 608 to provide realtime changes to parameters and testing procedure in response to detected conditions. For example, in one case the data analysis module 610 may halt testing upon detection of the early stages of a TDDB event, such that later physical failure analysis may locate precursors to TDDB failures. A display module 612 displays real-time or offline results and analysis, allowing human operator to further control the testing procedure.
The testing system 308 furthermore has a DUT interface 614 , which allows testing module 608 to provide, e.g., stress voltage to the DUT, and a measuring interface 616 that allows the testing module 608 to communicate with the electrical measurement device 306 and the camera 304 . It should further be recognized that the testing system 308 may include additional interfaces and modules to enable subdivision of the functions of the system, for example by splitting testing and analysis functions into separate devices. In such a case, additional processors 602 and memory 604 may be employed to prevent, e.g., analysis from interfering with measurements.
Having described preferred embodiments of a system and method for integrated time-dependent dielectric breakdown reliability testing (which are intended to be illustrative and not limiting), it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments disclosed which are within the scope of the invention as outlined by the appended claims. Having thus described aspects of the invention, with the details and particularity required by the patent laws, what is claimed and desired protected by Letters Patent is set forth in the appended claims.
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Systems for reliability testing include a picometer configured to measure a leakage current across a device under test (DUT); a camera configured to measure optical emissions from the DUT based on a timing of the measurement of the leakage current; and a test system configured to apply a stress voltage to the DUT and to correlate the leakage current with the optical emissions using a processor to determine a time and location of a defect occurrence within the DUT by locating instances of increased noise in the leakage current that correspond in time with instances of increased optical emissions.
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BACKGROUND OF THE INVENTION
[0001] (a) Technical Field of the Invention
[0002] The present invention relates to an electric fan and more particularly, to an adjustable multi-outlet vertical tower fan that has multiple air outlets arranged at different elevations and that allows a user to adjust the direction of each air outlet individually.
[0003] (b) Description of the Prior Art
[0004] A conventional fan generally comprises a base and a fan body supported on the base and horizontally rotatable relative to the base within a limited range. There is another design of fan that has a rotating grill provided over the front side of the fan blade for continuously regulating the direction of output air streams.
[0005] Further, many vertical tower fans have been created for the purpose of space saving. A typical vertical tower fan comprises a housing supported on a base. The housing has at least one air inlet and at least one air outlet. Each air outlet is provided with an outlet grill. When in use, the housing can be controlled to oscillate relative to the base within a predetermined angle.
[0006] According to the aforesaid various different types of fans, the direction of each air outlet in the housing is not adjustable. Further, due to the drawback of limited air blowing angle, the cover range of a conventional fan is limited.
SUMMARY OF THE INVENTION
[0007] The primary purpose of the present invention is to provide a vertical tower fan, which includes multiple air outlets arranged at different elevations for output air streams in different directions. It is another object of the present invention to provide a vertical tower fan, which allows adjustment of the direction of each air outlet individually.
[0008] To achieve these and other objects of the present invention, the vertical tower fan comprises a frame structure, a fan module, and multiple housing members. The frame structure comprises a plurality of posts, and a plurality of partition plates fixedly fastened to the posts at different elevations and defining a plurality of vertically spaced fan spaces. The fan module comprises a fan motor, a fan shaft vertically inserted through the partition plates and rotatable by the fan motor, and a plurality of fan blades respectively suspending in the fan spaces and affixed to the fan shaft for rotation with the fan shaft. The housing members are respectively sleeved onto the posts of the frame structure and surrounding the fan spaces and the fan blades of the fan module and individually rotatable relative to the frame structure. Each housing member comprises an air inlet, an air outlet, and a grill provided over the air outlet.
[0009] The vertical tower fan comprises further includes a base that supports the frame structure. The frame structure is rotatable relative to the base. Further, each housing member comprises a wind baffle disposed at one side of the respective air outlet for guiding generated air stream out of the air outlet. The grill of each housing member is comprised of a plurality of inclination angle-adjustable louvers.
[0010] Further, each partition plate comprises a series of teeth arranged on the bottom wall thereof, and each housing member comprises a springy protrusion engageable with the teeth of one housing member.
[0011] The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.
[0012] Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 illustrates the outer appearance of an adjustable multi-outlet vertical tower fan in accordance with the present invention.
[0014] FIG. 2 is an exploded view of the adjustable multi-outlet vertical tower fan in accordance with the present invention.
[0015] FIG. 3 is an elevational view of the present invention, showing the frame structure of the adjustable multi-outlet vertical tower fan.
[0016] FIG. 4 is an elevational view of a part of the present invention, showing the structure of the fan motor.
[0017] FIG. 5 is a sectional plain view of a part of the present invention, showing an engagement status between the top protrusion of one housing member and the associated partition plate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.
[0019] Referring to FIG. 1 , an adjustable multi-outlet fan 1 in accordance with the present invention is a vertical tower fan comprising a plurality of housing members 2 rotatably arranged at different elevations. Each housing member 2 has an air inlet 23 and an air outlet 21 . Air inlet and output grills 22 are respectively provided over the air inlet 23 and the air outlet 21 . Each grill 22 is comprised of a plurality of inclination angle-adjustable louvers. The user can manually rotate each housing member 2 to adjust the direction of the air inlet 23 and air outlet 21 of the respective housing member 2 . The adjustable multi-outlet fan 1 further comprises a base 14 disposed at a bottom side for positioning on a flat floor surface stably, an operation panel 12 disposed at a top side for operation by a person directly by hand to control the operation of the internal fan module (not shown), and a remote control sensor 13 for receiving control signals from an external remote controller and driving the internal fan module to operate subject to the control of the external remote controller. Further, a person can control a driving mechanism (not shown) in the adjustable multi-outlet fan 1 to rotate the body of the adjustable multi-outlet fan 1 on the base 14 alternatively back and forth within a predetermined angle by means of the operation panel 12 or the remote controller.
[0020] Referring to FIGS. 2˜4 , the adjustable multi-outlet fan 1 further includes a frame structure formed of multiple posts 11 and circular partition plates 15 , and a fan module 3 . The partition plates 15 are horizontally fixedly fastened to the posts 11 at different elevations. The fan module 3 comprises a fan motor 31 fixedly mounted on the base 14 , a fan shaft 32 vertically inserted through (the center opening of each of) the partition plates 15 fixedly connected to the rotor of the fan motor 31 , and a plurality of fan blades 33 affixed to the fan shaft 32 at different elevations corresponding to the space defined between each two adjacent partition plates 15 .
[0021] Referring to FIG. 5 and FIG. 2 again, the housing members 2 are sleeved onto the posts 11 and respectively rotatably supported on the partition plates 15 . Each partition plate 15 has a series of teeth 16 protruded from the bottom wall and arranged along the border. Each housing member 2 has a springy top protrusion 25 engaged with the teeth 16 of one associating partition plate 15 , and a wind baffle 24 disposed at one side of the air outlet 21 for guiding generated air stream out of the air outlet 21 . When rotating one housing member 2 relative to the posts 11 , the top protrusion 25 is forced to deform temporarily and moved over the teeth 16 of the associating partition plate 15 . When the user released the hand, the top protrusion 25 immediately returns to its former shape and is kept in engagement with the teeth 16 of the associating partition plate 15 again. Therefore, the user can directly rotate each housing member 2 to adjust the direction of the respective air outlet 21 .
[0022] It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.
[0023] While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.
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A vertical tower fan includes a frame structure defining multiple vertically spaced fan spaces, a fan module controllable to rotate vertically spaced fan blades, and multiple housing members mounted on the frame structure at different elevations and respectively surrounding the fan blades and respectively rotatable to adjust the direction of one respective air outlet.
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RELATED APPLICATION
This application hereby claims priority under 35 U.S.C. §119 to U.S. Provisional Patent Application No. 60/332,925, filed on Nov. 14, 2001, entitled “Improving Performance In Virtual Machines,” by inventors Lars Bak, Jacob R. Andersen, Kasper V. Lund and Steffen Grarup.
BACKGROUND
1. Field of the Invention
The present invention relates to compilers for computer systems. More specifically, the present invention relates to a method and an apparatus that facilitates lazy type tagging for compiled activations to facilitate garbage collection.
2. Related Art
The exponential growth of the Internet has in part been fueled by the development of computer languages, such as the JAVA™ programming language distributed by Sun Microsystems, Inc. of Palo Alto, Calif. The JAVA programming language allows an application to be compiled into a module containing platform-independent byte codes, which can be distributed across a network of many different computer systems. Any computer system possessing a corresponding platform-independent virtual machine, such as the JAVA virtual machine, is then able to execute the byte codes. In this way, a single form of the application can be easily distributed to and executed by a large number of different computing platforms.
When an application is received in platform-independent form, it can be interpreted directly through an interpreter, or alternatively, it can be compiled into machine code for the native architecture of the computing platform. Executing native code is typically significantly faster than interpreting platform-independent byte codes. However, native code occupies considerably more space than the corresponding byte codes. Some “mixed-mode” computer systems support both interpretation of byte codes and execution of compiled native code.
A platform-independent virtual machine periodically performs garbage collection operations to reclaim previously allocated memory space that is no longer being used. During a garbage collection operation, it is necessary to identify pointers within activation frames on the stack. Traditionally, this has been done by maintaining stack maps for each method that is currently executing, or by maintaining a tag for each value in each activation frame indicating whether the value is a reference type or a primitive type. While maintaining tags for each value facilitates simpler garbage collection, the overhead involved in maintaining tags for each value can reduce execution speed. This can be explained by the fact that many methods execute to completion without having to be examined by a garbage collection operation. Hence, the time involved in maintaining tags for these methods is largely wasted.
Furthermore, in “mixed-mode” systems, garbage collection operations typically work with two different types of activation frames, because activation frames for compiled methods are typically different in structure than activation frames for interpreted methods. Note that an activation frame for an interpreted version of a method is typically larger than a corresponding activation frame for a compiled version of the method. This is because the activation frame for the interpreted version typically includes additional data, such as type tags, which occupy more space. Hence, working with two different types of activation frames greatly complicates the garbage collection operation, as well as other operations that deal directly with activation frames.
Hence, what is needed is a method and an apparatus that facilitates type tagging for compiled activations without the problems described above.
SUMMARY
One embodiment of the present invention provides a system for type tagging values in a compiled activation frame in a lazy manner to facilitate garbage collection. This system operates in a mixed-mode environment that supports both interpretation of byte codes and execution of compiled native code. Upon receiving an invocation of a method, the system creates an activation frame for the method on the execution stack. If the method is executing in interpreted mode, the interpreter maintains a tag for each value in the activation frame during execution. The tag indicates whether the value is a reference type or a primitive type. However, if the method is executing in compiled mode, the system allocates space for tags for each value in the activation frame, but does not fill in the tags during execution. This allows the tags to be filled in at a future time when needed.
In a variation on this embodiment, prior to receiving an invocation of a method, the system compiles the byte codes of the method into native code, and in doing so, gathers type information for each value in the activation frame of the method. The system embeds this type information into the native code associated with the method.
In a further variation on this embodiment, the system embeds the type information as bit vectors, wherein each bit specifies whether a corresponding value in the activation frame is a primitive type or a reference type.
In yet a further variation on this embodiment, the system embeds the bit vectors in the operands of dummy instructions in the native code.
In yet a further variation on this embodiment, the system embeds the bit vectors at locations following instructions in the native code that invoke other methods or the runtime system.
In a variation on this embodiment, the system performs a garbage collection operation. During this garbage collection operation, the system retrieves type information from the native code and stores the type information in the tags in the activation frame of the method.
In a variation on this embodiment, the system creates activation frames that are identical in structure for a method executing in compiled mode and the same method executing in interpreted mode.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 illustrates a computing device in accordance with an embodiment of the present invention.
FIG. 2 illustrates an activation frame in accordance with an embodiment of the present invention.
FIG. 3 illustrates an interpreted activation frame and a compiled activation frame in accordance with an embodiment of the present invention.
FIG. 4 illustrates the process of retrieving tag information from the compiled code stream in accordance with an embodiment of the present invention.
FIG. 5 is a flowchart illustrating the process of retrieving tag information during a garbage collection operation in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
The data structures and code described in this detailed description are typically stored on a computer readable storage medium, which may be any device or medium that can store code and/or data for use by a computer system. This includes, but is not limited to, magnetic and optical storage devices such as disk drives, magnetic tape, CDs (compact discs) and DVDs (digital versatile discs or digital video discs), and computer instruction signals embodied in a transmission medium (with or without a carrier wave upon which the signals are modulated). For example, the transmission medium may include a communications network, such as the Internet.
Computing Device
FIG. 1 illustrates a computing device 110 coupled to a development system 106 in accordance with an embodiment of the present invention. Development system 106 can generally include any type of computer system, including, but not limited to, a computer system based on a microprocessor, a mainframe computer, a digital signal processor, a portable computing device, a personal organizer, a device controller, or a computational engine within an appliance. Development system 106 contains development unit 108 , which includes programming tools for developing platform-independent applications. This generally involves compiling an application from source code form into a platform-independent form, such as JAVA byte codes.
Development system 106 is coupled to computing device 110 through a communication link 112 . Computing device 110 can include any type of computing device or system including, but not limited to, a mainframe computer system, a server computer system, a personal computer system, a workstation, a laptop computer system, a pocket-sized computer system, a personal organizer or a device controller. Computing device 110 can also include a computing device that is embedded within another device, such as a pager, a cellular telephone, a television, an automobile, or an appliance.
Communication link 112 can include any type of permanent or temporary communication channel that may be used to transfer data from development system 106 to computing device 110 . This can include, but is not limited to, a computer network such as an Ethernet, a wireless communication link or a telephone line.
Computing device 110 includes data store 114 , for storing code and data. Computing device 110 also includes virtual machine 116 for processing platform-independent applications retrieved from data store 114 .
During the development process, a class file 118 is created within development unit 108 . Class file 118 contains components of a platform-independent application to be executed in computing device 110 . For example, class file 118 may include methods and fields associated with an object-oriented class. Note that these methods are specified using platform-independent byte codes 119 .
Next, class file 118 is transferred from development unit 108 , through communication link 112 , into data store 114 within computing device 110 . This allows virtual machine 116 to execute an application that makes use of components within class file 118 . Note that virtual machine 116 can generally include any type of virtual machine that is capable of executing platform-independent code, such as the JAVA VIRTUAL MACHINE™ developed by SUN Microsystems, Inc. of Palo Alto Calif. (Sun, Sun Microsystems, Java and Java Virtual Machine are trademarks or registered trademarks of Sun Microsystems, Inc. in the United States and other countries.)
Virtual machine 116 includes object heap 122 for storing objects that are manipulated by code executing on virtual machine 116 . Object heap 122 also stores compiled methods 123 .
Virtual machine 116 also includes an interpreter 120 , which interprets platform-independent byte codes 119 retrieved from data store 114 to facilitate program execution. During operation, interpreter 120 generally executes one byte code at a time as byte codes 119 are continuously read into interpreter 120 .
Alternatively, virtual machine can use compiler 121 to compile methods from byte code form into native code form to produce compiled methods 123 , which are stored in object heap 122 .
Note that a compiled method, along with information from an associated activation record, can be used to restore an interpreter code equivalent of the compiled method. Alternatively, the interpreter code equivalent of the compiled method can be retrieved again from data store 114 . Thus, the interpreter code equivalent of a compiled method may generally be obtained at any time.
Virtual machine 116 includes a runtime system 124 . Runtime system 124 maintains state information for threads 130 – 131 . This state information includes execution stacks 140 – 141 , respectively. Execution stacks 140 – 141 store activation records for methods being executed by threads 130 – 131 , respectively.
Runtime system 124 can either execute code using interpreter 120 , or using compiled methods 123 received from object heap 122 . When a method is invoked by virtual machine 116 , the system first determines if the method is to be invoked as an interpreted method. If so, runtime system 124 activates interpreter 120 .
If, on the other hand, the system determines that the method is to be invoked as a compiled method, runtime system 124 executes the compiled native code associated with the method. If the native code is not available it can be generated by activating compiler 121 , which generates native code instructions from the byte codes.
Virtual machine 116 also includes garbage collector 150 , which periodically reclaims unused storage from object heap 122 . Note that garbage collector 150 may also remove compiled methods to reclaim storage.
Activation Frame
FIG. 2 illustrates an activation frame in accordance with an embodiment of the present invention. Activation frame 200 contains values 204 , 208 , and 212 . Activation frame 200 also contains tag 202 , which describes value 204 , tag 206 , which describes value 208 , and tag 210 , which describes value 212 . Both values 204 and 212 are primitive values as indicated by their respective tags. Value 208 is a reference type as indicated by tag 206 .
Interpreted and Compiled Activation Frames
FIG. 3 illustrates an interpreted activation frame and a compiled activation frame in accordance with an embodiment of the present invention. Interpreted activation frame 300 contains value 306 which is a reference type as indicated by corresponding tag 304 . Interpreted activation frame 300 also contains value 310 which is a primitive type as indicated by corresponding tag 308 . Interpreter 120 maintains type tags eagerly (updates them as soon as possible) when interpreting byte codes 119 that manipulate the values in interpreted activation frame 300 . This ensures that the interpreted activation frame 300 has type tags available for all values.
Compiled activation frame 302 contains values 314 , 318 , and 322 . Compiled activation frame 302 also contains tag 312 , which describes value 314 , tag 316 , which describes value 318 , and tag 320 , which describes value 322 . Tags 312 , 316 , and 320 are left blank, and are filled in when a situation arrives where they are needed, such as during a garbage collection, or during a de-optimization operations as is discussed in U.S. Pat. No. 5,933,635, entitled “Method and Apparatus for Dynamically Deoptimizing Compiled Activations”, by inventors Urs Holze and Lars Bak, filed on Oct. 6, 1997, and issued on Aug. 3, 1999. This application is hereby incorporated by reference. If at some point in the future the tags are filled in, then compiled activation frame 302 becomes essentially identical to interpreted activation frame 300 and can be treated in an identical manner.
Filling in Tag Information in a Compiled Activation Frame
FIG. 4 illustrates the process of retrieving tag information from the compiled code stream in accordance with an embodiment of the present invention. When a situation arises where tags 312 , 316 , and 320 are needed to determine whether or not values 314 , 318 , and 322 are primitive or reference types, the type information for the tags is retrieved from code stream 402 . This is accomplished by using program counter 400 to identify the location in code stream 402 of the native code for the method associated with compiled activation 302 .
In one embodiment of the present invention, code stream 402 contains a dummy instruction 406 immediately following the instruction “call foo” 404 which invokes a method or the runtime system. The values for tags 312 , 316 , and 320 are stored in an operand of dummy instruction 406 .
In another embodiment of the present invention, code stream 402 contains the values for tags 312 , 316 , and 320 , which are stored in a 32-bit word immediately following the instruction call foo 404 . In this embodiment, the call to foo returns to an address 4-bytes after the call to foo, so that the execution stream skips over the 32-bit word.
Note that the 32-bit word immediately following the instruction foo contains a single bit for each tag indicating whether or not the tag is associated with a reference type. Hence, the 32-bit word can store information for up to 32 tags.
Retrieving Tag Information During a Garbage Collection Operation
FIG. 5 is a flowchart illustrating the process of retrieving tag information during a garbage collection operation in accordance with an embodiment of the present invention. The garbage collection operation starts by traversing the execution stack to locate roots, which are references into the heap that are used to locate objects in the heap to garbage collect (step 502 ). Next, the garbage collection operation uses the program counter to retrieve the type tag information for the activation from the compiled code stream (step 504 ). Once this information has been retrieved, the garbage collection operation inserts the tag information into the appropriate tags within the activation frame (step 506 ). Next, the garbage collection operation proceeds using the identified references in the activation frame (step 508 ). Note that the above-described process of retrieving tag information during a garbage collection operation can work in a system where all methods are compiled before execution, as well as in a mixed-mode system.
The foregoing descriptions of embodiments of the present invention have been presented for purposes of illustration and description only. They are not intended to be exhaustive or to limit the present invention to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the present invention. The scope of the present invention is defined by the appended claims.
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One embodiment of the present invention provides a system for type tagging values in a compiled activation frame in a lazy manner to facilitate garbage collection. This system operates in a mixed-mode environment that supports both interpretation of byte codes and execution of compiled native code. Upon receiving an invocation of a method, the system creates an activation frame for the method on the execution stack. If the method is executing in interpreted mode, the interpreter maintains a tag for each value in the activation frame during execution. The tag indicates whether the value is a reference type or a primitive type. However, if the method is executing in compiled mode, the system allocates space for tags for each value in the activation frame, but does not fill in the tags during execution. This allows the tags to be filled in at a future time when needed.
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a process for chocolate crumb manufacture. In particular, the present invention relates to a process for the manufacture of chocolate crumb whereby the drying parameters employed result in superior flavour and texture development.
BACKGROUND TO THE INVENTION
[0002] The use of chocolate crumb in the manufacture of milk chocolate is well known in the chocolate industry. In particular, the low water content, and the presence of sugar and cocoa (which contains antioxidants) ensure that chocolate crumb has a far greater shelf life than the fresh milk from which it is made. This in turn removes the need for final chocolate production to take place at a location with plentiful access to milk.
[0003] However, it can be difficult to achieve an efficient production process giving consistent quality and taste of crumb. A key feature of crumb production is the Maillard reaction between proteins (present in milk and cocoa), water and reducing sugars (such as lactose, present in milk), which is responsible for the generation of caramel flavours in the crumb. Overexposure to conditions which promote this reaction (such as prolonged heat and moisture) will lead to the crumb having an unwanted flavour profile, and so must be avoided.
[0004] Generally speaking, the manufacture of crumb involves a number of steps comprising mixing the ingredients and processing the mixture under certain conditions so as to produce the crumb product. One of the most critical stages of the production of crumb is the “phase change” stage—whereby the mass of the material is converted from a “doughy” paste to a powder by sucrose or sugar crystallisation. The right conditions and parameters are essential for the phase change to occur in the correct manner and even slight variations can result in problems associated with inappropriate fat expression in the crumb and the texture of the crumb being too powdery resulting to an inferior crumb and fouling of the to crumb processing equipment.
[0005] It is an object of the present invention to provide a process for producing chocolate crumb having an improved flavour and texture profile.
SUMMARY OF THE INVENTION
[0006] In accordance with a first embodiment of the invention, there is provided a process for preparing chocolate crumb comprising:
a) providing a milk and sugar mixture or mixing together, milk and sugar so as to form a mixture; b) evaporating liquid from the mixture; c) adding cocoa mass/liquor to the mixture during and/or after steps (a) and/or (b); d) subjecting the mixture to conditions effective to bring about sugar crystallisation in the mixture; e) drying the mixture at a temperature in the range of 50 to 95° C. for 35 to 200 minutes so as to form chocolate crumb; and f) cooling the chocolate crumb by subjecting it to a temperature which is less than the drying temperature.
[0013] The invention provides a process in which the drying and cooling stage takes place at lower temperatures and for longer periods of time than prior art processes. It has been advantageously found that drying and cooling within these parameters result in a chocolate crumb with superior flavour and texture profiles.
[0014] Step (e) may comprise drying the mixture to a temperature in the range of 50° C. to 90° C., 55° C. to 95° C., 60° C. to 90° C., 65° C. to 85° C., 70° C. to 80° C. or any intermediate range thereof Step (e) may last for 45 to 200 minutes, or 60 to 200 minutes. It will be understood that for 45 to 200 minutes means from 45 to no more than 200 minutes. A reduced drying time is advantageous for commercial and environmental reasons since it increases the capacity of the plant and the efficiency of the process.
[0015] Step (f) may comprise cooling the chocolate crumb to a temperature between 29° C. and the temperature used for drying the mixture for 20 to 1000 minutes. Step (f) may last for 20 to 200 minutes, 20 to 120 minutes or 20 to 60 minutes.
[0016] After step (e), the chocolate crumb may have a moisture content in the range of 0.5 to 7%, 0.8% to 2%, 0.5% to 2%, 1% to 2% or 0.8% to 1.3%. The chocolate crumb may have a moisture content of no more than 7%, 5%, 3% or 2%. The chocolate crumb may have a moisture content of at least 0.1%, 0.3 or 0.5%.
[0017] Steps (e) and/or (f) may further comprise subjecting mixture and/or chocolate crumb to a lowered pressure. A “lowered pressure”, will be one which is lower than the pressure commonly regarded as normal atmospheric pressure (101.325 kPa). The mixture in step (e) may be subjected to a lower pressure than the chocolate crumb in step (f). The mixture in step (e) may be subjected to a pressure in the range of 3.5 to 20 kPa or 5 to 20kPa. The chocolate crumb in step (f) may be subjected to a pressure in the range of 3.5 to 100 kPa. In one embodiment the chocolate crumb is maintained at normal atmospheric pressure.
[0018] Step (b) may comprise evaporation of liquid from the mixture. Step (b) may comprise subjecting the mixture to heat. Step (b) may additionally comprise subjecting the mixture to a lowed pressure. The mixture may be subjected to heat and/or a lowered pressure between steps (b) and (c) and/or between steps (c) and (d).
[0019] It will be apparent that the process could be employed for producing chocolate crumb from powdered milk, liquid milk, or a mixture thereof. Step (a) may further comprise the addition of water. If powdered milk is used in the process, it may be mixing with water initially. If the milk is liquid milk, it may comprise concentrated liquid milk. If desired, the process may further comprise adding milk solids, prior to undertaking step (d).
[0020] At least steps (a) to (d) may be undertaken in a single reaction vessel. If desired, all the steps of (a) to (f) are undertaken in a single reaction vessel. Alternatively, at least one of steps (a) to (d) may be undertaken in different reaction vessels.
[0021] The process may further comprise the step of adding a fat to the mixture before or during step (e). The fat may be cocoa butter, butterfat, a cocoa butter equivalent (CBE), a cocoa butter substitute (CBS), a vegetable fat that is liquid at standard ambient temperature and pressure (SATP, 25° C. and 100 kPa) or any combination of the above. CBEs are defined in Directive 2000/36/EC. Suitable CBEs include illipe, Borneo tallow, tengkawang, palm oil, sal, rhea, kokum gurgi and mango kernel, CBE's may be used in combination with cocoa butter. The addition of fat to the mixture will result in increasing the overall fat content of the crumb and assisting in the drying step. It will also be evident that increasing the fat content may be desirable so that the chocolate confectionery produced with the crumb will have an increased mouth feel and desirable melt characteristics.
[0022] The process may further comprise the step of:
g) forming the chocolate crumb into briquettes.
[0024] Briquettes, allow the crumb to be handled and transported with ease. Of course, other ways of reducing the size of the crumb into manageable pieces, may also be apparent to the skilled addressee.
[0025] In a second embodiment of the invention, there is provided a chocolate crumb formed using the process as herein above described.
[0026] In a third embodiment of the invention, there is provided a confectionery product formed using a chocolate crumb herein above described.
DETAILED DESCRIPTION OF THE INVENTION
[0027] A specific embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
[0028] FIG. 1 shows a cut-away diagram of the apparatus used in accordance with the present invention; and
[0029] FIG. 2 shows a schematic flow diagram illustrating the various steps used in the process of the present invention.
[0030] With reference to FIG. 1 , there is shown a reactor 10 briefly comprising a generally cylindrical reaction vessel 12 having a single horizontal shaft 14 which is rotatable through the centre of the vessel. A number of agitator paddles 16 , extend outwardly from the shaft 14 , to a position close to the interior surface of the vessel 12 so that when the shaft rotates, the paddles run close to the interior surface and sweeps across the whole inner surface of the vessel. The exterior surface of the vessel 12 is covered by a number of jackets 18 which are divided into different sections, through which fluids can flow so as to heat and cool the vessel during operation.
[0031] The vessel 12 has a condensation tower 20 extending vertically upright from a central location in the vessel. The tower 20 is formed from a large cylindrical extension which is of a diameter approximately ¼ the size of the diameter of the vessel 12 itself. The tower 20 terminates with a removable cover plate 22 and has an outlet 24 which connects to the vapour handling system (not shown) for the processing of vapour 28 and the tower 20 also accommodates inlet valves 26 for liquid.
[0032] At the base of vessel 12 , there is provided a discharge valve 30 which is used to discharge of finished product.
[0033] The shaft 14 is driven by a high-powered motor 32 capable of a speed ratio of approximately 100 rpm. The rotation of the shaft 14 is permitted by means of mechanical shaft seals 34 , 36 located within end caps 38 , 40 disposed at either end of the vessel 12 . The mechanical shaft seals 34 , 36 have water flowing through them under pressure, so as to cool and lubricate the seal faces. The seals are protected by temperature, pressure and may also include flow level switches if desired.
[0034] The vessel 12 also has an additional powder inlet 42 , extending vertically from the vessel, through which powdered constituents 44 can be inserted into the vessel 12 if required.
[0035] In use, the reactor 10 is used to produce chocolate crumb from the various constituents. Generally speaking, the milk, sugar and cocoa mass and/or liquor are added to the vessel via the inlet valve 26 and/or the powder inlet 42 . The inlet used for a particular constituent will be dependent upon whether they are in a liquid or powder form 44 and in some instances—only the liquid inlet valve will be used. The constituents can be added at the same time, or added sequentially if desired. During addition, the motor 32 is used to rotate the shaft 14 and in doing so, the agitator blades 16 thoroughly mix the constituents together. The vessel 12 is substantially sealed during mixing as it is sealed at both ends via the end caps 38 , 40 and the shaft 14 freely rotates within the mechanical face seals 34 , 36 .
[0036] During the mixing, the jackets 18 are heated with a hot fluid (such as water or steam) to a particular temperature so as to evaporate excess liquid from the mixture into vapour. The vapour forms in the tower 20 and the vapour 28 is removed via the outlet 24 for further processing by means of the vapour handling system (which will be described in greater detail below). The jackets 18 are subjected to different heating and cooling parameters which are dictated by the particular chocolate crumb protocol which is employed. After sugar crystallisation, the crumb is dried and is discharged via the discharge valve 30 for further processing/storage/shipment. To facilitate cleaning and servicing, the cover plate 22 on the tower is removable so as to allow entry to the interior of the vessel 12 .
[0037] The Reactor 10 is an extremely effective mixer and the incorporation of ingredients is accomplished in a shorter time when compared to conventional apparatus which requires separate mixing vessels for evaporating excess liquid from the initial mixture. The tower 20 reduces the gas velocity and solids carry-over during the low-pressure high gas flow stage, occurring during crystallisation. The motor 32 is sized to cope with the power required at the peak of crystallisation. The shaft 14 speed can also be automatically reduced by the motor 32 if the drive rating is exceeded for a certain period of time.
[0038] With reference to FIG. 2 , there is shown a schematic flow diagram and process chart illustrating the overall steps used in the process of the present invention. The key to the letters used in the FIG. 2 is as follows:
[0039] A. Liquid Milk;
[0040] B. Concentrated Milk;
[0041] C. Milk Solids & Sugar;
[0042] D. SCM;
[0043] E. Initial Crystallisation;
[0044] F. Final Crystallisation;
[0045] G. Dry Material;
[0046] H. Crumb;
[0047] I. Heat & Vacuum
[0048] J. Evaporation;
[0049] K. Water as steam & condensate;
[0050] L. Heat;
[0051] M. Cocoa Liquor/Mass;
[0052] N. Vacuum;
[0053] O. Evaporation;
[0054] P. Water as steam/condensate;
[0055] Q. Water as steam/condensate;
[0056] R. Water as steam/condensate; and
[0057] S. Heat & Vacuum.
[0058] T.S. Total Solids
[0059] If liquid milk (A) is used, then it is first placed in the reactor and heated under vacuum (I) conditions, so that evaporation (J) of the excess liquid takes place. The excess liquid is expelled as water as steam and condensate (K). If concentrated milk (B) is used, then this is mixed with milk solids and sugar (C) so as to form SCM (D). The mixture is heated (L) and cocoa liquor/mass (M) is added. A vacuum (N) is applied during the heating so as to initiate crystallisation and excess liquid is subjected to evaporation ( 0 ) and disposed of as water as steam/condensation (P). Water as steam/condensate (Q) is released during the initial crystallisation (F). Finally, heat and vacuum (S) is applied to the mixture, so as to dry the material (G)—again resulting in the removal of water as steam/condensate (R), so as to produce the crumb (H) product.
[0060] The vapour handling system which effects the removal of the water as steam/condensate after evaporation relies upon a vacuum system. There are three stages of the Reactor Crumb process when the vacuum system is critical: (i) during low pressure evaporation of condensed milk; (ii) during the crystallisation stage at low pressure; and (iii) during the drying process.
[0061] The water evaporates through the tower 20 and passes through the following components:
[0062] Condenser—The condenser is a large shell and tube heat exchanger mounted vertically with the process vapours on the tube side. Tubes are used to avoid blockage by any solids carried over from the Reactor. A large surface area is required to condense the very high vapour load at low pressure during and immediately after Crystallisation.
[0063] Condensate Receiver—Where applicable, condensate is collected in a vessel below the condenser. In liquid milk Reactors, measurement of the condensate o weight that has been collected is used during the milk evaporation phase to identify the end of the evaporation process and to trigger the next stage of the process.
[0064] Vacuum Pump—The vacuum pump achieves a pressure 50-90 mbar. Charging of liquids (milk and liquor/mass) into the reactor 10 is generally through butterfly valves mounted on the tower 20 . Powders (milk powder, sugar) are loaded through the main body of the machine.
[0065] Milk powder wetting is required if the milk constituent is at least partially formed from powder. Water is either added to milk powder, or after milk powder and sugar have been mixed together. This powder and water is mixed for a short time before heating starts.
[0066] Heating—Heating is controlled with steam pressure/temperature and vacuum. The application of vacuum reduces the boiling temperatures and the use of low pressure steam for heating will reduce surface temperatures and so help control burn-on. Typically the agitator is run at high speed during heating.
[0067] Evaporation—Evaporation is effected by heating the mixture to a temperature in the range of 90° C. to 100° C. under a lowered pressure of approximately 24 kPa for approximately 30 minutes. The milk evaporation stage takes place at a reduced pressure to maximise heat transfer. Frothing and boil over of the milk into the condenser can occur if the pressure is reduced to below the boiling pressure at the current mass temperature. The process is most commonly monitored and controlled by measuring the condensate collected although boiling point evaluation can also be used.
[0068] Adjusting the % of Total Solids—It is desirable to modify the mixture so that the total solids present in the sweetened condensed milk is in the range of 75% to 90% of the mixture.
[0069] Heating and Liquor/mass addition—Once the correct solids of the sweetened condensed milk (SCM) are reached, the vacuum is released and the SCM is heated with steam in the jacket 18 to about 85° C. for between 10 to 60 minutes. Cocoa Liquor/mass is then added and the mass is heated, cooled or temperature maintained to between 80° C. and 110° C. At this time, the steam on the jacket 18 is turned off, the jacket vented and vacuum is pulled again to initiate Initial Crystallisation (F).
[0070] Crystallisation (F)—is when the mass of material in the reactor 10 is converted from a liquid, pasty solid to a substantially dry material by sucrose or sugar crystallisation. The process step before Crystallisation has to deliver a mass that has sufficient energy stored within it so that when a vacuum is applied, a sufficient amount of water will evaporate whereby crystallisation (E) can be initiated and develop through the mass. If there is insufficient energy (due to low temperature prior to Crystallisation or high moisture) the mass will not crystallise and break up and may either stall the drive or release fat. If there is too much stored energy, a very rapid rate of sucrose crystallisation will result generating very fine crystals along with a lot of carry over of dust into the condenser. Sugar crystallisation is effected by subjecting the mixture to a temperature of about 100° C., under a lowered pressure of approximately 15 kPa for 10 to 20 minutes.
[0071] Drying—Immediately following Crystallisation, the crumb is at about 60° C. and is extremely reactive, rapidly developing flavours due to the reaction of milk protein and lactose (Maillard Reaction). This is in addition to any flavour developed prior to Crystallisation when there is more moisture with cocoa liquor available.
[0072] Drying is effected at a temperature in the range of 70° C. to 80° C. for about 25 minutes.
[0073] The pressure is initially kept low to evaporate some of the remaining moisture thus reducing the temperature of the mass during crystallisation. Evaporative cooling is far more effective than any other form of cooling because it removes heat from the reactive sites (where moisture, lactose and milk protein are concentrated as the sucrose crystallises).
[0074] Once the reactions have been “quenched”, the option exists to either continue drying to achieve the final desired moisture content at low pressure or to allow the pressure to rise slightly, so as to stop evaporation and allow the flavour development reactions to continue.
[0075] Cooling—The crumb is then cooled to about 30° C. for about 120 minutes.
[0076] Pasting (optional)—In some embodiments, fat is added directly to the material in the Reactor and a paste is discharged, whilst in other embodiments, the dry crumb is discharged for later mixing.
[0077] Discharge—Discharge from the Reactor is generally through a bottom mounted, discharge valve and is generally quite rapid.
EXAMPLE 1
Liquid Milk
[0078] Initial process:
[0079] The initial ingredients are loaded into the mixing vessel and the shaft rotated at a low speed. The milk and sugar are loaded into reactor and the shaft rotated at a pre-determined speed. The vacuum system is started and evaporation pressure is reduced. Steam and condensate valves are then opened.
[0080] Evaporation and Heating:
[0081] The milk and sugar mix is evaporated to between 85-88% solids by heating the mixture to between about 85° C. to 95° C. under a lowered pressure of approximately 24 kPa for 30 minutes. The end point is determined by the measurement of the weight of the condensate collected. The vacuum system is stopped so as to break the vacuum, and the condensate is drained into a collection vessel. The loading of molten cocoa liquor (−50° C.) to liquor weighing vessel is initiated, so that the cocoa liquor is already in the liquor feed vessel above the Reactor. The reactor is heated further to a “liquor addition” temperature, which is typically between 95-105° C.
[0082] Addition of Liquor:
[0083] The liquor from the weighing vessel is loaded into the reactor and heating is continued to “Vacuum On” temperature. The cocoa liquor is often West African or Asian with a fat content of between 50 to 56% and non-fat cocoa solids in the range of 40 to 48%.
[0084] Vacuum ramp and Crystallisation:
[0085] At the vacuum on temperature, the steam and vent jackets are turned off. The motor speed is reduced to about 50% and the vacuum system is started with control valve fully open. The vacuum ramp is initiated at approximately 15 kPa/min and the reactor heated, or cooled to about 100° C. for 10 to 20 minutes. Evaporation starts and the crumb paste cools and thickens. The drive power is increased steadily and then more rapidly as the process continues. Crystallisation is initiated by the mixing action and the mass changes from a paste to a powder with a rapid evolution of vapour. At this point the power is reduced and a pressure “spike” occurs as the vapour evolution briefly overwhelms the condenser and affects the vacuum pump. The process then continues either via flavour development and drying or directly to drying.
[0086] Final drying:
[0087] The pressure is adjusted to the drying set point and the crumb is heated to approximately 80° C. for about 25 minutes. Heating is continued under low pressure (3.5-10 kPa) until drying is complete. The steam and vent jackets are then turned off and the vacuum and vent systems released and the condensate vessel drained.
[0088] Cooling: Cold water is introduced into the Reactor jacket for about 120 minutes so as to cool the crumb down to about 30° C.
[0089] Fat addition:
[0090] If required, fat is added and mixed with the crumb.
[0091] Discharge:
[0092] Lastly, the discharge and vent valves are opened and motor at low speed to assist discharge via the discharge valve.
EXAMPLE 2
Powdered Milk
[0093] Initial Process:
[0094] The reactor is started at low speed and powder milk and sugar loaded into the mixing vessel. The mix is allowed to dry and water is then loaded into the reactor and blended at low speed. The reactor is then run at a higher speed and the steam and condensate valves opened.
[0095] Heating:
[0096] The milk/sugar/water paste is then heated to between 85° C. to 95° C. under a lowered pressure of about 24 kPa for approximately 30 minutes to result in a mixture having between 85-88% solids. The loading of cocoa liquor to liquor weigh vessel is initiated and the reactor heated to the “liquor addition” temperature.
[0097] Addition of Liquor:
[0098] The liquor from weighing vessel is loaded into the reactor and heating is continued to the “Vacuum On” temperature.
[0099] Vacuum ramp and Crystallisation:
[0100] The steam and vent jackets are turned off and speed reduced to 50% at which point the motor has maximum torque. The vacuum system is started with the control valve fully open. The vacuum ramp at 15 kPa/min and the pressure is reduced steadily to the Crystallisation set point and the temperature of the reactor raised to 100° C. for 10 to 20 minutes. Evaporation commences and the paste cools and thickens. The drive power increases steadily at first but more rapidly as the process continues. Crystallisation is then initiated by the mixing action and the mass changes from a paste to a powder along with a rapid evolution of vapour. The power is then reduced and evaporation is continued until the end point temperature is reached or drying time has been exceeded. Steam can be applied to obtain the final drying temperature. The process then continues either via flavour development and drying or directly to drying.
[0101] Final drying:
[0102] Pressure is reduced and the crumb is heated to approximately 80° C. for about 25 minutes. Heating is continued under low pressure until drying is complete. The steam and vent jackets are turned off and the vacuum and vent system released. The condensate vessel is then drained.
[0103] Cooling:
[0104] Cold water is added to the jacket of the Reactor for about 120 minutes so as to cool the crumb down to about 30° C.
[0105] Fat addition:
[0106] If required, the fat is added and mixed with crumb.
[0107] Discharge:
[0108] The discharge and vent valves are opened and the crumb discharged through the discharge valve.
[0109] The foregoing embodiments are not intended to limit the scope of protection afforded by the claims, but rather to describe examples how the invention may be put into practice.
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The present invention relates to a process for chocolate crumb manufacture and to chocolate crumb and confectionery products made using the process. The process comprises: a) providing a milk and sugar mixture or mixing together, milk and sugar so as to form a mixture; b) evaporating liquid from the mixture; c) adding cocoa mass/liquor to the mixture during and/or after step (a) and/or (b); d) subjecting the mixture to conditions effective to bring about sugar crystallisation in the mixtune; e) drying the mixture at a temperature in the range of 50 to 95° C. for 35 to 200 minutes so as to form chocolate crumb; and f) cooling the chocolate crumb by subjecting it to a temperature which is less than the drying temperature. The drying parameters employed in the process result in superior flavour and texture development of the chocolate crumb.
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FIELD OF THE INVENTION
The invention is directed generally to a device and method for the collection of a stool sample.
BACKGROUND OF THE INVENTION
A properly collected sample of stool (feces) is necessary in certain diagnostic assays. For many illnesses, particularly stomach and intestinal tract disorders, examining and testing a patient's feces is needed for diagnostic and treatment purposes. In addition, some postoperative monitoring procedures also require periodic examination of the patient's feces. Pediatricians may instruct parents to monitor various characteristic of their child's feces. For example, fecal material may be macroscopically examined for size, shape, color, odor, consistency, and concretions (gallstones and fecaliths). Gross macroscopic examination can also be directed at finding parasites (whole worms or their fragments), and undigested food, and evaluating the amount of blood, pus, mucus, and fat. Microscopic examination of the fecal material may be for undigested food particles (starch, muscle fibers, elastic fibers, etc.), parasite eggs and segments of parasites, fats, and yeasts. Cultures of fecal material may be taken to determine the presence of bacteria, fungi, viruses and protozoa. Chemical examinations may include the determination of pH and electrolytes, qualitation and quantitation of occult blood, bilirubin and some of its derivatives, ingested iron, trypsin, total fat, fatty acids, vitamin A and carotene, and tests for absorption of lactose and D-xylose.
Collection of the stool by the patient, with or without assistance, is often found to be unpleasant. The stool sample is most favorably obtained from a toilet after defecation. The expelled stool, however, may reside on the bottom of the toilet bowl and, if the stool is semi-liquid, obtaining the sample becomes even more difficult.
Currently, there are two general ways to address the problem of stool collection.
The first method for stool collection is by use of a sheet of flexible material that forms a receptacle, using attachments to secure it to a toilet seat. Some of these devices either have holes, or are made of a mesh-like material which allows liquid to pass through while retaining fecal material. After defecation, the individual obtains a sample from the feces residing on the material, breaks the attachments, and then flushes the remaining feces and material in the toilet. The use of such collection devices requires dexterity and hand contact with both the toilet seat and the device prior to and after defecation.
The second method for stool collection is by use of a sheet material that floats on the water in the toilet bowl. The sheet is hydrophillic and flotation is due either to the action of surface tension or to the generation of contained gas or foam, as disclosed in U.S. Pat. No. 4,705,050. After obtaining a sample from the feces residing on the material, the floating material and remaining fecal material are flushed In the toilet. When adding the sheet material to the toilet, however, the individual's hands are in the bowl, close to the edges and sides of the bowl, thus risking unsanitary contact. Furthermore, the deposit of the stool, or pressure exerted on the stool when obtaining the sample, can cause the sheet and stool to become submerged. This makes the sampling process difficult and contaminates the fecal sample with material present in the toilet bowl.
Another problem with currently available devices is the backup of contaminated water in the toilet bowl. This problem particularly occurs with devices made of hydrophilic sheets with moisture activated foaming material. Such sheets may plug the drainage pipes due to shear mass.
A need thus exists to make the process of obtaining a stool sample simple, easy, and as non-distasteful as possible. A need also exists to minimize or eliminate the potential for unsanitary contact with the toilet bowl itself and its contents (water, chemicals, etc), and to have a collection device that is disposed of in both a simple and environmentally friendly manner.
SUMMARY
The invention is directed to a method for forming a stool collection device, and a method of collecting a stool sample using the inventive device.
A sufficient amount of a liquid absorbent or hydratable polymer is hydrated to form a gel-like matrix in the bowl, simply by adding the polymer to a toilet bowl. This matrix, formed in situ, is capable of supporting stool upon defecation into the prepared bowl. Because the stool is supported on the matrix, it is not contaminated by bowl water and may be easily sampled, collected, or evaluated. The polymer may be, for example, an acrylic acid polymer or a starch graft copolymer of 2-propenenitrile.
The device and method avoids the need for a pre-manufactured receptacle. Such receptacles have attendant problems, for example, the need for attachment to a toilet seat, which may be difficult for some individuals and which allow for hand contamination during attachment. Such receptacles may also clog pipes if disposed by flushing. In contrast, the inventive device is easily formed without any manipulation by the user, and is readily degraded upon flushing, posing no disposal problems.
The polymer may be added to water contained in any toilet bowl, even bowls containing sanitized water. For additional convenience, the polymer may be pre-measured in packets, which may be dropped into the bowl and which may be easily and discretely carried and used by an individual.
These and other embodiments will be apparent with further reference to the following detailed description and examples.
DETAILED DESCRIPTION
A stool (feces) collection device and method to form and use the collection device is disclosed. The collection device contains a hydratable polymer or resin, also referred to as a liquid absorbent or superabsorbent polymer or resin, that forms a matrix of a gel-like substance when in contact with water, such as water within the toilet bowl itself. The liquid absorbent or superabsorbent polymers and resins are generally acrylamide based and are commercially available. Examples of the polymers and resins that may be used in the invention include the following: polyacrylic acid salts, copolymers of acrylic acid salts and methacrylic acid salts, saponification products of methylacrylate-vinyl acetate copolymers, saponification products of starch-ethylacrylate graft copolymers, starch-acrylic acid graft copolymers, saponification products of starch-methyl methacrylate graft copolymers, acrylate homopolymers, acrylate copolymers, alkali acrylate polymers, crosslinked polyacrylic acid salts, crosslinked copolymers of acrylic acid salts and methacrylic acid salts, crosslinked saponification products of methyl acrylate-vinyl acetate copolymers, crosslinked saponification products of starch-ethyl acrylate graft copolymers, crosslinked starch-acrylic acid salt graft copolymers, crosslinked saponification products of starch methyl methacrylategraft copolymers, crosslinked saponification products of starch acrylonitrile graft copolymers and crosslinked sodium carboxymethyl cellulose, crosslinked products of polyacrylates, crosslinked products of hydrolysates of starch-acrylonitrile graft copolymers, crosslinked products of carboxymethylcellulose, crosslinked products of polyvinyl alcohols, crosslinked products of hydrolysates of methyl (meth)acrylate-vinyl acetate copolymers, crosslinked products of cellulose-sodium acrylate graft copolymers, polyethylene oxide, polyvinyl-pyrrolidine, hydroxyethyl cellulose, hydroxypropylcellulose, polymerized α,β-unsaturated carboxylic acids, crosslinked acrylic acid salt polymers, saponification products of crosslinked acrylic acid ester-vinyl acetate copolymers, saponification products of crosslinked starch-acrylonitrile graft copolymers, crosslinked polyvinyl alcohols grafted with maleic anhydride, saponified polymers or copolymers or starch graft copolymers of 2-propenenitrile, 2-methyl-2-propenenitrile, saponified crosslinked homopolymers of acrylonitrile or methacrylonitrile, saponified graft copolymers of starch and polyacrylonitrile or polymethacrylonitrile, and combinations thereof. The above materials are disclosed in, for example, U.S. Pat. Nos. 4,340,706; 4,507,438; 4,541,871; 4,558,100; 4,590,277; 4,732,968; 4,769,414; and 5,886,124.
Examples of commercially available absorbent polymers containing acrylic acid polymers that may be used in the invention are Aqua Keep® Polymers, such as Aqua Keep® J-550 (Absorbent Technologies, Inc., Muscatine, Iowa). Examples of starch graft copolymers of 2-propenenitrile that may be used in the invention are the Water Lock® A-100 series and Water Lock® D-223 (Grain Processing Corporation, Muscatine, Iowa). These absorbent polymers are used in the field of sanitation articles such as diapers, menstrual articles, disposable cloths, and in the field of agriculture and horticulture as water retentive materials. However, the primary use of the absorbent polymers in these fields is either to retain a liquid from wetting other articles, such as clothing, or to retain and provide a source of water for botanical life.
The inventive method results in a matrix or device that is conveniently and easily formed in situ, for example, in the toilet bowl, to support and retain a deposited fecal sample. In use, the matrix is formed by adding a sufficient amount of the polymer to the water in the toilet bowl to form the matrix. In one embodiment, between about 10 g to about 30 g of polymer is added to four liters of bowl water. The polymer is preferably added in a granular form to prevent dispersion of the polymer as fines, but may be added in any form, such as a powder as long as it contacts sufficient water for hydration to form the matrix.
Within about one minute after addition of the polymer, the water in the bowl is converted into a gel-like matrix. Conversion to the matrix occurs even in the presence of water that contains chemical disinfectants, sanitizers, etc.
The polymer may be added using any means such as sprinkling, pouring, shaking, depositing, or by any other means as apparent to those skilled in the art. Addition may occur from any convenient distance above the water, which eliminates hand contact with unsanitary portions of the toilet bowl during preparation.
A desired amount of polymer can be removed from a container with some type of measuring device. The prescribed amount can also be pre-measured in a package or container, thus eliminating the measurement step. The prescribed amount can also be packaged in a packet that is simply added to the bowl water. The packet material allows the polymer to contact the bowl water, for example, it may dissolve, disintegrate, etc. upon contact with the water, or the packet may be sufficiently porous to allow water to pass through the material and hydrate the polymer, causing swelling and breaking the packet due to the pressure exerted by the polymer. This would be advantageous, for example, during travel, for use by a child, etc.
One advantage of this invention is that it provides a disposable collection device that enables an individual to accurately and easily remove fecal material deposited on the gel-like matrix in a sanitary manner. Samples of the stool can be easily obtained with a sampling device, such as a stick or spoon, without the stool moving or getting near the edge of the bowl. In addition to conventional stool sampling devices such as the aforementioned stick or spoon, a suction type sampling device such as a pipette with a wide orifice can be used to easily obtain fecal material without dilution of the sample with the bowl water, or contamination from other areas of the toilet bowl.
Another advantage of the inventive method is the formation of a matrix to provide adequate support to prevent submersion of the stool into the toilet bowl water. The gel-like matrix is sturdy enough to withstand pressure during both deposition and sampling of fecal material. The matrix also allows semi-liquid feces to be retained on the surface of the material.
Another advantage is that both the matrix and the stool are easily disposed. Flushing removes both the device and stool without any hand contact, thus making the collecting and sampling process less distasteful. The device can be used in the privacy of the home, in a medical office or institution, or even in a public restroom. This makes travel less troublesome when a stool collection or sample is needed for examination or testing. Still another advantage is that the matrix does not cause plumbing blockage problems since it disintegrates with flushing.
The following examples demonstrate various embodiments of the invention, but should not be construed as limiting the invention in scope.
EXAMPLE 1
About 20 g of Aqua Keepe® J-550, an acrylic acid polymer in a granular form, was added to approximately four liters of water in a toilet bowl. The gel matrix formed in the toilet bowl within one minute. Three potato wedges, approximately 20 g each, representing a solid stool, were dropped onto the matrix from heights ranging from about 10 to about 30 inches. The wedges were easily removed from the gel surface without contaminating the gel surface with the toilet bowl water. The wedges were then dropped back onto the matrix surface without altering the surface, thus demonstrating the robustness of the matrix. Upon flushing, the gel rapidly dissipated and was completely disposed without any backup in the plumbing system.
EXAMPLE 2
About 20 g of Aqua Keeps® J-550 polymer, is added to approximately four liters of water in a toilet bowl. The gel matrix forms within one minute. About 20 g of soft flour dough, with a consistency similar to that of a stool sample and in a cylindrical form, is dropped onto the gel from a height of about 20 inches. Two flat wooden tongue depressors are then used to remove a sample of the dough. The sample is removed without disturbing the gel or contaminating the gel surface with the bowl water.
EXAMPLE 3
The stool collection device was formed using the same procedure as in Example 1. Mustard, representing semi-liquid stools, was squeezed from a bottle onto the gel surface from a height of about 10 inches. A representative sample was easily scooped from the surface.
EXAMPLE 4
About 20 g of Aqua Keep® 10SH-NF, a spherical acrylic acid polymer, is added to approximately four liters of water in a toilet bowl. The gel matrix formed in the toilet bowl within one minute. Three potato wedges, approximately 20 g each, representing a solid stool, are dropped onto the matrix from heights ranging from about 10 to 30 inches. The wedges are easily removed from the gel surface without contaminating the gel surface with the toilet bowl water. The wedges are then dropped back onto the matrix surface without altering the surface, thus demonstrating the robustness of the matrix. Upon flushing, the gel rapidly dissipates and is disposed completely without any backup in the plumbing system.
EXAMPLE 5
About 20 g of Aqua Keep® 10SH-NF polymer is added to approximately four liters of water in a toilet bowl. The gel matrix forms within one minute. About 20 g of soft flour dough with a consistency similar to that of a stool sample and in a cylindrical form is dropped onto the gel from a height of about 10 inches. Two flat wooden tongue depressors are used to remove a sample of the dough. The sample is removed without disturbing the gel or contaminating the gel surface with the bowl water.
EXAMPLE 6
The stool collection device is formed using the same procedure as in Example 4. Mustard, representing semi-liquid stools, is squeezed from a bottle onto the gel surface from a height of about 10 inches. A sample of the representative stool is easily scooped from the surface without disturbing the gel and contaminating the gel surface with bowl water.
EXAMPLE 7
About 20 g of the Water Locke® A-100 polymer, a starch graft copolymer of 2-propenenitrile, is added to about four liters of water in a toilet bowl. The gel matrix forms in the toilet bowl within one minute. Three potato wedges, approximately 20 g each, which represent a solid stool, are dropped onto the matrix from heights ranging from about 10 to about 30 inches. The wedges are easily removed from the gel surface without contaminating the gel surface with the toilet bowl water. The wedges are then dropped back onto the surface without disturbing the gel, thus demonstrating the robustness of the matrix. Upon flushing, the gel rapidly dissipates and is disposed without any backup in the plumbing system.
EXAMPLE 8
About 20 g of Water Lock® A-100 polymer is added to approximately four liters of water in a toilet bowl. The gel matrix forms within one minute. About 20 g of soft flour dough, with a consistency similar to that of stool and in a cylindrical form, is dropped onto the gel from a height of about 10 inches. Two flat wooden tongue depressors are then used to remove a sample of the representative stool. The sample is removed without disturbing the gel or contaminating the gel surface with the bowl water.
EXAMPLE 9
The stool collection device is formed using the same procedure as in Example 7. Mustard, representing semi-liquid stools, is squeezed from a bottle onto the gel surface from a height of about 10 inches. A sample of the representative stool is easily scooped from the surface.
It should be understood that the embodiments of the present invention shown and described in the specification are only preferred embodiments of the inventor who is skilled in the art, and are not limiting in any way. Therefore, various changes, modifications or alterations to these embodiments may be made or resorted to without departing from the spirit of the invention and the scope of the following claims.
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A method and device for collection of a stool specimen. Formation of the device occurs in situ by providing a liquid absorbent polymer to water contained in a toilet bowl. The hydrated polymer forms a matrix that is capable of supported a stool specimen deposited thereon. The method and device provides a simple, economical, and less distasteful means for collecting, sampling and evaluating a stool specimen for diagnosis and/or therapy.
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BACKGROUND OF THE INVENTION
1. Technical Field
The invention relates to a fastening system with a rear grip element for introduction in a first position into a mounting opening of a elongated hollow body and in a second position for rear gripping mounting projections arranged in the hollow body, as well as having at least one stop for frontal external contact of the edges abutting the hollow body longitudinal walls. The stop is connected with the rear grip element by means of a fastening element. A device for introducing a relative rotary movement is provided between the stop and the rear grip element about the axis of the fastening elements.
2. Description of the Prior Art
Fastening systems of the above type are known for fastening of an object, for example, to C-shaped mounting rail fixed to a surface. The fastening system is introduced into the mounting opening of the mounting rail and rotated, for example, by an angle of 90°. When this is done the rear grip part of the fastening system grips the mounting projections in the mounting rail. Accordingly, it is possible to displace the fastening system in the longitudinal direction of the mounting rail to a final position on the mounting rail. In order to effect a fastening of the fastening system on the mounting rail, the rear grip part is clamped against the stop, for example, using a threaded bar, tightened and thus affixed to the mounting projections. This type of fastening system is suitable for fastening elongated objects and conduit lines, such as pipelines or the like. This type of fastening system is, for example, known from DE 197 36 933 A1.
For fastening a conduit line to a hollow body a number of fastening systems are placed in the hollow body. On the one hand, in order to accelerate the setting operation of the individual fastening systems and to assure in each fastening system perfect orientation of the rear grip part, an anchoring unit is proposed in DE 196 17 750 C1, wherein the rear grip part connected rotationally with the stop, between the stop and grip part a reset spring is provided that can be tensioned by rotation of these two parts relative to each other. The reset spring creates a resetting force when rotated. Rotary limitation stops are provided at the stop. As soon as the rear grip part is situated on the inside of the hollow body at the time of the setting operation of the anchoring unit, the later is oriented for rear gripping of the edges of the hollow body by the reset force of the reset spring.
The drawback of the known solution is that the anchoring unit must be further rotated after introduction through the mounting opening of the mounting rail by a specific angle, in order to optimally grip the mounting projections. Especially at difficult to access locations, this circumstance is a drawback when mounting the anchoring unit.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a fastening system having a rotatable rear grip part, which makes it possible to pre-fix the fastening system to a hollow body without a rotaton about a specific angle, wherein a correct positioning of the rear grip part is secured with the mounting projections. Further, the fastening system can be economically manufactured and allow simple assembly.
According to the invention, a fastening system comprises a rear grip part for introduction into a mounting opening of a hollow body in a first position and for rear gripping of mounting projections provided in the hollow body in a second position, as well as at least one stop for frontal outer contact of the edges of the hollow body longitudinal walls adjacent to the mounting opening. The stop is connected to the rear grip part by means of a fastening means. A system for introducing a relative rotary movement is provided between the stop and the rear grip about the axis of the fastening means. The system is configured as a transmission system for transforming a translatory movement of the fastening means relative to the stop into a rotary movement of the rear grip relative to the stop.
By means of the transmission system a pressure movement on the fastening means is sufficient, for example, in order to fix the fastening system, introduced into the hollow body through the mounting opening, on the hollow body. The transmission system determines the degree of conversion of the translatory movement into a rotary movement, whereby the rotation of the rear grip part relative to the mounting opening is defined. The positioning of the rear grip part is defined by an elastically contacted element and the transmission system. Accordingly, the orientation of the rear grip part is allowed even in the case of an imprecise construction of the hollow body. The user has the security, that the rear grip part is correctly oriented relative to the rear gripping of the rear grip part. A rotation, for example, of the stop or the fastener means is eliminated, whereby the fastening system according to the invention can be used also in difficult to access places. Then, by means of the fastening means, the fastening system is tensioned and detachably fixed to the hollow body. If the fastening system according to the invention is arranged in a mounting opening configured as an elongated opening or a C-shaped mounting opening, the fastening system can, after preliminary fixation, be displaced along the elongation direction of the hollow body and clamped in the desired position with the hollow body by means of the fastening means.
Preferably, the transmission system comprises a slotted member and an elastically loaded element, whereby the elastically loaded element engages in the slotted member of the transmission system. The slotted member forms the guide and defines the degree of the resulting rotational movement of the rear grip part resulting from the translational movement of the fastening means. The elastically loaded element grips the guide of the slotted member. By virtue of the elastic loading of this element, for example, the slotted member has a variable of this element, the slotted member can, for example, have a varying extent in the radial direction relative to the fastening means, without the contact between the slotted member and the element engaging in the slotted member being interrupted during the entire rotary movement.
Preferably, the slotted member of the transmission system has an inclination that runs from the first position of the fastening system into the second position. The first position is a so-called transport position, in which the fastening system is transported, engaged and introduced into the mounting opening of the hollow body. The second position is, for example, the securing position in which the rear grip part of the fastening system is arranged for rear gripping of the mounting projections provided in the hollow body. In order to provide perfect alignment of the rear grip part in the setting operation of the fastening system it is advantageous in particular for reasons of structural design, when the rotational movement at the start is stronger than at the end. Furthermore, the user is sensibly informed by virtue of this design of the slotted member, that the rear grip part is oriented for rear gripping of the mounting projections.
By virtue of the inclination of the slotted member the rotational angle can be controlled over the entire range of the slotted member. For example, a constant inclination is provided on the slotted member.
Advantageously, the rear grip part has a shaft oriented in the direction of the stop, whereby the slotted member of the transmission system on the shaft is formed, optionally as a groove, whereby the slotted member comprises a flattened or planar zone. The slotted member can be milled on the shaft, or can be formed using a laser. The base of the slotted member, for example, by virtue of an increasing or decreasing depth of the groove, forms a slope on the shaft. Due to the configuration of the slotted member as a groove the guide of the elastic loaded element is assured. An unintended sliding out of the elastically loaded element out of the slotted member is largely excluded in this design. The flattening represents essentially a changeover in the slope, which reduces rotational movement of the rear grip part prior to reaching the second, or the safety position relative to the initial rotation when introducing the rotational movement.
In one variant according to the arrangement of the shaft on the rear grip part, the stop has a shaft oriented in the direction of the rear grip part, wherein the slotted member of the transmission system on the shaft is optionally configured as a groove, wherein the slotted member has a planar surface.
The shaft, if it is provided on the rear grip or on the stop, makes possible, with a minor adjustment of the fastening system, a wide range of applications of the fastening system for arrangement on variously shaped hollow bodies. For example, in the case of C-shaped mounting rails the mounting projections are formed by deflecting the free ends inwardly of the side walls running parallel to each other. The mounting projections have different dimensions, depending on the manufacturer, the material used or size of the mounting rail. Instead of providing a plurality of fastening systems matched to the various types of mounting rails, using a small number of fastening systems having parts provided with the shaft, this variety of mounting rail as well as other hollow bodies can be covered. If the shaft is configured on the rear grip part, the rear grip part is selected as a factor of the extent of the coverage of the mounting projections in the direction of setting of the fastening system. With an arrangement of the shaft on the stop the latter is correspondingly replaced. This embodiment of the fastening system according to the invention reduces the costs appreciably relative to the known embodiments of fastening systems, since no longer does a fastening system precisely matched to each type and form of hollow body need to be provided.
Advantageously, the change in the inclination to the planar part is 5° to 50°, preferably 15° to 45°. To this end, the sensory perception of the user is enhanced with regard to the orientation of the rear grip part in the hollow body at the time of the setting operation of the fastening system according to the invention.
Preferably, the groove and/or the planar surfacre is shaped to be helicoidal on the shaft. In this embodiment, along with the rotary movement a translatory movement of the rear grip part is made. Accordingly, the distance between the rear grip part and the stop in the first position or transport position is configured less than the extension of the mounting projections in the sense of the setting direction of the fastening system. The pitch of the helicoidal groove and/or the planar surface defines the path of the translatory movement of the rear grip part. The pitch must correspond at least to the difference between the distance between the rear grip part and the stop and the extension of the rear grip parts in the second position so that the rear grip part in the second position or in the secured position can grip behind the mounting projections.
Preferably, the transmission system has at least two, preferably diametrically opposed slotted members, wherein each slotted member is engaged by an elastically loaded element. With two slotted members a high degree of fitness for the purpose of the fastening system is provided, since an undesirable cant when operating the transmission system is substantially avoided. This is particularly advantageous, when the fastening system is used multiple times.
Advantageously, a pitch is provided in at least one of the slotted members of the transmission system upstream of the inclination. By virtue of the inclination, two advantages are provided. On the one hand the inclination prevents accidental operation or autonomous operation of the fastening system in the transport position. And on the other hand, the sensory feedback upon operating the fastening system provided to the user is enhanced. In order that the rotary movement is initiated in the desired direction of rotation, the initial resistance caused by the pitch must be overcome at the time of initiating the translatory movement. Since the pressure for initiating of the translatory movement is not immediately reduced on the fastening means after overcoming the pitch as a result of the reaction speed of the user, as a result of the resulting rotary movement of the rear grip part makes possible the rear gripping of the mounting projections by the rear grip part. An inadequate orientation of the rear grip part relative to the mounting projections, for example by virtue of an ineffective operation of the fastening means, is substantially excluded.
Preferably, the transmission system comprises at least two slotted member segments, wherein the first slotted member segment has an axially increasing inclination and the at least one additional slotted member segment has an inclination oriented opposite to that of the first slotted member segment, wherein the second slotted member segment abuts the first slotted member segment. The rear grip part is guided into the interior of the hollow body with the first slotted member segment so that the distance between the rear grip part and the stop is increased up to reaching the extent of the mounting projection to be rear gripped and rotated under the mounting projections. The changeover from the first slotted member segment to the second slotted member segment represents a bend or a inflection point. The rear grip part is, if necessary, further rotated under the mounting projections by means of the guide in the second slotted member segment; however, the distance between the rear grip part and the stop is preferably continuously reduced until the rear grip part securely grips behind the mounting projections.
Preferably, the at least one further slotted member segment runs parallel to the axis of the fastening element. If the first slotted member segment is so configured that the rear grip part has reached the desired position for gripping behind the mounting projections upon reaching the bend or the inflection point of the slotted member, the second slotted member segment serves only in the reduction of the distance between the rear grip part to the stop.
Advantageously, the rear grip part is connected by a threaded bolt with the stop, whereby the rear grip part is friction—lockingly or force—lockingly engaged with the stop rotatably connected with the bolt, whereby the bolt has a torque transmission means at its end facing away from the rear grip part, with such means radially overlapping the stop at least in part. The fastening means comprises, for example, a threaded bolt with a hexagonal head.
Preferably, the elastically loaded element is a spring-biased element and comprises a spring-biased guide tip, optionally a spring clip. The elastically loaded element is, for example, arranged on the stop, when the slotted member is provided on the rear grip part. Accordingly, the elastically loaded element is preferably arranged on the rear grip part, if the slotted member is provided on the stop. The elastically loaded element is fixedly arranged on the corresponding part, so that a movement, for example of the spring-biased guide tip, is possible for engaging the slotted member but the elastically loaded element cannot come loose from the part of the fastening system on which it is arranged. A preferably inwardly pre-stressed spring clip can work unlaterally to the engagement in the slotted member or, preferably, two diametrically opposed slotted members can engage as a one-piece element. In particular in the case of the design of the rear grip part or of the stop having one shaft and two slotted members arranged diametrically opposing each other and on the shaft, a preferably substantially U-shaped spring clip is provided as the elastically loaded element.
Preferably, a spring loaded element is provided between the fastening system and the stop. The spring-loaded element is, for example, a flat spring having an opening for passing through of the fastening means, whose free end rests on the stop. A metal bolt is preferably used as the fastening means, whose head projects radially beyond the diameter of its threaded zone. Accordingly, upon pressing down the fastening system the flat spring is loaded; by releasing the pressure on the fastening means the spring is released and lifts the fastening means as well as the rear grip part arranged inside the hollow body until the rear grip part engages the mounting projections. This embodiment is particularly advantageous for the arrangement of the fastening system on a C-shaped mounting rail. The fastening system situated in the secured position can disengage the rear grip part from the mounting projections by again pressing on the fastening means and repositioned along the mounting opening in the elongated direction of the mounting rail.
Other advantageous embodiments and combinations of features of the invention will become apparent from the following detailed description and the set of patent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a–d represents a first exemplary embodiment of the fastening system according to the invention in four individual steps of the setting operation shown in cross-section;
FIG. 2 a represents a cross-section through the slotted member design of the first exemplary embodiment along the line IIa—IIa of FIG. 1 a;
FIG. 2 b represents a cross-section through the slotted member design of the first exemplary embodiment along the line IIb—IIb of FIG. 1 d;
FIG. 3 a , 3 b each represents a cross-section through a variant of the slotted member represented in FIGS. 2 a and b;
FIG. 4 represents a side view on another slotted member design;
FIG. 5 a , 5 b each represents a top view, in part in cross-section, along the line V—V of FIG. 4 ;
FIG. 6 represents a side view on another slotted member design, and
FIG. 7 represents a top view in partial cross-section along the line VII—VII of FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
In principle, in the figures identical parts are identified using identical reference numerals.
FIGS. 1 a–d represents a first exemplary embodiment of the fastening system according to the invention in four individual steps of the setting operation. The fastening system 1 is represented in FIG. 1 a after introduction into an elongated hollow body 2 shaped as a mounting rail. The stop 3 bears on the edges adjacent to the mounting opening, on the hollow body 2 shaped as a mounting rail. In this position the distance between the rear grip part 5 and the stop 3 is inadequate so that the rear grip part 5 cannot be rotated under the mounting projections 6 . 1 and 6 . 2 in this position.
A spring clip is provided as the spring-loaded element 7 between the stop 3 and the rear grip part 5 , the element engaging in two diametrically opposed slotted members 22 . 1 , 22 . 2 arranged on the shaft 8 . The interplay between the spring clip and the slotted member(s) 22 . 1 , 22 . 2 is described in detail below.
The rear grip part 5 is securely connected with the fastening means 9 configured as a threaded bolt, which is led through the stop 3 . Between the bolt head acting as a torque transmission means 10 and the stop 3 , a spring-loaded element 11 configured as a flat spring is provided on the upper surface of the hollow body.
By exerting a pressure on the bolt head in the direction of the arrow 16 note FIG. 1 b the rear grip part 5 of the fastening system 1 moves into the inside of the hollow body 2 . The distance between the rear grip part 5 and the stop 3 is thus enlarged in such a fashion that the rear grip part 5 can grip behind the mounting projections 6 . 1 and 6 . 1 after it is rotated.
By virtue of the spring clip engaging the slotted members 22 . 1 , 22 . 2 the rear grip part 5 rotates according to the design of the slotted members 22 . 1 , 22 . 2 in the direction of the arrow. The rear grip part 5 arranged for gripping behind the mounting projections 6 . 1 and 6 . 2 is represented in FIG. 1 c . The mounting projections 6 . 1 and 6 . 2 are with their free ends and the rear grip part 5 in the engagement zone with the mounting projections 6 . 1 and 6 . 2 for allowing an improved engagement with each other using an edge milling. At this point it is stated that the rear grip part 5 , upon operating the bolt according to the design of the slotted members 22 . 1 , 22 . 2 it moves continuously translatorily and rotationally; i.e. it is loosened. For a better understanding of the invention, the translatory movement of the rear grip part 5 is represented in FIG. 1 b and the rotary movement is represented in FIG. 1 c.
By releasing the pressure on the bolt it is, for example, lifted by the flat spring and the knurled zone of the rear grip part 5 engage in the milled parts on the mounting projections 6 . 1 , 6 . 2 . In order to reposition the fastening system 1 in the hollow body 2 configured as a mounting rail, pressure is reapplied to the bolt serving as the fastening means 9 , whereby the engagement between the rear grip part 5 and the mounting projections 6 . 1 and 6 . 2 is released. This translatory movement preferably is not adequate to rotate the rear grip part 5 so that it no longer can be brought into engagement with the mounting projection 6 . 1 and 6 . 2 . The fastening system 1 , when the bolt is depressed along the mounting opening 4 is moved in the longitudinal direction of the mounting rail until the desired position of the fastening means 1 is reached in the mounting rail. By releasing the bolt, the rear grip part 5 again engages the mounting projections 6 . 1 and 6 . 2 . By tightening the bolt, the rear grip part 5 clamps with the mounting projections 6 . 1 and 6 . 2 for fixing the fastening system 1 .
FIG. 2 a represents a section through the slotted member design 22 . 1 , 22 . 2 of the first exemplary embodiment along the line IIa—IIa of FIG. 1 a . The spring clip serving as the spring-loaded element 7 is manufactured of spring steel so that the inwardly biased spring clip (acting in the direction of the arrow 26 . 1 and 26 . 2 ) are in continuous engagement with its members 21 . 1 and 21 . 2 with the slotted members 22 . 1 or 22 . 2 . The slotted member 22 . 1 is decribed in detail in the following. The statements made in this regard apply accordingly to the slotted members 22 . 2 arranged diametrically opposing the slotted member 22 . 1 .
The slotted member 22 . 1 runs axially along the shaft 8 increasingly and has an inclination 23 . 1 as well as a planar part 24 . 1 . The inclination 23 . 1 serves in the conversion of the translatory movement of the fastening means 9 to a rotary movement of the rear grip part 5 . Using the inclination 23 . 1 it is assured that at the start of the rotation of the rear grip part 5 is rotated more powerfully than towards the end of the rotary movement. The transition between the inclination 23 . 1 and the planar surface part 24 . 1 represent the bending point 25 . 1 of the slotted member 22 . 1 . The bending point 25 . 1 is utilized by the user when setting the fastening system 1 . Accordingly, the user is provided with the security that the rear grip part is oriented in order to grip behind the mounting projections of the mounting rails and can take the pressure from the bolt.
FIG. 2 b represents a section through the slotted member design 22 . 1 , 22 . 2 of the first exemplary embodiment along the line IIb—IIb in FIG. 1 d . The planar surface part 24 . 1 or 24 . 2 is released vis-à-vis the inclination 23 . 1 or 23 . 2 in the angular range approximately 5° to 50°. The members 21 . 1 and 21 . 2 of the spring clip lie on the planar surface parts 24 . 1 and 24 . 2 so that the rear grip part 5 remains essentially in the intended orientation when tightening.
One section through a variant relative to the slotted design shown in FIGS. 2 a and b is represented in FIGS. 3 a and 3 b . The slotted members 31 . 1 and 31 . 2 each have a cam 32 . 1 or 32 . 2 at which the members 33 . 1 and 33 . 2 of the spring clip 34 abut in the transport position of the fastening system. For introducing the rotary movement of the rear grip part, the initial resistance built up by the cams 32 . 1 and 32 . 2 must be overcome by pressure on the fastening means. This increased required pressure relative the required pressure of FIGS. 2 a and 2 b for introduction of the rotary movement of the rear grip part rotates the rear grip part after overcoming the resistance resulting from the design of the slotted members 31 . 1 and 31 . 2 . Apart from the arrangement of the cam serving as the inclination 32 . 1 and 32 . 2 the slotted members 31 . 1 and 31 . 2 are configured essentially identically to the slotted members 22 . 1 and 22 . 2 shown in FIGS. 2 a and 2 b and have the same mode of operation.
FIG. 4 represents a side view on another slotted member design. The rear grip part 41 is provided with a shaft 42 on which two diametrically opposed slotted members 43 . 1 (and 43 . 2 not shown here) are arranged. The slotted member 43 . 1 has a first slotted member segment 44 . 1 and a second slotted member segment 45 . 1 , wherein the second slotted member segment 45 . 1 has an inclination running opposite to the inclination of the first slotted member segment 44 . 1 and connects to the first slotted member segment 44 . 1 .
A view along the line of section V—V of FIG. 4 is represented in FIGS. 5 a and 5 b.
In the transport position of the rear grip part 41 represented in FIGS. 5 a and 5 b , the spring clip 46 engages at the starting point of the respective first slotted member segment, e.g. 44 . 1 . By virtue of the translatory movement of the fastening means, the free ends 47 . 1 and 47 . 2 of the spring clip glide along the bottom of the slotted member segment 44 . 1 or 44 . 2 , whereby the rear grip part 41 is urged into the inside of the hollow body 2 and at the same time rotated under the mounting projections of the hollow body 2 . Once the inflection point of the slotted member 43 . 1 and 43 . 2 , for example the inflection point 48 . 1 of the slotted member 43 . 1 , is reached, the free ends 47 . 1 and 47 . 2 glide into the second slotted member segments 45 . 1 and 45 . 2 , as represented in FIG. 5 b . When this is done, the rear grip part 41 raises under the mounting projections in the direction of the stop, until the rear grip part engages with the mounting projections of the hollow body.
FIG. 6 represents a side view on another slotted member design. The rear grip part 61 has, in contrast with the rear grip part described previously in FIG. 4 , only one slotted member 63 on the shaft 62 , which is configured like the slotted members 43 . 1 and 43 . 2 .
FIG. 7 represents a view along the section line VII—VII of FIG. 6 . In lieu of a grip by means of a spring clip, the slotted member 63 is gripped by a spring-loaded guide tip 64 .
In summary, it is stated that an easy to use, easy to install fastening system having a rotatable rear grip part is provided, which makes possible a preliminary fixation, which assures correct positioning of the rear grip part relative to the mounting projections.
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A fastening system ( 1 ) comprises a rear grip part ( 5 ) for introduction into a mounting opening ( 4 ) of an elongated mounting rail ( 2 ) in a first position and for gripping behind the mounting projections ( 6.1, 6.2 ) in a second position and a stop ( 3 ) for frontal external loading of the mounting rail ( 2 ). The stop ( 3 ) is connected to the rear grip part ( 5 ) by means of a threaded bolt ( 9 ). In addition, on the fastening system ( 1 ) a system is provided for providing a relative rotary movement between the stop ( 3 ) and the rear grip part ( 5 ) about the axis of the bolt ( 9 ). The system is configured as a transmission system for transforming a translatory movement of the bolt ( 9 ) relative to the stop ( 3 ) into a rotary movement of the rear grip part ( 5 ) relative to the stop ( 3 ).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a plasma display panel in which a discharge of gas between glass substrates are utilized for displaying an image, and more particularly, to a discharge electrode in a plasma display panel.
2. Background of the Related Art
Having all the advantages of the clear picture and the variety of screen sizes of the cathode ray tubes, and of the light and thin liquid display panel, the plasma display panel is considered as the next generation display. In general, the plasma display panel is light as it weighs approx. ⅓ of the cathode ray tube of the same screen size, and thin as it has a thickness below 10 cm even for a large sized panel of 40 to 60″. Moreover, though the cathode ray tube or the liquid crystal display has a limitation on a size in displaying a digital data picture and a full motion picture on the same time, the plasma display panel has no such a problem. And, while the cathode ray tube is influenced from a magnetic force, the plasma display panel is not influenced from the magnetic force, permitting to provide a stable picture to the watchers. And, since the pixels are controlled in a digital fashion, with no distortion of images at corners of the screen, the plasma display panel can provide a picture quality better than the cathode ray tube. The plasma display panels, using a gaseous discharge inside of the panel in displaying an image, are used as TV receivers, monitors, indoor and outdoor signboards and the like having large sized displays, particularly, directing to displays of the HDTV(High Definition Television) age, since the plasma display panel has a simple fabrication process as provision of active element to every cell is not required, is easy to provide a large sized screen, and has a fast response speed. The plasma display panel is provided with two glass substrates sealed together having electrodes coated thereon perpendicular, and opposite to each other, and gas filled in a space between the two glass substrates. There are pixels at portions the electrodes are crossed. In operation, a voltage higher than 100 volts are provided between the perpendicular electrodes, to cause a glow discharge of the gas, for displaying an image by using a light provided in the discharge. There are a two electrode type, a triode type, and a four electrode type in the plasma display panels with respect to a number of electrodes each cell has, wherein the two electrode type has two electrodes to which addressing and sustain voltages are provided on the same time, and the triode type, called as a surface discharge type, is adapted to be switched or sustained by a voltage provided to a electrode at a side of a discharge cell.
A related art triode surface discharge type plasma display panel will be explained with reference to the attached drawings. FIG. 1 illustrates a perspective view of a disassembled upper and lower substrates of the related art plasma display panel, FIG. 2 illustrates a section of a related art plasma display panel, FIG. 3 illustrates a plan view of scan electrodes and sustain electrodes of a related art plasma display panel, FIG. 4 illustrates a section across line I-I′ in FIG. 3, FIG. 5 illustrates wiring of scan electrodes and sustain electrodes of a related art plasma display panel, FIGS. 6 A˜ 6 D illustrate a discharge principle of a related art plasma display panel, and FIG. 7 illustrates an electric field formed between a pair of discharge electrodes and spreading of a discharge.
Referring to FIG. 1 and 2, the related art triode surface discharge type plasma display panel has an upper substrate 10 and a lower substrate 20 bonded and sealed together to face each other. On the upper substrate 10 , there are scan electrodes 16 and 16 ′ and sustain electrodes 17 and 17 ′ parallel to each other, a dielectric layer 11 coated on the scan electrodes 16 and 16 ′ and the sustain electrodes 17 and 17 ′, and a protection film 12 . On the lower substrate 20 , there are address electrodes 22 , a dielectric film 21 on an entire surface of the substrate including the address electrodes 22 , partition walls 23 on the dielectric film 21 between the address electrodes 22 , and a fluorescent material 24 on surfaces of the partition wall 23 and the dielectric film 21 in each discharge cell. The upper substrate 10 and the lower substrate 20 are bonded together by frit glass, and a space between the upper and lower substrates 10 and 20 is filled with a mixture of inert gas, such as helium He and xenon Xe, to a pressure in a range of 400˜500 Torr, to form a discharge space. In general, the inert gas filled in the discharge space of a D.C. plasma display panel is a mixture of helium and xenon (He—Xe), and the inert gas filled in the discharge space of an A.C. plasma display panel is a mixture of neon and xenon (Ne—Xe).
Referring to FIGS. 3 and 4, of the scan electrodes 16 and 16 ′ and the sustain electrodes 17 and 17 ′, the electrodes 16 and 17 are formed of transparent material, and the electrodes 16 ′ and 17 ′ are formed of a metal for enhancing light transmission of each discharge cell. The metal scan electrode and sustain electrode 16 ′ and 17 ′ are provided with a discharge voltage from a driving IC fitted outside of the panel, and the transparent scan electrode and sustain electrode 16 and 17 are provided with the discharge voltage to the metal electrodes 16 ′ and 17 ′, to cause a discharge between adjacent transparent electrodes 16 and 17 . The transparent electrode 16 or 17 is formed of indium oxide or tin oxide of a total width of approx. 300 μm, and the metal electrode 16 ′ or 17 ′ is a thin film consisting of three layers of chrome-copper-chrome. A width of the bus electrode 16 ′ or 17 ′ line has approx. ⅓ of a width of the transparent electrode 16 or 17 line.
FIG. 5 illustrates wiring of the scan electrodes Sm−1, Sm, Sm+1, - - - , Sn−1, Sn, Sn+1 and the sustain electrodes Cm−1, Cm, Cm+1, - - - , Cn−1, Cn, Cn+1 arranged on the upper substrate, wherein, while the scan electrodes are insulated from each other, all the sustain electrodes are connected in parallel. In FIG. 5, the section enclosed by the dashed line represents an effective surface an image is displayed thereon, and the other section represents a non-effective surface no image is displayed thereon. The scan electrodes on the non-effective surface are in general called dummy electrodes 26 , a number of which are not particularly limited.
The operation of the aforementioned triode surface discharge type AC type plasma display panel will be explained with reference to FIGS. 6 A˜ 6 D.
Referring to FIG. 6A, when a driving voltage is applied between the address electrode and the scan electrode, an opposed discharge is occurred between the address electrode and the scan electrode. The opposed discharge excites the inert gas in the discharge cell, so that a portion of the inert gas is divided to electrons, ions and excited species. As shown in FIG. 6B, a portion of the ions collides onto a surface of the protection film, which causes emission of secondary electrons from the surface of the protection film. The secondary electrons collide with the gas in a plasma state, to spread the discharge. As shown in FIG. 6C, when the opposed discharge between the address electrode and the scan electrode ends, wall charges with opposite polarities are generated on surfaces of the protection film over the sustain electrode and the scan electrode, respectively. And, as shown in FIG. 6D, when the driving voltage provided to the address electrode is cut off during the wall charges with opposite polarities build up at the scan electrode and the sustain electrode continuously, there is a surface discharge occurred in a discharge region on a surface of the dielectric layer and the protection layer due to a potential difference between the scan electrode and the sustain electrode. These opposed discharge and the surface discharge cause electrons in the discharge cell to collide onto the inert gas in the discharge cell, to generate an UV ray of 147 nm wavelength in the discharge cell as the inert gas is excited. The UV ray collide onto the fluorescent material coated on the address electrode and the partition wall, to excite the fluorescent material, which generates a visible light, that permits to form a picture on the screen.
However, the related art plasma display panel has the following problems.
As described, it can be known that a sustain discharge between one pair of the sustain electrodes in each cell sustains light emission of an initially lighted cell. Therefore, it is required to increase a width of the transparent electrode 16 or 17 to increase an amount of discharge between the electrodes for enhancing luminance in lighting the cell, which, however, increases a discharge capacitance in proportion to an increase of a transparent electrode area, that drops a luminous efficiency and increases a power consumption. And, even if the transparent electrode has a comparatively high transmittivity, since the transparent electrode has certain extent of transmission reduction factor, to drop the transmittivity relative to the increase of the width of the transparent electrode, the luminance drops, on the contrary.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a plasma display panel that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a plasma display panel which can minimize an increase of power consumption and drop of transmittivity while a width of a transparent electrode is increased for increasing an amount of discharge.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the plasma display panel includes a plurality of pairs of sustain electrodes on one of two bonded substrates, each having a transparent electrode and a metal electrode for sustaining an initial discharge between the electrodes for a preset time period, wherein the transparent electrode has a plurality of pass through holes.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention:
In the drawings:
FIG. 1 illustrates a perspective view of a disassembled upper and lower substrates of the related art plasma display panel;
FIG. 2 illustrates a section of a related art plasma display panel;
FIG. 3 illustrates a plan view of scan electrodes and sustain electrodes of a related art plasma display panel;
FIG. 4 illustrates a section across line I-I′ in FIG. 3;
FIG. 5 illustrates wiring of scan electrodes and sustain electrodes of a related art plasma display panel;
FIGS. 6 A˜ 6 D illustrate a discharge principle of a related art plasma display panel;
FIG. 7 illustrates an electric field formed between a pair of discharge electrodes and spreading of a discharge;
FIG. 8 illustrates a plan view of electrodes of a plasma display panel in accordance with a first preferred embodiment of the present invention;
FIG. 9 illustrates a section across line I-I′;
FIG. 10 illustrates a plan view of electrodes of a plasma display panel in accordance with a second preferred embodiment of the present invention;
FIG. 11 illustrates a plan view of electrodes of a plasma display panel in accordance with a third preferred embodiment of the present invention;
FIG. 12 illustrates a plan view of electrodes of a plasma display panel in accordance with a fourth preferred embodiment of the present invention;
FIG. 13 illustrates a plan view of electrodes of a plasma display panel in accordance with a fifth preferred embodiment of the present invention; and,
FIG. 14 illustrates a plan view of electrodes of a plasma display panel in accordance with a sixth preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
FIRST EMBODIMENT
FIG. 8 illustrates a plan view of electrodes of a plasma display panel in accordance with a first preferred embodiment of the present invention, and FIG. 9 illustrates a section across line I-I′.
On an upper glass substrate of the plasma display panel in accordance with a first preferred embodiment of the present invention, there are scan electrodes 16 and 16 ′ and sustain electrodes 17 and 17 ′ formed thereon. Of the scan electrodes 16 and 16 ′ and the sustain electrodes 17 and 17 ′, the electrodes 16 and 17 are transparent each with a width wider than the same of the related art, and the electrodes 16 ′ and 17 ′ are of a metal each with perforation of circular pass through holes 18 formed in row and column directions. Particularly, when the transparent electrode 16 or 17 has the width greater than 300 μm, the pass through hole 18 has a diameter of approx. 30˜50 μm. In the foregoing structure of the scan electrodes 16 and 16 ′ and the sustain electrodes 17 and 17 ′, even if the widths of the transparent electrodes 16 and 17 are increased for increasing an amounts of discharge between electrodes, there is no increase of a discharge capacitance in comparison to the related art because an entire area of the transparent electrodes 16 and 17 are offset by the pass through holes 18 . That is, because the pass through holes 18 reduce the area of the transparent electrodes 16 and 17 , while sizes of the pass through holes 18 are formed small not to affect discharge spreading, the discharge amount of the scan electrodes 16 and 16 ′ and the sustain electrodes 17 and 17 ′ can be increased as much as the increased transparent electrodes 16 and 17 , at the end. However, the pass through hole 18 with a too small radius can not influence to a reduction of an area of the transparent electrodes 16 and 17 , and, opposite to this, the pass through hole 18 with a too large radius impedes the spreading of the discharge path, with drop of a discharge efficiency. And, because the visible light from the fluorescent material caused by the discharge between the scan electrodes 16 and 16 ′ and the sustain electrodes 17 and 17 ′ forms an image as the light passes through the pass through holes, there is no reduction of a transmittivity of the transparent electrodes 16 and 17 caused by the increased width of the electrodes. Thus, the plasma display panel in accordance with a first preferred embodiment of the present invention can improve a luminance of a plasma display panel and prevent an increase of power consumption provide for discharge between electrodes.
SECOND EMBODIMENT
FIG. 10 illustrates a plan view of electrodes of a plasma display panel in accordance with a second preferred embodiment of the present invention. Though the plasma display panel in accordance with a second preferred embodiment of the present invention includes scan electrodes 16 and 16 ′ and sustain electrodes 17 and 17 ′ identical to the first embodiment, pass through holes 18 are formed in a diagonal direction. That is, the circular pass through holes 18 are arrange in the diagonal direction, which has the same effect with the first embodiment.
THIRD EMBODIMENT
FIG. 11 illustrates a plan view of electrodes of a plasma display panel in accordance with a third preferred embodiment of the present invention. Though the plasma display panel in accordance with a third preferred embodiment of the present invention includes scan electrodes 16 and 16 ′ and sustain electrodes 17 and 17 ′ identical to the first embodiment, pass through holes 18 are, not circular, but oval. That is, the oval pass through holes 18 are arrange in vertical and horizontal directions, which has the same effect with the first embodiment.
FOURTH EMBODIMENT
FIG. 12 illustrates a plan view of electrodes of a plasma display panel in accordance with a fourth preferred embodiment of the present invention. Though the plasma display panel in accordance with a fourth preferred embodiment of the present invention includes scan electrodes 16 and 16 ′ and sustain electrodes 17 and 17 ′ identical to the first embodiment, pass through holes 18 are, not circular, but square arranged in a vertical and a horizontal directions. That is, the square pass through holes 18 are arrange in vertical and horizontal directions. Of course, the square pass through holes 18 may be arrange in a diagonal direction. The fourth embodiment has the same effect with the first embodiment.
FIFTH EMBODIMENT
FIG. 13 illustrates a plan view of electrodes of a plasma display panel in accordance with a fifth preferred embodiment of the present invention. Though the plasma display panel in accordance with a fifth preferred embodiment of the present invention includes scan electrodes 16 and 16 ′ and sustain electrodes 17 and 17 ′ identical to the first embodiment, pass through holes 18 are, not circular, but rectangular in a horizontal direction, which has the same effect with the first embodiment.
SIXTH EMBODIMENT
FIG. 14 illustrates a plan view of electrodes of a plasma display panel in accordance with a sixth preferred embodiment of the present invention. Though the plasma display panel in accordance with a sixth preferred embodiment of the present invention includes scan electrodes 16 and 16 ′ and sustain electrodes 17 and 17 ′ identical to the first embodiment, pass through holes 18 are, not circular, but rectangular in a vertical direction, which has the same effect with the first embodiment.
As has been explained, the plasma display panel of the present invention has the following advantage.
First, the perforation of the transparent electrodes among the scan electrodes and the sustain electrodes can improve a discharge efficiency between electrodes because an increase of a discharge current and a reduction of transmittivity is prevented even if a width of the transparent electrode is increased for improving an overall luminance of the plasma display panel.
It will be apparent to those skilled in the art that various modifications and variations can be made in the plasma display panel of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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Plasma display panel including a plurality of pairs of sustain electrodes on one of two bonded substrates, each having a transparent electrode and a metal electrode for sustaining an initial discharge between the electrodes for a preset time period, wherein the transparent electrode has a plurality of pass through holes, thereby improving a discharge efficiency between electrodes because an increase of a discharge current and a reduction of transmittivity is prevented even if a width of the transparent electrode is increased for improving an overall luminance of the plasma display panel.
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BACKGROUND OF THE INVENTION
This invention relates to a bubble bath assembly which generates a multiplicity of minute bubbles in the water in a bathtub, in particular, to the bubble bath assembly of a portable type.
In the related art, U.S. patent application Ser. No. 855,628 filed Apr. 2, 1986 discloses a health bath structure having a nozzle which is retained above the water in a bathtub. This health bath structure has a pump-encasing housing which is fixedly mounted on the wall of a bathroom, and therefore installment work is necessary upon the installation of this structure. Moreover, since this structure is fixed at a specific position, an auxiliary equipment is required in order to transfer the nozzle to a desired position.
U.S. Pat. No. 3,842,823 discloses a portable hydromassage unit designed to straddle the side wall of a bathtub. This unit has a clamping bracket which is movable along the bridge portion of the housing, which is adapted to rest on the top of the side wall of the bathtub. By adjusting the position of the clamping bracket, the clamping bracket is capable of clamping the side wall in cooperation with a power unit housing, which is adapted to be disposed outside the bathtub, and whereby the hydromassage unit is removably installed on the side wall of the bathtub. However, when the side wall of the bathtub has a thickness exceeding the range of adjusting movement of the bracket, it is not possible to mount the hydromassage unit on the bathtub. In particular to a bath of dugout type, hydromassage unit of the above-mentioned type can not be applied.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a portable bubble bath assembly which is not only applicable to any type of bathtub but also able to be easily installed on any type of bathtub.
Another object of the present invention is to provide a bubble bath assembly, the nozzle of which can easily be transferred to the desired position.
With these and other objects in view, the present invention provides a bubble bath assembly including: an underwater electric pump having an inlet and an outlet; a nozzle member connected to the outlet of the pump; and means for retaining the nozzle member over the water in a bathtub upon the installment of the assembly in the bathtub. The retaining means comprises: means for stably setting the pump on the bottom wall of the bathtub; and support means, interposed between the pump and the nozzle member, for supporting the nozzle member over the pump. The only step due upon the installment of this bubble bath assembly is the placing of the pump on the bottom wall of the bathtub with the nozzle member positioned above the pump. Therefore, this assembly is applicable to any type of bathtub without any difficulty such as troublesome installment work. Also, since this assembly is transferrable within the bathtub, the nozzle can easily be moved to a desired position at the convenience of users.
Upon the operation of the pump, water is drawn into the pump from the bathtub through the inlet of the pump, and is discharged in a jet from the nozzle member against the surface of the bath water. This jet of water introduces oxygen into the bath water, resulting in the formation of a layer of minute bubbles covering the surface of the bath water. When these innumerable bubbles break, they generate ultrasonic waves which help in the prevention of skin diseases and muscular pains which can afflict on the human body.
The setting means may be a bottom housing enclosing the pump. The bottom housing has a lower end and is adapted to be disposed in the bathtub with its lower end placed on the upper face of the bottom wall of the bathtub. The support means may be a connecting pipe having opposite ends. The connecting pipe is attached at one of its ends to the nozzle member and at the other end to the pump so that the nozzle member is in fluid communication with the outlet of the pump.
The setting means may include a suction cup member attached to the lower end of the bottom housing. The suction cup member secures the bottom housing to the bottom wall of the bathtub when the suction cup member is applied to the upper surface of the bottom wall of the bathtub.
The bottom housing may have a suction opening in fluid communication with the inlet of the pump. The bottom housing may also have a lower end surface which faces to the bottom wall of the bathtub when the bottom housing is placed in the bathtub. It is preferred that the suction opening is formed in the lower end surface of the bottom housing so that the assembly is urged by suction toward the bottom wall of the bathtub when the bath water is drawn into the pump through the suction opening.
It is preferred that the babble bath assembly has electric power supplying means for supplying dc current to the pump. This power supplying means is adapted to be disposed outside the bathtub.
A silencer tube may be coaxially attached at one of its ends to the nozzle member for reduction of noise due to the jet of water. This silencer tube must have an axial length such that at least the other end of the silencer tube is immersed in the bath water upon the placing of the assembly and upon the filling up of the bathtub with water.
Also, an auxiliary nozzle member, which is connected to the outlet of the pump, may be attached to the bottom housing so that water is jetted out of the auxiliary nozzle member in a generally horizontal direction.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a side-elevational view of a portable bubble bath assembly according to the present invention;
FIG. 2 is a front view of the bubble bath assembly in FIG. 1;
FIG. 3 is a bottom view of the bubble bath assembly in FIG. 1;
FIG. 4 is an axial-sectional view of the bubble bath assembly in FIG. 1;
FIG. 5 is an enlarged sectional view of an underwater electric pump in FIG. 4; and
FIG. 6 is an enlarged front view of a silencer tube applicable to the bubble bath assembly in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, wherein like reference characters designate corresponding parts throughout several views, and descriptions of the corresponding parts are omitted once given.
In FIGS. 1 to 4, reference numeral 10 designates a portable bubble bath assembly embodying the principle of the present invention. The casing of this assembly is constituted of a series of three housing, that is, a bottle-like bottom housing 12, an elongated neck housing 14 and a fist-like head housing 16. The bottom housing 12 has a lower end 12a having a flat end surface 13 and an upper end 12b joined to the neck housing 14. The upper end portion of the bottom housing 12 tapers toward its upper end 12b so that the upper end 12b has a smaller diameter than that of main portion of the bottom housing 12. As shown in FIGS. 3 and 4, a suction opening 18 is formed in the lower end surface 13 of the bottom housing 12, and a plurality of suction cups 20 are attached on that portion of the lower end surface 13 surrounding the suction opening 18. On the side surface of the bottom housing, as shown in FIG. 1, there is formed an aperture 22 in which an auxiliary nozzle hereinafter described is fitted. The neck housing 14 is joined at one of its opposite ends to the upper end 12b of the bottom housing 12 so that it extends along an axis extending between the opposite ends 12a and 12b of the bottom housing 12. The head housing 16 has first and second ends 16a and 16b and is joined at its first end 16a to the other end of the neck housing 14 so that an axis extending between the first and second ends 16a and 16b is generally perpendicular to the longitudinal axis of the neck housing 14. In the lower face of the head housing 16 near the second end 16b, there is formed an aperture (not shown) open toward the bottom housing 12. Into this aperture, a main nozzle hereinafter described is fitted. The head housing 16 also has a off/on switch 24 provided on the side face of the head housing 16. In addition, the sum of the lengths L 1 +L 2 of the bottom and neck housings 12 and 14 is designed to be substantially larger than the depths of conventional bathtubs.
As shown in FIG. 4, within the bottom housing 12 is rigidly mounted an underwater electric pump 26. As shown in FIG. 5, this pump 26 has an inlet 26a and an outlet 26b. The inlet 26a of the pump 26 is in communication with the suction opening 18 through the strainer 28 which consists of two sieves 28a and 28b and a filter medium 28c interposed between the sieves. A recumbent T-shaped branch pipe 30 is connected at its lower end 30a to the outlet 26b of the pump 26. Another end 30b of the branch pipe 30 is connected to the auxiliary nozzle 32 which fits in the aperture 22 of the bottom housing 12 so as to project out of the bottom housing 12 through the aperture 22, in a direction generally perpendicular to the neck housing 14. The other end 30c of the branch pipe 30 is connected to the lower end 34a of an inverted L-shaped connecting pipe 34. This connecting pipe 34, as shown in FIG. 4, extends from the branch pipe 30 toward the head housing 16 through the inside of the neck housing 14, bends and goes into the head housing 16. At the upper end 34b of the connecting pipe 34, there is attached the main nozzle 36 via an L-shaped coupling 38. This main nozzle 36 fits in the aperture of the head housing 16 and projects out of the head housing 16 through the aperture. That is to say, the main nozzle 36 is in communication with the outlet 26b of the pump 26 through the connecting pipe 34 and also is supported over the pump 26 by both the connecting pipe 34 and the housings 12, 14 and 16.
In FIG. 4, reference numeral 40 denotes an electric cord which connects the pump 26 to an electric power box 42 (see FIG. 2) to be separately installed from the other part of the assembly. This electric cord 40 extends from the pump 26 to the off/on switch 24 through the inside of the neck housing 14 and, as shown in FIG. 2, passes out of the head housing 16 through the side wall of the head housing 16. The electric power box 42 is, for example, a converter for converting a current of AC 100 V into a current of DC 12 V and for supplying the pump 26 with the current of DC 12 V. Otherwise, the power box 42 is a battery charger able to continuously supply a current of DC 12 V for more than 3 hours without the charging of electric power and able to be charged from a electric power source supplying a current of AC 100 V. In addition, reference numeral 60 in FIG. 5 denotes an impeller of the pomp 26 which is drivingly connected to an electric motor 62 disposed in a hermetically sealed chamber 64 in the bottom housing 12.
The operation of the bubble bath assembly thus constructed will now be described. Upon using the bubble bath assembly, the entire body of the assembly except for the power box 42 is brought into a bathroom in which a bathtub is installed, while the electric power box 42 is left outside the bathroom. Then, as shown in FIG. 1, the assembly body is installed in the bathtub 44 filled with water 46. This installment is achieved merely by placing the bottom housing 12 on the bottom wall 44a of the bathtub 44 with the neck housing 14 extending upright. Upon the placement of the bottom housing 12, the suction cups 20 are applied to the upper surface of the bottom wall 44a, whereby the housing 12 is stably secured to the bottom wall 44a of the bathtub 44. In this state, the bottom housing 12 is disposed in the bath water 46 with its lower end surface 13 facing the bottom wall 44a of the bathtub 44, and the head housing 16 is supported over the bath water 46 by the neck housing 14.
When the switch 24 is turned on, the pump 26 is actuated. Then, the water 46 in the bathtub 44 is drawn into the pump 26 through the suction opening 18. When the water passes through the suction opening 18, the assembly body is urged by suction toward the bottom wall 44a of the bathtub 44 so that the body is held in its position more stably. Also by suction, the suction cups 20 are pressed against the bottom wall 44a of the bathtub 44, whereby the bottom housing 12 is secured to the bottom wall 44a more stably. The water drawn into the pump 26 is, then, pressurized by the pump 26 and is sent to the main and auxiliary nozzles 32 and 36. The water sent to the auxiliary nozzle 32 is, then, discharged horizontally in a jet from the auxiliary nozzle 32 into the bath water 46. This jet of water generates a swirl in the bathtub 44 and massages a human body in the bath water when it impinges against the human body. On the other hand, the water sent to the main nozzle 36 is discharged in a jet from the nozzles 36 against the surface of the bath water 46. When the jet of water impinges on the surface of the bath water 46, it introduces oxygen in the atmosphere into the bath water 46. This results in the formation of a layer of minute bubbles covering the whole surface of the bath water 46 as well as the generation of a multiplicity of minute bubbles suspended throughout the water 46. When these innumerable bubbles in the water 46 contact the human body immersed in the bath water 46, they break instantly, and generate ultrasonic waves of about 60,000 to 80,000 Hz throughout the bathtub 44. These ultrasonic waves enhance the heat transfer rate between the bath water 46 and the human body, massage the human body and promote the removal of dirt and oils from the skin of the human body, which help in the prevention of skin diseases and muscular pains which can afflict the human body.
In addition, when it is not necessary to keep the aforementioned assembly in the bathtub, the assembly can easily be removed from the bathtub 44 merely by causing the assembly body to be inclined so that the suction cups 20 release the bottom wall 44a of the bathtub 44. Also, when the impact of the jetted water is required on a specific part of the human body, by transferring the assembly body within the bathtub 44, the nozzles 32 and 36 can easily be moved to the exact position where the nozzles can affect the specific part.
FIG. 6 illustrates a silencer tube 48 applicable to the bubble bath assembly. This silencer tube 48 has a bellowslike portion 50 between its upper and lower end portions 52 and 54. The bellowslike portion 50 of this silencer tube 48 is made of a pliant material such as a flexible plastic, and thus, as shown by the phantom line, the tube 48 is expandable, contractible and flexible. The upper end portion 52 of the tube 48 has a thread (not shown) formed on its outer face, and the main nozzle 36 has a thread formed on its inner face, whereby, as shown by the phantom line in FIG. 1, the tube 48 is capable of being coaxially and detachably attached at its upper end to the main nozzle 36. A pair of air intake holes 56 are formed in the upper end portion 52 of the tube 48 so that the external air is taken into the tube 48 through the holes 56. This silencer tube 48 has a length such that, upon its attachment to the main nozzle 36, at the very least, even when the tube 48 is contracted to a minimum length, the lower end of the tube 48 is immersed in the bath water 46. Accordingly, by attaching the tube 48 to the main nozzle 36, the tube 48 serves as a silencer for the reduction of noise that is due to the collision between the bath water 46 and the jet of water discharged from the nozzle 36. Also, by attaching the tube 48, it is possible to change the direction of the flow of the bubble-containing water in the bathtub 44.
In addition, the above-described bubble bath assembly works more effectively, if it is used together with the additive consisting of components including 60% of polyethylene glycol, 28% of sodium hydrogencarbonate, 11.5% of sodium sulfate anhydride, 0.5% of coloring matter and a very small amount of perfume. When a suitable amount of this additive is put into the bubble bath utilizing the bubble bath assembly, the properties of the additive and the bubbles including oxygen influence upon each other so that there is accelerated the formation of the layer of the bubbles over the bath water.
It is understood that although a preferred embodiment of the present invention has been shown and described, various modifications thereof will be apparent to those skilled in the art, and, accordingly, the scope of the present invention should be defined only by the appended claims and equivalents thereof.
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A portable bubble bath assembly disclosed is designed to be installed in the bathtub and includes an underwater electric pump, a nozzle and a retaining member for retaining the nozzle over the bath water upon the installment of the assembly. The pump has an inlet and an outlet. The nozzle is connected to the outlet of the pump. The retaining member includes: a setting member for stably setting the pump on the bottom wall of the bathtub; and a support member, interposed between the pump and the nozzle, for supporting the nozzle over the pump. The only step due upon the installment of this bubble bath assembly is the placing of the pump on the bottom wall of the bathtub with the nozzle positioned above the pump.
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FIELD OF THE INVENTION
The present invention relates to a micromechanical component, and also relates to a corresponding manufacturing method.
BACKGROUND INFORMATION
The structure of piezoelectric or piezoresistive pressure sensors today is based exclusively on the use of monocrystalline silicon membranes into which piezoelectric resistors are introduced using doping technology. In particular, the piezoelectric or piezoresistive circuit traces may be formed in the silicon layer of an SOI substrate.
Overall, these manufacturing methods may be expensive and complicated.
SUMMARY OF THE INVENTION
Although applicable to any number of micromechanical components and structures, particularly sensors and actuators, the present invention (as well as its basic underlying problem) definition are explained with reference to a piezoelectric or piezoresistive pressure sensor.
The micromechanical component of the present invention, and the manufacturing method of the present invention have the advantage of allowing simple manufacturability.
One advantage of the present invention is that a piezoelectric or piezoresistive sensor, in particular a pressure sensor, is provided with a dielectric membrane and monocrystalline piezoelectric resistors, using surface micromechanic technology.
In the method according to the present invention or the micromechanical component according to the present invention, piezoelectric or piezoresistive circuit traces are defined by being patterned out of a layer of the circuit-trace material, which is separated from a substrate by an intermediate layer.
A membrane layer is then deposited above the piezoelectric or piezoresistive circuit traces and etching access to the substrate is created. By selective removal of a substrate area underneath the membrane, a cavity is produced which will be sealed again in a later step, a predefined reference pressure being able to be enclosed.
A micromechanical component according to the present invention has a membrane that has at least two layers between which one or several piezoelectric or piezoresistive circuit trace strip(s) are embedded. The piezoelectric or piezoresistive circuit trace strips may be made of monocrystalline silicon. A reference pressure may be enclosed in the cavity, the substrate having the form of a tub.
According to an exemplary embodiment, the piezoelectric or piezoresistive circuit trace strip(s) is/are at least partially arranged above the hollow cavity.
According to another exemplary embodiment, the piezoelectric or piezoresistive circuit trace strip(s) is/are arranged above or near an edge region of the hollow cavity. According to another exemplary embodiment, the two layers are made of an insulating material and the piezoelectric or piezoresistive circuit trace strip(s) is/are made of a monocrystalline material.
According to another exemplary embodiment, the piezoelectric or piezoresistive circuit trace strip(s) is/are connected by means of a contacting device, which extends through the upper layer of the membrane.
According to another exemplary embodiment, the membrane has a lowest first layer, a second-lowest second layer, a third-lowest third layer and an uppermost fourth layer, the piezoelectric or piezoresistive circuit trace strip(s) being embedded between the first and the second layer, the third layer being made of a permeable material, and the fourth layer being produced in such a way that it hermetically seals the third layer.
According to another exemplary embodiment, the first and second layers have at least one through-hole above the hollow cavity, the at least one through-hole being sealed by the third and fourth layers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a shows a schematic cross-sectional view of the essential manufacturing steps of a micromechanical component according to an exemplary embodiment and/or exemplary method of the present invention.
FIG. 1 b shows another schematic cross-sectional view of the essential manufacturing steps of a micromechanical component according to an exemplary embodiment and/or exemplary method of the present invention.
FIG. 1 c shows another schematic cross-sectional view of the essential manufacturing steps of a micromechanical component according to an exemplary embodiment and/or exemplary method of the present invention.
FIG. 1 d shows another schematic cross-sectional view of the essential manufacturing steps of a micromechanical component according to an exemplary embodiment and/or exemplary method of the present invention.
FIG. 1 e shows another schematic cross-sectional view of the essential manufacturing steps of a micromechanical component according to an exemplary embodiment and/or exemplary method of the present invention.
FIG. 1 f shows another schematic cross-sectional view of the essential manufacturing steps of a micromechanical component according to an exemplary embodiment and/or exemplary method of the present invention.
FIG. 1 g shows another schematic cross-sectional view of the essential manufacturing steps of a micromechanical component according to an exemplary embodiment and/or exemplary method of the present invention.
DETAILED DESCRIPTION
In the figures, identical reference numbers designate the same or functionally comparable or corresponding components. According to FIG. 1 a , the starting point of the process sequence according to the exemplary embodiment of the present invention is an SOI substrate stack, which includes a monocrystalline silicon substrate 1 , a superposed silicon oxide layer 3 and a monocrystalline silicon layer 5 being situated above. Such an SOI substrate stack may be produced by various manufacturing processes known from the related art and can be purchased from the manufacturer in large quantities at the required quality. According to this specific embodiment, the SOI substrate stack may also be already preprocessed with IC circuit elements prior to the start of the process sequence, so that the sensor is able to be integrated into a circuit environment. It is only useful that the region where a membrane and piezoelectric resistors will later be formed is not interrupted by circuit elements.
Additionally, with reference to FIG. 1 b , piezoelectric or piezoresistive circuit trace strips 5 a , 5 b are patterned in monocrystalline silicon layer 5 as subsequent strain gauges in a first process step. The resistance of circuit trace strips 5 a , 5 b is able to be adjusted via their lateral geometry, the layer thickness of layer 5 and via the doping of layer 5 . The etching procedure for patterning circuit trace strips 5 a , 5 b selectively stops on silicon oxide layer 3 , which expediently has a thickness of approximately 5 to 500 nm. A practical layer thickness for layer 5 is between 100 and 1000 nm.
Furthermore, with reference to FIG. 1 c , at least one dielectric layer 7 is deposited above piezoelectric or piezoresistive circuit trace strip 5 a , 5 b and the exposed regions of layer 3 . This layer 7 assumes the supporting function of a membrane M (cf. FIG. 1 g ) and should therefore be under tensile stress in order to prevent uncontrolled arching. It is especially preferred to provide a layer 7 of LPCVD silicon nitride, which has a thickness of between 100 and 300 nm.
In a subsequent process step, which is illustrated in FIG. 1 d , layers 3 and 7 are patterned with through-holes 10 a , 10 b by an etching process, through-holes 10 a , 10 b lying between piezoelectric or piezoresistive circuit-trace strips 5 a , 5 b . Both an anisotropic, one-stage etching process and a selective anisotropic, two-stage etching process may be used as etching process.
In a subsequent process step, which is illustrated in FIG. 1 e , a permeable, porous layer 15 is deposited across the entire surface above the resulting structure. Permeable layer 15 is penetratable by a predefined etching agent, such as an etching gas, and reduces the effective cross section of through-holes 10 a , 10 b . This not only considerably increases the etching rate in a subsequent C1F3 etching step, but also provides for easily resealing the nanopatterned pore structure of layer 15 at a later point utilizing a CVD process. Permeable layer 15 may also be a dielectric.
The following, for example, may be used for permeable layer 15 : 10 to 200 nm thin PECVD oxide on silane basis (SiH 4 ) with O 2 , N 2 O or other oxidation agents, 10 to 200 nm thin PECVD or LPCVD silicon nitride. The desired permeability of the nitride is able to be obtained by an appropriate aftertreatment, for instance in that the nitride is subsequently converted—completely or partially—to silicate such as SiF 6 (NH 4 ) 2 under hydrogen fluoride (HF), which is permeable as continuous layer. Furthermore, 10 to 200 nm thin polymer films from a plasma deposition such as aluminum fluoride may be used as material for layer 15 , or organic compounds, for instance from C 4 F 8 processes or similar thin, sputtered or vapor-deposited metals such as gold, aluminum, AlSiCu etc. When AlSiCu is used, the selective solving out of silicon and copper deposits may be used to produce micro-porosity.
Finally, photoresists with a silicon portion in the polymer chain, BCB (butyl cyclobutane) porous dielectric layers from vapor deposition or centrifugal processes may be used as material for permeable layer 15 .
Finally, permeable layer 15 may be formed as cover layer by deposition of two different polymers, which are dissolved in a common or in (a) different solvent(s), whereupon the one or plurality of solvents is evaporated and one of the two polymers is selectively removed from the other from the formed layer.
Furthermore, with reference to FIG. 1 f , substrate 1 is now selectively removed with respect to dielectric layers 3 , 7 and 15 by a ClF 3 etching step or some other gas etching step that spontaneously etches silicon. In the process, a cavity 20 is produced which is able to be controlled in its lateral and vertical extension in a satisfactory manner. The control of the etching front is simple, in particular when the edge region R of cavity 20 is suitably oriented with respect to particular crystal directions of silicon substrate 1 since this provides for forming smooth etching fronts. An orientation of the edge region of cavity 20 may be in parallel to the (100) surfaces. The geometry of the cavity is defined by the arrangement of through-holes 10 a , 10 b.
Piezoelectric or piezoresistive circuit trace strips 5 a , 5 b may be arranged in such a way that they lie above the edge region of cavity 20 since the greatest deformation occurs at the particular edge, that is, the subsequent sensor signal or the sensor sensitivity is at a maximum. After etching of cavity 20 , permeable layer 15 is sealed by at least one further dielectric layer 30 according to FIG. 1 g . Layer 30 in turn may be under tensile stress or receives the tensile stress of layer stack 3 , 7 , 15 , 30 , which together forms membrane M.
The deposition of dielectric layer 30 may be implemented in a PVD or CVD process during which a defined process pressure prevails, so that a reference pressure may be enclosed below the membrane. The material of dielectric layer 30 may be PECVD-TEOS or thermal TEOS, PECVD-silane oxide, PECVD nitride or a similar material, for instance. Finally, with reference to FIG. 1 g , piezoelectric or piezoresistive circuit trace strips 5 a , 5 b are contacted via a contacting device 40 , for example a Wolfram contact provided in a contact hole.
Piezoelectric circuit trace strips 5 a , 5 b are able to be connected to parts of the evaluation circuit or bond pads via this contacting device 40 .
Although the present invention was described above in light of the exemplary embodiments, it is not so restricted to it, but is able to be modified in various ways.
In particular, any micromechanical basic materials such as germanium, may be used and not only the silicon substrate which was cited as an example.
Likewise, a variety of sensor structures and not only the illustrated pressure sensor may be formed. Instead of ClF 3 , XeF 2 or BrF 3 may be used as etching agents.
The reference numeral list is as follows:
1 Silicon wafer substrate; 3 Silicon oxide layer; 5 Monocrystalline silicon layer; 5 a , 5 b Piezoelectric circuit trace strips; 7 Silicon nitride layer; 10 a , 10 b Through holes; 15 Permeable layer; 20 Cavity; R Edge area; M Membrane; 30 TEOS layer; and 40 Contacting device.
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A micromechanical component having a substrate, a cavity formed in the substrate, a membrane provided on the surface of the substrate, which seals the cavity, the membrane having at least two layers between which one or several piezoelectric or piezoresistive circuit trace strip(s) is/are embedded, and a corresponding manufacturing method therefor.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to communications networks and, in particular to a system for configuring subscriber equipment upon installation within a communication network.
2. Background Art
Transmission of data (voice, video and/or data) over fiber optic cabling is becoming common place. For instance, optical transmission is heavily used for long-distance (or inter-LATA) telephone transmission. Where fiber optic communication has been used in local exchanges (sometimes referred to as a Local Access & Transport Area or “LATA”) a passive optical network (“PON”) has been used. The name PON arises from the use of passive splitters (e.g. star couplers) to distribute signal between the central office (CO) and multiple, spatially distributed subscriber locations via fiber optic cables. PONs are one example of point to multipoint wire line networks.
Point to multipoint wire line networks have various benefits including, but not limited to, the lower equipment costs. These lower equipment costs over traditional point to point networks arise, in part, due to the absence of dedicated lines and ports for each subscriber. However, because there is no unique port (path) linking each subscriber to the network, there is no inherent means for uniquely identifying the downstream path to any particular subscriber. Such a path is required, for instance, to appropriately terminate an incoming voice call for any particular subscriber (e.g. the subscriber at (212) 555-1212). Thus, while the service provider knows the identity of any particular subscriber at installation, a passive optical network does not. Consequently, in order to deliver communications and uniquely desired service to each subscriber, there is a need to establish some correlation between the subscriber's identification and the optical network unit (“ONU”) serving that location.
SUMMARY OF THE DISCLOSURE
A number of technical advances are achieved in the art, by implementation of a method for correlating a subscriber unit to a physical port in a point to multipoint wire line network. The method comprises: (a) prompting an installer to manually input a location code associated with the subscriber; (b) receiving the location code in the subscriber unit; (c) transmitting the location code via the network to a central repository; and (d) storing the location code in the central repository toward associating the location code with the physical port. In some approaches, storing may further including checking the location code for errors before storing and upon finding an error, transmitting an instruction to the subscriber unit to indicate error to the installer and upon finding no errors, storing the location code. When the installer receives an error indication there may also be a further prompt to reinput the location code.
The method may also include transmitting the site code and storing it in the central repository.
Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principals of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views.
FIG. 1 of the drawings is a block diagram of one universal demarcation point connected to a passive optical network that has a universal demarcation point associated with each of its plurality of subscribers.
FIG. 2 of the drawings is flow diagram of the method for correlating a optical network unit with the central office.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
When a universal demarcation point (“UDP”) 50 is installed in a passive optical network (“PON”) 40 by installer 20 , optical network unit (“ONU”) 51 of UDP 50 must be configured to receive and transmit signals correctly over the PON. Configuration of the ONU 51 with the PON facilitates proper communication to occur between installed UDP 50 and its associated optical line termination (“OLT”) 52 (shown in FIG. 1 as being located at central office 41 ). Thus, for instance, configuration may register the serial number of the UDP 50 , ONU 51 and even correlate that UDP and ONU with the equipment along the branch by which UDP 50 is operably connected to the PON. However, configuration does not correlate the identity of subscriber 30 (i.e. John Smith) with ONU 51 or even OLT 52 . This correlation is important because generally a PON will include a plurality of subscribers, OLTs and ONUs. Each of these subscribers are operably connected to the central office via a series of fiber optic cables, passive optical splitters, and a specific optical line terminator (“OLT”) located at the central office in a “tree structure.”
FIG. 1 generally illustrates, among other things, one PON tree topology and particularly one particular branch in the PON tree structure. As shown in FIG. 1 , UDP 50 is equipped to receive information including voice, video and data content. It would be understood by those of skill in the art having the present specification before them that alternative topologies will also work with the disclosed invention. As illustrated, subscriber 30 is operably connected to central office 41 via OLT 52 , fiber optic cable 53 , optical splitter 60 a , fiber optic cable 54 a and UDP 50 . Thus, as depicted in FIG. 1 , OLT 52 is a conduit to fiber optic cables 54 a through 54 n (in preferred approach n=32) via optical splitter 60 a . Of course, other OLTs in PON 40 will support other branches of the PON via other optical splitters 60 b through 60 n . As further depicted in FIG. 1 , it is contemplated that additional optical splitters (see reference number 61 a ) will exist in the system even at secondary (and deeper) levels toward supporting even further subscribers on each OLT branch via fiber optic cables 56 a through 56 n.
Once installer 20 has operably installed UDP 50 on the PON, the configuration may be initiated manually or automatically. Although not relevant to the present invention, it should be understood that communications could be implemented over the PON using a frequency-division, wavelength-division or time-division multiplexing scheme. Thus, for instance, where a time-division multiplexing scheme is used, upon installation (or hard start up) among other possible configuration requirements, ONU 51 must be ranged such that upstream transmissions are inserted by the UDP at the appropriate time onto the PON. For purposes of the present invention, once configuration has completed, the UDP and its ONU can properly communicate with the central office.
Once configuration has been completed, general practice indicates that the installer should verify the receipt of dial tone at the subscriber location. This verification is has generally been performed in all types of telephone networks by operably connecting a butt set (or any other touch tone phone) to the UDP using one of electrical connectors 70 . Of course, various types of testing device may be utilized with the present invention as will be apparent in view of the present disclosure. In a preferred approach, installer 20 would connect butt set 21 to the last POTS binding post among the electrical connectors 70 to run this test. While using the last binding post adds some complexity to UDP controller and installer training, it greatly decreases the odds that subscriber 30 will ever pick up a phone set on a line that is in registration mode after a power outage.
In addition to testing for dial tone, the installer 20 may be required to establish the site key for the UDP 50 . The site key identifies the customer or UDP 50 , which in turn identifies the ONU location and the service parameters associated with the customer or UDP 50 . The ONU location is generally the same as the customer location. Where necessary, in a preferred approach, the installer would take the butt set 21 off-hook and enter a “#.” In response, the UDP 50 prompts the installer 20 to enter the site key of the location. This prompt may take any form that would be perceivable to the installer 20 including, but not limited to, audible and textual prompts. In the preferred approach using a butt set, audible prompting is most likely. This audio feedback would preferably be generated by ONU 51 —in response to download announcements—using the existing voice processing hardware in the ONU.
The installer 20 enters (via the testing device) the site key. The location site key is a numeric code assigned by the utility company for each UDP in the PON. In a preferred approach, this entry will be accomplished using the touch tone keys on the butt set 21 followed by the pound sign. However, another testing device with other forms of manual entry may also be used. In response, to the completed entry of the site key, UDP 50 transmits the site key along with the UDP's serial number (stored in non-volatile memory in the UDP (not shown) to the Element Management System (EMS) via the host digital terminal (“HDT”).
Now that configuration of the UDP has been completed, correlation can be performed. If the testing device (e.g. butt sett 21 ) in not already connected to one of the electrical connectors 70 of UDP 50 , the installer would operably connect such a device. Alternatively, it is contemplated that the device may be directly connected to the ONU within UDP 50 a (the utility company side of the UDP 50 ) for correlation. Upon connection, correlation would be initiated. In the approach where electrical connectors 70 are utilized by the installer a manual signal, such as a key activation or series of key activations may be required. In the approach where the installer operably connects the testing device directly to the ONU, the connection, itself, may automatically initiate correlation. Other connections may also be programmed to automatically initiate correlation.
In response to correlation initiation, manual feedback unit 100 will provide a user perceivable instruction to enter a location key for the UDP 50 (a unique integer assigned to the location). This user perceivable instruction may take various forms, such text or audio. Where an audio instruction is used the audio may be stored in various formats, such as CD-audio, “.WAV”, MP3, PARCOR speech synthesis, etc. In such an approach, UDP 50 will include a media player or speech synthesizer, depending upon the format in which the audio is stored. It is alternatively possible to include an analog tape player to playback an analog tape recording of various phrases.
The installer, in turn, inputs the digits of the location key. This input may be pre-programmed in the installer's testing device or may be entered manually via a keypad on the testing device. In the preferred embodiment, the location key is an integer, which reflects a customer number already used by the service provider operations support system (“OSS”)(e.g. the methods that directly support the daily operation of a LEC) identifying the subscriber 30 . More generally, the location code/key is any identifier that can be input via the mechanism provided to the installer that identifies geographic location of the customer. It would be a desirable attribute of the location IDs to be “sparse” so that if the location ID is mis-entered the probability is high that the mis-entered id can be distinguished as a non-valid id rather than the wrong subscriber ID. Where the testing device is a butt set or other telephone-paradigm based device, UDP 50 would be provided with equipment to convert the DTMF tones received into the corresponding digits.
The location key input by the installer 20 is then transmitted to the central office 41 . In a preferred embodiment, the location key is placed into an IP package along with the unique identifier for the optical network unit 51 (“ONU”). This IP package is routed over the PON to the OLT 52 . In turn, the OLT 52 passes the location key and ONU identifier information to the Element Management System (EMS) 80 . It is contemplated that EMS 80 can be provisioned with the remaining pieces of the puzzle so that EMS 80 may correlate the location key with the specific ONU.
The transmitted correlation information will be validated and generally checked for errors. For instance, validation may consider one or more of the following: (1) sufficiency of the information received about the site key; (2) existence of other UDPs on the PON associated with the entered site key; and (3) correct type of the UDP installed at the site. Other potential errors could also be checked as would be understood. This validation may be conducted at any one of various levels, such as the Central Office 41 or the EMS 80 .
Once validated, one or more of the OLT 52 , central office 41 , EMS 80 and/or other EMS modules store the received correlation data. Of course, it would be understood to those of ordinary skill in the art that the correlation could be stored elsewhere in the central office, such as a central router, which would further correlate the location/UDP codes with a OLT identifier to ensure that the traffic to the subscriber is appropriately routed.
Once the correlation is validated and stored, a message may be transmitted to the UDP 50 with instructions to indicate to the installer either: (1) successful registration or (2) erroneous correlation. In a preferred approach, an “erroneous correlation: indication could be accompanied by commands that cause the UDP to provide directions to the installer 20 on how to handle errors in the ONU Location Correlation process.
The installer would then re-initialize correlation after correcting any errors in installation. In the cases where the installer 20 is unable to successfully correlate the UDP, the installer would have to call into a center to resolve the problem.
At the completion of an installer registering UDP 50 , the EMS will have made the correlation between the appearance of UDP 50 on the PON 40 and the site at which the UDP 50 is located (i.e. fiber 54 a via splitter 60 a , fiber 53 and OLT 52 ). Thus, the network now has all the information it needs to activate any services that have been pre-provisioned for the site.
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A system for correlating a subscriber unit to a physical port in a point to multipoint wire line network is disclosed. An installer is prompted to manually input a location code associated with the subscriber. The location code in the subscriber unit is received, and is transmitted via the network to a central repository. The location code is stored in the central repository toward associating the location code with the physical port.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 14/457,519 filed Aug. 12, 2014, which is a divisional of U.S. patent application Ser. No. 13/277,333, filed Oct. 20, 2011, now U.S. Pat. No. 8,991,936, which is a continuation of U.S. patent application Ser. No. 12/335,114, filed Dec. 15, 2008, now U.S. Pat. No. 8,042,875; the entire disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to dump bodies on trucks. More particularly the present invention relates to dump bodies which are pivotally mounted such that the front may be elevated and the contents removed by gravity through a chute located in a rear tailgate. Specifically, the present invention relates to an improvement in coal chutes which enhances the longevity and operability by means of an easily replaceable coal chute door within an elastomeric track.
[0004] 2. Background Information
[0005] Many trucks have a bed or body that is lifted upwardly relative to the vehicle to unload materials by gravity from within the bed. Dump bodies for industrial use, such as dump trucks and coal trucks, typically employ a tailgate which is pivotally mounted to the top of the side walls of the dump body and extends across the width of the bed, such that it may swing between an open and closed position as the front of the dump body varies in elevation.
[0006] These rear tailgates oftentimes include a center door assembly called a “coal chute”. The coal chute is substantially narrower than the rear tailgate and includes a door that can be selectively opened or closed. Common coal chute designs involve sliding the door up and down within tracks mounted in the sidewalls of the chute. Using a pivot arm, the user draws the door upwards along the chute door track before the bed of the dump truck is lifted. As the bed is lifted, the material within the bed exits through the coal chute in a contained and controlled stream that can be fed directly onto a ditch, intake basin, or onto a conveyor belt.
[0007] Due to the enormous tonnage carried by such trucks and the abuse to the walls of such truck bodies, the retaining chute door and the door track is subjected to distorting forces and are oftentimes broken or dented by movement of the material within the dump body or through the chute itself. When the cute door or track becomes distorted, the chute's effectiveness is diminished as the door cannot form a proper seal or slide within the track. Therefore gravel, coal, sand or other particulate matter can escape through the resulting gap. Consequently, it is not uncommon for the chute door to become unusable and require replacement or repair.
[0008] Replacing or repairing parts of the chute is very time consuming and expensive. Typical chutes have welded tracks, pivot arms, plates, and various other components. The chute assembly itself is welded onto the tailgate and difficult to remove. Furthermore, when the chute door or track is repaired or replaced, these items must be re-welded to the tailgate body, adding more time and expense to the process of replacing or repairing a part of the chute.
[0009] Therefore, the need exists for a center door assembly for a dump bed which includes easily replaceable and repairable parts, which parts are not welded to the tailgate so disassembly and reassembly time and expense will be minimized.
BRIEF SUMMARY OF THE INVENTION
[0010] One object of the invention is to provide an easily replaceable door on a center door assembly for a dump bed.
[0011] A further object of the invention is to provide a chute assembly which employs elastomeric material for the tracks which slidably receive the edges of the chute door therein to provide a removable insert to receive the edges of the chute door and facilitate removal of the chute door from within the tracks for repair or replacement.
[0012] It is the object of the invention to provide a tailgate having a center door assembly which remains in alignment without degradation of the seal therebetween.
[0013] Another object of the invention is to provide a tailgate and center door assembly which is positively secured to prevent inadvertent gate openings. These features are obtained by the center door assembly for a dump bed of the present invention, the general nature of which includes a center door assembly for a dump bed comprising: a frame adapted to be mounted in a wall of a dump bed; a pair of opposite and spaced apart channels defined by said frame; at least one insert removably mounted in one of said channels; a retractable door having a pair of edges slidably received in the at least one insert; and movable linearly between a closed position and an open position; an axle rotatably mounted with respect to the frame; a pivot linkage having a spaced apart first and second end, wherein the first end is secured to the axle and the second end is secured to the door; and a handle for rotating the axle whereupon rotation of the axle slidably moves the door between the closed position and the open position through the pivot linkage; and wherein said insert when removed from the channel enables the door to be removed from the frame.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0014] A preferred embodiment of the invention, illustrated of the best mode in which Applicant contemplates 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 appended claims.
[0015] FIG. 1 is a side elevational view of a dump truck and dump body shown in the raised position;
[0016] FIG. 2 is a perspective view of the center door assembly of the present invention mounted on a tailgate of a dump body and shown in the closed position;
[0017] FIG. 3 is an enlarged perspective view of the center door assembly with parts cut away;
[0018] FIG. 4 is front elevational view of the center door assembly in the closed position;
[0019] FIG. 5 is a rear elevational view of the center door assembly in the closed position;
[0020] FIG. 6 is an enlarged sectional view taken on line 6 - 6 of FIG. 4 ;
[0021] FIG. 7 is an exploded perspective view of the center door assembly as shown in FIG. 2 ;
[0022] FIG. 8 is a perspective view with the linkage assembly removed from the frame and chute door;
[0023] FIG. 9 is a perspective view of the door linkage assembly;
[0024] FIG. 10 is an exploded perspective view of the center door assembly with the linkage assembly removed;
[0025] FIG. 11 is a perspective view of the center door assembly with the outer cover plate and the door linkage assembly removed;
[0026] FIG. 12 is a front elevational view of the center door assembly as shown in FIG. 11 with portions broken away to show the elastomeric tracks;
[0027] FIG. 13 is an enlarged sectional view taken on line 13 - 13 of FIG. 12 ;
[0028] FIG. 14 is an enlarged sectional view of the encircled portion of FIG. 13 ;
[0029] FIG. 15 is a front elevational view similar to FIG. 12 of the center door assembly with parts cut away and with the door in the raised open position;
[0030] FIG. 16 is an enlarged sectional view taken on line 16 - 16 of FIG. 15 ;
[0031] FIG. 17 is a view similar to FIG. 16 with the insert being deformed;
[0032] FIG. 18 is a view similar to FIG. 17 with the insert being partially removed from the channel;
[0033] FIG. 19 is a front elevational view similar to FIGS. 12 and 15 with parts cut away and the door in the open position and the lower inserts shown in phantom being removed;
[0034] FIG. 20 is a view similar to FIG. 19 with the door in the closed position and the upper inserts shown in phantom being removed;
[0035] FIG. 21 is a view similar to FIG. 20 after removal of the door and with the door being moved laterally within the supporting tracks;
[0036] FIG. 22 is an enlarged sectional view taken along line 21 - 21 .
[0037] Similar numbers refer to similar parts throughout the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0038] The center door assembly of the present invention is generally indicated at 1 , and is shown in FIGS. 1-22 . Center door assembly 1 is typically disposed in a rear tailgate wall 7 of a dump bed 5 of a vehicle 3 as shown in FIGS. 1 and 2 .
[0039] Referring to FIGS. 3 , 4 , 5 , and 6 , door assembly 1 includes a rectangular frame 9 having top and bottom ends 19 and 21 respectively, first and second sides 18 and 20 respectively, an inner cover plate 11 secured to frame 9 by a weld 14 ( FIG. 6 ), and an outer cover plate 13 externally secured to frame 9 with a plurality of bolts 15 or other type of fasteners. Outer cover plate 13 extends in a spaced parallel relationship with respect to inner cover plate 11 . Outer cover plate 13 extends from top end 19 of frame 9 to the general longitudinal midpoint of frame 9 , indicated by dot dash line 12 in FIG. 4 . As shown in FIG. 5 , inner cover plate 11 is generally longer and extends past line 12 . Frame 9 includes a U-shaped channel 17 extending around the periphery of frame 9 , and is shaped to receive tailgate wall 7 for securing center door assembly 1 to dump bed 5 .
[0040] Frame 9 further includes a pair of U-shaped channels 23 ( FIGS. 14 , 16 , 17 , and 18 ) extending longitudinally along each side 18 and 20 of frame 9 , each terminating in a notch 27 proximate bottom end 21 of frame 9 . Each channel 23 slidably receives a pair of elastomeric inserts 24 conforming to the shape of channels 23 ( FIGS. 6 , 13 - 16 ). Inserts 24 are sized to slidably receive side edges 22 of a chute closure door 25 therein. Door 25 has a generally flat planer plate shape and is sized to extend between each side 18 and 20 within inserts 24 and extending approximately one-half the longitudinal length of frame 9 . Door 25 is slidably movable between cover plates 11 and 13 between an open position as shown in FIG. 15 and a closed position as shown in FIG. 12 . A pair of lobes 33 are attached to and extend from adjacent a bottom edge of door 25 as shown in FIGS. 10 and 11 . Each lobe 33 is formed with a hole 35 , the purpose of which is described below.
[0041] Referring to FIGS. 13 , 14 , and 16 , elastomeric inserts 24 have a general U-shaped cross-sectional configuration having a pair of spaced legs 34 extending from an end wall 36 . Each insert 24 includes a door receiving recess 26 , a bend recess 28 formed in end wall 36 , and a D-shaped protruding nub 30 sized to fit into a corresponding D-shaped recess 32 formed in one of the legs of U-shaped channel 17 of frame 9 .
[0042] Referring to FIGS. 3 , 4 , and 6 , and shown particularly in FIGS. 7 and 9 , a pivot linkage assembly indicated generally at 37 is removably secured to frame 9 . Pivot linkage 37 includes an axle 39 secured at each end by a pillow block bearing 41 . Each block bearing 41 extends outwardly from frame 9 and is comprised of a first and second blocks 43 and 45 each having a half-moon recess 42 . First block 43 is welded to frame 9 proximate top end 19 and includes a pair of threaded receiving holes 47 . Second block 45 is removably secured to first block 43 by means of a pair of threaded bolts 49 extending through holes 51 formed in second block 45 and into threaded receiving holes 47 . Pivot linkage 37 is further comprised of a crank arm 53 having annular mounting bosses 55 secured to axle 39 by welding or other attachment means. Crank arm 53 extends from axles 39 and terminates in a crank handle 57 sized to be manipulated by a user's hand.
[0043] A pair of lift arms 59 extend from and are welded to axle 39 intermediate pillow block bearings 41 . Each lift arm 59 is pivotally connected to a U-shaped bracket 61 by a bolt 63 , each bracket 61 forming a bottom threaded hole 62 for receiving a first end 65 of a threaded stud bolt 67 therein. Bolt 67 extends to second threaded end 69 which is received in a threaded receiving hole 70 of a second U-shaped bracket 71 . Each bracket 71 is pivotally attached to lobe 33 by a removable bolt 73 secured by a cotter pin 75 . A securing handle 64 extends from one bolt 63 .
[0044] In operation, as shown in FIG. 1 , center door assembly 1 is located in tailgate wall 7 of dump bed 5 on truck 3 with chute closure door 25 in the closed position ( FIG. 21 ). A material 2 (not shown) such as stones, sand, mulch, or any other matter which is typically transported by truck within a dump bed, is loaded into dump bed 5 . Truck 3 moves material 2 to the desired material deposit location and positions tailgate wall 7 to release material 2 in the desired location. The user slidably moves chute closure door 25 from a closed position to an open position ( FIG. 15 ) and locks door 25 in the open position by turning handle 64 ( FIG. 4 ). Dump bed 5 then is extended from a generally horizontal position to an angled position with the ground which allows the gravitational force to pull material 2 towards tailgate wall 7 within dump bed 5 . Material 2 is dumped out of dump bed 5 through the opening defined by frame 9 and the open position of coal chute door 25 in tailgate wall 7 . After the desired amount of material 2 is dumped, dump bed 5 is returned to the horizontal position. Handle 64 is loosened to unlock coal chute door 25 . The user then moves coal chute door 25 from an open position to a closed position by pivotal movement of crank arm 53 in preparation for loading dump bed 5 with material 2 .
[0045] Pivot linkage assembly 37 allows the user to slidably move coal chute door 25 between open and closed positions. As shown in FIGS. 3 and 4 , axle 39 extends between pillow block bearings 41 which allow axle 39 to rotate within half moon recess 42 of each bearing 41 . Crank arm 53 is secured to one end of axle 39 and rotates axle 39 when crank handle 57 is moved by a user. The rotation of axle 39 rotates lift arms 59 which are secured to axle 39 at one end. At the opposite end, lift arms 59 are engaged with first U-shaped bracket 61 which rotates about bolt 63 . First U-shaped bracket 61 extends to receive threaded stud bolt 67 which extends to be received by second U-shaped bracket 71 . Second U-shaped bracket 71 is pivotally engaged with lobe 33 about a removable bolt 73 .
[0046] To move chute closure door 25 from a closed to an open position, the user rotates crank arm 53 causing axle 39 to rotate. Axle 39 raises lift arms 59 which pivot about bolt 63 , pulling first U-shaped bracket 61 , stud bolt 67 and second U-shaped bracket 71 in an upward direction. The movement of these elements within pivot linkage assembly 37 results in an upward force on lobes 33 which transfers the force to chute closure door 25 , drawing door 25 upwards.
[0047] Each sidewall 22 of chute closure door 25 is slidably received by door receiving recesses 26 formed in inserts 24 . Inserts 24 fit in U-shaped channel 23 formed in frame 9 . One desired property of the material comprising inserts 24 is to reduce the difficulty of sliding chute closure door 25 by providing a low friction coefficient between door 25 and inserts 24 . To this end, inserts 24 are typically made from Teflon® or other similar low friction material. As upward force is applied to door 25 and sidewalls 22 thereof, door 25 slides within receiving recesses 26 formed in inserts 24 . The sliding movement is guided by the general shape of U-shaped channels 23 and recesses 26 , and is generally co-planer with tailgate wall 7 . When door 25 is in the open position, the hole through tailgate wall 7 is exposed and material may exit dump bed 5 . When door 25 is in the closed position, the hold through tailgate wall 7 is sealed and material will not exit dump bed 5 .
[0048] As material 2 is loaded and unloaded, stress is applied to the elements comprising door assembly 1 . Chute door 25 including sidewalls 22 thereof may become damaged or dented, hindering the sliding movement of door 25 within door receiving recess 26 . A distortion of the general planar shape of door 25 typically renders door 25 unable to open or close as recesses 26 closely conform to the shape of sidewalls 22 to slidable hold door 25 within frame 9 . If door 25 becomes damaged, it must be replaced. However, door 25 is typically very difficult to replace. Parts within a typical center door assembly are welded and fixedly attached to one another, making removal of the center door very difficult. Center door assembly 1 provides for a method to easily replace elements within assembly 1 . The elements comprising center door assembly 1 are held in position by easily removable parts allowing a user to disassemble and reassemble center door assembly 1 .
[0049] The method for removing pivot linkage assembly 37 from center door assembly 1 is shown in FIGS. 7 and 8 . First, threaded bolts 49 are removed from threaded receiving hole 47 and hole 51 within pillow block bearings 41 . This allows first block 43 to be separated and removed from second block 45 , releasing axle 39 . Second, cotter pins 75 are removed from bolts 73 . Bolts 73 are then free to be removed from second U-shaped brackets 71 and lobes 33 , releasing second U-shaped brackets 71 from center door assembly 1 . As shown in FIG. 8 , pivot linkage assembly 37 may then be removed from center door assembly 1 . As shown in FIG. 9 , pivot linkage assembly 37 is a sub-assembly which is easily removed as a unit from center door assembly 1 . This exposes the area behind assembly 37 and further facilitates removal of the elements comprising center door assembly 1 .
[0050] As shown in FIG. 10 , center door assembly 1 is further disassembled by removing bolts 15 which releases outer cover plate 13 . Bolts 15 are common hex-head type screws which fit typical wrenches. With outer cover plate 13 removed, door 25 is exposed ( FIGS. 11 and 12 ). As shown in FIG. 15 , door 25 is manually lifted in the direction of arrow “A” to move center door assembly 1 into the open position. This exposes inserts 24 A at lower notch 27 in U-shaped channels near bottom end 21 of frame 9 . The exposing of inserts 24 A allow a user to manually grasp insert 24 at notch 27 . As shown in FIGS. 17 and 18 , the user manually distorts legs 34 of insert 24 in the direction of arrow “B”. This bending is facilitated by bend recess 28 formed in end wall 36 of insert 24 , which reduces the bend strength of insert 24 by providing a ready crease in the material. As legs 34 of insert 24 are bent inwardly, D-shaped nub 30 is released from D-shaped recess, allowing insert 24 to slide out of U-shaped channel 23 in the direction of arrow “C” at bottom end 21 of frame 9 . As shown in FIG. 19 , inserts 24 A are manually pulled out of U-shaped channels 23 proximate bottom end 21 of frame 9 in the direction of arrow “C”. Inserts 24 A are fully extracted and may be replaced if worn or damaged.
[0051] As shown in FIG. 20 , door 25 is then manually lowered to the closed position by moving door 25 in the direction of arrow “D”. The process of removing inserts 24 A is then repeated for inserts 24 B. Door 25 is now less restrained within U-shaped channels 23 because the space occupied by inserts 24 is empty. As shown in FIG. 21 , to remove door 25 , it is manually moved in the direction of arrow “E”. This exposes sidewall 22 B as it retracts from U-shaped channel 23 . As shown in FIG. 22 , sidewall 22 B is free to move in the direction of arrow “F”, releasing the entire door 25 from center door assembly 1 .
[0052] Door 25 and inserts 24 may then be replaced or fixed to restore center door assembly 1 to workable condition. To install the elements of center door assembly 1 , the removal process is simply reversed. Elements are added and secured by the same process, allowing the user to quickly and easily fix the elements within assembly 1 . The truck owner may replace elements such as door 25 with common tools and without breaking welds or welding parts back into place. This dramatically eases the replacement of parts within assembly 1 .
[0053] In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed.
[0054] Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described.
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A center door assembly for a dump bed and a method for removing the door from the dump bed. A frame is mounted in a wall of the dump bed and has a pair of opposite and spaced apart channels. A pair of elastomeric inserts are removably mounted in the channels. A retractable door has a pair of edges slidably received in the inserts and is movable linearly within the channels between a closed position and an open position. A pivot linkage assembly is operatively connected to the door for linearly moving the door between the closed and open positions. The elastomeric inserts are removed from the channels through a bottom opening in the channels providing lateral space between the channels to enable the door to be removed from the frame. The elastomeric inserts are provided with bend areas enabling them to be compressed for removal from the channels.
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TECHNICAL FIELD
[0001] The present invention is generally directed to a receiver and, more specifically, to a technique for reducing multipath distortion in a mobile FM receiver having a single analog front-end.
BACKGROUND OF THE INVENTION
[0002] As is well known, multipath interference is caused when two or more signal rays of an original transmitted signal converge upon a receiving antenna of a receiver at significantly different times. This misalignment or superposition of several delayed signals, which are replicas of the original signal, may cause distortion in audio recovered from the signals. Distortion caused by the multipath interference may be attributable to long delay (e.g., greater than five microseconds between signals) multipath interference or short delay (e.g., less than five microseconds between signals) multipath interference.
[0003] In a typical urban environment, RF signals experience changes in amplitude and phase due to short delay multipath. This amplitude and phase shift may result in broadband signal fades of up to 40 dB, as the receiver and its associated motor vehicle change locations. At typical highway speeds, signal fluctuation rates in the range of 100 to 1 kHz may occur. In general, long delay multipath (or frequency selective multipath) is found in areas where reflectors are greater than four to five miles away. Typically, long delay multipath occurs in cities with large buildings and in mountainous regions.
[0004] Typically, long and short delay multipath coexists and creates frequency selectivity and broadband fading, simultaneously. For example, an FM demodulated signal may contain a 1 kHz tone with a 75 kHz deviation. In such a situation, a reflected signal may have an amplitude of, for example, 0.9 units while a direct signal has, for example, an amplitude of 1 units. In the case where the time delay of the reflected signal is about 30 microseconds, the distortion attributable to the time delay may be on the order of approximately twelve percent.
[0005] In various receiver systems, antenna diversity has been implemented in conjunction with an FM receiver to reduce degraded reception performance caused by multipath interference. Antenna diversity has been accomplished through the use of two or more uncorrelated antennas. Prior art antenna diversity reception for mobile communication systems has been achieved by a number of different implementations. For example, antenna diversity has been accomplished with equal gain combiner (EGC) systems, maximal ratio combiner (MRC) systems and antenna diversity systems, such as the adaptive reception system (ARS) disclosed in U.S. Pat. No. 5,517,686, the disclosure of which is hereby incorporated herein by reference in its entirety.
[0006] EGC and MRC systems utilize signals from all antennas through a variety of combining techniques that attempt to optimize certain characteristics of the received signal. In a switched antenna diversity system, only one antenna is utilized for reception at any instant in time and, thus, the non-selected antennas do not contribute to the demodulated signal. EGC and MRC systems generally outperform switched antenna diversity systems. However, EGC and MRC systems tend to be more expensive to implement, as they require multiple receiver analog front-ends.
[0007] What is needed is an economical technique for further reducing multipath distortion in a mobile FM receiver having a single analog front-end.
SUMMARY OF THE INVENTION
[0008] One embodiment of the present invention is directed to a technique for reducing multipath distortion in an FM receiver, with a plurality of switchable antennas. The technique includes providing a fast distortion detector that monitors a received signal for distortion events less than about fifteen microseconds in duration, which indicates a multipath disturbance. A slow distortion detector is also provided that measures distortions of the received signal related to the signal quality. In response to a multipath disturbance, an output of the fast distortion detector initiates a search for a lower distortion (better quality) antenna. The search involves selecting a trial antenna and comparing its measured signal quality (provided by an output of the slow distortion detector) to that previously measured for the antenna that initiated the search (i.e., a reference antenna). An antenna having better signal quality is accepted for continued use and the search is ended. An antenna having a worse signal quality is rejected and the search is continued by selecting another trial antenna.
[0009] To prevent frequent searches that can result in audible switching noise, a threshold is introduced that desensitizes the fast distortion detector for a period following an antenna search. The threshold is decayed at a rate dependent on the overall RF signal level to provide a longer desensitized period for weak signals, which are more susceptible to disturbances. The slow distortion detector uses an averaging time that is a function of the received overall RF signal level, since, in weak signal conditions, the distortion being measured is more corrupted by noise. The averaging time may typically range between twenty-five microseconds for large signal levels to five hundred microseconds when the overall RF signal level is below a predetermined RF level. Antennas are ranked for trial selection based on their recently measured RF level. This approach helps to minimize antenna switching since an antenna having a larger signal level, which is more likely to be lower in distortion, is selected as the next trial antenna.
[0010] The slow distortion detector may implement a filter that passes frequency components of the received RF signal that are higher than about 60 kHz. According to another aspect of this embodiment of the present invention, the filter passes frequency components of the received RF signal that are less than about 100 kHz. According to one aspect of the present invention, the slow distortion detector implements a rectifier and a low-pass filter. In at least one embodiment, the slow distortion detector functions as an ultra sonic noise (USN) detector.
[0011] These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0013] FIG. 1 is a block diagram of an exemplary radio with a single analog front-end and a digital signal processor (DSP);
[0014] FIG. 2A is a block diagram of a receiver system implementing a classic switched diversity system;
[0015] FIG. 2B is a graph depicting an RF signal level and an FM demodulator output signal (MPX) for the receiver system of FIG. 2A ;
[0016] FIG. 3A is an exemplary graph of an FM baseband spectrum for an FM receiver;
[0017] FIG. 3B is a block diagram of a relevant portion of an FM receiver system, including a slow distortion detector for detecting high-frequency components in the signals of the graph of FIG. 3A ;
[0018] FIG. 4 is a system block diagram for an FM receiver implementing switched diversity, according to one embodiment of the present invention;
[0019] FIGS. 5A-5B are graphs depicting regions of operation for the system of FIG. 4 ;
[0020] FIG. 6A is a high-level flow chart of an exemplary process for reducing multipath distortion in an FM receiver, with a plurality of switchable antennas, according to one embodiment of the present invention; and
[0021] FIG. 6B is a lower-level flow chart of an exemplary process for reducing multipath distortion in an FM receiver, with a plurality of switchable antennas, according to another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Today, manufacturers of automotive radios have moved from analog receiver systems to receiver systems that have increasingly incorporated more digital components within the receiver systems. As a general rule, the functions that are performed by these digital components are being increasingly implemented in digital signal processing (DSP) software.
[0023] With reference to FIG. 1 , an exemplary receiver system 100 is shown, which includes a plurality of antennas A 1 , A 2 through AN, which are coupled to a single analog front-end 106 (of an FM receiver 104 incorporated within a radio 102 ) by a different one of a plurality of switches SW 1 , SW 2 through SWN. The output of the front-end 106 is provided to an input of an analog-to-digital converter (ADC) 108 , which converts the received analog signal to a digital signal. An output of the ADC 108 is coupled to an input of a digital signal processor (DSP) 110 A, which digitally processes the digital signal to provide an audio signal.
[0024] According to one aspect of the present invention, as is discussed further below, software algorithms (see FIGS. 6A-6B ) executed by a DSP implement switched antenna diversity for the receiver system 100 . According to another aspect of the present invention, an FM demodulator (not shown separately in FIG. 1 ) outputs an MPX signal, which is directed to the DSP 110 A, which implements a switched antenna diversity routine 150 (see FIG. 4 ). In general, the routine 150 improves FM reception by reducing multipath distortion by choosing a least distorted antenna signal from one of a plurality of antennas. As noted above, switched antenna diversity is generally the simplest algorithm to implement among antenna diversity systems. In essence, the switched antenna diversity system selects the antenna with the best signal-to-noise ratio (SNR). However, because only one antenna can truly be selected at a time, the diversity algorithm must generally make the antenna selection based on incomplete knowledge.
[0025] FIG. 2A depicts an FM receiver system 180 that implements a classic switched diversity system using a fast distortion detector 160 that detects spikes, in an FM demodulator output (MPX) signal provided by an FM receiver 104 A, with a spike filter 162 . The detector 160 also detects negative dips, in a received RF level signal, with a dip filter 164 . The outputs of the spike filter 162 and dip filter 164 are provided to threshold comparators 166 A and 166 B, respectively. Outputs of the threshold comparators 166 A and 166 B are provided to inputs of a decision logic block 168 , which determines when an antenna switch 107 should be switched to another antenna, i.e., a next one of the antennas A 1 , A 2 , A 3 and A 4 . In general, the logic 168 causes a next antenna to be selected when a spike is detected in the MPX signal coincident with a negative dip in the RF level signal, i.e., when the occurrence of spikes and dips are correlated.
[0026] With reference to FIG. 2B , a graph 200 includes an exemplary RF level signal 202 and an exemplary FM demodulator output (MPX) signal 204 . As the RF signal level 202 becomes weaker (decreases in magnitude), the received SNR degrades and the spike and dip detection may be corrupted by noise. In this case, the system 180 may increase antenna switching erroneously, which tends to cause audible switching noise in an audio signal. As such, the system 180 may fail to settle on an appropriate antenna, i.e., ‘thrash’ between antennas or select an antenna that does not provide the best received signal.
[0027] With reference to FIG. 3B , a receiver system 190 includes an FM receiver 104 A, whose output is coupled to an input of a slow distortion detector 170 . It should be appreciated that the detector 170 may be implemented in hardware or software. The detector 170 includes a filter 172 , which may be, for example, a bandpass filter that passes frequencies between about 60 kHz and 100 kHz. In general, the detector 170 provides an indication of signal quality for weak RF signals, long delay multipath or adjacent channel interference. When the RF signal is weak (or in the presence of adjacent channel interference), high-frequency components 302 appear in the FM baseband spectrum, as is shown in graph 300 of FIG. 3A .
[0028] The slow distortion detector 170 averages energy of the components 302 , with a relatively long-time constant, to provide an indication of the received signal quality. The less high-frequency component energy present, the better the antenna signal quality. In general, the high-frequency components can be thought of as ultrasonic noise (USN). With reference again to FIG. 3B , an output of the filter 172 may be rectified and low-pass filtered by DSP routines. According to one aspect of the present invention, higher noise levels (associated with weak signal reception) require longer time averaging for reliable statistics. This, in turn, reduces both ‘thrashing’ among antennas and poor antenna selection under weak signal conditions.
[0029] With reference to FIG. 4 , a receiver system 400 , configured according to one embodiment of the present invention, exhibits robust operation over a full dynamic range of a received signal. In this embodiment, implemented, for example, in software, the digitized signal output of the ADC 108 represents the pre-detected FM signal. The FM demodulator 110 performs FM detection on this signal to recover the FM multiplex (MPX) signal. The ADC signal is also level detected (AM detected) by the RF level detector 112 to obtain the received signal strength, referred to as Level. Stereo decoding and de-emphasis of the MPX signal is performed by audio processor 114 to recover the left and right audio signals. Multipath disturbances are generally manifested as distortion of the MPX signal, and dynamic variations (AC component) of the Level signal that is otherwise essentially constant for FM. The distortion of the MPX signal results in a distortion of the recovered audio. Though the audio processor 114 may employ techniques to suppress or conceal audio distortion, the function of the antenna diversity system is to minimize distortion of the MPX signal, which correspondingly minimizes audio distortion.
[0030] A separate level average calculation block 403 , LevelA(n), is maintained for each antenna (n=1 to N) as a measure of its average received signal strength. The level average calculation block 403 averages the Level signal (using approximately a 6 mS time constant) to provide an update of LevelA(n) for the currently selected antenna. As a measure of the overall received signal strength, an overall average calculation block 402 is produced by averaging the LevelA(n) signals across all antennas to provide a LevelC signal. The LevelC signal is then used by a decay τ H calculation block 410 to determine a decay time τ H for an event trigger threshold and an average T A calculation block 408 to provide an averaging time T A for the quality measurement (see FIGS. 5A and 5B ).
[0031] An event trigger is provided by an event trigger function block 414 and is based on an implementation of a fast distortion detector that correlates between RF level dip and an MPX signal spike, as shown in FIG. 2B . An event threshold provided by a threshold function calculation block 412 is introduced to slow down antenna switching, to minimize audible disturbance (“thrashing”), when excessive events, which are more frequent with weak RF signals, occur. The event trigger initiates a search for a less distorted (better quality) antenna signal, which then becomes the new favored (reference) antenna. The threshold calculation is based on prior antenna event levels that triggered the search, which provides desensitization to reduce switching. This threshold decays at a rate provided by an average decay rate function block 410 that is determined from the combined average RF level, LevelC. A slower decay (longer desensitization) is used at weak signal levels where distortion events are expected to occur more frequently.
[0032] A quality measure function block 406 derives a received signal quality, based on the MPX and RF level signals. The quality measure may include signal strength (DC or low-frequency components), AM level (AC or high-frequency components) and ultrasonic noise (USN), i.e., energy beyond the known MPX bandwidth. A quick determination of signal quality is desirable with the switched antenna system to minimize the time possibly connected to a poor antenna. However, a sufficient averaging time is needed for a confident measurement. The quality measurement averaging time is based on the combined RF level, LevelC, provided by the overall average calculation function block 402 . It should be appreciated that lower RF levels require longer averaging time to obtain reliable quality statistics, due to more noise.
[0033] The decision logic function block 404 compares the quality statistics of the trial antenna (currently connected antenna) to that of the reference antenna (i.e., the reference antenna, before the search was trigged by the event trigger). The search terminates when the system 400 finds an antenna signal with better quality than the reference antenna. This selected antenna becomes the new reference antenna. By performing the quality comparison to accept a new antenna, an antenna is chosen which is less likely to encounter distortion events that would lead to another antenna search.
[0034] Switching between antennas creates some disturbance in the detected audio as a result of discontinuity between received antenna signals and from selecting an antenna with a poor signal quality. To minimize the audible disturbance, the decision logic block 404 selects trial antennas (other than the currently favored) in order of larger LevelA(n) signals recorded at the time of the triggering event. Since a larger signal level is more likely to provide better quality, a new favored antenna can be found with a minimum of antenna switching and less chance of trying a poor antenna. Reselecting the presently favored antenna, only after all other antennas have been tried, prevents exclusion of antennas from the search.
[0035] The system 400 utilizes short-term statistics (events) of the received signal, as detected by a fast distortion detector, to trigger a search for an antenna with a signal having better long-term statistics (quality) as detected by a slow distortion detector. To prevent frequent antenna searches from causing an audible disturbance, a threshold is introduced to desensitize the fast distortion detector. The threshold attacks on a triggering event value and then decays at a rate ( FIG. 5A ) that ranges from about 100 mS for signal strengths less than an RF level reference (e.g., a 5 V level) to about 25 μS for strong signals. To maintain confidence in the long-term statistics, the averaging time used with the slow distortion detector ( FIG. 5B ) transitions from about 500 μS for signal strengths less than the RF level reference 506 to about 25 μS for strong signals.
[0036] With reference to FIGS. 5A and 5B , these operation modes are further depicted in graphs 500 and 510 . The operation modes include a transition region 508 that is located between a strong signal mode 502 and a weak signal mode 504 . The RF level reference 506 (e.g., a 5 μV level) defines a point where the operation mode transitions between the strong signal mode 502 and the weak signal mode 504 .
[0037] With reference to FIG. 6 , an exemplary antenna switching routine 600 , implemented according to one embodiment of the present invention, is depicted. In step 602 , the DSP 110 A (implementing routine 150 ) monitors a present reference antenna for fast distortion events (i.e., a dip in an RF level signal and an MPX signal spike). Next, in decision step 604 , the DSP 110 A determines whether an event trigger has occurred. If an event trigger has occurred, control transfers to step 606 . Otherwise, control returns from step 604 to step 602 . In step 606 , the DSP 110 A stores the quality statistics of the present antenna, to use as a reference. Next, in step 608 , the DSP 110 A searches for an antenna with better quality statistics. Then, in decision step 610 , the DSP 110 A determines whether an antenna with better quality has been located. If so, control transfers to step 612 , where the antenna with better signal quality becomes the reference antenna, at which point control transfers to step 602 . If an antenna with better signal quality is not located in step 610 , control returns to step 608 , where the DSP 110 A continues to search for an antenna with quality statistics that are better than the current reference antenna.
[0038] With reference to FIG. 6B , a routine 600 A is depicted that provides a more detailed process flow for implementing various embodiments of the present invention. As is shown, steps 602 A and 630 receive an MPX signal value and steps 602 A, 630 and 620 receive an RF level signal value. The step 602 A represents a routine that monitors a present reference antenna for distortion events, which are indicated when an event threshold, provided in step 626 , is exceeded. In decision step 604 A, when an event trigger occurs, control transfers to step 606 A, where a quality measure of the present reference antenna is stored. Next, in step 608 A, a trial antenna is selected.
[0039] Then, in step 609 , the quality of a signal received by the trial antenna is compared to the quality of a signal received by the current reference antenna. Next, in decision step 610 A, it is determined whether the quality of the signal received by the trial antenna is better than that of the current reference antenna. If the quality of the signal provided by the trial antenna is better, the trial antenna becomes the new reference antenna in step 612 A and control returns to step 602 A. If the quality of the signal provided by the trial antenna is not better than that of the signal provided by the current reference antenna in step 610 A, control transfers to decision step 611 . In step 611 , it is determined whether the quality of the signal provided by the trial antenna is better than the quality of the signal provided by the current reference antenna. If so, control transfers to step 612 A, where the trial antenna becomes the new reference antenna. Otherwise, control transfers to step 608 A, where a next trial antenna is selected.
[0040] The quality of the signals received by the antennas is determined by a quality measure calculation in step 630 . The average level for a current antenna is determined by a calculation in step 620 . The average level is provided to another calculation in step 622 , which combines the average level of all antennas to provide a combined average of all antennas signal ‘LevelC’. The LevelC signal value is used in step 624 to calculate an event threshold decay time τ H , which is used in step 626 to calculate the event threshold. The LevelC signal is also used in step 628 to calculate an averaging time T A , which is used in step 630 to calculate a quality measure.
[0041] The above description is considered that of the preferred embodiments only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the doctrine of equivalents.
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A technique for reducing multipath distortion in an FM receiver, with a plurality of switchable antennas, provides a fast distortion detector that monitors a received signal for significant distortion events of less than about 15 microseconds in duration. In response to a multipath event, the output of the fast distortion detector initiates a search for a lower distortion (better quality) antenna. To prevent frequent antenna searches from causing an audible disturbance, a threshold is introduced to desensitize the fast distortion detector. Threshold decay is a function of an overall received RF signal level. A slow distortion detector is also provided that measures distortions of the received signal relating to signal quality.
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BACKGROUND OF THE INVENTION
This invention relates to token ring local area networks, and more particularly to a means for diagnosing the integrity of a particular hardware component without connecting the component into the network.
One local area network ("LAN") architecture is the Token Ring topology local area network at 4- and 16-Mbit/second. IEEE 802.5 is an IEEE local area network standard that closely follows the token ring standard, and currently supports 4-Mbit/second token ring networks. IEEE 802.5 is described in "Token Ring Access Method and Physical Layer Specifications," ISBN 1-55937-012-2, IEEE Std. 802.5-1989 (ANSI), IEEE, 345 E. 47th Street, New York, N.Y. 11017. Token ring and IEEE 802.5 topologies connect computer systems in a local environment.
In order to test hardware components connected into a token ring or IEEE 802.5 LAN, one must also consider lobe cables connecting the components, other devices on the ring, and the risk of degrading the network performance while performing the testing. It has been necessary in the past to supply a "known good" lobe cable and a "known good"0 Token Ring Multi-Station Access Unit (MsAU) with no other nodes attached to achieve adequate troubleshooting capability. The MsAu is a passive device which includes a relay set, and receives power to operate the relays from node devices inserted into the ring.
It would therefore represent an advance in the art to provide a means for diagnosing the integrity of a particular hardware component for a token ring LAN without connecting the component into the network.
SUMMARY OF THE INVENTION
A test connector system is described for permitting a Token Ring local area network (LAN) component to be tested without hooking the component into the network, wherein the component includes a multi-pin electrical connector for connecting the component into the network. In a general sense, the test connector includes a compatible connector means for connecting to the component connector. The connector means includes a pin pattern for mating with the component connector, and load simulating means connected to selected ones of the pins of the test connector means for simulating the nominal electrical load presented to the network component when connected into the Token Ring network. The load simulating means includes first and second resistors connected across first and second pairs of the connector means pins.
Preferably, the connector means of the system includes first and second connectors of different types, e.g., DB9 and a RJ45 connectors connected by a short two-wire pair cable. The two connector types share common load simulating means. Preferably the load simulating means are two resistors molded into the housing of one of the two connectors. In this manner, the test connector system is multipurpose, having the capability of connecting to two different connector types.
In accordance with the invention, a method for testing a Token Ring LAN component using the test connector is described, wherein the component to-be-tested is not connected into the LAN. The compatible connector means is connected to the connector of the component to-be-tested, instead of to a LAN as in the conventional testing sequence, and functional electrical tests are performed on the LAN component to determine its functionality in the LAN.
BRIEF DESCRIPTION OF THE DRAWING
These and other features and advantages of the present invention will become more apparent from the following detailed description of an exemplary embodiment thereof, as illustrated in the accompanying drawings, in which:
FIG. 1 is an isometric view of a token ring loopback connector in accordance with the invention.
FIG. 2 is a schematic representation of the connector of FIG. 1.
FIG. 3 is an electrical schematic diagram of the loopback connector of FIG. 1.
FIG. 4 is an isometric view of an RJ45--RJ45 adaptor which may be used with the loopback connector of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A Token Ring loopback connector system 20 in accordance with this invention is illustrated in FIG. 1. The connector system 20 includes two connectors 30 and 40 separated by a short cable 50. Connector 30 in this embodiment is a nine pin DB9 connector. Connector 40 is an eight pin RJ45 connector. The cable 50 is required to include only two wire pairs, and has a typical length in this embodiment of 90 mm.
FIG. 2 shows the connector system 20 in further detail. The connector 30 includes nine pins 30-1 . . . 30-9. The connector 40 includes eight pins 40-1 . . . 40-8.
The first wire pair comprising the cable 50 is made up of wires 51 and 52. Wire 51 is connected between pin 40-3 of connector 40 and pin 30-1 of connector 30. Wire 52 is connected between pins 40-6 and 30-5.
The second wire pair comprising the cable 50 is made up of wires 53 and 54. Wire 53 is connected between pin 40-4 and pin 30-6. Wire 54 is connected between pin 40-5 and pin 30-9.
The connector system 20 further includes a first resistor 60 shunting the wire 51 of the first cable pair and the wire 54 of the second wire pair. A second resistor 62 shunts the wire 53 of the second wire pair and the wire 52 of the first wire pair. Each resistor 60 and 62 has a resistor value of 3.16 Kohm in this embodiment, which is designed to provide the load expected by the Texas Instrument Token Ring chipset, including the controller chip TMS38053 and the ring interface chip TMS38053. This chipset can be used in Token Ring components to provide the necessary protocol interface into the LAN.
An electrical schematic of the system 20 is shown in FIG. 3. The resistors 60 and 62 are respectively connected between two transmit-receive pairs, to permit the unit under test to transmit signals from the unit transmitter which are "looped back" to the unit receiver via the resistor loads. The Token Ring interface employs a protocol using balanced drivers and differential receivers. The receivers determine the differential voltage appearing across two receiver terminals, in an arrangement which tends to cancel noise transmitted across the network. Thus, there are two transmit terminals, labeled here as XMIT and NXMIT, and two receive terminals RCV and NRCV. As shown in FIG. 3, the XMIT and NXMIT terminals correspond to pins 30-9 and 30-5, respectively, of the RJ45 Connector 30, and pins 4-5 and 40-6 of the DB9 connector 40. The RCV and NRCV terminals correspond to pins 30-1 and 30-6, respectively of the RJ45 connector 30, and to pins 40-3 and 40-4 of the DB9 connector 40.
To provide compatibility with the Token Ring protocol, the TI chipset referenced above provides the capability of sensing when it has been properly inserted into the ring, by sensing the MsAU load. The load the TI chipset expects to see is that provided by the 3.16 Kohm resistors 60 and 62. Only after proper insertion of the unit into the ring has been sensed will transmit operations by the unit be permitted, and the unit sends a signal to open a relay in the MsAU.
The loopback connector system 20 simulates the load that a Token Ring or IEEE 802.5 compatible interface expects when inserted into a ring. It also prevents a wire fault condition by simulating a ring insertion of the component under test.
The connector system 20 attaches directly to the Token Ring component being tested through either its DB9 or RJ45 connector. The Token Ring device being tested becomes the ring monitor in a single-node ring environment and simulates a short lobe cable. That is because there are no other node devices being simulated, and therefore, after the unit under test fails to receive a token from the simulated LAN, it will act to generate the token by default, under the Token Ring protocol.
For example, the test connector system 20 may be used to test LAN components such as routers or interface assemblies, without connection of the component to the network at large. As is well known, routers are types of interface equipment which adapt two dissimilar network protocols, e.g., Token Ring and Ethernet, to permit the interconnection of two different types of network. By way of example, the router equipment marketed by Hewlett-Packard Company, the assignee of this invention, includes a DB9 connector. The interface assemblies marketed by this company, which include plug-in board assemblies to permit a device such as a computer to be connected into a LAN, include both the DB9 and RJ45 connectors.
As presently written, the specification for the IEEE 802.5 network specifies only the DB9 connector, which is a shielded wire type of connector. However, RJ45 connectors, which are unshielded wire connectors, are also in common use in such networks.
The unit under test typically includes various self-testing capabilities. For example, units including the Texas Instrument chipset will include the self-diagnostic capabilities of that chipset. Thus, after connecting the connector system 20 to the unit-to-be-tested, the power to the unit can be turned on, which will initiate the self-diagnostics of the chipset comprising the unit. During the initial diagnostic routine, the chipset will determine whether it is properly connected into the Token Ring, by sensing the load of the MsAU. The connector system 20 simulates this load, and therefore the unit should if functional not only complete the self-diagnostic routines of the unit properly, but also permit additional testing. There are external test programs available today, which test the transmit and receive functions of the unit, by causing the unit to transmit known data over the LAN, and check to see whether the same data is properly received in the unit. While such programs are written for the case of a unit already connected into the LAN, they can also be used when the connector system 20 has instead been used. Data can be transmitted and received via the loopback connector arrangement, permitting the transmit and receive functionality of the unit to also be tested. Other functions can also be tested, since the connector system 20 simulates connection of the unit into the LAN.
Because the Token Ring topology has various connector interfaces, the system 20 combines both the DB9 connector and the RJ45 connector into a single component, making the system 20 a multi-purpose test device. This combination also permits each connector 30 and 40 to share the same load resistors. Moreover, the resistors can be protected in a common connector molding, typically the molding of the RJ45 connector housing.
Of course, it will be recognized that a loopback connector in accordance with this invention need not include both types of connectors, i.e., both the RJ45 and the DB9 connectors. For example, a test connector can be employed which includes only a DB9 connector, with the load resistors connected relative to the DB9 pins as shown in FIG. 3, or only an RJ45 connector with load resistors connected relative to the RJ45 pins as shown in FIG. 3.
With the addition of a female-female RJ45 receptacle, the connector system can be used to verify the integrity of an un-shielded twisted-pair lobe cable as well. FIG. 4 illustrates such an RJ45-RJ45 receptacle 70. A cable can be tested by use of the connector system 20 and a previously tested, known-to-be-good LAN node unit. This is done by hooking one end of the cable to the tested node unit, connecting the receptacle 70 to the other cable end, and connecting the connector system 20 to the other end of the receptacle. The unit can then be tested again, to determine if the cable is functional. Failure of the testing indicates failure of the cable, since the unit is known to be good. The same method can also be used to test a cable having six pin RJ-11 connectors, another type of unshielded wire connector. That is because the center four conductors/pins of the connectors map into the transmit/receive pairs used for connection to the RJ45 connectors.
The connector system can be used in a method to test Token Ring components, without connecting the component into the LAN. The method includes the following steps:
providing a test connector as described above including a compatible connector for connecting to the component connector, the compatible connector including a pin pattern for mating with the component connector, and load simulating means connected to selected ones of the pins of the test connector for simulating the nominal load presented to the LAN component when connected into the LAN;
connecting the compatible connector to the component connector, thereby simulating the connection of the component into the LAN; and
performing test operations on the component to determine its functionality.
It is understood that the above-described embodiments are merely illustrative of the possible specific embodiments which may represent principles of the present invention. Other arrangements may readily be devised in accordance with these principles by those skilled in the art without departing from the scope and spirit of the invention.
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A loopback connector system for testing token ring components such as routers or interface assemblies with requiring that the component to be tested be connected into the local area network (LAN). The connector permits the component to be tested to be isolated from the LAN, permitting the integrity of the component to be tested without regard to the integrity of lobe cables or other devices on the ring, and without degrading network performance. The connector system includes two different multi-pin connector types, a DB9 and an RJ45 connector, used to connect into the network, separated by a short two-pair cable. Resistors used to simulate the network loading on the component are connected between appropriate pins, with the resistors being shared between the two types of connectors.
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The present invention relates to improved apparatus for crystallizing whey and is a continuation-in-part of application Ser. No. 230,545, filed Aug. 10, 1988, now abandoned.
BACKGROUND OF THE INVENTION
Whey is the watery residue remaining after fat and casein have been removed from whole milk in the manufacture of cheese, or after casein has been removed from skim milk in the manufacture of casein or cottage cheese. The composition of whey varies, but a typical whey has a solids content of about 6%, about 60-70% of which is lactose or milk sugar. Also present is protein, mainly albumin, and small amounts of fat and various mineral salts or ash.
The lactose in raw whey is an equilibrium mixture of the alpha and the beta forms of the lactose. The alpha form crystallizes from solution as the monohydrate at temperatures below 93° C. and is the ordinary milk sugar of commerce. The beta form, present in the equilibrium mixture in the greater amount, is an anhydride which crystallizes above 93° C. When whey is rapidly dried to a low moisture content, the dry product contains alpha and beta lactose in essentially the same proportions as in the whey before it has been dried. The rapidly dried product is a non-crystalline, paste-like material, which is difficult to process.
Although the following disclosure is made with particular reference to the drying of whey, it will also be understood that the apparatus is useful in drying whey permeate which is a residue from ultrafiltration of protein from whey.
DESCRIPTION OF THE PRIOR ART
Prior art procedures for drying and crystallizing whey are described in U.S. Pat. Nos. 2,172,393; 2,188,907; 2,197,804, and 2,336,461. In a typical procedure, the raw whey is first concentrated by the removal of water in a series of multiple effect vacuum evaporators. The concentrated liquid whey from the evaporators, while still warm, is incompletely dried on a pair of steam-heated, outwardly rotating drums. The pasty material formed is stripped from the drums by means of doctor blades and deposited on an endless belt. The pasty material rests on the belt for some time and the lactose crystallizes to form the alpha hydrate (moisture in the pasty material provides the water required for forming the crystalline hydrate). The crystalline hydrate is non-hygroscopic and is easy to handle.
The endless belt is more than a means for conveying partially dried lactose from the drying drums to the next stage in its processing. The slow moving belt provides time, typically 10 minutes is generally sufficient, for the pasty material from the drying drums to crystallize so that it can be conveniently handled for packaging or further drying.
A more recent procedure, as illustrated in FIGS. 1 and 2, substitutes a spray dryer for the drum dryer previously utilized for drying the concentrated whey from the evaporators. The spray dried whey is then passed to the endless belt, which serves the same function as before. The crystallized material on the belt is then further dried, and also cooled, in a fluid bed to contain about 2% free water and about 3% crystal bound water.
Due to its structure and mode of operation, it is very difficult to keep the conveyor belt clean and sanitary in compliance with current regulatory standards. Also, the material on the belt tends to get into and foul the driving mechanism for the belt. In order to wash the belt and clean its driving mechanism, it typically is necessary to partially disassemble the apparatus and remove the belt, a time consuming procedure.
It is, therefore, an object of the present invention to provide apparatus for the drying of whey which is both sanitary and convenient to clean, and which can be cleaned-in-place.
BRIEF DESCRIPTION OF THE INVENTION
It has been discovered that the substitution of a rotating disc for the endless belt heretofore utilized as the final crystallization stage in the production of dried whey provides an improved crystallization apparatus. That apparatus comprises:
an evaporator, a pre-crystallizer, a spray dryer, a fluid bed, means for moving said whey from said evaporator to said pre-crystallizer, means for moving said whey from said pre-crystallizer to said spray dryer, a disc located between said spray dryer and said fluid bed and having a cone-shaped upper surface, a shaft supporting said disc for rotation in a horizontal plane, and means for rotating said disc whereby said surface of said disc will receive partially dried whey from said spray dryer and deliver said whey to said fluid bed while permitting crystallization of said whey as it rests on said surface of said rotating disc.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow sheet illustrating an overall process for the drying of whey.
FIG. 2 illustrates a portion of the apparatus of the prior art wherein an endless belt is utilized for the crystallizing stage.
FIG. 3 is a side elevation of a disc and related apparatus used as the crystallizing stage in the apparatus of the present invention.
FIG. 4 is a plan view of the disc and related apparatus of FIG. 3.
FIG. 5 is a rear view of the disc and related apparatus of FIG. 3.
FIG. 6 is a perspective view of a scraper used in the apparatus of FIG. 3.
FIG. 7 is a plan view of alternate means for supporting a disc used as the crystallizing stage in the apparatus of the present invention.
FIG. 8 is a side elevation, partly broken away, of the alternate disc support means shown by FIG. 7.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the drawings wherein like reference numerals refer to the same or like parts throughout, FIGS. 36 illustrate one embodiment of a disc 12 and related apparatus used as the crystallizing stage in the present invention. The disc 12 is supported by means of a shaft 14 suspended from a frame 16. The frame 16 is comprised of a base 20 and a box beam 22 supported by frame members 24 and 26 which in turn are supported from the base 20 by angular braces 25 and 27. The base 20 is supported for rolling movement across a supporting surface by means of a plurality of wheels 28.
The shaft 14 is rotatably suspended by means of a bearing assembly 15 from the box beam 22. A motor 18 also supported by the beam 22 drives the shaft 14 by means of a chain 17 engaging a sprocket 19 fixed to the upper end of the shaft. A curved scraper or doctor blade 32 is provided at the lower end of a similarly curved plate 30 which is supported by rods 34 and 36 from the beam 22. The lower edge of the scraper 32 is positioned to ride within about one-quarter inch of the cone-shaped upper surface of the disc 12 to remove the whey deposited thereon as will be more fully described here below. The base 20 of frame 16 is movably mounted on the wheels 28 to permit the disc 12 to be moved relative to a spray dryer and fluid bed. A second cone shaped surface 11 which is inverted relative to the cone shaped upper surface 10 is provided to cover the bottom of the disc and to impart rigidity and to optimize the structural integrity of the disc. The scraper 32 and supporting structure is shown in FIG. 6.
FIGS. 7 and 8 show an alternate apparatus for supporting a disc used as the crystallization stage in the apparatus of the present invention.
FIGS. 7 and 8 show a generally cylindrical, fabricated housing 40 which movably supports and fully encloses a crystallizing disc permitting cleaning-in-place of the disc. In FIG. 8 a portion of the side of the housing 40 is broken away to show a disc 12 having upper and lower cone shaped surfaces 10 and 11 supported and suspended by a shaft 14 which is rotatably mounted at the apex 41 of the housing 40. Also shown are built-in spray nozzles 52 used to clean-in-place the housing and the enclosed disc.
As in the previous embodiment, the shaft 14 is rotatably driven by a motor 18 and chain 17 engaging a sprocket 19 fixed to the upper end of the shaft 14. The motor 18 is supported by the housing 40.
The housing 40 is also provided with an upstanding circular inlet 38 for receiving whey from a spray drier. The disc 12 typically rotates in an counterclockwise direction as shown by the arrow in FIG. 7 and the crystallized whey is wiped off the disc 12 by a scraper typically positioned proximate the outlet 39.
The housing 40 is suspended by trolleys 44 provided at the upper end of four tubular rods 42. Each tubular rod 42 is suspended from a base plate 44 of a trolley 44. A pair of upstanding side plates 45 and 46 each rotatably mount a roller 47, 48. The rollers 47 and 48 are disposed to ride on the surfaces of a flange of I beam 50 or beam 51. The I beams 50, 51 constitute the major part of a supporting frame for the housing 40 and disc 12. The I beams 50 and 51 which are schematically represented by dot-dash lines in FIG. 7 may be supported at their opposite ends by pedestals or hung from a building framework in conventional manner.
With the embodiment shown by FIGS. 7 and 8, the housing 40 supporting the disc 12 and motor 18 can be moved by the trolleys 44 relative to the I beams 50, 51 which serve as rails to move the disc 12 and supporting housing 40 away from a spray dryer and fluid bed to permit direct connection between said spray drier and said fluid bed, so that the apparatus may be used in operations not requiring the disc.
Preferably, the crystallizing disc 12, as shown in FIGS. 3 and 8 comprises two cones welded together for increased strength. When the disc is cleaned by washing, the pointed shape of the upper cone and the sloped bottom of the housing 40 permits the wash liquid to drain freely off the disc and out of the housing. Since the whey may be slightly acidic and the disc is constantly in contact with moisture, the disc and housing should be fabricated of a corrosion resistant metal, preferably stainless steel.
The disc hangs from a shaft which is supported by a frame. The means for rotating the disc are preferably positioned above the disc to keep them dry and free of whey powder. The disc is conveniently rotated by a chain drive typically powered by a variable speed motor which is adjustable to rotate the disc at different speeds. The disc and shaft are movable relative to the body of the apparatus for convenience in inspecting and maintenance through conveniently located access openings in the housing.
The apparatus contains, in addition to the disc, a doctor blade or scraper for removing crystallized whey powder from the disc. The scraper is mounted using vertically adjustable fastening means so that its position relative to the disc can be readily adjusted. The scraper as shown in FIG. 6 is typically fabricated of a bent piece of sheet metal and has a diameter slightly bigger than the radius of the disc so that the scraper will urge the crystallized whey powder toward the edge of the disc. The lower part of the scraper is shaped like a cone to facilitate the easy removal of the powder from the disc.
Except for the disc and related rotating means, which can rotate the disc at an adjustable rate of rotation, and the scraper, the apparatus of the present invention utilizes equipment conventionally utilized for the drying and crystallization of whey. In operation, the raw whey is concentrated as much as feasible, without adversely affecting the whey or the ability to pump the concentrate, using multiple effect vacuum evaporators. The concentrated whey, from which most of the water has been removed, following pre-crystallization, is then pumped to the spray dryer. The pasty material from the spray dryer, containing about 10%-14% water, is passed to the rotating disc where it forms an irregular semi-round shaped discontinuous ring on the upper cone-shaped surface of the disc. The disc slowly rotates with an adjustable period of rotation of about 4-15 minutes, typically 10 minutes, during which period the lactose in the pasty material crystallizes. The scraper separates the now non-sticky crystallized whey powder from the disc and passes it to the fluid bed for drying to a final free moisture content of about 2%.
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An apparatus including an evaporator, a pre-crystallizer, a spray dryer and a fluid bed for drying whey and a rotating disc having a cone-shaped upper surface is provided for receiving partially dried whey from the spray dryer and delivering the whey to the fluid bed while permitting crystallization of the whey as it rests on the surface of the disc.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser. No. 10/590,949 filed on Nov. 8, 2006, which application is a national stage application under 35 U.S.C. §371 of PCT Application No. PCT/AT2005/000017 filed Jan. 25, 2005 which claims priority under 35 U.S.C. §119 from Austrian Patent Application No. A 318/2004 filed Feb. 27, 2004, the disclosures of each of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a device for bridging a difference in height between two floor surfaces, with said device comprising a profiled cover that is provided with a covering flange which covers the edge of each of the two floor surfaces and at least one clamping extension that protrudes downward from the covering flange, extends longitudinally with respect to the profiled cover, and clamps into and engages with a fixture. The said device also comprises a compensating strip located between the covering flange of the profiled cover and the lower of the two floor surfaces.
[0004] 2. Description of the Prior Art
[0005] A known method for bridging steps or joints in floor coverings is disclosed in WO 99/01628 A1, wherein profiled covers for steps and joints are invisibly attached by means of fixtures. For this purpose, the fixtures consist of a profiled section with a flat horizontal fastening element on the floor side. Extending upward from this flat horizontal element are vertical retaining legs, between which the downwardly protruding clamping extension of the profiled cover is inserted and held in place. In order to bridge height differences between adjacent floor coverings, a hollow cavity is formed adjacent to and along the length of the clamping extension of the metallic profiled cover, allowing the flange of the profiled cover that extends from the clamping extension to bend in such a way that the angle of flex of the profiled cover can adjust to the height difference between the floor coverings to be bridged in each case.
[0006] Such an adjustment for height differences with respect to the floor coverings being bridged requires the profiled covers to have the requisite flexural properties, which for instance timber building materials do not possess. In order to facilitate a height adjustment between two floor coverings using timber materials accordingly, without the necessity of using various profiled covers, WO 03/040492 A1 discloses a profiled cover with a compensating strip arranged on the low floor side. This compensating strip is provided with an undercut groove for attachment to the underside of the covering flange of the profiled cover. The purpose of the groove is to accommodate a projection on the underside of the covering flange parallel to the clamping extension of the profiled cover in a form-fitting manner. The primary disadvantage of this known device for bridging a difference in height between two floor surfaces is that the projection on the underside of the covering flange hinders the manufacture of the profiled cover and that it is virtually impossible to achieve a form-fitting joint between the profiled cover and the compensating strip due to the unavoidable manufacturing tolerances resulting from the separate production of the profiled cover and the compensating strip. Moreover, the profiled cover can only be used without a compensating strip as a cover for an expansion joint between two level floor coverings if the projection on the underside of the covering flange is removed beforehand.
SUMMARY OF THE INVENTION
[0007] Consequently, the object of the invention is to develop a device for bridging a difference in height between two floor surfaces of the aforementioned type that is able to fulfill the requirements for the exact fit of a profiled cover and compensating strip, while still being simple to manufacture.
[0008] The invention fulfills this object by means of the fixture forming a clamping seat for the compensating strip. Consequently, as the resultant fixture for accommodating the clamping extension of the profiled cover also creates a clamping seat for the compensating strip there is no need for a form-fitting joint between the profiled cover and the compensating strip. This not only facilitates the manufacture of the profiled cover, but also of the compensating strip as there is no provision of a projection on the underside of the covering flange of the profiled cover nor the provision of a longitudinal groove in the covering strip. The absence of a projection on the underside of the cover flange of the profiled cover also means that the profiled cover can be used to bridge expansion joints between level sections of floor, without having to perform additional work on the profiled cover.
[0009] The fixture for the profiled cover and also for the compensating strip can be designed differently as the only important thing is to have corresponding clamping joints to ensure the reciprocal spatial correspondence of the profiled cover and the compensating strip. However, construction is particularly simple if the fixture consists of a known profiled section with resilient retaining legs protruding upwardly from a mounting plate for clamping the clamping extension of the profiled cover. The mounting plate on the low floor side extends past the retaining leg and bears the clamping seat for the compensating strip, which only needs to be pushed onto the clamping seat before the profiled cover with the clamping extension is clamped firmly between the retaining legs and the covering flange rests on the compensating strip. It is advantageous if the clamping seat for the compensating strip can be developed as a retaining leg engaging with a longitudinal channel in the compensating strip, with said leg firmly holding the profiled cover clamped in the profiled section of the fixture transversely to its longitudinal axis. In addition, the covering flange of the profiled cover for the compensating strip can form an abutment on the clamping extension side so that the local clamping extension forms an abutment such that the profiled cover and the compensating strip are not only held in position by the fixture, but also directly by the abutment.
[0010] With the retaining leg serving as a clamping seat there is the advantage that the compensating strip lies against the abutment of the covering flange due to the resilient pretensioning of the retaining leg, facilitating compensation of manufacturing tolerances. If the profiled cover is employed without the compensating strip, for instance to bridge an expansion joint, the widened part of the mounting plate of the fixture can hinder its placement inside the expansion joint. For this reason the section of the mounting plate extending beyond the retaining leg can be removed from the remaining mounting plate by means of a predetermined breaking point.
[0011] The underside of the covering flange without the projection is an essential requirement for a simple manufacturing process with respect to the profiled cover and the compensating strip. This manufacturing process is characterized in that initially a common profiled section is produced, the cross-section of which is formed from the cross-section of the profiled cover and at least one adjoining compensating strip, including machining allowances for kerfing on the underside of the covering flange on the one hand and on the lateral surface of the clamping extension on the other. Then the compensating strip is separated from the profiled cover by cutting along the underside of the covering flange and the lateral surface of the clamping extension. By manufacturing the profiled cover and the compensating strip from a common profiled section with separating cuts along the underside of the covering flange on the one hand and along the lateral surface of the clamping extension on the other, not only can the material for the profiled cover and the compensating strip be utilized advantageously, but also the precision of fit increased enormously as the deviations from the specified cutting plane for the profiled cover and the compensating strip correspond to each other when the profiled cover and the compensating strip are mated, allowing the profiled cover and the compensating strip to be joined without any play.
[0012] Although the profiled section can be limited to the simultaneous production of the profiled cover and a single compensating strip, it can be advantageous to cut two differently shaped compensating strips from one common profiled section with one profiled cover. This can be done if a common profiled section is initially manufactured for one profiled cover and one compensating strip for each side of the clamping extension, before the two compensating strips are separated from the profiled cover by means of a cut along the underside of the covering flange and along each side of the clamping extension. This provides two compensating strips for one covering strip, to be employed as required.
[0013] Manufacturing the profiled cover and the compensating strip or strips at the same time provides additional advantages for coated profiled covers and compensating strips as the structure and appearance of the coating of the profiled cover and the compensating strips are identical if the common profiled section is initially coated on what will become the visible side of the profiled cover and the compensating strip or strips, before then being separated into the profiled cover and compensating strip or strips. The difference between the abutting coatings of the abutting profiled cover and compensating strips can at the most involve changes at the kerfs, changes that are visually negligible owing to the minimal kerf widths.
[0014] If the profiled covers and the compensating strips are coated using droplets, as for instance with spray coating, vacuum deposition or vaporization, the common profiled section can first be cut along the underside of the covering flange and then be coated before the profiled cover and the compensating strip or strips are completely separated by cutting along each lateral surface of the clamping extension. This partial cut prior to coating has for instance the advantage that the partial coating of the cut between the covering flange and the compensating strip coats the longitudinal edges of the profiled cover and the compensating strip, an outcome that is not achieved if cutting is performed afterwards. In order to prevent the creation of a gap between the covering flange and the floor covering under the covering flange when covering the higher of the two floor surfaces, the cut along the underside of the covering flange of the profiled cover can run at an acute angle, requiring the covering flange to be undercut. This undercutting also causes the compensating strip to be centred due to the wedging effect when the profiled cover is subject to load, pressing the compensating strip against the abutment.
[0015] If the kerfs of the cuts along the underside of the covering flange and the lateral surfaces of the clamping extension only overlap in part of the kerf width, a step is created in the section of kerf overlap that advantageously serves as an abutment for the compensating strip that is pressed against it by the fixture, achieving exact positioning of the compensating strip with respect to the profiled cover.
BRIEF DESCRIPTION OF THE DRAWING
[0016] The drawing illustrates examples of embodiments of the invention. In the drawing
[0017] FIG. 1 shows a device in accordance with the invention for bridging a difference in height between two floor surfaces in a simplified cross-section,
[0018] FIG. 2 shows a frontal view of a common profiled section for producing a profiled cover and two compensating strips,
[0019] FIG. 3 shows a cross-sectional view of the profiled section in accordance with FIG. 2 after a separating cut along the underside of the covering flange of the subsequent profiled cover in cross-section, and
[0020] FIG. 4 shows a cross-sectional view of the covering strip produced from the profiled section in accordance with the FIG. 2 by cutting along the lateral surface of the clamping extension, with the two compensating strips in an arrangement corresponding with the profiled section.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] In accordance with the embodiment in FIG. 1 , a difference in height between a floor surface 1 , for instance a floor covering 2 , and a floor surface 3 requires bridging, with the latter floor surface 3 in accordance with the embodiment being formed by the substrate for the floor covering 2 . The floor surface 3 can of course also be formed by another floor covering. A profiled cover 4 is employed to bridge the difference in height between the floor surfaces 1 and 3 , said profiled cover 4 consisting of a covering flange 5 and a clamping extension 6 protruding downwards from the covering flange 5 , said clamping extension being held and gripped in a fixture 7 . This fixture 7 is developed as a profiled section, having resilient retaining legs 9 protruding upward from a mounting plate 8 , with the clamping extension 6 of the profiled cover 4 being engaged by said legs.
[0022] As the profiled cover 4 is developed symmetrically with respect to a longitudinal middle plane, the profiled cover cannot bridge the difference in height between the floor surfaces 1 and 3 . Accordingly, to bridge this difference in height, provision is made for a compensating strip 10 , which attaches to the underside of the covering flange 5 of the profiled cover 4 on the side with the lower floor surface 3 and rests on this floor surface 3 . To ensure a flush connection between the compensating strip 10 and the covering flange 5 , without provision having to be made for a form-fitting connection between these structural components, the fixture 7 forms a clamping seat 11 for the compensating strip 10 . To this end, the mounting plate 8 extends past the retaining legs 9 and bears a retaining leg 12 at the longitudinal edge of the extension, said retaining leg 12 being inserted into a longitudinal groove 13 in the compensating strip 10 . The covering flange 5 of the profiled cover 4 forms an abutment 14 in the vicinity of the clamping extension 6 for the compensating strip 10 , which is pressed against this abutment by the resilient pretensioning of the retaining leg 12 of the clamping seat 11 , such that the compensating strip 10 is positioned precisely with respect to the profiled cover 4 .
[0023] Accordingly, the difference in height between two floor surfaces 1 and 3 is bridged in an advantageous manner with the assistance of the compensating strip 10 in conjunction with a profiled cover 4 that is symmetrical with respect to a longitudinal middle plane, without impinging upon the use of the profiled cover as a cover for an expansion joint in the vicinity of a floor covering that does not differ in height around the expansion joint. This is achieved by fastening the compensating strip 10 by means of the clamping seat 11 of the fixture 7 as in this case a form-fitting connection between the covering flange 5 and the compensating strip 10 is not required. However, the clamping seat 11 of the fixture 7 for the compensating strip 10 does not preclude an adhesive joint between the compensating strip 10 and the adjacent section of the covering flange 5 , which to this end can be provided with an adhesive strip, which is not represented for reasons of maintaining clarity. If the profiled cover 4 is used without the compensating strip 10 , the widened section of the mounting plate 8 with the retaining leg 12 generally hinders positioning of the fixture 7 . Therefore, the widened section of the mounting plate 8 with the retaining leg 12 is provided with a predetermined breaking point immediately adjacent to the profiled section of the fixture 7 , as indicated in FIG. 1 . Consequently, if required, the retaining leg 12 can be separated from the rest of the profiled section, together with the widened section of the mounting plate 8 .
[0024] Simply positioning the compensating strip 10 on the corresponding section of the covering flange 5 constitutes an advantageous condition for simple manufacturing of the compensating strip 10 and the profiled cover 4 , as the profiled cover 4 and the compensating strip 10 can be manufactured from a common profiled section in accordance with FIGS. 2 to 4 . In accordance with FIGS. 2 to 4 the common profiled section 15 encompasses not only one compensating strip 10 , but also two compensating strips 10 of differing form, something that further expands the application options of the profiled cover 4 thanks to the optional use of either of the two compensating strips 10 .
[0025] As can be seen in FIG. 2 , the cross-section of the common profiled section 15 is comprised of cross-sections of the profiled cover 4 on the one hand and the compensating strips 10 on the other, with provision being made accordingly for machining allowances 16 for kerfs between the covering flange 5 and the clamping extension 6 of the cross-section of the profiled cover 4 as indicated by the dash-dotted line and the abutting compensating strips 10 , the outline of which is also indicated by means of dash-dotted lines. FIG. 3 shows the compensating strips 10 partially separated from the subsequent profiled cover 4 by kerfs 17 along the underside of the covering flange 5 . Complete separation is achieved by cutting along the lateral surfaces of the clamping extension 6 , as indicated by the dash-dotted kerfs 18 . The compensating strips 10 that are completely separated from the profiled cover 4 are visible in FIG. 4 , specifically in a bilateral arrangement corresponding to the profiled section 15 , on which the device is based. It is demonstrated that the profiled cover 4 and the compensating strips 10 can be produced from the same profiled section 15 by simple, straight cuts corresponding to kerfs 17 and 18 , and in fact with the advantage that' unavoidable cutting inaccuracies are compensated when the profiled cover 4 and the compensating strips are placed together.
[0026] In accordance with FIG. 3 , the kerfs 17 and 18 only overlap for a section of the kerf width along the underside of the covering flange 5 and along the lateral surfaces of the clamping extension 6 such that a step is produced in the vicinity of the clamping extension 6 of the profiled cover 4 , said step able to serve as an abutment 14 for the corresponding compensating strip 10 .
[0027] In order to avoid gaps at the edges between the covering flange 5 extending over the floor surface 1 and the floor covering 2 , the covering flange 5 must form an undercut so that the longitudinal edge of the covering flange 5 is reliably supported on the floor covering 2 , as shown in FIG. 1 . In order to achieve such an undercut during manufacture of the profiled cover 4 , the kerfs 17 only need to run at an acute angle α with respect to the covering flange 5 , as shown in FIG. 3 . The corresponding inclination of the upper side of the compensating strips 10 formed by the kerfs 17 provides the advantage that the section of the covering flange 5 in the vicinity of the compensating strip 10 is supported across the full surface of the compensating strip 10 .
[0028] Manufacturing the profiled cover 4 and the compensating strips 10 from a common profiled section 15 also ensures advantageous conditions for coating the visible surfaces of the profiled cover 4 and the compensating strips 10 in a similar manner as the profiled cover 4 and compensating strips 10 can be coated at the same time as part of the profiled section 15 . Differences regarding the surface structure and the appearance of the coating can only occur as a result of changes near the kerfs 17 when the compensating strips 10 are separated from the profiled cover 4 after the common profiled section 15 has been coated. This separation by means of the kerfs 17 can be performed prior to or after coating, depending on the type of coating. Cutting along the kerfs 17 is recommended after coating with a foil for instance in order to achieve the smoothest transition possible between the coating structure and the appearance of the coating between the compensating strips 10 and the profiled cover 4 . On the other hand, in the case of spray coating, for instance varnishing, it is best to cut along the underside of the covering flange of the common profiled section 15 before coating in order to coat the edges producing by the kerfs 17 as indicated by the dot-dashed lines in FIG. 3 , which indicate the spray coating 19 that extends over the edges and into the kerfed areas.
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A device for bridging a difference in height between two floor surfaces ( 1, 3 ) is described, with said device comprising a profiled cover ( 4 ) that is provided with a covering flange ( 5 ) which covers the edge of each of the two floor surfaces ( 1, 3 ), with at least one clamping extension ( 6 ) that protrudes downward from the covering flange ( 5 ), extends longitudinally with respect to the profiled cover ( 4 ), and clamps into and engages with a fixture ( 7 ), with said device also comprising a compensating strip ( 10 ) located between the covering flange ( 5 ) of the profiled cover ( 4 ) and the lower of the two floor surfaces ( 1, 3 ). In order to create advantageous construction conditions it is proposed that the fixture ( 7 ) forms a clamping seat ( 11 ) for the compensating strip ( 10 ).
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CROSS REFERENCE
[0001] This application claims the priority of provisional application Ser. No. 61/147,517, filed Jan. 27, 2009.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to long-arm stitchers and, more particularly, to a stitch quality monitoring system for long-arm stitchers.
[0004] 2. Related Art
[0005] Conventional long-arm sewing machines are generally used for quilting and/or sewing fabrics that are not easily moved through a sewing machine. In particular, quilts generally include two outer layers and a filler material that is sewn between the outer layers. Accordingly, to limit the amount of fabric movement when quilting, long-arm sewing machines are typically mounted on a pair of rails that allow the operator to move the needle of the machine while keeping the quilt stationary.
[0006] However, the fabric thickness can cause the fabric to bunch during movement of the needle and/or may cause erratic feeding of the fabric through the needle. Moreover, the filler being stitched into the quilt is often uneven, thereby adding to sewing difficulties and creating difficultly for the operator to follow a stitching pattern, especially when the pattern is not straight. As such, the stitching in the quilt may become uneven and/or may have variable stitch lengths. Additionally, the sewing thread may break and/or loop undesirably when the speed of the machine is adjusted.
[0007] Typically, stitch quality is monitored visually by the operator of the machine. For example, U.S. Pat. 6,260,495, issued to Stewart, describes a monitoring system for a sewing machine that includes a camera to provide images of the article being sewn on a monitor. The image is held for approximately two or three seconds while a worker visually inspects a quality of the hem. In the event the worker sees a hem that is defective, the worker can hit an on/off switch to stop the sewing machine. Unfortunately, such monitoring systems are subject to human error and can often allow undesirable stitching to go undetected and/or slow the sewing process.
[0008] As such, it is desirable to have a sewing machine capable of monitoring and analyzing the stitching in a quilt as the quilt is assembled.
SUMMARY OF THE INVENTION
[0009] A stitcher is provided for placing stitches in a fabric. The stitcher includes a monitoring system having at least one sensor positioned below the fabric and angled toward a needle of the stitcher to monitor the stitches placed in the fabric. A microcontroller communicates with the sensor and is programmed with software that analyzes images of the stitches acquired by the sensor. The images are compared with a predetermined set of parameters stored in a memory associated with the microcontroller. These parameters may be either hardcoded in the memory and/or input by a user of the stitcher. When the attributes of the monitored stitches fall outside of the predetermined set of parameters, the stitcher is stopped. The microcontroller then notifies the user as to which parameter has not been met by the stitches. In one embodiment, a monitor is provided to display images of the stitches for manual stitch analysis and/or to display the parameters that have been violated by the stitches.
[0010] The stitcher may be a long-arm stitcher or a standard sewing machine that is configured for either commercial or household use. In the exemplary embodiment, the attributes of the stitches that are analyzed include any one of stitch looping, thread bunching, stitch length, and/or a distance between stitches. The system may also be configured to notify the user if no stitch is detected.
[0011] These aspects are merely illustrative of the innumerable aspects associated with the present invention and should not be deemed as limiting in any manner. These and other aspects, features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the referenced drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views.
[0013] FIG. 1 is a perspective view of a standard long-arm stitcher.
[0014] FIG. 2 is a schematic view of a monitoring system that may be used with the long-arm stitcher shown in FIG. 1 .
[0015] FIG. 3 is a schematic view of the monitoring system shown in FIG. 2 in use with the stitcher shown in FIG. 1 .
[0016] FIG. 4 is an algorithm of a monitoring process performed by the monitoring system shown in FIG. 2 to analyze a quality of stitches created by the stitcher shown in FIG. 1 .
[0017] FIG. 5 is an algorithm of image processing performed by the monitoring system shown in FIG. 2 to acquire images of the stitches created by the stitcher shown in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] In the following detailed description numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. For example, the invention is not limited in scope to the particular type of industry application depicted in the figures. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.
[0019] FIG. 1 illustrates a standard long-arm stitcher 10 including a base 12 , an arm 14 , and a take up lever box 16 . Although the present invention is described with respect to a long-arm stitcher, one of ordinary skill in the art would recognize that the present invention is also applicable to standard sewing machines. Moreover, the present invention is capable of operating with both commercial and household long-arm stitchers and sewing machines. The arm 14 is coupled to the base 12 at a back end 18 of the stitcher 10 . A first portion 20 of the arm 14 extends upward from the base 12 , and a second portion 22 of the arm 14 extends from the first portion 20 substantially parallel to the base 12 . The take up lever box 16 is disposed on the arm 14 at a stitching end 24 of the stitcher 10 that is opposite the back end 18 . The stitching end 24 of the stitcher 10 forms a workspace 26 where a fabric is stitched by an operator of the stitcher 10 . The stitching end includes a needle bar 28 having a needle 30 inserted therein and a hopping foot 32 each extending downward toward a needle plate 34 disposed on the base 12 . The needle plate 34 is attached to a square throat plate 36 . The throat plate 36 is configured to be removed to provide access to a rotary hook assembly (not shown) positioned within the base 12 below the throat plate 36 .
[0020] During operation, the needle bar 28 moves up and down thereby moving the needle 30 to form a stitch in the fabric. The needle bar 28 can be adjusted up or down to provide a proper machine timing height. A small hole in the needle plate 34 restricts movement of the thread as the stitch is formed. The hopping foot 32 raises and lowers with the movement of the needle 30 to press and release the fabric as the stitch is formed. The hopping foot 32 is designed to be used with rulers and templates and has a height that can be adjusted for proper stitch formation. A control box 48 is provided to control the operation of the stitcher 10 .
[0021] FIGS. 2 and 3 illustrate a monitoring system 38 used with the stitcher 10 shown in FIG. 1 to monitoring a stitch quality during operation of the stitcher 10 . Specifically, the monitoring system 38 is configured to detect and monitor stitches placed in the fabric as it is moved through the stitcher 10 . The monitoring system 38 includes a sensor or camera 40 configured to be positioned adjacent the workspace 26 of the stitcher and below the fabric. In the exemplary embodiment, the sensor 40 is a complementary metal-oxide-semiconductor (CMOS) sensor that provides images of the stitches placed in the fabric as the fabric moves through the stitcher 10 . As is well known in the digital arts, CMOS sensors accomplish the task of capturing light and converting it into electrical signals. A CMOS chip is a type of active pixel sensor made using the CMOS semiconductor process. Extra circuitry next to each photo sensor converts the light energy to a voltage. Additional circuitry on the chip may be included to convert the voltage to digital data. More specifically, the CMOS sensor as utilized in an embodiment of the disclosed monitoring system accumulates a signal charge in each pixel proportional to a local illumination intensity, serving a spatial sampling function. When exposure is complete, a charge-to-voltage conversion takes place in each pixel to create an image.
[0022] In another embodiment, the sensor 40 is any sensor or camera capable of detecting and monitoring the stitches as described herein, for example a charge-coupled device (CCD) sensor. A CCD is an analog device. When light strikes the chip it is held as a small electrical charge in each photo sensor. The charges are converted to voltage one pixel at a time as they are read from the chip. Additional circuitry in the camera converts the voltage into digital information. In short, a CCD sensor transfers each pixel's charge packet sequentially to a common output structure, which converts the charge to a voltage, buffers it and sends it off-chip as an image.
[0023] In the embodiment shown in FIG. 3 , three sensors 40 are positioned adjacent to the workspace 26 . Specifically, a first sensor 40 a is positioned in front 42 of the workspace 26 , and a pair of second sensors 40 b are positioned on each side 44 of the workspace 26 . Each sensor 40 is angled toward the needle 30 of the stitcher 10 . In an alternative embodiment, the monitoring system 38 includes only sensor 40 a positioned in front 42 of the workspace 26 and angled toward the needle 30 . In another embodiment, the monitoring system 38 only includes sensors 40 b positioned on each side 44 of the workspace 26 . In yet another embodiment, the monitoring system 38 includes only one of the pair of sensors 40 b . In each embodiment, the sensors 40 are angled toward the needle 30 of the stitcher 10 . The sensor 40 is configured to acquire images of the fabric and stitches as the stitches are placed in the fabric. These images are then transmitted to a microcontroller 46 in communication with the sensor 40 .
[0024] The microcontroller 46 may be disposed adjacent to the stitcher 10 and, in the exemplary embodiment, is digitally interfaced with the sensor 40 and electronically coupled to the control box 48 . In alternative embodiments, the microcontroller 46 may be physically coupled to the stitcher 10 or positioned remotely from the stitcher 10 and coupled to the sensor 40 and control box 48 in a wired or wireless manner. The microcontroller 46 is configured to analyze attributes of the stitches detected by the sensor 40 to determine if the attributes fall within a set of predetermined parameters that are defined for the stitches. Specifically, the microcontroller 46 includes a processor 50 programmed with software that analyzes images of the stitches taken by the sensor 40 to compare the attributes of the detected stitches with the predetermined set of parameters. In an embodiment including more than one sensor, the images from each sensor may be combined prior to analysis or each image may be individually analyzed. In the exemplary embodiment, the processor 50 is programmed with American National Standards Institute (ANSI) C software; however, as will be appreciated by one of ordinary skill in the art, the processor may be programmed with any software capable of analyzing the image as described herein.
[0025] In the exemplary embodiment, the attributes analyzed by the microcontroller 46 include the stitch looping and stitch bunching. For example, the microcontroller 46 determines if the stitch looping includes a predetermined amount of thread and/or a predetermined tightness and if a correct amount of thread is being run through the needle. In other embodiments, the microcontroller 46 can be programmed to determine if there is no stitch present in the fabric or if the stitch length and distance between the stitches falls within predetermined parameters. The predetermined parameters are hardcoded in the processor 50 based on a desired stitch length and/or thread size. Alternatively, the predetermined parameters may be programmed by a user prior to operation of the stitcher 10 . Accordingly, the monitoring system 38 allows for automatic detection of the stitches without user intervention. Further, the monitoring system 38 may be customized based on the stitch length and thread size. In the exemplary embodiment, the microcontroller 46 has the ability to save features embedded in the video in non-volatile and/or volatile memory that is used to compare the current stitch with the predetermined parameters for the purpose of “GOOD/BAD” stitch detection. Specifically the features of the stitch are seen as point to point lines of constant contrast in a video array output. This point to point line is analyzed to determine if the stitch is good or bad. For example, the criteria for “GOOD/BAD” may be the detection of the presence or absence of a loop from point to point. If the point to point line is straight, no loop is present and the stitch is flagged as “GOOD”. If the point to point line is not straight and loops from point to point, the stitch is flagged as “BAD”.
[0026] The algorithms shown in FIGS. 4 and 5 illustrate the steps taken by the monitoring system 38 during operation of the stitcher 10 . As the fabric is run through the stitcher 10 , the microcontroller 46 automatically analyzes each stitch placed in the fabric. Specifically, at step 100 an image of each stitch is taken by the sensor 40 as the fabric passes through the workspace 26 . The image is then processed at step 102 following the algorithm set forth in FIG. 5 . At step 104 , the microprocessor 46 determines whether the stitch quality falls within the predetermined parameters. If the stitch quality falls within the predetermined parameters 106 , the microcontroller begins analyzing the next stitch. If the stitch quality falls outside of the predetermined parameters 108 , a user warning is initiated 110 . In one embodiment, the stitcher 10 is stopped and a notification is sent to the user via a monitor 52 . The notification includes an analysis of what parameters have been violated by the stitch. The user is then able to adjust the stitcher 10 accordingly to correct the errors in stitching. When the error is corrected, the stitcher 10 is restarted and the microcontroller 46 continues to analyze each stitch. In the exemplary embodiment, the notification displays a description of each parameter violated on the monitor 52 . Alternatively, the notification may be an alarm, a light, and/or any other audio/visual notification. Further, in an alternative embodiment, the user can manually inspect the stitching on the monitor 52 to determine which parameters have been violated. In one embodiment, the user manually stops the stitcher 10 using a switch 54 . Although, the monitor 52 and the switch 54 are illustrated as being integral with the monitoring system 38 , as will be appreciated by one of ordinary skill in the art, these features may be separate from and electronically coupled to the monitoring system 38 .
[0027] FIG. 5 illustrates an algorithm of the image processing step 102 . Upon initiation of the image processing step 102 , color separation 112 is performed to maximize the contrast between the fabric and the thread. Next, the microprocessor 46 detects 114 loops in the stitch by analyzing the thread line. Specifically, loops in the stitch are detected 114 as curves rather than straight lines which indicate a proper stitch. If a loop is detected 116 , a poor quality flag is set 118 to initiate 110 the user warning. If a loop is not detected 120 , the poor quality flag is cleared 122 and the microprocessor 46 begins analyzing the next stitch 124 . Although the algorithm shown in FIG. 5 is described with respect to determining loops in the stitch, as will be appreciated by one of skill in the art, the same algorithm is also used to monitor each of the predetermined parameters being analyzed by the microprocessor 46 .
[0028] Accordingly, the present invention provides real-time analysis of stitches placed in a fabric by notifying a user of the stitcher 10 when a stitch quality falls outside of predetermined parameters. As such, the present invention provides a more cost efficient means of correcting stitch errors, thereby reducing costs associated with wasting or re-stitching incorrectly prepared fabrics.
[0029] As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.
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A stitcher is provided that includes a needle configured to place stitches in a fabric that is moved therethrough. The stitcher includes a sensor positioned below the fabric to monitor stitches placed in the fabric. A microcontroller is provided configured to receive data from the sensor and, based on such data, to compare one or more attributes of the monitored stitches with one or more predetermined parameters relating at least one attribute of the fabric. The predetermined parameter may be either hardcoded inn the microcontroller or input by a user of the stitcher prior to beginning operation of the machine. When the attributes of the monitored stitches fall outside of the predetermined parameters, the microcontroller initiates notification of the user.
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BACKGROUND OF THE INVENTION
The present invention relates to a digital frequency synthesizer which is immune to small variations of an analog program control signal to maintain the frequency division ratio constant when the variations lie within a predetermined range.
Conventional frequency synthesizers of the type which employs a programmable frequency divider make use of an analog-to-digital converter for converting an analog program control signal into a digital signal for controlling the frequency division ratio of the programmable frequency divider. However, the inherent small variation of the analog control signal tends to adversely affect the frequency division ratio.
SUMMARY OF THE INVENTION
Accordingly, an object of the invention is to overcome the aforesaid problem by incorporating a memory device for storing the digital signal to maintain the program input constant regardless of the presence of insignificant variations of the analog control signal.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be further described by way of example with reference to the accompanying drawings, in which:
FIG. 1 is a block diagram of a prior art frequency synthesizer;
FIG. 2 is a block diagram of a frequency synthesizer of the invention;
FIGS. 3a to 3m are a waveform diagram useful for describing the operation of the embodiment of FIG. 2 in cases where insignificant variations occur in the analog control signal;
FIGS. 4a to 4m are a waveform diagram useful for describing the operation of the embodiment of FIG. 2 in cases where the analog control signal is varied manually for changing the frequency division ratio;
FIG. 5 in an illustration of details of the digital-analog converter of FIG. 2; and
FIG. 6 is an illustration of details of the digital comparator of FIG. 2.
DETAILED DESCRIPTION
Before describing the present invention reference is first made to FIG. 1 in which a prior art frequency demultiplier or divider is illustrated. In FIG. 1, reference numeral 1 is an inverter, which together with a crystal quartz oscillator element 2, resistance 3 and capacitors 4 and 5 constitutes an oscillator. An inverter 6 is provided which serves as a buffer amplifier whose output is connected to the clock input terminal 7a of a flip-flop 7. To the output terminal 7b of the flip-flop 7 is connected an input terminal of an Exclusive-OR gate 8, and to the complementary output terminal 7c of the flip-flop 7 is connected the clock input terminal 9a of a flip-flop 9. To the true output terminal 9b of the flip-flop 9 is connected an input terminal of an Exclusive-OR gate 10 and to the complementary output 9c of the flip-flop 9 is connected the clock input terminal 11a of a flip-flop 11. To the true output terminal 11b of the flip-flop 11 is connected an input terminal of an Exclusive-OR gate 12 and to the complementary output terminal 11c of the flip-flop 11 is connected the clock input terminal 13a of a flip-flop 13. To the true output terminal 13b of the flip-flop 13 is connected an input terminal of an Exclusive-OR gate 14 and to the complementary output 13c of the flip-flop 13 is connected the clock input terminal 15a of a flip-flop 15. To the complementary output 15c of the flip-flop 15 is connected the clock input terminal 16a of a flip-flop 16 whose complementary output 16c is connected to the clock input terminal 17a of a flip-flop 17.
Furthermore, another input terminal of each of the Exclusive-OR gates 8, 10, 12 and 14 is connected to program input terminals A, B, C and D, respectively. The output terminals of these Exclusive-OR gates and the true output terminals 15b, 16, and 17b of flip-flops 15, 16 and 17 are connected to respective input terminals of an AND gate 18 whose output terminal is connected to the set input terminals of flip-flops 7, 9, 13 and 15 and also to the reset input terminals of flip-flops 11, 16 and 17, and further to an output terminal E of the frequency divider.
Each of the flip-flops 7, 9, 11, 13, 15, 16 and 17 is designed to switch to logic "1", which appears as a high voltage level at the true output terminal, in response to the leading or positive edge of an input clock pulse when the set and reset input terminals are both at logic "0" or low voltage level, and also switch to logic "1" when each flip-flop receives a logic "1" signal at its set input terminal regardless of the binary state of its clock input terminal, and switch to logic "0" level whenever a logic "0" signal is applied to the reset input regardless of the binary state of the clock input terminal.
Assuming that a set of binary signals "0000" is applied to the program input terminals, D, C, B and A, each flip-flop generates a logic "1" output, so that the output of the AND gate 18 is switched to logic "1", causing flip-flops 17, 16, 15, 13, 11, 9 and 7 to reset to logic levels "0 0 1 1 0 1 1", respectively. In other words, the output terminal E is preset to a set of binary states "0011011" which is a decimal value of "27" when all the flip-flops are at logic level "1 1 1 1 1 1 1" equivalent to a decimal value of "127", whereby the frequency divider changes its binary state in 100 discrete steps starting from the decimal value 27 to the decimal value 127. Therefore the output frequency of the driver is 1/100 of the input frequency.
Assuming next that the program input is changed to "0001", the flip-flops will be reset to "0 0 1 1 0 1 1" as counted from flip-flop 17 down to flip-flop 7 when these flip-flops are at logic levels "1 1 1 1 1 1 0", respectively. In this case, the frequency divider is preset to a division ratio of 1/99. In the same manner, a program signal of "1111" will produce a set of logic levels "1 1 1 0 0 0 0" which cause the flip-flops to change to "0 0 1 1 0 1 1", presetting the frequency divider to a ratio of 1/85. As seen from Table I, as the program input is varied with a step of binary digit "1" from decimal "0" to decimal "10", for example, with corresponding frequency division ratios from 1/100 to 1/90 and the input frequency is set at 100 kHz, the output frequency varies from 1000 Hz to 1111 Hz with a variation ranging from +0.000 to +11.111%.
TABLE I______________________________________PROGRAMINPUT OUTPUT VARIA- BINARY DIVISION FREQUENCY TIONDECIMAL "DCBA" RATIO (Hz) (%)______________________________________0 0000 1/100 1000 +0.0001 0001 1/99 1010 +1.0102 0010 1/98 1020 +2.0413 0011 1/97 1031 +3.0934 0100 1/96 1042 +4.1675 0101 1/95 1053 +5.2636 0110 1/94 1064 +6.3837 0111 1/93 1075 +7.5278 1000 1/92 1087 +8.6969 1001 1/91 1099 +9.89010 1010 1/90 1111 +11.111______________________________________
If the digital frequency synthesizer of FIG. 1 is employed as a standard variable frequency source in a radio tuner or motor control system, It is desirable that the output frequency be instantly varied in response to the control signal and that the control data be not lost even when power is turned off.
For this purpose the use of an analog-to-digital converter may be employed to convert a voltage developed across a variable resistor into a digital value and the latter is used as a control signal for altering the frequency division ratio. However, the voltage developed across the variable resistor tends to fluctuate in response to noise or aging of the variable resistor. This introduces an error in the analog control value which results in an error of at least one digital count.
For example, if the user makes and adjustment to the analog control value so that the output frequency of the system of FIG. 1 undergoes a frequency shift of 2%, the corresponding digital control value may fluctuate between "0 0 0 1" and "0 0 1 0" or between "0 0 1 0" and "0 0 1 1", and as a result the output frequency discretely varies between 1% and 2% values or between 2% and 3% values as seen from Table I. In other words, the system as a whole has a low degree of precision due to the inherent fluctuation factors which are present in the interface between analog and digital systems, even though a high precision type frequency oscillator such as crystal controlled oscillator is employed as a standard frequency source.
The present invention will now be described with reference to FIG. 2. The system of FIG. 2 comprises a programmable frequency divider 20 which receives input clock pulses from a clock source or any external signal source 19 and delivers frequency-divided output signal on terminal 20a depending on a set of binary states of its input terminals A, B, C and D arranged in the order from the least significant bit to the most significant bit. A frequency divider 21 is provided which divides the frequency of the input signal source 19 with a fixed division ratio and supplies its output to an input terminal 22a of a 6-bit down counter 22 and also to an input terminal 23a of a control circuit 23. The signal supplied from the divider 21 is used as a clock signal of the system of FIG. 3 and the 6-bit down counter 22 increments its count in response to this frequency divided clock pulse and delivers a set of 64 different combinations of binary states on its output terminals 22b, 22c, 22d, 22e, 22f and 22g arranged in the order of the least significant bit to the most significant bit. Therefore, the terminal 22g, which is the most significant bit terminal, remains at high voltage level during the first half of the counter cycle and remains at low voltage level during the second half cycle. The output terminals 22b to 22f of the down counter 22 are connected respectively to data input terminals D1 to D5 of a latch circuit 24 whose inverted output terminals Q1 to Q5 are connected to respective terminals of a digital comparator 26 and whose Q2 to Q5 terminals are connected respectively to terminals A to D of the programmable divider 20. The digital comparator 26 receives its other input signals from the down counter 22 through its terminals 22b to 22f to compare the input and output binary data of the latch 24 and delivers a logic "1" to an input terminal 23c of the control circuit 23 when there is a coincidence between them.
The output terminals 22b to 22f of the down counter 22 are also coupled to a digital-to-analog converter 25 wherein the latch input binary data is converted into an analog voltage which is applied to the noninverting input of a voltage comparator 29. The voltage comparator 29 compares it with a setting voltage derived from a tap 28b of a potentiometer 28 which is connected between a voltage stabilizer 27 and ground. The D-A converter 25 is also powered from the voltage stabilizer 27 to minimize the effect of source voltage fluctuation by cancelling it in the comparator 29. The output of this comparator is at low voltage level when the analog voltage from the D-A converter 25 is lower than the setting level, presented at its inverting input, and switches to a high voltage condition in response to the analog voltage exceeding the setting level and supplies its output signal to an input terminal 23d of the control circuit 23.
The control circuit 23 comprises generally a 2-bit counter 70 including flip-flops 47 and 48 and a NAND gate 49 having its one input coupled to the Q output of flip-flop 48 and its other input connected to the Q output of flip-flop 47 to generate a low level output when the counter 70 has received two input pulses supplied through terminal 23a and through a NAND gate 46 and inhibits the latter in response to that low level output. An edge detector 71 is provided which comprises three NAND gates 52, 53 and 58 to generate a low level pulse in response to the voltage applied to terminal 23d changing from low to high voltage levels, that is, when the analog voltage from converter 25 exceeds the setting level. Another edge detector 72 includes three NAND gates 56, 57 and 60 which are similar in operation to the edge detector 71 and receives its input signal from terminal 22g of down counter 22 through input terminal 23b, and applies its low level output pulse through an inverter 61 for purposes of resetting the flip-flops 47 and 48 of the 2-bit counter 70. The control circuit 23 further includes a flip-flop 73 comprised of two NAND gates 54 and 59 each having the output terminal connected to an input of the other NAND gate. The NAND gate 54 receives its another signal from the digital comparator 26 through terminal 23c and delivers a high voltage output to an input of an Exclusive-OR gate 51 whose other input is connected to the output of voltage comparator 29 through terminal 23d. The NAND gate 59 receives its other input signal from the output of NAND gate 56 of edge detector 72 for purposes of resetting the flip-flop 73, that is, the output of NAND gate 54.
As will be described later in detail, the down counter 22 generates all "1"s binary data initially and decrements it in response to each input clock pulse received at terminal 22a until all "0"s appear at its terminals 22b to 22f and on the other hand, the D-A converter 25 provides inversion of the binary decreasing input data and generates an analog voltage which increases with time until the contents of the down counter 22 become all "0"s. Thus, if the voltage setting at the potentiometer 28 should deviate from the initial setting level to which the binary contents of the latch circuit 24 correspond, there will be a difference in voltage level between the output of voltage comparator 29 and the output of flip-flop 73, causing a high voltage output to appear at the output of Exclusive-OR gate 51 to activate an AND gate 55 when the latter is enabled in the presence of a high voltage signal from the terminal 22g of the down counter 22. During the time when the AND gate 55 is activated the flip-flops 47 and 48 of the 2-bit counter 70 are enabled to initiate counting operation.
The control circuit 23 further includes an OR gate 50 which takes its inputs from the terminal 22g of the down counter 22, the output of NAND gate 49 of counter 70 and from the output of edge detector 71 to generate a low level pulse when its inputs are all at logic "0"s for purposes of resetting the latch circuit 24 through terminal 23e to store the binary count of down counter 22. Since the output of 2-bit counter 70 remains at high output state if it receives only one clock pulse, the contents of latch circuit 24 remain unchanged if the fluctuation of the voltage at the terminal 28b of the analog setting potentiometer 28 remains within a range which corresponds to a range of ±1 clock pulse or discrete variation of ±1 binary digit in down counter 22. The latch 24 is reset only if the voltage deviation exceeds an amount corresponding to a range of ±2 clock pulses.
This will be explained in more detail with reference to FIG. 3. Suppose that the logic states of the memory latch 24 are "1 1 1 0 0" which are the digital representation of the voltage given by the potentiometer 28, the inverted logic states "0 0 0 1 1" appear at the Q5, Q4, Q3, Q2 and Q1 output terminals, respectively, so that the logic states of the program terminals D, C, B and A of the frequency divider 20 are respectively "0 0 0 1" which corresponds to a frequency division ratio of 1/99 (see Table I). FIG. 3a shows the digital value of the down counter 22 in analog form. A decrement of the down counter to a level corresponding to "1 1 1 0 0" which is now stored in latch 24 will cause the digital comparator 26 to produce a logic "0" pulse (FIG. 3b) which is coupled to terminal 23c to cause NAND gate 54 to deliver a logic "1" to Exclusive-OR gate 51. If there is no voltage drift on the potentiometer terminal 28b, the voltage comparator 29 will deliver a logic "1" almost at the same instant as the output from the digital comparator 26, so that the output of Exclusive-OR gate 51 will remain unchanged. If the potentiometer 28 has a voltage drift "e" (FIG. 3c) which corresponds to one clock pulse count, the analog comparator 29 will produce a high level output 29-1 a one clock period later than the time the output from the digital comparator 26 is delivered (FIGS. 3d and 3e) and Exclusive-OR gate 51 will produce an output pulse 51-1 (FIG. 3g) in the presence of a high voltage state of the MSB terminal 22g of the down counter 22 (FIG. 3f). As a result, AND gate 55 is activated (FIG. 3h) to enable the 2-bit counter 70 to receive one clock pulse through NAND gate 46 (FIG. 3l). Therefore, the logic "0" output state of the counter 70 remains unchanged (FIG. 3m) and the OR gate 50 also remains disabled (FIG. 3k) to prevent delivery of a latch resetting pulse 52-2 to the latch 24 which is generated by NAND gate 52 of edge detector 71 in response to the leading edge of the output 29-2 from the voltage comparator 29 (FIG. 3i) when the MSB terminal 22g of the down counter changes to logic "0" state during the second half period of the counter cycle. The logic state of the latch 24 thus remains unchanged regardless of a setting voltage variation if it lies within a range of analog equivalents of ±1 clock pulse count.
Assume that the potentiometer 28 is readjusted to a new value which corresponds to a digital value of "1 1 0 1 0". As illustrated in FIG. 4d, the voltage comparator 29 produce an output 29-3 in response to the analog equivalent of the digital output from the down counter 22 coinciding with the voltage at terminal 28b when the down counter 22 decrements to logic state "1 1 0 1 0" at a point in time delayed by the period of two clock pulses from the time of delivery of an output 26-1 from digital comparator 26 (FIG. 4b), so that Exclusive-OR gate 51 produce a high voltage pulse 51-2 of two-clock-pulse period to allow the 2-bit counter 70 to count two clock pulses, thus resulting in a low output voltage at the output of the counter 70 (FIGS. 4l and 4m). An output pulse 29-4 generated by the voltage comparator 29 during the second half period of the down counter cycle will cause a logic "0" output 52-4 to be present at the output of NAND gate 52 of edge detector 71. Since OR gate 50 is enabled by the low level output from the counter 70, it produces a latch resetting pulse 50-1 in response to the pulse 52-4 to reset the latch 24 to the logic state "1 1 0 1 0" and shifts the frequency division ratio to 1/98.
FIG. 5 illustrates details of the D-A converter 25 which includes a plurality of CMOS inverters 30 to 34 connected to receive binary signals through terminals 22b to 22f of the down counter 22, respectively, having their positive power supply terminals connected together to a terminal 25a which is connected to the stabilized voltage source 27. The respective output terminals of the inverters 30 to 34 are connected to a digital-analog conversion resistance network generally known as R-2R network. The output voltage developed between lead 25x and ground is approximately 2 Es/3 when all the input voltages to the inverters 30 to 34 are logic "0"s, where Es is the voltage at terminal 25a, and is zero when all the input voltages are logic "1"s. Therefore, the voltage at lead 25x varies 32 discrete steps in a range between zero and 2Es/3 in response to each clock pulse. The circuit including transistors 35 to 39 serves to multiply the voltage at point 25x by 3/2 so that the voltage at a circuit point 25g discretely varies between zero and Es. More specifically, transistor 35 forms a constant current source which together with transistors 36, 37 and amplifier transistor 38 forms a voltage comparator whose output is supplied to a supply voltage control transistor 39 so that the voltage at a circuit point 25y varies stepwisely in a range between zero and 2Es/3 and in response to this the voltage at point 25g varies in the range of from zero to Es.
FIG. 6 is an illustration of details of the digital comparator 26 which, as shown, comprises a plurality of Exclusive-OR gates 40 to 44 each having their one input terminals connected respectively to the Q terminals of the latch 24 and have their another input terminals connected to the outputs of down counter 22 respectively. The output terminals of these Exclusive-OR gates are connected to a NAND gate 45 whose output is connected to terminal 23c of the control circuit 23. The NAND gate 45 thus delivers a logic "0" output when coincidence occurs between the logic states of the latch 24 and the logic states of the down counter 22.
The clock signal used to control the program input to the programmable frequency divider 20 may also be obtained from a suitable source independent from the input signal source 19. The operating frequency of the latch 24 and its associated circuitry is selected at a value much lower than the frequency of the standard frequency source 19. This allows the frequency divider 21 to be advantageously employed to reduce the standard frequency to the selected value. To minimize power consumption if the system is to be constructed of LSI circuitry, it is preferred that the operating frequency be as low as possible since the power consumption increases in proportion to the upper limit of the operating frequency.
The use of latch circuit 24 as a memory unit permits visual display of the output frequency value by operating the D-A converter 25, down counter 22, control circuit 23 and voltage comparator 29 on a time-sharing basis, and such time sharing operation would permit the counter 22 to be used for other purposes with a resultant decrease in number of the system components and a reduction of power consumption and manufacturing cost.
Another feature of the invention resides in the use of the stabilized voltage source 27 which supplies constant voltage to the D-A converter 25 and to the voltage setting potentiometer 28. Any voltage variation that occurs in the voltage stabilizer 27 will cause the voltages at the input terminals of the comparator 29 to vary by equal amounts so that such variations are cancelled out at the output of the comparator 29.
The foregoing description shows only preferred embodiment of the present invention. Various modifications are apparent to those skilled in the art without departing from the scope of the present invention. For example, a frequency multiplier may be constructed of a phase locked loop including the programmable frequency divider of the invention and a voltage controlled oscillator, whereby the output frequency of the voltage controlled oscillator varies in proportion to the adjustment of a potentiometer to derive a frequency-multiplied output. Therefore, the embodiment shown and described is only illustrative, not restrictive.
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A digital frequency synthesizer comprises a programmable frequency divider, an analog-to-digital converter for converting an analog program control signal into a digital signal, and a digital storage medium for storing the digital signal to control the frequency division ratio of the programmable frequency divider in accordance with the digital value of the stored signal.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a communication system, and more particularly, a double ring-type local area network (LAN) system using time division multiple access (TDMA).
2. Description of the Related Art
In a prior art double ring-type CAN system, a plurality of nodes are connected by a counterclockwise signal flow transmission line and a clockwise signal flow transmission line that provide distinct communication paths between each node in opposite directions. When a fault occurs in one of the transmission lines, data traveling between nodes on one communication path may be switched to travel between the nodes on the other communication path. On the other hand, when the fault which occurred in the above-mentioned transmission line recovers, the data switched to the other communication path may be switched back to the original communication path. This will be explained later in detail.
Thus, when the above-mentioned switching occurs in the communication paths, the continuity of signal transmission may be distrusted due to the difference in transmission delay time before and after the switching. Therefore, although the prior art ring-type LAN system is applicable to discrete communications such as packet communications, the prior art ring-type LAN system cannot be applied to complications over dedicated lines, since the quality of transmission is degraded.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a double ring-type LAN system capable of switching transmission paths without interruption.
According to the present invention, in a ring-type network system including a plurality of nodes connected by an L-ring and an R-ring, each of the nodes includes a branch unit for branching data to first and second directions, a first delay unit for delaying the data in the first direction by a first delay time period, a second delay unit for delaying the data in the second direction by a second delay time period, a first combiner for inserting delayed data in the first direction into a first time slot of a data frame on the L-ring, and a second combiner for inserting delayed data in the second direction into a first time slot of a data frame on the R-ring. Also, each of the nodes includes a first distributor for extracting data from a second time slot of a data frame on the L-ring, a second distributor for extracting data from a second time slot of a data frame on the R-ring, a third delay unit for delaying the data extracted by the first distributor by a third delay time period, a fourth delay unit for delaying the data extracted the second distributor by a fourth delay time period, and a switching unit for passing one of outputs of the third and fourth delay units.
If the transmission delay times of the two transmission paths are made equal to each other, a switching operation of the switching unit does not give rise to any interruption in the signal transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more clearly understood from the description as set forth below, with reference to the accompanying drawings, wherein:
FIGS. 1A and 1B are circuit diagrams illustrating a prior art double ring-type LAN system;
FIGS. 2A and 2B are circuit diagrams illustrating an embodiment of the double ring-type LAN system according to the present invention;
FIG. 3A is a data format of a data frame on the L-ring of FIGS. 2A and 2B;
FIG. 3B is a data format of a data frame on the R-ring of FIGS. 2A and 2B;
FIG. 4 is a block diagram of a modification of the LAN system of FIGS. 2A and 2B; and
FIG. 5 is a block diagram of another modification of the LAN system of FIGS. 2A and 2B.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Before the description of the preferred embodiment, a prior art double ring-type LAN system will be explained with reference to FIGS. 1A and 1B (see: JP-A-63-228849 & JP-A-61-264942).
In FIG. 1A, four nodes A, B, C and D are connected by a left-hand (L)-ring for a counterclockwise signal flow and a right-hand (R)-ring for a clockwise signal flow. The L-ring is formed by transmission lines L a-b , L b-c , L c-d and L d-a , and the R-ring is formed by transmission lines L a-d , L d-c , L c-b and L b-a .
In FIG. 1A, if the transmission lines L a-b and L b-a are normal communication between the nodes A and B is carried out by using the transmission lines L a-b and L b-a .
On the other hand, as illustrated in FIG. 1B, if the transmission lines L a-b and L b-a are abnormal, i.e., in a fault state, communication between the nodes A and B is carried out by the transmission lines L a-d , L d-c and L c-b and the transmission lines L b-c , L c-d , and L d-a .
Therefore, when a fault occurs in the transmission lines L a-b and L b-a , a communication path formed by the transmission line L a-b is switched to a communication path foxed by the transmission lines L a-d , L d-c and L c-b , and simultaneously, a communication path formed by the transmission line L b-a is switched to a communication path formed by the transmission lines L b-c , L c-d and L d-a .
On the other hand, when the fault which occurred in the transmission lines L a-b and L b-a recovers, the communication path formed by the transmission lines L a-d , L d-c and L c-b is switched to the communication path formed by the transmission line L a-b , and simultaneously, the communication path formed by the transmission lines L b-c , L c-d and L d-a is switched to the communication path formed by the transmission line L b-a .
Note that the above-mentioned switching of the communication paths may occur for maintenance purposes.
Thus, when the above-mentioned switching occurs in the communication paths, the continuity of signal transmission may be distrupted due to the difference in transmission delay time before and after the switching. Therefore, although the prior art ring-type LAN system of FIGS. 1A and 1B is applicable to discrete communications such as packet communications, the prior art ring-type LAN system of FIGS. 1A and 1B cannot be applied to communications over dedicated lines, since the quality of transmission is degraded.
FIGS. 2A and 2B are block diagrams illustrating an embodiment of the double ring-type LAN system according to the present invention, which can be applied to a TDMA system. In this TDMA system, note that a data frame on the L ring formed by the transmission lines L a-b , L b-c , L c-d and L d-a is divided into time slots LTS a-b , LTS b-a , LTS a-c , LTS c-a , . . . , LTS c-d and LTS d-c as shown in FIG. 3A, and a data frame on the R ring formed by the transmission lines L a-d , L d-c , L c-b and L b-a is divided into time slots RTS a-b , RTS b-a , RTS a-c , RTS c-a , . . . , RTS c-d and RTS d-c as shown in FIG. 3B. For example, the time slots LTS a-b and RTS a-b are allocated for the transmission of data DT a-b from the node A to the node A, and the time slots LTS b-a and RTS b-a are allocated for the transmission of data DT b-a from the node B to the node A.
In FIGS. 2A and 2B, the nodes A and B are illustrated in detail for showing transmission of the data DT a-b and DT b-a , and the circuits for transmission of the data DT a-c , DT c-a , DT a-d and DT d-a are omitted for simplifying the description.
In the node A, a distributor A1 and a combiner A2 are inserted in the L-ring, and a distributor A3 and a combiner A4 are inserted in the R-ring.
A branch unit A5 branches data DT a-b to error check bit allocating units A6 and A7. In the error check bit allocating units A6 and A7, error check bits are calculated for the data DT a-b , and as a result, each of the error check bits is allocated to the data DT a-b . The data DT a-b associated with one of the error check bits is delayed by a time period T1 in a delay unit A8, and then, in the combiner A2, the delayed data DT a-b associated with the error check bit is inserted as data LDT a-b in the time slot LTS a-b of a data frame on the L-ring. Simultaneously, the data DT a-b associated with the other of the error check bits is delayed by a time period T2 in a delay unit A9, and then, in the combiner A4, the delayed data DT a-b associated with the error check bit is inserted as data RDT a-b in the time slot RTS a-b of a data frame on the R-ring.
On the other hand, a delay unit A10 receives data LDT b-a of the time slot LTS b-a of a data frame on the L-ring in the distributor A1, so that the data LDT b-a is delayed by a time period T3. Also, a delay unit A11 receives data RDT b-a of the time slot RTS b-a of a data frame on the R-ring in the distributor A3, so that the data RDT b-a is delayed by a time period T4. Then an err detector A12 calculates an error check bit from the output of the delay unit A10, and compares the calculated error check bit with the error check bit included in the output of the delay unit A10. Only if both of the error check bits are different from each other, does the error detector A12 generate an error detection signal AE1. Simultaneously, an error detector A13 calculates an error check bit from the output of the delay unit A11, an compares the calculated error check bit with the error check bit included in the output of the delay unit A11. Only if both of the error check bits are different from each other, does the error detector A13 generate an error detection signal AE2. Further, a logic unit A14 such as an RS flip-flop receives the error detection signals AE1 and AE2 to control a switching unit A15. For example, when the error detection signal AE1 is generated, the logic unit A14 generates a high level signal so that the switching unit A15 passes the output of the delay unit A11 as data DT b-a . On the other hand, when the error detection signal AE2 is generated, the logic unit A14 generates a low level signal so that the switching unit A15 passes the output of the delay unit A10 as data DT b-a .
In the node A, a distributor B1 and a combiner B2 are inserted in the L-ring, and a distributor B3 and a combiner B4 are inserted in the R-ring.
Also, a branch unit B5 branches data DT b-a to error check bit allocating units B6 and B7. In the error check bit allocating units B6 and B7, error check bits are calculated for the data DT b-a , and as a result, each of the error check bits is allocated to the data DT b-a , The data DT b-a associated with one of the error check bits is delayed by a time period T1' in a delay unit B8, and then, in the combiner B2, the delayed data DT b-a associated with the error check bit is inserted as data LDT b-a in the time slot LTS b-a of a data frame on the L-ring. Simultaneously, the data DT b-a associated with the other of the error check bits is delayed by a time period T2' in a delay unit B9, and then, in the combiner B4, the delayed data DT b-a associated with the error check bit is inserted as data RDT b-a in the time slot RTS b-a of a data frame on the R-ring.
On the other hand, a delay unit B10 receives data LDT a-b of the time slot LTS a-b of a data frame on the L-ring in the distributor B1, so that the data LDT a-b is delayed by a time period T3'. Also, a delay unit B11 receives data RDT a-b of the time slot RTS a-b of a data frame on the R-ring in the distributor B3, so that the data RDT a-b is delayed by a time period T4'. Then, an error detector B12 calculates an error check bit from the output of the delay unit B10, and compares the calculated error check bit with the error check bit included in the output of the delay unit B10. Only if both of the error check bits are different from each other, does the error detector B12 generate an error detection signal BE1. Simultaneously, an error detector B13 calculates an error check bit from the output of the delay unit B11, and compares the calculated error check bit with the error check bit included in the output of the delay unit B11. Only if both of the error check bits are different from each other, does the error detector B13 generate an error detection signal BE2. Further, a logic unit B14 such as an RS flip-flop receives the error detection signals BE1 and BE2 to control a switching unit B15. For example, when the error detection signal BE1 is generated, the logic unit B14 generates a high level signal so that the switching unit B15 passes the output of the delay unit B11 as data DT a-b . On the other hand, when the error detection signal BE2 is generated, the logic unit B14 generates a low level signal so that the switching unit B15 passes the output of the delay unit B10 as data DT a-b .
The data DT a-b is transmitted from the node A to the node B via the following two transmission paths:
A5→A6→A8→A2→(L-RING)→B1→B10.fwdarw.B15
A5→A7→A9→A4→(R-RING)→B3→B11.fwdarw.B13→B15
In this case, a sum of the time periods T1 and T3' and a sum of the time periods T2 and T4' are predetermined, so that the delay time of transmission of the data DT a-b via the L-ring is substantially the same as the delay time of transmission of the data DT a-b via the R-ring.
Also, one of the above-mentioned two transmission paths is selected by the error detectors B12, B13 and the logic unit B14.
In a state where the switching unit B15 passes the signal from the L-ring, if a problem occurs on the transmission line L a-b , the error detector B12 detects the problem whereas the error detector B13 does not detect the problem, so that the logic unit B14 causes the switching unit B15 switch to pass the signal from the R-ring. Thus, one of the signal transmission paths can be switched to the other without interrupting the transmission of data.
Similarly, the data DT b-a is transmitted from the node B to the node A via the following two transmission paths:
B5→B6→B8→B2→(L-RING)→A1→A10.fwdarw.A15
B5→B7→B9→B4→(R-RING)→A3→A11.fwdarw.A13→A15
In this case, a sum of the time periods T1' and T3 and a sum of the time periods T2' and T4 are predetermined, so that the delay time of transmission of the data DT b-a via the L-ring is substantially the same as the delay time of transmission of the data DT b-a via the R-ring.
Also, one of the above-mentioned two transmission paths is selected by the error detectors A12, A13 and the logic unit A14.
In a state where the switching unit A15 passes the signal from the R-ring, if a problem occurs on the transmission line L b-a , the error detector A13 detects the problem whereas the error detector A12 does not detect the problem, so that the logic unit A14 causes the switching unit A15 switch to pass the signal from the L-ring. Thus, one of the signal transmission paths can be switched to the other without interrupting the transmission of data.
Note that, if the transmission path through the L-ring or the R-ring is selected, the signal transmission is not interrupted if it is switched to the R-ring or the L-ring for maintenance or some other purpose.
Therefore, a switching operation of the switching unit B15 or A15 does not give rise to any interruption in the transmission of the data DT a-b or DT b-a . Also, if the transmission lines are wireless and gradually degraded by a fading phenomenon, for example, then the degradation of the transmission lines can be detected to switch the transmission paths before they become fatal. Thus, any interruption of communication can be minimized or eliminated to provide a reliable transmission path.
In FIGS. 2A and 2B, the switching units A15 and B15 may be of a stable type or a non-stable type. Also, although the outputs of the error detectors A12 and A13 (B12 and B13) are supplied directly to the logic unit A14 (B14), it is possible to interpose an integration unit 41 and a comparator 42 between the error detector A12 (B12) and the logic unit A14 (B14) and interpose an integration unit 43 and a comparator 44 between the error detector A13 (B13) and the logic unit A14 (B14) as illustrated in FIG. 4. In this case, only after one error detector generates a number of continuous error signals, is the state of the logic unit A14 (B14) changed to switch the transmission path, thus avoiding the chattering operation of the switching unit A15 (B15). Further, although the error check bit allocating units A6 and A7 (B6 and B7) are connected to the two outputs of the distributor A5, (B5), it is possible to connect one error check bit allocating unit 51 to the input of the distributor A5 (B5) as illustrated in FIG. 5.
As explained hereinabove, according to the present invention, a switching operation of the switching unit does not give rise to any interruption in the signal transmission because the transmission delay times of the two transmission paths are made equal to each other and the switching operations on the respective transmission paths are carried out in the same time slot for maintenance and other purposes. If a problem occurs on one transmission line, the transmission path can be switched with a minimal interruption, thus establishing a highly reliable transmission.
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In a ring-type network system including a plurality of nodes connected by an L-ring and a R-ring, each of the nodes is constructed by a branch unit for branching data to first and second directions, a first delay unit for delaying the data in the first direction by a first delay time period, a second delay unit for delaying the data in the second direction by a second delay time period, a first combiner for inserting the delayed data in the first direction into a first time slot of a data frame on the L-ring, and a second combiner for inserting the delayed data in the second direction into a first time slot of a data frame on the R-ring. Also, each of the nodes is constructed by a first distributor for extracting data from a second time slot of a data frame on the L-ring, a second distributor for extracting data from a second time slot of a data frame on the R-ring, a third delay unit for delaying the data extracted by the first distributor by a third delay time period, a fourth delay unit for delaying the data extracted the second distributor by a third delay time period, and a switching unit for passing one of outputs of the third and fourth delay units.
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CROSS REFERENCE TO RELATED APPLICATION
This application is related to commonly assigned copending application Ser. No. 07/724,018, filed Jul. 1, 1991 under Attorney's Docket No. 8CL-6894.
FIELD OF THE INVENTION
This invention relates to thermoplastic condensation polymers which are terpolymers having aromatic polyester, polysiloxane and polycarbonate segments. These polymers exhibit non-Newtonian melt viscosities, advantageous low temperature properties and resistance to solvents, chemicals, hydrolysis and to photodecomposition. The terpolymers are especially useful as engineering thermoplastics.
BRIEF DESCRIPTION OF THE RELATED ART
Condensation copolymers having polysiloxane and polycarbonate blocks are known. Representative of such polymers are those disclosed by Schmidt et al., U.S. Pat. No. 4,681,922, Vaughn, U.S. Pat. No. 3,189,662, Vaughn, U.S. Pat. No. 3,419,635, and Merritt, U.S. Pat. No. 3,832,419. Some of these copolymers, while useful, have lower than desired flow properties, requiring high torque or high molding pressures during processing. From the standpoint of ease of processing, it is desirable for a thermoplastic to have higher melt flow properties. This makes possible rapid and complete mold filling and is especially important for molding complex and thinwalled articles.
Other siloxane-carbonate copolymers, such as described by Vaughn, U.S. Pat. No. 3,419,635, have an elastomeric character and are not considered as engineering thermoplastics, being more useful as adhesives, coatings, sealants, roofing material, impact modifying additives and the like.
Shortcomings of other siloxane-carbonate polymers are inadequate impact strength at low temperatures and inadequate resistance to distortion at elevated temperatures.
Another property which needs improvement beyond the levels achieved with the prior art copolymers is solvent resistance, as manifested for instance by resistance to crazing upon exposure to solvents, motor fuels, and the like.
A shortcoming of certain other known polycarbonate-siloxane copolymers is the presence of an aryloxysilicon linkage, which is hydrolysis prone.
In said copending application, Ser. No. 07/724,018, filed, Jul. 1, 1991, are disclosed condensation polymers which are terpolymers having aliphatic polyester, polysiloxane and polycarbonate segments (blocks). In comparison with the prior art, these polymers exhibit advantageous melt flows, advantageous low temperature properties and resistance to solvents, chemicals, and to hydrolysis.
It has now been discovered that, if such terpolymers are prepared, but instead of aliphatic polyester segments, aromatic polyester segments are employed, commercially important and unexpected additional advantages are obtained.
The new polymers of this invention are terpolymers having aromatic polyester, polysiloxane and polycarbonate segments (blocks). They exhibit unexpectedly advantageous non-Newtonian melt viscosity behavior and better low temperature ductility and thick section impact than the corresponding non-siloxane containing polyester carbonates.
These advantages are commercially significant because currently available high heat resistant resins are difficult to injection mold, but the decrease in viscosity under shearing conditions of the new resins makes it easier to fill molds to produce difficult to fill parts. Furthermore parts exposed to low temperatures, e.g. -30° C., made from the new resins maintain a high percentage of their ductility and are much less prone to failure when impacted.
A further advantageous feature of the invention from a process standpoint is the formation of the new segmented polymers in a convenient and novel one-step process which forms the aromatic polyester segment from an aromatic diacid halide, the carbonate segment from a bisphenol and links them with the polysiloxane segment. This is in contrast to processes for making block copolymers, where it is usually necessary to synthesize the individual blocks and to combine them in a separate step, thus imposing additional labor and time on the process.
SUMMARY OF THE INVENTION
The invention comprises a thermoplastic terpolymer, which comprises; (a) about 1 to about 50 weight percent of a repeating or recurring polysiloxane unit, based on the total weight of the terpolymer, of the formula: ##STR2## where R 1 and R 2 are each independently selected from hydrogen, hydrocarbyl, halogen-substituted hydrocarbyl (R 1 preferably is methyl and R 2 preferably is methyl or phenyl); D is the average block length and is from about 10 to about 120, preferably about 30-70, and more preferably 40-60; and Y is hydrogen, alkyl or alkoxy (and where alkoxy, preferably methoxy); and (b) about 99 to about 50% by weight of the terpolymer of a polycarbonate-aromatic polyester condensation copolymer consisting essentially of from about 80 to about 10% by weight, relative to the total weight of recurring units in (b), of polycarbonate units of the formula: ##STR3## where R 3 and R 4 are each selected from hydrogen, hydrocarbyl or halogen-substituted hydrocarbyl, (preferably methyl); and from 20 to 90% by weight, relative to the total weight of the recurring units in (b), of aromatic diester units of the formula: ##STR4## where A is phenylene, preferably iso-phenylene, tere-phenylene or a mixture thereof.
The term "hydrocarbyl" as used herein means the monovalent moiety obtained upon removal of a hydrogen atom from a parent hydrocarbon. Representative of hydrocarbyl are alkyl of 1 to 25 carbon atoms, inclusive such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, undecyl, decyl, dodecyl, octadecyl, nonodecyl eicosyl, heneicosyl, docosyl, tricosyl, tetracosyl, pentacosyl and the isomeric forms thereof; aryl of 6 to 25 carbon atoms, inclusive, such as phenyl, tolyl, xylyl, napthyl, biphenyl, tetraphenyl and the like; aralkyl of 7 to 25 carbon atoms, inclusive, such as benzyl, phenethyl, phenpropyl, phenbutyl, phenhexyl, napthoctyl and the like; cycloalkyl of 3 to 8 carbon atoms, inclusive, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and the like.
The term "phenylene" means the divalent moiety obtained on removal of two hydrogen atoms, each from a carbon atom of a benzene and includes phenylene of 6 carbon atoms such as 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, mixtures of any of them and the like.
The term "halogen-substituted hydrocarbyl", as used herein means the hydrocarbyl moiety as previously defined wherein one or more hydrogen atoms have been replaced with a halogen atom.
The term "halogen" and "halide" are embracive of chlorine, bromine, iodine and fluorine; preferably chlorine and bromine.
DETAILED DESCRIPTION OF THE INVENTION
The following description presents embodiment compositions of the invention and the manner and process of conducting the process of the invention.
The process of this invention comprises reacting a carbonate precursor such as phosgene simultaneously with (1) a siloxane, terminated by phenolic hydroxyls, of the formula: ##STR5## where R 1 , R 2 , D and Y are as defined above, (2) a bisphenol of the formula: ##STR6## where R 2 and R 4 are as defined above; and (3) an aromatic dicarboxylic acid halide having the formula: ##STR7## where A is phenylene and X is chloro or bromo; in the presence of sufficient aqueous alkali to maintain an alkaline pH and in the presence of a substantially water-immiscible solvent; the reactants (1), (2) and (3) being in the ratio required for the terpolymer structure described above.
The procedure is the well-known interfacial polymerization technique, used to prepare polycarbonate resins.
The method of preparation of polycarbonates by interfacial polymerization are well known; see for example the details provided in the U.S. Pat. Nos. 3,028,365; 3,334,154; 3,275,601; 3,915,926; 3,030,331; 3,169,121; and 4,188,314, all of which are incorporated herein by reference thereto.
Although the reaction conditions of the preparative processes may vary, several of the preferred processes typically involve dissolving or dispersing the bisphenol reactant in aqueous caustic soda or potash, adding the resulting mixture with the siloxane and the aromatic diacid halide to a suitable water immiscible solvent medium and contacting the reactants with the carbonate precursor, such as phosgene, in the presence of a suitable catalyst such as triethyl amine and under controlled pH conditions, e.g., 8-10. The most commonly used water immiscible solvents include methylene chloride, 1,2-dichloroethane, chlorobenzene, toluene, and the like.
A catalyst may be employed to accelerate the rate of polymerization of the dihydroxy phenol reactant with the carbonate precursor. Representative catalysts include but are not limited to tertiary amines such as triethylamine, quaternary phosphonium compounds, quaternary ammonium compounds, and the like. The preferred process for preparing resins of the invention comprises the phosgenation reaction. The temperature at which the phosgenation reaction proceeds may vary from below 0° C., to above 100° C. The phosgenation reaction preferably proceeds at temperatures of from room temperatures (25° C.) to 50° C. Since the reaction is exothermic, the rate of phosgene addition may be used to control the reaction temperature. The amount of phosgene required will generally depend upon the amount of the dihydric phenol reactant and the amount of aromatic dicarboxylic acid halide also present.
The process of the invention may be conducted without a chain limiting amount of a monohydric phenol chain stopper, but it is preferable that such an agent be present so that the molecular weight is controlled. Any monohydric phenol can be used, unsubstituted or with one or more substituents such as hydrocarbyl, hydrocarbyloxy or halogen, but the preferred monohydric phenols are phenol and p-cumyl phenol. The typical amount of monohydric phenol to result in the desired molecular weight (chain length) being in the desired range is about 0.5% to 5.0% by weight of bisphenol. The preferred end groups for the terpolymers of the invention are aryloxy groups, especially phenoxy, optionally substituted by one or more hydrocarbyl, hydrocarbyloxy, and/or halogen substituents. Preferred endcapping phenols are phenol, p-tertiary butyl phenol, p-cumyl phenol, and the like. Special mention is made of p-cumyl phenol.
The terpolymers of the invention comprise recurring segments of the Formulae as sot forth above.
Particularly preferred polysiloxane blocks are made from bisphenolpolysiloxanes, which may be prepared in accordance with the method described in U.S. Pat. No. 3,419,635. A preferred compound is readily provided by eugenol (2-methoxy-4-allylphenol) reacted to cap a hydrogen-terminated polysiloxane by an addition reaction advantageously catalyzed by platinum or its compounds. The essential features of the capping process are described by Vaughn, U.S. Pat. No. 3,419,635, which is incorporated by reference. For instance, the process is exemplified in example 8 of this Vaughn patent which describes the addition of a hydrogen-terminated polydimethylsiloxane to allylphenol in the presence of a catalytic amount of platinum catalyst at an elevated temperature.
The bisphenols of the above described formula are preferably used for the preparation of the polycarbonate segment of the terpolymer. Examples of preferred R 3 and R 4 groups are hydrogen, methyl, ethyl, n-propyl, isopropyl, octyl, eicosyl, vinyl, cyclohexyl, phenyl, trifluoromethyl, chlorophenyl, benzyl, and pentabromophenyl. The most preferred R 3 and R 4 groups are methyl, thus the most preferred bisphenol is bisphenol A. Representative of other bisphenol are those listed in U.S. Pat. No. 4,994,532 (col. 3, lines 33-55) which is incorporated herein by reference thereto.
The aromatic dicarboxylic acid halide is preferably iso-phenylene, tere-phenylene or a mixture thereof.
The amount of alkali to be used in the process of the invention is at least that amount needed to neutralize the hydrochloric acid stoichiometrically produced by the reaction of the phosgene and the aromatic dicarboxylic acid halide with the phenolic groups of the bisphenol and the phenolically-terminated siloxane, although an excess over this amount can be used. The alkali is conveniently an alkaline metal hydroxide, such as sodium, potassium or lithium hydroxide, although a soluble alkali carbonate can also be used. The preferred alkali is aqueous sodium hydroxide.
The process of the invention features the simultaneous formation and incorporation of the siloxane, the aromatic polyester and the polycarbonate segments into the terpolymer product.
The products can be recovered from the reaction mixture in known ways. For example, the organic layer can be separated, washed with aqueous acid and water until neutral, then steam treated to precipitate the terpolymer which is recovered and dried.
The terpolymers of the invention may be compounded with the addition of various types of additives known to the art of plastics compounding. Such additives can include for example fillers (such as clay or talc), reinforcing agents (such as glass fibers), impact modifiers, other resins, antistats, plasticizers, flow promoters and other processing aids, stabilizers, colorants, mold release agents, other flame retardants, ultraviolet screening agents, and the like. The thermoplastic of the invention can also be blended with other resins such as ABS and thermoplastic polyesters to produce useful thermoplastic blends.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will be better understood with reference to the following examples, which are presented for purposes of illustration rather than for limitation, and set forth the best mode contemplated for carrying out the invention.
PREPARATION 1
Representative preparation of eugenol capped polydimethylsiloxane fluid;
Octamethylcyclotetrasiloxane (8.3 kg, 28.0 soles), tetramethyldisiloxane (330 g, 2.46 moles) and Filtrol 20 (86 g, 1% by weight, Harshaw/Filtrol Clay Products) were combined in a 12 L flask and heated to 45° C. for 2 hours. The temperature was raised to 100° C. and the mixture was rapidly agitated for 5 hours. The mixture was allowed to cool then filtered through a plug of Celite filtering aid. To the crude product was added a mixture of eugenol (774 g, 4.72 moles) and Karstedt's platinum catalyst (1.57 g, 10 ppm Pt) at a rate of 40 g/minute. Reaction completion was monitored by the disappearance of the siloxane hydrogen in the FTIR spectrum. The reaction product was stripped of volatiles using a falling thin film evaporator operating at 200° C. and 1.5 torr. The isolated material was a light brown oil with a viscosity of 100 cstokes at 25° C. and a degree of polymerization of 49 siloxane units. The material was used without further purification.
EXAMPLE 1
A polyester-polycarbonate-polysiloxane terpolymer, in accordance with the present invention, is prepared by charging a vessel with 150.0 g of the siloxane from Preparation 1, 1772.0 g of 2,2-bis-(4-hydroxyphenyl)propane (hereinafter BPA), 57.7 g of p-cumylphenol, 21.0 g of triethylamine (TEA) in methylene chloride and 6.0 liters of water. While the mixture is being stirred, 1165.0 g of a 93:7 isophthaloyl chloride:terephthaloyl chloride mixture dissolved in methylene chloride is added to the vessel. The total volume of methylene chloride in the vessel is 11 liters. During the addition of the diacid chloride mixture to the vessel, the pH is maintained between 8 and 10 by the addition of sodium hydroxide.
After the diacid chloride mixture is added, 240.0 g of phosgene is added to the vessel.
The organic layer is separated, washed with dilute hydrochloric acid, washed with water, steam precipitated and dried. The resulting polyester-polycarbonate-polysiloxane block terpolymer has 5% by weight siloxane, 80 weight percent eater units based on the total ester and carbonate units in the terpolymer and a resin molecular weight of 28,700.
The resulting product is compounded with a phosphite stabilizer (0.05 wt %) and tumbled in a stainless steel can prior to extrusion on a Werner and Pfleider 28 or 30 mm co-rotating twin screw extruder operating at 550 to 570° F. barrel temperature. Test specimens where prepared by injection molding at 570° F. melt temperature and 180° F. mold temperature. Notched IZOD impact of single gated bars is determined according to ASTM D-256. The heat distortion temperature (HDT) at 264 PSI and the apparent melt viscosities at 350° C. is also determined for the copolymer. The results are reported in Table 1.
EXAMPLE 2
A polyester-polycarbonate-polysiloxane terpolymer, in accordance with the present invention, is prepared by charging a vessel with 150.0 g of the siloxane from Preparation 1, 1772.0 g of BPA, 57.7 g of p-cumylphenol, 21.0 g of TEA in methylene chloride and 6.0 liters of water. While the mixture is being stirred, 1165.0 g of a 93:7 isophthaloyl chloride:terephthaloyl chloride mixture dissolved in methylene chloride is added to the vessel. The total volume of methylene chloride in the vessel is 11 liters. During the addition of the diacid chloride mixture to the vessel, the pH is maintained between 8 and 10 by the addition of sodium hydroxide.
After the diacid chloride mixture is added, 240.0 g of phosgene is added to the vessel.
The organic layer is separated, washed with dilute hydrochloric acid, washed with water, steam precipitated and dried. The resulting polyester-polycarbonate-polysiloxane terpolymer has 5% by weight siloxane, 80 weight percent ester units based on the total ester and carbonate units in the terpolymer and a resin molecular weight of 31,000.
The resulting product is compounded and tested according to the procedures outlined in Example 1. The results are reported in Table 1.
EXAMPLE 3
A polyester-polycarbonate-polysiloxane terpolymer, in accordance with the present invention, is prepared by charging a vessel with 150.0 g of the siloxane from Preparation 1, 1772.0 g of SPA, 57.7 g of p-cumylphenol, 25.0 g of TEA in methylene chloride and 6.0 liters of water. While the mixture Is being stirred, 1165.0 g of a 50:50 isophthaloyl chloride:terephthaloyl chloride mixture dissolved in methylene chloride is added to the vessel. The total volume of methylene chloride in the vessel is 11 liters. During the addition of the diacid chloride mixture to the vessel, the pH is maintained between 8 and 10 by the addition of sodium hydroxide.
After the diacid chloride mixture is added, 240.0 g of phosgene is added to the vessel.
The organic layer is separated, washed with dilute hydrochloric acid, washed with water, steam precipitated and dried. The resulting polyester-polycarbonate-polysiloxane block copolymer has 5% by weight siloxane, 80 weight percent ester units based on the total ester and carbonate units in the terpolymer and a resin molecular weight of 31,500.
The resulting product is compounded and tested according to the procedures outlined in Example 1. The results are reported in Table 1.
EXAMPLE 4
A polyester-polycarbonate-polysiloxane block terpolymer, in accordance with the present invention, is prepared by charging a vessel with 150.0 g of the siloxane from Preparation 1, 1772.0 g of BPA, 57.7 g of p-cumylphenol, 25.0 g of TEA in methylene chloride and 6.0 liters of water. While the mixture is being stirred, 1165.0 g of a 50:50 isophthaloyl chloride:terephthaloyl chloride mixture dissolved in methylene chloride is added to the vessel. The total volume of methylene chloride in the vessel is 11 liters. During the addition of the diacid chloride mixture to the vessel, the pH is maintained between 8 and 10 by the addition of sodium hydroxide.
After the diacid chloride mixture is added, 240.0 g of phosgene is added to the vessel.
The organic layer is separated, washed with dilute hydrochloric acid, washed with water, steam precipitated and dried. The resulting polyester-polycarbonate-polysiloxane block copolymer has 5% by weight siloxane, 80 weight percent ester units based on the total aster and carbonate units in the terpolymer and a resin molecular weight of 33,400.
The resulting product is compounded and tested according to the procedures outlined in Example 1. The results are reported in Table 1.
EXAMPLE 5
A polyester-polycarbonate-polysiloxane terpolymer, in accordance with the present invention, is prepared by charging a vessel with 150.0 g of the siloxane from Preparation 1, 1772.0 g of BPA, 57.7 g of p-cumylphenol, 25.0 g of TEA in methylene chloride and 6.0 liters of water. While the mixture is being stirred, 1165.0 g of a 50:50 isophthaloyl chloride:terephthaloyl chloride mixture dissolved in methylene chloride is added to the vessel. The total volume of methylene chloride in the vessel is 11 liters. During the addition of the diacid chloride mixture to the vessel, the pH is maintained between 8 and 10 by the addition of sodium hydroxide.
After the diacid chloride mixture is added, 240.0 g of phosgene is added to the vessel.
The organic layer is separated, washed with dilute hydrochloric acid, washed with water, steam precipitated and dried. The resulting polyester-polycarbonate-polysiloxane block copolymer has 5% by weight siloxane, 80 weight percent ester units based on the total ester and carbonate units in the terpolymer and a resin molecular weight of 30,400.
The resulting product is compounded and tested according to the procedures outlined in Example 1. The results are reported in Table 1.
EXAMPLE 6
A polyester-polycarbonate-polysiloxane block terpolymer, in accordance with the present invention, is prepared by charging a vessel with 158.0 g of the siloxane from Preparation 1, 2125.9 g of BPA, 69.2 g of p-cumylphenol, 25.0 g of TEA in methylene chloride and 6.0 liters of water. While the mixture is being stirred, 694.4 g of a terephthaloyl chloride dissolved in methylene chloride is added to the vessel. The total volume of methylene chloride in the vessel is 12 liters. During the addition of the diacid chloride to the vessel, the pH is maintained between 8 and 10 by the addition of sodium hydroxide.
After the diacid chloride is added, 684.0 g of phosgene is added to the vessel.
The organic layer is separated, washed with dilute hydrochloric acid, washed with water, steam precipitated and dried. The resulting polyester-polycarbonate-polysiloxane block copolymer has 5% by weight siloxane, 45 weight percent ester units based on the total ester and carbonate units in the terpolymer and a resin molecular weight of 30,800.
The resulting product is compounded and tested according to the procedures outlined in Example 1. The results are reported in Table 1.
EXAMPLE 7
A polyester-polycarbonate-polysiloxane block terpolymer, in accordance with the present invention, is prepared by charging a vessel with 158.0 g of the siloxane from Preparation 1, 2125.9 g of BPA, 69.2 g of p-cumylphenol, 25.0 g of TEA in methylene chloride and 6.0 liters of water. While the mixture is being stirred, 694.4 g of a terephthaloyl chloride dissolved in methylene chloride is added to the vessel. The total volume of methylene chloride in the vessel is 12 liters. During the addition of the diacid chloride to the vessel, the pH is maintained between 8 and 10 by the addition of sodium hydroxide.
After the diacid chloride is added, 684.0 g of phosgene is added to the vessel.
The organic layer is separated, washed with dilute hydrochloric acid, washed with water, steam precipitated and dried. The resulting polyester-polycarbonate-polysiloxane block copolymer has 5% by weight siloxane, 45 weight percent ester units based on the total ester and carbonate units in the terpolymer and a resin molecular weight of 30,400.
The resulting product is compounded and tested according to the procedures outlined in Example 1. The results are reported in Table 1.
COMPARATIVE EXAMPLE 1
A polyester-polycarbonate copolymer, not in accordance with the present invention, is prepared by charging a vessel with 1367.9 g of BPA, 48.3 g of p-cumylphenol, 16.7 g of TEA in methylene chloride and 5.0 liters of water. While the mixture is being stirred, 929.0 g of a 93:7 isophthaloyl chloride:terephthaloyl chloride mixture dissolved in methylene chloride is added to the vessel. The total volume of methylene chloride in the vessel is 11 liters. During the addition of the diacid chloride mixture to the vessel, the pH is maintained between 8 and 10 by the addition of sodium hydroxide.
After the diacid chloride mixture is added, 200.0 g of phosgene is added to the vessel.
The organic layer is separated, washed with dilute hydrochloric acid, washed with water, steam precipitated and dried. The resulting polyester-polycarbonate copolymer has 0% by weight siloxane, 80 weight percent ester units based on the total ester and carbonate units in the copolymer and a resin molecular weight of 28,800.
The resulting product is compounded and tested according to the procedures outlined in Example 1. The results are reported in Table 1.
COMPARATIVE EXAMPLE 2
A polyester-polycarbonate copolymer, not in accordance with the present invention, is prepared by charging a vessel with 1367.9 g of BPA, 48.3 g of p-cumylphenol, 16.7 g of TEA in methylene chloride and 5.0 liters of water. While the mixture is being stirred, 929.0 g of a 93:7 isophthaloyl chloride:terephthaloyl chloride mixture dissolved in methylene chloride is added to the vessel. The total volume of methylene chloride in the vessel is 11 liters. During the addition of the diacid chloride mixture to the vessel, the pH is maintained between 8 and 10 by the addition of sodium hydroxide.
After the diacid chloride mixture is added, 200.0 g of phosgene is added to the vessel.
The organic layer is separated, washed with dilute hydrochloric acid, washed with water, steam precipitated and dried. The resulting polyester-polycarbonate copolymer has 0% by weight siloxane, 80 weight percent ester units based on the total ester and polycarbonate units in the copolymer and a resin molecular weight of 28,900.
The resulting product is compounded and tested according to the procedures outlined in Example 1. The results are reported in Table 1.
TABLE 1__________________________________________________________________________EXAM-PLE 1 2 3 4 5 6 7 1* 2*__________________________________________________________________________Resin MW28,700 31,000 31,500 33,400 30,400 30,800 30,400 28,800 28,900Melt -- -- 1,400 1,300 850 1,100 990 480 --Viscosity100 sec.sup.-1Melt -- -- 744 650 410 470 440 510 --Viscosity1000 sec.sup.-2HDT 291° F. 306° F. -- 305° F. 313° F. 293° F. 291° F. 311° F. 317° F.125 milNotchedIZODRT 8.9 8.3 5.8 5.3 5.7 7.5 8.1 8.5 8.40° C.8.3 7.2 5.7 5.5 5.8 7.4 8.0 7.7-10° C.7.9 7.2 5.3 5.7 5.4 6.5 6.9 3.6-20° C.6.5 6.0 6.3 7.0 1.4-30° C. 6.4 6.7-40° C.5.2 4.8250 milNotchedIZODRT 5.6 5.2 3.0__________________________________________________________________________ *Comparative Examples with 0% siloxane RTroom temperature HDTheat of distortion temperature at 264 PSI The melt viscosities are apparent melt viscosities at 350° C. in pascal seconds at the given apparent shear rate.
The results reported in Table 1, show that polyester-polycarbonate-polysiloxane terpolymers prepared in accordance with the present invention, Examples 1-7, exhibit non-Newtonian melt viscosities whereas conventional polyester-polycarbonate copolymers, Comparative Examples 1 and 2, exhibit Newtonian melt viscosities.
Furthermore, the results in Table 1 indicate that the melt viscosity of polyester-polycarbonate-polysiloxane terpolymers, Example 1-7, decreases by approximately 50% at high shear rates, whereas the melt viscosity of polyester-polycarbonate copolymer, without polysiloxane units, Comparative Examples 1-2, is almost constant with the shear rate. The decrease in melt viscosity at high shear rates allows the present invention to be used in injection molding processes of parts that are normally difficult to fill.
The results reported in Table 1 also show that polyester-polycarbonate-polysiloxane terpolymers prepared in accordance with the present invention, Examples 1-7, have better low temperature ductility and thick section impact than polyester-polycarbonate copolymers without polysiloxane blocks, Comparative Examples 1-2. The results specifically show that polyester-polycarbonate-polysiloxane terpolymers prepared in accordance with the present invention, Examples 1-7, have good ductility down to about -30° C., whereas polyester-polycarbonate copolymers without polysiloxane blocks, Comparative Examples 1-2, lose half their impact strength by -10° C.
The above mentioned patents, publications, and test methods are incorporated herein by reference.
Many variations in the present invention will suggest themselves to those skilled in this art in light of the above, detailed description. For example, instead of a terpolymer containing 5 weight percent of polysiloxane segments, one containing 45 weight percent can be used. Instead of a polysiloxane segment with an average degree of polymerization of 49 siloxane units, the average degree of polymerization could be varied from 10 to 120. In addition, two siloxane blocks of different degrees of polymerization could be mixed and used. Instead of iso- and tere-phthaloyldichloride, there can be used 2-6-naphthaloyl dibromide. Instead of cumyl phenol as a molecular weight modifier, phenol can be used. All such obvious modifications are within the full intended scope of the appended claims.
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Terpolymers suitable as molding resins are provided having aromatic polyester segments polycarbonate segments and polysiloxane segments of the structure ##STR1## where R 1 , R 2 , Y and D are as defined herein, and where the weight percentage of polyester and polycarbonate segments is from 50 to 99%, preferably 92 to 96%, and the weight percentage of polysiloxane segments is from 50 to 1%, preferably from 8 to 4%. Also provided is a one-step process to prepare the new terpolymers by reacting together a siloxane, a bisphenol and an aromatic dicarboxylic acid halide.
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CROSS REFERENCE OF RELATED APPLICATIONS
[0001] Pursuant to 35 U.S.C. Section 119, the benefit of priority from Provisional Application 60/223,569 with filing date Aug. 7, 2000 is claimed for this Non-Provisional Application.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] This invention relates to the protective apparatus for the hands, and more particularly, multiple sleeves coupled to a palm apron for inserting multiple digits of the grasping hand of a user. The sleeves and palm apron provide for insulation of the fingers and contiguous part of the grasping hand from contact with the operative portions of doors, door handles and surfaces of public conveniences
[0004] 2. Description of the Prior Art
[0005] The use of devices for receiving a user's fingers for a variety of purposes is known in the prior art. More specifically, sleeves, cots and puncture resistant gloves for a wide variety of purposes heretofore devised and utilized for protecting the user from infectious diseases, corrosive or poisonous agents. Others have been developed to facilitate the grasping of objects by extending the effective lengths of fingers. Garrett-Roe in U.S. Pat. No. 5,749,097 (1998) described a protective apparatus consisting three sheaths tethered together for protecting two fingers and a thumb of the hand of a manicurist from solvents present during the natural discourse of the manicurist duties. Davis et. al. in U.S. Pat. No. 4,796,302 (1988) disclosed a multi-finger guard with two sheaths for protecting the fingers from impacts. Kim in U.S. Pat. No. 5,363,508 described a finger and palm guard for barbers and cosmetologists made up of a pair of tubular members or rings that accommodate the middle and index fingers of the user's hand. Attached to and extending from each of these members is a projection that extends over the palmar fascia in the region immediately adjacent the knuckles joining the metacarpals and the third phalanges of both the middle and index fingers. The finger and palm guard is designed to prevent a path for the transmission of various diseases. Sullivan et al. in U.S. Pat. No. 5,087,499 disclosed a puncture-resistant and medicinal treatment garment.
[0006] In addition to the possible transmission of disease by sharp implements such as needles an surgical knifes, the ecology of infection is complex and involves interactions with climate, food and water supply, arthropod vectors, animal contacts, contact with objects handled by carriers of infectious diseases. In public facilities, such as restrooms it is the contact of the hands with objects that are touched or grasped by many users that results in the spread of infectious disease. The washing of hands by workers in convenient food places is therefore encouraged or otherwise mandated for the restaurant workers.
[0007] It is an object of this invention to provide a protector for the preferred working hand from germs and other infectious agents resulting from exposure to contaminated surfaces during normal activities. A second object of this invention is to provide a multiple finger contamination protector that will receive without assistance the thumb and a multiplicity of adjacent fingers of a working hand. A still further objective of this invention is to provide a palm and finger protector, which is contact-coated with fungicide and disinfectant agents, that prevent the vectoring of a fungi and a virus to the hand of a wearer. Other objects of this invention will become apparent during a reading of the detailed description of the invention.
SUMMARY OF THE INVENTION
[0008] An apparatus for protecting the operable part of a working hand comprises multiple finger sleeves, a palm shield, and a sheath for receiving the hand protecting apparatus. The sleeves being composed of hydrophobic polymeric or other materials coated or otherwise laden with disinfecting or pharmaceutical agents for destroying disease causing virus inter alia. The hand protector being designed to be attached separately or in a sheath in a non-obtrusive position on the users body such that only the hand to be protected is required to employ the hand protector for use.
DETAILED LIST OF FIGURES
[0009] [0009]FIG. 1 is a plan view of the apparatus of this invention shown as it would be deployed on the hand of a user.
[0010] [0010]FIG. 2 is a side view of the device of this invention deployed on the belt of a user.
[0011] [0011]FIG. 3 shows a second embodiment of the device of this invention complete with a receiving sheath and mounted on the belt of a user.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Referring now to the figures and more particularly to FIG. 1, a sketch according to one embodiment of the palm and finger protector of the present invention as referenced by the numeral 2 . The palm and finger protector referenced by the numeral 2 has palm apron 14 which is attached to the finger sleeves 8 , 6 , and 4 proximate their first ends using first terminal edge 15 a as shown in FIGS. 1 and 2. Throughout this application, the palm and finger protector may be referred to interchangeably via the phrase protective shield. The first face 16 of apron 14 is for contacting surfaces while the second face 17 contacts the users' palm. In FIGS. 1 and 2, the fingers sleeves 4 through 8 are attached to the apron via adhesive 10 (not shown in FIG. 1). It should be understood, however, that the fingers and apron could have been made in one integral unit. Also, they could have been joined by sewing the finger sleeves to the first terminal edge of the apron. The finger sleeves 8 , 6 and 4 are design to receive the thumb, index and middle fingers at their open first ends 5 , 7 and 9 of FIG. 2, respectively. When employed on a hand, the sleeves 4 through 8 and the first face 16 of the apron prevents the physical contact between the palm and fingers with surfaces in public use. The palm apron and finger sleeves of the device of this invention were made of plastic. However, even though the initial finger and palm protectors were made of plastic, they could just as well been made of rubber, organic or other polymeric materials. They could have also been made of a combination of the aforementioned materials. Returning to the protective shield of this invention, the closed distal ends of finger sleeves 8 , 6 and 4 are set at linear distances from their open first ends that substantially parallels the average relative differences in the lengths of fingers of adults. Likewise, the closed distal ends of finger sleeves 8 , 6 and 4 are set at linear distances from their open first ends that substantially parallels the average relative differences in the lengths of fingers of children. The open first ends 5 , 7 and 9 are defined by rings 11 a , 11 b , 11 c which are embedded in plastic finger sleeves 8 , 6 and 4 (see FIGS. 1 and 2) near the open first ends of the sleeves 8 , 6 , and 4 . Rings 12 , which are not connected to sleeves, serve to help hold the apron 14 —second face in good contact with the surface of the palm of a hand. When the protective shield is mounted on the hand, phalanges 3 are inserted through rings 12 . The inclination of the plastic rings 11 a , 11 b and 11 c is set such that the plastic rings at the open first ends 5 , 7 and 9 are displaced linearly in a manner substantially identical to the relative position of the heel of the thumb to the knuckle of the index and middle finger. The angle of the plane containing the thumb ring 11 a being essentially at a right angle relative to the plane containing the rings 11 b and 11 c for the index and middle fingers, respectively. Rings 11 a through 11 c provide for easy insertion of the fingers of the users. The outer surface 18 of the finger sleeves 8 , 6 and 4 and that of palm apron 14 are coated with a disinfectant or a fungicide (not shown in the FIG. 1). The disinfectant could be any of a number of chemicals anti disease and viral destructive agents. For example, any disinfecting and pharmaceutical agents that are compatible with plastics Furthermore any known conventional means of coating the various types of disinfecting and pharmaceutical agents on plastics may be used. Depending whether or not the palm and finger protector is a disposal unit, the manner and type of disinfectant or pharmaceutical agent will be chosen accordingly. The disinfecting agent and the fungicide can be applied with commercially available bonding agent for coating or binding active elements to a surface. The disinfectant and or fungicide can also be immersed in the fabric or material of construction of the protective shield. Throughout this specification the inventors have described a palm and finger protector that make use of a disinfectant inter alia added to its surface or immersed in its material of construction. However, a disposable palm and finger protector could provide a barrier to viruses and infectious disease transmission with and without the conjunctive use of a disinfectant or chemical agent. The hand shields of FIGS. 1 and 2 are shown attached to belt 24 of a user in FIG. 2. It could, however, be kept for ready use and safekeeping in an independent container wherefrom it is removed only when needed. In the case of disposable shields, a plurality of shields may be housed in a single container
[0013] [0013]FIG. 2 shows the palm and finger protector of this invention, as it could be stored on a user. The palm and finger protector could be suspended in a front or rear pocket or the side belt area 22 of a skirt, dress or pants. . In any case, the second edge 23 of apron 14 (FIGS. 1 and 2) maybe attached to a wear's belt as shown in FIG. 2 as by mating hoop and loop fabrics fasteners 26 a and 26 b , respectively. Loop 26 a may be mechanically attached to a host belt or garment while loop 26 b is attached to the first surface 16 of apron 14 near its second edge 23 . As mentioned previously, both apron 14 and finger sleeves 8 , 6 and 4 were composed of plastic. However, any type of fiber, whether they are the high strength polymeric type, conventional fabrics or combinations of both, may be utilized to fabricate the apparatus of this invention. A wide variety of materials could be used in manufacturing the finger and palm protector, depending on whether it was desired to have the protector to be reusable or disposable. Various types of plastics, metal, leather, or combinations thereof are contemplated. The use of fiber construction can be used to enhance the absorption of the disinfectants or pharmaceutical agents to increase the effective lifetime of the finger and palm protector. For example a, 10% solution of 1-ethenyl-2-pyrrolidinone homopolymer with iodine and 1-vinyl-2-pyrrolidinone polymers in an iodine complex would make an adequate disinfectant. The disinfectant could be an integral part of the polymeric materials.
[0014] A second embodiment of the device of this invention is shown in FIG. 3. The second embodiment of FIG. 3 shows absorber 28 as it is disposed in the interior of sheath 30 and palm and finger protector 2 ′ as it would be positioned during non use within sheath 30 . Sheath 30 is composed of a liquid impervious material having a first part 31 and a second part 33 that are mechanically held together in non leaking contact as by adhesive (not shown in FIG. 3) or by stitching (not shown in FIG. 3) so as to form pocket 35 . Parts 31 and 33 each have first and second surfaces. Absorber 28 is attached to the entire second face of part 31 and a substantially portion of the first surface of part 33 . Hoop fastener 32 a is attached to the second surface of part 33 at its first end 34 . The mating loop fastener 32 b is as by adhesive or other mechanical methods to belt 24 ′. The sheath 30 is thereby attached to the belt 24 ′ of the user. The nook and loop fastener 26 a ′ and 26 b ′ function as described previously. The difference being that loop 26 b ′ is attached by adhesive to the second surface of part 33 . It should be clear that the loop fastener 32 b could have been attached at other positions on the body to an article of clothing. Absorber 28 , which is impregnate with disinfectant and pharmaceutical agents which are designed to coat the grasping surfaces of the fingers sleeves 8 ′, 6 ′, and 4 ′ (not shown in FIG. 3) and the first face 16 (not shown in FIG. 3) of apron 14 such that the effective disease and virus fighting capability of the protector is rejuvenated each time it is placed in sheath 30 . The absorber 28 is encased over substantially the full inner surface of sheath 30 . Together the protective shield 2 and sheath 30 forms an assembly that rejuvenates the active disease and virus fighting strength of the system after each use. The disinfectant and pharmaceutical agents maybe added to the absorber when need via a standard commercial container.
[0015] The use and function of the apparatus of this invention will now be discussed. In this case, the user, utilizing the apparatus of the first embodiment, insert the thumb index and middle fingers into the sleeves and breaks the bonding of loop 26 b to hook 26 a . The palm and finger protector 2 is now ready for use. The user can now grasp a surface without fear of exposure to dangerous viruses and disease.
[0016] The purpose and design of the device of this invention have been discussed in clear detail that would make clear the claimed invention. The invention is susceptible to variations and modifications from the embodiments, materials and methods of fabrication described herein. For example the finger sheaths may include all the fingers of the grasping hand. Likewise they could be made of highly absorbent paper fibrous materials.
[0017] Several different variations and or modifications of the present invention are possible from the embodiments and method of fabrication described above. For example, the number of sleeves may be changed to include more or fewer digits. Further, the sleeves could be replaced with single sleeve that encompass the full hand. Additionally, the size and shape of the apron may be changed. Finally, the user need not carry the protective shield on his/her person. The protective shield(s) may be transported in a separate container. In view of these facts, it should be understood that the present invention is limited only by the scope of the claims presented below.
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A protective shield 2 for protecting the operable part of a working hand comprises multiple finger sleeves and a palm shield. The sleeves being composed of hydrophobic polymeric or other materials coated or otherwise laden with disinfecting or pharmaceutical agents for destroying disease causing virus inter alia. The hand protector being designed to be attached separately or in a sheath in a non-obtrusive position on the users body such that only the hand to be protected is required to employ the hand protector for use.
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BACKGROUND OF THE INVENTION
At the present time, in this country, considerable difficulty and expense are involved in disposing of liquid waste sewage from municipal and privately owned treatment plants. Various types of equipment have been installed, none of which are fully integrated units, but which utilize individual pieces of equipment which function separately, thereby requiring considerable manpower, space and expense in accomplishing the desired sludge drying operation.
SUMMARY
It is a primary object to provide an apparatus and method which may be utilized efficiently and economically to convert objectionable waste liquid sludge, having a water content of 97 to 99 per cent, into a completely dry, pelletized and sterilized product, bagged and ready for sale as a plant nutrient and as a soil conditioner which can be applied by conventional spreaders.
Another object of the invention is to provide such an apparatus and process wherein the resulting end product is of a value far exceeding the cost of processing the material, thus converting the disposal of sewage sludge from a very expensive to a profitable procedure.
Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, illustrating a presently preferred embodiment thereof, and wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow sheet representing the various parts of the apparatus and the various steps in the process, and
FIG. 2 is a diagramatic view illustrating the electrical control center.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more specifically to the drawings, the apparatus and process for producing a dry, pelletized and sterilized organic product from liquid waste sludge is designated generally 5 and constitutes an integrated unit which includes a dewatering section 6, a drying, pelletizing and sterilizing section 7, and an air-solids separation section 8. The invention also includes an electrical control center 9, FIG. 2, for controlling the operation of the various motors of the apparatus of FIG. 1.
Referring to FIG. 1, the dewatering section includes a receptacle 10 for storing liquid sludge from a sewage treatment plant and which has a water content of 97 to 99 per cent. A pump 11 conveys the sludge from the receptacle 10 to a chemical mixer 12. The pump 11 operates simultaneously with a pump 13 which conveys a chemical from a storage receptacle 14 to the mixer 12. Only a small amount of the chemical is required to coagulate and floculate the solids contained in the liquid sludge in the chemical mixer. The mixture of liquid sludge and chemical is conveyed from the mixer 12 to a dewatering press 15 wherein the free water is pressed from the sludge to reduce the moisture content to about 80 per cent. A pump 16 supplies fresh water by means of a spray system to the dewatering press for continuously cleaning the elements of the press while said press is in operation. The parts 10 to 16, previously described, all constitute elements of the dewatering section.
A conveyor 17 conveys the sludge cake, having a moisture content of approximately 80 per cent, to a dewatered material storage bin 18. Water which has been extracted from the liquid sludge by the dewatering press 15 is returned by way of a conduit 15' by gravity flow to the influent works of the sewage treatment plant. A conveyor 19 conveys the dewatered material from the bin 18 to a mixing chamber 20 where it is mixed with pellets, constituting the final product supplied to the chamber 20 by a conveyor 21 driven by an adjustable motor 22. The final product supplied to the mixing chamber 20 has just been produced and constitutes a hot dry material which can be mixed with the dewatered sludge to a consistency containing a low moisture content, by regulation of the conveyor motor 22, prior to deliver of the mixture from the chamber 20 to a dryer 23, by means of a conveyor 24.
Mixing of the final hot dried product with the moist dewatered sludge cake is necessary to enable drying temperatures to be low enough to prevent formation of clinkers and the ignition of the organic material being fed to the dryer. The percentage of the final product returned to the chamber 20 also determines the size of the pellets produced as the final product. The larger the percentage of the final product returned to the chamber 20, the smaller will be the pellets formed in the dryer 23. Fuel, either gas or petroleum, and ignition is supplied to the dryer 23 by the equipment 25. Air required to support combustion in the dryer 23 is supplied by an air blower 26 which sucks air through the dryer 23 by means of a conduit 27.
The conduit 27 leads from the section 7 into the air-solids separation section 8 where it connects with the inlet of an air-solids separator 28, in which the pelletized, dried and sterilized product falls to the bottom of the separator 28 to be discharged by gravity through a conduit 29 to a finished product storage bin 30. The air from the dryer 23 and separator 28, which contains dust and fine particles of sludge solids, is drawn through a conduit 31 to a wet scrubber 32. Water is conveyed by a pump 33 to the scrubber 32 for cleaning the dust and fine solids from the hot air. These solids in solution are returned to the treatment plant influent by the conduit 34. The blower 26 extracts the waste water from the scrubber 32 and discharges it into the atmosphere as a clean plume of water vapor which condenses rapidly and presents no air pollution problem.
The conveyor 21, previously described, leads from the finished product storage 30 for returning the just produced hot dry pellets to the mixing chamber 20. The remainder of the pellets of the storage bin 30 can either be discharged into a bagging machine 30' for bagging prior to delivery to the market or may be discharged for conveyance in bulk to the market.
Referring to FIG. 2, the electrical control center 9 automatically governs the operation of the motors and accessories of the apparatus as illustrated in FIG. 1, in such a way as to require no attention of an operator. The control center 9 is operated by a time sequence on switch 35 and a time sequence off switch 36, each of which may be located at some central point in the area of the apparatus of FIG. 1, with wiring, as illustrated in FIG. 2, to each of the motors and other electrical accessories of FIG. 1. Each such motor or other accessory is preferably provided with a normally closed manually operated switch 37, so that any individual motor or other electrically operated device may be shut off or started manually in the event of a breakdown or for necessary testing purposes.
When the switch 35 is energized, circuit 38 will be energized for starting the motor of the dewatering press 15 and the water pump motor 16, so that the press 15 will be entirely wet and in operation before it receives any sludge to be dewatered. Simultaneously, the motor of the dryer 23, the dryer ignition unit 25, the blower 26 and the motor of the pump 33 are energized in order to preheat the drying equipment before the dryer 23 receives any material to be dried.
After a variable predetermined time interval of one to five minutes following the closing of the switch 35, circuit 39 is energized for starting the liquid sludge pump 11 and the chemical pump 13. When this occurs, the liquid sludge together with the chemical are fed into the chemical mixer and this mixture flows to the dewatering press 15. Simultaneously, the motors of the conveyors 17, 19, 22 and 24 are energized together with the mixer motor 20 at which time all electrically actuated elements of the apparatus are functioning.
After a predetermined time interval and when it is desired to discontinue operation of the apparatus, the switch 36 is energized. This initially energizes the circuit 40 causing the motors of the sludge pump 11 and chemical feed pump 13 and the conveyor motor 22 to be deenergized. After a predetermined variable time lapse of 5 to 15 minutes, circuits 41 and 42 are deenergized for cutting off automatically the supply of current to all of the other motors and electrical devices.
Various modifictions and changes are contemplated and may be resorted to, without departing from the function or scope of the invention.
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A completely integrated and automated apparatus by which liquid sewage sludge from any sewage or waste treatment plant may be processed into a completely dry, pelletized and sterilized product of an organic nature containing nutrients valuable for the support of plant life. The apparatus involves one completely integrated and automated unit together with a control center by means of which electric circuits program each component of the apparatus to automatically regulate the operation of each component, so that no labor or other manpower is required in the operation, except for observation, lubrication, maintenance and repair of the various motors and machineries involved.
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FIELD OF THE INVENTION
The present invention relates to non-volatile semiconductor memory chips and more particularly to magnetoresistive memory cells adapted for spin-polarized electron current induced switching.
BACKGROUND
Magnetic (or magnetoresistive) random access memory (MRAM) is a non-volatile memory technology considered to be of great future importance as the standard memory technology for computing devices.
A schematic representation of a typical magnetoresistive memory cell is shown in FIG. 1 . A magnetoresistive memory cell (also referred to as a tunneling magneto-resistive or TMR-device) includes a structure having ferromagnetic layers 2 , 4 respectively having a resultant magnetic moment vector 5 , 6 separated by a non-magnetic layer (tunnel barrier) 3 and arranged into a magnetic tunnel junction (MTJ) 1 . Digital information is stored and represented in the magnetic memory cell as directions of magnetic moment vectors in the ferromagnetic layers. More specifically, the resultant magnetic moment vector 6 of one ferromagnetic layer 4 is magnetically fixed or pinned (typically also referred to as the “reference layer”, “pinned layer” or “fixed layer”), while the resultant magnetic moment vector 5 of the other ferromagnetic layer 2 (typically also referred to as the “free layer”) is free to be switched between two preferred directions, i.e., the same and opposite directions with respect to the fixed magnetization 6 of the reference layer 4 . The orientations of the magnetic moment vector 5 of the free layer 2 are also known as “parallel” and “antiparallel” states, respectively, wherein a parallel state refers to the same magnetic alignment of the free and reference layers (upper diagram of FIG. 1 ), while an antiparallel state refers to opposing alignments therebetween (lower diagram of FIG. 1 ). Accordingly, a logic state of a magnetoresistive memory cell is not maintained by power as in DRAMs, but rather by the direction of the magnetic moment vector of the free layer with respect to the direction of the magnetic moment vector of the reference layer (for instance, a logic “0” in the case of a parallel alignment of magnetic moment vectors and a logic “1” in the case of an antiparallel alignment therebetween).
Depending upon the magnetic states of the free layer, the magnetic memory cell exhibits two different resistance values in response to a voltage applied across the magnetic tunnel junction barrier, wherein the resistance is “low” when the magnetization is parallel and “high” when the magnetization is antiparallel, so that a detection of changes in resistance allows an MRAM-device to provide logic information stored in the magnetic memory element.
A magnetic memory cell typically is written to through the application of magnetic fields from bi- or uni-directional currents. For writing of magnetic memory cells different writing (switching) scenarios are known depending on the actual configuration of the magnetoresistive memory cell such as Stoner-Wohlfahrt-switching or adiabatic rotational switching (toggle-switching) which are well-known to those skilled in the art and therefore need not be further detailed here.
To be useful in present day electronic devices, such as digital cameras or the like, very high density arrays of magnetic memory cells must be used, thus rendering a scaling-down of MRAM cells one of the most important issues, which, however, requires several problems to be solved.
Down-scaling of MRAM cells requires smaller and smaller magnetic tunnel junctions, which proves problematic, since for a given aspect ratio and free layer thickness, the activation energy, being dependent on the free layer volume, scales down like w, where w is the width of the magnetic cell. Otherwise, in down-scaling, the switching fields increase roughly like 1√{square root over (w)}, so that magnetic field selected switching becomes ever harder, but at the same time the magnetic cells loose their information more and more rapidly due to thermal activation. A major problem with having a small activation energy (energy barrier) is that it becomes extremely difficult to selectively switch one MRAM cell in an array, where selectability is seen to allow switching without inadvertently switching other MRAM cells. The memory cells therefore still need to retain a sizeable shape or induced anisotropy in order to maintain thermal stability.
Reference is now made to FIG. 2 showing a diagram in which the energy barrier height ΔE for switching of magnetic moment vector 5 of magnetic free layer 2 of rectangular MTJ 1 of FIG. 1 having lateral dimensions L for length and 1 for width (see insert) and a low thickness of about 2 nm is plotted against its width 1. It is further assumed that magnetization of the magnetic free layer 2 is aligned along directions ±x. Considering a simple Arrhenius law with a 0.1 nsec characteristic attempt time, requesting a ten years stability is equivalent to setting the barrier height between stable states (−x and −x) at about 45 k B T (T=300°K, room temperature, k B is Boltzmann constant).
As can be seen from FIG. 2 , an aspect ratio L/1=2 proves sufficient for overcoming the energy barrier height lower limit criterion if 1 remains greater than about 60 nm. A slight increase of the aspect ratio pushes the limit further out. It also becomes clear that as sizes shrink down, the superparamagnetic limit becomes closer and closer.
Another problem in scaling down magnetoresistive memory cells may be seen in that in the case of magnetic field selected switching of memory cells the cell sizes need to be smaller than sizes of the current lines for generating of magnetic fields in order to ensure essentially homogeneous magnetic fields over the whole memory cell area.
In an attempt to overcome the above problems, a new concept of writing to magnetoresistive memory cells has been recently proposed, where the reversal of the magnetic moment vector of the magnetic free layer is generated not by external magnetic fields but by spin-polarized electrons passing perpendicularly through the stack of memory cell layers. For a detailed description of that concept, see for instance seminal U.S. Pat. No. 5,695,864 to Slonczewski and U.S. Pat. No. 6,532,164 to Redon et al., the disclosures of which are incorporated herein by reference.
In the above new concept, by sending an electric current through a magnetic layer having a particular magnetization, spins of electrons are oriented by quantum-mechanical magnetic exchange interaction with the result that the current electrons leave the magnetic layer with a polarized spin. Alternatively, where spin-polarized electrons are passed through a magnetic layer having a particular magnetic moment vector in a preferred easy axis direction, these spin-polarized electrons will cause a continuous rotation of the magnetic moment vector which may result in a reversal of the magnetic moment vector along its easy axis. Hence, switching of the magnetic moment vector between its two preferred directions along the easy axis may be effected by passing spin-polarized electrons perpendicularly through the magnetic layer.
Recent experimental data (see S. I. Kiselev et al., Nature 425 (2003), 380 and W. H. Rippard et al., Phys. Rev. Lett. 92 (2004) 027201) confirm the very essence of magnetic moment transfer as a source of magnetic excitations and, subsequently, switching. These experiments confirm theoretical predictions (see J. C. Sloncezwski, J. Magn. Magn. Mater. 159 (1996) LI and M. D. Stiles & A. Zangwill, Phys. Rev. B66, (2002) 014407) stating that the leading torque term acting on the magnetization under conditions of spin-polarized DC current is proportional to:
ⅆ m ⅆ t ∝ P [ m ⨯ ( m ⨯ p ) ]
where m, p and P are the magnetization direction in space, the polarization direction of the electron current (density per unit area J) and a polarization function, respectively. A direct inspection of above equation indicates that the torque will be maximum when p is orthogonal to m.
Reference is now made to FIGS. 3A and 3B , where a schematic representation of both a magnetic free layer 2 and a magnetic layer 7 for spin-polarizing of current electrons in a stacked arrangement is shown. In that configuration, the magnetic free layer 2 is provided with a magnetization easy axis where a magnetic moment vector 5 is free to be switched between two preferred directions thereof. Magnetic layer 7 is provided with a fixed magnetic moment vector 8 being perpendicular to the magnetic moment vector 5 in the configuration of FIGS. 3A and 3B . FIG. 3A illustrates a case where a current density J of an electron current (not illustrated) flowing perpendicularly through the layers is assumed to be nil, while in FIG. 3B the current density J is assumed to be different from zero. Accordingly, on the one hand, in FIG. 3A where no current is passing through the layers, magnetic moment vector 5 remains unchanged, while, on the other hand, in FIG. 3B , electrons passing through the layers are spin-polarized when flowing through magnetic layer 7 by the effect of magnetic exchange interaction. If a polarization direction p of the current electrons belongs to the plane of the magnetic free layer 2 , then rotation of the magnetic moment vector 5 occurs in the plane of magnetic free layer 2 and the torque becomes nil when m becomes parallel to p (that case is not shown in FIGS. 1A , 1 B). Alternatively, if p is perpendicular to the plane of the magnetic free layer 2 (case shown in FIGS. 1A , 1 B), then the initial torque pulls the magnetic moment vector 5 out of its plane, thus creating a demagnetizing field H D perpendicular to the magnetic free layer 2 plane, with the result that a precession movement of the magnetic moment vector 5 around the demagnetizing field H D may now take place.
In other words, in a magnetic element such as the soft element of an MRAM cell, the magnetization direction though not far from being uniform fails to be so as a result of demagnetizing effects. Coherence during magnetic switching may nevertheless be preserved if the field exerting a torque on the magnetization is perpendicular to the soft layer. In order to achieve this, the best strategy is to apply a magnetic field normal to the mean magnetization direction within the soft element and in the plane of the layer. The initial torque γ 0 [m×H α ], where γ 0 , m, H α are a gyromagnetic ratio, magnetization vector and applied magnetic field, respectively, pulls the magnetization out of the plane leading to the growth of a demagnetizing field that remains essentially normal to the plane of the layer. The magnetization may now precess around the demagnetizing field under the torque γ 0 [m×H D ], where HD is the demagnetizing field.
In order to observe precessional switching, three conditions have to be fulfilled, namely, both the rise and fall times of the field pulse need to be “short” and the length of the pulse has to be tailored very accurately, where “short” means a time small when compared to time requested for the magnetization to make half a turn. Let T and ƒ be the period and precession frequency, respectively. A half a turn rotation means a time equal to T/2. One has T=1/ƒ and ƒ depends on the amplitude of the demagnetizing field: ω=2Πƒ=γ 0 H d . On the other hand, the demagnetizing field scales with the angle of the magnetization out of the sample plane.
An example may illustrate this: suppose the magnetization leaves its plane by an angle of =10°, then the demagnetizing field amplitude will amount to about H d ≈M s sin(10°). For a typical soft material with saturation induction μ 0 M s =1 Tesla, this means a precession frequency equal to ƒ=(ω/2Π)=γ 0 M s sin(10°)≈5 GHz. The period then amounts to 200 picoseconds, and the time necessary for a half turn rotation would typically be T/2=100×10 −12 sec (100 picoseconds (ps)). In summary, owing to values chosen in the sample, the pulse length should be close to 100 ps and the fall and rise times much shorter than 100 ps. Laboratory realizations allow for pulse rise and fall times of the order of 20 ps.
Precessional switching is a very robust and fundamental effect. In a large scale memory, however, due to various sources of impedance, it is expected that maintaining such an accuracy in the definition of the field pulses might prove extremely problematic.
In order to result in a desired reversal of the free magnetic moment vector, precession movement has to be controlled appropriately, which, however, has not been demonstrated in prior art.
SUMMARY
In light of the above, the invention provides a magnetoresistive memory cell allowing a further cell size down-scale without causing severe problems as to an increase of switching-fields and decrease of activation energy.
The invention further provides a method of writing to (switching) and reading of resistance states of above magnetoresistive memory cells.
According to a first aspect of the invention, a magnetoresistive hybrid memory cell comprises a first stacked structure being provided with a magnetic tunnel junction including first and second magnetic regions which are stacked in a parallel, overlying relationship and are separated by a layer of non-magnetic material. The first magnetic region is provided with a fixed first magnetic moment vector, while the second magnetic region is provided with a free second magnetic moment vector which is free to be switched between the same and opposite directions with respect to above fixed first magnetic moment vector of the first magnetic region. The magnetoresistive hybrid memory cell further comprises a second stacked structure which at least partly is arranged in a lateral relationship as to the first stacked structure and comprises both a third magnetic region and the second magnetic region, the latter one thus being a common magnetic region of both first and second stacked structures. The third magnetic region is provided with a fixed third magnetic moment vector, which typically and preferably is aligned in an othogonal direction as to the free second magnetic moment vector of the second magnetic region. Furthermore, the first and second structures are arranged in between at least two electrodes in electrical contact therewith.
Magnetic anisotropy of the second magnetic region may be due to shape anisotropy and/or intrinsic anisotropy. In the former case, the second magnetic region may, for instance, be elliptic in shape.
In a particularly preferred embodiment of the first aspect of the invention, one of above-cited electrodes for contacting the first and second structures being arranged on one side of the first and second structures is a common electrode in electrical contact with both first and second stacked structure. Such common electrode is preferably positioned adjacent the second magnetic region, in particular in direct electrical contact therewith.
In another particularly preferred embodiment which preferably may be combined with a common electrode connecting the first and second structures on the one side, separate electrodes for each one of the first and second structures are provided on the other side of the first and second structures. Such particular design allows for an advantageous decoupling of write and read functions, which, hence, can be optimized independently.
Alternatively, it is also possible to envisage separate electrodes for each one of the first and second structures which are provided on both sides of them.
According to a second aspect of the invention, a method of writing to and reading of a magnetoresistive hybrid memory cell is given, which comprises the following steps: providing of a magnetoresistive hybrid memory cell as above-described with regard to the first aspect of the invention; applying of a writing voltage pulse to electrodes on both sides of only the second structure (and not the first structure) resulting in a current pulse flowing through the second magnetic region for writing of the free second magnetic moment vector; applying of a reading voltage pulse to electrodes on both sides of only the first structure (and not the second structure) resulting in a current pulse flowing through the magnetic tunnel junction. Accordingly, applying writing and reading voltage pulses to second and first stacked structures, respectively, allows for an advantageous decoupling of writing and reading functions.
In a mostly preferred embodiment of the second aspect of the invention, a switching voltage pulse is applied which is adapted to result in a coherent rotation over half a full turn of the free second magnetic moment vector in total. Such coherent rotation over half a full turn of the free second magnetic moment vector may preferably be achieved in applying writing voltage pulses having a slow rise time and a fast fall time. The terms “slow” and “fast”, here, have a meaning exactly analogous to the precessional switching case described in the introductory portion, that is, “fast” means times shorter than a half precession cycle, while “slow” means times substantially larger than a full precession cycle. Hence, precessional switching requires both “fast” field pulse rise and fall times, whereas spin injection in the present geometry requires “slow” current rise times. This is a result of extended numerical simulation work done by the inventors. A “fast” current rise time would lead to a lot of unwanted magnetization “ringing” (response oscillations).
As also explained in the introductory portion with respect to the precessional switching case, “coherent rotation” means that, irrespective of the magnetization distribution (not a perfectly uniform distribution), the torque acts in such a way that all moments are subjected to a torque acting in the same direction, thus maintaining coherence of the distribution. This is not at all the case for the conventional spin injection cells for which by different simulations markedly chaotic behaviors have been predicted. Other and further objects, features and advantages of the invention will appear more fully from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description given below, serve to explain the principles of the invention.
FIG. 1 is an exemplary schematic representation of a typical magnetic tunnel junction included in an MRAM cell;
FIG. 2 shows a diagram illustrating energy barrier height for switching of an MRAM cell versus width dimension 1 ;
FIGS. 3A and 3B illustrate a stacked structure comprised of a magnetic layer having fixed magnetization and a magnetic free layer having a free magnetization free to be rotated with respect to the fixed magnetization due to spin-polarized electron current flowing therethrough;
FIG. 4 is a schematic representation of an embodiment of a hybrid magnetoresistive memory cell of the invention;
FIG. 5 shows a diagram illustrating writing current I and procession angle Φ in the single spin limit versus time;
FIGS. 6A and 6B show a typical writing current pulse having slow rise and fast decay times resulting in a typical sawtooth profile ( FIG. 6A ) and curve illustrating writing current versus pulse length resulting in single reversal events; and
FIGS. 7A and 7B show diagrams analogous to that one FIGS. 6A and 6B in the case of a limitation to the half of the platelet area.
DETAILED DESCRIPTION
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Referring to FIG. 4 , an embodiment of the hybrid memory cell of the invention is explained. Based on a conventional magnetic memory cell, the hybrid magnetic memory cell of the invention comprises a first stacked structure 9 being comprised of a magnetic tunnel junction (MTJ) which includes a fixed first magnetic region 10 and a free second magnetic region 11 stacked in a parallel, overlying relationship and separated by a layer 12 tunneling barrier. Magnetic free region 11 is made of a magnetic material such as CoFe/NiFe and is provided with a free second magnetic moment vector 18 free to be switched between oppositely aligned orientations along its magnetic easy axis. Magnetic reference region 10 comprises two layers 13 , 14 of ferromagnetic materials such as CoFe with its magnetizations being antiferromagnetically coupled resulting in a fixed first magnetic moment vector 17 . Intermediate layer 12 is made of a nonmagnetic material such as AlO x . The hybrid memory cell of the invention further comprises a second stacked structure 23 which includes the free second magnetic region 11 , a third magnetic region 20 having a fixed third magnetic moment vector 21 which is perpendicularly directed to the second magnetic moment vector 18 , a conductive layer 24 for instance made of Au and being arranged on top of third magnetic region 20 in contact therewith, and a further conductive layer 19 for instance made of Cu and being arranged beneath third magnetic region 20 in contact therewith. Above second magnetic region 11 , first and second stacked structures 9 and 23 , respectively, are arranged in a lateral relationship leaving an intermediate gap G between them. Further, first and second stacked structures are arranged between a common bottom electrode 16 connecting both first and second structures and separate top electrodes 15 , 22 , that is to say a separate top electrode for each one of stacked structures.
Having separate top electrodes 15 , 22 for each one of both first and second stacked structures, hybrid magnetoresistive memory cell of FIG. 4 enables a desirable decoupling of write and read functions.
Further characteristics of the invention are now explained. Let's call F the minimum feature size (smallest dimension) of the technology used, e.g. 0.11 μm, 90 nm, 65 nm following the semiconductor roadmap. A magnetic memory cell today may barely be smaller than 2F 2 due to the necessity for maintaining some kind of shape anisotropy (toggle switching, however, allows for circular elements). As mentioned above within the context of field addressing, the field necessary to commute cells grows with decreasing cell size. In contrast, the smaller the active region of spin-injection, the smaller the detrimental effect due to the field created by the requested current density (the so-called Oersted field). It is well known that, for usual 3d ferromagnetic materials, spin-injection ceases to be relevant for cell sizes exceeding some 100 nm.
In the proposed scheme, the minimal cell size is 3F 2 . This means that the distance G in FIG. 4 may not be smaller than F due to processing constraints. On the other hand, allowing for a 1F 2 area for the spin-injection region (the right part of FIG. 4 ) is extremely favorable, because it complies with the necessity to decrease as much as possible the Oersted field. The present scheme mimics through spin-injection a precessional type motion of the magnetization in the spin-injection region. It is a fundamental process due to the relative orientations of the magnetization 21 in layer 20 and magnetization 18 in layer 11 .
Once the magnetization 18 in layer 11 has been reversed under layer 20 , a wall is created, which has inertia, so that once it is set into motion, it will continue moving for some time that is mainly controlled by the damping in the material. As simulations by the inventors have shown, this “wall launching” mechanism allows for wall motion through out the extent of the cell layer 11 . Additionally, some current flowing from layer 22 into sublayer 16 will also flow along the full length of the cell layer 11 . Because it's flowing in a ferromagnetic material, such a current is spin-polarized and exerts a pressure on the wall, thus assisting wall motion. This last effect is, however, hard to quantify, because it depends crucially on the difference in electrical resistivity between layers 111 and 16 . This last effect has been neglected by the simulations made by the inventors.
Using cell design for spin injection suffers from the drawback of needing to simultaneously optimize both the writing current and the read signal. Giant magnetoresistance structures would exhibit weak read signals. Moreover, the signal decreases with decreasing cell size. Tunnel junctions do not suffer from this basic drawback, but the mechanisms that eventually allow cell switching through very shallow tunnel junctions remain unclear. Shallow tunnel junctions result in smaller read signals. From an engineering point of view, the larger the read signal, the better.
In the proposed scheme, thermal stability is improved through the geometry: a 3F 2 cell size remains thermally stable over a long term for the smallest F dimensions because of the aspect ratio, as shown in FIG. 2 (F is 1 in FIG. 2 ). Additionally, the magnetostatic coupling between layer 20 with magnetization 21 and layer 11 with magnetization 18 will contribute to an increased thermal stability.
As above stated, in the proposed scheme, write and read functions may be independently optimized, where optimization means here both optimization of the read signal (state of the art tunnel junction 9 in the low current regime, and the best materials between layers 11 and 13 ), and optimization of the write current (optimized spin-polarization through the choice of materials in layers 11 and 20 , and optimized spin-accumulation through a proper choice of the thicknesses of layers 21 , 20 and 19 ).
Now referring to FIGS. 5–7 , a numeric simulation concerning the method of writing to a magnetoresistive hybrid memory cell is explained.
As can be seen from FIG. 5 , a numeric simulation in the single spin limit reveals that controlled precession of the free second magnetic moment vector may be achieved through the application of current pulses with a slow rise time and a fast fall time.
FIG. 5 (single spin type simulations) further shows that, for asymmetrical current pulses, a proper choice of the current density allows for a controlled magnetization rotation. Φ (in °) to the right of the figure is seen to move in steps of 180°, meaning one half a turn, a full turn, three half-a-turn etc. The figure applies to the case of FIG. 3B , not to FIG. 4 . This was an initial step to illustrate that control was solely possible if allowing for pulse asymmetry.
An extension of such calculations to the micromagnetic regime confirms this prediction, as can be seen from FIGS. 6A and 6B . Current injection through half of the platelet area yields the following results, which are given in FIGS. 7A and 7B .
FIGS. 6B and 7B are computed operational margins as determined by full micromagnetic simulations (meaning that now the detailed aspects of the magnetization distribution both in space and time are taken into account) in a parameter space where the horizontal scale is the pulse length as defined in FIGS. 6A and 7A , respectively, and the vertical scale the current density at the end of the pulse.
FIGS. 6A and 6B concern current densities that are homogeneous through the entire cell and are therefore not directly usable for the present invention. In contrast, FIGS. 7A and 7B apply to cells where the current flows in only half of a 2F 2 cell, i.e. a cell, where distance G in FIG. 4 would be ideally zero. FIGS. 7A and 7B show that a fairly sizeable operational margin may be expected with pulse durations in the 0.15 to 0.45 ns (150 to 450 ps) and maximum current densities in 0.4 to close to 0.475 A/μm 2 . Constraints on pulse durations are expected to be rather weak. Current densities are more challenging, as the margin does not exceed some 15%, according to extended and state of the art numerical simulations.
Many modifications and variations of the present invention are possible in light of the above description. It is therefore to be understood, that within the scope of appended claims, the invention may be practiced otherwise than as specifically devised.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. Accordingly, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
REFERENCE LIST
1 Magnetic tunnel junction
2 Ferromagnetic layer
3 Tunnel barrier layer
4 Ferromagnetic layer
5 Magnetic moment vector
6 Magnetic moment vector
7 Ferromagnetic layer
8 Magnetic moment vector
9 First stacked structure
10 Fixed first magnetic region
11 Free second magnetic region
12 Tunnel barrier layer
13 Ferromagnetic layer
14 Ferromagnetic layer
15 Top electrode
16 Common bottom electrode
17 Fixed first magnetic moment vector
18 Free second magnetic moment vector
19 Conductive layer
20 Third magnetic region
21 Fixed third magnetic moment vector
22 Top electrode
23 Second stacked structure
24 Conductive layer
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A magnetoresistive hybrid memory cell includes first and second stacked structures. The first stacked structure includes a magnetic tunnel junction including first and second magnetic regions stacked in a parallel, overlying relationship separated by a layer of non-magnetic material, wherein the first magnetic region has a fixed first magnetic moment vector and the second magnetic region has a free second magnetic moment vector that is switchable between the same and opposite directions with respect to the fixed first magnetic moment vector. The second stacked structure is at least partly arranged in a lateral relationship with respect to the first stacked structure and includes a third magnetic region having a fixed third magnetic moment vector and the second magnetic region. The first and second structures are arranged between at least two electrodes in electrical contact therewith.
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BACKGROUND
Steel support beams have many applications. They may be used to support architectural forms and building structures. Steel support beams may also be used in building vehicles or rebuilding damaged vehicles.
Typically, a support beam, whether constructed of steel or another support material, is constructed of pieces joined at angular intersections. For example, two portions of a steel beam may be welded at a 45-degree angle, or a 90-degree angle, or another angle appropriate to the final use of the beam. Beams made of other materials may be adhered to one another, or may be bolted together with brackets, etc.
A beam that includes smooth curves will often require the use of a jig or fixture and heavy tools to form its final structure. For example, placing a beam in a jig and bending it progressively to a final structure may result in construction of a curved beam. Alternatively, first portions of a beam may be removed so that other portions may be bent, with the first portions (or replacement portions) of the beam then being placed in their final configuration.
Because standard support beams are limited in their ability to assume nonstandard shapes (such as a beam with smooth curves, or a beam with one or more broadened portions), and because support beams often require heavy tools to form, it would be desirable to make a beam with complex shapes and/or with a minimum of tooling and reshaping. The described support beams, and the method of making those beams, have such characteristics. It should be appreciated that the disclosed beams and methods may be constructed of a variety of materials, as desired for a given application, and used in many situations.
Typical steel support beams and their methods of manufacture are found in U.S. Pat. Nos. 2,794,650, 2,844,864, 5,210,921, 6,058,673, 6,092,864, 6,305,136, 6,557,930, 6,733,040, 6,896,320, and 7,156,422, the disclosures of which are incorporated herein by reference.
SUMMARY
The present disclosure relates generally to a beam for providing support to a vehicle body, an architectural structure, or any other structure needing support. More specifically, it relates to a steel beam manufactured without the use of extensive machinery, and containing compound curves made without a dedicated fixture or jig.
One method of manufacturing a support beam may include providing a first piece and a second piece of beam material, arranging the first and second pieces of beam material in close spatial relation, and securing to each other the first and second pieces of beam material to form the support beam. A support beam formed by the method may have a width dimension on a first axis, a height dimension on a second axis, and a length dimension on a third axis, where the length dimension is measured from a first end to a second end of the support beam, and the second end of the beam may be displaced from the first end along both the first and second axes.
The pieces of beam material used in the manufacturing method may be cut or otherwise formed from material stock, and the stocks for the first and second pieces may be substantially the same material (such as steel, wood, plastic, or another material) or they may be of different materials (such as one of steel and one of a plastic). Typically, for pieces made from a stock material, such as steel, the pieces may be cut by water jet cutting or laser cutting, but any appropriate method of cutting or forming the component pieces of a beam may be used.
An extension of the method described above may further include providing a third piece of beam material, and arranging the third piece of beam material in close spatial relation to the first and second pieces of beam material such that the first, second, and third pieces of beam material form an I-shaped support beam. In some embodiments, the I-shaped support beam may have a width dimension on a first axis, a height dimension on a second axis, and a length dimension on a third axis, with the length dimension measured from a first end to a second end of the I-shaped support beam, and the second end of the I-shaped support beam may be displaced from the first end along both the first and second axes of the I-shaped support beam.
A further extension of the method described above may include providing fourth and fifth pieces of beam material, arranging the fourth and fifth pieces of beam material in close spatial relation to the first, second and third pieces of beam material, and securing the fourth and fifth pieces of beam material to the first, second, and third pieces of beam material to form a boxed, I-shaped support beam. In some embodiments, the boxed, I-shaped support beam may have a width dimension on a first axis, a height dimension on a second axis, and a length dimension on a third axis, with the length dimension measured from a first end to a second end of the boxed, I-shaped support beam, and the second end of the boxed, I-shaped support beam may be displaced from the first end along both the first and second axes of the boxed, I-shaped support beam.
Another method of manufacturing a support beam may include providing first and second pieces of beam material, arranging the first and second pieces of beam material in close spatial relation, and aligning into an aligned spatial relation the first and second pieces of beam material with an alignment apparatus, where the alignment apparatus is configured reversibly to embrace the first and second pieces of beam material.
This may further include securing to each other the aligned pieces of beam material such that the first and second pieces of beam material remain in an aligned spatial relation upon removal of the alignment apparatus.
An extension of this method may further include providing a third piece of beam material, and arranging the third piece of beam material in close spatial relation to the first and second pieces of beam material, where the first, second, and third pieces of beam material may be aligned with the alignment apparatus, which may reversibly embrace the first, second, and third pieces of beam material. The alignment apparatus may have a number of alignment, or support, openings having shapes complementary to the pieces of beam material, and the openings may be adjustable in position to each other and the body of the alignment apparatus.
A further extension of this method may include securing to each other the aligned pieces of beam material such that the first, second, and third pieces of beam material remain in an aligned spatial relation upon removal of the alignment apparatus.
A support beam fashioned according to this method may assume an I-beam form, or any other appropriate form for a given structural function.
The present disclosure also provides for a support beam having a width dimension on a first axis, a height dimension on a second axis, and a length dimension on a third axis, where the length dimension may be measured from a first end to a second end of the beam, and where the second end of the beam is displaced from the first end along both the first and second axes of the beam. The beam may also include at least one smooth curve between the first end and the second end.
To provide structural support, the beam may have at least a partial I-beam shape, having a first flange with first and second edges and a midline between the first and second edges, and a first web with first and second edges, where the web is secured to the flange such that either the first or second edge of the web is coupled to the midline of the first flange. The beam may also include a second flange having first and second edges and a midline between the first and second edges, where the second flange is secured to the first web such that a first or second edge of the web is coupled to the midline of the second flange.
In this structure, the first flange and the first web of the support beam may be configured to be held reversibly in alignment by an alignment tool including first and second support openings having shapes complementary to the first flange and the first web. In some embodiments, the alignment tool may be adjustable, allowing adjustment of the relative locations of the first and second support openings and, thus, the relative orientations of the flange(s) and web.
To further provide structural support, the I-beam shape may be boxed, with the beam including first and second walls each having first and second edges, where the first edges of the first and second walls are secured to the first flange, and where the second edges of the first and second walls are secured to the second flange.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a left perspective view of a first embodiment of a steel beam according to the present disclosure.
FIG. 2 is a right perspective view of the steel beam of FIG. 1 .
FIG. 3 is a side view of the steel beam of FIG. 1 .
FIG. 4 is a front view of a first embodiment of the steel beam of FIG. 1 .
FIG. 5 is a right perspective view of components used to form a second embodiment of a steel beam according to the present disclosure.
FIG. 6 is a perspective view of a first embodiment of an alignment tool according to the present disclosure.
FIG. 7 is a front view of an operational relationship between the alignment tool of FIG. 6 and the steel beam of FIG. 1 , according to the present disclosure.
FIG. 8 is a plan cutaway view of a third embodiment of a steel beam according to the present disclosure.
FIG. 9 is a plan cutaway view of a fourth embodiment of a steel beam according to the present disclosure.
FIG. 10 is a partial left perspective view of an intermediate step in a method of constructing a first embodiment of a steel beam according to the present disclosure.
DETAILED DESCRIPTION
The present disclosure describes a support beam. The support beam is typically a steel beam, and it may be used as, for example, a structural support beam in a vehicle frame. Alternatively, the support beam may be used in any application requiring a strong structural support beam including nonstandard shapes (i.e. other than a typical cylinder, tube, typical combinations of those shapes, etc.). The illustrated support beam of the present disclosure is a beam having a roughly rectangular cross-section but also having complex curves along its length, which can be manufactured by a straightforward process requiring only a minimum of effort. In other embodiments, the support beam may follow a semicircular path, may include multiple curves, or take another non-standard shape.
FIGS. 1-4 show an illustrated first embodiment of a support beam 10 according to the present disclosure. The illustrated embodiment is a steel beam having a boxed I-beam shape. As such, the central portion of the beam includes a number of support elements, such as a web 12 , a first flange 14 , and a second flange 16 . To “box” this central I-beam backbone, the illustrated beam might include a first wall 18 and a second wall 20 . As illustrated, the support beam has, essentially, three vertical portions (web 12 , wall 18 , and wall 20 ) bracketed by two horizontal portions (flange 14 and flange 16 ). Although illustrated in this manner, it is understood that the beam may be constructed with fewer walls, fewer flanges, more webs, or any other desired combination of these support elements.
Initially, the illustrated beam can be described as having a first leg 22 and a second leg 24 at either end of a curved midportion 26 . The midportion can be any shape necessary as needed for a particular application of the support beam, but the illustrated embodiment includes a first curve 28 and a second curve 30 . Each of the first and second legs 22 , 24 of the support beam may follow a short, substantially linear path. As such, a length edge 32 of the first leg 22 may define an axis L along which a length of a support beam may be measured. A length edge 34 of the second leg 24 may be parallel to edge 32 and, as such, may be parallel to the axis L. Typically, the length of the illustrated support beam may be measured as the distance along axis L from a first end 36 to a second end 38 of the beam.
The illustrated support beam may also have height and width dimensions. A height edge 40 may follow a substantially linear path so as to define an axis H along which a height of a support beam may be measured. In the same way, a width edge 42 may follow a substantially linear path and define an axis W along which a width of a support beam may be measured. As with the length edges 32 , 34 , height edge 40 of the first end 36 may have an analogous height edge 44 at the second end 38 , and width edge 42 of first end 36 may have an analogous width edge 46 at the second end 38 .
As is apparent from the Figures, the length, height, and width of a support beam may be measured in multiple ways. For example, the length of a support beam could be measured as the distance from the first end to the second end along the axis L. As an alternative, if the first and second ends were located closely in space (as in a support beam having a horseshoe shape, or following a semicircular path), then the length might be measured as the separation distance along axis L between the two most-separated points on the support beam.
As another example, the width of the support beam could be measured as the distance from the first wall to the second wall along the axis W (this could correspond to the width of a first or second flange, depending on construction of the beam). An alternative width could be measured as the separation distance along axis W between the two most-separated points on the support beam. In the illustrated embodiment, for example, the greatest separation on the width axis W is not the width of the first or second flanges because the illustrated support beam is not a linear structure, and the second end is displaced along the W axis from the first end (seen most clearly in FIG. 3 ).
As another exemplary measurement, the height of the support beam could be measured as the distance from the first flange to the second flange along the axis H (this could correspond to the width of the web, or first or second wall, depending on construction of the beam). An alternative height could be measured as the separation distance along axis H between the two most-separated points on the support beam. In the illustrated embodiment, for example, the greatest separation on the height axis H is not the height of web 12 , or first wall 18 or second wall 20 because the illustrated support beam does not lie on a planar surface, the second end being displaced along the H axis from the first end (seen most clearly in FIG. 4 ).
The illustrated steel beam has a non-standard shape which can be described relative to a set of axes defined by the beam. In the illustrated embodiment of a support beam, the second end 38 of the support beam is displaced from the first end 36 along both the W and H axes at its location on the L axis. This three-dimensional displacement of one end from the other in the illustrated beam is the result of the presence of the first curve 28 and the second curve 30 in the midportion 26 of the beam. In other words, moving along the L axis of the beam, a comparison of the first end of the beam to the second end of the beam shows that the second end of the beam is displaced upward along the H axis and rightward on the W axis from the first end (if the point of origin of the axes is considered to be the first end of the beam).
FIGS. 2-4 show other views of the support beam of FIG. 1 , making clear the complex structure of the illustrated embodiment and the two-dimensional displacement (along axes W and H) of the first and second ends of the beam. Though showing a very similar beam, FIG. 4 illustrates a beam having reverse curvature to the beams of FIGS. 1-3 (the second end of the beam of FIG. 4 is displaced to the left relative to the first end of the beam).
FIG. 5 shows two component parts, a web 12 ′ and a flange 16 ′, used in making a second embodiment of a steel beam according to the present disclosure. FIG. 5 shows that the component parts used in making a beam can each have multiple curves in the plane of the component material, each curve having different characteristics, to form a final beam having multiple complex curves rather than a pair of relatively simple curves (as shown in FIGS. 1-4 ). Additionally, web 12 ′ and flange 16 ′ may each be described as having a longitudinal centerline running the length of the part. Examples of these centerlines are labeled A and B, respectively, in FIG. 5 .
FIG. 6 is an illustration of an alignment tool 50 according to the present disclosure, which can be used in a method of manufacturing the illustrated beams of FIGS. 1-5 , and other beams according to the present disclosure. The alignment tool may generally be constructed of a relatively stiff material, being configured to hold portions of the illustrated support beam in alignment during a support beam manufacturing process. However, other materials appropriate for performing the manufacturing method described below may be used. In some embodiments, the support beam 10 and alignment body 50 are of substantially the same materials, while in other embodiments the support beam and alignment body are of substantially or somewhat different materials.
The exemplary alignment tool 50 of FIG. 6 has a roughly rectangular alignment body 52 supporting a pair of alignment legs 54 , 56 . In the illustrated embodiment, the alignment legs are somewhat longer than the central portion of the alignment body, thus forming an alignment surface 58 between the alignment legs. The illustrated alignment body also includes alignment openings 60 , 62 , formed by the close, but not complete, abutment between the alignment surface and the alignment legs.
As is apparent from the Figures, the alignment tool can be placed into an operative relationship with elements of the support beam, facilitating the manufacture of the beam. FIG. 7 is an illustration of one possible operational relationship between the alignment tool of FIG. 6 and the steel beams of FIGS. 1-5 , according to the present disclosure. FIG. 7 makes clear that a given alignment tool may be useful for making a given embodiment of a support beam, since the various alignment portions of the tool may be designed to place components of the support beam into a close, temporarily fixed relationship. The temporary alignment of the elements of the support beam can then be made more permanent by, for example, welding the elements of the support beam to one another.
FIG. 7 shows an aligning relationship between alignment tool 50 and portions of a support beam 10 , partway through a method of manufacturing the support beam (described in more detail below). In FIG. 7 one can see that a first flange 14 and a second flange 16 can each be slidingly inserted into alignment openings 60 and 62 , respectively. As well, web 12 can be placed between the flanges so that it lays against the alignment surface 58 . In this way, the central spine of the boxed I-beam can be laid out, with the three components of the central spine in temporary alignment with one another. As seen in FIG. 7 , the web is aligned with the two flanges so that the web is positioned roughly along the midline of the two flanges (i.e. about midway between the two edges of each flange). Other arrangements or alignments are possible depending on the use or desired construction of the beam. For example, in some embodiments, the web may be positioned away from the midline of each flanges, such that it lies closer to one side or the other of each flange.
As is clear from the Figures, the illustrated embodiment of alignment tool 50 in FIGS. 6 and 7 is uniquely suited to making the illustrated embodiment of a support beam 10 in FIGS. 1-5 because of the placement of the alignment legs, surface, and openings. In like manner, another embodiment of alignment tool 50 could be uniquely suited for making a subtly different, or substantially different, embodiment of a support beam. For example, the alignment tool could have alignment openings that are placed at angles relative to each other, forming a beam with flanges or walls that are angled relative to each other or the web. Another embodiment might have shallower alignment openings, to accommodate or align narrower flanges. As another example, an alignment tool might be adjustable, where the alignment legs, surface, and/or openings could be moved relative to one another and then temporarily fixed in place (for example, with a series of nuts and bolts). Such an alignment tool could allow a manufacturer to make multiple types of beams with a single tool.
It bears repeating that the illustrated beam is simply one embodiment of a non-standard beam shape possible to be constructed with the method of manufacture described below. For example, the beam might follow a semi-circular path; it might contain more than two curves; and so on. Also, although the beam of the present disclosure is shown as a boxed I-beam with a web that is continuous from the first end to the second end, other designs are possible, such as a beam with a discontinuous web, or flanges with projections (as seen in FIG. 5 ), etc.
It also bears noting that a unique feature of the illustrated beam is the ability of the beam to embody complex curves with a minimum of effort on the part of a manufacturer of the beam. As is clear from the description of the above Figures, each of the pieces forming the central I-beam structure is a substantially planar element cut out of a substantially planar stock material. Each substantially planar element embodies a curve in a single dimension (i.e. in the plane of the stock material from which the element was cut). However, when brought together into an I-beam structure, the combination of two substantially planar elements, each having a curve in a single dimension, results in a non-planar I-beam embodying at least one complex curve (i.e. a curve having components in at least two dimensions). In the illustrated embodiment, for example, the central I-beam structure has complex curves embodying both the substantially one-dimensional “upward” (along the H axis) curve of web 12 (or 12 ′) and the substantially one-dimensional “sideways” (along the W axis) curve of flanges 14 , 16 (or 16 ′).
An exemplary embodiment of a beam containing more than one continuous or discontinuous web within an otherwise uniform exterior is shown in cross-section in FIG. 8 . Such a design may allow a beam to have a relatively shallow side profile (i.e. a small dimension along axis H) while still providing increased strength relative to the beams illustrated in FIGS. 1-5 . In the embodiment of FIG. 8 , the beam 10 may include a midportion 26 that is broader than the beam's first and second legs. The midportion may be broadened to include multiple webs 12 spaced from each other. Though the illustrated beam embodiment includes two walls 18 , 20 and three webs (two continuous webs 12 a , 12 b passing from end-to-end, and one discontinuous web 12 c only in the midportion), other numbers of webs are possible according to the desired performance parameters of the support beam.
An exemplary embodiment of a beam having a relatively broader midportion between two relatively narrower portions, with the broader portion housing multiple webs or a web having a nonlinear portion is shown in cross-section in FIG. 9 . Like the embodiment of FIG. 8 , this beam embodiment may allow increased strength with a shallow side profile.
In the embodiment of FIG. 9 , the walls may extend outward along the midportion 26 of the support beam, much like the embodiment of FIG. 8 . Rather than housing multiple webs, however, the larger midportion of the beam of FIG. 9 may house a nonstandard central web 12 . The central web of the embodiment of FIG. 9 may be configured as a single-thickness plate at either of its ends. The central portion, however, of the web of this embodiment may be “split” in the middle (i.e. configured with two web arms 63 extending from the web toward the sides of the beam) such that the central portion of the web is configured as a roughly hexagonal web loop 64 . As an alternative, loop 64 could be configured as a rectangular, pentagonal, ovoid, or other appropriate shape for providing structure within the larger midportion 26 of the illustrated beam.
Having described exemplary embodiments of support beams and an alignment tool, there follows a description of a method of making a typical support beam with a typical tool. The described method does not require heavy shop equipment unless heavy-gauge steel (or other material that is difficult to manipulate) is utilized in the construction. For example, 12-gauge and 10-gauge (about ⅛ inch) plate steel can be worked by hand, while ¼-inch plate steel may need to be worked with machinery, powered or otherwise.
The method may include a first step and a second step of providing a first piece of beam material; for example, providing pieces of steel from steel stock. One way of providing these pieces of steel is to cut (by, for example, laser or water jet cutting) shaped pieces of steel from a steel sheet. As noted, for easier working, the steel may be about ⅛ of an inch in thickness.
For making a boxed I-beam structure of the types illustrated in FIGS. 1-5 , a user may require five pieces of shaped steel: one piece for the central web, two pieces each for the first and second flanges, and two pieces each for the first and second walls. The pieces may be held individually or as a group at one end, with the other end of each piece being manipulated by a user, or a group of cooperating users, making a support beam. Typically, a pair of users may work together to align the pieces of the support beam before fastening them into place.
The one or more users may arrange first and second pieces of the beam material into close spatial relation. One way to do this would be to align the pieces using an alignment tool 50 like the one illustrated in FIGS. 6 and 7 . Initially, a user may slide an edge of one flange 14 into one of the alignment openings 60 on the alignment tool. The user may then place a web piece 12 on the alignment surface 58 of the alignment tool. In this way, an edge of the web piece may abut a midline of the adjacent flange. When one piece “abuts” another, the pieces may actually be in contact or they may merely be in sufficiently close spatial relation so that they may be connected later with a minimum of further adjustment in their positions (i.e. they may be close enough that they could be welded, glued, or otherwise fastened).
The user or cooperating users may then secure to each other the first and second pieces of beam material to form all or a portion of the support beam. To secure the first and second pieces of beam material, the user may simply tack-weld the pieces to each other as they are held in place by the alignment tool. Alternative methods of attachment may be used according the desired use of the beam or further work to be done in finishing the beam. If, for example, a simple support beam is desired, it may be enough to form the beam by securing a single flange and a single web by welding. As another example, a user or group of users may align the components of the beam with the alignment tools, and then use a series of clamps to hold the components in place. A final tack welding may then be performed along the whole length of the beam in one step.
If the support beam will have a central I-beam structure, the user may add another flange 16 to the arrangement of pieces, for example by sliding an edge of the flange 16 into an unoccupied alignment opening 62 of alignment tool 50 . In this way, a relatively simple alignment tool like the one in FIGS. 6 and 7 may align two flange pieces 14 , 16 and a web 12 so that each edge of the central web abuts a midline of a different flange. The web may then be tack-welded to the flange pieces or completely welded to the flange pieces, depending on the performance requirements of the beam.
An exemplary arrangement during the process described above is shown in FIG. 10 , where two flanges 14 , 16 and a central web 12 are in operative association with alignment tools 50 . In the Figure, first and second alignment tools 50 are closely positioned, with each tool's alignment opening supporting a flange and the alignment surface contacting the web (as in FIG. 7 ); thus, the alignment tools may be said to “bracket” the central I-beam structure. As illustrated in the Figure, a user may use the pair of tools 50 to initially align two flanges and a web at a given point. The user may then secure the pieces in place with a clamp 66 , allowing the alignment tools to be moved to the next location along the nascent beam that has flanges and a web to be aligned. Alternatively, the user could tack weld 68 the aligned portion of the I-beam before moving the alignment tools. In either case, using a pair of alignment tools at the same time can allow a user to precisely align the components of the I-beam before tack welding or clamping the aligned arrangement before moving to and aligning the next section of the beam.
To form a beam like the one illustrated in FIGS. 1-5 , the central “I” structure may only be tack-welded in place, as walls will be added to the final structure. In this case, the central “I” structure may act as a pattern for the final boxed I-beam. Once the central spine of the boxed I-beam is formed, the side walls, also cut or otherwise formed as pieces from stock material, may be lined up with the edges of the flanges. Once in final placement, the walls may be welded into place, securing them firmly with the flanges.
The alignment tool may not be necessary for the final step of securing the walls to the I-beam spine, but it may be necessary to hold the walls in place with clamps or other tools while the final fixing occurs. Typically, final placement could be done with two users and a series of clamps, with no requirement for heavy tools or machinery.
Although the present invention has been shown and described with reference to the foregoing operational principles and preferred embodiments, it will be apparent to those skilled in the art that various changes in form and detail can be made without departing from the spirit and scope of the invention. The present invention is intended to embrace all such alternatives, modifications and variances. The subject matter of the present invention includes all novel and non-obvious combinations and subcombinations of the various elements, features, functions and/or properties disclosed herein. Inventions embodied in various combinations and subcombinations of features, functions, elements, and/or properties may be claimed through presentation of claims in a subsequent application.
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The present invention generally relates to a beam suitable for providing support to, for example, an automobile body. More specifically, the present invention relates to a steel boxed I-beam structure having compound curves, formed without use of a dedicated fixture or jig. Typically, the steel boxed I-beam structure provides a strong support that can be manufactured with a minimum of effort, and without the use of heavier shop machinery.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to corresponding provisional applications U.S. Ser. No. 61/120,924, filed Dec. 9, 2008 in the name of the applicants of this application.
FIELD OF THE INVENTION
[0002] The present invention relates to patio awnings and security screens/storm barricades, and more specifically, to a device capable of remote operation that functions as a security screen, reducing light and preventing access into a building, and that also functions as a storm barricade when in its closed or down/vertical position, and that functions as a patio cover or awning capable of providing shade when in its open or up/horizontal position.
BACKGROUND OF THE INVENTION
[0003] Home security has taken numerous shapes and forms over the ages. Many inventions have sought to accomplish security in various forms with various constraints in mind, such as appearance, ease of operation, and cost. Some of the most easily used forms of home security, as well as the most cost effective, have been in the form of security screens. However, designing these security screens to be aesthetically pleasing in their open position has proven to be a difficult task.
[0004] Additionally, various shading devices, including different designs of patio covers or awnings, are present on the market. However, many of the various forms of shading devices have lacked the function of being removable or retractable, preventing the user from moving or hiding the shading device when desired. Furthermore, constructing a patio cover has also proven to be difficult and expensive task.
[0005] Furthermore, in geographic areas that are prone to seasonal storms, the availability of an effective, remotely operable retractable storm barricade enables property owners to have their residences readily securable at all times of the year and also enables property owners to secure their residences against the weather without being forced to travel to the residence itself and without having to take part in the physically demanding task of boarding up every entry way and window. The property owners would also be able to remotely raise the storm barricades once the storm event has subsided, thereby allowing increased light into the structure and reducing potential mildew growth.
[0006] Therefore, it would be beneficial to provide an effective remotely operable security screen that provides a retractable patio awning when the security screen is in its unused position, and that also provides a permanent yet retractable and remotely operable storm barricade.
SUMMARY OF THE INVENTION
[0007] In accordance with one embodiment, a patio cover and storm protection device is disclosed. The device is preferably a flexible garage door-like apparatus comprising a screen and a pair of tracks that curve from substantially vertical to substantially horizontal and abutting the external façade of a doorway or window. The substantially horizontal portion(s) of track will be preferably slightly pitched as to cause rain and precipitation to be directed away from the façade of the building structure when the screen is in its substantially horizontal position. The device acts as a patio door security screen as well as a storm barricade for a window or a doorway when in its closed or down/vertical position and also acts as an awning or patio cover when in its open or up/horizontal position. The device will be capable of being operated in the same fashion as a standard garage door, in which an electric motor drives the screen from one position to another. The device is preferably also capable of being operated remotely, thereby allowing a vacationing homeowner to lower the screen and create a storm barricade in an emergency despite being miles away from home. In this embodiment of the device, the length of the screen may be longer than the height of the substantially vertical portion of the tracks, thereby providing more shade in its open or up/horizontal position than it would otherwise. In such a situation, the device in its closed or down/vertical position will also have a small portion of the screen remain in a substantially horizontal position, thereby causing the device to act as both a smaller awning and as a patio door security screen/storm barricade at the same time.
[0008] In accordance with another embodiment of the present invention, a patio cover and storm protection device is disclosed. The tracks upon which the screen travels on the exterior of the building structure preferably have a shade fixture between the tracks and located at the distal end of the substantially horizontal portion of the tracks so that the shade produced while the screen is in its open or up/horizontal position is increased and extended beyond the distal end of the substantially horizontal portion of the tracks. This feature increases the stability of the device in the event of strong winds in that the screen of the device is completely flush with the façade of the building structure when in its closed or down/vertical position yet has no horizontal component exposed to the wind. Accordingly, even if the shade fixture or the tracks were damaged or destroyed by strong winds, the wind is unable to “grab” the screen itself, and the door or window covered by the screen remains covered and continues to protect the interior of the building structure.
[0009] In accordance with yet another embodiment of the present invention, a patio cover and storm protection device is disclosed. The device will preferably have an additional pair of substantially horizontal portions of track that lead inside the building structure above the top of the window or door frame to which it is coupled. Accordingly, the device will preferably have three different positions: one position being up and substantially horizontal on the exterior of the structure, thereby providing shade; one position being down and substantially vertical, thereby providing a security screen/storm barricade and preventing access through the door or window; and one position being up and substantially horizontal within the building structure to which it is attached, thereby being hidden from view.
[0010] In accordance with a further embodiment of the present invention, a patio cover and storm protection device is disclosed. The device preferably will have various water diverting mechanisms to ensure that water does not flow toward the façade of the building and to protect the various components of the device, namely the track rollers and the tracks upon which they run, from water damage. To prevent water from flowing toward the façade of the building, a small fascia will preferably be located above the curved portion of the tracks so that water is drained away from the façade of the building structure and onto the substantially horizontal screen, which then causes the water to run toward the top edge of the screen being furthest from the building structure. To protect the tracks and the track rollers, a fluid diverter consisting of a continuous piece of material is preferably positioned above the substantially horizontal portion of the tracks, causing water to run to either side of the tracks. Preferably, the tracks will be at least partially embedded in structural members, thereby making the entire device more aesthetically pleasing, although it should be understood that the device may be constructed without embedding any portion of the tracks in structural members without departing from the scope and spirit of the invention.
[0011] In any of the aforementioned embodiments, there may be a plurality of independent patio cover and storm protection devices directly next to one another. Accordingly, a user with such a plurality of devices is preferably able to provide shade for different portions of a patio while also securely protecting less than all of the portions of the building structure to which the plurality of devices are attached.
[0012] It should be noted that in each of the aforementioned embodiments, the device is capable of being integrated with a building structure while remaining in compliance with the Americans with Disabilities Act.
[0013] The features, functions, and advantages can be achieved independently in various embodiments of the disclosure or may be combined in yet other embodiments.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] In accordance with one embodiment of the present invention, a patio cover and storm protection device is disclosed, comprising, in combination, at least one screen, each screen having a front face and a back face and a first side and a second side and a top side and a bottom side, at least one track, each at least one track comprising, a substantially vertical portion having a higher end and a lower end, the substantially vertical portion being proximate a building structure, a curved portion having a vertical end and a horizontal end, the vertical end being coupled to the higher end of the substantially vertical portion, and a substantially horizontal portion having a proximate end and a distal end, the proximate end being coupled to the horizontal end of the curved portion and the distal end of the substantially horizontal portion extending away from the building structure, and at least one track roller coupled to each at least one screen, the at least one track roller dimensioned to permit the at least one screen to travel along the at least one track so that at least a portion of the at least one screen being disposed anywhere between a substantially vertical position covering the building structure and a substantially horizontal position extending away from the building structure.
[0015] In accordance with another embodiment of the present invention, a patio cover and storm protection device is disclosed, comprising, in combination, a screen having a front face and a back face and a first side and a second side and having a width equal to the distance between the first side and the second side, a first substantially vertical track having a higher end and a lower end and being proximate a building structure, a second substantially vertical track having a higher end and a lower end and being proximate the building structure and being substantially parallel to the first substantially vertical track, a first dual-curved track comprising, a vertical portion having a top and a bottom, the bottom of the vertical portion being coupled to the higher end of the first substantially vertical track, a first substantially horizontal portion coupled to the top of the vertical portion and extending in a first direction, a second substantially horizontal portion coupled to the top of the vertical portion and extending in a second direction being substantially opposite the first direction, and a track switch for causing a track roller traveling from the bottom of the vertical portion to the top of the vertical portion to transition to either the first substantially horizontal portion or the second substantially horizontal portion, a second dual-curved track comprising, a vertical portion having a top and a bottom, the bottom of the vertical portion being coupled to the higher end of the second substantially vertical track, a first substantially horizontal portion coupled to the top of the vertical portion and extending in a first direction, a second substantially horizontal portion coupled to the top of the vertical portion and extending in a second direction being substantially opposite the first direction, and a track switch for causing a track roller traveling from the bottom of the vertical portion to the top of the vertical portion to transition to either the first substantially horizontal portion or the second substantially horizontal portion, a first substantially horizontal portion of track having a proximate end and a distal end, the proximate end being coupled to the first substantially horizontal portion of the first dual-curved track, the first substantially horizontal portion of track extending away from the building structure, a second substantially horizontal portion of track having a proximate end and a distal end, the proximate end being coupled to the second substantially horizontal portion of the first dual-curved track, the second substantially horizontal portion of track extending into the building structure, a third substantially horizontal portion of track having a proximate end and a distal end, the proximate end being coupled to the first substantially horizontal portion of the second dual-curved track, the third substantially horizontal portion of track extending away from the building structure and being substantially parallel to the first substantially horizontal portion of track, a fourth substantially horizontal portion of track having a proximate end and a distal end, the proximate end being coupled to the second substantially horizontal portion of the second dual-curved track, the fourth substantially horizontal portion of track extending into the building structure and being substantially parallel to the second substantially horizontal portion of track, a first plurality of track rollers coupled to the first side of the screen and being capable of traveling along the first substantially vertical track and the first dual-curved track and the first substantially horizontal portion of track and the second substantially horizontal portion of track, and a second plurality of track rollers coupled to the second side of the screen and having a distance from the first plurality of track rollers substantially equal to the width of the screen and being capable of traveling along the second substantially vertical track and the second dual-curved track and the third substantially horizontal portion of track and the fourth substantially horizontal portion of track.
[0016] The foregoing and other objects, features, and advantages of the invention will be apparent from the following, more particular description of the preferred embodiments of the invention, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Embodiments of the disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0018] FIG. 1 is an elevated perspective view of an embodiment of the patio cover and storm protection device of the present invention and the building structure to which it is attached, the screen of the device being in a substantially horizontal position, and the substantially horizontal portion of the tracks of the device being supported by two vertical support members at the distal end of the substantially horizontal portion of the tracks;
[0019] FIG. 2 a is a side perspective view of the embodiment of the device shown in FIG. 1 ;
[0020] FIG. 2 b is a side perspective view of another embodiment of the patio cover and storm protection device of the present invention wherein the substantially horizontal portions of the tracks are supported by tensile members anchored to the building structure to which the device is connected;
[0021] FIG. 2 c is a side perspective view of another embodiment of the patio cover and storm protection device of the present invention wherein the substantially horizontal portions of the tracks are supported by truss members;
[0022] FIG. 3 is an elevated perspective view of the embodiment of the device shown in FIG. 2 b with multiple devices placed side by side;
[0023] FIG. 4 is an elevated perspective view of the embodiment of the device shown in FIG. 1 wherein the screen of the device is in its fully closed or down/vertical position, while a portion of the screen is also partially in a substantially horizontal position due to the fact that the screen is slightly longer than the height of the substantially vertical portions of track;
[0024] FIG. 5 is an elevated perspective view of another embodiment of the patio cover and storm protection device of the present invention wherein a shade fixture is provided at the end of the substantially horizontal portion of the tracks to provide additional shade while doing nothing to compromise the screen's integrity with respect to strong winds, as the screen will be substantially vertical and flush with the façade of the house in its closed position, thereby minimizing the screen's potential wind exposure, and making this particular embodiment more attractive for use in geographic locations that are more prone to severe weather;
[0025] FIG. 6 is an elevated perspective view of the embodiment of the device shown in FIG. 1 with much of the building structure and the device shown in phantom in order to accentuate the tracks of the device and a portion of the driving means for moving the screen along the tracks;
[0026] FIG. 7 a is a side perspective view of the device as shown in FIG. 6 ;
[0027] FIG. 7 b is a cross-sectional view of another embodiment of the patio cover and storm protection device of the present invention showing the screen engaged with the tracks via track rollers coupled to the screen. Also shown is a fluid diverter for directing water away from the tracks. The tracks will preferably be embedded in structural members which hide the tracks from view, making the overall appearance of the device more aesthetically pleasing;
[0028] FIG. 7 c is an elevated perspective view of another embodiment of the patio cover and storm protection device of the present invention showing the substantially horizontal portion of the tracks and a fascia covering the proximate end of the substantially horizontal portions of the tracks, the substantially vertical portions of the tracks, and the curved portion of the tracks;
[0029] FIG. 8 is an elevated perspective view of another embodiment of the patio cover and storm protection device of the present invention wherein an additional pair of substantially horizontal portions of track enable the device to be completely hidden from view;
[0030] FIG. 9 is a side view of the embodiment of the device shown in FIG. 8 demonstrating the additional pair of substantially horizontal portions of tracks;
[0031] FIG. 9 a is a side view of the embodiment of the device shown in FIG. 8 demonstrating the additional pair of substantially horizontal portions of track; and
[0032] FIG. 10 is a front view of the patio cover and storm protection device of the present invention accentuating a portion of the driving means for moving the screen of the device from its substantially vertical position to one of its substantially horizontal positions.
[0033] FIG. 11 is a front view of another embodiment of the patio cover and storm protection device of the present invention in which the track rollers are coupled to the sides of the screen.
[0034] FIG. 11A is a front perspective view of the embodiment of the device shown in FIG. 11 demonstrating how the track rollers are engaged with the track.
[0035] FIG. 12 is a front view of another embodiment of the patio cover and storm protection device of the present invention in which the track rollers are coupled to a face of the screen.
[0036] FIG. 12A is a side perspective view of the embodiment of the device shown in FIG. 12A demonstrating how the track rollers are engaged with the track.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] Referring to the Figures, a patio cover and storm protection device 10 is shown. The device consists of a screen 12 ( FIGS. 1 , 3 - 6 , and 7 b - 12 A) mounted upon two tracks 14 placed in front of the exterior of a door or window 16 ( FIGS. 1 , 3 , 6 , and 8 ) being proximate the façade 18 ( FIGS. 1-7 a and 7 c - 8 ) of the building structure abutting the door or window 16 , and the tracks 14 curving substantially horizontally and outwardly and from the building after reaching a height at least equal to the height of the door or window 16 which is covered by the device 10 in its closed or down/vertical position. Accordingly, when the screen 12 is in its open or up/horizontal position it rests on the substantially horizontal portion of the tracks 14 at a height above the top of the door or window 16 in a substantially horizontal position, thereby enabling the device 10 to provide shade from the sun, and when the screen 12 is in its closed or down/vertical position, the device completely or partially blocks the door or window 16 thereby acting as both a patio door security screen and a storm barricade. Although this embodiment of the invention uses a pair of tracks 14 engaged with track rollers 38 coupled to each side of the screen 12 , it should be understood that substantial benefit may be derived from an alternative embodiment of the present invention in which only a single track 14 engaged with track rollers 38 coupled to a single face 46 of the screen 12 without departing from the scope and spirit of the invention.
[0038] Referring to FIGS. 2 a , 2 b , 2 c , 3 , and 4 the different methods for supporting the substantially horizontal nature of the tracks 14 are shown. The different methods are either vertical support members 32 placed at the distal end of the substantially horizontal portion of the tracks 14 ( FIG. 2 a ), tensile members 34 attached to the distal end of the substantially horizontal portion of the tracks and anchored to the façade 18 of the building structure ( FIGS. 2 b and 3 ), a pair of truss members 36 between the façade 18 of the building structure and the substantially horizontal portions of the tracks 14 ( FIGS. 2 c and 4 ), or by cantilevering the substantially horizontal portion of the tracks of the device with respect to the building structure. Although various methods of supporting the substantially horizontal portions of the tracks 14 of the device 10 are disclosed, it should be clearly understood that substantial benefit could be derived from an alternative embodiment of the present invention in which the substantially horizontal portions of the tracks 14 of the device 10 are supported by different means without departing from the scope and spirit of the invention.
[0039] Referring to FIG. 3 , a plurality of combined patio cover and storm protection devices 10 , each having a separate screen 12 with its own tracks 14 , may be placed directly next to one another, thereby enabling a user of the devices to provide shade for a portion, or portions, of a patio while simultaneously securely closing off the remaining portions of the patio. Again, it should be understood that this embodiment of the invention may be practiced with a single track 14 used for each screen 12 , without departing from the scope and spirit of the invention.
[0040] Referring to FIG. 5 , one embodiment of the device has, in addition to the aforementioned features of the first embodiment, a shade fixture 20 having the same width as the distance between the tracks 14 and extending horizontally and outwardly from the distal end of the substantially horizontal portion of the tracks 14 , the shade fixture 20 providing extended shade. It should be clearly understood that substantial benefit could be derived from an alternative embodiment of the present invention in which no shade fixture 20 is used without departing from the scope and spirit of the invention.
[0041] Referring to the FIGS. 8 , 9 , and 9 a , an additional embodiment of the device 10 provides an additional pair of substantially horizontal portions of track 30 travelling inwardly into the building structure, and a track switch 33 between the tracks 14 and the additional pair of substantially horizontal portions of track 30 , thereby allowing the screen 12 to be made completely hidden from view by placing the screen 12 within the building structure. It should be clearly understood that substantial benefit could be derived from an alternative embodiment of the present invention in which no track switch 33 or additional pair of substantially horizontal portions of track 30 are used without departing from the scope and spirit of the invention.
[0042] Referring to FIGS. 1 , 3 - 6 , 7 a , and 7 c , another embodiment of the device has a fascia 22 having the same width as the distance between the tracks 14 and extending horizontally over the substantially vertical portions and the curved portions of the tracks 14 and abutting the façade 18 of the building structure so that when the screen 12 is in its open or up/horizontal position the fascia 22 comes in close proximity to the bottom side of the screen 12 , thereby providing continuous shade from the edge of the building structure to the top side of the screen 12 while also providing means for causing water to flow away from the façade 18 of the building structure and toward the top side of the screen 12 . It should be clearly understood that substantial benefit could be derived from an alternative embodiment in which other mechanisms for diverting water may also be used, such as a series of rain gutters, or in which no mechanism for diverting water is used, without departing from the scope and spirit of the invention.
[0043] Referring to FIGS. 7 b and 7 c , a cross-sectional view of the track 14 of the device is shown with the track rollers 38 coupled to the screen 12 shown engaged with the track 14 ( FIG. 7 b ). Additionally provided is a fluid diverter 40 positioned above the tracks 14 for directing rain and precipitation away from the tracks 14 ( FIGS. 7 b and 7 c ). It should be clearly understood that substantial benefit could be derived from an alternative embodiment of the present invention in which a different mechanism is used to divert fluid away from the tracks 14 , or in which the tracks 14 are protected from weather via different means, or in which no fluid diverter 40 is used, without departing from the scope and spirit of the invention.
[0044] Referring to FIGS. 6 , 8 , and 10 , the driving mechanism 28 of the screen 12 is shown. The driving mechanism 28 may be an electric motor coupled to the screen 12 in a manner similar to common garage door openers using a torsion spring 42 and a pair of cable drums 44 , or may be a simple user-operated hand-driven pulley system. The driving mechanism 28 may be operated by a localized electronic actuator, such as button, and may even be operated remotely by a secure remote actuating device. It should be clearly understood that substantial benefit could be derived from an alternative embodiment of the present invention in which no driving mechanism 28 is used without departing from the scope and spirit of the invention.
[0045] Referring to FIGS. 11 and 11A , an embodiment of the screen 12 , track 14 , and track rollers 38 is shown. The track rollers 38 are coupled to the side of the screen 12 and engaged with the track 14 .
[0046] Referring to FIGS. 12 and 12A , an embodiment of the screen 12 , track 14 , and track rollers 38 is shown. The track rollers 38 are coupled to a face 46 of the screen 12 and engaged with the track 14 , to allow multiple screens 12 to be placed side by side without tracks 14 in between the multiple screens 12 .
[0047] While embodiments of the disclosure have been described in terms of various specific embodiments, those skilled in the art will recognize that the embodiments of the disclosure can be practiced with modifications within the spirit and scope of the invention.
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An adjustable patio cover and storm protection device capable of remote operation which acts as a security screen that prevents access through a doorway or window to which it is coupled, reduces the amount of light able to pass through the doorway or window, and also acts as a storm barricade when in its closed or down/vertical position, and which acts as an awning or sun shade that provides shade for the area in front of the door or window to which it is coupled when it is in its open or up/horizontal position.
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BACKGROUND OF THE INVENTION
The invention relates to a versatile utensil for use in the preparation of food, including meats, fruits and vegetables. The trend to time- and labor-saving devices in the kitchen, of homes, restaurants and fast-food emporiums, is impressive and unmistakable. One reason is the continuous increase in the number of women gainfully employed and who are desirous of spending as little of their spare time as possible in the preparation of meals. Another reason is the general increase in outdoor and social activities as well as the popularity of viewing television. These and other factors augment the urge to both men and women, to decrease to a minimum the time spent in preparation of meals. As an example of the result of this tendency it is of interest to note the present popularity and increase in use of pressure cookers and pans, and microwave ovens by which food can be prepared in a fraction of the time otherwise required by use of open vessels.
The trend above noted is also responsible for the desire to save time presently required by needless searching for, cleaning and storage of a multitude of items commonly used in the kitchen in the preparation of food. Among these are slicers, dicers, choppers, severing devices, juicers, presses, can openers and nut crackers. When such a multitude of items must be separately stored and operated, much time is needlessly consumed in searching for them and cleaning and replacing them after use.
SUMMARY OF THE INVENTION
The present invention solves the aforesaid problems by affording in one compact and efficient group, all of the utensils commonly required for the preparation of food. In a basic combination a single receptacle and permanently attached pressure lever, together with a number of attachments conveniently stored in the receptacle, the housewife whether or not employed outside the home, as well as restaurant and fast-food emporium operators, have available for immediate and rapid use all of the means previously supplied by a wide range of devices ordinarily stored, each in a separate place.
With my invention the assembly ready for use, of the devices commonly needed in the kitchen, is practically instantaneous. All items forming the combined elements thereof, are in a compact package including a receptacle or container which may be taken off a convenient shelf, the needed components quickly assembled and used, and readily washed or cleaned and replaced for subsequent use.
It is therefore the chief object and purpose of the invention to provide in one basic assembly and components therefore, means by which food may be processed and readied for use, in a wide variety of ways as by chopping, severing, slicing, comminuting, dicing, opening of cans, pressing and cracking of nuts.
A further object is to provide a utensil wherein a basic assembly of receptacle with shaft and press lever permanently attached thereto, are adapted to receive and usefully employ attachments for the several uses above identified.
Another object is to provide novel means by which (a) attachments such as a chopping blade or can opener may be easily but rigidly and instantaneously detachably connected to the press lever of the instrument, (b) other attachments for slicing etc., are fixedly but detachably connected with the receptacle and/or the lever, for use individually or in combination with other attachments, (c) cooperation between the press lever and attachments is effected by platens or blocks detachably connected with the lever without the use of tools such as wrenches or screwdrivers.
Yet another object is to provide a utensil as in the preceding paragraphs, wherein all food processed is collected in the recpetacle for facile recovery for complete use and avoidance of waste.
An important object is the provision of a kitchen utensil which is very strong and effective for its intended purposes, long-lived, and which may be manufactured and sold at a price competitive with the total cost of the many separate items it replaces.
Other objects and advantages of the invention will be apparent to those skilled in the art, after a study of the following detailed description in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of the utensil assembled for use in slicing;
FIG. 2 is a broken perspective view showing part of the receptacle of FIG. 1, with the first slicer in position and a second slicing or dicing attachment about to be slid into operating position over the first;
FIG. 3 is a plan view showing the second slicer attachment in operating position over the first one;
FIG. 4 is a plan view corresponding to FIG. 3 but with the second attachment at 90° to its position of FIG. 3, as where dicing of foodstuff is to be effected;
FIG. 5 is a detail side view partly in section, of the slicing attachment as seen in vertical planes through line 5 -- 5 of FIG. 2;
FIG. 6 is a detail of one corner of the basic or first slicer, inverted to illustrate the tensioning means for the slicing or cutting strips;
FIG. 7 is a sectional view to a scale enlarged over FIG. 6, showing the mounting of one of the tensioning screws and its connection with one of the mounting bars for the slicing strips, as seen in a vertical plane through line 7 -- 7, FIG. 6;
FIG. 8 is a perspective view similar to FIG. 2 but showing the juicer attachment about to be slid into operating position over the base plate of the utensil;
FIG. 9 is a detail view of the base plate with juicer attachment in position thereon;
FIG. 10 is a side elevation partly in section, showing the operating lever in vertical position and attached to its shaft, with chopping blade detached to illustrate how it is releasably connected to the lever;
FIG. 11 is a side elevation partly in section, showing the chopping blade coupled to the operating lever and resting with its cutting edge on a board specially shaped for the base receptacle;
FIG. 12 shows in perspective a can opener with a supporting bracket for attachment to the shaft or column of the base receptacle;
FIG. 13 is a view partly in section and to a scale reduced from that of FIG. 12, showing how the can opener is firmly but releasably connected with the shaft of the base receptacle;
FIG. 14 is a detail showing in section and to about full scale, the swivel mounting for the lower end of the press lever supporting shaft;
FIG. 15 is an end view of the lever showing its pivotal attachment to the top end of the support shaft;
FIG. 16 is a detail section in a plane identified by line 16 -- 16, FIG. 11;
FIG. 17 is a perspective view from below and to one side, of the frame for supporting and tensioning the cutting or slicing strips of the base plate as in FIG. 1; and
FIG. 18 is a bottom plan to a reduced scale, showing in detail the tensioning means for the slicing strips or ribbons of the base plate.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring particularly to FIG. 1, a one-piece receptacle or container 1 of metal or hard strong plastic comprises a imperforate bottom 2, side walls 3 and end walls 4 and 5 the latter being formed with an integral projection 6 extending rearwardly from its top central portion. From FIG. 14 it is noted that this projection is vertically bored at 7. A metal sleeve or grommet 8 is fixed in the bore, as by a press fit therein and/or ends such as 9 which may be flanged after the sleeve is emplaced.
A metal shaft or column 10 has its lower end reduced in diameter to form an annular shoulder. The reduced end is sized for a smooth fit in sleeve 8 so that the shaft is journaled therein for free accurate rotation about a vertical axis. The lower end of the shaft is axially drilled and tapped to receive a machine screw 11 which, with washer 12 releasably secures shaft 10 in position with its shoulder bearing on the top end of sleeve 8. FIG. 14 also shows that the top end of the shaft is vertically and centrally slotted as at 13, and drilled diametrically at 14 to form a pivot bearing extending across and normal to the slot, it being noted that upon FIG. 14 shaft 10 is turned about 90° from its position of normal use.
FIGS. 1 and 15 show a lever 15 having its lower surface channeled as at 16, anoting also FIG. 10. At its rearward end the lever is transversely bored to accomodate a pivot 17 which also traverses hole 14 in shaft 10 and thus mounts the lever for turning about a normally horizontal axis. The lever is thus universally pivotable about mutually normal vertical and horizontal axes. An ornamental head 18 on one end of pivot 17 and nut 19 threaded thereon hold the pivot in place. As seen at 20, FIG. 1, the distal end of the lever is shaped to provide a handle.
As shown upon FIGS. 10 and 16 channel 16 extends substantially the entire length of lever 15. At the rearward or proximal end thereof a specially-shaped locking plate 21, subsequently described in detail, is fixed within the channel, centrally thereof as shown at FIG. 15. Since pivot 17 passes with a smooth fit through a bore 22 in the plate, the latter is firmly held in the channel at the rearward end thereof. The forward end of plate or element 21 is reduced to the shape of a rod which may be circular or rectangular in transverse section and which, as subsequently explained, forms an abutment for the chopping blade 23 and when in use extends linearly of and along the lever, noting FIG. 16 in particular. The parts described in the foregoing paragraphs form a basic utensil combination which is adaptable to a number of uses.
Chopping blade 23 is shown in detail upon FIGS. 10 and 11, from which it is seen to be a one-piece item of steel, preferably stainless, with a lower essentially straight cutting edge 24. Lightening holes 25 and 26 are formed in and through the blade. The forward upper edge of the blade is straight, as indicated at 27 and which when in use linearly abuts the rod-like forward part of element 21. See FIGS. 10 and 16. The rearward end of the blade is formed with a rearward projection 28, having therein notches 29, 30 and 31. Inspection of FIG. 10 shows that when the blade is fixed to the lever, notch 29 fits about and receives a lug 32 integrally formed on element 21. Notch 30 is formed to accomodate and fit about a pressure element 33 integrally attached as by welding, to element 21 and used when the utensil is employed for cracking nuts in the manner subsequently explained.
Projection 28 is also formed with an arcuate lower edge 34. The radius of this edge is closely equal to or slightly less than the radial distance from the axis of pivota 17 to the lower end of slot 13 in shaft 10, as indicated at "r," FIG. 15. The projection is also constructed and proportioned so that when lever 15 is in its erect or substantially vertical position blade 23 may be easily emplaced by moving it to the left from the position of FIG. 10, into slightly offset contiguous relation with element 21, until notch 29 is in registration with lug 32 and edge 27 is within channel 16. At this the specially-shaped notch 31, FIG. 10, registers with projection 35 which is specially shaped for use in pressing, as subsequently explained. Then the blade may be moved slightly in a direction normal to its plane so that its upper edge 27 linearly contacts that portion of element 21 within channel 16; and when lever 15 is pivoted downwardly about pivot 17, projection 28 rides into slot 13 of shaft 10, with its arcuate edge 34 in smooth sliding contact with the end of the slot. This movement positively locks the blade to the lever for operation in chopping, because it cannot move sideways that is, in a direction normal to its plane, due to its fit in slot 13, and it cannot drop downwardly because of the interfit between projection 35 and notch 31. This is clear from inspection of FIG. 10.
At 36, FIG. 11, is indicated a chopping board which may be of hard wood. The board has a flat upper surface and a periphery corresponding in size and shape to the top edge of the walls of receptacle 1. Its lower edge is rabbetted to a shape fitting smoothly within the receptacle so that when in place it cannot move or shift laterally. Thus when blade 23 is fixed to lever 15 and board 36 is emplaced as previously described, foodstuffs such as fruits, vegetables and meats may be placed upon the board and sliced or comminuted, as desired, by pivotal movement of the lever about the axis of pivot 17 with interspersed swinging of the lever about the axis of shaft 10. Release of chopping blade 23 for cleaning and/or conversion of the invention to other uses may be readily effected merely by raising the lever to about its vertical position as in FIG. 10. This moves arcuate edge 34 clear of slot 13 in shaft 10 and enables the blade to be shifted slightly transversely of its plane, thus moving notch 31 free of projection 35.
The invention is easily adapted to use as a press for producing fruit and vegetable juices, for slicing and dicing fruits and vegetables and for numerous other uses as generally shown upon FIG. 1. A base plate of heavy gage sheet metal is generally indicated at 37, FIG. 8, and is provided with flanges 38, 39 at its front corners and which when the plate is emplaced, rest upon the top edges of side walls 3.
The central portion of plate 37 is cut out to form a rectangular opening 40, open at the back. The side portions of the plate at the back, right and left, are bent upwardly at about 90°. One of these bends is indicated at 41, FIG. 8. The upward extensions 42, 43 (FIG. 9) thus formed are integrally united with and by the lower portion of a riser 44 and which as shown upon FIG. 1, has essentially vertical laterally-spaced slots 45, 46 with an interposed notch 47 to enable downward pivoting of lever 15. Ears 48, 49, right and left FIG. 9, are also integral with plate 37 so that when it is in operating location the ears rest upon respective back corner edges of reseptacle 1. As is clear from inspection of FIG. 1 the ears have integral downwardly-turned tabs as at 50 for ear 49, and which fit down about the beveled corners of the receptacle. Thus when emplaced, plate 37 is fixed against lateral movement with respect to the receptacle and can only be removed by upward translation. Further, in the emplaced position, riser 44 and its slots 45, 46 are fixed with the receptacle and form guide means for the press platen subsequently described. When in operating position the plate slopes downwardly and rearwardly into the receptacle 1, as best shown upon FIG. 8.
Opening 40 in base plate 37 is traversed by parallel cutting or slicing bars 51 of rust-proof metal and shown upon FIGS. 1 and 8 as extending transversely of the receptacle, when emplaced, in closely-spaced relation. The bars are tensioned and thin so that they present coplanar upper cutting edges. In addition these bars or ribbons may be 1/4 inch or more in width, that is, in the normally vertical direction so that they are powerful in resisting downward forces exerted upon them.
FIG. 17 shows detached and in perspective from below, a reinforcing and stiffening bar or frame 52 and which in the assembled instrument is welded or otherwise rigidly secured to the under side of base plate 37. As shown, the frame is a continuous metal bar square in cross section and about 3/8 inch on a side. Its forward transverse run 53 extends along and in registration with the forward edge of opening 40. Runs 54, 55, both normal to run 53 extend rearwardly along and outwardly spaced from the inner side edges of opening 40. Riser portions 56, 57 of the frame extend behind and in contact with the right and left upward extensions of plate 37 formed by bends 41 therein, noting FIG. 8 in particular. The rearward transverse run 58 of the frame has its lower edge about flush with the lower edge 59 of riser 44. Since the frame is welded or otherwise rigidly attached to plate 37, continuously or at closely-spaced points along its length, the plate is extremely strong and rigid in all directions.
FIG. 17 also shows that side runs 54, 55 of frame 52 are each drilled with a number of holes such as 59, 60, four such holes being shown in each run in the model selected for illustration. The holes are preferably uniformly spaced in each side run but for reasons which will later appear, each hole is offset in the direction along its run, with respect to the corresponding hole at the opposite side. FIG. 18 shows four relatively short bars 61, 62, 63, 64 between which the metal slicing strips or ribbons 51 extend. The bars are of the same transverse dimensions as the material of frame 52 and are transversely slotted at locations uniformly spaed therealong, from their top surfaces downwardly. Each slot has a depth equal to the width of strips or ribbons 51 and, of course, stops a material distance short of the lower surface of the bars. In the model shown there are two slicing ribbons 51. Beginning at the top right, FIG. 18, the first ribbon is headed over to prevent it from passing through its slot in bar 63. It then passes to the left through the first slot in bar 61, then about the bar and through the second slot therein, back to bar 53, through the second slot in bar 63, back to bar 61, through the second slot therein, back to bar 61, through the third slot therein and around the end of this bar to bar 63 and through the fourth slot, where its other end is headed over. The second ribbon 51 is passed or threaded in the same way through and about the slots in bars 62 and 64, as clearly appears from FIG. 18. The eight passes of the two ribbons thus form equally-spaced parallel cutting or slicing edges.
Each bar 61 through 64 is held to its side run of frame 52, by a pair of Allen-head machine screws. FIG. 7 illustrates one such screw 65 as having its head seated within a counterbore 66 of one bore 59 of side run 55. The threaded end of the screw engages a tapped hole in short bar 61. This figure also shows that each of the four short bars is in sliding contact with the under surface of the sides of plate 37.
In a way clear from inspection of FIGS. 7 and 18, the pair of screws threaded into each short bar 61 through 64, may be turned to draw it toward the corresponding side run 54 or 55, as the case maybe, to thereby tension ribbons 51 to any desired extent. Thus the upper edges of these ribbons collectively define a very rigid and efficient cutting or slicing plane surface when fruit, vegetables or other foodstuffs are forced downwardly over and through them, into receptacle 1.
Force to effect slicing, comminuting and juicing is exerted by lever 15 acting upon a platen or block 67, FIG. 1, and which may be of hard wood. An internally threaded metal sleeve 68 is fixedly embedded in the center of the top surface of the block, to accept the threaded lower end of a plunger 69, shown as square in cross section. The upper end of the plunger is axially slotted as at 70. A pin 71 has a press fit in a bore in the plunger, traversing the slot near its upper end. The construction and dimensions are such that the slot receives with a smooth fit between its lower end and pin 71, the projection 35 of plate or element 21, previously described. Thus when projection 35 and plunger 69 are releasably coupled as shown upon FIG. 1, operation of the lever effects vertical movement or reciprocation of block 67 toward and from the slicing surface conjointly defined by the top edges of ribbons 51.
The two slots 45, 46 in riser portion 44 of base plate 37 have been previously described. FIG. 1 shows that block 67 has first and second screws 72, 73 threaded into its rearward surface near the top edge thereof. The guide screws are spaced the same as the slots so that each may pass freely through its respective slot. Each screw is formed at its free end with an enlarged flat head whose plane lies in and along the axis of the screw. The screws are preferably threaded into metal sleeves fixedly embedded in the block and so located that the axis of each screw when in place, extends upwardlly and rearwardly at an acute angle of 10 to 15 degreees with respect to the top surface of the block. By turning the screws so that the head of each is parallel to the slots, they easily pass therethrough. Then when they are turned 90° their flat ends extend transversely of the slots and thus act to retain the block to riser 44, for guided reciprocation in parallel with the slots and toward and from plate 37, by and in response to vertical pivoting of lever 15. By raising the block, inserting an article of foodstuff between it and ribbons 51, forcing the lever downwardly effects a very neat and efficient slicing.
If desired the lower surface of block 67 may be formed with shallow parallel slots spaced like ribbons 51 and located so that when the block is forced downwardly the ribbons enter the slots with a smooth fit to completely shear off the material being sliced. The slots just described are not shown. But FIG. 1 shows a number of them at 74 extending across one end of the block. With such a construction the end of the block opposite the slots has a threaded sleeve like 68, FIG. 1, embedded centrally in its surface. The threads of the sleeve are sized to accept the threaded lower end of a plunger like 69. This construction is very useful where smaller articles such as radishes or boiled eggs are to be sliced. While screws 72, 73 previously described, are convenient and useful in guiding block 67 in vertical movement, they are not absolutely necessary at all times because the block may be guided by hand.
Where dicing or fine division of foodstuff is desired the attachment indicated generally at 75, FIG. 2, is very useful. This comprises a one-piece rectangular frame 76 of metal, with end plates 77, 78 shaped alike as shown upon the figure and welded to the respective end runs of the frame. Each end plate has a coplanar extension such as 79, 80. The dimensions of attachment 75 are such that it may rest atop base plate 37 with a smooth fit beneath edge 59 of riser portion 44, and between the two vertical inside edges thereof such as 81, FIG. 8. This position is illustrated upon FIG. 4 wherein extension 79 is shown as abutting the inside surface of rear wall 5 of receptacle 1. The cutting or splicing strips 82 of frame 76 are mounted and tensioned by essentially the same means as have been described previously in connection with FIG. 18. It is therefore deemed not necessary to repeat the description. Suffice it to say that parallel ribbon strips 82 are shown as twelve in number, spaced the same as ribbons 51. The short slotted bars like 61, 62, FIG. 18, are three in number along each side of frame 76. These are identified at 83, 84, 85, each being slotted from its lower side upwardly, to accomodate with a close fit a respective number of passes of ribbons 82. The three bars, not shown, at the other side are similarly arranged. All of these bars are in smooth sliding contact with the under side surfaces of end plates 77 and 78. A total of three lengths of ribbon are used, one for each pair of opposed bars. As in FIGS. 7 and 18 the runs of ribbons 82 are tensioned by Allen-head screws 86, FIGS. 2 and 5, there being at least two for each bar. The inner end of each screw is threaded into its bar in the way indicated upon FIG. 7 for items 61 and 65. As in the construction of FIG. 18, turning of the screws effects high tension in the thin metal ribbons 82 so that their coplanar upper edges form efficient and effective cutting or slicing means.
FIG. 4 shows the arrangement when attachment 75 is used with its ribbons normal to those of base 37. In this position the two sets of ribbons define means by which vegetables or fruit may be diced or cut into relatively fine strips when force is applied by operation of lever 15, it being noted that the upper edges of ribbons 51 are essentially in contact with the under edges of ribbons 82 at their crossover points.
FIG. 3 shows the position of attachment 75 when operatively located over base 37. with its cutting ribbons 82 parallel to ribbons 51. This position is determined by the abutment of shoulders such as 88, 89, FIG. 3, with the riser portions such as 81, FIG. 2, of the base, it being noted that frame 76 is dimensioned to slide freely below edge 59. The construction and dimensions are such that in the postion and relations of FIG. 3 each pass of ribbons 82 is located in a vertical plane midway between two contiguous passes of ribbons 51 so that food may thus be sliced into layers having a thickness about one-half of those produced when using plate 37 alone.
As indicated generally at 90, FIG. 8 shows a very useful attachment for the production of juice and the like. This comprises a heavy metal plate generally rectangular in shape and rounded at its front corners. The rear edge is upturned to form a flange 92. Perforations 93 are disposed as shown, in regularly-spaced or geometrical relation over the main area of the plate and the flange. The plate is dimensioned to fit over and in surface contact with base 37. The distance between end edges 94 of flange 92 is slightly less than that between riser portions 42, 43, FIG. 9, that is, between the inside edges thereof. The vertical dimension of the flange is slightly less than the corresponding dimension from edge 59 downwardly to the plane defined by the top surface of the side portions of base 37. Since flange 92 is rearwardly offset from plate 91, it fits smoothly within the slot below edge 59 and thus the attachment is firmly but releasably fixed in position against lateral movement on and with respect to plate 37. Thus when in operating position the flange fits and closes the opening otherwise present from edge 59 downwardly. This feature assures that juice flowing rearwardly is strained by passing through holes 93 in the flange.
Referring to FIGS. 12 and 13, a can opener of novel construction is indicated generally at 95. The base or supporting bracket 96 comprises an initially flat heavy metal plate bent at right angle along line 97, FIG. 12, to define a first arm 98 drilled to journal the inner end of shaft 99. The second arm 100 is sheared to define a tab 101 parallel with and spaced from arm 98 and pierced at 102 to form a second bearing for the shaft. A first collar 103 fixed to the shaft bears against tab 101 and prevents axial motion of the shaft in one direction. A handle 116 is affixed to the outer or distal end of the shaft. The inner end of the shaft has a collar 104 fixed thereto. This abuts the end surface of arm 98 and prevents axial motion of the shaft in the other direction. The end of the shaft protruding from first arm 98 has a gear 105 fixed thereto. A crimping wheel 106 of about the same diameter as the gear, is also fixed to the shaft slightly axially spaced from the gear.
Cutter control lever 107 has an offset thumb tab 108 and is pivoted to arm 98 by a machine screw 109 secured by a nut, not shown, on its inner end. Also to be noted is the fact that the upper portion of arm 98 is bent outwardly along line 110 at an angle of about 20° so that the axes of shaft 99 and screw 114 are vertically coplanar but are inclined relatively, at a corresponding angle. A slot 111 in arm 98 is arcuate about the axis of screw 109. Lever 107 is of bellcrank form with its shorter arm at about right angle to the arm shown upon FIG. 12. The distal end of the shorter arm has a stub shaft fixed therein and on which is journaled a gear 112 of larger pitch diameter and number of teeth than gear 105. The ratio may be about 2:3. That is, when the gears intermesh, 105 makes about two revolutions for three for gear 112. The exact ratio is not critical but may be varied within small limits.
Cutting wheel 113 having the usual continuous sharp circular edge is fixed with gear 112 as, for instance, being integral with the same sleeve, journaled on the aforesaid stub shaft. The free end of the stub is axially drilled and tapped to accept a screw 114 having an enlarged slotted head which maintains the gear and wheel against axial movement along the stub shaft. The lower end of arm 98 has an integral outward flange 115 which engages the side walls of a can being opened. In the cutting position the stub contacts one end of slot 111. This is the position shown upon FIG. 12.
Upward force on tab 108 pivots the stub, gear 112 and wheel 113 upwardly out of the operating position with respect to the axis of shaft 99. This limiting position is determined by abutment of the stub with the other end of the slot. In this position of the parts a can to be opened is located with its rim between wheel 106 and gear 105. Then when lever 107 is forced downwardly to cutting position, wheel 113 pierces the top of the can and gears 105 and 112 intermesh. Then the handle may be turned while crimping wheel 106 engages beneath the rim of the can to turn the same, while cutting wheel 113 is positively rotated at somewhat greater linear speed to sever the metal of the can's top.
FIG. 12 shows second arm 100 of bracket 96 as having a shape similar to that of the rearward part of the upper edge of chopping blade 23, noting FIG. 10 in particular. Thus the bracket is formed with a notch 117 corresponding to notch 29 of the chopping blade, and a second notch 118 to accomodate press element 33, FIG. 10. The arcuate edge 118 is curved as concentric with the axis of pivot 17 when the opener is emplaced as shown upon FIG. 13.
Thus in a way which will be clear from the foregoing description, and inspection of FIG. 13, the can opener may be rigidly and detachably fixed to shaft 10, by raining lever 15 until it is at about 45° with respect to the horizontal. Then the end 119 of arm 100 may be inserted into slot 13 of shaft 10, with arcuate edge 118 in contact with the end of the slot, and notch 117 fitting about plug 32. When lever 15 is then pivoted to about the horizontal, a straight edge 120, FIG. 13, of bracket 96 linearly contacts along shaft 10. The opener is then rigidly fixed to the shaft. In this position the opener can be swung with the shaft, about the axis of the latter, to a position over receptacle 1 so that any juice or liquid escaping from the opened can falls into the receptacle and may be recovered. In this position handle 116 is disposed in laterally offset relation with respect to the receptacle and is thus free of any interference therefrom. While opener lever 116 is being rotated with one hand, press lever 15 may be gripped with the other to thus firmly maintain the instrument against undesired swinging with and about the axis of shaft 10.
FIGS. 10 and 11 show an anvil 121 of heavy gage metal, having a hole loosely fitting about shaft 10 so that it may be freely adjusted upwardly to any extent but locks to the shaft in response to a downward force thereon offset from the axis of the shaft. A circular depression 122 in the top surface of the anvil has its center offset from the axis of the shaft by the same distance therefrom as the center of metal pressure element 33 previously described as fixed with the under side of lever 15. Thus the invention may be used for cracking nuts when all attachments are removed from the receptacle and/or detached from lever 15, by adjusting anvil 121 vertically to accomodate the average diameter of the particular nuts to be cracked, and swinging it over receptacle 1. Then when lever 15 is pivoted downwardly a nut resting in depression 122 may be cracked by force thereon exerted between element 33 and the anvil. A leaf spring 123 is held on the anvil, as by machine screw 124, so that its lower end frictionally and resiliently engages the shaft, thus releasably holding the anvil in any position of vertical adjustment. The end of the spring also prevents the anvil from descending too far along the shaft, by engagement with the upper end of sleeve 8, noting FIG. 14. When swung to a position with depression 122 directed away from the receptacle the anvil is clear of and does not interfere with use of any of the other attachments previously described.
The operation and use of the invention for numerous purposes will be clear from the foregoing description. It can be rapidly easily and sequentially converted to use in chopping, cutting, severing, slicing, dicing, comminuting, juicing, can opening and cracking. The user has available the selection of a plurality of thicknesses into which the food is sliced. All solids and liquids are collected directly into the receptacle and thus completely recovered for use thus eliminating waste of food. All metal parts are preferably of stainless steel; and all parts or attachments are freely separable from the receptacle or from the shaft for cleaning and drying.
While I have disclosed herein the embodiments presently preferred by me, the disclosure is to be taken in an illustrative rather than a limiting sense. For numerous changes in shape, constructions, relations of the parts, substitutions of equivalents and modifications of structure and mode of operation, will readily occur to those skilled in the art, after a study of the forgoing specification.
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A kitchen utensil for the preparation of food and adaptable and easily convertible to numerous uses such as chopping, juicing, dicing, slicing, comminuting, can opening and cracking of nuts. All food processed is collected in a receptacle forming a basic element of the apparatus. Novel means are disclosed for the quick but firm attachment of a chopping blade and can opener, to an operating lever, for use over the receptacle.
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