description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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This application claims priority to U.S. Provisional Application Ser. No. 60/442,336, filed Jan. 24, 2003, the entire contents of which are incorporated herein by reference.
BACKGROUND AND FIELD OF THE INVENTION
This invention relates to compacting vehicles, and more particularly to vibration mechanisms for such compacting vehicles.
Compacting vehicles are generally known and are basically used to compact paved or unpaved ground or “work” surfaces (e.g., asphalt mats, roadway base surfaces, etc.). A typical compacting vehicle includes a frame and one or two vibrating drums rotatably mounted to the frame, the drums compacting the surfaces as the vehicle passes over. Compacting vehicles often include vibration assemblies that generate vibrations and transfer these vibrations through the drum to the work surface. Such vibration assemblies typically include two or more eccentric weights that are adjustable relative to each other in order to vary the amplitude of the vibrations that are generated by rotating the eccentric assembly.
SUMMARY OF THE INVENTION
In one aspect, the present invention is a vibratory system for a compacting vehicle that includes a frame and at least one compacting drum rotatably connected with the frame. The vibratory system comprises first and second weights each disposed within the drum so as to be rotatable about an axis, at least one of the two weights being adjustably positionable about the axis so as to vary a value of a spacing angle between the two weights. A motor is configured to rotate the first and second weights about the axis. A sensor is configured to sense at least one of the first and second weights. Further, a controller is coupled with the sensor and is configured to determine the value of the spacing angle. The controller is further configured to operate the motor such that the motor rotates the two weights at a rotational speed having a value that is generally directly proportional to the value of the spacing distance.
In another aspect, the present invention is a control system for a vibratory mechanism of a compacting vehicle. The vibratory mechanism includes first and second rotatable members and an actuator configured to rotate the members. The control system comprises a sensor configured to sense an spacing angle between the first and second rotatable members and a controller. The controller is coupled with the sensor and is configured to automatically operate the actuator such that the two members rotate at about a first rotational speed when the spacing distance has a first value and alternatively the two members generally rotate at about a second rotational speed when the spacing distance has a second value. The first distance is greater than the second distance and the first speed is greater than the second speed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The foregoing summary, as well as the detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, which are diagrammatic, embodiments that are presently preferred. It should be understood, however, that the present invention is not limited to the precise arrangements and instrumentalities shown.
In the drawings:
FIG. 1 is a perspective view of a compacting vehicle including a vibratory system and related control system in accordance with the present invention;
FIG. 2 is an exploded perspective view of a drum assembly of the compacting vehicle shown in FIG. 1 ;
FIG. 3 is a perspective view of the drum assembly shown in FIG. 2 ;
FIG. 4 is view similar to FIG. 3 , illustrating the drum assembly with the frame removed;
FIG. 5 is view similar to FIG. 4 , illustrating the drum assembly with the drive assembly removed;
FIG. 6 is view similar to FIG. 5 , illustrating the drum assembly with the support shaft removed;
FIG. 7 is view similar to FIG. 6 , illustrating the drum assembly with the hand wheel removed;
FIG. 8 is a perspective view of the support shaft shown in FIG. 5 ;
FIGS. 9-11 are schematic views of the eccentric assembly shown in FIG. 2 , illustrating the relative positions of the inner and outer eccentric weights corresponding to the maximum, intermediate, and minimum vibration amplitudes; and
FIG. 12 is a schematic view of a control system of the compacting vehicle shown in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Certain terminology is used in the following description for convenience only and is not limiting. The words “inner”, “inwardly” and “outer”, “outwardly” refer to directions toward and away from, respectively, a designated centerline or axis, or a geometric center of an element being described, the particular meaning being readily apparent from the context of the description. Further, as used herein, the word “connected” is intended to include direct connections between two members without any other members interposed therebetween and indirect connections between members in which one or more other members are interposed therebetween. The terminology includes the words specifically mentioned above, derivatives thereof, and words or similar import.
Referring now to the drawings in detail, wherein like numbers are used to indicate like elements throughout, there is shown in FIGS. 1-12 a presently preferred embodiment of a control system 10 for a vibratory mechanism or system 12 for a compacting vehicle 1 in accordance with the present invention. The compacting vehicle 1 basically includes a frame 2 and at least one and preferably two compacting drums 3 A, 3 B rotatably connected with the frame 2 . The vibratory system 12 basically comprises first and second rotatable members or weights 14 , 16 each disposed within one of the drums 3 so as to be rotatable about an axis 15 and forming an eccentric assembly 17 , as described in further detail below. At least one of the two weights 14 , 16 , preferably the first weight 14 , is adjustably positionable about the axis 15 so as to vary a value of a spacing angle A S between the two weights 14 , 16 , preferably by means of an adjustment mechanism 19 . A motor 18 is configured to rotate the first and second weights 14 , 16 about the axis 15 , alternatively in either a counterclockwise or clockwise direction, such that vibrations are generated by the rotating weights 14 , 16 , as discussed below. The amplitude of the vibrations generated by the rotating weights 14 , 16 is basically inversely proportional to the value of the spacing angle A S , i.e., the greater the spacing angle A S , the lesser the net eccentric moment of the weights 14 , 16 and the lesser the vibration amplitude, and vice-versa, as described in further detail below.
The control system 10 basically comprises a sensor 20 configured to sense at least one of the first and second weights 14 , 16 and a controller 22 coupled with the sensor 20 . The controller 20 is preferably configured to determine the value of the spacing angle A S from information provided by the sensor 20 , as discussed below. The controller 22 is further configured to automatically operate or adjust the motor 18 such that the motor 18 rotates the two weights 14 , 16 at a rotational speed R S having a value that is generally directly proportional to the value of the spacing angle A S . In other words, the controller 22 is configured to operate the motor 18 such that the motor 18 rotates the two weights 14 , 16 at about a first, substantially greater rotational speed R S1 (e.g., 4200 rpm) when the spacing angle A S has a first, relatively greater value A S1 (e.g., 180 degrees). Alternatively, the controller 22 operates the motor 18 such that the motor 18 rotates the two weights 14 , 16 at about a second, substantially lesser rotational speed R S2 (e.g., 2500 rpm) when the spacing angle has a second, relatively lesser value A S2 (e.g., 0 degrees). As such, the weights 14 , 16 are rotated at a higher speed when the vibration amplitude is lesser and the weights 14 , 16 are rotated at a lower speed when the vibration amplitude is greater.
Preferably, the sensor 20 is configured to sense when one of the first and second weights 14 , 16 is disposed (i.e., momentarily during rotation) at a particular angular position P A ( FIG. 9 ) about the axis 15 and to generate a signal. Alternatively, the sensor 20 may be configured to directly sense or measure the spacing angle A S between the two weights 14 , 16 . The controller 22 is configured to determine the value of the spacing angle A S using the signal(s) from the preferred sensor 20 . More specifically, the sensor 20 is configured to generate one signal when the first weight 14 is temporarily located or disposed at the angular position P A and another signal when the second weight is temporarily disposed at the angular position P A . In other words, the sensor 20 generate the signals whenever the sensor 20 detects the weights 14 , 16 as they pass through the angular position P A when rotating about the axis 15 . The controller 22 also determines the rotational speed of the two weights 14 , 16 from one of the two signals, preferably the signal generated when the sensor 20 detects the first weight 14 , based upon at least two signals generated by detecting the weight 14 twice as it rotates about the axis 15 , as described in further detail below. Alternatively, the control system 20 may have any another device to measure rotational speed of the weights 14 , 16 , such as a sensor directly measuring motor shaft speed. Based on the frequency of detecting the two weights 14 , 16 , the controller 22 is able to calculate the spacing angle A S , as is also discussed further below.
Further, the control system 10 preferably further comprises a first reference member 24 connected with the first weight 14 and a second reference member 26 connected with the second weight 16 . The sensor 20 is located at a fixed location on the vehicle 1 with respect to the axis 15 and is configured to generate a signal when either one of the two reference members 24 , 26 is disposed generally proximal to the fixed location P A as the weights 14 , 16 rotate past the sensor 20 . Preferably, each one of the first and second reference members 24 , 26 is a magnet 60 , 62 , respectively, and the sensor 20 is a proximity sensor 66 configured to sense the two magnets 60 , 62 .
Furthermore, the controller 22 preferably includes a microprocessor 72 electrically coupled with the sensor 20 and with the motor 18 . The microprocessor 72 has a memory and a reference table stored in the memory, the reference table including a plurality of speed values each corresponding to a separate value of the spacing angle A S . With this arrangement, the microprocessor 72 is configured to select a desired speed value from the reference table based on the sensed spacing angle A S , and to adjust the motor 18 accordingly. In addition, the vibratory system 10 preferably further comprises a pump 5 operatively coupled with the motor 18 , with the controller 22 being operatively connected with the pump 5 . The controller 22 is further configured to adjust the pump 5 so as to thereby adjust rotational speed of the motor 18 , and thus the weights 14 , 16 . Having discussed the basic components and operation of the present invention, these and other elements of the control system 10 and the vibratory system 12 are described in further detail below.
Referring first to FIG. 1 , the vibratory system 12 is preferably used with a compacting vehicle 1 that includes a frame 2 , a leading drum 3 A, and a trailing drum 3 B, but may alternatively be used with single drum compacting vehicles (not shown). The leading drum 3 A is rotatably mounted to the forward end 2 a of the frame 2 and the trailing drum 3 B is rotatably mounted to the rearward end 2 b of the frame 2 . The compacting vehicle 1 also includes an operator's station 4 that is connected to the frame 2 at a position substantially above and between the leading and trailing drums 3 A, 3 B such that an operator located in the operator's station 4 is sufficiently elevated above the compacting vehicle 1 to view the area ahead of the leading drum 3 A.
The leading and trailing drums 3 A, 3 B are substantially similar, with each drum 3 A, 3 B having a separate eccentric assembly 17 including the two weights 14 , 16 , as described above and in further detail below. For simplicity's sake, only the leading drum 3 A and the associated eccentric assembly 17 is described in detail herein. As best shown in FIG. 2 , the drum 3 A includes one eccentric assembly 17 that is mounted for rotation about the axis 15 , which extends laterally or transversely through the drum 3 A. Rotating the eccentric assembly 17 creates eccentric moments that cause vibrations that are transferred to the drum 3 A. The drum 3 A transfers these vibrations to the ground in order to level paved and unpaved surfaces.
The compacting vehicle 1 includes an engine (not shown) that is mounted to the frame 2 . The engine drives two hydraulic pumps 5 that are also mounted to the frame 2 . The first hydraulic pump (not shown) is operably connected to a drive assembly 6 that is connected to one side 30 of the drum 3 A in a conventional manner. The drive assembly 6 includes a hydraulic motor 32 that operates to rotate the drum 3 A relative to the frame 2 to thereby move the compacting vehicle 1 over the ground. The second hydraulic pump 5 ( FIG. 12 ) is operably connected to a drive assembly 7 that is connected to another side 36 of the drum 3 A in a conventional manner. The drive assembly 7 includes the hydraulic motor 18 that rotates the eccentric assembly 17 , and thus the first and second weights 14 , 16 , relative to the drum 3 A. The second hydraulic pump 5 includes an electronic displacement control 40 (“EDC”) ( FIG. 12 ) that adjusts the flow of hydraulic fluid from the second hydraulic pump 5 to the hydraulic motor 18 rotating the drive assembly 7 .
The eccentric assembly 17 further includes a shaft 42 that is mounted at each end to bearings 44 . The bearings 44 are secured to parallel supports 46 that extend across the inner diameter of the drum 3 A. The supports 46 are welded to an interior wall of the drum 3 A and are generally perpendicular to the longitudinal axis of the drum 3 A.
Referring to FIGS. 9-11 , the two weights 14 , 16 of the eccentric assembly 17 are preferably formed as inner weight 48 and an outer weight 50 , respectively. The inner weight 48 has a generally solid, cylindrical body 49 with an offset portion 49 a extending radially outwardly from a remainder of the body 49 . The outer weight 50 has a generally tubular body 51 with an offset portion 51 a extending radially inwardly from a remainder of the body 51 and having a longitudinal central bore 51 b . The inner weight 48 is disposed within the central bore 51 b of the outer weight 50 such that the two weights 48 , 50 are radially spaced apart, the two weights 48 , 50 being releasably connectable so as to be rotatable about the axis 15 as a single unit (i.e., without relative angular displacement). Alternatively, the first and second weights 14 , 16 may be formed in any other appropriate manner, such as for example, two axially spaced-apart weighted members and/or having other appropriate shapes, and/or may include three or more weights (no alternatives shown).
In addition, the inner weight 48 is preferably adjustably positionable, specifically angularly displaceable, relative to the outer weight 50 so as to adjust or vary the vibration amplitude of the eccentric assembly 17 . More specifically, the net moment of eccentricity of the two rotating weights 48 , 50 is varied or adjusted by adjusting the relative position of the center of mass C 1 of the inner weight 48 with respect to the center of mass C 2 of the outer weight 50 , as indicated in FIGS. 9-11 . For purposes of illustration, each weight 48 , 50 may be considered as having a centerline 48 a , 50 a , respectively, extending perpendicularly between the center of mass C 1 , C 2 , and the axis of rotation 15 . As such, the spacing angle As between the two weights 48 , 50 is preferably defined as the angle between the two centerlines 48 a , 50 a of the inner weight and outer weights 48 , 50 , respectively. For example, FIG. 9 illustrates a relative arrangement of the weights 48 , 50 that results in a maximum vibration amplitude of the eccentric assembly 17 . At the maximum amplitude arrangement, the center of mass C 1 , C 2 of two weights 48 , 50 are generally radially aligned with each other such that the spacing angle A S2 is about 0 degrees. In contrast, FIG. 11 depicts a weight arrangement that results in minimum vibration amplitude of the eccentric assembly 17 . At the minimum amplitude setting, the centers of mass C 1 , C 2 of the two weights 48 , 50 are offset by a spacing angle A S1 of about 180 degrees. Further, FIG. 10 illustrates an intermediate vibration amplitude of the eccentric assembly 17 where the spacing angle A S3 between the inner and outer weights 48 , 50 has a value between 0 and 180 degrees.
Referring to FIGS. 2 , 5 and 6 , the adjustment mechanism 19 , as discussed above, preferably includes a hand wheel 52 coupled with the eccentric assembly 17 and configured to angularly displace the inner weight 48 with respect to the outer weight 50 . When it is desired to adjust the vibration amplitude of the vibratory system 12 , the hand wheel 52 is pulled against a spring bias to disengage the inner weight 48 from a splined connection (not shown) with the outer weight 50 . With the inner weight 48 disengaged, the hand wheel 52 can be rotated to move the inner weight 48 relative to the outer weight 50 to a desired position. The position of the inner weight 48 relative to the outer weight 50 is identified by the location of the hand wheel 52 relative to an indicator 54 that is connected to the outer weight 50 ( FIG. 7 ). The hand wheel 52 can also include identifying indicia 56 to display to the operator the general vibration amplitude of the eccentric assembly 17 relative to the maximum (identified as “8” on indicia 56 in FIG. 6 ) and minimum (identified as “1” on indicia 56 in FIG. 6 ).
FIG. 12 schematically illustrates the control system 10 , which both senses the vibration amplitude on a compacting vehicle 1 adjusts the rotational speed R S of the eccentric assembly 17 such that the eccentric assembly 17 to rotate the eccentric assembly 17 at its optimum speed for the adjusted vibration. It is advantageous to operate the eccentric assembly 17 at optimum speeds for all adjusted vibration amplitudes because it allows the eccentric assembly 17 at lower vibration amplitudes to operate at higher speeds to improve the effectiveness of the compacting vehicle 1 , and it reduces the speed of rotation for the eccentric assembly 17 at higher vibration amplitudes to minimize wear to each of the load bearing components in the compacting vehicle 1 . Preferably, the controller 22 is configured to operate the motors 18 of the eccentric assemblies 17 of both drums 3 A, 3 B, as depicted in FIG. 12 , but the vehicle 1 may alternatively be provided with two separate control systems 10 , each controlling the eccentric assembly 17 of a separate one of the drums 3 A, 3 B.
Referring to FIGS. 6 and 9 - 11 , the control system 10 preferably includes a first magnet 60 connected to the indicator 54 that is connected to the outer weight 50 , and a second magnet 62 that is connected to the hand wheel 52 that is connected to the inner weight 48 . As best shown in FIG. 6 , the hand wheel 52 includes apertures 64 that correspond to each setting identified on the indicia 56 . As the hand wheel 52 is rotated to each position, the corresponding aperture 64 aligns with the magnet 60 . Both magnets 60 , 62 are generally located at a common radial distance from the axis of rotation 15 .
Referring to FIGS. 5 and 6 , the sensor 20 of the control system 10 is preferably a proximity sensor 66 that is connected to the end of a support shaft 68 so as to located at the fixed angular position P A with respect to the axis 15 . The support shaft 68 is connected to the frame 2 by any appropriate means, such as bolts 70 , etc. As the eccentric assembly 17 rotates, the sensor 66 generates a signal each time a magnet 60 , 62 passes the sensor 66 . The sensor 66 generates different signals for the first and second magnets 60 , 62 as the eccentric assembly rotates the magnets 60 , 62 past the sensor 66 . The sensor 66 senses the presence of the magnet 60 through the corresponding aperture 64 , while the sensor's reading of the magnet 62 is unobstructed.
Referring again to FIG. 12 , the preferred microprocessor 72 receives the signals generated by the sensor 66 and interprets the signals to determine the relative positions of the inner and outer weights 48 , 50 , and thereby the spacing angle A S . As discussed above, the spacing angle A S is associated with a specific vibration amplitude setting for the eccentric assembly 17 . Based on this calculation, the microprocessor 72 determines the optimal speed for that specific vibration amplitude, preferably by comparing the calculated value of the spacing angle A S to the stored table of speed values as discussed above, and generates and transmits a signal to the EDC 40 of the pump 5 . The EDC 40 controls the flow of hydraulic fluid to the motor 18 rotating the eccentric assembly 17 thereby controlling the speed of rotation R S of the eccentric assembly 17 .
The control system 10 automatically operates the motor 18 such that the eccentric assembly 17 rotates at the optimum speed based on the particular vibration amplitude of the eccentric assembly 17 . In this regard, the control system 10 enables the compacting vehicle 1 to operate more efficiently because the prior machines either ran continuously at a single speed or required the operator to visually monitor the vibration amplitude setting on the hand wheel 52 , determine the optimum speed of rotation for the eccentric assembly 17 based on the observed setting, and manually adjust and monitor the speed of rotation to match the optimum speed.
The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and the skill or knowledge of the relevant art, are within the scope of the present invention. The embodiments described herein are further intended to explain best modes known for practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with various modifications required by the particular applications or uses of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art. | The present invention is directed to a control system for sensing the vibration amplitude on a vibration compacting machine. In addition, the control system modifies the rotational speed of the eccentric assembly based on the vibration amplitude of the eccentric assembly. In one embodiment, the control system modifies the rotational speed of the eccentric assembly to match the optimum speed for the adjusted vibration amplitude when the eccentric assembly is adjusted to increase or decrease the vibration amplitude. Reducing the rotational speed of the eccentric assembly at high vibration amplitudes minimizes wear to each of the load bearing components in the vibration compacting machine resulting in an extended service life for the vibration compacting machine. Similarly, increasing the rotational speed of the eccentric assembly at low vibration amplitudes increases the effectiveness of the vibration compacting machine. | 4 |
FIELD OF THE INVENTION
The present invention relates to an apparatus for producing pulp molded plate and a special-shaped pulp molded plate produced by the same and having a convex part, (i.e., a concave-convex structure).
BACKGROUND OF THE INVENTION
There are favorable economic and social benefits that the plates and special-shaped plates made from pulp may be used as a material for electrical insulation, industrial packaging, building finishing furniture and so on. For example, the Chinese Patent Publication No. CN101070688A described one patent of invention “Method and Mold for Producing Pulp Molded Plates” of the applicant, and the Chinese Patent Publication No. CN101634124 described another patent of invention “Method and Mold for Producing Special-Shaped Pulp Molded Plate having a Convex Part” of the applicant. However, in the implementation of above two patents, it has been found that the following two aspects should be improved under the scope of the two patents:
1. In the aspect of mounting relation between the molds and the press machine, in the first embodiment, the enclosing frame is fixed to the frame of the press machine, the upper mold (referred to as “cover plate” in the publication document) is driven by the upper cylinder of the press machine so as to open and close the upper opening of the enclosing frame, and the lower mold (referred to as “press block” in the publication document) is driven by the lower cylinder of the press machine so as to move up and down within the enclosing frame. There is the problem as follows: in the pressing process, the upper mold needs to balance the pressure from the lower mold, besides, a pressure required for sealing between the upper mold and the enclosing frame must be provided; therefore, the pressure of the upper cylinder of the press machine must be higher than the pressure of the lower cylinder, or the pressure maintaining capability of the upper cylinder must be very high. However, in practice, the pulp often is leaked from the fitting surfaces between the upper mold and the enclosing frame. In the second embodiment, the upper mold is fixedly connected under the press ram of the upper-acting press machine, and which is always moved within the enclosing frame, the enclosing frame is driven by a two-piston hydraulic cylinder so as to move up and down, while the lower mold is fixedly connected to the working platform of the press machine; under such structure, it is difficult to inject pulp into the molds and achieve synchronization between the enclosing frame and the upper mold in the mould splitting process; moreover, there is the biggest disadvantage as follows: the upper mold can't be drained off completely; therefore, at the moment of mold splitting, all residual water in the grooves and holes of the upper mold will flow back to the wet green of work piece, and the moisture content in the wet green will be increased, thereby resulting in: (1) reducing the strength of wet green, which is adverse to the transport and handling of the wet green; (2) increasing the energy consumption of the hot pressing drier and reducing working efficiency thereof. 2. In the aspect of molding technique, with regard to the pulp molded plate having a convex part, when the pressure increases to a certain value in the pressing process, the fiber layer having high water content deposited on the flat part around the convex part is easy to crush, and some paper fibers will be squeezed into the cavity of the female mold at the convex part, thereby causing uneven distribution of paper fibers in the cavity of the female mold; in addition, the defects (e.g., fractures) may form easily around the convex part.
SUMMARY OF THE INVENTION
Considering the requirement for further reducing the cost of pulp molded plate and improving the performance of product with the molding technique utilizing a three-piece mold constituted by upper mold, enclosing frame, and lower mold, the present invention discloses an apparatus for producing pulp molded plate having an optimal structure of three-piece mold; in addition, the present invention discloses a molding apparatus for the convex part of non-flat special-shaped pulp molded plate, so that it may achieve the lower cost, the higher technical performance, and the wider applicability of high-pressure pulp molded plate (product) produced by the method described above.
The technical solution of the present invention is as follows:
An apparatus for producing pulp molded plate, comprising a press machine and a three-piece mold, the three-piece mold comprises an upper mold, an enclosing frame, and a lower mold to form a mold cavity with variable capacity; the molding surface of the upper mold is provided with a drain grooves and is covered by a wire mesh, the molding surface of the lower mold is provided with a drain groove and/or hole, and is covered with a wire mesh, wherein:
one of the upper mold and the lower mold is a movable mold, the other is a fixed mold, and the lower mold is always within the enclosing frame; the enclosing frame is supported by two or more plunger-type cylinders or piston-type cylinders fixed to the press machine, and which is movable relative to the upper mold and the lower mold;
The apparatus further comprises two seal grooves and seal rings inlaid in the seal grooves, the seal rings are arranged on the contact surface between the opening of the enclosing frame and the upper mold, and one or more guiding water grooves are arranged between the two seal grooves; in a pressed state of the upper mold and the enclosing frame, the drain groove on the molding surface of the upper mold is extended to above the guiding water grooves, so as to form a channel with the guiding water grooves.
In that arrangement, any both of the upper mold, enclosing frame and lower mold may be movable relative to each other, and the enclosing frame may be movable up and down.
Further, when a upper-acting press machine is used, the upper mold is a movable mold, which is fixed to the lower surface of the press ram of the upper-acting press machine; the lower mold is a fixed mold, which is fixed to the working platform of the upper-acting press machine;
In a initial state, the enclosing frame is supported at the highest position by two or more plunger-type cylinders fixed to the working platform of the press machine;
In a working state, the upper mold is driven by the press ram of the press machine to move down, contact with the enclosing frame, form pressed sealing, and thereby push the enclosing frame to move down; that is to say, the downward movement of the enclosing frame is accomplished as a result that the upper mold contacts with the enclosing frame and transfers the pressure of the press machine to the enclosing frame so that the hydraulic oil in the at least two plunger-type cylinders supporting the enclosing frame overflows under pressure; and thereby the pressing force required for sealing between the enclosing frame and the upper mold is also provided.
Moreover, the upward movement of the enclosing frame may be accomplished by means of at least two telescoping handle; the telescoping handle is inserted in an unthreaded hole of the enclosing frame and is slide-fitted with the unthreaded hole; and the lower end of the telescoping handle passes through a fastener or a stepped shaft, and the outer diameter of the fastener or the stepped shaft is greater than the diameter of the unthreaded hole of the enclosing frame, so as to prevent the telescoping handle from pulling out of the unthreaded hole; the upper end of the telescoping handle is fixed to the upper mold or the press ram of the press machine.
Another solution may be: when a lower-acting press machine is used, the lower mold is a movable mold, which is fixed to a press ram of the lower-acting press machine, or which is fixed directly to the piston rod end or plunger end of the main cylinder of the lower-acting press machine; the upper mold is a fixed mold, which is fixed to the lower surface of the upper beam of the lower-acting press machine; an upward and downward movement of the enclosing frame is accomplished by means of two or more piston-type cylinders fixed to the press machine, and thereby a pressing force required for sealing between the enclosing frame and the upper mold is provided.
The process for producing pulp molded plate with the apparatus described above, comprises a step of soaking a pulp plate or a waste paper and then smashing them to produce a pulp at a concentration≦6%, a step of squeezing out water and molding with a three-piece mold, and a step of demolding and drying; the upper mold and enclosing frame in the three-piece mold may be movable relative to each other, so as to open or close the upper opening, of the enclosing frame; the lower mold may be movable towards the upper mold within the enclosing frame relatively, so as to squeeze the water out of the pulp for forming.
When the pulp molded plate is a special-shaped pulp mold product having a convex part, the squeezing out water for forming of the convex part may be accomplished by a method of using a flexible male mold, i.e., when enough paper fibers have been deposited on the surface of a rigid female mold at the convex part, the flexible male mold placed in the center of the rigid female mold and having a variable shape and having the smallest initial radial dimension may be controlled to expand in radial direction, to exert a pressure to the deposited paper fiber layer containing high water content around the convex part, so as to accomplish the water squeezing out and forming procedure for the convex part, wherein:
The apparatus further comprises a rigid female mold and a flexible male mold matching the rigid female mold, both of which are coaxially mounted on the upper mold and the lower mold respectively;
The ratio of a height to a minimum aperture of the rigid female mold is greater than 0.6;
The flexible male mold is connected to the lower mold or the upper mold via a telescopic mold column, which is nested and connected to the flexible male mold; a support spring is mounted on the other end of the mold column, the mold column is inserted in the hole on the lower mold or the upper mold arranging the flexible male mold, so as to form movable fitting and a movable sealing with the hole, and the cross section of the mold column matches the horizontally projected shape of the flexible male mold after expansion.
In a initial state, the mold column is supported at the extended limit position by the support spring, while a certain length of mold column is exposed out the hole on tire lower mold or the upper mold; in a working state, i.e., in the process of that the upper mold and the lower mold move towards each other relatively, the end of the flexible male mold reaches the bottom of the rigid female mold and squeezes the paper fiber layer deposited there; when the sum of a pressure exerted on the flexible male mold and the mold column exceeds the sum of the initial tension force of the support spring and seal friction resistance, the support spring is compressed; as the pressure exerted on the flexible male mold and the mold column increases, the exposed part of the mold column reduces gradually, till the mold column enters into the hole completely; in that process, the sealed spaces between the flexible male mold, the support spring, the mold column and the hole on the respective mold is compressed, and the flexible male mold is expanded from the initial radial dimension to the maximum radial dimension.
Further, the flexible male mold is constituted by fitting a capsular sheath made of an elastomeric material over a mold core made of a rigid material; the mold core has perforated liquid pore passages;
The mold column is hollow to form a syringe with variable capacity with a receiving hole on the lower mold or upper mold; the syringe is communicated with the liquid pore passages of the mold core, and is filled with the liquid.
In a initial state, the mold column is supported at a position allowing a maximum capacity of the syringe cavity by the support spring, and the liquid is fully drawn into the syringe cavity; in a working state, as the mold column and the lower mold or upper mold move towards each other relatively, and thereby the capacity of the syringe cavity is reduced, the liquid in the syringe cavity will be forced into the capsular sheath, therefore the capsular sheath will be expanded; in the reverse process, as the mold column and the respective mold move away from each other in the reverse direction, the liquid in the capsular sheath will be drawn back into the syringe cavity, and therefore the capsular sheath will be recovered to its original shape.
Another solution may be the flexible male mold is a solid part made of an elastomeric material.
In a initial state, the radial dimension of the flexible male mold is the smallest, and the height there of is the highest; in a working state, as the mold column and the respective mold move relative to each other in the pressing process, the counter force of the support spring of the mold column will cause deformation of the flexible male mold made of an elastomeric material, and therefore the height will decrease, while the radial dimension will increase (the volume will remain constant substantially).
When the apparatus described above is used to produce pulp molded plate and non-flat special-shaped pulp molded plate, the procedures and the devices involved are shown in the following table:
No.
Name of Procedure
Description of Procedure
Devices and Molds Involved
Remarks
1
Pulp preparation
Soak a pulp plate or a
Hydraulic pulp shredder,
Any adhesive is
waste paper and then
pulp pump, etc.
not required.
smash them to produce a
pulp at concentration ≦6%
2
Pulp injection
Inject the prepared pulp
A three-piece mold constituted of
into the mold
a upper mold, a lower mold, and
a enclosing frame;
Pulp pump, valve, etc.
3
Forming
Mold pressing, squeeze
Press machine, air compressor;
(the convex part
out water and forming
A three-piece mold constituted of
and the
(further including
a upper mold, a lower mold, and
non-convex part
squeezing out water and
a enclosing frame;
are formed at the
forming of the convex
(further including a rigid female
same time)
part by means of a rigid
mold and a flexible male mold
female mold and a
with a telescopic mold column)
flexible male mold with a
telescopic mold column)
4
Transferring wet
Take out molded wet
Mechanical arm
green
green from the mold
5
Sizing by
Drying and setting in hot
Press machine
hot pressing
mold
Hot pressing mold
A non-flat special-shaped pulp molded plate produced with the apparatus described above, having one or more convex part, wherein:
The ratio of a height to a minimum aperture of the convex part on the pulp molded plate is greater than 0.6;
In addition, a maximum density ρ max and a minimum density ρ min of the convex part satisfy: (ρ max −ρ min )/ρ max <0.2;
In the pulp molded plate, the density is greater than 0.69/cm 3 and the thickness is 2-20 mm.
Moreover, the plate is in a tray shape formed integrally with plank and leg by high-pressure water squeezing out, and the density is 0.6-1.3 g/cm 3 , and the thickness of the plank is 5-15 mm, the ratio of a height to a aperture of the legs is greater than 0.8.
Compared to the prior art, the present invention has apparent advantages as follows:
(1) The solution of the movable enclosing frame in the present invention (i.e., the enclosing frame is movable, and one of the upper mold and the lower mold is movable, the other is fixed, and the lower mold is within the enclosing frame) overcomes the drawbacks in the prior art, i.e., in the prior art, though the enclosing frame is movable, the upper mold is within the enclosing frame; therefore, the water can't be drained from the upper mold completely, and the residual water will flow back to the wet green after mold splitting, and it is difficult to achieve synchronization between the enclosing frame and the upper mold its the mold splitting process; or, the enclosing frame is fixed, and both of the upper mold and the lower mold are movable, and the upper opening of the enclosing frame is sealed by the upper mold; the upper mold needs to balance the pressure from the lower mold, besides, a pressure required for sealing between the upper mold and the enclosing frame must be provided, therefore, the pressure of the upper cylinder of the press machine must be greater than the pressure of the lower cylinder, or the pressure maintaining capability of the upper cylinder must be very high. (2) In the present invention, the flexible male mold having a telescopic mold column enters into the cavity of the female mold prior to the pressure of squeezing arrives to a specified value, and the flexible male mold expands gradually in radial direction as the upper mold and the lower mold move relative to each other; such arrangement successfully overcomes a technical difficulty in production of special-shaped pulp molded plate having a convex part in the prior art, i.e., in the pressing process, when the pressure increases to the specified value, the deposited paper fiber layer containing high water content around the convex part will be crushed, and some paper fibers will be squeezed into the cavity of the female mold, around the convex part, thereby causing uneven distribution of paper fibers in the cavity of the female mold; in addition, a fractures may occur around the convex part; (3) The special-shaped pulp molded plate having a convex part and the goods tray products described in the present invention may be a model in the circular economy, owing to its characteristics, such as production from pure wastepaper, high density, high strength, and infinitely repeating the process of “recycling-molding-use-recycling again” theoretically; in addition, the process of production has the environmental protection, the low carbon, and the low cost characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic structural diagram of an embodiment of the present invention, in which a upper-acting press machine is used.
FIG. 2 is a schematic structural diagram of another embodiment of the present invention, in which a lower-acting press machine is used.
FIG. 3 is a schematic structural diagram of the capsular flexible male mold made of an elastomeric material in the present invention.
FIG. 4 is a schematic structural diagram of the solid flexible male mold made of an elastomeric material in the present invention.
FIG. 5 is an embodiment of special-shaped pulp molded plate with convex part in the present invention.
FIG. 6 is an embodiment of tray product in the present invention.
FIG. 7 is a schematic diagram of the draining structure of the upper mold and the sealing structure between the upper mold and the enclosing frame.
FIG. 8 is a schematic structural diagram of the telescoping handle for raising the enclosing frame.
In the drawings: 1 —upper mold; 2 —enclosing frame; 3 —lower mold; 4 —plunger-type hydraulic cylinder for supporting the enclosing frame; 5 —press ram of upper-acting press machine; 6 —working platform of upper-acting press machine; 7 —piston-type hydraulic-cylinder for supporting and raising/lowering the enclosing frame; 8 —upper beam of lower-acting press machine; 9 —piston rod of main cylinder of lower-acting press machine; 10 —rigid female mold; 11 —capsular sheath; 12 —mold core; 13 —liquid pore passage; 14 —liquid; 15 —mold column; 16 —cavity of syringe; 17 —spring; 18 —solid flexible male mold; 21 —convex part; 25 —plank; 26 —leg; 31 —seal ring and seal groove between the upper mold and the enclosing frame; 32 —guiding water groove; 33 —drain grooves evenly distributed on the surfaces of upper mold; 34 —wire mesh; 35 —telescoping handle; 36 —smooth holes on the enclosing frame; 37 —lower nut of the telescoping handle
DETAILED DESCRIPTION OF THE EMBODIMENTS
Embodiment 1
Hereunder the apparatus for producing pulp molded plate in the present invention will be detailed with reference to FIG. 1 , in which it mainly relates to the mounting relation between the three-piece mold and a upper-acting, press machine: the main cylinder of the upper-acting press machine is mounted on an upper beam of the press machine, and the piston rod in the main cylinder pushes tire press ram 5 of the press machine to move downwards in the pressing process. The upper mold 1 of the three-piece mold is fixed to the lower surface of the press-ram 5 by using the T-blocks and bolts and utilizing the T-slots on the lower surface of the press ram, and the upper mold moves up and down with the press ram 5 ; the enclosing frame 2 is supported by at least two plunger-type hydraulic cylinders 4 fixed to the working platform 6 of the press machine, and it utilizes the plunger-type hydraulic cylinders 4 to provide pressure required for sealing between the enclosing frame and the upper mold; when the upper mold 1 moves down to seal the upper opening of the enclosing frame 2 , and pushes the enclosing frame 2 and the plungers of the hydraulic cylinders 4 to move downwards together, the hydraulic oil in the plunger-type hydraulic cylinders 4 will be forced to drain at a preset pressure, so that the pressure required for sealing between the enclosing frame 2 and the upper mold 1 is provided, and the enclosing frame 2 may descend steadily; the lower mold 3 is fixed to the working platform 6 of the press machine, and moves in relation, to the enclosing frame 2 and upper mold 3 , and which is always fitted within the enclosing frame 2 .
The upward movement of the enclosing frame 2 is accomplished by means of jacking action of the hydraulic cylinder 4 or lifting action of the upper mold 1 by a set of slidable rod; in case the enclosing frame 2 is lifted by means of the upper mold 1 , the plunger end of the hydraulic cylinder 4 may be separated from the enclosing frame 2 , after the enclosing frame 2 is lifted to a specified height, the plunger of the hydraulic cylinder 4 may jack up to fit the enclosing frame 2 .
Hereunder the draining structure of the upper mold 1 and the sealing structure between the upper mold 1 and the enclosing frame 2 will be further detailed with reference to FIG. 7 : the enclosing frame 2 is provided with two seal grooves 31 inlaying seal rings around the opening of the enclosing frame on the contact surfaces with the upper mold, and one or more guiding water groove 32 is arranged between the seal grooves 31 inlaying seal rings; in a compressed state of the upper mold 1 and enclosing frame 2 , the drain grooves 33 evenly distributed on the working surfaces of the upper mold 1 are extended to above the guiding water groove 32 and form channels with the guiding water grooves 32 ; and the working surfaces of upper mold and lower mold are covered with a wire mesh 34 respectively.
Alternatively, the raising action of the enclosing frame 2 may be accomplished by means of at least two telescoping handle 35 ; as shown in FIG. 8 , the upper end of the telescoping handle 35 is connected to the upper mold 1 or directly connected to the press ram, when the upper mold 1 returns, the telescoping handle 35 will move synchronously with the upper mold 1 ; the lower ends of the telescoping handle 35 are slide-fitted into unthreaded holes 36 on the enclosing frame 2 ; in the case the enclosing frame 2 is supported by at least two plunger-type hydraulic cylinders 4 , when the upper mold 1 moves downwards, the telescoping handle 35 will slide down in the unthreaded holes 36 on the enclosing frame 2 , till the upper mold 1 is tightly fitted to the enclosing frame 2 ; when the upper mold 1 returns, the telescoping handle 35 will slide up in the unthreaded holes 36 on the enclosing frame 2 , while the enclosing frame 2 doesn't move; when the round nuts 37 on the lower ends of the telescoping handle 35 is contacted with the lower end faces of the unthreaded holes 36 , the enclosing frame 2 will be pulled up. After the upper mold 1 returns to the upper limit position and the enclosing frame 2 is pulled up to certain height, at least two plunger-type hydraulic cylinders 4 will jack up, till they support the enclosing frame 2 .
Embodiment 2
Hereunder the apparatus for producing pulp molded plate in the present invention will be further detailed with reference to FIG. 2 , in which it mainly relates to the mounting relation between the three-piece mold and a lower-acting press machine; in the case the press machine is lower-acting, the upper mold 1 is fixed to the lower surface of an upper beam 8 of the press machine, the enclosing frame 2 utilizes two piston-type cylinders 7 fixed to the press machine to accomplish the upward and downward movement and provide a pressure required for sealing between the enclosing frame 2 and the upper mold; the lower mold 3 is fixed to the press ram of the press machine, or, as shown in FIG. 2 , the lower mold 3 is directly fixed to the end of a piston rod 9 in the main cylinder of the press machine.
Embodiment 3
Hereunder the molding method for a capsular flexible male mold made of an elastomeric material in the present invention will be further detailed with reference to FIG. 3 :
A rigid female mold 10 , is mounted on the upper mold 1 , and its molding surface is provided with a drain groove and covered with a wire mesh to allow the paper fibers to deposit;
A capsular sheath 11 , made of an elastomeric material, is sleeved on a mold core 12 made of a rigid material to form a flexible male mold together with the mold core 12 ; the flexible male mold is inserted into the upper end of a mold column 15 , which has a spring 17 mounted on the bottom and has a cross section substantially in the same shape as the horizontally projected shape of the capsular sheath 11 after expansion, the mold column 15 is inserted into a hole on the lower mold 3 and which is movable fitted, and dynamic sealed with mold column 15 , so as to form a syringe cavity 16 having variable capacity and communicating with the capsular sheath 11 through liquid pore passages 13 on the mold core 12 ; the flexible male mold and mold column 15 are coaxial to the female mold 10 .
For a purpose of simplicity, in this embodiment, the horizontal sections of the female mold 10 , capsular sheath 11 , and mold column 15 are in circular shape, and the diameter of the lower segment of the mold column 15 is larger than the diameter of the upper segment of the mold column 15 slightly, so as to balance fee pretension force of the spring 17 .
The syringe cavity 16 is filled with liquid 14 ; in initial state, the mold column 15 is supported at a position allowing a maximum capacity of the syringe cavity 16 by the spring 17 and the liquid 14 is fully drawn into the syringe cavity 16 ;
In the initial state, the mold column 15 is supported at an upper limit position by the pretension force of the spring, while a certain length of mold column is exposed out the hole on the lower mold 3 ; when the upper mold 1 and lower mold 3 move towards each other so that enough paper fibers are deposited on the surface of the rigid female mold 10 at the convex part, the end of the flexible male mold reaches to the bottom of the rigid female mold 10 and begins to squeeze the paper fiber layer there; when the sum of the pressure exerted on the flexible male mold and the mold column 15 exceeds the sum of the pretension force of the spring 17 and the seal friction resistance, the spring 17 under the mold column 15 is compressed; as the pressure, exerted on the flexible male mold and the mold column 15 increases, the exposed part of the mold column 15 will be reduced gradually, till the mold column 15 enters into the lower mold 3 completely;
When tire mold column 15 and the lower mold 3 move towards each other, the liquid 14 in the syringe, cavity 16 will be forced to flow into the capsular sheath 11 , so that the capsular sheath 11 is expanded to exert a pressure on the deposited paper fiber layer containing high water content around the capsular sheath 11 , so as to accomplish the water squeezing and forming procedure of the convex part. In the reverse process, the mold column 15 and lower mold 3 move away from each other in the reversed direction, and the liquid 14 in the capsular sheath 11 is drawn back into, the syringe cavity 16 ; as a result, the capsular sheath 11 will be recovered to its original shape.
In the case the rigid female mold 10 is mounted on the lower mold 3 , the flexible male mold assembly described above is mounted on the upper mold 1 accordingly.
Embodiment 4
Hereunder the molding method for a solid flexible male mold made of an elastomeric material in the present invention will be further detailed with reference to FIG. 4 :
A rigid female mold 10 , is mounted on the upper mold 1 , and its molding surfaces is provide with a drain grooves and covered with a wire mesh to allow the paper fibers to deposit;
A solid flexible male mold 18 , made of an elastomeric material, is mounted on the upper end of a mold column 15 , which has a spring 17 mounted on the bottom and has a cross section substantially in the same shape as the horizontally projected shape of the solid flexible male mold 18 after expansion, the mold column 15 is inserted in a hole on the lower mold 3 , and which is movable fitted, and dynamic sealed with, the mold column 15 , and the solid flexible male mold 18 and the mold column 15 are coaxial to the female mold 10 ;
For a purpose of simplicity, in this embodiment, the horizontal sections of the female mold 10 , solid flexible male mold 18 , and mold column 15 are in circular shape, and the diameter of the lower segment of the mold column 15 is larger than the diameter of the upper segment of the mold column 15 slightly, so as to balance the pretension force of the spring 17 ;
In the initial state, the mold column 15 is supported at an upper limit position by the pretension force of the spring, while a certain length of mold column is exposed out the hole on the lower mold 3 ; when the upper mold 1 and lower mold 3 move towards each other so that enough paper fibers are deposited on the surface of the rigid female mold 10 at the convex part, the end of the solid flexible male mold 18 reaches to the bottom of the rigid female mold 10 and begins to squeeze, the paper fiber layer there; when the sum of the pressure exerted on the solid flexible male mold 18 exceeds the sum of the pretension force of the spring 17 and the seal friction resistance, the spring 17 under the mold column 15 is compressed; as the pressure exerted on the solid flexible male mold 18 increases, the exposed part of the mold column 15 will be reduced gradually, till the mold column 15 enters into the lower mold 3 completely;
When the mold column 15 and the lower mold 3 move towards each other, solid flexible male mold 18 made of an elastomeric material is deformed by the counter force of the paper fiber layer on the bottom of the rigid female mold 10 and the counter force of the spring 17 under the mold column 15 ; the radial dimension thereof increases as reducing of the height (the volume remains constant substantially); therefore, the solid flexible male mold 18 exerts a pressure on the deposited paper fiber layer containing high water content, around the solid flexible male mold 18 ; in that way, the water squeezing and forming procedure of the convex part is accomplished.
In the case the rigid female mold 10 is mounted on the lower mold 3 , the flexible made mold assembly described above is mounted on the upper mold 1 accordingly.
Hereunder the special-shaped pulp molded plate with convex part in the present invention will be further detailed with reference to FIG. 5 .
The pulp molded plate is a special shape of non-flat, which has at least one convex part 21 there on, and the ratio of a height H of the convex part 21 to a minimum aperture d of the convex part 21 is greater than 0.6;
The maximum density ρ max of the convex part and the minimum density ρ min of the convex part satisfy: (ρ max −ρ min )/ρ max <0.2;
The density of the pulp molded plate is greater than 0.6 g/cm 3 , and the thickness is 2-20 mm thereof;
What an example to a plate purely made of wastepaper pulp by high-pressure molding (>6 MPa), the convex part is in a circular truncated cone shape, wherein, H=60 mm, d=86 mm, H/d=0.7; ρ avg =1.0 g/cm 3 , (ρ max −ρ min )/ρ max =(1.03−0.98)/1.03=0.0485; thickness=7 mm.
Hereunder a high-pressure pulp molded tray produced with the apparatus described above will further detailed with reference to FIG. 6 :
The high-pressure pulp molded tray is a goods tray, which is a special-shaped pulp molded plate having a convex part.
The tray is made of wastepaper, and formed by high-pressure water squeezing, the density is at 0.6-1.3 g/cm 3 ; the thickness of the plank part is 5-15 mm, and the plank 25 and the legs 26 are formed integrally.
The ratio of the height to the aperture of the legs 26 is greater than 0.8;
Hereunder an example of tray is provided. The plank 25 is in 620×470 mm (L×W) dimensions, the tray is in 132 mm total height, the ratio of the height to the aperture of the legs 26 is 1, the density is 1 g/cm 3 , the plank 25 is in thickness of 6 mm, and the legs 26 are in thickness of 4 mm.
While the present invention has been illustrated and described with reference to some preferred embodiments, the present invention is not limited to these. Those skilled in the art should appreciate that various variations and modifications may be made without, departing from the spirit and scope of the present invention as defined by the accompanying claims. | An apparatus for the preparation of pulp molded plate includes a press and a three-piece mold including an upper die ( 1 ), a surrounding frame ( 2 ) and a lower die ( 3 ), wherein one of the dies is a moving die and the other is a fixed die, and lower die is always within the press, and moves in relation to the upper and lower dies. The apparatus also includes a rigid matrix and a flexible punch with a retractable die bar, which are installed respectively on the upper die and lower die, so as to prepare a heterotypic pulp-molded plate with a convex part. Also disclosed is a pulp molded plate prepared by this preparation apparatus. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
Non-Provisional Application based on Provisional Application No. 60/269,231 filed on Feb. 16, 2001, which is based on Patent Memorandum 2000 CL89
BACKGROUND OF THE INVENTION
The present invention relates to determining the output performance of a process unit in an oil refinery. Such units include pipestills, hydrocracking units, catalytic cracking units, hydroprocessing units, and reforming units. In particular, the present invention relates to a new and advanced process unit monitoring computer software (called “unit monitoring toolset”) for specific process units.
A Unit Monitoring Toolset is an advanced monitoring computer software capability developed for specific process units that makes use of intelligent, automatic data collection, workup calculations, selective execution of process models to monitor and predict performance and provide input to assessments, reports, etc. The Toolset enables close monitoring, problem diagnosis, model tuning and assists in optimum operation identification, to the extent that the models themselves are capable of identifying these optimum operations. By bringing this to the contact engineer/unit engineer level, we are able to monitor the unit to the extent that best performance should be a daily event.
Current Monitoring Technology relies on monitoring plant measurements (flows, temperatures, etc.) and often comparing them to targets. The fundamental question of “what is happening within an individual process unit” is more complex than that described by such measurements. The Toolset provides process unit information for the user, rather than just measurements. Information comes from detailed calculations, analyses, data workup and the execution of simple or highly complex models which can simulate expected performance. Information like this provides an order of magnitude improvement in the ability to monitor a process unit.
The objectives of a Unit Monitoring Toolset include the following:
Provide state of the art monitoring capability;
Increase the frequency and sophistication at which model-based monitoring is performed;
Use detailed and often design-only models for routine unit monitoring and improvement;
Establish a means to automatically capture high quality data regarding process unit performance in a history database;
Perform calculations and/or run models and store key results in a database to provide a history of operating comparisons from which to use as a knowledge base for future operations;
Diagnose emerging problems sooner;
Replace or retire numerous standalone tools by consolidating them;
Provide better data interchange between analysis tools and components; and
Interact with/exploit desktop computing, engineering tools, and vendor plant information systems.
SUMMARY OF THE INVENTION
The present invention (hereinafter referred to as “unit monitoring toolset”) is a method to monitor and analyze the performance of a hydrocarbon-processing unit such as a pipestill or hydrocracker unit. The method may also be used to monitor and analyze the performance of other refinery units including distillation units, hydrotreating units, catalytic cracking units, lubricating oil units and reforming units. For distillation units, the analysis uses equations that relate to the blending of feeds or different crude types, calculations of flash zone performance, hydraulic performance of tower sections, and hydrotreating. For hydrotreating units, the analysis uses equations that relate to catalyst performance and activation, and hydrogen purity. For catalytic cracking units, the analysis uses equations that relate to bed fluidization, catalyst circulation, catalyst additions, cracking estimations, emissions and regeneration. For lubricating oil units, the analysis uses equations that relate to extract and raffinate efficiency, composition impacts of qualities such as wax, additive use, and performance limits that impact qualities. For reforming units, the analysis uses equations that relate to catalyst performance, recycle gas quantity and quality, and regeneration effectiveness.
The invention includes the steps of collecting historical data relating to the hydrocarbon processing unit, from a process history database, validating the historical data, correcting the data, performing a workup to determine the output measurements for the hydrocarbon processing unit, and storing the results of the workup in the process history database. In a preferred embodiment, the historical data and the results of the workup are put into a process unit model for the oil refinery unit to determine an expected performance and potentially also an optimal performance.
The unit monitoring toolset has the following algorithm, shown in the overview FIG. 1, which includes the following steps:
1. Collecting data (as shown in FIG. 1, Step 2 a ) from the process history computer system (FIG. 1, Step 1 a ). In this regard, data refers to process instrument measurements, laboratory data, manually entered data, operational switches and stored constants for the unit. The collection is an intelligent matching of information from various sources and is a novel approach resulting in higher quality information.
2. Validating the data (FIG. 1, Step 3 ) by a set of logical rules (such as min/max checking, non-null and confidence checks, and other logical data validation rules such as increasing temperature boiling curves, etc.). This validation assures that the performance analysis is done on good data.
3. Performing a data workup (FIG. 1, Step 4 ), including a set of calculations that represent the sum total of all the experience of the process and operations experts in the organization for analyzing the operation of that unit. This calculation set yields many results which are all indicators of performance. The data workup varies for every type of process unit. Each Toolset workup is envisioned to be a distinct entity that can be installed, configured, upgraded or operated independently for each type of process unit. Toolset workups may share some underlying utilities or calculation modules, but since each process is fundamentally different, each Toolset workup will be unique.
4. Storing these workup results back into the same process history computer system (FIG. 1, Step 2 b ) where the original operating data was collected.
The toolset may also include the additional steps:
5. Collecting and inputting the data into a sophisticated process model that can be run to predict the expected operation of that unit (FIG. 1, part of step 3 ). This model contains the best technology from the organization or available commercially for that process. The models are often fundamental kinetic or molecular models but can also be correlation-based and are custom to the process unit. The models often require tuning, validation and customization to the unit being monitored. Calibration and tuning is often included as a part of the Toolset and may require independent calibration runs of the model in addition to the normal monitoring prediction runs. These models can also include anticipated or planned future operations as a part of the model prediction (for example, catalyst replacement planning requires anticipated future operations estimates).
6. Storing these model results back into the same process history computer system (FIG. 1, Step 2 b ) where the original operating data was collected.
7. Developing an effective set of reports and alerts (FIG. 1, Step 4 ) for monitoring (for example, hourly, daily, and weekly reports and exception reports for various people—plant operator, plant process engineer, central engineering expert, etc.).
The overall control of the entire process is achieved through the global attribute mapping (FIG. 1, Step 1 b ) kept in the Data Reference Attribute Table. This novel table holds the mapping and transposition master information that identifies how information is collected, transposed and moved throughout the various modules of the Toolset in a way that enables it to be automated and applicable to a wide variety of unit designs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an overview of the present invention.
FIG. 2 shows a schematic diagram of the toolset algorithm with the associated interfaces to the database and the calculation modules.
FIG. 3 shows a schematic of the workup calculation module creation
FIG. 4 shows a detailed schematic of how the toolset interfaces with the database, calculation modules and process reference models
DESCRIPTION OF THE PREFERRED EMBODIMENT
A schematic of the algorithm of the present invention is shown in FIG. 2 . The basic steps are data collection (FIG. 2, Step 1 ), data validation (FIG. 2, Step 6 ), and data workup (FIG. 2, Step 9 ).
Data Collection Step
Data collection modules (FIG. 2, Step 1 ) provide automated data loading from plant information data, Lab analyses, control system stored data and other manually entered data into a Toolset. Where possible, the modules fully automate the loading process thus minimizing user effort required to load data into the Toolset's database. The overall control of the entire process is achieved through the global attribute mapping (FIG. 2, Step 2 ) kept in the Data Reference Attribute Table. This novel table holds the mapping and transposition master information that identifies how information is collected, transposed and moved throughout the various modules of the Toolset in a way that enables it to be automated and applicable to a wide variety of unit designs.
Each Toolset contains logic set for determining how and when to collect data and this is called a balance period (FIG. 2, Step 3 ); this is needed as deferring hydrocarbon process units have unique operating modes which require careful consideration when collecting data. For example, certain toolsets will make use of the hourly averages or the entire day averages while other toolsets may prefer to apply a “tight” window around the availability of a lab sample. The former would execute on a known frequency, while the latter would be driven by the availability of thorough feed and product lab samples, as well as the length of time from a unit “upset”, the residence time of the unit and possibly the detection of steady state operations. The trigger for data collection can be different for each type of Toolset.
Toolset computations are executed for this “balance period” which is a high quality operating point for the process unit. This may imply different balance period logic for different process units; thus the time window may vary from a fixed time to a variable time. The variable time window could be defined by LAB sample times for feed and product or determined other business practices. Once the time window is determined for the balance point, the Toolset retrieves Average Data. The sample frequency used is the time window PLUS 1- second. This, when combined with a tag reduction type of “Average”, returns a single value over any time window (the average is not an arithmetic average but a time-weighted average).
Should a balance period be determined to be bad, the cycle is restarted. If the balance period is good, data is stored as “Toolset Data” in the Process Historian (FIG. 2, Step 4 ). Monitoring a unit at any given time requires measuring a prescribed set of attributes or properties of the unit at that time. Thus, this realistic time window, called the “balance period”, during which most or all of these attributes can be measured or computed, is chosen.
Data Validation Step
With the balance period data now stored back into the Toolset Data in the Process Historian, a data validation step is required (FIG. 2, Step 5 ). Comprehensive data validation can include completeness, range, checking, comparison with previous operating history, and relationship consistency (e.g., are distillation data points in ascending order, etc.) and is required to insure that high quality data is used for unit monitoring and/or optimization. Data validation also marks suspect data and allows users to define required data such that processing of the subsequent step(s) will not occur with bad or missing data. Three levels of validation may occur:
1. A check that a value is within an acceptable range for different measurements.
2. A check that the value is consistent with other data loaded.
3. A validation that the data for the current balance is reasonable relative to variation expected from recent previous data.
If the data is incorrect, data correction modules (FIG. 2, Step 8 allow users to override the stored input data values. With this data correction, all changes are tracked and linkages to other runs are established as required. The ability to correct data and re-run the Toolset is a very important and adequate logging of changes is critical.
With correct data (FIG. 2, Step 6 ), either the data workup or process reference models, or both, are started (FIG. 2, Step 9 ). The Workup Program performs calculations for the balance period in question (FIG. 2, Step 11 ). These Data Workups for the balance periods are used to analyze unit data for a time window of interest. The balance data is time-stamped with the start date of the chosen time window. Executing a “Data workup for a Balance Period” means that you are requesting that the Toolset program perform a set of calculations for a specific time window and compare the input measurements against those of the output. Each time a set of data is collected, a complete mass and heat balance on the unit is completed, along with a yields workup and a catalyst characterization (if applicable). After the workup is completed, the Toolset program indicates which attributes are input and which are output from the workup. Although all the data in the Balance Period will automatically load all the data from the process data historian, data can be entered manually as well. Each value of the balance period data is entered as an attribute identifying it and a unit identifier. After execution, the user can view the data, create a report, or use it as an input to another tool, such as a detailed process unit model.
When these calculations are finished, the results are sent back as Toolset Data in the process historian (FIG. 2, Step 12 ). From these results, and the balance period data, charts/graphs and other representations are prepared (FIG. 2, Step 13 ) to understand the health of the hydrocarbon-processing unit.
Data Workup Step
Data Workup (FIG. 2, Step 11 ) is a standard, technically sound, and documented set of calculations for the unit. These calculations represent the technology needed for effective unit performance monitoring. This includes detailed performance calculations and summary calculations yielding key performance indicators based on measured process data (temperatures, pressures, flowrates, etc.) laboratory data and equipment design parameters. The Workup may also either prepare data and interface to a model, act completely as the model, or incorporate external model routines within its calculation modules.
Workup procedures typically include the following kinds of computations:
1. Meter corrections to correct raw flow rates. The calculations are based on the measured raw flow rates and stream properties along with meter design information stored in the database.
2. Distillations converted to standard bases (15/5 wt % and LV%) and are stored back in the database.
3. Product streams are blended and a total yield slate is calculated based on standard and user defined cut point bases.
4. One or more flashes are performed to provide fluid properties as input to models or further Workup
Workup Development
Workup calculations are developed by one skilled in the art to reflect key performance calculations for individual process units and FIGS. 3 and 4 represents how a typical workup program would be developed. In effect, these calculations represent the knowledge base reflecting the experience of expert engineers in running a process unit over time. These can be found in engineering manuals, documents, journals and technical symposia for each Toolset process unit. The development of a workup often requires the cooperation of a team of individuals with skills ranging from process unit domain expertise to instrumentation and measurement expertise, to laboratory analysis experts, to computer program development. In effect, this group of experts forms one skilled in art.
Process Unit Determination
To enable the development of the Data Workup modules, certain parameters, calculations and/or prediction techniques need to be identified. The identification of these key parameters, calculations, and prediction techniques begins with the selection of the process unit (FIG. 3, Step 1 ). This is an important step since a particular process unit predetermines a number of things about the unit. For example; does the unit have catalyst, does it have particular physical characteristics, does it consume large quantities of utilities (heat, steam, additives, etc), does it have intermediate drawoffs/feeds, where is the instrumentation places, what type of lab samples are taken, etc.
With the particular process unit identified, the next step is to identify the available measurable inputs (FIG. 3, Step 2 ) and available measurable outputs (FIG. 3, Step 3 ) for the unit. These measurable values are key since they represent the key volumes/compositions/pressures/temps that enable the unit to be monitored in the base. The measurable inputs are typically plant measurements such as temperatures, pressures and flowrates supplemented by analyzer readings or analysis values from samples taken of the process and sent to a Laboratory. The measurable outputs are the overall results that the experts believe are indicative of the performance of the unit.
Process Unit Settings (FIG. 3, Step 4 )
One skilled in the art would now identify the controllable unit settings. These are often the setpoints for the various controls that can be used to adjust the performance of the unit. It is important to know which variables on the unit can be directly adjusted or controlled.
Intermediate Variables (FIG. 3, Step 5 )
Next one skilled in the art would now define the unmeasurable but important intermediate variables that are needed to be calculated. Ideally, one would like to have plant measurements for each of these, but the physical reality often does not permit direct measurement or it is too expensive. A good example would be a mixed stream temperature, or a vapor volume fraction, or a flow maldistribution factor or a fluidized bed expansion factor. These unmeasurable items would likely require intermediate prediction or calculation as input to other calculations. The identification of the unmeasurable inputs and outputs would consist of reviewing the unit operations and determining the gaps from the available measures and the specific workup calculations
For example; the unit may have blocked operations during which critical intermediate streams are fed into the unit but no measurement of the flowrate is available. This may mean that the flowrate would be assessed to be a constant based upon interpretation of information where the flow was coming from.
Process Unit Workup Calculations (FIG. 3, Step 6 )
Next, one skilled in the art would develop equations for critical calculations that would predict the performance of the unit. These equations would result from rules of thumb, publications, historical behavior, engineering relationships or statistics. These could specifically calculate End of Run for Catalyst activity, hydrogen consumption, pressure drops, riser velocities, etc. All would be specific to a given process unit. This development is an iterative process where one selects the intermediate variables, develops workup equations, tests the results, and then improves it by identifying more intermediate variables, researching more computations, etc until an effective data workup is created for that specific type of process unit.
High Level Performance Indicators (FIG. 3, Step 7 )
As the last step in the process, one skilled in the art would select the high-level overall performance indicators for routine monitoring of the unit's performance. These are often similar to the controllable unit settings and the measurable outputs but may be more selective and may include some of the intermediate results that clearly indicate performance but may often not be something that can be measured or monitored in a real plant unit (FIG. 4 ).
Develop Workup Program (FIG. 3, Step 8 )
Finally, one skilled in the art would develop the workup program that can be a plug in callable module of the Toolset for that specific type of process unit.
Example of Data Workup
Taking the above to a crude distillation unit as an example, the following shows the above process in more detail
Inputs
Column Configuration
Other physical equipment
Feed type or fraction of crude type
Qualities of the feed, Feed Distillation/Assay
Rates
Pressures./temperatures
Settings on the Unit
Tower Internals (trays, packing, both)
Recycle (number and location)
Reflux (number and location
Steam Rate
Flash Zone
Draw offs (number and location)
Outputs
Yields of each stream
Qualities of each Stream
Performance Calculations
Tower Hydraulics
Tower Velocities
Tower Loadings
Predicted Qualities
Plant Wide Data Storage and Toolset Performance Database
The Toolset contains two primary data categories that require long term storage:
1. Toolset data values (either collected inputs or computed results) to be stored (FIG. 1, Step 5 and FIG. 2, Step 4 ).
These data values include all the input measurements (after validation), yields, operational data, yield predictions, process model calibration factors, unit geometry and configurations, and other unit information. It also includes unit monitoring results as well as prediction results, allowing the comparison of predicted and actual results for monitoring of intrinsic unit performance. These data values are stored in the plant history database as plant Tags with a designation that they are Toolset monitoring Tags. This provides a secure long-term history capability and makes the results easily accessible by the suite of tools and applications that exist and are used with the plant history database.
2. Toolset data mapping describing the data attributes to be collected or calculated (FIG. 1, Step 1 ; FIG. 2, Step 2 ; FIG. 4, Step 4 ).
Reference data tables describe each item of data to be stored. This allows each site to properly configure a unit with its requisite number of streams, measurements, etc. Reference data also describe the inputs and outputs of models. The main table in the Toolset reference database is the Unit Attribute Table, which is a list of all the properties of the site's monitored units.
A plant historian (FIG. 1, Step l a and FIG. 2, Step 1 ) provides the means to acquire and validate a set of data, and store all the data. All monitoring data will be stored in the plant historian database (Phd) as tag data. There are three types of data:
1. Tag Data (averaged over a Toolset Balance Period) is directly acquired from the process (e.g., temperatures, pressures, flow rates)—this averaged process tag data is referred to as “direct data”.
2. Reference Data (Toolset Balance Period start and end times, model parameters and flags used for this time period).
3. Calculated Data is computed using the Data Workup Calculations (e.g., equivalent isothermal temperature) or a process model (e.g., predicted yield).
A plant historian may be any commercial database such as the Honeywell Plant History Database or the Oil Systems Plant Information Database. This plant historian has the ability to store a massive amount of plant data and is highly effective with Timeseries plant data. The commercial historian provides the capability for a program, such as a Toolset, to store all its results. This approach of matching the Toolset to the plant history database have a number of synergy benefits, because the Toolset results are stored in the same place as the plant measures and can be used by users and many other plant applications just as easily as measures. For example, Toolset results can be read by control programs and optimizers, results can be part of operations monitoring and target exception reporting, results can be sent to the operators and used in automated alerting/paging systems. Once the results are stored in the Phd, the door is open for a new generation of capabilities.
Typical Toolset Example—The Powerforming Toolset
FIG. 4 shows a schematic diagram of the relationship between the toolset, process historian, calculation modules and process reference model. This example explains the data flow in the Powerforming, which is for catalytic reforming to improve octane.
Collect Raw Plant Data: FIG. 4, Step 1
Raw plant data is automatically collected and stored in the plant historian (FIG. 4, Step 1 a ) (in this case, Honeywell Process History Database PHD is used). All lab data (FIG. 4, Step 1 a ) is available and stored in the plant historian as well. Should any data need to be averaged from process data or lab data, this would also come from the Process Historian in the form of Virtual Tags (FIG. 4, Step 1 b ). Lastly, all Toolset input data would come from the plant historian (FIG. 4, Step 1 c ).
Raw Plant Data Validation: FIG. 4, Step 2
The Toolset will automatically pull data (FIG. 4, Step l c ) from Phd for a time period (balance period) determined by the site (FIG. 4, Step 2 a ). The Toolset can be scheduled to run at any frequency depending on data availability and need.
All data inputs to calculation programs will be extracted from Phd and validated (FIG. 4, Step 2 b ). The raw data will be low/high range checked and all data falling out of range will be automatically flagged and substituted with a default value. The engineer reviews all data that falls out of range before the calculations are run and in most cases, the engineer accepts the default value. Validated data is stored back into the process historian (FIG. 4, Step 2 c ).
Valid Low/High values for each Toolset input will be stored in a Reference Table. The Reference Table stores all site-specific information about the Powerformer and is critical for providing a means to distinguish one type of Powerformer form another (ie Cyclic versus Semi-Cyclic).
Powerformer feed samples are collected at a regularly scheduled time and feed lab analysis is performed. The Toolset requires this lab data to perform a material balance and other calculations. In plant operations, it is not uncommon for the lab to analyze the feed later than the scheduled time sometimes this delay can be a day or more. An automated Toolset running on a daily basis makes decisions when yesterday's lab data is unavailable for today's calculations. Thus, the Toolset will perform calculations using the last available set of lab data. In the case of unavailable lab data, the plant historian returns the previously stored value (i.e., yesterday's lab results) so that the calculations can proceed. For Powerformers, this approach works well since the Powerformer feed does not change significantly on a day to day basis. All substituted or assumed values are clearly indicated on all output reports. The engineer may rerun balances for those periods in question when the correct lab data is available
General Powerforming Data Workup on Valid Data: FIG. 4, Step 3
Once balance period data is validated and stored back into the plant historian Data Workup calculations are performed (FIG. 4, Step 3 a ). All of the general calculations currently to currently monitor a Powerformer are included in the Powerformer toolset. These include Catalyst Activity Monitoring calculations). For each type of hydrocarbon processing unit, there is a unique set of calculations that are used to perform performance monitoring. Each Toolset utilizes that existing calculation set as a module to perform the needed computations. For any given type of process unit, one skilled in the art can develop the needed performance monitoring calculations for use by the Toolset and shown in FIG. 3 and discussed in this document.
The Toolset performs all calculations in English units and with the plant historian is able to display the results in units customary to that location.
The Toolset will perform a material balance. This uses an eight hour time window centered around when the lab samples are normally taken. Hourly data points, for each input variable, are averaged to get the value to use for the material balance calculation. If all of the data is not available for the material balance calculation, then the material balance calculation is skipped and is noted on a daily execution log. Therefore, the material calculation frequency corresponds with the lab analysis frequency.
The material balance outputs and the general calculation outputs are stored (FIG. 4, Step 3 b ) back into the plant historian (FIG. 4, Step 3 ) as Toolset output Tags. A copy of the validated Toolset inputs is also stored in the plant historian to facilitate changing incorrect data in the Toolset.
Run a Powerformer Kinetic Model and Store Key Results Back into Phd: FIG. 4, Step 5
The Powerformer kinetic model(s) is specially designed this process. These models are not part of the Toolset and are commercially available from a number of vendors. The Toolset, because of its mapping of attributes, has the ability to drive information into the model (FIG. 4, Step 5 a ) tell the model to execute (FIG. 4 . Step 5 b ), and then extract the model results back into the Toolset (FIG. 4, Step 5 c ), for storage back into the process historian (FIG. 4, Step 5 d ). The Toolset also provides non-automated capability to run kinetic model cases based on actual plant data to obtain a predicted yield to compare against a measured yield. Further it is possible to automatically schedule these model cases to run on a daily basis.
In the above example, the Kinetic model was run in a forward prediction mode; however, a model written in an open form, can be run in many different modes with different and uniquely important results. In this way, the Toolset can utilize a model in prediction or optimizing modes. The forward prediction mode simply takes the inputs to the process unit and predicts the yields based on the feed composition, operating conditions and unit/catalyst status. The Toolset monitoring can both assess how the unit is behaving, how it should behave and how it potentially could behave if adjusted for optimal performance. Thus the monitoring could identify missed opportunity.
Step 6: Graphs of Unit Performance: FIG. 4, Step 6
Powerformer data is best viewed graphically in the form of XY plots. These plots convey the current state of the system when the data was collected. In Powerformer terms, this means that the plots need to indicate which reactors are on-oil or which reactor is regenerating (off-oil).
After the calculations have been run, the Toolset provides the plots that are essential for determining the health of the unit. A core set of these plots are used to determine the health of the unit. If everything looks good with these plots, the unit is healthy. The plot descriptions below provide a brief explanation of how to use the plots to assess unit health.
1. Stabilizer Bottoms Lab Research Octane Number (RON) vs. Date—An important and well-known measured parameter in reforming is Research Octane Number (RON). RON is reformate product specification (when used for mogas blending). The engineer checks this plot each day to ensure that the unit's final product meets spec. Sites that use reformate to feed a chemical plant may have another target specification. For these sites, a target chemical specification is plotted.
2. Measured C 5 +, H 2 Yields vs. Date—The most direct measure of unit health, but usually the most inaccurate since several flow meter measurements are required. The engineer will compare the measured yield to predicted yields from the kinetic model. Large predicted minus measured yield deltas indicates a potential unit health problem or a bad flow measurement. In either case, action is required.
3. Catalyst Activity vs. Date—Is an overall measure of the ability of the unit to upgrade the low octane feed into high-octane products. The activity correlation is a good measure of overall system health because it accounts for day to day variations in feed quality, product octane, unit pressure and temperature.
4. Total Corrected Unit Temperature Drop vs. Date—This plot looks at the sum of the temperature differences between the reactor inlets and outlets. A “corrected” temperature drop signifies that the observed temperature drop has been recalculated based on a standard recycle gas ratio, recycle gas hydrogen purity, and feed naphthenes content. This correction dampens variations in the temperature drop caused by changes in such items as recycle gas ratio. The thermocouples are the eyes of the unit and indicate changes in unit performance quickly.
5. Individual Reactor 50% point vs. Date—These plots look at the fraction of the temperature drop that occurs in the top 50% of the catalyst bed of each reactor. These plots indicate the condition of the catalyst at the top of each catalyst bed (since the top of the bed is affected by a feed upset/contamination sooner than the rest of the bed). These plots also indicate the reactor's 50% point when it is placed in service and one of the reactors is removed.
6. Overall Catalyst Deactivation vs. Date—Overall catalyst deactivation correlates with the average coke level on the catalyst. This plot is useful to determine if the regen frequency is sufficient to prevent a long-term coke build-up.
7. Recycle Gas Hydrogen Purity vs. Date—The hydrogen content of the recycle gas is a significant indicator of process performance. Changes in hydrogen purity reflect variations in catalyst activity or process severity
Step 7: Write Daily Output Report to the Engineer's Computer: FIG. 4, Step 6
The Cyclic/Semi-Cyclic Toolset provides three reports The key features of the reports are summarized below:
1. The Toolset will provide the engineer with an enhanced version of the reports on a more frequent basis (daily versus every 7-10 days) and with less required effort.
2. Plots—The Toolset will provide plots of key performance on a regular basis. These are likely the first thing that the contact would look at in the morning to ensure that the unit is healthy. Additional plots are also available, if the engineer notices a potential problem with the unit. The engineer will also have the capability to generate additional ad-hoc plots quickly and easily.
3. 2-3 Page Summary Report—The Toolset will provide a simplified 2-3 page tables report containing the most critical information about the unit. The simplified 2-3 page report contains a section on all substitutions made for data that fell outside pre-determined valid ranges. The report also contains a section containing predicted kinetic model yields. | The present invention is a method to monitor and analyze the performance of a hydrocarbon-processing unit such as pipestill or hydrocracker unit. The invention includes the steps of collecting historical data relating to the hydrocarbon processing unit, from a process history database, validating the historical data, correcting the data performing a workup to determine the output measurements for the hydrocarbon processing unit, and storing the results of the workup in the process history database. | 6 |
OBJECT OF THE INVENTION
[0001] The object of the present invention is a digital glaze suitable for being applied by means of digital inkjet printing techniques which allows high grammage to be applied, maintaining the same aesthetic and technical characteristics which are obtained with traditional glazes and non-digital application techniques.
DESCRIPTION OF THE PRIOR ART
[0002] The incorporation of digital inkjet printing technology as a method for decorating ceramic tiles has enabled an evolution in the type of product which is marketed, as well as a whole series of management, processing and product advantages which have contributed to maintaining the competitiveness of the ceramics sector in general. These digital systems for decorating are based on high resolution DOD technology (greater than 220 dpi) in which printheads are used which generate drops of dozens of picoliters at a frequency which, depending on the manufacturer of the printhead, oscillates between 5-30 KHz, the most well-known manufacturers of these types of printheads being the companies, Dimatix (Fujifilm), Xaar, Seiko, K&M or Ricoh amongst others.
[0003] Nowadays, an attempt is made to utilize the advantages which digital technology offers, not only for the decoration step, but also for the glazing of ceramic tiles, the tendency being to cover the entire surface of the tile by means of a mixture of two or more digital glazes, which provides new aesthetic effects of greater added value. In this sense and using the same high resolution DOD technology, in the Spanish patent application, P201231722, a series of glazes suitable for application using this type of technology are described, which focus on glazing large format ceramic tiles which require a relatively low quantity of glaze and a high resolution for achieving the required aesthetic effects.
[0004] When, due to the aesthetic and technical characteristics of the ceramic tiles, a larger quantity of glaze is required to be applied than high resolution DOD technology allows, it is necessary to use other techniques, also digital inkjet printing technique such as electrovalve systems or that described in the patent applications, EP1972450A2 and EP2085225A2. The size of the drops which these systems generate is many dozens of nanoliters, the frequency of discharge from the printhead is in the order of 1 KHz and the resolution approximately 50 dpi. Given this large size of the drops, the grammage which is achieved is much greater than those using high resolution DOD technology, reaching values which exceed a kilogram per square meter.
[0005] In the patent application ES 2 386 267 A1, digital inks/glazes are described for these types of inkjet printing systems, which have a liquid means which is based on a mixture of water and polar solvents and a solid part which is characterized, amongst other things, by the use of anti-settlement agents which are normally used in the formulation of traditional glazes that are applied by non-digital methods, such as the bell, disk, waterfall, etc. These anti-settling agents are different types of clays (montmorillonites, bentonites, etc.) and kaolins, although carbon black or colloidal oxides and hydroxides may also end up being used.
[0006] All of these are solids and do not dissolve in a liquid medium formed by water and polar solvents. Furthermore, all of these mainly interact with the molecules of the solvents which the liquid medium composes, without having a direct interaction with the solid particles of the glaze.
[0007] In the case of clays and kaolins, these materials incorporate the solvent molecules in their laminar structure. When the glaze is at rest or subjected to a low shear force (Y<10 s-1 ) the incorporation of the solvent molecules on the part of the clay or the kaolin causes the viscosity of the glaze to increase considerably, thereby achieving the anti-settling effect. Contrarily, when the glaze is subjected to a high shear force, the incorporated molecules are released, reducing the viscosity of the glaze. The glazes which have this behavior are commonly termed thixotropic glazes.
[0008] In the case of carbon black, the anti-settling action is due to its high specific surface, such that the molecules of the solvents which compose the liquid medium penetrate through the interstices of the black carbon particles and cause the increase of the viscosity as in the case of clays and kaolins, again providing thixotropic glazes.
[0009] In the case of colloidal oxides, the anti-settling effect is due to the fact that they create three-dimensional networks in which the solvent molecules are trapped, similarly causing that which happens in the previous cases, an increase of the viscosity when the glaze is at rest or subjected to low shear forces and a reduction of the viscosity as the shear force increases, again providing thixotropic glazes.
[0010] Normally this is an advantage when conventional techniques for applying glaze are used (bells, waterfalls, disks, sprays, etc.), since using said techniques, high viscosities are required (in some cases in the order of hundreds of cps) and the presence of a small amount of sedimentation is not critical since the glaze is under continuous agitation, generally very energetic and there do not exist small tubes, small orifices, small passage or three-dimensional filters, nooks, etc. which can become blocked by sedimentation problems of the glaze.
[0011] Contrarily, the use of digital thixotropic glazes such as those described in the patent application ES 2 386 267 A1 based on the use of anti-settling agents such as those previously mentioned, poses a serious problem when it is desired to use them in digital inkjet printing techniques to proceed with glazing or decorating ceramic media.
[0012] In the digital inkjet printing techniques, such as for example those described in the patent applications EP1972450A2 and EP2085225A2 or the systems based on electrovalves for being able to apply high grammage (greater than 200 g/m 2 ), the digital glaze travels a closed circuit in which it is subjected to relatively low shear forces (<10 s-1 ), amongst other things in order to avoid the formation of bubbles which cause defects in the print drops. If the digital glaze is thixotropic, its viscosity at the time of being injected is greater than that required in the inkjet technique, therefore the drop does not form immediately, numerous impulses being necessary until finally beginning to inject, which causes the effect known as delay. This effect is translated into absences of glaze in the first moments of the printing, and given that using the digital systems, motifs are generally printed which do not cover the entire piece (images, geometric shapes, etc.), the printing process is continuously started and stopped, therefore the final result is a defective printing with numerous absences of glaze on the surface of the piece, which means that the printed piece does not comply with the minimum quality criteria required by the ceramics industry.
[0013] Therefore, in order to characterize a digital glaze from a rheological point of view, it is not sufficient to indicate the viscosity at the working temperature as mentioned in patent ES 2 386 267 A1, but it is necessary to express the viscosity as a function of the shear force since the case may arise where for high shear forces, the viscosity is suitable, but it is not the same for low shear forces, posing problems which make their industrial use unviable.
[0014] In addition, all the inkjet printing techniques are very demanding in terms of the stability of the digital glazes which are to be used, since there are numerous small tubes, small orifices, small passage and three-dimensional filters, nooks, etc. in which the glaze can become retained if it is not sufficiently stable, causing the corresponding blockages and printing problems.
[0015] An added difficulty when achieving perfectly stable digital glazes without the use of anti-settling agents, is the use of particles with relatively large sizes (D100<50 μm, compared to D100<1.2 μm which characterizes the digital glazes for high resolution DOD). The use of particles with D100<50 μm is essential in order to achieve a competitive process when high grammage (greater than 200 g/m 2 ) is required since the greater the size of the particle, the more economically expensive the process for preparing the digital glaze is.
[0016] There is also the need to achieve perfectly stable digital glazes without the use of anti-settling agents, the loss of weight of which through evaporation does not cause problems of drying up in the printhead.
[0017] In order to overcome the previously described drawbacks, there exists the need to provide perfectly stable digital glazes without the use of anti-settling agents with a value of loss of weight through evaporation lower than 5% and with a particle size of D100<50 μm for the digital glazing systems conceived to apply grammage greater than 200 g/m 2 .
DESCRIPTION OF THE INVENTION
[0018] The digital glazes, object of the following invention, solve the drawbacks of the prior art previously described and are characterized by being constituted by a solid part and a liquid medium.
[0019] The solid part of the digital glaze, the percentage by weight of which is between 30 and 80% of the total weight of the digital glaze, is constituted by a mixture of ceramic raw materials, frits and in the cases in which a colored finish is desired, ceramic pigments, all of which are commonly used in the ceramic sector. The mixture and the percentage of each of these raw materials, frits and ceramic pigments, are defined as a function of the final finish which is desired to be provided to the glazed layer of the ceramic tile following the firing of the same (shiny transparent, shiny opaque, matte, luster, etc.). As ceramic raw materials, the following are used: frits, pigments, ceramics, sands, feldspars, aluminas, clays, zirconium silicates, zinc oxide, dolomite, kaolin, quartz, barium carbonate, mullite, wollastonite, tin oxide, nepheline, bismuth oxide, boracic products, colemanite, calcium carbonate, cerium oxide, cobalt oxide, copper oxide, iron oxide, aluminium phosphate, iron carbonate, manganese oxide, sodium fluoride, chrome oxide, strontium carbonate, lithium carbonate, spodumene, talc, magnesium oxide, cristobalite, rutile, anatase, bismuth vanadate, vanadium oxide, ammonium pentavanadate or a mixture thereof.
[0020] In order to prevent the digital glaze, object of the invention, being thixotropic and therefore having problems in the inkjet printing process, anti-settling agents are not used in the composition of the same, given that these are solid and are not soluble in the liquid medium which also forms part of the digital glaze.
[0021] The digital glazes, object of the present invention, are also characterized in that the solid part thereof has the following granulometric distribution:
[0022] =>D100<50 μm
[0023] =>D90<35 μm
[0024] =>D50<20 μm
[0025] =>D25<15 μm
[0026] =>D10<10 μm
[0027] This is also the case in order to be industrially competitive, since going to smaller particle sizes would significantly drive up its preparation cost and therefore the end cost of the ceramic tile since these digital glazes are used in the majority of cases with high grammage, greater than 200 g/m 2 . This high particle size, if compared with that of the digital glazes for high resolution DOD (D100<1.2 μm), adds an additional difficulty at the time of formulating stable glazes which function correctly during the printing process, therefore it is of great importance to suitably define the type and percentage of the solvents and agents which are going to form part of the liquid medium.
[0028] The liquid medium of the digital glazes, object of the present invention, the percentage by weight of which is between 20 and 70% of the total weight of the digital glaze, is formed by a mixture of water in a content of between 10% and 50% by weight and of polar solvents of medium to low polarity, also in a percentage of between 10% and 50% by weight.
[0029] Solvents which can be used are alcohols, fatty alcohols, aliphatic fatty alcohols, aromatic fatty alcohols, amines, octylamines, cyclic amines, hydrocarbonated solvents, naphthenic solvents, paraffinic solvents, aromatic derivatives such as diisopropylnaphthalene, glycols, polyglycols, esters, branched monoesters, oleic esters, benzoic esters, lactic acid esters, myristic acid esters, palmitic acid esters, fatty acid esters in general, propylene glycol acetates, dipropylene glycol ether acetate, polyethylene glycol acetates, diethylene glycol monobutyl ether acetate, glycol ethers, polypropylene glycols ethers, tripropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, propylene glycol phenyl ether, tripropylene glycol monobutyl ether and polyethylene glycol ethers, hexyl carbitol ether, phenols, alkylphenols, fatty acids, terpene alcohols, terpene acids, copolymers of vinylpyrrolidone, polyglycols, polypropylene glycol or a mixture thereof.
[0030] Additionally, so as the digital glaze has the required stability and correct behavior during the printing process, soluble agents in the liquid medium are used, such as dispersants or stabilizers, binders, surfactants or humectants, rheological modifiers, anti-foaming agents and preservatives.
[0031] The dispersants or stabilizers prevent the agglomeration of the solid particles and are used in a percentage by weight lower than 8%, preferably lower than 5%. As dispersants or stabilizers the following can be used: derivatives of aromatic hydrocarbons, polyamides and phosphoric salts of polymers with acidic groups, polymeric dispersants, phosphates, phosphonates, acrylics, polymerics based on polyurethane, on polyesters or mixtures thereof.
[0032] The binding agents provide greater cohesion between the molecules of the solvents which form the liquid medium and the solid particles and in the cases in which they are used, they are used in a percentage lower than 5%, preferably lower than 3%. As binding agents, the following can be used: cellulosic derivatives, polyacrylamides, polyethylene glycols, polyurethanes, polyvinylpyrrolidones or a mixture thereof.
[0033] The surfactants or humectants modify the surface tension of the liquid medium and improve the moisture of the surface of the solid particles on the part of the solvent. The percentage of use thereof in the cases in which they are used is lower than 1%. As surfactants, the following can be used: fatty acids, alcohol alkoxylates, fatty alcohols, fluorinated surfactants, acrylic copolymers, EO/PO copolymers, esters, derivatives of sorbitol, derivatives of glycerol, derivatives of silicone or a mixture of the foregoing. All of which for the purpose of achieving a surface tension of between 30 and 50 dynes/cm.
[0034] The agents termed rheological modifiers make the mobility of the solid particles difficult, being used when they are required in a percentage lower than 2%. As rheological modifiers, the following can be used: acrylics, polyurethanes, smectites, hectorites, aluminosilicates, derivatives of urea, starches, celluloses, hexahydrated magnesium chloride, sodium chloride or a mixture thereof.
[0035] The anti-foaming agents prevent the formation of foam and in the cases in which they are required, they are used in a percentage lower than 1%. As anti-foaming agents, derivatives of polysiloxanes, derivatives of mineral oil, fatty derivatives or a mixture thereof can be used.
[0036] Lastly, agents which prevent the deterioration or the decomposition of the liquid medium can also be used, commonly termed bactericides, fungicides, preservatives or similar, being used in percentages lower than 1% in the cases in which they are required. As preservatives, the following can be used: isothiazolinones, carbendazims, bronopols or others.
[0037] With all the above, the digital glazes, object of the present invention, have a rheological behavior close to Newtonian, that is to say, the viscosity thereof is not modified to a large extent with shear force, characterized by the following values of viscosity as a function of the shear force:
[0038] =>Viscosity (μ) lower than 50 cps for a shear force (y) of 10 s −1 .
[0039] =>Viscosity (μ) lower than 40 cps for a shear force (y) of 100 s −1 .
[0040] =>Viscosity (μ) lower than 40 cps for a shear force (y) of 1,000 s −1 .
[0041] In turn, these digital glazes also have the advantage that they do not cause the blockage of filters or small tubes or orifices which are in the circuit of the printing device, since their sedimentation is very small, even when they are at rest.
[0042] Similarly, the digital glazes, object of the present invention, have the advantage that they do not dry in the printhead, with a value of loss of weight through evaporation lower than 5%. The method for measuring the loss of weight is based on the thermogravimetry technique (TG), the result being expressed in % by weight lost during 60 minutes, having been subjected to the sample at a constant temperature of 50° C. It was experimentally checked that with losses of weight greater than 5%, problems of drying up in the printhead begin to appear.
[0043] The digital glazes, object of the present invention, can also be used as inkjet inks applied on base glazes (applied in turn by any method) in order to achieve certain decorative effects not related to the color, such as the microrelief effect, gloss/matte contrast, luster effect, etc.
[0044] The digital glazes, object of the present invention, can also be used as inkjet inks applied at the end of the line of glazing, as a final application after the base glazing and the decoration with the purpose of providing protection.
Preferred Forms of Embodiment
[0045] In order to complement the description and with the aim of aiding a better understanding of its characteristics, the present specification is accompanied by various exemplary embodiments of digital glazes to provide the final finish desired for the glazed layer, according to the invention.
[0046] All of the exemplary embodiments indicated are done so in an illustrative and non-limiting manner.
[0047] Digital Glaze which Provides a Shiny Transparent Effect
[0048] In the table shown below, four exemplary embodiments for digital glazes with a shiny transparent effect according to the invention are shown:
[0000]
SHINY TRANSPARENT
GLAZES
1
2
3
4
COMPONENT
NATURE
%
%
%
%
SOLVENT
WATER
30-35
30-35
10-15
25-30
SOLVENT
MONOETHYLENE
30-35
10-15
20-25
GLYCOL
SOLVENT
BUTYL DIGLYCOL
25-30
DISPERSANT
PHOSPHATE
<3
DISPERSANT
SODIUM
<8
POLYACRYLATE
DISPERSANT
POLYMERIC
<5
2-5
HYPERDISPERSANT
BINDER
CELLULOSIC
<5
DERIVATIVE
BINDER
POLYACRYLAMIDE
<3
<2
SURFACTANT
ETHOXYLATED
<1
<1
FATTY ALCOHOL
SURFACTANT
FLUOROCARBON
<1
POLYMER
RHEOLOGICAL
POLYURETHANE
<2
MODIFIER
RHEOLOGICAL
UREA DERIVATIVE
<1
MODIFIER
ANTI-FOAMING
MINERAL OIL
<1
<1
<1
AGENT
DERIVATIVE
PRESERVATIVE
ISOTHIAZOLINONES
<1
<1
CERAMIC RAW
FRIT 1
25-30
25-30
MATERIAL
CERAMIC RAW
FRIT 2
70-75
MATERIAL
CERAMIC RAW
FRIT 3
45-50
MATERIAL
CERAMIC RAW
ALUMINA
5-10
5-10
<5
1-3
MATERIAL
[0049] Digital Glaze which Provides an Opaque Shiny Effect
[0050] In the table shown below, an exemplary embodiment for digital glazes with an opaque shiny effect according to the invention is shown:
[0000]
OPAQUE SHINY
GLAZE
COMPONENT
NATURE
%
SOLVENT
WATER
25-30
SOLVENT
MONOETHYLENE
20-25
GLYCOL
DISPERSANT
POLYMERIC
2-5
HYPERDISPERSANT
SURFACTANT
ETHOXYLATED FATTY
<1
ALCOHOL
ANTI-FOAMING
MINERAL OIL
<1
AGENT
DERIVATIVE
CERAMIC RAW
FRIT 6
45-50
MATERIAL
CERAMIC RAW
ALUMINA
1-3
MATERIAL
[0051] Digital Glaze which Provides a Luster Effect
[0000] In the table shown below, three exemplary embodiments for digital glazes with a luster effect according to the invention are shown:
[0000]
POLISH GLAZES
1
2
3
COMPONENT
NATURE
%
%
%
SOLVENT
WATER
25-30
45-50
10-15
SOLVENT
MONOETHYLENE
20-25
30-35
GLYCOL
SOLVENT
BUTYL DIGLYCOL
10-15
SOLVENT
PROPYLENE
15-20
GLYCOL
DISPERSANT
PHOSPHATE
<3
DISPERSANT
SODIUM
<1
<2
POLYACRYLATE
DISPERSANT
POLYMERIC
<5
<4
HYPERDISPERSANT
BINDER
CELLULOSIC
<1
<3
<2
DERIVATIVE
SURFACTANT
ETHOXYLATED
<1
<1
FATTY ALCOHOL
ANTI-FOAMING
MINERAL OIL
<1
<1
AGENT
DERIVATIVE
PRESERVATIVE
ISOTHIAZOLINONES
<1
CERAMIC RAW
FRIT 4
45-50
30-35
40-45
MATERIAL
[0052] Digital Glaze which Provides a Matte Effect
[0000] In the table shown below, three exemplary embodiments for digital glazes with a matte effect according to the invention are shown:
[0000]
MATTE GLAZE
1
2
3
COMPONENT
NATURE
%
%
%
SOLVENT
WATER
25-30
25-30
25-30
SOLVENT
MONOETHYLENE
20-25
10-15
10-15
GLYCOL
SOLVENT
DIETHYLENE
10-15
MONOBUTYL
ETHER
SOLVENT
PROPYLENE
10-15
GLYCOL
DISPERSANT
PHOSPHATE
<2
DISPERSANT
SODIUM
<3
<1
POLYACRYLATE
DISPERSANT
POLYMERIC
<5
HYPERDISPERSANT
BINDER
CELLULOSIC
<1
<2
DERIVATIVE
BINDER
POLYACRYLAMIDE
<3
SURFACTANT
ETHOXYLATED
<1
<1
FATTY ALCOHOL
SURFACTANT
FLUOROCARBON
<1
POLYMER
RHEOLOGICAL
POLYURETHANE
<1
MODIFIER
RHEOLOGICAL
UREA DERIVATIVE
<1
MODIFIER
ANTI-FOAMING
MINERAL OIL
<1
AGENT
DERIVATIVE
PRESERVATIVE
ISOTHIAZOLINONES
<1
CERAMIC RAW
FRIT 5
30-35
30-35
28-33
MATERIAL
CERAMIC RAW
SODIUM
5-8
5-8
4-7
MATERIAL
POTASSIUM
FELDSPAR
CERAMIC RAW
CALCIUM SILICATE
3-5
3-5
2-4
MATERIAL
CERAMIC RAW
ALUMINIUM
5-8
5-8
4-7
MATERIAL
SILICATE
CERAMIC RAW
COBALT SPINEL
4-6
MATERIAL
[0053] The preparation of the digital glazes with the indicated effects is carried out by means of the conventional methods generally used in the industry.
[0054] The main components of the frits used in the exemplary embodiments previously described are shown in the following table:
[0000]
FRITS
Main components
FRIT 1
SiO 2 , CaO and ZnO
FRIT 2
SiO 2 , CaO, ZnO and Al 2 O 3
FRIT 3
SiO 2 , CaO, ZnO, K 2 O and Al 2 O 3
FRIT 4
SiO 2 , B 2 O 3 , CaO, ZnO, K 2 O, CeO 2 , Z r O 2 and Al 2 O 3
FRIT 5
SiO 2 , CaO, ZnO, K 2 O, BaO and Al 2 O 3
FRIT 6
SiO 2 , CaO, Z r O 2 , ZnO, K 2 O and Al 2 O 3 | A digital glaze for high grammage, without the use of anti-settling agents, referred to as digital glazes for digital inkjet printing techniques to apply high grammage, maintaining the same aesthetic and technical characteristics obtained with traditional glazes and non-digital application techniques. No anti-settling agents are used in the composition to prevent the digital glaze from being thixotropic and creating problems in the inkjet printing. The composition includes at least one medium that is liquid at ambient temperature, formed by a mixture of water and polar solvents and/or solvents of medium to low polarity, having a percentage by weight of between 20 and 70% of the total weight of the digital glaze; and at least one mixture of ceramic raw materials and/or frits as a glaze-forming material, having a percentage by weight of between 30 and 80% of the total weight of the digital glaze. | 2 |
RELATED APPLICATION
[0001] This is a continuation-in-part of patent application Ser. No. 11/744,807, filed on May 4, 2007 and entitled “Sealing and Thermal Accommodation Arrangement in LED Package/Secondary Lens Structure.”
FIELD OF THE INVENTION
[0002] The invention relates generally to the field of LED lighting systems and, more particularly, relates to configurations for LED modules in lighting fixtures.
BACKGROUND OF THE INVENTION
[0003] In the field of lighting, many different types of light sources have been developed. Recently, LED light sources involving multi-LED arrays, each with a large number of LED packages, have been developed as a means of bringing the many advantages of LED lighting—LED efficiency and long life—into the general illumination field. In particular, such LED light fixtures have been developed for use in outdoor settings, including by way of example lighting for parking lots, roadways, display areas and other large areas.
[0004] LED fixtures in the prior art have certain shortcomings and disadvantages. Among these, there is a need for an improved arrangement for operation of LEDs having one lens positioned over another. Significant heat levels in such products can pose particular problems for lens-over-lens mounting and stability. One potential problem is that temperature changes may cause thermal expansion and related alignment problems.
[0005] Protection against various environmental factors is also rendered difficult for LED general illumination products which necessarily utilize a large number of LEDs—sometimes plural LED modules with each module having many LED packages thereon.
[0006] The product safety of lighting fixtures creates an additional area of difficulty, and such fixtures are most often required to comply within standards put forward by organizations such as Underwriters Laboratories Inc. (UL) in order to gain acceptance in the marketplace. One such set of standards deals with the accessibility of the electrically-active parts of a fixture during operation, and, more importantly, during periods of stress on the fixture such as in a fire situation during which some elements of the lighting fixture are compromised. The UL “finger test” mandates that a human finger of certain “standard” dimensions (defined in NMX-J-324-ANCE, UL1598, Dec. 30, 2004, FIG. 19.22.1, page 231) should not be able come in contact with any electrically-live parts of the fixture under such circumstances. The standards also establish certain material limitations on the enclosures of such products, all of which are dependent on the voltages and power levels within the fixtures.
[0007] Increased product safety can be costly to achieve, both in terms of the economic cost associated with providing safety as well as with the loss of lighting performance such as reduced optical efficiency. For example, placing a fixture behind a sheet of glass to provide increased safety can result in an optical efficiency loss of up to 10%.
[0008] For LED-based lighting fixtures, the cost of the power supply is an important part of the overall fixture cost. When a large number of LEDs are used to provide the necessary level of illumination, it is advantageous to use a single power supply providing higher voltages and higher power levels, which, in turn, requires more stringent safety standards. In particular, power supplies with a Class 2 power supply rating are limited to 100 watts at a maximum of 60 volts (30 volts if under wet conditions). LED-based lighting fixtures with a large number of LEDs can benefit (both by cost and efficiency) by using a Class 1 power supply, in which both the power and voltage limitations of a Class 2 power supply are exceeded. If power requirements for a lighting fixture are higher than the Class 2 limits, then multiple Class 2 power supplies are required (which can be costly) unless the more stringent safety standards which using a Class 1 supply brings about can be achieved.
[0009] As mentioned above, such more stringent requirements include satisfying the “finger test” under certain fire conditions during which it is possible that lighting module elements such as lenses made of polymeric materials may be removed. For example, in an LED package with a primary lens made of glass and a secondary lens made of polymeric material, ti is necessary to provide enclosure barriers over the entire electrical portion of the module (on which the LED packages are mounted) except over the primary lenses. It is assumed that under these circumstances, the polymeric secondary lenses will be destroyed in the fire, leaving the primary lenses exposed. Also for example, if a single polymeric lens is used in place of both the primary and secondary lenses, then the enclosure barriers must prevent “standard finger” access to the electrical elements under the assumption the single lens has been removed.
[0010] Thus there is a need for improved LED lighting fixtures which can better serve the requirements of general-illumination lighting fixtures and which can provide both the safety and cost-effectiveness which the marketplace requires and/or prefers.
OBJECTS OF THE INVENTION
[0011] It is an object of this invention to provide LED modules which overcome certain problems and shortcomings of the prior art including those referred to above.
[0012] An object of the invention is to provide an improved LED module which achieves the electrical product safety demanded by the marketplace.
[0013] Another object of the invention is to provide an improved LED module which achieves such safety in a cost-effective manner.
[0014] Still another object of the invention is to provide an improved LED module which achieves such electrical product safety under conditions during which no lens remains place over each LED package.
[0015] These and other objects of the invention will be apparent from the following descriptions and the drawings.
SUMMARY OF THE INVENTION
[0016] The invention is LED apparatus which provides electrical safety by satisfying a set of stringent safety standards for the enclosures in which such LED apparatus are encased, and doing so in a cost-effective manner. The LED apparatus of this invention includes a mounting board having a plurality of LED packages thereon with a lens member over each LED package and a safety barrier positioned over the mounting board. The barrier has sufficient thickness for enclosure of electrical elements on the mounting board and includes a plurality of openings each sized to permit light from an LED package to pass therethrough and through a light-transmission portion of the lens member over such LED package to prevent finger-contact of electrical elements on the mounting board when the light-transmission portion is not present.
[0017] In some embodiments of the LED apparatus, the barrier includes a metal layer, which in more preferred embodiments, the barrier also includes an insulating layer positioned between the mounting board and the metal layer. In some of these embodiments, the metal layer and the insulating layer form a laminate.
[0018] In other embodiments of the inventive apparatus, the safety barrier has a layer portion spaced from the mounting board, and in some of these embodiments, the safety barrier has at least one spacing structure supporting the layer portion on the mounting board.
[0019] In preferred embodiments of the invention, the LED apparatus further includes a resilient gasket member having apertures for each of the lens members, and the gasket member yieldingly constrains movement caused by thermal expansion during operation.
[0020] In more preferred embodiments of the inventive LED apparatus, the lens members each include a light-transmission portion and a flange thereabout. The gasket member is positioned against the flanges and includes an inner surface which faces and yieldingly abuts the flanges.
[0021] In highly-preferred embodiments of the invention, the LED apparatus further includes a cover which has openings aligned with the lens members and secures them over the LED packages, pressing the gasket member toward the safety barrier.
[0022] In other highly-preferred embodiments of the inventive LED apparatus, each of the lens members is a secondary lens and each LED package includes a primary lens in alignment with the secondary lens over such LED package. In some of these embodiments, the safety barrier is positioned between the flanges of the secondary lenses and the mounting board.
[0023] Further, this invention includes an LED light fixture which has a plurality of such inventive LED modules.
[0024] The term “LED package” as used herein means an assembly including (a) a base, (b) at least one LED (sometimes referred to as “die”) on the base, and (c), optionally, a primary lens over the die(s). One or more, typically several, LED packages are arranged on a mounting board in forming what is referred to as an “LED module.” One or more LED modules are used as the light source for various innovative lighting fixtures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is an exploded perspective view of one embodiment of the LED lighting apparatus of this invention.
[0026] FIG. 2 is an perspective view of the inventive LED lighting apparatus of FIG. 1 .
[0027] FIG. 3 is a cross-sectional view of the lighting apparatus of FIG. 1 , taken along line 3 - 3 of FIG. 2 .
[0028] FIGS. 4A and 4B are schematic drawings illustrating a safety barrier embodied in a laminate structure.
[0029] FIG. 5 is a simplified view of the inventive apparatus, illustrating the cross-sectional plane CS at which the cross-sectional views of FIGS. 6-10 are taken.
[0030] FIG. 6 is an enlarged detailed cross-sectional view of another embodiment of the LED lighting apparatus of this invention, the apparatus having a safety barrier with a metal layer and an insulating layer.
[0031] FIG. 7 is an enlarged detailed cross-sectional view of yet another embodiment of the LED lighting apparatus of this invention, the apparatus having a safety barrier comprising a single layer.
[0032] FIG. 8 is an enlarged detailed cross-sectional view of yet another embodiment of the LED lighting apparatus of this invention, the apparatus having additional space between the mounting board and the safety barrier.
[0033] FIG. 9 is an enlarged detailed cross-section view of yet another embodiment of the LED lighting apparatus of this invention, the apparatus having a single lens member over each LED package and no optional primary lens in each LED package.
[0034] FIG. 10 is an enlarged detailed cross-sectional view of yet another embodiment of the LED lighting apparatus of this invention, the apparatus having the safety barrier positioned above the flange of each secondary lens member.
[0035] FIG. 11 is an enlarged detailed cross-sectional view of yet another embodiment of the LED lighting apparatus of this invention, the apparatus having the safety barrier positioned above the flange of each lens member, with the LED packages not including the optional primary lens.
[0036] FIG. 12A is a perspective view of a lighting fixture of this invention incorporating a plurality of LED modules.
[0037] FIG. 12B is a bottom view of the lighting fixture of FIG. 12A .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0038] FIGS. 1-3 illustrate an LED apparatus 10 which includes a mounting board 12 with a plurality of LED packages 14 thereon. The LED packages include primary lenses 16 . Secondary lens 20 are positioned over primary lenses 16 , establishing light paths 32 therebetween. Mounting board 12 is connected to a heat sink 18 as shown in FIG. 1 . Apparatus 10 , having such plural LED packages mounted thereon, is also referred to as an LED module 42 as indicate din FIG. 1 . One or more LED modules 42 are used as the light source for various inventive lighting fixtures. One example of such an inventive LED lighting 100 is shown in FIGS. 12A and 12B . LED apparatus 10 includes a resilient member 22 against secondary lenses 20 in positions other than in light path 32 . Resilient member 22 is yieldingly constrains secondary lenses 20 and accommodates the movement of secondary lenses 20 caused by thermal expansion during operation, primarily by that of primary lenses 16 in the embodiment shown in FIG. 1 .
[0039] As shown in FIG. 1 , resilient member 22 , in the form of a gasket layer, is positioned over mounting board 12 and LED packages 14 . Gasket 22 has a plurality of gasket apertures 34 . Resilient member 22 is preferably made from closed-cell silicone which is soft, solid silicone material which is not porous. Resilient member 22 may also be made from any non-porous material which may be tailored for gasket use.
[0040] Secondary lens 20 includes a lens portion (or “light-transmission portion”) 36 which is substantially transparent and a flange 38 portion thereabout. Lens portions 36 are adjacent to flange portions 38 as illustrated in FIG. 1 . Flange portion 38 is planar and has outer and inner surfaces. Resilient member 22 includes an inner surface 44 which faces and yieldingly abuts flange 38 .
[0041] Secondary lenses 20 , as illustrated in FIGS. 1 and 2 , are in close proximity to primary lenses 16 and at least partially abut primary lenses 16 . Preferably separate and discrete secondary lenses 20 are each provided over each LED package 14 and primary lens 16 as seen in FIG. 2 . However, persons skilled in the art will appreciate that plural secondary lenses 20 can be formed together as a single part.
[0042] FIGS. 1 and 2 illustrate that cover 26 secures resilient member 22 with respect to secondary lens 20 , primary lens 16 and LED package 14 . Cover 26 has openings 28 aligned with the light paths 32 as shown in FIGS. 1-3 . Resilient member 22 is sandwiched between cover 26 and flanges 38 of secondary lenses 20 , causing outer surface of the flange portion 38 to abut the facing resilient member 22 inner surface 44 . This action forms a sandwich-like structure in which cover 26 urges resilient member 22 against flange portions 38 as illustrated in FIG. 2 .
[0043] Thermal expansion of primary lenses 16 results in abutment of lenses and displacement of secondary lenses 20 . Resilient member 22 permits the displacement while holding secondary lenses 20 in place over primary lenses 16 .
[0044] In certain embodiments a shield member 24 , in the form of a layer, is positioned over the resilient member layer 22 as illustrated in FIG. 1 .
[0045] LED apparatus 10 includes a metal layer 30 , preferably of aluminum. Layer 30 is positioned preferably immediately over the LED packages and includes a plurality of openings each sized to receive primary lens 16 . Layer 30 is sandwiched between mounting board 12 and secondary lens 20 as seen in FIG. 1 . Metal layer 30 is herein referred to as safety barrier 30 , the details of which are described further below.
[0046] LED apparatus 10 can include only one LED package 14 on a mounting board 12 with primary lens 16 , a corresponding secondary lens 20 and a resilient member layer 22 against the secondary lens 20 .
[0047] FIGS. 4A and 4B illustrate a layered structure of safety barrier 30 ; barrier 30 includes a metal layer 30 m and an insulating layer 30 i. Layers 30 m and 30 i may be laminated together, forming laminate 46 as indicated. Layers 30 m and 30 i may also be separate layers. Under certain UL standards, metal layer 30 m is a made of a flat, unreinforced aluminum sheet having a thickness of at least 0.016 inches. The minimum thickness requirements of layer 30 depends on the structure and composition of metal layer 30 as set forth in the specific UL the standards referred to above. If safety barrier 30 is a laminate 46 , the different layers of laminate 46 may or may not have the same width and length dimensions. FIGS. 4A and 4B illustrate laminate 46 with layers 30 m and 30 i having such different width and length.
[0048] Insulating layer 30 i serves to electrically isolate layer 30 m from the electrical elements on mounting board 12 . In some embodiments, these electrical elements may be isolated from layer 30 m by a conformal coating on mounting board 12 . Such conformal coating may be any of a number of available coatings, such as acrylic coating 1B73 manufactured by the HumiSeal Division of Chase Specialty Coatings of Pittsburgh, Pa.
[0049] Safety barrier 30 may also be made of a single layer of polymeric material having minimum thickness as set forth by the UL standards. Acceptable polymeric materials include BASF 130FR (polyethylene terephthalate with glass fiver reinforcement) supplied by the Engineering Plastics Division of BASF Corporation in Wyandotte, Mich. The layer has a minimum thickness of 0.028 inches. Other acceptable polymeric materials must satisfy certain detailed specifications related to material behavior such as hot-wire ignition, horizontal burning, and high-current arcing resistance, all of which are set forth in the UL standards referred to above.
[0050] LED module 46 may include safety barrier 30 which is positioned in several ways relative to mounting board 12 and secondary lenses 20 . When LED packages 14 do not include optional primary lens 16 , secondary lenses 20 are herein referred to as “lens members 50 .”
[0051] FIGS. 6-11 illustrate several such configurations of safety barrier 30 in LED module 46 . FIG. 5 illustrates cross-sectional plane CS-CS which applies to each of FIGS. 6-11 .
[0052] FIG. 6 is an enlarged detailed cross-sectional view of one embodiment of LED module 46 with safety barrier 30 comprising metal layer 30 m and insulating layer 30 i.
[0053] FIG. 7 is an enlarged detailed cross-sectional view of another embodiment of LED module 46 with safety barrier 30 comprising metal layer 30 m.
[0054] FIG. 8 is an enlarged detailed cross-sectional view of another embodiment of LED module 46 in which there is additional space 52 provided between mounting board 12 and safety barrier 30 . Spacing structures 54 are provided as part of the bases of LED packages 14 but may also be configured as separate elements. FIG. 9 illustrates a similar embodiment in which LED packages 14 do not include optional primary lenses 16 . LED module 46 includes lens members 50 each having light-transmission portions 50 p and flanges 50 f.
[0055] FIGS. 6-9 , LED module 46 has safety barrier 30 positioned below secondary lenses 20 or lens members 50 . FIGS. 10 and 11 illustrate enlarged detailed cross-sectional view of additional embodiments of LED module 46 in which safety barrier 30 is positioned above flanges 38 of each secondary lens 20 ( FIG. 10 ) and above flanges 50 f of lens members 50 ( FIG. 11 ). In both such embodiments, additional space 52 from mounting board 12 is provided.
[0056] FIG. 11 is an enlarged detailed cross-sectional view of yet another embodiment of the LED lighting apparatus of this invention, the apparatus having the safety barrier positioned above the flange of each lens member, with the LED packages not including the optional primary lens.
[0057] In some forms of such highly preferred embodiments with the plurality of LED packages on the mounting board, it is preferred to use a Flame Resistant 4 (“FR4”) board formed by a conductor layer and an insulator layers. The conductor layer may be made of any suitable conductive material, preferably copper or aluminum. It is most highly preferred that such mounting board include, for each LED package thereon, a plurality of channels (“thermal vias”) extending through the mounting board at positions beneath the package, such channels having therein conductive material and/or an opening to facilitate transfer of heat through the board. The thermal vias provide an isolated thermal path for each LED package.
[0058] In the forms of the present invention using the FR4 mounting board with thermal vias, it is most highly preferred that each LED package 14 is constructed to have its cathode terminal electrically neutral from the thermal path, thus avoiding shortage of other LED packages 14 on the board.
[0059] A wide variety of materials are available for the various parts discussed and illustrated herein. While the principles of this apparatus have been described in connection with specific embodiments, it should b understood clearly that these descriptions are made only by way of example and are not intended to limit the scope of the invention. | An LED apparatus including (a) a mounting board, (b) a plurality of LED packages thereon, (c) a lens member over each LED package, and (d) a safety barrier positioned over the mounting board, the barrier having sufficient thickness for enclosure of electrical elements on the mounting board and including a plurality of openings each sized to permit light from an LED package to pass therethrough and through a light-transmission portion of the lens member over such LED package to prevent finger-contact of electrical elements on the mounting board when the light-transmission portion is not present. | 5 |
FIELD OF THE INVENTION
This invention relates to a process and equipment to obtain efficient combustion of gas by means of an atmospheric burner.
BACKGROUND OF THE PRIOR ART
Burners for gaseous fuels are generally divided into fan-assisted burners and atmospheric burners.
In general, in using atmospheric burners an imperfect combustion may occur, with harmful emissions of carbon monoxide and nitric oxides which can cause atmospheric pollution.
EP-A-0009831 refers to an atmospheric burner (POLIDORO) in which the perforated surface of a cylindrical burner diffuser consists of transverse groups comprising subgroups of slots spaced out 2 mm in a transverse direction, with pilot holes at each end. Each sub-group consists of a densely-packed series of parallel transverse slot with center distance of only 1.2 mm, in order to obtain a "single flame front" from each group, i.e., a big vertical flame, with the aim of reducing burner noise and providing high thermal power.
Also known, per EP-A-0217470, is an atmospheric burner (NEFIT) in which the primary air-gas mixture, drawn in through a Venturi tube, is then directed downwards at the outlet of this tube. The flow is then fed back, up at the side with turbulence reduced to a minimum, to feed the slots in a perforated diffuser. The purpose is to obtain combustion which is as uniform as possible, "without any disturbing noise being produced". In fact (see figures) the surfaces of the diffuser of the body present groups of slots similar to EP-A-0009831.
Also, DE-A-2132968 (FOGLIANI, PANINI and VECCHI), teaches covering of an atmospheric burner equipped with small groups of slots arranged close together and/or rows of holes, aligned transversely, with the relative pilot holes at the ends. The burner body has a polygonal cross-section, in particular featuring a diffuser with two angled sides which, as shown in FIG. 2, have slots across the joint between these sides, creating a double-horned flame on a transverse plane of the diffuser itself. The flame in this burner is more stable and noise level is reduced.
However, prior art does not envisage the reduction of harmful emissions of nitrogen oxides and carbon monoxide. This may be justified by the fact it was considered impossible to solve the problem of reducing pollutant emissions from atmospheric burners simply by acting on the combustion method or on the proportioning of the burner itself.
SUMMARY OF THE DISCLOSURE
The object of this invention is to provide a process and an atmospheric burner to obtain gas combustion having very low levels of harmful emissions.
This and related objects are realized by providing a combustion process, in a novel atmospheric burner.
The novel process involves the steps of:
aspiring, by means of a Venturi tube, an amount of primary air equal to at least 80% of the air stoichiometrically required for combustion;
enabling a flow of secondary air to contact the gas-primary air mixture immediately after ignition to bring the total air involved to a level above the stoichiometric value; and
starting and completing combustion within the thickness of a blade of a wing-shaped flame providing a luminous emission of violet color within the visible spectrum, at a wavelength below 0.42 micron, from the combustion of natural gases.
BRIEF DESCRIPTION OF THE DRAWING
The present invention is described on the basis of some exemplary embodiments illustrated in the attached drawings, in which:
FIG. 1 shows a longitudinal sectional view of a burner;
FIG. 2 shows a cross-sectional view along the line A--A in FIG. 1;
FIG. 3a and 3b show of possible variations in the slot groups;
FIG. 4 shows a view of a possible arrangement of the slot groups;
FIG. 5 shows a variant of FIG. 4;
FIG. 6 shows a plan view of the upper part of a burner;
FIG. 7 shows a plan view of a variant of the burner in FIG. 6;
FIGS. 8 and 9 show variants of FIG. 2;
FIGS. 10a, 10b, 10c and 10d show views of possible variants of the sub-groups of holes in which the mutual positions of a sub-group of slots and a sub-group of holes is shown.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The bladed flame is a new phenomenon. In reality, the bladed flame is not vertical, nor big or compact, but divergent small and thin.
This new process reduces harmful emissions to extremely low levels, even in combustion chambers whose thermal power, in reference to their base area, is at least 40 W/cm 2 . Even if it could be known, in general terms, that it was possible to supply the burner with a quantity of primary air exceeding 80% of the stoichiometric air value, given the availability of secondary air to bring the total above the stoichiometric parameter, however the burner bodies produced according to the prior art were not of a type which would function satisfactorily in these conditions because of the overheating of the thin sheet metal of which the burner's diffuser is constructed. Moreover, the prior art did not allow the construction of burners with low harmful gas emissions for combustion chambers with thermal power exceeding 40 W/cm 2 of base area. In addition, if a thermal power rating of 1.1 kW/cm 2 of burner's diffuser mixture outlet area was exceeded, it would then become impossible to draw in a quantity of primary air exceeding 80% of the stoichiometric value. The values of thermal power (equal to specific combustion capacity) were generally 1.3-1.7 kW/cm 2 , which allowed the risk of overheating to be eliminated.
The mixture in the prior art devices travelled at high speed inside the burner, leading to high load losses and making it impossible to draw in large quantities of primary air.
The gas burner implementing the present invention with the burner diffuser made of thin sheet metal, e.g. of thickness around 0.5 mm, is equipped with a Venturi tube having a parabolic intake, with all parts proportioned aerodynamically to allow infeed with primary air in a proportion of over 80% of the stoichiometric requirement. Its specifications are: thermal power not exceeding 1.1 kW/cm 2 of area of the ports for the outflow of the mixture from the burner diffuser, air-gas mixture average speed not exceeding 4.5 m/s. Preferably, the air-gas mixture average speed is 4 m/s in the neck of the Venturi tube and, between the tube and the diffuser, has an average speed not exceeding 2.5 m/s and is preferably 2 m/s.
The slots in the burner diffuser are arranged in aligned transverse groups, each group being appropriately subdivided longitudinally into two subgroups of slots lying not very close together. Each group thereby generates a double bladed flame which may be characterized as being generally of a butterfly-wing shape, having its center line perpendicular to the longitudinal axis of the burner and its lower vertex on the stretch of burner between the two sub-groups of slots.
This specially shaped flame allows secondary air to come into contact with it on all sides over a wide surface area, providing complete combustion in the bladed flame from the very first moment. By contrast, in conventional flames there are no less than three zones in which combustion gradually occurs: an internal low-temperature area (blue-green in colour) where the air-fuel mixture is heated to the ignition temperature; an intermediate zone (blue in colour) where incomplete combustion of the mixture occurs, leaving residues of carbon monoxide and hydrogen; and a single external zone which is violet in colour, where the gases not burnt in the intermediate zone undergo combustion as they come into contact with the secondary air.
The groups of slots are arranged in rows perpendicular to the burner axis. The distance between each group of slots in any one row is equivalent to at least 65% of the length of the longest slot. The axial distance between two rows of slots is at least nd/2, where d is the axial length of the group and n is the number of groups in a row, or the number of groups in two adjacent rows when the groups are staggered to form a chess-board type lay-out.
The number of slots in any one group must be between 2 and 5. Moreover, the slots may be arranged so that the outline of the flame halo corresponds to the exposed profile of the heat-exchanger. In addition to providing excellent heat-exchange conditions, this reduces CO emissions to a minimum. The stretch between the to sub-groups of slots in each group must be between 2.4 and 2.8 mm, and this ensure the generation of stable bladed flames.
When burning natural gases, the application of this method in a burner according to this invention generates bladed flames of violet colour: measurements made have given wavelength values below 0.42 micron, which is within the violet field of the visible spectrum.
In the case of atmospheric burners having thin sheet-metal diffusers of the type according to this invention, the bladed flame is the only shape providing minimal emissions of NO x and CO. This, therefore, represents the achievement of the object of this invention.
The bladed flame, when it is violet in colour for combustion of natural gases, is the phenomenon which indicates the effect of a new, highly advantageous combustion method in the burner according to the invention.
The prior art does not provide atmospheric burners with bladed flames; quite the contrary, in order to increase thermal power and flame stability, the known burners incorporate features intended to group the flames together into solid vertical formations as far as possible, to provide the so-called "single front". POLIDORO and FOGLIANI, PANINI and VECCHI fall into this category; NEFIT, while not discussing the question, however shows a similar slot lay-out. This, in fact, reduces the flame-secondary air contact surface considerably.
On the other hand, the burner which implements the method described in the invention is designed to increase the flame-secondary air contact surface to the greatest possible extent. It generates thin individual flames, each with a large surface area beginning from the stretch between the two sub-groups, with a couple of divergent wings which remain completely separate.
The great advantage in relation to the prior art is the achievement of high thermal power without harmful emissions, and without overheating of the burner.
In fact, the burners according to the prior art, provided with groups or sub-groups of slots, with the body designed in such a manner to allow an intake of primary air certainly below 80%, did not generate bladed flames, producing harmful emission.
If the air intake is not coaxial to the Venturi tube, the latter preferably should be slightly bent with respect to the injector axis in order to obtain concentricity with the diverted mixture flow.
In some cases, in order to facilitate the backflow of the mixture coming out from the Venturi tube, louvers on the latter are kept open to obtain a gradual backflow. In particular, these louvers are open on the Venturi tube in zones far from the flame ports of the burner diffuser. Preferably, the upper part of the burner diffuser, where the slots in small groups are located, has a bending radius that is larger than the radius at a lower part.
Preferably, the number of slots in each group of a row decreases towards the burner's vertical symmetry plane. Moreover the slots can be parallel to each other. In particular, small groups are created by slots of different lengths, outward decreasing. For example, the area occupied by a small group can be a rhombus. This is favorable in general, and particularly so with a chess-board configuration.
So that the halo of the bladed flame may follow the shape of the heat exchanger, the rows made up of small groups are longitudinally located at a variable distance. It is also possible to vary the distance among the groups of a single row. Moreover each group can have a different port area.
The flame lift preventing holes are numerous and at a certain mutual separate according to need. In particular, and they may be placed at the apexes of a square and/or equilateral triangle at a distance of 1.3 to 1.5 mm, preferably 1.4 mm.
FIGS. 1 and 2 show a burner consisting of a burner body 1 containing inside it a Venturi tube 2, which has a smooth, funnel-shaped mouthpiece 3 with a parabolic form. The Venturi tube 2 leaves a free area (hatched in FIGS. 2, 8 and 9) inside the burner body 1, such as to give an average air/gas mixture speed not exceeding 2 m/sec. The upper part of the burner body has holes out of which comes a series of small flames F. The section of the burner body 1 where the holes are located is convex, with a bending radius greater than the bending radius of the lower part. See FIG. 2. The holes are formed as small groups 5 of slots 7, each consisting of two sub-groups 4 forming a flame F with two wings (FIG. 7). The small groups 5 are arranged in rows 8 perpendicular to the burner axis 10. Flame lift preventing holes 6 are provided between the various small groups 5 (FIGS. 10a to 10d). The rows of small groups can be arranged alongside one another with the small groups lined up as shown in FIG. 4, the distance "a" between the small groups 5 in this case being at least 0.65b, where "b" is the maximum length of the slots in a group, while the distance "c" between the rows is at least nd/2, where "n" is the number of small groups making up the row and "d" is the width of the totality of slots 7 forming a small group 5. Alternatively the rows 8 of small groups 5 can be offset with respect of rows 8,, as shown in FIG. 5. with this chess-board configuration, the distances "a" and "c" must comply with the conditions described earlier; "n" in this case is the sum of the small groups in the two adjacent, offset rows 8 and 8'. The distance between the sub-groups 4 of each small group 5 is 2.4-2.8 mm.
Each sub-group may consist of slots 7, equal in length and parallel (FIGS. 3a, 4 and 6); the number of slots can be two, three or four. Alternatively, the sub-group (FIG. 3b) may consist of slots 7' of different lengths (decreasing from the center of the group outward) so that the area occupied by each group corresponds to a rhombus. In this case the number of slots making up the sub-group may be two, three, four or a maximum of five.
The flame lift preventing holes 6 can be arranged as illustrated in FIGS. 10a to 10d, i.e., at the apexes of a square and/or an ideal equilateral triangle, their center distance I being from 1.3 to 1.5 mm., preferably 1.4 mm.
Lastly, in the burner shown in FIG. 7 the rows of small groups 5 are separated at varying distances D1, D2, D3, D4, D5, D6.
This makes it possible to adapt the flame halo 11 to follow the shape of the heat exchanger. A similar adaptation is achieved transversely to the burner by varying the number of slots in each small group (FIG. 9) or spacing out the small groups of a single row.
Louvers 12 are provided far from small groups 5 in order to distribute the backflow along the burner body 1. The particular shape and colour of the flame makes it possible to achieve combustion of a high capacity of gas--40 W per square cm of combustion chamber measured in a plan view--with a very low level of harmful emissions.
In this disclosure, there are shown and described only the preferred embodiments of the invention, but, as aforementioned, it is to be understood that the invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein. | The process obtains a plurality of small flames which become violet when combusting natural gas. In particular the amount of primary air induced is at least 80% of the air stoichiometrically required for combustion; the secondary air laps all sides of each singly small flame arising from the small group of slots on the burner body, in the area where each flame leaves the surface of the burner body so as to swell it making its width at least as big as its height and/or alternatively the contact surface between each flame and the secondary air is increased right from the first steps in combustion, so that each small group creates a small flame with two divergent bladed wings, similar to "butterfly wings." | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based on and claims the benefit of priority to Korean Patent Application No. 10-2015-0050396, filed on Apr. 9, 2015 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a method for controlling an advanced emergency braking system depending on a load change of a vehicle, and more particularly, to a technology capable of minimizing an influence of a load in an advanced emergency braking system by controlling a braking control factor depending on the load of a vehicle.
BACKGROUND
[0003] Generally, a vehicle is provided with a braking device serving to decelerate or stop the vehicle during being driven.
[0004] The braking device is configured to include a booster doubling a foot effort of a brake pedal using vacuum pressure (engine suction pressure) generated by power of an engine, a master cylinder generating brake oil pressure in a brake circuit depending on the pressure doubled by the booster, and a wheel cylinder decreasing a rotation speed of a wheel or stopping the wheel by the brake oil pressure. Here, the booster is generally classified into a vacuum type booster using negative pressure of an engine intake manifold and an air type boost using pressure provided from a compressor driven by the engine.
[0005] Since the braking device starts the braking of the vehicle after a driver performs an operation of stepping on the brake pedal regardless of a configuration of the braking device, there is a limitation in a viewpoint of the driver having a limitation in a reaction time.
[0006] An automatic emergency brake system (AEBS) to complement this limitation includes a radar to activate emergency braking regardless of whether or not the driver performs braking based on a relative speed and a spaced distance to an object, determined by the radar, in the case in which the object appears in front of the vehicle that is being driven.
[0007] The AEBS has system performance determined depending on various driving conditions and is set so as to correspond to the most general driving condition.
SUMMARY
[0008] The present disclosure has been made to solve the above-mentioned problems occurring in the prior art while advantages achieved by the prior art are maintained intact.
[0009] An aspect of the present disclosure provides a method for controlling an automatic emergency braking system capable of optimizing a control of the automatic emergency braking system depending on a load of a vehicle by classifying the load of the vehicle into load groups depending on the load of the vehicle and controlling control factors including a braking command point in time corresponding to a time to collision (TTC) and a deceleration depending on the load groups.
[0010] Objects of the present disclosure are not limited to the above-mentioned object, and other objects and advantages of the present disclosure that are not mentioned may be understood by the following description and will be more clearly appreciated by exemplary embodiments of the present disclosure. In addition, it may be easily appreciated that objects and advantages of the present disclosure may be realized by means mentioned in the claims and a combination thereof.
[0011] According to an exemplary embodiment of the present disclosure, a method for controlling an advanced emergency braking system depending on a load change of a vehicle includes: calculating a load of the vehicle by receiving braking information from an engine controller; classifying the calculated load of the vehicle into a load group among a plurality of load groups; and controlling a control factor of the advanced emergency braking system depending on the classified load group.
[0012] The braking information may include a revolution per minute (RPM) of the vehicle, an engine torque, or an acceleration of the vehicle.
[0013] The plurality of load groups may include a first group, a second group, and a third group, and the control factors of the advanced emergency braking system corresponding to the plurality of load groups may be different from one another.
[0014] The controlling of the control factor of the advanced emergency braking system may include controlling a braking command point in time corresponding to a time to collision and a deceleration.
[0015] In a process of controlling the control factor of the advanced emergency braking system depending on the first group, the braking command point in time corresponding to the time to collision and the deceleration may be controlled to be preset values.
[0016] In a process of controlling the control factor of the advanced emergency braking system depending on the second group, the braking command point in time corresponding to the time to collision and the deceleration may be controlled to be decreased as compared with the braking command point in time and the deceleration in the first group.
[0017] In a process of controlling the control factor of the advanced emergency braking system depending on the third group, the braking command point in time corresponding to the time to collision and the deceleration may be controlled to be decreased as compared with the braking command point in time and the deceleration in the second group.
[0018] According to an exemplary embodiment of the present disclosure, a method for controlling an advanced emergency braking system depending on a load change of a vehicle, includes: calculating a load of the vehicle based on braking information from an engine controller; determining a control factor of the advanced emergency braking system based on the calculated load of the vehicle; and controlling the advanced emergency braking system in accordance with the determined control factor.
[0019] The control factor may include a braking command point in time corresponding to a time to collision and a deceleration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The above and other objects, features and advantages of the present disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings.
[0021] FIG. 1 is a flow chart for describing a method for controlling an advanced emergency braking system depending on a load change of a vehicle according to an exemplary embodiment of the present disclosure.
[0022] FIG. 2 is a view for describing a distance secured from a front vehicle or a preceding vehicle after emergency braking depending on a control factor for each load group of the advanced emergency braking system according to the exemplary embodiment of the present disclosure.
[0023] FIG. 3 is a graph for describing a braking command point in time corresponding to a time to collision (TTC) and a distance secured from a front vehicle or a preceding vehicle after emergency braking in the advanced emergency braking system depending on a load change of a vehicle according to the exemplary embodiment of the present disclosure.
[0024] FIG. 4 is a graph for describing a load of a vehicle and a distance secured from a front vehicle or a preceding vehicle after emergency braking in the advanced emergency braking system depending on a load change of a vehicle according to the exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION
[0025] The above-mentioned objects, features, and advantages will become more obvious from the following description described below in detail with reference to the accompanying drawings. Therefore, those skilled in the art to which the present disclosure pertains may easily practice a technical idea of the present disclosure. Further, in describing the present disclosure, in the case in which it is judged that a detailed description of a well-known technology associated with the present disclosure may unnecessarily make the gist of the present disclosure unclear, it will be omitted. Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.
[0026] FIG. 1 is a flow chart for describing a method for controlling an advanced emergency braking system depending on a load change of a vehicle according to an exemplary embodiment of the present disclosure.
[0027] Referring to FIG. 1 , a controller of the advanced emergency braking system calculates a load of a vehicle using a revolution per minute (RPM) of the vehicle, an engine torque, an acceleration of the vehicle, or the like, received from an engine control unit (ECU) (S 100 ).
[0028] Here, the load or a weight of the vehicle may be calculated by dividing a value obtained by subtracting a friction torque from an engine output torque transmitted from an engine by a dynamic load radius and dividing an output value of the division by an acceleration value in a longitudinal direction measured from an acceleration sensor.
[0029] In addition, since the controller of the advanced emergency braking system, which is a requisite component, is a general component according to the related art, a detailed description therefor will be omitted.
[0030] Next, the controller of the advanced emergency braking system classifies the calculated load of the vehicle into each load group (S 110 ).
[0031] In detail, depending on the load of the vehicle, a group (that is, a loaded group) of vehicles having the largest load is defined as a first group (S 120 ), a group (that is, a partial loaded group) of vehicles having a medium load is defined as a second group (S 140 ), and a group (that is, an unloaded group) of vehicles having the smallest load is defined as a third group (S 160 ). That is, the group of the vehicles having the largest load means vehicles having a maximum load among loads preset in the advanced emergency braking system, and the group of the vehicles having the smallest load means vehicles having a minimum load among the loads preset in the advanced emergency braking system. According to another embodiment of the present disclosure, the load of the vehicle may be classified into two load groups or four or more load groups. Here, the vehicle means vehicle in which only a weight of a vehicle body and a weight of a driver are present except for a weight of an article loaded in the vehicle.
[0032] For example, it may be assumed that a weight of the vehicle in the group of the vehicles having the largest load is 6 tons, which is the sum of a weight of the vehicle and a weight of a person getting in the vehicle or an article loaded in the vehicle, it may be assumed that a weight of the vehicle in the group of the vehicles having the medium load is 4.5 tons, which is the sum of a weight of the vehicle and a weight of a person getting in the vehicle or an article loaded in the vehicle, and it may be assumed that a weight of the vehicle in the group of the vehicles having the smallest load is 3 tons, which is the sum of a weight of the vehicle and a weight of a person getting in the vehicle or an article loaded in the vehicle. Here, set ranges of loads or weights of the vehicles corresponding to each group may be controlled by of the controller of the advanced emergency braking system.
[0033] Next, when the load group of the vehicles, determined by the controller, has the largest load (first group) (S 120 ), the controller of the advanced emergency braking system of the vehicle controls a braking command point in time (time) corresponding to a time to collision (TTC) and a deceleration (g) among control factors for controlling braking of the vehicle to be preset values (S 130 ). Here, when advanced emergency braking of the vehicle is first controlled to classify the load of the vehicle into the load group, a control factor for controlling the braking of the vehicle may be controlled in a state in which the load of the vehicle is set to the group of the vehicles having the largest load. In the case of the group of the vehicles having the largest load, a distance secured between an own vehicle and a front vehicle or a preceding vehicle is not changed from a preset secured distance.
[0034] Next, when the load group of the vehicles, determined by the controller, has the medium load (second group) (S 140 ), the controller of the advanced emergency braking system may decrease a braking command point in time corresponding to a time to collision and a deceleration among the control factors for controlling the braking of the vehicle as compared with the braking command point in time corresponding to the time to collision and the deceleration in the group of the vehicles having the largest load (S 150 ).
[0035] In detail, in case of the group of the vehicles having the medium load, the controller of the advanced emergency braking system may decrease the braking command point in time corresponding to the time to collision by X and decrease the deceleration by Y.
[0036] For example, the controller of the advanced emergency braking system may decrease the braking command point in time corresponding to the time to collision by 0.1 s and decrease the deceleration by 1 m/s 2 . Here, the controller of the advanced emergency braking system may variously control a decrease amount of the braking command point in time corresponding to the time to collision and a decrease amount of the deceleration.
[0037] Next, when the load group of the vehicles, determined by the controller, has the smallest load (third group) (S 160 ), the controller of the advanced emergency braking system may further decrease a braking command point in time corresponding to a time to collision and a deceleration among the control factors for controlling the braking of the vehicle as compared with the braking command point in time corresponding to the time to collision and the deceleration in the group of the vehicles having the medium load (S 170 ).
[0038] In detail, in case of the group of the vehicles having the smallest load, the controller of the advanced emergency braking system may decrease the braking command point in time corresponding to the time to collision by 2X and decrease the deceleration by 2Y. For example, the controller of the advanced emergency braking system may decrease the braking command point in time corresponding to the time to collision by 0.2 s and decrease the deceleration by 2 m/s 2 . Here, the controller of the advanced emergency braking system may variously control a decrease amount of the braking command point in time corresponding to the time to collision and a decrease amount of the deceleration.
[0039] FIG. 2 is a view for describing a distance secured from a front vehicle or a preceding vehicle after emergency braking depending on a control factor for each load group of the advanced emergency braking system depending on a load change of a vehicle according to the exemplary embodiment of the present disclosure.
[0040] Referring to FIG. 2 , in the case of the group of the vehicles having the largest load, the controller of the advanced emergency braking system controls the braking command point in time corresponding to the time to collision and the deceleration among the control factors for controlling the braking of the vehicle to be the preset values.
[0041] In addition, in the case of the group of the vehicles having the largest load, a distance secured between an own vehicle and a front vehicle or a preceding vehicle after emergency braking is not changed from a preset braking distance.
[0042] In the case of the group of the vehicles having the medium load, the controller of the advanced emergency braking system may decrease the braking command point in time corresponding to the time to collision and the deceleration among the control factors for controlling the braking of the vehicle as compared with the braking command point in time corresponding to the time to collision and the deceleration in the group of the vehicles having the largest load.
[0043] That is, in the case of the group of the vehicles having the medium load, when the control factors for controlling the braking of the vehicle are not controlled by the controller, a distance secured from a front vehicle or a preceding vehicle after emergency braking is further increased from a preset braking distance by Z. For example, the distance Z secured from the front vehicle or the preceding vehicle after the emergency braking may be further increased by 0.6 m. Therefore, after the emergency braking, the own vehicle may be controlled so that the distance secured between the own vehicle and the front vehicle is the same as in the case of the group of the vehicles having the largest load using the control factors for controlling the braking of the vehicle by the increased distance to the front vehicle.
[0044] In the case of the group of the vehicles having the smallest load, the controller of the advanced emergency braking system may further decrease the braking command point in time corresponding to the time to collision and the deceleration among the control factors for controlling the braking of the vehicle as compared with the braking command point in time corresponding to the time to collision and the deceleration in the group of the vehicles having the middle load.
[0045] In addition, in the case of the group of the vehicles having the smallest load, a distance secured from a front vehicle or a preceding vehicle after emergency braking is further increased by 2Z as compared with the distance secured from the front vehicle or the preceding vehicle after the emergency braking in the case of the group of the vehicles having the medium load. For example, the distance 2Z secured from the front vehicle or the preceding vehicle after the emergency braking may be further increased by 1.2 m. Therefore, after the emergency braking, the own vehicle may be controlled so that the distance secured between the own vehicle and the front vehicle is the same as in the case of the group of the vehicles having the medium load using the control factors for controlling the braking of the vehicle by the increased distance to the front vehicle.
[0046] FIG. 3 is a graph for describing a braking command point in time corresponding to a time to collision (TTC) and a distance secured from a front vehicle or a preceding vehicle after emergency braking in the advanced emergency braking system according to the exemplary embodiment of the present disclosure.
[0047] Referring to FIG. 3 , as a result of comparison between the braking command point in time corresponding to the time to collision and the distance secured between the own vehicle and the front vehicle or the preceding vehicle depending on the load of the vehicle, the distance secured between the own vehicle and the front vehicle is increased as the braking command point in time corresponding to the time to collision becomes fast.
[0048] In addition, the controller of the advanced emergency braking system may instruct the braking command point in time corresponding to the time to collision to become fast as the load of the vehicle is increased.
[0049] FIG. 4 is a graph for describing a load of a vehicle and a distance secured from a front vehicle or a preceding vehicle after emergency braking in the advanced emergency braking system depending on a load change of a vehicle according to the exemplary embodiment of the present disclosure.
[0050] Referring to FIG. 4 , it is illustrated that the distance secured between the own vehicle and the front vehicle is increased as the load of the vehicle is decreased. That is, it may be appreciated that the distance secured between the own vehicle and the front vehicle or the preceding vehicle is increased as the load of the vehicle is decreased in both of groups A and B of different kinds of vehicles.
[0051] As described above, the present technology is a technology capable of minimizing an influence depending on the load of the vehicle in the advanced emergency braking system depending on a load change of a vehicle according to the exemplary embodiment at the time of the emergency braking.
[0052] In addition, the present technology is a technology capable of preventing unnecessary braking generated depending on the load of the vehicle and controlling the control factors depending on the load of the vehicle at the time of the emergency braking for each load group, thereby optimizing a control of the advanced emergency braking system.
[0053] Hereinabove, although the present disclosure has been described with reference to restrictive configurations and the accompanying drawings, the present disclosure is not limited thereto, but may be variously modified and altered by those skilled in the art to which the present disclosure pertains without departing from the spirit of the present disclosure and equivalents to the following claims. | A method for controlling an automatic emergency braking system is able to optimize a control of the automatic emergency braking system depending on a load of a vehicle by classifying the load of the vehicle into load groups depending on the load of the vehicle and by controlling control factors including a braking command point in time corresponding to a time to collision (TTC) and a deceleration depending on the load groups. The method for controlling an advanced emergency braking system depending on a load change of a vehicle includes: calculating a load of the vehicle by receiving braking information from an engine controller; classifying the calculated load of the vehicle into a load group among a plurality of load groups; and controlling a control factor of the advanced emergency braking system depending on the classified load group. | 1 |
FIELD OF THE INVENTION
The present invention is generally concerned with plasma devices, more particularly with the confinement, stabilization and control of plasma in fusion devices by means of plasma relaxation effects and global topological magnetic constraint for the production of particular magnetic configurations with region of toroidal plasma and divertor, most particularly with open-ended vessel systems.
BACKGROUND OF THE INVENTION
Toroidal confinement plasma devices are devices in which a toroidal plasma is created in the space of a vessel which may be topologically that of a torus or of a cylinder, usually axisymmetric, and is confined therein by appropriate confining magnetic fields. Toroidal plasma devices are useful in the generation, confinement and heating, and study and analysis of plasmas. In particular, these devices are useful for reacting deuterium and tritium, deuterium and deuterium or other nuclear fusible mixtures, with the production of high energy neutrons and energetic charged particles as products of the nuclear fusion reactions.
At large, the problems in nuclear fusion devices are heating a dense enough plasma to a high enough temperature to enable the desired reactions to occur and confining the heated plasma for a time long enough to release energy in excess of that required to heat the plasma to reaction temperature and to maintain it thereat. The present invention is directed to the magnetic confinement of such plasma and finds particular utility in devices of this kind and their applications, including experimental devices and their use in experimentation and investigation related to plasma devices with toroidal discharges.
Several toroidal confinement plasma devices have been suggested and built. Most closely related to the present invention are: tokamak devices including divertor tokamaks, z-pinch devices including Reversed-Field-Pinch (RFP) devices; and spheromak devices, including those produced or sustained by z-pinch. In devices of this type, gas is confined in a toroidal region of the vessel and is heated to form a plasma which is generally held away from the walls of the vessel by appropriate magnetic fields. The topology of the vessel in such devices may be either toroidal (tokamak, RFP) or cylindrical (spheromaks), and these devices are generally axisymmetric. A topological torus/cylinder is any geometric solid figure that can be produced by an imaginary elastic deformation of an initial axisymmetric torus/cylinder. An axisymmetric torus has a hole, i.e. a region outside the toroidal volume, in the vicinity the rotational axis (major axis), whereas a cylinder is simply-connected, implying there is no such hole. An axisymmetric device is one in which all quantities are invariant to rotation about the rotational axis. A necessary condition for the magnetic confinement of plasma in a toroidal region is that there exist sets of nested toroidally closed magnetic surfaces in this region. A magnetic surface is defined as a mathematical surface, everywhere on which the magnetic field is tangential thereto. The magnetic surface enclosing zero volume in the center of a nest is called an elliptic magnetic axis. From the devices with a toroidal confinement region, those with toroidal vessel, called toroidal devices, ideally have only nested closed magnetic surfaces. Devices with open-ended vessel have, in addition, open magnetic surfaces which intersect the two end-surfaces of the topologically cylindrical vessel, in which case they have at least one separatrix, that is one magnetic surface separating the region of open magnetic surfaces from that of closed magnetic surfaces.
However, even for toroidal devices, it is sometimes found convenient to add a region with open magnetic surfaces, so as to produce a separatrix, having the role of an open-ended divertor. A divertor is a separatrix which establishes a transition between the set of magnetic nested toroidal surfaces and magnetic surfaces directed to the boundary. A divertor may have a profound influence on a plasma confinement device. Not only does it have as a primary effect, the isolation of the toroidal confinement plasma region from the surrounding region of the vessel by contributing to redirecting to the boundary impurities scraped off the wall, but it may also lead to an improved confinement state. This is illustrated by the so-called H-mode found in tokamaks, which is a regime of enhanced confinement, and requires almost always a divertor to be established. The presence of a divertor is also beneficial for ash-removal.
In some toroidal plasma confinement devices, the confining magnetic field includes magnetic field components produced by currents flowing through the confined plasma itself. However, in some of these devices, such as the tokamak, the toroidal field, much larger than the poloidal field, remains essentially produced by external means. External toroidal coils then determine the plasma equilibrium and avoid instabilities. On the other hand, in other devices, the toroidal field--of comparable amplitude to that of the poloidal field--is in great part, as in RFP, or entirely, as in spheromak, produced by the plasma current itself. The equilibrium is then reached at the outcome of a self-consistent process called plasma relaxation. These may be called therefore relaxation devices.
During relaxation, a plasma initially produced in an unstable state releases part of its free energy through a turbulent process till it reaches a lowest energy equilibrium state. Relaxation is a complex process of self-organization of a resistive plasma, which may involve substantial modification in its magnetic field, in particular in the topology of the magnetic surfaces. In its general behaviour, the relaxation process in relaxation devices seems to be quite well accounted for by J. B. Taylor's conjecture, Phys. Rev. Lett. 33 (1974), pp. 1139-1141. This conjecture states that very few magnetohydrodynamic (MHD) invariants from amongst the infinity of ideal MHD invariants holding for null resistivity, still hold on the time-scale of resistive relaxation. For the considered toroidal devices, the essential long-life invariant is global helicity, defined as:
H=∫A.B dV (1)
the integral being performed over the total volume of the toroidal vessel. A is any potential vector of B, satisfying V×A=B. For open-ended devices, the definition for helicity must be substituted by a less simple one, taking into account boundary effects. Remaining invariant on a large time-scale, helicity provides therefore a central constraint, determining the final equilibrium state. If this is the unique MHD invariant on large time-scals, then the relaxing plasma decays to the lowest energy state compatible with the geometry of the vessel and the value of H. This state may be shown to satisfy the equilibrium equation:
μ.sub.o J=V×B=μB (2)
where J is the current density, μ o is the magnetic permeability at vacuum, and μ is a constant, independent of space, and has dimension of inverse length.
The physicality of the assumption that constant helicity plays a central role in modeling of relaxation has been largely confirmed by subsequent observations on prototypes built in different laboratories: RFP, multipinch, spheromaks.
In most relaxation devices, the only main additional magnetic constraint is the conservation of toroidal magnetic flux, for toroidal devices, or poloidal flux when externally imposed in open-ended devices. In such case, the stable equilibrium of the relaxed state is the solution of equation (2) with lowest μ among the possibly multiple solutions compatible with the values of the helicity, of the conserved flux and of the geometry of the vessel. Only that lowest energy solution, called the Taylor state, may be stable. Since no more free energy is available unless H is changed, the Taylor state is stable to ideal MHD instabilities, as well as to some resistive instabilities. However, the lowest energy solution is not necessarily the most favorable one for fusion application, in particular, as will be discussed below, when plasma pressure is taken into account. Yet the other equilibrium solutions of equation (2) are bound to decay unstably to the Taylor state, because, in present art relaxation devices, there is no additional constraint in the relaxation process to prevent this decay.
In certain MHD systems, however, there may be present an additional robust invariant of topological origin. This is a homotopic invariant, implying that it is insensitive to local change of topology of the magnetic surfaces, and that it may therefore be of comparable life-time to that of global helicity having a central role in modeling relaxation. Homotopy theory is the branch of topology which deals with the continuous deformations of fields. It should be distinguished from homeomorphy, which deals with the deformation of one surface into another. Homotopy, by contrast, determines whether one field configuration can be continuously deformed into another. The set of all configurations continuously deformable one into the other is called a homotopy class. Two configurations belonging to two different homotopic classes are not continuously deformable one into the other, and therefore one will not dynamically evolve into the other, which introduces an additional constraint. Conditions can be created in MHD systems where there is more than one homotopy class for the magnetic field, each class corresponding to a different value of a homotopic invariant. Existence of such systems was proved by Finkelstein, D. and Weil, D., International Journal of Theoretical Physics, Vol. 17, No. 3 (1978), pp. 201-217. In present art plasma relaxation devices, no device takes advantage of a magnetic homotopic invariant as a topological constraint in the relaxation. Yet, as already mentioned, from all the solutions of equation (2) for a given geometry, the lowest energy one is not necessarily the most favorable one in fusion reactor context, in particular with respect to the maximal plasma pressure tolerated by the magnetic configuration.
Equilibrium states obeying Equation (2) have no pressure gradient, because Vp=J×B. For practical purposes, real plasma must differ from Taylor state at least slightly, since real plasma must have finite pressure, and, actually, substantially high pressures are desired for fusion application. Such pressure is measured in terms of the quantity: ##EQU1## β being the ratio of the mean plasma pressure to the mean magnetic pressure (here and throughout the remainder of this disclosure the system of units used is SI mks). For finite β, instabilities due to plasma pressure may arise, in particular the MHD interchange instabilities.
The MHD stability of a magnetically confined plasma with finite pressure is dependent on the pitch of the magnetic field lines encircling the magnetic axis. In toroidal plasma devices it is customary to use instead the safety factor q where: ##EQU2## this integration being performed, for axisymmetry, along close field lines of poloidal magnetic field B p . R is the distance from major axis and B p is the toroidal magnetic component.
In order to be MHD stable, toroidal plasma devices with finite pressure gradient must satisfy certain necessary conditions on q. In particular, if r is the mean minor radius of the toroidal surface, then: ##EQU3## must be large enough to satisfy relevant criteria including the Mercier criterion. s is the magnetic shear, which exerts a stabilizing effect on many classes of instabilities, particularly on MHD interchange instabilities.
It has been computed (C. M. Bishop, Nuclear Fusion 26 (1986), pp. 1063-1071) that stability to these interchanges is enhanced with the presence of a divertor, and that the stability properties become better as the poloidal null-point of the divertor is moved progressively towards the inside of the torus. Thus an inner divertor on the very inside may be the best operation for a toroidal confinement plasma device.
The most commonly used toroidal magnetic confinement configuration at present is the tokamak, whose principle defining characteristic is to achieve MHD stability requirements by supplying a sufficiently large toroidal magnetic field intensity B t , so as to be much higher (typically 5 to 10 times higher) than the poloidal magnetic field. The toroidal field must be provided by a large toroidal field coil system disposed around the confinement vessel. The theoretically predicted maximum β is limited to be of the order of 0.10. Because of the small β of the tokamak, fusion reactors based on this concept must either be large or must employ extraordinary high toroidal field strength.
Reversed-Field-Pinches (RFP) devices are most readily distinguished from tokamaks, which they superficially resemble, by being relaxation devices where the toroidal field is of approximate same amplitude as that of its poloidal field. As a consequence, a RFP device can achieve the same plasma density at much lower toroidal field than the tokamak. A recent review of the RFP art has been given by Bodin, H. A. B., Krakowski R. A., and Ortolani S., Fusion Technology 10 (1986), pp 307-353. The theory of relaxation under constant helicity accounts remarkably well for the universality of the RFP equilibrium states reached after relaxation. In particular, it is observed, as predicted by the theory, that for sufficiently high current densities, so that the product of μ by the the minor radius of the torus exceeds the critical value of 2.4, spontaneous reversal of the toroidal field at the edge of the plasma takes place. That is, the magnetic field component sensibly parallel to the magnetic axis has a direction in the outside region of the plasma opposite to its direction in the inner region, and as a result, g(r) passes through zero and changes sign near the boundary of the plasma. In general, the magnitude of q in the RFP remains everywhere substantially smaller than 1, but the shear is relatively high and, as a consequence, the maximal β achievable in RFP devices is greater than in a tokamak. β p may be as high as 0.4. Fusion reactors based on the RFP concept can, therefore, either be smaller or use lower magnetic fields than with tokamaks.
However, the RFP device, as the tokamak, requires for its functioning toroidal field coils which link the plasma. The presence of this hard core at the center of the device introduces a most severe technological constraint in the practical design of such toroidal devices and it particularly complicates actual reactor design by requiring a toroidal blanket. In addition, the implementation of an inner poloidal divertor, considered as most suitable for enhanced stability and confinement, is rendered problematic by the presence of the hard core. In such toroidal devices, a divertor is introduced as an extraneous structure by additional coils. So far, several tokamaks have been built with poloidal divertors but none of them with an inner divertor. For RFP devices, most considered divertors divert the toroidal field, preserving the poloidal circular symmetry around the elliptic magnetic axis, and no RFP with inner poloidal divertor has been developed. The small-major radius side of these toroidal devices with inner hard core, for the RFP as well as for the tokamak, is already crowded and under high stress. An inner divertor would further complicate the design.
Other relaxation devices with toroidal region of confinement have been developed which do not involve an inner hard core. These bear the generic name of spheromaks. In a spheromak, the toroidal field is produced entirely by the plasma current. This has for an advantage obviating the requirement for the toroidal field coils. Unfortunately, the spheromak does not have high shear and it has been theoretically predicted to have small maximal β. There are data suggesting that interchange instability is observable in contemporary spheromak experiments (see, in particular, Wysocki, F. J., et al., Physical Review Letters, Vol. 21, p. 2457 (1988). In the spheromak, there is no reversal of the toroidal field. The spheromak has a low shear because q varies between 0.8 and 0.7 in the classical spheromak, or between 0.8 and 0 in the spheromak with a hole. Some spheromaks have plasma on open field lines, yielding some kind of divertor, but no spheromak has a unique poloidal divertor situated in the innermost part of the toroidal region. The lack of reversal and the low shear, as well as the absence of an inner divertor, are linked to the fact that the lower energy Taylor states do not satisfy these properties and that there is no additional constraint to withhold decay to these Taylor states.
SUMMARY OF THE INVENTION
The present invention involves a fundamentally different confinement principle, combining best advantages of spheromaks and of RFP devices in a relaxation device. The basic invention can be viewed as a RFP relaxation device in which the solid linner axial core has been replaced by a straight high-current plasma relaxation channel so as to produce a RFP with an inner divertor. A non-zero homotopic invariant is introduced, which provides an additional constraint in relaxation, provided the component of the poloidal magnetic field at the boundary of the vessel is maintained at a definite sign, which can be achieved by small currents in toroidal coils exterior to the conducting shell. The relaxation of the straight and toroidal plasma regions under the topological constraint produces an open-ended separatrix with reversed toroidal component and with one poloidal divertor, detached from the wall, and situated in the inner small major-radius side of the torus. The precise shape of the plasma can be adjusted and sustained by control of the axial current and of the poloidal magnetic field coils.
Stability in the topomac (device in accordance with the present invention) is obtained by a q profile and conducting shell as in the RFP, plus the additional topological constraint. The poloidal divertor introduces high magnetic shear, and is mostly effective as the toroidal component at the divertor increases. Its innermost location is optimal to reach enhanced stability to ballooning modes which threaten to limit RFP β. The topological constraint prevents the configuration to decay to a lower energy equilibrium state without inner reversed poloidal divertor, and hence with lower β. In general terms, introduction of the non-zero homotopic invariant, according to the present invention, increases the maximum β p that can be accomodated. Like the spheromaks, the toroidal field of the topomak is essentially produced by the self-currents; moreover, the boundary poloidal fields to be produced by the external toroidal coils are small (typically one half) compared to the maximum field-amplitude created at the core of the plasma. This considerably alleviates the technical requirements concerned with having high fields in the center of the Reversed-Field-Pinch region of the plasma.
The device of the present invention is distinctly different from prior art RFP, by the absence of a hard core conductor linking the plasma for providing a toroidal field, which frees it from severe engineering constraints inherent to toroidal RFP and tokamak geometries. In particular, it is distinctly different from RFP's and tokamaks involving poloidal divertor: it is distinctly different from prior art helical pinches as in T. Ohkawa's U.S. Pat. No. 4,302,284, sometimes referred to as OHTE, whose poloidal nulls are at the plasma surface rather than internal; it differs from prior art multiple pinch method, as in T. Ohkawa's U.S. Pat. No. 4,543,231, whose current channels, being surrounded by a set of nested closed magnetic surfaces are all toroidal, so that the separatrix null does not provide an open-ended divertor and the shell is toroidally closed; it is also distinctly different from the prior art doublet device, as in T. Ohkawa's U.S. Pat. No. 3,692,626, which involves tokamak current channels with large toroidal field, hence lacking reversal, and with toroidal vessel.
The device of the present invention is also distinctly different from the prior art spheromaks which, while having toroidal and poloidal fields of comparable intensity, do not involve a toroidal field reversal, thus keeping β low. In particular, it is distinctly different from open-ended spheromaks such as the bumpy z-pinch (Jensen T. H. and Chu, M. S., J. Plasma Physics, Vol. 25, part 3, pp. 459-464, 24 May 1980), and related spheromaks with open field-lines, which, in some of the forms discussed in literature, superficially resemble. These devices essentially adjoin a spheromak to the open field lines regions in the vessel with cylindrical topology, and as a result, there is no reversal. By contrast, the present invention, in its simplest form, adjoins to the open field lines one RFP region, hence with toroidal field reversal, allowing for high magnetic shear. This differentiation is linked to the more fundamental difference, that in the present invention there is a non-zero homotopic invariant, providing an additional constraint on the relaxation, whereas in the open-ended spheromak, there is no such invariant. Moreover, the topomak also differs from the open-ended spheromak in the respective shape of the separatrix. A spheromak has two poloidal nulls, symmetrically distant away from the midplane, whereas in the present invention, there is one unique poloidal null situated in the midplane, and in the small major-radius side of the torus. As a result, the separatrix of the topomak has the advantage that it can fulfill most efficiently the role of a divertor, that its divertor null is at optimal location for stability, and that the conducting shell can be close-fitted to most part of the boundary of the RFP region. The topomak is further differentiated from the open-ended spheromak device by their different q profiles. The open-ended spheromak profile is everywhere greater than zero, from +∞ at separatrix down to some positive value (less than one) at elliptic axis; whereas in the topomak, q is monotonically varying from +∞ at the separatrix down to negative values as low as -0.5 at elliptic axis (with absolute value of q less than one in most part of the toroidal region), yielding a substantially higher magnetic shear.
Thus it is a primary object of the present invention to provide a toroidal Reversed-Field-Pinch (RFP) plasma within an open-ended vessel, with separatrix involving one poloidal null in the innermost part of the torus, generated by the relaxation of straight and toroidal plasma regions, using a non-zero homotopic invariant as additional constraint in relaxation. Other objects and advantages of the present invention will become evident from the consideration of the following detailed description, particularly when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the magnetic surfaces obtained, including the inner reversed poloidal divertor, when one straight and one toroidal relaxing plasma region are combined in accordance with a preferred form of the present invention;
FIG. 2 is a poloidal sectional view of a schematic preferred embodiment of the present invention for producing the magnetic surfaces shown in FIG. 1;
FIGS. 3A and 3B illustrate the simplest arrangement of straight and toroidal relaxing plasma regions for configurations with homotopic invariant K=2;
FIGS. 4A, 4B and 4C show, respectively, toroidal and poloidal components of the magnetic field at midplane, q profile, and maximal Mercier pressure profile, as computed from a specific topomak equilibrium solution corresponding to FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
Central to the concept of the invention is the generation and control of one straight and at least one toroidal relaxing plasma region within a simply-connected common volume so as to produce a RFP configuration with an inner open-ended poloidal divertor, utilizing a non-zero homotopic invariant. The preferred embodiment described herein uses, where possible, techniques and apparatus that are known in the art of producing and applying hot, magnetically confined plasmas. A preferred embodiment of the invention is illustrated in FIG. 2, such device producing magnetic surfaces as illustrated in FIG. 1. As illustrated in FIGS. 1 and 2, a plasma comprising one toroidal relaxing plasma channel (10) with region of toroidal reversal (12) and one straight relaxing plasma channel (14) is created within a primary vacuum chamber formed by a wall (16) so as to form an open-ended divertor separatrix (18) having poloidal null (20) in the inner side of the toroidal region, with elliptic axis (22) and nested closed magnetic surfaces (24) and (26), and with nested open magnetic surfaces (28) and (30), respectively. In the Figures, flux surfaces where the toroidal magnetic component is negative are dotted. Surrounding magnetic surfaces (32) and (34) at the outerboard of the toroidal pinch are also illustrated in FIGS. 1 and 2. Relaxing plasmas regions (10) and (14) and chamber wall (16) are symmetric with respect to the toroidal major axis (vertical axis of rotational symmetry) (36) and midplane (38). The chamber wall (16) is made of a material having low electrical conductivity and compatible with high vacuum technique as practiced in RFP devices. It should have sufficiently high toroidal resistance so as to permit penetration of induced toroidal electric field in time desired to drive toroidal plasma current. Standard vacuum pumping systems are used for evacuating the chamber to high vacuum. The chamber wall (16) is shaped so as to closely approximate the desired shape of the plasma.
The major radius R 0 of the plasma device illustrated is 0.24 m from the major axis (36) to the elliptic axis (22). The chamber is 0.27 m high with 0.35 m radius at its widest midplane point and 0.05 m radius at its extremities. The minimal vertical diameter of the "neck" (39), establishing transition between the open-ended region ("shaft") (10) around the axis (36) and the toroidal region (14), is 0.11 m in the illustrated embodiment, but the exact value of this dimension may be changed as desired or required for improved plasma performance with no change in the nature of the invention. Large necks allow for a more effective helicity pumping from the cylindrical region (14) surrounding the major axis (36) into the toroidal region (10), whereas small necks allow for a more effective close-fitting shell for stabilization.
Chamber cross-sectional dimensions may be scaled to be larger or smaller, maintaining proportions close to those given above.
The characteristic boundary shape, the purpose of which is to force the relaxation of the straight plasma discharge (14) and toroidal plasma region (10) and the formation of the inner divertor (18), is imparted by a shaped shell (40) and distributed poloidal field windings (42) and (46).
Shaped conducting shells have been used for many years to impart particular shapes to plasmas, with the most similar prior art applications being in multipinch toroidal devices, as in Ohkawa's U.S. Pat. No. 4,543,231. The exact shape of the shell (40) is determined by solution of the Grad-Shafranov equation for MHD equilibrium to be described in subsequent paragraphs, in order to yield a plasma with the properties sought. At the same time, the close-fitting shell (40) allows, together with the divertor (18), for benefiting from stabilization by image-currents to surface-modes without detrimental interactions of the plasma with the wall (16). The shaped shell is made of a highly conducting metal. The shell also includes an electrically non-conductive break to prevent the flow of net toroidal current in the shell, which would otherwise act as a short-circuited secondary circuit for induction winding.
The purpose of the electrodes (44) is to create an axial electric field to ionize gas within chamber (16), thereby generating plasma, and to drive sufficient current through said plasma to contribute an important part in its resistive heating to high temperature. The axial current also contributes an important part of the toroidal magnetic field in the toroidal region of confinement of the hot plasma, as well as of its poloidal magnetic field, through helicity injection. The basic principles of this technique are nowadays well understood and have been applied in several devices, such as in the sustainment of a spheromak, using a kinked z-pinch as the helicity source (Jarboe T. R., Barnes C. W., Platts D. A. and Wright B. L., in Comments Plasma Phys. Controlled Fusion, 1985, Vol. 9, No. 4, pp. 161-168). Thus, the current driven between the electrodes must be sustained for the desired duration of plasma confinement. For the embodiment illustrated in FIGS. 1 and 2, at steady state, a d.c. voltage of 20 V is to be maintained between the electrodes, in order to sustain the desired toroidal magnetic field, driving a vertical current of 15 kA. Since large currents are required to be driven between the electrodes, they must be made of a material particularly resistant to high heat loads. Special shaping of the electrode may reduce the heat load per surface unit; moreover, in order to allow for a rapid reversal of the axial magnetic flux, according to the preferred method of production described hereunder, the electrodes should be hollow (not illustrated). The electrodes (44) are separated from the wall (16) and from the shell (40) by electrical gaps.
The primary purpose of the poloidal field coils ((42) and (46)) is to provide magnetic boundary conditions required for the preservation of the topological variant. Poloidal field coils (46) serve also as vertical field coils in the discharge channel (14) between the electrodes (44) according to a technique standard in "stabilized z-pinch" devices.
Both coils ((42) and (46)) may also conveniently serve as induction coils, and supplement the electrodes (44) in heating the plasma. Namely, they may induce sufficient high toroidal current through said plasma to contribute significantly to its resistive heating. In the illustrated embodiment, the plasma toroidal current in the toroidal region at steady state would be around 60 kA. The electrically non-conductive break in the shell (16) prohibits the flow of net toroidal current in the shell, which would otherwise act as a short-circuited secondary circuit for the induction winding. This aspect of the device and the basic design considerations thereof, especially for coils (42), such as energization through capacitor bank, are similar in the present invention to those in RFP and other ohmically heated toroidal plasma devices.
Finally, the induction coils (42) and (46) may also conveniently serve for an additional purpose, namely, to supplement the shell (40) in shaping the plasma. Because magnetic flux diffuses through a shell with finite resistivity, the power of the shell to control the shape of the plasma is lost after the so-called T shell time. The currents in external conductors such as coils (42) and (46) may be distributed so as to provide magnetic boundary conditions identical to those of the shell. The field amplitudes to be produced are of order of 0.1 T in the mean for the illustrated embodiment. Shaping by external coils has been demonstrated in Doublet tokamaks experiments and, using this technique, the duration of the plasma is not limited by the T shell diffusion time. In FIG. 2, the individual turns of coils (42) and (46) are shown with a distribution that achieves the fundamental purpose. An infinitude of such distributions may be found, and satisfactory designs may also be obtained with different number of turns than illustrated.
The general behaviour of relaxing plasmas within an open-ended vessel, containing at least a small magnetic field with open-ended field lines, can be deduced from Taylor's original theory of relaxation of plasmas in toroidal vessels. Although the helicity, as expressed in Equation (1), becomes ill-defined when the vessel boundary is not a magnetic flux-surface, an alternative quantity can be introduced with analogous properties (such "alternative helicity" has been discussed, e.g., by Finn, J. M. and Antonsen, T. M., Comments Plasma Phys. Controlled Fusion, 1985, Vol. 9, No. 3, pp. 111-126). In particular, its approximate conservation can be assumed during resistive relaxation, and minimization of the energy under this sole constraint and the appropriate boundary conditions yields again Equation (2) for the relaxed state.
This extension of Taylor's relaxation theory describes the principal features of open-ended toroidal plasmas as observed in experiments. In particular, plasmas tend to approach the configuration described by Equation (2), independently of their initial state and the particular method used to produce them. There may be more than one solution to Eq. (2) in the given shell geometry with the given boundary conditions, in which case, Taylor's theory predicts that only the equilibrium with lowest energy is stable. However, higher energy solutions of Equation (2) may be found as more suitable equilibria for plasma confinement, in particular because they involve generally a higher magnetic shear.
A principal object of the present invention, stated in the context of the preceding discussion, is to introduce an additional constraint in relaxation, to prevent decay to an unfavorable lower energy solution, by means of a homotopic invariant. For MHD systems admitting a homotopic invariant, this lowest energy solution is not available, if it belongs to a different homotopy class than the relaxing configuration.
The magnetic field of an MHD system in an axisymmetric simply-connected vessel has more than one homotopy class provided two conditions are satisfied:
1. There is no three-dimensional null point in the plasma. This may be controlled by the external coils and mainly by the current driven by the electrodes which assure, in particular, that at poloidal null, the toroidal component is substantially far from zero. More generally, the higher the temperature of the resistive plasma, the larger the time-scale during which the development of such null-point is inhibited.
2. In some vicinity of the major axis, the field has a normal component, and, on the remaining part of the vessel surface, the direction of the field is tangential and is nowhere antiparallel to its direction on the major axis. This latter condition can be simply obtained by external toroidal coils controlling the boundary poloidal field.
If said two conditions are maintained, then one has a homotopic invariant, related to the relative homotopy of π 3 (S2), itself related to the so-called Hopf invariant (see Finkelstein, D. and Weil, D., the International journal of Theoretical Physics, Vol. 17, No. 3 (1978), pp. 201-217), which has an integer value K. The class with K=0 includes the configurations which have no toroidal field-reversal, to which the lowest energy Taylor's states belong. Thus, it is the object of the present invention to have a plasma equilibrium configuration with K different from zero. Present inventors have named such a configuration a Dag. In the case of axisymmetry, the presence of at least two magnetic axes with toroidal field of opposite sign, is a necessary crucial condition. Otherwise, one of the toroidal directions is certainly excluded from the total range of directions of the field configuration, and configurations where all possible azimuthal directions are not reached by the field always have K=0. For the simply-connected geometry of the plasma vessel considered in the present invention, with the above boundary conditions, a Dag configuration should possess at least one pair of elliptic and hyperbolic axes, the toroidal component of which are reversed one with respect to the other. The simplest example is the Topomak configuration, examples of which are given in the followings.
The general nonsingular axisymmetrical solution in cylindrical coordinates of Equation (2) for Taylor equilibrium states is given by the Chandrasekhar-Kendall form: ##EQU4## The solution consists of the sum of linearly independent modes, specified by mode number k, with amplitude a k : J o and J 1 are the Bessel functions of the first kind, respectively of order 0 and order 1.
A topomak equilibrium has one pair of elliptic and hyperbolic axes with reversed toroidal orientation of one with respect to the other. This implies having the direction of B at midplane of symmetry performing at least one full rotation, as distance from major axis r increases. The k=0 mode alone realizes that, provided μ·r can be as high as 7 within the vessel. However, this mode does not have closed magnetic surfaces. Thus, we consider as next simplest trial solution a superposition of the k=0 mode with one additional k mode. To prevent the occurrence of null points on the major axis (one of the conditions for the topological constraint), we impose |ak/ao|<1. Poloidal nulls are then located on midplane at the roots of the equation B z (r)=0. Thus, the first two consecutive roots should have opposite signature (signaling whether it is an 0 point or an X point) and opposite B.sub.φ. One can show that this happens if k is sufficiently close to μ for a definite range of negative values of a.sub. k /a o . In addition, to obtain a Topomak, the separatrix originating at the X point should enclose the 0 point. For the convenient choice of μ=25, this is satisfied for k=22 provided -9.6<a k /a o <-4.5, and for k=23 provided -8.6<a k /a o <-3.8.
Thus, diverted RFP Taylor states with non-zero homotopic invariant exist. Basically, the axial hard core of a conventional RFP system is replaced by a relaxed equilibrium of an axial straight plasma current channel, and the resultant is a Reversed-Field-Pinch with an inner reversed divertor Taylor state.
Solutions with a higher topological number can be constructed in a similar manner. For example, a Dag with topological number K=2, consists of two toroidal current channels, forming together a doublet with a figure-eight-like separatrix, together with a vertical straight relaxation current channel with an inner divertor. The toroidal magnetic field at the two elliptic axes is in opposite direction to the direction of the toroidal field at both hyperbolic axes on the close and open-ended separatrices. It is clear that still higher K states can be readily constructed. It is also obvious that if one does not require the Dag to be in a Taylor state, the x point with reversed toroidal direction relative to the direction at the 0 point may be situated at other location than at most inboard location on the torus surface. FIGS. 4A and 4B illustrate plasmas with K=2, in their most symmetric orientations in axisymmetric geometry. Intermediate orientations could be possible, but they add complexity with no apparent increased benefit.
The most straight-forward method to produce plasmas approximating a desired Taylor state is to:
1. Construct a conducting metal shaping shell whose shape is identical with the outermost magnetic surface of the desired state.
2. Prior to formation of the plasma, establish a vertical magnetic field in the shaft region of the enclosed evacuated cylindrical volume, using coils (42).
3. Inject the gas that will be ionized into plasma, using any conventional means. Optionally, the gas may be preionized.
4. Establish a vertical electric field along the axis of the shaft region of the vessel by external electrodes so as to ionize the gas completely and drive a vertical current creating open poloidal field lines in this region.
5. Let the straight-plasma column relax into the toroidal region. In virtue of Taylor principle, the plasma state reached will have for appropriate parameters a toroidal region with closed poloidal field lines and with toroidal component. Analogous technique of relaxation has been probed in several recent experiments on spheromak, RFP, and tokamak. If necessary, one may assist the desired relaxation process by using the shaping coils (46) at the boundary of the toroidal part of the vessel as inductive coils to create closed nested magnetic surfaces with relaxation to the desired Taylor state. This state however will not be a Dag, as there is no field reversal, and the separatrix, in general, involves two x-points on the wall.
6. Reverse the direction of the axial current discharge between the electrodes, and the direction of the external vertical magnetic field (together with toroidal current component created by inductive coils around the axial region). Optional shaping coils (46) of the toroidal region may be maintained during this stage with same current orientation as in previous stage. This assures the proper boundary condition for the poloidal field and has for result to modify the separatrix to the desired one: one inner divertor with toroidal field reversed with respect to the direction of the toroidal component of the core of the toroidal region obtained in previous stage.
7. Once the proper topology has been produced (toroidal component at the inner divertor reversed with respect to that at the elliptic axis), adjust electrode current and boundary poloidal field (by shaping coil) to level of the desired plasma state, so as to reach the optimally stable relaxed state of the resistive plasma. Gas may be let into the chamber slowly to replenish gas absorbed by the metal walls.
8. The shape of the flux surface does not change radically as the mode amplitude ratio is changed within some controlled range. Therefore, a single shaping shell (16) can be used to study a continuum of neighboring equilibria by magnetically adjusting the boundary conditions by means of small currents through additional toroidal coils of various location exterior to said shell, as, for instance, in T. Okhawa U.S. Pat. No. 4,543,231 for shaping of multipinch plasma.
9. The possibility of helicity injection by the electrodes along the vertical field produced by external coils allows for maintenance in a steady-state regime. Sustainment of Taylor state in steady state using helicity injection by means of electrodes has been realised in several spheromak and tokamak devices (such as in M. Ono et al., "Steady-State Tokomak Discharge via dc Helicity Injection", Physical Review Letters, Vol. 59, No. 19, Nov. 9, 1987).
Axisynmetric plasma equilibria with finite plasma pressure and a general specified toroidal current density may be calculated by solving the finite pressure Grad-Shafranov equation. For instance, a family of solutions with pressure field function p(ψ), specified arbitrarily, is obtained by adding ##EQU5## to the zero pressure toroidal flux solution ψ. However, not all these solutions are stable. Mercier criterion allows for an estimate for the maximal pressure acceptable without driving an interchange instability, assuming that the back effects of the pressure on the magnetic field configuration can be reasonably neglected. The magnetic flux-surfaces of FIG. 1 are drawn from a numerical solution of the Grad-Shafranov equation with zero pressure. For FIG. 1 the aspect ratio A=R 0 /a is 1.7, where R 0 is the major radius of the elliptic axis and a is the half width of the toroidal plasma width at its widest point. The toroidal field on the separatrix is reversed and substantial, due to finite current along the vertical axis. Plots of B p , B.sub.φ, q and maximal p derived from this numerical solution are given in FIGS. 4A, 4B and 4C as a function of r at midplane z=0.
Thus, the desired inner reversed divertor is still obtained with a realistic plasma current distribution by means of the present invention, consisting of a combination of straight and toroidal relaxing current channels generating a non-zero magnetic homotopic invariant.
The occurrence of the non-zero homotopic invariant in the combination of straight and toroidal relaxing plasma regions can be explained in simplified qualitative terms. The toroidal magnetic field at the hyperbolic axis is reversed with respect to that of the elliptic axis. Moreover, the poloidal field at the boundary vessel is approximately parallel to that on the central axis. Therefore, the magnetic field, as it progresses from the central axis outwards to the boundary, at midplane, has performed a complete rotation of 360° (or somewhat more). This corresponds to a closed circle on the sphere representing all possible directions. As the total surface of the poloidal cross-section is swept by an imaginary deformation of the z=0 chord, the sphere of directions is covered once. This yields K=1, which remains invariant under any deformation. If the toroidal field is not reversed, this implies that only a portion of the sphere of directions is covered. Thus, K is certainly zero. In the most common present art toroidal magnetic confinement systems, namely the tokamak and stellarators families, the toroidal field greatly exceeds the poloidal field; thus the toroidal field does not change sign, and therefore non-zero homotopic invariants cannot be obtained. In relaxation devices, such as the RFP, toroidal field strength is comparable to its poloidal counterpart, and can have a large variation across flux surfaces. Thus, in the topomak the toroidal field can be reversed at the separatrix, yielding the invariant.
To strictly ensure the conservation of the homotopic invariant, it is required to prevent the possibility of null point occurrence, in particular at the poloidal null, and on the axis (as present in spheromak). For this reason, it is advantageous to operate the present invention with the geometric and current/field ratio parameters, such that the toroidal field reversal takes place well inside the separatrix surface. This implies a substantial axial current. Too high a current may, however, lead to a defavorable energy balance, due to heat dissipation along the open field lines, and it may as well reduce efficiency of transfer of helicity from the shaft region. The position of reversal within separatrix may be varied to obtain best plasma confinement and most efficient energy balance by experimental measurement.
The present invention therefore provides a method for generating and maintaining magnetically torroidal plasma of the Reversed-Field-Pinch type with an inner poloidal divertor and without linking coils, by means of inserting a topological constraint. Having a RFP without linking coils is not possible in prior art RFP configurations. The present invention closely approximates a high energy Taylor state. The location of the topological invariant according to the present invention is such as to exert a stabilizing influence on global instabilities preventing decay to lower energy Taylor states with unfavourable magnetic shear, or to total reconnection to open field-lines. The location of the poloidal divertor implied by the invariant is also favorable for the amelioration of effects arising from the increased magnetic shear near the separatrix, as well as for effective impurity cure. Therefore, advantages of greater stability and/or greater β, generically termed improved plasma confinement, as well as technical advantages, specific to reacotor embodiment, may be expected compared with prior art RFP and spheromak devices.
While the novel aspects of a magnetic confinement plasma device in accordance with the present invention have been shown in a preferred embodiment, many modifications and variations may be made therein within the scope of the invention, as in the size, shape, and current and field intensities, as well as in application of alternate methods and techniques well known in the art of plasma and fusion. For example, the axial current in the shaft region may be produced by other means than electrodes, as used in other devices for helicity injection. This includes electron beam injection along the open field lines. This includes also the possibility that the open-ended cylindrical vessel described in the invention may be an approximation of a larger closed toroidal vessel, in which case the axial discharge may be produced by inductive coils; such vessel can include along its axis more than one configuration as described in the invention. Moreover, the intermediate plasma state reached at stage 5 of the preferred method of production described above, may be obtained by other means. These include the injection in the vessel of a plasma ring produced by a coaxial-plasma source. One would then proceed along the same subsequent steps 6 to 9, as above. Additional possible variations include the adjunction of various standard means known to improve stability, such as the introduction of a conducting bar at the major axis of the shaft region. The particular embodiment described is designed for experimental and research purposes. Scaled-up embodiments intended for the production of a fusion and power reactor will likely include various additional well-known appurtenances of plasma and fusion devices, such as power supplies, vacuum pumps, instrumentation, auxiliary heating systems, blankets, heat exchangers, supporting structures and control systems. | A method and apparatus for plasma relaxation under magnetic global topological constraint produces a hot magnetically confined toroidal Z-pinch plasma with a plurality of straight and toroidal relaxing plasma discharges so as to generate at least one open-ended poloidal null separatrix in the magnetic field with one poloidal null within the plasma space situated in the small major radius side of the toroidal discharge, forming thereby a magnetic configuration (called DAG) with non-zero homotopic invariant, including a toroidal reversed-field pinch with inner poloidal divertor, in a region of open plasma magnetic surfaces surrounding the toroidal discharges, when toroidal magnetic field component is also made to be substantially different from zero at the poloidal null. The topologically constrained relaxation invention, called topomak, may be operated in equilibria with regions of nested closed magnetic surfaces of high magnetic shear with safety factor Q radially varying from negative, but greater than -1, values to +infinity, and with high plasma/magnetic pressures ratio, closed to known theoretical stability conditions, the topological invariant opposing plasma relaxation to less favorable lower-energy states without reversal. The toroidally reversed poloidal divertor is effectively produced in the topomak by replacing the solid conducting inner core of prior art reversed-field-pinch relaxation devices by straight-pinch-like current discharge of plasma along the major axis under conditions where the topological constraint holds. The DAG plasma configuration has cylindrical topology. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to French application No. 0757675 filed on Sep. 19, 2007.
FIELD OF THE INVENTION
[0002] The present invention relates to an orthopedic device for reconstruction of an articulating joint. The invention also relates to a method for positioning such an orthopedic device.
BACKGROUND OF THE INVENTION
[0003] In so far as a prosthesis is installed for a long period of time, it is important to ensure the rigidity and mechanical stability of a prosthesis component. If the screw is not tightened sufficiently during the positioning of the prosthesis, the risk of disassembly of the prosthetic component is aggravated.
[0004] EP-A-1 769 050 mentions the principle of locking a screw for controlling the displacement of a wedge-like ring which dilates a widened portion of an anchor stem of a prosthesis. This arrangement is specific to locking by means of a wedge-like ring. The means allowing such locking to be obtained are not described.
BRIEF SUMMARY OF THE INVENTION
[0005] The invention is intended more particularly to overcome such disadvantages by providing a new component of an articular prosthesis wherein undesirable unscrewing of the fixing screw may be avoided. Owing to the invention, the locking assembly prevents the screw from becoming loose in an inadvertent manner which ensures the mechanical stability of the orthopedic device. The locking assembly is effective even if the fixing screw is not screwed completely into the corresponding threaded hole.
[0006] In one embodiment, the orthopedic device for ball and socket joint reconstruction includes an anchor stem with a distal portion adapted to be anchored in a medullary canal and a proximal portion with a threaded hole oriented along a longitudinal axis of the anchor stem. Metaphyseal portion includes a proximal end with recess and a longitudinal bore in fluid communication with the recess, and a distal end adapted to interface with the proximal portion of the anchor stem. An anti-rotation structure is preferably located at an interface of the anchoring stem to the metaphyseal portion to prevent rotation of the anchor stem relative to the metaphyseal portion around the longitudinal axis. A fastener is provided to extend through the longitudinal bore and to engage with the threaded hole on the anchor stem to fix the metaphyseal portion to the anchoring stem. The locking assembly is located in the recess and mechanically couples the head of the fastener to the metaphyseal portion to limit rotation of the fastener relative to the metaphyseal portion. An insert with an articular surface is provided that engages with the proximal end of the metaphysical portion and extends over the recess in the metaphyseal portion.
[0007] According to advantageous but non-compulsory embodiments of the invention, such a orthopedic device may incorporate one or more of the following features.
[0008] The locking assembly is provided with at least one projecting member which is capable of being introduced between a head of the screw and the metaphyseal portion adjacent to a housing for receiving the head in an assembled configuration of the orthopedic device.
[0009] The locking assembly comprises at least two projecting members which are capable of being introduced simultaneously between the head of the screw and the metaphyseal portion, at one side and the other of the head.
[0010] The external radial surface of the head of the screw is provided with reliefs that are capable of co-operating with the projecting member in order to fix the head of the screw and the locking assembly in terms of rotation. Those reliefs are advantageously concave channels which have a shape which complements the shape of the projecting member(s).
[0011] In another embodiment, the metaphyseal portion comprises a notch or a number of notches equal to the number of projecting members, and the or each notch opens in the housing for receiving the screw head. Each notch is capable of partially receiving the projecting member or one of the projecting members in an assembled configuration of the orthopedic device.
[0012] A fastener is provided for fixing the locking assembly and the screw in a configuration in which the locking assembly prevents rotation of the screw about its longitudinal axis. For example, a threaded hole is provided in the head of the screw and an auxiliary screw is screwed into the threaded hole, pressing the locking assembly against the head of the screw, in a configuration in which the projecting member(s) is/are arranged between the head of the screw and the metaphyseal portion.
[0013] In one embodiment, the locking assembly is provided with at least a first relief which is capable of co-operating with at least a corresponding relief of the head of the screw in order to fix the locking assembly and the screw in terms of rotation and with at least a second relief which is capable of co-operating with at least a relief which is fixed relative to the metaphyseal portion in order to lock rotation of the locking assembly.
[0014] According to some embodiments, the locking assembly is a ring, and its first relief is internal and the corresponding relief is an external radial relief of the head of the screw. In this case, the first relief of the ring may be a tooth and the corresponding relief of the head of the screw is a notch. In a variant, the ring is provided with an internal peripheral tooth arrangement which forms a plurality of first reliefs, and the head of the screw is provided with an external peripheral tooth arrangement which forms a plurality of reliefs corresponding to the first reliefs of the ring.
[0015] According to other embodiments, the locking assembly is a stopper which covers the head of the screw and the first relief is provided at a side of the stopper directed towards the head of the screw, and the corresponding relief is provided at the face of the head of the screw opposite the shank thereof. The head of the screw may carry at least one projection which projects relative to its face opposite the shank, and the stopper is provided with at least one housing for receiving the projection. In a variant, the stopper is provided with a tooth arrangement which forms a plurality of first reliefs and the face of the head of the screw opposite its shank is provided with a tooth arrangement which forms a plurality of reliefs corresponding to the first relief of the stopper.
[0016] The second relief of the locking assembly extends over or from the external peripheral edge of the orthopedic device.
[0017] A spacer may be arranged between the anchor stem and the metaphyseal portion, the spacer being provided, at its opposing faces directed towards the anchor stem and the metaphyseal portion, respectively, with reliefs which are intended to come into engagement with corresponding reliefs which are provided on the anchor stem and the metaphyseal portion, respectively, preventing rotation of the metaphyseal portion relative to the anchor stem about a longitudinal axis of the spacer.
[0018] The invention also relates to an articular prosthesis, particularly a shoulder prosthesis, which comprises an orthopedic device as set out above. Such a prosthesis is more reliable and easier for a surgeon to install than those in the prior art.
[0019] The present invention also relates to a method of implanting an orthopedic device for ball and socket joint reconstruction. The method includes the steps of:
[0020] inserting a distal portion of an anchor stem in a medullary canal;
[0021] engaging a distal end of a metaphyseal portion with a proximal end of the anchor stem;
[0022] limiting rotation of the metaphyseal portion relative to the anchor stem;
[0023] inserting a distal end of a fastener through a longitudinal bore in the metaphyseal portion;
[0024] engaging threads on the distal end of the fastener with corresponding threads on the anchor stem so a head of the fastener is located in a recess on the metaphyseal portion;
[0025] mechanically coupling a locking assembly to the head of the fastener and to the metaphyseal portion to limit rotation of the fastener relative to the metaphyseal portion; and
[0026] engaging an insert to a proximal end of the metaphysical portion so that an articular surface on the insert extends over the recess in the metaphyseal portion.
[0027] The invention also relates to a method for positioning an orthopedic device as set out above and, more specifically, a method which comprises steps involving:
[0028] a) anchoring the anchor stem in a bone;
[0029] b) securing the metaphyseal portion to the anchor stem, with a spacer optionally being interposed;
[0030] c) introducing the screw into a longitudinal bore of the metaphyseal portion;
[0031] d) screwing the screw into a threaded hole of the anchor stem until the metaphyseal portion is firmly pressed against the stem, with the spacer optionally being interposed;
[0032] e) moving a locking assembly into engagement with at least one corresponding relief of a head of the screw and at least one corresponding relief of the metaphyseal portion.
[0033] Advantageously, during step e), at least one projecting member of a locking assembly is introduced between a head of the screw and the metaphyseal portion adjacent to a housing for receiving the head.
[0034] An additional step may be provided, wherein the locking assembly is immobilised in the configuration in which its projecting member(s) lock(s) the head of the screw in terms of rotation relative to the metaphyseal portion.
[0035] In a variant, during step e), at least a first relief of the locking assembly is engaged with a corresponding relief of the screw head in order to fix the locking assembly and the screw in terms of rotation, and at least a second relief of the locking assembly is engaged with a relief which is fixed relative to the metaphyseal portion in order to lock rotation of the locking assembly.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0036] The invention will be better understood and other advantages and features thereof will be appreciated more clearly from the following description which is given purely by way of example and with reference to the appended drawings, in which:
[0037] FIG. 1 is a schematic perspective illustration, partially exploded, of a humeral component of a shoulder prosthesis according to an embodiment of the present invention.
[0038] FIG. 2 is a front view of the humeral component of FIG. 1 in an assembled configuration.
[0039] FIG. 3 is a section view of the humeral component of FIG. 2 along line III-III in FIG. 2 .
[0040] FIG. 4 is a view, drawn to an enlarged scale, of detail IV in FIG. 3 .
[0041] FIG. 5 is a section along line V-V in FIG. 3 .
[0042] FIG. 6 is a view, drawn to an enlarged scale, of detail VI in FIG. 5 .
[0043] FIG. 7 is a partial section, drawn to an enlarged scale, along line VII-VII in FIG. 6 .
[0044] FIG. 8 is a perspective view of the locking assembly for the orthopedic device of FIGS. 1 to 7 during assembly.
[0045] FIG. 9 is a partial perspective view of an alternate locking assembly in according with an embodiment of the present invention.
[0046] FIG. 10 is a top view of the locking assembly illustrated in FIG. 9 in an assembled configuration of the orthopedic device.
[0047] FIG. 11 is a perspective view of an alternate locking assembly in according with an embodiment of the present invention.
[0048] FIG. 12 is a perspective view of an alternate locking assembly in according with an embodiment of the present invention.
[0049] FIG. 13 is a perspective view of an alternate locking assembly in according with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0050] The humeral orthopedic device 1 of a shoulder prosthesis illustrated in FIGS. 1 to 6 comprises an anchor stem 2 which is intended to be introduced and anchored in the medullary canal of a humerus, after resection of its upper end. The stem 2 is provided with external channels 21 which are intended to facilitate its immobilisation in terms of rotation inside the medullary canal. The stem 2 is provided with an axial threaded hole 22 which extends along the longitudinal axis X 2 thereof.
[0051] The orthopedic device 1 also comprises a spacer 3 which is intended to allow longitudinal adjustment of the orthopedic device 1 taking into consideration the morphology of the patient and the fitting depth of the stem 2 in the humeral medullary canal. The spacer 3 may be selected from a set of spacers having different lengths and different diameters.
[0052] The spacer 3 has a cylindrical external radial wall 31 having a circular base. The spacer 3 also has a central bore 32 whose longitudinal axis X 3 is intended to be aligned with the axis X 2 in an assembled configuration of the orthopedic device 1 . The axis X 3 is also the axis of symmetry of the surface 31 . The bore 32 comprises a median portion 321 which has a first diameter D 1 and two portions 322 and 323 which form the opening of the bore 32 at the upper face 33 and the lower face 34 of the spacer 3 , respectively. The portions 322 and 323 have the same diameter D 2 which is greater than the diameter D 1 . In this manner, the median portion 321 of the bore 32 forms two shoulders at the bottom of the opening portions 322 and 323 .
[0053] The face 33 of the spacer 3 is provided with grooves 331 which extend radially around the axis X 3 . The face 34 is provided with grooves 341 of the same type, only the outline of which is visible in FIGS. 1 and 2 .
[0054] The upper face 23 of the stem 2 , at which the threaded hole 22 opens, is provided with radial grooves 231 which co-operate with the grooves 341 in order to immobilise the spacer 3 relative to the stem 2 in terms of rotation, about the aligned axes X 2 and X 3 , when the surfaces 34 and 23 are in abutment against each other.
[0055] The orthopedic device 1 also comprises a metaphyseal portion 4 which forms a support for an insert 5 which defines a concave articular surface 51 which is intended to interact with a convex articular surface which belongs to a glenoid component of the shoulder prosthesis or an intermediate component when use is made of such an intermediate component.
[0056] The metaphyseal portion 4 is provided with a longitudinal bore 41 which is centred about an axis X 4 which is intended to be aligned with the axes X 2 and X 3 in an assembled configuration of the orthopedic device 1 . The bore 41 comprises a median portion 411 whose diameter is designated D 3 . The bore 41 also comprises a portion 412 which opens at a face 42 which is intended to be in abutment with the face 33 of the spacer 3 in an assembled configuration of the orthopedic device 1 . The diameter of the portion 412 is designated D 4 . This diameter D 4 is substantially equal to the diameter D 2 . The bore 41 comprises a third portion 413 which adjoins the portion 411 and extends counter to the portion 412 in relation to the portion 411 . The diameter of the portion 413 is designated D 5 . The bore 41 finally comprises a fourth portion 414 which opens at a face 43 of the portion 4 which is inclined relative to the axis X 4 and which defines the bottom of the housing for receiving the insert 5 in the portion 4 . The diameter of the recess 414 is designated D 6 . The diameter D 5 is greater than the diameter D 4 and less than the diameter D 6 .
[0057] The threaded hole 22 does not extend as far as the level of the face 23 of the stem 2 , since a countersinking 221 is brought about in the connection zone between the threaded hole 22 and the face 23 . The countersinking 221 has a diameter D 7 which is substantially equal to the diameter D 2 . In fact, the portions 322 , 323 , 412 , 413 and 414 of the bores 32 and 41 are also countersinkings which are brought about around the median portions 321 and 411 , respectively.
[0058] Grooves 421 extend radially over the face 42 of the portion 4 around the axis X 4 . Those grooves have a shape similar to that of the grooves 331 , with which they can be engaged.
[0059] When the orthopedic device 1 is assembled, two rings 81 and 82 are secured in the countersinkings 221 and 322 , respectively. The rings 81 and 82 allow relative transverse immobilisation of the portions 2 , 3 and 4 of the orthopedic device 1 to be brought about during assembly. In practice, the rings 81 and 82 are identical.
[0060] When those portions 2 , 3 and 4 are in abutment with each other, it is possible to rotate the portion 4 about the axis X 4, with the surfaces 23 and 34 or 33 and 42 being moved away from each other in order to adjust the angular orientation of the insert 5 relative to the axes X 1 , X 2 and X 3 which define the longitudinal axis X 1 of the orthopedic device 1 .
[0061] When this temporary assembly is brought about, a screw 9 is introduced successively into the bore 41 then the bore 31 and the threaded hole 22 . The shank of the screw 9 is designated 91 and its head is designated 92 . The longitudinal axis of the shank 91 is designated X 9 and is aligned with the axes X 1 , X 2 , X 3 and X 4 in an assembled configuration of the orthopedic device 1 .
[0062] The head 92 is provided with engagement features 921 which are arranged at its external radial face 922 . In the illustrated embodiment the engagement features 921 comprise a plurality of peripheral channels. The head 92 is also provided with four grooves 923 which allow it to co-operate with a flat or cross-head screwdriver in order to move it in rotation about the axis X 9 when it is screwed into the threaded hole 22 . When the orthopedic device 1 is assembled, the screw 9 is screwed into the threaded hole 22 until its head 92 moves firmly into abutment against the bottom 4131 of the portion 413 of the bore 41 . The elements which constitute the orthopedic device 1 are then firmly retained in position relative to each other, the grooves 231 and 341 , on the one hand, and 331 and 341 , on the other hand, being engaged with each other, which contributes to the immobilisation in terms of relative rotation of the portions 2 , 3 and 4 about the aligned axes X 1 , X 2 , X 3 and X 4 .
[0063] In order to prevent accidental unscrewing of the screw 9 , under the effect of repeated forces on the orthopedic device 1 , and particularly vibrations to which it may be subject, a locking stopper 10 is installed on the head 92 . That stopper comprises an annular portion 101 at the centre of which an opening 102 is defined and from which two pins 103 and 104 extend and are diametrically opposed in relation to the opening 102 . The pins 103 and 104 extend from the same face of the portion 101 . Those pins are separated by a distance d 10 which is substantially equal to or slightly greater than the diameter D 92 of the head 92 taken at the level of the bottom of the channels 921 . In this manner, the pins 103 and 104 may be arranged at one side and the other of the head 92 , being partially engaged in the channels 921 , the shape of the channels 921 being selected so as to substantially complement the shape of the internal portions of the pins 103 and 104 directed towards the opening 102 . In practice, the channels 921 are cylindrical and have generating lines in the form of an arc of a circle, and the pins 103 and 104 are cylindrical having a generating line which is circular, with a diameter substantially equal to that of the channels. The stopper 10 and the head 92 are fixed in terms of rotation when the pins 103 and 104 are engaged in the channels 921 .
[0064] The portion 413 of the bore 41 is further bounded by two engagement features 45 and 46 , in which the pins 103 and 104 are engaged when they are arranged around the head 92 in position in that portion 413 which forms a housing for receiving the head 92 . In the illustrated embodiment, the engagement features 45 , 46 comprise notches. The notches 45 and 46 open in the portion 413 . In this manner, when the head 92 is received in the housing formed by the portion 413 , it may be covered by the stopper 10 with the pins 103 and 104 being partially engaged in two of the channels 921 and the remainder being received in the notches 45 and 46 .
[0065] If the screw 9 begins to become unscrewed, indicated by the arrow F 1 in FIG. 7 , the pins 103 and 104 are moved in rotation by the channels about the axis X 9 and move into abutment with sides 451 and 461 of the notches 45 and 46 , which has the effect of locking the screw 9 in terms of rotation, which cannot be unscrewed any further.
[0066] Therefore, the stopper 10 constitutes a first embodiment for locking the screw 9 in terms of rotation relative to the metaphyseal portion 4 and, on that basis, other elements of the orthopedic device 1 , that is to say, the stem 2 and the spacer 3 .
[0067] An auxiliary screw 11 is provided in order to immobilise the stopper 10 on the head 92 . To that end, the head 92 is provided with a threaded hole 924 which is aligned with respect to the axis X 9 and in which the shank 111 of the screw 11 can be engaged, extending through the opening 102 of the stopper 10 . Once the stopper 10 is in position on the head 92 , with its pins engaged both in two of the channels 21 and in the notches 45 and 46 , it can thereby be immobilised on the head 92 by tightening the auxiliary screw 11 in the threaded hole 924 using a male key which is inserted into a polygonal recess 112 of the screw 11 .
[0068] In this manner, once the stopper 10 and the auxiliary screw 11 are in position, the screw 9 is not at risk of becoming unscrewed with an angular clearance greater than that corresponding to the displacement of the pins 103 and 104 in order to move into contact with the sides 451 and 461 of the notches 45 and 46 . That angular clearance may be relatively small owing to judicious selection of the respective dimensions of the pins 103 and 104 and the notches 45 and 46 .
[0069] Furthermore, the locking of the screw 9 in terms of rotation is brought about owing to co-operation of the pins 103 and 104 , on the one hand, and the notches 45 and 46 , on the other hand, even if the screw 9 is not completely tightened in the threaded hole 22 . In this manner, the assembly of the orthopedic device 1 is permanent even if the surgeon has not completely tightened the screw in the threaded hole 22 .
[0070] According to a variant of the invention which is not illustrated, the stopper 10 may be maintained in position on and around the head 92 by other mechanisms than the auxiliary screw 11 , in particular by a flange which is provided on the rear surface of the insert 5 , which flange then moves into abutment with the stopper 10 when the insert 5 is assembled on the portion 4 .
[0071] The invention has been illustrated with an orthopedic device 1 provided with a spacer 3 . However, it is applicable without such a spacer, the metaphyseal portion 4 being directly in contact with the stem 2 . For example, the grooves 231 , 341 , 331 , 421 preferably have the same size, shape and pitch. Consequently, the grooves 231 on the upper face 23 of the stem 2 can engage directly with the grooves 421 on the metaphyseal portion 4 .
[0072] The grooves 231 , 341 , 331 , 421 comprise an anti-rotation structure at the interface of the components 2 , 3 , 4 , which still permitting the components 2 , 3 , 4 to be positioned relative to each other in a discrete number of orientations around the longitudinal axes X 1 , X 2 , X 3 , X 4 (collectively “X”) of the orthopedic device 1 . The grooves 231 , 341 , 331 , 421 retain the components 2 , 3 , 4 in the desired orientation around the longitudinal axis X both before and after the screw 9 is engaged with the stem 2 . A variety of other structures are possible to perform the anti-rotation feature of the grooves 231 , 341 , 331 , 421 .
[0073] The stopper 10 may have only a single locking pin of the same type as the pins 103 and 104 or, conversely, more than two pins, for example, three or four pins which are advantageously distributed regularly around the centre axis of the opening 102 . The geometry of the portion 413 , in particular the number and the distribution of the notches 45 , 46 and the like, is/are adapted to the number and distribution of the pins.
[0074] In the embodiments illustrated in FIGS. 9 to 13 , elements similar to those of the first embodiment have identical reference numerals.
[0075] The orthopedic device 1 partially illustrated in FIGS. 9 and 10 comprise a screw 9 whose shank 91 is supposed to be screwed into an anchor stem which is not illustrated. The head 92 of the screw 9 is provided with an external peripheral tooth arrangement 921 , whose teeth generally have a triangular cross-section. In an assembled configuration of the orthopedic device 1 , the head 92 is received in a housing 413 which is provided in the metaphyseal portion 4 of the orthopedic device 1 . The housing 413 has a circular cross-section with a diameter which is strictly greater than that of the head 92 , and a notch 45 is provided in the portion 4 and opens in the housing 413 .
[0076] Furthermore, a locking ring 10 is provided in order to be introduced into the housing 413 around the head 92 , as illustrated by the arrow F 10 in FIG. 9 . The ring 10 is provided with an internal tooth arrangement 105 whose teeth have a triangular cross-section and a shape which complements the teeth of the tooth arrangement 921 . The radius of the tooth arrangement 105 is adapted to the radius of the head 92 in such a manner that, when the ring is arranged around the head 92 , the tooth arrangements 921 and 105 are engaged, which brings about fixing of the head 92 and the ring 10 in terms of rotation about the axis X 9 of the screw 9 .
[0077] The external radial surface 106 of the ring 10 has a circular cross-section with a diameter which is slightly less than that of the housing 413 , with the exception of a portion in which a rib 107 projects radially relative to the surface 106 which forms the external edge of the ring 10 . When the ring 10 is positioned around the head 92 in the housing 413 , the rib 107 is engaged in the notch 45 . The rib 107 extends radially outwards relative to the surface 106 sufficiently in order to lock the ring 10 relative to the portion 4 in terms of rotation about the longitudinal axis X 1 of the orthopedic device 1 with which the axis X 9 of the screw 9 is in alignment.
[0078] In this manner, once the screw 9 is tightened relative to the anchor stem and the portion 4 , its rotation about the axis X 9 is prevented by the ring 10 whose rib 107 can have only a small angular clearance in the notch 45 .
[0079] In FIGS. 9 and 10 , the reference numeral 925 designates a hexagonal recess for manoeuvring the screw 9 using an Allen key.
[0080] In the embodiment of FIG. 11 , the screw 9 is provided with a shank 91 and a head 92 whose external peripheral edge is circular, with the exception of a notch 921 . The head 92 is also provided with a hexagonal manoeuvring recess 925 .
[0081] The screw 9 is intended to be inserted into a bore 41 whose upper portion 413 forms a housing for receiving the head 92 . A pin 46 which extends parallel with a centre axis X 1 of the orthopedic device 1 and a longitudinal axis X 9 of the screw 9 , which are therefore in alignment, is arranged in the housing.
[0082] A locking ring 10 is provided so as to be arranged around the head 92 in the housing 413 . That ring carries, at its internal edge 108 , a tooth 105 whose dimensions allow it to be engaged in the notch 921 with minimal or zero angular clearance. The external peripheral edge 106 of the ring 10 is circular, with the exception of a sector in which a cut-out 107 is provided, which is intended to receive the pin 46 in an assembled configuration of the orthopedic device 1 . The edges of the cut-out 107 are designated 1071 and 1072 , respectively. When the screw 9 is positioned in the bore 41 , with its head 92 being received in the housing 413 , it is possible to engage the ring 10 around the head 92 and in the housing 413 , with the tooth 105 being arranged in the notch 921 , and the cut-out 107 is positioned around the pin 46 . Any rotational movement of the screw 9 about the axis X 9 is limited owing to the abutment of one of the surfaces 1071 or 1072 against the pin 46 .
[0083] In the embodiment of FIG. 12 , the screw 9 of the orthopedic device 1 comprises a shank 91 and a head 92 which is provided with a manoeuvring recess 925 . The head 92 is provided, at its upper face 926 opposite the shank 91 , with an annular tooth arrangement 921 which is provided around the centre axis X 9 of the screw and the recess 925 .
[0084] The housing 413 for receiving the head 92 which is provided in the metaphyseal portion 4 generally has a circular cross-section with an extension 45 which communicates with the main portion of the housing 413 .
[0085] A stopper 10 is further provided so as to be arranged above the head 92 in an assembled configuration of the orthopedic device 1 . That stopper comprises a centring portion 108 which is intended to be engaged in a correspondingly shaped recessed housing 928 formed at the face 926 . The stopper 10 is further provided with a tooth arrangement 105 whose geometry is adapted to that of the tooth arrangement 921 . In this manner, when the portion 108 is engaged in the housing 928 , the tooth arrangements 921 and 105 are in engagement and the components 9 and 10 are fixed in terms of rotation about the axis X 9 .
[0086] The peripheral edge of the stopper 10 is provided with a catch 107 which is engaged in the notch 45 in an assembled configuration of the orthopedic device 1 . The possibility of angular rotation of the screw 9 about the axis X 9 is thereby limited owing to the abutment of the catch 107 against one or other of the edges 451 and 452 of the notch 45 .
[0087] In the embodiment of FIG. 13 , the screw 9 of the orthopedic device 1 comprises a shank 91 and a head 92 which is provided with two projections 921 and 921 ′ which extend from the face 926 of the head 92 opposite the shank 91 .
[0088] A stopper 10 is further provided so as to be mounted on the head 92 in an assembled configuration of the orthopedic device 1 . That stopper comprises two housings 105 and 105 ′ whose geometry is adapted in order to receive the projections 921 and 921 ′ when the stopper 10 is assembled on the head 92 . In this manner, the components 9 and 10 are fixed in terms of rotation.
[0089] The stopper 10 is further provided with two fins 107 and 107 ′ which are intended to be engaged in two notches 45 and 46 which are provided in the metaphyseal portion 4 adjacent to a housing 413 for receiving the head 92 .
[0090] As above, when the stopper 10 is assembled on the head 92 , its rotation about the axis X 9 is prevented by co-operation of the fins 107 and 107 ′, on the one hand, and the notches 45 and 46 , on the other. This allows rotation of the screw 9 to be locked.
[0091] In the embodiments illustrated in FIGS. 9 to 13 , it is possible to use a member for immobilising the ring or the stopper 10 which is similar to the auxiliary screw 11 of the first embodiment in terms of its function.
[0092] The invention has been illustrated in the case of a humeral component of a shoulder prosthesis whose articular surface is concave. However, it may be applied to components whose articular surface is convex. Generally, the invention may be applied to any prosthesis component comprising an anchor stem, irrespective of the geometry of that stem, and a metaphyseal portion which are fixed by a screw, whatever the prosthesis to which it belongs. In particular, the invention also applies to elbow, hip and knee prostheses.
[0093] According to a variant of the invention which is not illustrated and which may be applied to all the embodiments, the metaphyseal portion 4 may itself form the articular surface 51 .
[0094] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the inventions. The upper and lower limits of these smaller ranges which may independently be included in the smaller ranges is also encompassed within the inventions, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either both of those included limits are also included in the inventions.
[0095] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which these inventions belong. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present inventions, the preferred methods and materials are now described. All patents and publications mentioned herein, including those cited in the Background of the application, are hereby incorporated by reference to disclose and described the methods and/or materials in connection with which the publications are cited.
[0096] The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present inventions are not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed.
[0097] Other embodiments of the invention are possible. Although the description above contains many specific examples, these should not be construed as limiting the scope of the invention, but as merely providing illustrations of some of the presently preferred embodiments of this invention. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the inventions. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventions. Thus, it is intended that the scope of at least some of the present inventions herein disclosed should not be limited by the particular disclosed embodiments described above.
[0098] Thus the scope of this invention should be determined by the appended claims and their legal equivalents. Therefore, it will be appreciated that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. | An orthopedic device for ball and socket joint reconstruction. The anchor stem is adapted to be anchored in a medullary canal. A proximal portion of the anchor stem includes a threaded hole oriented along a longitudinal axis thereof. Metaphyseal portion includes a proximal end with recess and a longitudinal bore in fluid communication with the recess, and a distal end adapted to interface with the proximal portion of the anchor stem. An anti-rotation structure is preferably located at an interface of the anchoring stem to the metaphyseal portion to prevent rotation of the anchor stem relative to the metaphyseal portion around the longitudinal axis. A fastener is provided to extend through the longitudinal bore and to engage with the threaded hole on the anchor stem to fix the metaphyseal portion to the anchoring stem. The locking assembly is located in the recess and mechanically couples the head of the fastener to the metaphyseal portion to limit rotation of the fastener relative to the metaphyseal portion. An insert with an articular surface is provided that engages with the proximal end of the metaphysical portion and extends over the recess in the metaphyseal portion. | 0 |
BACKGROUND OF THE INVENTION
The use of carbon discs as a friction element in aircraft wheel and brake assemblies have gained acceptance as a way of increasing the payload of an aircraft.
In U.S. Pat. No. 3,639,197, it is disclosed how a continuous carbon fiber can provide a carbon disc with the structural unity needed to absorb repeated braking torque. Unfortunately, carbon oxidizes in an oxidizing atmosphere such as air and when the temperature of the carbon is above 800° F. the oxidization increases very rapidly. When carbon friction discs are used in aircraft braking systems, thermal conditions above 800° F. are often experienced. The swept or mated areas of such carbon discs shield each other from the oxidizing effects caused by air, however, the non-swept or mated areas are fully exposed to the oxidizing effects resulting from being exposed to air. Prolonged oxidization of the exposed areas of the carbon discs results in a loss of thermal heat sink capacity and structural strength which ultimately can cause a brake failure.
In U.S. Pat. No. 3,914,508 a method is disclosed for protecting a carbon substrate in a moist environment from oxidation by coating a selected surface thereof with a boron and metallic mixture. However, it is difficult to maintain a uniform coating thickness over the entire peripheral surface and as a result where the coating is limited or absent, deterioration of the carbon substrate often takes place after repeated brake applications.
In a further attempt to protect a carbon friction material, a metal driving ring as disclosed in U.S. Pat. No. 3,473,637, was pressed on to the outer periphery of a carbon disc to establish a unitary structure and thereby prevent oxidation of the non-swept or rubbed area of the carbon disc. During frictional operation when the thermal energy produced is low, such protection is effective. However, as the thermal energy generated during a brake application increases, the unity of the carbon material and steel ring change in direct proportion to the differences in their thermal coefficients of expansion placing a stress on the carbon disc. As a result of such stress, after a repeated number of frictional engagements at high temperatures, structural defects can occur along the periphery of the carbon disc. Thereafter, oxygen in the surrounding air can enter and degrade the underlying carbon friction disc.
U.S. Pat. No. 3,972,395 discloses a protection member which matches the coefficient of friction of the carbon friction disc. The protection member, which includes a woven carbon sheath and a protecting screen, is bonded to the peripheral non-swept surface to protect the underlying carbon friction disc. In order to protect the driving slots on the rotor member, a reinforcing plate is attached to the peripheral surface by a driving pin that extends through the carbon friction disc. Unfortunately, these driving pins are located in a high stress area and under some extreme conditions a structural failure may occur in the area of the driving pins.
In copending U.S. Patent Application Ser. No. 958,213, a series of flexible metal cap members surround the driving splines of a carbon disc. The metal cap members have projections which extend into the root section between the driving splines. These projections are connected together to establish a continuous ring of protection for the peripheral surface of the carbon disc. During a brake application, adjacent carbon disc contact the metal cap members to establish a barrier that prevents the passage of air to carbon discs that could degrade the driving splines through oxidization.
SUMMARY OF THE INVENTION
I have discovered a protection system that reduces the possibility of degradation of a plurality of carbon discs in a wheel and brake assembly resulting from a brake application. The protection system includes a metal drive ring having an inner surface separated from an outer surface by both rubbed and non-rubbed surfaces. A series of drive keys are located on either the inner or outer surfaces of the metal drive ring while a series of slots are located on the other surfaces. Each carbon disc has a friction producing surface that extends from a first peripheral surface to a second peripheral surface. The first peripheral surface has either torsional keys or slots that engage the inner or outer surface of the metal drive ring to establish a coupling between the drive ring and the carbon disc. During a brake application, the wear surfaces adjacent to the second peripheral surface of the carbon disc engage the rubbed surfaces on adjacent metal drive rings to prevent the passage of air to the coupling which could degrade or oxidize the first peripheral surface on an adjacent carbon disc.
It is an object of this invention to provide a protection system for reducing the possibility of oxidization of a carbon disc in a wheel and brake system.
It is another object of this invention to provide a coupling system between a wheel and brake assembly through a series of metal drive rings and concentric carbon disc that reduces the possibility of degradation of the carbon disc as a result of a brake application.
It is a further object of this invention to provide a wheel and brake assembly having a plurality of friction members, each of which includes a metal drive ring loosely coupled to a substantially concentric carbon disc. The carbon disc engages an adjacent carbon disc and a portion of the metal drive rings during a brake application to develop a barrier that prevents the passage of air to an adjacent coupling which could degrade the carbon disc.
It is a still further object of this invention to provide a friction member made of a metallic drive ring and a carbon disc with a coupling that permits the drive ring and carbon disc to expand and contract in response to thermal energy changes without inducing stress in each other.
These and other objects should be apparent from reading this specification and viewing the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a wheel and brake assembly for use on an aircraft having a plurality friction member made according to the principles of this invention;
FIG. 2 is an external view of a stator for use in the wheel and brake assembly of FIG. 1;
FIG. 3 is an external view of a rotor for use in the wheel and brake assembly of FIG. 1; and
FIG. 4 is a sectional view of a portion of the stators and a rotor of FIG. 1 showing the relationship between the friction members during a brake application.
DETAILED DESCRIPTION OF THE INVENTION
The wheel and brake assembly 10 shown in FIG. 1 includes a wheel 12, only partially shown that is rotatably mounted on a stationary axle 11 and a brake 15 that is mounted on a stationary carrier member 14 fixed to the axle 11 by locating pin 16 in slots 18 and 20. Since the structure for rotatably mounting wheel 10 to axle 11 and fixing the stationary carrier member 14 to the axle 11 is well known, further description thereof is not deemed to be necessary.
The wheel 12 has a first section 32 that includes a hub 36 and a rim 38 interconnected to each other by a plurality of spokes 40 and a second section 34. The first and second sections 32 and 34 are joined together by a plurality of bolts 30 after a tire is mounted on the wheel 12.
The carrier member 14 contains a plurality of fluid motors 17 (only one is shown in FIG. 1) which are connected to a fluid pressure source through conduit 23.
Each fluid motor 17 has a piston 24 located in a bore 22 that moves a pressure plate 26 toward a backing plate 28 in response to a brake actuation signal in the form of an increase in fluid pressure transmitted through conduit 23 to actuation chamber 30. The backing plate 28 is connected to a flange 42. The sleeve 44 radially projects from sleeve 44 which is secured to the carrier member 14 by a plurality of circumferentially spaced bolts 48.
The disc brake illustrated in FIG. 1 includes a plurality of interleaved rotors 50, which are splined to and are rotated by the aircraft wheel 12 and a plurality of stators 52, which are splined to sleeve 44 of the torque tube. Both the rotors and stators are movable axially by piston 24 and are sometimes referred to as a brake "stack".
The pressure plate 26, which is attached to piston 24 of the fluid motor 16 has a carbon friction pad 46 for forcing the rotors 50 and stators 52 against each other and the entire stack against a carbon friction pad 48 on the backing plate 28. It is the frictional engagement of the rotatable rotors 50 with the stationary stators 52 which produces the braking action of the aircraft wheel.
Each of the rotors 50, one of which is shown in more detail in FIG. 3, and each of the stators 52, one of which is shown in more detail in FIG. 2, includes a metallic drive ring which surrounds or is surrounded by a carbon friction disc.
In more particular detail, each rotor 50 has a metal drive ring 54 which surrounds a carbon friction disc 56. The metal drive ring 54 has an inner surface 58 separated from an outer surface 60 by a swept or rubbed section 62 and a non-swept or rubbed section 64. As shown in FIG. 3, the limit of the swept section 62 is defined by dashed line 63. The non-swept section 64 has a plurality of slots 66, 66' . . . 66 n located on the outer surface 60 which are mated with corresponding keys 68 . . . 68 n , only one being shown, fixed to rim 38 of the wheel 12. A series of torsional keys 70, 70' . . . 70 n which are located on the inner surface 58 of drive ring 54 are matched with a series of slots 72, 72' . . . 72 n on peripheral surface 74 of the carbon disc 56. The wear surface of the carbon disc 56 extends from the inner diameter or peripheral surface 76 to the outer diameter or peripheral surface 74. The coupling created through the engagement of keys 70, 70' . . . 70 n in slots 72, 72' . . . 72 n is designed to have sufficient tolerance between peripheral surface 74 and inner surface 58 such that any dimensional changes in either the carbon disc 56 or the metal drive ring 54 resulting from a temperature change does not place the other member in a stressed condition.
Similarly, each stator 52 shown in FIG. 2 has a metal drive ring 78 surrounded by a carbon disc 80. The metal drive ring 78 has an inner diameter 82 separated from an outer diameter or surface 84 by a swept or rubbed section 86 and a non-swept or rubbed section 88. As shown in FIG. 2, the limit of the swept section 86 is defined by dashed line 87. The non-swept section 86 has a series of slots 90, 90' . . . 90 n located on the inner diameter 82 that are matched with corresponding keys 92 . . . 92 n on sleeve or barrel 44 of the torque tube and a series of torsional keys 94, 94' . . . 94 n located on the outer diameter surface 84 that are mated with slots 96, 96' . . . 96 n on the inner peripheral surface 98 of carbon disc 80 to establish a coupling. The wear surface of the carbon disc 80 extends from inner peripheral surface 98 to the outer peripheral surface or diameter 100. Similarly, as with the rotor coupling, tolerance between the outer surface 84 of the metal drive ring 78 and inner peripheral surface 98 of the carbon disc 80 is such that any dimensional changes in the carbon disc 80 and the metal drive ring 78 caused by changes in temperature does not place either member in a stressed condition.
MODE OF OPERATION OF THE INVENTION
When an aircraft is moving on the ground, the tire on wheel 12 engages the ground and rotates the wheel 12. Since rotors 50 are connected to wheel 12, they also rotate while stators 52 remain stationary with respect to axle 11. To operate the brakes, the pilot activates a fluid pressure source (not shown) which is communicated through conduit 23 into chamber 30. This fluid pressure in chamber 30 acts on piston 24 and provides an axial force which moves pressure plate 26 toward backing plate 28 to bring the friction members of the rotors 50 and stators 52 into frictional engagement. This frictional engagement converts mechanical energy to thermal energy in the rotors 50 and stators 52.
As shown in FIG. 4, the wear surface on carbon disc 80 of each stator 52 engages the carbon disc 56 and the swept surface 62 on the metal drive ring 54. Similarly, the wear surface on carbon disc 56 of each rotor engages carbon disc 80 and the swept surface 86 on metal drive ring 78.
Thus, during a brake application, with the stators 50 and rotors 52 moved toward the backing plate 28 by the pressure plate 26, a barrier is created that prevents the passage of air to the couplings between the metal drive rings and the carbon discs. Without oxygen from the air being available to combine with the carbon discs, the drive splines are protected from degradation and thus the structural strength is not reduced after repeated brake engagements.
It should be noted that the metallic drive rings 78 and 54 act as heat shields to inhibit the transfer of thermal energy toward the wheel 12 and the torque tube 44. Thus, the pressure of the fluid in the tires is not increased substantially by the heat generated in the brake 15.
Since the metal drive rings 54 and 78 and the carbon friction discs 56 and 80 of each rotor 50 and stator 52 have the same thickness, the rubbed surfaces 62 and 86 produce friction when engaged with the carbon discs. However, as the brake lining wears, these rubbed surfaces 62 and 86 of the metallic drive rings also wear and must be replaced with the carbon friction discs when the brake is relined. | A wheel and brake assembly having a plurality of friction members moved by a pressure plate toward a backing plate to affect a brake application. Each friction member has a metallic drive ring coupled to a carbon disc. The carbon disc on a first friction member engages a portion of the drive ring on adjacent friction members to prevent the passage of air to the coupling that could degrade the carbon disc through oxidization. | 5 |
FIELD OF THE INVENTION
[0001] The present invention relates to a container that is used to contain biopharmaceutical material that is intended to be frozen for storage and shipping.
BACKGROUND OF THE INVENTION
[0002] Biopharmaceutical drugs are manufactured in bulk amounts in order to lower the cost per unit of the drug. Oftentimes, the drugs are manufactured in a liquid form, with drug-containing solutes being homogeneously dissolved in a liquid solution. In order to enhance the lifetime of the drug, the drug is frozen in a container that is suitable for transport.
[0003] It is well known that solutes in bulk liquid solutions are subject to a stress force induced by the advancement of the ice front during the freezing process. Depending on the ice front velocity, solutes can be either trapped in the solid phase or pushed away from the ice-liquid interface into the bulk liquid region. The migration of the solute into the liquid phase results in a heterogeneous solute distribution in the frozen material. Testing of such migration has indicated that the difference of solute percentage in the solution can be between 60% and 300% of the initial (pre-freezing) value. One solution to limit this migration is to reduce the time required to freeze the solution.
[0004] The heat transfer process during freezing is well characterized by the Stefan solution equation, which correlates the thickness of the ice formed after a period of time when the temperature of the cold surface as well as the ice conductivity and heat of fusion are known. The equation indicates that the time required to freeze liquid in a container is a function of the square of the distance that heat travels from the liquid. Therefore, a reduction in the time required to freeze the liquid requires a reduction in the distance that the heat must travel to be removed from the liquid.
[0005] It would be beneficial to develop a container in which a liquid drug may be stored and frozen, such that the container has a geometry that reduces the migration of solute during the freezing process.
SUMMARY OF THE INVENTION
[0006] Briefly, the present invention provides a container for storing a biopharmaceutical drug product. The container includes two side surface walls, typically planar, and a plurality of smaller side walls, which circumscribe and connect the surface area planar walls and define the interior of the container.
[0007] In one embodiment, the invention relates to a container for storing a biopharmaceutical drug product comprising two relatively large surface area planar surfaces extending opposite to one another. For example, a first and second planar surface can be intersecting, non-parallel, or parallel to each other. In addition, one embodiment also includes a plurality of relatively small surface area side walls circumscribing each of the first and second planar surfaces, wherein the plurality of side walls connect the first and second relatively large surface area surfaces, all of said surfaces collectively defining the interior of the container.
[0008] In another embodiment, the first and second relatively large surface area planar surfaces are parallel surfaces.
[0009] In yet another embodiment of the invention, one of the plurality of side walls extends at an oblique angle relative to an adjacent of the plurality of side walls. In another embodiment, the remaining side walls each define at least a portion of a side of a rectangle.
[0010] In another embodiment, the container further comprises an opening formed within one of the plurality of side walls. In another embodiment, container further comprises a nipple formed around the opening and extending outwardly from the one of the plurality of side walls. In yet another embodiment, the container has a nipple that extends within the rectangle.
[0011] In another embodiment of the invention, the container's second planar surface is spaced from the first planar surface by a distance of between about 5 to 11 centimeters. In another embodiment, the second planar surface is spaced from the first planar surface by a distance of about 8 centimeters.
[0012] In a further embodiment, the container's first planar surface is spaced from the second planar surface by a distance, and wherein a maximum dimension of each of the first and second planar surface is no more than ten times that of the distance.
[0013] In another embodiment of the invention, the container's first and second planar surface and the plurality of side walls all have a thickness of between about 0.1 to 0.95 centimeters.
[0014] Additionally, the present invention includes a method of freezing a biopharmaceutical product. The method comprises the step of providing a container, as described above. The method further includes the steps of inserting the biopharmaceutical product into the container; subjecting the container to freezing conditions; and freezing the biopharmaceutical product within the container while maintaining a generally homogenous solution.
[0015] In another embodiment of the invention, the specification discloses a method of freezing a biopharmaceutical product comprising the steps of providing a container having two relatively large surface area planar walls extending opposite to one another and a plurality of relatively small surface area side walls circumscribing each of the first and second planar surfaces, wherein the plurality of side walls connect the first and second planar surfaces, all of said surfaces collectively defining the interior of the container. The method also includes, inserting the biopharmaceutical product into the container, subjecting the container to freezing conditions, and freezing the biopharmaceutical product within the container while maintaining a generally homogenous solution.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The foregoing summary, as well as the following detailed description of desired embodiments of the invention, will be better understood when read in conjunction with the appended drawings, which are incorporated herein and constitute part of this specification. For the purposes of illustrating the invention, there are shown in the drawings an embodiment that is presently desired. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings, the same reference numerals are employed for designating the same elements throughout the several figures. In the drawings:
[0017] FIG. 1 is a perspective view of a container according to one embodiment of the present invention;
[0018] FIG. 2 is a sectional view of the container of FIG. 1 ; and
[0019] FIG. 3 is a sectional view of the container taken along lines 3 - 3 of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0020] Certain terminology is used herein for convenience only and is not to be taken as a limitation on the present invention. The terminology includes the words specifically mentioned, derivatives thereof and words of similar import. The following describes a desired embodiment of the invention. However, it should be understood based on this disclosure, that the invention is not limited by the desired embodiment of the invention.
[0021] Referring generally to the figures, a container 100 for receiving, freezing, and storing a biopharmaceutical product 102 is shown.
[0022] Referring specifically to FIGS. 1 and 2 , the container 100 includes a first generally planar wall 110 and a second generally planar wall 112 . In one embodiment, the first and second planar walls 110 and 112 are generally parallel to each other and are spaced apart from each other by a distance. The “distance” that separates the first and second planar walls 110 and 112 is determined by the width of the smaller side walls. In another embodiment of the invention, the dimensions of the container mentioned herein are the outside dimension/measurements of the container. For example, the distance between the first and second planar walls 110 and 112 can be 8 cm if the width of the smaller side walls 120 , 122 , 124 , 126 , and 128 are all 8 cm wide. In another embodiment, the first and second side planar walls 110 and 112 may be spaced apart from each other by about 5 to about 11 centimeters in order to provide a sufficient rate of freezing of the biopharmaceutical product 102 in the container 100 , while still providing acceptable height and length dimension of the container 100 to retain a desired fluid volume.
[0023] The time, t, required to fully freeze a solution in such a container is determined by the Stephan Equations (below), which calculate freezing time in a container as a function of distance. The Stephan equations are as follows:
[0000] t = ρ s λ ′ 2 k s ( T f - T W ) δ 2 Equation 1 λ′=λ+ Cp L ( T i −T f ) Equation 2
[0024] where:
[0025] δ=heat transfer length (m)
[0026] λ=latent heat of fusion (J/kg)
[0027] ρ s =density of ice (kg/m 3 )
[0028] Cp L =heat capacity of the solution (J/kg.° K.)
[0029] k s =heat conductivity of ice (W/m. ° K.)
[0030] T i =initial temperature of the solution (° K.)
[0031] T f =freezing temperature of the solution (° K.)
[0032] T w =freezer wall temperature (° K.)
[0033] t=time (s)
[0034] Different solutions, which represent solutions that may be stored in the container 100 , were analyzed to determine freeze rates for different container sizes. The solutions tested were distilled water, 0.5 M NaCl solution, and formulation buffers comprising 12% and 18% sucrose. The freezing times were about the same for these solutions, with the note that the freezing temperature of the 0.5 M NaCl and the formulation buffers was −1.5+0.5 degrees Celsius, as opposed to 0 degrees Celsius for the water.
[0035] Using equations 1 and 2, and the aforementioned baseline solutions, with the distance between the planar walls 110 and 112 of the container 100 being 5 cm, which corresponds to a heat transfer length of 2.5 cm since the beat is removed from both sides of the container 100 , freezing time was calculated to be about 12.6 minutes. Thus, the average ice front velocity is about 119 mm/hr. Similarly, the average ice front velocity of the container 100 with a distance 8 of 11 cm, which corresponds to a heat transfer length of 5.5 cm, is about 54 mm/hr. Freezing time was calculated to be about 61.1 minutes.
[0036] In one embodiment, in order to minimize solute re-distribution in the container 100 during freezing, the freezing velocity is to be at least 50 mm/hr or faster, corresponding to a maximum surface area planar wall spacing of about 11 cm. Further, in another embodiment, a minimum planar wall spacing of the container 100 is about 5 cm. Otherwise, the container 100 to be used for large bulk material, for example about 5 to about 50 liters would necessarily have to be very thin and very tall in order to contain a sufficient volume of solution. An increase in the height of the container 100 would be required to obtain a desired internal volume, but would raise the center of gravity of the container 100 , allowing the container 100 to flip over easily. In one embodiment, a maximum dimension of each of the first and second planar walls 110 and 112 is no more than ten times that of the distance between the first and second planar walls 110 and 112 .
[0037] In one embodiment, the “dimensions” of each of the first and second planar walls are the height and width of 110 and 112 . For example, if the distance between 110 and 112 is 6 cm, then the height and width of 110 and 112 should not exceed 60 cm. In another embodiment, the outside dimensions of the container are only limited in size and shape by the size and shape of the freezer used to store the containers.
[0038] Generally, in one embodiment of the invention, the planar interwall spacing is about midway between the limits of 5 cm and 11 cm (about 8 cm) to cover a range of conditions of materials to be contained. In another embodiment, planar interwall spacing is about 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, or 11 cm to cover a range of conditions of materials to be contained. However, an interplanar wall distance from about 5 cm to about 11 cm should provide a desired freezing time for a wide range of materials and should keep any common solute redistribution within an acceptable limit. For different solutions with different thermodynamic properties, the rate of freezing will likely vary slightly, but it is believed by the inventor(s) that the distilled water, 0.5 M NaCl solution, and formulation buffers discussed above are representative of the thermodynamic properties of the types of solutions that may be stored within the container 100 .
[0039] While the interplanar wall spacing may be from 5 to 11 cm and is generally to be about 8 cm in one embodiment, the height and width of each of the first planar wall 110 and the second planar wall 112 may be varied, depending upon the size of the freezer (not shown) into which the container 100 is intended to be placed to freeze the biopharmaceutical product 102 in the container 100 , or by the desired interior volume of the container 100 . For example, for the container 100 having a volume of 8 liters, either a length of about 300 millimeters and a height of about 500 millimeters or a length of about 400 millimeters and a height of about 400 millimeters provides the desired volume of the container 100 .
[0040] A plurality of side walls circumscribe each of the first planar wall 110 and the second planar wall 112 . As can be seen in FIG. 2 , five side walls 120 , 122 , 124 , 126 , 128 connect the first planar wall 110 and the second planar wall 112 , forming an interior volume within which the biopharmaceutical product 102 is contained. Four of the side walls 120 , 122 , 124 , 126 are orthogonal to an adjacent side wall 120 , 122 , 124 , 126 , while the fifth side wall 128 extends at an oblique angle relative to at least one of its adjacent side walls 120 , 126 . The side walls 120 , 122 , 124 , 126 , 128 all fit within an area defined by an imaginary rectangle 130 , with the side walls 122 , 124 forming the entire corresponding side walls of the rectangle 130 and side walls 120 , 126 forming a portion of the remaining side walls of the rectangle 130 . In another embodiment, the side walls 120 , 122 , 124 , 126 , 128 all fit within an area defined by an imaginary square (not shown).
[0041] The first and second planar walls 110 , 112 and the side walls 120 , 122 , 124 , 126 , 128 also serve to enhance heat transfer between the biopharmaceutical product 102 in the container 100 and the environment external to the container 100 . In one embodiment, the first and second planar walls 110 , 112 and the side walls 120 , 122 , 124 , 126 , 128 all have a thickness of between about 0.1 and 0.95 centimeters. In another embodiment, the first and second, planar walls 110 , 112 and the side walls 120 , 122 , 124 , 126 , 128 all have a thickness of between about 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, or 0.95 cm. The walls 110 , 112 , 120 , 122 , 124 , 126 , 128 are of such thickness to enhance heat transfer through the walls 110 , 112 , 120 , 122 , 124 , 126 , 128 during freezing of the biopharmaceutical product 102 within the container 100 .
[0042] The side wall 128 includes a circular opening 132 formed therein. The opening 132 allows the biopharmaceutical product 102 to be poured into and out of the container 100 . In one embodiment, the circular opening 132 is sealed with a plug (not shown) that provides adequate sealing of the opening 132 and containment of the biopharmaceutical product 102 . In another embodiment, a nipple 134 having external threads 136 is formed around the opening 132 and extends outwardly from the side wall 128 . The nipple 134 is sized such that the nipple 134 remains within the rectangle 130 . The nipple 134 remains within the rectangle 130 to accommodate the entire container 100 when the container 100 is placed into a larger container, such as a freezer, with minimal wasted space between the container 100 and the freezer.
[0043] A removable cap 138 is releasably connectable to the nipple 134 . In one embodiment, the cap 138 includes internal threads (not shown) that engage with the external threads 136 of the nipple 134 for a threaded fit. In another embodiment, the cap 138 includes a seal (not shown) that is located on the underside of the cap 138 to provide adequate sealing of the cap 138 with the nipple 134 .
[0044] In one embodiment, the container 100 is constructed from high density polyethylene (HDPE), because it is known that HDPE is biocompatible with the types of biopharmaceutical product 102 that is intended to be stored within the container 100 . However, those skilled in the art will recognize that other biocompatible materials may be used for the container 100 as well. For example, glass, metal, other biocompatible plastics, etc. One embodiment of the invention is that the material used to construct the container 100 should be rigid enough to maintain is structure or shape during its use and under freezing conditions. Furthermore, the material should be able to sustain the handling at a temperature ranged between +20° C. and −70° C.
[0045] In use, the cap 138 is removed from the nipple 134 and the biopharmaceutical product 102 is placed, transferred, or poured into the interior of the container 100 . After the container 100 is filled with a desired amount of the biopharmaceutical product 102 , the cap 138 is replaced over the nipple 134 , sealing the container 100 . The container 100 may now be transported to a freezer for freezing of the biopharmaceutical product 102 . The container 100 is subjected to a heat transfer process by which heat contained in the container 100 and in the biopharmaceutical product 102 being stored within the container 100 is absorbed by the lower temperature of the exterior environment of the freezer surrounding the container 100 . The relatively large surface areas of the first and second planar walls 110 , 112 allow the biopharmaceutical product 102 to freeze while maintaining a generally homogeneous concentration of solute within the frozen solution. In another embodiment, the biopharmaceutical product 102 may be a mixture of at least one biopharmaceutical product, such as monoclonal antibodies, DNA, DNA vaccines, peptides, and other protein molecules.
[0046] Further, in another embodiment, the present invention is directed to a container that is used to remove heat from within the container over a reduced period of time to reduce the formation of a heterogeneous solution within the container, those skilled in the art will recognize that the container may also be used to add heat to material within the container over a reduced period of time and with reduced localized temperature differentiation, if so desired.
[0047] Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention. | A container for storing a biopharmaceutical drug product is disclosed. The container includes two surface area planar walls. A plurality of smaller side walls circumscribing each of the planar walls. A method of freezing at least one biopharmaceutical product in the container is also disclosed. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application Ser. No. 60/805,629, filed on Jun. 23, 2006, herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
This invention relates generally to a modular boiler control, and more particularly to a modular boiler control in which a master boiler is networked with a least one slave boiler to control the heating loop of a structure.
BACKGROUND OF THE INVENTION
Known boiler systems include a boiler connected to an external control such as a thermostat or a building management system. The external control typically senses boiler temperature, controls boiler setpoint, performs outdoor reset functions and controls the boiler firing cycle.
In multiple boiler systems, each boiler is connected to a single centralized external control from which all boiler operations are performed. The centralized control typically performs the above-listed functions for each individual boiler as well as sequencing or staging the firing of all boilers to control heating throughout a structure. To accomplish this, each boiler is separately connected to the external control via wiring that is run within the structure to be heated. Moreover, boiler wiring is generally run through conduits to protect the wiring and ensure the reliability of the system.
As will be appreciated, multiple boiler systems can be costly to purchase and install as they require significant wiring from the external control to each individual boiler. In one known system, for example, control cables between a boiler control module and individual boilers consist of extended runs of 3-wire circuits. As stated, such wiring is typically protected with a conduit of plastic or like material, which requires installation.
Moreover, the addition of a boiler in known multiple boiler systems requires supplemental wiring to connect the new boiler to the external control. The subtraction of a boiler from such systems requires removal of control wiring which can also be costly. Further, the addition or subtraction of a boiler may also necessitate manually resetting or adjusting the external control, such as a building management system, to account for a changed number of total boilers. It is also possible that the existing external control may not have the capacity for an additional boiler and may require modification or replacement.
Additionally, if a boiler is not functioning properly or requires routine maintenance, it must be brought offline. In known systems, bringing an individual boiler offline can necessitate shutting the entire system down creating a no heat situation within a structure. Such system-wide shutdowns can be undesirable particularly when the outside air temperature is low. Further, if a boiler is not functioning properly manual adjustment of the external control may be necessary to adjust the firing of the other boilers to compensate for the faulted unit. Manual adjustment may also be required to bring a previously failed boiler back online if the fault resolves itself. As will be appreciated, manual adjustment of an external control can be time consuming and can result in periods of insufficient heat until adjustment is complete.
Furthermore, in known multiple boiler systems, individual boilers are typically fired in a first on/first off or first on/last off methodology. Neither of these approaches, however, directly assesses which individual boiler has the least runtime. As will be apparent, it is generally desirable to evenly distribute runtime among all boilers in a multiple boiler system. If runtimes are not uniformly distributed, premature maintenance of the more frequently used boilers may be necessary.
Finally, known external controls typically consist of numerous components. These components can include, for example, an outdoor air temperature sensor, an outdoor reset control, a control module and a terminal board. As will be appreciated, it is advantageous to reduce the number of required components to diminish the possibility of failure and reduce purchase and installation costs.
With the forgoing problems and concerns in mind, it is the general object of the present invention to provide a modular boiler control which overcomes the above-described drawbacks and which eliminates the need for a separate connection between individual boilers and a centralized external control in a multiple boiler system.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a modular boiler control.
It is another object of the present invention to provide a modular boiler control that reduces costs associated with installing a multiple boiler system by eliminating the need for wiring between each individual boiler and a centralized external control.
It is another object of the present invention to provide a modular boiler control that reduces costs associated with installing a multiple boiler system by networking a master boiler with at least one slave boiler wherein the master boiler functions as a centralized external control to regulate the networked slave boiler.
It is another object of the present invention to provide a modular boiler control that facilitates the addition of boilers to a multiple boiler system.
It is another object of the present invention to provide a modular boiler system that facilitates the addition of boilers to a multiple boiler system through a master boiler that automatically detects and controls a newly added/networked boiler.
It is another object of the present invention to provide a modular boiler control that facilitates the removal of a boiler from a multiple boiler system.
It is another object of the present invention to provide a modular boiler control that facilitates the repair or replacement of a failed boiler by automatically assigning a new boiler to replace the failed boiler allowing the failed boiler to be brought offline.
It is another object of the present invention to provide a modular boiler control that directly detects a boiler having the least runtime among multiple boilers and adjusts the boiler firing sequence to evenly distribute runtime among the boilers.
These and other objectives of the present invention, and their preferred embodiments, shall become clear by consideration of the specification, claims and drawings taken as a whole.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified schematic diagram illustrating a multiple boiler system including a modular boiler control in accordance with an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a simplified boiler setup subroutine of a modular boiler control in accordance with an embodiment of the present invention.
FIG. 3 is a flowchart illustrating a simplified boiler fault subroutine of a modular boiler control in accordance with an embodiment of the present invention.
FIG. 4 is a flowchart illustrating a simplified boiler runtime subroutine of a modular boiler control in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a simplified schematic illustration of a multiple boiler system 10 featuring a modular boiler control 22 according to one embodiment of the present invention. As shown in FIG. 1 , the system 10 includes an external control 20 such as a building management system or a thermostat, a modular boiler control 22 , and multiple individual boilers 30 , 40 . The external control 20 is connected to a first boiler 30 via a network cable 80 . The first boiler 30 is also operatively connected to a temperature sensor 32 . In the system shown in FIG. 1 , the first boiler 30 is the “master boiler” as it is operatively connected to the system temperature sensor 32 . The remaining secondary boilers, i.e., the “slave boilers” 40 are serially connected to the master boiler 30 , and to each other, by way of network cables 90 . The master boiler is, by definition, the boiler connected to a system temperature sensor. As will be appreciated, the master boiler does not need to be the boiler directly connected to the modular boiler control 22 .
Preferably, the master boiler 30 performs several functions, typically referred to as “wall-mount” functions, which are carried out by an external control such as a building management system. These functions include sensing system temperature, controlling system setpoint, controlling outdoor reset and ratio, and staging/firing the master and slave boilers. The master boiler 30 is also capable of communication with the external control 20 which, as stated above, may be a simple thermostat or a more complex building management system.
As will be readily apparent, having the master boiler perform wall-mount functions and control slave boilers through a serial connection is an important aspect of the present invention. In known multiple boiler systems, each boiler is independently connected to the external control through control wiring. With the present system, a single master boiler is connected to an external control eliminating the need for separate control wiring and protective conduit between the control and each system boiler. As such, the present system reduces costs associated with the installation of a multiple boiler system.
As shown in FIG. 1 , a first slave boiler 40 is serially connected to the master boiler 30 via network cable 90 . Likewise, each slave boiler is serially connected to the adjacent slave boiler through the use of network cables 90 . Preferably, the master 30 and slave boilers 40 , 50 , 60 and 70 are all interconnected through RS485 serial lines. The master boiler 30 is also serially connected via a network cable 80 to the controller 22 , which, in turn, is serially connected to the external control 20 . These connections are also preferably RS485 serial lines. As will be appreciated, however, other connecting hardware may be employed provided it allows the master boiler 30 to effectively communicate with the slave boilers. The preferred network protocol is Modbus RTU although other serial communications protocol may be utilized such as LonWorks® or BACnet®.
The master boiler 30 controls the slave boilers 40 , 50 , 60 , 70 , through a control algorithm that resides in software in the modular boiler control 22 . The control algorithm is yet another important aspect of the present invention as it allows the master boiler 30 to perform the wall-mount tasks typically associated with an external control. Moreover, the algorithm allows for the adjustment of the total number of boilers and their firing rates to achieve a system setpoint temperature. The control algorithm also allows for the automatic detection and recognition of all networked boilers. The modular boiler control 22 is also capable of sensing and controlling optional components such as pumps, dampers, valves and additional sensors.
Automatic boiler detection is a significant feature of the present invention as it simplifies and reduces costs associated with the setup process when installing a multiple boiler system. To setup the present system, a unique address is assigned to each of the installed boilers and a network cable is connected between each boiler. As stated previously, the boiler that has a temperature sensor attached becomes the master boiler. All connected slave boilers are then automatically detected and configured to maintain a system setpoint. This process is analogous to a “plug and play” arrangement and greatly simplifies the installation of a multi-boiler system.
A simplified automatic detection subroutine of the present invention is illustrated in FIG. 2 . At an initial step 100 , the boilers and modular boiler control are installed and network cables connected. As shown at step 110 , a unique address is then assigned to each boiler. All system boilers are then automatically detected by the modular boiler control, as shown at step 120 . If a networked boiler is connected to a temperature sensor in step 130 , it is designated the master boiler. All other networked boilers are designated as slave boilers. As illustrated at step 140 , after the boilers have been designated as master or slave, they are configured and, at step 150 , a setpoint is determined and maintained for the entire system.
The control algorithm also allows the master boiler to adjust the firing rate of networked slave boilers and assign a new slave boiler should one of the slaves go into a fault condition. The algorithm also allows a boiler to be brought off-line for maintenance without impacting the system.
A simplified boiler fault subroutine of the present invention is shown in FIG. 3 . As shown at step 200 , the modular boiler control automatically detects whether a boiler is in a fault condition. The control then determines whether the faulted boiler is the master or a slave at steps 210 and 220 respectively. As shown at step 230 , if the master has faulted, the slaves will run locally at the last system setpoint. If the faulted boiler is a slave, then master adjusts the firing sequence of the non-faulted slave boilers and assigns a new slave to replace the faulted boiler, steps 240 and 250 respectively. Finally at step 260 , the modular boiler control automatically detects whether the fault has resolved itself on its own. If so, the system returns to normal operation at step 270 .
Additionally, the algorithm directly determines the boiler(s) that has the least runtime and automatically adjusts the firing sequence to uniformly distribute runtime among all system boilers. With the present system, the runtime for each boiler can be weighted to the either the Maximum BTU output/Mean Time to Failure Rate or the percentage of modulation/BTU output.
A simplified runtime subroutine of the present invention is depicted in FIG. 4 . As shown at step 300 , a user selects runtime-based boiler firing. Upon selection, the modular boiler control directly assesses the runtime of each slave boiler, as shown at step 310 . The control then identifies the boiler with the least runtime (step 320 ) and then adjusts the firing sequence of all of the system boilers to uniformly distribute runtime (step 330 ).
The distribution of boiler runtime is yet another important aspect of the present invention as known multiple boiler systems are typically fired on a first on, first off or first on, last off protocol and do not consider runtime. As will be apparent, it is generally desirable to evenly distribute runtime among all boilers in a multiple boiler system. If runtimes are not uniformly distributed, premature maintenance of the more frequently used boilers may be necessary.
Moreover, the system uses a predictive algorithm to determine when to fire/stop firing a boiler before its process input variable, e.g., system temperature, moves too far from its setpoint. The method looks at the slope (mx+b) of the process input variable over a boiler “to be fired” time period and predicts when to start and stop the boiler based on its BTU output. This slope method is also used to dynamically adjust the firing rate to control over and undershoots of the process input variable.
In sum, the present invention provides a modular boiler control that eliminates the need for separate control wiring from each boiler in a multiple boiler system to an external control. Moreover, the present invention allows for automatic detection and setup of networked boilers and for a master boiler to control the setpoint and firing sequence of multiple slave boilers. The present invention also directly measures boiler runtime to identify the boiler with the least runtime and adjust the firing sequence of the other boilers for even runtime distribution.
While the invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various obvious changes may be made, and equivalents may be substituted for elements thereof, without departing from the essential scope of the present invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention includes all embodiments falling within the scope of the appended claims. | A modular boiler system includes a boiler control, a first boiler in operative connection with the boiler control, and a temperature sensor in operative connection with the first boiler. The system also features at least one secondary boiler in operative connection with the master boiler. The boiler control is operatively connected to only the first boiler and it enables the first boiler to control a boiler parameter of the first boiler and the at least one secondary boiler. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 11/112,110, filed Apr. 22, 2005; which is a continuation of application Ser. No. 10/047,422, filed Jan. 14, 2002; which applications are incorporated herein by reference.
TECHNICAL FIELD
[0002] The principles disclosed relate to an enhanced sonde housing and method of manufacture. More particularly, this disclosure concerns a sonde housing constructed for use in a variety of applications and method of making such housing.
BACKGROUND
[0003] Horizontal directional drilling is a process commonly utilized to create boreholes for the installation of utilities underground. The process involves a drilling machine, a drill string and a drill head. The drill string is typically composed of individual sections of hollow drill rod, and is attached above ground between the drilling machine and the drill head. The drilling machine is typically capable of rotating and longitudinally propelling and thrusting the drill string, while simultaneously pumping a fluid through the drill string. The drill head is typically composed of an adapter assembly and a drill bit. There are many types of adapter assemblies, including static and dynamic, each typically connecting on one end to the drill string, and on the other end to the drill bit. There are a variety of drill bits, each designed to be used in conjunction with a specific type of adapter.
[0004] The process starts with installing the drill head onto a single drill rod above ground. The drill rod is then connected, at the opposite end, to a drilling machine. The drilling machine then rotates and pushes the drill rod and drill head into the ground. At the same time, a fluid is pumped through the drill rod and typically directed to the cutting surface of the drill bit to assist in cutting the ground material.
[0005] The pumped fluid has a variety of purposes. One primary purpose relates to removal of material to create the borehole. In this application, fluid transports cuttings created by the drill bit back along the bored hole and out to the ground surface. In most setups, a particular drill bit is configured to cut a hole larger than the drill rod diameter by disturbing the soil formation as it is rotated. Examples of such bits can be found in U.S. Pat. No. 5,799,740 and U.S. Pat. No. 5,899,283. At the same time, a water-based fluid is pumped through the drill string and through the bit to thoroughly mix with the disturbed soil, creating a slurry. The slurry then follows the path of least resistance, which is typically back along the drill string, and exits at the point the drill string enters the ground. In this application the adapter assembly is static, simply adapting from the drill rod threaded connection, which is smaller diameter, to the drill bit, which is larger in diameter to cut the larger hole required for the proper transfer of cuttings.
[0006] In some other applications there is no requirement to transport the cuttings and the ground is simply compacted, forming a borehole without any material removal. Impact or hammering load on the drill bit increases the productivity of drilling. For this type of application, the adapter assembly includes a dynamic component, typically a pneumatic hammer, in addition to a static adapting element. (An example disclosed in U.S. Pat. No. 4,858,704.) The fluid being pumped in the drill string is compressed air that transfers power to actuate the pneumatic hammer. The path of fluid flow includes the drill string, the static component of the adapter assembly, and the hammer.
[0007] In yet other applications, typically highly compressed soils and or rock, a similar setup utilizing a down hole hammer can be used in conjunction with a different drill bit to create cuttings for transport. The hammers can be pneumatic hammers or water hammers. The drill bits are designed primarily to fracture the soil or rock formation by the impact loading received from the hammer. Once the formation is fractured, the cuttings need to be transported away from the cutting face.
[0008] Transportation of the cuttings is aided by rotation of the drill bit and drill string, along with the resulting flow of the fluid. The fluid is typically air or a mixture of air and a water based fluid or other suspension material which functions to aid the air's ability to transport the cuttings. In this type of application, the fluid is utilized to transfer power to actuate a hammer to transport cuttings. The path of fluid flow includes the drill string, adapter assembly and drill bit.
[0009] In still another arrangement involving cutting highly compressed soils or rock, the drill bit is adapted to rotate. One such design includes the use of a mud motor capable of converting fluid power (from the pumped fluid) into rotational power to rotate the drill bit. In this type of application, the adapter assembly includes a dynamic component, the mud motor, along with the previously described static element. The fluid is typically water based. The path of fluid flow includes the drill string, the adapter assembly and the drill bit.
[0010] In all these applications, the transfer of fluid assists in the efficient functioning of the drill bit and/or transportation of the cuttings; relatively large flow rates may be required. The path of fluid flow, in all cases, is through the adapter. Thus a key characteristic of the adapter is fluid transfer capability.
[0011] Another key aspect of horizontal directional drilling is the detection of location and position of the drill head. This information is necessary to properly control the drilling process so that the bored hole is properly positioned. This is typically accomplished by installing tracking electronics in the drill head, typically in the form of a sonde. Sondes are currently available in a variety of sizes, from a variety of manufacturers and include 2 basic types; a type powered by a battery and a type powered by a wire that is threaded through the drill string to an above-ground power source.
[0012] An example of a battery powered sonde and its mounting configuration within a drill head is described in U.S. Pat. No. 5,633,589. FIG. 4 of '589 illustrates a drill head with the adapter assembly connected on one end to the drill string and to the drill bit at the other end. This is a schematic representation illustrating primarily the electronic package. This arrangement illustrates that the adapter assembly is configured to hold the sonde or transmitter which is generally cylindrical and whose diameter is significant in relation to the diameter of the drill rod. This static section of the adapter assembly has become known as the sonde housing.
[0013] Other examples of sonde housings can be seen in U.S. Pat. No. 5,799,740 (hereinafter '740), U.S. Pat. No. 5,253,721 (hereinafter '721), and U.S. Pat. No. 6,260,634 (hereinafter '634). FIG. 11 of '740 more closely exemplifies the design of typical sonde housings. The housing is configured to accept a sonde, to mate to a drill bit, to mate to the drill string, and to provide a passage for fluid. The mechanical configuration is such that a cavity for the sonde is positioned off center and located as close as possible to the edge of the adapter, as constrained by minimum material thickness. This provides a maximum cross-sectional area of the fluid passages, also constrained by minimum material thickness surrounding the passage. The location of the fluid passages is thus close to the outer diameter of the sonde housing.
[0014] In order to manufacture typical sonde housing passages, the sonde housing is made as two pieces. The cylindrical main section, illustrated as FIG. 11 in '740, includes a threaded section with an inner diameter sufficiently large to allow the fluid passages to be manufactured with normal drilling. This thread is much larger than the threads utilized on the drill rod. Thus a second piece, illustrated in FIG. 10 , screws into these large threads on one end and adapts to the threads of the drill string on the other end. In this manner, the sonde housing is constructed from multiple parts that are screwed together. The sonde is installed into the sonde housing by separating the two pieces at this threaded connection. This type of sonde housing is referred to as an end load sonde housing as the sonde is inserted from an end of the sonde housing.
[0015] The cylindrical sonde housing illustrated in the '634 patent also utilizes a two piece construction. FIG. 2 illustrates a similar main section adapted to accept a sonde, adapted to a drill bit on one end, and to a second adapter on the opposite end. Rather than utilizing a threaded connection between the main section and the adapter, this sonde housing utilizes a splined connection. One such adapter is illustrated in FIG. 22 of U.S. Pat. No. 6,148,935 (hereinafter '935), and herein incorporated in its entirety by reference. Here again, the inner diameter of the splined connection is such that the fluid transfer holes can be drilled with normal drilling techniques. The sonde housing illustrated in the '634 patent is generally referred to as a side load housing as the sonde housing includes a door that covers the sonde cavity mounted on the side of the sonde housing and the sonde is accessed from the side.
[0016] FIG. 1 of '935 and FIG. 3 of '721 illustrate the difficulty of manufacturing a one-piece sonde housing. In '935 the fluid transfer holes are drilled at an angle, adding cost and complexity to the assembly. In '721 the fluid transfer holes require 4 separate, intersecting drilled holes creating 90-degree angles in the fluid pathway. This configuration results in significant flow restriction.
[0017] In addition to providing a flow passage, the sonde housing also serves to support and position the sonde. U.S. Pat. No. 6,260,634 and U.S. Pat. No. 6,148,935 illustrate the use of a splined connection between the sonde housing and the drill bit that can only be Assembled in one rotary orientation. This, combined with the rotary orientation control of the sonde, coordinates the orientation between the sonde and the drill bit. This arrangement is dependent on the splined connection, which results in restricting the variety of drill bits that can be utilized with the housing, as not all bits include such splines.
[0018] Other mounting requirements for sondes include vibration isolation, particularly when the adapter assembly includes a hammer, and/or provision for a wire passage for use with a wire-line sonde. The sonde housing, being located near the drill bit, is subjected to severe load conditions. The mechanical rigidity and assembly characteristics affect the durability of the sonde housing. The requirement for durability is exemplified by the existence of industry standards for certain types of drilling components. For instance, the American Petroleum Institute has adopted a specific thread configuration for use with drilling components that imposes an additional physical constraint affecting the mechanical configuration of the sonde housing.
SUMMARY
[0019] One aspect of the present invention relates to an enhanced sonde housing for use in the horizontal directional drilling industry. Another aspect of the present invention relates to the method of manufacturing the enhanced sonde housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a side view of one embodiment of a drill head assembly according to the present invention mounted onto a drill string in a first set-up with a bit adapted for boring in soft rock;
[0021] FIG. 2 is a side view of another embodiment of a drill head assembly according to the present invention mounted onto a drill string in a second set-up with a bit adapted for boring in soils;
[0022] FIG. 3 is a side view of yet another embodiment of a drill head assembly according to the present invention mounted onto a drill string in a third set-up with a hammer and bit adapted for boring in hard rock;
[0023] FIG. 4 is an exploded view of a sonde housing assembly according to the present invention;
[0024] FIG. 5 is an end view of a sonde housing according to the present invention;
[0025] FIG. 6 is a cross section of the sonde housing of FIG. 5 taken along line 6 - 6 ;
[0026] FIG. 7A is an exploded side view of a sonde housing according to the present invention prior to assembly for welding;
[0027] FIG. 7B is an assembled top view of the sonde housing of FIG. 7A ;
[0028] FIG. 8 is an enlarged cross section of the sonde door retaining pin section shown in FIG. 6 ;
[0029] FIG. 9 is an isometric view of the sonde mounting block according to the present invention;
[0030] FIG. 10 is a cross-sectional view of the sonde mounting assembly according to the present invention;
[0031] FIG. 11 is an isometric view of a typical sonde;
[0032] FIG. 12 is an exploded view of an alternate sonde mounting assembly according to the present invention;
[0033] FIG. 13 is a cross-sectional view of the wireline routing for a wireline sub according to the present invention;
[0034] FIG. 14 is an isometric view of a second embodiment of a sonde rotary orientation control including a tab on the door that engages a gear on the sonde;
[0035] FIG. 15A is a longitudinal cross sectional view of a third embodiment of a sonde rotary orientation control including a tab on the door that engages a plug;
[0036] FIG. 15B is an enlarged view of the rotary orientation control section of FIG. 15A ;
[0037] FIG. 16A is a longitudinal cross sectional view of a fourth embodiment of a sonde rotary orientation control including a tab on the door that engages an o-ring in contact with the sonde;
[0038] FIG. 16B is an enlarged view of the rotary orientation control section of FIG. 16A ;
[0039] FIG. 17A is a longitudinal cross sectional view of a fifth embodiment of a sonde rotary orientation control including a tab on the door that engages an o-ring in contact with a plug that engages the sonde;
[0040] FIG. 17B is an enlarged view of the rotary orientation control section of FIG. 17B ;
[0041] FIG. 18 is a radial cross sectional view representative of the sonde door and plug within the housing of FIG. 15B taken along the line 18 - 18 ; and
[0042] FIGS. 19A-19E are schematic illustrations of the stages of manufacturing for an alternate method of manufacturing a sonde housing of the present invention.
DETAILED DESCRIPTION
[0043] With reference now to the various figures in which identical elements are numbered identically throughout, a description of various exemplary aspects of the present invention will now be provided. The preferred embodiments are shown in the drawings and described with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the embodiments disclosed.
[0044] Referring now to the drawings, FIG. 1 illustrates one embodiment of a drill head set-up having a sonde housing assembly 50 according to the present invention. Drill string 10 terminates at a first end of a drill head assembly 14 and connects at an opposite end to a drilling machine (not shown) capable of providing rotation and longitudinal power. The drill string 10 is typically constructed of hollow tubing and is capable of transferring pressurized fluid. In the configuration shown in FIG. 1 , a drill bit 12 connects to an opposite end of the drill head assembly 14 .
[0045] The drill head assembly 14 consists of a rear transition sub 16 , a rear adapter sub 18 , a front adapter sub 20 and the sonde housing assembly 50 . In this configuration the rear adapter sub 18 is configured to mate with the rear transition sub 16 in order to utilize a joint 24 . An exemplary joint used in this type of configuration is described in U.S. Pat. No. 6,148,935, which is herein incorporated by reference in its entirety. Joint 24 allows for convenient separation between the drill string 10 and the rest of the drill head, in particular, the rear transition sub 16 remains attached to the drill string 10 while the remaining portion of the drill head assembly 14 and the drill bit 12 are removed. In use, this configuration requires less tools to remove the portion of the drill head assembly and drill bit after drilling a pilot hole and attach a reamer having a similar transition sub. In the embodiment of FIG. 1 , the backreaming would be completed without the sonde housing assembly 50 .
[0046] FIG. 2 illustrates an alternative embodiment of a drill head set-up having a sonde housing assembly 50 according to the present invention. In this illustration, the drill head assembly 14 ′ does not include a rear transition sub, as in 16 of FIG. 1 , but does include a front transition sub 22 configured with a joint 24 ′ and a front adapter sub 20 ′. This configuration allows a drill bit 12 ′ and front transition sub 22 to be removed with minimal tools. A reamer (not shown) configured with a splined transition sub that mates with joint 24 ′, similar to that found on transition sub 22 , can then be connected. In the embodiment of FIG. 2 , the sonde housing assembly 50 is left installed during backreaming.
[0047] FIG. 3 illustrates yet another embodiment of a drill head set-up having a sonde housing assembly 50 according to the present invention. An exemplary joint used in this type of configuration is described in U.S. Pat. No. 6,148,935, which is herein incorporated by reference in its entirety. Drill head assembly 14 ″ includes a rear adapter sub 18 ″, a sonde housing assembly 50 , a front adapter sub 20 ″, and a hammer 26 . The hammer includes a front shaft 28 capable of supporting a bit 12 ″.
[0048] From these three exemplary embodiments it is obvious that there is a multitude of possible set-ups, each potentially affecting the configuration of the sonde housing assembly 50 . These three are only typical examples, and many other configurations and embodiments are possible. As a result of the many various applications and requirements, there are currently a number of specific configurations of sonde housings available. It is an desirable to provide a universal sonde housing that is capable of being used in a wide variety of drill head configurations that also provides minimum flow restriction, maximum mechanical rigidity, flexibility in mounting arrangements for differing sondes, and flexibility in accepting adapters between the housing and drill bits or drill string. In addition, the use of sondes during backreaming is possible and a sonde housing capable of handling relatively large flow rates with flexibility in accepting adapters will be an improvement.
[0049] FIG. 4 illustrates the components found in the sonde housing assembly 50 according to the principles disclosed. The main component is main housing 100 . A cavity 102 is accessible by removing a sonde door 52 . The sonde door 52 is retained on one end by a tab 58 , which engages into a slot 104 (see FIG. 6 ) of the main housing 100 . The other end is retained by a door latch pin 54 which is installed into hole 106 . A surface 120 , best shown in FIG. 6 , supports the sonde door 52 . The door latch pin 54 is then retained in the main housing 100 by a retainer pin 56 which is driven into a through hole 108 that intersects hole 106 as illustrated in FIGS. 6 and 8 . In order to remove the sonde door, the retainer pin 56 is easily removed with standard tools, including a hammer and punch. The door latch pin 54 is then free to be removed by lifting the sonde door 52 in an angular motion, pivoting around its tab 58 , until the sonde door and latch pin clear the sonde cavity.
[0050] The sonde 60 fits into cavity 102 . The cavity 102 is defined by a depth 112 as illustrated in FIG. 6 and a width 110 as illustrated in FIG. 7B . The sonde 60 is supported by mount blocks 64 A & 64 B, one on each end. As illustrated in FIG. 9 , the mount blocks 64 A and 64 B include a cavity 65 with an inner diameter selected relative to the outer diameter of sonde 60 to position and support sonde 60 . The cavity 65 may include a groove manufactured to capture an O-ring 151 to support and center the sonde 60 .
[0051] The mount blocks 64 A and 64 B are supported within the cavity 102 . The cavity 102 is defined by the main housing 100 and the sonde door 52 . The blocks 64 A and 64 B are constructed so that their width 111 is slightly less than the cavity width 110 . In this illustrated embodiment the sonde door 52 includes a slot of depth 154 , as illustrated in FIG. 10 , that cooperates with cavity 102 to retrain the blocks 64 A and 64 B. The height 113 of blocks 64 A and 64 B is slightly less than the sum of cavity depth 112 and the slot depth 154 respectively. In this manner, the blocks are mounted so that they are free to move, specifically, slide longitudinally relative to the sonde housing 100 and sonde door 52 , yet are securely supported when the sonde door 52 is installed.
[0052] The mount blocks 64 A and 64 B are constructed from any material that will aid in properly supporting the sonde 60 . The preferred material is a type of plastic so that the cavity 65 can be sized to fit the sonde 60 relatively tight without causing any damage to the sonde 60 . Several configurations of mount blocks 64 A and 64 B can be made available, each having a cavity 65 specific for a certain type of sonde, yet with the same outer dimensions (i.e. width 111 and height 113 ). In this manner the main housing 100 remains unchanged, while the assembly is capable of accepting sondes 60 of various diameter and or configuration.
[0053] The bottom surface 114 of the cavity 102 and the bottom surface of the sonde door 52 support the mount blocks 64 A and 64 B along the radial axis. They are supported along the axis perpendicular to the radial axis and the longitudinal axis by the side surfaces 118 of the cavity 102 . Along the longitudinal axis the mount blocks 64 A and 64 B are supported by axial vibration isolators 66 which are supported by end surfaces 120 , which are effective due to the built-in clearances in the block mounting. The assembly is illustrated in FIG. 10 .
[0054] The axial vibration isolators 66 can be constructed of a variety of materials, selected for the dynamic compression characteristics, to act to reduce the vibration loading transferred to the sonde 60 . This is useful in applications involving a percussive hammer where the percussive hammer produces primarily longitudinal vibrations. Isolation in the other two axis may be provided by constructing the mount blocks 64 A and 64 B of material with appropriate compression characteristics or implementing non-axial vibration isolators between the support blocks 64 A and 64 B and surfaces 118 and 114 .
[0055] One possible embodiment of such isolators is illustrated in FIGS. 9 and 10 . External o-rings 152 are designed to fit into grooves machined on the outer surface of blocks 64 A and 64 B. Proper clearances between the block dimensions 111 and 113 and the cavity dimensions 110 and (112+154) need to be determined for the vibration isolation to be effective.
[0056] In addition to being supported along the longitudinal axis, the longitudinal axis of the sonde 60 is ideally aligned with the longitudinal axis of the sonde housing assembly 50 . This is useful in certain applications that require precise control of the grade of the bore, such as installation of gravity sewers. Commonly, traditional sondes include pitch sensors capable of measuring the pitch of the longitudinal axis, for example, when the sonde housing is level, the measured pitch is zero. However, there are inherent manufacturing tolerances and stack-up problems of the mounting component that can introduce some angularity error. Thus, it is desirable to improve the process of drilling with sondes by providing a mechanical adjustment that can be used to compensate for the error inherent with the sonde. Also, sonde housings are generally constructed to approximately align the longitudinal axis of the sonde with the longitudinal axis of the sonde housing. However, the precision of the orientation of the sonde's mounting in the sonde housing may also introduce unwanted alignment error. In order to correct such errors, an adjustment assembly 171 as shown in FIG. 12 can be utilized to correct the alignment.
[0057] In utilizing an adjustment assembly 171 , the block 64 B is replaced with the assembly 171 shown in FIG. 12 . The adjustment assembly includes an adjustment screw 170 capable of moving the centerline of a supporting cap 174 , in a first direction, relative to an outer surface 178 of a lower base 176 . The adjustment screw 170 threads into upper base 184 and seats against upper surface 186 of the lower base 176 such that if the screw 170 is screwed into the upper base 184 , the upper base 184 will move away from the lower base 176 . The supporting cap 174 engages with the upper base 184 and is thus moved. Screws 182 are utilized to lock the upper base 184 to the lower base 176 once the proper setting is achieved. The lower base 176 will seat in the cavity 102 and be supported by surface 114 .
[0058] In assembling the components, the sonde will be positioned in the supporting block 64 on one end, and in the adjustment assembly 171 on the other end (e.g. a similarly sized cavity within the supporting cap 174 (not shown) as that of the supporting block cavity 65 ). That assembly is then inserted into the cavity 102 , supporting the sonde. The sonde housing assembly is positioned to be at a known pitch, typically level. The reading from the sonde is checked. The screws 182 and 170 can then be manipulated until the sonde pitch reading is correct. Once correct, an isolator block 180 is installed on top of screws 182 and the upper base 184 . When the sonde door 52 is installed, this assembly is slightly compressed to assure the lower base 176 remains properly positioned against surface 114 of the sonde housing 100 .
[0059] Screws 172 are also provided to position the supporting cap 174 in relation to the upper base 184 in order to provide adjustment in the other plane.
[0060] Referring now to FIGS. 10 and 13 , a cylindrical plug 62 , orientation tab 68 and screw 70 define the rotary orientation of the sonde within the assembly. The mount blocks 64 A and 64 B are rectangular in cross section, fitting into cavity 102 that is likewise rectangular in cross section. Thus mount blocks 64 A and 64 B are fixed relative to the main housing 100 . The plug 62 is cylindrical and fits into the cylindrical cavity 65 within mount block 64 A. The sonde 60 , typically cylindrical, also fits into the cylindrical cavity 65 of mount block 64 A.
[0061] In one embodiment, the sonde 60 includes a slot 61 that assists in defining its rotary orientation, as shown in FIG. 11 . Upon installing the plug 62 , mount blocks 64 A & 64 B, orientation tab 68 , sonde 60 and isolators 66 into the cavity 102 , the sonde 60 may be rotated within cavity 65 of mount blocks 64 A and 64 B. As the sonde 60 is rotated, the plug 62 also rotates relative to mount blocks 64 A and 64 B. Once the sonde 60 is positioned in the proper rotary orientation, a screw 70 is installed through the mount block 64 A and into the plug 62 locking the plug into position and thereby defining the rotary orientation of the sonde 60 relative to the mount blocks 64 A and 64 B, and ultimately relative to the main housing 100 . This embodiment requires a simple through hole be provided in the mount block 64 A for the screw to pass through. In an alternate embodiment, not shown, mount block 64 A could include a threaded hole. A set screw could engage these threads and then simply contact the plug, without extending into the plug, to lock the plug into position.
[0062] Yet another alternative embodiment that rotationally orients a sonde is illustrated in FIG. 14 . In this embodiment the sonde door 52 includes a rib 158 that projects downward to engage with a gear 156 . The gear 156 is secured to the sonde 60 . In this configuration, the rotary orientation of the sonde 60 is set or locked upon installation of the sonde door. Additional embodiments are illustrated in FIGS. 15 A-B, 16 A-B and 17 A-B wherein the rib engages: the plug 62 , as shown in FIGS. 15 A-B; an o-ring 153 that is in contact with the sonde 60 , as shown in FIGS. 16 A-B; or an o-ring 155 that is installed onto the plug 62 , as shown in FIGS. 17 A-B. In all of these embodiments, the rib restrains the rotation of the sonde whenever the door 52 is installed.
[0063] The rotary orientation of the sonde ultimately needs to be defined relative to a directional control element of a drill head. In the horizontal directional drilling process, the ability to control the direction of the boring is a result of some physical property of the drill bit, or of some other physical property of the drill head. There are a variety of designs available that provide directional control, each having its own benefits associated with various soils or setups. The operators typically know how the setups will steer in the ground and are thus capable of positioning the assembled drill head in a rotary position to steer in a certain direction. For instance an operator is expected to be able to assemble a drill head and roll the drill head into a rotary position so that the drill head steers upward. This is typically known as steering at 12:00. Likewise the operator is expected to be able to position the drill head in the rotary position to steer right, 3:00, downward, 6:00, or left 9:00.
[0064] The method of setting the rotary orientation of a sonde within a drill head according to the principles of this disclosure are as follows:
1) operator assembles the drill head completely, including drilling bit, except for installation of the sonde door 52 ; 2) operator positions the drill head into any desired rotary position (ie: 12 o'clock); 3) operator checks the output from sonde 60 via sonde signal receiver/decoder and then modifies the rotary orientation of the sonde 60 by rotating it within the cavity 102 until it is reading the correct orientation, as determined by how the drill head was previously positioned; and 4) operator then installs screw 70 through the mount block 64 a and into the cylindrical plug 62 to lock the assembly into position or simply installs the sonde door with one of the embodiments illustrated in FIGS. 14, 15 , 16 and 17 .
[0069] One advantage of this method is that this method allows for an infinitely accurate rotational orientation of the sonde to the sonde housing, and allows the operator to modify the position of the sonde in the cavity. Another advantage of this method is that this method allows the sonde housing to be adaptable to any drill head assembly. In many instances the directional control element of the drill head relative to the sonde housing assembly will be defined by the rotary orientation of the front adapter sub 20 as located on the sonde housing assembly 50 ; this connection is seldom modified. In such cases, the mounting block 64 A, plug 62 and screw 70 can be left assembled when changing drill bits or sondes. Thus, the process of orienting the sonde is not necessary each time the drill head is worked on. It is expected that once assembled, the drill heads are typically dedicated to a certain type of set-up, and adjustments are not performed frequently. It is therefore beneficial that one sonde can easily be adapted to any known drill head set-up.
[0070] Aside from the variations in drill head physical characteristics, and physical variations of sondes, there are two basic types of sondes: a battery powered sonde and a wire line powered sonde. FIG. 13 illustrates the sonde mounting of the present disclosure adapted for use with a wireline sonde.
[0071] In FIG. 13 the wire line is threaded through the drill string from the ground surface to the drill head in any known manner. Present drill head configurations provide for a wire routing path that allows the wireline to be connected to a sonde. This routing generally involves a strain relief plug 74 , strain relief 76 and tapped hole 150 , as illustrated in FIG. 13 . The tapped hole 150 projects from one end of the main housing 100 into the cavity 102 . When a battery powered sonde is used, there is no need for anything to project through this hole, so a plug 72 (shown in FIG. 4 ) is installed. However, when a wireline sonde is used, this plug 72 is removed and a similar plug (i.e. strain relief plug 74 ) is installed.
[0072] The strain relief plug 74 includes a cavity large enough for a strain relief 76 to be installed. The strain relief 76 is cylindrical and includes a through hole aligned with the axis of the outer cylindrical surface of the strain relief The through hole is sized to fit tightly over the outer diameter of a wire 25 projecting out of the wireline sonde. The wire 25 from the wireline sonde is routed through a hole 160 in 64 a or 64 b, then through a hole 162 in isolator 60 , then through a slot 164 in main housing 100 . (The slot 164 is also shown in FIG. 7B .) The wire 25 is routed from slot 164 through a threaded hole 150 . Strain relief 76 is then slid over the wire and into the void in the strain relief plug 74 .
[0073] Once these components are assembled, the strain relief plug 74 is assembled into the threaded hole 150 and tightened. The threaded hole 150 includes a larger threaded section and a smaller through hole section so that strain relief 76 can be inserted through the threaded diameter, but cannot pass through the smaller through hole section. Thus as the strain relief plug 74 is tightened, strain relief 76 is compressed thereby restricting the movement of the wire 25 and sealing the wireline to prevent transfer of fluid into cavity 102 . In this manner the sonde housing assembly is adaptable to allow use of wireline sondes or battery powered sondes
[0074] Another element that makes the sonde housing adaptable is the use of a threaded connection on each end of the main housing 100 . Referring back to FIG. 6 , the main housing 100 is shown as a one-piece design having three sections. The three sections may have standard API (American Petroleum Institute) threads on each end. The three sections of the main housing 100 include: a center section 130 , a top end section 132 and a bottom end section 134 . FIG. 7A illustrates how these three sections fit together.
[0075] The threaded connections of the top end section and the bottom end section 132 and 134 of the illustrated embodiment are female threaded connections. It is contemplated the threaded connections of the top and bottom end sections may also include male threaded connections. In general the threaded connection preferably include standard API tapered thread connection having a major diameter and a minor diameter.
[0076] The top end section 132 includes a projection 140 of length 141 . Center section 130 includes a cylindrical cavity 142 of depth 143 . The cavity depth 143 is deeper than the projection length 141 which results in a gap or void 136 as shown in FIG. 6 . This void is utilized as a part of the fluid flow path. The bottom end section 134 has similar features including a projection 140 ′ of length 141 ′ and center section including a cavity 142 of depth 143 . It is not necessary the projection 140 have a mating configuration to the cylindrical cavity 142 . A portion of the projection 140 may be utilized to assist in proper orientation of the components, and is optional. One key aspect of this configuration is the resulting void 136 created by the cavity 142 in the center section 130 which is utilized as a part of the fluid flow path.
[0077] The complete fluid flow path through the main housing 100 in FIG. 6 as viewed from left to right, starts through the top end section 132 which will accept fluid from the drill string 10 , as delivered through the rear adapter sub 18 , as in FIG. 2 . The fluid is transferred into the void 136 and then into drilled holes 138 . Exiting the drilled holes 138 , the fluid encounters the other void 136 and is directed through the bottom end section 134 . With this construction, the location of the drilled holes 138 in the center section 130 is not affected by the dimensions of the threaded connections of either the top end section 132 or the bottom end section 134 . Both sections are illustrated with female threads in FIGS. 6 and 7 , but there is no restriction on the configuration selected. The threads could be any size, male or female.
[0078] The fluid flow advantages of this configuration are in the size of the drilled holes 138 and the flow transition required for the fluid to transfer into these holes. The void 136 provides the fluid with a gentle transition in contrast to 90 degree turns found in conventional configurations. The gentle transition provided by the voids thereby reduce fluid flow constrictions.
[0079] In addition, the size of the drilled holes 138 can be optimized easily and efficiently as the hole locations are not affected by the physical characteristics of the threaded connections. Thus, this configuration allows the center section to be constructed to maximize its strength while at the same time maximizing the fluid flow path provided.
[0080] The completed main housing 100 is thus constructed by manufacturing a top end section 132 a bottom end section 134 and a center section 130 . The center section is constructed to provide a cavity 102 for mounting a sonde while at the same time provide fluid flow passages via drilled holes 138 and cavities 142 . The end sections 132 and 134 are constructed with threaded connections and preferably joined to the center section 130 by welding.
[0081] One method of manufacturing the main housing involves the following:
1) machine holes 138 in housing section 130 ; 2) machine pockets 142 in both ends of housing section 130 ; 3) machine end pieces 1134 and 132 except for the thread connection; 4) leave overstock on outer diameters of parts 132 , 134 , and 130 for clean up machining; 5) slide end 140 of part 132 into pocket 142 and slide end 140 of part 134 into opposite pocket 142 of part 130 ; 6) clamp three pieces together to hold orientation; 7) performing welding operation in v-grooves generate at mating location of parts 132 , 130 , and 134 ; 8) post heat treatment;
a) stress relieve assembly b) throughly harden assembly to Rc 28 - 32 ′ and
9) post heat treat, machine the following geometric features:
a) threaded ends b) outer diameter c) sonde pocket and related geometry
[0096] An alternate method of manufacturing a sonde housing is illustrated in FIGS. 19A-19E . This method starts with a single piece of bar stock wherein the fluid transfer holes are drilled in step 1 , shown in FIG. 19A . Step 2 , shown in FIG. 19B involves plugging those fluid transfer holes in a manner that the plugs will become substantially integral with the bar stock material. This process may involve several optional methods. The method illustrated being to insert plugs that are larger than the holes such that they are press-fit into the holes. These plugs could then be further retained by heating the plugs nearly to the melting temperature to effectively bond them to the bar stock material. Many other techniques could be practiced. Step 3 , shown in FIG. 19C involves machining threads and step 4 , shown in FIG. 19D involves machining annular cylindrical voids with an outer diameter that exceeds the inner diameter of the threads such that the originally drilled fluid transfer holes are fluidly connected to the annular cylindrical voids extending outwardly from the threads. Step 5 , shown in FIG. 19E involves machining the sonde cavity.
[0097] The embodiments of the present disclosure may be used in a variety of applications. For example, the sonde housing is designed to be utilized in multiple applications of drilling including: dirt boring, rock boring, sewer product installation, back reaming, percussive drilling, and other drilling applications.
[0098] In addition, it is obvious that many other modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | A sonde (transmitter) housing having a one-piece design for improved housing rigidity. The housing includes a mechanically-adjustable mounting configuration adaptable to a variety of sonde applications. A method of making the sonde housing in a one-piece design and infinitely orienting the sonde clocking electronics. | 4 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an aesthetically pleasing light-emitting basin with lighting function.
[0002] Conventional lighting apparatus with single function are mostly used for lighting. With the trend towards a diversified and personalized life, lighting apparatus used in environment such as indoor and outdoor and courtyard have also increased. These lighting apparatus have to satisfy the decorative need, and sealability has to be taken into consideration when used outdoors. Thus, the structure of a lighting component and location where it will be placed are particularly important. In addition, the lamp beads used in the lighting apparatus are in one single color. The lighting effect produced is monotonous. It cannot be fully blended into the environment in which it is used.
[0003] Thus, the applicant has applied for a “solar-powered bird bath” under publication number CN102871570A, which comprises a basin body, a base box and a solar panel, wherein the base box is installed at the bottom of the basin body, and the solar panel is provided on the base box.
[0004] However, the following problems exist in such bird bath: 1. A light-emitting LED light is installed on a lateral surface of the base box. Only part of the bottom of the basin body near the LED light is brightened, while a very big part of the basin body still cannot be brightened, thus failing to achieve an ideal night view decorative effect. 2. Fittings such as electric parts are exposed, thus affecting the overall appearance of products. 3. If the product adopts a table-top configuration, the pressure point of the whole product is on the electric parts; the electric parts are damaged easily.
BRIEF SUMMARY OF THE INVENTION
[0005] In view of the aforesaid disadvantages now present in the prior art, the present invention aims to provide a novel light-emitting basin which can both improve the illuminating effect and accommodate the fittings.
[0006] To attain this, the technical solution of the present invention is as follows:
[0007] A novel light-emitting basin comprises a body. A surface of the body protrudes or is recessed to form a chamber. The body and/or a chamber wall of the chamber is in an atypical shape or a polyhedron shape. At least part of the chamber wall of the chamber forms a luminous body which is light reflective or light refractive.
[0008] The luminous body is made into a translucent body with light-penetrative materials, and/or is made into a refractive body with light-reflective materials.
[0009] A bottom surface of the body protrudes inwards or is recessed inwards to form the chamber, and/or a top edge of a lateral chamber wall of the chamber is higher than, at a same level as or lower than a top edge of the body.
[0010] A light-emitting component is provided inside and/or outside the chamber to brighten the chamber wall of the chamber and brighten the body using light passing through the chamber wall.
[0011] The luminous body has one or more than two refractive indices.
[0012] A projected area of the luminous body accounts for 20-60% of a projected area of the body.
[0013] A projected area of the luminous body accounts for 30-40% of a projected area of the body.
[0014] The body is formed by glass, ceramic, resin, rubber, plastic material, plastic and/or metal.
[0015] The bottom surface of the body is provided with a light diffuser plate. The light diffuser plate is provided corresponding to light emitted from the light-emitting component.
[0016] The body and/or the light diffuser plate is opened with a through hole.
[0017] The novel light-emitting basin also comprises a power which provides electricity for the light-emitting component. The power is provided inside and/or outside the body, and/or is provided inside and/or outside the chamber, and/or is provided inside and/or outside the luminous body.
[0018] An interface is provided on the body and/or the light-emitting component of the novel light-emitting basin. The power electrically connects to the light-emitting component through the interface.
[0019] After adopting the above structure, the novel light-emitting basin of the present invention has the following the following advantages:
[0020] The surface of the body protrudes or is recessed to form a chamber. Fittings such as electric parts can be disposed in the chamber and thus could not be damaged easily. Besides, the light-emitting component can be provided inside and/outside the chamber as needed. Thus, the illuminating area and range of the light-emitting component can be freely provided without limiting to the bottom of the body, thereby improving the illuminating effect and achieving a night view decorative effect which is gorgeous and perfectly clear and bright. The body and the chamber are made into an atypical shape or a polyhedron shape. As ornamental crafts, they are highly ornamental, aesthetically pleasing and practical.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a perspective view of the novel light-emitting basin of the present invention.
[0022] FIG. 2 is a schematic view showing the chamber of the present invention being cut horizontally.
[0023] FIG. 3 is a schematic view showing the chamber of the present invention being cut vertically.
[0024] FIG. 4 is a cross-sectional view showing the chamber located above the body of the present invention.
[0025] FIG. 5 is a cross-sectional view showing the chamber located below the body of the present invention.
[0026] FIG. 6 is a schematic view showing the electric parts assembled in the chamber of the present invention.
[0027] FIG. 6 a is a schematic view showing a solar panel serving as the external power of the present invention.
[0028] FIG. 6 b is a schematic view showing the present invention connecting to the external power through the interface.
[0029] FIG. 6 c is a schematic view showing the wire passing through the through hole to electrically connect to the external power.
[0030] FIG. 7 is a schematic view showing the present invention being used as an inserted light in courtyard.
[0031] FIG. 8 is a schematic view showing the present invention being used as a bird bath or an ornamental pot.
[0032] FIG. 9 is a schematic view showing the present invention being used as a hanging planter, a hanging basket or a pendant light.
[0033] FIG. 10 is a schematic view showing the present invention being used as a bracket light or a wall light.
[0034] In the figures:
[0000]
Body
1
Chamber
2
Luminous body
3
Light diffuser plate
4
Interface
41
Through hole
42
Electric parts
5
Light-emitting component
51
Power
52
Wire
53
DETAILED DESCRIPTION OF THE INVENTION
[0035] To further explain the technical proposal of the present invention, the present invention will be described in detail with reference to the embodiments below.
[0036] As illustrated in FIGS. 1-10 , the novel light-emitting basin of the present invention comprises a body 1 . The body 1 is made of glass, resin, metal, rubber, plastic, plastic material, ceramic, etc. It can be integrally molded or formed by combining or laminating the materials above.
[0037] The body 1 is in an atypical shape or a polyhedron shape. As illustrated in FIG. 4 , viewing from the top, the center of the bottom of the body 1 is recessed inwards to form a chamber 2 above. Alternatively, as illustrated in FIG. 5 , viewing from the top, the center of the bottom of the body 1 protrudes inwards to form a chamber 2 below.
[0038] The chamber 2 is in an atypical shape, a polyhedron shape, an inverted-trapezoidal shape, a dome shape or a bow shape. At least part of a chamber wall of the chamber 2 form a luminous body 3 which is light reflective or light refractive. The luminous body 3 is made into a translucent body with light-penetrative materials, so that light passes through the translucent body from inside to outside or from outside to inside, thus producing a variety of light changes such as refraction and diffused reflection. Alternatively, the luminous body 3 is made into a refractive body with light-reflective materials. Thus, the refractive body can reflect external light, which can also achieve a luminous effect.
[0039] The luminous body 3 as illustrated in FIGS. 2 and 3 is split horizontally or vertically to form an atypical shape, a polyhedron shape or a dome shape with multiple refractive indices. The projected area of the luminous body 3 accounts for 20-60% of the projected area of the body 1 , preferably 30-40%.
[0040] The light diffuser plate 4 is provided at the bottom of the body 1 . The light diffuser plate 4 is assembled at the body 1 by means of adhering, rotatable fastening, fastening or close-fitting.
[0041] Electric parts 5 are placed in the chamber 2 . Electric parts 5 mainly comprise circuit board, light-emitting component 51 , power 52 , etc.
Embodiment 1
[0042] As illustrated in FIG. 4 , the body 1 is integrally molded into a basin shape by the use of glass. The bottom surface of the body 1 is recessed inwards to form the chamber 2 above. A lateral chamber wall of the chamber 2 extends upwards to form a conical or cylindrical shape, and the top edge of the lateral chamber wall is at the same level as or lower than the top edge of the body 1 , preferably higher than the top edge of the body 1 . A bottom chamber wall of the chamber 2 protrudes towards the bottom to form an arc shaped luminous body 3 . The luminous body 3 can be made into a translucent body with light-penetrative materials.
[0043] Circuit board, power 52 etc. are placed in the chamber 2 above. The light-emitting component 51 can be provided inside and/or outside the chamber 2 above, and the light-emitting component 51 is roughly provided at a position higher than the top edge of the body 1 . Thus, light emitted from the light-emitting component 51 can pass through the lateral chamber wall of the chamber 2 to brighten the body 1 .
Embodiment 2
[0044] As illustrated in FIG. 5 , the bottom surface of the body 1 protrudes inwards to form the chamber 2 below. The top edge of a lateral chamber wall can also be higher, at the same level as or lower than the top edge of the body 1 . As illustrated in FIG. 6 , light-emitting component 51 is placed in the chamber 2 below.
[0045] As illustrated in FIG. 6 a , the power 52 can be in form of an external solar panel, alternating current, DC power or battery cell. The power 52 electrically connects to the light-emitting component 51 through a wire.
[0046] Electrical connecting methods can be in form of the following:
[0047] As illustrated in FIG. 6 b , an interface 41 is provided on the light diffuser plate 4 . The interface 41 can be a socket or a plug. The light-emitting component 51 electrically connects to an external solar panel, alternating current or DC power through the interface 41 .
[0048] As illustrated in FIG. 6 c , the light diffuser plate 4 is opened with a through hole 42 . One end of the wire 53 passes through the through hole 42 and electrically connects to the light-emitting component 51 . Another end of the wire 53 electrically connects to an external alternating current, DC power or solar panel.
[0049] Certainly, an interface and a through hole can also be provided on the body 1 or the light-emitting component 51 , so that the light-emitting component 51 can electrically connect to the external solar panel, alternating current, DC power and battery cell.
[0050] In short, the power 52 can be provided inside and/or outside the body 1 , and/or be provided inside and/or outside the chamber 2 , and/or be provided inside and/or outside the luminous body 3 .
[0051] The light-emitting component 51 can be in form of LED lamp beads. Part of the light emitted from the LED lamp beads passes through the translucent body. The other part of the light first passes through the light diffuser plate 4 at the bottom surface and then through the translucent body to turn the translucent body into a bright and gorgeous light package which does not only brighten the chamber wall of the chamber 2 , but also further brighten the body 1 by the light passing from the chamber wall 2 .
[0052] When in use as illustrated in FIGS. 7-10 , the light-emitting basin is placed in an environment such as indoor and outdoor and courtyard. It can also be used as inserted light, bird bath, ornamental pot, hanging planter, hanging basket, pendant light, bracket light, wall light etc. in courtyard. With such bow-shaped translucent body absorbing the light emitted from the LED lamp beads provided in the chamber 2 , the light concentrates in the entire chamber 2 , which make the shape of the body 1 outstanding and highlight the patterns and colors on the chamber wall as well as the uneven patterns on the body 1 surface. Thus, the entire light-emitting basin is perfectly clear and bright, gorgeous and dazzling in the night. Also, after water is filled in the body 1 , as the water in the basin ripples, patterns on the chamber wall of the chamber 2 and body 1 surface such as fish, dragon and grass appear more realistic, vivid and lively.
[0053] The present invention changes the sole ornamental function of conventional basins. It is both practical and aesthetically pleasing. Water and food are placed in the body 1 , bringing convenience to lives with pets. As ornamental crafts, they are perfectly clear and bright, gorgeous and dazzling in the night. They have a high ornamental value and bring and visual enjoyment to people.
[0054] The foregoing embodiments and drawings are not limiting the product form and style of the present invention. All suitable modifications and equivalents made by those skilled in the art may be resorted to falling within the scope of the invention. | The present invention is a novel light-emitting basin which includes a body. A surface of the body protrudes or is recessed to form a chamber. The body and/or a chamber wall of the chamber is in an atypical shape or a polyhedron shape. At least part of the chamber wall of the chamber forms a luminous body which is light reflective or light refractive. By using the novel light-emitting basin of the present invention, the surface of the body protrudes or is recessed to form a chamber. Fittings such as electric parts can be disposed in the chamber and thus could not be damaged easily. | 8 |
This is a divisional of application Ser. No. 08/053,551 filed on Apr. 27, 1993, now abandoned, and refiled on Oct. 25, 1994 as application Ser. No. 08/328,551 which is a continuation of application Ser. No. 07/839,305 filed on Feb. 20, 1992, now abandoned for MODULAR CUSHION CONSTRUCTIONWITH FOAMED BASE.
BACKGROUND OF THE INVENTION
This invention relates in general to cushions for seating and more particularly to a modular wheelchair cushion which has a shaped foam base, a fluid filled or foam cellular pad covering part of the base, and a fabric cover enclosing the base and the pad.
Those who must spend extended time in wheelchairs run the risk of tissue breakdown and the development of pressure sores, which are extremely dangerous and difficult to cure. These pressure sores are decubitus ulcers, typically formed in areas where bony prominences exist, such as the ischia, heels, elbows, ears and shoulders. Typically, when sitting much of the individual's weight concentrates in the regions of the ischia, that is at the bony prominences of the buttocks and unless frequent movement occurs, the flow of blood to the skin tissue in these regions decreases to the point that the tissue breaks down. This problem is well known and many forms of cushions are especially designed for wheelchairs for reducing the concentration of weight in the region of the ischia, and these cushions generally seek to distribute the user's weight more uniformly over a larger area of the buttocks.
Another area where problems occur is in the trochanter area and both cushions and bases for the cushions are shaped so that the thighs are loaded and pressure is relieved on the ischia and the trochanters. Still another problem with wheelchair type cushions is stabilization of the user so that he has a feeling of security when sitting in the wheelchair.
A number of patents show cellular cushions which comprise an array of closely spaced air cells which project upwardly from a common base and are interconnected. These cushions combine the most uniform distribution of weight and thus provide the greatest protection from the occurrence of pressure sores. Since the air cells communicate with each other, all exist at the same internal pressure and each air cell exerts essentially the same restoring force against the buttocks, irrespective of the extent to which it is deflected. U.S. Pat. No. 4,541,136 shows a cellular cushion currently manufactured and sold by Roho, Inc. of Belleville, Ill. for use on wheelchairs.
The stability problem has been attacked by the use of shaped bases such as shown in Graebe U.S. Pat. No. 4,953,913 and Jay U.S. Pat. No. 4,726,624. These bases are generally used in conjunction with cushions and Graebe U.S. Pat. No. 4,953,913 has been used in conjunction with a cellular cushion and a fabric cover. The stability problem also has been addressed in the cellular cushion field by the use of zoned areas of inflation as shown in Graebe U.S. Pat. No. 4,698,864 which shows a zoned cellular cushion with cells of varying height and Graebe U.S. Pat. No. 5,052,068 which shows another form of zoned cushions with cells of different heights.
Graebe U.S. Ser. No. 07/723,408, now U.S. Pat. No. 5,111,544 shows a cover for a zoned cellular cushion which keeps the cells from deflecting outwardly. This cover has a stretchable top, a skid resistant base and a non-stretchable fabric side panel area.
The present invention resides in a foamed base having a flat rear area onto which may be fastened a variety of pads, including those which have a shaped surface to conform to body shapes, preferably a pad formed with upstanding air inflated cells. The base has a raised shaped front designed to load the thighs and separate the legs to stabilize the pelvis. A fabric cover forms the outside of the composite cushion and has a portion of the top formed of stretchable material and the remainder of the top and sides formed of a slick non-stretchable fabric with a skid resistant base. The base by itself is useful by able bodied persons who have good tissue bulk around their legs, whereas disabled persons who do not have good thigh bulk benefit by having a fluid filled module, such as an inflated air module, or a suitable foam module installed on the rear area.
The invention also consists in the parts and in the arrangements and combinations of parts hereinafter described and claimed.
DESCRIPTION OF THE DRAWINGS
In the accompanying drawings which form part of the specification and wherein like numerals and letters refer to like parts wherever they occur:
FIG. 1 is a perspective view of the modular cushion of this invention;
FIG. 2 is a perspective view similar to FIG. 1 with the cover removed and showing only the base and a cellular cushion;
FIG. 3 is a sectional view taken along line 3--3 of FIG. 1;
FIG. 4 is a fragmentary plan view with part of the cover broken away;
FIG. 5 is a fragmentary sectional view taken along line 5--5 of FIG. 4;
FIG. 6 is a perspective view of the cellular cushion;
FIG. 7 is a fragmentary plan view of a portion of the base of the cover.
FIG. 8 is a fragmentary plan view of another modified cushion;
FIG. 9 is a fragmentary sectional view taken along line 9--9 of FIG. 8;
FIG. 10 is a fragmentary plan view of another modified cushion;
FIG. 11 is an end elevational view of the modification shown in FIG. 10;
FIG. 11A is a rear view of a modification of the cushion shown in FIG. 10;
FIG. 12 is a bottom perspective view of a modified base;
FIG. 13 is a bottom perspective view of a cushion designed to be used with the base shown in FIG. 12;
FIG. 14 is a sectional view taken along line 14--14 of FIG. 12;
FIG. 15 is a fragmentary sectional view taken along line 15--15 of FIG. 14.
FIG. 16 is a top plan view showing storage of an inflation hose;
FIG. 17 is a sectional view taken along line 17--17 of FIG. 16 showing storage of an inflation hose;
FIG. 18 is a perspective view of a leg positioner module; and
FIG. 19 is a partial sectional view taken along line 19--19 of FIG. 18.
DETAILED DESCRIPTION
FIGS. 1 and 2 show the preferred form of the composite modular cushion 10 which comprises an outer cover 11 and, as shown in FIG. 2, a shaped base 12 and an inflatable cellular cushion 13 formed with upstanding air cells 14.
The base 12 is shown in more detail in FIGS. 2, 3 and 4 and comprises a flat rear area 20 and a raised front area 21. A sloped or inclined connecting area 22 connects the rear area 20 with the front area 21. The sloped connecting area 22 is shown more clearly in FIG. 3. This step down offset is designed to force support to the thighs and relieve pressure to the ischial and the trochanters. The base also includes a tapered front face 23 as seen in FIGS. 3 and 4 and inwardly curved thigh loading areas 24 at the side edges of the front 21. These areas are sloped inwardly from the outer side edges to provide the proper thigh loading characteristics without providing too much pressure against the thighs. In the center of the front area 21 is a raised pommel 25 which is higher than the side areas 24 and is designed to separate the legs, stabilize the pelvis, and to help keep the user from sliding out of his seat. Between the raised side areas 24 and the pommel 25 are dish shaped leg retaining valleys 26 which are angularly inclined outwardly away from the rear base area 20 along the lines X X in FIG. 4 so as to separate the legs in conjunction with the pommel 25.
The base 12 is formed of foamed plastic of polyurethane type and may have various indent densities based on the needs of the user. During molding a skin is formed which is resistant to moisture and chemicals and can be washed and sterilized, if necessary, using conventional techniques.
The underside of the pommel 25 can be hollowed out at 75 to give a softer feel to the center section 25. This is shown in FIGS. 3 and 4. If this feel is not necessary, the hollowed out section 75 may be molded solid with the rest of the base 12. Recesses 27 are molded in selected locations, such as the center of the underside of the flat rear base area 20, and are designed to accommodate the male portion 28 of a snap fastener. The snap fastener is exposed to the top surface of the rear base area 20 so that the air cell module 13 can be attached thereto as will be hereinafter described. Other suitable fastening means such as hook and loop type fasteners of the type sold under the trademark VELCRO can be used where needed, if desired.
An alternative construction is shown in FIGS. 12, 14 & 15 in which slots 70 are molded into the underside of the front of the base 12a. The slots 70 are parallel to and spaced inwardly from the base side edges and terminate in access openings 71 which open into the top surface of the base 12a adjacent to the connecting area 22. The slots 70 terminate short of the base front 23 and also have openings at 72 to the front 23 of the base 12. The solid webs 73 help stabilize the base front 23. The slots 70 accommodate tubes 33a for the air inflatable pad 13 so that the air valves 34a for the pad 13 are accessible from the front of the cushion 10 whereby they can be inflated and adjusted readily by the user while he is sitting on the modular cushion 10. This can be used with any number of sets of air cells and can be used with the pad of FIG. 2 or the pad of FIG. 8.
The alternative construction also lends itself to the concept of communicating with the undersurface of a module through the base. Using the concept, individual cells can be monitored and a profile of the weight distribution of the user can be determined. This involves a pressure measuring system beyond the scope of this disclosure but the communication with the underside of a cushion through the base makes this possible. The slots 70 may be located to exit at any edge and in any number as may be required.
The inflatable cushion or module 13 has a flexible base 30 of substantially rectangular shape and the air cells 14 project upwardly from the base 30. In the preferred embodiment shown in detail in FIGS. 2-6, there are two zones A and B which are distinct and separated by a center area 31. The air cells 14 in each of the zones A and B are interconnected by means of passages 32. Thus, the air pressure in the cells 14 in each zone is the same but the air pressure in the zones A and B can be different based on the configuration of the patient. Each of the zones has a separate fill tube 33 which has a closure valve 34 on the end thereof. If the fill tube 33 with the closure valve 34 is not used, each of the zones A and B is provided with a test opening connected to one of the air cells 14. This is designed to be closed with a plug which is removable for factory testing and air pressure preshipment adjustment.
These passages 32 may be constructed as described in Graebe U.S. Pat. No. 4,541,136 or may be raised tunnels molded into the top member where the air cells 14 are formed. The tunnels may have a high aspect ratio to exclude glue from the tunnels when the top and base are glued together.
This arrangement is shown and hereinafter described in conjunction with the modification of the invention shown in FIGS. 8 and 9, but also can be used with the pad shown in FIGS. 1-6 or any other variation of the air inflated cellular module.
Positioned through the module base 30 in alignment with the shaped base recesses 27 are the female portions 37 of a snap fastener arrangment. This is shown in FIG. 5 and allows the module 13 to be snapped and fastened to the base 12.
As previously noted the module 13 can be formed from preinflated cells 14 rather than using the fill tube 33. If the fill tube 33 is eliminated, the modules 13 are prefilled at the factory with a predetermined air pressure and this pressure cannot be adjusted by the user. The cells 14 are still interconnected within each zone A and B but the pressure in the zones A and B cannot be adjusted after once being established.
The air cells 14 are of pyramidal shape and have a square bottom, rectangular side edges 38, tapered top side 39 of trapezodial shape, and a substantially flat top 40. The purpose of the pyramid shape is to provide a means to collapse the air cell in a controlled manner during the engagement phase by the person sitting on the points formed by the pyramid. The higher the point the greater the engagement travel which gradually builds up the internal pressure of the cell giving a low force entry zone. This entry zone is especially useful when prefilled or sealed air cells are used. The air cells 14 are spaced from each other by lateral and longitudinal passages 15 and stand independently of each other when erected and filled with air. The inflatable module 13 is formed of a flexible material such as neoprene rubber, or the like.
Other types of snap fastened cushions or pads can be used and several of these are shown in FIGS. 8 and 10. The module 41 of FIGS. 8-9 has two separate inflatable cells 41a,41b separated by a seam 42 and filled through air valves 43a,43b. As hereinbefore noted, this form of the invention is shown as having the air chambers 41a,41b prefilled at the factory with a predetermined air pressure and the fill tubes 43a,43b are sealed with plugs 44a,44b which are similar to pencil erasers. Thus, the air pressure in the chamber 41a,41b cannot be adjusted by the user. As mentioned, this type pad can use the inflation systems shown in FIGS. 1-6 or FIGS. 12-15. Individual sealed cells also can be used in the pad.
A modification of the pad 41 is shown in FIGS. 12-15. This modification is used with the base shown in FIG. 12 and the pad 41 is adjustable from the front. The pad 41 is provided with fill tubes 33a which extend from the underside of the pad 41 and are positioned in the base slots 70 so that the fill nozzles 34a are accessible from the front to more readily be adjustable by the user. This construction also can be used with the inflatable pad 13 shown in FIG. 1-6.
The cushion 65 shown in FIGS. 10 and 11 is made of a molded foamed plastic and, as shown, has hollow dome shaped members 66 similar to those shown in Sias et al U.S. Pat. Nos. 4,673,605, 4,605,582 and Des. 294,212. The foamed pad 65 can be "T-Foam", molded domes 66, or arch elements as shown in Graebe U.S. Pat. No. 4,713,854, and can be made to better fit the patient by shaping the surface of the foam or adjusting the size or resiliency of the projections. A modification of the cushion 65a is shown in FIG. 11A which shows a shaped cushion surface in which the domes 66a are of different heights.
The base 12 can be used alone or in combination with any one of the cushions 13, 41, 65 or 65a. The base and cushion also can be used in combination with the cover 11.
The cover 11 contains some features in common with Graebe application Ser. No. 07/723,408, filed Jul. 1, 1991, now U.S. Pat. No. 5,111,544 and as shown in FIGS. 1, 3, 4 and 7, includes a top panel 45, a bottom panel 46, side panels 47, a front panel 48 and a rear panel 49. The front, bottom, side, rear and bottom panels are stitched together along their edges to define the cover 11. The respective panels generally conform to the shape of the portions of the shaped base 12 over which they fit. The rear panel 49 is severed into two sections 50,51 which are connected by suitable fastening means, such as a zipper 52, which also can extend into the side panels 47 as far as is necessary to obtain access to the fill valve 33. For example, the zipper 52 can extend completely to a valve stem stored in the sloped wall 22 of the base 12 as described hereinafter in FIGS. 16 and 17. This allows the cover 11 to be slipped over the base 12 and the attached inflatable module 13. It also allows the cover 11 to be removed for cleaning, etc. The rearward ends of the top panel 45 are shortened at the corners to define openings 52,53 through which the fill tubes 33 and valves 34 extend to allow the module 13 to be filled without removing the cover 11. If the fill tube is positioned in the slots 70, the openings 52,53 are at the front edges of the cover 11 to provide access to the fill tubes 33. The top cover 45 is formed of two sections of dissimilar material. The rear section 55 is formed from a highly elastic fabric, i.e., one that stretches in any direction. The elasticity of the top panel 55 enables that panel to conform to the shape of the user's buttocks when the user sits on the inflatable module 13 and minimizes the "membrane effect" of the cover. The top panel section 55 simply follows the contour of the seating surface created by the upper ends 40 of the air cells 14. It detracts little from the capacity of the array of air cells 14 to conform to the shape of the user's buttocks. The forward portion 56 of the top panel 45, the side panels 47, the front panel 48, and the rear panel 49 are formed from a traditional fabric, i.e., one that offers low friction with flexibility, yet is very durable. Typical nylon fabric is suited for this purpose. The forward portion 56 of the top panel 45 offers low friction to aid the user in performing slide transfers on and off the cushion. These sections can be formed from one or more parts and stitched together and stitched to the other panels.
The bottom panel 46 is formed from a high friction mesh 60 (FIG. 7) known as vinyl coated skrim. The mesh 60 consists of polyester fibers woven into an open weave and a polyvinyl chloride coating covering the polyester vinyl fibers without obliterating the openings of the weave. The polyvinyl chloride coating allows the cushion cover 11 to be cleaned and sterilized without causing the fabric coating to become slick and slippery. In other words, it retains its anti-skid or high friction characteristics. The weave of the bottom panel 46 is such that the mesh 60 has relatively thick ribs 61 extending parallel between opposite edges of the panel 46 and thinner connecting segments 62 extending between the ribs 61 and oriented at right angles with respect to the ribs 61, with the spacing between the connecting segments 62 being about the same as the spacing between the ribs 61. This forms a series of square openings which are divided by diagonal segments 63 that extend between the connecting segments 62 and cross at the centers of the square openings. The coating is a high co-efficient of friction against traditional seating surfaces such as wood, metal or fabric, and the friction that develops is particularly affective along the thick ribs 61. The co-efficient of friction between the coating and such surfaces is substantially greater than the co-efficient of friction between the top or side panels 45, 47, 48 and 49 and such surfaces. The mesh 60 is commonly used as an underlayment for throw rugs to prevent them from slipping on traditional flooring materials such as tile, vinyl and hardwood. It may be obtained from Vantage Industries, Inc. of Atlanta, Ga. The high friction mesh 61 of the bottom panel 46 prevents the cover 11, base 12 and module 13 overwhich it fits from sliding over a supporting surface such as the seat of a wheelchair or the seat of a traditional chair or bench. In addition, it admits air to the interior of the cover 11 where the air can circulate through the array of air cells 14. Finally, it permits moisture to drain from the interior of the cover 11.
In use, the cover 11 containing the shaped base 12 and with or without the inflatable module 13 is placed on a supporting surface such as the seat of a wheel chair or a seat of a traditional chair or bench with the bottom panel 46 presented downwardly against the supporting surface. The user's weight is distributed generally uniformly over the portion of the cushion 10 which is defined by the rear section 50 of the top panel 46, i.e., that portion supported by the inflatable module 13. The portion of the user's weight which is supported by that portion of the base 12 which is covered by the front section 56 of the top panel 45 is directed by the shape of the base 12 to the thighs and to relieve pressure on the ischial and the trochanters. The directed contours 26 and the pommel 25 separate the legs and in combination with the new slip cover helps to prevent a user from sliding out of position and the chair seat.
The high co-efficient of friction that exists between the bottom panel 46 and the underlying supporting surface, coupled with the concentration of the user's weight on that panel 46, stabilizes the cover 11 and the encased base 12 and module 13 that is difficult to displace. Indeed, it is practically impossible to slid the combination cover 11, base 12 and module 13 over a traditional wood seating surface without lifting the combination slightly. The bottom panel 46 is rendered particularly effective by reason of the mesh 60 and the thicker ribs 61 within that mesh 60, for it is along the ribs 61 that most of the friction develops with a supporting surface.
FIG. 16 shows an alternative construction for the base 12 in which the inflation valve and hose or fill tube 33 is positioned on the front of the pad 13 and is retained in an opening 80 formed in the base 12 and opening at the inclined connecting surface 22. The inflation valve 34 and hose 33 are stored in the opening 80 when not in use. Other type projections on the pad or module 13 can also be inserted into the openings 80 and, if the fit is sufficiently tight, can be used as a means for holding the module 13 in position in lieu of, or in combination with snaps or hook and loops or other fastener.
FIGS. 18 and 19 show another modification of the invention which is a U-shaped retainer 90 positioned on the cushion 10 over the cover 11. The leg positioner and restraint 90 has a base 91 and two upstanding uprights 92 which project upwardly from the front of the base 12. Hand grips 93 can be provided in the free ends of the uprights 92. The base has stiffeners 94 stamped in it to give it rigidity. The leg positioner 90 can be covered with a rubber or vinyl coating, which, in combination with the vinyl coated skrim on the cover 11 will hold the positioner 90 in place. If the positioner 90 is used without a cover 11, VELCRO hook and loop type fasteners or other fastening tape can be used. The uprights 92 flare outwardly slightly and have padding 95 at the top inner surface to help protect the legs of the user.
The structure 90, when placed under the cushion 10, serves as a supplemental leg positioner and restraint to hold the legs of the person toward the center of the cushion 10. The vertical sides 92 are long enough to project beyond the leg to not cause indentation into the flesh. A slight outward flare can be provided on the top portion of the vertical uprights 92 to assure easy and safe entering onto the cushion 10. The hand grip opening 93 can also be provided in each upright 92 to aid in lifting the person or provide a push off purchase to aid in independent transfer off onto the cushion 10.
The leg positioner and restraint 90 is constructed of molded plastic or 1/16" to 1/8" thick aluminum, such as 6061-T6 alloy and can have V-shaped groves 94 along its length to improve its stiffness. The preferred construction will have a vinyl or rubber coating over the metal. Supplemental padding 95 of foam or air filled cushion can be attached by VELCRO hook and loop type fasteners or snaps to the inside of the position sides 92 to further protect the soft tissue of the body.
This invention is intended to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure which do not constitute departures from the spirit and scope of the invention. | A modular cushion comprising a shaped base which has a flat rear portion and a raised front portion with angularly directed valleys and a raised pommel to direct weight to the thighs and in combination with a resilient pad positioned on the flat portion of the base to relieve pressure on the ischial and trochanters and in combination with a cover having a non-skid undersurface and a portion of the top being two-way stretchable. The resilient pad may be of inflatable cells having a pyramidal shape with a flattened top. A U-shaped restraining member may be positioned at the front of the base with upwardly projecting sides to retain the legs of the user. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to a mechanism for attaching an implement such as a snowplow onto a vehicle while allowing some free motion of the implement in service.
BACKGROUND OF THE INVENTION
[0002] Float mechanisms are employed for mounting material-moving implements such as loader buckets and snowplows onto vehicles. The float mechanism allows a limited degree of free motion of the implement, allowing it to accommodate uneven terrain surfaces. Preferably, the float mechanism is designed to attach to an instant transfer connector on the vehicle to allow the implement, with the float mechanism attached thereto, to be readily removed for transportation, use on a different vehicle, or to free the vehicle for other uses. One such float mechanism is taught in U.S. Publication 2008/0028643.
[0003] While the float mechanism taught in the '643 publication offers a significant improvement over earlier implement mounting structures, it has been found to suffer from limited stability under some operating conditions. When mounted to a wheeled vehicle having relatively low-pressure tires, it has been found the bouncing of such vehicles over relatively uneven surfaces results in an undesirable degree of pitching of the implement due to the free play in the float mechanism.
SUMMARY
[0004] The present invention is for a float mechanism for attaching a material-moving implement such as is taught in the U.S. Pat. No. 7,360,327 to an instant transfer connector on a vehicle. One such instant transfer connector is available from Caterpillar Inc. The float mechanism allows the material-moving implement a limited degree of free motion relative to the instant transfer connector on the vehicle to accommodate irregularities in the surface over which the vehicle and the material-moving equipment travel.
[0005] The float mechanism has a mounting frame which has a pair of substantially vertical supports affixed at a set separation configured to slidably and lockably engage the instant transfer connector which is attached to the vehicle. A fixed frame is attached to the material-moving implement, and may be formed as an integral part of the implement.
[0006] A pivot bracket is pivotally attached with respect to one of the frames about a pivot bracket axis and is slidably connected with respect to the other of the frames so as to accommodate a limited degree of translational motion sliding along a nominally vertical axis. The pivot bracket serves to maintain the motion of the fixed frame relative to the mounting frame within the nominally vertical plane while allowing limited translation between the frames, and thereby prevents unintended pitching of the material-moving implement.
[0007] The slidable connection of the pivot bracket to one of the frames can be provided by a pair of guides that are fixed to either the pivot bracket or the frame, in combination with a pair of sleeves that are affixed to the other of these elements. Stops on the guides can be employed to limit the translational motion between these elements.
[0008] In some applications, it can also be beneficial to limit the rotational motion between the fixed frame and the mounting frame. This motion could be limited by one or more stops affixed to one of the frames or to the pivot bracket. However, to reduce the bending moments on the pivot bracket resulting from loads due to the scraping action of the material-moving implement, it is preferred to limit the rotation by a mechanism that is substantially spaced apart from the pivot bracket which, in addition to limiting the rotation of the frames, also serves to guide the motion along a path that maintains the two frames in parallel relationship. This action can be provided by one or more slots in one of the frames, and one or more corresponding stabilizing elements on the other of the frames, configured to slidably engage the slot(s), thereby providing limited motion in a plane that is substantially normal to the pivot bracket axis.
[0009] In one embodiment, a horizontally-extending transfer bar affixed to either the mounting frame or the fixed frame slidably engages one or more substantially vertical slots in the other frame. Providing a pair of substantially vertical slots that are spaced apart will tend to balance the forces to reduce wear and reduce the likelihood of binding.
[0010] When one or more slots in combination with one or more stabilizing elements are employed to limit rotational motion between the fixed frame and the mounting frame, movable blocks can be employed to deactivate the float mechanism and prevent free movement. These blocks can be positioned to block a portion of the slot(s) to prevent movement of the stabilizing element(s) therein. Preventing free movement can be particularly advantageous when the float mechanism is employed with a loading bucket during loading operations, to prevent any motion that could result from uneven loading.
BRIEF DESCRIPTION OF THE FIGURES
[0011] FIG. 1 is a partially-exploded isometric view showing a float mechanism that forms one embodiment of the present invention, the float mechanism serving to support a material-moving implement. The float mechanism has a fixed frame that is affixed to the implement and a mounting frame that has a pair of vertical members configured to attach to an instant transfer connector of a vehicle (not shown). The fixed frame has a centrally-positioned cross-brace with a pivot shaft affixed thereto. A pivot bracket is pivotably attached to the pivot shaft so as to rotate with respect to the fixed frame about a pivot bracket axis. The pivot bracket in turn has a pair of guides that are slidably engaged by sleeves on the mounting frame. The guides extend along a plane that is normal to the pivot bracket axis; in service, the guides are positioned so as to generally extend vertically. The guides pass through top and bottom plates that limit the translation of the sleeves thereon. The rotation of the pivot bracket with respect to the fixed frame can be limited by a bracket stop protrusion that extends from the top plate so as to engage the cross brace of the fixed frame to limit rotation of the pivot bracket.
[0012] FIG. 2 is an exploded view showing further details of how the pivot bracket shown in FIG. 1 is connected to the remaining structures. The pivot bracket has a bracket passage therethrough configured to slidably engage the pivot shaft, and a retaining collar is provided that attaches to the pivot shaft to trap the pivot bracket thereon. To engage the pivot bracket with the mounting frame, the guides are provided by a pair of guide pins that slide into guide passages in the top and bottom plates of the pivot bracket. The guide pins are inserted into the passages while the sleeves of the mounting frame are positioned between the top and bottom plates with sleeve passages aligned with the guide passages. When the guide pins are installed, the sleeves are trapped on the guide pins between the top and bottom plates.
[0013] FIG. 3 is an isometric view showing the pivot bracket shown in FIGS. 1 and 2 when connected to the fixed frame and the mounting frame.
[0014] FIG. 4 is an isometric view that illustrates another float mechanism of the present invention; this embodiment provides greater stability for the implement attached to the fixed frame. In this float mechanism, pivoting of the fixed frame relative to the mounting frame is further limited by a pair of substantially vertical slots that are slidably engaged by a transfer bar that serves as a stabilizing element as well as reducing bending moments on the pivot bracket. As illustrated, the transfer bar is affixed to the fixed frame, spaced apart vertically from the pivot shaft, and the slots are provided on the mounting frame. The slots are formed by slot plates affixed to the mounting frame in combination with closure plates that attach to the slot plates to close the remaining side of the slots. The use of a pair of slots to engage the transfer bar provides an effective three-point support for the implement to increase stability and reduce bending moments on the pivot shaft.
[0015] FIG. 5 is an isometric view of the embodiment shown in FIG. 4 when partially exploded to show further details of the structure associated with the vertical slots, including extendable blocks that can be positioned to immobilize the transfer bar in the slots to provide a rigid connection between the mounting frame and the fixed frame.
[0016] FIG. 6 is an isometric view illustrating an embodiment similar to that shown in FIGS. 4 and 5 , but where two vertical slots are provided on the fixed frame and engage a transfer bar attached to the mounting frame.
[0017] FIGS. 7 and 8 are isometric views showing an embodiment having a fixed frame that is provided with a pair of horizontal guide slots, each of which is slidably engaged by a vertically-extending transfer post affixed to the mounting frame. FIG. 7 shows the float mechanism partly exploded.
[0018] FIG. 8 is an isometric view showing the float mechanism shown in FIG. 7 when assembled and where relative motion between the frame members can be prevented by locking pins that engage both a mounting frame and at least one of the bars that define the horizontal guide slots.
[0019] FIG. 9 is a partially-exploded isometric view showing an embodiment similar to that shown in FIGS. 4 and 5 , but where the pivot bracket is provided with sleeves that slidably engage guides provided on the mounting frame.
[0020] FIG. 10 is a partially-exploded isometric view showing an embodiment similar to that shown in FIG. 9 , but where the pivot bracket engages a pivot shaft on the mounting frame, and has sleeves that slidably engage guides mounted to the fixed frame.
DETAILED DESCRIPTION
[0021] FIGS. 1-3 illustrate a float mechanism 10 that is designed for supporting a material moving implement such as a snowplow 12 to allow the snowplow 12 to move freely to traverse uneven ground surfaces while being supported on a vehicle (not shown). The float mechanism 10 has a fixed frame 14 that is affixed to the snowplow 12 , and can be made an integral part thereof. The float mechanism 10 also has a mounting frame 16 that is connected to the fixed frame 14 by a pivot bracket 18 . The mounting frame 16 in turn has a pair of substantially vertical supports 20 that are configured to releasably engage a conventional instant transfer connector on the vehicle, such as the instant transfer provided by Caterpillar Inc.
[0022] The fixed frame 14 has a pivot shaft 22 that extends along a pivot axis 24 . The pivot axis 24 is substantially horizontal when the float mechanism is in service, and extends in the direction of travel of the vehicle. In the float mechanism 10 , the pivot shaft 22 is mounted to a centrally-located cross-brace 26 that is affixed to the remainder of the fixed frame 14 . The pivot bracket 18 has a bracket passage 28 therethrough, which is lined with an appropriate weight-bearing low-friction bracket bushing 30 that slidably engages the pivot shaft 22 on the fixed frame 14 . The bracket bushing 30 can be a conventional grooved metal bushing. The pivot shaft 22 has a length sufficient that it extends beyond the bracket passage 28 . As shown in FIG. 2 , a pivot shaft passage 32 is provided through the pivot shaft 22 to accommodate a pivot shaft bolt 34 . A retaining collar 36 is configured to slidably engage the portion of the pivot shaft 22 that extends beyond the bracket passage 28 , and has a collar passage 38 into which the pivot shaft bolt 34 can be threadably secured. When the pivot bracket 18 and the retaining collar 36 are slidably engaged on the pivot shaft 22 , the collar passage 38 is aligned with the pivot shaft passage 32 and the pivot shaft bolt 34 can be inserted into the aligned passages ( 32 , 38 ) to retain the retaining collar 36 on the pivot shaft 22 with the pivot bracket 18 trapped between the retaining collar 36 and the fixed frame 14 , as shown in the assembled view of FIG. 3 . Preferably, bracket washers 40 of a durable, low-friction material such as nylon are interposed between the pivot bracket 18 and the fixed frame 14 , and between the pivot bracket 18 and the retaining collar 36 (as best shown in the exploded view of FIG. 2 ).
[0023] The pivot bracket 18 in turn is connected to the mounting frame 16 by a slide mechanism 42 that allows limited translation between the pivot bracket 18 and the mounting frame 16 , this motion being limited to translation in a plane that is normal to the pivot axis 24 . As shown in FIG. 2 , the pivot bracket 18 is provided with a top plate 44 and a bottom plate 46 , each having a pair of guide passages 48 into which guide pins 50 can be inserted. The guide passages 48 are centered on guide axes 52 which reside in a plane that is normal to the pivot axis 24 ; typically, the guide axes 52 are substantially vertical.
[0024] The mounting frame 16 has a pair of sleeves 54 , each having a sleeve passage 56 that is sized to slidably engage one of the guide pins 50 . When the sleeves 54 are placed between the top plate 44 and the bottom plate 46 with the sleeve passages 56 aligned with the guide passages 48 , the guide pins 50 can be inserted into the aligned passages ( 48 , 56 ) and secured to the pivot bracket 18 by guide pin bolts 58 that each pass through a bracket pin passage 60 on the pivot bracket 18 and a guide pin passage 62 through one of the guide pins 50 . The sleeve passages 56 are preferably lined with sleeve bushings 64 of a durable, low friction material such as nylon.
[0025] When the fixed frame 14 , the mounting frame 16 , and the pivot bracket 18 are so connected, the snowplow 12 is free to rotate about the pivot axis 24 to accommodate changing angles of road surfaces over which the snowplow 12 is operated. Additionally, the slidable engagement between the pivot bracket 18 and the mounting frame 16 allows the snowplow 12 a limited degree of vertical translation along the guide axes 52 to allow the snowplow 12 to ride over small obstructions.
[0026] While the position of the snowplow 12 is typically limited by the ground surface to be traversed, it is frequently desirable to limit the rotation of the snowplow 12 to maintain it in a generally horizontal position when lifted from the ground. The rotation of the snowplow 12 can be limited by means for limiting the rotation between the fixed frame 14 and the mounting frame 16 . One example of such means, shown in FIGS. 1-3 , is to provide a stop protrusion 66 affixed to the pivot bracket 18 and positioned to engage the cross-brace 26 of the fixed frame 14 when the fixed frame 14 rotates relative to the pivot bracket 18 by a predetermined angle.
[0027] While the float mechanism 10 can provide more stable support to the snowplow 12 than earlier float mechanisms, it relies solely on the connections of the pivot bracket 18 to maintain the motion of the fixed frame relative to the mounting frame constrained within a plane. This places great requirements for structural integrity on the pivot bracket, and makes it highly susceptible to wear. These disadvantages can be reduced by employing means for limiting the rotation between the fixed frame and the mounting frame that also aid in limiting the motion between these elements to motion within a plane.
[0028] FIGS. 4 and 5 illustrate a float mechanism 100 , which provides greater stability for an implement 102 attached to a fixed frame 104 compared to the float mechanism 10 discussed above. Again, a pivot bracket 106 is rotatably mounted to a pivot shaft 108 on the fixed frame 104 , and is connected and to a mounting frame 110 by a slide mechanism 112 . However, the float mechanism 100 differs in the means for limiting rotation between the fixed frame 104 and the mounting frame 110 that are employed.
[0029] In the float mechanism 100 , the pivot shaft 108 is located in a lower region 114 of the fixed frame 104 ; this position of the pivot shaft 108 will tend to reduce the moment of torques on the pivot bracket 106 resulting from forces transmitted by the implement 102 when in operation. Rotation of the fixed frame 104 relative to the mounting frame 110 is limited by a transfer bar 116 that is slidably restrained by engagement with a pair of guide slots 118 . The use of a pair of guide slots 118 to engage the transfer bar 116 provides an effective three-point support for the implement 102 to further reduce bending moments on the pivot shaft 108 and the pivot bracket 106 , as well as increasing the stability of the implement 102 when in motion.
[0030] The transfer bar 116 in this embodiment is affixed to the fixed frame 104 so as to extend substantially horizontally, and is spaced apart vertically from the pivot shaft 108 so as to be located in an upper region 120 of the fixed frame 104 . The guide slots 118 are provided on the mounting frame 110 , and extend substantially vertically, extending parallel to the direction of motion provided by the slide mechanism 112 . The guide slots 118 are each formed by a slot plate 122 affixed to the mounting frame 110 , in combination with a closure plate 124 that attaches to the slot plate 122 to close the remaining side of the guide slot 118 . The slot plate 122 and the closure plate 124 are each provided with a replaceable bearing surface ( 126 , 128 ) of a durable, low-friction material such as nylon. The transfer bar 116 has a pair of opposed bar vertical sides 130 , and when the closure plate 124 is attached to the slot plate 122 with the transfer bar 116 interposed therebetween, the bearing surfaces ( 126 , 128 ) are positioned against the bar vertical sides 130 to limit the motion of the transfer bar 116 relative to the guide slot 118 to motion within a nominally vertical plane. Each of the closure plates 124 can be attached to its associated the slot plate 122 by bolts 132 that are inserted through aligned passages ( 134 , 136 ) in the closure plate 124 and the slot plate 122 .
[0031] Rotation of the fixed frame 104 with respect to the mounting frame 110 is limited by the motion of the transfer bar 116 in the guide slots 118 . Each of the slot plates 122 has a slot upper plate 138 that defines an upper end of the guide slot 118 , while a lower end of the guide slot 118 is defined by a blocking plate 140 that slidably engages a block mounting bracket 142 affixed to the slot plate 122 . Both the slot upper plate 138 and the blocking plate 140 are preferably provided with resilient pads 144 for respectively engaging a bar upper surface 146 and a bar lower surface 148 of the transfer bar 116 to limit its movement with respect to the guide slot 118 . As the fixed frame 104 rotates with respect to the mounting frame 110 about a pivot axis 150 defined by the pivot shaft 108 , at some point the bar upper surface 146 or the bar lower surface 148 will engage one of the resilient pads 144 , this engagement serving to block further rotation in that direction.
[0032] When the blocking plates 140 that form the lower ends of the guide slots 118 are movably mounted to the mounting frame 110 , they can allow the float mechanism 100 to be disabled to provide a rigid connection between the mounting frame 110 and the fixed frame 104 . This can be beneficial when the implement 102 is capable of being used as a loader bucket; such an implement that can be configured to operate either as a plow or as a loader bucket is taught in U.S. Pat. No. 7,360,327.
[0033] In the float mechanism 100 , each of the blocking plates 140 has an upper block passage 152 and a lower block passage 154 therethrough, either of which can be aligned with a block bracket passage 156 in the block mounting bracket 142 to allow a block pin 158 to be passed through the aligned passages ( 152 or 154 , 156 ) to fix the position of the blocking plate 140 with respect to the slot plate 122 . When the block upper passage 152 is aligned with the block bracket passage 156 and pinned, the blocking plate 140 is fixed in a retracted position (as shown in FIG. 4 ) where it is spaced apart from the slot upper plate 138 by a sufficient distance to allow the desired degree of movement of the transfer bar 116 in the guide slot 118 . However, when the blocking plate 140 is positioned such that the block lower passage 154 is aligned with the block bracket passage 156 , passing the block pin 158 through the aligned passages ( 154 , 156 ) fixes the blocking plate 140 in an extended position (shown in FIG. 5 ) where its separation from the slot upper plate 138 (measured between the opposed surfaces of the resilient pads 144 ) is about the same as the separation between the bar upper surface 146 and the bar lower surface 148 of the transfer bar 116 , thereby preventing vertical movement of the transfer bar 116 in the guide slot 118 . Since horizontal motion of the transfer bar 116 relative to the guide slot 118 is prevented by the connection of the pivot bracket 108 to the fixed frame 104 and the mounting frame 110 , pinning the blocking plates 140 into their extended positions effectively immobilizes the fixed frame 104 relative to the mounting frame 110 , allowing the implement 102 to be used as a loading bucket without undesirable free movement resulting from shifting of loads supported by the implement 102 .
[0034] FIG. 6 is an isometric view of a float mechanism 200 which shares many features in common with the float mechanism 100 discussed above, having a fixed frame 202 that is pivotably connected to a pivot bracket 204 which in turn is slidably connected to a mounting frame 206 . In the float mechanism 200 , rotation of the fixed frame 202 with respect to the mounting frame 206 is again provided by a transfer bar 208 that is slidably engaged in a pair of guide slots 210 . However, in this embodiment, the transfer bar 208 is affixed to the mounting frame 206 , while the guide slots 210 are formed by slot plates 212 affixed to the fixed frame 202 , in combination with closure plates 214 . The closure plates 214 attach to the slot plates 212 with the transfer bar 208 trapped therebetween. Again, the slot plates 212 are each provided with a block mounting bracket 216 in which a blocking plate 218 can be affixed in either an extended or retracted position. With respect to the third stabilizing element to prevent tilting between the frames ( 202 , 206 ) such is provided by the pivot bracket 204 which engages a pivot shaft 220 and is further stabilized by washers 222 and a retaining collar 224 .
[0035] FIGS. 7 and 8 illustrate an alternative float mechanism 300 , which again has a fixed frame 302 pivotably connected to a pivot bracket 304 that in turn slidably engages a mounting frame 306 . In this embodiment, the fixed frame 302 is stabilized with respect to the mounting frame 306 by a pair of guide slots 308 that extend horizontally along the fixed frame 302 , in combination with a pair of vertically-extending guide bars 310 affixed to the mounting frame 306 . However, in the float mechanism 300 illustrated, the guide slots 308 and the guide bars 310 are not employed to limit the rotation of the fixed frame 302 relative to the mounting frame 306 .
[0036] The fixed frame 302 is provided with a horizontally-extending slot bar 312 that is provided with a slot bearing surface 314 of a durable, low-friction material. A series of slot brackets 316 are also provided, to which a closure bar 318 can be attached by slot bar bolts 320 . The closure bar 318 has a bar bearing surface 322 of a durable, low-friction material, positioned so as to be opposed to the slot bearing surface 314 when the closure bar 318 is secured to the slot brackets 316 , these opposed surfaces ( 314 , 322 ) defining parallel sides of the guide slots 308 .
[0037] The guide bars 310 are each provided on a guide plate 324 affixed to the mounting frame 306 . The guide bars 310 have opposed guide surfaces 326 spaced apart to slidably engage the slot bearing surface 314 and the bar bearing surface 322 , to provide additional support regions between the frames ( 302 , 306 ), thereby reducing the torques on the pivot bracket 304 .
[0038] While the slot brackets 316 which serve to terminate the guide slots 308 and the guide bars 310 could serve to limit the rotation of the fixed frame 302 with respect to the mounting frame 306 , in this embodiment such rotation is more restrictively limited by stops 328 on the fixed frame 302 that are positioned to engage the guide plates 324 to limit such rotation, thereby providing a narrower limit of motion. Preferably, the stops 328 are each provided with a resilient pad 330 .
[0039] This embodiment also employs a different scheme for deactivating the float mechanism 300 for use supporting a loading bucket. The guide plates 324 are each provided with a guide plate passage 332 , which can be aligned with closure bar passages 334 provided in the closure bar 318 . When so aligned, deactivation pins 336 can be inserted into the aligned passages ( 332 , 334 ) to prevent movement of the fixed frame 302 with respect to the mounting frame 306 .
[0040] FIG. 9 illustrates a float mechanism 400 that has many features in common with the float mechanism 100 shown in FIGS. 4 and 5 , but which differs in the connection between a pivot bracket 402 and a mounting frame 404 . In this embodiment, the pivot bracket 402 is provided with bracket sleeves 406 that are configured to slidably engage guides 408 that are attached to the mounting frame 404 so as to provide a slide mechanism 410 . The guides 408 each terminate at a top plate 412 and a bottom plate 414 to limit the slidable engagement between the pivot bracket 402 and the mounting frame 404 . The pivot bracket 402 in turn is pivotably mounted to a fixed frame 416 in a manner similar to the connection between the pivot bracket 18 and the fixed frame 14 discussed in detail above with regard to FIGS. 1 - 3 .
[0041] FIG. 10 illustrates another alternative embodiment, a float mechanism 450 where a pivot bracket 452 is pivotably connected to a mounting frame 454 and slidably connected to a fixed frame 456 . In this embodiment, the mounting frame 454 is provided with a pivot shaft 458 that slidably engages a bracket passage 460 through the pivot bracket 452 . A retaining collar 462 attaches to the pivot shaft 458 to trap the pivot bracket 452 thereon to pivotably connect the pivot bracket 452 to the mounting frame 454 .
[0042] The pivot bracket 452 in turn has a pair of bracket sleeves 464 that slidably engage a pair of guides 466 that are mounted to the fixed frame 456 to allow a limited degree of translational motion between the pivot bracket 452 and the fixed frame 456 . The translation is limited by a top plate 468 and a bottom plate 470 .
[0043] While the novel features of the present invention have been described in terms of particular embodiments and preferred applications, it should be appreciated by one skilled in the art that substitution of materials and modification of details can be made without departing from the spirit of the invention. | A float mechanism for movably attaching an implement to a vehicle has a mounting frame that connects onto the vehicle and a fixed frame that affixes to the implement. A pivot bracket pivotally attaches to one of the frames and is slidably connected to the other to accommodate a limited degree of translational motion. The pivot bracket can slidably connect to the frame by a pair of guides in combination with a pair of sleeves. Rotational motion between the fixed frame and the mounting frame can be limited by slots in one of the frames that are slidably engaged by a stabilizing element on the other frame. When the stabilizing element is a horizontal bar, it can engage a pair of vertical slots. To optionally eliminate the free motion between the frames, movable blocks can be employed to limit the motion of each stabilizing element in its slot. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of invention relates to brake light apparatus, and more particularly pertains to a new and improved brake light apparatus mounted to an associated all-terrain vehicle frame.
2. Description of the Prior Art
All-terrain vehicles are utilized frequently through various terrain wherein drivers rearwardly of a lead vehicle are frequently not aware of the lead vehicle's intentions, such as stopping and the like. The use of brake light apparatus, while available in the prior art, has not heretofore been particularly tailored to all-terrain vehicles and their particular driving terrain or geography. Examples of prior art include U.S. Pat. No. 4,894,640 to Beasley utilizing a signal system for automotive vehicles. An amber light is operated in cooperation with an accelerator pedal with a red light of the brake light organization cooperative with a brake light switch of the vehicle.
U.S. Pat. No. 4,703,398 to Huth, et al. sets forth a brake light vehicle mounted within a particularly configured housing for mounting to a motor vehicle for securement to the rear window surface of the associated vehicle.
U.S. Pat. No. 4,663,609 to Rosario and 4,843,369 to Gimenez, et al. are further examples of motor vehicle brake light organizations and electrical circuitry therefore.
As such, it may be appreciated that there continues to be a need for a new and improved brake light apparatus as set forth by the instant invention which addresses both the problems of ease of use as well as effectiveness in construction for mounting to all-terrain vehicles and in this respect, the present invention substantially fulfills this need.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of brake light apparatus now present in the prior art, the present invention provides a brake light apparatus wherein the same is arranged for retrofit and mounting to an associated all-terrain vehicle. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved brake light apparatus which has all the advantages of the prior art brake light apparatus and none of the disadvantages.
To attain this, the present invention provides a brake light organization arranged for mounting to all-terrain vehicle structures to alert drivers rearwardly of a vehicle as to application of brakes and terrain. The organization includes a stop light assembly that is actuated, wherein the organization is mounted to a frame of an associated all-terrain vehicle.
My invention resides not in any one of these features per se, but rather in the particular combination of all of them herein disclosed and claimed and it is distinguished from the prior art in this particular combination of all of its structures for the functions specified.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. Those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
It is therefore an object of the present invention to provide a new and improved brake light apparatus which has all the advantages of the prior art brake light apparatus and none of the disadvantages.
It is another object of the present invention to provide a new and improved brake light apparatus which may be easily and efficiently manufactured and marketed.
It is a further object of the present invention to provide a new and improved brake light apparatus which is of a durable and reliable construction.
An even further object of the present invention is to provide a new and improved brake light apparatus which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such brake light apparatus economically available to the buying public.
Still yet another object of the present invention is to provide a new and improved brake light apparatus which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
Still another object of the present invention is to provide a new and improved brake light apparatus wherein the same is arranged for mounting to an all-terrain vehicle utilizing light enhancing structure to alert rearwardly positioned vehicles of geographical conditions and intentions of a driver of a lead all-terrain vehicle.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is an orthographic diagrammatic illustration of a prior art brake light apparatus.
FIG. 2 is a diagrammatic depiction of the organization of the instant invention.
FIG. 3 is a diagrammatic illustration of the organization in association with a brake light lever utilized by the instant invention.
FIG. 4 is an isometric illustration of the mounting clamp structure for mounting a stop light assembly, as is typically utilized by the instant invention.
FIG. 5 is an orthographic side view of a lighted assembly cage structure utilized by the instant invention.
FIG. 6 is an isometric illustration of the light assembly cage structure utilized by the instant invention.
FIG. 7 is an isometric illustration of the indicator ring utilized by the instant invention.
FIG. 8 is an orthographic view, taken along the lines 8--8 of FIG. 7 in the direction indicated by the arrows.
FIG. 9 is an isometric bottom view of the light and mounting housing utilized by the instant invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings, and in particular to FIGS. 1 to 9 thereof, a new and improved brake light apparatus embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described.
FIG. 1 sets forth a prior art brake light organization, as depicted in U.S. Pat. No. 4,894,640, utilizing a combination of amber and red lights cooperative with the accelerator and braking system of an associated automotive vehicle.
More specifically, the brake light apparatus 10 of the instant invention essentially comprises a system in electrical communication with a battery 11 of an associated all-terrain vehicle, wherein the battery 11 is directed to a stop light assembly 12 mounted to a vehicle frame 14 by a mounting bracket 13 (see FIG. 4). A brake lever 15 is pivotally mounted to the vehicle frame 14 about a brake lever pivot 16. A brake lever boss 17 is orthogonally mounted to the brake lever 15 between the pivot 16 and a forward terminal end of the lever 15 spaced from the pivot 16. A brake lever coil spring 18 is mounted at its lower end to the brake lever boss 17 and an upper end to a light actuator switch 19 that in turn is mounted to a bracket plate 20 mounted to an associated all-terrain vehicle.
FIG. 2 illustrates the contents of the light assembly 12 incorporating a first and second amber light 38 and 39 mounted to opposed sides of a central red light 40. A flasher unit 37 receives current through the switch 19 upon depressing the brake lever 15 to direct current to effect flashing of the amber lights 38 and 39, as well as effecting actuation of the stop and tail light 40.
FIG. 4 illustrates the use of a typical mounting bracket 13 for mounting to the vehicle frame 14, wherein the bracket includes a bottom bracket plate 20 spaced from and parallel a top bracket plate 21. A bracket base plate 23 is orthogonally directed between the top and bottom brackets and arranged parallel to a bracket leg 22a threadedly receiving a securement bolt 22 orthogonally therethrough, wherein the securement bolt 22 is orthogonally oriented relative to the bracket base plate 23 to mount the frame 14 between the bolt 22 and the base plate 23.
FIG. 5 illustrates the light mounting housing 25 formed of a generally cylindrical configuration to receive an upper terminal end of the light assembly mounting coil spring 24 that in turn has its lower terminal end mounted to the top bracket plate 21, as illustrated in FIG. 4. The light mounting housing 25 includes a spring receiving lower cylindrical chamber 26 (see FIG. 9), with a light bulb receiving internally threaded upper cylindrical chamber 28 coaxially aligned with and positioned overlying the lower cylindrical chamber 26. A separating web 41 separates the lower and upper chambers 26 and 28.
The light mounting housing 25 includes a cage member 29 integrally mounted and extending upwardly thereof, wherein the cage member 29 includes a plurality of parallel legs 30 defined by plural pairs of such legs 30 that are spaced symmetrically about the light mounting housing 25 arranged pairs, with each leg of each pair diametrically opposed relative to an opposing leg, with each leg pair oriented ninety degrees relative to an adjacent pair of the legs to define a generally encircling cage member 29.
An indicator ring 31 is fixedly mounted to the legs 30 of the cage member 29 and extends axially spaced from the cage 29. The indicator ring 31 includes a translucent outer ring 32 formed with a convex outer wall 34 and a planar cylindrical inner wall 33. The indicator ring 31 includes a plurality of mounting springs 35, each orthogonally mounted to the cylindrical inner wall 33 at a forward terminal end of each mounting spring 35, and a rear terminal end of each mounting spring 35 including a leg mounting cylinder 36, wherein each leg mounting cylinder is mounted in surrounding relationship relative to an associated leg 30. Upon undulation of the all-terrain vehicle about terrain of a rough contour, the translucent polymeric outer ring 32 will vibrate and thereby distort viewing of the light assembly 12 to provide enhanced warning to a rearwardly oriented driver of a further all-terrain vehicle about the terrain conditions of a lead all-terrain vehicle.
It should be further noted that the light mounting housing 25 may be removably but alternatively securably mounted to an upper terminal end of the light assembly mounting coil spring 24 by utilizing a plurality of locking bolts 27 radially directed through the light mounting housing projecting into the lower chamber to secure the upper terminal end of the light assembly mounting coil spring 24 therewithin. In this manner, the stop light assembly 12 may be removed from the bracket 13 as required for service and maintenance thereof.
As to the manner of usage and operation of the instant invention, the same should be apparent from the above disclosure, and accordingly no further discussion relative to the manner of usage and operation of the instant invention shall be provided.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | A brake light organization is arranged for mounting to all-terrain vehicle structures to alert drivers rearwardly of a vehicle as to application of brakes and terrain. The organization includes a stop light assembly that is actuated, wherein the organization is mounted to a frame of an associated all-terrain vehicle. | 1 |
[0001] The entire disclosure of Japanese Patent Application No. 2008-021983 filed on Jan. 31, 2008, including specification, claims, drawings and abstract is incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] One aspect of the present invention relates to a thin-sized mobile apparatus, and more particularly, to arrangement of an antenna and the like.
[0004] 2. Description of the Related Art
[0005] As a type of mobile phone, there is a thin-sized mobile phone. Since the mobile phone is than, the mobile phone may be used closer to a human body. In this case, it is necessary to examine the optimal arrangement of an antenna, in consideration of the effect of the human body on performance of the antenna.
[0006] It is well known that a human body deteriorates performance of an antenna. There is a mobile wireless terminal studied in consideration of such an effect (see JPA-2005-354501 (page 1, page 5, FIG. 1, and FIG. 2, for instance). The mobile wireless terminal is formed in a chest pocket type and has a flat side A and an uneven side B, and the antenna is disposed on the side B. A user puts the mobile wireless terminal in the chest pocket unconsciously to have the flat side A facing a user's body, and thus an antenna on the side B is away from the user's body, thereby securing performance of the antenna.
[0007] A non-contact type IC card such as an employee identification card has been well known (see JP-A-11-328348 (page 1 and FIG. 1)). Such an IC card has a printed face for identifying an employee with eyes and has an antenna for a non-contact IC therein.
[0008] In JP-A-2005-354501, a configuration for putting the mobile wireless terminal in a chest pocket is described, but there is no description of arrangement of an antenna in a case of using the mobile wireless terminal with a neck strap hanging on a neck. In JP-A-11-328348, there is no description of antenna communication in a state where an IC card hung on a neck with a neck strap close to a human body, and a user performs communication for non-contact IC generally in a state where the IC card is put close to an external reader/writer device. The IC card does not have a function of a mobile phone, and there is no description about a phone communicating antenna.
SUMMARY
[0009] According to one aspect of the invention, there is provided a mobile apparatus including: a main face; a back face opposite to the main face, the back face being printed with visible user information; a thickness from the main face to the back face; an antenna disposed at a position nearer the back face than the main face; and an attachment portion attachable with a wearing tool, the wearing tool, allowing a user to wear the mobile apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Embodiment may be described in detail with reference to the accompanying drawings, in which:
[0011] FIGS. 1A to 1D are exemplary views illustrating an appearance of a mobile apparatus according to a first Embodiment, a second Embodiment, and a third Embodiment of the invention;
[0012] FIGS. 2A to 2C are exemplary views illustrating how a user wears the mobile apparatus according to the first to the third Embodiments;
[0013] FIGS. 3A to 3D are exemplary partially transparent views illustrating arrangement of antennas of the mobile apparatus according to the first Embodiment;
[0014] FIGS. 4A to 4C are exemplary partially transparent views illustrating arrangement of antennas of the mobile apparatus according to the first Embodiment;
[0015] FIGS. 5A and 5B are exemplary partially transparent views illustrating an arrangement of antennas of the mobile apparatus according to the second Embodiment; and
[0016] FIGS. 6A to 6D are exemplary partially transparent views illustrating an arrangement of antennas of the mobile apparatus according to the third Embodiment.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0017] Hereinafter, embodiments of the invention will be described with reference to the drawings.
First Embodiment
[0018] FIGS. 1A to 1D are views illustrating an appearance of a mobile apparatus according to a first Embodiment, a second Embodiment, and a third Embodiment of the invention, in which FIG. 1A is a perspective view illustrating a main face. FIG. 1B is a plan view illustrating the main face, FIG. 1C is a plan view illustrating a back face, and FIG. 1D is a plan view illustrating a back face with the mobile apparatus housed in a holder. A mobile apparatus 100 has a substantially rectangular shape formed of long sides and short sides, and is formed of a card type having a thickness from the back face to the main face.
[0019] In FIG. 1A and FIG. 1B , a user interface such as a receiver 1 , a display 2 , a plurality of operation keys 3 , a microphone 4 as a transmitter is provided on the main face of the mobile apparatus, from one short side to the other short side, that is, in a length direction in order, which is a longitudinal arrangement of a general mobile apparatus. An attachment portion 5 is provided on one long side. The mobile apparatus is generally shaped by resin 6 surrounding the components and to show surfaces thereof.
[0020] In FIG. 1C , visible user information such as an employee identification is printed on the back face of the mobile apparatus 100 . The user information is printed to be visible in a transverse direction of the rectangular shape. The attachment portion 5 is provided on the top of the printed user information, that is, the top of characters or a photograph. A neck strap 200 is attached to the attachment portion 5 , so that the top of the user information is upward and the back face is outward. The mobile apparatus 100 is hung down on a user's neck, so that the user information can be shown to the other people.
[0021] As described above, the user interface provided on the main face is arranged longitudinally as the general mobile apparatus, and thus the operation of the mobile phone is easy. The visible user information printed on the back face is arranged transversely, and thus it is easy to see the user information.
[0022] In FIG. 1D , the mobile apparatus 100 is put into a holder 201 , a neck strap 200 attached to the holder 201 is hung on the user's neck. The holder 201 is formed of a window or transparent type to show the back face of the mobile phone 100 , and a type having a window to operate the main face of the mobile apparatus 100 . The mobile apparatus 100 may not be provided with the attachment portion 5 for attaching the neck strap 200 .
[0023] The neck strap 200 may be replaced by a clip (not show) attached to the holder 201 , and anything may be used as long as the top of the user information is upward and the back face is outward.
[0024] As described above, if the printed face is kept to be disposed on the opposite side to a human body, the printed face is visible to the other people anytime. To do so, a holder may be used, or the mobile phone may be fixed to easily show the printed face to the other people by the other means.
[0025] FIGS. 2A to 2C are views illustrating how a user wears the mobile apparatus according to the first Embodiment to the third Embodiment. FIG. 2A is a view illustrating a state of hanging the mobile apparatus on a neck, FIG. 2B is a transparent view illustrating the printed face of the mobile apparatus as viewed from the user side, and FIG. 2C is a view illustrating appearance of the main face of the mobile apparatus as viewed from the user side.
[0026] FIG. 2A is a view illustrating a state of hanging the mobile apparatus on a neck. A user who is a possessor of the mobile apparatus 100 wears the mobile apparatus 100 to consciously make the employee identification printed face outward, since the other people identifies the possessor of the mobile apparatus 100 with the eyes by the employee identification printed face (back face) of the mobile apparatus 100 .
[0027] FIG. 2B is a transparent view illustrating the printed face of the mobile apparatus as viewed from the user side, and is a mirror image of FIG. 1C . FIG. 2C is a view illustrating appearance of the main face of the mobile apparatus as viewed from the user side.
[0028] On the main face of the mobile apparatus 100 , the receiver 1 is provided on the right side from the top to the bottom of the user information, and the microphone 4 is provided on the left side.
[0029] In the hanging state, to use a phone function of the mobile apparatus 100 , when a user catches the long side of the mobile apparatus 100 with a user's left hand and takes it to a user's left ear, the receiver 1 approaches the user's ear and the microphone 4 approaches a user's mouth. When the user holds the mobile apparatus 100 with the left hand and takes it to user's eyes, the display 2 is disposed on the upside, and the operation keys 3 are disposed on the downside, thereby easily operating the mobile apparatus 100 .
[0030] For a case where the user catches the long side of the mobile apparatus 100 with the user's right hand and takes it to the right ear, the receiver 1 and the microphone 4 may be provided reversely. In addition, the display and the operation keys 3 may be provided reversely.
[0031] FIGS. 3A to 4C are partially transparent component arrangement views illustrating antenna arrangement of the mobile apparatus according to the first Embodiment. FIG. 3A and FIG. 3B show Antenna 1 , FIG. 3C and FIG. 3D show Antenna 2 , FIG. 4A shows Antenna 3 , and FIG. 4B and FIG. 4C show Antenna 4 .
[0032] (Antenna 1 )
[0033] FIG. 3A is a component arrangement view as viewed from the back face side in a partial transparent state. FIG. 3B is a component arrangement view illustrating the side of FIG. 3A as viewed in a direction indicated by Arrow IIIB-IIIB in a partial transparent state. A printed circuit board 30 is provided in the mobile apparatus 100 hardened by the resin 6 . A radio unit 7 , a wireless charging module 8 , a control unit 9 , an antenna 20 , and the like are mounted on the back face of the printed circuit board 30 . The user interface such as the operation keys 3 , the microphone 4 , and the like is mounted on the main face of the printed circuit board 30 , and the surface of the user interface is shown from the outside of the resin 6 .
[0034] The wireless charging module 8 is a power supply unit charged by non-contact electromagnetic induction from a charger-provided outside the mobile apparatus 100 , and supplies power to the whole mobile apparatus 100 .
[0035] When a user hangs the mobile apparatus 100 on the user's own neck with the neck, strap 200 , the user consciously makes the employ identification printed face (back face) outward and makes the main face be toward the human body. Accordingly, the antenna 20 is away from the human body, thereby preventing deterioration in performance of the antenna.
[0036] (Antenna 2 )
[0037] In FIG. 3C and FIG. 3D , an antenna 20 and an antenna 21 are provided as the antenna. As described in Antenna 1 , the antennas 20 and 21 are mounted on the back face of the printed circuit board 30 . The antenna 20 and the antenna 21 are provided in the vicinity of the short sides of the back face away from each other on a diagonal line, to prevent interference between both antennas. Both antennas may be used, for example, as diversity antennas or the like.
[0038] Also in Antenna 2 , the antennas are away from the human body, thereby preventing deterioration in performance of the antennas, as described in Antenna 1 .
[0039] (Antenna 3 )
[0040] In FIG. 4A , the antenna 20 and the antenna 21 are L-shaped plates, faces of which are parallel to the thickness direction of the mobile apparatus 100 . The antenna 20 and the antenna 21 are mounted on the back face of the printed circuit board 30 in the vicinity of the corner between the long side and the short side.
[0041] According to such a configuration, there is the same effect as Antenna 1 and Antenna 2 , and it is possible to improve rigidity of the mobile apparatus 100 against bending.
[0042] (Antenna 4 )
[0043] In FIG. 4B and FIG. 4C , the antenna 20 is provided on the back face of the printed circuit board 30 , and the antenna 21 is provided on the main face of the printed circuit board 30 . When a user hangs the mobile apparatus 100 on the user's own neck with the neck strap 200 , the user consciously makes the employee identification printed face (back face) outward. However, the neck strap 2 00 may be twisted by moving or shaking of the human body and thus the employee identification printed face (back face) may be toward the human body.
[0044] Even when any one of the employee identification printed face (back face) and the main face is toward the human body, any one of the antenna 20 and the antenna 21 is always outward away from the human body. Accordingly, it is prevent deterioration in performance of the antenna against the twist of the neck strap 200 .
Second Embodiment
[0045] FIGS. 5A and 5B are a partially transparent component arrangement view illustrating antenna arrangement of the mobile apparatus according to the second Embodiment. FIG. 5A shows Antenna 5 , FIG. 5B shows a state of inserting a plurality of mobile apparatuses 100 in cases. FIGS. 1A to 2C are common with the first Embodiment, and the description thereof is omitted.
[0046] As shown in FIG. 5A , the antenna 20 and the antenna 21 are mounted in the vicinity of the long sides on the back face of the printed circuit board 30 . As shown in FIG. 5B , when the plurality of mobile apparatuses 100 are inserted to a plurality of cases for mobile apparatuses, the antennas 20 of the mobile apparatuses 100 do not overlap with each other. In addition, the antennas 21 do not overlap with each other. Only any one of the antenna 20 and the antenna 21 may be provided.
[0047] In the second Embodiment, when the mobile phone 100 is put on the human body, the antenna 20 and the antenna 21 are away from the human body, as described in Embodiment 1. Accordingly, it is possible to prevent deterioration in performance of the antennas. In addition, even when the plurality of mobile apparatuses 100 are inserted to the cases, it is possible to prevent deterioration in performance of the antennas 100 .
Third Embodiment
[0048] FIGS. 6A to 6D are partially transparent component arrangement view illustrating antenna arrangement of the mobile apparatus according to the third Embodiment. In the first Embodiment and the second Embodiment, the antennas are mounted on the printed circuit board 30 . However, in the third Embodiment, to further separate the antennas from the human body, a film is provided on the back face portion, and the antennas are provided on the film. FIG. 6A is a component arrangement view as viewed from the back face side, FIG. 6B shows Antenna 11 , and FIG. 6C shows Antenna 12 , FIG. 6C shows Antenna 13 . FIGS. 1A to 2C are common with the first Example, and the description thereof is omitted.
[0049] In FIG. 6A , the antenna 20 and the antenna 21 are provided in the vicinity of the short, sides, but the invention is not limited thereto. For example, they may be provided in the vicinity of the long sides as shown in Embodiment 1 and Embodiment 2.
[0050] (Antenna 11 )
[0051] FIG. 6B is a component arrangement view as viewed from the side in a direction indicated by Arrow viB-viB shown in FIG. 6A . The printed circuit board 30 has a power supply point 31 for supplying power to the antenna. A film 40 is attached to the resin 6 on the back face of the printed circuit board 30 . The antenna 21 has been already printed on the back face of the film 40 with plating or the like (antenna 20 is not shown). The visible user information is printed on the back face thereof by coating print or the like.
[0052] Power is supplied, from the power supply point 31 to the antenna 20 or the antenna 21 by space coupling supply using a floating capacitor.
[0053] (Antenna 12 )
[0054] In FIG. 6C , the antenna 21 is printed by plating or the like from the back face of the film 40 through the film edge to the main face of the film (antenna 20 is not shown). The power supply point 31 has, for example, a sharp shape such as a pin shape, and is attached to the antenna 21 in a direct contact manner.
[0055] (Antenna 13 )
[0056] In FIG. 6D , the antenna 21 has been already printed on the main face of the film 40 by plating or the like (antenna 20 is not shown). The power supply point 31 has, for example, a sharp shape such as a pin shape, and is attached to the antenna 21 in a direct contact manner.
[0057] According to the third Embodiment, the antennas can be further separated from the human body. When the mobile apparatus 100 is put on the human body, the antenna 20 and the antenna 21 are further separated from the human body. Therefore, it is possible to prevent deterioration in performance of the antennas.
[0058] The antenna is printed on the film by plating or the like. However, directly, a pattern is made using ink formed by mixing with catalyst on the resin 6 , and the antenna may be formed in a film removing manner using the pattern.
[0059] The mobile apparatus 100 can be applied to a card type mobile phone, PHS, PDA, or the like. In addition, the invention can be applied to various cards having no operation key and display. | According one aspect of the invention, there is provided a mobile apparatus including: a main face; a back face opposite to the main face, the back face being printed with visible user information; a thickness from the main face to the back face; an antenna disposed at a position nearer the back face than the main face; and an attachment portion attachable with a wearing tool, the wearing tool allowing a user to wear the mobile apparatus. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates generally to an apparatus and method for straightening a basement wall which has been pushed in by hydrostatic pressure, and more particularly to a straightening apparatus and method which utilizes an anchoring device.
A very common problem with many below ground basement walls is that water tends to build up on the outside of such basement walls which causes a very high hydrostatic pressure against the wall. If this pressure becomes significant, it causes the wall to be pushed into the basement to some extent. Commonly, a large horizontal crack will appear in the wall. Besides the obvious problem of the unsightly nature of the crack, it will also permit water into the basement and if the hydrostatic pressure continues to increase the wall could eventually collapse.
The most common accepted methods and apparatus for straightening a basement wall are illustrated in U.S. Pat. Nos. 4,189,891 and 4,970,835.
The former patent relates to a method for anchoring and straightening a wall wherein a hole is formed in the ground at a distance from the wall and an opening is provided in the wall from the inside below ground level. Then an elongated rod member is positioned through the opening in the wall and forced through the ground so that one end of the member extends into the hole previously formed. An anchor structure, such as an anchor plate, is secured to one end of the rod member in the hole, and a wall plate is attached to the other end of the elongated rod member inside and against the wall. The wall plate is then forced against the wall by use of a threaded attaching mechanism for thereby straightening the wall.
The wall anchoring and straightening device of the latter referenced patent is in many ways similar, but eliminates the need for digging the hole into the earth at a spaced distance from the wall. This device comprises a horizontal elongated rod member having a chisel point end which is driven through the foundation wall into the earth and carries a plurality of pivotal spade arms adjacent the chisel point. The end of the rod member which is positioned at the interior of the wall is provided with threads. In similar fashion a wall plate is forced against the wall by a nut which is tightened to pull the rod member and chisel arm and spade arms closer to the foundation wall which thereby firmly causes the spade arms to spread and dig in to the surrounding earth to provide an anchor. Further tightening of the nut causes the wall plate to be forced against the wall and to straighten the wall.
The present invention pertains to an improvement on these two prior art methods and apparatus for anchoring and straightening a below ground wall.
SUMMARY OF THE INVENTION
The below ground wall anchoring and straightening device of the present invention also, as is the case with the prior art systems, incorporates a horizontally disposed elongate rod member and an earth anchoring means or mechanism secured to one end of the rod member. This earth anchoring means may of course be of either type as mentioned in the referenced patents.
The apparatus and method of the present invention is characterized in that instead of using the conventional wall plate described by the prior art, the apparatus and method of the present invention utilizes an elongate wall brace plate. This wall brace plate extends upright in its direction of the elongation and includes a securing means or mechanism at its bottom end for securing the bottom end of the elongate wall brace plate to a base portion of the wall structure. Then, as before, a fastener engages the rod member and presses the elongate plate against the wall to be anchored and straightened.
The advantage is that the plate is elongate, usually over seven feet tall, and is secured at its bottom end to a base portion of the wall and this wall brace plate is of sufficient rigidity to thereby anchor, brace and straighten the wall for its entire height, whereas the backup plates of the prior art structures engage only a small portion of the wall and accordingly did not guarantee complete and full straightening and anchoring and bracing of the wall as is accomplished by the apparatus and method of the present invention.
The elongate wall brace plate is preferably constructed of a rigid steel strip which has a vertical slot therein to adjustably receive the rod member therethrough. Normally the fastener device for pressuring the plate against the wall is a threaded nut, but other acceptable fastening devices may be utilized.
BRIEF DESCRIPTION OF THE DRAWINGS
Since the present invention is an improvement in the structure and methods of U.S. Pat. Nos. 4,189,891 and 4,970,835, the following drawings are extracted from these patent references and are appropriately modified to illustrate the principals of the present invention, thereby rendering it more easy to comprehend the improvements of the present invention.
Other objects and advantages appear hereinafter in the following description and claims. The accompanying drawings show, for the purpose of exemplification, without limiting the invention or appended claims, certain practical embodiments of the present invention wherein:
FIG. 1 is a cross sectional view of a basement wall which has been pushed in by hydrostatic pressure forces;
FIG. 2 is an exploded perspective view of an anchoring apparatus utilized in the present invention;
FIG. 3 is a cross sectional view similar to that of FIG. 1, but showing an initial positioning of the anchoring apparatus of FIG. 2 as utilized in the present invention;
FIG. 4 is a view in front elevation illustrating the structure of the present invention as shown in FIG. 3 from inside the basement wall;
FIG. 5 is a cross sectional view similar to FIG. 3, but showing the relative positions of the wall and anchoring device after straightening of the wall has been accomplished.
FIG. 6 is an exploded view in side elevation of a different or modified anchoring apparatus utilized in the present invention; and
FIG. 7 is a cross sectional view of a basement wall which has been pushed in by hydrostatic pressure forces and has applied thereto the apparatus of the present invention as illustrated in FIG. 6 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, FIG. 1 shows a wall 10 which has been pushed inwardly because of hydrostatic forces against the exterior thereof as indicated by the force arrows 11 . A building 12 , such as a house, rests on top of the basement wall 10 and a concrete slab 13 supports the bottom of the wall 10 . The numeral 14 designates the earth around the basement wall 10 . Attention is directed to the crack 15 in the wall 10 which can allow water from within the ground 14 to seep into the basement and which crack 15 also can become large enough due to hydrostatic forces 11 to cause the entire wall 10 to collapse within the basement.
Referring now to FIG. 2 an anchoring structure 16 is shown. The anchoring structure includes a shaft or elongate rod member 17 which is externally threaded on the ends 18 and 19 . An anchoring plate 20 , comprised of a pair of plates 21 and 22 welded together, has an opening 23 disposed centrally thereof. A pair of flanges 24 are welded to the plate 22 and are spaced so as to allow a nut 25 to be received therein and held from rotating so that the rod member 17 can be threaded into the nut 25 , thereby securing the anchoring plate structure 20 to the rod member 17 . An elongated upright wall brace plate 26 is provided for the other end of the rod member 17 and includes a central vertical slot 27 for allowing the end 19 of the rod member 17 to extend therethrough. A washer 28 and an internally threaded nut structure 29 is provided for holding the wall plate 26 from moving outwardly with respect to the rod member 17 once the nut 29 is threadably received on the threads 19 of the rod member 17 .
In order to straighten the wall 10 shown in FIG. 1, a hole 30 is first dug into the earth 14 as is shown in FIG. 3 . Then from inside of the basement 31 , an opening must be formed through the crack 15 to allow the rod member 17 to be driven therethrough so that the end 18 extends into the hole 30 . Normally this would require the use of a drill or chisel or the like in order to make an opening through the crack 15 , but it is entirely possible that an opening large enough to receive the shaft 16 would already be present if the wall 10 had buckled to a large degree. Once the rod member 17 is driven inwardly to the position shown in FIG. 3, then the nut 25 is utilized by placing it between the flanges 24 , aligning it with the threads 18 of the rod member 17 and then rotating the entire anchoring plate structure 20 so that the nut 25 is firmly secured onto the rod member 17 . While this is a preferred embodiment of the invention, it is to be understood that other anchoring structures could be used instead of the specific anchoring structure 20 shown, as will be explained in more detail hereinafter, and likewise fastening structures other than the threaded one shown by threads 18 and nut 25 can be utilized to secure such anchoring structure to the rod member 17 and still be within the inventive concept of this invention.
The next step for straightening the wall 10 is then to slide the elongate wall brace plate 26 onto the rod member 17 such that the slot 27 surrounds the threads 19 of the rod member 17 . Then the washer 28 is placed over the end 19 of the rod member 17 and the nut 29 is threaded onto the threads 19 resulting in the structure as substantially shown in FIG. 3 . Next, the foot 40 at the bottom end plate 26 is secured with concrete bolts 41 to concrete slab 13 at an interior base portion of wall 10 .
Once the structure shown in FIG. 2 has been positioned substantially as shown in FIG. 3, then a large wrench (not shown) or the like is utilized to thread the nut 29 further onto the threads 19 of the rod member 17 so as to force the wall plate 26 towards the wall 10 and thereby force the wall 10 back to the straight position as shown in FIGS. 4 and 5. At such time then the hole 30 can be refilled and the job is complete.
Elongate wall brace plate 26 is a stiff steel plate provided with forged elongate stiffening ribs 36 to further stiffen the plate.
Referring to FIGS. 6 and 7, similar elements are indicated with the same reference numerals. With the exception of the innovative elongate wall brace plate 26 and method of attachment utilized for the present invention, this embodiment otherwise follows the teachings of prior art reference U.S. Pat. No. 4,970,835.
Here the anchoring structure 16 comprises a hollow horizontally disposed elongate rod member 17 with a pointed chisel end 30 that is threadably engaged with the elongate threaded rod member 17 . A sleeve 31 is provided to be inserted through the foundation wall 10 , if desired, as a sealing means, but rubber grommets 32 a and 32 b may be optionally used as a wall sealing means. The sleeve 31 and/or grommets 32 a , 32 b , are provided for arrangement on the elongate threaded rod member 17 at an opening bored through the foundation wall 10 . The hollow tube 17 carries pivotal spade arms 21 ′ and 22 ′, which are trough-shaped and arranged to pivot away from hollow tube 31 for anchoring engagement with the earth. At the opposite end of threaded elongate rod member 17 , an elongate upright wall brace plate 26 of the present invention is provided to be placed against the interior of foundation wall 10 so that nut 29 may be threadably tightened on the threaded rod member 17 to pull the hollow tube 31 toward the foundation wall and thereby fully pivot the pivotal spade arms 21 ′ and 22 ′ outwardly to dig into the earth as is more fully explained in U.S. Pat. No. 4,970,835.
In this embodiment, elongate wall brace plate 26 is a steel plate of greater thickness than that illustrated in the previous figures and accordingly is not provided with the forged elongate stiffening ribs 36 . Also, in this embodiment, as is best illustrated in FIG. 7, the securing means or mechanism at the bottom foot 40 of elongate plate 26 is secured directly to the foundation support 37 for wall 10 instead of to the slab floor 13 . In this embodiment, the outer edge of slab floor 13 has been removed to expose foundation support 37 , which is commonly done in any regard to provide drainage for any water which finds its way to the interior of the wall 10 .
In practice, the threaded elongate rod member 17 is driven into the soil 14 through the opening provided in wall 10 and on into the adjacent earth, then the elongate brace plate 26 of the present invention is applied together with securing nut 29 and foot 40 is secured with bolts 41 to foundation 37 . Securing nut 29 is then turned against elongate brace plate 26 which causes the spade arms 21 ′ and 22 ′ to be pulled inwardly towards wall 10 and in turn causes the spade arms 21 ′ and 22 ′ to spread and securely anchor the distal end of rod member 17 into earth 14 . Further engagement and securing of nut 29 then causes elongate plate 24 to press against the interior of wall 10 for substantially its full height causing the wall to be straightened. | A below ground wall anchoring and straightening device including a horizontally disposed elongate rod member and an earth anchor secured to one end of the rod member. An elongate wall brace plate is attached intermediate its ends to the other end of the rod member and a wall brace plate extends upright in its direction of elongation and this elongate plate is secured at its bottom end to a base portion of the wall structure to be straightened. The rod member includes a fastener for engaging the rod member and thereby pressing the elongate plate against the wall to anchor and straighten the wall. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application Ser. No. 10/262,621 filed on Sep. 30, 2002 and entitled “PACKET PRIORITIZATION AND ASSOCIATED BANDWIDTH AND BUFFER MANAGEMENT TECHNIQUES FOR AUDIO OVER IP”, the entire disclosure of which is herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates generally to audio communications over distributed processing networks and specifically to voice communications over data networks.
BACKGROUND OF THE INVENTION
Convergence of the telephone network and the Internet is driving the move to packet-based transmission for telecommunication networks. As will be appreciated, a “packet” is a group of consecutive bytes (e.g. a datagram in TCP/IP) sent from one computer to another over a network. In Internet Protocol or IP telephony or Voice Over IP (VoIP), a telephone call is sent via a series of data packets on a fully digital communication channel. This is effected by digitizing the voice stream, encoding the digitized stream with a codec, and dividing the digitized stream into a series of packets (typically in 20 millisecond increments). Each packet includes a header, trailer, and data payload of one to several frames of encoded speech. Integration of voice and data onto a single network offers significantly improved bandwidth efficiency for both private and public network operators.
In voice communications, high end-to-end voice quality in packet transmission depends principally on the speech codec used, the end-to-end delay across the network and variation in the delay (jitter), and packet loss across the channel. To prevent excessive voice quality degradation from transcoding, it is necessary to control whether and where transcodings occur and what combinations of codecs are used. End-to-end delays on the order of milliseconds can have a dramatic impact on voice quality. When end-to-end delay exceeds about 150 to 200 milliseconds one way, voice quality is noticeably impaired. Voice packets can take an endless number of routes to a given destination and can arrive at different times, with some arriving too late for use by the receiver. Some packets can be discarded by computational components such as routers in the network due to network congestion. When an audio packet is lost, one or more frames are lost too, with a concomitant loss in voice quality.
Conventional VoIP architectures have developed techniques to resolve network congestion and relieve the above issues. In one technique, voice activity detection (VAD) or silence suppression is employed to detect the absence of audio (or detect the presence of audio) and conserve bandwidth by preventing the transmission of “silent” packets over the network. Most conversations include about 50% silence. When only silence is detected for a specified amount of time, VAD informs the Packet Voice Protocol and prevents the encoder output from being transported across the network. VAD is, however, unreliable and the sensitivity of many VAD algorithms imperfect. To exacerbate these problems, VAD has only a binary output (namely silence or no silence) and in borderline cases must decide whether to drop or send the packet. When the “silence” threshold is set too low, VAD is rendered meaningless and when too high audio information can be erroneously classified as “silence” and lost to the listener. The loss of audio information can cause the audio to be choppy or clipped. In another technique, a receive buffer is maintained at the receiving node to provide additional time for late and out-of-order packets to arrive. Typically, the buffer has a capacity of around 150 milliseconds. Most but not all packets will arrive before the time slot for the packet to be played is reached. The receive buffer can be filled to capacity at which point packets may be dropped. In extreme cases, substantial, consecutive parts of the audio stream are lost due to the limited capacity of the receive buffer leading to severe reductions in voice quality. Although packet loss concealment algorithms at the receiver can reconstruct missing packets, packet reconstruction is based on the contents of one or more temporally adjacent packets which can be acoustically dissimilar to the missing packet(s), particularly when several consecutive packets are lost, and therefore the reconstructed packet(s) can have very little relation to the contents of the missing packet(s).
SUMMARY OF THE INVENTION
These and other needs are addressed by the various embodiments and configurations of the present invention. The present invention is directed generally to a computational architecture for efficient management of transmission bandwidth and/or receive buffer latency.
In one embodiment of the present invention, a transmitter for a voice stream is provided that comprises:
(a) a packet protocol interface operable to convert one or more selected segments (e.g., frames) of the voice stream into a packet and
(b) an acoustic prioritization agent operable to control processing of the selected segment and/or packet based on one or more of (i) a level of confidence that the contents of the selected segment are not the product of voice activity (e.g., are silence), (ii) a type of voice activity (e.g., plosive) associated with or contained in the contents of the selected segment, and (iii) a degree of acoustic similarity between the selected segment and another segment of the voice stream.
The level of confidence permits the voice activity detector to provide a ternary output as opposed to the conventional binary output. The prioritization agent can use the level of confidence in the ternary output, possibly coupled with one or measures of the traffic patterns on the network, to determine dynamically whether or not to send the “silent” packet and, if so, use a lower transmission priority or class for the packet.
The type of voice activity permits the prioritization agent to identify extremely important parts of the voice stream and assign a higher transmission priorities and/or class to the packet(s) containing these parts of the voice stream. The use of a higher transmission priority and/or class can significantly reduce the likelihood that the packet(s) will arrive late, out of order, or not at all.
The comparison of temporally adjacent packets to yield a degree of acoustic similarity permits the prioritization agent to control bandwidth effectively. The agent can use the degree of similarity, possibly coupled with one or measures of the traffic patterns on the network, to determine dynamically whether or not to send a “similar” packet and, if so, use a lower transmission priority or class for the packet. Packet loss concealment algorithms at the receiver can be used to reconstruct the omitted packet(s) to form a voiced signal that closely matches the original signal waveform. Compared to conventional transmission devices, fewer packets can be sent over the network to realize an acceptable signal waveform.
In another embodiment of the present invention, a receiver for a voice stream is provided that comprises:
(a) a receive buffer containing a plurality of packets associated with voice communications; and
(b) a buffer manager operable to remove some of the packets from the receive buffer while leaving other packets in the receive buffer based on a level of importance associated with the packets.
In one configuration, the level of importance of the each of the packets is indicated by a corresponding value marker. The level of importance or value marker can be based on any suitable criteria, including a level of confidence that contents of the packet contain voice activity, a degree of similarity of temporally adjacent packets, the significance of the audio in the packet to receiver understanding or fidelity, and combinations thereof.
In another configuration, the buffer manager performs time compression around the removed packet(s) to prevent reconstruction of the packets by the packet loss concealment algorithm. This can be performed by, for example, resetting a packet counter indicating an ordering of the packets, such as by assigning the packet counter of the removed packet to a packet remaining in the receive buffer.
In another configuration, the buffer manager only removes packet(s) from the buffer when the buffer delay or capacity equals or exceeds a predetermined level. When the buffer is not in an overcapacity situation, it is undesirable to degrade the quality of voice communications, even if only slightly.
The various embodiments of the present invention can provide a number of advantages. First, the present invention can decrease substantially network congestion by dropping unnecessary packets, thereby providing lower end-to-end delays across the network, lower degrees of variation in the delay (jitter), and lower levels of packet loss across the channel. Second, the various embodiments of the present invention can handle effectively the bursty traffic and best-effort delivery problems commonly encountered in conventional networks while maintaining consistently and reliably high levels of voice quality reliably. Third, voice quality can be improved relative to conventional voice activity detectors by not discarding “silent” packets in borderline cases.
These and other advantages will be apparent from the disclosure of the invention(s) contained herein.
The above-described embodiments and configurations are neither complete nor exhaustive. As will be appreciated, other embodiments of the invention are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a simple network for a VoIP session between two endpoints according to a first embodiment of the present invention;
FIG. 2 is a block diagram of the functional components of a transmitting voice communication device according to the first embodiment;
FIG. 3 is a block diagram of the functional components of a receiving voice communication device according to the first embodiment;
FIG. 4 is a flow chart of a voice activity detector according to a second embodiment of the present invention;
FIG. 5 is a flow chart of a codec according to a third embodiment of the present invention;
FIG. 6 is a flow chart of a packet prioritizing algorithm according to a second embodiment of the present invention;
FIG. 7 is a block diagram illustrating time compression according to a fourth embodiment of the present invention; and
FIG. 8 is a flow chart of a buffer management algorithm according to the fourth embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 1 is a simplistic VoIP network architecture according to a first embodiment of the present invention. First and second voice communication devices 100 and 104 transmit and receive VoIP packets. The packets can be transmitted over one of two paths. The first and shortest path is via networks 108 and 112 and router 116 . The second and longer path is via networks 108 , 112 , and 120 and routers 124 and 128 . Depending upon the path followed, the packets can arrive at either of the communication devices at different times. As will be appreciated, network architectures suitable for the present invention can include any number of networks and routers and other intermediate nodes, such as transcoding gateways, servers, switches, base transceiver stations, base station controllers, modems, router, and multiplexers and employ any suitable packet-switching protocols, whether using connection oriented or connectionless services, including without limitation Internet Protocol or IP, Ethernet, and Asynchronous Transfer Mode or ATM.
As will be further appreciated, the first and second voice communication devices 100 and 104 can be any communication devices configured to transmit and/or receive packets over a data network, such as the Internet. For example, the voice communication devices 100 and 104 can be a personal computer, a laptop computer, a wired analog or digital telephone, a wireless analog or digital telephone, intercom, and radio or video broadcast studio equipment.
FIG. 2 depicts an embodiment of a transmitting voice communication device. The device 200 includes, from left to right, a first user interface 204 for outputting signals inputted by the first user (not shown) and an outgoing voice stream 206 received from the first user, an analog-to-digital converter 208 , a Pulse Code Modulation or PMC interface 212 , an echo canceller 216 , a Voice Activity Detector or VAD 10 , a voice codec 14 , a packet protocol interface 18 and an acoustic prioritizing agent 232 .
The first user interface 204 is conventional and be configured in many different forms depending upon the particular implementation. For example, the user interface 204 can be configured as an analog telephone or as a PC. The analog-to-digital converter 208 converts, by known techniques, the analog outgoing voice stream 206 received from the first user interface 204 into an outgoing digital voice stream 210 .
The PCM interface 212 , inter alia, forwards the outgoing digital voice stream 210 to appropriate downstream processing modules for processing.
The echo canceller 216 performs echo cancellation on the digital stream 214 , which is commonly a sampled, full-duplex voice port signal. Echo cancellation is preferably G.165 compliant.
The VAD 10 monitors packet structures in the incoming digital voice stream 216 received from the echo canceller 216 for voice activity. When no voice activity is detected for a configurable period of time, the VAD 10 informs the acoustic prioritizing agent 232 of the corresponding packet structure(s) in which no voice activity was detected and provides a level of confidence that the corresponding packet structure(s) contains no meaningful voice activity. This output is typically provided on a packet structure-by-packet structure basis. These operations of the VAD are discussed below with reference to FIG. 4 .
VAD 10 can also measure the idle noise characteristics of the first user interface 204 and report this information to the packet protocol interface 18 in order to relay this information to the other voice communication device for comfort noise generation (discussed below) when no voice activity is detected.
The voice codec 14 encodes the voice data in the packet structures for transmission over the data network and compares the acoustic information (each frame of which includes spectral information such as sound or audio amplitude as a function of frequency) in temporally adjacent packet structures and assigns to each packet an indicator of the difference between the acoustic information in adjacent packet structures. These operations are discussed below with reference to FIG. 5 . As shown in box 236 , the voice codec typically include, in memory, numerous voice codecs capable of different compression ratios. Although only codecs G.711, G,723.1, G.726, G.728, and G.78 are shown, it is to be understood that any voice codec whether known currently or developed in the future could be in memory. Voice codecs encode and/or compress the voice data in the packet structures. For example, a compression of 8:1 is achievable with the G.78 voice codec (thus the normal 64 Kbps PCM signal is transmitted in only 8 Kbps). The encoding functions of codecs are further described in Michaelis, Speech Digitization and Compression, in the International Encyclopedia of Ergonomics and Human Factors , edited by Warkowski, 2001; ITU-T Recommendation G.78 General Aspects of Digital Transmission Systems, Coding of Speech at 8 kbit/s using Conjugate - Structure Algebraic - Code - Excited Linear - Prediction , March 1996; and Mahfuz, Packet Loss Concealment for Voice Transmission Over IP Networks , September 2001, each of which is incorporated herein by this reference.
The prioritization agent 232 efficiently manages the transmission bandwidth and the receive buffer latency. The prioritization agent (a) determines for each packet structure, based on the corresponding difference in acoustic information between the selected packet structure and a temporally adjacent packet structure (received from the codec), a relative importance of the acoustic information contained in the selected packet structure to maintaining an acceptable level of voice quality and/or (b) determines for each packet structure containing acoustic information classified by the VAD 10 as being “silent” a relative importance based on the level of confidence (output by the VAD for that packet structure) that the acoustic information corresponds to no voice activity. The acoustic prioritization agent, based on the differing levels of importance, causes the communication device to process differently the packets corresponding to the packet structures. The packet processing is discussed in detail below with reference to FIG. 6 .
The packet protocol interface 18 assembles into packets and sequences the outgoing encoded voice stream and configures the packet headers for the various protocols and/or layers required for transmission to the second voice communication device 300 ( FIG. 3 ). Typically, voice packetization protocols use a sequence number field in the transmit packet stream to maintain temporal integrity of voice during playout. Under this approach, the transmitter inserts a packet counter, such as the contents of a free-running, modulo-16 packet counter, into each transmitted packet, allowing the receiver to detect lost packets and properly reproduce silence intervals during playout at the receiving communication device. In one configuration, the importance assigned by the acoustic prioritizing agent can be used to configure the fields in the header to provide higher or lower transmission priorities. This option is discussed in detail below in connection with FIG. 6 .
The packetization parameters, namely the packet size and the beginning and ending points of the packet are communicated by the packet protocol interface 18 to the VAD 10 and codec 14 via the acoustic prioritization agent 232 . The packet structure represents the portion of the voice stream that will be included within a corresponding packet's payload. In other words, a one-to-one correspondence exists between each packet structure and each packet. As will be appreciated, it is important that packetization parameter synchronization be maintained between these components to maintain the integrity of the output of the acoustic prioritization agent.
FIG. 3 depicts an embodiment of a receiving (or second) voice communication device 300 . The device 300 includes, from right to left, the packet protocol interface 18 to remove the header information from the packet payload, the voice codec 14 for decoding and/or decompressing the received packet payloads to form an incoming digital voice stream 302 , an adaptive playout unit 304 to process the received packet payloads, the echo canceller 216 for performing echo cancellation on the incoming digital voice stream 306 , the PCM interface 212 for performing continuous phase resampling of the incoming digital voice stream 316 to avoid sample slips and forwarding the echo cancelled incoming voice stream 316 to a digital-to-analog converter 308 that converts the echo cancelled incoming voice stream 320 into an analog voice stream 324 , and second user interface 312 for outputting to the second user the analog voice stream 324 .
The adaptive playout unit 304 includes a packet loss concealment agent 328 , a receive buffer 336 , and a receive buffer manager 332 . The adaptive playout unit 304 can further include a continuous-phase resampler (not shown) that removes timing frequency offset without causing packet slips or loss of data for voice or voiceband modem signals and a timing jitter measurement module (not shown) that allows adaptive control of FIFO delay. The packet loss concealment agent 328 reconstructs missing packets based on the contents of temporally adjacent received packets. As will be appreciated, the packet loss concealment agent can perform packet reconstruction in a multiplicity of ways, such as replaying the last packet in place of the lost packet and generating synthetic speech using a circular history buffer to cover the missing packet. Preferred packet loss concealment algorithms preserve the spectral characteristics of the speaker's voice and maintain a smooth transition between the estimated signal and the surrounding original. In one configuration, packet loss concealment is performed by the codec.
The receive buffer 336 alleviates the effects of late packet arrival by buffering received voice packets. In most applications the receive buffer 336 is a First-In-First-Out or FIFO buffer that stores voice codewords before playout and removes timing jitter from the incoming packet sequence. As will be appreciated, the buffer 336 can dynamically increase and decrease in size as required to deal with late packets when the network is uncongested while avoiding unnecessary delays when network traffic is congested.
The buffer manager 332 efficiently manages the increase in latency (or end-to-end delay) introduced by the receive buffer 336 by dropping (low importance) enqueued packets as set forth in detail below in connection with FIGS. 7 and 8 .
In addition to packet payload decryption and/or decompression, the voice codec 18 can also include a comfort noise generator (not shown) that, during periods of transmit silence when no packets are sent, generates a local noise signal that is presented to the listener. The generated noise attempts to match the true background noise. Without comfort noise, the listener can conclude that the line has gone dead.
Analog-to-digital and digital-to-analog converters 208 and 308 , the pulse code modulation interface 212 , the echo canceller 216 a and b , packet loss concealment agent 328 , and receive buffer 336 are conventional.
Although FIGS. 2 and 3 depict voice communication devices in simplex configurations, it is to be understood that each of the voice communication devices 200 and 300 can act both as a transmitter and receiver in a duplexed configuration. The operation of the VAD 10 will now be described with reference to FIGS. 2 and 4 .
In the first step 400 , the VAD 10 gets packet structure j from the echo canceled digital voice stream 218 . Packet structure counter i is initially set to one. In step 404 , the VAD 10 analyzes the acoustic information in packet structure j to identify by known techniques whether or not the acoustic information qualifies as “silence” or “no silence” and determine a level of confidence that the acoustic information does not contain meaningful or valuable acoustic information. The level of confidence can be determined by known statistical techniques, such as energy level measurement, least mean square adaptive filter (Widrow and Hoff 1959), and other Stochastic Gradient Algorithms. In one configuration, the acoustic threshold(s) used to categorize frames or packets as “silence” versus “nonsilence” vary dynamically, depending upon the traffic congestion of the network. The congestion of the network can be quantified by known techniques, such as by jitter determined by the timing measurement module (not shown) in the adaptive playout unit of the sending or receiving communication device, which would be forwarded to the VAD 10 . Other selected parameters include latency or end-to-end delay, number of lost or dropped packets, number of packets received out-of-order, processing delay, propagation delay, and receive buffer delay/length. When the selected parameter(s) reach or fall below selected levels, the threshold can be reset to predetermined levels.
In step 408 , the VAD 10 next determines whether or not packet structure j is categorized as “silent” or “nonsilent”. When packet structure j is categorized as being “silent”, the VAD 10 , in step 412 , notifies the acoustic prioritization agent 232 of the packet structure j beginning and/or endpoint(s), packet length, the “silent” categorization of packet structure j , and the level of confidence associated with the “silent” categorization of packet structure. When packet structure j is categorized as “nonsilent” or after step 412 , the VAD 10 in step 416 sets counter j equal to j+1 and in step 420 determines whether there is a next packet structure j . If so, VAD 10 returns to and repeats step 400 . If not, VAD 10 terminates operation until a new series of packet structures is received.
The operation of the codec 14 will now be described with reference to FIGS. 2 and 5 . In steps 500 , 504 and 512 , respectively, the codec 14 gets packet structure j , packet structure j−1 , and packet structure j+1 . Packet structure counter j is, of course, initially set to one.
In steps 508 and 516 , respectively, the codec 14 compares packet structure j with packet structure j−1 , and packet structure j with packet structure j+1 . As will be appreciated, the comparison can be done by any suitable technique, either currently or in the future known by those skilled in the art. For example, the amplitude and/or frequency waveforms (spectral information) formed by the collective frames in each packet can be mathematically compared and the difference(s) quantified by one or more selected measures or simply by a binary output such as “similar” or “dissimilar”. Acoustic comparison techniques are discussed in Michaelis, et a., A Human Factors Engineer's Introduction to Speech Synthesizers , in Directions in Human - Computer Interaction , edited by Badre, et al., 1982, which is incorporated herein by this reference. If a binary output is employed, the threshold selected for the distinction between “similar” and “dissimilar” can vary dynamically based on one or more selected measures or parameters of network congestion. Suitable measures or parameters include those set forth previously. When the measures increase or decrease to selected levels the threshold is varied in a predetermined fashion.
In step 520 , the codec 14 outputs the packet structure similarities/nonsimilarities determined in steps 508 and 516 to the acoustic prioritization agent 232 . Although not required, the codec 14 can further provide a level of confidence regarding the binary output. The level of confidence can be determined by any suitable statistical techniques, including those set forth previously. Next in step 524 , the codec encodes packet structure. As will be appreciated, the comparison steps 508 and 516 and encoding step 524 can be conducted in any order, including in parallel. The counter is incremented in step 528 , and in step 532 , the codec determines whether or not there is a next packet structure.
The operation of the acoustic prioritization agent 232 will now be discussed with reference to with FIGS. 2 and 6 .
In step 600 , the acoustic prioritizing agent 232 gets packet j (which corresponds to packet structure j ). In step 604 , the agent 232 determines whether VAD 10 categorized packet structure j as “silence”. When the corresponding packet structure j has been categorized as “silence”, the agent 232 , in step 608 , processes packet j based on the level of confidence reported by the VAD 10 for packet structure j .
The processing of “silent” packets can take differing forms. In one configuration, a packet having a corresponding level of confidence less than a selected silence threshold Y is dropped. In other words, the agent requests the packet protocol interface 18 to prevent packet j from being transported across the network. A “silence” packet having a corresponding level of confidence more than the selected threshold is sent. The priority of the packet can be set at a lower level than the priorities of “nonsilence” packets. “Priority” can take many forms depending on the particular protocols and network topology in use. For example, priority can refer to a service class or type (for protocols such as Differentiated Services and Internet Integrated Services), and priority level (for protocols such as Ethernet). For example, “silent” packets can be sent via the assured forwarding class while “nonsilence” packets are sent via the expedited forwarding (code point) class. This can be done, for example, by suitably marking, in the Type of Service or Traffic Class fields, as appropriate. In yet another configuration, a value marker indicative of the importance of the packet to voice quality is placed in the header and/or payload of the packet. The value marker can be used by intermediate nodes, such as routers, and/or by the buffer manager 332 ( FIG. 3 ) to discard packets in appropriate applications. For example, when traffic congestion is found to exist using any of the parameters set forth above, value markers having values less than a predetermined level can be dropped during transit or after reception. This configuration is discussed in detail with reference to FIGS. 7 and 8 . Multiple “silence” packet thresholds can be employed for differing types of packet processing, depending on the application. As will be appreciated, the various thresholds can vary dynamically depending on the degree of network congestion as set forth previously.
When the corresponding packet structure j has been categorized as “nonsilence”, the agent 232 , in step 618 , determines whether the degree of similarity between the corresponding packet structure j and packet structure j−1 (as determined by the codec 14 ) is greater than or equal to a selected similarity threshold X. If so, the agent 232 proceeds to step 628 (discussed below). If not, the agent 232 proceeds to step 624 . In step 624 , the agent determines whether the degree of similarity between the corresponding packet structure j and packet structure j+1 (as determined by the codec 14 ) is greater than or equal to the selected similarity threshold X. If so, the agent 232 proceeds to step 628 .
In step 628 , the agent 232 processes packet j based on the magnitude of the degree of similarity and/or on the treatment of the temporally adjacent packet j−1 . As in the case of “silent” packets, the processing of similar packets can take differing forms. In one configuration, a packet having a degree of similarity more than the selected similarity threshold X is dropped. In other words, the agent requests the packet protocol interface 18 to prevent packet j from being transported across the network. The packet loss concealment agent 328 ( FIG. 3 ) in the second communication device 300 will reconstruct the dropped packet. In that event, the magnitude of X is determined by the packet reconstruction efficiency and accuracy of the packet loss concealment algorithm. If the preceding packet j−1 were dropped, packet j may be forwarded, as the dropping of too many consecutive packets can have a detrimental impact on the efficiency and accuracy of the packet loss concealment agent 328 . In another configuration, multiple transmission priorities are used depending on the degree of similarity. For example, a packet having a degree of similarity more than the selected threshold is sent with a lower priority. The priority of the packet is set at a lower level than the priorities of dissimilar packets. As noted above, “priority” can take many forms depending on the particular protocols and network topology in use. In yet another configuration, the value marker indicative of the importance of the packet to voice quality is placed in the header and/or payload of the packet. The value marker can be used as set forth previously and below to cause the dropping of packets having value markers below one or more selected marker value thresholds. Multiple priority levels can be employed for multiple similarity thresholds, depending on the application. As will be appreciated, the various similarity and marker value thresholds can vary dynamically depending on the degree of network congestion as set forth previously.
After steps 608 and 628 and in the event in step 624 that the similarity between the corresponding packet structure j and packet structure j+1 (as determined by the codec 14 ) is less than the selected similarity threshold X, the agent 232 proceeds to step 612 . In step 612 , the counter j is incremented by one. In step 616 , the agent 232 determines whether there is a next packet j . When there is a next packet j , the agent 232 proceeds to and repeats step 600 . When there is no next packet j , the agent 232 proceeds to step 632 and terminates operation until more packet structures are received for packetization.
The operation of the buffer manager 332 will now be described with reference to FIGS. 3 and 7 - 8 . In step 800 , the buffer manager 332 determines whether the buffer delay (or length) is greater than or equal to a buffer threshold Y. If not, the buffer manager 332 repeats step 800 . If so, the buffer manager 332 in step 804 gets packet k from the receive buffer 336 . Initially, of course the counter k is set to 1 to denote the packet in the first position in the receive buffer (or at the head of the buffer). Alternatively, the manager 332 can retrieve the last packet in the receive buffer (or at the tail of the buffer).
In step 808 , the manager 332 determines if the packet is expendable; that is, whether the value of the value marker is less than (or greater depending on the configuration) a selected value threshold. When the value of the value marker is less than the selected value threshold, the packet k in step 812 is discarded or removed from the buffer and in step 816 the surrounding enqueued packets are time compressed around the slot previously occupied by packet k .
Time compression is demonstrated with reference to FIG. 7 . The buffer 336 is shown as having various packets 700 a - e , each packet payload representing a corresponding time interval of the voice stream. If the manager determines that packet 700 b (which corresponds to the time interval t 2 to t 3 ) is expendable, the manager 332 first removes the packet 700 b from the queue 336 a and then moves packets 700 c - e ahead in the queue. To perform time compression, the packet counters for packets 700 c - e are decremented such that packet 700 c now occupies the time slot t 2 to t 3 , packet 700 d time slot t 2 to t 3 , and packet 700 d time slot t 3 to t 4 . In this manner, the packet loss concealment agent 328 will be unaware that packet 700 b has been discarded and will not attempt to reconstruct the packet. In contrast, if a packet is omitted from an ordering of packets, the packet loss concealment agent 328 will recognize the omission by the break in the packet counter sequence. The agent 328 will then attempt to reconstruct the packet.
Returning again to FIG. 8 , the manager 332 in step 820 increments the counter k and repeats step 800 for the next packet.
A number of variations and modifications of the invention can be used. It would be possible to provide for some features of the invention without providing others.
For example in one alternative embodiment, the prioritizing agent's priority assignment based on the type of “silence” detected can be performed by the VAD 200 .
In another alternative embodiment though FIG. 2 is suitable for use with a VoIP architecture using Embedded Communication Objects interworking with a telephone system and packet network, it is to be understood that the configuration of the VAD 10 , codec 14 , prioritizing agent 232 and/or buffer manager 332 of the present invention can vary significantly depending upon the application and the protocols employed. For example, the prioritizing agent 232 can be included in an alternate location in the embodiment of FIG. 2 , and the buffer manager in an alternate location in the embodiment of FIG. 3 . The prioritizing agent and/or buffer manager can interface with different components than those shown in FIG. 2 for other types of user interfaces, such as a PC, wireless telephone, and laptop. The prioritizing agent and/or buffer manager can be included in an intermediate node between communication devices, such as in a switch, transcoding device, translating device, router, gateway, etc.
In another embodiment, the packet comparison operation of the codec is performed by another component. For example, the VAD and/or acoustic prioritization agent performs these functions.
In another embodiment, the level of confidence determination of the VAD is performed by another component. For example, the codec and/or acoustic prioritization agent performs these functions.
In yet a further embodiment, the codec and/or VAD, during packet structure processing attempt to identify acoustic events of great importance, such as plosives. When such acoustic events are identified (e.g., when the difference identified by the codec exceeds a predetermined threshold), the acoustic prioritizing agent 232 can cause the packets corresponding to the packet structures to have extremely high priorities and/or be marked with value markers indicating that the packet is not to be dropped under any circumstances. The loss of a packet containing such important acoustic events often cannot be reconstructed accurately by the packet loss concealment agent 328 .
In yet a further embodiment, the analyses performed by the codec, VAD, and acoustic prioritizing agent are performed on a frame level rather than a packet level. “Silent” frames and/or acoustically similar frames are omitted from the packet payloads. The procedural mechanisms for these embodiments are similar to that for packets in FIGS. 4 and 5 . In fact, the replacement of “frame” for “packet structure” and “packet” in FIGS. 4 and 5 provides a configuration of this embodiment.
In yet another embodiment, the algorithms of FIGS. 6 and 8 are state driven. In other words, the algorithms are not triggered until network congestion exceeds a predetermined amount. The trigger for the state to be entered can be based on any of the performance parameters set forth above increasing above or decreasing below predetermined thresholds.
In yet a further embodiment, the dropping of packets based on the value of the value marker is performed by an intermediate node, such as a router. This embodiment is particularly useful in a network employing any of the Multi Protocol Labeling Switching, ATM, and Integrated Services Controlled Load and Differentiate Services.
In yet a further embodiment, the positions of the codec and adaptive playout unit in FIG. 3 are reversed. Thus, the receive buffer 336 contains encoded packets rather than decoded packets.
In yet a further embodiment, the acoustic prioritization agent 232 processes packet structures before and/or after encryption.
In yet a further embodiment, a value marker is not employed and the buffer manager itself performs the packet/frame comparison to identify acoustically similar packets that can be expended in the event that buffer length/delay reaches undesired levels.
In other embodiments, the VAD 10 , codec 14 , acoustic prioritization agent 232 , and/or buffer manager 332 are implemented as software and/or hardware, such as a logic circuit, e.g., an Application Specific Integrated Circuit or ASIC.
The present invention, in various embodiments, includes components, methods, processes, systems and/or apparatus substantially as depicted and described herein, including various embodiments, subcombinations, and subsets thereof. Those of skill in the art will understand how to make and use the present invention after understanding the present disclosure. The present invention, in various embodiments, includes providing devices and processes in the absence of items not depicted and/or described herein or in various embodiments hereof, including in the absence of such items as may have been used in previous devices or processes, e.g., for improving performance, achieving ease and\or reducing cost of implementation.
The foregoing discussion of the invention has been presented for purposes of illustration and description. The foregoing is not intended to limit the invention to the form or forms disclosed herein. Although the description of the invention has included description of one or more embodiments and certain variations and modifications, other variations and modifications are within the scope of the invention, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter. | The present invention is directed to voice communication devices in which an audio stream is divided into a sequence of individual packets, each of which is routed via pathways that can vary depending on the availability of network resources. All embodiments of the invention rely on an acoustic prioritization agent that assigns a priority value to the packets. The priority value is based on factors such as whether the packet contains voice activity and the degree of acoustic similarity between this packet and adjacent packets in the sequence. A confidence level, associated with the priority value, may also be assigned. In one embodiment, network congestion is reduced by deliberately failing to transmit packets that are judged to be acoustically similar to adjacent packets; the expectation is that, under these circumstances, traditional packet loss concealment algorithms in the receiving device will construct an acceptably accurate replica of the missing packet. In another embodiment, the receiving device can reduce the number of packets stored in its jitter buffer, and therefore the latency of the speech signal, by selectively deleting one or more packets within sustained silences or non-varying speech events. In both embodiments, the ability of the system to drop appropriate packets may be enhanced by taking into account the confidence levels associated with the priority assessments. | 7 |
[0001] This application claims priority of PCT application PCT/CH2007/000475 having a priority date of Sep. 28, 2006, the disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The invention relates to a shedding apparatus for a weaving machine, in particular for a ribbon weaving machine.
BACKGROUND OF THE INVENTION
[0003] Shedding apparatuses for weaving machines which have a heddle apparatus and a heddle frame are known in principle from numerous documents. WO-A-98/24955 discloses a weaving machine in which the dragging element for dragging the warp threads of a weaving machine and comprising for example a heddle frame is clamped between two springs. There, the dragging element oscillates and a holding device is capable of stopping the oscillation for a certain time, and so forming a shed during the weft insertion. The holding device from WO-A-98/24955 is intended to be controllable by means of a control unit. Permanent magnets which can be influenced by electromagnets have already been proposed for this.
[0004] However, the configuration with the two springs of WO-A-98/24955 takes up a relatively large space, as the drawings there also show. Furthermore, the controlled holding device is complicated, even if it takes the form of permanent magnets, because of the electromagnetic influence on the permanent magnets.
SUMMARY OF THE INVENTION
[0005] The object of the invention is to improve a shedding apparatus for weaving machines which have a heddle apparatus and a heddle frame.
[0006] The object is achieved by a shedding apparatus. In this case, the measures of the invention firstly result in a very small space requirement. The kinetic energy of the heddle motion can be provided for the most part by a tension/compression spring. The tension/compression spring is in this case set up in such a way that, in an upper position and in a lower position, it respectively provides a great potential energy as a force which moves the heddle in the direction of a middle position. The middle position is preferably characterized in that, in this position, no potential energy is emitted by the spring, but instead the heddle has a maximum speed, and is then moved further into the other position respectively, that is to say the lower position or the upper position, the tension/compression spring then being able to take up the kinetic energy of the heddle in the form of potential energy. In order, however, to make a controlled heddle motion possible, and optional pausing in the upper position or lower position, magnetically acting holding means are respectively provided in the upper position and the lower position, means which stop the heddle motion and hold the heddle in the respective position. In order to make a controlled motion possible, an optionally switchable, electric linear motor is additionally provided. Together with the spring force, it overcomes the holding force of the holding means and can therefore free the heddle from its held position. In principle, the linear motor is therefore intended for releasing the heddle from the holding means and initiating the heddle moving operation. Furthermore, the linear drive means serves the purpose of compensating for energy losses and adapting the heddle apparatus to changing operating conditions. The heddle apparatus is controlled exclusively by the control of the linear motor.
[0007] It is advantageous if at least 75% of the kinetic energy is taken from the tension/compression spring, and the linear motor provides at most 25% of the kinetic energy.
[0008] An advantageous refinement of the invention is obtained if the holding means are formed in an uncontrolled manner as permanent magnets which interact with magnetic counter-holders.
[0009] A form is particularly advantageous, since the entry of the magnetically acting holding elements, which are advantageously formed from iron, into the effective range of the coil magnets avoids direct contact, resulting in particularly low-noise running of the shedding apparatus.
[0010] Advantageously, no force is exerted on the heddle frame in a third shed position, between the upper shed position and the lower shed position.
[0011] It is particularly advantageous with respect to the allocation of space and the dynamic properties of the system if the tension/compression spring is formed as a leaf spring, and thereby formed in an ring-like manner. It goes without saying that in this context a ring does not have to be interpreted as a circular formation. Rather, the term “ring-like” is to be understood as meaning closed formations such as round, oval, elliptical or similarly formed springs, which are possibly suitable for accommodating components within them for the purpose of reducing the space requirement. In one particular embodiment, it is provided that the spring force to be applied is divided between two springs, which are arranged at the ends of the heddle apparatus. In order to eliminate the transverse forces, it is advantageous if the heddle apparatus is formed symmetrically with respect to its center axis.
[0012] An advantageous shedding apparatus has a number of heddle apparatuses arranged in a group. It is particularly advantageous in this respect if the tension/compression springs are arranged alternating with one another, one or more on top and one or more underneath.
[0013] In the case of the embodiment with stop magnets and magnetic counter-holders, it is more advantageous if they heddle apparatus has a support frame that is connected to the heddle frame and encloses a fixed block part. In this case, the stop magnets and the magnetic counter-holders are arranged on the upper and lower parts of the support frame or on the upper side and underside of the block part, respectively. If the block part then has a respectively adjustable upper part and lower part, these can be adjusted according to the inclination of the running of the warp threads of the upper shed and the lower shed, respectively.
[0014] It is advantageous if the linear motor has a flat coil, which is arranged in the plane of the heddle frame.
[0015] The aforementioned elements to be used according to the invention, as well as those claimed and described in the following exemplary embodiments, are not subject to any particular conditions by way of exclusion in terms of their size, shape, use of material and technical design, with the result that the selection criteria known in the respective field of application can be used unrestrictedly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Exemplary embodiments of a shedding apparatus for weaving machines with a heddle apparatus and a heddle frame are described in more detail below on the basis of the drawings, in which:
[0017] FIG. 1 shows the weaving region of a weaving machine with a shedding apparatus according to a first embodiment of the present invention, in side view;
[0018] FIG. 2 shows a single heddle apparatus of the shedding apparatus from FIG. 1 in a view from the front;
[0019] FIG. 3 shows a force diagram for the sequences of movements of the heddle motion of the apparatus according to FIGS. 1 and 2 ;
[0020] FIG. 4 shows a shedding apparatus with a heddle apparatus according to an alternative embodiment of the present invention in a perspective view;
[0021] FIG. 5 shows an enlarged representation of a detail from FIG. 4 ;
[0022] FIG. 6 shows the weaving region of a weaving machine with a shedding apparatus according to a further embodiment of the present invention, in side view; and
[0023] FIG. 7 shows a single heddle apparatus of the shedding apparatus from FIG. 6 in a view from the front.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] A first exemplary embodiment for carrying out the present invention is represented in FIGS. 1 and 2 .
[0025] FIG. 1 shows the diagram of the weaving region of a weaving machine in side view. A shedding apparatus with a number of heddle apparatuses 2 serves the purpose of opening warp threads 50 to form a weaving shed with an upper shed and a lower shed, into which a weft insertion element inserts a weft thread with every change of shed. A weaving reed 42 beats up the inserted weft thread at the edge of the fabric produced.
[0026] As FIG. 2 reveals, each heddle apparatus 2 includes a heddle frame 4 , with heddle supports 6 , on which heddles 40 for guiding the warp threads 50 are arranged. In the present example, the heddles 40 are grouped together in four groups for four weaving locations of a ribbon weaving machine. The heddle frame 4 is connected to a linear motor 12 by way of a heddle connector 8 . In FIG. 1 , the heddle apparatus 2 has at the top and bottom and upper, fixed stop magnet 24 and a lower, fixed stop magnet 26 , which in the state in which they are brought into close proximity, interact with the respective magnetic counter-holders 30 and 32 , which are assigned to the moved heddle frame 4 .
[0027] In FIG. 2 , the heddle apparatus 2 is represented from the front. Shown in FIG. 2 as an addition to the representation in FIG. 1 is a leaf spring 14 , which is formed in a ring-like manner and assists a heddle motion in the vertical direction. One particular feature of this exemplary embodiment is that here the lower stop magnet 26 is accommodated within the leaf spring 14 and the corresponding lower magnetic counter-holder 32 is mounted on the leaf spring 14 . The stop magnet 24 is mounted on the spring holder 20 , which holds the leaf spring. In this exemplary embodiment, the upper magnetic counter-holder 30 is attached to the heddle frame 4 , while the upper stop magnet 24 is fixedly mounted.
[0028] The heddle apparatus is formed symmetrically with respect to a center line M, in order to avoid transverse forces.
[0029] The operating mode of the shedding apparatus is now described below, according to the exemplary embodiment described above. The heddle frames 4 with the heddle supports 6 are raised and lowered for the purpose of shedding. As the driving means for this movement, the spring drive, in the exemplary embodiment the leaf spring 14 arranged on the spring holder 20 , and a linear motor 12 interact. The linear motor 12 comprises a flat coil 34 and an upper coil magnet 36 and a lower coil magnet 38 , which are arranged on the heddle connector 8 . During the lifting or lowering movement, the greatest proportion of energy is applied by the spring drive. However, the movement is initiated by the linear motor 12 , as described below.
[0030] By means of the upper stop magnet 24 or the lower stop magnet 26 and the respective magnetic counter-holders 30 and 32 , the heddle frame 4 is securely held in the upper end position or the lower end position—which correspond to the upper shed position and the lower shed position of the warp threads of a weaving shed—as long as the linear motor 12 is not in operation. This is achieved by the stop magnets 24 and 26 , which are formed as permanent magnets, having a greater holding force than the restoring force of the leaf spring 14 in the case of the deflection to the end positions. It should be pointed out that the holding force of the permanent magnets 24 and 26 has a short range and is therefore only relevant at all in the vicinity of the magnetic counter-holders 30 and 32 , and consequently only in or in the vicinity of the respective end position.
[0031] In order then to set the heddle frame 4 in motion, in order therefore to initiate a shedding motion from the upper end position into the lower end position or from the lower end position into the upper end position, the linear motor 12 is put into operation. The sum of the effective forces of the linear motor 12 and the spring force of the leaf spring 14 in the deflected state, that is to say in one of the end positions, is greater than the holding force of the permanent magnets 24 and 26 , respectively.
[0032] When the holding force of the permanent magnets 24 and 26 is overcome, the motion of the heddle is brought about for the most part by the spring force of the leaf spring 14 , and the linear motor 12 moves along with this motion without significantly contributing to it. When the other end position is reached, that is to say for example when the lower stop magnet 26 enters the effective range of the lower magnetic counter-holder 32 , the renewed end position is reached and the leaf spring 14 remains deflected, since the force of the permanent magnet 26 in this position is greater than the restoring force of the leaf spring 14 , and the linear motor 12 does not assist the latter.
[0033] The force profile of the motion is shown in the diagram of forces in FIG. 3 . In the exemplary embodiment mentioned here, the ring-like leaf spring 14 is operated in the linear range, so that the spring force diagram 100 can be represented by a straight line. The spring force is assisted by the warp thread force 106 only insignificantly, so that the warp thread force 106 plays no part here. The stop magnet diagram 102 clearly shows the short range of the magnetic forces, which only act when the stop magnets 24 , 26 are in the direct vicinity of the magnetic counter-holders 30 , 32 and an end position has been assumed. The diagram of coil forces 104 of the linear motor 12 has a constant force in the operating mode described here, which may be directed in one direction or the other, depending on polarity.
[0034] In the exemplary embodiments described here, the linear motor 12 is formed in such a way that, in addition to the upper position and the lower position, a middle position of the heddle can be assumed, and the heddle can be moved from this middle position into the upper position or into the lower position.
[0035] This operating mode has the purpose that a rest position can be assumed, a position in which the leaf spring 14 does not exert any force on the heddle frame. The heddle apparatus is controlled exclusively by means of the linear motor, which for this purpose is connected to a control unit of a weaving machine in a way that is not represented in any more detail.
[0036] FIG. 4 and FIG. 5 show a shedding apparatus according to a second exemplary embodiment, comprising a multiplicity of heddle apparatuses 2 1 - 2 6 with in each case a heddle frame 4 according to a preferred exemplary embodiment. Of the heddle frames 4 , only the heddle supports 6 are represented here. In the embodiment that is shown in FIGS. 4 and 5 , the heddle frames 4 are connected at the top or bottom by means of a heddle connector 8 to a support frame 10 , which for its part is connected to a linear motor 12 and then further connected to a leaf spring 14 or 16 formed in a ring-like manner. The lower leaf springs 14 are attached to a lower, fixed shedding block 18 with a spring holder 20 , whereas the upper leaf springs 16 are attached to an upper, fixed shedding block 22 , likewise with a spring holder 20 . The leaf springs 14 and 16 act in turn as tension/compression springs and the spring arrangement and adjustment is chosen such that the heddle frames 4 are in the middle shed position in the rest position of the springs 14 , 16 .
[0037] In the support frames 10 , the magnetic counter-holders 30 and 32 are respectively attached from the inside at the top and bottom. The lower shedding block 18 and the upper shedding block 22 respectively have at the upper and lower ends a block part 28 , to which stop magnets 24 and 26 are attached. In the present exemplary embodiment, the stop magnets 24 and 26 are arranged in an inclined plane. In this respect, the inclinations are adjustable according to the desired inclination of the running of the warp thread of the upper shed and the lower shed, respectively.
[0038] The linear motors 12 have in each case electrical conductors 46 , which are led to a connection plate 48 , by way of which the linear motors 12 can be connected to a control unit.
[0039] A further exemplary embodiment for carrying out the present invention is represented in FIGS. 6 and 7 .
[0040] FIG. 6 shows the diagram of the weaving region of such a weaving machine according to a further exemplary embodiment in side view. The shedding apparatus with the heddle apparatuses 2 corresponds to the first exemplary embodiment and is not described any further here.
[0041] In FIG. 6 , the heddle apparatus 2 respectively has above and below the flat coil 34 of the linear motor 12 an upper and lower magnetically acting holding element 130 , 132 —in the exemplary embodiment made of iron—which alternately enter the magnetic field of the coil magnets 26 and 38 and form with them upper and lower holding means 130 , 36 ; 132 , 38 .
[0042] The heddle apparatus is in turn formed symmetrically with respect to a center line M, in order to avoid transverse forces.
[0043] By means of the upper holding means 130 , 36 or the lower holding means 132 , 38 , the heddle frame 4 is in turn securely held in the upper end position or the lower end position—which correspond to the upper shed position and the lower shed position of the warp threads of a weaving shed—as long as the linear motor 12 is not in operation. This is achieved by the holding means having a greater holding force than the restoring force of the leaf spring 14 in the case of the deflection to the end positions. It should be pointed out that the holding force of the holding means has a short range and is therefore only relevant at all in the state in which it has entered the range of the counter-element, and consequently only in or in the region of the respective end position.
[0044] In order then to set the heddle frame 4 in motion, in order therefore to initiate a shedding motion from the upper end position into the lower end position or from the lower end position into the upper end position, in this exemplary embodiment too the linear motor 12 is put into operation. The sum of the effective forces of the linear motor 12 and the spring force of the leaf spring 14 in the deflected state, that is to say in one of the end positions, is greater than the holding force of the holding means.
[0045] When the holding force of the holding means is overcome, the motion of the heddle is brought about for the most part by the spring force of the leaf spring 14 , and the linear motor 12 moves along with this motion without significantly contributing to it. When the other end position is reached, the leaf spring 14 remains deflected, since the holding force of the holding means in this position is greater than the restoring force of the leaf spring 14 , and the linear motor 12 does not assist the latter.
LIST OF DESIGNATIONS
[0046] 2 heddle apparatus
[0047] 2 1 - 2 6 group of heddle apparatuses
[0048] 4 heddle frame
[0049] 6 heddle support
[0050] 8 heddle connector
[0051] 10 support frame
[0052] 12 linear motor
[0053] 14 leaf spring
[0054] 16 leaf spring
[0055] 18 shedding block
[0056] 20 spring holder
[0057] 22 shedding block
[0058] 24 upper stop magnet
[0059] 26 lower stop magnet
[0060] 28 block part
[0061] 30 upper magnetic counter-holder
[0062] 32 lower magnetic counter-holder
[0063] 34 flat coil
[0064] 36 upper coil magnet
[0065] 38 lower coil magnet
[0066] 40 heddles
[0067] 42 weaving reed
[0068] 44 reed support
[0069] 46 electrical conductors
[0070] 48 connection plate
[0071] 50 warp threads
[0072] 100 spring force diagram
[0073] 102 magnetic force diagram
[0074] 104 coil force diagram
[0075] 106 warp thread force diagram
[0076] 130 upper holding element
[0077] 132 lower holding element
[0078] M center line | In order to make a small space requirement, a low energy requirement and therefore an increased weaving frequency possible in a shedding apparatus, a spring drive is proposed which is connected to magnetically acting holding means. The holding means are capable of holding the heddle frame in an upper shed position and in a lower shed position counter to the spring force. Furthermore, the heddle frame is connected to a linear motor. A heddle movement can be initiated by said linear motor. According to the invention, the spring drive is configured as a tension/compression spring which is designed in such a way that, during operation of the heddle frame at the resonant frequency of the spring drive the greater part of the kinetic energy can be obtained from the spring drive. | 3 |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This patent application claims the benefit of U.S. provisional patent application 60/575,669, filed May 28, 2004.
FIELD OF THE INVENTION
[0002] The present invention relates generally to recovery boilers and furnaces which are used to process waste liquor, and more particularly relates to the liquor gun used to spray the waste liquor into the recovery furnace.
BACKGROUND OF THE INVENTION
[0003] Paper pulp is manufactured by treating wood in a boiling liquid at high temperatures and pressures. After the boiling process, the remaining liquid contains a number of chemicals and retains some of the wood substance, forming a “weak liquor”. In a typical mill, the water is removed from the weak liquor and a “black liquor” is obtained, and is then supplied as fuel to the recovery boiler. The recovery boiler provides a reduced atmosphere at 1000° C. to burn the remaining wood substance and release energy that is conveyed away in the form of high-pressure steam. A regeneration of the chemicals contained in the black liquor is also performed in the recovery boiler.
[0004] The black liquor is normally supplied to the recovery furnace through burners commonly referred to as liquor guns. These liquor guns often include simple nozzles provided with some form of splash or deflection plate that is mounted on the nozzle. Typically, the liquor guns are mounted for rotation about a horizontal axis, whereby the vertical position of the nozzle and deflector plate may be adjusted in order to direct the spray of the black liquor. Due to the harsh environment of the mill and recovery furnace, the entire spray gun assembly, including the tilting mechanism, must be very sturdily constructed. At the same time, the harsh environment requires that the liquor guns be serviced relatively frequently. For example, the nozzle portion of the gun projects inside the recovery furnace and is constantly exposed to high temperatures and the black liquor. Thus, the nozzles need cleaning, repair or replacement.
[0005] Accordingly, there exists a need to provide a liquor gun assembly that is not only well adapted for the harsh environment of a recovery furnace, but which also facilitates access and service of the liquor gun.
BRIEF SUMMARY OF THE INVENTION
[0006] A liquor gun holder in accordance with this invention generally comprises a spray rod (splash plate cleaning device), a carriage assembly and a rail assembly. The spray rod and gun holder is rotatably connected to the carriage assembly. The carriage assembly is mounted to the rail assembly for linear translation relative to a wall of the recovery furnace. The liquor gun thus includes a retractable spray rod which may be translated from an active position where its nozzle is positioned within the interior chamber of the furnace, to a service position where the spray rod is retracted and the nozzle is outside the chamber. The retractable spray rod permits service on liquor gun, including the nozzle of the spray rod.
[0007] According to more detailed aspects, the carriage assembly includes a tilting mechanism which allows the spray rod and gun holder to be tilted relative to a horizontal axis. Preferably, the tilting mechanism and the carriage assembly are positioned laterally (i.e. to the side) of the spray rod. When a cleaning assembly is provided to remove accumulated black liquor from the deflector plate, the cleaning assembly is preferably vertically aligned with the spray rod, and thus also positioned laterally from the carriage assembly. In this manner, the spray rod and cleaning assembly may be tilted, while at the same time permitting axial translation of the spray rod and scraper assembly via the carriage and rail assemblies which are positioned to prevent interference with the spray rod.
[0008] According to even further aspects of the invention, the rail assembly is preferably positioned vertically below the carriage assembly, and importantly is also positioned laterally from the spray rod. The rail assembly typically includes a connection plate and tab which correspond with vertically extending mounting plates attached to a wall plate of the recovery furnace wall. The wall plate generally includes an elongated slot or aperture for providing access to the interior chamber of the recovery furnace. While the nozzle of the spray rod must be aligned with this opening for spraying black liquor into the furnace, the carriage assembly and rail assembly are preferably laterally positioned from the spray rod so that these mechanisms are not aligned with the opening, and thereby partially sheltered from that environment. At the same time, the retraction of the spray rod and its nozzle does not cause any black liquor to leak or seep onto the carriage assembly or rail assembly, as they are laterally positioned therefrom.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a side view, partially in cross-section and partially in hidden, of a liquor gun constructed in accordance with the teachings of the present invention;
[0010] FIG. 2 is an end view of the liquor gun depicted in FIG. 1 ; and
[0011] FIG. 3 is a side view partially in cross-section and partially in hidden, showing the liquor gun of FIG. 1 in a retracted service position.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Turning now to the figures, FIGS. 1 and 2 depict side and end views of a liquor gun holder 20 designed to support a liquor gun 22 to provide black liquor to the internal chamber 10 defined by the exterior wall 12 of a recovery furnace. The liquor gun holder 20 generally comprises a cleaning assembly 16 connected to a carriage assembly 40 , which in turn is connected to a rail assembly 60 for linear translation of the cleaning assembly 16 relative to the chamber 10 of the furnace. FIG. 1 depicts the cleaning assembly 16 and carriage assembly 40 in an extended active position.
[0013] The liquor gun 22 generally comprises an inlet tube 24 fluidically connected to a spray tube 26 , which in turn is fluidically connected to a nozzle 28 . The inlet tube 24 is connected to the spray tube 26 by way of a hinge coupling 30 which allows the inlet tube 24 and spray tube 26 to rotate relative to one another. The nozzle 28 is coupled to the spray tube 26 by way of a coupling 32 , thereby allowing the nozzle 28 to be individually replaced or repaired. The nozzle 28 projects through a port 14 formed in the exterior wall 12 of the recovery furnace. The distal end of the nozzle 28 includes a deflector plate 34 as is known in the art for forming a spray pattern with the black liquor to promote vaporization and recovery in the recovery furnace.
[0014] The liquor gun 22 is connected to the carriage assembly 40 by way of a clamp 35 . The clamp 35 is secured to the horizontal arm of an L-shaped bracket 36 . The downwardly depending arm of the L-shaped bracket 36 is mechanically connected to the cleaning assembly 16 which includes a cylinder 17 operatively connected to a scraper or cutting head 18 . As is known in the art, the cleaning assembly 16 translates the cutting head 18 into engagement with the deflector plate 29 to scrape the deflector plate 34 and free any black liquor or other debris that has collected thereon. In sum, the liquor gun 22 and cleaning assembly 16 are rigidly connected by way of the L-shaped bracket 36 .
[0015] The L-shaped bracket 36 is attached to a pivot pin 38 which extends laterally from the cleaning assembly 16 , as best seen in FIG. 2 . The carriage assembly 40 includes opposing first and second plates 42 , 44 which have a bearing 46 extending therebetween for receiving the pivot pin 38 . Accordingly, it will be seen that the cleaning assembly 16 and the liquor gun 22 are thus pivotally connected to the carriage assembly 40 by way of the pivot pin 38 and the bearing 46 . As is known in the art, the cleaning assembly 16 and the liquor gun 22 are rotatable about a horizontal axis defined by the pivot pin 38 to change the position of the nozzle 28 . The carriage assembly 40 includes a mechanism to rotate the cleaning assembly 16 and the liquor gun 22 and to secure the cleaning assembly 16 and the liquor gun 22 in a particular pivoted position. As shown, a crank 39 is rotated to drive a toothed shaft (not shown), which in turn drives a gear mechanism (not shown) housed in the carriage assembly 40 between the opposing plates 42 , 44 .
[0016] The first plate 42 extends downwardly from the pivot pin 38 and the bearing 46 for connection to the rail assembly 60 , as will be described below. As best seen in FIG. 1 , the rail assembly 60 generally includes a bracket 62 attached to a connection plate 64 . The connection plate 64 includes a pair of distally projecting tabs 66 for attaching the rail assembly 60 to a wall plate 72 forming a portion of the furnace wall 12 . The wall plate 72 defines an elongated slot or aperture 74 ( FIG. 2 ) providing access to the internal chamber 10 of the recovery furnace. The wall plate 72 includes a pair of opposing mounting plates 68 having a plurality of apertures 70 which are vertically spaced. The mounting plates 68 receive the tabs 66 , and the plurality of apertures 70 allow the rail assembly 60 to be vertically positioned relative to the furnace and internal chamber 10 . This in turn allows the liquor gun holder 20 to be vertically positioned on the furnace.
[0017] Referring now to FIG. 2 , an end view of the rail assembly 60 can be seen. The bracket 62 includes a rail 76 projecting laterally therefrom, the rail including a pair of opposing guides 78 . The guides 78 each preferably comprise a cylindrically shaped metal rod which provides stable translation of the carriage assembly 40 relative to the rail assembly 60 . It can also be seen in FIG. 2 that the first plate 42 of the carriage 40 includes an axle plate 48 which supports a pair of opposing rollers 50 shaped to correspond with the guides 78 . The rollers 50 translate over with the guides 78 formed in the rail 76 . A stop 82 is positioned at a proximal end of the rail 76 to prevent inadvertent removal of the carriage assembly 40 , cleaning assembly 16 , and liquor gun 22 therefrom. The liquor gun holder 20 is structured for manual translation of the liquor gun 22 and carriage assembly 40 , although a motor or other mover can be employed to facilitate the withdrawal of the liquor gun 22 from the recovery furnace.
[0018] A block 52 is connected to a lower end of the first plate 42 , and includes a plurality of apertures 74 as seen in FIG. 1 . In this way, a pin 80 may be fitted through the bracket 62 of the rail and positioned within one of the apertures 74 of the block 52 . Thus, the pin 80 and block 52 form a lock which fixes the position of the carriage assembly 40 , cleaning assembly 16 , and liquor gun 22 relative to the rail assembly 60 . Other locking mechanisms will be readily envisioned by those of ordinary skill in the art.
[0019] In operation, the liquor gun holder 20 permits axial, preferably horizontal, translation of the cleaning assembly 16 and the liquor gun 22 via the carriage assembly 40 , to selectively position the liquor gun 22 relative to the internal chamber 10 of the recovery furnace. A retracted service position of the liquor gun 22 and carriage assembly 40 has been depicted in FIG. 3 . As shown, both the liquor gun 22 as well as the cleaning assembly 16 may be horizontally adjusted relative to the internal chamber 10 , and to move the nozzle 28 into or out of the internal chamber 10 of the recovery furnace. In, the service position, the ports into the furnace may be closed off, and the liquor gun 22 allowed to cool prior to servicing. Furthermore, the cleaning assembly 16 may be activated while the liquor gun 22 is in either the active or service positions. As is known, the liquor gun 22 is periodically purged with steam to clean the interior passageway of the liquor gun 22 .
[0020] In addition to the axial translation of the liquor gun 22 described above, the carriage assembly 40 and its tilt mechanism (not shown) permit the liquor gun 22 , and the cleaning assembly 16 , to be rotated about a horizontal axis defined by the pivot pin 38 . The opening 71 formed in the wall plate 72 , as well as the port 14 defined in the furnace wall 12 , are sized to permit the axial translation of the liquor gun 22 and carriage assembly 40 relative to the rail assembly 60 regardless of whether the liquor gun 22 is in a horizontal or tilted position. Likewise, the ability to tilt as well as axially translate the liquor gun 22 , either sequentially or simultaneously, is permitted by virtue of placing the carriage assembly 40 and corresponding rail assembly 60 laterally from the cleaning assembly 16 and the liquor gun 22 , as best seen in the end view of FIG. 2 .
[0021] It will also be seen that the opposing plates 42 , 44 of the carriage assembly 40 , which house the bearing 46 and gearing assembly for tilting the cleaning assembly 16 and the liquor gun 22 , are vertically positioned above the rail assembly 60 , and in particular the rail 76 and guides 78 . Accordingly, the liquor gun 22 may be translated horizontally and away from the internal chamber 10 of the recovery furnace, to thereby allow service or replacement of the liquor gun 22 as well as cleaning or other maintenance. At the same time, the liquor gun 22 may be tilted and the carriage assembly 40 , including the tilting mechanism, and rail assembly 60 are protected from the harsh environment of the recovery furnace. | A liquor gun holder for a recovery furnace includes a rail assembly, a carriage assembly moveably mounted onto the rail assembly such that the carriage assembly is moveable longitudinally along the rail assembly, a pivot pin supported by a bearing and extending laterally from the carriage assembly, and a cleaning assembly pivotally mounted onto the pivot pin such that the cleaning assembly is rotatable about a horizontal axis extending longitudinally through the pivot pin and is positioned laterally from the carriage assembly and the rail assembly, the cleaning assembly including a clamp adapted to secure a liquor gun thereon such that the liquor gun is rotatable with the cleaning assembly and is positioned laterally from the carriage assembly. | 5 |
FIELD OF THE INVENTION
This invention relates generally to tube-type boilers, and particularly concerns both a method and apparatus that may be advantageously utilized in connection with the removal of a boiler tube or tubes from installation in a boiler as for subsequent replacement.
BACKGROUND OF THE INVENTION
Heretofore it has been common practice in connection with the removal of water tubes or fire tubes from within a steam boiler for subsequent replacement to first cut the installed tubes adjacent their header-mounted ends with a cutting torch, to next remove the cut tube lengths, and afterwards forcefully drive the severed tube ends out of engagement with the boiler headers. Such conventional practice is time consuming, expensive to accomplish, and frequently results in damage to the tube mounting bores provided in the boiler headers. Each damaged tube mounting bore in a tube header must be repaired by welding, re-drilling, and honing to proper size for later re-use.
We have discovered a novel method and apparatus that may be utilized to effect the removal of boiler-tube ends from their mountings within a boiler header without causing damage to the co-operating header tube mounting bores, thus eliminating the necessity for subsequent header metal repair and header bore re-drilling and honing.
Other advantages and objectives of the invention will become apparent in the course of considering the descriptions, drawings, and claims which follow.
SUMMARY OF THE INVENTION
The apparatus of the present invention is basically comprised of a rigid support structure, a pair of spaced-apart hydraulic clamping cylinders carried by the support structure and clamped to the interior surfaces of two installed boiler tube ends adjacent the boiler tube end to be removed, and a centrally-positioned and hydraulically actuated tube end slitting tool also carried by the support structure but co-operating with the boiler tube end to be removed. Also comprising the slitting tool is an electric stepper motor mounted on the support structure and linked to spaced-apart tool bit elements included in the slitting tool. The stepper motor functions to radially advance the reciprocating tool bits through the wall thickness of the boiler tube to be replaced. Further, the apparatus includes a source of pressurized hydraulic fluid, a suitable electrical energy supply, and a selectively operated controller that co-ordinates the reciprocating movement of the hydraulically-actuated slitting tool and the radial advancement of the apparatus tool bits by the system stepper motor.
From a method standpoint, the invention involves the conventional initial step of cutting the boiler tube that is to be replaced adjacent the header tube mounting bores in which the tube is installed, and such is followed by the removal of the cut length of boiler tube. Subsequently the boiler tube ends retained in the boiler headers are removed using the properly clamped invention apparatus to machine a longitudinal gap or slot having a depth corresponding to the thickness of the wall of the retained tube end throughout the tube end length, which length is generally somewhat greater than the thickness of the boiler header plate retaining the tube end. After the gap metal has been removed from the tube end wall throughout its length, the tube end is compressed to close the machined gap and then withdrawn in its compressed condition from co-operation with the boiler header tube mounting bore. Such method steps are readily accomplished without causing any damage to the metal of the tube mounting bore in the boiler header and are less time-consuming and costly to achieve than are conventional boiler tube removal methods.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is schematic elevation view of a preferred embodiment of the apparatus assembly of the present invention illustrating its installed relationship relative to a boiler tube end that is to be removed from installation in a boiler header;
FIG. 2 is a top end plan view of the apparatus assembly of FIG. 1;
FIG. 3 is a section view through a clamping cylinder subassembly taken at line 3--3 of FIG. 2;
FIGS. 4 and 5 are section views taken at line 4--4 of FIG. 2 through the apparatus slitter subassembly in two different operating positions;
FIG. 6 is a section view taken at line 6--6 of FIG. 4;
FIG. 7 is a section view taken at line 7--7 of FIG. 4;
FIG. 8 is a section view taken at line 8--8 of FIG. 4; and
FIG. 9 is a view of a gear drive mechanism.
DETAILED DESCRIPTION
A preferred embodiment of the apparatus of the present invention is designated generally as 10 in the drawings and is an assembly basically comprised of rigid support structure 12, a pair of hydraulically-actuated clamp subassemblies 14 and 16 supported by structure 12, and a hydraulically-actuated tube slitter subassembly 18 also supported by structure 12. Although described as being a "tube slitter", subassembly 18 actually functions to form an compression gap throughout the length of the boiler tube end that is to be removed.
Apparatus assembly 10 is illustrated in FIG. 1 as co-operating with the cut-off ends 20 through 26 of boiler tubes previously installed in boiler header 28. Tube end 24 is the tube element part designated for removal from installation within header 28, and its removal typically occurs in connection with subsequent replacement with a new full-length boiler tube.
Support structure 12 of apparatus 10 is basically comprised of a base element 30, a case element 32 which is connected to base element 30 and which houses the principal cutting tool components of subassembly 18, and a support arm element 34 which is connected to case element 32 and which supports the electrically-actuated stepper motor element 36 of subassembly 18. Case element 32 also supports the hydraulic actuator 38 included in subassembly 18 to accomplish powered reciprocable movement of cutting tools installed within case element 32.
The apparatus 10 system also includes sources of pressurized hydraulic fluid and electrical energy (not illustrated), a conventional selectively-operated controller sub-assembly 40 which controls the actuation of subassemblies 14, 16, and 18 through conventional hydraulic control valves 42, and of stepper motor 36.
FIG. 2 details the elongated slots 44 provided in structure base element 30 to permit lateral adjustments to the positions of hydraulic clamp subassemblies 14 and 16 and thereby facilitate their proper alignment for insertion in respective tube ends 20 and 26.
Each clamp subassembly 14 and 16 includes, in addition to disclosed expandable clamping mandrel element 46, a tapered expander element 48 that co-operates with a conical recess in mandrel element 46 and that is connected by a rigid rod 50 to a piston element 52 positioned within a subassembly hydraulic actuator 54. Pressurized hydraulic fluid is flowed into (and from) the interior of hydraulic actuator 54, usually at a fluid pressures of approximately 2,000 psi, through a supply port referenced as 56. When controller 40 operates to open particular control valves 42 to flow pressurized hydraulic fluid to clamping cylinder subassemblies 14 and 16, such flow causes piston element 52, connecting rod element 50, and attached tapered expander element 48 to move upwardly (FIG. 3) and cause the expansion of mandrel element 46 within tube end 20. When the clamping action by subassemblies 14 and 16 is subsequently discontinued and pressurized fluid within actuators 50 is flowed by action of controller 34 and the associated control valve 36 to the hydraulic fluid reservoir provided in apparatus 10, expandable mandrel elements 46 are released from substantial frictional engagement with the interior wall surface of tube ends 20 and 26 through the downward movement of piston 52, rod 50, and expander 48 to permit withdrawal of apparatus 10 from engagement with header 28 and its included tube ends. Spring 57 assists in this downward movement. A tension spring component 58 is connected to base element 30 and to expandable mandrel 46 to maintain the components of subassembly 14 as a unit during insertion/removal in boiler header 28 and during lateral movement in co-operating slot element 44. In one actual embodiment of the invention we preferred that expandable mandrel elements 46 be formed of a dense polyurethane material and that rigid expander element 48 be formed of an aluminum alloy. Alternatively, mandrel 46 can be formed of an aluminum alloy and be partially segmented.
The construction and operation of slitter subassembly 18 included in apparatus 10 is best disclosed by reference to FIGS. 4 and 5 of the drawings. Such subassembly essentially functions in the general manner of a reciprocating, metal-shaving shaper machine tool and includes, in addition to conventional, double-acting hydraulic actuator element 38, a cutting head designated as 60. Cutting head 60 has a generally cylindrical base element 62 that is both slidably contained within structural case 32 and rigidly connected at one end to the actuator rod component 64 of hydraulic actuator 38 by co-operating retainer fitting 66. FIG. 4 illustrates the position of cutting head 60 when rod component 64 of hydraulic actuator 38 is fully retracted. FIG. 5 illustrates the position of cutting head 60 when rod 64 is fully extended. Also, FIGS. 4 and 5 respectively illustrate a subassembly tool holder 68 in its extreme retracted and projected positions before commencing and after completing the cutting of a compression gap in tube end 24.
Cutting head 60 also includes a generally tubular drawbar sleeve element 70 that is rigidly secured to the end of base element 62 opposite retainer fitting 66. Drawbar sleeve 70 has an upper surface opening 72 through which toolholder 68 and its included pair of cutting tool bits 74 and 76 (see FIG. 8) may be advanced into or withdrawn from contact with wall-thickness metal of tube end 24. Toolholder 68 has an inclined under surface 78 that co-operates with the inclined ramp surface 80 of height-adjustment wedge 82 for vertical support, and a contact face 83 that engages an aft face of opening 72 in drawbar sleeve 70. When actuator rod 64 is retracted during a metal-removal stroke, the force required to consequently move engaged cutting tool bits 74 and 76 along their metal-cutting path is transmitted to the tool bits from rod 64 and through retainer fitting 66, slitter head base element 62, attached drawbar sleeve 70, co-operating toolholder face 84, and toolholder 68.
The advancement and retraction of the radial position of toolholder 68 (and included cutting tool bits 74 and 76) within tube end 24 is controlled by actuation of stepper motor 36 and its connected drive train. Such drive drain includes, in part and in addition to height-adjustment wedge 82 which has support wheels 84 and an integral hook 86, an internally-threaded thimble 88 having an integral hook element 90 that engages the integral hook element 86 of wheeled wedge element 82, and an adjustment shaft 92 that is rotatably supported within base element 62 and that has a threaded end 94 that co-operates with the internal thread of thimble element 88.
Also included in the adjustment drive train that is powered by stepper motor 36 are a toothed sprocket 96, preferably formed integral with the end of adjustment shaft 92 opposite threaded end 94, journaled drive shaft 97 connected to stepper motor 36, a toothed sprocket 98 carried by drive shaft 96, and an endless chain element 100 which connects sprockets 96 and 98. (See FIGS. 6 and 7). Note that three meshing gears 101, 102 and 103 shown in FIG. 9 could be substituted for the sprocket and chain drive unit 96, 98, 100.
Although adjustment shaft 92 can rotate relative to its journal support in base element 62, co-operating threaded thimble 88 is prevented from rotating with it by the rotational restraint of wheeled wedge 82 in a bottom-opening slot 102 provided in the lower face of drawbar sleeve element 70 (see FIG. 8) and the interlocking arrangement of wedge hook 86 and thimble hook 90. Also, structure case section 32 is provided with a bottom-opening slot 104 (see FIG. 6) to facilitate the longitudinal movement of chain 100 as actuator rod 64 is extended and retracted and consequently moves adjustment shaft 92, sprockets 96 and 98, and endless chain 100 with it. Further, it should be noted that the support wheels 84 of wheeled wedge element 82 ride on the inner wall surface of boiler tube end 24 as shown in FIGS. 4 and 5.
FIG. 8 discloses the spaced-apart positioning of tool bits 74 and 76 in their toolholder 68 installation. In one embodiment of our invention we utilize cutting tool bits of approximately one-eighth inch width and with a one-half inch space separating the adjacent tool bits. Thus, the reciprocating toolholder and tool bits, upon completion of the longitudinal cuts, have actually formed a longitudinal gap in the retained boiler tube end that is approximately three-fourths inch wide. Such in effect causes formation of a compression gap in the tube wall that has a larger cross-section than the cross-sectional area of the metal actually removed from the tube end by the cutting action of the tool bits.
Although the toolholder 68 of the preferred embodiment has two radially extending cutter bits 74 and 76, the tube slitter assembly 18 also would function if the toolholder had only one bit. If this were the case the assembly would have to be rotated with respect to a tube to make two parallel slots sequentially.
Boiler tubes to which the present invention has had widest application generally are in the size range of from 2 inches diameter to 4 inches diameter, and with wall thicknesses ranging approximately from 0.095 to 0.180 inches. An operating hydraulic pressure of approximately 2,000 pounds per square inch has proven satisfactory with a cutting head reciprocating frequency of 60 cycles per minute being utilized. (Actuator strokes typically may range to approximately 7-8 inches). Also, the pulsed actuation of the apparatus stepper motor to reposition a 30° inclined ramp surface provided in the apparatus wheeled wedge element has been controlled to move the toolholder and included tool bits radially toward tube end wall metal in increments of 0.006 inches per completed cutting stroke (per cycle).
Summarizing the method steps of the present invention, it is first necessary to conventionally cut each boiler tube to be removed adjacent the boiler headers in which it has been installed and the severed tube length removed. The apparatus of the present invention is located in a manner whereby the tube slitter subassembly 18 is aligned with a tube end of the severed boiler tube and with the apparatus clamp subassemblies 14 and 16 properly inserted in adjacent installed tube ends. Pressurized hydraulic fluid is next ported to the clamp assembly actuators to firmly anchor the invention apparatus in place for forming a compression gap in the wall of the retained tube end using the apparatus tube slitter subassembly 18.
Once the apparatus is firmly anchored, pressurized hydraulic fluid is ported to and from the tube slitter subassembly hydraulic actuator to extend the cutter head and included toolholder and tool bits into the length of the retained tube end. Thereafter, the apparatus stepper motor is actuated to advance the included toolholder and tool bits radially relative to the tube to a desired cutting depth. Subsequently pressurized hydraulic fluid is ported to and from the tube slitter subassembly hydraulic actuator to retract the cutter head and included toolholder and tool bits from the length of the retained tube end to cause two parallel longitudinally extending slots to be formed in the tube wall. Next the apparatus stepper motor is actuated to retract the included toolholder and tool bits radially relative to the tube in preparation for the next cutting cycle. This causes a remaining strip of metal to be defined between the parallel pair of slots which enables the strip to be removed and which when removed together with said slots defines a compression gap.
Subsequently the retained boiler tube end is compressed to substantially close the so-formed compression gap whereby the compressed tube end has a significantly reduced cross-sectional circumference and may be readily withdrawn from retention in the co-operating the boiler header. | A method and apparatus is provided for removing the severed end-portions of boiler tubes installed and retained in a boiler header without consequential boiler header metal damage and in a manner whereby a compression gap of uniform width is machined throughout the length and thickness of each retained boiler tube end-portion selected for removal, the machined boiler tube end-portion is subsequently compressed to significantly close the machined compression gap and reduce the tube end cross-sectional circumference, and the compressed tube end is withdrawn longitudinally from engagement with the boiler header tube-mounting bore. | 5 |
This application is a continuation of application Ser. No. 08/542,086, filed Oct. 12, 1995, now abandoned, which is a continuation of application Ser. No. 08/101,162, filed Aug. 3, 1993, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to beamsplitters for light beams, and relates more particularly to a beamsplitter device whose outputs are insensitive to polarization changes of an input beam.
2. Description of the Relevant Art
In the field of laser diagnostics, a laser or other light beam may be monitored for power level in various frequency ranges, each frequency range having a separate detector or sensor. This requires the laser beam to be split into several beams, each becoming an input to a detector or other set of diagnostic sensors. Beamsplitters may be used to divide the laser beam.
It is desirable for a power measurement to be independent of any polarization of the monitored light beam. Unfortunately, the beams output from a beamsplitter are not independent of the polarization of an incident beam. The E-vector of an incident beam can be resolved along two orthogonal axes, one perpendicular to a plane of incidence and the other parallel to the plane of incidence, which is the plane that contains the incident and reflected beams. The component of the E-vector that is perpendicular to the plane of incidence is called the s-component, while the component of the E-vector that is parallel to the plane of incidence is called the p-component.
A beamsplitter tends to polarize light. The s-component of the incident beam is reflected more effectively than it is transmitted. Conversely, the p-component of the incident beam is transmitted more effectively than it is reflected. Due to the sensitivity of a beamsplitter to polarization of the incident beam, the power levels in the transmitted and reflected beams are a function of polarization.
What is needed is a beamsplitter apparatus that outputs a plurality of beams of nearly equal power, regardless of incident beam polarization. More importantly, when diagnosing power, an output beam should not demonstrate power fluctuations if only the polarization of the input is changing.
SUMMARY OF THE INVENTION
In accordance with the illustrated preferred embodiment, the present invention provides a beamsplitter assembly that includes several beamsplitters arranged to define a plurality of polarization-balanced light paths. Each beamsplitter has a transmission light path and a reflection light path and a directional polarizing effect. The beamsplitters are arranged to define several polarization-balanced light paths, each containing one or more balanced pairs of light paths. Each balanced pair of light paths includes either two transmission light paths with orthogonal polarization effects or two reflection light paths with orthogonal polarization effects.
The orthogonal pairing of transmission and reflection light paths is the key to cancelling polarization effects. For each transmission through a beamsplitter, there is a balancing transmission where the polarization effect is orthogonal to the polarization effect of the first transmission. Also, for each reflection by a beamsplitter, there is a balancing reflection where the polarization effect is orthogonal to the polarization effect of the first reflection.
Preferably, all of the beamsplitters perform an equal 50/50 split of an incident beam into transmitted and reflected beams. Also, the beamsplitters are preferably non-polarizing beamsplitter cubes of identical construction.
The features and advantages described in the specification are not all inclusive, and particularly, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification and claims hereof. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter, resort to the claims being necessary to determine such inventive subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective diagram of three beamsplitter cubes in a second-order beamsplitter assembly according to the present invention.
FIG. 2 is a perspective diagram of planes of incidence of the three-cube, second-order beamsplitter assembly of FIG. 1.
FIG. 3 is a perspective diagram of thirteen beamsplitter cubes in a fourth-order beamsplitter assembly according to the present invention.
FIG. 4 is a perspective diagram of six beamsplitter cubes in a subassembly of the fourth-order beamsplitter assembly of FIG. 3.
FIG. 5 is a perspective diagram of planes of incidence of the beamsplitter subassemblies of FIGS. 4 and 6.
FIG. 6 is a perspective diagram of four beamsplitter cubes in a subassembly of the fourth-order beamsplitter assembly of FIG. 3.
FIG. 7 is a perspective diagram of four beamsplitter cubes in a subassembly of the fourth-order beamsplitter assembly of FIG. 3.
FIG. 8 is a perspective diagram of four beamsplitter cubes in a subassembly of the fourth-order beamsplitter assembly of FIG. 3.
FIG. 9 is a perspective diagram of four beamsplitter cubes in a subassembly of the fourth-order beamsplitter assembly of FIG. 3.
FIG. 10 is a perspective diagram of planes of incidence of the beamsplitter subassemblies of FIGS. 7, 8, and 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 through 10 of the drawings depict various preferred embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein.
The preferred embodiment of the present invention is a beamsplitter assembly comprised of several beamsplitter cubes arranged to define a plurality of polarization-balanced light paths. First, a three-cube, second-order beamsplitter assembly with two balanced outputs will be described with respect to FIGS. 1 and 2. Then, a thirteen-cube, fourth-order beamsplitter assembly with six balanced outputs will be described with respect to FIGS. 3-10.
As shown in FIGS. 1 and 2, a three-cube, second-order beamsplitter assembly 10 includes beamsplitter cubes 12, 14, and 16, and two polarization-balanced outputs 18 and 20. Beamsplitter cube 12 is a first-order cube that receives an incident beam 22, while beamsplitter cubes 14 and 16 are second-order cubes that receive incident beams output from the first-order cube 12. Beamsplitter cube 12 receives the incident beam 22 and splits it into a transmitted beam 24 and a reflected beam 26. A partially reflective plane 28 is contained in beamsplitter cube 12, as well as the other beamsplitter cubes described herein. Preferably, all of the beamsplitters cubes are identical, non-polarizing beamsplitters that perform an approximately equal 50/50 split of an incident beam into transmitted and reflected beams.
Beamsplitter cube 14 receives the transmitted beam 24 from beamsplitter cube 12, and splits it into a transmitted beam 18 that is polarization-balanced and a reflected beam 30 that is not polarization-balanced. Beamsplitter cube 14 has a beam-entry face 32 where the incident beam enters the cube, a transmission face 34 where the transmitted beam 18 leaves the cube, and a reflection face 36 where the reflected beam 30 leaves the cube. As used herein, a "transmission" face is a face where a transmitted beam exits the cube, while a "reflection" face is a face where a reflected beam exits the cube. All of the beamsplitter cubes have comparable beam-entry, transmission, and reflection faces. Beamsplitter cube 16 receives the reflected beam 26 from beamsplitter cube 12, and splits it into a transmitted beam 38 and a reflected beam 20. Output beam 20 is polarization-balanced, while transmitted beam 38 is not polarization balanced.
Transmitted beam 18 is polarization balanced because the polarization effect of beamsplitter cube 12 on the transmitted beam 24 is balanced by an orthogonal polarization effect of beamsplitter cube 14. Transmitted beams 24 and 18 form a balanced pair of light paths. Likewise, reflected beam 20 is polarization balanced because the polarization effect of beamsplitter cube 12 on the reflected beam 26 is balanced by an orthogonal polarization effect of beamsplitter cube 16. Reflected beams 26 and 20 form a balanced pair of light paths.
Polarization balancing is illustrated in FIG. 2. Any polarization in the incident beam 22 can be resolved along two orthogonal axes, an s-component axis 40 and a p-component axis 42. The s-component axis 40 is perpendicular to an incident plane 44 of beamsplitter cube 12 and the p-component axis 42 is parallel to the incident plane 44. An incident plane is that plane which contains both an incident beam and a reflected beam; incident plane 44 contains incident beam 22 and reflected beam 26. The polarization effect of beamsplitter cube 12 is such that the s-component of the incident beam 22 is reflected more effectively than it is transmitted, and the p-component of the incident beam is transmitted more effectively than it is reflected. Consequently, the transmitted beam 24 has less s-component and more p-component than does the reflected beam 26. Transmitted beam 24 and reflected beam 26, therefore, are not polarization balanced.
Beamsplitter cubes 14 and 16 are so oriented to balance the polarization effect of beamsplitter cube 12. Beamsplitter cube 14 has an incident plane 46 that is orthogonal to the incident plane 44 of beamsplitter cube 12. The s-component of the transmitted beam 24 (along axis 40) becomes the p-component of incident beam 48 relative to beamsplitter cube 14, since the two incident planes 44 and 46 are orthogonal. Likewise, the p-component of the transmitted beam 24 (along axis 42) becomes the s-component of incident beam 48 relative to beamsplitter cube 14. Beamsplitter 14 has a balancing effect, because the transmitted output 18 has gone through two orthogonal transmissions. The second transmission in beamsplitter cube 14 is more effective along axis 40 than along axis 42, which is opposite to and balances with the effect of the first transmission in beamsplitter cube 12.
If the incident beam 22 is assumed to be polarized along the s-axis 40, then the transmitted beam 18 has undergone an s-type transmission in beamsplitter cube 12 and a p-type transmission in beamsplitter cube 14. This is denoted herein as "TsTp." The transmitted beams 24 and 18 and their associated light paths through the beamsplitter cubes 12 and 14 make up a balanced pair of transmission light paths that define a polarization-balanced light path. The reflected beam 30 of beamsplitter cube 14 is denoted "TsRp," and is not polarization-balanced.
In similar fashion, the reflected beam 20 of beamsplitter cube 16 is polarization balanced. Incident plane 50 of beamsplitter cube 16 is orthogonal to the incident plane 44 of beamsplitter cube 12. The s-component (along axis 40) of the reflected beam 26 from beamsplitter cube 12 becomes the p-component of incident beam 52 relative to beamsplitter cube 16, since the two incident planes 44 and 50 are orthogonal. Likewise, the p-component of beam 26 becomes the s-component of incident beam 52 relative to beamsplitter cube 16. Beamsplitter 16 has a balancing effect, because the reflected output 20 has gone through two orthogonal reflections. The second reflection in beamsplitter cube 16 is more effective in the p-direction than in the s-direction, which is opposite to and balances with the effect of the first reflection in beamsplitter cube 12.
If the incident beam 22 is assumed to be polarized along the s-axis 40, then the reflected beam 20 has undergone an s-type reflection in beamsplitter cube 12 and a p-type reflection in beamsplitter cube 16. This is denoted herein as "RsRp." The reflected beams 26 and 20 and their associated light paths through the beamsplitter cubes 12 and 14 make up a balanced pair of reflection light paths that define a polarization-balanced light path. The transmitted beam 38 of beamsplitter cube 16 is denoted "RsTp," and is not polarization-balanced.
A thirteen-cube, fourth-order beamsplitter assembly 100 with six balanced outputs 102-107 is illustrated in FIG. 3. Beamsplitter assembly 100 includes a first-order beamsplitter cube 112 that receives an incident light beam 110, two second-order beamsplitter cubes 114, 116 adjacent to the first-order cube, four third-order beamsplitter cubes 118, 120, 122, and 124 adjacent to the second-order cubes, and six fourth-order beamsplitter cubes 126, 128, 130, 132, 134, and 136 adjacent to the third-order cubes. Beamsplitter cubes 112, 114, and 116 correspond to beamsplitter cubes 12, 14, and 16, respectively, of FIG. 1.
If the incident beam 110 is assumed to be polarized along an s-axis 140 (relative to plane of incidence of beamsplitter cube 112), then the balanced outputs are defined as follows:
Balanced output 102 is created by an s-type transmission in beamsplitter cube 112, a p-type transmission in beamsplitter cube 114, an s-type transmission in beamsplitter cube 118, and a p-type transmission in beamsplitter cube 126. This is denoted as "TsTpTsTp." The light path of balanced output beam 102 includes two balanced pairs of transmission light paths through beamsplitters 112, 114, 118, and 126.
Balanced output 103 is created by an s-type transmission in beamsplitter cube 112, a p-type transmission in beamsplitter cube 114, an s-type reflection in beamsplitter cube 118, and a p-type reflection in beamsplitter cube 128. This is denoted as "TsTpRsRp." The light path of balanced output beam 103 includes a balanced pair of transmission light paths through beamsplitters 112 and 114, and a balanced pair of reflection light paths through beamsplitters 118 and 128.
Balanced output 104 is created by an s-type transmission in beamsplitter cube 112, a p-type reflection in beamsplitter cube 114, a p-type transmission in beamsplitter cube 120, and an s-type reflection in beamsplitter cube 130. This is denoted as "TsRpTpRs." The light path of balanced output beam 104 includes a balanced pair of transmission light paths through beamsplitters 112 and 120, and a balanced pair of reflection light paths through beamsplitters 114 and 130.
Balanced output 105 is created by an s-type reflection in beamsplitter cube 112, a p-type reflection in beamsplitter cube 116, a p-type transmission in beamsplitter cube 124, and an s-type transmission in beamsplitter cube 136. This is denoted as "RsRpTpTs." The light path of balanced output beam 105 includes a balanced pair of reflection light paths through beamsplitters 112 and 116, and a balanced pair of transmission light paths through beamsplitters 124 and 136.
Balanced output 106 is created by an s-type reflection in beamsplitter cube 112, a p-type reflection in beamsplitter cube 116, a p-type reflection in beamsplitter cube 124, and an s-type reflection in beamsplitter cube 134. This is denoted as "RsRpRpRs." The light path of balanced output beam 106 includes two balanced pairs of reflection light paths through beamsplitters 112, 116, 124, and 134.
Balanced output 107 is created by an s-type reflection in beamsplitter cube 112, a p-type transmission in beamsplitter cube 116, a p-type reflection in beamsplitter cube 122, and an s-type transmission in beamsplitter cube 132. This is denoted as "RsTpRpTs." The light path of balanced output beam 107 includes a balanced pair of reflection light paths through beamsplitters 112 and 122, and a balanced pair of transmission paths through beamsplitters 116 and 132.
In addition to the balanced outputs 102-107, the beamsplitter assembly 100 also generates outputs that are not polarization balanced. These unbalanced outputs are attenuated by absorbing beam blocks 142 applied to the appropriate faces of the beamsplitter cubes. Absorbing beam block 142 is preferably anodized aluminum.
In order to clarify the construction of the beamsplitter assembly 100, FIGS. 4-10 illustrate various subassemblies of the whole beamsplitter assembly. FIG. 4 shows the beamsplitter cubes that generate balanced outputs 102 and 104. Balanced output 102 is created by a transmission 150 through beamsplitter cube 112, a balancing transmission 152 through beamsplitter cube 114, a transmission 154 through beamsplitter cube 118, and a balancing transmission 156 through beamsplitter cube 126. The light path of balanced output beam 102 includes a balanced pair of transmission light paths through beamsplitters 112 and 114, and another balanced pair of transmission light paths through beamsplitters 118 and 126.
FIG. 4 also illustrates that balanced output 104 is created by transmission 150 through beamsplitter cube 112, a reflection 158 through beamsplitter cube 114, a balancing transmission 160 through beamsplitter cube 120, and a balancing reflection 162 through beamsplitter cube 130. The light path of balanced output beam 104 includes a balanced pair of transmission light paths through beamsplitters 112 and 120, and a balanced pair of reflection light paths through beamsplitters 114 and 130. Beams reflected from beamsplitter 126, reflected from beamsplitter 120, and transmitted by beamsplitter 130 are not balanced and are attenuated by absorbing beam blocks 142.
Beamsplitter cube 118 generates a reflected beam 166 in addition to the transmitted beam 154. FIGS. 5-6 illustrate the further splitting of beam 166 into balanced output 103. Absorbing beam blocks 142 attenuate the emission of unbalanced light beams.
As shown in FIG. 5, beamsplitters 112, 114, 118, 120, 126, 128, and 130 have associated planes of incidence 168, 170, 172, 174, 176, 178, 180, respectively, each plane containing an incident beam and a reflected beam. Note that the four transmission light paths 150, 152, 154, and 156 that define balanced output beam 102 pass through two pairs of orthogonal incident planes: (168, 170) and (172, 176). As to balanced output 104, note that the incident planes 168 and 174 of the two transmission light paths 150 and 160, respectively, are orthogonal, as are the incident planes 170 and 180 of the two reflection light paths 158 and 162. Each orthogonal pair of incident planes balances the polarizing effects of the beamsplitters.
The beamsplitters that create balanced output 103 are illustrated in FIG. 6. Balanced output 103 is created by a transmission 150 through beamsplitter cube 112, a balancing transmission 152 through beamsplitter cube 114, a reflection 166 through beamsplitter cube 118, and a balancing reflection 182 through beamsplitter cube 128. The light path of balanced output beam 103 includes a balanced pair of transmission light paths 150 and 152 through beamsplitters 112 and 114, and a balanced pair 166 and 182 of reflection light paths through beamsplitters 118 and 128. A beam transmitted through beamsplitter 128 is not balanced and is attenuated by absorbing beam block 142. As shown in FIG. 5, the incident planes 168 and 170 of the transmission light paths 150 and 152 are orthogonal, and the incident planes 172 and 178 of the reflection light paths 166 and 182 are orthogonal.
Beamsplitter cube 112 generates a reflected beam 164 in addition to the transmitted beam 150. FIGS. 7-10, described below, illustrate the further splitting of reflected beam 164 into balanced outputs 105-107.
The beamsplitters that create balanced output 105 are illustrated in FIG. 7. Balanced output 105 is created by a reflection 164 through beamsplitter cube 112, a balancing reflection 184 through beamsplitter cube 116, a transmission 186 through beamsplitter cube 124, and a balancing transmission 188 through beamsplitter cube 136. The light path of balanced output beam 105 includes a balanced pair of reflection light paths 164 and 184 through beamsplitters 112 and 116, and a balanced pair of transmission light paths 186 and 188 through beamsplitters 124 and 136. Beamsplitter 124 also generates a reflection 190, which is used to generate balanced output 106, as shown in FIG. 8. Beamsplitter 116 also generates a transmission 192, which is used to generate balanced output 107, as shown in FIG. 9. A beam reflected from beamsplitter 136 is not balanced and is attenuated by absorbing beam block 142.
The beamsplitters that create balanced output 106 are illustrated in FIG. 8. Balanced output 106 is created by a reflection 164 through beamsplitter cube 112, a balancing reflection 184 through beamsplitter cube 116, a reflection 190 through beamsplitter cube 124, and a balancing reflection 194 through beamsplitter cube 134. The light path of balanced output beam 106 includes a balanced pair of reflection light paths 164 and 184 through beamsplitters 112 and 116 and another balanced pair of reflection light paths 190 and 194 through beamsplitters 124 and 134. A beam transmitted through beamsplitter 134 is not balanced and is attenuated by absorbing beam block 142.
The beamsplitters that create balanced output 107 are illustrated in FIG. 9. Balanced output 107 is created by a reflection 164 through beamsplitter cube 112, a transmission 192 through beamsplitter cube 116, a balancing reflection 196 through beamsplitter cube 122, and a balancing transmission 198 through beamsplitter cube 132. The light path of balanced output beam 107 includes a balanced pair of reflection light paths 164 and 196 through beamsplitters 112 and 122, and a balanced pair of transmission paths 192 and 198 through beamsplitters 116 and 132. A beam transmitted through beamsplitter cube 122 and a beam reflected by beamsplitter cube 132 are not balanced and are attenuated by absorbing beam blocks 142.
FIG. 10 illustrates the incident planes for the beamsplitter cubes that generate balanced outputs 105, 106, and 107. As shown in FIG. 10, beamsplitter cubes 112, 116, 122, 124, 132, 134, and 136 have associated planes of incidence 168, 202, 204, 206, 208, 210, and 212, respectively, where each plane is defined by an incident beam and a reflected beam. In generating balanced output 105, the incident planes 168 and 202 of the two reflection light paths 164 and 184, respectively, are orthogonal, as are the incident planes 206 and 212 of the two transmission light paths 186 and 188. The four reflection light paths 164, 184, 190, and 194 that define balanced output beam 106 pass through two pairs of orthogonal incident planes: (168, 202) and (206, 210). As to balanced output 107, note that the incident planes 168 and 204 of the two reflection light paths 164 and 196, respectively, are orthogonal, as are the incident planes 202 and 208 of the two transmission light paths 192 and 198. Each orthogonal pair of incident planes balances the polarizing effects of the beamsplitter cubes.
The thirteen cube configuration of FIGS. 3-10 is especially efficient in creating six balanced outputs with a minimum number of beamsplitters and a minimum loss of power. If the three-cube configuration of FIGS. 1-2 were used as a basic building block, then a four output assembly could be constructed from nine cubes, with each output passing through four cubes. To obtain six polarization-balanced outputs, one could add two more three-cube configurations to two of the balanced outputs of the nine-cube configuration for a total of fifteen cubes. Such a fifteen-cube configuration would have two balanced outputs passing through four cubes and four balanced outputs passing through six cubes. Such a configuration is less desirable than the thirteen cube configuration of FIGS. 3-10 because more cubes are needed and because the power of four of the outputs is further attenuated.
From the above description, it will be apparent that the invention disclosed herein provides a novel and advantageous beamsplitter assembly that creates a plurality of polarization-balanced light paths. The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. As will be understood by those familiar with the art, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.
The particular orientations of the beamsplitter cubes described herein could be changed, so long as the polarization cancellation effects described herein are maintained. For example, certain cubes such as cube 16 (FIG. 1) could be turned upside-down so that balanced output 20 exits downward instead of upward. As another example, the "RsRpRpRs" orientation of the beamsplitters that produces balanced output 106 (FIG. 8) could be reconfigured as any of the following orientations: "RsRpRsRp," "RsRsRpRp," "RpRsRpRs," "RpRsRsRp," or "RpRpRsRs." Furthermore, sixth-order or eighth-order beamsplitter assemblies could be constructed using the principles disclosed herein to provide more outputs. Non-polarizing or partially polarizing beamsplitters can be used. The outputs need not be equal, and it is contemplated that unequal outputs could be obtained by using partially polarizing beamsplitters, or different numbers of balancing pairs of beamsplitters, or reflectances other than the 50% reflectance beamsplitters disclosed herein.
Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims. | A beamsplitter assembly that includes several beamsplitter cubes arranged to define a plurality of polarization-balanced light paths. Each polarization-balanced light path contains one or more balanced pairs of light paths, where each balanced pair of light paths includes either two transmission light paths with orthogonal polarization effects or two reflection light paths with orthogonal polarization effects. The orthogonal pairing of said transmission and reflection light paths cancels polarization effects otherwise caused by beamsplitting. | 6 |
BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure relates to heat dissipating devices, and particularly, to a heat dissipating device having a bracket.
[0003] 2. Description of the Related Art
[0004] It is important to dissipate heat from an electronic device, such as a server chassis or a computer chassis. One way to dissipate heat from an electronic device is to fix a fan to a thermal sink of a central processing unit (CPU). Another way is to fix a fan to an inner wall of the computer chassis. However, the fan needs to be fixed at a specific position of the computer chassis causing limitations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is an exploded, isometric view of an exemplary embodiment of a heat dissipating device, the heat dissipating device including a latching member.
[0006] FIG. 2 is an inverted, enlarged view of the latching member of FIG. 1 .
[0007] FIG. 3 is an assembled, isometric view of the heat dissipating device of FIG. 1 .
[0008] FIG. 4 is an exploded, isometric view of a board and the heat dissipating device of FIG. 3 .
[0009] FIG. 5 is an assembled view of the board and the heat dissipating device of FIG. 4 .
DETAILED DESCRIPTION
[0010] Referring to FIG. 1 , an exemplary embodiment of a heat dissipating device 100 includes a heat dissipating element such as a fan 10 and a bracket 60 . The bracket 60 includes a first fixing portion 20 and a second fixing portion 30 . The fan 10 defines four fixing holes 12 in four corners of the fan 10 .
[0011] The first fixing portion 20 includes a frame 22 and two screw pillars 28 . The frame 22 includes a bottom wall 21 , a top wall 23 parallel to the bottom wall 21 , two sidewalls 24 connecting to corresponding ends of the bottom wall 21 and the top wall 23 , and a flange 25 extending from corresponding sides of the bottom wall 21 , the top wall 23 , and the sidewalls 24 to form an annular part at a side of the first fixing portion 20 . A receiving cavity 26 is bounded by the bottom wall 21 , the top wall 23 , the end walls 24 , and the flange 25 , and configured to receive the fan 10 . An edge of the flange 25 bounds to define an opening 252 , corresponding to the fan 10 . Two through holes 222 are defined in two opposite corners of the flange 25 . Two elongated locating grooves 224 are defined in the other two opposite corners of the flange 25 with one locating groove 224 being perpendicular to the bottom wall 21 . The other locating groove 224 is parallel to the bottom wall 21 . The screw pillars 28 are perpendicularly positioned under the bottom wall 21 , to support the frame 22 .
[0012] The second fixing portion 30 includes two spindle collars 34 , two latching members 36 , and two screw nuts 38 .
[0013] Referring to FIG. 2 , each of the latching members 36 includes a screw pole 361 and a latching portion 362 positioned at a first end of the screw pole 361 . The latching portion 362 includes a plurality of wedge-shaped elastic protrusions 364 distantly extending out from a circumference of the screw pole 361 towards a second end opposite to the first end of the screw pole 361 . Each protrusion 364 includes two guiding surfaces 365 , 366 at a top and a bottom of the protrusion 364 , respectively. The spindle collar 34 axially defines a threaded hole 342 , corresponding to the corresponding screw pillar 28 and the screw pole 361 of a corresponding latching member 36 .
[0014] Referring to FIG. 3 , in assembly, the fan 10 is received in the receiving cavity 26 of the first fixing portion 20 and fixed in the first fixing portion 20 via four elastic pins 40 passing through the locating grooves 224 and the through holes 222 of the frame 22 to engage in the fixing holes 12 of the fan 10 . The screw nuts 38 fit about the screw poles 361 of the latching members 36 . The screw pillars 28 and the screw poles 361 of the latching members 36 are engaged in the corresponding spindle collars 34 from opposite ends of the spindle collars 34 . In other embodiments, the fan 10 with other dimensions can be fixed in the first fixing member 20 via adjusting positions of the pins 40 in the locating grooves 224 .
[0015] Referring to FIGS. 4 and 5 , in use, the heat dissipating device 100 is mounted to a board 50 , such as a motherboard of a computer, that defines two through holes 52 in the vicinity of a central processing unit (CPU) (not shown) set on the board 50 . A diameter of each through hole 52 is smaller than a diameter of the latching portion 362 of the corresponding latching member 36 . In other embodiments, the through holes 52 can be located on other positions of the board 50 according to need.
[0016] The latching portions 362 of the locating members 36 are inserted through the through holes 52 of the board 50 to deform the protrusions 364 via sidewalls bounding the through holes 52 resisting against the guiding surfaces 365 of the protrusions 364 of the latching members 36 . The screw nuts 38 are adjusted to firmly resist against the board 50 , therefore firmly engaging the board 50 together with the latching portions 362 of the latching member 36 .
[0017] The heat dissipating device 100 can be disengaged from the through holes 52 of the board 50 via the sidewalls bounding the through holes 52 resisting against the guiding surfaces 366 of the protrusions 364 of the latching members 36 to deform the latching portions 362 .
[0018] In one embodiment, a distance between the fan 10 and the board 50 can be adjusted via rotating the spindle collars 34 . In other embodiments, the screw pillars 28 and the spindle collars 34 can be omitted, and two spindle collars 34 having threaded holes 342 are mounted to the bottom wall 21 of the frame 22 to engagably fit about the screw poles 361 of the latching members 36 . A fixing block can directly extend from the screw pole 361 of each latching member, to replace the corresponding screw nut 38 . Accordingly, a distance between the fixing block and the latching portion 362 is about equal to a thickness of the board 50 .
[0019] It is to be understood, however, that even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structure and function of the embodiments, the disclosure is illustrative only, and changes may be made in details, especially in matters of shape, size, and arrangement of parts within the principles of the embodiments to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. | A heat dissipating device includes a heat dissipating element and a bracket. The bracket includes a first fixing portion and a second fixing portion. The first fixing portion is to fix the heating dissipating element. The second fixing portion is movably mounted to the first fixing portion. The second fixing portion is configured to fix the bracket to another apparatus to adjust a distance between the heat dissipating element and the apparatus. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an apparatus that eliminates the laser in an Optical Network Unit (ONU) in a Wave Division Multiplexed (WDM) Passive Optical Network (PON).
[0003] 2. Description of the Related Art
[0004] Optical networks have become a standard technology for the transport of information in the telecommunications industry. A number of different optical network standards have been defined, with each having advantages and disadvantages for different uses. Synchronous optical network (SONET) is one standard for optical telecommunications transport. SONET is often used for long-haul, metro level, and access transport applications.
[0005] Another standard for optical telecommunications transport is passive optical networks (PONs). PONs are commonly used to address the last mile of the communications infrastructure between the service provider's central office, head end, or point of presence (POP) and business or residential customer locations. Also known as the access network or local loop, the last mile consists predominantly, in residential areas, of copper telephone wires or coaxial cable television (CATV) cables. In metropolitan areas, where there is a high concentration of business customers, the access network often includes high-capacity synchronous optical network (SONET) rings, optical T3 lines, and copper-based T1s.
[0006] Bandwidth is increasing dramatically on long-haul networks through the use of wavelength division multiplexing (WDM) and other new technologies. Recently, WDM technology has even begun to penetrate metropolitan-area networks (MAN), boosting their capacity dramatically. At the same time, enterprise local-area networks (LAN) have moved from 10 Mbps to 100 Mbps, and soon many LANs will be upgraded to gigabit Ethernet speeds. The result is a growing gulf between the capacity of metro networks on one side and end-user needs on the other, with the last-mile bottleneck in between.
[0007] PONs are one solution to this problem in an attempt to break the last-mile bandwidth bottleneck that other access network technologies do not adequately and economically address.
[0008] Important parts of the PON architecture are the Optical Network Unit (ONU) and the Optical Line Termination (OLT), which are active network elements located at end points of a PON. The OLT provides an interface for data to be transmitted over the PON. The ONU provides an interface between the customer's data, video, and telephony networks and the PON. The primary function of the ONU is to receive traffic in an optical format and convert it to the customer's desired format. Many PONs use wavelength division multiplexing (WDM) of multiple signals over each optical fiber. WDM PON provides dedicated optical wavelengths in each direction, for each ONU. This provides improved operations over other types of PON, where the same wavelength(s) are shared by up to 32 (or more) ONU's. However, a typical implementation of WDM PON requires a tuned narrowband laser in the ONU, and a fixed narrowband laser in the OLT dedicated to each ONU. This results in too costly an implementation for access applications. Most PON's today aren't based on WDM PON due to cost, they are APON, EPON, etc where ONU's share wavelengths in both directions. Thus, a need arises for a technique that can both eliminate tuned lasers in the ONU's and also provide shared optical carrier sources for the OLT's.
SUMMARY OF THE INVENTION
[0000] Shared Multi-Lambda Source for PON
[0009] The present invention eliminates tuned lasers in the ONU's and also provide shared optical carrier sources for the OLT's.
[0010] In one embodiment of the present invention, an apparatus comprises a plurality of optical carrier generators, each optical carrier generator outputting an optical carrier at a different wavelength, an optical multiplexer operable to combine the plurality of optical carriers to form a wave division multiplexed optical carrier, and an optical power splitter having a plurality of outputs, each output connectable to an optical line termination unit, the optical power splitter operable to split the wave division multiplexed optical carrier to form a plurality of wave division multiplexed optical carriers.
[0011] In one aspect of the present invention, each optical carrier generator comprises a narrowband laser. The apparatus further comprises an optical amplifier operable to amplify at least one of the plurality of wave division multiplexed optical carriers. The apparatus further comprises a protection switch operable to provide switching between working and protect optical WDM carriers. At least some of the optical line termination unit are in separate physical enclosures.
[0000] Avoiding ONU Laser by Optical Modulation and Remodulation
[0012] The present invention eliminates tuned lasers in the ONU's and also provide shared optical carrier sources for the OLT's.
[0013] In one embodiment of the present invention, a method of communicating over a passive optical network comprises generating an optical signal modulated with a first data signal at a first network element, transmitting the modulated optical signal over the passive optical network from the first network element to a second network element, remodulating the received modulated optical signal with a second data signal at the second network element, and transmitting the remodulated optical signal from the second network element to the first network element.
[0014] In one embodiment of the present invention, an apparatus for communicating over a passive optical network comprises a transmitting portion operable to generate an optical signal modulated with a first data signal and to transmit the modulated optical signal over the passive optical network and a receiving portion operable to receive an optical signal comprising the transmitted optical signal remodulated with a second data signal.
[0015] In one aspect of the present invention, the transmitting portion comprises an optical modulator operable to modulate an unmodulated optical signal with the first data signal. The first data signal comprises a line code signal having a symbol rate greater than a symbol rate of the first data. The receiving portion comprises an optical demodulator operable to demodulate the received optical signal to recover the second data signal.
[0016] In one embodiment of the present invention, an apparatus for communicating over a passive optical network comprises a receiving portion operable to receive an optical signal modulated with a first data signal over the passive optical network, a remodulating portion operable to remodulate the received optical signal with a second data signal, and a transmitting portion operable to transmit the remodulated optical signal over the passive optical network.
[0017] In one aspect of the present invention, the receiving portion comprises a power splitter operable to split the received optical signal between the receiving portion and the remodulating portion and a line code demodulator operable to detect the first data signal from the received optical signal. The optical signal modulated with the first data signal comprises a training interval and the line code demodulator further comprises a framing device operable to identify the training interval. The receiving portion further comprises circuitry operable to output a signal phase locked to the training interval signal that is locked to the downstream frame and clock identified by the framing device.
[0018] In one aspect of the present invention, the remodulating portion comprises a line code modulator operable to remodulate the received optical signal with a second data signal based on the signal phase locked to the training interval signal. The remodulating portion comprises a line code modulator operable to remodulate the received optical signal with a second data signal
[0019] In one aspect of the present invention, the transmitting portion comprises an optical amplifier operable to amplify the remodulated optical signal.
[0020] In one embodiment of the present invention, an apparatus for communicating over a passive optical network comprises a beamsplitter operable to split a received optical signal between a receiving portion and a remodulating portion, a remodulating portion operable to remodulate the received optical signal with a second data signal, and a photodetector operable to detect the first data signal from the received optical signal.
[0021] In one aspect of the present invention, the remodulating portion comprises a silicon optical amplifier reflective operable to receive the modulated optical signal from the beamsplitter, to remodulate the received optical signal with the second data signal, and to reflect the remodulated optical signal back to the beamsplitter.
[0000] Eliminating ONU Laser for WDM PON by Burst Mode
[0022] The present invention eliminates tuned lasers in the ONU's and also provide shared optical carrier sources for the OLT's.
[0023] In one embodiment of the present invention, a method of communicating over a passive optical network comprises generating at a first network element an optical signal comprising a first portion modulated with a first data signal and a second portion that is unmodulated, transmitting the optical signal over the passive optical network from the first network element to a second network element, modulating the second portion of the received optical signal with a second data signal at the second network element, and transmitting the modulated second portion of the received modulated optical signal from the second network element to the first network element.
[0024] In one embodiment of the present invention, an apparatus for communicating over a passive optical network comprises a transmitting portion operable to generate an optical signal comprising a first portion modulated with a first data signal and a second portion that is unmodulated and to transmit the optical signal over the passive optical network and a receiving portion operable to receive an optical signal comprising the second portion of the transmitted optical signal modulated with a second data signal.
[0025] In one aspect of the present invention, the transmitting portion comprises an optical modulator operable to modulate the first portion of an unmodulated optical signal with the first data signal and to not modulate the second portion of the unmodulated optical signal.
[0026] In one aspect of the present invention, the receiving portion comprises an optical demodulator operable to demodulate the received optical signal to recover the second data signal.
[0027] In one embodiment of the present invention, an apparatus for communicating over a passive optical network comprises a receiving portion operable to receive an optical signal comprising a first portion modulated with a first data signal and a second portion that is unmodulated over the passive optical network, a modulating portion operable to modulate the second portion of the received optical signal with a second data signal to form a second optical signal, and a transmitting portion operable to transmit the second optical signal over the passive optical network.
[0028] In one aspect of the present invention, the receiving portion comprises a power splitter operable to split the received optical signal between the receiving portion and the remodulating portion and a demodulator operable to detect the first data signal from the received optical signal. The demodulator further comprises a framing device operable to identify the second portion of the received optical signal.
[0029] In one aspect of the present invention, the modulating portion comprises a modulator operable to modulate the second portion of the received optical signal with a second data signal based on the identification of the second portion of the received optical signal from the framing device. The transmitting portion comprises an optical amplifier operable to amplify the second optical signal.
[0030] In one embodiment of the present invention, an apparatus for communicating over a passive optical network comprises a beamsplitter operable to split a received optical signal between a receiving portion and a modulating portion, the received optical signal comprising a first portion modulated with a first data signal and a second portion that is unmodulated, a modulating portion operable to modulate the second portion of the received optical signal with a second data signal to form a second optical signal, and a photodetector operable to detect the first data signal from the received optical signal.
[0031] In one aspect of the present invention, the modulating portion comprises a silicon optical amplifier reflective operable to receive the second portion of the optical signal from the beamsplitter, to modulate the second portion of the optical signal with the second data signal to form the second optical signal, and to reflect the second optical signal back to the beamsplitter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 a is an exemplary block diagram of a WDM PON system, in which the present invention may be implemented.
[0033] FIG. 1 b is an exemplary block diagram of a WDM PON system, in which the present invention may be implemented.
[0034] FIG. 2 is an exemplary block diagram of a shared lambda source shown in FIG. 1 b.
[0035] FIG. 3 is an exemplary block diagram of a PON system, in which the present invention may be implemented.
[0036] FIG. 4 is an exemplary format of a line code that may be used in an embodiment of the present invention.
[0037] FIG. 5 is an exemplary block diagram of optical and electrical components in an OLT that that may be used to implement the present invention.
[0038] FIG. 6 a is an exemplary block diagram of optical and electrical components in an ONU that that may be used to implement the present invention.
[0039] FIG. 6 b is an exemplary block diagram of optical and electrical components in an ONU that that may be used to implement the present invention.
[0040] FIG. 6 c is an exemplary illustration of a downstream training signal used for phase locking in an embodiment of the present invention.
[0041] FIG. 6 d is an exemplary illustration of a downstream training signal used for phase locking in an embodiment of the present invention.
[0042] FIG. 6 e is an exemplary illustration of a downstream training signal used for phase locking in an embodiment of the present invention.
[0043] FIG. 7 is an exemplary format of signals that may be used in an embodiment of the present invention.
[0044] FIG. 8 is an exemplary block diagram of optical and electrical components in an ONU that that may be used to implement the present invention.
[0045] FIG. 9 is an exemplary block diagram of optical and electrical components in an OLT that that may be used to implement the present invention.
[0046] FIG. 10 is an exemplary block diagram of optical and electrical components in an ONU that that may be used to implement the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] An exemplary PON system 100 , in which the present invention may be implemented, is shown in FIG. 1 a . One or more Optical Line Termination Units (OLTs) 102 provide the interface with data to be transmitted over the Optical Distribution Network (ODN) 104 to the Optical Network Unit (ONU) 106 portion of the PON. The passive elements of the PON are located in ODN 104 and may include single-mode fiber-optic cable, and passive optical devices such as splitters/couplers, connectors, multiplexers, and splices. In the example shown in FIG. 1 a , ODN 104 includes lambda multiplexer 105 and a number of optical fibers.
[0048] The ONU 106 portion of the PON includes one or more ONUs that provide the interface between the customer's data, video, and telephony networks and the PON. The primary function of an ONU is to receive traffic in an optical format and convert it to the end user's desired format and to receive traffic from the end user and convert it to an optical format. Alternatively, the end user's format is typically an electrical format, such as Ethernet, IP multicast, POTS, T1, etc., but the end user's format may be an optical format, such as SONET/SDH.
[0049] The exemplary PON system 100 , in which the present invention may be implemented, is shown in more detail in FIG. 1 b . OLT 102 includes or is connected to a shared lambda source 108 . Shared lambda source 108 includes a plurality of single wavelength optical carrier generators such as optical carrier generators 108 - 1 to 108 - 32 . Each optical carrier generator outputs an optical carrier at a different wavelength. In the example shown in FIG. 1 b , there are 32 optical carrier generators shown as an example. However, the present invention contemplates usage of any number of optical carrier generators. The optical carrier generators are typically narrowband lasers. Shared lambda source 108 also includes lambda multiplexer 110 , which multiplexes the plurality of optical carriers from optical carrier generators 108 - 1 to 108 - 32 onto a single optical fiber, to form a wavelength division multiplex (WDM) carrier on the optical fiber. Shared lambda source 108 also includes optical power splitter 112 , which splits the WDM carrier into a plurality of WDM carrier, each of which may be used by a particular PON. Optionally, optical amplifiers may be used to amplify the plurality of WDM carrier, if higher WDM carrier amplitude is needed for a particular application. Optical amplifiers are typically used to compensate for losses incurred in the power splitters. In addition, if shared source 108 is used to provide a WDM carrier to multiple OLTs in different physical enclosures, then preferably shared source 108 includes a protection switch to provide switching between the working and protect optical WDM carriers. It is to be noted that the need for protection may apply even if shared source 108 and the OLTs are in the same location. Typically, shared lambda source 108 provides optical carriers having wavelengths in a range from 1525 to 1565 nm. However, this is merely an example. The present invention contemplates operations over any range of optical wavelengths.
[0050] OLT 102 includes a plurality of Semiconductor Optical Amplifier Reflective (SOAR) devices 114 - 1 to 114 - 32 , a plurality of photodetector circuits 116 - 1 to 116 - 32 , lambda multiplexers 118 and 120 , and optical circulators 122 and 124 . A WDM carrier from one tap of optical power splitter 112 is input to input 122 - 1 of optical circulator 122 . The WDM carrier is circulated from input 122 - 1 to input/output 122 - 2 , where the WDM carrier is output to lambda multiplexer/demultiplexer 118 . The WDM carrier is demultiplexed by lambda multiplexer/demultiplexer 118 and separated into a plurality of narrow wavelength carriers. Each narrow wavelength carrier is input to a SOAR device 114 - 1 to 114 - 32 , where it is modulated with data to be transmitted over the PON. A modulated narrow wavelength signal is output from each SOAR device 114 - 1 to 114 - 32 and input to lambda multiplexer/demultiplexer 118 . These may be termed the OLT modulated signals. The input OLT modulated signals are multiplexed in lambda multiplexer/demultiplexer 118 to form a modulated WDM signal. This may be termed the OLT WDM signal. The OLT WDM signal is output from lambda multiplexer/demultiplexer 118 and input to input/output 122 - 2 of optical circulator 122 . The OLT WDM signal is circulated in optical circulator 122 and output from output 122 - 3 of optical circulator 122 . The OLT WDM signal is input to input 124 - 1 of optical circulator 124 , circulated and output from input/output 124 - 2 of optical circulator 124 . The OLT WDM signal is carried via ODN 104 to the ONU 106 portion of the PON.
[0051] The modulation present in the OLT modulated signals varies in different embodiments of the present invention. In some embodiments, the narrow wavelength signal is not modulated 100% of the time, but rather, unmodulated or continuous-wave (CW) portions of the narrow wavelength signal may be output from one or more SOAR devices 114 - 1 to 114 - 32 . For simplicity, the signal output from a SOAR device in the OLT is referred to as an OLT modulated signal, even if it includes unmodulated or CW portions.
[0052] A second modulated WDM signal is also carried via ODN 104 from the ONU 106 portion of the PON to OLT 102 . This second modulated WDM signal is termed the ONU WDM signal. The ONU WDM signal is input to input 124 - 2 of optical circulator 124 , circulated and output from output 124 - 3 of optical circulator 124 . The second ONU WDM signal is demultiplexed by lambda multiplexer/demultiplexer 120 and separated into a plurality of modulated narrow wavelength signals. Each modulated narrow wavelength signal is input to a photodetector 116 - 1 to 116 - 32 , where the data modulated onto the signal is detected. Each photodetector outputs an electrical signal carrying the data stream extracted from its input modulated narrow wavelength signal.
[0053] ODN 104 includes the passive elements of one or more PONs. ODN 104 may include single-mode fiber-optic cable, and passive optical devices such as splitters/couplers, connectors, multiplexers, and splices. Active network elements, such as OLT 102 and the ONU 106 portion of the PON, are located at the end points of the PON. Optical signals traveling across the PON are either split onto multiple fibers or combined onto a single fiber by optical splitters/couplers, depending on whether the light is traveling up or down the PON. The PON is typically deployed in a single-fiber, point-to-multipoint, tree-and-branch configuration for residential applications. OLTs may also be connected in a protected ring architecture for business applications or in a bus architecture for campus environments and multiple-tenant units (MTU).
[0054] As shown in FIG. 1 b , ODN 104 includes lambda multiplexer/demultiplexer 105 and a plurality of optical fibers 128 . Lambda multiplexer/demultiplexer 105 receives a modulated WDM signal from OLT 102 and demultiplexes it to from a plurality of modulated narrow wavelength signals, each of which is transmitted over an optical fiber 128 . Likewise, lambda multiplexer/demultiplexer 105 receives a modulated narrow wavelength signal from each optical fiber 128 and multiplexes them to form a modulated WDM signal that is transmitted to OLT 102 . In this way, ODN 104 provides bi-directional optical communications paths.
[0055] The ONU 106 portion of the PON includes one or more ONUs 130 - 1 to 130 - 32 . Each modulator/detector unit, such as modulator detector unit 130 - 1 , includes a beam splitter 132 - 1 , a SOAR device 134 - 1 , and a photodetector 136 - 1 . Beam splitter 132 is an optical device that splits a beam of light in two. In its most common form, it is a cube, made from two triangular glass prisms that are glued together at their base using a resin. The thickness of the resin layer is adjusted such that approximately half of the light incident through one “port” (i.e. face of the cube) is reflected and the other half is transmitted. Another possible design is the use of a “half-silvered mirror”. This is a plate of glass with a thin coating of silver (usually deposited from silver vapor) with the thickness of the silver coated such that of light incident at a 45 degree angle, one half is transmitted and one half it reflected. Instead of a silver coating, a dielectric optical coating may be used instead. In order to be usable with the present invention, beamsplitter 132 must work over the range of optical wavelengths generated by the OLT, since the same ONU may be connected to any of the wavelengths generated by the OLT.
[0056] An OLT modulated signal, which is a modulated narrow wavelength signal generated in OLT 102 , is output from an optical fiber, such as fiber 128 and is input to a beam splitter, such as beam splitter 132 - 1 . A portion of the OLT modulated signal is output to SOAR device 134 - 1 and a portion of the OLT modulated signal is output to photodetector 136 - 1 . The data modulated onto the OLT modulated signal is detected by photodetector 136 - 1 . Each photodetector outputs an electrical signal carrying the data stream extracted from its input OLT modulated signal. Thus, photodetector 136 - 1 extracts the data transmitted over one wavelength of one fiber of the PON from OLT 102 to ONU 106 .
[0057] The OLT modulated signal is also input to SOAR device 134 - 1 . As noted above, the modulated narrow wavelength signal may include some unmodulated or CW portions. These unmodulated or CW portions of the OLT modulated signal are modulated in the SOAR device 134 - 1 based on input electrical signals that carry data to be modulated onto the optical signal. The portions of an OLT modulated signal that are modulated by SOAR device 134 - 1 are termed an ONU modulated signal. The ONU modulated signal is output from SOAR device 134 - 1 , passes through beam splitter 132 - 1 , and is transmitted over optical fiber 128 to lambda multiplexer/demultiplexer 105 . The plurality of ONU modulated signals from modulator detector units 130 - 1 to 130 - 32 are multiplexed by lambda multiplexer/demultiplexer 105 to form a WDM signal termed the ONU WDM signal. As described above, the ONU WDM signal is input to input 124 - 2 of optical circulator 124 , circulated and output from output 124 - 3 of optical circulator 124 . The second ONU WDM signal is demultiplexed by lambda multiplexer/demultiplexer 120 and separated into a plurality of modulated narrow wavelength signals. Each modulated narrow wavelength signal is input to a photodetector 116 - 1 to 116 - 32 , where the data modulated onto the signal is detected. Each photodetector outputs an electrical signal carrying the data stream extracted from its input modulated narrow wavelength signal.
[0058] An example of a shared lambda source 108 is shown in FIG. 2 . Shared lambda source 108 includes a plurality of single wavelength optical carrier generators such as optical carrier generators 108 - 1 to 108 -K. In the example shown in FIG. 2 , there are K optical carrier generators shown as an example. However, the present invention contemplates usage of any number of optical carrier generators. The optical carrier generators are typically narrowband lasers. Shared lambda source 108 also includes lambda multiplexer 110 , which multiplexes the plurality of optical carriers from optical carrier generators 108 - 1 to 108 -K onto a single optical fiber 202 , to form a wavelength division multiplexed (WDM) carrier on the optical fiber 202 . Shared lambda source 108 also includes optical power splitter 112 , which splits the WDM carrier into a plurality of WDM carriers, each of which may be routed to an OLT. In the example shown in FIG. 2 , optical power splitter 112 routes the WDM carriers to N OLTs. However, the present invention contemplates routing to any number of OLTs. Optionally, optical amplifier 204 may be used to amplify the plurality of WDM carriers, if higher WDM carrier amplitude is needed for a particular application. Optical amplifier 204 is typically used to compensate for losses incurred in the power splitters. In addition, if shared source 108 is used to provide a WDM carrier to multiple OLTs in different physical enclosures, then preferably shared source 108 includes a protection switch to provide switching between the working and protect optical WDM carriers. It is to be noted that the need for protection may apply even if shared source 108 and the OLTs are in the same location. Typically, shared lambda source 108 provides optical carriers having wavelengths in a range from 1525 to 1565 nm. However, this is merely an example. The present invention contemplates operations over any range of optical wavelengths.
[0059] An exemplary PON system 300 , in which the present invention may be implemented, is shown in FIG. 3 . In this example, one or more OLTs 102 provide the interface with data to be transmitted over the Optical Distribution Network (ODN) 104 to the Optical Network Unit (ONU) 106 portion of the PON. OLT 102 provides interconnection with electrical networks, such as Ethernet, optical networks, such as SONET, and receives a plurality of optical carriers from a shared lambda source. The passive elements of the PON are located in ODN 104 and may include single-mode fiber-optic cable, and passive optical devices such as splitters/couplers, connectors, multiplexers, and splices. In the example shown in FIG. 1 a , ODN 104 includes a plurality of cascaded lambda multiplexers and a number of optical fibers.
[0060] The ONU 106 portion of the PON includes one or more ONUs that provide the interface between the customer's data, video, and telephony networks and the PON. The primary function of an ONU is to receive traffic in an optical format and convert it to an electrical signal in the end user's desired format and to receive traffic as an electrical signal from the end user and convert it to an optical signal and format. Typically, the end user's format is an electrical format, such as Ethernet, IP multicast, POTS, T1, etc., but alternatively, the end user's format may be an optical format, such as Ethernet over fiber.
[0061] As described above, the modulation performed in the OLT varies in different embodiments of the present invention. In one embodiment, the optical signal modulated in the OLT is transmitted to the ONU, where the modulated signal is remodulated and transmitted back to the OLT. The operation of this embodiment may be termed “modulation—remodulation”. An example of the operation of modulation—remodulation is shown in FIG. 4 . In this example, a downstream signal is modulated to carry data in the OLT and transmitted to the ONU. At the ONU, the data carried by the signal is recovered, and the downstream signal is remodulated to carry data to form an upstream signal that is transmitted to the OLT. At the OLT, the data carried by the upstream signal is recovered.
[0062] In the example shown in FIG. 4 , a data bit “0” is modulated onto the downstream signal using a line code of “01” 402 , while a data bit “1” is modulated onto the downstream signal using a line code of “10” 404 . When the downstream signal is received at the ONU, the ONU remodulates the signal to carry upstream data. In this example, a data bit “0” is remodulated onto the upstream signal using a line code of “00” 406 , while a data bit “1” is remodulated onto the upstream signal using a line code of “01” 408 or “10” 410 . The upstream line code is obtained by multiplying the downstream line code by full bit period “0” (modulator switch off), or full bit period “1” (modulator switch on). Either “01” 408 or “10” 410 is read by the OLT as a “1” from the ONU.
[0063] It is seen that in this example, the downstream line code is twice the frequency of information bit rate. In this example, a 310 MHz line code, which provides a 155 Mbs data rate, is shown. It is to be noted that these rates and line codes are merely examples, the present invention is not limited to these rates and line codes. Rather, the present invention contemplates any and all rates and line codes for data transmission.
[0064] The modulation—remodulation technique may be implemented in the embodiment of the present invention shown in FIG. 1 b . Likewise, the modulation—remodulation technique may be implemented in the embodiment of the present invention shown in FIG. 5 , which is an exemplary block diagram of optical and electrical components in OLT 500 .
[0065] OLT 500 includes an optical power splitter 502 , a lambda demultiplexer 504 , a plurality of optical modulators 506 - 1 to 506 -K, a lambda multiplexer 508 , an optical amplifier 510 , an optical coupler 512 , a lambda demultiplexer 514 , and a plurality of optical demodulators/CDRs 516 - 1 to 516 -K. An unmodulated WDM carrier (including a plurality of optical carriers) is input to optical power splitter 502 , which splits the WDM carrier into a plurality of WDM carriers, each of which may be used by a particular PON. One or more optical amplifiers may be used to amplify the WDM carrier, if higher WDM carrier amplitude is needed for a particular application. In addition, since the WDM carrier is provided to multiple PONs, a protection switch is included to provide switching between the working and protect optical WDM carriers.
[0066] The unmodulated WDM carrier is input to lambda demultiplexer 504 , which separates the signal into a plurality of narrow wavelength carriers. Each narrow wavelength signal is input to an optical modulator 506 - 1 to 506 -K, where it is modulated with data to be transmitted over the PON. A modulated narrow wavelength signal is output from each optical modulator 506 - 1 to 506 -K and input to lambda multiplexer 508 . These may be termed the OLT modulated signals. The input OLT modulated signals are multiplexed in lambda multiplexer 508 to form a modulated WDM signal. This may be termed the OLT WDM signal. The OLT WDM signal is output from lambda multiplexer 508 and input to optical amplifier 510 , where the signal is amplified for transmission over the optical fiber. The amplified signal is input to optical coupler 512 , where it is coupled onto the optical fiber for transmission to the ONU.
[0067] Turning briefly to FIG. 6 a , an example of optical and electrical components in an ONU 600 , in which the modulation—remodulation technique may be implemented, is shown. The ONU shown in FIG. 6 a operates in conjunction with the embodiment of the OLT shown in FIG. 5 . ONU 600 includes optical coupler 602 , optical power splitter 604 , line code demodulator 606 , line code modulator 608 , and optical amplifier 610 . The signal from the OLT is received over the optical fiber and input to optical coupler 602 . The signal is input to optical power splitter 604 , which transmits the signal to line code demodulator 606 and line code modulator 608 . Line code demodulator 606 demodulates the optical signal and extracts the downstream data and clock signals from the optical signal. The downstream data and clock signals are output from line code demodulator 606 as electrical signals.
[0068] Line code modulator 608 remodulates the optical signal with upstream data according to the line code modulation scheme shown in FIG. 4 , or another equivalent scheme. The upstream data is input to line code modulator 608 as an electrical signal. Line code modulator 608 syncs to the downstream optical line code, then multiplies signal by upstream electrical bits (1 or 0). Thus, multiplying the downstream line code (01 or 10) by two periods of “0” (00) results in upstream modulation of “00”. Likewise, multiplying the downstream line code (01 or 10) by two periods of “1” (11) results in upstream modulation of “01” or “10”. Accurate phase alignment is required for upstream modulation.
[0069] The remodulated optical signal is input to optical amplifier 610 , which amplifies the optical signal and outputs the signal to coupler 602 . Coupler 602 couples the amplified remodulated signal onto the optical fiber for transmission to the OLT.
[0070] Returning to FIG. 5 , the upstream, remodulated signal is received at coupler 512 , which outputs the upstream signal to lambda demultiplexer 514 . Lambda demultiplexer 514 separates the signal into a plurality of narrow wavelength remodulated signals. Each modulated narrow wavelength signal is input to an optical demodulator/CDR 516 - 1 to 516 -K, where the data modulated onto the signal is detected. Each photodetector outputs an electrical signal carrying the data stream extracted from its input modulated narrow wavelength signal.
[0071] There are additional considerations related to the modulation-remodulation example described above. At the end of a received frame, a training interval is provided, which is a fixed downstream 1,0,1,0 . . . pattern. The training interval is a small fraction in bandwidth of the frame payload. Consistent with the normal payload, each “0” is a (0,1) at double line rate and each “1” is a (1,0) at double line rate. During the training interval, the ONU sends upstream a 1,0,1,0 . . . pattern. Consistent with normal payload, each 1 is a full period 1, each 0 is a full period 0. The receiving framer identifies the portion of time dedicated to the training interval.
[0072] An example of ONU circuitry 650 that can provide the accurate phase alignment that is required for upstream modulation is shown in FIG. 6 b . ONU circuitry 650 includes optical coupler 652 , optical power splitter 654 , photodetector 656 , line code decoder and framer 658 , ONU transmit electrical circuitry 660 , line code modulator and optical amplifier 662 , optical power splitter 664 , photodetector and amplifier 666 , field-effect transistor (FET) 668 , low pass filter 670 , DC amplifier 672 , and voltage-control crystal oscillator (VCXO) 674 . The operation of ONU 650 is similar to that of ONU circuitry 600 , shown in FIG. 6 a , with additional functionality. As shown in FIG. 6 b , during the training interval, a sampling FET 668 is turned on, so as to pass the recovered electrical signal from the line code modulator 662 (via the photo detector 666 ). The sampled signal is filtered by a low pass filter 670 , such that the DC output of the filter is a measure of the duty cycle of the optical pulses. The filter's electrical output is then amplified and fed to a VCXO 674 to create a phase lock loop.
[0073] Referring briefly to FIG. 6 c , an example of a downstream training signal 680 is shown. In this example, downstream training signal 680 includes a series of 1s and 0s, which is a square wave of 50% duty cycle. An upstream modulating signal 681 , which, in this example, is in correct phase alignment with the downstream training signal 680 , is shown. The downstream training signal 680 is modulated (anded) with the upstream modulating signal 681 to form upstream modulated signal 682 . With upstream modulating signal 681 in correct phase alignment with the downstream training signal 680 , upstream modulated signal 682 has a duty cycle of 25%.
[0074] The DC output of low pass filter 670 is a measure of the duty cycle of the optical pulses of upstream modulated signal 682 . For example, referring to FIG. 6 d , upstream modulating signal 683 is early relative to downstream training signal 680 . When downstream training signal 680 is modulated with upstream modulating signal 683 , the resulting upstream modulated signal has a duty cycle greater than 25%. Alternatively, referring to FIG. 6 e , upstream modulating signal 685 is late relative to downstream training signal 680 . When downstream training signal 680 is modulated with upstream modulating signal 683 , the resulting upstream modulated signal has a duty cycle less than 25%. In either case, the feedback loop is designed to drive the duty cycle to ¼ during the training interval, thereby assuring phase alignment for the re-modulation.
[0075] Between training intervals, the FET 668 is turned off, such that the filter retains its DC value during the rest of the frame. The total phase control can optionally utilize the following: analog to digital converter, digital processor, and digital to analog converter. This could be used between the filter 670 output and the VCXO 674 , or between the DC AMP 672 output and the VCXO 674 .
[0076] As described above, the modulation performed in the OLT varies in different embodiments of the present invention. In one embodiment, the narrow wavelength signal is not modulated 100% of the time, but rather, unmodulated or continuous-wave (CW) portions of the narrow wavelength signal may be output from the OLT. The unmodulated portions of the narrow wavelength signal are modulated by the ONU and transmitted to the OLT. The operation of this embodiment may be termed “ping-pong”. An example of the operation of the ping-pong technique is shown in FIG. 7 . In this example, the OLT transmits a burst of modulated optical signal followed by a period of unmodulated optical signal. The optical signal is received by the ONU, which demodulates the modulated portion of the optical signal and extracts the downstream data, and which modulates the unmodulated portion of the optical signal with upstream data, and transmits the upstream modulated optical signal to the OLT.
[0077] In the example shown in FIG. 7 , an effective data rate of 310 Mbs in each of the upstream and downstream directions is achieved with the use of transmission bursts at 622 Mbs for one half of the time. It is to be noted that these rates and timings are merely examples, the present invention is not limited to these rates and timings. Rather, the present invention contemplates any and all rates and timings for data transmission. For example, other transmission duty cycles are possible and may be advantageous for various reasons, such as to reduce the effect of reflections on the system performance.
[0078] As shown in FIG. 7 , the OLT transmits a burst of modulated optical signal 702 . In this example, the burst includes 8 STS3 frames of data transmitted at a 622 Mbs rate. This burst lasts 250 μS. The OLT then transmits a period 704 of unmodulated optical signal, which lasts 250 μS. The unmodulated optical signal 704 A is received at the ONU at a time that is dependent upon the length of the optical fiber connecting the OLT and the ONU, and upon the time delays of the other optical components in the path, such as lambda multiplexers and demultiplexers, optical power splitters, couplers, circulators, etc. The ONU then modulates the unmodulated optical signal 704 A and transmits the modulated upstream signal 704 B to the OLT. There is some time delay in the optical path in the ONU and time delay in the return path back to the OLT. After this total path delay, the ONU burst 706 is received at the OLT.
[0079] This embodiment assumes the optical return loss as seen by an OLT is not severe enough to prevent reliable detection of desired the ONU upstream optical signal, and similarly reflections as seen at the ONU are not severe enough to prevent reliable detection of the OLT downstream signal
[0080] The ping-pong technique may be implemented in the embodiment of the present invention shown in FIG. 1 b . Likewise, the ping-pong technique may be implemented in the embodiment of the present invention shown in FIG. 8 , which is an exemplary block diagram of optical and electrical components in ONU 800 .
[0081] ONU 800 includes coupler 802 , optical power splitter 804 , optical to electrical receiver 806 , downstream framer 808 , upstream framer 810 , electrical transmitter 812 , optical modulator 814 , and optical amplifier 816 . The optical signal from the OLT is input to coupler 802 and thence to optical power splitter 804 , which transmits the signal to optical to electrical receiver 806 and optical modulator 814 . Optical to electrical receiver 806 demodulates the optical signal and extracts the downstream data and clock signals from the optical signal. The downstream data and clock signals are output from optical to electrical receiver 806 as electrical signals. These electrical signals are input to downstream framer 808 , which detects the start and/or end of the downstream frames and outputs a timing signal 818 that is used by upstream framer 810 to set the start of the upstream frames. Upstream data is input to upstream framer 810 and assembled into frames in accordance with the timing indicated by signal 818 . At the appropriate time, the upstream frames are input to electrical transmitter 812 , which drives the electrical input of optical modulator 814 .
[0082] Optical modulator 814 modulates the unmodulated optical signal from optical power splitter 804 with upstream data as framed by and at the time controlled by upstream framer 810 . The upstream data is input to optical modulator 814 as an electrical signal. The modulated optical signal is input to optical amplifier 816 , which amplifies the optical signal and outputs the signal to coupler 802 . Coupler 802 couples the amplified remodulated signal onto the optical fiber for transmission to the OLT.
[0083] An example of optical and electrical components in an OLT 900 , in which the ping-pong technique may be implemented, is shown in FIG. 9 . OLT 900 includes an optical power splitter 902 , a lambda demultiplexer 904 , a plurality of optical modulators 906 - 1 to 906 -K, a lambda multiplexer 908 , an optical amplifier 910 , an optical coupler 912 , a lambda demultiplexer 914 , a plurality of optical receivers 916 - 1 to 916 -K, and a plurality of upstream framers. An unmodulated WDM signal (including a plurality of optical carriers) is input to optical power splitter 902 , which splits the WDM signal into a plurality of WDM signals, each of which may be used by a particular PON. One or more optical amplifiers may be used to amplify the WDM signal, if higher WDM signal amplitude is needed for a particular application. In addition, since the WDM signal is provided to multiple PONs, a protection switch is included to provide switching between the working and protect optical WDM carriers.
[0084] The unmodulated WDM signal is input to lambda demultiplexer 904 , which separates the signal into a plurality of narrow wavelength signals. Each narrow wavelength signal is input to an optical modulator 906 - 1 to 906 -K, where it is modulated with data to be transmitted over the PON. A modulated narrow wavelength signal is output from each optical modulator 906 - 1 to 906 -K and input to lambda multiplexer 908 . These may be termed the OLT modulated signals. The input OLT modulated signals are multiplexed in lambda multiplexer 908 to form a modulated WDM signal. This may be termed the OLT WDM signal. The OLT WDM signal is output from lambda multiplexer 908 and input to optical amplifier 910 , where the signal is amplified for transmission over the optical fiber. The amplified signal is input to optical coupler 912 , where it is coupled onto the optical fiber for transmission to the ONU.
[0085] The upstream modulated signal is received at coupler 912 , which outputs the upstream signal to lambda demultiplexer 914 . Lambda demultiplexer 914 separates the signal into a plurality of narrow wavelength remodulated signals. Each modulated narrow wavelength signal is input to an optical receiver 916 - 1 to 916 -K, where the data modulated onto the signal is detected. Each photodetector outputs an electrical signal carrying the data stream extracted from its input modulated narrow wavelength signal.
[0086] Each electrical signal carrying the data stream extracted from its input modulated narrow wavelength signal is input to an upstream framer, which detects the start and/or end of the upstream frames and outputs the data in these frames as electrical signals. In the ping-pong technique, the OLT and ONU bursts require preambles for clock recovery and start of burst detection. Once the OLT acquires burst start, it starts looking for burst start in the next frame a few microseconds before the expected start of burst. This reduces the likelihood of false sync detection.
[0087] There are additional considerations related to the ping-pong example described above. In particular, it is preferred that the data clock of the downstream data is recovered at the ONU and used as the data clock for the upstream data as well. In order to accomplish this, a circuit such as that shown in FIG. 10 may be used. An example of ONU clock recovery and holdover circuitry 1000 is shown in FIG. 10 . The circuitry shown in FIG. 10 may be used in conjunction with the ONU circuitry shown in FIG. 1 b , or with some minor modifications, with the ONU circuitry shown in FIG. 9 .
[0088] ONU block diagram including clock recovery and holdover circuitry 1000 includes SOAR device 1002 , transmitter electronics 1004 , first-in, first-out (FIFO) buffer 1006 , photodetector, amplifier, and line clock recovery circuitry 1008 , beam splitter 1010 , phase detector 1012 , FET 1013 , framer 1014 , low pass filter 1016 , amplifier 1018 , and VCXO 1020 .
[0089] Downstream data passes thru beam splitter 1010 to photo detector, amplifier, and line clock recovery circuitry 1008 . The line clock recovery function may be performed, for example, by a wideband phase-locked loop (PLL). Photo detector, amplifier, and line clock recovery circuitry 1008 has electrical outputs including a line data output and a line clock output. The line data output and a line clock output are both input to FIFO 1006 and framer 1014 , while the line clock output alone is input to phase detector 1012 . The output of phase detector 1012 is fed thru a FET 1013 to low pass filter 1016 . FET 1013 is controlled by framer 1014 so that the ONU clock generation loop only functions while a downstream burst is received. Between downstream bursts, FET 1013 is opened to allow holdover of the state of the ONU clock loop. The VCXO 1020 output is a continuous ONU clock that traces its reference to the clock rate of the downstream burst. This clock is used to read out downstream data from the FIFO 1006 . This clock is also clock for transmitter electronics 1004 . It is possible to optionally utilize the following: analog to digital converter, digital processor, and digital to analog converter. This could be used between the low pass filter 1016 output and VCXO 1020 , or between the subsequent amplifier 1018 and the VCXO 1020 . The transmitter electronics 1004 , using the ONU clock, outputs electrical data to modulate the SOAR device 1002 , which sends modulated light upstream via the beam splitter 1010 .
[0090] Although specific embodiments of the present invention have been described, it will be understood by those of skill in the art that there are other embodiments that are equivalent to the described embodiments. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrated embodiments, but only by the scope of the appended claims. | Tuned lasers in the ONU's are eliminated in WDM PON by use of a burst mode transmission. An apparatus for communicating over a passive optical network comprises a transmitting portion operable to generate an optical signal comprising a first portion modulated with a first data signal and a second portion that is unmodulated and to transmit the optical signal over the passive optical network and a receiving portion operable to receive an optical signal comprising the second portion of the transmitted optical signal modulated with a second data signal. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a novel synthesis of aluminoxanes. Aluminoxanes are well known as components for olefin polymerization catalysts.
Aluminoxane compounds are chemical species that incorporate Al--O--Al moieties. While a wide range of aluminoxane species are known their exact structures are not precisely known. The following structures (where R is alkyl and X is an integer of from about 1 to about 40) have been depicted: ##STR1## Cyclic and cage cluster structures have also been proposed. Such materials, as would be recognized by the person of ordinary skill in the art are complex mixtures of various species which can easily undergo dynamic exchange reactions and structural rearrangements. A recent review of these materials was authored by S. Pasynkiewicz and appears in Polyhedron, Vol. 9, pp. 429-453 (1990).
Polymethylaluminoxanes (PMAOs), for example, are well known materials with wide utility in olefin polymerization using single-site, or metallocene-based, polymerization catalyst systems (See, for example, Col. 1, lines 14-29 of U.S. Pat. No. 4,960,878 to C. C. Crapo et al.). PMAOs are prepared by controlled hydrolysis of trimethylaluminum (TMAL). Since TMAL is an expensive starting material, the resulting PMAO is expensive. Generally, hydrolysis occurs with some loss of aluminum to insoluble species. Generally, PMAOs also have very low solubility in aliphatic solvents, which limits their utility, as well as poor storage stability for solutions containing them. (See, for example, Col. 1, lines 30-46 of U.S. Pat. No. 4,960,878). Finally, it is generally polymethylaluminoxanes that have been the most useful products of this general class of material: other alkylaluminoxanes do not work as well.
The problems of low yield, poor solubility, poor storage stability, and expensive reagents in preparation of PMAO have previously been attacked, with only limited success, in several ways. One method was to make predominantly PMAO, but include some components from hydrolysis of other aluminum alkyls, to form the so-called "modified methylaluminoxane" (MMAO). This yields predominantly methyl-containing aluminoxanes in improved yields, with improved solution storage stability as well as improved solubility in aliphatic solvents, at lower cost. However, since alkyl groups other than methyl are present, these materials are not always as effective as conventional PMAO.
The prior art contains certain disclosures germane to the composition derived from the instant invention. For example, U.S. Pat. No. 5,329,032 to N. H. Tran illustrates, in Col. 7, the addition of triethylsilanol, as a solution stabilizer additive, at 1 mole %, to a toluene solution containing PMAO, with a generic description of using such solution stabilizer additives at from 0.1 mole % to 10 mole % (at Col. 3, lines 25-27). The composition formed by such processes would form trialkylsiloxide (R 3 SiO--Al) moieties in the aluminoxanes. Also relevant to the composition of the instant invention is European Patent Application 621 279 (issued in the US as U.S. Pat. No. 5,391,529), to S. A. Sangokoya, which discloses the treatment of aluminoxanes with alkyldisiloxanes to form siloxy aluminum compounds. The aforementioned patent, U.S. Pat. No. 5,329,032, teaches that solution stabilizer additives can be introduced "(1) by originally reacting and/or complexing trimethylaluminum, the compound containing the electron rich heteroatom and the selected hydrocarbyl moiety or moieties, and water as reagents; or (2) by combining . . . with a pre-formed aluminoxane" (Col. 2, line 2).
None of these disclosures address the problem of improving the yield of soluble aluminoxane.
SUMMARY OF THE INVENTION
The present invention, in one embodiment, relates to a process for forming a composition comprising oligomeric alkylaluminoxane and moieties having the structure --OSiR 3 , where R, which can be the same or different, is hydrocarbyl, such as lower alkyl, such as methyl. This process comprises initially treating a composition comprising trialkylaluminum with a reagent containing an aluminum trialkyl siloxide moiety, such as dimethyl aluminum trimethyl siloxide, followed by oxygenation.
Oxygenation of trialkylaluminum compositions has often been accomplished by the addition of water in some form. Copending U.S. Ser. No. 08/576,892, filed Dec. 22, 1995 shows that oxygenation can also be accomplished using a non-hydrolytic process. In regard to the present invention, oxygenation should therefore be construed as covering any method for introducing the aluminoxane moieties into the desired composition.
DESCRIPTION OF PREFERRED EMBODIMENTS
While broader aspects of the process of the present invention relate to use of a trialkylaluminum reagent or even triaryl or alkyl-aryl aluminum reagents, it is preferred to utilize trimethylaluminum as the organoaluminum compound in such a process. Hence, the remaining discussion will focus on such a preferred embodiment, although it is to be understood that the process claims contained herein are not so limited.
As just mentioned, a preferred embodiment of the present invention relates to a process for forming a composition comprising oligomeric methylaluminoxane and moieties having the structure Al--OSi(R) 3 , where R is methyl or a mixture of methyl and hydrocarbyl, which comprises initially treating a composition comprising trimethylaluminum, in an appropriate organic solvent (aliphatic and/or aromatic, as known to the person of ordinary skill in the art), or in the absence of solvent, with a reagent containing the Al--O--SiR 3 moiety, followed by oxygenation to ultimately form a composition comprising oligomeric methylaluminoxane and moieties having the structure AlOSi(R) 3 , as earlier defined.
The present invention is most useful where an improved composition or process for a methylaluminoxane is needed, and the methylaluminum portion of the composition must remain relatively unmodified. The invention leaves the methylaluminum component (derived from the TMAL reagent) relatively unmodified, unless a higher alkyl group-containing hydrocarbylaluminum reagent is also used.
Once some aluminum trialkyl siloxide is introduced, for example, by treatment of TMAL with dimethylaluminum trimethylsiloxide (DMAL-S), this intermediate composition can be further oxygenated (forming additional aluminoxane). Because of the prior introduction of trialkyl siloxide moieties, the amount of water required for hydrolysis to catalytically useful aluminoxane compositions is reduced. This results in improved recovery of soluble aluminum, while still yielding good polymerization activity.
Other advantages of this invention include improved solubility, or storage stability, or both, for the aluminoxane product formed.
If desired, supported polyalkylaluminoxane compositions can be prepared by conducting the aforementioned reaction in the presence of a suitable support material. Alternatively, supported alkylaluminoxanes may also be prepared by forming the alkylaluminoxanes of this invention in a discrete, separate step and subsequently allowing the alkylaluminoxane to react with the support material. Oxidic support materials, such as silica, are especially preferred.
As will be appreciated by the person of ordinary skill in the art, the aluminoxane products that can be made by the process of the present invention are useful as cocatalysts in those single-site (metallocene-based) catalyst systems which are useful in the polymerization of olefin monomers in a manner analogous to that in current use with the aluminoxane compositions that are currently known and used in that manner.
The present invention is further exemplified by the Examples which follow.
EXAMPLES
Standard air-free glove box and Schlenk line techniques were used in these Examples. TMAL was provided by the Deer Park plant of Akzo Nobel Chemicals Inc. and contained 36.9 or 36.6 wt % Al. Dimethylaluminum trimethylsiloxide (DMAL-S) was prepared from dimethylaluminum chloride and sodium trimethylsiloxide, and sublimed before use. The DMAL-S was found to contain 17.75 wt % Al.
Comparative Example A, Examples 1-10
A series of trialkylaluminum compounds or mixtures of trialkylaluminum compounds were combined with solvent and charged to 130 mL glass serum capped vials. The solution of organoaluminum compounds was then cooled as required with a dry ice/isopropanol bath, and oxygenated by the slow dropwise addition of water. The water was added in small aliquots at reaction temperatures of from -50° to -25° C., with vigorous stirring, and the reaction allowed to warm to about 0° C. to permit complete reaction of each aliquot. This sequence of cooling and water addition was repeated until the entire charge of water had been added to the vial. This reaction can be exothermic and vigorous. Gas can be evolved. In many samples, solids formed. After the oxygenation was complete, the sample was allowed to settle, and the clear supernatant collected. The concentration of aluminum in the supernatant was assayed, and this result compared to the aluminum concentration calculated from aluminum charged and total sample mass. The aluminoxane product produced in each example was then evaluated in ethylene polymerizations with rac-ethylenebis-indenylzirconium dichloride at 85° C., an Al/Zr ratio of 1000, and an applied ethylene pressure of 150 psig. The reagents amounts and results are summarized in Tables 1 and 2.
TABLE 1__________________________________________________________________________TMAL DMAL-S toluene Water Water/Al O/Al soluble Al soluble Al(g) (g) (g) (g) mole/mole mole/mole recovery (%) found (wt %)__________________________________________________________________________Comparative 5.0.sup.1 0.0 45.1 0.62 0.51 0.51 80 2.9Example AComparative 5.0.sup.1 0.0 45.0 1.00 0.81 0.81 54 2.0Example BExample 1 2.5.sup.2 5.6 45.3 0.97 0.76 1.26 47 1.7Example 2 2.5.sup.2 5.6 45.0 0.61 0.48 0.98 72 2.6Example 3 2.4.sup.2 5.1 45.5 0.36 0.30 0.80 93 3.1Example 4 0.8.sup.2 2.5 25.5 0.15 0.30 0.90 91 2.3Example 5 2.5.sup.2 2.5 45.1 0.42 0.47 0.80 81 2.2Example 6 1.8.sup.2 2.5 30.9 0.29 0.39 0.79 86 2.7Example 7 0 10.9 48.3 0.60 0.46 1.46 100 3.3Example 8 0 10.8 48.3 0.95 0.74 1.74 100 3.3Example 9 0 5.0 22.8 0.06 0.10 1.10 100 3.2Example 10 0 3.9 23.2 0.12 0.25 1.25 100 2.6__________________________________________________________________________ .sup.1 36.9 wt % Al. .sup.2 36.6 wt % Al.
TABLE 2__________________________________________________________________________TMAL DMAL-S O/Al DMAL-S/TMAL Supernate Soluble Al Activity(g) (g) mole/mole mole/mole mass (g) recovery (%) (kg PE/g Zr hr)__________________________________________________________________________Comparative 5.0* 0.0 0.51 0/1 30.1 47 390Example AComparative 5.0* 0.0 0.81 0/1 26.5 29 590-640Example BExample 1 2.5† 5.6 1.26 1/1 29.5 26 0Example 2 2.5† 5.6 0.98 1/1 35.2 48 530-590Example 3 2.4† 5.1 0.80 1/1 40.3 70 390-430Example 4 0.8† 2.5 0.90 3/2 24.4 73 380Example 5 2.5† 2.5 0.80 2/1 39.5 64 570Example 6 1.8† 2.5 0.79 2/3 30.6 75 660Example 7 0 10.9 1.46 1/0 57.6 98 0Example 8 0 10.8 1.74 1/0 57.0 98 0Example 9 0 5.0 1.10 1/0 27.8 100 0Example 10 0 3.9 1.25 1/0 27.1 100 0__________________________________________________________________________ * = 36.9 wt % Al. † = 36.6 wt % Al.
Examples 1 through 6 show that with proper choice of reagent amounts, an aluminoxane composition with the same activity as conventional PMAO can be prepared in much higher yield by the process of this invention.
The foregoing Examples, since they merely illustrate certain embodiments of the present invention, should not be construed in a limiting sense. The scope of protection sought is set forth in the claims which follow. | A process is disclosed for forming an aluminoxane composition comprising methylaluminoxane by mixing trimethylaluminum, or a mixture of trimethylaluminum and one or more other trihydrocarbylaluminum compounds, with an organoaluminum compound containing a trialkylsiloxide moiety and then oxygenating the mixture to form the aluminoxane. Oxygenation can be carried out by controlled hydrolysis or by treatment with an organic compound containing carbon-oxygen bonds, such as carbon dioxide. A preferred trialkylsiloxide moiety is of the formula --OSi(CH 3 ) 3 , such as in a compound of the formula (CH 3 ) 2 AlOSi(CH 3 ) 3 . | 2 |
BACKGROUND OF THE PRIOR ART
1. Technical Field
This invention relates to a paper bulking promoter with which the sheets of paper obtained from a pulp feedstock can be bulky without impairing paper strength.
2. Description of the Prior Art
Recently, there is a desire for high-quality paper, e.g., paper excellent in printability and voluminousness. Since the printability and voluminousness of paper are closely related to the bulkiness thereof, various attempts have been made to improve bulkiness. Examples of such attempts include a method in which a crosslinked pulp is used (JP-A 4-185792, etc.) and a method in which a mixture of pulp with synthetic fibers is used as a feedstock for papermaking (JP-A 3-269199, etc.). Examples thereof further include a method in which spaces among pulp fibers are filled with a filler such as an inorganic (JP-A 3-124895, etc.) and a method in which spaces are formed (JP-A 5-230798, etc.). On the other hand, with respect to mechanical improvements, there is a report on an improvement in calendering, which comprises conducting calendering under milder conditions (JP-A 4-370298).
However, the use of a crosslinked pulp, synthetic fibers, etc. makes pulp recycling impossible, while the technique of merely filling pulp fiber spaces with a filler and the technique of forming spaces result in a considerable decrease in paper strength. Furthermore, the improvement in mechanical treatment produces only a limited effect and no satisfactory product has been obtained so far.
Also known is a method in which a bulking promoter is added during papermaking to impart bulkiness to the paper. Although fatty acid polyamide polyamines for use as such bulking promoters are on the market, use of these compounds results in a decrease in paper strength and no satisfactory performance has been obtained therewith.
SUMMARY OF THE INVENTION
The inventors have made intensive investigations in view of the problems described above. As a result, they have found that by incorporating at least one compound selected among specific cationic compounds, amine compounds, acid salts of amine compounds, amphoteric compounds, amide compounds, quaternary ammonium salts, and imidazoline derivatives, optionally together with at least one specific nonionic surfactant into a pulp feedstock, e.g., a pulp slurry, in the papermaking step, the sheet made from the feedstock can have improved bulkiness without detriment to paper strength. This invention has thus been achieved.
Namely, this invention provides a process for producing a bulky paper, comprising the step of making paper from pulp in the presence of a bulking promoter comprising at least one compound selected from the group consisting of a cationic compound, an amine compound, an acid salt of an amine compound, an amphoteric compound, an amide compound, a quaternary ammonium salt, and an imidazoline derivative.
The term “paper bulking promoter” used herein means an agent with which a sheet of paper obtained from a pulp feedstock can have a larger thickness (can be bulkier) than that having the same basis weight obtained from the same amount of a pulp feedstock.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Examples of the cationic compounds for use in this invention include compounds represented by the following formulae (a 1 ) and (b 1 ):
wherein R 11 and R 12 are the same as or different from each other, and an alkyl, alkenyl or β-hydroxyalkyl group having 8 to 24 carbon atoms; R 13 , R 14 and R 15 are the same as or different from each other, and an alkyl or hydroxyalkyl group having 1 to 8 carbon atoms, benzyl or —(AO)n 11 -Z 11 wherein AO is an oxyalkylene unit having 2 or 3 carbon atoms, Z 11 is a hydrogen atom or an acyl group and n 11 is an integer of 1 to 50; R 16 is an alkyl, alkenyl or β-hydroxyalkyl group having 8 to 36 carbon atoms; and X − is an anionic ion.
In the formula (a 1 ), R 11 and R 12 , which are the same or different, each preferably is an alkyl or alkenyl group having 10 to 22 carbon atoms. R 13 and R 14 , which are the same or different, each preferably is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Examples of X − , which is an anionic ion, include hydroxy, halide, and monoalkyl (C1-C3) sulfate ions and anions derived from inorganic or organic acids. X − is preferably a halide ion, especially Cl − .
In the formula (b 1 ), R 13 , R 14 , and R 15 , which are the same or different, each is preferably an alkyl group having 1 to 3 carbon atoms or a benzyl group. R 16 is preferably an alkyl group having 10 to 22 carbon atoms. Examples of the anionic ion X − are the same as those in the formula (a 1 ). X − is preferably a halide ion, especially Cl − .
In the present invention, the cationic compounds may include quaternary ammonium salts.
Hereinafter X − may be an anionic ion as an anionic ion.
Examples of the amine compounds and the acid salts of amine compounds for use in this invention include compounds represented by the following formulae (a 2 ) to (f 2 ):
wherein R 21 is an alkyl, alkenyl or β-hydroxyalkyl group having 8 to 36 carbon atoms; R 22 and R 23 are the same as or different from each other, and a hydrogen atom, an alkyl group having 1 to 24 carbon atoms or an alkenyl group having 2 to 24 carbon atoms; R 24 and R 25 are the same as or different from each other, and a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; HB represents an inorganic acid or an organic acid; AO is an oxyalkylene unit having 2 or 3 carbon atoms; l 21 and m 21 are 0 or a positive integer, and the sum in total of l 21 and m 21 is in an integer ranging from 1 to 300; and n 2 is a number of 1 to 4.
In the formulae (a 2 ) to (f 2 ), R 21 is preferably an alkyl group having 10 to 22 carbon atoms. R 22 and R 23 , which are the same or different, each preferably is a hydrogen atom or an alkyl group having 1 to 22 carbon atoms. In HB in the acid salts of amine compounds, B is preferably a halogen or a carboxylate having 2 to 5 carbon atoms, especially preferably a carboxylate having 2 or 3 carbon atoms. Preferred amine compounds and preferred acid salts of amine compounds are the compounds represented by the formulae (a 2 ) and (b 2 ), respectively.
The acid salt represented by the formula (b 2 ) may be signified by the following formula (b 21 ):
wherein R 21 , R 22 and R 23 are same as above-mentioned; H is hydrogen atom; and B − represents a base.
That is, the acid salt may be an ionized compound.
Examples of the amphoteric compounds for use in this invention include compounds represented by the following formulae (a 3 ) to (j 3 ):
wherein R 31 , R 32 and R 33 are the same as or different from each other, and an alkyl group having 1 to 24 carbon atoms or an alkenyl group having 2 to 24 carbon atoms; R 34 is an alkyl, alkenyl or β-hydroxyalkyl group having 8 to 36 carbon atoms; M is a hydrogen atom, an alkali metal atom, a half a mole of an alkaline earth metal atom or an ammonium group; Y 31 is R 35 NHCH 2 CH 2 —, wherein R 33 is an alkyl group having 1 to 36 carbon atoms, or an alkenyl or a hydroxy alkyl group having 2 to 36 carbon atoms; Y 32 is a hydrogen atom or R 35 NHCH 2 CH 2 —, R 35 being defined above; Z 31 is —CH 2 COOM, M being defined above; and Z 32 is a hydrogen atom or —CH 2 COOM, M being defined above.
In the formulae (a 3 ) to (j 3 ), R 31 , R 32 , and R 33 , which are the same or different, each preferably is an alkyl group having 1 to 22 carbon atoms. Especially preferably, R 31 is an alkyl group having 10 to 20 carbon atoms, and R 32 and R 33 each is an alkyl group having 1 to 3 carbon atoms. R 34 is preferably an alkyl group having 10 to 22 carbon atoms. Preferred amphoteric compounds are those represented by the formulae (a 3 ) and (b 3 ).
Examples of the other amine compounds and the other acid salts of an amine compound for use in this invention include compounds represented by the following formulae (a 4 ) to (d 4 ):
wherein R 41 is an alkyl, alkenyl or β-hydroxyalkyl having 8 to 35 carbon atoms; R 43 and R 44 are same as or different from each other, an alkyl, alkenyl or β-hydroxyalkyl group having 7 to 35 carbons atoms; R 46 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; R 45 is an alkyl group having 1 to 3 carbon atoms; R 42 is a hydrogen atom or R 47 , wherein R 47 is an alkyl, alkenyl or β-hydroxyalkyl group having 7 to 35 carbons atoms; Y 41 is a hydrogen or —COR 44 ; and Z 41 is —CH 2 CH 2 O(AO)n 41 -OCOR 47 , wherein A is a liner or branched alkylene unit having 2 to 3 carbon atoms, or —CH 2 CH(OH)—CH 2 OCOR 47 and n 41 is an average added-number ranging 1 to 20.
Examples of the amide compounds for use in this invention include compounds represented by the following formulae (a 5 ) and (b 5 ):
wherein R 51 and R 54 are same as or different from each other, an alkyl, alkenyl or β-hydroxyalkyl group having 7 to 35 carbon atoms; R 52 and R 53 are same as or different from each other, a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; and Y 51 and Y 52 are same as or different from each other, and a hydrogen atom, R 52 CO—, R 54 CO—, —(AO)n 51 -COR 55 , wherein A is a liner or branched alkylene unit having 2 to 3 carbon atoms n 51 is an average added-number ranging 1 to 20, and R 55 is an alkyl, alkenyl or β-hydroxyalkyl group having 7 to 35 carbon atoms, or —(AO)n 51 -H, wherein A and n 51 , are defined above.
Examples of the cationic compounds for use in this invention include quaternary ammonium salts represented by the following formulae (a 6 ) and (b 6 ):
wherein R 61 and R 63 are same as or different from each other, an alkyl, alkenyl or β-hydroxyalkyl group having 7 to 35 carbons atoms; R 65 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; R 62 and R 64 are same as or different from each other, an alkyl group having 1 to 3 carbon atoms; and X − is an anionic ion.
Examples of the imidazoline derivative for use in this invention include compounds represented by the following formulae (a 7 ):
wherein R 71 is an alkyl, alkenyl or β-hydroxyalkyl group having 7 to 35 carbons atoms.
The paper bulking promoter of this invention preferably further contains at least one specific nonionic surfactant. By the use of at least one of compounds represented by the above formulae (a 1 ) and (b 1 ) , (a 2 ) to (e 2 ), (a 3 ) to (h 3 ) , (a 4 ) to (d 4 ), (a 5 ) and (b 5 ), (a 6 ) and (b 6 ) , and (a 7 ); and at least one specific nonionic surfactant in combination, the effect of this invention can be improved. Examples of the nonionic surfactant for use in this invention include the following (A) to (C).
(A): a compound represented by the following formula (A)
R 81 O(EO) m 81 (PO) n 81 H (A)
wherein R 81 is a C6 to C22 straight or branched alkyl or alkenyl group or an alkylaryl group having a C4 to C20 alkyl group; E is an ethylene unit; P is a propylene unit; m 81 and n 81 are an average number of added moles, m 81 is a number in the range of 0 to 20 and n 81 is a number in the range of 0 to 50; and the addition form of EO and PO may be any of block and random and the addition order of EO and PO may be not limited.
The compounds represented by the formula (A) are ones each obtained by causing a higher alcohol, an alkylphenol, or the like in which the alkyl has 6 to 22 carbon atoms to add an alkylene oxide such as ethylene oxide (EO) or propylene oxide (PO). In this invention is used the compound in which the average number of moles of ethylene oxide added is in the range of 0≦m 81 ≦20. The range of the average number of moles added, m 81 , is preferably 0≦m 81 ≦10, more preferably 0≦m 81 ≦5. If m 81 exceeds 20, the effect of imparting bulkiness to paper is lessened. Further, the compound used is one in which the average number of moles of propylene oxide (PO) added, n 81 , is in the range of 0≦n 81 ≦50, preferably 0≦n 81 ≦20. When n 81 exceeds 50, such a compound is economically disadvantageous although the decrease in performance is little.
R 81 in the formula (A) is preferably a linear or branched, alkyl or alkenyl group having 8 to 18 carbon atoms. If R 81 in the formula (A) is an alkyl or alkenyl group in which the number of carbon atoms is outside the range of from 6 to 22 or if R 81 is an alkylaryl group in which the number of carbon atoms of the alkyl group is outside the range of from 4 to 20, then the compound is less effective in imparting bulkiness to paper
Examples of E and P in the formula (A), which each represents a linear or branched alkylene group having 2 or 3 carbon atoms, include ethylene and propylene. When the group (EO) m 81 (PO) n 81 in the formula (A) is composed of a combination of polyoxyethylene and polyoxypropylene, the C 2 H 4 O and C 3 H 6 O units may have any of random and block arrangements (or the addition form of EO and PO may be any of block and random). In this case, the polyoxypropylene (C 3 H 6 O) group(s) account for preferably at least 50 mol %, especially preferably at least 70 mol %, of all groups added on the average. The alkylene oxide group bonded to R may begin with any of EO and PO (or the addition order of EO and PO may be not limited).
(B): Compounds represented by the following formula (B)
R 81 COO(EO) m 81 (PO) n 81 R b (B)
wherein R 81 , E, P, m 81 and n 81 are the same as those of the formula (A); and R b is H, an alkyl, an alkenyl or an alkylaryl group.
Preferred examples of R 81 , E, P, m 81 , and n 81 in the formula (B) are the same as those in the formula (A). Examples of the alkyl and alkenyl groups represented by R b in the formula (B) include those having 1 to 4 carbon atoms, while examples of the alkylaryl group represented by R b include alkylphenyl groups in each of which the alkyl has 1 to 4 carbon atoms.
(C): a nonionic surfactant selected from the followings (1) to (3):
(1) an oil-fat type nonionic surfactant (i.e. a ninionic surfactant based on fat),
(2) a sugar-alcohol type nonionic surfactant (i.e. a nonionic surfactant based on sugar alcohol) and
(3) a sugar-type nonionic surfactant (1.e. a nonionic surfactant based on sugar).
(1) Nonionic Surfactants Based on Fat
Examples of the nonionic surfactants based on a fat (1) include ones obtained by mixing an alcohol having 1 to 14 hydroxy groups with a fat such as those given in, e.g., JP-A 4-352891 or with a product of the reaction of the fat with glycerol and causing the mixture to add an alkylene oxide (AO). Preferred is one obtained by causing a mixture of a fat and a polyhydric alcohol to add an AO. The AO is ethylene oxide (EO) and/or propylene oxide (PO). In the case of using both EO and PO, the EO/PO polymer may have any of random and block arrangements. The average number of moles of EO added is preferably 0 to 200, more preferably 10 to 100, while that of PO added is preferably 0 to 150, more preferably 2 to 100.
Examples of the fat usable for this type of nonionic surfactant include land animal fats, marine animal fats, hardened or semihardened oils obtained therefrom, and recovery oils obtained during the purification of these fats. Preferred examples thereof include coconut oil, beef tallow, fish oils, linseed oil, rapeseed oil, and castor oil. In the case where any of these fats is reacted beforehand with glycerol, the fat/glycerol ratio is preferably from 1/0.05 to 1/1.
Examples of monohydric alcohols among the alcohols having 1 to 14 hydroxy groups usable for this type of nonionic surfactant include linear or branched, saturated or unsaturated alcohols having 1 to 24 carbon atoms and cyclic alcohols. Preferred are linear or branched, saturated alcohols having 4 to 12 carbon atoms. Examples of dihydric alcohols include α,ω-glycols having 2 to 32 carbon atoms, 1,2-diols, symmetric α-glycols, and cyclic 1,2-diols. Preferred are α,ω-glycols having 2 to 6 carbon atoms. Examples of trihydric and higher alcohols include those having 3 to 24 carbon atoms, such as glycerol, diglycerol, sorbitol, and stachyose. Especially preferred alcohols are di- to hexahydric alcohols having 2 to 6 carbon atoms.
(2) Nonionic Surfactants Based on Sugar Alcohol
Examples of the nonionic surfactants based on a sugar alcohol (2) include sugar alcohol/AO adducts, fatty acid esters of sugar alcohol/AO adducts, and fatty acid esters of sugar alcohols. The sugar alcohol as a component of a nonionic surfactant based on a polyhydric alcohol is an alcohol obtained from a monosaccharide having 3 to 6 carbon atoms through reduction of the aldehyde or ketone group. Examples thereof include glycerol, erythritol, arabitol, sorbitol, and mannitol. Especially preferred are those having 6 carbon atoms. The fatty acid as a component of the fatty acid ester in a sugar alcohol/AO adduct may be any of saturated and unsaturated fatty acids each having 1 to 24, preferably 12 to 18, carbon atoms. Preferred is oleic acid. With respect to the degree of esterification of the sugar alcohol, the number of OH groups which have undergone esterification may be any of from zero to all of the OH groups. However, the degree of esterification is preferably 1 to 3. The kinds of AO and the average number of moles of AO added are the same as in (1).
(3) Nonionic Surfactants Based on Sugar
Examples of the nonionic surfactants based on a sugar (3) include sugar/AO adducts, fatty acid esters of sugar/AO adducts, and sugar/fatty acid esters. The sugar may be a polysaccharide such as sucrose, besides any of the monosaccharides mentioned above with regard to the sugar alcohol. Preferred are glucose and sucrose. The kinds of AO and the average number of moles of AO added are the same as in (1). Especially preferred of the nonionic surfactants based on a sugar (3) are sugar/AO adducts, in particular, glucose/PO adducts in which the average number of moles of PO added is 1 to 10.
When at least one compound (i) selected among cationic compounds, amine compounds, acid salts of amine compounds, amphoteric compounds, amide compounds, quaternary ammonium salts, and imidazoline derivatives is used in combination with at least one nonionic surfactant (ii) such as the compounds (A) to (C) described above, the proportion of the compound (i) to the nonionic surfactant (ii) is from 100/0 to 1/99, preferably from 100/0 to 10/90 by weight.
The compounds (i) and (ii) maybe added either as a mixture of both or separately.
The bulking promoter of this invention is applicable to a variety of ordinary pulp feedstocks ranging from virgin pulps such as mechanical pulps and chemical pulps to pulps prepared (deinked) from various waste papers. The point where the bulking promoter of this invention is added is not particularly limited as long as it is within the papermaking process steps. In a factory, for example, the bulking promoter is desirably added at a point where it can be evenly blended with a pulp feedstock, such as, the refiner, machine chest, or headbox. After the bulking promoter of this invention is added to a pulp feedstock, the resultant mixture is subjected as it is to sheet forming. The bulking promoter remains in the paper. The paper bulking promoter of this invention is added in an amount of 0.01 to 10 wt. %, preferably 0.1 to 5 wt. %, based on the pulp.
The pulp sheet obtained by using the paper bulking promoter of this invention has a bulk density (the measurement method is shown in the Examples given later) lower by desirably at least 5%, preferably at least 7% than the product not containing the paper bulking promoter and has a tearing strength as measured according to JIS P 8116 of desirably at least 90%, preferably at least 95% of that of the product.
EXAMPLES
This invention will be explained below in more detail by reference to Examples, but the invention should not be construed as being limited thereto. In the Examples, all parts and percents are based on weight unless otherwise indicated.
When the unit number of an (AO) group is defined by an integer, the compound is one of a mixture of reaction products. When it is defined by an average value, the compound is a mixture of reaction products.
Examples 1 to 42 and Comparative Example 1
[Pulp Feedstocks]
The deinked pulp and virgin pulp shown below were used as pulp feedstocks.
<Deinked Pulp>
A deinked pulp was obtained in the following manner. To feedstock waste papers collected in the city (newspaper/leaflet=70/30%) were added warm water, 1% (based on the feedstock) of sodium hydroxide, 3% (based on the feedstock) of sodium silicate, 3% (based on the feedstock) of a 30% aqueous hydrogen peroxide solution, and 0.3% (based on the feedstock) of EO/PO block adduct of beef tallow/glycerol (1:1), as a deinking agent, in which the amounts of EO and PO were respectively 70 and 10 (average number of moles added). The feedstock was disintegrated and then subjected to flotation. The resultant slurry was washed with water and regulated to a concentration of 1% to prepare a deinked pulp (DIP) slurry. This DIP had a freeness of 220 ml.
<Virgin Pulp>
A virgin pulp was prepared by disintegrating and beating an LBKP (bleached hardwood pulp) with a beater at room temperature to give a 1% LBKP slurry. This LBKP had a freeness of 420 ml.
[Bulking Promoters]
The cationic compounds, amine compounds, acids salts of amine compounds, and amphoteric compounds shown in Tables 1 to 5 were used optionally together with the nonionic surfactants shown in Table 6 in the combinations shown in Tables 7 and 8, which will be given later.
TABLE 1
Compound
Structure in the formula (a1)
No.
R 11
R 12
R 13
R 14
X −
Cationic
A-1
C18
C18
C1
C1
Cl −
compound
A-2
C12
C14
C1
C1
Cl −
a-1
C2
C2
C1
C1
Cl −
a-2
C4
C4
C1
C1
Br −
TABLE 2
Compound
Structure in the formula (b1)
No.
R 13
R 14
R 15
R 16
X −
Cationic
B-1
C1
C1
C1
C12
Cl −
compound
B-2
C1
C1
C1
C16
Br −
B-3
C1
C1
C1
C18
Cl −
B-4
benzyl
C1
C1
C12
Cl −
b-1
C1
C1
C1
C2
Cl −
b-2
C1
C1
C1
C4
Br −
TABLE 3
Com-
pound
Structure in the formula (a2) or (b 2 )
No.
R 21
R 22
R 23
HB
Amine
C-1
C12
H
H
—
compound
C-2
C18
H
H
—
and acid
C-3
C16/C18 =
C16/C18 =
H
—
salt
3/7
3/7
of
C-4
C18
C1
C1
—
amine
c-1
C4
H
H
—
compound
c-2
C6
H
H
—
c-3
C2
C2
H
—
c-4
C4
C1
C1
—
C-5
C16/C18 =
H
H
CH 3 COOH
3/7
c-5
C4
H
H
CH 3 COOH
TABLE 4
Structure in the
Compound
formula (a 3 )
No.
R 31
R 32
R 33
Amphoteric
D-1
C12
C1
C1
compound
d-1
C4
C1
C1
TABLE 5
Structure in the formula
Compound
(b 3 )
No.
R 31
R 32
R 33
Amphoteric
D-2
C12
C1
C1
compound
D-3
C18
C1
C1
d-2
C6
C1
C1
TABLE 6
(1)/(2)/(3)
Nonionic surfactant
Weight
No.
(1)
(2)
(3)
ratio
1
C12 alcohol
100/0/0
2
C12/C14
100/0/0
alcohol = 5/5
PO = 5
3
Beef tallow/
100/0/0
fatty acid,
PO = 5
4
Methyl laurate,
100/0/0
EO2/PO3 block
5
Coconut
100/0/0
oil/glycerol =
1/1, EO2/PO10
block
6
Sorbitan
100/0/0
monooleate,
EO20
7
Dobanol23
Sorbitan
75/25/0
EO2/PO4
monooleate, EO10
random
8
C12 alcohol
Sorbitan
Hardened
80/15/5
monooleate, EO15
castor oil,
EO25
9
C18 alcohol,
100/0/0
PO = 10
10
Castor oil/
100/0/0
fatty acid,
EO5/PO15
random
11
C12/C14/C18
C12 alcohol EO = 5
Fish oil/
75/15/10
alcohol =
sorbitol = 1/1
6/2/2,
PO = 15
PO = 10
12
Beef tallow/
100/0/0
glycerol =
1/0.3 EO10/
PO10 block
13
Sorbitan
100/0/0
monolaurate,
EO15
14
C12/C14/C18
lauric acid EO5,
90/10/0
alcohol =
PO25
60/30/10,
PO20
15
C12/C14
100/0/0
alcohol = 70/30
16
Lauric acid/
100/0/0
stearic
acid = 50/50,
PO = 18
17
Dobanol23,
lauric acid/myristic
Sorbitan
70/15/15
PO = 2
acid/palmitic acid =
trioleate EO6
70/20/10, EO10,
PO20
(Note) In the table, Cn means an alkyl group having n carbon atoms. In Table 6, each fat/polyhydric alcohol ratio is by mole, and the other ratios are by weight. EO and PO mean ethylene oxide and propylene oxide, respectively, and the numbers following these are the average numbers of moles added. “Dobanol 23” is an alcohol manufactured by Mitsubishi Chemical.
[Papermaking Method]
Each of the above 1% pulp slurries was weighed out in such an amount as to result in a sheet of paper having a basis weight of 60 g/m 2 . The pH thereof was adjusted to 4.5 with aluminum sulfate. Subsequently, various bulking promoters shown in Tables 7 and 8 were added in an amount of 3% based on the pulp. Each resultant mixture was formed into a sheet with a rectangular TAPPI paper machine using an 80-mesh wire. The sheet obtained was pressed with a press at 3.5 kg/cm 2 for 2 minutes and dried with a drum dryer at 105° C. for 1 minute. After each dried sheet was held under the conditions of 20° C. and a humidity of 65% for 1 day to regulate its moisture content, it was evaluated for bulk density as a measure of paper bulkiness and for tearing strength as a measure of paper strength performance. The results obtained are shown in Tables 7 and 8. Ten found values were averaged.
<Evaluation Item and Method>
Bulkiness (bulk density)
The basis weight (g/m 2 ) and thickness (mm) of each sheet having a regulated moisture content were measured, and its bulk density (g/cm 3 ) was determined as a calculated value
Equation for calculation:
Bulkiness (bulk density)=(basis weight)/(thickness)×0.001
The smaller the absolute value of bulk density, the higher the bulkiness. A difference of 0.02 in bulk density is sufficiently recognized as a significant difference.
Paper strength (tearing strength)
Each sheet having a regulated moisture content was examined according to JIS P 8116 (Testing Method for Tearing Strength of Paper and Paperboard).
Equation for calculation:
Tearing strength= A/S× 16
Tearing strength: (gf)
A: Reading
S: Number of torn sheets
The larger the absolute value of tearing strength, the higher the paper strength. A difference of 20 gf in tearing strength is sufficiently recognized as a significant difference.
TABLE 7
Cationic
compound, amine
compound, acid
Nonionic
Deinked
salt of amine
surfactant
pulp
LBKP
compound, or
used in
Bulk
Tearing
Bulk
Tearing
amphoteric
combination
(i)/(ii)
density
strength
density
strength
Example
compound (i)
(ii)
Weight ratio
(g/cm 3 )
(gf)
(g/cm 3 )
(gf)
1
B-1
none
—
0.330
420
0.377
480
2
B-2
↑
—
0.328
420
0.376
480
3
B-3
↑
—
0.325
415
0.374
475
4
B-4
↑
—
0.330
415
0.378
480
5
A-1
↑
—
0.325
420
0.375
475
6
A-2
↑
—
0.330
420
0.377
480
7
C-1
↑
—
0.342
430
0.385
485
8
C-2
↑
—
0.340
430
0.383
485
9
C-3
↑
—
0.338
425
0.383
480
10
C-4
↑
—
0.335
420
0.379
480
11
C-5
↑
—
0.332
420
0.377
480
12
D-1
↑
—
0.331
415
0.377
475
13
D-2
↑
—
0.331
415
0.377
475
14
D-3
↑
—
0.328
420
0.375
475
15
B-1
1
20/80
0.313
410
0.349
470
16
B-3
2
30/70
0.308
400
0.342
460
17
B-3
3
50/50
0.309
405
0.344
455
18
B-3
4
85/15
0.312
410
0.346
460
19
B-3
5
90/10
0.314
410
0.349
465
20
A-1
6
85/15
0.309
400
0.345
460
21
B-4
7
30/70
0.310
405
0.345
455
22
B-3
8
20/80
0.308
400
0.341
460
23
C-2
9
65/35
0.324
410
0.360
470
24
C-3
10
80/20
0.323
415
0.358
470
25
C-4
11
10/90
0.317
415
0.355
465
26
C-5
12
70/30
0.321
410
0.357
465
27
C-5
13
55/45
0.322
415
0.357
470
28
C-5
14
20/80
0.319
415
0.356
465
29
D-1
15
15/85
0.314
410
0.348
460
30
D-3
16
80/20
0.312
405
0.345
460
31
D-3
17
35/65
0.308
400
0.342
455
TABLE 8
Cationic
compound,
amine
compound,
acid salt
of amine
Nonionic
compound,
surfactant
or
used in
Deinked pulp
LBKP
amphoteric
combi-
Bulk
Tearing
Bulk
Tearing
Ex-
compound
nation
density
strength
density
strength
ample
(i)
(ii)
(g/cm 3 )
(gf)
(g/cm 3 )
(gf)
32
b-1
none
0.366
440
0.405
495
33
b-2
↑
0.365
440
0.402
485
34
a-1
↑
0.365
435
0.404
490
35
a-2
↑
0.366
430
0.405
490
36
c-1
↑
0.367
435
0.404
495
37
c-2
↑
0.368
430
0.407
490
38
c-3
↑
0.365
425
0.404
490
39
c-4
↑
0.365
435
0.403
485
40
c-5
↑
0.366
430
0.405
490
41
d-1
↑
0.364
440
0.404
495
42
d-2
↑
0.363
430
0.406
490
Control (no bulking
0.375
430
0.414
490
promoter)
Comparative example 1
0.330
280
0.379
345
(Note) In Comparative Example 1 was used commercial bulking promoter “Bayvolume P Liquid” (fatty acid polyamide polyamine type; manufactured by Bayer AG). | This invention is to provide a paper bulking promoter with which a highly bulky sheet can be obtained without impairing paper strength.
Namely, this invention provides a process for producing a bulky paper, comprising the step of making paper from pulp in the presence of a bulking promoter comprising at least one compound selected from the group consisting of a cationic compound, an amine compound, an acid salt of an amine compound, an amphoteric compound, an amide compound, a quaternary ammonium salt, and an imidazoline derivative. | 3 |
BACKGROUND OF THE INVENTION
In the manufacture of tissue products such as bath tissue, a wide variety of product characteristics must be given attention in order to provide a final product with the appropriate blend of attributes suitable for the product's intended purposes. Improving the softness of a tissue product has always been a major objective for premium products. The major components of softness include stiffness and bulk (density), with lower stiffness and higher bulk (lower density) generally improving perceived softness.
One traditional approach to producing tissue products has involved compression of a wet laid web between an absorbent felt and the surface of a rotating heated cylinder such as a Yankee dryer. The dried web is thereafter dislodged from the Yankee dryer in a creping process in which a blade is used to partially de-bond the dried web by breaking many of the bonds previously formed during the wet pressing stages of the process. Creping generally improves the softness of the web, albeit at the expense of a significant loss in strength.
More recently, throughdrying has become a more prevalent means of drying tissue webs. Throughdrying provides a relatively non-compressive method of removing water from the web by passing hot, dry air through the web until it is dry. More specifically, a wet-laid web is transferred from a forming fabric to a coarse, highly permeable throughdrying fabric and retained on the throughdrying fabric through passage of a “through air dryer”, (hereinafter TAD). The resulting dried web is softer and bulkier than a wet-pressed uncreped dried sheet because fewer paper-making bonds are formed and because the web is less dense.
Although throughdried tissue products exhibit good bulk and softness properties, throughdrying tissue machines are expensive to build and operate. Accordingly, there is a need for improvements for a throughdrying apparatus and process which produces high quality tissue products.
SUMMARY OF THE INVENTION
It has now been discovered that in the manufacture of uncreped, throughdried tissue sheets, improved efficiencies and a higher quality end tissue product may be obtained by the addition of high temperature steam to the drying medium. In so doing, tissue sheets can be made which have improved absorbance and softness values. Further, the addition of high temperature steam to the drying medium allows the throughair drying process to be carried out more economically and under conditions which eliminate the scorching or burning of the drying web.
Hence, in one aspect, the invention resides in a method for making a throughdried tissue comprising depositing an aqueous suspension of papermaking fibers onto a forming fabric to form a wet web, transferring the wet web to a throughdrying fabric, and throughdrying the web to form a tissue sheet. The use of a drying medium having a high steam content of between 10 percent to 100 percent by volume of the medium allows the use of higher drying temperatures compared to a conventional heated air drying medium. The steam enhanced drying medium converts the free moisture within the fabric web to a water vapor and which is removed by the passage of the drying medium.
Hence, in another aspect, the invention resides in the foregoing method wherein the tissue sheet is dried using a drying medium in which high temperature steam is added to increase the temperature of the drying medium above the burning temperature of paper. The addition of live steam reduces the concentration of oxygen and allows a higher drying temperature to be achieved without scorch or burning of the paper web.
In a further aspect, the invention resides in supplying a drying medium to a fabric web in which the drying medium is substantially free of oxygen. As used herein, the term “substantially free” is defined as having a free oxygen content of a sufficiently low concentration such that burning or scorching of a paper web is prevented when the drying medium temperature is above the traditional scorch or burning temperature for a heated air TAD process. Likewise, the term “reduced oxygen drying medium” is defined as a heated air medium in which a percentage of the drying medium comprises live steam. As such, the oxygen gas concentration within the drying medium is reduced compared to a heated drying medium without the addition of live steam. Typically, heated air will have an O 2 percentage of about 21%.
The use of a reduced concentration oxygen gas or substantially oxygen-free drying medium allows a drying temperature higher than the scorch or burn temperature of a paper web to be used. The scorch temperature of a paper web may vary depending upon the thickness and quality of the referenced web. However, the scorch temperature for any particular paper web may be readily determined and such temperatures are, in fact, known values within the industry for various types of commercially produced webs.
The use of an elevated throughair drying temperature brings about an additional improvement in the water absorbency and softness of the tissue fabric by the provision of a supply-side drying temperature above the glass transition point of paper fiber. The elevated temperatures allow the paper fiber to mold and permanently set the pulp fibers in an altered and desired shape.
In yet a further aspect, the invention resides in the foregoing method wherein the introduction of pressurized steam into the drying medium increases the velocity of the drying medium. This, in turn, lowers the energy demand on electric blowers and fans proportional to the motive energy provided by the introduced steam.
In yet a further aspect, the invention resides in a papermaking process in which the drying medium, upon leaving the throughdried web, has a portion of the resulting exhaust stream discharged along annular gaps defined between a throughair dryer hood and the associated paper web and drum. The discharge of the used drying medium forms a curtain seal along the annular gap seals and dryer web entry slot, thereby preventing cooler, oxygen-rich ambient air from infiltrating into the drying medium loop. Simultaneously, the exhaust curtain seals allow the discharge of a portion of the used drying medium so as to maintain an equilibrium of the drying medium circulation loop.
In yet another aspect, the invention resides in a method of making a tissue sheet wherein the throughair drying step is carried out by a drying medium comprising substantially about 100 percent (by volume) live steam. The use of substantially about 100 percent live steam will greatly reduce and may eliminate the need for electric motors used to circulate the drying medium. As a result, increased efficiencies can be obtained by the cost savings reflected in the use of pressurized steam as opposed to electric blowers to move the drying medium.
These and other aspects of the invention will be described in greater detail in reference to the figures and specification set forth below.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings.
FIG. 1 is a perspective view of a process line for producing a throughdried tissue product in accordance with this invention;
FIG. 2 is a schematic flow diagram of a TAD apparatus and drying process in which high energy steam is added as a component of the drying medium;
FIG. 3 is a schematic flow diagram of a TAD apparatus and process for the substantially oxygen-free drying of a tissue web;
FIG. 4 is a schematic view setting forth details of a steam injection apparatus and process for a TAD; and
FIG. 5 is a schematic view setting forth details of the gap sealing feature of the present invention using a portion of the discharged dryer medium exhaust to prevent the entrainment of ambient air into the drying medium loop.
DETAILED DESCRIPTION OF THE INVENTION
Reference now will be made in detail to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features, and aspects of the present invention are disclosed in the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions.
In describing the various figures herein, the same reference numbers are used throughout to describe the same apparatus or process pathway. To avoid redundancy, detailed descriptions of much of the apparatus once described in relation to a figure is not repeated in the descriptions of subsequent figures, although such apparatus or process is labeled with the same reference numbers.
Referring first to FIG. 1, there is illustrated a process line 10 suitable for carrying out the preferred process of the present invention. The description given in reference to FIG. 1 is illustrative of but one process and apparatus for making a tissue product in which a throughair dryer is utilized. It is understood and appreciated by one having ordinary skill in the art that a variety of throughair drying apparatuses and paper-making processes may be used in conjunction with the present invention.
The process line begins with a papermaking furnish 12 comprising a mixture of secondary cellulosic fiber, water, and a chemical debonder which is deposited from a conventional headbox (not shown) through a nozzle 14 on top of a foraminous wire forming belt 16 as shown in FIG. 1 . The forming belt 16 travels around a path defined by a series of guide rollers. The forming belt 16 travels from an upper guide roller 20 , positioned below and proximate to the headbox nozzle 14 , horizontally and away from the headbox nozzle to another upper guide roller 22 , passes through the upper guide roller 22 and diagonally and downwardly to a lower guide roller 24 , passes under the lower guide roller 24 and diagonally and upwardly toward the nozzle 14 to a lower guide roller 26 , passes over lower guide roller 26 and diagonally and downwardly to lower guide roller 28 , passes under lower guide roller 28 and turns upwardly and slightly inwardly to a guide roller 32 , passes behind the guide roller 32 and upwardly and outwardly returns to upper guide roller 20 .
A vacuum forming box 34 positioned beneath the forming belt 16 proximate to the opening 36 of the headbox nozzle 14 immediately extracts water from the moist fibrous web 38 deposited on top of the forming belt by the headbox nozzle. The partially dewatered fibrous web is carried by the forming belt 16 in the clockwise direction as shown in FIG. 1, towards the upper guide roller 22 . The fibrous web 38 as it moves away from the vacuum forming box 34 , in one embodiment may comprise from about 19 percent to about 30 percent cellulosic fiber by weight. An edge vacuum 40 positioned below the forming belt 16 and proximate to the upper guide roller 22 assists in trimming the edges of the fibrous web 38 .
The fibrous web 38 passes over the upper guide roller 22 and downwardly between the forming belt 16 and a throughdryer belt 42 . The throughdryer belt 42 travels around a path defined by a series of guide rollers. The throughdryer belt 42 travels from a guide roller 44 positioned above and vertically offset from guide roller 22 downwardly towards the forming belt 16 , contacts the fibrous web 38 , and then downwardly and diagonally away from guide roller 24 to guide roller 46 , passes under guide roller 46 and turns horizontally away from the forming belt 16 towards a throughdryer guide roller 48 , passes under the throughdryer guide roller 48 and turns upwardly and over a throughdryer 50 and downwardly to a second throughdryer guide roller 55 , passes under through guide roller 54 and turns upwardly to an upper guide roller 56 which it passes over and thereafter turns slightly downwardly to an upper guide roller 58 , and turns slightly upwardly in the direction of the forming belt 16 to an upper guide roller 60 , passes over upper guide roller 60 and turns downwardly to a guide roller 62 , passes under guide roller 62 and turns substantially horizontally away from forming belt 16 to a guide roller 64 , passes around guide roller 64 and turns horizontally in the direction of the forming belt 16 and returns to guide roller 44 .
A vacuum pickup 66 pulls the fibrous web 38 towards the throughdryer belt 42 and away from forming belt 16 as the fibrous web passes between the throughdryer belt and the forming belt. The fibrous web 38 adheres to the throughdryer belt 42 and is carried by the throughdryer belt downwardly below the lower guide roller 46 towards the throughdryer 50 . Vacuum boxes 68 positioned above and proximate to the throughdryer belt 42 between the lower guide roller 46 and the throughdryer guide roller 48 extract additional water from the moist fibrous web 38 . The fibrous web 38 may preferably comprise between about 25 percent and 35 percent fiber by weight after passing beneath the vacuum boxes 68 .
The TAD 50 generally comprises an outer rotatable perforated cylinder 51 and an outer hood 52 . Hood 52 is used to direct a drying medium from the drying medium supply duct (not illustrated) and which is discharged against and through the fibrous web 38 and the throughdryer belt 42 as is known to those skilled in the art. The throughdryer belt 42 carries the fibrous web 38 over the upper portion of the throughdryer outer cylinder 51 . A drying medium is forced through the fibrous web 38 and through the throughdryer belt 42 and through the perforations 53 in the outer cylinder 51 of the TAD 50 . The drying medium removes the remaining water from the fibrous web 38 and exits the cylinder 51 along conduits (not illustrated) in proximity to outlets 57 positioned along the axis 59 of cylinder 51 . The temperature of the drying medium forced through the fibrous web by the throughdryer is desirably about at least 300° F.
The throughdryer belt 42 carries the dried fibrous web 38 towards the lower guide roller 54 . The dried web 38 is directed to a take-up roller 70 where the fibrous web is wound into a product roll 74 .
Turning to FIG. 2, there is illustrated a schematic representation of a throughair dryer and process for carrying out the present invention. The drying medium in this embodiment comprises a mixture of the combustion products from a fuel burner 80 and live high temperature pressurized steam 82 . Burner 80 uses a fuel source, such as natural gas, which is burned in the presence of excess air. The resulting heated combustion products are further mixed with high energy live steam 82 and recycled drying medium 92 to provide a high temperature drying medium 90 . Drying medium 90 may have a supply side temperature of between 300° F. to 600° F. when using 1000° F. live steam as a component of the drying medium 90 . However, an even greater drying medium temperature is envisioned and may be obtained by increasing the relative amount and/or temperature of the introduced live steam. It is readily appreciated by one having ordinary skill in the art that the supply temperature of released steam may be greater or lesser than the 1000° F. live steam example set forth above. Such variations in steam temperature do not alter the ability to use the varying temperature steam so as to bring about the improvements of the present invention.
The drying medium 90 is introduced to the TAD 50 within the interior enclosure defined by hood 52 . The velocity of the drying medium 90 directs the drying medium to contact the outer supply side of moving web 38 , passing the drying medium through web 38 as the medium 90 continues through the throughbelt 42 , and into the interior cylinder 51 before exiting through outlets 57 , as seen in reference to FIG. 1 .
As the drying medium 90 passes through web 38 , the drying medium 90 raises the temperature of web 38 , thereby converting the water content of the web to steam. The steam is released from the web fibers/matrix and passes into the drying medium. The circulating fan 100 is used to circulate the drying medium as it exits the web 38 . The used drying medium 92 is then recirculated in part to the feed stream of the drying medium along with additional live steam.
The returning or used dryer medium 92 , upon exiting the web 38 , will experience a temperature drop upon entry into the interior of the cylinder 51 . Further, ambient air is typically entrained into the recirculating loop pathway of mediums 90 and 92 by air leakage along gap regions of the hood baffle 61 associated with the passage of web 38 into and out of TAD 50 . To maintain a proper balance of the dryer medium constituents 90 , a portion of the used dryer medium 92 may be vented using exhaust fans 101 to maintain a desired balance of the heated combustion products, including combustion air, high energy steam, and the recycled used dryer medium 92 . The latter component may include ambient air entrained by movement of the web relative to the dryer.
Referring now to FIG. 3, an additional embodiment of the present invention is set forth in which a substantially oxygen-free drying medium 190 is used with the TAD 50 . In this embodiment, the burner 80 is operatively engaged with a heat exchanger 83 . Heat exchanger 83 is used to transfer the thermal energy from the combustion products of burner 80 to the return drying medium 192 . The actual combustion products, however, are vented from the system and do not form part of the actual drying medium 190 .
The return drying medium 192 , upon passage through heat exchanger 83 , is further mixed with live steam. The resulting heated mixture comprises the supply side drying medium 190 .
As further set forth in reference to FIGS. 3 and 5, a portion of the cooled exiting drying medium 192 may be diverted to form an air curtain along the air entrainment locations associated with the throughair dryer. A portion 195 of the exiting drying medium is discharged along an outlet adjacent the baffle and air gaps 110 defined between the throughair hood 52 and the web 38 . A partial vacuum pathway 112 may be used to establish a sustained flow path of the resulting air curtain. The air curtain precludes entry of ambient air into the throughair dryer and therefore excludes the ambient air from entry into the drying medium pathway. As seen in FIG. 3, the used drying medium 112 associated with the air curtain is thereafter vented as an exhaust product by a blower 103 . Additional portions of the used dryer medium 192 is vented by exhaust fan 101 as needed to accommodate the introduction of new quantities of live steam to reestablish the high temperature steam profile of drying medium 190 .
The pressurized release of live steam into the drying medium accomplishes several objectives. First, the steam increases the temperature of the drying medium and allows a supply side temperature of the drying medium to exceed the drying temperatures of a conventional dry air TAD. Second, the release of pressurized live steam into the drying medium pathway increases the velocity of the drying medium. As a consequence, the energy demands and capacity of electric fans or blowers associated with the drying medium circulation loop may be reduced. Third, the use of a high steam content drying medium also improves certain desirable qualities of the resulting throughair dried web. For instance, the absorbency and softness of a tissue TAD product, may be improved by raising the tissue to a temperature greater than the glass transition temperature of the cellulosic fibers. The steam content of the drying medium lowers the glass transition point of the cellulosic fibers. Further, the steam allows a higher drying temperature to be achieved. The combination of a lower glass transition temperature and higher drying temperature allows an improved product molding to occur. The molding process, as known in the art, provides a three-dimensional texture to the resulting web which is desirable for certain tissue products. The resulting molded shape is softer, more absorbent, and allows the tissue product to maintain its textured shape when exposed to moisture.
In reference now to FIG. 4, details of one example of the addition of a live steam component to a TAD medium is set forth. In the illustrated embodiment of FIG. 4, burner 80 releases an initial stream of heated combustion products. The heated combustion products are then intermixed with a fan-driven return drying medium 92 along with live steam 82 . A system of one or more baffles 84 may be placed within the respective flow paths to achieve an improved intermixing of the component fractions of the drying medium. Additional injection nozzles 86 may be provided so that live steam is injected along additional locations of the enclosed flow path of the drying medium loop. As illustrated, steam injection along turning elbows of the flow path ductwork are believed particularly useful. Such regions are associated with high turbulence and provide an opportunity to intermix the newly injected live steam with the other components of the drying medium.
As set forth above, it has been found that live steam may be added to an existing throughair dryer apparatus and process to bring about the stated improvements. It is readily appreciated by one having ordinary skill in the art that as the relative amount of live steam introduced into the drying medium is increased, the relative percentage of drying medium atmospheric oxygen is decreased. Accordingly, as the live steam content of the drying medium is increased, the temperature of the drying medium which may be used without scorching or burning the tissue web also increases. The drying medium may have a free oxygen concentration of less than the ambient oxygen concentration of air of 21%. Optimally, the drying medium has a free oxygen concentration of less than 15% and desirably, less than 10%. It is yet still more desirable to provide a drying medium which is substantially free of atmospheric oxygen.
With respect to an existing TAD apparatus and process, live steam may be added as a component of the existing drying medium. The introduction of live steam is believed useful in that the energy demands placed upon the electric fans and blowers used to circulate the drying medium will be reduced. The pressurized release of live steam contributes to the displacement and velocity of the drying medium. Further, the increased temperature of the drying medium permits a more efficient drying of the associated web. As such, the improved efficiency may permit a more rapid throughput of the web through the throughair dryer process or allow a reduction in the drying medium volume and/or flow rate, either of which would also contribute to overall cost savings of operation.
It is also possible to provide a throughair dryer and process in which the TAD uses a drying medium of substantially 100 percent live steam. As such, the throughair drying medium is substantially free of atmospheric oxygen which allows the web to be raised to much greater temperatures which, heretofore, would have resulted in a scorching or burning of the fabric web.
In certain embodiments of this invention, it is envisioned that the requirement of motorized blowers and fans may be substantially reduced in terms of size and capacity or eliminated altogether from the system. In their place, the circulation pathway of the drying medium loop can be established and maintained through the pressurized release of steam.
In one embodiment of the present invention, an apparatus and process of oxygen-free drying is disclosed. While this embodiment discloses the use of substantially 100 percent steam as the drying medium, it is possible that other inert gases could be used in combination with the live steam. Such a use is envisioned within the scope of applicants' substantially oxygen-free drying process.
Although various embodiments of the invention have been described using specific terms, devices, and methods, such description is for illustrative purposes only. The words used are words of description rather than of limitation. It is to be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or scope of the present invention, which is set forth in the following claims. In addition, it should be understood that aspects of the various embodiments may be interchanged, both in whole or in part. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained therein. | A paper web drying apparatus and process is provided in which the heated air drying medium is replaced with between 10 percent to 100 percent of live steam. The addition of a steam component to the drying medium provides for a higher drying temperature to be supplied to the wet moving web. The introduction of live pressurized steam contributes to the load of force of the drying medium, thereby decreasing the energy requirements of blower motors. The introduction of pressurized live steam also lowers the free atmospheric oxygen content of the drying medium which reduces the burning or scorch hazard associated with high temperature drying of a cellulose web. | 3 |
RELATED APPLICATION INFORMATION
[0001] This application is a continuation of U.S. application Ser. No. 12/904,766, filed on Oct. 14, 2010, which application is a continuation of U.S. application Ser. No. 12/240,294, filed on Sep. 29, 2008, which application is a continuation of U.S. application Ser. No. 09/718,931, filed on Nov. 21, 2000, which applications are incorporated herein by reference in their entirety.
[0002] This application is also related to U.S. application Ser. No. 09/611,620, filed Jul. 6, 2000, which is now U.S. Pat. No. 7,079,113, which application was incorporated by reference in U.S. application Ser. No. 09/718,931.
FIELD OF THE INVENTION
[0003] The present invention relates to media systems, hand-held electronics and control modules. Specific exemplary embodiments discussed relate to remote controls and televisions.
BACKGROUND OF THE INVENTION
[0004] The description of art in this section is not intended to constitute an admission that any patent, publication, or other information referred to herein is prior art with respect to this invention, unless specifically designated as such.
[0005] Recently, cable television and broadcast television has become rife with commercials and other interruptions to the primary programming, or feature (referred to herein, separately and collectively, as commercials). While some commercials are amusing, they lose their appeal very soon. Changing channels during a commercial break, so-called “channel surfing” or simply “surfing” is at least as old as the first known remote control. With more and more channels to surf, a user is prone to become engrossed in the process of surfing itself and miss the primary feature he was viewing on the primary channel.
[0006] The prior art teaches a method of detecting commercials in a television to avoid video taping the commercials. During a television broadcast, when the program changes to a commercial, both the video and audio components of the composite television signal fade to a low amplitude level. Momentary loss of both the video and audio components at the beginning of each commercial may be used as an indicator of a commercial. U.S. Pat. No. 4,319,286, issued to Hanpachern describes in more detail a system for detecting fades in television signals to avoid recording from a commercial television broadcast. U.S. Pat. No. 4,319,286 is hereby incorporated by reference.
[0007] U.S. patents and applications relevant to remote control technology include U.S. Pat. Nos. 5,515,052; 5,255,313; U.S. patent application Ser. No. 09/418,091, filed Oct. 14, 1999, and U.S. patent application Ser. No. 09/611,620, filed Jul. 6, 2000, all of which are incorporated herein by reference. Patent '052 discloses a universal remote control with function syntheses. The remote control comprises driver circuitry for communicating code signal generation sequences, including a code generated command system, powered by a code setting signal; and memory for storing information therein. Patent '313 discloses a universal remote control system having a signal generator to transmit signals which will cause specific functions to occur in specific control devices. Pat. App. Ser. Nos. '091 and '620 disclose means and methods, inter alia, for operating a remote control. Application '620 discloses means and methods for interfacing, and navigating with secondary material on a removable digitally encoded medium. Application '620 also teaches means and methods for monitoring keystroke navigation sequences and other processes related to remote control technology.
[0008] Other U.S. patents related to remote control technology, and in particular relating to learning technology, include U.S. Pat. Nos. 4,959,810; 5,288,077; and 5,537,463, which are incorporated herein by reference. Patent '810 discloses means for transferring instructions to RAM wherein the instructions and/or data are transferred from a source external to the RAM. Patent '077 discloses a remotely upgradable universal remote control. Patent '463 discloses means in the remote control for picking up an electromagnetic signal for an electromagnetic signal source and storing output signal data in memory. The output signal data stored in memory may correspond to control function data, which may be transmitted to a device to be controlled.
[0009] U.S. Pat. No. 6,029,239 describes a remote control in which the user first enters one or more digits of channel number information and then presses a SEND key to transfer the channel change information to a TV set or Cable/satellite decoder box.
[0010] While the present invention relates to a wide variety of electronics and media systems, discussion of exemplary embodiments directed towards remote controls and televisions will facilitate understanding.
SUMMARY OF THE INVENTION
[0011] An object of the invention is to provide a television viewer who “channel surfs” during commercials with a mechanism to automatically return to the original channel at the conclusion of the commercial break. Thus, even if the viewer becomes engrossed in the alternate program content, he is still assured that his television will return to the original program at the appropriate time.
[0012] One possible implementation of this return to channel feature would be to build it into the television set in conjunction with a system capable of detecting advertising content (e.g., the system disclosed by Hanpachern in U.S. Pat. No. 4,319,286). An alternate implementation, for use in conjunction with existing TVs not so equipped, uses a timer in the remote control to approximate this feature. Other alternatives will be apparent from the teachings of this application.
[0013] For one application the present invention is directed toward a media system comprising a television with a tuner connected to receive a media transmission and to select a channel. A signal monitor is operably connected to monitor the transmission. Channel data may be stored in memory. A primary timer connected to the signal monitor may be reset to time predetermined intervals, e.g., 32 seconds, upon receipt of a predetermined signal indicator, e.g., a black frame or a generated signal from the signal monitor. Upon expiration of the predetermined interval, the tuner returns the system to the primary channel, i.e. it selects a channel corresponding to the channel data stored in memory.
[0014] The invention also comprises an embodiment directed towards a media system adapted to return to a user-selected channel. A signal monitor connected to a tuner of a television monitors a media signal (also referred to as media transmission) for a predetermined event. In response to the occurrence of the predetermined event, the timer begins timing a predetermined interval, or/and may be reset to time the predetermined interval. Stored in memory is programming that, in response to a user-initiated signal, initiates monitoring of the media signal for the predetermined event. In general, contemporaneously with the onset of the signal monitoring, the current channel is stored in memory. Upon expiration of the predetermined event, the programming provides for the return to the stored current channel. Preferably the user may initiate signal monitoring via a remote control. Such user-initiated signal may be, e.g., in response to a user depressing a button, or key, etc., on the remote control.
[0015] An object of the present invention is also to provide a remote control adapted to provide a return to channel feature for a television not equipped for a return to channel feature. Such a remote control may, e.g., comprise programming steps stored in memory for storing a primary channel indicator in memory in response to a user predetermined action, e.g., such as selecting a key. Programming also includes timing a predetermined interval in response to a second predetermined user action; and upon expiration of a predetermined interval, transmitting a signal that corresponds to an indicator of the primary channel to a media device. It will be understood that the second predetermined user action may be the same as the first predetermined user action, or it may be different yet similar, such as depressing the same key but for a longer duration, or it may be entirely different.
[0016] A method of effecting a return to a primary channel in a media device is taught herein. In one embodiment a primary channel, e.g., the channel or an indicator, is stored in device readable memory in response to the input of a user. The primary channel is monitored for a predetermined event indicative of a change in programming sources. Upon occurrence of, i.e., in response to, the predetermined event, a timer is initiated, or reset or both. Upon expiration of a predetermined interval, timed by the timer, the system is returned to the stored primary channel.
[0017] One method of monitoring the media channel comprises monitoring the primary channel for a predetermined event and notifying the user upon expiration of a predetermined interval. The predetermined interval was preferably initiated upon the occurrence of a predetermined event. Such notification may be achieved by exposing the user to either the audio or video component of the primary channel, or both. Other means for notification, such as a blinking light on the remote, as well as other audio and visual indicators may be used. It will be appreciated that although this document describes a method that results in an automatic return to the primary channel, it is also possible to implement either system to offer only an audible or visible reminder signal rather than an actual channel change.
[0018] Various embodiments directed toward a device readable medium are taught in the present invention. The device readable medium, depending on the application, may be located in the television, the remote control, a separate adapter, or a combination thereof. Such a device readable medium typically comprises programming steps for carrying out the desired application.
[0019] Other objects and advantages in accordance with the present invention will be apparent to those of skill in the art from the teachings disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In the interest of enabling one of skill in the art to practice the invention, exemplary embodiments are shown and described. For clarity, details apparent to those of skill in the art without undue experimentation are generally omitted from the drawings and description.
[0021] FIG. 1 is a flowchart depicting one method for implementing a television-based embodiment of the invention.
[0022] FIG. 2 is a flowchart depicting one method for implementing a remote control-based embodiment of the invention.
[0023] FIG. 3 depicts a media system comprising a television without 2 way remote wireless communication.
[0024] FIG. 4 depicts a media system with a television and a remote control adapted for bi-directional communication with each other.
[0025] FIG. 5 shows a block diagram of a television according to an embodiment of the invention.
[0026] FIG. 6 shows a remote control according to an embodiment of the invention.
[0027] FIG. 7 shows a block diagram of a remote control according to an embodiment of the invention.
[0028] FIG. 8 depicts a consumer electronic system including a control module having navigation keys.
[0029] FIG. 9 depicts an enlargement of the navigation keys shown on the remote control of FIG. 8 .
[0030] FIG. 10 shows a flowchart representing one method of storing and playing back a sequence of navigation keys.
[0031] FIG. 11 shows a flow chart representing a method of adding a key to a stored sequence.
[0032] FIGS. 12( a )- 12 ( d ) show changes to a key sequence table as keys in a sequence are stored in the table.
[0033] FIG. 13 shows a flowchart representing a process for playing back a stored sequence.
[0034] FIG. 14 shows a flowchart representing a process for storing and playing back a sequence that includes interkey time delays.
[0035] FIG. 15( a )- 15 ( g ) depict a key sequence table, similar to that shown in FIG. 12 , changing as sequence values, including interkey values, are stored in the key sequence table.
[0036] FIG. 16 shows a flowchart representing a process for playing back a stored sequence having interkey time delay values.
[0037] FIG. 17 shows a flowchart representing a process for implementing a so called quick macro.
[0038] FIG. 18 shows a remote control capable of displaying at least one menu on a display screen.
[0039] FIG. 19 shows an example of a DVD menu tree.
[0040] FIG. 20 shows a remote control displaying menu pages corresponding to pages of the tree depicted in FIG. 19 .
[0041] FIG. 21 shows a remote control having menus displaying graphics along with text.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0042] The present invention is discussed in relation to remote controls and televisions; however, other uses will be apparent from the teachings disclosed herein. The present invention will be better understood from the following detailed description of exemplary embodiments with reference to the attached drawings, wherein like reference numerals and characters refer to like parts, and by reference to the following claims.
[0043] Television Set-Based Implementation
[0044] Hanpachern (U.S. Pat. No. 4,319,286) teaches a method of detecting the start of a commercial by monitoring the received video and audio signals for a momentary absence of both picture and sound, the so-called “black frame” that typically results when the signal is switched from one program source to another.
[0045] When detected, this black frame occurrence is used to start a timer set to expire 32 seconds later. Since most TV commercials are seconds or less, each new commercial restarts the timer before it expires. Finally, 32 seconds after the end of the last commercial, the timer will expire. The period the timer is active can thus be used to signal the duration of a commercial break plus 32 seconds. An additional override timer of a 2 minute duration (or other value deemed typical of a standard commercial break) can optionally be implemented to ensure that this “commercial active” signal does not 10 extend beyond that period, even if the program material itself contains black frames.
[0046] The Hanpachern invention then proposes use of this commercial active signal to automatically pause a VCR during taping of a show or sporting event, thereby eliminating commercials from the final recording of the feature. The television system is not, however, effected—one must still endure the commercials if the broadcast is being viewed contemporaneously with the recording.
[0047] The present invention proposes, e.g. use of such a signal generated as described above, or in any other suitable manner, to facilitate “channel surfing” during commercials by providing an automatic return to the original, i.e. primary, program at the end of the commercial break.
[0048] In one embodiment, the remote control is equipped with a button labeled, e.g., “Surf.” FIG. 1 is a logic flowchart for carrying out one embodiment of the TV-based invention. The use of the term “step” herein is not intended to imply a required order to carry out the steps. The designated numbers are for convenience. At the commencement of a commercial break, the viewer simply presses this surf button before starting to channel-surf. Upon receipt of this surf command 30 (step 2 ), the TV set: stores its current channel number (step 4 ); initiates a background process to monitor that primary channel for black frames in the manner described above (step 6 ); and starts 32-second-and-two-minute timers (step 8 ), again as described above. It should be noted that the background process, generally, requires an independent tuner in order to monitor the current channel while the viewer surfs alternative channels. Due to this two-tuner reason, this embodiment is especially suited to TV models that incorporate picture-in-picture capability. The existing secondary PIP tuner can be used for these surfing or monitoring purposes.
[0049] With the surf feature thus activated, the viewer is now free to issue other remote control commands as needed. However, as soon as either of the two timers expires (steps 10 or 12 ), the TV set will automatically tune itself back to the saved channel number (step 14 ), returning the viewer to the program of primary interest at the appropriate time. Additionally, the viewer can cancel the so-called surf timers and immediately return to the primary channel at any time by pressing the surf key a second time (step 16 ).
[0050] FIG. 3 shows a media system 20 comprising a remote control 22 in communication with a plurality of electronic devices 24 . Preferably the communication link between the remote control 22 and the electronic devices 24 is wireless and may include a unidirectional IR or RF link 28 . The TV 32 in FIG. 3 does not include two-way IR 20 capability. By contrast the media system 34 shown in FIG. 4 , the TV 36 comprises two-way IR or RF capability 30 for bi-directional communication with the remote control 22 ′. For convenience the invention will be described by reference to TV 32 , though it will be understood that a two-way interface may be used in certain 25 applications.
[0051] FIG. 5 shows a block diagram of a TV 32 according to an embodiment of the present invention. The TV 32 includes a first tuner 38 connected to receive a media transmission 40 and to select a channel. A signal monitor 42 is connected to the first tuner 38 to monitor the media transmission 40 , and memory 44 is used for storing channel data. A primary timer 46 , associated with the control logic 53 , is reset, or begins timing, or restarts timing a predetermined interval upon receipt of (i.e. in response to) a predetermined signal indicator from the signal monitor 42 . In one preferred embodiment, the predetermined interval is 32 seconds and the predetermined signal indicator is a, or corresponds to a, so-called “black frame.” As discussed above, the TV 32 preferably includes a second tuner 48 for channel selecting, connected to the picture decoding and display circuitry of the TV set (not shown). This allows the first tuner 38 to continue to monitor a specific channel of the media transmission 40 while the second tuner 48 is used to surf various other channels. Upon (i.e., in response to) expiration of the predetermined interval, the tuner 48 is directed by the control logic 53 to select (e.g., tune to) a channel corresponding to the channel data stored in memory 44 . FIG. 6 depicts a remote control 23 such as may be used with the media system 24 . The remote control 23 comprises a signal generator 49 (see FIG. 7 ), adapted to transmit a control signal, e.g. signal 28 , compatible with the television 32 . In response to a predetermined user action, such as operation of a surf key 50 , the signal generator 49 transmits a signal to the television 32 . Receipt of this signal via the TV's IR receiver 45 (see FIG. 5 ) causes the control logic 53 to initiate monitoring of the media transmission 40 by the signal monitor 42 . The media transmission 40 is also referred to herein as a media signal 40 or program signal 40 .
[0052] Preferably programming 51 is stored in memory 44 to control monitoring of the media signal 40 for the occurrence of a predetermined event. Monitoring may be initiated in response to a user-initiated signal (such as IR transmission 28 generated by depressing surf key 50 ). Contemporaneously, or subsequently, the current channel may be stored in memory 44 . Again, upon expiration of the predetermined interval, the system will return to the stored current channel. It should be noted that the predetermined interval 30 may be an override interval timed by an override timer 52 (see FIG. 5 ). However, preferably, the system reconfigures upon expiration of the first of the predetermined interval, as timed by timer 46 , or the override interval, as timed by override timer 52 .
[0053] Remote Control-Based Implementation
[0054] In an alternate implementation contained entirely, or substantially, within the remote control 23 , or preferably 23 ′, the received program signals 40 are not available to be monitored, so a simple timer 54 set for the typical duration of a commercial break is used instead. In a media system such as 34 in which the television set 36 is capable of two-way communication with the remote control 22 , it may be possible for the remote control to automatically determine the active channel number at the moment the surf button 50 is activated. However, in general the remote 23 is not able to automatically determine the active channel number at the moment the surf button 50 is activated. In a media system such as 24 , a means must thus be provided for the user to indicate his desired primary viewing channel ahead of time. Such indication may, however, be performed only once at the outset of each show or sporting event watched, rather than prior to each commercial break. In an alternative embodiment, the remote control may determine the current channel by monitoring direct channel inputs and Up/Down channel changes. This embodiment is discussed in more detail later.
[0055] Referring to FIG. 2 , when the user initially begins viewing a program or event, he indicates to the remote 23 ′ which channel is of primary interest as follows:
Press and hold the surf button 50 for approximately three seconds (step 60 ) until the visible LED blinks twice (step 62 ), signaling that the remote 23 ′ is ready to accept channel information. Enter whatever sequence of keystrokes is necessary to tune the TV set to the channel in question. Depending on the particular model of TV, this will usually consist of one or more digits, possibly in conjunction with an “enter” or similar key (step 64 ). The remote may, however, be programmed to accept and store any sequence of up to three keystrokes (step 66 ). Also, the three keystroke limit imposed at step 66 is implementation specific and in practice any reasonable limit up to the maximum keystroke storage capacity available in the unit may be used. To signal the end of key entry, the user presses the surf key 50 once again (step 68 ). This causes the remote to exit this channel entry state and return to normal operation, with the keystroke sequence stored for future use. (In addition, if at any time during the entry process no key is pressed for, e.g., 10 seconds, the remote will automatically exit this channel entry state (step 70 ).)
[0058] Whenever a commercial begins and the user wishes to “channel surf” he first briefly presses the surf button 50 (step 72 ). This starts a timer 54 running within the remote control 23 ′ (step 74 ). The timer 54 is nominally set for a two-minute interval (but configurable by the user for shorter or longer times if desired). During the timing period (i.e. the commercial break), the remote 23 ′ operates in the usual manner (steps 76 a - 76 b ) to allow the user to switch channels and view other material. When the timer expires (step 78 ), the remote 23 ′ retrieves the previously stored keystroke sequence, the channel data (step 80 ), and plays it back, thereby automatically returning the TV to the desired primary channel (step 82 ).
[0059] While the user is actively surfing (i.e. the timer in remote control 23 ′ is running), he can, at any time, cancel the timer 54 and return immediately to the original channel by pressing the surf button 50 a second time (step 84 ).
[0060] In one embodiment the remote control 23 ′ comprises programming steps stored in memory 88 of the remote 23 ′. The programming may, for example, comprise storing a primary channel indicator in memory 88 in response to a user predetermined action, and starting the timer 54 in response to a second predetermined user action. Note, however, the second predetermined action may be identical with the first predetermined user action and may be, for example, depressing the surf key 50 .
[0061] The memory 88 also includes programming steps for transmitting a signal 28 to a media device 24 , such as television 32 , wherein the signal 28 corresponds to a primary channel indicator. The transmission may preferably occur upon expiration of a predetermined interval, upon expiration of an override interval, or upon cancellation of the surf mode, for example.
[0062] The predetermined user action for storing the primary channel in memory 88 may comprise performing the secondary predetermined action. In response to the user action, the programming may also determine if the media system is tuned to the primary channel, and if the system is not tuned to the primary channel, tuning it to the primary channel. The channel store operation may occur contemporaneous with, or subsequent to a user action, where such action may for example comprise depressing the surf key 50 .
[0063] From the foregoing, it should be apparent that the present invention teaches a method of effecting, or bringing about, a return to a primary channel in a media device 24 , such as a television 36 . In one embodiment, the method comprises, in response to a user input, storing a primary channel in device readable memory (such as memory 88 or 44 , for instance). The primary channel is monitored for a predetermined event indicative of a change in programming sources. The aforementioned black frame is one example of such an indicative event. A timer 54 of a predetermined interval is initiated, either based upon the user input or upon the predetermined event. The timer 54 is preferably reset upon occurrence of the predetermined event. Finally, the system is returned to the stored primary channel upon expiration of the predetermined interval.
[0064] An override timer, for timing an override timed interval, may also be initiated based upon the predetermined event. If the predetermined interval has not expired, the system may be returned to the stored current channel upon expiration of the override time interval. Preferably, the timing of the predetermined interval is terminated upon expiration of the override timer and the return to the stored current channel.
[0065] In another embodiment, a signal corresponding the primary channel stored in memory 88 is transmitted to a media device 24 adapted to receive the primary channel. For example, the remote control 22 may transmit a signal 28 to the television 36 to return to channel 2 . The television 36 then receives the transmission 28 and changes to channel 2 .
[0066] Embodiments of the invention may comprise monitoring a media channel for a predetermined event, and notifying the user upon expiration of (i.e. in response to) a predetermined interval. Such notification may include exposing the user to either the audio component of the primary channel, the video component of the 15 primary channel, or both.
[0067] A more general objective of the present invention is to provide a device readable medium adapted for use in a media system to facilitate providing a notification feature. The medium, in a preferred embodiment, comprises programming steps for storing, in response to the user input, a primary media channel of the media system in device readable memory. More generally, the state of the media system is stored in device readable memory. The media system state typically comprises the status of a plurality of features, parameters and the like. Such parameters include, inter alia, channel status, volume status, and picture control status; and may apply to one or more of the devices comprising the overall media system. For example, in system 24 the volume function may be performed by the audio amplifier′ and the channel selection may be performed by a combination of the TV set and the Cable Box. In such a case a return to channel function may involve switching of TV inputs as a well as changing channel numbers on one or both of the TV and Cable box. The state of the media system is frequently and easily altered, typically by a user, from a first state to a second state. Generally, the system is altered most often as a result of channel surfing, or other parameter changes such as the muting of the audible portion of a program.
[0068] Prior to altering the media system, the user would, generally, actuate the surf key 50 to store the first state of the media system, which includes storing the primary channel and any other desired parameters. Such actuation also sets a timer for a predetermined interval. Upon expiration of the predetermined interval, the user may be notified via visible or audible indicators. Such notification may comprise disengaging the mute button, returning the system back to its first state, or displaying the first channel visual component within a visual display of the second channel, such as picture-in-picture, or any sufficiently notable change such that the user is notified. Preferably the primary media channel is monitored while the secondary media channels are altered. For example, channel 2 , as the primary channel, would be monitored while the user surfs through the other available channels, i.e., the secondary media channels.
[0069] In systems where the signal for the current channel is not available, the remote control 23 may be programmed with the available channels through known means. As it is desirable to know the current channel for some applications of this event, it is useful to monitor an identifier of the media channel. This may be done, for example, by updating to a current channel register the identifier of the current channel, preferably using a channel entry method such as described in U.S. Pat. No. 6,029,239 or alternatively by monitoring number button presses and the intervals between them in order to derive channel information. In such an example, direct entry of the channel digits could be transferred to the register, and channel up/down controls would likewise effect the identifier stored in the current channel register. Preferably, however, the television 36 could transmit the current channel to the remote.
[0070] To reduce processing, the current register may preferably be updated after a delay of several seconds or longer. Thus, for example, changing through the channel would not update the current register because the user is just traversing the available channels to arrive at the soon-to-be-current channel. After the user has paused at the now current channel, the current channel register may update with the current channel information read from the available channel cue in the current pointer location. Then, if the user wants to surf, or alter the system but return to the primary, stored channel, the user presses the surf button 50 . Depressing the surf button 50 records the media system's current state and starts available timers. If monitoring is available, that may be initiated as well. Upon occurrence of a predetermined event, the system may return to the first state, or merely notify the user. In an alternative embodiment, the remote 23 ′ plays, in reverse order, all of the commands entered between selecting the surf key 50 and either selecting the surf key 50 again, or the expiration of one of the timers. If desired, non-channel control and non-audio commands can be filtered out such that only the channel and audio status are reset.
[0071] While the invention has been particularly shown and described with reference to particular embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. The scope of the claimed invention is intended to be defined by following claims as they would be understood by one of ordinary skill in the art with appropriate reference to the specification.
[0072] As to U.S. patent application Ser. No. 09/611,620, filed Jul. 6, 2000, this application discloses an exemplary consumer electronic system 210 . The system 210 includes a consumer electronic device 212 , which is a DVD player 213 in a preferred embodiment. Other devices operable with removable digital media are envisioned as being within the scope of the invention. Accordingly, the system preferably includes at least one removable digital medium. In the system 210 shown in FIG. 8 the consumer electronic device 212 is adapted to operate with a digital video disc 214 or a digital memory card 216 .
[0073] The digital memory card may be a secure memory card such as may be obtained from Matsushita Electronic Industrial, also known as Panasonic, SanDisc, or Toshiba Corporation or other types known in the art. In one embodiment the secure digital memory card (SD memory card) is approximately 24 mm by 32 mm by 2.1 mm 9 pins. It has a capacity from 32 MB (megabytes) to 250 MB. Generally SD memory cards or memory sticks may be rated at different respective sizes, e.g., from 2 MB to 10 MB. Preferably, the SD card is SDMI (Secure Digital Music) compliant.
[0074] The system 210 also includes a control module 220 which in the preferred embodiment is a hand-held remote control 221 . The remote control 221 includes navigation keys 222 . In an alternative embodiment the navigation keys 222 may be integral navigation keys 222 ′. In FIG. 8 the integral navigation keys 222 ′ are integral with the player 213 .
[0075] FIG. 9 shows an enlarged view of some of the navigation keys of remote control 221 , including MENU key 224 , SELECT key 226 , and the four directional keys 228 , 230 , 232 , and 234 . FIG. 9 also shows the JUMP key 236 .
[0076] The remote control 221 , preferably includes mode keys 238 for allowing the remote control to change, in the embodiment shown in FIG. 8 , between DVD, VCR, TV and cable modes. Remote control 221 generally includes standard keys such as volume key 240 and channel key 242 . Digit keys 244 provide for direct entry and numeric response to queries which so require. The remote control 221 is also generally provided with a power key 246 and set up means, such as programming initiated with set up key 248 .
[0077] It is desirable to provide the remote control 221 with additional navigation keys such as a GUIDE key 250 , an INFO key 252 , PAGE UP and PAGE DOWN keys 254 , 256 , and an EXIT key 258 . Preferably the remote control 221 is provided with, so called “quick macro” keys “LAST” 260 and “DO” 262 which will be described in further detail below.
[0078] FIG. 10 shows a flowchart 266 representing the basic logic, of one preferred embodiment, that may be carried out every time a key press of the remote control 221 is detected (step 70 ). Flowchart 268 of FIG. 11 , which is discussed in more detail below, represents one method of storing a key's value.
[0079] In one embodiment, the remote control 221 checks to see if the key pressed is the JUMP key 236 , i.e, remote control 221 monitors key activation. If the JUMP key is activated, the remote control 221 initiates (at step 72 ) playback of the currently stored sequence of the Menu navigation key presses. This will be described in more detail in conjunction with FIG. 13 .
[0080] If the key activated is not the JUMP key, the remote control 221 then determines if its current mode setting is “DVD,” for example. If not DVD mode, the user interface, e.g., the remote control 221 , bypasses any further checking and performs the key function in the usual manner. This process ensures that only menu and navigation key presses applicable to control of the desired digital player device (i.e., the DVD player) are captured. (If the remote in question were a “single mode” or “modeless” unit, i.e. capable of controlling only the DVD player, for example, this step may easily be omitted.)
[0081] If the remote control 221 is in DVD mode, the remote 221 then checks to see if the activated key is the menu function (or MENU key) 224 . If the MENU key 224 is pressed, one may assume this action to be the start of a new series (new sequence) of menu navigation keystrokes by the user. The sequence storage (e.g., sequence table 281 ) is then set to “empty” by setting the “IN” pointer 290 equal to the “OUT” pointer 292 . Other methods of clearing the key sequence memory will be apparent. (The functioning and description of the IN and OUT pointers will be described in more detail in conjunction with FIGS. 11 and 12 below.) Note that in the process set forth in FIG. 10 , the MENU key 224 is not stored in the sequence table 281 . This is advantageous if MENU key 224 is always the start of a new navigation sequence. Thus, one need not use memory space to store the MENU key 224 . In other implementations, there may be more than one key which initiates entry into a menu system (e.g., “GUIDE,” “INFO” etc., used alone or in conjunction with a “MENU” button, and so forth) in which case the initiating key function should be stored as well for playback.
[0082] The remote 221 determines whether the key pressed is one of the set of functions associated with the menu navigation (up, down, left, right, select and play in this example) at step 274 . If the key pressed is a navigation key, the remote 221 stores the key value into the sequence table 281 at step 276 , if a navigation key was not pressed, the storage step is bypassed. This filtering means may occur when the values are being loaded into memory, or upon execution of the stored sequence. The storage process is discussed more fully below with reference to FIGS. 11 and 12 .
[0083] In a preferred embodiment, the remote 221 , at step 278 , completes the processing and sends the transmitted, preferably IR, function corresponding to that pressed key. RF technology and or communication techniques are also compatible with the inventor.
[0084] FIGS. 11 and 12 depict the process for saving a sequence of menu navigation keystrokes 280 (see FIG. 12 d ). FIG. 11 shows a flowchart 268 representing how data is entered into the sequence table 281 using the IN pointer. First the IN pointer 290 (see FIG. 12 ) at step 294 is checked against a maximum predetermined value. This is one method of preventing overflow of table data into areas of memory allocated to other remote control functions. Other methods safeguarding memory will be apparent to those of skill in the art. Without this safeguard, such an overflow could, for example, be created by a user idly jiggling one of the navigation keys while not actually using the DVD device. The maximum IN limit can be set to any value compatible with the aforementioned goal of memory protection. However, for practical purposes, a number on the order of 32 is expected to be more than adequate.
[0085] If the maximum IN value has not been reached, the remote 221 simply stores the current key value at the location indicated by the IN pointer 290 increments the IN pointer 290 to point to the next available location (see FIGS. 12( a )- 12 ( d )) and returns to the main routine.
[0086] Referring to FIG. 12 , one method of storing the navigation sequence is by controlling two pointers to a table space in memory, e.g., the sequence table 281 . The pointers are labeled IN 290 and OUT 292 . The IN pointer 290 indicates where the next keystroke to be stored will be placed, while the OUT pointer 292 indicates where playback of a key sequence will begin. During entry of data into the table 281 , the OUT pointer 292 never changes. (Conversely, during retrieval of data from the table 281 , the IN pointer 290 never changes.) Other methods of storage will be apparent to those of skill in the art from the teachings disclosed herein. FIGS. 12( a )- 12 ( d ) show the progression of table data contents and pointers as a sequence of keystrokes “DOWN ARROW,” “RIGHT ARROW,” and “SELECT” are stored.
[0087] FIG. 13 shows a playback logic flowchart 2100 representing a method to effect playback of the stored keystrokes 282 once the JUMP key 236 is activated. (More generally, a sequence may be stored between a first predetermined key and a second predetermined key, and playback initiated by a third predetermined key.) First the remote control 221 checks to see if it is currently in the applicable mode, e.g., DVD mode. If not, it switches to that mode (i.e., the JUMP key 236 effects control of the DVD device regardless of the current mode of the remote control 221 .) In the playback implementation shown in flowchart 2100 , the remote contr 221 automatically sends the implied “MENU” command (because the MENU command was not stored to save memory).
[0088] The logic then checks to see if the OUT pointer 292 equals the IN pointer 290 . When the keystroke storage table (the sequence table) 281 is empty, the OUT pointer 292 equals the IN pointer 290 . A sequence table 281 that is empty is shown in FIG. 12( a ). If the OUT pointer 292 equals the IN pointer 290 , the remote control 221 then preferable exits the DVD menu mode. Though the menu mode has been exited, the secondary material is still accessible. This is particularly so when, for example, the menu system was navigated to add an alternative viewing angle, or show special effects features, etc. along with play of the primary material.
[0089] In this embodiment pressing the JUMP key 236 when no key sequence has been stored is the equivalent of, or results in the same effect as, pressing the “MENU” key 224 . That is the menu screen is displayed upon activation of JUMP key 236 .
[0090] If the OUT pointer 292 does not match the IN pointer 290 , the key data at the location corresponding to the OUT pointer 292 is retrieved, and then the corresponding IR command is transmitted. Programming then increments the OUT pointer value and repeats the OUT=IN? test. If OUT and IN are not equal, the control module continues to repeat the retrieve and transmit sequence until the OUT=IN? test is true. Alternative methods of changing and comparing pointer values is acceptable. More generally still, other methods of key storage and retrieval are acceptable and within the scope of the invention described herein.
[0091] When the two pointers are equal after the key sequence has been transmitted, the sequence playback is complete and the unit 221 resets the OUT pointer 292 back to its starting value (i.e., the unit 221 readies itself to play the same sequence back again if required) and then returns to the main routine. In this manner, one may navigate material, e.g., secondary material, to a desired screen. Intermediate screens may be displayed or the logic may allow the user to go directly to the desired screen.
[0092] In some applications, it is anticipated that the time interval between key presses may be significant, i.e., relevant to the menu selection, etc. For example, where a key press causes a sub-menu display to be initiated, and the target device must wait to recognize a subsequent selection key press until the sub-menu display is ready. In these and other cases, it is advantageous to store not only key press values, but also the elapsed time between the key presses and then replicate these pauses during playback—i.e., a “real time” playback. FIGS. 14-16 show an alternative approach for storing and playing back key sequences. The methods discussed in reference to FIGS. 14-16 account for an interkey pause sequence 282 (see FIG. 15 ), or a sequence having an interkey pause time. For comparison and clarity, FIGS. 14-16 show how this feature can be implemented by modification of the routines shown in FIGS. 10-13 .
[0093] FIG. 14 depicts a flowchart 2120 representing a process for interkey delay storage. The flowchart 2120 is modification of the routine shown in FIG. 10 . Flowchart 2120 is modified to include capture and storage of the interkey pause time 284 (see FIGS. 15( c ) and 15 ( g )). The initial selection process (e.g., determining whether a key press is a DVD menu navigation key) and storage of the key press value remains similar. However, after transmitting the key function, the remote 221 remains active to measure the elapsed time between this keystroke and the next. When the next key press in a sequence is detected, or if a predetermined maximum time has elapsed (e.g., 5 seconds), the remote 221 times the value and stores it as a second entry into the sequence table 281 (see FIG. 15( g )).
[0094] FIG. 15 shows this time delay storage process in more detail regarding the sequence storage table s 81 . The same sequence of keystrokes in FIG. 13 is used. Playback of such a sequence of interleaved key values and delay times is shown in flowchart 2130 of FIG. 16 . Note that the delay time saved after the final key press need not be implemented.
[0095] The embodiments described above offers the user a convenient way to, among other features, repeat a sequence, preferably the last sequence, of keystrokes applicable to a particular sub-set of keys on a user interface. Features such as the “user macro” described in U.S. Pat. No. 5,959,751 allow the user to program often-used fixed sequences of keystrokes for controlling hardware, e.g., controlling the player vice accessing the storage medium, on a semi-permanent basis.
[0096] Another desirable feature would be a sequence definition process that falls somewhere between the “fully automatic,” and filter capable, systems described in the above embodiments and the semi-permanent system described in U.S. Pat. '751. An objective is to allow the user to very quickly program and use a sequence of keystrokes of short-term usefulness, for example, for the duration of a show or sports event or portion of the video. This may be particularly useful in reviewing secondary material where one may want to see the same scenes multiple times from different angles, rather than watch the scenes simply play out. Further, this “DO” feature can be implemented as a sub set of the JUMP feature wherein the DO key sequence is not stored as part of the JUMP sequence.
[0097] One method of implementing a DO feature is represented by Flowchart 2140 of FIG. 17 with the DO key, number 262 shown in FIG. 8 . In general, if the user presses and holds this special, or predetermined key (DO key 262 ), the remote 221 will memorize all other keystrokes entered while DO is held down. If, however, the user presses and releases DO with no intervening input of other keys, the remote 221 will play back the last-entered DO sequence. Other variations on this exemplary process will be apparent from the teachings disclosed herein.
[0098] FIG. 17 shows Flowchart 2140 setting forth an embodiment of the above-described process. When the DO key 262 is initially pressed, the remote 221 enters a state where it monitors the other keys on the unit, storing key values into a DO table for as long as the DO key remains depressed, i.e., adding keys to the DO sequence table. Storage of key values may be performed in exactly the same ways as previously described in conjunction with FIGS. 11 and 12 , except, perhaps to a second storage location independent of any jump key sequence that may exist. This provides for both JUMP and DO features. (When the DO key 262 is released, the remote 221 will then play back the storage sequence of keystrokes.) In the implementation shown in FIG. 17 , it may be noted that the key sequence entered is played back immediately after entry, by way of confirmation. It will be appreciated that minor changes in logic can be made to effect playback of the sequence only on subsequent presses of the DO key 262 . Also, the capture of inter-key timings can be included if desired, in a manner similar to that described above in conjunction with FIGS. 14-16 .
[0099] In another embodiment, the user interface, e.g., a control module 220 , reads at least one menu from the material provided on the removable digital medium 214 and stores the at least one menu in memory. In a preferred variation of this embodiment, the at least one menu is displayed on the control module 220 . FIG. 18 shows a remote control 2150 capable of displaying the at least one menu on a display screen 2152 . In a preferred embodiment, the display screen 2152 is an LCD screen. The display screen 2152 , preferably via a touch screen, provides access to secondary material, such as special effects (F/X), different angle views (ANGLE), multiple angle views (Multi/Angle), and other such material as discussed previously.
[0100] In yet another embodiment, the remote control unit includes a larger LCD capable of displaying the menu graphic(s) and/or buttons as defined by the material provided on the removable digital medium and transmitted to the remote by the player hardware. If this LCD is also equipped with touch screen capability, the arrow keys may be dispensed with as the remote can automatically generate the appropriate sequence of navigation keystrokes followed by a “select” command in response to a single touch by the user on the desired choice. Alternatively, the remote can send just an “x-y” coordinate for the button touched and the player hardware can decode this to the appropriate function command.
[0101] FIG. 12 depicts how a typical DVD menu tree 2160 may be arranged in terms of the choices 2162 - 2174 offered the viewer. In a conventional system, these would be displayed on the TV screen and navigated using the directional keys on the remote control. However, an alternative approach on DVD players equipped to communicate with a two-way capable remote control including a touch screen LCD display might be to present the menu choices as a series of displays, e.g., 2164 - 2168 , on the remote control itself. Selection is performed by the user touching the desired choice.
[0102] FIGS. 20 and 21 show how such an application including a display menu may appear. FIG. 20 shows a remote control 2180 having a touch screen display 2182 . The first two menu pages 2162 and 2164 of the tree 2160 are shown in FIG. 19 as these might appear in a “text only” format. Text screen 2164 may be obtained by touching heading 2184 (“scene selection”) on display 2162 . FIG. 21 shows portions 2190 and 2192 of a different menu tree which in this case includes black and white graphics 2194 - 2202 which are downloaded to the remote 2180 to enhance the menu display appearance.
[0103] From the foregoing it will be apparent that a primary aspect of the invention is directed toward an improved remote control characterized in that the user interface is enhanced. In one embodiment, the enhancement is achieved by improving the navigation system. In one aspect, the navigation system is improved through use of means for accessing desired media in an expeditious manner. In another embodiment, the user interface is improved through an improved menu display. In a particular embodiment, the navigation system is enhanced through use of an improved display screen.
[0104] Accordingly, another aspect of the invention is directed toward means for achieving such user interface enhancements. In a particular embodiment, a microcontroller (a microprocessor combined with memory) is proved with the interface enhancement means.
[0105] While the invention has been particularly shown and described with reference to particular embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. | A system includes a consumer electronic device adapted to render a media content and a hand-held, portable device having a touch screen display, a transmitter, a receiver, and a processing unit. The processing unit of the hand-held, portable device uses data related to the media content received via the receiver to cause command icons related to rendering of the media content to be defined and displayed in the touch screen display and to cause the transmitter to transmit one or more commands for controlling a functional operation related to rendering of the media content by the consumer electronic device in response to a user interaction with one or more of the command icons caused to displayed in the touch screen display. | 7 |
TECHNICAL FIELD
The present disclosure generally relates to the field of implantable ocular devices, pharmaceutics, and methods of drug delivery to the eye. More particularly, the present disclosure relates to implantable ocular devices for sustained delivery of a therapeutic compound to the eye.
BACKGROUND
Glaucoma is the leading cause of blindness worldwide and the most common cause of optic neuropathy. Various forms of glaucoma leads to elevated intraocular pressure, and may also lead to damage to the optic nerve. If glaucoma or ocular hypertension is detected early and treated promptly with medications that effectively reduce elevated intraocular pressure, loss of visual function or its progressive deterioration can generally be ameliorated. Drug therapies that have been proven useful for the reduction of intraocular pressure include both agents that decrease aqueous humor production and agents that increase the outflow facility. Such therapies may be administrated in a number of different ways.
One example of administrating suitable therapies includes topical application to the eye, such as eye drops. However, one of the limitations of topical therapy is inadequate and irregular delivery of the therapeutic agent to the eye. For example, when an eye drop is applied to the eye, a substantial portion of the drop may be lost due to overflow of the lid margin onto the cheek. Moreover, compliance with a necessary drug regime is also always an issue with this method. For example, for some medications, 4 to 5 applications a day are required to achieve therapeutic drug levels.
Other suitable delivery mechanisms for therapeutic devices include injection at the pars plana. However, aside from discomfort for the patient, this method also requires that the patient return monthly.
Various ocular drug delivery implants have also been employed in an effort to improve and prolong drug delivery. One such example includes a reservoir drug-delivery device. A reservoir drug-delivery device is a device that contains a receptacle or chamber for storing the drug while implanted in the eye. However, reservoir drug devices are difficult to manufacture, difficult to achieve drug content uniformity (i.e., device to device reproducibility, particularly with small ocular devices), and carry the risk of a “dose dump” if they are punctured.
Another type of drug delivery device is a punctal plug device that is inserted into one or more of the tear ducts within the eye. However, because the geometry of the tear duct varies from person to person, there have been problems with plugs migrating within the tear duct. Other issues occur whereby the punctal plugs may inadvertently fall out of the eye.
Accordingly, there exists a need for a therapeutic delivery mechanism that allows for controlled and sustained release of ophthalmic drugs over a predetermined period of time, while sufficiently securing the delivery device within the eye so as to prevent inadvertent migration or removal of the delivery device.
BRIEF SUMMARY
A punctal plug is disclosed, wherein the punctal plug includes a body portion and a retaining portion. The body portion is defined by an open distal end, an open proximal end and a wall portion. The wall portion further includes at least one window extending therethrough. The retaining flange is configured to have an outer periphery that is larger than the outer periphery of the body portion. A method of delivering a therapeutic agent to a patient using a punctal plug is also disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the present disclosure will now by described by way of example in greater detail with reference to the attached figures, in which:
FIG. 1 is a perspective view of a distal end of a delivery device with a punctal plug releasably connected thereto;
FIG. 2 is a perspective view of an exemplary embodiment of a punctal plug;
FIG. 3 is a perspective view of the punctal plug of FIG. 2 with an exemplary therapeutic compound disposed therein;
FIG. 4 is a front, partially sectional view of a lacrimal duct system of a mammalian eye with a punctal plug disposed therein; and
FIG. 5 is an enlarged front sectional view of the lacrimal canaliculi of FIG. 4 , with a punctal plug disposed therein.
DETAILED DESCRIPTION
Referring now to the discussion that follows and also to the drawings, illustrative approaches to the disclosed devices and methods are shown in detail. Although the drawings represent some possible approaches, the drawings are not necessarily to scale and certain features may be exaggerated, removed, or partially sectioned to better illustrate and explain the present disclosure. Further the descriptions set forth herein are not intended to be exhaustive or otherwise limit or restrict the claims to the precise forms and configurations shown in the drawings and disclosed in the following detailed description.
Referring to FIGS. 1-5 , an exemplary arrangement of a punctal plug 10 is illustrated. Punctal plug 10 includes a body portion 12 and a retaining flange 14 . Body portion 12 includes an open distal end 16 and an open proximal end 18 that is in communication with retaining flange 14 . Formed within body portion 12 is at least one window 20 . In one exemplary arrangement, a plurality of windows 20 are formed, separated by land members 22 . Windows 20 may be formed so as to be spaced equi-distant from one another. Body portion 12 of punctal plug 10 may be made from a biocompatible material such as titanium, stainless steel, plastics, elastomers or any other material which may be formed into body portion 12 .
In one exemplary arrangement, at least one cross-member 24 is disposed within body portion 12 . Alternatively, a pair of cross-members 24 is provided. Each cross-member 24 is defined by ends 25 that are fixedly secured to an inner wall 26 of body portion 12 . In one exemplary arrangement, cross-members 24 are arranged within body portion 12 in an intersecting manner, such that one cross-member 24 a is disposed above the other cross-member 24 b . In another exemplary arrangement, cross-members 24 a , 24 b are integrally connected together so as to lie along a common plane (not shown). Cross-members 24 are also constructed of a biocompatible material, whereby the material allows for some degree of flexibility, as will be explained below in further detail.
Retaining flange 14 is defined by a distal end 28 and a proximal end 30 . Distal end 28 is defined by a diameter that generally corresponds to the diameter of proximal end 18 of body portion 12 . Proximal end 30 is defined by a diameter that is larger than the diameter of distal end 28 and body portion 12 . In one exemplary arrangement, an interior surface 32 slopes outwardly from distal end 28 to proximal end 30 .
As shown in FIG. 1 , a delivery device 34 is shown releasably connected to punctal plug 10 . More specifically, delivery device 34 includes a delivery cannula 36 having a distal end that secures to interior surface 32 of retaining flange 14 . In one exemplary arrangement, the distal end of delivery cannula 36 includes retaining apertures (not shown) that releasably receives retaining members 38 that extend from interior surface 32 . More specifically, retaining members 38 may be constructed of a flexible material that permits selective engagement and disengagement between punctal plug 10 and delivery cannula 36 . Alternatively, the distal end of delivery cannula 36 may be provided with retaining members that engage complementary retaining apertures (not shown) formed on interior surface 32 . Other suitable mechanisms for releasably securing punctal plug 10 to deliver cannula 36 are also within the scope the present disclosure.
Turning now to FIGS. 4 and 5 , the lacrimal duct system 100 of a mammalian eye 102 will be described. System 100 includes a lower punctum 104 connected to a lower lacrimal canaliculus 106 , and an upper punctum 108 connected to an upper lacrimal canaliculus 110 . Canaliculli 106 and 110 are connected to a lacrimal sac 112 and a nasolacrimal duct 114 . A lacrimal gland 116 is connected to eye 102 via a lacrimal duct 118 . In general, tears are produced by lacrimal gland 116 and are provided to eye 102 via lacrimal duct 118 , and tears are drained from 102 via punctum 108 and canaliculus 110 , punctum 104 and canaliculus 106 , and nasolacrimal duct 114 .
In operation, punctal plug 10 is secured to the distal end of delivery cannula 36 . Delivery cannula 36 is secured to a suitable drug supply. Once secured to delivery cannula 36 , but before a drug 40 is injected into punctal plug 10 via delivery cannula 36 , distal end 16 is implanted into either lower or upper punctums 104 , 106 . In FIGS. 4 and 5 , distal end 16 of body portion 12 of punctal plug 10 is implanted into lower punctum 104 until retaining flange 14 contacts an outer surface of the eye. Once positioned, a suitable therapeutic drug is injected through delivery cannula 36 and into punctal plug 10 . More specifically, a phase transition drug formulation 40 is injected through delivery cannula 36 into punctal plug 10 . Because body portion 12 includes at least one window 20 , a portion of phase transition drug formulation 40 flows through window 20 and some also flows out distal end 16 of body portion 12 , as shown in FIG. 3 . This action causes drug formulation to conform to the irregular shape of the walls of lower punctum 104 . As drug formulation 40 cools, it solidifies into a drug bolus such that the drug formulation 40 serves to lock punctal plug 10 into place in lower punctum 104 , thereby preventing migration of punctal plug 10 , as well as preventing inadvertent dislodgement of punctal plug 10 from punctum 104 . As shown in FIG. 5 , because drug formulation is able to conform to the irregularities in shape of the punctum, puntal plug 10 is able to adapt to various contours of the respective punctums without requiring unique geometry for each plug 10 for each individual into which the puntal plug 10 is inserted.
Further, when injected, drug formulation 40 also flows around cross-members 24 . Because cross-members 24 have some degree of flexibility, as drug formulation 40 flows into punctal plug 10 , cross-members 24 serve to generally retain the basic shape of punctal plug 10 to keep punctal plug 10 properly positioned within the punctum 104 , but allow some degree of flexing of body portion 12 . Further, as drug formulation 40 cools, the drug bolus attaches to cross-members 24 , thereby locking the drug bolus into punctal plug 10 , such that the drug bolus itself is prevented from migrating down punctums 104 and 106 . Windows 20 also may aid in the locking effort.
Once drug formulation 40 has been injected and permitted to solidify, punctal plug 10 is released from delivery cannula 36 , thereby leaving punctal plug 10 in place within the eye. In one embodiment, forceps may be utilized to release delivery cannula 36 from punctal plug 10 . Drug formulation 40 , which is retained within punctal plug 10 , is configured to allow for sustained release of ophthalmic drugs over a predetermined period of time (e.g., 3-6 months). Other predetermined time periods are also possible (e.g., 1-2 days, 1-2 months, 1 year, etc). As drug formulation 40 is released into the patient over time, the drug bolus shrinks such that punctal plug detaches from the interior wall of punctum 104 , 106 . Once so released, punctal plug 10 may be easily removed in a non-invasive manner.
It will be appreciated that the devices and methods described herein have broad applications. The foregoing embodiments were chosen and described in order to illustrate principles of the methods and apparatuses as well as some practical applications. The preceding description enables others skilled in the art to utilize methods and apparatuses in various embodiments and with various modifications as are suited to the particular use contemplated. In accordance with the provisions of the patent statutes, the principles and modes of operation of this invention have been explained and illustrated in exemplary embodiments.
It is intended that the scope of the present methods and apparatuses be defined by the following claims. However, it must be understood that this invention may be practiced otherwise than is specifically explained and illustrated without departing from its spirit or scope. It should be understood by those skilled in the art that various alternatives to the embodiments described herein may be employed in practicing the claims without departing from the spirit and scope as defined in the following claims. The scope of the invention should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future examples. Furthermore, all terms used in the claims are intended to be given their broadest reasonable constructions and their ordinary meanings as understood by those skilled in the art unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as “a,” “the,” “said,” etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary. It is intended that the following claims define the scope of the invention and that the method and apparatus within the scope of these claims and their equivalents be covered thereby. In sum, it should be understood that the invention is capable of modification and variation and is limited only by the following claims. | A punctal plug is disclosed, wherein the punctal plug includes a body portion and a retaining portion. The body portion is defined by an open distal end, an open proximal end and a wall portion. The wall portion further includes at least one window extending therethrough. The retaining flange is configured to have an outer periphery that is larger than the outer periphery of the body portion. A method of delivering a therapeutic agent to a patient using a punctal plug is also disclosed. | 0 |
INTRODUCTION
[0001] The present invention relates to methods for the production of sol-gel based matrixes as well as sol-gel based matrixes obtainable by such methods. The sol-gels of the present invention are useful for various purposes including use in sensors for measuring of pH, radiation, oxygen concentration etc. due to their high stability and porosity. Composites comprising the sol-gels of the present invention and a platform of microstructure area are also disclosed. Methods for preparing these composites or sensors are provided se well.
BACKGROUND OF THE INVENTION
[0002] First generation optical sensors are currently being introduced in biotechnological production platforms. The sensors are composed of five different units, excluding the fiber optical connectors: i) light source, ii) substrate, iii) matrix, iv) indicator dye components, and v) detector. 1-5
[0003] Light sources and detectors are highly developed and is just a question of costs. The substrate has to be chosen based on the platform in which the sensing will take place, typically a glass or a polymer support is used. The key parameter regarding the substrate is that the matrix material must be able to be at least partly immobilized in or on the substrate.
[0004] The wish list for the matrix material is long: the matrix material should allow the analytes to pass through the film as unhindered as possible, it should encapsulate the sensor molecules, it should be transparent and have a low auto-fluorescence, and it has to be stable in biological media for extended periods of time. The indicator dye components may be either a single ratiometric pH responsive dye, or two dyes with similar properties. The latter is only possible if the physical stability of the matrix ensures that no dye is lost to the medium.
[0005] The benchmark in materials for optical sensors has been set in sensors, where fluorescein has been used as the indicator dye component 4-8 despite the poor photostability of fluorescein. 5 The critical parameters are the response time of the sensor, the leakage of the dye, the stability of the signal and the response to pH. While leakage of the highly water soluble fluorescein from the prior art optical sensors has not been completely removed, 9 other more lipophilic dyes have been successfully encapsulated in sol-gel matrices. 10, 11 However, even lipophilic dyes may be prone to leakage during long term use or in lipophlic/amphiphilic environments.
[0006] Preparation of organically modified silicates (ORMOSILs) using alkyl and 3-glycidoxypropyl substituted trialkoxysilanes and various polymerization conditions have been reported previously in the scientific literature.1, 12, 13 Leakage has been controlled either using apolar additives 11, 14 or by attaching the dyes to bulky macromolecules.6, 7, 15, 16 It has been reported that Lewis acids can be a catalyst for polymerization of 3-glycidoxypropyltrialkoxysilanes, accelerating both the polyether and the polysiloxane formation. 12, 13, 17
[0007] WO 2009/020259 discloses in example 2 a method in which 3-glycidoxypropyltrimethoxysilane (GPTMS), methyltriethoxysilane (MTES), ethanol (6.95 mM) and 35% HCl were mixed together and stirred at room temperature for three days to induce a condensation reaction. To the sol-gel solution thus prepared, 1 mM HPTS solution, which had been dissolved in ethanol was added to give a HPTS mixture solution. The HPTS mixture solution was evenly coated onto the bottom surface of wells of a microtiter plate to prepare a fluorescent sensing membrane that can be used for detection of carbon dioxide. The sol-gel solution comprising coated HPTS was dried at room temperature for five days and further dried at 70° C. for two days for improving a mechanical strength and surface smoothness. WO 2009/020259 uses HCl as the initiator and the indicator moiety (HPTS) is non-covalently attached to a silane.
[0008] WO 2004/077035 discloses a CO 2 sensor comprising a pH-indicator and a porous sol-gel matrix. The pH-indicator may be hydroxypyrene trisulfonate (HPTS) and immobilised in the sol-gel. The sol-gel may be prepared from the monomer ethyltriethoxysilane (ETEOS). In the specific method, two silanes are used (trimethylsilylpropane and triethoxysilane). However, none of the silanes suggested in the description contains an epoxy group. Furthermore, the indicator moiety is not covalently linked to a silane.
[0009] WO 12/032342 discloses a sensor comprising a sol-gel layer incorporating a phosphorescent material, such as ruthenium oxide (Ru0 2 ). The sensor may be used for measuring the O 2 or the H 2 S concentration. Details on the monomers used in the sol-gel are not disclosed.
[0010] J. Mater. Chem. 2012, 22, 11720 shows a method in which two monomers (ETEOS and GPTMS) are used in the sol-gel. The monomers are separately reacted and methylimidazole is used to initiate the reaction of GPTMS. When the separately reacted monomers are mixed, the indicator moiety (HPTS) is added. Thus, a Lewis acid for initiating the reaction is not used and an indicator moiety (e.g. HPTS) is not covalently attached to a silane. Methods based on catalysis by methylimidazole may be inferior, as tests performed by the present inventors have shown that methylimidazole reacts and form fluorescent compounds, which are immobilized in the sol-gel.
[0011] It is the purpose of the present invention to improve the porosity of sol-gel materials for optical sensing, while at the same time maintaining a high physical stability and a low auto-fluorescence. A high porosity results in a short response time, which makes it possible to react on a change faster.
SUMMARY OF THE INVENTION
[0012] The present invention relates to a method for the production of a sol-gel based matrix comprising the steps of:
[0013] a) providing a first alkoxysilane of the general formula:
[0000] R 1 —Si(OR 2 ) 3
[0014] and a second alkoxysilane of the general formula:
[0000]
[0015] wherein
[0016] R 1 represents a straight or branched C 1 -C 6 alkyl or C 2 -C 6 alkenyl, a C 3 -C 6 cycloalkyl, a C 1 -C 6 aminoalkyl, a C 1 -C 6 hydroxyalkyl, a C 1 -C 6 cyanoalkyl, a phenyl, a group of the formula —Y—(X—Y) n H, wherein Y independently is selected from straight or branched C 1 -C 6 alkylene, X is a hetero atom or group selected among O, S, NH, and n is an integer of 1-5,
[0017] or R 1 represents a C 1 -C 6 alkyl substituted with a group Z,
[0018] wherein Z independently is selected form the group comprising hydrogen, cyano, halogen, hydroxy, nitro, amide C 1 -C 24 -alkyl, C 1 -C 24 -haloalkyl, C 2 -C 24 -alkenyl, C 2 -C 24 -alkynyl, aryl, C 1 -C 24 -alkoxy, C 1 -C 24 -alkylsulfonyl, amino, aminocarbonyl, aminothiocarbonyl, aminocarbonylamino, aminothiocarbonylamino, aminocarbonyloxy, aminosulfonyl, aminosulfonyloxy, aminosulfonylamino, amidino, carboxyl, carboxyl ester comprising a C 1 -C 6 alkyl alcohol moiety, (carboxyl ester)amino comprising a C 1 -C 6 alkyl alcohol moiety, (carboxyl ester)oxy comprising a C 1 -C 6 alkyl alcohol moiety, sulfonyl, sulfonyloxy, thiol, thiocarbonyl, C 1 -C 24 -alkylthio, 5 or 6 membered heteroaryl, or a C 3 -C 7 cycloalkyl;
[0019] R 2 independently represents a straight or branched C 1 -C 6 alkyl; and
[0020] R 3 represents a linker chosen from a group of the formula
[0000] —R 4 —(X—R 4 ) n —
[0021] wherein R 4 independently is selected from straight or branched C 2 -C 6 alkylene, C 2 -C 24 -haloalkylene, X is a hetero atom or group selected among O, S, NH, and n is an integer of 0-12,
[0022] b) preparing a first sol-gel component by polymerisation of the first alkoxysilane in the presence of an acid catalyst,
[0023] c) preparing a second sol-gel component by polymerisation of the second alkoxysilane in the presence of an Lewis acid catalyst,
[0024] d) Mixing the first sol-gel component and the second sol-gel component for the preparation of a sol-gel based matrix.
[0025] It was discovered by the inventors that the use of a Lewis acid for the catalysis of the second sol-gel component did not result in the formation of fluorescent compounds or other by-products, as was the case for methylimidazole. Furthermore, the Lewis acid showed the added potential of being incorporated in the sol-gel, thus adding to the porosity.
[0026] In another aspect of the present invention an additional alkoxysilane is added to step b) and/or c), said additional alkoxysilane being of the formula:
[0000] R 5 —Si(OR 2 ) 3
[0027] wherein R 2 is as defined above and R 5 represents a group having covalently attached an indicator or reference dye.
[0028] While the present invention may work well in many applications with an indicator dye or reference dye non-covalently attached to the silane scaffold matrix a more durable sol-gel based matrix may be obtained by attaching the indicator or reference dye covalently to the matrix. A more stable product may collect reliable data for prolonged time. The added physical stability may further broaden the application of the sensor incorporating the sol-gel based matrix to applications in which the indicator or reference dye may otherwise easily leak to the media.
[0029] The indicator dye or the reference dye may be attached to the silane matrix in a variety of ways. In a certain embodiment R 5 is of the general formula
[0000] —R 3 —NH—C(═O)—X—R 3 -Q
[0030] wherein R 3 is as defined above and independently selected, and Q represents an indicator and/or a reference dye.
[0031] The reference dye and/or the indicator dye can be selected from a variety of possibilities well known for the person skilled in the art. According to a certain aspect of the present invention Q is an indicator dye derived from 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS), fluorescein, or rhodamine B.
[0032] The type of reference dye is not particularly limited to a certain class of compounds. Thus, in an embodiment of the present invention Q in the above formula is a reference dye derived from triangulenium compounds, acridinium compounds, ruthenium doped sol-gel particles, ruthenium-based compounds with a-diimine ligands, porphorin with Pt or Pd as the central metal atom, Ru(bpy) 2 (dpp)Cl 2 , Ru(bpy) 3 Cl 2 , a lanthanide containing complex, or polymeric metal containing structure.
[0033] According to the present invention a Lewis acid is used in the polymerization of the second sol-gel component. Definitions of Lewis acids may vary from textbook to textbook. The IUPAC definition is “a molecular entity (and the corresponding chemical species) that is an electron-pair acceptor and therefore able to react with a Lewis base to form a Lewis adduct, by sharing the electron pair furnished by the Lewis base”. Usually, the Lewis base is − OH present in the media. In a certain embodiment of the present invention a Lewis acid is a triagonal planar species, such as BF 3 or AlCl 3 . Specific examples of Lewis acids according to the present invention include TiCl 4 , AlCl 3 , and BF 3 , or solvates or etherates thereof.
[0034] The additional alkoxysilane may be added at any suitable point in time during the method. In a preferred aspect, the additional alkoxysilane is added to first sol-gel component, the second sol-gel component or both during the preparation.
[0035] When an indicator dye as well as a reference dye is present it is preferred that either the reference dye or the indicator dye is added to the first sol-gel component of step b) and the other dye is added to the second sol-gel component of step c).
[0036] The first alkoxysilane may be selected in accordance with the formula indicated above. Specifically, the first alkoxysilane is selected among ethyltriethoxysilane (ETEOS), methyltriethoxysilane (MTEOS), propyltriethoxysilane (PrTEOS), n-octyltriethoxysilane (n-octyl TEOS), methyltrimethoxysilane (MTMOS), aminopropyltrimethoxysilane (APTMOS), phenyltriethoxysilane (PhTEOS), and phenyl trimethoxysilane (PhTMOS). In certain matrixes a first silane with a less bulky side groups may be preferred to ensure high response times. Examples of such preferred first alkoxysilanes are ETEOS, MTEOS, PrTEOS, and MTMOS.
[0037] The second alkoxysilane may be selected in accordance with the formula indicated above. Specifically, second alkoxysilane is selected among 3-glycidoxypropyltrimethoxysilane (GPTMS).
[0038] The method described herein produces a sol-gel based matrix. The sol-gel based matrix so produced is also part of the present invention.
[0039] The relative amount of the individual components of the sol-gel based matrix may be adjusted in accordance with the need and desired properties of the final product. In a certain aspect the amount in mole of first alkoxysilane to second alkoxysilane is in the range of 10:1 to 1:10. Suitably, the amount of the first alkoxysilane to second alkoxysilane is in the range of 5:1 to 1:5, such as 2:1 to 1:2, preferable around 1:1.
[0040] In one aspect, the invention relates to a composite comprising a layer of sol-gel based matrix and a platform comprising a microstructure area, wherein the sol-gel based matrix is attached to the microstructure area. In one embodiment, the composite comprises a sol-gel based matrix according to the invention.
[0041] The composite of the invention provides a fast response time for the detection of analytes. The response of the composite may be detectable by detecting light or other electromagnetic radiation emitted by the sol-gel matrix, e.g. fluorescence and/or phosphorescence, and/or the like.
[0042] The platform may comprise a plurality of microstructures, such as 2, 10, 50, 100, 1000, or more microstructures. The microstructure may be arranged in an array measurring various analytes and concentrations thereof.
[0043] For the purpose of the present description, the term microstructure area refers to a structure having a plurality of micrometer-scale pillars. The plurality of micrometer-scale pillars may be depressions and/or protrusions of a predetermined cross-sectional geometry, e.g. cylindrical or conical pillars. The microstructure may have a shape having an extent in at least one dimension, e.g. in two or even all three dimensions, between 0.1 μm and 50 mm, e.g. between 1 and 20 mm, preferable between 5 and 10 mm.
[0044] The pillars may be cylindrical, cubic, or any other form. The pillars may be arranged in a pattern, e.g. a regular pattern, in a square or hexagonal grid. However, a random pattern of pillars may be used as well. The pillars may have any size and shape. The pillars may be between 0.1 μm and 500 μm, preferably between 5 and 100 μm, more preferable between 10 and 40 μm in height.
[0045] The distance or length between each pillar may be between 0.1 μm and 500 μm, preferably between 5 and 100 μm, more preferable between 10 and 40 μm. The width or diameter of the pillars may be between 2 and 100 μm, more preferable between 5 and 40 μm.
[0046] In a preferred embodiment the distance between each pillar is between 5 and 40 μm, the height of the pillars are between 10 and 40 μm and the width of each pillar is between 5 and 40 μm. The pillars are preferably aranged in a hexagonal geometry. An example of such preferred arrangement and geometry of the pillars in the microstructure in the platform area is shown in FIG. 10 . The advantage of this embodiment is that it allows single step manufacturing of blown molded flask and injection molded container parts with one or more microstructures and at the same time is suited for attaching the sol-gel based matrix to the microstructure because it is an optimal compromise between the rheology of the plast/glass of the container and the ability to form a strong attachement with the sol-gel based matrix.
[0047] The microstructure may comprise a plurality of pillars in which the pillars, depressions and/or protrusions have different heights. The distance between the pillars, depressions and/or protrusions may be different.
[0048] The microstructure may be made of any suitable material such as a polymer, a plastic, glass, etc. Examples of suitable materials include inorganic materials, such as silicon, silicon oxides, silicon nitrides, III-V materials, such as, e.g., GaAs, AlAs, etc. Further examples of suitable materials include organic materials, such as, but not limited to, SU-8, polymethylmethacrylate (PMMA), polycarbonate (PC), polystyrene (PS),TOPAS(R) (cyclic olefin copolymer), organically modified ceramics (ORMOCER(R)). The material may be optically transparent or reflective at the used wavelengths of light or other electromagnetic radiation.
[0049] In one embodiment, the microstructure area comprises a plurality of pillars having a height between 0.1 μm and 500 μm and a distance between each pillar between 0.1 μm and 500 μm. The microstructure may also be applied to a curved surface. However, irrespective of whether the surface is curved or not, the shape of the pillars forming the microstructure area may be designed such that the microstructure area also improves or even optimizes the extraction of the light from a deposited sol-gel based matrix material during use as an optical sensor. For example, when the microstructure is an multitude of pillars that have a truncated-conical shape, the light emitted from a deposited sensor material may be directed to the optical sensing element through reflections on the inner surfaces of the pillar.
[0050] In one embodiment, the layer of the sol-gel based matrix has a thickness smaller than the height of the microstructure or the height of the pillars. Thus the microstructure or the pillars of the microsture penetrates the layer of the sol-gel based matrix, thereby providing stability to the sol-gel based matrix. Thus, the attachment of the sol-gel based matrix to the microstructure is improved.
[0051] In another embodiment, the composite comprises one or more sol-gel based matrixes comprising indicator or reference dyes. If the composites of the invention comprise different reference and indicators dyes, it will be possible to monitor one or more analytes and/or conctrations thereof simultaneously. The use of the composites of the invention reduces the amount of space required for the monitoring.
[0052] In yet another embodiment, the invention relates to an array of sol-gel based matrixes attached to different areas on the microstructure area. In yet another embodiment, the plurality of sol-gel based matrixes includes at least two sol-gel based matrixes having different indicator or reference dyes.
[0053] A plurality of separate platform areas, e.g. a plurality of of sol-gel based matrixes on respective of sol-gel based matrixes areas, may be provided; in particular the plurality of sol-gel based matrixes may include at least two of sol-gel based matrixes having different thickness of the respective layer of the sol-gel based matrixes. Hence, different properties, e.g. sensitivity, may be provided. Further, different layers of sol-gel based matrixes may be obtained by providing variations in height/spacing profile of the microstructure.
[0054] This is particularly suitable for providing of sol-gel based matrixes on an inside surface of a container, e.g. a container for accommodating a fluid, e.g. a bottle, a tube, a flask, a bag, a microtitre plate, and/or the like. The surface may be planar or have a curvature in one or more directions. The deposited of sol-gel based matrixes may thus be used to sense e.g. analytes or other properties of a medium (e.g. a fluid) in contact with the surface, e.g. a medium inside a container or or laboratory consumable. In particular, the sol-gel based matrixes may be read by detecting light emitted from the of sol-gel based matrixes responsive to the detected property. The light emission may be detected through the wall of a container by a detector placed outside the container or or laboratory consumable.
[0055] In yet another embodiment, platform of the composite is an inner surface of a container or conduit for transporting a fluid. In yet another embodiment, the container comprises an opening and cylindical or tapered sides, and is closed opposite to the opening. In yet another embodiment, the platform is an inner surface of a disposable container for transporting a fluid.
[0056] The composite may amongst other without being limited be deposited in and/or constitute a part of open or closed containers, or laboratory vessels, dedicated sensing equipments and laboratory consumables to act as a build-in sensor for analytes such as pH, dissolved oxygen (DO), conductivity, etc.
[0057] The composite may be deposited and constitute a part of open or closed containers, or laboratory vessels to yield a sensor spot, which may be circular or take any other form. The amount deposited may be 1 ul, 10 ul, 100 ul or even more. Any number of sensor spots can be deposited in a piece of equipment, consumable or vessel. The size of the spot may be 100 um 2 , 1 mm 2 , 10 mm 2 , 100 mm 2 , 1 cm 2 , 10 cm 2 , 100 cm 2 or even more.
[0058] The container or laboratory consumable may be made of glass, polystyrene, polycarbonate or any polymer or composite material transparent to light, preferable green and red light (450 nm to 800 nm).
[0059] In one aspect, the invention relates to the use of a composite according to the invention for monitoring of a bioculture. The environment and development of the bioculture may be followed, periodically or continuously, e.g. by detecting light emitted from the composite or sensor.
[0060] Thus, the sol-gel based matrixes and composites of the invention may be used as integrated sensors or propes, thereby reducing the risk of contamination as these can be read from the outside of the container and/or laboratory vessels.
[0061] In one aspect, the invention relates to a method for the preparation of a composite, comprising
providing a platform with a predetermined microstructure, and depositing a layer of sol-gel based matrix on at least a part of the microstructured area.
[0064] Methods for deposition of sensor material, such as a sol-gel based matrix, on a homogeneous layer in a well-defined region of a surface are well known in the art, Quéré D 2008, Annu. Rev. Mater. Res. 38 71-99. A drop of liquid material that is deposited on the microstructured area will spread, guided by the structures of the pillars, to homogeneously fill the volume between the pillars.
[0065] Generally, a sol-gel process, also known as chemical solution deposition, is a wet-chemical technique suitable for the fabrication of materials, e.g. a metal oxide, or glass, starting from a chemical solution acting as a precursor for an integrated network, or gel, of discrete particles or network polymers. The process typically includes the removal of liquid after deposition of the precursor on the surface, e.g. by sedimentation and removal of the remaining solvent, by drying, and/or the like. Afterwards, a thermal treatment, or firing process, may be employed.
[0066] Microstructuring of e.g. the inside of blow-molded plastic containers may be performed using step-and-stamp imprint lithography (Haatainen T and Ahopelto J 2003 Phys. Scr. 67 357), and for plastic components produced by injection molding, microstructures can be integrated directly in the mold (Utko P, Persson F, Kristensen A and Larsen N B 2011 Lab Chip 11 303-8). Both of these fabrication methods are suited for large-scale industrial production.
[0067] Spreading of the liquid is governed by the geometry of the microstructures and the thickness of the deposited film is determined by the height of the pillars and is thus independent of the volume of the deposited drop. This enables easy and reproducible deposits of spots of the sol-gel based matrix of precise thickness to be made surfaces, such as metallic and plastic surfaces.
[0068] Spreading of the sol-gel based matrix enables direct, controlled deposition of spots of the sensor material inside containers, and it simplifies the fabrication of optical sensors in disposable lab ware.
[0069] The term immobilising is intended to refer to any process for causing deposited layer to remain fixed as an integral layer covering and attached to at least a portion of the deposition area. The immobilising or fixation of the deposited sol-gel based matrix may be performed by a variety of techniques, e.g. by curing, hardening the deposited liquid, by evaporation of a solvent, by a sedimentation process, by covering the deposited sol-gel based matrix by a sealing layer, e.g. a foil, membrane etc. and/or a combination of the above. For example, the deposited sol-gel based matrix may be immobilized on the surface by solvent evaporation, by cross-linking due light exposure, exposure by other forms of electromagnetic radiation, and/or by thermal treatment, and/or by any other suitable curing process. Materials which remain liquid after deposition on the microstructures are also a possibility; such materials may be immobilized by depositing a cover layer, e.g. a membrane, on top of the deposited sol-gel based matrix. Hence, the process results in a composite layered product in which the microstructure area and a layer of deposited sol-gel based matrix are efficiently bonded to each other.
[0070] In some embodiments, e.g. due to the removal of the liquid, e.g. by solvent evaporation, the immobilising process may cause a volume reduction of the immobilised sol-gel based matrix compared to the initially deposited volume. This may result in the immobilised sol-gel based matrix having a local thickness, measured in the spaces between protrusions of the microstructure, smaller than the height of the microstructure. This may also result in a convex upper surface of the immobilised deposited sensor material. In that case the optical path through the film on vertical side walls is much larger than the thickness of the film that an analyte has to diffuse through, and a larger surface is achieved, thus reducing the response time of the sensor.
[0071] In one embodiment of the invention, at least a part of the sol-gel based matrix is immobilised resulting in an immobilised layer of sol-gel based matrix attached to the surface of the microstructure area. In another embodiment of the invention, the immobilised layer of sol-gel based matrix has a thickness smaller than the height of the microstructure. In yet another embodiment of the invention, the microstructurea area is prepared by a process chosen from injection molding, hot embossing, laser microstructuring, micromachining, chemical etching, photoresist layer structuring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0072] FIG. 1 shows the general preparation steps for deposition of sensor material on a substrate,
[0073] FIG. 2 shows the leakage over time of sensor spots.
[0074] FIG. 3 shows the development over time for the ratiometric signal in four different buffer solutions,
[0075] FIG. 4 shows the ratiometric responses; FIG. 4 a shows TMAAcr-4 immobilised in the GPTMS-ETEOS matrix via lipophilic entrapment, and FIG. 4 b shows TMAAcr-6 immobilised in the GPTMS-ETEOS matrix via covalent entrapment.
[0076] FIG. 5 shows the emission spectra of the sensors in action; FIG. 5 a shows the emission spectra of a GPTMS-ETEOS matrix with TMAAcr-4 and DMQA-1 lipophilic entrapped in the matrix, and FIG. 5 b shows the emission spectra of the GPTMS-ETEOS matrix with TMAAcr-6 covalently and DMQA-1 lipophilic entrapped in the GPTMS-ETEOS matrix.
[0077] FIG. 6 shows the response times of the pH active dye DAOTA-2; FIG. 6 a shows the response time in PhTEOS-GPTMS matrix, FIG. 6 b shows the response time for ETEOS-GPTMS matrix, and FIG. 6 c shows the response time for the PrTEOS-GPTMS matrix.
[0078] FIG. 7 discloses the response time of the pH active dye DAOTA-2 in an ETEOS-GPTMS matrix, compared to a matrix PVA and PEG-DA.
[0079] FIG. 8 discloses the intensity ratio of lipophil bounded DQMA and a ruthenium kompleks (Tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) bis(hexafluorophosphate) kompleks CAS Nummer 123148-15-2) measured by ratiometic titration (I(Ru)/I(DMQA)) in aqueous solutions having different oxygen concentrations. The measurements are determined with an optical DO electrode from Mettler-Toledo.
[0080] FIG. 9 . Example of laboratory consumables comprising a sol-gel matrix according to the invention.
[0081] FIG. 10 shows a preferred arrangement and geometry of the microstructure in the platform area.
DETAILED DESCRIPTION OF THE INVENTION
[0082] The sol-gel based matrix is usually deposited on a substrate as a part of a sensor. The substrate is generally selected to optimise the ability of the sol-gel to form an immobilized attachment to the substrate. Suitable substrates include glass, plastics, ceramics, and polymers. Suitable polymer substrates include polycarbonates, acrylics such as poly(methyl methacrylate), acrylonitrile-butadiene-styrene copolymer, polyvinylchloride, polyethylene, polypropylene, polystyrene, polyurethanes, silicones, and vinylidene fluoride-hexafluoropropylene copolymer.
[0083] The first sol-gel component is prepared by polymerisation of the first alkoxysilane defined above in the presence of an acid catalyst. The acid catalyst may be any suitable acid, such as an inorganic or organic acid. Suitable inorganic acids include hydrochloric acid (HCl), nitric acid (HNO 3 ), phosphoric acid (H 3 PO 4 ), sulphuric acid (H 2 SO 4 ), hydrofluoric acid (HF), hydrobromic acid (HBr) and perchloric acid (HClO 4 ). A preferred inorganic acid is hydrochloric acid. Suitable organic acids include lactic acid, acetic acid, formic acid, citric acid, oxalic acid, and malic acid. Furthermore, the acid catalyst may be any combination of the above compounds.
[0084] To be suitable, the acid chosen must be able to hydrolyse the first alkoxysilane under the acidic conditions. The hydrolysis initiates the polymeric condensation reaction upon formation of a polymer silicon oxide network.
[0085] The procedure for the preparation of the first sol-gel component generally include that the first alkoxysilane is dissolved in an organic solvent, usually an alcohol like ethanol prior to the addition of the acid catalyst. The amounts in mole of acid are generally at the same level or lower as the molar amount of the first alkoxysilane. The mixture of first alkoxysilane, organic solvent and acid catalyst is left until the reaction is completed. The reaction time may be several days.
[0086] The second sol-gel component is prepared by either dissolving the second alkoxysilane in a solvent before the addition of the Lewis acid catalyst or by mixing the alkoxysilane and the Lewis acid and then adding the solvent. The molar amount of Lewis acid catalyst is generally lower than the molar amount of the second alkoxysilane. In a preferred embodiment the molar amount of Lewis acid to second alkoxysilane is 1:2, such as 1:3, preferably 1:4. The solvent is usually an alcohol like ethanol but may be chosen among various solvents assumed by the skilled person to be inert under the conditions.
[0087] The Lewis acid is believed to attack the epoxy ring of the second alkoxysilane whereby a secondary carbocation is formed. This intermediate carbocation can then react with another molecule in the polymerisation process. The amount and the type of second alkoxysilane should be chosen so as to be able to participate in the intended chemical reaction within a reasonable time. The formation of the second sol-gel component normally proceeds much faster than the formation of the first sol-gel component. A typical reaction time for the second sol-gel component is between 10 min and 3 hours. After the reaction the second sol-gel component is typically allowed to rest for a few hours.
[0088] After the two sol-gel components have been prepared separately, they are mixed. Typically, the molar amount of the first sol-gel component to the second sol-gel component is in the range of 5:1 to 1:5, such as 3:1 to 1:3, typically 2:1 to 1:2, and suitably approximately 1:1.
[0089] If the sol-gel matrix is used for sensing, an indicator and/or reference dye may be incorporated in to the matrix by a number of methods to obtain either a non-covalent or a covalent attachment. If a non-covalent attachment is used it is preferred to anchor the dye in some way to the matrix to avoid excessive leakage. A preferred anchoring method is the so-called lipophilic entrapment, according to which the dye core is provided with one or more lipophilic linkers. The lipophilic linkers will engage with the lipophilic environment of the network formed by the sol-gel components and thereby retard the leakage. In a preferred method the dye core provided with one or more lipophilic linkers is added either to one or both of the sol-gel components or to the mixture of the first and the second sol-gel component. To ensure a sufficient maturation of the mixture it may be kept for 1 hour to 7 days before it is deposited on the substrate and cured.
[0090] A covalent attachment of the dye is possible by linking the dye to one of the monomers before polymerisation. In a preferred method, an additional alkoxysilane is prepared as a derivative of the first alkoxysilane by attaching the dye thereto. The additional alkoxysilane may be incorporated into either the first sol-gel component or the second sol-gel component. In a preferred aspect the first or second alkoxysilane is allowed to polymerise a short time, such as at least 15 minutes, before the further alkoxysilane is added to avoid end positioning.
[0091] The mixture of the first sol-gel component and the second sol-gel component may be allowed to mature before the deposition on a suitable substrate. The substrate is generally transparent at the wavelength used for monitoring the emitted light. The amount of the mixture used for deposition varies in dependence of the purpose and geometry of the sensor. In a certain aspect the amount is 100 μl or less, such as 50 μl or less, suitably 20 μl or less. The deposition may be referred to herein as a “spot”.
[0092] The addition of the mixture to the substrate may be allowed deliberately to solidify or the added amount of mixture may be spread on the substrate to form a film with an essentially uniform thickness. After the deposition of the mixture on the substrate it is cured. The curing may be performed in a number of ways, including heating at elevated temperatures so as to form a solid film attached to the substrate. The temperature of the curing is suitably 70° C. or above, such as 90° C. or above, and suitably 100° C. or above. Usually, the curing temperature does not exceed 150° C. to avoid degradation of the materials, i.e. to maintain the porous three dimensional polymer networks, which allow for fast diffusion of the analyte, such as a proton. The relatively unhindered diffusion of the analyte in the porous network is believed to be the reason for the observed fast response time.
[0093] The research reported herein suggests that covalent attachment of the dye to the polymer network is preferred when a long-time stability is of importance. Even when the dyes are provided with lipophilic linkers to retard the leakage from the film, the leakage is still too high for a product stabile over a longer time period to be obtained. For short-time use, such as in non-reusable sensors, non-covalently attached dyes may be acceptable.
[0094] An aspect of the invention relates to the manufacturing of a container or laboratory equipment with a composite, i.e. a container or laboratory equipment respectively comprising one or more platforms. Particularly suited laboratory equipment is ehrlenmeyer flasks, beaker glasses, tissue culture flasks, tissue culture dishes, tissue culture plates and storage systems. Examples of laborative equipments comprising the composite of the invention are shown on FIG. 9 .
EXAMPLES
[0095] Methods and Materials
[0096] Compounds were used as received. Sol-gel monomers were purchased from Sigma-Aldrich. Sol-gel catalysts were purchased from Sigma-Aldrich and used as recieved. Solvents used were analytical or HPLC grade. An electronically controlled oven was used to cure the ORMOSIL thin-films.
[0097] Synthesis
[0098] The synthesis of compounds 1.BF4and 2.PF6are reported elsewhere. 18
[0099] General preparation of tetramethoxyamino-acridinium (TMAAcr):
[0100] 2 (162 mg, 0.23 mmol) was dissolved in 15 ml acetonitrile and n-octylamine (26 ml, 0.14 mmol) was added to the solution. The reaction mixture was heated to slight reflux temperature and stirred in 5 h. The reaction mixture was allowed to cool down when the color of the mixture had changed from blue to red-brown and MALDI-TOF analysis indicated that a mass corresponding to that of the starting material was not present any more. The reaction mixture was washed with heptane (3×50 ml). The crude product was isolated by evaporation and recrystallized from ethanol, and the product was washed with ether and heptane several times. The product was isolated as a red-purple powder, which was metallic-green when filtered.
[0101] General approach to activate TMAAcr for covalent attachment:
[0102] TMAAcr (100 mg, 0.11 mmol) was dissolved in 20 ml acetonitrile and then triethoxy(3-isocyanatopropyl)silane (1.1 ml, 0.45 mmol) was added dropwise using a syringe at room temperature. The mixture was stirred for 1 h, when MALDI-TOF analysis indicated that 9 was not present. The reaction mixture was washed with heptane (3×50 ml) and then the acetonitrile phase was mixed with a 0.2 M KPF 6 solution. The slurry was stirred for 20 min and then gently filtered. The precipitate was washed with water several times. The product was dissolved in dichloromethane through the filter and the non-dissolved solid in the filter was discarded. The product is collected by removal of the solvent yielding metallic-green flakes.
[0103] General preparation of dimethoxyquinacridinium (DMQA):
[0104] A primary amine (20 eq, 40 mmol) was added to a solution of DMB 3 C.BF 4 19 in NMP (1.0 g, 2 mmol in 8 mL). The solution was warmed to 140° C. for 10-20 minutes (the degree of reaction is followed by MALDI-TOF mass spectroscopy). After cooling to RT the reaction mixture was poured on to 0.2 M KPF 4 (aq) (200 mL). The precipitate was collected, washed and dried. The crude can be recrystallized from methanol, reprecipitated from dichloromethane with ethylacetate or reprecipitated from acetonitrile with ether depending on the how lipophile the side chains are.
[0105] General approach to activate DMQA for covalent attachment:
[0106] DMAQ (70 mg, 0.143 mmol) was dissolved in 8 ml anhydrous acetonitrile and then 3-(triethoxysilane)propyl isocyanate (cold, 100 ul, d=0.999 g/ml, 0.404 mmol) was added. The flask was fitted with a stopper and stirred at room temperature for 4 h. After 4 h MALDI-TOF analysis indicated that the reaction mixture only contained starting material. Then excess of isocyanate (1 ml) was added together with approx. 1 ml of triethylamine. The mixture was heated to 65° C. and stirred for 1.5 h. Then MALDI-TOF analysis indicated that the reaction mixture contained a compound with a mass of 649 m/z, which is the mass of the desired product and no mass corresponding to that of the starting material was present. The reaction mixture was washed (still warm) with heptane (2×50 ml) and then dried over MgSO 4 for 10 min. The solvent was removed by evaporation at 50° C. in vacuum and the crude product was dissolved in a minimum of CH 2 Cl 2 and then diethyl ether (200 ml) was added and a green precipitate was allowed to form. The dark product was collected and dried in vacuum over KOH over night.
[0107] Spectroscopy
[0108] Emission spectroscopy was performed in front-face set-up for sensor spot samples and in a conventional L-shape set-up for measurements in solution. A Perkin-Elmer LS50B and a Horiba Fluorolog 3 were used interchangeably. Intensity based sensor measurements were only performed on the LS50B platform. Fluorescence lifetime based sensor measurements were only performed on the Fluorolog 3. Absorption spectroscopy was performed on a Perkin Elmer Lambda 1050, with integrating sphere (for sensor spots) and with a 3-detector module for solution samples.
[0109] Sol-Gel Preparation
[0110] The procedure includes preparation of two separate gel components of the organic modified silanes: Ethyltriethoxysilane (ETEOS) or a similar alkyl or aryl trialkoxy silane (XTEOS) and 3-(glycidoxy)propyltrimethoxysilane (GPTMS). All the different preparations and combinations are compiled in table 1, and the detailed procedures are as follows.
[0000]
TABLE 1
The different compositions of sol-gels tested in this work; variations
can be seen in the alkyltrialkoxy silane part, the Lewis acid, and
the dye additives. The pKa of the resulting sensor is included.
Mono-
Mono-
Entry
mer 1
mer 2
Catalyst
Dye 1
Dye 2
pKa
1
GPTMS
ETEOS
BF 3
TMAAcr-1
—
3.8
2
GPTMS
ETEOS
BF 3
TMARh
—
1.1
3
GPTMS
ETEOS 1
BF 3
TMAAcr-3
—
2.6
4
GPTMS
ETEOS 2
BF 3
TMAAcr-3
—
3.1
5
GPTMS
ETEOS
BF 3
TMAAcr-4
DMQA-1
4.9
6
GPTMS
ETEOS 1
BF 3
TMAAcr-6
DMQA-1
4.8
7
GPTMS
ETEOS
BF 3
DAOTA-1
DMQA-2
6.5
8
GPTMS
ETEOS
BF 3
DAOTA-2
DMQA-2
6.5
9
GPTMS
PrTEOS
BF 3
DAOTA-2
DMQA-2
6.5
10
GPTMS
PhTEOS
BF 3
DAOTA-2
DMQA-2
6.7
11
GPTMS
ETEOS
TiCl 4
DAOTA-2
DMQA-2
—
12
GPTMS
ETEOS
AlCl 3
DAOTA-2
DMQA-2
—
1 Dye 6 pre-mixed with ETEOS component,
2 Dye 6 pre-mixed with GPTMS component.
[0111] ETEOS
[0112] The ETEOS gel component is prepared from polymerization of the silicon network under acidic conditions. ETEOS is hydrolysed under acidic conditions, which initiates a polymeric condensation reaction upon formation of a polymer silicon oxide network. The presented procedure is an equivalent to the procedure reported by Wencel et al. 10,11
[0113] Procedure for preparation of ETEOS gel component: 5 ml ETEOS (0.02 mol) is dissolved in 8 ml absolute ethanol (0.14 mol) upon stirring. Hereafter, 1.6 ml of 0.1 M HCl solution (0.16 mmol) is added dropwise. This mixture is then left on a stirring table for a minimum of 7 days to allow the polymerization process to proceed.
[0114] GPTMS Gel Component.
[0115] The GPTMS gel component is prepared from polymerization of the organic linker using a Lewis acid as initiator. In this procedure we use boron trifluoride diethyletherate as the Lewis acid. The Lewis acid attacks the epoxy ring that allows for ring opening of the epoxy ring upon formation of a secondary carbocation. This intermediate carbocation can then react with another GPTMS molecule, initiating a polymerization reaction. Due to the acidic environment a polymerization of the silicon network equivalent to that described for the ETEOS component will proceed alongside.
[0116] Procedure for preparation of GPTMS gel component: 6 ml of GPTMS (0.027 mol) is mixed with 11 ml of absolute ethanol (0.19 mol) upon stirring. Then 0.75 ml of cold borontrifluoride diethyletherat (BF 3 .O(CH 2 CH 3 ) 2 , 5.8 mmol) is added dropwise. The mixture is left with stirring for 30 min in a sealed container until the temperature of the mixture has dropped to room temperature. After 30 min 2 ml of MilliQ water (0.11 mol) is added to the solution. The resulting mixture was left with stirring for 4 h.
[0117] When the two gel components have been prepared they are mixed in 1:1 molar ratio and left for a minimum of 3 days to allow the networks to mix. This is referred to as the GPTMS-ETEOS mixture.
[0118] GPTMS-ETEOS Mixture
[0119] When the GPTMS and ETEOS components have been prepared they are mixed to obtain a 1:1 molar ratio (1.1 ml GPTMS+1 ml ETEOS) and the dyes are added in order to obtain a concentration of approx. 0.1 mM. The resulting mixture is then allowed to further mix for a minimum of 3 days.
[0120] The GPTMS-ETEOS mixture with the dye entrapped can now be deposited onto a glass or plastic surface. When deposited it has to be cured at 110 degrees for 3-4 h. The result is a porous and transparent matrix.
[0121] XTEOS Variations
[0122] A procedure analogous to that for the ETEOS Gel component described above used to make XTEOS gel components, with X=Pr and Ph.
[0123] Preparation of XTEOS Gel Components
[0124] X=Phenyl (Ph): Phenyltriethoxyilane (PhTEOS, 10 ml, M=240.14 g/mol, d=0.996 g/ml, 0.041 mol) and absolute ethanol (15 ml, d=0.789 g/ml, 0.26 mol) was mixed and the freshly prepared 0.1 M HCl solution (2.8 ml, 0.28 mmol) was added. The solution was stirred for 15 min in the sealed vial, and then left at a vibration table for 20 days in the dark at room temperature.
[0125] X=Propyl (Pr): Propyltriethoxyilane (PrTEOS, 10 ml, M=206.13 g/mol, d=0.892 g/ml, 0.043 mmol) and absolute ethanol (16 ml, d=0.789 g/ml, 0.27 mol) was mixed and then freshly prepared 0.1 M HCl solution (3.2 ml, 0.32 mmol) was added. The solution was stirred for 15 min in the sealed vial, and then left at a vibration table for 20 days in the dark at room temperature.
[0126] Lipophilic Entrapment
[0127] In the lipophilic entrapment method the dyes in entrapped in the GPTMS-ETEOS network requires that the dye has one or several lipophilic linker(s) attached to the dye to prevent leakage from the resulting matrix material.
[0128] General Procedure for Lipophilic Entrapment of Dyes
[0129] The ETEOS and GPTMS gel components are prepared and mixed as described above with the addition of the dye such that a final concentration of 0.1 mM is obtained. The resulting GPTMS-ETEOS-dye mixture is then left at a stirring table for at least 3 days before deposition and curing at 110° C. for 3-4 hours.
[0130] Covalent Method:
[0131] This procedure requires that the dye has been activated by linking to a trialkoxysilane group that can mix into the silicon network of either the ETEOS or GPTMS gels.
[0132] General Procedure for Covalent Entrapment of Dyes into the GPTMS-ETEOS Matrix
[0133] The ETEOS and GPTMS gel components are prepared and mixed as described above, with the exception that the silane functionalized dye is mixed into the either the ETEOS or the GPTMS gel component after 1 h after mixing of the materials described to mix the ETEOS or the GPTMS gel components. The GPTMS and ETEOS components are left for polymerization reaction time described in the general procedure. The two components are then mixed in the described 1:1 molar ratio and left at a stirring table for no less than 3 days. The dye should be added in an amount so that a final concentration of 0.1 mM of dye is obtained in the final GPTMS-ETEOS mixture. The resulting GPTMS-ETEOS-dye mixture is then deposited and cured at 110° C. for 3-4 hours.
[0134] Fabrication of Sensor-Spots
[0135] The sensor spots were drop coated on a glass or polycarbonate substrate and then cured. The substrate material appears to be inconsequential as long as thin films can be prepared. For comparison sensor spots were prepared from direct incorporation of the dyes in PVA (from 10% w/w solutions in water) which were subsequently drop coated on glass. PEG-DA hydrogel with dye entrapped was prepared by mixing PEG-DA (M n =700) and ethanol in a 1:1 v/v ratio and then the dye was added to obtain 1 mM. Then a catalytic amount of a solution of 2,2′-azobis(2-methylpropionitrile) in CH 2 Cl 2 (25 mg/ml) was added. The mixture was spread out on a petri dish, the dish was equipped with a glass lid, and the mixture was baked in the oven at 110° C. for 1 h. A thin piece of the resulting hydrogel was immobilized on a clean glass slide using double-sided tape and the regular tape.
[0136] Titrations
[0137] To perform titrations rapidly a set-up employing an epi-fluorescence microscopy equipped with a halogen light source and an Ocean Optics spectrometer for detection. The sensor spot was attached to a homemade holder, which kept the spot in place in a large chamber filled with water, where pH was externally monitored with a pH meter. Alternatively the sensor spot was affixed on the wall of a cuvette and the titration was performed in a Perkin Elmer LS50B, controlling the pH between measurements.
[0138] Stability Testing
[0139] The photostability was followed by constant illumination of the sensor spot with wavelength selected light from a xenon lamp. The physical stability was tested by immersing the sensor spot in low or high pH aqueous solution, and monitoring the fluorescence from the solution.
[0140] Response Analysis
[0141] The signal from the sensor is monitored after inducing a significant (more than 4 pH units) jump in pH. The time it takes to obtain a full (100%) and partial (90%) response, compared to the equilibrium signal is recorded.
[0142] FIG. 1 shows the general preparation of sensor spots.
[0000]
[0143] Results
[0144] The tested sensors are prepared as illustrated in FIG. 1 , on glass and polycarbonate substrates. The five components are mixed in a fashion that allows for the formation of a porous covalently linked 3D polymer network, which allows for fast diffusion of protons.
[0145] Scheme 2 shows the structure of the pH-responsive and the reference dyes used in this study. The pKa values of the resulting sol-gel based sensors are compiled in table 1. Cursory inspections of the structures, which are physically immobilized in the sol-gel show that a long alkyl chain is required to prevent leakage, while the molecules covalently linked to the matrix can have either a long or a short linker.
[0000]
[0146] Stability
[0147] Table 2. Leaking of 5(6)-carboxyfluorescein (CF), DMQA-2, DAOTA-1, and 6-stearamido-fluorescein (AF18) from the ETEOS-GPTMS matrix given as fluorescence intensity measured from a PBS solution at pH 7 surrounding a glass slide coated with ETEOS-GPTMS-dye matrix using maximum sized slit widths at the emission and excitation sites of the spectrometer.
[0000]
Dye
Intensity (a.u.)
Leaking Period
pH
pK a
CF
>>800
2 h
7.0
6.5
DMQA-2
0
15 h
7.0
—
DAOTA-1
80
15 h
7.0
6.5
AFC18
100
4 d
7.0
6.5
[0148] FIG. 2 shows leakage over time of sensor spots: non-bound 5(6)-carboxyfluorescein (plus-signs), covalently bound DAOTA-1 (crosses), and covalently bound DMQA-2 (dots).
[0149] FIG. 2 shows the performance in leakage studies, against the performance of molecules without anchoring groups, and the data are collected in table 2. Leaking of the dyes entrapped or bound to the matrix was investigated by measuring the emission intensity from a PBS solution at pH 7.0 surrounding a non-bound dye (5(6)-carboxy fluorescein, CF), covalently bound (DMQA-2 and DAOTA-1) using the largest possible slit widths on the excitation and emission sites of the spectrometer and an excitation wavelength of 450 nm, these data are shown in FIG. 2 . While the physically bound dye and 6-stearamido-fluorescein (AF18) was also tested, we did not record the transient curve. All the leakage data is compiled in table 2. The results reveal that DAOTA-1 leaked to a small extend, which we, based on NMR data, can assign to a fraction of un-linked dye in the ETEOS-GPTMS matrix, this issue has previously been reported for fluorescein, which was only partially activated. The compound DMQA-2 could based on NMR data be shown to be 100% activated and did as a consequence not show any leakage. This shows that effective binding can indeed be obtained in the ETEOS-GPTMS matrix and leakage can be avoided completely by fully activating the dye for polymerization. The unbound CF showed extensive leakage and the data in table 2 is obtained using half the sizes of the slit widths as those used for DMQA-2 and DAOTA-1.
[0150] To evaluate the photostability of the sensor we performed a 16-hour scan, see FIG. 3 . No perceivable slope of the curves could be seen in this time interval, which proves that this system has a very high long-term stability under constant irradiation.
[0151] FIG. 3 shows the development in the ratiometric signal in four different buffer solutions at pH 3 during 16 h of irradiation at 525 nm of a DAOTA/DMQA based sensor.
[0152] Sensor Action
[0153] The performance of the sensors is shown as titration curves in FIG. 4 . The spectra behind the titration curves are shown in FIG. 5 . It is clear that a pH-dependent sensor action is achieved for these two sensor systems. For the examples given in FIGS. 4 and 5 the pKa values are ˜5, the data for all prepared sensors are compiled in table 1, sensors with a pK a from 1.1 to 6.7 was made.
[0154] FIG. 4 a shows the ratiometric pH response of TMAAcr-4 immobilized in GPTMS-ETEOS matrix via lipophilic entrapment. FIG. 4 b shows the pH response of TMAAcr-6 immobilized in the GPTMS-ETEOS matrix via covalent entrapment. The pK a values of TMAAcr-4 and TMAAcr-6 are determined to 4.9 (lipophilic entrapment) and 4.8 (covalent entrapment).
[0155] FIG. 5 shows spectra of the sensors in action. FIG. 5 a shows the emission spectra of a GPTMS-ETEOS matrix with TMAAcr-4 and DMQA-1 lipophilic entrapped in the GPTMS-ETEOS matrix at different pH values between 3 (black) and 7.5 (red). FIG. 5 b shows emission spectra of a GPTMS-ETEOS matrix with TMAAcr-6 covalently and DMQA-1 lipophilic entrapped in the GPTMS-ETEOS matrix at different pH values between 2 (black) and 7.5 (red). Excitation at 475 nm±25 nm.
[0156] In order to evaluate the response time the temporal evolution of the detected signal (intensity ratio) was monitored, when the sensor was monitoring a solution where the pH was changed drastically as well as moderately. FIG. 6 shows the result, each panel shows the response of different matrices. It is clear that the response of the Lewis acid catalyzed sol-gel is much faster than the others tested. To highlight the differences an overlay is shown in FIG. 7 . All the data are compiled in table 3. The alkyltrialkoxy-GPTMS matrixes have by far the fastest response times, showing some hysteresis, with a response going from high pH to low pH of ˜10 s and going from low pH to high pH of ˜20s. Propyltrialkoxy silane derived matrices are faster responding than the ethyltrialkoxy silane derived matrices when the signal level of 90% is considered, while the full response occur on a similar timescale for both matrices.
[0157] FIG. 6 shows the response time of pH-active dye DAOTA-2 in a PhTEOS-GPTMS ( FIG. 6 a ), an ETEOS-GPTMS ( FIG. 6 b ) and PrTEOS-GPTMS ( FIG. 6 c ) matrices. High intensity: Low pH (<2). Low intensity: High pH (>10).
[0158] FIG. 7 shows the response time of pH active dye DAOTA-2 in an ETEOS-GPTMS (red), PVA (blue) and PEG-DA (green) matrix. High intensity: Low pH (<2). Low intensity: High pH (>10).
[0159] Table 3. The response times (t 90 and t 100 ) given in seconds (s) of the ETEOS-GPTMS, PrTEOS-GPTMS, and PhTEOS-GPTMS matrices with of the pH-active dye DAOTA-2 incorporated, and the response times of PVA film and PEG-DA hydrogel with the pH-active dye TMAAcr-4 incorporated. H-L refers to the response time going from high (H) pH (>10) to a low (L) pH (<2) value, L-H has the opposite meaning. Numbers in parentheses refer to response times measured in the ETEOS-GPTMS matrix with the dyes DAOTA-1 and DMQA-2 covalently bound.
[0000]
t 90
t 100
t 90
t 100
Matrix
Dye
(H-L)/s
(H-L)/s
(L-H)/s
(L-H)/s
PhTEOS-GPTMS
DAOTA-2
59
171
108
271
ETEOS-GPTMS
DAOTA-2
9
24
19
40
(DAOTA-1
(10)
(30)
(23)
(47)
DMQA-2)
PrTEOS-GPTMS
DAOTA-2
6
34
7
31
PVA
TMAAcr-4
6
50
25
55
PEG-DA
TMAAcr-4
40
98
192
262
[0160] Conclusion
[0161] We have shown that our system has a shorter or comparable response time than what was previously reported and a high degree of photostability. Furthermore, with this sensor we have solved the leaking issue, using either covalent attachment or lipophilic entrapment of the active components. We have also shown that the activation of the active component is important in making leakage free film.
REFERENCES AND FOOTNOTES
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[0180] 19. J. C. Martin and R. G. Smith, J. Am. Chem. Soc., 1964, 86, 2252-2256. | The present invention relates to a method for the production of a sol-gel based matrix. The method comprises the steps of: a) providing a first alkoxysilane of the general formula: R 1 —Si(OR 2 )3 and a second alkoxysilane of the general formula (I): b) preparing a first sol-gel component by polymerisation of the first alkoxysilane in the presence of an acid catalyst, c) preparing a second sol-gel component by polymerisation of the second alkoxysilane in the presence of an Lewis acid catalyst, d) Mixing the first sol-gel component and the second sol-gel component for the preparation of a sol-gel based matrix. The above method results in a sol-gel based matrix with high stability and high porosity. The sol-gel based material may be used for the production of a composite or sensor suitable for monitoring analytes. Methods for preparing these composites or sensors are provided as well. | 2 |
CROSS REFERENCE
The present invention is a continuation of U.S. patent application Ser. No. 11/139,908 filed 27 May 2005, now U.S. Pat. No. 7,632,265, issued 15 Dec. 2009, which claims priority to U.S. Provisional Application No. 60/575,741, filed 28 May 2004, both of which are incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
The present invention relates generally to radio frequency ablation catheter systems and more particularly to an interactive and automated catheter for producing lesions to treat arrhythmias in the atrium of a patient's heart.
BACKGROUND OF THE INVENTION
Many atrial arrhythmias are caused by anatomical accessory pathways in the heart, which provide spurious conduction paths. Conduction of electrical depolarization's along these pathways within a chamber gives rise to arrhythmias. Although drugs have been used to treat such arrhythmias for many years, cardiac ablation, or destruction of localized regions of tissue, can provide a permanent cure for the patient. For this reason cardiac ablation is preferred in many instances. This treatment is especially preferred for patients that experience detrimental effects from drugs.
Cardiac ablation has traditionally been a tedious procedure performed under fluoroscopy by a physician who sequentially maps the electrical potentials within the heart using a manually directed EP catheter. Once an appropriate site has been selected identified and selected for ablation, RF energy is delivered to the site. Ablation energy is typically delivered through the same catheter used to “map”. The purpose of the ablation is to destroy a small bolus of tissue at the location. This tissue lesion can no longer conduct and the arrhythmia is interrupted and the arrhythmia stops.
One common intervention is ablation around the annulus or the ostium of the pulmonary vein that is located in the left atrium. However, navigating to this location reliably and sequentially and delivering electrical energy is an extremely tedious procedure requiring substantial amount of skill and time to complete successfully.
For this reason there is a continuing need to improve catheter technology.
SUMMARY OF THE INVENTION
The present invention provides a system that allows for the automated rapid and successful ablation of cardiac tissue. The overall system interfaces with an Endocardial Solutions Ensite “work station” endocardial mapping system of the type sold by Endocardial Solutions, Inc. of St. Paul, Minn., or other equivalent devices.
The “Ensite” system is preferred as it includes a “NavX” feature that allows the physician to see a representation of the physical location of his catheter in a presentation of an anatomic model of the patient's heart.
The system includes a “servo catheter” and a servo catheter control system that are interfaced with the work station. The work station is the primary interface with the physician and it is anticipated that the servo catheter control software will run on the work station. The servo catheter will also be coupled to a conventional RF generator.
In use the physician will locate site for ablation therapy and then he will confirm the location of the catheter which will automatically navigate to the lesion site desired by the physician. Once the catheter is located at that desired point or site the physician will activate the RF generator to deliver the therapy.
BRIEF DESCRIPTION OF THE DRAWINGS
Throughout the several drawings identical reference numerals indicate identical structure wherein:
FIG. 1 is a schematic representation of the overall system;
FIG. 2 is a schematic representation of a portion of the overall system;
FIG. 3 is a schematic representation of an image displayed by the system;
FIG. 4A is a flow chart representation of a method of the system;
FIG. 4B is a flow chart representation of a method of the system;
FIG. 5 is a representation of a servo catheter of the system; and,
FIG. 6 is a representation of a servo catheter of the system.
DETAILED DESCRIPTION
Overview
For purposes of this disclosure the NavX features of the Ensite system as sold by ESI of St Paul Minn., allows for the creation of a chamber geometry reflecting the chamber of interest within the heart. In a preferred embodiment a mapping catheter is swept around the chamber by the physician to create a geometry for the chamber. Next the physician will identify fiducial points in the physical heart that are used to create a base map of the heart model. This base map may be merged with a CT or MRI image to provide an extremely high resolution, highly detailed anatomic map image of the chamber of the heart. Or in the alternative the base map may be used for the method. The physician identifies regions of this model heart for ablation by interacting with a computer terminal and for example using a mouse to lay down a collection of target points which he intends to ablate with RF energy.
In summary the servo catheter is also interfaced with the Ensite system and makes use of the NavX catheter navigation and visualization features of NavX. In operation the physician navigates the servo catheter to the approximate location of the therapy and a relatively complicated control system is invoked that navigates the servo catheter tip to various locations sequentially identified by the physician. Once in place and after its position is verified the physician will activate the RF generator to provide the ablation therapy.
Servo Catheter
The catheter has a number of attributes that permit the device to carry out this function. An illustrative and not limiting prototype version of the device is seen in FIG. 5 and FIG. 6 . The catheter 100 has been constructed with eight pull wires (of which 4 are shown for clarity) and two associated pull rings labeled 102 and 104 in the figures.
The pull wires typified by pull wire 106 and 108 are manipulated by servo mechanisms, such as stepper or driven ball screw slides illustrated in FIG. 1 . These mechanisms displace the wire with respect to the catheter body 110 and under tension pull and shape the catheter in a particular direction. The use of multiple wires and multiple pull rings allows for very complex control over the catheter's position, shape and stiffness, all of which are important to carry out the ultimate therapy desired by the physician. Multiple pull rings and multiple individual wires permits control over the stiffness of the catheter which is used to conform the shape of the catheter so that the entire carriage may be advanced on a ball screw to move the catheter against the wall of the heart.
At least one force transducer 112 is located within the catheter provide feedback to the control system to prevent perforation of the heart and to otherwise enhance the safety of the unit. Preferably the force transducer takes the form of a strain gauge 112 coupled to the control system via connection 120 .
The catheter distal tip will carry an ablation electrode 124 coupled via a connection not shown to the RF generator as is known in the art. It is preferred to have a separate location electrode 126 for use by the Ensite system as is known in the art. Once again no connection is shown to simply the figure for clarity.
As seen in FIG. 6 pulling on pull wire 108 deflects the distal tip while pulling on pull wire 106 deflects the body 110 of the catheter. Since each wire is independent of the others the computer system may control both the stiffness and deflection of the catheter in a way not achieved by physician control of the wires. In general the physician will use a joystick of other input device to control the catheter. However, this control system also invokes many of the automated procedures of the servo catheter and is not strictly a direct manipulator.
Although robotic control has made great headway in surgery most conventional systems use a stereotactic frame to position the device and the coordinate systems with respect to the patient. One challenge of the current system is the fact that the target tissue is moving because the heart is beating and the catheter within the heart is displaced and moved by heart motion as well so that there is no permanently fixed relationship between the catheter and its coordinate system, the patient and its coordinate system, and the patient and its coordinate system at the target site. This issue is complicated by and exacerbated by the fact that the map may not be wholly accurate as well, so the end point or target point's location in space is not well resolved.
Operation Overview
Turning to FIG. 1 there is shown a patient's heart 10 in isolation. A series of patch electrodes are applied to the surface of the patient (not shown) typified by patch 12 . These are coupled to an Ensite catheter navigation system 14 which locates the tip of the Servo catheter 16 in the chamber 18 of the patient's heart. The Ensite system is capable of using this catheter or another catheter to create a map of the chamber of the heart shown as image 20 on monitor 22 of a computer system. In operation the physician interacts with the model image 20 and maps out and plans an RF ablation intervention that is applied to the Servo catheter 16 through its proximal connection to the Servo catheter interface box 24 . The interface box allows RF energy from generator 26 to enter the catheter upon the command of the physician and ablate tissue in the cardiac chamber. Critical to the operation of the servo catheter is the translation mechanism 28 , which provides a carriage for translating the catheter proximal end advancing or retracting the catheter from the chamber as indicated by motion arrow 30 . An additional group of sensors and actuators or other servo translation mechanism 32 are coupled to the proximal end of the catheter 16 to allow the device to be steered automatically by software running on the Ensite 14 workstation.
Thus, in brief overview, the physician navigates the catheter into the chamber of interest, identifies locations of interest within that chamber which he desires to ablate, then the Servo mechanism moves the catheter to various locations requested by the physician and once in position the physician administers RF radiation to provide a therapeutic intervention.
FIG. 2 shows the interaction of the physician with the heart model. The locations for ablation are shown on the map 20 as X's 32 which surround an anatomic structure that may be, for example, the pulmonary vein 34 . These locations are typically accessed on the map image through a mouse or other pointer device 36 so that the physician may act intuitively with the model. As is clear from the Ensite operation manual the catheter 16 may also be shown on the image to facilitate planning of the intervention. Turning to FIG. 3 the servo catheter 16 has been activated and the catheter has been retracted slightly as indicated by arrow 41 and has been manipulated to come into contact with the cardiac tissue at location 40 . In this instance the physician is in a position to perform his ablation.
The control system to achieve this result is shown in FIG. 4A and FIG. 4B which are two panels of a software flow chart describing software executed by the Ensite work station.
Turning to FIG. 4 a , initially the catheter is placed in the desired heart chamber as seen in FIG. 2 by the positioning of catheter 16 as represented on the Ensite work station within the chamber of the heart 20 . This process occurs after the creation of the chamber geometry. In block 202 the Ensite system determines the location of the location ring of catheter 16 in the chamber and in process 204 a small motion is initiated by the operation of the steppers 32 controlling the various pull wires of the catheter. The Ensite system tracks the motion of the location electrode and establishes a relationship between the operation of the various pull wires and motion in the chamber. It is important to note that this process eliminates the need to keep track of the X, Y, Z references of the body and the catheter. In process 206 the physician manipulates the joystick or other control mechanism and places the target location, for example target location 32 , around an anatomic feature of interest, for example the OS of the pulmonary vein. The user then activates a “go” command on the workstation and the catheter 16 automatically navigates to the location 32 by measuring the difference between its current position and the desired location position in block 210 . If it is within 0.5 millimeters or so, the process stops in block 212 . However, if the catheter is farther away from the target location than 0.5 millimeters, the process defaults to step 212 wherein a displacement vector is calculated in process 212 . In process 214 the displacement vector is scaled and in process 216 an actuation vector is computed to drive the catheter toward the location. In process 218 the actuation vector is applied to the pull wires 32 and to the carriage 28 to move the catheter tip toward the desired location. After a short incremental motion in process 220 a new location for the catheter is computed and the process repeats with comparison step 210 . It is expected that in most instances the algorithm will converge and the catheter will move smoothly and quickly to the desired location. However, after a certain number of tries if this result is not achieved it is expected that an error condition will be noted and the physician will reposition the catheter manually and then restart the automatic algorithm. | A system that interfaces with a workstation endocardial mapping system allows for the rapid and successful ablation of cardiac tissue. The system allows a physician to see a representation of the physical location of a catheter in a representation of an anatomic model of the patient's heart. The workstation is the primary interface with the physician. A servo catheter having pull wires and pull rings for guidance and a servo catheter control system are interfaced with the workstation. Servo catheter control software may run on the workstation. The servo catheter is coupled to an RF generator. The physician locates a site for ablation therapy and confirms the location of the catheter. Once the catheter is located at the desired ablation site, the physician activates the RF generator to deliver the therapy. | 0 |
BACKGROUND OF THE INVENTION
1. Field of Invention
Aspects of the invention can relate to an organic electro-luminescence apparatus and electronic equipment.
2. Description of Related Art
Related art organic electro-luminescence apparatus can use an organic matter (Organic EL) as a self light-emitting display unit replacing a liquid crystal display unit. As related art methods of fabricating such organic EL apparatus, there have been proposed a method of forming small molecules by a vapor method, such as vacuum evaporation method, and a method of forming polymers by a wet process. See, for example, Appl. Phys. Lett. 51(12), 21 Sep. 1987, p, 913 and Appl. Phys. Lett. 71(1), 7 Jul. 1997, p, 34.
Further, in a related art structure of the organic EL apparatus, to improve efficiency and long life, a hole injection/transport layer (Hole Transport Layer) is often formed between an anode and a light-emitting layer. For methods of forming such hole transport layer and the like and a buffer layer, there have been proposed, in a case of using a small molecule material, a method of forming a phenylamine derivative by vapor evaporation, and in a case of using a polymer material, a method of forming a film of a conductive polymer such as polythiophene derivative or a polyaniline derivative by means of a coating process, such as a spin coat method. See, for example, Nature, 357, 477 1992.
SUMMARY OF THE INVENTION
Now, in regard to the related art organic EL apparatus described above there are several problems. As the multi-layered structure, a typical structure is one in which the hole transport layer, the light-emitting layer, and an electron transport layer are stacked in order, and further, at each layer, a film thickness, a film thickness ratio, and a multi-layered structure are determined by carrier mobility. For example, in a case of the hole transport layer, by the carrier mobility of a hole, and in a case of the light-emitting layer and the electron transport layer, by the carrier mobility of an electron, the thickness of each layer is determined, and the hole and the electron are arranged to be moved to the light-emitting layer in a proper balance.
Nonetheless, since a balance of the carrier mobility is achieved by multi-layering such structure, for example, if the film thickness of the hole transport material is thick, a voltage is set high, so that there are problems, such as the light-emitting layer not emitting unless more holes are transported and light-emitting spots becoming uneven.
Further, as light-emitting characteristics of the organic EL apparatus shown in FIG. 13 , there is a characteristic in which a change “de” of efficiency of the longitudinal axis makes a steep change relative to a change “dv” of a drive voltage on the transverse axis. Specifically, slightly increasing the drive voltage results in raising the efficiency greatly, and further, there is another characteristic in which slightly decreasing the drive voltage results in increasing the efficiency largely. Such characteristics are considered to be caused by the fact that since the materials of various light-emitting functional layers are in such a condition that surfaces are evenly in contact with one another on the interfaces of various light-emitting functional layers such as the hall transport layer and the light-emitting layer contact, by increasing a predefined drive voltage level, the holes and the electrons are excited, combined, and emitted all at once. Consequently, there is a problem of difficulty to control the efficiency of the organic EL apparatus. Further, to emit light at the luminance of a desired gradation, a driver circuit and the like to control finely the change “dv” of the drive voltage are needed. This creates another problem of making peripheral circuits complicated.
Aspects of the present invention can provide an organic electro-luminescence apparatus and electronic equipment provided with the organic electro-luminescence apparatus, which can accomplish high efficiency and long life of the light-emitting characteristics as well as facilitate gradation control.
To accomplish the above-mentioned objects, the invention can be employed with the following configuration.
An organic EL apparatus of the invention can be an organic EL apparatus having a light-emitting functional part formed between electrodes. The light-emitting functional part can include a plurality of functional layers, the plurality of functional layers being formed only by phase separation. Further, in the organic EL apparatus, it is preferable for mutual interfaces of the plurality of functional layers to be formed substantially parallel to the electrode. It is preferable, at this point, for each of the plurality of functional layers to be constituted by a polymer material.
Further, to be formed by phase separation as mentioned above can mean that the plurality of functional layers are formed in multi-layers by using a phenomenon in which, when mixed liquid materials obtained by mixing a plurality of liquid materials, which are to serve as the plurality of functional layers, are coated on one electrode, phase separation takes place such that the mixed liquid materials are substantially parallel to the electrode surface to form a phase-separated interface.
Further, substantially parallel as mentioned above can mean the above interface and the electrode surface to be in parallel from a macro-viewpoint, whereas, from a micro-viewpoint, the plurality of functional layers are mingled mutually in concave and convex shapes in the vicinity of the interface. Furthermore, from the micro-viewpoint, the material of each functional layer in the vicinity of the interface inside each functional layer is in a mixed state more than at a part away from the interface.
In this manner, effective results may be obtained by comparison to the case of forming the multi-layered structure of small molecule materials.
To explain specifically, generally, the small molecule material was amorphously formed with an isotropic structure of molecules, so that carrier mobility is the same in the small molecule material in terms of isotropy. And the thickness of each layer of film making up the multi-layered structure was determined such as to provide a good balance of carrier mobility. To form a multi-layer of the small molecule materials, the vacuum evaporation method was typically used. However, the interface of the multi-layered film formed by the small molecule materials was in the state of uniform facial contact without the material of each film mixing. Hence, in such multi-layer structure, unless the voltage was set high in the case of a thick film thickness of the hole transport material so as to transport more holes, no light emission occurred at the light-emitting layer, and further, there were uneven light-emitting spots. And, since the interface of each film was a uniform junction surface, as the drive voltage level slightly increased, the holes and the electrons were excited, combined, and emitted all at once.
On the other hand, in the invention, the phase-separated interface can be formed as the functional layer composed of the polymer material undergoes phase separation, and further, the phase-separated interface and the electrode are substantially parallel to each other from the macro-viewpoint, and from a micro-viewpoint, the plurality of functional layers are mingled mutually in concave and convex shapes. Furthermore, the material of each functional layer in the vicinity of the interface inside each functional layer is in a mixed state more than in a part away from the phase-separated interface.
Consequently, because the interface of the functional layer is in the state in which concave and convex shapes are mingled, a contact area between each functional layer enlarges to widen a recombination site of the electron and the hole. Then, this recombination site exists at a part away from the electrode, and the light-emitting site expands as a result. Namely, improvement of the efficiency and long life of the light-emitting functional part may be accomplished.
Further, since the phase-separated interface is not uniform, but in the concave and convex shapes, even if a certain predefined drive voltage is increased, the holes and the electrons will not get excited and combine all at once, and so the intensity of emitted light will not rise steeply. Therefore, luminance may be increased gradually in response to the drive voltage level, so that control of the efficiency of the organic EL apparatus as well as gradation control low luminance can be easily performed. Furthermore, there is an advantage of dispensing with a need of complicated peripheral circuitry to perform a minute control of changes in the drive voltage.
Moreover, in the organic EL apparatus, the functional layer positioned on the surface side of the electrode has one material as its main component, and it is preferable for the one material to occupy more than 80% of the constituent elements of the functional layer.
At this point, the constituent elements of the functional layer positioned on the surface side of the electrode may be detailed as follows it means that one material occupies more than 80% by volume and that the material of the functional layer in abutment through the phase-separated interface occupies less than 20% by volume. In this manner, one material not only exists inside the above-mentioned functional layer, but one component exists as the main component, while, at the same time, there exists, as a sub-material, the material of the functional layer in abutment through the phase-separated interface, hence, the recombination site of the electron and the hole further expands. Because the recombination site exists at the part away from the electrode, the light-emitting site expands as a result. Namely, the improvement of the efficiency and long life of the light-emitting functional part may be promoted.
Further, in the organic EL apparatus, one of the plurality of functional layers is a hole transport layer having a hole transport material. Also, one of the plurality of functional layers is a light-emitting layer having a light-emitting material. It is preferable for the hole transport material to have a host function to accept the light-emitting material as a guest.
The meaning of the hole transport material has a host function to accept the light-emitting material as a guest herein can be a large overlapping of a distribution of an emission spectrum (emission energy) of the hole transport material on an absorption spectrum of the light-emitting material. In this manner, by establishing a host-guest relationship, energy movement is efficiently performed, so that in the same way as the organic EL apparatus mentioned above, the improvement of the efficiency and long life may be promoted.
It should be noted that in the invention, the hole transport layer can also includes a meaning of a hole injection layer having a hole injection property.
Still further, exemplary electronic equipment of the invention can include the organic EL apparatus mentioned above. This makes it possible to provide the electronic equipment having a long life as well as a bright display.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with reference to the accompanying drawings, wherein like numerals reference like elements, and wherein:
FIG. 1 is a sectional view to show an organic EL apparatus fabricated by a method of an embodiment according to the invention;
FIG. 2 is a sectional view to explain a fabrication process of an organic EL apparatus in FIG. 1 ;
FIG. 3 is a sectional view to explain a fabrication process of an organic EL apparatus in FIG. 1 ;
FIG. 4 is a sectional view to explain a fabrication process of an organic EL apparatus in FIG. 1 ;
FIG. 5 is a sectional view to explain a fabrication process of an organic EL apparatus in FIG. 1 ;
FIG. 6 is a sectional view to explain a fabrication process of an organic EL apparatus in FIG. 1 ;
FIG. 7 is a sectional view to explain a fabrication process of an organic EL apparatus in FIG. 1 ;
FIG. 8 is a sectional view to explain a fabrication process of an organic EL apparatus in FIG. 1 ;
FIG. 9 is a diagram to explain a host-guest function;
FIG. 10 is a diagram to explain a detailed configuration of a light-emitting functional part;
FIG. 11 is a diagram to explain light-emitting characteristics of an organic EL apparatus according to the invention;
FIG. 12 is a perspective view to show electronic equipment provided with an organic EL apparatus according to the invention; and
FIG. 13 is a diagram to explain the light-emitting characteristics of a conventional organic EL apparatus.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
An exemplary embodiment according to the invention will be described as follows.
Referring to FIG. 1 to FIG. 10 , a fabrication method of an organic EL apparatus corresponding to an exemplary embodiment of the invention will be described. It should be noted that in each drawing, a different scale is used for each layer and each part to present each layer and each part on an recognizable size on the drawings.
The organic EL apparatus to be fabricated herein is a color organic EL apparatus. Its sectional view can include, as shown in FIG. 1 , many pieces of a red light-emitting functional section 7 R, a green light-emitting functional section 7 G, a blue light-emitting functional section 7 B as respective pixels at pre-defined positions inside the substrate surface.
First, as shown in FIG. 2 , after a thin-film transistor 2 of each pixel was formed on a glass substrate 1 , an insulating layer 3 was formed. Next, a wiring 24 was formed on this insulating layer 3 to connect a thin-film transistor 2 for each pixel and an anode (pixel electrode, electrode) to the insulating layer 3 . Then, formation of the anode 4 consisting of ITO (In 2 O 3 —SnO 2 ) for each pixel position was carried out by using a typical ITO thin-film formation process, a photolithography process, and an etching process. By this, the anode 4 consisting of ITO was formed at each pixel position on the glass substrate 1 after the formation of the wiring 24 .
Next, on this glass substrate 1 , a first bulkhead 51 made of silicon oxide having an opening 51 a corresponding to each light-emitting area was formed by the typical silicon oxide thin-film formation process, the photolithography process, and the etching process. FIG. 2 shows this condition. The first bulkhead 51 is formed such that a periphery of the opening 51 a overlaps a periphery of the anode 4 .
Next, as shown in FIG. 3 , on the first bulkhead 51 , there was formed a second bulkhead 52 having an opening 52 a corresponding to each light-emitting area. This second bulkhead 52 was made of a polyamide resin and formed by a coating process of a solvent containing the polyamide resin, a drying process of a coated film, the photolithography process, and the etching process.
The opening 52 a of the second bulkhead 52 was formed in such a tapered fashion that a section perpendicular to a substrate surface is small on the glass substrate 1 side and grows larger towards a side away from the glass substrate 1 . Also, an opening area of the opening 52 a of the second bulkhead 52 is larger than the opening 51 a of the first bulkhead 51 at a position on the glass substrate 1 side. This enabled a bulkhead having an opening 5 of a two-tiered structure to be formed.
It should be noted that the light-emitting area of each pixel is precision controlled by the opening 52 a of the second bulkhead 52 . Also, the second bulkhead 52 is in a pre-defined thickness to secure a depth of the opening 5 . Also, it is formed in a tapered fashion so that even if the solvent dropped is on an upper surface of the bulkhead 52 , entering the opening 5 is facilitated.
Next, as shown in FIG. 4 , a light-emitting functional part forming material 61 is coated and formed inside each opening 5 .
As coating methods of the light-emitting functional part forming material 61 , a known wet process (wet coating process) can be employed. For example, an inkjet process (droplet discharge), a spin coating process, a slit coat process, a dip coat process, a spray film-forming method, a printing process and the like may be used. Such processes are suitable methods for film-making of polymer materials. As compared to the vapor phase process, without using expensive equipment such as vacuum apparatus, it is possible to fabricate the organic EL apparatus at low cost.
In the exemplary embodiment, it is preferable to use the spin coating process. By using the wet process in this way, the light-emitting functional part forming material 61 is formed on each pixel electrode 4 inside each opening 5 .
The light-emitting functional part forming material will now be described in detail. The light-emitting functional part forming material can be a material for forming a part corresponding to a light-emitting functional part of the present invention, and further, it has a mixture of a hole transport material to form the hole transport layer (functional layer) and a light-emitting material to form the light emitting layer (functional layer) which is dissolved by the solvent.
Next, specific examples of the hole transport material, the light-emitting material, and the solvent will e described.
First, as the hole transport material, it is preferable to employ a polymer material having triphenylamine as a skeleton. In the exemplary embodiment, ADS254BE made by ADS shown below as Compound 1 is used.
Further, as the light-emitting material, there may be used poly(9-vinylcarbazole), polyofluorene polymer derivative, (poly-)p-phenylenevinylene derivative, polyphenylene derivative, olythiophen derivative, perylene pigment, coumalin pigment, rhodamine pigment, or the above-mentioned polymer doped with an organic EL material. For doping materials, for example, there may be cited rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, Nile red, coumarin 6, quinacridone and the like.
As regards the molecular weight of polymer materials which serve as the hole transport material and the light-emitting material, it is preferably less than 200,000, and particularly under 10.
Furthermore, it is possible to use as the red light-emitting material, for example, MEH-PPV poly[2-methoxy-5-(2-ethyl hexyloxy)-p-phenylenevinylene]; as the blue light-emitting material, for example, poly(9,9-dioethylfluorene); and as the green light-emitting material, for example, PPV (poly(p-phenylenevinylene)).
Moreover, as the solvent to dissolve the above-mentioned hole transport material and light-emitting material, it is preferable to adopt xylene. It should be noted that solvents other than xylene may very well be used, for example, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, and tetramethylbenzene.
And, since the hole transport material and the light-emitting material are formed through phase separation (to be explained later) in such light-emitting functional part forming materials, molecular weight reduction is applied to the hole transport material. As a method of applying molecular weight reduction, a high pressure homogenizer system or an ultrasonic system is used. In the exemplary embodiment, the homogenizer system will be described.
The high pressure homogenizer system can be performed by using a high pressure pump equipped with a homo valve capable of adjusting an watercourse interval. This system may be explained roughly as follows. While the high pressure pump is in a condition of applying high homogeneous pressure against a matter subject to processing (hole transport material), the homo valve squeezes a flow of the matter subject to process, and by spurting it out through a minute gap, the matter subject to process is homogenized. In this way, by homogenizing the matter subject to process, there are obtained respective operations/working-effects of (1) shearing action accompanying an ultra high speed flow, (2) fine powder-making action arising from impacting a breaker ring, (3) a cavitation phenomenon caused by an ultra high speed fluid as accelerated at the homo valve gap when pressure is reduced from high pressure to low pressure, and (4) breaking action due to drastic acceleration and deceleration of the flow of the matter subject to process.
Further, as equipment to perform the high pressure homogenizer system, L-01 made by Sanwa Machinery may be used. Next, a specific example may be described. First, xylene is used as a link up to a pressure increase. After the pressure reaches 160 MPa (±20 MPa), the matter subject to process is charged. After charging approx. 50 ml of the matter subject to process, about 25 ml is recovered at 150 MPa, and further continuously adjusted to 100 MPa (±20 MPa), the remaining 25 ml is recovered.
Each pass frequency is one time.
By using the high pressure homogenizer system this way, it becomes possible to reduce the molecular weight of the hole transport material to about 10,000, and when the hole transport material is mixed with the light-emitting material and coated, phase separation suitably and easily occurs. It should be noted that the hole transport material and the light-emitting material are mixed in the light-emitting functional part forming material such that its mix ratio is 1:2 by weight. Further, in the present embodiment, it is preferable for the hole transport material to have a host function having the light-emitting material as a guest.
Referring to FIG. 9 , a host-guest relationship between the hole transport material and the light-emitting material will be described. In the drawing, solid lines showing reference numeral HTL indicate a distribution of emission spectrum of the hole transport material and broken lines showing reference numeral EML indicate a distribution of the absorption spectrum of the light-emitting material.
As shown in FIG. 9 the hole transport material has a host function to accept the light-emitting material as a guest can mean that there is a considerable overlapping of the distribution of the emission spectrum HTL of the hole transport material on the distribution of the absorption spectrum EML of the light-emitting material as a guest.
FIG. 5 is a diagram showing a state in which a solvent contained in the light-emitting functional part forming material has completely evaporated after the coating and formation of the light-emitting functional part forming material. As shown in the drawing, the light-emitting section of each color 7 R, 7 G, and 7 B is formed on each pixel electrode 4 .
At this point, referring to FIG. 10 , a detailed configuration of the light-emitting section 7 will be explained. FIG. 10A is a sectional view in macro terms of the principal part of the light-emitting section 7 and FIG. 10B is a sectional view in micro terms of the principal part of the light-emitting section 7 .
As shown in FIG. 10A , the light-emitting section 7 ( 7 R, 7 G, and 7 B) is formed on the anode 4 , the hole transport layer (functional layer) 7 a is disposed on the anode 4 side, and the light-emitting layer (functional layer) 7 b is disposed on the hole transport layer 7 a . When the above-mentioned light-emitting functional part forming material was coated and formed, phase separation occurred and it was separated by a phase-separated surface 7 c and disposed as the hole transport layer 7 a and the light-emitting layer 7 b . The phase-separated surface 7 c is formed substantially parallel to the anode surface.
Further, as shown in FIG. 10B , when the phase-separated surface 7 c is viewed in micro terms, the hole transport layer 7 a and the light-emitting layer 7 b are in a condition such that they are mutually mixed together in concave and convex shapes. Still further, at each layer of the hole transport layer 7 a and the light-emitting layer 7 b in the vicinity of the phase-separated surface 7 c , the material of each functional layer is in the condition of being mixed in more quantities than a part away from the phase-separated interface 7 c . To describe specifically by taking the hole transport layer 7 a as an example, in the vicinity of the phase-separated interface 7 c inside the hole transport layer 7 a , for instance, the hole transport layer and the light-emitting layer are mixed in relatively large quantities, while in the vicinity of the anode 4 away from the phase-separated interface 7 c , the condition is for the hole transport layer and the light-emitting layer to be scarcely mixed. Furthermore, in the same way, in the vicinity of the phase-separated interface 7 c inside the light-emitting layer 7 b , for instance, the hole transport layer and the light-emitting layer are mixed in relatively large quantities, while at the upper part (the first cathode side to be explained later) of the light-emitting layer 7 b away from the phase-separated interface 7 c , the condition is for the hole transport layer and the light-emitting layer to be scarcely mixed.
And the ratio of components of the material constituting the hole transport layer 7 a may be described as the hole transport material occupying over 80% by volume thereof, while the light-emitting material occupies under 20% by volume of the remainder. Also, the ratio of components of the material constituting the light-emitting layer 7 a may be described as the light-emitting material occupying over 80% by volume thereof, while the hole transport material occupies under 20% by volume of the remainder.
As shown in FIG. 6 , from directly above each opening 5 , a dispersed liquid 80 of ultra minute particles (average particle diameter: over 1 nm under 100 nm) of ytterbium (Yb) is dripped by the inkjet process (droplet discharge) towards the light-emitting functional section of each color, 7 R, 7 G, and 7 B. Reference numeral 100 of FIG. 8 shows an inkjet head. This enables a droplet 81 consisting of the above-mentioned dispersed liquid to be formed on each light-emitting functional section 7 R, 7 G, and 7 B.
The inkjet process is a color printing technique well known in the so-called inkjet printer. A liquid droplet of a material ink, in which various materials are made into a liquid form, is ejected from the inkjet onto a transparent substrate and fixed. According to the droplet discharge method, since droplets of the material ink may be accurately ejected to a minute area, the material ink may be fixed directly on a desired area to be colored without performing photolithography. Hence, no waste of the material is generated and fabrication cost is reduced, thus making itself a very rational method.
The ultra minute particles of ytterbium may be obtained by the following method (solvent trap process) according to the in-gas evaporation method. Under a condition of a helium pressure of 0.5 Torr, ytterbium is evaporated, and the ultra micro particles of ytterbium during the generation process are brought into contact with a vapor of tri decan and cooled. By this, there is obtained a dispersed liquid in which the ultra micro particles of ytterbium are dispersed in tri decan. This dispersed liquid may be used as the above-mentioned dispersed liquid 80 .
Next, by carrying out the drying process, the solvent was evaporated from the liquid droplet 81 . This drying process may be performed, for example, by maintaining 150° C. in an inert gas atmosphere. By this, as shown in FIG. 7 , a cathode layer (first cathode, electrode) 8 consisting of ytterbium is formed on each light-emitting functional section 7 R, 7 G, and 7 B.
Next, as shown in FIG. 8 , on the entire surface of the substrate 1 under the condition of FIG. 7 , a dispersed liquid 90 of conductive micro particles was dripped by the inkjet process. As this dispersed liquid 90 , a dispersed liquid containing micro particles of gold or silver may be used. Specifically, there may be cited Perfect Gold (product name) made by Vacuum Metallurgy Co. Ltd. and a dispersed liquid of ultra micro particles of silver obtained by adding a water solution of sodium citrate to a water solution of silver nitrate. Reference numeral 100 of FIG. 8 shows the inkjet head. By this, a liquid layer 91 consisting of the above-mentioned dispersed liquid is formed on the first cathode layer 8 inside each opening 5 and on the second bulkhead 52 .
Next, the solvent was evaporated from the liquid layer by performing the drying process. By this means, as shown in FIG. 1 , the second cathode (electrode) is formed on the entire surface (that is, on the first cathode 8 inside the opening 5 and on the second bulkhead 52 ) of the substrate 1 .
Next, on the entire surface of the substrate 1 and on the outside of the second bulkhead 52 at the periphery position of the substrate surface, an epoxy resin adhesive was coated at a pre-defined thickness, and this adhesive was hardened in a condition of a glass plate being placed thereon. Namely, the entire surface of the second cathode 9 was covered with the epoxy resin adhesive. In this manner, by performing sealing with a sealant and the glass plate, the organic EL apparatus is completed.
And attaching the organic EL apparatus to the body having the drive circuit and the like, there is completed an organic EL display panel equipped with the organic EL apparatus.
Next, the light-emitting characteristic of the above-mentioned organic EL apparatus will be described with reference to FIG. 11 .
FIG. 11 is a diagram showing a result of an experiment on the light-emitting characteristics of the organic EL apparatus, with the drive voltage (V-drive) on the transverse axis and the efficiency on the longitudinal axis.
In this diagram, a curve shown in reference numeral indicates the light-emitting characteristics of an organic EL apparatus (hereinafter referred to as phase-separated structure A) formed through phase separation of the above-mentioned hole transport layer 7 a and the light-emitting layer 7 b via the phase-separated interface 7 c , while a curve shown in reference numeral B indicates the light-emitting characteristics of an organic EL apparatus (hereinafter referred to as the conventional structure B) formed in the multi-layered structure of the hole transport material and the light-emitting material in the same way as the conventional technology.
As shown in FIG. 11 , the conventional structure B has a characteristic in which the change “de” of the efficiency relative to the change “dv” of the drive voltage undergoes a steep change. Specifically, there are characteristics in which increasing the drive voltage only slightly causes the efficiency to rise greatly and reducing the drive voltage only slightly causes the efficiency to exteriorize to a large degree.
On the other hand, the phase-separated structure A is a curve milder than the characteristic curve of the conventional structure B, and it is apparent that in the phase-separated structure A, by the change “dv′” which has a larger voltage width than the above-mentioned change “dv”, there is obtained the change “de” of the efficiency. Consequently, in the phase-separated structure A, it is possible to change the efficiency without supplying the drive voltage in high precision and in high resolution, and apparently, it is possible to carry out gradation easily in low luminance.
Further, there was obtained a result that the maximum efficiency of the phase-separated structure A is higher than the conventional structure (refer to Y part in the drawing). Still further, in high voltage, a level of decrease of the efficiency in the phase-separated structure A is small, thus suggesting an expansion of the light-emitting position.
As mentioned above, in the organic EL apparatus of the present embodiment, since the hole transport layer 7 a and the light-emitting layer 7 b are formed through the phase-separated interface 7 c , as a contact area between the hole transport layer 7 a and the light-emitting layer 7 b enlarges, the recombination site of the electron and the hole expands, whereas this recombination site exists in the part away from the electrode, so that the light-emitting site expands. Namely, the improvement of the efficiency and long life of the light-emitting functional part may be accomplished.
And, because the phase-separated interface 7 c is not a uniform plane but in concave and convex shapes, even if a pre-defined voltage should be raised, the hole and the electron do not get excited and combine all at once, the intensity of light emitted does not make a steep rise. Consequently, depending on the drive voltage, luminance can be slowly increased, thus making it possible to control easily the efficiency of the organic EL apparatus as well as gradation of low luminance. In addition, there is an advantage of dispensing with complicated peripheral circuitry to control finely the change of the drive voltage.
Further, in the above-mentioned organic EL apparatus, the hole transport layer 7 a occupies over 80% by volume of the constituent components with the hole transport material as its main component. Furthermore, the light-emitting layer 7 a positioned on the first cathode 8 side has the light-emitting material as its main component, occupying over 80% by volume of the constituent components.
Accordingly, only one material not exist in each layer, but one material exists as the main component, while, at the same time, the material of a layer in abutment through the phase-separated interface exists as a sub-material, hence, the recombination site of the electron and the hole expands even further; since the recombination site exists at a part away from the electrode, the light-emitting site expands as a result. Namely, the improvement of the efficiency and long life of the light-emitting functional part may be accomplished.
Further, in the above-mentioned organic EL apparatus, the hole transport layer 7 a has the host function for treating the light-emitting material as a guest, resulting in enlarging an overlapping of the distribution of the emission spectrum of the hole transport layer 7 a on the absorption spectrum of the light-emitting material; by establishing the host-guest relationship, energy movement is efficiently performed, thereby further contributing to the improvement of the efficiency and long life.
Still further, since the wet process is used to form the light-emitting functional section 7 , the photolithography process becomes unnecessary. Consequently, reduction of the fabrication cost is made, thus providing a very rational method and enabling the light-emitting functional section 7 to be formed at low cost and with accuracy.
Furthermore, by using the inkjet process, the first cathode 8 and the second cathode 9 are formed. Consequently, it is possible to form the light-emitting functional section 7 , the first cathode 8 , and the second cathode 9 all by the wet process. Accordingly, expensive equipment, such as vacuum equipment becomes unnecessary, simplification of the production process is accomplished, and inexpensive organic EL apparatus may be fabricated.
It should be noted that by using the light-emitting functional part forming material which mixed the hole transport material and the light-emitting material, there is produced a configuration in which the hole transport layer 7 a and the light-emitting layer 7 b are formed through the phase-separated interface 7 c . An electron injection material may be further mixed in the light-emitting functional part forming material. In this manner, when the light-emitting functional part is formed by using the light-emitting functional part forming material in which the electron injection material is further injected, configuration will be such that the first phase-separated interface 7 c is formed between the hole transport layer 7 a and the light-emitting layer 7 b and that a second phase-separated interface is formed between the light-emitting layer 7 b and the electron transport layer. In such configuration, there is made available an organic EL apparatus of not only hole transportability but also electron injectability.
Next, various exemplary electronic equipment provided with the organic EL apparatus of the present invention will be described with reference to FIG. 12 .
FIG. 12A is a perspective view showing an example of a mobile phone. Reference numeral 600 in FIG. 12A shows the mobile phone body, while reference numeral 601 shows a display unit using the above-mentioned organic EL apparatus.
FIG. 12B is a perspective view showing an example of a portable information processing device such as a word processor and a personal computer. Reference numeral 700 in FIG. 12B shows a portable information device, reference numeral 701 shows an input section such as a keyboard, reference numeral 703 shows an information processing device body, and reference numeral 702 shows a display unit using the above-mentioned organic EL apparatus.
FIG. 12C is a perspective view showing an example of wrist watch type electronic equipment. Reference numeral 800 in FIG. 12C shows a watch body, and reference numeral 801 shows a display unit using the above-mentioned organic EL apparatus.
Each electronic equipment shown in FIG. 12A to C is that which is provided with the organic EL apparatus, which was fabricated by a method of the above-mentioned embodiment, as a display unit, featuring the characteristics of the fabrication method of the organic EL apparatus according to the above-mentioned embodiment. As a result, the fabrication methods of these electronic equipment are made easy.
It should be noted that in the above-mentioned exemplary embodiment, the cathode layer consisting of ytterbium is formed by the liquid process using the dispersed liquid of ultra minute particles of ytterbium. It should be understood that the method of the invention is not restricted to such a method using the dispersed liquid of ultra minute particles of a rare earth element, and, for example, there is included a method of processing to remove a ligand of a rare earth element complex after a liquid containing the rare earth element is dripped by the inkjet process and the like.
Further, in the above-mentioned exemplary embodiment, the organic EL apparatus was described, whereas it may be applicable to organic EL apparatus other than a display unit, for example, a source of light. Still further, in regard to materials making up constituent parts other than the cathode of the organic EL apparatus, those publicly known, conventional materials may be used. | Aspects of the invention can provide an organic electro-luminescence apparatus which has accomplished the light-emitting characteristics of high efficiency and long life and in which gradation control is facilitated, and electronic equipment provided with the electro luminescence apparatus. The organic electro-luminescence apparatus can include light-emitting functional sections formed between electrodes, the light-emitting functional sections being provided with a plurality of functional layers, the plurality of functional layers being formed only through phase separation. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a division of application Ser. No. 576,611, filed May 12, 1975, now U.S. Pat. No. 4,044,652.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to electrohydraulic actuator systems and, more particularly, to such systems for positioning the nozzle of an associated turbine.
2. Description of the Prior Art
The development of a satisfactory gas turbine engine for automotive vehicle power depends to a significant extent upon the effectiveness of its control systems. To compete successfully as an alternative to the already highly-developed piston engine as a vehicle power source, the gas turbine must not only be capable of comparable performance under all operating conditions, but preferably in a way and with a type of response which is familiar to the conditioned user of a piston engine-powered vehicle.
Most of the techniques required to satisfactorily control an automatic gas turbine are available from past experience with aircraft gas turbine engines. In a sense, the control system design may be more difficult because of the use by less sophisticated operators and the fact that it is practically necessary to cause the control system to simulate piston engine operation in the operator-machine interface. However, a more difficult problem is to realize the required control functions in devices which are acceptable on an economic basis for automotive utilization. Accordingly, many of the control devices and designs which are devised for use with gas turbine aircraft engines cannot be directly adapted to automotive use.
One of the particular control functions required for the automotive gas turbine engine is the positioning of the power turbine nozzles. Engine fuel flow and turbine nozzle position are controlled in response to various control and condition parameters such as accelerator pedal position, ambient temperature, ambient pressure, gas generator speed, gas generator turbine temperature, regenerator "hot side in" temperature, and transmission output shaft velocity. Because of the complexity of the control requirements, a computer is employed to operate with signals from a multiplicity of sensors and to develop the requisite control functions. Suitable actuators are required to operate in response to the computer control signals. Various types of electromechanical actuators are known, directed to a variety of output functions. Among these are the devices disclosed in the following U.S. Pat. Nos.: 2,055,209 of Schaer; 2,256,970 of Bryant; 2,570,624 of Wyckoff; 2,696,196 of Adams et al; 2,738,772 of Richter; 2,886,010 of Hayos et al; 3,264,947 of Bidlack; and 3,380,394 of Fornerod. Such prior art is exemplary of the technology to which the present invention relates.
SUMMARY OF THE INVENTION
In brief, arrangements in accordance with the present invention comprise a servoactuator which is particularly adapted to position the turbine nozzles of a vehicle power turbine in response to electrical command signals. In the vehicular system for which the present invention is developed, the electrical signals are produced by a control computer operating in accordance with the characteristics of the system and in response to condition signals provided by various sensors. The design of the computer is no part of the present invention. The servoactuators of this invention may be used in other systems and operated in response to signals derived from other sources. The servoactuators of the present invention produce an output motion in proportion to the input electrical control signals. In the particular vehicular turbine system with which these servoactuators are presently employed, the output movement of the servoactuator acts through a suitable linkage mechanism to drive a ring gear which in turn rotates the power turbine nozzles through the desired angular travel. In this system, nozzle position is modulated between 0° and 20° as a function of regenerator or gas generator inlet temperature during steady-state operation. Particular angular settings of the nozzles are specified during acceleration, deceleration and startup, in which case the idle and steady-state conditions are overridden. In addition, the actuators may be used to reverse the nozzles by positioning them in a braking mode so that some braking of the vehicle is actually attained from the turbine.
In one particular arrangement in accordance with the present invention, the servoactuator comprises a hydraulic motor having an output shaft for coupling to the ring gear which is connected to position the turbine nozzles. Movement of the hydraulic motor is controlled by a hydraulic servo valve which is actuated by a proportional solenoid. A lever is pivotably anchored at one end and is pivotably connected to the protruding rod of the hydraulic motor at the other end. A second rod, which protrudes from the proportional solenoid coil portion, is pivotably mounted intermediate the ends of the lever such that the motion of the hydraulic motor piston causes a translation of the solenoid and valve, thereby providing a follow-up mechanism for the servoactuator which serves to linearize the response of the servoactuator.
In accordance with particular aspects of the present invention, the servoactuator comprises a main body housing a hydraulic four-way valve, a transducer, and a piston so arranged as to provide linear movement of an output shaft attached to the piston which is proportional to an electrical input signal. The output shaft is arranged for coupling to a load which, in the vehicular turbine system described, is a ring gear coupled to rotate the turbine nozzles through the desired angular travel. The servo valve comprises a proportional solenoid-type, linear motion transducer and a high-gain, four-way hydraulic valve. The solenoid plunger has a conically-shaped face in order to minimize the range of operating force with travel. A hole through the plunger may be provided to control damping and thereby stabilize the valve spool. The plunger is spring-loaded and develops a travel which is proportional to input current to the solenoid coil.
In another arrangement in accordance with the present invention, a rotary actuator is employed, coupled to be driven by a rotary solenoid. The rotary actuator has a rotational output shaft for providing rotary output motion which is linearly proportional to an electrical input signal to the rotary solenoid. The position of the actuator is controlled by a rotary valve, the shaft of which is coupled to the rotary actuator by a follow-up spring. The rotary valve shaft is connected to the rotary solenoid shaft by a load spring such that when the actuator is in the "null" position, the load spring and follow-up spring are balanced in tension against each other.
BRIEF DESCRIPTION OF THE DRAWING
A better understanding of the present invention may be had from a consideration of the following detailed description, taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a front elevational view, partially broken away, of one particular arrangement in accordance with the present invention;
FIG. 2 is a similar view of a portion of the device of FIG. 1, showing a particular modification thereof;
FIG. 3 is a similar view in longitudinal cross-section of another particular arrangement in accordance with the present invention;
FIG. 4 is a partially-exploded view, in perspective, of a portion of the arrangement of FIG. 3;
FIG. 5 is an exploded view of a portion of FIG. 4;
FIG. 6 is a schematic representation illustrating the fluid flow in the device of FIGS. 3 and 4;
FIG. 7 is a front elevational view of still another arrangement in accordance with the invention;
FIG. 8 is an exploded view of the spring feed back system arrangement of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a particular linear servoactuator 10 in accordance with the invention is shown comprising a main body or housing 12 which houses a four-way hydraulic valve 14, a proportional solenoid 16 and a piston 18. A follow-up linkage 20 connects the proportional solenoid 16 and piston 18, thus providing an output which is linearly proportional to the electrical signal input to the solenoid.
The hydraulic valve 14 has an inlet line 22 for connection to a supply of pressurized fluid (not shown) and an outlet 24 for connection to a fluid return line. Internal fluid lines 26 and 28 connect from the valve 14 to opposite sides of the piston 18 within its cylinder 30. A spool 32 is mounted to move laterally within the valve chamber 34 to admit pressurized fluid from the inlet 22 to a selected one of the internal lines 26, 28. Another internal line 36 connects the portion of the chamber 34 on the right-hand side of the spool 32 with the portion of the chamber on the left-hand side of the spool 32 to which the outlet 34 is connected.
The solenoid 16 comprises a coil 40 attached to a core 42 which is movable within the housing 12 in sealing relationship provided by a seal 44. The solenoid 16 has a plunger 46 shown with a central port 48. The plunger 46 is connected to the spool 32 by means of a link 50. The proportional solenoid is loaded by a compression spring 52 extending between adjacent faces of the coil 40 and the plunger 46 to provide a feedback force. The direct connection between the solenoid plunger 46 and the valve spool 32 via the link 50 provides zero backlash and simultaneously accommodates the close clearance of the spool valve. The plunger 46 operates in the fluid return passage of the servoactuator body, thus providing minimum operating force for plunger 46 and the valve spool 32. The hydraulic seal 44 for the solenoid is at the outer diameter of the coil 40, and the force for follow-up motion is provided by the piston 18. Since the valve 14 has a high-pressure gain, the error introduced to overcome seal friction is very small.
Coupled to the piston 18 is an output shaft 60 which is sealed within the housing 12 against leakage by means of the seal 62. The follow-up linkage 20 comprises a lever 64 which is pivotably anchored to the housing 12 at a pivot point 66 and is also pivotably connected to the shaft 60 at pivot point 68 and to a shaft extension 70 of the solenoid core 42 at pivot point 72. Coupling to the shaft 60 to drive the associated turbine nozzle ring gear (not shown) may be afforded via a coupling point 74. The phantom outline of the lever 64 shows the position of the linkage 20 corresponding to the movement of the piston 18 to the extreme right-hand position within the cylinder 30.
In the operation of the arrangement of FIG. 1, the system begins in a stable condition with the spool 32 closing off the fluid lines 26, 28 for a given level of input signal to the solenoid 16. As signal current is increased, a point is reached where the preload of the spring 52 is overcome by the electromagnetic force on solenoid plunger 46. This moves the servovalve spool 32 to the left, causing hydraulic fluid to flow from the pressurized fluid inlet 22 into the line 26 extending to the output shaft side of the piston 18. The piston 18 responds by moving to the right in the cylinder 30, thereby, by virtue of the linkage 20, also moving the solenoid core 42 and coil 40 toward the right. This causes the servovalve spool 32 to return to the null position, thereby closing off the lines 26, 28 and stopping the piston 18 at the new position. Further increase in signal current will cause the piston 18 to continue to the right by an amount proportional to the increase in signal current. Reduction in signal current causes the piston 18 to move to the left in similar manner.
In one particular embodiment of the invention corresponding to FIG. 1, the piston 18 is provided with a stroke of 2.50 inches and provides a force of 100 lbs. maximum with 100 psi supply pressure. Under maximum slew rate of 2.5 inches in 0.10 seconds, the actuator 10 provides a 15 lb. output force. Full actuator travel of 2.50 in. is equivalent to 90° total nozzle blade angle change. A piston diameter of 1.32 in. serves to meet the design maximum of 100 lb. output force. The solenoid plunger 46 has a travel of 0.50 in. in which its motion is proportional to input current to the coil 40. The four-way valve 14 develops the maximum slew rate with a travel of 0.04 in. of the spool 32. A selected size of the plunger port 48 serves to provide effective damping of the internal control system of the servoactuator.
FIG. 2 shows the cylinder portion of the arrangement of FIG. 1 with a minor modification in which the output shaft 60 extends out both ends of the cylinder 30 so that the drive coupling to the associated turbine nozzle ring gear may be effected at the right-hand end of the cylinder 30. In all other respects, the operation of a servoactuator corresponding to FIG. 2 would be the same as indicated for the actuator of FIG. 1.
The embodiment of the invention represented in FIGS. 3, 4 and 5 comprises a rotary actuator 80 of the proportional solenoid type. As indicated in FIG. 3, the actuator 80 comprises a housing 82 containing a rotary solenoid 84, a valve assembly 86 and a drive assembly 88. The rotary solenoid 84 is of a type known in the art and may be purchased from Ledex, Inc., 123 Webster Street, Dayton, Ohio. It acts to provide a direct rotation of its output shaft 90 in response to electrical input signals.
The drive assembly 88 is shown more clearly in FIG. 4 as comprising a cylinder 100 between end plates 102 (see FIG. 3) that guide a dual-vane rotor 104 designed to travel through an angle of 90°. Two abutments 106, diametrally opposite from each other, are permanently attached to the inner walls of the cylinder 100 and form a close fit to the shaft 108 of the rotor 104. The abutments 106 serve as stops for angular travel of the rotor 104 and form two separate chambers 110 within which the two vanes 112 of the rotor 104 travel. The rotor output shaft 116 extends through the right-hand plate 102, which also serves as a mounting plate for the unit 80. The rotary shaft 108 also extends to the left-hand plate 102 and through a swivel manifold 118 (FIG. 3) that directs fluid into and out of the cylinder 100. Inlet 120 and outlet 122 conduct fluid between the swivel manifold and a source of pressurized fluid. The swivel manifold 118 remains fixed with respect to the housing 82 and allows the free flow of fluid during the full angular travel of the rotor 104.
The servovalve assembly 86 comprises a servovalve spool 130 (see FIGS. 4 and 5) having an inner shaft 132 drilled at the right-hand end for the hydraulic fluid return passage and at the left-hand end for coupling to the solenoid shaft 90 by means of a pin 134. The servovalve spool 130 also includes an outer sleeve 136, tubular spacers 138 and 140 for manifolding of the hydraulic fluid, and a plug 142 for mounting in the hollow section of the inner shaft 132. The supply passage of the servovalve spool 130 is between the inner diameter of the outer sleeve 136 and the outer diameter of the inner shaft 132.
The operation of the rotary actuator of FIGS. 3-5 may be better understood by reference to FIG. 6, which is a cross-sectional view taken along the line 6--6 of FIG. 3, looking in the direction of the arrows. When the servoactuator 80 is in the static mode, pressure is equalized in the chambers A, B, C and D of the cylinder 100. However, when the servovalve assembly 86 is positioned as shown in FIG. 6 to develop the actuator in the pressurized mode, pressure is directed to the chambers A and C from the spaces between the sleeve 136 and the shaft 132. At the same time, porting is arranged to permit the connection of the chambers B and D to the return via the hollow section of the shaft 132. As a result of the pressure differential across the rotor vanes 112 (supply pressure in chambers A and C, zero pressure in chambers B and D), the vanes 112 cause a counter-clockwise rotational movement which is coupled to the output shaft 116. Movement of the rotor 108 in this fashion brings the spool assembly 86 to a position where the fluid ports are again closed, thus maintaining the position of the rotors 112 and output shaft 116 as determined by the solenoid shaft 90 in response to a given electrical signal current level in the solenoid 84. Increased solenoid current causes a further rotation of the solenoid shaft 90, a corresponding rotation of the valve spool assembly 86, again creating a differential pressure condition across the vanes 112 in the cylinder 100, thereby developing further rotation of the vanes 112 and the output shaft 116 to the new position determined by the level of current in the solenoid 84. Reduction of current level in the solenoid 84 causes a differential pressure across the vanes 112 in the opposite direction and a resulting rotation of the vanes 112 and output shaft 116 in the clockwise direction of FIG. 6.
Close working clearances are provided between the ends of the vanes 112 and the inner cylinder walls, between the left and right-hand sides of the vanes and the cylinder side plates, and between the inner diameter of the abutments 106 and the rotor shaft 108 to minimize leakage through these clearances during operation. Proper fit between the ends of the vanes 112 and the inner wall of the cylinder 100 requires close control of concentricity of all mating parts. Spring-loaded slippers can be provided on the ends of the vanes 112 to minimize leakage with relaxed machine tolerances if desired. Clearances between the left and right-hand edges of the vanes 112 may be controlled by shimming adjacent the flanges of the cylinder end plates 102.
FIG. 7 and 8 illustrate a rotary actuator in accordance with the invention which is essentially the same as that shown and described in connection with FIGS. 3-6, except that a torsion load spring is interposed as the connection between the rotary solenoid shaft 90 and the shaft 132 of the rotary valve assembly 86. Also, a follow-up spring is inserted to provide a connection between the rotary valve assembly 86 and the vane rotor shaft 108. The resulting rotary actuator 150 of FIG. 7 provides a force balance system in which the load spring 152, connected to the solenoid shaft 90 by pin 154 and to the valve shaft 132 by pin 156, and the follow-up spring 160, connected to the shaft 132 by a pin 162 and to the vane rotor 108 by pin 164, are balanced in tension against each other in the null position. Angular travel of the rotor 108 proportional to current input to the solenoid 84 is attained by proper matching of the solenoid characteristics and the rate of the load spring 152.
By virtue of the particular arrangements in accordance with the present invention as shown in the accompanying drawings and described hereinabove, improved proportional response operation is afforded in both the linear and rotary actuators of the present design. These actuators are particularly designed for and may be used to advantage in the turbine nozzle positioning systems for an improved and simplified automotive vehicle turbine propulsion system. The inherent linearization of these actuators enables the turbine nozzle control system to be operated without the need for the provision of closed loop control, thus substantially reducing the cost and complexity of the turbine control system so that turbine propulsion becomes a more viable alternative to the conventional piston engine for automotive vehicle propulsion.
Although there have been described above specific arrangements of electrohydraulic actuators in accordance with the invention for the purpose of illustrating the manner in which the invention may be used to advantage, it will be appreciated that the invention is not limited thereto. Accordingly, any and all modifications, variations or equivalent arrangements which may occur to those skilled in the art should be considered to be within the scope of the invention as defined in the appended claims. | An electrohydraulic proportional actuator for converting an electrical input signal to proportional mechanical output. Fluid power may be derived from pressurized fuel or lubricating oil of an associated engine. The actuator may be used to drive any engine function requiring modulated control. The mechanical output is proportional to the electrical input. The actuator includes mechanical feedback to linearize the response function, thus eliminating the need for closed loop operation of the system in which the actuator is used. Both linear and rotary actuators are disclosed in various embodiments. Each type is capable of operation with either a proportional solenoid and valve or a force rebalance solenoid and valve. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to a continuous flow circulatory water heater. More particularly, the present invention relates to a new and improved continuous flow water heater which utilizes a submersible removable pulsating heating mechanism arranged to provide maximum heating efficiency wherein the water is preheated as it rises from the bottom to the top of the caldron, and is heated to its maximum temperature by a pretzel-shaped pulsating pipe prior to exiting the caldron near the top of the caldron.
Continuous flow water heaters of the type disclosed herein are known. For example, reference may be had to German Patent Publication No. DE PS 1,922,650. Further, in particular, the principles in design of the pulsation heater mechanisms utilized herein are known to those skilled in this art. For example, further reference may be had to German Patent Publication Nos. DE PS 1,911,192 and 1,911,193, and to articles published by the inventor herein, namely, in the magazine Betriebs-Okonom, No's. 1 and 2 (1970) regarding Procedures with Gas Operated Resonant or Pulsating Combustion Heater Mechanims, in No. 5 (1970) pp. 96-100, concerning Gas Operated Resonant or Pulsating Burners in Foreign Countries and, in No. 8 (1970) pp. 150-162, on Automatic Starting Process of Resonant or Pulsating Combustion Heating Mechanisms During the Course of their Development, and a special publication entitled Gas Operated Resonant or Pulsating Combustion Heater Mechanisms, published by the Engineering Association of Worttemberg in VD1, presented on the occasion of the conference in Stuttgart on Mar. 5, 1969. The bibliographical references cited in this literature are also worthy of note. In view of this known prior art, a detailed description of the operation of the pulsation heater system will not hereinafter be necessary.
Although continuous flow heater systems are known, the design of a continuous flow hot water system has not yet been optimized. It is an object of the present invention to further develop continuous flow water heaters in such a manner that the individual parts, particularly the intake muffler, the exhaust muffler and the circulation system formed by the combustion chamber and the pulsation pipe, are located in the smallest possible space with the best possible utilization of the space within the volume provided within the caldron. It is a further object of the present invention to provide an arrangement of the operating elements to make the operation of the continuous flow water heater as efficient as possible.
High efficiency of operation is especially important today where there is often a shortage of fuel, and if not a shortage, the cost of fuel is usually rather high. Therefore, efficiency in water heating systems is especially important. Resonant or pulsating combustion heating systems, especially gas fired, are becoming increasingly attractive and may achieve a very high degree of efficiency, possibly up to 99%. Therefore, pulsating combustion systems in accordance with the present invention are particularly appropriate for the solution of heating problems of the future. This is especially the case since it is possible to use explosive materials in the combustion material which could not be burned with an open flame. Thus, the present invention may utilize gases which cannot be burned with an open flame, such as hydrogen or mixtures with a high hydrogen content. There also existed a need for further inventive development in the area of continuous flow water heaters to provide an arrangement wherein the heating elements are arranged in the form of a dip-stick to be immersed in the water so that the material of the caldron was not exposed to a higher temperature than that to which the water will be heated. In this manner, it is even possible to use a synthetic material for the construction of the caldron thereby solving problems such as corrosion and the high cost of conventional prior art caldrons. In addition, the water surrounding the submerged heater unit also serves the function of a sound muffler.
In the case of known mechanisms, an optimal heating of the water circulating or continuously flowing through the container from water intake to water outlet has not, in fact, been achieved. Further, in known devices, the exhaust muffler surrounding the intake muffler in the approximate shape of a ring, caused a certain waste of space in consideration of the diameter of the total mechanism. Further, it should be taken into consideration that in order to achieve the necessary length of the pulsation pipe for a stable pulsation process, an arrangement with relatively great expenditure of cross sectional space must be selected in the mechanism shown there. The latter is necessitated in that there must be resonant conditions at approximately 120 Hz. It could be said that the length of the pulsation pipe is a constant to be considered here, one which nevertheless must be realized in a small space by means of a correspondingly curved shape, while on the other hand, a small curve radius should be avoided wherever possible due to the flow resistance thereby encountered.
SUMMARY OF THE INVENTION
According to the invention, the above-mentioned objects are accomplished by the apparatus set forth in the claims. In addition, the disclosure of the invention describes several other advantageous developments.
Briefly and basically the advantages of the present invention are achieved through the arrangement of an air cylinder, with an exhaust muffler, as basically cylindrical bodies, standing vertically next to each other, above which the pulsation pipe is located. An optimal space utilization within the caldron has been achieved by intake of the water from below and outlet therefrom at the top, that is, closely above the area in which the pulsation pipe is located. The heating results in a "thermosiphon" effect with the result that the water is pre-heated by the other parts before reaching the area where the pulsation pipe is located, and the water leaves the caldron at a point near the pulsation pipe where it reaches its highest temperature. By means of this arrangement of the pulsation pipe above the two vertical, basically cylindrical bodies located next to each other, namely the air cylinder and the exhaust cylinder, the advantageous development of the invention is achieved which is made possible through the pretzel shape of the pulsation pipe. This shape utilizes the space thus formed in a highly efficient manner, especially where according to a further development of the invention two pulsation firing systems formed by combustion chamber and pulsation pipe are mounted above each other at relatively little distance. In this manner, a relatively simple doubling of the performance is possible with otherwise identical individual parts. This shape also facilitates a relatively large curve radius, thus comparatively low flow resistance, although the cross-sectional area transversed by the water flow is, in fact, completely covered, especially when the combustion chambers are also taken into consideration as heat sources. This construction is further facilitated by the fact that pipes, which can be disconnected from the cover or lid covering the caldron, are led through the interior of the caldron providing intake or outlet for gas, fresh air, electricity, exhaust, etc. Thereby, the space possibly not occupied by the pretzel shape of the pulsation pipe and the combustion chamber is completely filled so that, practically, the heating can be uniformly achieved over the entire cross-section of the flow area. In this manner, efficiency coefficients of up to 99% of the so called "low heat value" may be achieved. In addition, even the "high heat value" may be utilized. According to an additional development of the invention, the conduits provided for transfer of air (fresh air intake) to the air cylinder may also be utilized as space for additional intakes such as, gas, starter air, and electrical wiring. Thereby additional sound muffling is achieved simultaneously.
An additional definite advantage is achieved thereby that the entire pulsating combustion immersion heating arrangement may be attached to the cover placed on the caldron in such a manner that that this mechanism can be removed by disconnecting the connectors and gaskets between caldron and cover, and all assembly and/or testing and/or service work may be performed on the unit. Specifically, this also facilitates testing during manufacturing.
Further, with this arrangement in the caldron in accordance with the present invention the heat producing parts are surrounded by minimal water distance.
In total, the described arrangement of individual parts makes it possible to achieve a much lower total height than was previously possible. Thus, a mechanism of this type is also suitable for mounting in or at hot water reservoirs for swimming pools, kitchens and as supplementary heating in conjunction with heat pumps, particularly absorption heat pumps and solar heating mechanisms.
The simplicity of improving performance makes it possible to realize performance variations of 10,000 Kcal/h with exactly identical measurements of the caldron; if the cross-section of conduits for fresh air and fuel are correspondingly designed, which is easily done, the performance may be doubled by mounting two pulsation systems above each other with little difference in elevation. When coupling these pulsation systems in such a manner that they work in counter-action, that is with a phase shift of 180°, no enlargement of the intake and muffler cylinders is necessary, since the pressure peaks of the detonations are equally high and only the frequencies are doubled corresponding to the dual arrangement.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purpose of illustrating the invention, there are shown in the drawings forms which are presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.
FIG. 1 is cross-sectional view of a continuous flow water apparatus in accordance with the present invention.
FIG. 2 is a cross-sectional view taken along line II--II of FIG. 1.
FIG. 3a is a view in perspective of a cover housing for a continuous flow water heater apparatus in accordance with the present invention.
FIG. 3b is a view in perspective of a resonant or combustion immersion heater apparatus for use in a continuous flow heater apparatus in accordance with the present invention.
FIG. 3c is a view in perspective of a caldron in accordance with the present invention.
FIG. 3d is a view in perspective of a housing for supporting the caldron of FIG. 3c in accordance with the present invention.
FIG. 3e is an elevation view of a resonant or pulsating combustion immersion heater apparatus mounted in a test tank in accordance with the present invention.
FIG. 3f is an elevation view of a continuous flow water heater apparatus without a housing cover in accordance with the present invention.
FIG. 3g is an elevation view of a caldron mounted on a housing prior to the installation of a pulsation combustion immersion heater and cover.
FIG. 3h is an elevation view of a continuous flow water heater apparatus in accordance with the present invention.
FIG. 4 is a partial cross-sectional elevation view of another embodiment of the present invention utilizing two pulsating combustion chambers in accordance with the present invention.
FIG. 5 is a plan cross-sectional view of the embodiment of FIG. 4 in accordance with the present invention.
FIG. 6 is a cross-sectional view taken along line VI--VI of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings in detail wherein like numerals indicate like elements, the continuous flow water heater according to FIG. 1 is comprised of a caldron 1, with a bottom 2 which rests on a housing 3. It is insulated by means of an insulation layer 4. In the bottom of the caldron, water is provided into the caldron by means of a water intake 5. By using the continuous flow water heater in a closed water circuit, this is the so called recoil, the water rises in the caldron after heating as described in the following and exits from the caldron through water outlet 6, the so called first run. At the top, caldron 1 is closed by cover 7, which is sealed to caldron 1 by means of gaskets 8. Cover 7 is provided with an insulation layer 4. From cover 7, resonant or pulsating combustion immersion heater mechanism 9 extends downwards into caldron 1.
The principles of operation and the design of resonant or pulsation combustion heaters are known and reference should be had to the German patent publications and the publications of the inventor herein referred to supra in the Background of the the Invention. Briefly the resonant or pulsating combustion immersion heater is comprised of air cylinder 10 in which pipe support 11 enters, which is connected with a permanently attached additional pipe support 13 in cover 7 via elastic hose 12, in order to provide air into air cylinder 10 from space 14 above cover 7. Air cylinder 10 includes an intake muffler 15 in which air enters from air cylinder 10 via entrance opening 16. Air from intake muffler 15 enters mixing pipe 18 via non-return valve 17. Gas serving as fuel is provided via conduit 20 to gas intake 19 and from which the gas exits into mixing pipe 18. Spark plug 21 is used for initiation of the combustion process when starting the pulsating combustion operation. High voltage is provided to spark plug 21 via wire 22. Combustion of the gas/air mixture takes place in combustion chamber 23 which is connected with mixing pipe 18. Pulsation pipe 24 is formed as may be best seen in FIG. 2 into a shape which may be referred to as "pretzel shape". The end 25 of pulsation pipe 24 extends into exhaust cylinder 26. Exhaust cylinder 26 is designed to serve as a sound muffler. Exhaust cylinder 26 is provided with an exhaust pipe 27 having an open end at the bottom, said open end ending near or just closely above the bottom of exhaust cylinder 26. Exhaust pipe 27 is connected via elastic hose 28 with pipe support 29. Pipe support 29 is attached to cover 7. An additional or second muffler 30 receives the exhaust from the upper end of pipe 29, which also serves as a pipe support for exhaust cylinder 29. The exhaust gases are eliminated from muffler 30 via connecting conduit 31 and exhaust pipe 32 (See FIGS. 1 and 2).
The connection of connecting conduit 31 with exhaust pipe 32 occurs by means of a screw connection 33 in such a manner that it can be disconnected. In such a manner that they may be disconnected, the conduits 20, 22 are connected with the conduits 20', 22', respectively, and these connections (not shown) are located above the cover 7 in the space 14 within housing cover 35, which space is provided for the instrumentation. Screw connection 33 is designed in such a manner that it constitutes a disconnectable connection of the exhaust pipe 32 with cover 7, so that when this connection is disengaged, the cover 7 may be removed. Exhaust pipe 32 is permanently attached under bottom 2 of the caldron 1.
Further, vertical pipe 36 is permanently attached to bottom 2 of caldron 1 and attached to cover 7 by means of a screw connection which may be disengaged. When this screw connection is disengaged, cover 7 may be removed from the vertical pipe 36. Conduit 20' for gas intake, which is connected with conduit 20, and wire 22', for providing electricity to the spark plug 21, which is connected with conduit 22, are both led through the vertical pipe 36 to the connection points in the housing 3. In addition, fresh air is sucked in through the vertical pipe 36. This occurs from the housing 3, where the fresh air can enter, dust free, through a slot 38 and an air filter (not shown). This is a significant advantage over systems with an open flame, where the combustion process would necessitate measures requiring additional air, if a filter were introduced. In the manner described, sufficient masses of fresh air can at any time flow via the slot 38, the interior of the housing 3 and the vertical pipe 36 into the space 14 above the cover 7 and within the cover housing 35, so that the air may then be sucked into the pulsating combustion system consisting of combustion chamber 23 and pulsation pipe 24 via the two pipe supports 11 and 13 at intake muffler 15. An additional conduit 39 is also led through the pipe supports 11 and 13. This conduit serves to provide air for the starter. Cover 7 is attached to caldron 1 by means of screws 40. The cover housing 35 is placed on top and attached by means of screws 40' to supports 43. After disengagement of screws 40 and 40' as well as screw connections 33 and 37, caldron cover 7 with the complete pulsation immersion heater system 9 may be removed, so that service work, etc., may be performed on the entire unit in an extremely simple manner. Above caldron cover 7 and in connection with the conduits and pipes shown, further instrumentation (not shown) is also provided within cover housing 35.
As may be seen, cold water enters caldron 1 via water intake 5 from below and flows around air cylinder 10, exhaust cylinder 26, as well as combustion chamber 23 and pulsation pipe 24. Thereby, the water contributes significantly to further muffling of sound, that is, in addition to the mufflers. Then, the water is heated above air cylinder 10 and exhaust cylinder 26 by means of heat radiation from pulsation pipe 24, whereafter it leaves slightly above this area through water outlet 6. By heating the water in the upper part of caldron 1, a constant flow of water upwards from below is achieved by means of the thermo-siphon effect, which also contributes to optimal performance efficiency by means of the water exiting in the area of the most intensive heating, that is, in the area closely above the heating effect of pulsation pipe 24. The above-mentioned efficiency co-efficients may be noted in conjunction with the desirable characteristics of the gas operated pulsation heating mechanisms. A reduction of vibrations is achieved by means of mounting air cylinder 10 and exhaust cylinder 26 on elastic hoses 12 and 28, respectively. Sound muffling is achieved through the mufflers as well as the arrangement of the various conduits, for example 22, 39, 20', 22', inside pipes. Additional vibration reduction is achieved by means of the entire unit standing on rubber feet 41.
FIG. 2 shows specifically the arrangement of pulsation pipe 24. Its length is determined by the resonance conditions at vibrations of 100-125 Hz; its length thus not variable. The illustrated arrangement solves the problem of arranging a pulsation pipe particularly well and with maximum efficiency in the smallest space possible. Specifically, the illustrated arrangement allows the largest possible curve radius and thereby provides low flow resistance in the interior of the pulsation pipe, as well as minimal space requirement, while at the same time facilitating the arrangement of the pulsation pipe at the position most advantageous for circulatory heating.
The course of pulsation pipe 24 may be described as follows if A and B stand for the vertical axes of air cylinder 10 and exhaust cylinder 26, respectively, which are located in the caldron: starting from combustion chamber 23, which is arranged somewhat eccentrically to axis A above the air cylinder, the pulsation pipe 24 goes first toward the interior wall of caldron 1 in such a manner that it leads to approximately point C, which may be defined as a point of tangency with exhaust cylinder 26, and proceeds in a circular curve tangentially and as close to the interior wall of the caldron 1 as possible. Following this circular line for slightly more than a semi-circle, the pulsation pipe 24 then circumvents B to point D. Pulsation pipe 24 then follows a straight piece from point D until it leads to E and then follows an imagined circle around A as close to caldron 1 as possible; from there, the pulsation pipe again follows a circular line for slightly more than a semicircle around A to F and then runs straight from F downwards to the opening in exhaust cylinder 26. This shape may be characterized as a "pretzel shape". Certainly, other curved, space saving shapes may be possible in order to achieve a predetermined length, for example, the form of a digit eight around the axes A and B, whereby, if necessary, some additional length could be gained, but whereby, due to the crossing point, slightly more space would be required.
At the right side of the housing 3 (in FIG. 2), the connection points 20', 5, 22', 32 for gas, water, electricity, and exhaust, respectively, are to be found.
FIGS. 3a--h serve to clarify the particularly advantageous manufacturing and mounting achieved by the described arrangement of individual parts and mechanisms. First come separate assembly and preparation of cover housing 35 according to FIG. 3a, pulsation immersion heater mechanism 9 attached to cover 7 according to FIG. 3b, caldron 1 according to FIG. 3c, and the housing 3 according to FIG. 3d. To further clarify subsequent descriptions, it should be noted in the context that an instrumentation panel 44, mounted by means of supports 43 on cover 7, also belongs to the pulsation immersion heater mechanism 9. When mounted (cf. also FIG. 1), this panel extends through an opening 42 in cover housing 35. The advantage of this distribution of the mechanisms is that it is possible to test pulsation immersion heater system 9, as shown in FIG. 3d for performance although it is not yet fully assembled. This test may be made in a test water container 45 as shown in FIG. 3e. The only requirement is that corresponding connections for gas, electricity, etc. be available on the test location. The entire pulsation immersion heater mechanism 9 may be submerged in a water container 45 and be fully calibrated and tested for performance prior to final assembly.
If this testing proceeds satisfactorily, pulsation immersion heater mechanism 9 may be placed in caldron 1, as shown in FIG. 3f, the caldron having previously been mounted on the housing 3 as shown in FIG. 3g. Then, as shown in FIG. 3h, cover housing 35 is mounted. FIG. 3h shows the complete assembly. Service is equally simple: it is only necessary to take off cover housing 35 and disengage the screws holding caldron cover 7. In this manner, the entire pulsation immersion heater mechanism 9 is easily accessible and may be immediately serviced or even--if repair is necessary--exchanged. Exchange of individual mechanisms is particularly simple for the same reason.
FIG. 4 and FIG. 5 show a construction sample with an increase of the heater performance to twice the original value. This is achieved by utilizing two combustion chambers and two pulsation pipes--with otherwise identical parts. As may be seen from FIG. 4, two combustion chambers 123-1 and 123-2 are located above air cylinder 110, connected with the cylinder in the manner shown in FIG. 6, each slightly eccentrically from the axis A. Their positioning relative to each other is achieved with an elevation difference of, for example, 30 mm in such a manner that the two pulsation pipes 124-1 and 124-2 exiting from them may be positioned directly above each other at this short distance and with basically identical shapes. At the ends 125-1 and 125-2, they are rotationally connected with each other via a coupling piece 146. This coupling piece serves to coordinate the pulsations in the two combustion chamber/pulsation pipe systems in such a manner that the rotation constantly has a phase shift of 180° between the two. This secures the stability of both pulsation systems in counter-stroke. At the same time, the coupling piece 146 serves as stabilizer for the exhaust cylinder 126. Thus, insofar the cross-sections for the intake air have been selected with sufficient size for the embodiment with only one pulsation system, the simple measure of mounting two pulsation systems one above the other with an insignificant difference in total height, the effect achieved may be doubled. As can be seen from FIG. 5, only a slight mutual dislocation of the combustion chambers is necessary, namely in such a manner that, in relation to axis A, the combustion chamber 123-1 is located opposite from combustion chamber 123-2 in order to accommodate the two pulsation pipe pretzels one above the other. The cross-sections may be calculated from the outset for two pulsation systems and, if only one system is built in, the pipe diameter for fresh air and exhaust may be decreased by insertion of narrower pipe elements.
In order to obtain two pulsation combustion systems, indentical in regard to pulsation characteristics, the lengths of the mixing pipes must be identical, so that the connection points of the mixing pipes to the intake mufflers must be at different elevations. This may be seen from FIG. 6. From the combustion chambers 123-1 and 123-2, mixing pipes 118-1 and 118-2 lead to non-return valves 117-1 and 117-2, respectively. As may be seen, these are now located at different elevations on the intake muffler 115, resulting in equal lengths for the two mixing pipes and, consequently, also identical pulsation conditions. In order to achieve this result, the non-return valve 117-1 is attached at the end of a short attachment support 147 which opens into the intake muffler 115.
In conjunction with FIGS. 4 through 6 only those items have been described and elaborated upon, where the arrangement differs from that described with reference to FIGS. 1 and 2. In other areas, particularly the connection of parts to be mounted in the caldron with the pulsation immersion heater mechanism, reference should be made to the presentation in FIGS. 1 and 2.
Furthermore, it should be noted that the cross-section of caldron 1 may deviate from the form shown in FIG. 2 or FIG. 5 in that the caldron surrounding the side by side vertical cylinders may also be round or any other suitable shape. With a round caldron the volume of the caldron is increased. The round shape is also advantageous for stability. In other respects, the arrangement may remain the same--with corresponding adjustment of cover 7. For reasons of manufacturing, assembly, and service, air cylinder 10 and exhaust cylinder 26 are designed in two parts.
In view of the above, the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention. | A continuous flow water heater utilizes a submersible pulsating heating mechanism. A continuous flow water heater is provided with a caldron which may be closed by means of a cover. The pulsating heating mechanism may be mounted to the caldron cover with the pulsating heating mechanism and the cover being readily removable. The pulsating heating mechanism extends downward into the caldron. The pulsating heating mechanism is formed by a vertically standing sound muffling air cylinder with an intake muffler, a combustion chamber and a pulsation pipe connected to the combustion chamber. The pulsation pipe exhausts into a cylindrically shaped substantially vertically mounted exhaust muffler cylinder mounted adjacent to the air cylinder within the caldron. The caldron may be made of a synthetic material as the highest temperature which it must withstand is that of the temperature of the water to be heated. The water to be heated enters from the bottom of the caldron, is heated by the air and exhaust cylinders as it rises, and is heated to its highest temperature near the top of the caldron where it exits by means of a pretzel-shaped pulsation pipe. The heating capacity may be doubled by using a second substantially identical pulsating heating mechanism which operates 180° out of phase without increasing the volume of the exhaust cylinder. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to a tool for use in gravel packing wells. More specifically, the invention relates to a retrievable gravel packing tool for effecting a circulation-squeeze type gravel pack.
In wells in geological formations where the production of sand from the formation along with the liquids and gases being produced therefrom is a problem, it is well known in the art to install a screen in the production tubing and pack gravel around the screen to prevent the sand from the formation flowing into the production tubing. In such an arrangement, a gravel pack screen assembly is run into the formation on a string of tubing to the desired location and gravel, typically coarse sand mixed in a gelled liquid, is pumped down to the exterior of the gravel pack screen assembly to fill the area between the screen assembly and the formation. After a sufficient amount of gravel has been pumped down to the exterior of the gravel pack screen assembly to completely fill the area between the screen assembly and the formation, the screen assembly is released from the tubing string and the tubing removed from the well with production tubing subsequently being installed in the well.
It is common in the art to circulate the gravel-laden liquid outside the screen assembly, and to return the liquid through the screen to the surface, leaving the gravel in place around the screen assembly. After the initial circulation, the operator may want to further consolidate the gravel pack, which is done through squeezing, or applying pressure to the gravel pack after closing the circulation path used to return the gravel-laden liquid to the surface. It is also desirable to reverse-circulate gravel-laden fluid out of the tubing string and gravel pack screen assembly prior to retrieving it from the wellbore.
SUMMARY OF THE INVENTION
The present invention relates to a weight-set single-zone retrievable gravel packer including a compression-set packer element, J-slot means to releasably maintain the gravel packer in an unset mode, ratchet means to releasably lock the gravel packer in a set mode, an intake passage to receive fluid from a tubing string, a return passage to receive fluid from a gravel screen below the gravel packer, a circulation passage extending from the exterior of the gravel packer to the intake passage, closeable crossover means to receive fluid from the return passage; first check valve means to prevent return flow back to the tubing string through the intake passage, second check valve means adapted to selectively open the intake passage to the circulation passage, and check valve release means for removing said second check valve means from the junction of the intake and circulation passages.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more readily understood by one of ordinary skill in the art through a review of the following detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, wherein:
FIGS. 1A-1D comprise a schematic sectional elevation of the gravel packer of the present invention disposed in a wellbore and having a gravel pack screen suspended therefrom via a hydraulic releasing tool.
FIGS. 2A-2H comprise a detailed half-section elevation of the gravel packer of the present invention in an unset mode.
FIGS. 3A-3H comprise a detailed half-section elevation of the gravel packer of the present invention in a set mode.
FIG. 4 comprises a development of the J-slot employed in the gravel packer of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 2A-2H, 3A-3H and 4, gravel packer 10 disposed in wellbore casing or liner 8 comprises mandrel assembly 12 surrounded by housing assembly 14, and having circulation assembly 16 suspended therefrom.
Mandrel assembly 12 includes crossover assembly 20, including tubular crossover housing 22 having threaded adapter bore 24 at its upper end to secure gravel packer 10 to a tubing string (not shown). Crossover housing 22 has a cylindrical exterior 26, and an interior bore 28 below adapter bore 24 including annular shoulder 30, first cylindrical seal bore 32, crossover bore wall 34, second cylindrical seal bore 36, and threaded exit bore 38. A plurality of crossover ports 40 extend through the wall of housing 22 to open on crossover bore wall 34.
Tubular crossover sleeve 42 is slidably disposed in housing 22, upward travel thereof limited by the abutment of annular stop 68 against shoulder 100 on keyway adapter 90. The exterior of crossover sleeve 42 includes first cylindrical seal surface 46 carrying O-ring 48, chamfered annular edge 50 leading to second cylindrical seal surface 52 carrying O-rings 54 and 56 bracketing annular crossover recess 58 to which crossover apertures 60 extend through the wall of sleeve 42, and recessed exterior 62. Stop collar 64 having threaded surface 66 thereon above annular stop 68 is disposed at the bottom of sleeve 42. Housing 22 is made up with sleeve 42 through the engagement of threaded exit bore 38 with threaded surface 66 until the lower edge of housing 22 contacts annular stop 68. The interior of stop collar 64 includes longitudinal, inward-extending keys 80.
The interior of crossover sleeve 42 includes a first seal bore 70 carrying O-ring 72 in the wall thereof, below which crossover bore 74 of greater diameter communicates with crossover apertures 60. Below crossover bore 74, second seal bore 76 of greater diameter and carrying O-ring 77 extends to threaded exit bore 78.
Keyway adapter 90 extends upwardly into sleeve 42, seal surface 92 on the exterior thereof sealing against second seal bore 76, and threaded surface 94 mating with threaded bore 78. Exterior surface 96 having keyways 98 cut therein extends downwardly to annular spring shoulder 100 at the bottom of keyway adapter 90. The interior of keyway adapter comprises a crossover bore 102 of substantially the same diameter as sleeve crossover bore 74, bore 102 extending down to spring shoulder 100, whereat it terminates at a seal bore 104 carrying O-ring 106, below which threaded exit bore 108 leads to the bottom of spring shoulder 100. Keyways 98 accommodate keys 80 of stop collar 64, permitting crossover housing 22 to longitudinally slide or telescope with respect to crossover sleeve 42, while restricting mutual rotation of the two components.
O-ring 106 provides a seal between seal surface 112 on upper mandrel 110 where threaded surface 114 thereon is made up in exit bore 108 of keyway adapter 90. Below threaded surface 114, upper mandrel 110 includes cylindrical exterior surface 116, which includes annular shoulder 118 thereon. At the lower end of surface 116, threaded surface 120 leads to seal surface 122 at the bottom of upper mandrel 110. The bore wall 124 of upper mandrel 110 is of substantially the same diameter as that of crossover bore 102 of keyway adapter 90.
Upper slip assembly 130 is disposed on upper mandrel 110 about shoulder 118. Upper slip collar 132, having annular shoulder 134 on the interior thereof, rides over shoulder 118. Longitudinally extending, circumferentially disposed slots 136 extending to the bottom of slip collar 132 accommodate slips 138 therein, laterally extending legs (not shown) at the upper ends of slips 138 residing in lateral channels 140 of slots 136. Slips 138 have arcuate inner surfaces 142, leading to oblique bottom surfaces 144, while the exterior of slips 138 includes a longitudinal slot 146 bounded by slip walls 148 having teeth 150 thereon. Leaf springs 152 contacting the bottoms 154 of slots 146, and anchored by bolts 156 in spring slots 158 of slip collar 132, maintain slips 138 against exterior surface 116 of upper mandrel 110.
Coil spring 160, surrounding upper mandrel 110, bears against the bottom of keyway adapter 90 and the top of slip collar 132 in a substantially relaxed state in FIG. 2B.
Bypass seal mandrel 170, having threaded entry bore 172 at the top interior thereof is sealed with seal surface 122 on upper mandrel 110 by O-ring 174 when made up therewith. The interior of bypass seal mandrel 170 below seal cavity 176, comprises bore wall 178 of substantially the same diameter as that of upper mandrel bore wall 124. At the upper exterior of bypass seal mandrel 170, seal saddle 180 including shallow annular groove 182 therein accommodates bypass seal 184. Below saddle 180, the exterior of bypass mandrel 170 necks down to cylindrical ratchet surface 186 having lefthand ratchet threads 188 extending outwardly therefrom. At the bottom of bypass seal mandrel 170, enlarged exterior cylindrical surface 190 leads to threaded surface 192 and seal surface 194.
J-slot mandrel 200 is secured to threaded surface 192 via threaded entry bore 202, O-ring 204 therebelow providing a seal with bypass seal mandrel 170 against seal surface 194 thereof. The interior of J-slot mandrel 200 comprises bore wall 206, of substantially the same diameter as bore wall 178. The exterior of J-slot mandrel 200 includes cylindrical surface 208 having recessed area 210 cut therein, from which J-slot lugs 212 radially protrude. The bottom of J-slot mandrel 200 terminates with exterior threads 214, by which circulation assembly 16 is secured thereto, O-ring 216 sealing therebetween.
Tubular intake mandrel 220, having a uniform cylindrical exterior surface 222 and a uniform cylindrical inner bore wall 224 defining slurry intake bore 226, extends from seal bore 70 of sleeve 42 through all of mandrel assembly 12 to connect to circulation assembly 16 via exterior threads 228.
Crossover assembly 20, upper mandrel 110, bypass seal mandrel 170, J-slot mandrel 200, upper slip assembly 130, coil spring 160 and intake mandrel 220 comprise mandrel assembly 12.
Housing assembly 14 includes upper slip wedge collar 230, having frusto-conical slip ramp 232 at the top thereof, threaded cylindrical surface 234 therebelow on the exterior, and an axial bore defined by bore wall 236 extending therethrough, through which upper mandrel 110 is slidably disposed, lower lip 238 on slip wedge collar 230 abutting the top of bypass seal mandrel 170.
Upper bypass case 240 is secured to collar 230 by threaded entry bore 242 mating with threaded surface 234. Exterior cylindrical surface 244 extends downward to packer compression ring 246, which surrounds the lower end of upper bypass case 240 and is joined thereto at threaded junction 248. The interior of upper bypass case 240 includes longitudinally extending splines 250, which extend substantially to radial shoulder 252, below which the interior necks down to seal bore 254, having O-rings 256 disposed in recesses therein. Bypass ports 258 extend through the wall of case 240, and the lower ends of case 240 and co-extensive packer compression ring 246 provide radially flat upper packer compression shoulder 260.
Tubular packer saddle 270 extends through seal bore 254 of case 240, the upper annular end 272 of saddle 270 being of larger diameter than cylindrical packer element surface 274 and containing longitudinal slots 276 therein which slidably mate with splines 250 on the interior of case 240. The upper interior of saddle 270 is undercut to provide an enlarged ratchet bore 278 to clear ratchet threads 188, and a seal surface against which seal 184 may act when gravel packer 10 is set. The lower interior of saddle 270 necks down to exit bore 280.
Saddle 270 is secured at threaded junction 282 to lower bypass case 290, case 290 having threads 292 on its upper exterior by which lower packer compression ring 294 is secured via threads 296. An O-ring 298 carried in seal bore 300 of ring 294 seals against packer element surface 274 of saddle 270. Lower packer compression ring 294 extending over the upper face 302 of lower bypass case 290 provides a radially flat lower packer compression shoulder 304. Three annular elastomeric packer elements 306 comprise packer element means 310 and are disposed about packer saddle 270.
The exterior 312 of lower bypass case 290 is substantially cylindrical while the middle bore 314 thereof below threaded junction 282 is cylindrical and of substantially the same diameter as exit bore 280 of saddle 270, lower bypass ports 315 extending through the wall of case 290 into middle bore 314. Below middle bore 314, chamfered surface 316 leads obliquely outward to ratchet dog bore wall 318, below which threaded exit bore 320 is secured to threaded surface 322 on the upper exterior of lower slip wedge collar 323. Ratchet dog annulus 324, defined between lower bypass case 290, lower slip wedge collar 323 and bypass seal mandrel 170, contains a plurality of arcuate ratchet dogs 330 having left-hand threads 332 cut on the interior thereof, and circumferentially extending slots 334 on the exterior thereof. Spacer legs 336 extending upwardly from lower slip wedge collar 323 separate ratchet dogs 330, legs 336 also containing slot 338 therein aligned with slots 334 on dogs 330. Garter springs or elastic bands 340 extend through slots 334 and 338 about ratchet dogs 330 and spacer legs 336.
The bore 342 of collar 323 is substantially the same as that of middle bore 314 of lower bypass case 290. The lower exterior of collar 323 comprises slip ramps 344 separated by spacer walls 346 having undercut therein lateral channels 348 adjacent the surface of ramps 344. Lower slips 350 ride on ramps 344, lateral webs (not shown) extending into channels 348 in walls 346. The upper exterior of slips 350 comprises slip face 352 having teeth 354 thereon. The lower exterior of slips 350 comprises T-shaped strut 356, the laterally oriented ends of which extend into grooves 358 in the sides of strut channels 360 at the upper end of lower slip collar 362, which is comprised of a plurality of arcuate sections secured together by means well known in the art to form a collar.
Drag block assembly 420 includes drag block housing 370 which interlocks via outwardly facing annular shoulder 372 and recess 374 with inwardly facing shoulder 364 and recess 366 on lower slip collar 362 as the arcuate segments forming slip collar 362 are secured together. Drag block housing 370 contains a plurality of drag block cavities 376 therein, separated by walls 378, arcuate spring bases 380 extending therebetween about J-slot mandrel 200. Drag blocks 390 are disposed in cavities 376 over leaf springs 392, the centers 394 of which bear against spring bases 380, and the ends 396 of which bear against drag blocks 390 in spring cavities 398. Lips 400 and 402 at each end of drag blocks 390 extend longitudinally therefrom, retainer ring 404 maintaining top lips 400 inside cavities 376, and retainer collar 406, which is secured at threaded junction 408 to drag block housing 370, maintains lower lips 402 in cavities 376. The exteriors 416 of drag blocks 390 bear against the walls of casing 8, and may have carbide inserts (not shown) embedded therein to reduce wear.
The lower end of drag block housing 370 comprises J-slot case 410, including J-slots 412 therein, which receive J-slot lugs 212 (see FIG. 4).
Circulation assembly 16 includes tubular circulation housing 422, which is secured via threaded bore 424 to threaded surface 214 on J-slot mandrel 200, seal bore 426 effecting a seal with O-ring 216. The exterior of circulation housing 422 is cylindrical, and circulation ports 426 extending through the wall thereof. Tubular circulation mandrel 428 is disposed within housing 422, and secured thereto by welds 430 between the periphery of circulation ports 426 and the outer surface of lateral protrusions 432 on mandrel 428, which protrusions 428 accommodate lateral circulation channels 434 extending between the interior of circulation mandrel 428 and the exterior of protrusions 432, which are aligned with circulation ports 426. Circulation mandrel is secured to intake mandrel threads 228 via threaded bore 436, below which annular shoulder protrudes 438 inwardly above smooth check valve bore 440, extending to the bottom of mandrel 428. Protrusions 432 rest on annular lip 442 on the interior of circulation housing 422 in addition to being welded at 430. Check valve assembly 444 is slidably disposed within check valve bore 440 of mandrel 428, and comprises elastomeric sleeve 446 bonded above shoulder 447 to tubular body 448, which is secured at threaded junction 450 to valve seat body 452, body 452 including frusto-conical ball seat 454 in the bore thereof, and shear pin recess 456 in its exterior surface 458, below which is carried O-ring 460. A plurality of shear pins 462 extend into shear pin recess 456 from shear pin apertures 464 in the wall of circulation mandrel 428, maintained therein by cylindrical housing 466 of spring check assembly 468, which is secured to the lower end of mandrel 428 at threaded junction 470, O-ring 471 on the exterior of mandrel 428 effecting a seal with seal bore 473 above junction 470 on housing 466. Check valve assembly 444 extends slightly into the upper bore 472 of housing 466, O-ring 460 slidably sealing thereagainst. Annular shoulder 474 in housing 466 defines constricted bore 476 above frusto-conical valve seal 478 at the top of spring check bore 480, check ball 482 being biased against seat 478 by coil spring 484, which is supported by tubular spring base 486 threaded to the interior of housing 466 at junction 488, until flange 490 abuts the bottom of housing 466.
Lower adapter 492 is secured to circulation housing 422 at threaded junction 493, O-ring 494 sealing therebetween. Cylindrical exterior surface 495 necks down at 496 to exterior threads 497, while interior bore wall 498 necks down below spring check assembly 468 to exit bore 499.
Various passages are defined within gravel packer 10. Central intake passage 1000 extends from the top of gravel packer 10 through check valve assembly 444 to spring check assembly 468. Return passage 1002 extends from the bottom of gravel packer 10 below spring valve assembly 468, becomes annular in shape thereat and continues upward around circulation mandrel 428 (past protrusions 432), around intake mandrel 220 upward to crossover assembly 20, ending at crossover apertures 60. Circulation passages 1004 extend from the interior of circulation mandrel 428 to the exterior of gravel packer 20 at circulation housing 422.
Concentric bypass passage 1006 extends from upper bypass ports 258 through annular channel defined between upper bypass case 240, packer saddle 270, lower bypass case 290 and bypass mandrel 170, to lower bypass ports 315.
OPERATION OF THE PREFERRED EMBODIMENT
Referring generally to FIGS. 1A-1D, 2A-2H, 3A-3H and 4 and more specifically to FIGS. 1A-1D, gravel packer 10 suspended from a tubing string (not shown) is schematically depicted in wellbore casing or liner 8, an hydraulic releasing tool 500 disposed below gravel packer 10 through slip joint 700 and a gravel screen 702 suspended from hydraulic releasing tool 500 below blank pipe. Gravel screens and slip joints are well known in the art, and hydraulic releasing tool 500 may be as more fully described in co-pending U.S. patent application Ser. No. 756,040, filed on even date herewith and assigned to Halliburton Company. A washpipe or tailpipe 704 is suspended from hydraulic releasing tool 500 and extends into screen 702, which extends across producing formation 6. As the tubing string is run into the wellbore, fluid can move around packer element means 310 via bypass passage 1006, and the tubing string is filled through circulation passages 1004 and intake passage 1000, due to inward deflection of sleeve 446 in response to the wellbore/tubing string pressure differential.
After running the tubing string into the wellbore, the bottom of the wellbore is tagged with gravel screen 702 and slip joint 700 is compressed. The string is then picked up to extend the slip joint 700 while leaving the screen on bottom.
Gravel packer 10 is then set by application of right-hand rotation through mandrel assembly 12, which moves J-slot lugs 212 to positions 212b (see FIG. 4) above the open bottoms of J-slots 412 from 212a, from which they were removed when the tubing string was picked up. The tubing string is then set down, which sets lower slips 350 against lower slip wedge collar 323 (FIG. 3D) through movement of mandrel assembly 12 with respect to housing assembly 14, the latter's movement being restricted by drag blocks 390. After lower slips 350 set against casing 8, continued downward travel of mandrel assembly 12 closes bypass passage 1006 (FIG. 3C) by bringing seal 184 against packer saddle 270, after which upper slip assembly 130, biased by spring 160, contacts upper slip wedge collar 230 and forces it and upper bypass case downward, compressing packer element means 310 against casing 8 (FIGS. 3C and 3D) after which upper slips 138 contact and set against casing 8 (FIG. 3B). The downward travel of mandrel means assembly 12 results in ratchet dogs 330 engaging ratchet teeth 188 (FIG. 3D), locking gravel packer 10 in a set mode, spring 160 aiding in maintaining it therein. The packer is then pulled upward by the tubing string to test the ratchet engagement and upper slips, and the annulus 4 between the tubing string and casing 8 is pressured up to test the seal of packer element means 310 against casing 8.
Gravel packer 10 may then be released from gravel screen 702 via hydraulic releasing tool 500, if desired. To effect release the tubing string is picked up to pull a specified force, for example, 1000 pounds, against the set gravel packer 10. Tubing pressure is then applied through intake passage 1000 of gravel packer 10, past ball 482 which is biased downward against spring 484, through slip joint 700 to seat ball 672 against seat 668 in hydraulic release tool 500. Pressure is continued until shear pins 578 shear, and releasing mandrel 506 moves downward inside collet sleeve 504, releasing collets 588 from the outward bias of annular shoulder 658 at the bottom of releasing mandrel 506, and uncovering reversing ports 555, which results in a perceptable pressure drop at the surface. Tubing pressure is then relieved, and weight set down on the gravel packer 10. This will align crossover ports 40 with crossover apertures 60 in crossover assembly 20 (see FIG. 3A); pressure is then applied to annulus 4, which will establish reverse circulation if screen release has been effected, through crossover assembly 20, return passage 1002, through slip joint 700, into hydraulic releasing tool 500, out reversing ports 555 past reversing boot 566, up the annulus 5 below gravel packer 10, into gravel packer 10 through circulation passages 1004 past sleeve 446 and up to the surface through intake passage 1000 and the tubing string.
Alternatively, screen 702 may be released via pressuring annulus 4 after setting down to open crossover assembly 20, which will be transmitted to hydraulic releasing tool 500 through the reverse circulation path described in the preceding paragraph, forcing releasing mandrel 406 downward.
To gravel pack, a ball 455 is then dropped or circulated down the tubing string through intake passage 1000 to ball seat 454 in check valve assembly 444. Pressure is then applied to shear pins 462, which when sheared permit check valve assembly 444 to move downward, uncovering circulation passage 1004 (see FIGS. 3F and 3G) and establishing circulation through passage 1004, into annulus 5, down to gravel screen 702, through the apertures 706 therein, up washpipe 704, through hydraulic releasing tool 500 past unseated ball 672, through slip joint 700 and into return passage 1002, out of crossover assembly 20 through apertures 60 and ports 40, and up annulus 4 to the surface.
A fluid injection rate is then established by pulling up on the tubing string to close crossover assembly 20, and pressuring up the tubing until it is ascertained that fluid can be pumped into formation 6 at a desired rate and pressure. If not, the formation may have to be treated with acid to increase its permeability. If the injection rate is satisfactory, bypass passage 1006 can then be opened to "spot" the gravel-laden slurry to gravel packer 10 by pulling against the tubing string, applying pressure to annulus 4, rotating the tubing string to the right 12 to 16 turns to release ratchet dogs 330 from ratchet threads 188 and seal 184 from packer saddle 270, indicated by a relieving of the pressure in annulus 4. Slurry can then be spotted down to the gravel packer 10 without circulating formation fines or other debris into screen 702, as fluid below packer element means 310 will be displaced upward into annulus 4 via bypass passage 1006 by the slurry traveling down the tubing string and into intake passage 1000. After slurry spotting, the tubing string is set down to close bypass passage 1006 and open crossover assembly 20. The slurry is circulated out passage 1004 and down to screen 702, the gravel being deposited outside screen 702 adjacent formation 6, fluid returns being taken up washpipe 704.
After the gravel pack is placed, the tubing string is again pulled against the set gravel packer 10 to close crossover assembly 20, and the pack slurry is squeezed into the formation and against screen 702 through intake passage 1000, circulation passages 1004 and lower annulus 5. If desired, the operator may alternate between circulating and squeezing several times to place more gravel and ensure the integrity of the pack. It should be noted that gravel packer 10 permits squeezing without subjecting the casing above packer element means 310 to squeeze pressure, an important feature in wells with old or otherwise deteriorated casing.
If the screen 702 has not previously been released, the tubing string is set down, and annulus 4 is pressurized, this pressure being transmitted through crossover assembly 20 and down return passage 1002 to hydraulic releasing tool 500 as previously described, to move releasing mandrel 506 downward.
Excess slurry can be reverse circulated out of the tubing string gravel packer 10 and annulus 5, by circulating clean fluid down annulus 4 to crossover assembly 20, down return passage 1002, through slip joint 700, out reversing ports 555 past boot 566, up annulus 5, into circulation passages 1004, and up intake passage 1000 to the surface through the tubing string.
The gravel pack can be retested if desired in the circulate and/or squeeze mode, and repacking done if necessary, in the same manner described above.
The gravel packer 10 may then be unset, by pulling the tubing string against gravel packer 10, applying pressure to the annulus, rotating the tubing string to the right to release the ratchets and open bypass passage 1006 (indicated by relief of annulus pressure). The tubing string is then pulled up to retract upper slips 138, unset packing element means 310, unset lower slips 350 and return lugs 212 back into J-slots 412. Gravel packer 10, with slip joint 700, collet sleeve 504 and releasing mandrel 506 may then be removed from the wellbore, leaving tool case 502 and screen 702 in place with the gravel pack about the latter. Subsequently, a tubing seal assembly on production tubing may be stabbed into tool case 502 to produce formation 6 through screen 702.
Thus has been described a novel and unobvious apparatus for gravel packing a well. Of course, numerous additions, deletions and modifications to the preferred embodiment of the apparatus may be made without departing from the spirit and scope of the invention, as defined by the following claims. | The present invention comprises a retrievable gravel packer for circulation and squeeze type gravel packing. The gravel packer includes a compression-set packer element, a J-slot assembly to releasably maintain the gravel packer in an unset mode, a ratchet assembly to releasably lock the gravel packer in a set mode, an intake passage to receive fluid from a tubing string, a return passage to receive fluid from a gravel screen below the gravel packer, a circulation passage extending from the exterior of the gravel packer to intake passage, a closeable crossover assembly to receive fluid from the return passage; a first check valve to prevent back flow back to the intake passage from the interior of the interior of a gravel screen therebelow, a second check valve adapted to selectively open the intake passage to the circulation passage, and a check valve release for removing said second check valve means from the junction of the intake and circulation passages. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation of PCT/EP2012/005227 filed on Dec. 18, 2012, which is based upon and claims the benefit to DE 10 2012 200 146.8 filed on Jan. 5, 2012, the entire contents of each of which are incorporated herein by reference.
BACKGROUND
Field
The invention relates to endoscopes and in particular to a relay set for an endoscope with a plurality of relay sets of the same type, comprising two plano-convex rod lenses which face one another with their planar end surfaces, and an achromat that is arranged between these rod lenses, particularly in a central aperture plane of said relay set, wherein said achromat is designed as an arrangement of at least two lenses which have different refractive indices and Abbe numbers, and is located at a distance from the rod lenses.
Prior Art
Corresponding endoscopes affected by the invention include rigid endoscopes, which have an opening with objective lenses on their distal tip, through which light from an operative field can enter the endoscope. Endoscopes normally also have light conductors or optical fibers next to the rod lens system, with which light from a light source on the proximal end of the endoscope is directed to the distal end in order to illuminate the operative field. Since the relay sets and the optical fibers share the existing space in the endoscope, a compromise must be found between the diameter of the lenses of the relay sets and the available cross-sectional surface for light conductors in order to achieve a maximum image brightness.
Rod lens systems with several relay sets of rod lenses transfer the perceived image to the proximal end of the endoscope, where it is received by an operator through an eyepiece or by means of an image sensor. Since the respective image is inverted in the image planes between the relay sets or respectively rotated by 180°, an odd number of relay sets is generally used. The rod lenses are used in order to direct as much of the light as possible to the eyepiece of the endoscope.
A rigid endoscope with for example 3, 5 or 7 relay sets, which in turn consists respectively of several rod lenses and additional lenses lying in between, thus has a high number of boundary surfaces with air or vacuum gaps or lenses connecting to it with different optical properties. A correction of image errors, called aberrations, is thereby possible. This includes spherical aberration, coma, astigmatism, image field curvature, distortion and color errors, the so-called chromatic aberrations.
Chromatic aberrations result due to the dispersion of optical glasses in that light of different wavelengths is deflected to different degrees. The refractive index of the glass is not a constant but rather a wavelength-dependent function. Simply put, the dispersion describes the steepness of the progression of the refractive index of an optical material.
Axial and lateral chromatic aberrations result from the different degrees of light refraction of different wavelengths of the light. The axial chromatic aberration describes the effect that, in a focusing system, the distance between the respective focus point and the lens system depends on the wavelength. The lateral chromatic aberration describes the wavelength dependency of the enlargement of an object in the image plane. The chromatic aberrations can be partially compensated or reduced through use of lenses with different materials. Thus, the axial chromatic aberration for two wavelengths can be corrected with an achromat. In the case of apochromatic optical systems, the axial chromatic aberration is corrected for three wavelengths. However, the aberration for the wavelengths which are not corrected exactly is thereby reduced as well.
In most cases, the relay sets used in the endoscopes of the applicant of the present patent application have two plano-convex rod lenses which face one another with their planar end surfaces. An achromat, i.e. an optical subassembly made up of several lenses, with which chromatic aberrations are at least partially compensated, is arranged in the gap between the rod lenses. The achromats are usually made up of two or three lenses with different optical properties, above all a different refractive index and different Abbe numbers. The Abbe number V, which is determined as
V = n e - 1 n F ′ - n C ′ ( 1 )
within the framework of the present application from the wavelength-dependent refractive index n of the material, is a measure for the dispersion of the material, wherein a low Abbe number stands for a high dispersion and a high Abbe number stands for a low dispersion. The indices e, F′ and C′ named in formula (1) stand for the Fraunhofer lines e (light source mercury, wavelength 546.074 nm), F′ (cadmium, 479.9914 nm) and C′ (cadmium, 643.8469 nm).
In high-quality optical systems, such as e.g. objectives for reflex (SLR) cameras, lenses made of glass with a particularly low dispersion are used to correct chromatic aberrations. In different contexts, these glasses, depending on their Abbe number and on the context, are also called “special low dispersion glass” (SLD glass), “extraordinary low dispersion glass” (ELD glass), “extra-low dispersion glass” (ED glass) or “ultra-low dispersion glass” (UL glass).
In the context of the present invention, these glasses are collectively referred to as “ED glasses”. ED glasses to be used within the framework of the invention have an Abbe number of 75 or greater. Fluoride glasses for example have Abbe numbers of approximately 77 or 80 or more. The limits are not clearly defined; different manufacturers offer different ED glasses with different Abbe numbers, which lie for example between 77 and 95. At the same time, such ED glasses have a relatively low refractive index of approx. 1.4 to 1.6 compared to optical glasses.
Since ED glasses are fluoride glasses and other special glasses, which are sensitive to humidity and are also considerably more brittle in their mechanical properties than optical glasses, they are very difficult to handle. Moreover, they are comparatively and considerably more expensive in their production and procurement than optical glasses with lower Abbe numbers. Thus, optical lens systems, which are corrected chromatically, normally just have one lens made of ED glass.
It is also necessary in the case of endoscopes with rod lens relay sets to correct chromatic aberrations. This is done with achromats that have combinations of optical glasses made of crown glass with a comparatively low dispersion and flint glass with a comparatively high dispersion. However, the Abbe numbers of these glasses are lower than those of ED glasses. In known endoscopes of the applicant, a mirror symmetrical triplet of lenses around a central plane is used as the achromat, wherein a central biconcave lens made of crown glass is framed by two biconvex lenses made of flint glass.
Since each of the three to seven relay sets already has at least four or five lenses and lenses for the objective and an ocular are also added, such optical systems for rigid endoscopes are complicated to calculate and to optimize since many different parameters must be set and optimized simultaneously. The replacement for example of the material of a single lens of the optical system generally leads to a strong change in the overall optical properties of the system so that a complete reoptimization is necessary.
U.S. Pat. No. 7,733,584 B2 describes an endoscope that is equipped with an objective and three relay sets, one of which is equipped with plano-convex rod lenses, on the concave boundary surface of which is cemented respectively a bi-convex ED lens. The other relay sets do not contain ED glasses. The chromatic aberration of the entire system is corrected with this pair of rod lenses/ED glass lenses combinations. The two additional relay sets do not contain ED glass lenses and are each designed differently from each other and thus respectively individually.
Due to the fact that only three relay sets are used according to U.S. Pat. No. 7,733,584 B2, the already considerably large number of boundary surfaces and materials to be counted is kept relatively small. This concept reaches its limits for longer endoscopes with a greater number of individual relay sets.
SUMMARY
With respect to this state of the art, the object of the present invention is to provide relay sets as well as an endoscope with corresponding relay sets, which are associated with a comparatively lower development effort even in the case of a larger number of relay sets, wherein chromatic aberrations as well as other aberrations of the optical system are limited.
This object is solved by a relay set for an endoscope with a plurality of relay sets of the same type, comprising two plano-convex rod lenses which face one another with their planar end surfaces, and an achromat that is arranged between the rod lenses, particularly in a central aperture plane of said relay set, wherein said achromat takes the form of an arrangement of at least two lenses which have different refractive indices and Abbe numbers, and is located at a distance from the rod lenses, which is further characterized in that a lens of the achromat is made of ED glass, the Abbe number of which is at least 75, in particular at least 77.
This relay set according to the invention is based on the special design of relay sets of the applicant in that it uses two symmetrically arranged, similar rod lenses and arranges an achromat made of two or more lenses between the rod lenses. The achromat is not connected with the rod lenses. Of these relay sets, several similar relay sets are used consecutively in one endoscope. In this case, similar means that the selection of the glasses, the dimensioning of the boundary surfaces and their distances, i.e. the thickness of the lenses and the distances between the lenses, are respectively the same. Through the similarity of the relay sets, the number of variables during the optimization is kept comparatively small and can be calculated with the same optimization effort for 3, 5 or 7 relay sets.
The relay set according to the invention has the further advantage that a very good correction of chromatic aberrations is possible through the use of ED glasses in the achromat in each of the similar relay sets in the endoscope, since chromatic aberrations can be corrected at several locations in the progression of the optical components in the endoscope and thus cannot build up very strongly. With the relay set according to the invention, endoscopes are producible that enable a considerably improved image sharpness up to the edge and a considerably higher contrast image compared to known endoscopes with the same dimensioning. This makes it possible to develop endoscopes with a smaller diameter that can compete optically with conventional endoscopes with larger diameters. These advantages outweigh the extra costs resulting from the increased number of ED glasses in the overall optical system of the endoscope.
The other lens or other lenses of the achromat preferably has or have an Abbe number of less than 75, wherein in particular the other lens or other lenses of the achromat simultaneously has or have a high refractive index and a high Abbe number, wherein in particular the refractive index is greater than 1.8 and the Abbe number is greater than 45. The limitation of the Abbe number of the other lens(es) to less than 75 means that they are glasses that are easier to handle and are cheaper to procure and manufacture. With a maximization of the refractive index and the Abbe number of the other lens or of the other lenses of the achromat given under these conditions, the correction of the chromatic aberrations can be achieved very well.
The achromat is preferably designed as a doublet or a triplet of lenses, wherein in particular in the case of a ratio of the diameter of the lenses of the relay set to the length of the relay set of less than 0.05 the achromat is designed as a doublet, otherwise as a triplet. In the process, the lenses of the doublet or the triplet are preferably cemented together so that the adjacent boundary surfaces of the lenses forming the doublet or the triplet have the same radii of curvature, wherein respectively the one boundary surface is designed as being convex and the associated other boundary surface as being concave. Within the framework of the present invention, a cementing is an adhesion with transparent optical adhesive or respectively optical cement.
The ED glass lens is preferably designed biconvex. This design of the ED glass lens in the achromat results in a good correction of chromatic aberrations in particular in combination with at least one meniscus-shaped additional lens made of an optical glass.
Also preferably, the central, in particular biconvex, lens of the triplet in an achromat designed as a triplet is made of ED glass. This design thus differs from the conventional triplet achromats of the standard design of relay sets of the applicant, in which the central lens for triplets is designed in a biconcave manner. The triplet is particularly preferably designed in a mirror symmetrical manner around a central plane perpendicular to the optical axis, which runs centrally through the central lens of the triplet. With this type of triplet design, in particular the entire relay set is designed around this central plane in a mirror symmetrical manner.
With respect to a doublet achromat, a symmetrical triplet achromat has the advantage that aberrations depending on an odd power of the image height are minimized. These are in particular the color magnification error and the distortion. Due to the higher number of lenses in a triplet, the costs are indeed also slightly higher than for a doublet. In the case of endoscopes with a small diameter, the corresponding aberrations carry less weight so that very good optical results are also achieved with achromats designed as doublets.
An important factor for the production of lenses is the so-called Z-factor. The factor is calculated within the framework of the present invention from the thickness and the diameter of the lens as well as the radii of curvature of the two lens surfaces with the following equation, which applies in particular for convex meniscus lenses:
Z
=
1
2
D
s
2
·
(
R
s
+
T
)
-
D
l
2
·
R
l
(
2
)
In formula (2), R s is the smaller of the two radii of curvature of the lens and R 1 is the larger of the two radii of curvature. D s denotes the outer diameter of the lens on the side of the boundary surface with the smaller radius of curvature and D 1 the diameter of the lens on the side of the boundary surface with the larger radius of curvature. The outer diameters do not normally differ. T is the central thickness of the lens.
Surprisingly, it was found that particularly good optical results and corrections of chromatic aberrations are achieved when preferably at least one lens of the achromat not consisting of ED glass has a Z-factor of less than 0.06, in particular less than 0.04. This facilitates the development for the optics developer since he can limit this parameter.
This selection of the Z-factor also results in that, in contrast to the state of the art, the corresponding lens does not center itself in production during enclosure, as was previously customary, but is henceforth first enclosed and then intricately and manually centered. The optics designers thus kept the Z-factor at a value above 0.06 up until now in order to permit the usual type of enclosure with self-centering.
In the case of the relay set according to the invention, a correction of a chromatic aberration achieved by the achromat of the relay set preferably compensates for a chromatic aberration created by the lenses of the relay set, wherein this correction also compensates in particular additionally for a part of a chromatic aberration created by objective lenses and/or ocular lenses of the endoscope. The objective lenses and the ocular lenses each create respectively a chromatic aberration. In the case of the use of several relay sets according to the invention, the correction, which is allotted to each individual achromat in each individual relay set, can be held relatively low, which keeps the requirements for the design of the achromat and the relay sets within easily controllable limits.
The object underlying the invention is further solved through an endoscope with a plurality of relay sets, wherein the instrument is in particular a laparoscope or uroscope, which is further developed in that several similar relay sets are designed respectively as the relay set according to the invention described above. Such endoscopes have a high contrast and a high sharpness as well as very well corrected, i.e. very small, chromatic aberrations, even in the case of smaller diameters.
Advantageously, at least one additional relay set is designed differently with respect to the other(s), in particular similar amongst themselves, relay sets, wherein the differently designed relay set in turn is a relay set according to the invention described above. This at least one additional relay set is designed in particular to correct the chromatic aberration caused by the lenses of the objective and/or the ocular of the endoscope so that the achromats of the other, similar amongst themselves, relay sets only need to correct the chromatic aberration of the respective own relay set.
With the endoscope according to the invention and the relay sets according to the invention, a considerably higher contrast and a considerably higher sharpness as well as a considerably stronger reduction in chromatic aberrations can be achieved with the same dimensioning of the endoscope, which is a great advantage in particular for endoscopes with a small diameter, such as in particular uroscopes. The trend is thus supported, which goes from endoscopes with a relatively large diameter, for example 10 mm, to endoscopes with a smaller diameter, for example to endoscopes with diameters of 5.4 mm or 4.0 mm.
Further features of the invention will become apparent from the description of the embodiments according to the invention together with the claims and the included drawings. Embodiments according to the invention can fulfil individual characteristics or a combination of several characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described below, without restricting the general idea of the invention, based on exemplary embodiments in reference to the drawings, whereby we expressly refer to the drawings with regard to the disclosure of all details according to the invention that are not explained in greater detail in the text. The figures show:
FIG. 1 illustrates a schematic representation of a relay set according to the invention with doublet achromat,
FIG. 2 illustrates a schematic representation of a relay set according to the invention with triplet achromat,
FIG. 3 illustrates an explanatory sketch with respect to the definition of the Z-factor,
FIGS. 4 a and 4 b illustrate explanatory sketches for the spherical aberration,
FIGS. 5 a and 5 b illustrate explanatory sketches for the axial chromatic aberration,
FIGS. 6 a and 6 b illustrate explanatory sketches for the lateral chromatic aberration,
FIGS. 7 a and 7 b illustrate a comparison of the spherical aberration, axial and lateral chromatic aberration for a conventional relay set with doublet achromats without and with ED glass,
FIGS. 8 a , 8 b and 8 c illustrate spherical, axial chromatic and lateral chromatic aberrations for doublet achromat relay set with different Z-factors of the ED glass as well as for a relay set according to the invention with triplet achromat and
FIGS. 9 a and 9 b illustrate a comparison of different aberrations for similarly dimensioned relay sets with different ED glasses.
DETAILED DESCRIPTION
In the drawings, the same or similar types of elements and/or parts are provided with the same reference numbers so that a corresponding re-introduction is omitted.
FIG. 1 shows schematically a first relay set 1 according to the invention for an endoscope. A typical endoscope contains an odd number of such relay sets 1 , for example 3, 5 or 7. The relay set 1 reaches from a first image plane 1 . 1 up to a second image plane 1 . 9 , to which another, in particular similar, relay set or an ocular or eyepiece connects. The image, which is present in the image plane 1 . 1 , is shown inverted on the image plane 1 . 9 . This is an inversion, i.e. a mirroring with respect to the middle point, i.e. the optical axis. This inversion is the same as a 180° rotation around the optical axis.
After a first gap 16 , a plano-convex rod lens 10 connects to the first image plane 1 . 1 , the convex boundary surface 1 . 1 of which faces the first image plane 1 . 1 , while the planar boundary surface 1 . 3 faces an achromat 11 , from which it is separated by a gap 16 ′. The achromat 11 consists of a doublet made of a biconvex lens 12 made of ED glass with a high Abbe number with boundary surfaces 1 . 4 and 1 . 5 , to which a meniscus lens 13 made of optical glass connects, which is designed in its boundary surfaces 1 . 5 and 1 . 6 as a concave meniscus. The lenses 12 and 13 are cemented together at the joint boundary surface 1 . 5 . After an additional gap 16 ″, an additional plano-convex rod lens 14 is connected, the planar boundary surface 1 . 7 of which faces the achromat 11 , while the convex boundary surface 1 . 8 faces the second image plane 1 . 9 , from which it is separated by a gap 16 ′.
An exemplary dimensioning of the lenses according to the invention as well as the selection of the glasses to be used for this arrangement is shown in Table 1 for the example of an endoscope with an outer diameter of 4.0 mm. The half diameter or respectively the radius of the lenses, not be confused with the radius of curvature of the boundary surfaces, is 1.329 mm, which still leaves room for optical fibers to illuminate the operative field. The length of the relay set is a total of 61.801 mm from image plane 1 . 1 to image plane 1 . 9 . The ratio of the half diameter to the length of the relay set is approximately 0.043.
The glasses used in this design can all be obtained from Ohara GmbH. Types include S-BAL35 (refractive index 1.591, Abbe number 60.88), S-FPL51 (refractive index 1.498, Abbe number 81.14) as ED glass and S-LAH55 (refractive index 1.839, Abbe number 42.47) as additional glass of the achromat. Other manufacturers also offer corresponding glasses.
TABLE 1
Relay set endoscope 4.0 mm
Radius of
Abbe
Area
curvature
Thickness
Refractive
number
Radius
no.
(mm)
(mm)
index n
V
(mm)
1.1
∞
4.397
1.000
Air
1.000
1.2
10.4304
22.209
1.591
60.88
1.329
1.3
∞
1.564
1.000
Air
1.329
1.4
11.0593
3.763
1.498
81.14
1.329
1.5
−3.8006
0.767
1.839
42.47
1.329
1.6
−6.3169
2.495
1.000
Air
1.329
1.7
∞
22.209
1.591
60.88
1.329
1.8
−10.4304
4.397
1.000
Air
1.329
1.9
∞
N/A
1.000
Air
1.000
The Z-factor according to formula (2) for the non-ED lens 13 with the boundary surfaces 1 . 5 and 1 . 6 is approx. 0.04.
FIG. 2 shows an alternative relay set 2 according to the invention. It reaches from a first image plane 2 . 1 to a second image plane 2 . 11 and comprises, through holes 27 , 27 ′, 27 ″ and 27 ′ spaced from one another, two plano-convex rod lenses 20 , 25 , each of which face the two image planes 2 . 1 and 2 . 11 with their convex boundary surface 2 . 2 and 2 . 10 and the planar boundary surfaces 2 . 3 and 2 . 9 of which face each other. An achromat 21 designed as a triplet, which comprises three lenses 22 , 23 , 24 , is located between the two rod lenses 20 , 25 .
The achromat 21 is designed symmetrically around a central plane 2 . 6 . The two symmetrical convex-concave lenses 22 , 24 consist of an optical glass; the central biconvex lens 23 consists of an ED glass. The central symmetry plane 2 . 6 does not form a boundary surface.
Both the achromat 11 according to FIG. 1 as well as the achromat 21 according to FIG. 2 consists of lenses cemented together. However, the optics developer is free to also provide gaps here between the lenses of the achromat.
The achromat 21 from FIG. 2 differs from the conventional triplet achromats in the case of corresponding relay sets of the applicant not only in the selection of the material but also in that the central lens is designed in a biconvex manner, while the central lenses of triplet achromats in the case of corresponding relay sets of the applicant were biconcave up to now. Accordingly, the two additional lenses according to the state of the art are respectively biconvex.
An exemplary dimensioning of the lenses according to the invention as well as the selection of the glasses to be used for the arrangement according to FIG. 2 is shown in Table 2 for the example of a laparoscope with an outer diameter of 5.4 mm. The half diameter of the lenses is 1.277 mm, which still leaves room for optical fibers to illuminate the operative field. The length of the relay set is a total of 46.072 mm from image plane 2 . 1 to image plane 2 . 11 . The ratio of the half diameter to the length of the relay set is approximately 0.055.
The glasses used in this design can also all be obtained amongst others from Ohara GmbH. Types again include S-BAL35 (refractive index 1.591, Abbe number 60.88), S-FPL51 (refractive index 1.498, Abbe number 81.14) as ED glass. The additional glass of the achromat is indeed of type S-LAH59 (refractive index 1.820, Abbe number 46.37).
TABLE 2
Relay set laparoscope 5.4 mm
Radius of
Abbe
Area
curvature
Thickness
Refractive
number
Radius
no.
(mm)
(mm)
index n
V
(mm)
2.1
∞
3.094
1.000
Air
1.000
2.2
7.9827
16.050
1.591
60.88
1.277
2.3
∞
0.820
1.000
Air
1.277
2.4
4.6352
1.899
1.820
46.37
1.277
2.5
2.5914
1.173
1.498
81.14
1.277
2.6
∞
1.173
1.498
81.14
1.277
2.7
−2.5914
1.899
1.820
46.37
1.277
2.8
−4.6352
0.820
1.000
Air
1.277
2.9
∞
16.050
1.591
60.88
1.277
2.10
−7.9827
3.094
1.000
Air
1.277
2.11
∞
N/A
1.000
Air
1.000
FIG. 3 shows a convex-concave lens, for example the lens 13 from FIG. 1 together with definitions for the dimensioning which are significant for the calculation of the Z-factor according to formula (2). The lens 13 comprises two optical boundary surfaces, which are designed in particular spherically. They have radii of curvature R 1 and R 2 , respectively. For the calculation of the Z-factor according to formula (2), the larger radius of curvature is R 1 and the smaller radius of curvature is R s .
The lens 13 shown in FIG. 3 has a uniform outer diameter D. In individual cases, the outer diameter can however differ on both sides of the lens. Thus, for the formula, a diameter D 1 is assumed for the side with the radius of curvature R 1 and an outer diameter D 2 is assumed for the side with the radius of curvature R 2 . With respect to the aforementioned formula (2) for the calculation of the Z-factor, the diameter belonging to the side with the smaller radius of curvature is labelled with D s while the outer diameter D 1 is the one relating to the side with the larger radius of curvature. Moreover, the central thickness of the lens 13 along the optical axis is labelled with T.
In the following FIGS. 4 to 6 , some principles of the chromatic and other aberrations are briefly sketched and explained.
FIG. 4 a shows a beam of rays originating from a point on an optical axis of a collective lens 35 , which is enclosed in an aperture 36 . A light beam 37 progresses through the optical axis according to aperture height 0. Two light beams 37 ′ progress through aperture height 0.5 of the collective lens 35 and two other light beams 37 ″ progress through the outermost edge of the collective lens 35 at aperture height 1.
The spherical aberration of this type of lens is expressed in that in the area near the optical axis the corresponding light beams are bundled in an image point 38 in the case of a certain distance from the lens 35 . Light beams 37 ″, which pass through the collective lens 35 further outside, i.e. in the case of a larger aperture height, are bent more strongly and cross the optical axis in a point in front of the image point 38 . It is hereby assumed in FIG. 4 a that the corresponding light beams 37 to 37 ″ are monochromatic and of the same wavelength. These spherical aberrations lead to the fact that an object point is not displayed over the entire surface of the collective lens 35 in the same image plane or respectively the same image point 38 so that an image point in the plane that comprises the image point 38 becomes a spot with a certain size. This effect reduces the sharpness of the image and can be improved for example through reduction of the aperture, but this reduces the light efficiency and the achievable resolution.
FIG. 4 b shows the so-called “spherochromatism” (abbreviation as “SA/CA” for the spherical aberration “SA” and the axial chromatic aberration “CA”), namely the progression of the distance between the image point and paraxial image point depending on the aperture height and the wavelength of the light. A separate progression of the spherical aberration results for each individual wavelength. The progressions shown in FIG. 4 b do not correspond with those for an individual lens as shown in FIG. 4 a , but rather for an exemplary relay set.
On the X-axis of the spherochromatism shown in FIG. 4 b , the deviation from the paraxial image point for a reference wavelength represented on the Y-axis is the aperture height that runs from 0 to 1, according to the aperture height which is shown in FIG. 4 a . The individual curves correspond to the progressions for the different wavelengths.
In the following, the individual curve 39 is singled out briefly for an individual wavelength, on which this progression is shown as an example. For this wavelength, the image point at aperture height 0 is approximately 0.06 mm from the paraxial image point. In the case of an increasing aperture height, this distance decreases and reverses itself to a negative above approximately 0.5 in order to switch in turn to a positive above approximately 0.9. Overall, the spherical aberration is thus fairly well corrected for this wavelength. The two long or respectively short dashed lines on the right side for positive values on the X-axis correspond to wavelengths that are in the blue or respectively red area and have correspondingly greater deviations of the image point from the paraxial image point for the optimized wavelength.
FIG. 5 a shows a similar situation like in FIG. 4 a ; however, in this case, polychromatic light beams 41 , 42 are shown at full aperture height and at low aperture height. After the passage through the collective lens 35 , the respective light beam 41 , 42 is expanded spectrally due to the dispersion of the material. This occurs most distinctly at a high aperture height, wherein the resulting beams 43 , 43 ′, 43 ″ in this order represent red light, green light and blue light, wherein blue light is deflected the strongest. Accordingly, these different wavelengths are focused at different positions along the optical axis. For the light beam 42 that passes through the collective lens 35 in the case of a lower aperture height, the corresponding dispersive expansion is less strong.
FIG. 5 b shows the same graph as in FIG. 4 b , but the attention here is directed at the different wavelengths. Thus, the graphs 46 to 46 ″″ are the graphs of the spherical aberrations, i.e. the difference between image point and paraxial image point depending on the image height for different wavelengths. The corresponding wavelengths thereby correspond with the normally used Fraunhofer lines. It can be seen for example that the line 46 for blue light is at a fairly large distance from the paraxial image point. A positive difference to the paraxial image point tends to be observed in the case of high values of the aperture height for all wavelengths.
The chromatic aberration shown in FIG. 5 is an axial chromatic aberration since the object points are arranged respectively on the optical axis of the lens system.
FIG. 6 sketches the effect of the lateral chromatic aberration. FIG. 6 a ) shows a collecting lens 35 , onto which a polychromatic parallel light beam 51 falls diagonally, i.e. under an angle to the optical axis of the lens. Due to the dispersion of the glass material, different wavelengths are in turn deflected to different degrees so that different light beams 52 , 53 and 54 result for the colors blue, green and red and accordingly different image points or respectively focus points 52 ′, 53 ′, 54 ′ in the case of different image heights. This means that an object appears more enlarged (or less reduced) in the blue range than in the red range. This effect is amplified with an increasing image height and disappears completely in the case of an axially hitting light beam.
Accordingly, the lateral chromatic aberration (“CC”) is plotted in FIG. 6 b depending on the image height. The thick vertical line is the image height that runs from 0, i.e. centrally, to 1, i.e. to the edge of the image plane. Reference numbers 56 , 57 and 58 show the graphs that represent the deviation from the illustration of the reference wavelength for central light beams, for light beams in the case of half the image height and for light beams in the case of a full image height. In this case, this deviation is shown in a coordinate system on the X-axis of −0.01 to 0.01, wherein these coordinate systems have been rotated by 90° for clarity.
The Y-axis, which is horizontal in FIG. 6 b , in turn shows the image height. Accordingly, it can be seen that the chromatic lateral aberration disappears in the case of 56 at image height 0. For half the image height in the case of reference number 57 , the wavelength-dependent lateral chromatic aberration is already considerably developed and increases even more in the case of reference number 58 for a full image height.
The chromatic aberrations shown in FIGS. 4 to 6 are to be minimized during the development of a relay set for an endoscope, wherein the aberrations shown in FIG. 6 do not occur in the case of symmetrical achromats. Other aberrations are also to be corrected simultaneously, like spherical aberration, coma, astigmatism, image field curvature and, if applicable, distortion and deformation of the image.
In FIGS. 7 a and 7 b , the graph bundles introduced in FIGS. 4 to 6 for the spherochromatism and the lateral chromatic aberration in the case of the use of relay sets with respectively one achromat designed as a doublet according to FIG. 1 are shown and compared with each other. A significant difference exists in that no ED glass is contained in the achromat according to FIG. 7 a and FIG. 7 b uses an ED glass in the doublet of the achromat.
It is clear that the graph bundle in the respective left system, which describes the spherochromatism, is bundled in a considerably stronger manner in the case of FIG. 7 b with the use of ED glass and the deviations from the zero point on the X-axis have become considerably smaller. This represents a significant improvement in the spherochromatism with respect to the known state of the art. The lateral chromatic aberration has also simultaneously dropped to a fraction of the previously achievable value.
The respective legends for the wavelengths of the Fraunhofer lines, which are shown in the graphs, are specified below the coordinate systems. These wavelengths are specified in nanometers.
The system shown in FIG. 7 a corresponds to a standard uroscope of the applicant with a diameter of 4.0 mm with five conventional relay sets. The system shown in FIG. 7 b is based on this known system, wherein however the ED glass S-FPL53 from Ohara GmbH with an Abbe number of 95.0 was used and the system was preliminarily optimized accordingly.
In FIGS. 8 a to 8 c , spherochromatism and lateral chromatic aberration are compared with each other in the case of use for three different relay sets.
FIGS. 8 a and 8 b are based on endoscopes with a diameter of 4.0 mm and five relay sets with doublet achromats. The material FCD1 from Hoya is used respectively as ED glass in the doublet, which is comparable in its optical properties with S-FPL51 from Ohara GmbH. In this case, the non-ED glass is S-LAM52 from Ohara GmbH (refractive index 1.720, Abbe number 43.7). The systems according to FIGS. 8 a and 8 b differ in the Z-factor of the non-ED glass lens, which is 0.06 in the system according to FIGS. 8 a and 0 . 037 in FIG. 8 b . A clear improvement in the spherochromatism and the lateral chromatic aberration results through the reduction of the Z-factor. This goes along with the need for an adjusted enclosure and centering during the production of the corresponding non-ED glass lens.
FIG. 8 c shows the graphs for spherochromatism (“SA/CA”) and lateral chromatic aberrations (“CC”) for a laparoscope with 5.4 mm diameter and a triplet achromat with central ED glass lens. A very good correction of the axial chromatic aberration is achievable with this system, which can be seen in that the lines of the spherochromatism diagram have come very close together for the different wavelengths. Thus, this is a comparatively small, almost wavelength-independent spherical aberration, which moves within an acceptable range. The lateral chromatic aberration in the right diagram is also very small and only differs at all from 0 in the case of image heights above approximately 0.6. The ED material in triplet according to FIG. 8 c is S-FPL51 from Ohara.
The diagrams shown in FIGS. 7 and 8 are respectively for systems with five relay sets and entry optics and exit optics.
The modulation transfer function, which specifies the resolution of the optical system in the radial and tangential direction depending on the image height in the unit for 80 line pairs/mm (lp/mm), is as follows for the optical systems shown in FIGS. 8 a and 8 b (values specified respectively radially/tangentially), wherein the optimal values achievable while taking the image field curvature into consideration are specified:
TABLE 3
MTF (80 lp/mm) for doublet achromats with a different Z-factor
Image height
0.0
0.5
0.8
0.9
1.0
FIG. 8a)
57.2/57.2
54.6/50.0
56.1/39.6
57.0/35.2
57.9/28.7
FIG. 8b)
60.0/60.0
57.8/57.7
59.7/56.2
59.1/54.9
58.2/51.9
The improvement in the MTF in the case of a small Z-factor is obvious in Table 3 in particular for tangential structures in the border area.
In the case of a change in the design of a relay set for an endoscope, on which the comparisons in FIGS. 7 and 8 are based, the start point is usually represented by an existing system, which is similar to the new planned system, for example a previous model. The new parameters are changed accordingly for the new system; for example the lens diameter is increased or decreased or, in the case of ED glass, the glass material is replaced. This results in a dramatic change in the image quality, as shown in FIG. 9 .
A first preliminary optimization is performed afterwards, with which the parameters like enlargement and image position, spherical aberration, astigmatism etc. are brought into acceptable ranges. Since the different image errors behave for the most part in opposite manners, it is then attempted to find a good compromise. For example, it is first attempted to reduce the spherical aberration. If it is then determined that for example the lateral chromatic error thereby increases in an unacceptable manner, it is weighted again more heavily in the optimization function. If for example the axial chromatic aberration then increases, this in turn is weighted more heavily. Between these steps, the optics designer continues to influence the optimization in that he selects or blocks for example the variable parameters or changes manually determined values in order to move the system in a certain direction.
In a closing process, the optics designer also manually changes if applicable radii or thicknesses in order to work out the last improvements.
Until an optimal compromise is found, dozens to hundreds of iterative steps and several weeks of development work are needed depending on the complexity, qualitative requirement and problem of producibility.
In order to clarify this task, FIGS. 9 a and 9 b show a comparison in which an identically dimensioned relay set with doublet achromat is equipped with two different ED glasses, namely in FIG. 9 a with S-FPL51 from Ohara and in FIG. 9 b with S-FPL53 from Ohara. The Abbe number thereby changes from 81.6 to 95.0 and the refractive index from 1.495 to 1.437. The system was calculated and optimized for the material S-FPL51.
The comparison with the same system with the one different material shows that all image properties, including the chromatic aberration, spherical aberration and other properties like coma or image field curvature, run out of control due to this one change. This shows that the selection of the glass types must be made very carefully and must also involve a readjustment of the relay set.
All named characteristics, including those taken from the drawings alone, and individual characteristics, which are disclosed in combination with other characteristics, are considered individually and in combination as essential to the invention. Embodiments according to the invention can be realized by the individual features, or a combination of several features.
LIST OF REFERENCES
1 , 2 Relay set
1 . 1 - 1 . 9 Image and boundary areas of the relay set 1
2 . 1 - 2 . 11 Image and boundary areas of the relay set 2
10 Plano-convex rod lens
11 Doublet achromat
12 Lens made of ED glass
13 Lens made of optical glass
14 Plano-convex rod lens
15 Image plane
16 - 16 ′ Gap
17 Image plane
18 Central beam of rays
19 Peripheral beam of rays
20 Plano-convex rod lens
21 Triplet achromat
22 Lens made of optical glass
23 Lens made of ED glass
24 Lens made of optical glass
25 Plano-convex rod lens
26 Image plane
27 - 27 ′ Gap
28 Image plane
29 Aperture plane
30 Central beam of rays
31 Peripheral beam of rays
35 Collective lens
36 Aperture
37 - 37 ″ Light beam
38 Image point
39 Graph of the aberration for a wavelength
41 , 42 Polychromatic light beam
43 Red light
43 ′ Green light
43 ″ Blue light
44 Red light
44 ′ Blue light
45 Distribution of the wave- and aperture-position-dependent focus points
46 - 46 ″″ Graph of the aberration for a wavelength
51 Diagonally incoming light beam
52 Bundled red light
52 ′ Focus point of the red light
53 Bundled green light
53 ′ Focus point of the green light
54 Bundled blue light
54 ′ Focus point of the blue light
55 Image plane
56 Deviation for illustration of the reference wavelength for central light beams
57 Deviation for illustration of the reference wavelength for light beams with half the image height
58 Deviation for illustration of the reference wavelength for light beams with full image height
D Outer diameter
D 1 Diameter on the first side
D 2 Diameter on the second side
R 1 Radius of curvature on the first side
R 2 Radius of curvature on the second side
T Thickness of the lens
SA Spherical aberration
CA Chromatic aberration
MTF Modulation transfer function | The invention relates to a relay set for an endoscope that includes a plurality of relay sets of the same type, having two plano-convex rod lenses which face one another with their planar end surfaces, and an achromat that is arranged between these rod lenses, particularly in a central aperture plane of said relay set. Said achromat takes the form of an arrangement of at least two lenses which have different refractive indices and Abbe numbers, and is located at a distance from the rod lenses. The invention also relates to a corresponding endoscope. The claimed relay set is improved in that one lens of said achromat consists of ED glass that has an Abbe number of at least 75, in particular at least 77. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority based on European patent application EP 09 167 924.1, filed Aug. 14, 2009.
FIELD OF THE INVENTION
The invention relates to a drive and guide device for a needle bar in a needle loom.
BACKGROUND OF THE INVENTION
The needle bar of a needle loom must be guided during its movement in the machine stand in a direction perpendicular or essentially perpendicular to the needle-punching support surface. The guide devices provided for this purpose, whether these be rails or rods, lead to problems with heat, lubrication, and sealing. Wear must be avoided as much as possible, because otherwise the punching accuracy during operation suffers. This is disadvantageous especially at high needle-punching densities.
A guide device for the needle bar in a needle loom containing at least one pair of rocker arms, which are arranged on opposite sides of the needle bar, is known from U.S. Pat. No. 4,241,479 A. One end of each of these arms is hinged to the needle bar, while a support device is present on the other end, which supports the rocker arm in question on the machine stand so that it is free to rock. For this purpose, a first bearing surface is formed on the machine stand for each rocker arm; this first bearing surface faces a second bearing surface on the end of the rocker arm. The bearing surface on the machine stand is designed in the manner of an involute gear recess, into which a tooth designed in complementary fashion on the opposite end of the associated rocker arm engages, the tooth thus being free to rock in the gear recess. In this way, the needle bar can be guided along a straight path, wherein the elements participating in its guidance perform exclusively rolling movements.
A needle loom in which the lateral guidance of the needle bar during its up and down stroke is provided by a symmetrically designed four-bar linkage, which is hinged to the needle bar or its carrier and to the machine stand, is known from DE 10 2006 008 485 A1. The dimensions of the four-bar linkage are chosen in such a way that the Ball's point which it forms and which lies on the needle bar describes a straight path within the stroke range of the needle bar.
Although the two previously described designs avoid the sliding type of guides, which are vulnerable to wear, they are relatively complicated mechanically. The two designs contain pivot bearings on the needle bar, which must be lubricated, and the latter design also has an additional number of non-stationary pivot bearings, which increases the difficulty of lubrication even more, because the lubricant must be supplied to these non-stationary pivot bearings continuously for as long as they are in operation.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a drive and guide device for a needle bar in a needle loom, which is simple technically and which makes do with a reduced number of lubrication points.
A preferred embodiment of the drive and guide device for a needle bar in a needle loom includes a machine stand and has a first crankshaft rotatably supported in the machine stand and a needle bar supported in the machine stand movable at least up and down. The drive and guide device also includes a first connecting rod supported on a first cam of the first crankshaft connected to the needle bar and a guide device for guiding the needle bar along a path extending substantially perpendicular to a needle-punching support surface. The first connecting rod and the guide device includes a leaf spring which is rigidly connected to the needle bar to transmit a drive or guide force. The first connecting rod can be rigidly connected to the needle bar and forms a rigid unit with it, whereas the guide device comprises a guiding leaf spring, which is rigidly anchored in the machine stand, and which extends on a level which is approximately the same as that of the needle bar in the needle loom.
In a another preferred embodiment, one end of a first connecting leaf spring is attached to the end of the first connecting rod facing away from the cam. This connecting spring comprises a second end, which is rigidly attached to the needle bar, and the guide device includes a second crankshaft, which is on approximately the same level as the needle bar in the machine stand and which has at least one second cam, on which a second connecting rod is supported, the end of this second rod facing away from the second cam is rigidly connected to the needle bar.
In an additional preferred embodiment, the first connecting rod is rigidly connected to the needle bar to form a single rigid unit, and the guide device comprises a second crankshaft, which is on approximately the same level as the needle bar in the machine stand and which has at least one second cam, on which a second connecting rod is supported. One end of a second connecting leaf spring is rigidly attached to the end of this second rod which faces away from the second cam, while the other end of the second connecting leaf spring is rigidly connected to the needle bar. With an arrangement such as this, a motion component in a direction parallel to the needle-punching support surface can be superimposed on the movement of the needle bar in the direction perpendicular to the base. During a punch, this parallel component follows the movement of the nonwoven web being processed on the needle loom.
In further preferred embodiments of the invention, a first connecting rod, which gives the needle bar the motion component in a direction perpendicular to the needle-punching support surface, is connected to the needle bar by a connecting leaf spring, which is rigidly connected at one end to the connecting rod, and at the other end to the needle bar. In comparison to a guiding leaf spring, which guides the needle bar during its punching movement, this connecting leaf spring is relatively short, which prevents it from buckling out to the side during the punching movement.
A connection between the connecting rod and the needle bar can also be realized for the second connecting rod, by which a motion component parallel to the needle-punching support surface is transmitted to the needle bar. Here too, the connecting leaf spring should be short enough to prevent it from buckling during operation.
The invention can also be used in needle looms which comprise two needle bars arranged parallel to each other, which are driven by first crankshafts individually assigned to them. Each needle bar can be guided individually from the side by a guiding leaf spring or by a second crankshaft with a second connecting rod and possibly a connecting leaf spring. It is also possible, however, for both needle bars to be guided by a single guiding leaf spring or by a single second crankshaft with a second connecting rod and possibly a connecting leaf spring, provided that the needle bars are coupled to each other. If the first crankshafts rotate in opposite directions, a single coupling leaf spring is sufficient to couple the needle bars together. If the first crankshafts rotate in the same direction, two coupling leaf springs arranged one above the other a certain distance apart are provided between the two needle bars, these springs being connected rigidly to the needle bars to prevent the needle bars from tipping toward each other uncontrollably.
To minimize the flexing of the connecting leaf spring and to increase its service life, the guiding leaf spring should be as long as possible. If in fact the guiding leaf spring is long, however, there is the danger that, during operation, the moving needle bar will cause it to oscillate and possibly to flutter. To avoid such undesirable action, the guiding leaf spring may be surrounded by a stiff guard which prevents the leaf spring from oscillating. A guard of this type can consist of two rails, which are parallel to each other and which rest on the narrow sides of the guiding leaf spring, the rails being connected to each other by several pairs of bars arranged a certain distance apart. The bars of each pair form a gap between them, through which the guiding leaf spring extends. The rails can be provided at their ends with buffers of plastic or rubber, because the ends of the rails can come into contact with the parts of the machine adjacent to them. The buffers dampen the noise which may develop during operation.
The needle bar of a needle loom is put in motion by at least two connecting rods. In the case of very large working widths, it is also possible for more than two connecting rods to be used. These connecting rods are set in motion by a corresponding number of cams on the associated crankshaft. The same applies to the guide devices. It should be appreciated that while the invention is explained on the basis of only a single connecting rod and one guide device, this should not be understood as a numerical limitation.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the advantages of the invention will be readily understood, a more detailed description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:
FIG. 1 is a schematic diagram of a drive and guide device according to the invention based on the example of a needle loom with one needle bar;
FIG. 2 is a schematic diagram of a drive and guide device according to the invention based on the example of a needle loom with two needle bars;
FIG. 3 is a schematic diagram of an alternative embodiment of a drive and guide device according to the invention based on the example of a needle loom with two needle bars;
FIG. 4 is a schematic diagram of a drive and guide device according to the invention based on the example of a needle loom in which a single needle bar has a first drive, which produces the actual punching action, and a second drive, which can move the needle bar horizontally;
FIG. 5 is a schematic diagram of a drive and guide device according to the invention based on the example of a needle loom in which each of the two needle bars has its own first drive, which produces the actual punching action, and a second drive, which can move the needle bars horizontally;
FIG. 6 shows an embodiment of the invention similar to that of FIG. 3 with an elastic connection between the needle bar and the connecting rod producing the punching movement;
FIG. 7 is a schematic diagram of an alternative embodiment of the connections of a guiding leaf spring;
FIG. 8 shows an embodiment similar to FIG. 1 , including a second drive, which gives the needle bar a motion component perpendicular to the punching motion, with an elastic connection between the needle bar and the connecting rod of the second drive;
FIG. 9 shows an embodiment of the invention similar to FIG. 6 with a second drive which is connected to the needle bar;
FIG. 10 is a perspective view of a guard surrounding the leaf spring to prevent the leaf spring from fluttering; and
FIG. 11 is an enlarged view of the circled area in FIG. 10 .
DETAILED DESCRIPTION OF THE INVENTION
In the following, specific embodiments of the invention shown in the drawings are described in detail. The diagrams in the drawings are limited for the sake of clarity to the parts of a needle loom essential to the explanation of the invention.
FIG. 1 shows a portion of the needle loom including a needle bar 1 , which carries on its bottom surface a needle board 3 equipped with needles 2 . A needle-punching support surface 4 is set up opposite the needles. Needle-punching support surface 4 serves to support the web of material (not shown) to be needled. Such web of material may be a nonwoven web or the like which, during the operation of the needle loom, is transported through the needle loom transversely with respect to the longitudinal direction of the needle bar 1 .
One end of a rigid first connecting rod 5 is rigidly connected to the side of the needle bar 1 facing away from the needles 2 . The other end of the connecting rod is supported on a first cam 6 of a first crankshaft 7 . The first crankshaft 7 is supported rotatably in a machine stand 8 of the needle loom, which also carries the needle-punching support surface 4 .
To guide the needle bar 1 up and down with respect to the needle-punching support surface 4 during operation, one end of a flexible guiding leaf spring 9 is rigidly attached to the needle bar. The other end of this guiding leaf spring 9 is attached rigidly to the machine stand. 8 .
During operation, the needle bar 1 is set into up-and-down motion with respect to the needle-punching support surface 4 by the first crankshaft 7 , operating by way of the first cam 6 and the first connecting rod 5 . As needle bar 1 executes this motion, it is guided by the elastic guiding leaf spring 9 , which bends elastically over its entire length but especially near the points where it is clamped to the needle bar 1 and to the machine stand 8 . Due to the stiffness of the first connecting rod 5 and its rigid connection to the needle bar 1 and due to restricting the needle bar 1 from sideways movement—a limitation which holds the bar in a position almost always directly below the first crankshaft 7 —the needle bar 1 executes a tipping movement around its longitudinal axis, which also leads to elastic flexing of the guiding leaf spring 9 . To minimize this tipping movement, the first connecting rod 5 should be as long as possible, that is, long in relation to the stroke of the needle bar 1 . To minimize the bending stress of the guiding leaf spring 9 , it should be as long as possible, that is, comparatively long in relation to the stroke of the needle bar.
FIG. 2 shows an exemplary embodiment of the invention in which the invention is realized in a needle loom comprising two needle bars 1 , which are arranged next to each other and which operate independently. Assigned to each needle bar 1 is its own punching drive, consisting of first crankshaft 7 , operating by way of first cam 6 and first connecting rod 5 . Each needle bar 1 , furthermore, is rigidly connected to one end of an individual guiding leaf spring 9 , the other end of which is rigidly clamped in the machine stand 8 . The two arrangements are mirror images of each other. Their behavior during operation is completely comparable to that already explained above on the basis of the example of FIG. 1 .
FIG. 3 shows a schematic diagram of an embodiment of a needle loom with two needle bars 1 , each of which has its own needle-punching drive, consisting of crankshaft 7 , operating by way of cam 6 and connecting rod 5 , in a manner completely comparable to the embodiment of FIG. 2 . For the sake of clarity, the needle-punching support surface 4 and most of the machine stand 8 are not shown. The only part of the machine stand 8 shown is the point where, when one end of a guiding leaf spring 9 is clamped, the other end is rigidly connected to one of the needle bars 1 , in the present case the needle bar 1 shown on the left hand side of the drawing. The two needle bars 1 are connected to each other on their facing sides by an elastic coupling leaf spring 10 , which is rigidly attached to the two needle bars 1 .
During operation, the rotation of the first crankshaft 7 leads to a rising and falling movement of the needle bars 1 . In addition, due to the rigid connection of the stiff first connecting rod 5 to the needle bars 1 and the limitation on the movement of the bars by the guiding leaf spring 9 and the coupling leaf spring 10 , needle bars 1 are tipped around their longitudinal axes, i.e., to the right and to the left in the drawing. The lateral guidance of the needle bar 1 shown on the left in the drawing is provided by the guiding leaf spring 9 attached to it, which behaves in the same way as guiding leaf springs 9 shown in FIGS. 1 and 2 . As shown in FIG. 3 , the lateral guidance of needle bar 1 shown on the right in the drawings is provided by the elastic coupling leaf spring 10 .
If the two first crankshafts 7 turn in the same direction, the coupling leaf spring 10 flexes into the shape of an “S”, that is, it bends in two opposite directions, because the needle bars tip in the same direction. If the two first crankshafts 7 turn in opposite directions, the coupling leaf spring 10 bulges out in only one direction, that is, first in the upward direction and then in a downward direction, which means that it is subject to less bending stress than that present in the first-mentioned operational variant. Counter-rotating operation of the first crankshafts 7 is preferred as it is easier to balance the inertia within the needle loom.
FIG. 4 shows another embodiment of the invention, which differs from the previously described embodiments primarily in that the unit consisting of first connecting rod 5 , which is moved by first cam 6 of first crankshaft 7 , and the needle bar 1 is not rigid. Instead, an elastic connecting leaf spring 11 is inserted between the free end of the connecting rod 5 and the needle bar 1 . The connecting leaf spring 11 is rigidly connected at one end to the first connecting rod 5 and at the other to the needle bar 1 . Connecting leaf spring 11 transmits the thrust forces for punching coming from the crankshaft 7 and is relatively short so that it does not buckle to the side under the effect of the thrust forces mentioned.
The lateral guidance of the needle bar 1 can in this case be accomplished by a guiding leaf spring 9 of the type shown in FIG. 1 . This variant is not shown in the example of FIG. 4 , but will be understood to be possible by one skilled in the art.
FIG. 4 shows, in contrast, a variant for the lateral guidance of the needle bar 1 by means of a second connecting rod 12 , which is moved by a second crankshaft 14 supported in the machine stand (not shown), acting by way of a second cam 13 . The second crankshaft 14 is arranged on approximately the same level as the needle bar 1 . The second connecting rod 12 and the needle bar together form a rigid unit. A rotation of the second crankshaft 14 at the same speed as that of the first crankshaft 7 is able superimpose a motion component oriented parallel to the needle-punching support surface onto the punching motion of the needle bar oriented essentially perpendicular to the base (not shown). During the time that the needles 2 remain in the web to be processed, this parallel component proceeds in the same direction as that of the web through the needle loom. Although it is true that, during this movement, the needle bar 1 also tips slightly around its longitudinal axis as a result of the rigid connection between the second connecting rod 12 and the needle bar 1 , nevertheless, if the second connecting rod 12 is long enough, the tipping angle is so small that it does not produce any noticeable disadvantageous effect in the processed web of material. A “long” connecting rod in this context means long with respect to the stroke of the needle bar 1 . The previously mentioned tipping movements of the needle bar 1 are absorbed by the elastic connecting leaf spring 11 , which flexes under the effect of the tipping movements.
In a manner fully comparable to that shown in FIGS. 1 and 4 , FIG. 5 shows the application of the features explained on the basis of the example of FIG. 4 to a needle loom with two needle bars 1 arranged next to each other. Each needle bar 1 has its own first drive for the needle-punching movement, consisting of a first crankshaft 7 , a first cam 6 , a first connecting rod 5 , and a connecting leaf spring 11 . In addition, each needle bar 1 has a second drive for the horizontal motion component oriented parallel to the needle-punching support surface 4 (not shown). The second drive consists of a rigid second connecting rod 12 , rigidly attached to the needle bar 1 , and a second cam 13 on a second crankshaft 14 , which is mounted on approximately the same level as the needle bar 1 . The arrangements are mirror images of each other. The way they function is the same as that described above in relation to the embodiment of FIG. 4 .
FIG. 6 shows an exemplary embodiment of the invention which is comparable to that of FIG. 3 with respect to function but which requires that the first crankshafts 7 turn in the same direction. It also differs in design from the embodiment in FIG. 3 in that each of the first connecting rods 5 are connected to the needle bar 1 by way of an elastic connecting leaf spring 11 —similar to the embodiment of FIGS. 4 and 5 . Another difference versus the embodiment of FIG. 3 is that the guidance of the needle bar 1 shown on the right in FIG. 6 is provided by two elastic coupling leaf springs 10 , which are arranged one above the other a certain distance apart, and each of which is rigidly connected to the needle bars 1 . Two coupling leaf springs 10 are required as a result of the elastic connection between first connecting rods 5 and needle bar 1 . In this embodiment, a certain freedom of movement is restrained which cannot be limited sufficiently by only a single coupling leaf spring according to the example of FIG. 3 .
In the preferred embodiments described on the basis of FIGS. 1-3 and 6 , both ends of the guiding leaf spring 9 are clamped rigidly in position, one end on the needle bar 1 and the other on the machine stand 8 , and in the bent states, i.e., when the needle bar is in its upper and lower end positions, the spring assumes a slightly “S”-like shape. According to the variant shown partially in FIG. 7 , the bending stress of the guiding leaf spring 9 can be reduced by supporting one end in a pivot bearing 15 . Preferably pivot bearing 15 is lubricated for life, that is, a bearing which requires little or no maintenance. In this case, the guiding leaf spring 9 shows only a simple form of flexure in the end positions of the needle bar 1 , and its overall bending stress is reduced in comparison with that present in the previously described exemplary embodiments.
FIG. 8 shows another preferred embodiment of the invention. This is similar to the exemplary embodiment of FIG. 1 to the extent that the needle-punching drive of the needle bar 1 consists of a first crankshaft 7 , which is connected to the needle bar 1 by way of a first cam 6 and a first connecting rod 5 rotatably supported thereon. The connecting rod 5 and the needle bar 1 , similar to the preferred embodiment of FIG. 1 , form a rigid unit. For the guidance of the needle bar 1 during its punching movement, a second crankshaft 14 is provided, which is rotatably supported in the machine stand (not shown) on approximately the same level as the needle bar 1 . The second crankshaft 14 has a second cam 13 , on which a second connecting rod 12 is rotatably supported. The second connecting rod 12 has a free end, which is connected to the needle bar 1 by a second elastic connecting leaf spring 16 . The second connecting leaf spring 16 has ends, one of which is rigidly connected to the needle bar 1 , the other to the free end of the second connecting rod 12 . With this design, a motion component oriented parallel to the needle-punching support surface (not shown in FIG. 8 ) can be superimposed on the punching movement of the needle bar in a manner completely comparable to the example of FIG. 4 . Such parallel movement again follows the forward movement of the web being processed in the needle loom during the time that the needles 2 remain in the web. The second connecting leaf spring 16 makes it possible for the needle bar to execute the tipping movements versus the needle-punching support surface which occur during operation as a result of the cams 6 and 13 acting by way of the connecting rods 5 and 12 . Again, the connecting rods 5 and 12 should be long in relation to the stroke of the needle bar 1 to minimize such tipping movements.
The exemplary embodiment of FIG. 9 shows a needle loom with two needle bars arranged next to each other, which are connected to each other by two elastic coupling leaf springs 10 . To this extent and also with respect to the needle-punching drives of the needle bars, this embodiment is the similar to that of FIG. 6 . The embodiment of FIG. 9 differs from that of FIG. 6 in that it adds a second drive to the two needle bars 1 , namely, a drive which gives the needle bars 1 a motion component parallel to the needle-punching support surface (not shown), as described on the basis of the example of FIG. 8 . The second drive comprises a second crankshaft 13 , supported in the machine stand on approximately the same level as the needle bar 1 , this crankshaft carrying a second cam 14 , on which a second connecting rod 12 is rotatably supported. The free end is connected to one of the needle bars 1 , namely, to the needle bar 1 shown on the left in the drawing, by means of a second connecting leaf spring 16 . The second connecting leaf spring 16 has two ends, one of which is rigidly connected to the second connecting rod 12 , the other to the previously mentioned needle bar 1 . The second connecting leaf spring 16 makes it possible for the left needle bar 1 to execute the tipping movements versus the needle-punching support surface which occur during operation as a result of the cams 6 and 13 acting by way of the connecting rods 5 and 12 , whereas the coupling leaf springs 10 make it possible for the two needle bars 1 to move with respect to each other. Again, the connecting rods 5 and 12 should be long in relation to the stroke of the needle bar 1 to minimize the previously mentioned tipping movements. To increase the stiffness, the needle bars 1 could be connected here by a diagonal strut (not shown), located in the area between the coupling leaf springs 10 . It is also contemplated that the interior area between the two needle bars 1 could be filled in completely by a wall of sheet metal, for example, to increase the stiffness.
It can be seen from the examples shown and explained above that the concept of the rigid connection between connecting rods and needle bars and the use of elastic leaf springs for guidance and also in the drive of the needle bars can be implemented in any desired way as long as it is ensured that at least one elastic leaf spring is used either to guide the needle bar or as part of the needle-punching drive. As a result of the invention, the need for lubrication is completely eliminated at least on the needle bar, which considerably reduces the effort required to lubricate the interior of the machine, as there is no need to introduce lubricant to the moving parts of the machine.
As has been explained above, it is desirable that the guide element, whether it be a second connecting rod with a second connecting leaf spring or a guiding leaf spring, be as long as possible in relation to the stroke of the needle bar. If the guide element is a guiding leaf spring 9 , it can easily, because of its length, start to oscillate under the effect of the up-and-down movement of the needle bar 1 . To suppress such natural oscillations, a guard 17 , which is shown in FIG. 10 and a detail of which is shown on a larger scale in FIG. 11 , is provided according to an elaboration of the invention.
According to FIG. 10 , the preferred embodiment with a guard 17 for a guiding leaf spring 9 consists of two stiff rails 18 , which are arranged parallel to each other and which are connected to each other by several pairs of rods 19 . The connecting rods 19 of one pair form a gap, through which the guiding leaf spring 9 extends, and the longitudinal edges of the spring rest on the rails 18 . If the rails 18 are flat, at least three pairs of connecting rods 19 must be present, as shown in FIG. 10 , to suppress the natural oscillations of the guiding leaf spring 9 . If the stroke frequency of the needle bar 1 arrives in a range in which the guiding leaf spring 9 could be caused to oscillate harmonically, the number of pairs of connecting rods 19 will have to be increased correspondingly.
Alternatively, the rails 18 could have a C-shaped cross section, wherein the side pieces of the rails face each other. If the guiding leaf springs 9 are embedded in soft plastic or rubber provided in the groove between the side pieces of a rail 18 , the connecting rods 19 can then under certain conditions be omitted entirely. The leaf spring in this case has sufficient freedom to flex in the groove and yet is still securely supported.
Because the ends of the guard 17 can come in contact with adjacent machine parts, the ends of the rails 18 are preferably provided with buffers 20 of rubber or plastic to dampen the noise which would otherwise occur during operation.
Reference throughout this specification to “one embodiment,” “an embodiment,” “a preferred embodiment,” “alternate embodiment” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” “in a preferred embodiment,” “in an alternate embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.
While the present invention has been described in connection with certain exemplary, alternate or specific embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications, alternatives, modifications and equivalent arrangements as will be apparent to those skilled in the art. Any such changes, modifications, alternatives, modifications, equivalents and the like may be made without departing from the spirit and scope of the invention. | The drive and guide device for a needle bar of a needle loom having a machine stand includes a first crankshaft rotatably supported in the machine stand; a needle bar supported in the machine stand; a first connecting rod supported on a first cam of the first crankshaft and connected to the needle bar; and a guide device for guiding the needle bar along a path extending perpendicular to the needle-punching support surface. The first connecting rod and/or the guide device comprises a leaf spring, which is rigidly connected to the needle bar to transmit a drive or guide force. As a result, lubrication points on elements of the needle loom which move from place to place are eliminated. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for preparing a water-dispersion varnish for electrodeposition, and more particularly, it relates to a process for preparing a water-dispersion varnish for electrodeposition which comprises a modified polyesterimide having ester groups and imide groups in the main chain or a modified polyesteramideimide having an ester group, an imide group and an amide group in the main chain.
2. Description of the Prior Art
Electrodeposition of resin coatings onto conductive substances is commonly used in many technologies. The electrodeposition coating method has several advantages: it is safe and hygienic because it employs no organic solvent; it can form a film of uniform thickness in a short period of time; and it is easily automated as compared with conventional spray coating or dip coating methods.
In the usual instance, a varnish is used in the electrodeposition process, wherein a coatable polymeric composition is either dissolved into an electrolyte medium or is dispersed in fine particles having diameters of 0.1μ. When a solution varnish is used, uniform deposition can be attained even in a thin layer. However, the thickness of the film may only be as large as several tens of microns. Accordingly, solution varnish is not suitable if a thickness larger than 100μ is required. Moreover, most water soluble or water insoluble polymers used for the solution varnish will contain many easily dissociated groups so that a coating employing such polymers would not be a good electrical insulator.
On the other hand, a dispersion varnish is inferior to a solution varnish from the viewpoint of uniformity of film thickness. It is difficult to form such a uniform film on a substrate having a complicated shape. However, dispersion varnish has the advantages in that a thick film can be formed easily in a short period of time and the durability of the finished film can be improved by using a polymer having a high molecular weight. Moreover, the polymer used in the dispersion varnish is not easily dissociated and, accordingly, a film containing it will have good electrical insulation properties.
A need therefore exists for a water-dispersion varnish that is capable of providing an electrodeposition coating of good uniformity. Such a varnish would be expected to find a great deal of acceptance in a wide variety of fields.
There are two methods for preparation of a water-dispersion polymer: by emulsion-polymerization using monomers having an unsaturated group; or by dispersing a polymer by suitable processes. The monomers used for the former method are limited to vinyl compounds and accordingly, the characteristics of the finished films are limited. In the latter method, good electrical insulation properties of the finished films can be produced by employing epoxy resin, polyester resin, formal resin, etc. However, it is quite difficult to prepare a water-dispersion varnish of the latter type which is suitable for electrodeposition. Accordingly, this type of varnish has not been commercialized.
Recently, polyesterimides and polyesteramideimides have been found to possess excellent electrical insulation characteristics and excellent thermal stability. They are quite economical and hence have been widely used. It would be most desirable to prepare a water-dispersion varnish which is suitable for electrodeposition by using such resins.
SUMMARY OF THE INVENTION
Accordingly, it is one object of the present invention to provide a process for preparation of a water-dispersion varnish of polyesterimide or polyesteramideimide which can be uniformly electrodeposited yielding a coating having good electrical insulation properties and thermal stability.
This and other objects of this invention, as will hereinafter be made clear by the discussion below have been attained by a process for preparing a water-dispersion varnish suitable for electrodeposition which comprises reacting the reaction product of (A) a polyesterimide having a carboxyl group in its chain or at the terminus of the chain, and having an ester group and an imide group in its repeating unit, or a polyesteramideimide having a carboxyl group in its chain or at the terminus of the chain and having an ester group, an imide group and an amide group in its repeating unit and (B) an organic compound having hydroxyl groups with (C) a polybasic acid or its anhydride in the presence or absence of a solvent yielding a modified polyesterimide or polyesteramideimide; dissolving said modified polyesterimide or polyesteramideimide in an organic solvent; dispersing said modified polyesterimide or polyesteramideimide solution in an aqueous solution containing a surfactant and a volatile base; and removing the volatile components.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The polyesterimides used in this invention are those having a carboxyl group in the chain or at the terminus of the chain and having a ester group and an imide group in the repeating unit and having a molecular weight of several thousands to several tens of thousands, or a polyesteramideimide having a carboxyl group in its chain or at the terminus of the chain and having an ester group, an imide group and an amide goups in the repeating unit and having an average molecular weight of several thousands to several tens of thousands. This material is reacted with a polyalcohol, e.g., glycol, glycerine or a polyester having free hydroxyl groups followed by reaction of an admixed polybasic acid or anhydride thereof, e.g., tetrahydrophthalic acid anhydride, adipic acid, trimellitic acid anhydride. The resulting product is used as a starting material (hereinafter referred to as a modified polyesterimide or a modified polyesteramideimide). The modified polyesterimide or polyesteramideimide is dissolved in suitable solvent and an aqueous solution containing a small amount of a surfactant and a volatile base, e.g., ammonium hydroxide are added to the solution and the mixture is stirred at a temperature within the range of ambient to 80° C. Then, an inert gas, e.g., nitrogen, is bubbled through the mixture so as to remove a part or all of the solvent and the volatile base, whereby a stable water-dispersion varnish is produced. A pair of conductive plates or wires are dipped into the resulting water-dispersion varnish and a DC voltage is applied to them, whereby a uniform electrodeposited film is coated onto the anode. Subsequent curing imparts excellent mechanical strength to the coated film.
The polyesterimides used in the invention include the reaction product of trimellitic acid anhydride, diaminodiphenylmethane and polyethyleneterephthalate. The polyesteramideimides used in the invention include the reaction product of trimellitic acid anhydride, diphenylmethane-4,4'-diisocyanate, polyethyleneterephthalate, ethyleneglycol and tris-(β-hydroxyethyl)-isocyanurate.
The polyesterimides used as starting material in this invention include the reaction product of 9-49 equivalent % of dibasic acid, 5-40 equivalent % of a polycarboxylic anhydride having at least 3 carboxyl groups, 16-48 equivalent % of a monobasic lower aliphatic diester of an aromatic dicarboxylic acid, 0-40 equivalent % of a polyol having at least 2 hydroxyl groups and 2.5-60 equivalent % of an amino compound having two amino groups. Suitable dibasic acids include terephthalic acid, isophthalic acid and adipic acid. Suitable polycarboxylic anhydrides include trimellitic acid anhydride, pyromellitic acid dianhydride and 3.3', 4.4'-benzophenonetetracarboxylic acid anhydride. Suitable monobasic lower aliphatic diesters of an aromatic dicarboxylic acid include dimethyl terephthalate and dimethyl isophthalate. Suitable polyols include glycerine, tris (β-hydroxyethyl)isocyanurate, trimethylolethane, pentaerythritol, ethylene glycol, propylene glycol and diethylene glycol. Suitable amino compounds include 4.4'-diaminodiphenylmethane, 4.4'-diaminodiphenylether, 4.4'-dioxydiphenylethane, octamethylenediamine and p-xylenediamine. The molecular weight of the polyesterimide as measured by a viscosity method, is preferably 1,000-100,000, especially 5,000-10,000.
The polyesteramideimides used as a starting material in the invention include the reaction product of 20-60 equivalent % of polycarboxylic anhydride having at least 3 carboxyl groups, 10-30 equivalent % of diisocyanate, 15-50 equivalent % of a monobasic lower aliphatic diester of an aromatic dicarboxylic acid, 0-40 equivalent % of a polyvalent alcohol and 3-60 equivalent % of an amino compound having two amino groups. Suitable polycarboxylic anhydrides have at least 3 carboxylic groups; suitable monobasic lower aliphatic diesters of an aromatic dicarboxylic acid, suitable polyvalent alcohols and suitable amino compounds having two amino groups for this reaction include the compounds mentioned above. Suitable diisocyanates include tolylenediisocyanate, diphenylmethanediisocyanate, diphenyletherdiisocyanate, hexamethylenediisocyanate and paraphenylenediisocyanate. The molecular weight of the polyesteramideimide as measured by the viscosity method is preferably 1,000-100,000 especially 5,000-10,000.
The concept of the invention is to prepare a water-dispersion varnish for electrodeposition by modifying these polyesterimides or the polyesteramideimides.
The polyalcohols used in the invention include ethylene glycol, propylene glycol, glycerine, tris-(β-hydroxyethyl)isocyanurate, or a polyester oligomer having a free hydroxyl group, etc. Each must have at least two hydroxy groups. The polybasic acids used in the invention include adipic acid, isophthalic acid, maleic acid, tetrahydrophthalic acid, trimellitic acid, etc., each of which has at least two carboxyl groups. The corresponding acid anhydrides thereof can also be used.
The purpose of the solvents used in the invention is to dissolve or swell the modified polyesterimide or polyesteramideimide. It is necessary to use solvents which have a boiling point lower than 100° C or which can be removed by an azeotropic distillation at lower than 100° C. Suitable solvents include ethylenedichloride, dioxane, methylethyl ketone, acetone, m-cresol, dimethylformamide, N-methylpyrrolidone, dimethyl acetamide, dimethyl sulfoxide, etc. or mixtures thereof. It is possible to add a small amount of a solvent having high boiling point, e.g., m-cresol, dimethyl formamide, N-methylpyrrolidone, etc. so as to improve solubility. The surfactants include anionic surfactants, nonionic surfactants and mixtures thereof. Suitable such surfactants include sodium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium octyl sulfosuccinate, polyoxyethylene alkylether, etc. The volatile bases used in the invention include ammonium hydroxide, trimethylamine, monoethanolamine, α-dimethylaminoethanolamine and mixtures thereof.
The modified polyesterimide or polyesteramideimide should have an average molecular weight of 5,000-100,000. Modified polymers having a molecular weight of less than 5,000 may dissolve in water. On the other hand, modified polymers having a molecular weight of higher than 100,000 may be difficult to disperse into water.
The acid value of the modified polyesterimide or polyesteramideimide should be in the range of 10-100, preferably 15-60.
Having generally described the invention, a more complete understanding can be obtained by reference to certain specific examples, which are included for purposes of illustration only and are not intended to be limiting unless otherwise specified.
REFERENCE 1
400 wt. parts of 80% m-cresol solution of polyesterimide prepared by polymerizing 103 g of diaminodiphenylmethane, 200 g of trimellitic acid anhydride, 150 g of polyethylene terephthalate and 60 g of glycerine (average molecular weight 5,000) was heated to 180° C and 12 wt parts of glycerine was admixed with the solution. Reaction was carried out at 180° C for 1 hour. 18 wt parts of tetrahydrophthalic anhydride was admixed with the reaction product. Reaction was carried out at 180° C for 30 minutes. After the reaction, 160 wt parts of dioxane was added dropwise to the reaction mixture to produce a solution having about 60% solid content. In a four necked flask, 300 parts of 0.4% ammonium hydroxide containing 1.0 wt part of sodium lauryl sulfate was charged. The flask was heated to 60° C and 150 wt parts of said solution having about 60% of solid content was then placed into the flask and the mixture was stirred for 30 minutes yielding an aqueous dispersion having a pH of 9.5. The aqueous dispersion was placed into a beaker and a coated film was obtained by electrodepositing the varnish onto a copper plate. Only a non-uniform electrodeposited film having a thickness of 10μ was produced.
EXAMPLE 1
Nitrogen was bubbled through the stirred aqueous dispersion of Reference 1 at 60° C for 4 hours so as to remove excess ammonia and the solvent, whereby an aqueous dispersion having a pH of 7.5 was obtained. The aqueous dispersion was placed in a beaker and a DC voltage of 20 volts was applied so as to electrodeposit the polymer on a copper plate, whereby a uniform electrodeposited film was produced. It was possible to form a uniform electrodeposited film having a thickness of about 300 μ by electrodepositing for a long period. The coated film cured at 250° C for 45 minutes had excellent mechanical strength.
EXAMPLE 2
150 wt parts of the solution of the modified polyesterimide having 60% solid content which is described in Reference 1 was added to 300 wt parts of aqueous solution containing 1.5 wt parts of monoethanolamine at 70° C. The mixture was refluxed for 30 minutes at 70° C and then was stirred for 6 hours at 70° C under a stream of nitrogen so as to remove volatile components, whereby an aqueous dispersion having a pH of 8 was obtained. In accordance with the process of Example 1, electrodeposition was carried out using the resulting aqueous dispersion, whereby a uniform electrodeposited film was produced. The coated film cured at 250° C for 45 minutes had excellent mechanical strength.
EXAMPLE 3
100 wt parts of the modified polyesterimide which is described in Reference 1, was dissolved in 50 wt parts of ethylenedichloride. The solution was heated to 50° C and was added to 300 wt parts of an aqueous solution containing 0.5 wt parts of sodium lauryl sulfate, 0.5 wt parts of polyoxyethylene lauryl ether, and 10 wt parts of trimethylamine at 50° C. The mixture was stirred for 5 hours under a stream of nitrogen so as to remove volatile components, whereby an aqueous dispersion having a pH of 7.2 was obtained. In accordance with the process of Example 1, electrodeposition was carried out using the resulting aqueous dispersion, whereby a uniform electrodeposited film was produced.
EXAMPLE 4
400 wt parts of 80% N-methylpyrrolidone solution of polyesterimide prepared by polymerizing 116 g of hexamethylenediamine, 384 g of trimellitic anhydride, 250 g of polyethyleneterephthalate, 120 g of tris-(β-hydroxyethyl)-isocyanurate (average molecular weight 9,000) was heated to 180° C and 5 wt parts of glycerine and 15 wt parts of trimellitic anhydride were admixed with the solution. Reaction was carried out for 30 minutes. After the reaction, 100 wt parts of methylethyl ketone was added dropwise to the reaction mixture producing a solution having about 65% solid content. The solution was heated to 70° C and was added to 2,000 wt parts of an aqueous solution containing 4.0 wt % of sodium dioctyl sulfosuccinate and 10 wt % of ammonium hydroxide, and the mixture was stirred for 7 hours at 70° C under a stream of nitrogen to remove volatile components whereby an aqueous dispersion having a pH of 7.0 was obtained. In accordance with the process of Example 1, electrodeposition was carried out using the resulting aqueous dispersion, whereby a uniform electrodeposited film was produced. The coated film cured at 250° C for 45 minutes had excellent mechanical strength.
EXAMPLE 5
400 wt parts of 90% N,N'-dimethylacetamide solution of polyesteramideimide prepared by polymerizing 384 g of trimellitic anhydride, 250 g of diphenylmethane-4,4'-diisocyanate, 300 g of polyethyleneterephthalate, 64 g of ethylene glycol and 100 g of tris-(β-hydroxyethyl)-isocyanurate (average molecular weight 7,000) was heated to 170° C and 10 wt parts of propylene glycol and 15 wt parts of isophthalic acid were admixed with the solution. Reaction was carried out for 20 minutes. After the reaction, 150 wt parts of acetone was added dropwise to the reaction mixture to produce a solution having about 60% solid content. The solution was heated to 80° C and was added to 1,500 wt part of an aqueous solution containing 2.5 wt parts of sodium dodecyl benzene sulfonate and 15 wt parts of triethanolamine, and the mixture was stirred for 4 hours at 80° C under a stream of nitrogen to remove volatile components, whereby an aqueous dispersion having a pH of 7.7 was obtained. In accordance with the process of Example 1, electrodeposition was carried out using the resulting aqueous dispersion, whereby a uniform electrodeposited film was produced. The coated film cured at 230° C for 1.5 hours had excellent mechanical strength.
EXAMPLE 6
200 wt parts of 90% m-cresol solution of the polyesteramideimide which is described in Example 5 was heated to 180° C and 3 wt parts of glycerine and 10 wt parts of trimellitic anhydride were added to the solution. Reaction was carried out for 40 minutes. After the reaction, 35 wt parts of ethyl acetate was added dropwise to the reaction mixture producing a solution having a solid content of about 75%. The solution was heated to 75° C and was added to 1,000 wt parts of an aqueous solution containing 1.0 wt part of sodium lauryl sulfate, 5 wt parts of trimethylamine and 5 wt parts of ammonia, and then the mixture was stirred for 3 hours at 75° C under a stream of nitrogen to remove volatile components, whereby an aqueous dispersion having a pH of 7.3 was obtained. In accordance with the process of Example 1, electrodeposition was carried out using the resulting aqueous dispersion, whereby a uniform electrodeposited film was obtained. The coated film cured at 230° C for 1.5 hours had excellent mechanical strength. The electrodeposition of Examples 1- 6 were applied to bare copper wire having a diameter of 1 mm. The coated wires were baked and their characteristics measured. The satisfactory results are shown in Table 1.
TABLE 1______________________________________Characteristics of Wiresthick- repeated *1 cut *2 break downness scrape through *3 voltageof film abrasion tempera- heat (twisted(μ) (times) ture shock pairs) KV______________________________________Example 30 40-50 300° C 2d 101 goodExample 29 40-50 300° C 2d 102 goodExample 29 40-50 300° C 2d 113 goodExample 30 50-60 300° C 2d 124 goodExample 31 80-90 300° C 2d 11.55 goodExample 30 80-90 300° C 2d 126 good______________________________________*1 600 g load Japanese Industrial Standard*2 2 kg load Japanese Industrial Standard*3 2 hours at 250°C Japanese Industrial Standard
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. | A water dispersion varnish suitable for electrodepositon is prepared by a process comprising reacting:
The reaction product of
A. a polyesterimide having a carboxyl group in its chain or at the terminus of the chain and having an ester group and an imide group in its repeating unit or a polyesteramideimide having a carboxyl group in its chain or at the terminus of the chain and having an ester group, an imide group and an amide group in its repeating unit and
B. an organic compound having at least two hydroxyl groups with
C. a polybasic acid or its anhydride in the presence or absence of a solvent yielding a modified polyesterimide or polyesteramideimide;
Dissolving said modified polyesterimide or polyesteramideimide in an organic solvent;
Dispersing said modified polyesterimide or polyesteramideimide solution in an aqueous solution containing a surfactant and a volatile base; and removing the volatile components. | 2 |
BACKGROUND OF THE INVENTION
[0001] The invention relates to a laying and fixing system for pipes of various circuits, domestic or industrial.
[0002] It therefore relates to pipes for heating, hot and cold water supply, and all other fluid circuits as well as pipes for the protection of electrical circuits or signal-transmission circuits. During the construction of a network of pipes, it is necessary to preform each pipe on site and preposition it before fixing it in place definitively. These operations then have to be repeated for each pipe or conduit.
[0003] This preparation is time-consuming for the metal or plastic pipes which are bent on demand, but also pipes made up of straight lengths connected by T or C fittings attached by welding, brazing or adhesive bonding.
DESCRIPTION OF THE PRIOR ART
[0004] Documents FR 1 319 291, FR 2 568 730 and BE 571 724 disclose moldings or ducts formed from a continuous profile comprising a fixing mounting plate with a flat back covered by an adhesive layer and at least two opposing flexible wings defining a closed C, these wings being able to be pushed apart elastically to allow the insertion of one or more conductors into the cavity which they form. In document FR 2 568 730 the profile may comprise several juxtaposed receiving cavities that can be separated at the time of laying, while in document BE 571 724 the duct comprises one or two juxtaposed and inseparable cavities formed by C-shaped wings, that is to say having separated edges.
[0005] In shape and structure, these ducts for electrical conductors are unsuitable for laying more rigid, heavier pipes of larger transverse dimensions than the conductors and in particular would be unable, by the force of the adhesive alone, to ensure permanent fixing of one or more pipes having a greater mass per unit length. Furthermore, with visible pipes, these supports would form an aesthetically unpleasing system requiring complementary means to conceal them.
SUMMARY OF THE INVENTION
[0006] Taking ducts for electrical conductors as a starting point, it is an object of the present invention to provide a fixing duct for pipes that simplifies the pipe installation process, and reduces laying time and costs while doing away with any finishing operation for pipes that remain visible.
[0007] The invention therefore relates to a duct comprising a plastic profile with a mounting plate whose back is supplied with an adhesive fixing means for fixing it to a wall and whose front is provided with elastically deformable wings in pairs defining a longitudinal cavity for receiving and retaining an elongate body.
[0008] According to the invention, the deformable wings are those of longitudinal open C-section gutters projecting from the front of the mounting plate and separated transversely from each other by a gap E, at least one of the wings of each gutter being molded integrally with the mounting plate and made of the same semirigid material, while, on the one hand, the said mounting plate of the profile is divided into sub-lengths by breakable or precut transverse lines coinciding with transverse slots formed through the gutters, in order to form independent ducts in this profile and on the other hand, the system also comprises a plastic finishing profile which, having fixing means for clipping it onto the gutters or pipes, can be cut to length to cover one or more ducts and the associated pipes, along a rectilinear part of laid, fixed pipes.
[0009] Thus, when the pipes have been formed to shape, that is to say bent and formed or cut into straight sub-lengths, they are put in position by clipping onto them sub-lengths of duct and pressing the back of these sub-lengths, their peel-off film having first been removed, onto the wall, to which they can later be fixed by other mechanical means, such as screws or equivalent. When all the pipes are laid and fixed and require concealing, the finishing profile is cut into straight sub-lengths, by straight or oblique cuts, and is clipped onto the installation. In this way, a single finishing sub-length conceals from view one or more ducts and the pipes contained inside them.
[0010] By this means all the laying operations are effected faster than by the traditional method and the resulting installations are more finished and more aesthetically pleasing.
[0011] In one embodiment, at least one longitudinal gutter, of smaller internal diametrical dimension than the pipe gutters, project from the mounting plate into the gap E between two pipe gutters to accommodate and retain an insulated conductor of a circuit for the transmission of electrical or optical signals.
[0012] In another embodiment, the finishing profile comprises, projecting from its back, various longitudinal open C-section gutters, each able to receive and retain an insulated conductor, for the transmission of electrical or optical signals, that fits in the gap E between the pipe gutters of the duct.
[0013] Each of these two provisions enables the pipe ducts or the finishing profile to be used for laying and retaining a variety of conductors. This is particularly beneficial when it comes to electrical or optical circuits which may be added well after the pipes have been installed, as it saves making chases in the walls, or using other contrivances to conceal these conductors in a habitable room where for example pipes have been laid along the baseboard or cornice and concealed by a finishing profile.
[0014] Other features and advantages will emerge from the following description referring to the appended schematic drawing showing, by way of examples, a number of embodiments of the duct according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of a first embodiment of the system according to the invention designed for two pipes,
[0016] FIG. 2 is a side view in cross section of another embodiment of the duct, when laid against a wall,
[0017] FIG. 3 is a front elevation showing the application of the device to the positioning of two pipes carrying hot and cold water to a hand wash basin,
[0018] FIG. 4 is an end view of another embodiment of the system,
[0019] FIGS. 5 and 6 are partial side views of a pipe gutter showing two embodiments of liners that can be put in it,
[0020] FIG. 7 is a partial sectional view of another embodiment of the pipe gutter,
[0021] FIG. 8 is a partial sectional view of another embodiment of the pipe gutter,
[0022] FIGS. 9 to 12 are sectional side views of other embodiments of the system,
[0023] FIG. 13 is a partial perspective view of a room fitted with the system laid along the baseboard and running around a door, and
[0024] FIGS. 14 to 18 show other embodiments of the system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] In FIG. 1 , the reference A denotes a semirigid plastic profile comprising a mounting plate 2 , on the back of which is a layer of adhesive 3 protected by a peel-off film 4 . Projecting from the front of the mounting plate 2 are two open C-section gutters 5 whose internal dimension is appropriate for the pipes 6 with which these gutters are intended to engage. The two gutters are separated by a space E equal to or greater than the usual spacing of the pipes of the network in question.
[0026] In this space, the mounting plate 2 comprises one or more breakable longitudinal lines 7 consisting of a reduction in the thickness of its component material, and/or consisting of precuts (not shown). It also comprises breakable transverse lines 11 that are also formed by a thinning of the material or by a precut, and coincide with slots 21 running through the gutters 5 all the way to the mounting plate 2 . In practice the spacing P from each breakable line and slit 21 to the next is about 10 centimeters.
[0027] The profile A is accompanied by a finishing profile B made of a semirigid or flexible plastic and intended to form a cap to conceal the ducts and pipes.
[0028] When constructing a hot and cold water supply system with two pipes, as shown in FIG. 3 , as the installer forms the pipes 6 to the correct shape, for example by bending them at 10 and cutting them to length, he prepositions them on the wall where they are to be fixed. Once all the components of a sub-length of the system are correct they are positioned on the wall using either a length of the duct profile, as shown at T 1 and T 3 in FIG. 3 , this length being a multiple of the spacing P between two breakable lines 11 of the profile A, or a number of independent ducts T 2 , obtained by cutting sub-lengths of the base profile A. Each element T 1 , T 2 or T 3 is first placed on the pipes 6 by clipping its gutters 5 onto them, i.e. by forcing their wings apart so that they pass the diametrical plane of the pipe before returning elastically to their original position. After removing the films 4 from the back of each of the elements T 1 and T 2 , the latter are stuck to the wall.
[0029] The adhesive layer 3 has sufficient holding power to keep the lengths of piping in position while the installer continues laying out the rest of the installation, for example fitting the tee joints 8 of the circuit branch consisting of two lengths of pipe 9 installed for example in a length T 3 of the support profile.
[0030] If need be, for example if the two pipes have to follow different paths, the profile A of the duct is divided lengthwise into two independent elements by separating it along one of its breakable longitudinal lines 7 .
[0031] Once all or part of the installation is in position, final fixing of the pipes is carried out by means of staples, collars, screws or any other means known to the installer. At this point the profile B is cut into covering sub-lengths C 1 , C 2 and C 3 so that they will cover a straight section of the laid pipe network, that is the supports T 1 , T 2 and T 3 and the pipes projecting from them.
[0032] The profile B entirely conceals the whole installation from view and forms a whole but does not detract from the appearance of the room in which it is laid, and even allows it to be run against the walls, along the baseboard or cornice, and if necessary to be run around window frames and doorframes.
[0033] The embodiment shown in FIG. 2 differs from the previous embodiment in that each of the two gutters 5 a is still C-shaped but has an opening 16 turned to one side rather than away from the mounting plate 2 . This figure also shows that the angle subtended by the opening 16 to the center a extends from a value of at least 90° up to 170° to suit the deformation characteristics of the material of the support, in order that the cylindrical pipes 6 can be clipped into and held by each gutter.
[0034] This FIG. 2 also shows that, in the gap between the two gutters 5 a , it is possible to provide a gutter 12 of smaller diametrical dimension: this can be used for laying insulated conductors, for transmitting low-voltage current or electrical or optical signals.
[0035] In the embodiment shown in FIG. 4 , the duct equipped with two gutters 5 a engages with a finishing profile 13 forming a cap. It has a U-shaped cross section with wings 13 b provided with clip-fastening means such as spurs 14 able to engage elastically in grooves 31 at the foot of each gutter. The web 13 a of the cap comprises, as shown in FIG. 4 , two gutters 17 , projecting from its back into the gap E between the pipe gutters 5 a . These gutters 17 are also intended to take insulated conductors for carrying low-voltage current or for transmitting electrical optical signals.
[0036] The number of pipe gutters 5 carried by any one support may of course be other than two, and may be one, three or four, for example, depending on the application.
[0037] In the same way the inside diameter D of each gutter 5 or 5 a varies as a function of the application, i.e. washing, heating, carrying industrial fluids. However, for ordinary applications the inside diameter D, in FIG. 5 , is that of the largest outside pipe diameter 6 encountered, such as 18 millimeters for a pipe carrying water for washing. In this case and in order to retain pipes 6 d of smaller outside diameter, liners 22 in the form of an open C are put in place in the gutters as shown in FIG. 5 . These liners are made of flexible plastic so as not to add their stiffness to that of the wings of the gutters. They have an outside dimension that enables them to be clipped into the gutters and an inside diameter equal to the outside diameter of standardized pipes, such as 16, 12 or 10 mm.
[0038] In FIG. 6 the liner 23 is H-shaped, that is it consists of a central straight bar connecting two curvilinear bars. It defines two housings 23 a , each able to accommodate and retain an insulated conductor 24 . This type of liner makes it possible to use the pipe gutter or gutters that have been left vacant, for carrying various conductors.
[0039] The liner 20 could have four housings if given a second straight bar perpendicular to the first straight bar.
[0040] FIG. 7 shows that each of the pipe gutters, which hitherto had two wings integral with the mounting plate 2 , may have only one wing integral with this mounting plate, for example the wing 5 f , and have a wing 5 m connected to a lug 25 . This lug is able to slide relative to the mounting plate 2 so as to form, between the wings 5 f and 5 m , an oblong housing capable of accommodating a pipe having this cross section or a pipe of larger diameter. The lug 25 is made fast by a screw 26 , which passes through an oblong hole 27 and screws into a nut 28 embedded in the mounting plate 2 .
[0041] Although not shown in the drawing, it is envisioned that each wing of the gutter 5 be able to slide relative to the mounting plate 2 . This enables the angle of the pipe to be adjusted so that a slope can be given to a drain pipe.
[0042] Notice that the mounting plate 2 can also be reinforced by a rigid plate embedded within it or may contain any insert that allows its final fixing such as wall plugs. As shown in FIG. 8 , the mounting plate 2 can also be pierced by holes 29 for the passage of screws, sleeves or wall plugs 30 , as shown in FIG. 12 .
[0043] In the embodiment of FIG. 8 , the longitudinal edge of each of the wings of each of the gutters 5 of a support is given a spur 32 , tooth or equivalent means for engaging with the spur 33 a , or complementary tooth, formed on each edge of a clip 33 . The latter is fitted onto the gutter after the latter has taken a pipe whose outside diameter is greater than that for which it is designed and which could therefore come out under the elastic loading on its wings.
[0044] This figure also shows that in order to avoid retention of condensation, at least one of the wings 5 i of each gutter 5 is pierced with holes 34 set out lengthwise at a regular pitch that is a submultiple of the pitch P at which the breakable lines 11 of the profile are set apart.
[0045] In FIG. 9 , the finishing profile 13 d is L-shaped and therefore comprises a web 13 e and a wing 13 f . The wing 13 f has a retaining spur 14 on the outer wing of the upper gutter 5 s of the ducts. The finishing profile 13 d also includes an integral rib 35 projecting from the web 13 e , one of the edges of which is provided with a spur 35 a able to engage with the other wing of the gutter 5 s , to help fix the profile 13 d on each of the ducts. Additionally, one or more gutters 36 for conductors project from the web 13 e of the profile and fit in the gaps E between pipe gutters 5 . When the profile 13 d is laid on a series of ducts, the whole has the general form of a baseboard and can be run along the bottom of a wall, as shown in FIG. 13 .
[0046] In FIG. 10 , the finishing profile 13 g is U-shaped and both of its wings have inner spurs 36 able to clip-fasten onto complementary spurs 37 formed on ribs 38 along the edge of the profile A and each duct T, detached from this profile. At least part of this profile 13 g is molded 13 h . Its web 13 j which is at a greater transverse distance from the pipe gutter 5 carries, projecting from its inside face, a number of gutters 36 for conductors.
[0047] With this arrangement it is possible, once the pipe network has been installed, to use the circuit described by the installation to install other electrical conductors added as the home expands its systems, e.g. telephone cable, computer cable, loudspeaker wires, computer-television link etc, and this without having to do anything more than remove and refit the finishing profile 13 g on the duct sub-lengths.
[0048] In the variant shown in FIG. 11 , the profile 13 k comprises, projecting from its web, a number of internal ribs 40 with spurs 41 along their free edges, opposing one another so that they can be clipped onto a pipe gutter 5 or 5 a . In the gap between the ribs 40 , the web projects outwards to form a throat 42 . In this throat the web comprises, locally and at regular intervals, zones 43 where its wall is thinner and can be cut or broken through to install an electrical accessory, such as a switch, socket, etc. Running alongside the wing 44 of the finishing profile 13 k is a longitudinal partition 45 with which it forms an open channel 46 capable of containing one or more insulated conductors for the transmission of electrical or optical signals. Lastly, the parts of the profile that are intended to come into contact with a surface, such as the wall 47 or the floor 48 , have seals against the entrance of at least dust, such as a lip seal 49 or compressible seal 50 .
[0049] FIG. 12 shows an embodiment suitable for cornice application. The mounting plate 2 of the duct profile is bordered by two lateral flaps 52 for fixing temporarily to the perpendicular surfaces of a corner between two surfaces 53 , 54 and each of these flaps has on its back an adhesive layer 55 protected by a peel-off film. The mounting plate is pierced by holes 56 for the passage of shouldered sleeves 30 which have an end shaped as a wall plug 30 a . The wings 13 m of the finishing profile 131 are shaped to hide the flaps 52 and form an attractive cornice. They may, like the web of the profile, take the form of any ordinary molding to improve the decorative effect, and they may be colored or translucent.
[0050] Similarly, the gutters for conductors can carry fixed or flashing hanging lights visible through the material of the finishing profile.
[0051] FIG. 16 illustrates another advantageous embodiment in which a partition 63 , parallel to the mounting plate 2 , is added to the profile A. This partition 63 is pierced with oblong holes 64 in which pipe fixing members 6 are engaged. These members comprise a spring clip and a T-shaped foot 66 which fits into one of the oblong holes 64 and after a quarter-turn is retained in the latter. The presence of ventilation openings 68 may also be noted.
[0052] Whatever its embodiment, the duct according to the invention saves the user having to prepare the positioning of various pipes and conduits, and in particular avoids the need to fix in wall plugs, screw lugs or collars at the same time as he is shaping the pipes, so that there is a considerable reduction in the amount of time required for installation.
[0053] Another advantage is that the duct can be used without any special skill or any special tool, all that is required being a hammer to cause its adhesive bonding to the wall and some sort of cutting blade to cut it into longitudinal sub-lengths or independent elements.
[0054] In the more elaborate embodiments, comprising means for retaining conductors and molded finishing profiles, the system according to the invention can be surface-mounted and may or may not follow the outlines of window or door frames. Furthermore, it is envisioned that the finishing profile 13 be equipped with clips 58 with elastically deformable wings that fit directly onto pipes 6 in order to conceal the latter. FIG. 15 shows another variant in which the finishing profile 13 has down-turned clips 59 , enabling the profile to be fixed from above. The profile may however have only one clip 59 as shown in FIG. 18 .
[0055] FIG. 17 shows a profile 13 containing a space 68 reserved for running cables, for example. The invention can of course be produced in any appropriate material. One possibility is to make the finishing profile 13 in wood, clips being attached to it.
[0056] Another possibility is to place a layer of insulating material in the system to insulate the pipes 6 .
[0057] Moreover, the system can be clipped unobtrusively to a pipe 6 or can be clipped to the collar holding this pipe in position. | The invention concerns a device comprising a profiled section A made of plastic material with a base plate ( 2 ) whereof the reverse side is equipped with means for adhesive fixing ( 3 ) against a wall and the face is provided with elastically deformable wings defining in pairs longitudinal troughs ( 5 ) with C-shaped cross-section, arranged projecting and transversely spaced apart from one another, at least one of the wings of each trough being integral with the base plate and made of the same semirigid material. The base plate ( 2 ) is divided into sections by cleavable or precut transverse lines, coincident with transverse grooves ( 21 ) provided in the trough ( 5 ), to form in the profiled section independent laying supports. A finish profiled section made of plastic material B provided with snap-on fixing means on the trough ( 5 ), is longitudinally cleavable to cover one or several laying supports and the associated pipes ( 6 ). | 5 |
BACKGROUND OF THE INVENTION
This invention relates to an apparatus and method for tentering sheet-like members and more particularly this invention relates to a tentering frame and method for tentering membranes used in electrolyzers.
Electrolyzers employing a membrane (hereinafter "membrane cells") may be of the filter press-type, for example, as described in U.S. Pat. Nos. 4,108,742 and 4,111,779. Membrane materials commonly used for membrane cells include, for example, those marketed by E. I. duPont de Nemours & Company under the trademark Nafion® and by Asahi Glass Company Ltd. under the trademark Flemion®. The membranes are available principally in sheet-like form. The membrane is used for separating the cell into electrode compartments containing electrolyte. For example, a membrane cell used for the production of a halogen and an alkali metal hydroxide may use an ion exchange membrane to separate an anode compartment containing anolyte and an anode member from a cathode compartment containing catholyte and a cathode member.
In a membrane cell used, for example, in the production of a halogen and an alkali metal hydroxide, it is important to keep the distance between electrodes to a minimum to reduce the voltage drop through the catholyte and anolyte, and thus reduce energy consumption of the cell. Furthermore, it is advantageous to keep a uniform spacing between an electrode and the membrane to obtain a uniform current distribution. Any contact between the membrane and an electrode may cause a great amount of current passage and membrane burning at the point of contact. In some applications, the spacing between an electrode and membrane may be no greater than 1 millimeter. Therefore, the membrane is kept as flat or planar as possible when installed between electrodes of an electrolytic cell.
Some membrane materials are known to absorb water and expand a certain percentage when wetted. Thus, it is common for these types of membranes to form wrinkles during operation of a cell when the membrane is wetted with electrolyte. A wrinkled membrane can come into contact with the cell electrodes and cause the problems described above. A wrinkled membrane can also reduce the circulation of the electrolyte and trap gases produced in the cell between the electrode and the membrane face. This may result in a non-uniform increase in resistivity of the electrolyte solution in the interelectrode space with a non-uniform current distribution across the membrane surface in the vertical direction. It is important, therefore, to keep the membrane as flat as possible and prevent wrinkles from forming on the membrane surface when installing in the cell.
Heretofore, the installation of membranes between electrode compartments required a crew of about six to eight people holding the membrane in place and pulling the membrane by hand to tension the membrane between electrode units until the electrode compartment units were squeezed together by, for example, a hydraulic ram. Invariably, this procedure led to formation of wrinkles on the membrane due to uneven forces pulling at the membrane by the crew. The wrinkles formed at a gasket bearing surface of the membrane caused leakage of electrolyte into the atmosphere or electrode compartments. Furthermore, installation of the membrane consumed a relatively long period of time and dropping the membrane, which meant starting the installation process over, was always a risk.
It is desired to minimize the problems discussed above by providing an apparatus and method for tentering a membrane used in a membrane cell and maintaining the membrane planar when installed in a membrane cell.
SUMMARY OF THE INVENTION
The present invention is directed to an apparatus and method for tentering a generally planar sheet-like member. The apparatus comprises (a) an outer frame member, (b) at least four clamping assemblies adjacent to each other and arranged in a picture-frame type configuration inside the outer frame member and spaced apart from the outer frame member, said clamping assemblies adapted for clamping at least a portion of the periphery of the sheet, said clamping assemblies comprising a pair of independent and separate elongated, generally planar members adjacent and parallel to each other and fixed together with a first fastening means, and (c) a second fastening means for fastening at least one of the clamping means to the outer frame member.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of one embodiment of the tentering apparatus according to the present invention showing an outer frame member and four clamping assemblies in a picture type configuration.
FIG. 2 is a front view of a portion of an assembled tentering apparatus of FIG. 1 with a sheet-like member.
FIG. 3 is a cross-section view taken along line 3--3 of FIG. 2, showing an outer frame member and a clamping assembly with a sheet-like member.
FIG. 4 is a cross-section view, similar to FIG. 3, of another embodiment of the apparatus according to the present invention, showing an outer frame member and a clamping assembly with a sheet-like member.
FIG. 5 is a cross-section view, similar to FIG. 3, of another embodiment of the apparatus according to the present invention, showing an outer frame member and a clamping assembly with a sheet-like member.
FIG. 6 is a side view of the assembled tentering apparatus of FIG. 1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to FIGS. 1-6, there is shown various preferred embodiments of the apparatus of the present invention which is designated generally as numeral 10 (hereinafter tentering frame 10). As shown in FIG. 1, the tentering frame 10 may consist essentially of an outer frame member F and four clamping assemblies C positioned inside the outer frame member in a picture frame type configuration. The tentering frame 10 is used for tensioning a sheet-like member 40, as shown in FIG. 2. The tentering frame 10, in this instance, is rectangular in shape, but broadly speaking, the tentering frame may be any shape as that of the sheet-like member, for example, square or hexagonal.
The outer frame member F may be a one-piece, rectangular-shaped member having two long sides and two short sides. In another embodiment, the outer frame member F may be a multi-section, rectangular-shaped member. Preferably, the outer frame member F is in four sections for ease in assembling and disassembling. The outer frame member F may consist essentially of a first pair of longitudinal sections 11 generally parallel and spaced apart positioned between a second pair of transversal sections 12 generally parallel and spaced apart. A means for fastening together the sections 11 and 12 of the outer frame member F may be, for example, a support flat plate 13 and bolts 14.
The tentering frame 10 contains at least four clamping assemblies C positioned inside the outer frame member F. Two of these clamping assemblies, each indicated by numeral 15, are attached to each of the outer frame member sections 11 by a fastening means T. In accordance with the present invention, the fastening means T is also used for tentering the sheet-like member 40 and, therefore, will be referred herein as the "fastening/tentering" means T. The other two clamping assemblies, each indicated by a numeral 16, are attached to each of the outer frame member sections 12 by a fastening/tentering means T.
The clamping assemblies 15 and 16 comprise a U-shaped clamp channel 17 and a first and second clamping bar 18 and 19, parallel and adjacent each other and juxtaposed between the arms of the "U" or flanges of the U-shaped clamp channel 17. "U-shaped" refers to the view of the channel member 17 in cross-section. A releasable means for tightening the first and second clamping bars together may be used in the form of a plurality of clamping screws 20 and threaded openings 21 adapted to receive the clamping screws 20. The clamping screws 20 and the threaded openings 21 are preferably located on at least one flange of the U-shaped clamp channel 17.
Referring to FIG. 3, one embodiment of the tentering frame 10 is shown consisting essentially of a clamping assembly C attached to a hollow outer frame member F with a fastening/tentering means T. The fastening/tentering means T of tentering frame 10 comprises, for example, a threaded bolt or rod 22 extending through a bore 23 in the outer frame member F, a wing nut 24 threaded on the rod 22 and positioned on the outer surface of outer frame F and a means for attaching the rod 22 to the clamping assemblies C. Any means for attaching the rod 22 to the clamping assemblies may be used, such as welding or threading. In this embodiment, a nut 25 is welded to the bottom of the "U" or web of the U-shaped clamp channel 17 and the threaded rod 22 is threaded to the nut 25. At least a pair of fastening/tentering means T are attached to the clamping assemblies 15 and 16, but any number of fastening/tentering T means may be used.
Referring again to FIG. 3, a means for tightly securing or gripping the sheet-like member 40 between clamping bars 18 and 19 is provided on at least one of the clamping bars. The gripping means, in this instance, may be, for example, a securing member 26 and a longitudinal recess 18a adapted to receive the securing member 26. The recess 18a is positioned along the inner surface 18b of bar 18 in contact with the sheet-like member 40. The securing member 26 may be in the form of a solid piece, a strip or a tubing. Preferably, the securing member 26 may be made of resilient materials such as rubber, ethylene-propylene-diene monomer (EPDM), chlorinated polyethylene (CPE) and neoprene. The recess 18a and securing member 26 provides a tightly secured or gripped sheet-like member 40 during tentering, stretching or tensioning the sheet-like member 40. Another gripping means (not shown) useful in the present invention may be, for example, a longitudinal rib on at least one clamping bar and a longitudinal recess adapted for receiving the rib on at least the other clamping bar. Other gripping means (not shown) may include, for example, a knurled surface or roughened, uneven surface located on at least a portion of the inner surface of at least one clamping bar in contact with the sheet-like member.
With reference to FIG. 4, another embodiment of the tentering frame 10, similar to FIG. 3, is shown consisting essentially of a clamping assembly C attached to a solid outer frame member F with a fastening/tentering means T. The fastening/tentering means T in this embodiment is, for example, a threaded rod 28 extending through a bore 23 positioned in the web of the U-shaped clamp channel 17. A flat head 30 on one end of the rod 28 retains the rod 28 to the U-shaped clamp channel 17. Optionally, the flat head 30 may be welded to the bore 23. A wing nut 24 is threaded on the rod 28 and is positioned on the outer surface of outer frame member F.
FIG. 5 shows another embodiment of the tentering frame 10 consisting essentially of a clamping assembly C attached to a solid outer frame F with a fastening/tentering means T. The fastening/tentering means T, similar to FIG. 3, in this embodiment is, for example, a threaded rod 22 extending through a bore 23 in the outer frame member F, a wing nut 24 positioned on the outer frame surface and a means for attaching the rod 22 to the clamping assemblies C. The clamping assemblies C, in this instance, consist essentially of two clamping bars 31 and 32 with threaded bores 33 and 34, respectively, with a clamping screw 35 used to tighten the clamping bars 31 and 32 together. A means for gripping the sheet-like member 40 in this instance, may be a securing member 26 and a recess 32a on the inner planar surface of clamping bar 32 similar to the recess 18a and securing member 26 shown in FIG. 3 above. Other gripping means may be used as described above for FIG. 3.
In a preferred method of carrying out the stretching or tensioning of the sheet-like member using the tentering frame 10 of the present invention, the edges of two opposite and generally parallel ends of a sheet-like member 40 are sandwiched between clamping bars 18 and 19 of clamping assemblies 15 and the edges of the sheet-like member 40 are secured by tightening the clamping screws 20. The two remaining edges of the ends of the sheet-like member 40 are sandwiched between clamping bars 18 and 19 of clamping assemblies 16 and the edges of the sheet-like member 40 are secured by tightening the clamping screws 20. The sections 11 and 12 of the outer frame member F are attached to the clamping assemblies 15 and 16, respectively, using the fastening/tentering means T. The sections 11 and 12 are fused together by the plate 13 and bolts 14. The wing nuts 24 on the outer frame section 11 are then tightened, to pull the sheet-like member in a direction perpendicular to the clamping assemblies 15. Then, the wing nuts 24 on the outer frame section 12 are tightened to pull the sheet-like member in a direction perpendicular to the clamping assemblies 16. The wing nuts may be tightened until any wrinkles formed on the surface of the sheet-like member 40 are removed or a desired tautness is achieved.
In its broadest application, the apparatus of the present invention may be used where a generally planar sheet-like member is desired to be tensioned or stretched. For example, the apparatus of the present invention is particularly useful for tensioning membranes employed in electrolyzers, in particular, electrolyzers of the filter press-type, which may be monopolar or bipolar. Such electrolyzers may be used, for example, for the production of chlorine and an alkali metal hydroxide by processes well known in the art. Examples of such electrolyzers are described in U.S. Pat. Nos. 4,108,742 and 4,111,779.
Membranes which are tensioned by the apparatus of the present invention and which are used in electrolytic cells of the filter press-type include, for example, flexible membranes having ion exchange properties and which are substantially impervious to the hydrodynamic flow of electrolyte and the passage of gas products produced in the cell. Cation exchange membranes succh as those composed of fluorocarbon polymers having a plurality of pendant sulfonic acid groups or carboxylic acid groups or mixtures of sulfonic acid groups and carboxylic acid groups are typically employed in electrolytic cells. The terms "sulfonic acid groups" and "carboxylic acid groups" are meant to include salt of sulfonic acid or salts of carboxylic acid which are suitably converted to or from the acid group by processes such as hydrolysis. One example of a suitable membrane of the sulfonic acid type cation exchange membranes are those sold commercially by E. I. duPont de Nemours and Company under the trademark Nafion®. Carboxylic acid type cation exchange membranes are commercially available from the Asahi Glass Company under the trademark Flemion®. | A tentering apparatus for tensioning a sheet-like member, for example, a membrane used in an electrolyzer. The apparatus includes four clamping assemblies arranged in a frame-shape configuration within an outer frame member, and a fastener, such as a threaded bolt and wing unit, for fastening the clamping assemblies to the outer frame members and for tensioning the sheet-like member. | 3 |
This application claims the benefit of U.S. Provisional Application No. 60/030,974 filed Nov. 15, 1996.
This invention relates to the method and machine for making and filling pouch-type packages and more particularly to increasing the capacity of existing horizontal type packaging machines.
It is well known in the horizontal packaging machinery industry that such machines are primarily designed to run in what is commonly referred to as the simplex mode. This is an arrangement by which single pouches are made, opened, filled and sealed. Many manufactures of such machinery modify their equipment to operate in what is known as the two-up mode or duplex mode. In this arrangement, two pouches instead of one are formed and handled at each station which doubles the output of the machine.
It is highly desirable to have a machine and method for handling three, four or even more pouches at each of the stations of a machine. By way of example; if a machine operates at 60 cycles per minute, operating a machine in a duplex mode results in 120 pouches per minute. In a triplex mode 180 pouches per minute would result and in a mode of four or even more, production would increase proportionately. Such an increase in production can be achieved with a relatively small investment by modifying an existing machine rather than purchasing multiple machines to obtain the same end results at a higher machinery and labor cost.
Prior art machines place limitation on the number of pouches that can be handled at a single station to two pouches because the clamping arrangements by which the pouches are held at each station usually require holding of the adjacent edges of adjacent pouches with a single clamp and the outer edges of the same pair of pouches with an additional pair of clamps making a total of three clamps to handle two pouches at each station. To open the pouches for filling, it is necessary for the pair of outer clamps to move toward each other to permit opening of the pouch. Such an arrangement is not usable with more than two pouches, for example, three or more pouches.
It is an object of this invention to provide a machine making it possible to convert a simplex machine to the handling of three or more pouches at each of its stations.
The purpose of the invention are achieved by pouch clamping arrangement by which a pair of clamps is used for each pouch at a single station. For example, if three bags are to be handled at a single station, three pairs of clamps are used with one clamp of each pair used at opposite edges of each pouch with all of the clamps attached to the left edges of pouches being actuated by a single mechanism and the clamp at the right edges by another, single mechanism and with all clamps simultaneously opened and closed by still another single mechanism.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic, perspective view of a horizontal flat bag machine which the present invention relates;
FIG. 2 is a top view of a turret of the type commonly used with the machine of FIG. 1;
FIG. 3 is a top view of a turret of the type used in connection with the present invention;
FIG. 4 is a perspective view of a pair of matching clamps forming part of the operating station of the turret seen in FIG. 3;
FIG. 5 is a view similar to FIG. 4 showing another operating condition of the clamps;
FIG. 6 is a view of four pairs of clamps used at one station of the turret seen in FIG. 3; and
FIG. 7 is a view similar to FIG. 6 showing another operating condition of the clamps.
DETAILED DESCRIPTION
The machine to which the present invention relates is referred to as a flat bag machine which, by way of example, can be of a type manufactured by Laudenberg Machinery, Inc., and generally designated as Model FBM-20. Such machines can be used for manufacturing a large variety of relatively flat pouches.
Referring to FIG. 1, the flat bag machine 10 is used to make bags or pouches 11 from a flat, continuous sheet 12 of material which typically may be a plastic laminate stored on a roll 13 from which it is fed around guide bars 14 after which a plow member 15 is disposed in engagement with the top surface of sheet 12 to fold the sheet material so that the top surface forms surfaces facing each other. The facing surfaces are a sealant surface, usually of a plastic material which responds to heat to fuse and bond together with a like surface.
At a first station after folding, heated sealant bars 16 are brought into contact at opposite sides of the folded sheet of material 12 to fuse the facing sealant surfaces to each other. At a subsequent station, bottom sealing bars 18 are disposed at opposite sides of the sheet 12 to seal the bottom of the sheet and to form open pouches 11 which remain attached to each other. At a subsequent station, attached pouches 11 pass between rolls 20 which apply pressure to the opposite side to insure that the heated surfaces bond to each other. Thereafter, the pouches are cut along parting lines 21 formed by the heated bars 16 by shears designated at 22 to separate the pouches 11 from the string of pouches. Immediately thereafter, the pouches 11 are transferred to a rotating turret 24 which can consists of eight stations 26 through 33 making it possible to simultaneously conduct eight different operations such as; clamping and supporting the pouches 11, opening the upper portion of the pouches, forming or shaping the pouch opening, filling the open pouch with product, as shown in FIG. 1 at station 29, and sealing the open end of the filled pouch with opposed heating bars 34 at station 32, as seen in FIG. 1. At station 33, the filled and sealed pouch 11 can be transferred to a conveyer or the like for transport to a storage or shipping area.
The machine 10 described is for conducting a simplex operation in which one pouch is handled at each of the stations of the turret 24 at any one time. The same form of machine can be used for conducting duplex operations by which two bags are handled at each of the stations. This requires increasing number of cutting bars 20 and cutting knives 22 so that two packages can be transferred simultaneously to the first station 26 of the rotating turret 24.
Referring to FIG. 2, which illustrates a prior art turret 38 arrangement showing eight stations, three clamps 40 are used at each station for the purpose of handling two pouches. Each set of three clamps is disposed at a separate, single station the center of which is designated at 26 through 33.
The clamps 42 of the present invention are of a different form than the prior art clamps 40 and are used in pairs as seen in FIG. 3 with the left clamp being designated 42 and the right clamp designated 44. The clamps 42 and 44 must be capable of opening and closing and must be capable of moving toward and away from each other to allow a pouch to enter the holding area on the turret to be moved towards each other to clamp and hold the pouch. A third requirement for such clamps is that they must be movable towards each other when the package is clamped to cause the opening at the top of the package to attain its open condition.
The left clamp 42 in FIG. 4 includes a horizontally extending base member 46 and upstanding finger 48 extending from one end of the horizontal base member 46. The other end of the base member 46 is provided with an adaptor 50 for attachment to an actuating bar 52, shown in FIGS. 6 and 7. The upstanding finger 48 provides a clamping surface 54 which engages the bag of the package when the clamp is in the closed position. The clamp 42 also includes a movable finger 56 which pivots about the axis of a pivot element 58 for movement between the closed position seen in FIG. 4 to the open position seen in FIG. 5. The upper end of the movable finger 56 is provided with an L-shaped clamping element 60 having a facing surface 62 for engagement with the clamping surface 54 to hold a pouch at one of its edges. An actuating arm 63 extends from the moveable finger 56 away from the pivot element 58. The free end of the actuating arm 60 is provided with a cam follower 64 which is engaged by a clamp cam bar 65, as seen in FIGS. 6 and 7, and is actuated by longitudinal movement to open and close all of the clamps 42.
The right hand clamp 44 is a mirror image of the left hand clamp 42 with one exception. This exception is an adaptor 66 having a different configuration than the adaptor 50. The adaptor 66 is rigidly connected to the right actuating bar 68, seen in FIGS. 6 and 7 for movement upon longitudinal movement of the bar 68. The free end of actuating arm 60 of clamp 44 also is provided with a cam follower 64 engaged with clamp cam bar 65 for opening and closing of claim 44 simultaneously with clamp 42.
Four pairs of clamps each made up of a left clamp 42 and a right clamp 44 are disposed at each of the eight work stations designated at 27-31 in FIG. 3 on a turret or platform 70 seen in FIG. 5. The turret 70 typically is larger than the turrets of simplex or duplex machines to afford an additional space for forming three or more pouches. Otherwise, the size of pouches would be limited to very small sizes. In the case of four pouches at each station, all four of the left clamps 42 are connected by way of support means in the form of a left clamp bar 52 by way of the adapters 50 and all of the right hand clamps 44 are connected by support means formed by the right hand clamp bar 68 through adapters 66 so that all four pairs of clamps are supported near the perimeter of the turret 70 and can be moved as a unit. The left clamp bar 52 and the right clamp bar 68 are disposed substantially parallel to each other and are movable in opposite directions to result in moving the four clamps 42 and four clamps 44 away from each other or towards each other. Movement of the clamp cam bar 65 results in opening or closing movement of all four sets of the clamps 42 and 44 simultaneously.
A possible sequence of operation would be to simultaneously open all of the clamps 42 and 44 at a first station 26 and place a pouch 11 in alignment with each pair of open clamps in the spaces between the clamping surfaces 54 and 68. The clamp cam bar 65 can be actuated to close all eight of the clamps to securely hold four pouches 11. After turret 70 has been indexed to the next station, the left clamp bar 54 can be moved to the right and the right clamp bar 68 can be moved to the left simultaneously causing the clamps to converge. This results in the desired motion to provide an opening of the upper end of the pouch, as best seen at 72 in FIG. 7. After indexing turret 70, the open pouches can be filled at station 29. If desired, the pouches can be closed at station 30. At a subsequent station 32, the pouches can be heat sealed by moving the left and right clamps 42 and 44 away from each other. At the final station 33 of the turret 70, the clamp cam bar 64 can be actuated to simultaneously open all of the clamps to release the pouches for transfer to a transporting mechanism such as a conveyer belt or the like (not shown). | A multiple packaging machine for conducting simultaneous operations on two or more pouches at each of several work stations by employing a pair of clamps for holding each pouch at each station during opening by moving the clamps toward each other, during filling and during closing by moving the clamps away from each other. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority under 35 U.S.C. §119(e) of U.S. provisional patent application Ser. No. 60/649,180 filed Feb. 3, 2005, the specification of which is incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates generally to a system and method for enabling a wireless computing device to determine its position using a wireless positioning network, e.g., a satellite-based positioning system, irrespective of the reception of positioning signals from the wireless positioning network by the computing device.
The present invention also relates to a system and method for passively building a database of wireless beacons by means of wireless computing devices equipped with positioning systems and disseminating the database to other computing devices.
The present invention also relates to a system and method ascertaining the geographical locations of wireless computing devices based on a database of wireless beacons and a system and method for creating the database of wireless beacons.
BACKGROUND OF THE INVENTION
As portable wireless computing devices proliferate, there is a growing demand to continuously and accurately know the geographic location of the computing devices. There are basically two different ways to determine the geographic locations of a computing device, either using a wireless positioning network such the GPS system or using a database of wireless beacons and determining position using this database.
The first technique suffers from the difficulty in continuously obtaining signals, e.g., from a network of satellite, to enable the position of the computing device to be determined. It is recognized that such difficulties commonly arise in enclosed areas and confined areas, such as in areas with a large concentration of tall buildings and in tunnels.
The second technique requires the creation of a database of wireless beacons, and the computing device to be within range of a plurality of such wireless beacons. In the absence of wireless beacons within range, the position of the computing device cannot be determined.
For the second technique, several systems are being used to enable wireless computing devices to determine their position. One such system is Place Lab. Place Lab is software providing low-cost, easy-to-use device positioning for location-enhanced computing applications. The Place Lab approach is to allow wireless computing devices such as notebook computers, PDAs and cell phones, to locate themselves by listening for radio beacons such as 802.11 access points, GSM cell phone towers, and fixed Bluetooth devices that exist in the surrounding environment. These beacons all have essentially unique identifications, for example, a MAC address. The devices compute their own location by hearing one or more IDs, looking up the associated beacons' positions in a stored map, and estimating their own position referenced to the beacons' positions. Additional information about Place Lab is found in: Place Lab: Device Positioning Using Radio Beacons in the Wild, by Anthony LaMarca et al., Pervasive 2005, Munich, Germany; Challenge: Ubiquitous Location-Aware Computing and the “Place Lab” Initiative, by Bill N. Schilit et al., Proceedings of The First ACM International Workshop on Wireless Mobile Applications and Services on WLAN (WMASH 2003), San Diego, Calif. September 2003; A Case Study in Building Layered DHT Applications, by Yatin Chawathe et al., January 2005; Accuracy Characterization for Metropolitan-scale Wi-Fi Localization, by Yu-Chung Cheng et al., Proceedings of Mobisys 2005, January 2005; Social Disclosure of Place: From Location Technology to Communication Practices, by Ian Smith et al., Pervasive 2005, Munich, Germany; and Privacy and Security in the Location-enhanced World Wide Web, by Jason I. Hong et al., Proceedings of Ubicomp 2003, Seattle, Wash. October 2003.
Another positioning system is that of Skyhook Wireless which uses a database of known Wi-Fi access points to calculate the precise location of any Wi-Fi enabled device. For this system, known Wi-Fi networks are mapped, e.g., by having hired drivers travel every street in a neighborhood, and a user's location is calculated based on the Wi-Fi networks the Wi-Fi enabled device detects at a given moment using proprietary software. If the device can identify three networks, it can determine its position, e.g., using triangulation. The more networks the device detects simultaneously, the more accurate the locational fix.
It would be desirable to provide a single positioning system for a wireless computing device which is capable of continuously determining the position of the wireless computing device using both a wireless positioning network and a database of wireless beacons to enable optimum positional determination.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a new system and method for enabling a wireless computing device to determine its position using a wireless and/or satellite-based positioning system irrespective of the reception of positioning signals therefrom by the computing device.
It is yet another object of the present invention to provide a new system and method for geographically locating wireless computing devices using signals broadcast by wireless beacons.
It is still another object of the present invention to provide a new system and method for passively building a database of wireless beacons by means of wireless computing devices equipped with positioning systems and disseminating the database to other computing devices.
Still another object of the present invention is to provide a new system and method ascertaining the geographical locations of wireless computing devices based on a database of wireless beacons and a system and method for creating the database of wireless beacons.
In order to achieve one of the above objects and others, a system for enabling a wireless computing device to continuously determine its position in accordance with the invention includes a wireless computing device and a wireless positioning system substantially collocated therewith. The wireless positioning system has a first positioning mode in which it communicates with a wireless positioning network to enable the geographic location of the wireless computing device to be determined upon reception of signals from the wireless positioning network and a second positioning mode in which it enables the geographic location of the wireless computing device to be determined upon reception of signals from one or more of the wireless beacons and analysis of the signals in light of positional information about wireless beacons contained in a database. The wireless positioning system switches between the first and second positioning modes to obtain a determination of its geographic location depending on reception of signals from the wireless positioning network. Since the locational information in the first positioning mode, i.e., that from the wireless positioning network, is more accurate, when such information is available it is used and when unavailable, a database-derived location is provided. The switch may be implemented as a software-switch.
In the second positioning mode, the wireless beacons provide identification information which is associated with data about the strength of a signal therefrom and received by the wireless computing device. This identification and signal strength data is input into a calculation algorithm which determines the geographic location of the wireless computing device therefrom, the identification information being used to obtain positional information about the wireless beacons which is contained in the database.
To create the database, particularly constructed wireless computing devices are used. Specifically, the wireless computing devices is provided with a scanner arranged to communicate with the wireless positioning network to enable its geographic location to be determined upon reception of signals from the wireless positioning network, for example, coupled to a GPS device. The scanner then obtains positional information about itself and identification and signal strength information about wireless beacons in order to derive the geographic location of the wireless beacons for inclusion in the database, using a calculation algorithm. In particular, software in the scanner analyzes the strength of signals received from the wireless beacons at a plurality of different positions of the scanner and applies an algorithm to determine the position of the wireless beacons therefrom.
A method for enabling a wireless computing device to continuously determine its position in accordance with the invention involves coupling the wireless computing device to a wireless positioning network to enable the geographic location of the wireless computing device to be determined upon reception of signals from the wireless positioning network, providing a database of identification and positional information about wireless beacons and enabling the geographic position of the wireless computing device to be continuously determined by obtaining a position signal derived from the signals from the wireless positioning network upon reception thereof and in the absence of reception of usable signals from the wireless positioning network, deriving a position signal from reception of signals from wireless beacons detected by the wireless computing device and analysis of the received signals using the database. The database is constructed by obtaining identification and signal strength data about each wireless beacon at a plurality of locations at which a signal from that wireless beacon is being received and applying an algorithm to determine positional information about the wireless beacons based on the signal strength data.
A method for administering a database of wireless beacons in accordance with the invention entails maintaining a central database of wireless beacons, providing the central database to a plurality of wireless computing devices, enabling each wireless computing device to determine identification and positional information about wireless beacons not contained in the central database, periodically forwarding the identification and positional information about wireless beacons not contained in the central database from the wireless computing devices to the central database, updating the central database to include the forwarded identification and positional information, and periodically directing the updates of the central database to the plurality of wireless computing devices. Each wireless computing device can be designed to determine identification and positional information about wireless beacons as described above with respect to use of the scanner.
A related embodiment of the invention is a system for enabling a wireless computing device to continuously determine its position in which a central database is provided containing identification and positional information about wireless beacons and receives identification and positional information about wireless beacons not previously contained therein and generates database updates based thereon. Wireless computing devices each include a local database containing positional information about wireless beacons and wirelessly communicate with the central database to receive the database updates and add the database updates to the local database. A wireless positioning system is substantially collocated with each wireless computing device and enable the geographic location of the wireless computing device to be determined upon reception of signals from at least one wireless beacon and analysis of the signals in light of the positional information about wireless beacons contained in the local database. This location determination can be performed in any of the ways described above.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals identify like elements, and wherein:
FIG. 1 is a schematic of a general concept used in the invention for enabling position of a wireless computing device to be determined.
FIG. 2 is a schematic showing a scanner used to create a database of wireless beacons in accordance with the invention.
FIG. 3 is an illustration of multiple scanner readings obtained to create the database of wireless beacons.
FIG. 4 is a flowchart showing the mapping of wireless beacons from the scanner readings.
FIG. 5 is a flowchart showing the determination of the position of a computing device based on instantaneously received signals from wireless beacons and the database thereof.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 1 , to provide a system and method for enabling a wireless computing device to determine its position using a wireless and/or satellite-based positioning system irrespective of the reception of positioning signals therefrom by the computing device, each computing device 10 is coupled to a wireless or satellite-based positioning systems such as a GPS device 12 such that the computing device 10 and GPS device 12 are effectively collocated. Using positional data provided by the GPS device 12 and data about wireless beacons, Wi-Fi access points, cell phone towers or other comparable systems (hereinafter referred to as beacons) within reception range of the computing device 10 , the computing device 10 creates a database of wireless beacons within a wireless positioning system 14 including the geographic location of each beacon (the exact manner in which such a database is formed is described below).
A software switch 16 is interposed between the GPS device 12 and the computing device 10 to vary the manner in which a determination by the computing device 10 of its position is made. Specifically, when the GPS device 12 receives an accurate positioning signal, switch 16 would allow this GPS signal to be directed to the computing device 10 so that the computing device would consider its position that determined by the GPS signal. On the other hand, when the GPS device 12 is unable to provide an accurate GPS signal, switch 16 would allow a positioning signal derived from the wireless positioning system 14 , and based on input from the computing device 10 at that time, to be directed to the computing device 10 and the computing device 10 would consider its position that indicated by this positioning signal.
Switch 16 would operate to revert back to allowing a GPS signal from GPS device 12 to be directed to computing device 10 once GPS device 12 provides an accurate GPS signal. Accuracy of the GPs signal can be made in a manner known to those skilled in the art.
Accordingly, the computing device 10 would be able to continuously know its position even in the absence of an accurate GPS signal. The computing device 10 could be designed to indicate the source of its positioning signal, e.g., an icon on a screen thereof could indicate either a satellite-derived signal (a signal from GPS device 12 ) or a database-derived signal (a positioning signal from wireless positioning system 14 ).
Although represented as separate elements in FIG. 1 , this is for the purposes of explanation only and it should be understood that computing device 10 can include wireless positioning system 14 and switch 16 can be software implemented in the computing device 10 . Moreover, GPS device 12 can also be incorporated into the computing device 10 so that a single hand-held or portable unit could include the entire system in accordance with this embodiment of the invention.
The database of wireless beacons in wireless positioning system 14 can be considered a map which associates the fixed physical location of each wireless beacon, i.e., where they are geographically located, with a unique or semi-unique identification code of each wireless beacon. The location of each beacon can be expressed, for example, by latitude and longitude, or possibly by another coordinate system.
Construction of such a map may be accomplished in a variety of ways, the simplest but most labor intensive being to place a positioning device, e.g., a GPS device, at the same location of each wireless beacon to thereby obtain the physical location of the wireless beacon from the GPS device. This however is highly impractical in view of the constant addition of wireless beacons and the manpower that would be required.
A preferred and far simpler method would be to collect data about each wireless beacon based on information about the strength of a signal provided by each wireless beacon at a plurality of locations at which a signal from that wireless beacon is being received. Basically, the geographic location of each wireless beacon is determined based on analysis of the signal strength provided by that wireless beacon as a function of geographic location.
To enable such an analysis, a scanner 18 is equipped or collocated with a GPS device 20 and during movement of the scanner 18 , a series of readings consisting of the position of the scanner 18 , obtained using the GPS device 20 , and the strength of the signal received at this position are obtained from a wireless beacon (see FIG. 2 ). The scanner 18 may be a hand-held computing device such as a PDA or cell phone including a processor having software 22 designed to analyze the signal received via an antenna 24 from every single beacon at different positions and estimate a geographic location thereof. A series of readings for each beacon will be stored in a database 26 . Thus, if multiple beacons are being mapped, there will be multiple series of readings.
Referring to FIG. 3 , these readings will look like a series of data sets designated (Xi, Yi, Si) where Xi and Yi are the latitude and longitude, respectively, of the position of the scanner 18 and Si is the strength of a signal received at this position from wireless beacon 28 . With the scanner 18 at position P 1 , a reading of (X 1 ,Y 1 ,S 1 ) is obtained, with the scanner 18 at position P 2 , a reading of (X 2 ,Y 2 ,S 2 ) is obtained and with the scanner 18 at position P 3 , a reading of (X 3 ,Y 3 ,S 3 ) is obtained.
Each series of readings, i.e., the readings obtained from each individual beacon 28 , recorded by the scanner 18 may be stored in the scanner's memory. To obtain an estimated position of each beacon, the series of readings relating only to that beacon is input to a calculation algorithm 30 that processes the readings to provide as output, an estimated position of the beacon 28 (see FIG. 4 ). If multiple series of readings are input to the algorithm, then the position of all of the beacons 28 from which readings were obtained will be output.
Note that at each position of the scanner 18 , multiple readings can be obtained, one for each beacon 28 in reception range of the scanner 18 . These readings can be stored with an identification of the beacon 28 so that the readings can later be combined with other readings from the same beacon 28 in order to determine the location of the beacon 28 .
Different calculation algorithms 30 can be used in the invention to process each series of readings into the position of the beacon 28 . These include Centroid, triangulation, Newton and the like. An exemplifying calculation algorithm 30 , namely the Centroid algorithm, is described below. Generally, regardless of which algorithm 30 is used, approximately the same estimated position of the beacon 28 will be obtained and thus, the invention is not limited to use of any particular algorithm.
It is important to bear in mind that scanner 18 can be and typically is the same as computing device 10 (in which case, GPS device 20 is the same as GPS device 12 , the software 22 and database 26 would be part of the wireless positioning system 14 and antenna 24 would be part of the wireless computing device 10 ). This embodiment will be considered hereinafter. In this case, computing device 10 would not only create and/or update the database 26 of wireless beacons in the wireless positioning system 14 via operation of the scanning software 22 (when GPS signals from GPS device 12 , 20 are available) but would also use the same database 26 of wireless beacons it is updating to determine its position in the absence of an accurate GPS signal from the GPS device 12 , 20 (when GPS signals from GPS device 12 , 20 are not available). Thus, when GPS signals are available and switch 16 is allowing the GPS signal from the GPS device 12 , 20 to be directed to the computing device 10 , computing device 10 is working as scanner 18 to scan the area around the computing device 10 to determine the presence of (unmapped) wireless beacons and obtain geographic positional information about these unmapped wireless beacons for inclusion in the database 26 of wireless beacons resident in the wireless positioning system 14 .
After the estimated position of the beacons is obtained, the final step in creating the database 26 of wireless beacons in wireless positioning system 14 is to store the positions of the beacons 28 in a database in a manner in which the position of the beacon is associated with an identification code. For example, the position of each beacon 28 can be stored in the database 26 in the form (Id, X, Y) where Id is a unique identification associated with or referencing the beacon 28 and X, Y are the latitude and longitude coordinates, respectively, of the beacon 28 as determined in the manner described above.
The database creation step continues whenever a GPS signal is available and the position of the scanner 18 has changed. Thus, when the scanner 18 is the same as computing device 10 , movement of the computing device 10 in the presence of a GPS signal from GPS device 12 , 20 can results in continuous updating of the database 26 of wireless beacons in wireless positioning system 14 .
In the exemplifying use described above with respect to FIG. 1 , the database 26 of wireless beacons in wireless positioning system 14 is used only when a GPS signal from GPS device 12 , 20 is unavailable. At this time, it is necessary to input data into the database 26 to determine the position of the computing device 10 .
With reference to FIG. 5 , determining the position of the computing device 10 using the database 26 of wireless beacons in wireless positioning system 14 entails querying a receiver unit of the computing device 10 , i.e., a network adapter or cell antenna 24 , to find out which wireless beacon(s) 28 are “visible” and what is the strength of the signal received by the receiver from each wireless beacon 28 . Visible beacons 28 are those from which the receiver receives a signal.
From the antenna 24 , the computing device 10 will obtain a series of readings each containing the unique identification associated with or referencing one of visible wireless beacons 28 and the strength of the signal from that wireless beacon 28 . This series of readings can be expressed in the form of (Id, Si) where Id is the unique identification of the wireless beacon 28 and Si is the signal strength.
The computing device 10 then submits this information to database 26 in wireless positioning system 14 which contains the geographic location of the wireless beacons 28 in association with their identification. Using the data contained in the database 26 , the corresponding, estimated geographic location of the wireless beacon 28 is obtained based on its identification contained in the information and is associated with the signal strength.
After the location of the visible beacon(s) 28 associated with the antenna 24 is known, a series of (Xi, Yi, Si) records is provided to the calculation algorithm 30 to estimate the position of the antenna 24 , i.e., the position of the computing device 10 .
As described above, a calculation algorithm 30 is used to determine the position of a wireless beacon 28 when creating the database 26 of wireless beacons and also to determine the position of the computing device 10 in the absence of a GPS signal from GPS device 12 , 20 .
When determining the position of a wireless beacon 28 in the mapping mode from the series of readings (Xi,Yi,Si) to determine the position (X,Y) of the wireless beacon 28 , the Centroid calculating algorithm averages the latitudes and longitudes recorded and adds the signal strength squared as a weight:
X =( S 1 2 *X 1 +S 2 2 *X 2 + . . . +Sn 2 *X 2)/( S 1 2 +S 12 2 + . . . +Sn 2 )
Y =( S 1 2 *Y 1 +S 2 2 *Y 2 + . . . +Sn 2 *Y 2)/( S 1 2 +S 12 2 +. . . +Sn 2 )
where X and Y are the estimated position of the beacon 28 and the Si, Xi, Yi the information recorded by the scanner 18 .
When estimating the position of the computing device 10 using the same formula, Xi, Yi would be the coordinates of the wireless beacons 28 referenced in the database 26 and Si would be the strength of the signal received from those same wireless beacons 28 .
Applying the database mapping technique described above using scanner 18 , when incorporated into the wireless computing device 10 with a common GPS device 12 , it becomes possible to create a collaborative database. That is, a database which is continually being updated with data about new wireless beacons can be formed. Scanner 18 obtains identification and signal strength data about new, unmapped wireless beacons when the GPS device 12 receives accurate positioning signals and determines the position of the unmapped wireless beacons for inclusion in the database of wireless beacons in the wireless positioning system 14 which is used when accurate GPS signals from GPS device are not available. The same positional information about previously unmapped wireless beacons being directed to the database in the wireless positioning system 14 can also be directed to a central monitoring or administration facility which is charged with the responsibility for providing an accurate database of wireless beacons. The positional information can be forwarded to this facility periodically, such as every 24 hours. In conjunction with an upload of positional information about new wireless beacons, positional information about new wireless beacons obtained from other wireless computing devices 10 can be downloaded from the facility.
The central facility thereby oversees collection of individual contributions to the database, one from each participating (collective) wireless computing device, and disseminates the collection of the individual contributions to all wireless computing devices using the same positioning technique. It must be understood that not all wireless computing devices 10 will be equipped with a scanner 18 in which case, only some wireless computing devices would contribute positional information to the central facility but all wireless computing devices would preferably receive the update of positional information. Since the uploading of the positional information from the wireless computing devices to the central facility and downloading of the positional information from the central facility to the wireless computing devices may be done without involvement of the user, the central and individual databases of wireless beacons can therefore be passively created, updated and disseminated.
While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. | System and method for enabling a wireless computing device to continuously determine its position includes a wireless computing device and a wireless positioning system substantially collocated therewith. The wireless positioning system has a first positioning mode in which it communicates with a wireless positioning network to enable the geographic location of the computing device to be determined upon reception of signals from the positioning network and a second positioning mode in which it enables the geographic location of the wireless computing device to be determined upon reception of signals from one or more of the wireless beacons and analysis of the signals in light of positional information about wireless beacons contained in a database. The wireless positioning system switches between the positioning modes depending on reception of signals from the wireless positioning network. | 6 |
FIELD OF THE INVENTION
The present invention relates to a valve, especially a proportional seat valve or gate valve, having a valve housing and at least three fluid ports extending through the valve housing. A main piston is guided in the valve housing. A pilot valve effects pilot control and can be actuated by a magnet means which can carry current.
BACKGROUND OF THE INVENTION
A generic valve is known from EP-A-0 893 607. This known valve is a magnetically operated drain valve in which, between a load pressure port (P) and a drain port (T) in the lifting module of a forklift, a seat closing element is assigned to the main valve seat and in the closing direction can be pressurized to a variable difference between the drain pressure and the control pressure derived from the load pressure. A pilot valve can be actuated by a magnet means provided with a pilot piston for the control pressure. The main valve formed by the main valve seat and the seat closing element is assigned a pressure compensator with a seat valve sealing function. With the main valve, the seat valve forms a two-way flow regulator independent of the load pressure and leak-proof under the load pressure in the closing position of the main valve.
This known approach discloses a structurally simple, magnetically operated drain valve of compact size, with which it is possible to implement a ramp function independently of the load pressure. A ramp function is defined as the possibility of controlling the flow amount depending on lift and independently of pressure. However, the known solution for lowering the load in hydraulic lifting devices does not meet the high demands as desired, specifically achieving a high no-load lowering speed with little leakage and a precise metering of this lowering speed.
Control devices for hydraulically operating lifting means are commercially available, and use directly controlled valves not suitable for high volumetric flow due to the design, so that in general pilot-controlled valves are preferred. In barometrically pilot-controlled valves, an independent pressure supply making available the required pressure for adjusting the main piston is necessary. This pressure is generally 10 to 20 bars, and is often produced by an external supply, for example, the feed pump of the traveling mechanism, in a forklift with an internal combustion engine. In lifts with an electric drive, there is no external supply so that the required control pressure can only be taken from the load pressure. When lowering at no load, the available control pressure can then drop to approximately 2 bars with the result that in no-load lowering the lowering process is hampered.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved valve which at low cost permits a high no-load lowering speed with few components in a reliable manner and allows precise metering of the lowering speed with simultaneously little leakage.
This object is basically achieved by a valve in which the pilot control opened, fluid travels from one of the two ports which can be actuated by the main piston by a cross-sectional constriction in the main piston and the pilot control to the third port. The third port can be actuated by the pilot piston. As a result of the accompanying pressure drop, the main piston travels into a respective control position which can actuate the two fluid ports with respect to the amount of fluid. A pilot-controlled proportional seat valve or gate valve is formed which at a very low pilot pressure, for example, <2 bars, already completely opens and thus permits prompt no-load lowering.
If current is supplied to the magnet means to open the pilot control, the main piston is pushed up. The piston lift of the main piston is proportional to the magnet current. Since the position of the main piston always corresponds to the force of the magnet, a valve can be configured permitting precise metering of the lowering speed with simultaneously low leakage for the valve.
In one preferred embodiment of the valve of the present invention, a compression spring is configured between the main piston and the pilot piston. The piston lift of the main piston with the pilot control opened is proportional to the magnet current of the magnet means. The compression spring acting on the main piston reports the position of the main piston back to the pilot piston and consequently to the pilot control so that any disturbing variables, caused by flow forces, for example, can be directly adjusted. The position of the main piston then corresponds to the applied magnet force. When no current is being supplied to the magnet means, flow through the valve is possible due to the compression springs of the two ports with the capacity to be controlled by the main piston as a spring-loaded return valve.
Preferably, the compression spring engages a recess of the main piston into which the cross-sectional constriction in the form of an orifice discharges. On the free end of the compression spring facing the pilot piston, a contact piece is connected to the free end of the pilot piston by a contact ball. The contact ball permits unhampered operation and interaction of the pilot piston with the main piston.
In another embodiment of the valve of the present invention, preferably a selector valve is in the main piston. The selector valve preferably has a cross-sectional constriction. In this version, in the absence of current, the valve can be blocked from one pressure port to another. The ports can be actuated by the main piston. When current is supplied to the magnet means under the corresponding pressure conditions, a volumetric flow between the fluid ports can then be controlled. In one alternative embodiment, the cross-sectional constriction (choke or orifice) can also be located in a fluid-carrying channel downstream from the selector valve in the direction of the interior of the main piston.
In another preferred embodiment of the valve of the present invention, the magnet means has at least one armature, a coil and a pole tube designed as part of a pushing or pulling system. The armature is moved out of or into the pole tube when the coil is supplied with current. When using a pulling system, another compression spring moves the pilot piston in the direction of an opened pilot control. If the “pulling” pole tube is equipped with the additional compression spring keeping the pilot piston in the open position, which corresponds to the fully energized state for the “pushing” pole tube, by switching the magnet means the pilot control and thus the valve can be completely closed. By replacing a “pushing” pole tube with a “pulling” pole tube, a valve which is open without current can therefore be formed from a proportional seat valve which is closed without current. If a pilot spring applies an adjustment force to the pilot piston, this is not absolutely necessary with respect to the operating property of the magnet system. However, it improves the return of the pilot piston and thus the operating dynamics for the entire valve.
In another preferred embodiment of the valve of the present invention, the pilot control is designed as a gate valve in which a pilot piston of cylindrical design at least on its free end is guided to be movable in the longitudinal direction into a corresponding elongated recess in parts of the valve housing. In this way, uniform operating behavior is achieved even under the most varied operating conditions. By maintaining a sufficiently small sealing gap on the pilot piston, the desired forklift tightness can be guaranteed.
In a different embodiment of the valve of the present invention, preferably the pilot control is designed as a seat valve in which, on the free end of the pilot piston, a preferably cone-like closing and sealing part interacts with a seat part formed by parts of the valve housing. In this version, as a seat valve the pilot control is free of leaks. The disadvantage of this version is that the pilot piston is no longer optimally pressure-equalized and is also subject to friction by the seal in its motion. If the pilot control is designed as a valve without a seal, the valve is no longer free of leaks, but inhibitory friction in operation may then be largely precluded. This arrangement ensures that the valve performs its choke function. Preferably, to enhance the sealing on the outside circumference of the pilot piston, additional sealing parts may be provided.
The described valve is especially well-suited for all applications in which a large volumetric flow must be controlled with a low control pressure. This need is often the case in the implementation of the lowering function in electric forklifts.
The proportional seat valve can generally be used as a proportional choke valve for very large volumetric flows. To keep Δ p small at high volumetric flows, it may be necessary to enlarge the seat diameter in the valve body. The necessary control pressure for complete opening of the valve thus in fact increases. However, it is always notably less than that of the known barometrically actuated valves.
In one preferred embodiment, the valve of the present invention in a valve system serves the function of an adjustable metering orifice of a flow regulator in conjunction with a pressure compensator. In this configuration, the flow amount can be controlled depending on the lift and independently of the pressure (ramp function). During lowering, the volumetric flow to be managed can be limited in terms of its maximum, serving to enhance reliability.
Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings which form a part of this disclosure and which are diagrammatic and not drawn to scale:
The valve design as claimed in the present invention is detailed below in the drawings in which in diagrammatic form, not drawn to scale,
FIG. 1 is a side elevational view in section of a proportional seat valve according to a first exemplary embodiment of the present invention, with a graphic representation of the valve shown at top left thereof;
FIG. 2 is a side elevational view in section of a proportional seat valve according to a second exemplary embodiment of the present invention, with a graphic representation of the valve shown at top left thereof;
FIG. 3 is an operating diagram that shows the use of the valve of FIG. 1 for a load lowering of forklift units with a maximum volumetric flow limitation and with load compensation; and
FIG. 4 is an enlarged side elevational view in section through the lower part of a proportional gate valve according to a third exemplary embodiment of the present invention with graphic representation of the valve at top left thereof.
DETAILED DESCRIPTION OF THE INVENTION
The valve shown in FIG. 1 in a longitudinal section is a proportional seat value with a valve housing 10 . The housing has seals and seal stacks on the outer circumferential side, and is designed as a screw-in cartridge for fixing the valve on other machines or vehicle parts for purposes of controlling a hydraulic circuit (not shown). Furthermore, the valve can also be designed as a kit. The valve housing 10 has three fluid ports 1 , 2 , 3 . One fluid port 1 is on the front engaging on the lower end of the valve housing 10 . The other two ports 2 and 3 are configured radially on the valve housing 10 on the outer circumferential side. The fluid port 2 is at two different points 2 a , 2 b extending radially through the valve housing 10 . The third fluid port 3 discharges by way of transverse holes 12 into the interior of the valve housing 10 having in this area a valve insert 10 a made with a screw-in bevel 14 . In the valve housing 10 , a main piston 18 can move axially along the longitudinal axis 16 of the valve and, on its free end and adjacently opposite the fluid port 2 a mates with a seat valve 20 on wall parts of the valve housing. For this purpose, the main piston 18 on its free end is provided with a conically extending valve surface 22 . Next to the main piston 18 within the valve housing 10 , a pilot piston 24 is guided in the longitudinal direction so as to be movable and is part of a pilot control 26 .
As viewed in FIG. 1 , the valve housing 10 on its top end has a magnet means or electromagnet 28 which can carry current. Attachment plugs 30 connect the magnet to an electrical power source to supply current to a coil winding 32 . Coil winding 32 comprises an armature 34 mounted to move in the longitudinal direction within a profiled tube 36 and used to actuate the pilot control 26 , especially in the form of a pilot piston 24 . This structure of a magnet means 28 is relatively well known in the prior art so that it is not described in detail.
According to the operating diagram as shown in FIG. 1 , the main piston 18 is in its closed position, i.e., the seat valve 20 is blocking the fluid path between the fluid ports 1 and 2 a . A cross-sectional constriction 38 located radially on the outer circumference of the main piston 18 , preferably in the form of an orifice, discharges into a radial recess 40 of the main piston 18 . Radial recess 40 extends between the fluid port 2 b and a radial projection 42 of the main piston 18 separating the fluid port 2 a from the radial recess 40 . The main piston 18 is provided with a recess 44 into which the orifice 38 discharges. Within this recess 44 extending in the direction of the longitudinal axis 16 , there is a compression spring 46 with its one free end in contact with the bottom of the recess 44 and with its other free end acting on a contact piece 48 movably mounted in the valve housing and biased against pilot piston 24 by compression spring 46 . The opposite free end of the contact piece 48 bears a contact ball 50 in a corresponding depression or recess that extends only partially and not through the contact piece, on the top of which the contact ball free end of the pilot piston 24 is supported. In this way, unhampered operation and actuation between the pilot piston 24 and the main piston 18 is achieved, even in the event of possible tilting processes which can be equalized by the contact ball 50 .
In the FIG. 1 embodiment as viewed therein in terms of its operation in a conventional operating diagram at top left, the fluid ports 1 , 2 , and 3 correspond to the ports as shown in the valve cross section. The pilot control 26 is designed as a gate valve in which the cylindrically configured pilot piston 24 at least on its free end is guided to be movable in the longitudinal direction in a corresponding longitudinal recess 52 which is circular in transverse cross section in parts of the valve housing 10 in the form of a valve insert 10 a . The pilot piston 24 on its outer circumferential side is conventionally enclosed by pressure relief grooves which at least partially ensure leak-tightness in this area of the pilot control 26 . Between the underside of the valve insert 10 a and the upper terminating end of the main piston 18 forming its back 54 , the inner circumferential side of the valve housing 10 borders the control chamber 56 into which longitudinal channels 58 , 60 of the valve insert 10 a discharge. One longitudinal channel 58 at its other or upper end discharges into an annular recess 62 of the pilot piston 24 . The other longitudinal channel 60 with its other or upper free end discharges into an annular chamber 64 in which another compression spring 66 is supported. The lower spring end is on the inner circumference of the valve insert 10 a , the other or upper spring end being on the radial widening 68 of the pilot piston 24 . In the illustrated operating diagram of FIG. 1 , the radial widening 68 is supported with its outer flange on the front end of the magnet housing 70 inserted at this point in the valve insert 10 a by a screw-in section. A radial annular channel 72 discharges into a radial chamber 74 between the inner circumferential side of the top end of the valve housing 10 and the outer circumferential side of the valve insert 10 a in this area. In turn, the fluid port 3 (holes 12 ) discharges into this radial chamber 74 . On the opposite end in the illustrated operating position shown in FIG. 1 , the annular channel 72 is closed by the outside circumference of the pilot piston 24 . The actuated pilot piston 24 is pressed down by the magnet means 28 when viewed in the direction of FIG. 1 , capable of establishing a fluid-carrying connection between the control chamber 56 , the longitudinal channel 58 , the annular recess 62 , the annular channel 72 , the radial chamber 74 , and the fluid port 3 by way of channel-shaped transverse holes 12 .
For the sake of better understanding, at this point the proportional seat valve shown in FIG. 1 , specifically intended for use in hydraulically operating lifting means, will be described in detail using a working example. If the magnet means 28 is supplied with current by the attachment plug 30 , the armature 34 under the action of the field of the coil winding 32 migrates out of the pole tube 36 , and in the process actuates the pilot piston 24 of the pilot control 26 against the action of the other compression spring 66 . The reset force of spring has the tendency to keep or bias the radial widening 68 in contact with the lower end of the magnet housing 70 . The magnet force is sufficient to open the pilot control 26 against the action of the other compression spring 66 , with the pilot oil flowing from the load port 2 by the respective connecting point 2 b into the radial recess 40 of the main piston 18 . From there, the pilot oil flows through the cross-sectional constriction 38 (orifice) into the recess 44 of the main piston 18 in which the compression spring 46 is mounted. From there the pilot oil flows into the control chamber 56 and then by the longitudinal channel 58 and the annular recess 62 in the pilot piston 24 into the annular channel 72 . From channel 72 the pilot end flows by the radial chamber 74 and the oblique holes 12 to the fluid port 3 . In the process the pressure drops on the rear 54 of the main piston 18 and by the load pressure acting on the annular surface between the outside piston diameter and the valve seat diameter of the main piston 18 at the location of its seat valve 20 , the main piston is pushed up against the action of the compression spring 46 , as viewed in FIG. 1 . This piston lift of the main piston 18 is proportional to the magnetic current. The compression spring 46 located in the main piston 18 reports the position of the main piston 18 back to the pilot piston 24 so that disturbing variables, such as, for example, the flow forces, can be adjusted in this way. The position of the main piston 18 thus always corresponds to the magnetic force of the magnet means 28 in the current-carrying state. Without current, the main piston 18 assumes its position shown in FIG. 1 , and in this position as a result of the compression spring 46 the valve acts like a spring-loaded return valve 76 relative to the control of possible fluid flow between the fluid ports 1 and 2 .
With this configuration, a pilot-controlled proportional seat valve is implemented which at a very low pilot pressure, for example, <2 bars already completely opens. This operation permits rapid no-load lowering so that its use is of interest especially in electrically operated forklifts which do not have an external supply necessary to ensure the required pressure for setting the main piston in barometrically pilot-controlled valves, as they are known in the prior art.
The pilot spring in the form of the other compression spring 66 is not absolutely necessary, but, as already described, it improves the return of the pilot piston 24 and the dynamics of the valve as a whole. The pilot control 26 in FIG. 1 is designed as a gate valve, the best solution for uniform operating behavior under different operating conditions. This solution is accompanied by the disadvantage that the valve shown in FIG. 1 consequently is subject to leakage. By maintaining a sufficiently small sealing gap on the pilot piston 24 , the desired forklift tightness can be ensured.
The pole tube 26 used in FIG. 1 is designed as a pushing system in which the armature 34 emerges from the pole tube 36 when the coil winding 32 is supplied with current. In “pulling” systems, that is in a “pulling” pole tube, the armature 34 moves into the pole tube 36 . If the “pulling” pole tube is equipped with a compression spring (not shown) biasing the pilot piston 24 towards the open position corresponding to the state of full current supply for the pushing pole tube 36 , by switching the magnet means 28 the pilot control 26 and thus the valve can be completely closed. By replacing a “pushing” pole tube 36 by a “pulling” pole tube, a valve which is open without current can thus easily be configured from a proportional seat valve which is closed without current, if the requirements of practical application make this necessary.
FIG. 3 shows one example of an application of the proportional seat valve shown of FIG. 1 for a hydraulically operating lifting means 78 . The hydraulic lifting means 78 has a load fork 80 of conventional design which can be raised and lowered by an actuator cylinder 82 . For the sake of clarity of illustration, the behavior of the lifting frame of the lifting means 78 is shown here as a choke 84 in terms of its hydraulic behavior. Moreover, the piston side of the actuator cylinder 82 can be connected to the tank T by the connecting line 86 . The symbolically shown pressure gauges with designations P H , P 2 , P 1 , and P T within the scope of a test set-up would permit tapping of pressure valves in individual travel positions of the lifting means 78 within the connecting line 86 . As FIG. 3 furthermore shows, a known pressure compensator 90 with a choke function is connected to the connecting line 86 , and is controlled by the prevailing pressure in the connecting line 86 by the connecting point 92 . In this way, as shown in FIG. 3 , a valve system is implemented with a valve as shown in FIG. 1 and the known pressure compensator 90 . An adjustable metering orifice of a flow regulator is implemented. The proportional seat valve shown in FIG. 1 can be used in this way as a proportional choke valve for very large volumetric flows. With the illustrated valve system shown in FIG. 3 , the maximum volumetric flow can be limited when the load fork 80 is being lowered (with or without a load). This arrangement benefits reliability during operation of the lifting means. In particular, with this solution at a low control pressure a large volumetric flow can be controlled.
The second embodiment shown in FIG. 2 constitutes a version of the embodiment shown in FIG. 1 , and accordingly is only explained to the extent it differs significantly from the embodiment in FIG. 1 . In this respect, the same reference numbers as in FIG. 1 are used for the same parts. What has been stated previously also applies in this respect to the modified embodiment shown in FIG. 2 .
In the embodiment as shown in FIG. 2 , on the lower front end of the main piston 18 there is a selector valve 95 . The selector valve 95 has a cross-sectional constriction. The orifice function is present twice in two throughflow directions from 1 to 2 and vice versa relative to the fluid ports. The selector valve 95 has a valve ball 98 which can be moved in a transverse channel 96 and which, depending on the incident fluid flow direction from the fluid port 1 to 2 or vice versa, on the one hand blocks the fluid connection point of one selector valve insert 95 a and of the other selector valve insert 95 b with their respective cross-sectional constrictions 38 . The transverse channel 96 in the longitudinal direction of the valve has a longitudinal channel 100 which discharges into the recess 44 in the main piston 18 with the compression spring 46 . In the embodiment shown in FIG. 2 , the pilot control 26 is designed as a seat valve with a seal. For this purpose, the pilot piston 24 on its bottom free end has a cone-shaped closing and sealing part 102 interacting with the seat part 104 on the bottom end of the valve insert 10 a . Instead of the longitudinal channel 58 , the modified solution shown in FIG. 2 in the pilot piston 24 has transverse channels 106 connected to one another to carry fluid by a central longitudinal channel 108 . In this way, with the pilot control 26 opened, the fluid flow from the fluid port 2 to the fluid port 3 is ensured. Furthermore, the pilot piston 24 on the outer circumferential side has a sealing system 110 within the annular chamber 64 . In the illustrated version shown in FIG. 2 , the pilot control 26 is free of leaks. The pilot piston 24 no longer is optimally pressure-equalized, but rather is also made subject to friction by the sealing system 110 . If the seal are omitted, the disadvantage of friction would not arise. However, this valve would then no longer be free of leaks.
With the valves shown in FIGS. 1 and 2 , high no-load lowering speeds can be achieved in hydraulic lifting means with simultaneously precise metering of the lowering speed and with little leakage.
FIG. 4 relates to another modified valve embodiment compared to the illustrated versions in FIGS. 1 and 2 . FIG. 4 relates to the lower valve part designed as a gate valve, especially a proportional gate valve. Instead of the previously described conical valve seat 20 , the free end of the main piston 18 is made cylindrical, and is guided in a cylindrical inner circumferential surface of the lower end of the valve housing 10 . With the main piston 18 raised, in this way the fluid-carrying choked connection between the valve port 2 a and the free fluid entry side is established by the fluid-carrying part 112 on the front end of the valve housing 10 . The corresponding operating diagram is shown at top left of FIG. 4 . The pilot control for this valve version is designed as a gate valve is executed accordingly, as described in the foregoing for the valve versions as shown in FIGS. 1 and 2 .
While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims. | A valve, in particular, a proportional seat valve or gate valve, includes a valve housing ( 10 ) and at least three fluid connections ( 1, 2, 3 ) extending through the valve housing. A main piston ( 18 ) extends in the valve housing ( 10 ). A pilot piston ( 24 ) for executing a pilot control ( 26 ) may be controlled by a current-carrying magnetic device ( 28 ). During an open pilot control ( 26 ), fluid from one ( 2 ) of the connectors ( 1, 2 ), controlled by the main piston ( 18 ), reaches the connector ( 3 ), controlled by the pilot piston ( 24 ), by a cross-sectional narrowing ( 38 ) in the main piston ( 19 ). The pilot control ( 26 ) and, as a result of the corresponding pressure drop, the main piston ( 18 ) achieves a control position, controlling both fluid connections ( 1, 2 ) with regard to fluid amount. | 5 |
This is a continuation of application Ser. No. 458,602, filed Jan. 17, 1983, now abandoned.
This invention relates as indicated to substituted 2,5-dimethylpyrroles and more particularly to a process for the preparation of such compounds.
BACKGROUND OF THE INVENTION
The substituted pyrroles of this invention are useful as intermediates in the syntheses of polymer additives which in turn are effective to protect various polymers from deterioration caused by exposure to ultraviolet light. The substituted pyrroles of the invention can be reacted with acetylene dicarboxylic acid, in a Diels-Alder reaction, for example, to form a much larger, less volatile compound which is effective to inhibit the deterioration of polypropylene upon exposure to ultraviolet light. This Diels-Alder product, containing an olefinic double bond, may be hydrogenated to yield a product which is an even more effective ultraviolet light stabilizer. Other active dienophiles may of course also be used for this purpose and illustrative examples include dialkyl maleates, alkyl acrylates and methacrylates, diethyl acetylene dicarboxylate, propargyl alcohol and butynediol.
The effectiveness of these Diels-Alder reaction products as light stabilizers is believed to be due to the hindered amide group.
Also, the acyl and phosphoryl groups may be removed (by hydrolysis) from these Diels-Alder condensation products and the resulting hindered amines likewise are effective ultraviolet light stabilizers in polymer compositions.
While a wide variety of polymers are benefitted by the protective action of these Diels-Alder products, olefin polymers are especially benefitted. Polypropylene, in particular, is susceptible to stabilization by the addition of a small proportion of such an additive.
The condensation of gamma-diketones such as hexane-2,5-dione, i.e., acetonylacetone, with primary amines to form pyrroles, is shown at page 77 of "The Chemistry of Pyrroles" by Jones et al., Academic Press (1977). The reaction is referred to as the Paal-Knorr condensation. It appears that the condensation reactions were carried out in aqueous systems because there is a considerable discussion about the optimum pH at which the reaction may be carried out. Moreover, it is stated that 2,5-dimethylpyrrole may be prepared from the reaction of hexane-2,5-dione and formamide; such a result was obtained in an aqueous environment.
SUMMARY OF THE INVENTION
The invention here is a substituted 2,5-dimethylpyrrole having the molecular structure ##STR1## where R is alkyl or aralkyl and contains 1-19 carbon atoms, A is carbon or phosphorus, n is 1 or 2, and R' is hydrogen or carboalkoxy having 2-13 carbon atoms. The invention also includes a process for preparing such substituted 2,5-dimethylpyrroles comprising reacting acetonylacetone or a 3-carboalkoxyacetonylacetone with a urethane or phosphoramidate having the molecular structures, respectively, ##STR2## wherein R is alkyl or aralkyl of 1-19 carbon atoms. The process is illustrated by the following equations: ##STR3##
DETAILED DESCRIPTION OF THE INVENTION
R in the above structure may, as indicated, be alkyl or aryl. It may contain 1-19 carbon atoms. Illustrative examples of such R groups include methyl, ethyl, n-propyl, n-heptyl, n-nonyl, n-decyl, n-octadecyl, benzyl, beta-phenylethyl, etc.
Specific illustrative urethanes include aralkyl carbamates such as benzyl carbamate, alkyl carbamates such as methyl carbamate, ethyl carbamate and the like, as well as mixtures thereof, while the phosphoramidates useful for the purposes of this invention include dialkylphosphoramidates such as diethylphosphoramidate, di-n-hexylphosphoramidate, etc.
It will be noted that the amide group of the composition of the invention is hindered by the two methyl groups in the 2- and 5-positions. It is believed that such hindrance is a factor in the notable effectiveness as light inhibitors of the Diels-Alder products which may be prepared from these substituted pyrroles.
The process of the invention is carried out in an anhydrous system. In some instances, to insure the substantial absence of water, it is advisable to heat, at reflux temperature, a solution of the amide in a water-immiscible solvent such as toluene, collecting any water in a Dean-Stark trap. Then when no more water is thus collected, acetonylacetone is added and the whole is heated until the reaction is complete.
The process requires the reaction of one mol of amide per one mol of acetonylacetone and, generally, these are the proportions of reactants that should be used for a most efficient reaction. The use of a substantial excess of either reactant merely results in the loss of the excessive amount of that reactant.
A catalyst ordinarily is used. Acidic catalysts are preferred. Illustrative examples of suitable acidic catalysts include p-toluenesulfonic acid, methanesulfonic acid, sulfonic acid, phosphoric acid, cationic resins such as sulfonated copolymers of butadiene and styrene, dilauryl phosphoric acid and the like.
It is desirable to use a solvent. Among other reasons, it facilitates removal of water, as it is formed, from the reaction mixture, viz., by means of a Dean-Stark trap. Water-insoluble solvents should be used. Toluene, benzene, xylene, heptane, tetrachloroethane and chlorobenzene are illustrative. The boiling point of the solvent may range from about 75° C. to about 200° C., although a narrower range is preferred so as to permit easy removal (at a lower temperature) of the solvent from the product mixture, i.e., from about 100° C. to about 140° C.
The process is carried out quite simply; the reaction mixture is heated at a temperature within the range of from about 75° C. to about 200° C., usually at the reflux temperature of the solvent. Water is removed from the product mixture as it is formed and when no more water is formed the reaction is halted. The N-acyl-2,5-dimethylpyrrole product is isolated by distillation. The distillate usually comprises a mixture of the desired pyrrole and a small proportion of unreacted acetonylacetone. This latter can be removed by extraction with a solvent such as heptane; i.e., one which dissolves acetonylacetone more readily than the substituted pyrrole.
EXAMPLE 1
A solution of 55 g. (0.364 mol) of benzyl carbamate, 42 ml. (40.4 g.-0.372 mol) of acetonylacetone and 0.25 g. of p-toluenesulfonic acid in 100 ml. of toluene is heated at reflux temperature for 7.5 hours, collecting evolved water in a Dean-Stark trap. A total of 13.5 ml. (0.75 mol) of water is thus collected. The product mixture is concentrated by heating to 130° C./5 mm. The residue is taken up in 100 ml. of heptane and filtered. The filtrate is concentrated to a purple solid, M.P. 62°-65° C., the desired carbobenzyloxy-2,5-dimethylpyrrole.
EXAMPLE 2
A solution of 10 g. (0.0653 mol) of diethyl phosphoramidate, 7.5 ml. (7.3 g.-0.0632 mol) of acetonylacetone and 0.1 g. of p-toluenesulfonic acid in 50 ml. of benzene is heated at reflux temperature. Evolved water is collected in a Dean-Stark trap. The residue is distilled at 90°-92°/0.1 mm. The distillate (shown below) ##STR4## weighs 14.5 g.
EXAMPLE 3
A solution of 28 g. (0.246 mol) of acetonylacetone and 22 g. (0.247 mol) of ethyl carbamate in 50 ml. of ethanol is heated at reflux temperature for 1.5 hours. Gas chromatographic analysis indicates the formation of a small proportion of desired N-carboethoxy-2,5-dimethylpyrrole. The mixture is freed of ethanol by stripping, then heated at 150°-180° C. for six hours and distilled.
The distillate is shown by gas chromatographic analysis to be a mixture of starting materials and desired product. This mixture is dissolved in 50 ml. of carbon tetrachloride, 0.1 g. of p-toluenesulfonic acid is added, and the whole is heated at reflux temperature for ten hours during which period four ml. of water is collected in a Dean-Stark trap. The product mixture is distilled yielding two principal fractions of which the first fraction, weighing 30 g., was shown to contain mostly desired product and the second fraction, weighing 7 g., was shown to be substantially pure desired product, i.e., n-carboethyloxy-2,5-dimethylpyrrole.
It is apparent from this example that while the process of the invention can be carried out without an acidic catalyst, and without a water-immiscible solvent, it is carried out more efficiently when these two conditions obtain.
EXAMPLE 4
A solution of 70 g. (0.458 mol) of diethyl phosphoramidate, 52.5 ml. (51.1 g.-0.449 mol) of acetonylacetone and 0.1 g. of p-toluensulfonic acid in 200 ml. of benzene is heated at reflux temperature for several hours until a total of 15 ml. of water had been collected in a Dean-Stark trap. The product mixture is distilled into three fractions weighing 8.5 g. (B.P., <80° C./0.1 mm.), 71 g. (B.P. 80° C./0.1 mm.) and 15 g. (B.P. 82°-85° C. mm.), respectively. The middle fraction is shown by infrared analysis to be substantially pure substituted pyrrole of the following structure: ##STR5##
EXAMPLE 5
A solution of 28.0 g. (0.151 mol) of 3-carboethoxy-2,5-hexanediene, 13.4 g. (0.151 mol) of ethyl carbamate and 0.1 g. of p-toluenesulfonic acid in 100 ml. of heptane is heated at reflux temperature until a total of 5.0 g. water is collected in a Dean-Stark trap. The product mixture is distilled yielding 15 g. of a fraction boiling at 115°-120° C./0.1 mm., n D 20 , 1.4897, and shown by gas chromatographic analysis to be the compound shown below: ##STR6##
EXAMPLE 6
A solution of 114 g. (1.54 mols) of methyl carbamate, 180 ml. (175.3 g.-1.54 mols) of acetonylacetone and 0.1 g. of p-toluenesulfonic acid in 300 ml. of benzene is heated at reflux temperature until a total of 52 ml. of water is collected (in a Dean-Stark trap). The product mixture is stripped, then distilled yielding 208.5 of distillate which is identified as the desired N-carbomethoxy-2,5-dimethylpyrrole by means of infrared and gas chromatographic analysis.
All parts and precentages herein are by weight unless otherwise expressly stated. | N-substituted 2,5-dimethylpyrroles and a method for their preparation. The method requires the reaction of a 2,5-hexadione such as acetonylacetone with a urethane or a phosphoroamidate. The reaction is carried out at elevated temperatures, preferably in a water-immiscible solvent. | 2 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The present application claims priority of U.S. Provisional Application No. 62132484, dated Mar. 12, 2015, filed by same applicant.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates to pillows and portable chargers, specifically to portable travel pillows. The present invention is directed to a portable travel pillows that simultaneously supports the user's head and neck while providing portable charging capabilities to the user's personal handheld mobile devices.
BACKGROUND OF THE INVENTION
[0003] Of the estimated 6 billion people in the world, over an estimated 4 billion people have mobile phones or personal handheld mobile devices. Texting and emailing on these personal handheld mobile devices has become a dominant form of communication. Viewing the internet, emails, videos, movies and television has also become a daily function of the personal handheld mobile device user. Mobile technology has been designed for just about every application. Tablets, PDA, MP3, e-readers, media players, wireless gaming controllers, the list goes on. On average, it is estimated that Americans spend 2.7 hours per day communicating and socializing on their phones or personal handheld mobile devices and even more time looking down at their mobile devices for web searching, emails, videos, movies and television.
[0004] People of all ages are estimated to spend countless hours daily hunched over numerous types of handheld devices. While an estimated 75% of the world's population re all in constant danger and at risk of developing headaches, upper back pain, shoulder pain, neck pain and increased curvature of the spine. The frequent forward flexion is claimed to cause changes in the cervical spine, its curvature, supporting ligaments, tendons, and musculature, as well as the bony segments, commonly causing postural change.
[0005] Widespread overuse of handheld mobile technology is resulting in a harmful and dangerous physical condition on the human body. Such health condition is derived from the onset of cervical spinal degeneration resulting from the repeated stress of frequent forward head flexion while looking down at the screens of mobile devices and ‘texting’ for long periods of time. This health condition has become a world-wide health concern, affecting millions of all ages and from all walks of life. Among the chief complaints claimed to be associated with such condition are pain felt in the neck, shoulder, back, arm, fingers, hands, wrists and elbows, as well as headaches and numbness and tingling of the upper extremities.
[0006] Public transportation vehicles, such as trains, planes, automobiles or intra-city buses all require passengers to occupy their seats for extended periods of time. Passenger seating is usually arranged to efficiently pack as many people together, over the smallest area possible. Such arrangements can make long periods of time uncomfortable and tedious for passengers and travelers. Attempting to relax in such environment usually results in poor posture. This, without neck support, can result in headaches, upper back pain, shoulder pain, neck pain and increased curvature of the spine.
[0007] A large percentage of travelers resort to travel pillows to provide stable support for the neck. These pillows are ideally small, often with a foam or memory-foam core and a fabric cover.
[0008] Some are U-shaped to receive and maintain the head and neck in an upright manner. This permits the user to rest, relax and sleep in an up-right position.
[0009] Mobile consumer products such as cell phones, tablet computers, audio players, portable video players, video games and the like use rechargeable batteries. The device battery may be depleted when a device is used extensively. In an effort to address this problem, portable power banks are available that can provide additional power to recharge the battery of a device after the device's battery is depleted.
[0010] A portable power bank is a portable device that can supply USB power using stored energy in its built-in batteries. Portable power banks usually re-charge with USB power. A portable power banks specifications are ideally measured in mAh: amount of mA×time at 5V with an external 5V Type-A USB Output Only connector and an internal 5V microUSB (Micro-USB) Input Only connector for storing electric energy and then use it later to charge up a mobile device. The portable power banks mentioned are used to charge any USB-charged or USB-powered device such as mobile phones, wireless gaming controllers, cameras, GoPros, portable speakers, GPS systems, MP3 players, smartphones and tablets.
[0011] Three issues of present travel pillows are addressed by the present invention: Viewing handheld mobile devices comfortably; traveling comfortably; and not having power sources to charge the handheld mobile device while traveling or simply viewing the handheld mobile device with comfort. To overcome these issues, the present invention provides novel features such as the portable pillow body, the removable fabric cover and the portable power bank to allow users to text or view handheld mobile devices while charging said handheld mobile device portably and comfortably.
BRIEF SUMMARY OF THE INVENTION
[0012] Accordingly, the present invention is directed to a portable, charging travel pillow comprising: A portable pillow body having a U shaped design having a removable fabric covering that is secured about said portable pillow body wherein said covering provides access to the portable pillow body, and a charging and re-chargeable portable power bank disposed at one end of the portable pillow body, said portable power bank operable to output electric energy to a portable handheld mobile device using Universal Serial Bus (USB) power as well as being able to receive electric energy via micro Universal Serial Bus (micro- USB) power. The portable pillow body further includes a housing for said portable power bank having a closure means to secure the portable power bank within said housing while allowing said portable power bank to be removed from within said portable pillow body for use as an individual portable power bank.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 illustrates the perspective view of the portable, charging travel pillow with the portable power bank disposed at one end of the pillow body;
[0014] FIG. 2 illustrates the top view of the portable, charging travel pillow with the portable bank disposed at one end of the pillow body;
[0015] FIG. 3 illustrates the bottom view of the portable, charging travel pillow with the portable bank disposed at one end of the pillow body;
[0016] FIG. 4 illustrates the front view of the portable, charging travel pillow with the portable bank disposed at one end of the pillow body; and
[0017] FIG. 5 illustrates the front view of an embodiment of the portable, charging travel pillow wherein the pillow body possesses an inflatable compartment with the portable bank disposed at one end of the pillow body.
DETAILED DESCRIPTION OF THE INVENTION
[0018] A portable, charging travel pillow, according to the present invention, is shown at 1 in FIG. 1 . The portable, charging travel pillow is comprised of a portable pillow body 3 , a removable fabric covering 5 and the portable power bank 7 . As shown in FIGS. 1-5 , the portable pillow body 1 may be a U shaped design wherein the two ends 9 and 11 of the pillow body 3 lie parallel to one another and designed to cradle the sides of a user's neck to provide comfort to the user. Although the pillow body 3 is disclosed and shown as a U shaped design, the pillow body 3 may be any conventional shape, including square, rectangular, elliptical, circular, round, oval or any conventional shape.
[0019] The pillow body 3 may be constructed of polyurethane memory foam. Alternatively, the portable pillow body 3 may be constructed of different materials and textiles such as visco-elastic memory foam, Zoned Dough® memory foam, Dough® memory foam, Tempur-pedic® memory foam, Styrofoam, silicone, gel, gel memory foam, cooling gel, cooling gel memory foam, beads, microbeads, beanbag filler, foam, down feathers, rubber, polyester fiberfill, polyester pellets, latex, cotton, air-filled, wool and others.
[0020] In one embodiment, as shown as FIG. 5 , the pillow body 3 may be an inflatable pillow body wherein the pillow body 3 is comprised of a casing or bladder made from an elastomeric material, plastic material, rubber like material or the like. The casing or bladder provides an interior cavity 13 designed to be inflated with air. The casing or bladder of the present embodiment fills the same volume of space the pillow body 3 of FIGS. 1-4 would fill. As with other embodiments, the pillow body 3 may be of any shape, including U-shaped, square, rectangular, elliptical, circular, round, oval or any conventional shape. In the present embodiment, the portable charging pillow 1 possesses a valve, flap, air conduit or opening 15 to provide air to the internal cavity 13 of the casing or bladder of the pillow body 3 . The valve, flap, air conduit or opening 15 would allow air to be pumped into the internal cavity 13 to allow the pillow body 3 to be inflated. The valve 15 may possess a closure or sealing member 17 to prevent air from escaping the interior cavity 13 during use of the invention. The valve 15 may allow air to be removed from the interior cavity 13 only when the closure or sealing member 17 is removed and/or when pressure is placed upon the pillow body 3 forcing air to escape from the interior cavity 13 so that the pillow body 3 may be deflated. In one embodiment, the valve 15 may be a one way valve to allow air to be pumped into the internal cavity 13 and prevent backflow of air out of the interior cavity 13 . The ability to deflate the pillow body 3 in the present invention allows the portable charging pillow 1 to be easily stored or transported.
[0021] In the present invention, as shown in FIGS. 1-5 , the pillow body 3 is covered by the removable fabric covering 5 . The removable fabric covering 5 comprises at least one fabric member that wraps around the pillow body 3 wherein the edges of the at least one fabric member meet to be fastened together via fastening means (not shown). The removable fabric covering 5 may be constructed of a washable, woven or knitted material. Materials suitable for removable fabric covering include man-made fibers, natural fibers, and combinations thereof, further including cottons, poly/cottons, fleeces, wools, flannels, etc. In the present invention, the fastening means for the removal fabric covering 5 may be a zipper closure, a hook and loop fastener, buttons, snap closures, clasps or any other conventional fastening means. In a preferred embodiment, a portion of the edges of the at least one fabric member may be sewn together wrapping around the pillow body 3 and at least a portion of the edges meet to be fastened together via fastening means. The fastening means allow the user to remove the removable fabric covering 5 from the pillow body 3 to allow the user to clean or freshen the removable fabric covering 5 .
[0022] In one embodiment, the removable fabric covering may have a handle or grip so that the user can easily carry the present invention. In another embodiment, the removable fabric covering may provide a hood that is fastened to the periphery of the portable charging pillow 1 to allow the user to cover his or head during use of the invention.
[0023] In the present invention, as shown in FIGS. 1-3 , the portable power bank 7 may be arranged anywhere along the pillow body 3 . In a preferred embodiment, the portable power bank 7 is placed within a housing 19 having a cylindrical body 21 and an aperture to allow the user to insert or remove the portable power bank 7 . The housing 19 may further possess closure or fastening means at the aperture end of the housing 19 to allow the user to secure the portable power bank 7 in the housing 19 and also allow the user to remove the portable power bank 7 from the housing 19 for use as an individual portable power bank. In one embodiment, the housing 19 possesses fastener tabs to allow the portable power bank 7 to be removable and replaceable.
[0024] In the present invention, the housing 19 may be located anywhere along the pillow body 3 as long as the cylindrical body 21 of the portable power bank 7 is contained within the removable fabric covering 5 . As shown in the figures, the pillow body 3 may surround the cylindrical body of the housing 19 of the portable power bank 7 for a secure fit.
[0025] In one embodiment, as shown in FIGS. 1-5 , the housing 19 and portable power bank 7 may be located at one end of the pillow body 3 . It will be appreciated by anyone of ordinary skill in the art that the housing 19 and portable power bank 7 may be removably fastened anywhere within the portable charging pillow 1 .
[0026] The housing 19 may be custom molded into the pillow body 3 . The custom molded housing 19 is intended to house the portable power bank 7 and keep the portable power bank 7 in place but also allows for easy removal from the portable charging pillow 1 . This allows the portable power bank 7 to be removable and provides the option to the user of either utilizing the portable power bank 7 in conjunction with the portable charging pillow 1 or alternatively as a stand alone portable power bank 7 .
[0027] In one embodiment of the present invention, the portable power bank 7 operates to output electric energy to a portable handheld mobile device using Universal Serial Bus (USB) power as well as being able to receive electric energy via micro Universal Serial Bus (micro-USB) power. The portable power bank 7 provides a USB port to charge mobile USB powered devices and the microUSB port to charge the portable, charging travel pillow 1 .
[0028] The portable power bank 7 is a device that can supply USB power using stored energy in its built-in batteries. Other portable power banks usually re-charge with USB power. The portable power bank's 3 specifications are ideally measured in mAh: amount of mA×time at 5V with an external 5V Type-A USB Output Only port and an internal 5V microUSB (Micro-USB) Input only port for storing electric energy and then using it later to charge up a handheld mobile device. Portable power banks are used to charge any USB-charged or USB-powered device such as mobile phones, wireless gaming controllers, cameras, GoPros, portable speakers, GPS systems, MP 3 players, smartphones and tablets. The portable power bank 4 may include a casing, a printed circuit board disposed in the casing, a rechargeable battery disposed in the casing and electrically connected to the printed circuit board, a curly transmission wire, and an adapter tip. The curly transmission wire has a first adapting end, and a fixing end passing through the casing and. electrically connecting to the rechargeable battery via the printed circuit board. The adapter tip has a second adapting end connecting to the first adapting end, and a coupling end for electrically connecting to the portable electronic device. It will be appreciated by those of ordinary skill in the art that the portable, charging, travel pillow can be embodied in other specific forms without departing from the spirit of its essential character thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive.
[0029] In the present invention, the portable power bank 7 is not limited in shape, size or capacity and can be different sizes, shapes and capacities. The size can range from small to large and shapes can range from square, rectangle, cubed, oval, round, circular, odd-shaped and cylinder-shaped or any other conventional shape. The portable power bank 7 is capable of charging any standard USB powered handheld mobile device and varies from the capacity of 1500 mAh up to 30000 mAh. The portable power bank is also capable of being recharged and maintaining the charge to provide electric charging capability to any standard USB powered outlet. The capacity of the battery may range from 1500 mAh up to 30000 mAh or above or other.
[0030] The portable power bank 7 is not limited to be constructed of lithium polymer and may be constructed of different materials such as Lithium-Ion (Li-ion), Lithium-Polymer (Li-Polymer), NIMH battery cells, Ni—Cd battery cells, solar charged power banks, solar panels, Universal Serial Bus (USB-based) chargers and others.
[0031] The portable power bank 7 is not limited to being charged via USB power and is not limited to charging handheld mobile devices via USB power. Furthermore, the portable power bank 7 may be charged, re-charged and may charge portable handheld devices via solar power, inductive charging, conductive wireless charging and others.
[0032] The present invention may also possess more than one portable power bank 7 . The number of portable power banks 7 is not limited and each portable power bank may be located at any location along the pillow body 3 so that one or more mobile devices may be charged at the same time.
[0033] Further, each portable power bank 7 may possess a plurality of USB and microUSB ports and/or connectors. The number of ports or connectors on each portable power bank 7 is not limited and may include one or more USB charging ports connectors per portable power bank 7 . The type of connector ports on the power bank is also not limited to standard USB and microUSB.
[0034] In the present invention, the portable power bank 7 is not limited to being a stationary piece within the portable charging pillow 1 and may be movable within the portable charging pillow 1 or removable.
[0035] While possible embodiments of the portable, charging travel pillow 1 have been disclosed, it should be appreciated that alternatives or variations of any type of material, size, shape, capacity, placement and additions used and future types of material, size, shape, capacity, placement and additions used are within the scope of the present invention.
[0036] Thus, the portable charging travel pillow 1 of the present invention provides a more convenient and comfortable device to text and view portable handheld mobile devices while simultaneously charging that said portable handheld mobile device.
[0037] Although the preceding description contains significant detail, it should not be construed as limiting the scope of the portable, charging, travel pillow but rather as providing illustrations of the preferred and/or alternative embodiments of the portable, charging, travel pillow. | Described is the portable, charging travel pillow having a removable portable power bank for providing the user with a comfortable place for resting the neck and head and charging the user's handheld portable mobile device. The portable, charging travel pillow provides a portable pillow body with the removable fabric cover and a removable portable power bank.
The portable, charging travel pillow is a fully-functional portable pillow body with portable charging capability via the portable power bank. device for texting or viewing handheld mobile devices while charging said handheld mobile device portably and comfortably. | 0 |
STATEMENT OF GOVERNMENT LICENSE RIGHTS
[0001] This invention was made with government support by the Small Business Innovation Research program of the U.S. Department of Energy, Contract SC0002291. The government has certain rights in the invention.
FIELD OF THE INVENTION
[0002] Our invention provides a rotary bypass shear comminution process to produce precision wood feedstock particles from veneer.
BACKGROUND OF THE INVENTION
[0003] Wood particles, flakes, and chips have long been optimized as feedstocks for various industrial uses (see, e.g., U.S. Pat. Nos. 2,776,686, 4,610,928, 6,267,164, and 6,543,497), as have machines for producing such feedstocks.
[0004] Optimum feedstock physical properties vary depending on the product being produced and/or the manufacturing process being fed. In the case of cellulosic ethanol production, the feedstock should be comminuted to a cross section dimension of less than 6 mm for steam or hot water pretreatment, and to less than 3 mm for enzymatic pretreatment. Uniformity of particle size is known to increase the product yield and reduce the time of pretreatment. Uniformity of particle size also affects the performance of subsequent fermentation steps.
[0005] Piece length is also important for conveying, auguring, and blending. Over-length pieces may tangle or jam the machinery, or bridge together and interrupt gravity flow. Fine dust-like particles tend to fully dissolve in pretreatment processes, and the dissolved material is lost during the washing step at the end of preprocessing.
[0006] Particle shape can be optimized to enhance surface area, minimize diffusion distance, and promote the rate of chemical or enzyme catalyst penetration through the biomass material. Such general goals have been difficult to achieve using traditional comminution machinery like shredders, hammer mills, and grinders.
[0007] Gasification processes that convert biomass to syngas present a different set of constraints and tradeoffs with respect to optimization of particle shape, size, and uniformity. For such thermochemical conversions, spherical shapes are generally favored for homogeneous materials, and enhancement of surface area is less important. Cellulosic plant derived feedstocks are not homogeneous, and thus optimal properties involve complex tradeoffs.
[0008] A common concern in producing all bioenergy feedstocks is to minimize fossil fuel consumption during comminution of plant biomass to produce the feedstock.
SUMMARY OF THE INVENTION
[0009] Herein we describe a comminution process to produce a new class of wood feedstock particles characterized by consistent piece size and shape uniformity, high skeletal surface area to volume ratio, and good flow properties. Such precision feedstock particles are conveniently manufactured from wood veneer materials at relatively low cost using the disclosed low-energy comminution processes.
[0010] The invention provides a process of comminution of wood veneer having a grain direction and a substantially uniform thickness (Tv) to produce wood particles characterized by a disrupted grain structure, a substantially uniform length dimension (L) aligned substantially parallel to the grain direction, a width dimension (W) normal to L and aligned substantially cross grain, and a height dimension (H) normal to W and L and substantially equal to the Tv. The wood veneer is fed in a direction of travel substantially normal to the grain direction through a counter rotating pair of intermeshing arrays of cutting discs arrayed axially perpendicular to the direction of veneer travel wherein the cutting discs have a uniform thickness (Td) that is substantially equal to the desired particle length (L). This comminution process produces uniform wood particles of roughly parallelepiped shape, characterized by L×H dimensions that define a pair of substantially parallel side surfaces with substantially intact longitudinally arrayed fibers, L×W dimensions that define a pair of substantially parallel top and bottom surfaces, and W×H dimensions that define a pair of substantially parallel end surfaces with crosscut fibers and a disrupted grain structure characterized by end checking between fibers.
[0011] The veneer is preferably aligned within 30° parallel to the grain direction, and most preferably the direction of veneer travel is within 10° parallel to the grain direction.
[0012] To further enhance grain disruption, the veneer and cutting discs may be selected such that Td÷Tv=4 or less, and preferably 2 or less, in which case the comminution process tends to promote pronounced surface checking between longitudinally arrayed fibers on the top and bottom surfaces of the particles.
[0013] For production of feedstocks for bioenergy processes, a Td is typically selected in the range between 1/32 inch and ¾ inch. For use in many conversion processes the veneer Tv and the cutting disc Td are paired such that at least 80% of the produced wood particles pass through a ¼ inch screen having a 6.3 mm nominal sieve opening but are retained by a No. 10 screen having a 2 mm nominal sieve opening. For particular end uses, the veneer Tv and cutting disc Td may be co-selected to produce precision feedstocks such that at least 90% of the particles pass through either: an ¼ inch screen having a 6.3 mm nominal sieve opening but are retained by a ⅛-inch screen having a 3.18 mm nominal sieve opening; a No. 4 screen having a 4.75 mm nominal sieve opening screen but are retained by a No. 8 screen having a 3.18 mm nominal sieve opening; a ⅛-inch screen having a 3.18 mm nominal sieve opening but are retained by a No. 16 screen having a 1.18 mm nominal sieve opening; a No. 10 screen having a 2.0 mm nominal sieve opening but are retained by a No. 35 screen having a 0.5 mm nominal sieve opening; a No. 10 screen having a 2.0 mm nominal sieve opening but are retained by a No. 20 screen having a 0.85 mm nominal sieve opening; or, a No. 20 screen having a 0.85 mm nominal sieve opening but are retained by a No. 35 screen having a 0.5 mm nominal sieve opening.
[0014] The wood veneer may be comminuted in a green, seasoned, or rehydrated condition, but to minimize feedstock recalcitrance in downstream fractionation processes the veneer should be comminuted at a field moisture content greater than about 30% wwb.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a photograph of similarly sized (A) prior art wood cubes typical of coarse sawdust or chips, and (B) wood feedstock particles produced from veneer by the disclosed comminution process; and
[0016] FIG. 2 is a perspective view of a prototype rotary bypass shear machine suitable for comminuting wood veneer into precision particles.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] We have applied engineering design principles to develop a low-energy comminution process that produces a new class of wood particles from veneer. The comminution process produces prominent end checks and some surface checks that disrupt the grain structure and greatly enhance the particles' skeletal surface area as compare to envelope surface area. Representative wood feedstock particles of the invention are shown in FIG. 1B , which indicates how the nominal parallelepiped shape or extent volume of the particles is cracked open by pronounced checking that greatly increases surface area.
[0018] The term “veneer” as used herein refers generally to wood peeled, sawn, or sliced into sheets of a given constant thickness (Tv).
[0019] The term “grain” as used herein refers generally to the arrangement and longitudinally arrayed direction of plant fibers within a wood veneer material. “Grain direction” is the orientation of the long axis of the dominant fibers in a sheet of wood veneer.
[0020] The terms “checks” or “checking” as used herein refer to lengthwise separation and opening between fibers in a wood particle. “Surface checking” may occur on the lengthwise surfaces a particle (that is, on the L×W surfaces); and “end checking” occurs on the cross-grain ends (W×H) of a particle.
[0021] The term “skeletal surface area” as used herein refers to the total surface area of a wood particle, including the surface area within open pores formed by checking between plant fibers. In contrast, “envelope surface area” refers to the surface area of a virtual envelope encompassing the outer dimensions the particle, which for discussion purposes can be roughly approximated to encompass the particle's extent volume dimensions.
[0022] The term “field moisture content” refers to veneer that retains a harvested moisture content above the approximately 30% fiber saturation point below which the physical and mechanical properties of wood begin to change as a function of moisture content. Such a veneer has not been dried below its fiber saturation point and then rehydrated, e.g., by soaking in water.
[0023] The adjectives “green” and “seasoned” indicate veneers having moisture contents of more than or less than 19%, respectively.
[0024] The term “disc” refers to a circular object having a uniform thickness (Td) between two opposing flat sides of equal diameter. Td is conveniently measured with an outside caliper.
[0025] The feedstock particles produced by our rotary bypass shear comminution process can be readily optimized for various bioenergy conversion processes that produce ethanol, other biofuels, and bioproducts. The particles advantageously exhibit: a substantially uniform length (L) along the grain direction that is determined by the uniform thickness (Td) of the cutter discs; a width (W) tangential to the growth rings (in wood) and normal to the grain direction; and a height (H), oriented radial to the growth rings and normal to the W and L dimensions, that is substantially equal to the thickness (Tv) of the veneer raw material.
[0026] We have found it very convenient to use wood veneer from a centerless rotary lathe process as a raw material. Peeled veneer from a rotary lathe naturally has a thickness that is oriented with the growth rings and can be controlled by lathe adjustments. Moreover, within the typical range of veneer thicknesses, the veneer contains very few growth rings, all of which are parallel to or at very shallow angle to the top and bottom surfaces of the sheet. In our process, we specify the veneer thickness (Tv) to match the desired wood particle height (H) to the specifications for a particular conversion process.
[0027] The veneer may be processed into particles directly from a veneer lathe, or from stacks of veneer sheets produced by a veneer lathe. Our preferred manufacturing method is to feed veneer sheet or sliced materials into a rotary bypass shear with the grain direction oriented across and preferably at a right angle to the feed direction through the machine's processing head, that is, parallel to the shearing faces.
[0028] The rotary bypass shear that we designed for manufacture of precision wood feedstock particles is a shown in FIG. 2 . This prototype machine 10 is much like a paper shredder and includes parallel shafts 12 , 14 , each of which contains a plurality of cutting disks 16 , 18 . The disks 16 , 18 on each shaft 12 , 14 are separated by smaller diameter spacers (not shown) that are the same width or greater by 0.1 mm thick than the Td of the cutting disks 16 , 18 . The cutting disks 16 , 18 may be smooth 18 , knurled (not shown), and/or toothed 16 to improve the feeding of veneer sheets 20 through the processing head 22 . Each upper cutting disk 16 contains five equally spaced teeth 24 that extend 6 mm above the cutting surface 26 . The spacing of the two parallel shafts 12 , 14 is slightly less than the diameter of the cutting disks 16 , 18 to create an intermeshing shearing interface. In our machine 10 , the cutting disks 16 , 18 are approximately 105 mm diameter and the shearing overlap is approximately 3 mm.
[0029] This rotary bypass shear machine 10 used for demonstration of the manufacturing process operates at an infeed speed of one meter per second (200 feet per minute). The feed rate has been demonstrated to produce similar particles at infeed speeds up to 2.5 meters per second (500 feet per minute).
[0030] The width, or thickness (Td), of the cutting disks 16 , 18 establishes the length (L) of the particles produced since the veneer 20 is sheared at each edge 28 of the cutters 16 , 18 and the veneer 20 is oriented with the fiber grain direction parallel to the cutter shafts 12 , 14 and shearing faces of the cutter disks 16 , 18 . Thus, wood particles from our process are of much more uniform length than are particles from shredders, hammer mills and grinders which have a broad range of random lengths. The desired and predetermined length of particles is set into the rotary bypass shear machine 10 by either installing cutters 16 , 18 having uniform widths (Td) equal to the desired output particle grainwise length (L) or by stacking assorted thinner cutting disks 16 , 18 to the appropriate cumulative cutter width (Td).
[0031] It should be understood that, alternatively, an admixture of for example nominal 2×2 mm and 2×4 mm particles can be produced directly from 2 mm veneer by stacking the shafts 12 , 14 of machine 10 with a desired ratio of alternating pairs of 2 mm- and 4 mm-wide cutting discs 16 , 18 .
[0032] Fixed clearing plates 30 ride on the rotating spacer disks to ensure that any particles that are trapped between the cutting disks 16 , 18 are dislodged and ejected from the processing head 20 .
[0033] We have found that the wood particles leaving the rotary bypass shear machine 10 are broken (or “crumbled”) into short widths (W) due to induced internal tensile stress failures. Thus the resulting particles are of generally uniform length (L) along the wood grain, as determined by the selected width (Td) of the cutters 16 , 18 , and of a uniform thickness (H, as determined by the veneer thickness, Tv), but vary somewhat in width (W) principally associated with the microstructure and natural growth properties of the raw material species. Most importantly, frictional and Poisson forces that develop as the veneer material 20 is sheared across the grain at the cutter edges 28 tend to create end checking that greatly increases the skeletal surface areas of the particles. Substantial surface checking between longitudinally arrayed fibers further elaborates the L×W surfaces when the length to height ratio (L/H) is 4:1 and particularly 2:1 or less.
[0034] The output of the rotary bypass shear 10 may be used as is for some conversion processes such as densified briquette and pellet manufacture, gasification, or thermochemical conversion. However, many end-uses will benefit if the particles are screened into more narrow size fractions that are optimal for particular end-use conversion processes. In that case, an appropriate stack of vibratory screens or a tubular trommel screen with progressive openings can be used to remove particles larger or smaller than desired. In the event that the feedstock particles are to be stored for an extended period or are to be fed into a conversion process that requires very dry feedstock, the particles may be dried prior to storage, packing or delivery to an end user.
[0035] We have used this prototype machine 10 to make feedstock particles in various lengths from a variety of plant biomass materials, including: peeled softwood and hardwood veneers; sawed softwood and hardwood veneers; softwood and hardwood branches and limbs crushed to a predetermined uniform height or maximum diameter; cross-grain oriented wood chips and hog fuel; corn stover; switchgrass; and bamboo. The L×W surfaces of peeled veneer particles generally retain the tight-side and loose-side characteristics of the raw material. Crushed wood and fibrous biomass mats are also suitable starting materials, provided that all such biomass materials are aligned across the cutters 16 , 18 , that is, with the shearing faces substantially parallel to the grain direction, and preferably within 10° and at least within 30° parallel to the grain direction.
[0036] We currently consider the following size ranges as particularly useful biomass feedstocks: H should not exceed a maximum from 1 to 16 mm, in which case W is between 1 mm and 1.5×the maximum H, and L is between 0.5 and 20×the maximum H; or, preferably, L is between 4 and 70 mm, and each of W and L is equal to or less than L.
[0037] For flowability and high surface area to volume ratios, the cutter disc thickness Td and veneer thickness T dimensions are co-selected so that at least 80% of the particles pass through a ¼ inch screen having a 6.3 mm nominal sieve opening but are retained by a No. 10 screen having a 2 mm nominal sieve opening. For uniformity as reaction substrates, at least 90% of the particles should preferably pass through: a ¼″ screen having a 6.3 mm nominal sieve opening but are retained by a No. 4 screen having a 4.75 mm nominal sieve opening; or a No. 4 screen having a 4.75 mm nominal sieve opening but are retained by a No. 8 screen having a 2.36 mm nominal sieve opening; or a No. 8 screen having a 2.36 mm nominal sieve opening but are retained by a No. 10 screen having a 2 mm nominal sieve opening. Most preferably, the subject biomass feedstock particles are characterized by size such that at least 90% of the particles pass through: a ¼ inch screen having a 6.3 mm nominal sieve opening but are retained by a ⅛-inch screen having a 3.18 mm nominal sieve opening; or a No. 4 screen having a 4.75 mm nominal sieve opening screen but are retained by a No. 8 screen having a 2.36 mm nominal sieve opening; or a ⅛-inch screen having a 3.18 mm nominal sieve opening but are retained by a No. 16 screen having a 1.18 mm nominal sieve opening; or a No. 10 screen having a 2.0 mm nominal sieve opening but are retained by a No. 35 screen having a 0.5 mm nominal sieve opening; or a No. 10 screen having a 2.0 mm nominal sieve opening but are retained by a No. 20 screen having a 0.85 mm nominal sieve opening; or a No. 20 screen having a 0.85 mm nominal sieve opening but are retained by a No. 35 screen having a 0.5 mm nominal sieve opening.
[0038] Suitable testing screens and screening assemblies for empirically characterizing the produced wood particles in such size ranges are available from the well-known Gilson Company, Inc., Lewis Center. Ohio, U.S. (www.globalgilson.com). In a representative protocol, approximately 400 g of the subject particles (specifically, the output of machine 10 with 3/6″-wide cutters and ⅙″ conifer veneer) were poured into stacked ½″, ⅜″, ¼″, No. 4, No. 8, No. 10, and Pan screens; and the stacked screen assembly was roto-tapped for 5 minutes on a Gilson® Sieve Screen Model No. SS-12R. The particles retained on each screen were then weighed. Table 1 summarizes the resulting data.
[0000] TABLE 1 Screen size ½″ ⅜″ ¼″ No. 4 No. 8 No. 10 Pan % retained 0 0.3 1.9 46.2 40.7 3.5 7.4
These data show a much narrower size distribution profile than is typically produced by traditional high-energy comminution machinery.
[0039] Thus, the invention provides precision wood particles characterized by consistent piece size as well as shape uniformity, obtainable by cross-grain shearing a veneer material of selected thickness by a selected distance in the grain direction. Our rotary bypass shear process greatly increases the skeletal surface areas of the particles as well, by inducing frictional and Poisson forces that tend to create end checking as the biomass material is sheared across the grain. The resulting cross-grain sheared plant biomass particles are useful as feedstocks for various bioenergy conversion processes, particularly when produced in the size classifications described above.
EXAMPLES
[0040] Wood particles of the present invention were manufactured as described in above described machine 10 using 3/16″ wide cutters from a knot-free sheet of Douglas fir ⅙″ thick veneer (10-15% moisture content). The resulting feedstock was size screened, and from the Pass ¼″, No Pass No. 4 fraction for the precision desired in this particular experiment a 10 g experimental sample was collected of particles that in all dimensions passed through a ¼″ screen (nominal sieve opening 6.3 mm) but were retained by a No. 4 screen (nominal sieve opening 4.75 mm). Representative particles from this experimental sample (FS-1) are shown in FIG. 1B .
[0041] Similarly sized cubes indicative of the prior art were cut from the same veneer sheet, using a Vaughn® Mini Bear Saw™ Model BS 150D handsaw. The sheet was cut cross-grain into approximately 3/16″ strips. Then each strip was gently flexed by finger pressure to break off roughly cube-shaped particles of random widths. The resulting feedstock was size screened, and a 10 g control sample was collected of particles that in all dimensions passed through the ¼″ screen but were retained by the No. 4 screen. Representative cubes from this control sample (Cubes-1) are shown in FIG. 1A .
[0042] The outer (or extent) length, width, and height dimensions of each particle in each sample were individually measured with a digital outside caliper and documented in table form. Table 2 summarizes the resulting data.
[0000]
TABLE 2
Samples (10 g)
Number of pieces
Length (L)
Width (W)
Height (H)
Control cubes
n = 189
Mean 5.5
Mean 5.0
Mean 3.9
(Cubes-1)
SD 0.48
SD 1.17
SD 0.55
Experimental
n = 292
Mean 5.3
Mean 5.8
Mean 3.3
particles (FS-1)
SD 0.74
SD 1.23
SD 0.82
[0043] The Table 2 data indicates that the extent volumes (extent L×extent W×extent H) of these rather precisely size-screened samples were not substantially different. Accordingly, the cubes and particles had roughly similar envelope surface areas. Yet the 10 gram experimental sample contained 54% (292/189) more pieces than the 10 gram control sample, which equates to a mean density of 0.34 g/particle (10/292) as compared to 0.053 g/cube. FIG. 1 indicates that the roughly parallelepiped extent volumes of typical particles ( 1 B) contain noticeably more checks and air spaces than typical cubes ( 1 A). These differences demonstrate that the feedstock particles produced from veneer by rotary bypass shear comminution had significantly greater skeletal surface areas than the control cubes indicative of prior art coarse sawdust and chips.
[0044] While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. | Comminution process of wood veneer to produce wood particles, by feeding wood veneer in a direction of travel substantially normal to grain through a counter rotating pair of intermeshing arrays of cutting discs arrayed axially perpendicular to the direction of veneer travel, wherein the cutting discs have a uniform thickness (Td), to produce wood particles characterized by a length dimension (L) substantially equal to the Td and aligned substantially parallel to grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) substantially equal to the veneer thickness (Tv) and aligned normal to W and L, wherein the W×H dimensions define a pair of substantially parallel end surfaces with end checking between crosscut fibers. | 3 |
This application is a continuation of application Ser. No. 07/632,529, filed on Dec. 24, 1990, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a pile, that is, a so-called gravel drain pile comprising aggregates such as crushed stones, slag, gravel or cobbles, etc. having permeability and bearing capacity placed on a relatively loose sand foundation saturated with ground water, and more specifically to a method for automatically driving a gravel drain pile and an execution apparatus for carrying out the method which compacts the foundation in the periphery of the piles during the process of driving the gravel drain piles.
2. Description of the Prior Art
The present applicants have previously proposed the invention of a method for driving a gravel drain pile of this kind and an execution apparatus therefor in Japanese Patent No. 1,432,555 (Patent Publication No. 62(1987)-40,482, hereinafter referred to as "prior art").
That is, the method for driving a gravel drain pile according to the aforesaid invention is characterized by interpenetrating a hollow casing, an extreme end of which is closed, into predetermined depth, thereafter charging aggregates for driving a gravel drain pile into the casing and releasing the aggregates out of the extreme end of the casing, placing a compaction rod at a compacting position adjusted to the soil of the peripheral foundation and the grain size of aggregates, said compaction rod being disposed within the casing, transmitting impact force to the charged aggregates to compact the aggregates, and continuously performing the charging of the aggregates and the compacting with the compaction rod.
The driving apparatus according to the aforesaid invention comprises a hollow casing having an open- and closable lid at the extreme end thereof; a compaction rod which has a substantially equi-section, has a small diameter and is lengthy, said compaction rod being inserted from the lower end to the upper portion of the casing along a center axis within the casing; an impact drive device for a compaction rod disposed upwardly of the casing and being operatively connected to the compaction rod to transmit impact force to the compaction rod; and rod-height adjusting device for variably adjusting movement of an extreme end surface of the compaction rod.
That is, the invention according to prior art has aimed at compacting action by the compaction rod on crushed stones to achieve driving an effective gravel drain pile.
The aforesaid prior art has already proposed (1) the compaction of the peripheral ground by tamping during the driving process of the gravel drain pile can be expected, and (2) the gravel drain pile is driven while controlling decision factors of a tamping degree such as a raising speed of a hollow pipe, i.e., a casing, a period and amplitude of the compaction rod and a height of the extreme end surface thereof or a charging amount of crushed stones in accordance with the tamping degree determined while adjusting to the peripheral soil and the grain size of aggregates.
However, in the existing circumstances, it is not easy to control these factors, and such control greatly depends upon operators' experiences or intuitions. Therefore, it is also difficult to compact the peripheral foundation to the degree as desired.
The strength of the compacted ground is merely judged by a sounding test after a gravel drain pile has been driven. Even though the peripheral ground around the pile was not compacted enough to get higher strength, the pile can not be re-driven and it is left as it is. Therefore, the former method has a problem on quality control of ground compaction and becomes the bottleneck in raising efficiency of pile driving.
SUMMARY OF THE INVENTION
According to a new method for driving a gravel drain pile automatically and an execution apparatus therefore, the invention of prior art is further developed and the aforementioned problems have been overcome. It is an object of the present invention to improve the whole ground composed of gravel drain piles and a peripheral ground to the property as desired.
According to the present invention, there is provided a method for driving a gravel drain pile automatically, the method comprising interpenetrating a hollow casing into a relatively loose sand layer saturated with ground water till its predetermined depth keeping a spacing, thereafter raising the casing while tamping crushed stones charged into the casing by a compaction rod disposed within the casing, and driving a gravel drain pile in the sand layer while continuing raising of the casing and tamping the crushed stones by the compaction rod, characterized by detecting the magnitude of reaction by a reaction detecting device provided on the compaction rod or a load current measuring device of the compaction rod after the casing reaches the predetermined depth and charging of the crushed stones has been confirmed, comparing said reaction value with a set reaction value, and controlling one or plural factors (a raising speed of the casing, a period and amplitude of the compaction rod or height of extreme end thereof) for determining a compacting degree of peripheral ground on the basis of said compared value.
Further, an apparatus for driving a gravel drain pile automatically according to the present invention comprises a casing raising device for raising a hollow casing guided vertically movably along the leader and varying a raising speed of said casing; a drive device for a compaction rod for vertically moving a compaction rod disposed within said casing and varying a period and amplitude of the vertical movement of said compaction rod; a rod height adjusting device for vertically movably supporting said drive device or a compaction rod to vary an entered position of said compaction rod into said hollow casing; a compaction rod reaction detecting device disposed in the midst of said compaction rod to detect reaction of said compaction rod; a crushed stone top-end detecting device for detecting depth of a top end of crushed stones charged into the casing; and a casing depth detecting device for detecting an interpenetrated depth of the casing, characterized by the provision of a processing device wherein after said casing has reached predetermined depth and charging of crushed stones has been confirmed by said crushed stone top-end detecting device and said casing depth detecting device, a detected value from said compaction rod reaction detecting device is compared with a set reaction value, and one or plural factors (raising speed of casing, a period and amplitude of compaction rod or height of extreme end surface thereof) for determining a compacting degree of a peripheral ground are controlled through said casing raising device, said drive device for a compaction rod and said rod height adjusting device.
The grain size of the crushed stones is selected according to the situation of the soil of ground, and set values of tamping reaction according to a compacting degree of a predetermined peripheral ground calculated from the situation of the soil and the grain size of crushed stones are inputted as an upper limit value, a lower limit value or a representative value.
In the operation of the apparatus for driving a gravel drain pile, the reaction of the compaction rod driven up and down detects a tamping degree of a gravel drain pile without delay time, at a so-called real time.
The compacted ground having strength as desired is made within the range of the set value under the comparison of the set value on the basis of the detected value.
Accordingly, according to the present invention,
(1) According to the method for driving a gravel drain pile automatically, properties of ground are grasped at real time by the reaction value of the compaction rod to improve the ground to a ground having a compacting degree as desired. Therefore, execution having reliability is realized. A sounding test need not be carried out after execution as in prior art, and efficient execution can be made. Furthermore, a wide spacing between drain piles in cooperation with a compacted ground can be secured to considerably reduced expenses of works.
(2) According to the apparatus for driving gravel drain pile automatically of the present invention, it is possible to place drain piles in a manner such that a ground in the periphery of the drain piles may be compacted to a value as desired without reliance on the skill of mechanical operation of an operator in correspondence to the state of ground which variously varies in terms of place (in terms of plane and depth) by using an execution apparatus for automatically controlling a reaction value of the compaction rod. Therefore, reliability after execution is enhanced and reduction in execution cost can also be attained.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the whole apparatus according to one embodiment of the present invention;
FIG. 2 is a schematic structural view of the whole apparatus;
FIG. 3(a) is a partially sectional side view showing the whole structure of an upper portion of a compaction rod including a compaction rod reaction detecting device and a compaction rod drive device, and FIG. 3(b) is a view taken on line III of FIG. 3(a);
FIG. 4 is a view showing an internal construction of the compaction rod detecting device;
FIG. 5 is a hydraulic circuit of a casing raising device;
FIG. 6 is a flow chart; and
FIG. 7(a) is a construction view showing one example of a mechanism for varying an amplitude of a compaction rod, and FIG. 7(b) is a sectional view taken on line VII--VII of FIG. 7(a).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 to FIG. 6 show one embodiment of the present invention. That is, FIG. 1 shows a schematic structure of the whole apparatus for embodying the present invention; FIG. 2 schematically shows the structure of essential parts thereof; FIG. 3 to FIG. 5 show partial constructions of various parts; and FIG. 6 is a flow chart of the method according to the present invention.
In FIG. 1, reference character E designates a sand layer as the object for improvement in ground according to the present invention, which sand is loosely compacted and level of ground water is high. Gravel drain piles P composed of aggregates S for driving a gravel drain pile such as crushed stones, salg, gravel, cobbles, etc. are placed into the sand layer E at suitable spacings.
An apparatus for driving a gravel drain pile K according to the present embodiment has the function of automatically driving the gravel drain pile while compacting the peripheral ground at a predetermined tamping degree. The apparatus K comprises a pile hammer body 1 having a vertically erected leader 1A and a wire 1B suspended along the leader 1A and which can be wound and unwound by a winch; a hollow casing 2 guided along the leader 1A; a compaction rod 3 disposed to be projected from the lower end of the upper end along the center axis within the casing 2; a pile hammering upper device 7 comprising a casing rotatively drive device 4, a crushed stone charging hopper 5 and a compaction rod drive device 6 fixedly mounted on the upper end of the casing to be rotatable through or not through a frame, said upper end being connected to said wire 1B (which elements constitute a so-called actuator section); detection devices disposed on said elements; a work instruction device; and a processor 100 for processing signals outputted from said detection devices in accordance with a predetermined program (which elements constitute a so-called control section).
The apparatus K is further provided with an equipment operation and control section 101 and a display section 102.
As shown in FIG. 1, a crushed stone charging signal and a crushed stone top end signal are detected from the crushed stone charging hopper 5 portion, a compaction rod reaction signal is detected from the compaction rod drive device 6, and the casing depth signal is detected from a casing 2 portion.
Construction of the aforesaid elements will be described hereinafter.
The pile hammer body 1 can be moved by a crawler 1C. The casing 2 has a spiral blade 2A provided in the outer periphery thereof and an open- and closable lid 2B provided at the lower end thereof.
FIG. 2 schematically shows the relative structure between the actuator section and the control section. The detection section of the control section will be first described.
The detection section is provided with a casing depth detection device 10, a crushed stone top end detection device 11 and a compaction rod reaction detection device 12.
The casing depth detection device 10 is secured to the casing 2. A cable 15 which is moved as the casing 2 moves up and down is passed over between an upper sheave 16 and a lower sheave 17, and a rotary shaft 18 of the upper sheave 16 is operatively connected to a rotary encoder 19. With this arrangement, as the casing 2 moves up and down, the cable 15 causes the upper sheave 16 to rotate, and the encoder 19 operatively connected thereto detects rotation of the upper sheave 16 and depth of the casing 2.
The crushed stone top end detection device 11 is designed so that a cable 22 having a weight 21 secured to the lower end thereof is wound on a winch 24 driven by a motor 23, and a rotary encoder 26 is operatively connected to a rotary shaft 25 of the winch 24.
The compaction rod reaction detection device 12 is disposed above the compaction rod 3. More specifically, the compaction rod 3 has its upper end coupled to a crank shaft 29 rotatively driven by an electric drive motor 28 constituting the compaction rod drive device 6 through a pin and connecting rod mechanism. The detection device 12 is disposed in the vicinity of the crank shaft 29.
FIG. 3 and FIG. 4 show the detailed construction of the compaction rod reaction detection device 12. That is, FIG. 3 shows the whole upper portion of the compaction rod including the compaction rod detection device 12 and the compaction rod drive device 6, and FIG. 4 shows the internal construction of the compaction rod reaction detection device 12.
As shown in FIG. 4, in the compaction rod reaction detection device 12, a cylinder wall 32 between upper and lower cylinder bodies 30 and 31 is interiorly formed with a liquid-tight cylindrical space, into which is fixed a piston 33 having a piston head 33A. The cylindrical space is divided into upper and lower chambers 34 and 35 by the piston head 33A, each of said chambers being filled with a non-compressive liquid (normally, mineral oil) L. The cylinder bodies 30 and 31 are bored with mounting ports 36 and 37, respectively, in communication with the upper and lower chambers 34 and 35. The compaction rod 3 is removably mounted through upper and lower flanges 38 and 39.
In the present embodiment, a pressure detection sensor shown in FIG. 4 is mounted on the upper chamber 34 in a pressure conductive manner through the mounting port 36. The pressure sensor 40 is of the load cell type, for example, detection signal of which is transmitted to the processor 100. The mounting port 37 of the lower chamber 35 is closed by a blind lid, and the pressure detection sensor is not provided.
As shown in FIG. 3, in the compaction rod drive device 6, rotation of the motor 28 is suitably reduced through a pulley and belt transmission device and a reduction gear 41 and then transmitted to the crank shaft 29. The compaction rod drive device 6 is placed on the frame 42 and is supported as a whole through a floor plate 44 on a piston rod 43a of a hydraulic cylinder 43 constituting a height adjusting mechanism.
Turning back to FIG. 2, the processor 100 receives a tamping device operation signal and a compaction rod reaction range set value. The tamping device operation signal is inputted as a work instruction signal by an operating panel within an operation chamber of the pile hammer body 1A. The compaction rod reaction range set value is likewise inputted from the operating panel of the operation chamber.
On the other hand, in the actuator section controlled by the aforementioned control section, the casing raising device 8 including the compaction rod drive device 6 and the winch mounted on the pile hammer body 1 is selected in the present embodiment.
The compaction rod drive device 6 sends its operation signal to the processor 100. The device receives a period signal from the processor 100 to vary the rotational speed of the drive motor 28 to vary the period of the compaction rod, which will be described later. In the present embodiment, the compaction rod drive device 6 is installed through the floor plate 44 on the hydraulic cylinder 43 constituting the height adjusting mechanism, but the device 6 is directly installed on the frame 42 in the case where a height adjusting mechanism is not provided.
The casing raising device 8 includes a winch 45 mounted on the pile hammer body 1, a hydraulic motor 46 for driving the winch 45 and a variable capacity type hydraulic pump 47 driven by the engine for driving the hydraulic motor 46. The hydraulic pump 47 receives a signal from the processor 100 through a regulator 48 located at the hydraulic pump to vary a displacement to control the rotational speed of the hydraulic motor 46 to thereby adjust the raising speed of the casing 2 connected to the wire 1B wound on the winch 45.
FIG. 5 shows one example of a hydraulic system of a hydraulically driven pile hammer. That is, according to this pile hammer, pressure oil is supplied to the hydraulic motor 46 through a switching valve 50 by the hydraulic pump 47 driven by the engine 49 and returned to a tank 51.
Reference numeral 52 designates a relief valve, and 53 denotes a filter 53.
The gravel drain pile is driven in accordance with the flow chart shown in FIG. 6 using the gravel drain pile driving apparatus comprising the actuator section and the control section as described above.
The operation of the present driving apparatus, that is, the procedure of the method for driving a gravel drain pile will be described hereinafter.
When an operation button is automatically switched, step 1 starts, and step 2 is shifted to step 3. In step 3, charging of crushed stones is determined, and if the crushed stones are not present, the stones are charged. The step is returned to step 2, and step 3 is again carried out. The determination of charging of the crushed stones is in accordance with the signal from the aforementioned crushed stone charging detection device 11.
In the case where the crushed stones are present in the determination by step 3, step 5 is shifted to step 6. In step 6, depth of the casing is determined. In the case where the maximum set depth is 10 m, if the depth exceeds 10 m, the casing is pulled out by 2 m in step 7, and step 7 is shifted to step 8. The determination of the depth of the casing is in accordance with the signal from the aforementioned casing depth detection device 10.
In the case where the depth of the casing is less than 10 m, step 8 is shifted to step 9. In step 9, determination is made if the depth of the casing is less than 0 m. If the depth is less than 0 m, step 9 is shifted to step 10, where raising of the casing is stopped. In the case where the depth of the casing exceeds 0 m, step 10 is shifted to step 11, where determination is made if the tamping device is off. In case of off, raising of the casing is stopped in step 10. The on and off of the tamping device means a work instruction. If the work instruction is off, the apparatus immediately stops.
In the case where the tamping device is not off, step 12 is shifted to step 13. In step 13, determination is made if a real reaction Po of the compation rod is between a lower limit P 1 and an upper limit P 2 of reaction set value. If it is within a predetermined range, step 13 is shifted to step 14 where the displacement of the pump is made constant through the regulator to make the raising speed of the casing constant. Step 15 is shifted to step 5.
If the real reaction of the compaction rod is not within the predetermined range, determination is first made in step 16 if the real reaction is smaller than the lower limit value. If the real reaction is smaller than the lower limit value, the displacement of the pump is reduced through the regulator in step 17 to reduce the raising speed of the casing. Step 18 is returned to step 12.
If the real reaction is larger than the lower limit value, determination is made in step 19 if the real reaction is larger than the upper limit value. If the real reaction is larger than the upper limit value, the displacement of the pump is increased in step 20 to increase the raising speed of the casing. Step 18 is returned to step 12. If the real reaction is smaller than the upper limit value, step 21 is returned to step 12.
In this manner, in the present embodiment, the actuator section is operated in accordance with a program provided in the processor 100 in response to a detection value detected by each of the detection portions, whereby the gravel drain pile is automatically driven.
If set values of the lower limit value P 1 and upper limit value P 2 are inputted so that the compaction of the ground may be achieved, the ground improving method by the gravel drain piles is carried out. In the case where only the drain effect of the gravel drain pile is expected, the upper and lower limit values may be set to be smaller.
According to the case where the ground improvement by the gravel drain piles is expected, the grain size of crushed stones according to the soil of the subject ground, and reaction enough to compact the peripheral ground for the drain piles calculated from the soil and the grain size of crushed stones is provided as a set value.
The compaction rod tamps the crushed stones in exact quantities in response to the set value, and therefore, the ground having a predetermined compacting degree is obtained without disconnection of drain piles.
According to the present invention, properties of the ground are detected at real time with the reaction value of the compaction rod during the driving of gravel drain piles, and the ground is improved at a predetermined compacting degree in response to the detected value. Thus, the efficiency of execution may be enhanced without occurrence of incomplete execution.
According to the embodiment of a method for driving a single drain pile, a set reaction value is set to a degree not to loosen the strength of the peripheral ground, whereby drain piles having a constant and homogeneous compacting degree are driven.
In the driving method according to the aforementioned embodiment, the raising of 2 m after confirmation of charging of crushed stones in the initial step is shown as an example, and a suitable value from 0.5 to 2.5 m adjusted to the soil is employed every time. In case of an electric winding device in place of a hydraulic control mechanism of a varying mechanism of the raising driving device, a speed adjusting device such as an inverter is disposed between an electric motor (in this case, an induction motor is preferably used) for driving the winch and a power source to supply a signal to the speed control device to variably control the speed of the motor.
Other Embodiments
While in the aforementioned embodiment, determination factors such as the period and amplitude of the compaction rod and the height of the extreme end thereof other than the compacting degree as the casing is raised have been constant, it is to be noted that the following mode in which these factors in addition to the raising speed of the casing are made variable may be employed.
First, in the mode wherein the raising speed of the casing is made constant and the period of the compaction rod is made variable, the rotational speed of the electric motor 28 of the compaction rod driving device 6 is suitably increased or decreased by the signal from the processor 100. In this case, as the electric motor 28, an inverter type motor is employed, rotational frequency of which can be varied to easily control the speed. In a normal electric motor, a method may be employed in which the speed is controlled by employment of a stepless speed change gear which is electromagnetically driven.
In the aforesaid mode, when the detected reaction value of the compaction rod is small, judgement is made that the tamping degree is small, and the rotational speed of the driving motor 28 is increased and the period of the compaction rod is decreased. When the detected reaction value is large, judgement is made that the tamping degree is large, and the rotational speed of the driving motor 28 is decreased and the period of the compaction rod is increased. In this way, a predetermined compacting degree is maintained.
In the mode wherein the raising speed of the casing is made constant and the height of the extreme end of the compaction rod is varied, this may be accomplished by extending and contracting the piston rod 43a of the hydraulic cylinder 43 constituting a height adjusting mechanism in response to a signal from the processor 100.
More specifically, the signal from the processor 100 is provided by moving a spool of an electromagnetic direction switching valve (not shown) disposed in a hydraulic circuit for supplying pressure oil to the hydraulic cylinder 43 to thereby suitably switch the pressure oil to the hydraulic cylinder 43.
In the aforesaid mode, in the case where judgement is made that the tamping degree need to be further increased or need to be harder, the hydraulic cylinder 43 is contracted, the compaction rod driving device 6 is lowered, and the extreme end surface of the compaction rod 3 is projected from the lower surface of the casing 2. On the other hand, in the case where the tamping degree is decreased or loosened, the hydraulic cylinder 43 is extended, and the compaction rod driving device 6 is raised, and the extreme end surface of the compacted rod 3 is raised from the lower surface of the casing 2.
In the mode wherein the raising speed of the casing is made constant and the amplitude of the compaction rod is made variable, a detailed example of a mechanism thereof is shown in FIG. 7.
This mechanism is incorporated in the compaction rod driving device 6, in which a crank shaft 55 of the mechanism includes a crank journal 55a, a disc-like crank arm disc 55b and a crank pin 55c and further a hydraulic cylinder 57 disposed within a recess 56 formed in the surface opposed to the crank arm disk 55b. The hydraulic cylinder 57 has its base fixedly mounted on the crank arm disc 55b, and a crank pin 55c is fixedly mounted on the extreme end of a piston rod 57a so that a shaft-center distance of the crank pin 55c is varied by movement of the piston rod 57a. The crank journal 55a has both sides thereof rotatably supported by means of a bearing 58 and a turning force is obtained by a pulley 59. The crank journal 55a is interiorly formed with two oil paths (indicated at broken lines) for feeding pressure oil to the hydraulic cylinder 57, and movement of pressure oil into and out of outside is effected by rotary joints 60 provided on opposite sides of the journal 55a. The oil paths formed in the journal 55a lead to the recess 56 of the crank arm disc 55b and are placed in communication with two oil chambers of the hydraulic cylinder 57 as piping in said recess.
A connecting rod 62 is rotatably connected to the crank pin 55c through bearing metal, and a piston 63 has its upper and lower ends connected between the connecting rod 62 and the compaction rod 3 by means of pin connections. A cylindrical bearing 64 is disposed externally of the piston 63 to guide upward and downward movement of the piston 63.
In this mechanism, though not shown, an electromagnetic direction switching valve is disposed in a hydraulic circuit for supplying pressure oil to the hydraulic cylinder 57. The signal from the processor 100 causes a spool of the direction switching valve to be moved to normal, reversal and neutral position whereby a flow of pressure oil to the hydraulic cylinder 57 may be suitably switched.
In the aforementioned mode, in the case where judgement is made that the tamping degree need to be further increased, pressure oil is supplied to the hydraulic cylinder 57 so that the piston rod 57a may be extended by the signal from the processor 100. Thereby, the shaft-center distance of the crank pin 55c increases to increase the eccentric distance of the connecting rod 62 and increase the amplitude of the compaction rod 3. In the case where the tamping degree is decreased, pressure oil is supplied to the hydraulic cylinder 57 so that the piston rod 57a may be contracted by the siganl from the processor 100. Thereby, the shaftcenter distance of the crank pin 55c decreases to decrease the amplitude of the compaction rod 3.
While in the aforementioned modes, only one element is made variable and others are made constant, it is to be noted needless to say that a plurality of elements may be made simultaneously variable and controlled.
That is, mechanisms for rendering these elements simultaneously variable are combined and some of predetermined target values are selected for control so that the predetermined target values may be achieved in the most adequate manner by the instructions from the processor 100. | A method comprising interpenetrating a hollow casing into a relatively loose sand layer saturated with ground water, thereafter raising the casing while tamping crushed stones charged into the casing by a compaction rod disposed within the casing, and driving gravel drain piles while continuously performing the raising of the casing and the tamping of the crushed stones. After the casing has reached the predetermined depth and the charging of crushed stones has been confirmed an, amplitude of reaction is detected by a reaction detection device provided on the compaction rod or a load current measuring device of the compaction rod. The reaction value is compared with a set reaction value, and one or more factors (a raising speed of the casing, a period, an amplitude and an extreme end surface-height of the compaction rod for determining a compacting degree of a peripheral ground) are controlled in response to the compared value. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates generally to the art of hydraulics, particularly hydrostatic wheel drive systems, and more particularly relates to an improved auxiliary hydrostatic drive system in which the motors are automatically destroked whenever the auxiliary hydrostatic drive system is in a neutral condition and the motors are driven mechanically by the wheels.
In order to obtain additional traction, many agricultural and industrial tractors and similar vehicles are provided with an auxiliary hydrostatic drive for the normally nondriven steerable wheels. An example of such an auxiliary hydrostatic drive system is disclosed and claimed in U.S. Pat. No. 3,458,005 which issued on July 29, 1969 to D. I. Malm et al. Such auxiliary hydrostatic drive systems are generally employed only during periods when the load on the vehicle is great and the vehicle is moving at a relatively slow speed. During periods when the vehicle is moving at a relatively high speed, the motor is disconnected from the source of fluid pressure and, during these periods, some precaution must be taken or the high speeds at which the motors are driven can cause damage to the pistons and/or cam. In previous auxiliary hydrostatic drive systems, damage has been prevented during periods of nonuse through the use of pressure responsive clutches or through the use of variable displacement motors of the swashplate-type in which the swash plate can be returned to the neutral position. Proposals have also been made to pressurize the drive chambers of the motors from some external source so that the pistons are held off the cam.
SUMMARY OF THE INVENTION
The principal object of the present invention is to provide an improved auxiliary hydrostatic drive system in which the motors, when forced to rotate in either a forward or reverse direction while disconnected from the source of fluid pressure, will act as pumps to pressurize their own drive chambers to push the pistons far enough into their cylinders to avoid damaging contact with the cam or other drive member.
Another important object of the present invention is to provide an improved auxiliary hydrostatic wheel drive system in which the ports of the wheel drive motors are automatically connected to the drive chambers of the motors whenever the motors are disconnected from the high pressure source of fluid so that if the wheels are driven mechanically in either a forward or reverse direction, they operate as pumps to pressurize their own drive chambers to push their pistons into the cylinders and thereby prevent damaging contact between the pistons and cam or drive member.
The above objects and additional objects and advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a side elevation view of a vehicle of the type in which the auxiliary hydrostatic drive system according to the present invention can be employed;
FIG. 2 is a schematic illustration of the hydrostatic drive system according to the present invention; and
FIG. 3 is a schematic illustration of a portion of the hydrostatic drive system illustrated in FIG. 2 and showing a modification thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, a typical agricultural tractor is illustrated in FIG. 1 and includes a chassis 10 mounted on a pair of rear main traction wheels 12 and a pair of forward steerable wheels 14. The tractor includes an engine 16 connected to the rear traction wheels 12 through a conventional variable ratio mechanical transmission 18. The tractor also includes a pair of reversible hydraulic motors 20, each of which has one part fixed to the tractor chassis and a rotatable part drivingly connected to one of the steerable wheels 14. The motors 20 can be either the type having a fixed housing and rotatable shaft or of the type having a fixed shaft and rotatable housing, and the rotatable member of the motors 20 can be connected directly to the wheels 14 or indirectly through suitable gearing.
The motors 20 are of the type having a plurality of reciprocating pistons projecting into a drive chamber for engagement with a drive member which may take the form of a cam or fixed swash plate. The motors 20 can be either of the radial-piston-type such as shown in U.S. Pat. No. 3,283,668 which issued on Nov. 8, 1966 to A. I. Louhio and U.S. Pat. No. 3,511,131 which issued on May 12, 1970 to J. H. Kress, or of the axial-piston-type as generally illustrated in U.S. Pat. No. 3,691,910 which issued Sept. 19, 1972 to E. Reichel et al.
A schematic illustration of the overall auxiliary hydrostatic drive system is shown in FIG. 2 and includes a main variable displacement hydraulic pump 22, a reservoir 24 providing a supply of fluid for the pump 22, a charge pump 26 which delivers fluid from the reservoir 24 to the main pump 22 through a filter 28 which is connected between the pumps 26 and 22 by fluid lines 30 and 32. The filter 28 is protected by a relief valve 34 which connects the charge pump 26 with the reservoir 24 if the pressure drop across the filter 28 becomes excessive. The output of the pump 22 is connected by a fluid line 36 to one port in a first side of a spring-centered, pilot-operated, three-position, four-way motor control valve 38. A second port in the first side of the motor control valve 38 is connected to the reservoir 24 by a fluid line 40, an oil coder 42, and a fluid line 44. A restrictor 46 in the fluid line 44 maintains a slight amount of back pressure in the fluid lines 40 and 44. Fluid lines 48 and 50 are connected to the fluid lines 36 and 40 to serve as the supply and exhause lines for hydraulic functions such as hydraulic steering and hydraulic brakes (not shown). Since functions such as steering and brakes are critical, these functions will take priority over others and to this end a priority valve 52 is interposed in the fluid line 36 between the motor control valve 38 and fluid line 48 so that fluid cannot be delivered to the motor control valve 38 unless a predetermined minimum pressure is maintained in the fluid line 48.
A first port in the second side of the motor control valve 38 is connected to a first port in a wheel drive motor 20L by a fluid line 54, and the fluid line 54 is connected by a fluid line 56 to a first port in the first side of a pilot-operated parallel-series valve or a high-torque low-speed, low-torque high-speed valve 58. An additional fluid line 60 extends between a second port in the second side of the motor control valve 38 and a second port in the first side of the parallel-series valve 58, and the fluid line 60 is also connected to a second port in a wheel motor 20R by a fluid line 62. A first port in the second side of the parallel-series valve 58 is connected to a first port in the wheel motor 20R by a fluid line 64 and a second port in the second side of the parallel-series valve is connected to a second port in the motor 20L by a fluid line 66. When valve 58 is in the position illustrated, it connects the wheel motors 20 in parallel relationship with each other, and when the valve 58 is shifted to its alternate position, it connects the motors 20 in series relationship with each other.
The drive chambers or crankcase of the wheel motors 20 are fluid-tight except for connections with fluid lines 68 and 70. The fluid line 68 is connected to the fluid line 70 which in turn is connected to a port one side of a spring-centered, pilot-operated, three-position, three-way crankcase control valve 72. One port on the second side of the crankcase control valve 72 is connected by a fluid line 74 to a fluid line 76 which extends between the fluid lines 54 and 60. A pair of check valves 78 are interposed in the fluid line 76 to prevent the flow of fluid from the fluid lines 74 and 76 to the fluid lines 54 and 60. A second port on the second side of the valve 72 is connected by a fluid line 80 to a fluid line 82 which extends between the fluid lines 54 and 60. A pair of check valves 84 are interposed in the fluid line 82 to prevent flow of fluid from the fluid lines 54 and 60 to the fluid lines 82 and 80. The fluid line 80 is also connected to the reservoir 24 through a fluid line 86.
The pilot system for operation of the valves 38, 58 and 72 includes a forward solenoid valve 88, a reverse solenoid valve 90 and a parallel-series solenoid valve 92. Each of the solenoid valves is a two-position, three-way valve. One port in the first side of the valve 88 is connected to the fluid line 36 by a pilot line 94 and a second port in the first side of the valve 88 is connected to the fluid line 40 by pilot lines 96 and 98. A port in the second side of the valve 88 is connected to one end of the motor control valve 38 by a pilot line 100 and the pilot line 100 is also connected to one end of the valve 72 by a pilot line 102.
One port in the first side of the valve 90 is connected to the fluid line 36 by the pilot line 94, a pilot line 104 and a pilot line 106, and a second port in the first side of the valve 90 is connected to the fluid line 40 by the pilot line 98 and a pilot line 108. A port in the second side of the valve 90 is connected to the second end of the motor control valve 38 by a fluid line 110 which is also connected to the second end of the valve 72 by a pilot line 112.
One port in the first side of the valve 92 is connected to the fluid line 36 by the pilot lines 94 and 104 and a second port in the first side of the valve 92 is connected to the fluid line 40 by the pilot line 98. A port in the second side of the valve 92 is connected to one end of the parallel-series valve 58 by a pilot line 114.
The operation of the above-described auxiliary hydrostatic drive system is as follows. With the tractor engine 16 running, the pump 26 will supply fluid at a relatively low pressure to the main pump 22 which in turn will supply fluid under a relatively high pressure to the motor control valve 38 as long as the demands of the priority hydraulic functions connected to the line 48 are satisfied. Fluid delivered to the pump 22 by the pump 26 which is not needed to supply the demands of either the priority functions or the auxiliary hydrostatic drive system is returned to the reservoir 24 through a fluid line 116, the fluid line 40, the oil cooler 42, and the fluid line 44.
If the tractor is being driven in a forward direction, the solenoid for the valve 88 is actuated so it moves to the left and fluid pressure in the pilot line 94 will flow through the valve 88 and pilot line 100 and act on the valve 38 to move it to the left. With the valve 38 moved to the left, high pressure fluid will flow through the motor control valve 38 and fluid lines 54, 56, and 64 to the first ports of the wheel motors 20 to drive these motors in a forward direction. Low pressure fluid will exhaust from the second ports of the wheel motors 20 through fluid lines 66, 62, and 60 and the motor control valve 38 to the fluid line 40 back to the reservoir 24 through the cooler 42. If the tractor is being driven at a low speed, the parallel mode of the valve 58 may be selected so that the motors 20 will provide a high torque and low speed. If traction limits use of the high torque mode, then the then the low torque mode may be selected. If the variable ratio mechanical transmission 18 is in an intermediate speed or traction prohibits use of high torque, the series mode of the valve 58 will be selected by activating the solenoid of the solenoid valve 92 so that fluid pressure will flow through the fluid lines 94, 104 and 114 to act on the valve 58 and move it to the left. It should be noted that when the valve 38 was moved to the left, the valve 72 was also moved to the left since the pilot lines 100 and 102 provide an operative connection between these two valves to cause them to move substantially in unison. When the valve 72 was moved to the left, the drive chambers of the wheel motors 20 were connected to the reservoir 24 through the fluid lines 68, 70, and 86 while the fluid line 74 was blocked so that the high pressure within the fluid line 54 could not escape through the fluid line 74.
If the tractor is to operate in reverse, the solenoid for the valve 88 is deactivated so that the valve 88 moves to the right and the fluid pressure within the pilot lines 100 and 102 is exhausted through the pilot lines 96 and 98 to the fluid line 40. Simultaneously, or at a later time, the solenoid for the valve 90 will be activated so that this valve moves to the left and permits fluid pressure to flow through the pilot lines 94, 104, 106, 110, and 112 to act on the valves 38 and 72 and move them to the right. With the valve 38 moved to the right, high pressure fluid is delivered to the second ports of the wheel motors 20 and low pressure exhausted through the first ports so that the wheel motors 20 are driven in a reverse direction. The valve 72 functions in the same manner when moved to the right as it does when moved to the left.
To cut out the auxiliary hydrostatic drive system, the solenoids for the valves 88 and 90 are both deactivated so that fluid is exhausted from both ends of both of the pilot-operated, spring-centered valves 38 and 72 and these valves move to their neutral positions. When in the neutral position, the motor control valve 38 blocks the fluid lines 54 and 60 so that high pressure fluid cannot be delivered to the wheel motors 20 and fluid cannot be exhausted from the wheel motors 20 back to the reservoir 24. When the crankcase control valve 72 is in a neutral position, it interconnects the fluid line 70 with the fluid line 74 so that fluid is free to flow from either of the fluid lines 54 or 60 through the fluid lines 76 and 74, through the valve 72, and through the fluid lines 70 and 68 to the drive chambers of the wheel motors 20.
If the tractor is driven through the mechanical transmission 18 while the auxiliary hydrostatic transmission is in its neutral condition, the wheel motors 20 will be driven mechanically and will operate as pumps. Depending upon whether the tractor is driven in a forward or reverse direction, the fluid line 54 or the fluid line 60 will be pressurized due to the wheel motors acting as pumps and this pressure will flow across one of the check valves 78, through the fluid lines 76 and 74, through the valve 72, and through the fluid lines 70 and 68 to the drive chambers of the wheel motors 20. The pressure within the drive chambers of the wheel motors will push the pistons into their cylinders so that they contact their drive member for only a short time. As the pressure differential across the pistons is at a very low level damage to the pistons and their associated drive member is avoided. When the wheel motors 20 are acting as pumps, makeup fluid is provided from the reservoir 24 through the fluid lines 86 and 80 and across one of the check valves 84 to either the fluid line 54 or the fluid line 60 depending upon which is pressurized due to the pumping action of the motors 20. In this regard, it should be noted that it is necessary that the reservoir 24 be located at a higher position than the wheel motors 20 so that a small fluid pressure head will ensure sufficient makeup fluid. In the absence of having the reservoir 24 located at a higher elevation than the wheel motors 20, the fluid line 86 could be connected to the fluid line 40 so that the small pressure head created in the fluid line 40 by the restrictor 46 will ensure that sufficient makeup oil is available. However, if pressure in fluid line 40 is relied on for makeup fluid there will be no fluid available if the tractor is being towed with the engine stalled. With this in mind, it is desirable to have the elevated reservoir.
A slightly modified portion of the auxiliary hydrostatic drive system is illustrated in FIG. 3 wherein the motor control valve 38 and valve 72 are combined into a single valve 118. In the FIG. 3 embodiment, the fluid lines 36, 40, and 74 are connected to ports in the first side of the valve 118 while the fluid lines 54, 60, 80, and 70 are connected to ports in the second side of the valve 118. Although the FIG. 3 embodiment has a single valve instead of two valves as employed in the FIG. 2 embodiment, the operation of the FIG. 3 embodiment is exactly the same as the operation of the FIG. 2 embodiment.
Although two embodiments of the invention have been described and illustrated, various modifications can be made without departing from the spirit and scope of the invention. For example, the pilot system for operating the valves 38, 58, and 72 can be omitted and these valves directly actuated by solenoids, or the valves 88 and 90 can be combined into a single valve. Also, the valve 72 could be changed to a two-position valve. Still additional modifications could be made without departing from the underlying principles of the invention, and therefore, the invention should not be limited to the specific illustration and description, but only by the following claims. | An auxiliary hydrostatic drive system for a vehicle includes a pump, a reservoir, fluid motors connected to the normally non-driven steerable wheels of the vehicle, reciprocating piston-type wheel drive motors connected to the normally nondriven steerable wheels, fluid lines interconnecting the pump and reservoir with the inlet and outlet ports of the wheel motors, and a motor control valve movable to either side of a neutral fluid blocking position to forward and reverse drive positions. An additional valve interconnects the motor ports with the drive chambers of the motors whenever the motor control valve is in the neutral position so that during periods when the motors are not connected to the pump and are driven mechanically, they function as pumps to pressurize their drive chambers and hold their pistons off the drive cams. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to new and useful improvements in power scrubbing and flushing the coolant system of automobile engines and the like.
These systems normally include an engine block having coolant passages therein, a coolant pump for circulating the coolant, an engine core radiator through which the coolant is passed in order to cool same, and a heater radiator core through which heater coolants may be passed selectively in order to heat the interior of the vehicle.
Even with the additives provided in antifreeze solutions normally available, considerable scale, rust and sludge still occurs and builds up throughout the system and this lowers the efficiency thereof considerably, even to the extent of completely blocking the circulation of the coolant under severe conditions.
Conventionally, radiator chemicals are available to assist in the removal of scale and the like and these are normally poured into the radiator core through the radiator cap.
After running the engine for a predetermined length of time, the system is drained and gravity flushing takes place by inserting a garden hose into the radiator cap and opening the various drain cocks throughout the system.
However it will be appreciated that no scrubbing action can take place under these conditions and this particular system leaves much to be desired particularly when the scale, rust and sludge conditions within the cooling system are severe.
PRIOR ART
The following prior art is known to applicant.
U.S. Pat. No. 2,029,232--F. W. Green, Jan. 28, 1936. This shows a radiator flushing device having a single valve and adapted to be connected to a pressure water system.
U.S. Pat. No. 3,431,145--F. D. Riley, Mar. 4, 1969. This utilizes a method for flushing and cleaning the lubrication system of internal combustion engines by injecting a petroleum derivative solvent with compressed air through the oil filler tube at the same time injecting through the filter opening in the crank case.
U.S. Pat. No. 3,350,223--R. G. Monteath, Oct. 31, 1967. This invention discloses a cleaning method for the liquid circulating system utilizing a mixture of water and air and pressure alternatively through the radiator and engine and out of the engine and through the engine and the radiator and out of the radiator utilizing a plurality of timers and automatic valves.
U.S. Pat. No. 3,409,218--Robert G. Moyer, Nov. 5, 1968. This shows apparatus for cleaning an engine cooling system and for injecting new coolant into the system and includes a distributor with a tank having a rolling diaphragm which divides the interior into an upper coolant reservoir and a lower water chamber.
U.S. Pat. No. 4,127,160--Kenneth L. Joffe, Nov. 28, 1978. This comprises a method and apparatus for flushing debris from a water circulating system of an engine and includes an inlet conduit for flushing liquid together with a series of branch conduits connected to points on the circulation system. A valve or series of valves set above between various positions which dictates different flow paths for the flushing liquid through the conduits and the circulating system.
U.S. Pat. No. 4,390,049--Robert W. Albertson June 28, 1983. This shows a portable operated apparatus for cleaning, flushing and filling the cooling system of an engine. The system is cleaned by sequentially moving liquid in opposite directions through the cooling system utilizing an air operated reciprocating piston pump assembly to agitate or sequentially move the liquid in opposite direction.
The present invention overcomes all of these disadvantages by providing a back flow scrubber and flushing system which is power operated and which can remove the majority of scale, rust and sludge efficiently and rapidly and at the same time can then top-up or replace the necessary quantity of antifreeze at the completion of the cycle. Furthermore, a pressure test of the system can be accomplished readily and easily during the operation of the apparatus.
In accordance with the invention there is provided a system of scrubbing and flushing automotive heater radiators, engine block and engine radiators comprising the steps of routing water under pressure to the outlet side of the heater radiator core, and returning the water after it has passed through the heater radiator core, the engine coolant passages within the engine block and the engine radiator core, routing same back to the outlet side of the heater radiator core and circulating the water for a predetermined time interval, draining the water, connecting a source of water under pressure to the heater radiator core outlet, the heater radiator core, the coolant passages within the engine block and the engine radiator core to a discharge and circulating fresh water through the system for a predetermined length of time.
In accordance with a further aspect of the invention there is provided apparatus for scrubbing and flushing the coolant system of an automobile engine which includes a heater core having an inlet and an outlet, an engine block having coolant passages therein and having inlets and outlets therefore, a coolant pump and an engine radiator core all operatively connected together, said apparatus comprising in combination a fluid pump, a liquid holding reservoir connected to said fluid pump, a first conduit extending from said fluid pump and being operatively connected to the outlet of the heater radiator core, a second conduit connected between the outlets of said coolant passages and said reservoir and a third conduit extending between said reservoir and said first conduit, and first valve means in said second conduit controlling the routing of fluid therethrough.
A still further advantage of the invention is to provide a device which can completely back scrub and flush the entire system, pressure test same and replace the required quantity of antifreeze in the minimum of and at extremely low cost. This means that a radiator flushing liquid and water flushes in a direction counter to the normal coolant flow which lifts off scale and rust formed on the walls of the coolant system during normal operations and normal direction of coolant flow.
A still further aspect of the invention is to provide a device of the character herewithin described which is simple in construction, economical in manufacture and otherwise well suited to the purpose of which it is designed.
With the foregoing in view, and other advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, the invention is herein described by reference to the accompanying drawings forming a part hereof, which includes a description of the best mode known to the applicant and of the preferred typical embodiment of the principles of the present invention, in which:
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the apparatus and system.
FIG. 2 is a top plane view of the apparatus.
FIG. 3 is an isometric view of the apparatus.
FIG. 4 is a schematic view of the three positions of one of the valves.
FIG. 5 is a schematic representation of the three positions of the other of the valves.
In the drawings like characters of reference indicate corresponding parts in the different figures.
DETAILED DESCRIPTION
Proceeding therefore to describe the invention in detail, reference should first be made to FIGS. 2 and 3 in which 10 illustrates a casing with a hinged cover 11 on the upper side thereof and a knee operated switch 12 on the front panel.
Not illustrated is a power cord connectable to a source of electrical power such as 110 VAC.
FIG. 2 shows a top plan view of the casing which includes a planar surface 13 and a cylindrical pot or reservoir 14 sunk into the top surface and supported thereby.
A pressure gauge 15 is illustrated in the top panel together with hose connections 16, 17, 18 and 19 all of which are extendable, flexible hoses similar to those used on washing machines, dishwashers and the like.
Hose 16 is adapted to be connected to a conventional water supply under pressure, hose 17 may be extended to a convenient drain, hose 18 is connectable to the heater radiator core inlet conduit 20 and hose 19 is connectable to the hose connection 21 which extends from the top of the engine block 22 to the intake header tank 23 of the engine radiator core assembly collectively designated 24.
These items are also shown in the schematic illustration of FIG. 1 in which the engine block 22 is provided with a plurality of coolant passages illustrated schematically by reference character 25.
These are connected via conduit 21 to the radiator intake header tank 23 and a further conduit 26 extends from the outlet manifold 27 of the radiator to a conventional water or coolant pump 28. From there, a conduit 20 normally extends to the inlet side 29 of a heater radiator core 30 with the inlet 31 of this core being connected by conduits 32, to the coolant passages in the top of the block 22 all of which is conventional.
Before connecting the system to the engine assembly, the conduit 20 is disconnected from the water pump 28 and this normal connection is shown in phantom in FIG. 1.
Furthermore a connector 33 is inserted in series in the hose or conduit 21 having a take-off upper radiator adaptor 34 which is preferrably a garden hose type connection so that the aforementioned conduit 19 from the casing is easily connected to the system.
The other connection is via conduit or hose 18 from the casing 10 which may be connected to the disconnected end of the conduit 20 leading to the heater radiator core 30.
Within the casing is the aforementioned open-topped reservoir 14 which is provided with a filter screen 35 through which all fluid must pass and which connects to a fluid pump and motor assembly shown schematically by reference character 36 and situated within the casing 10.
The outlet of this pump/motor combination is connected to the aforementioned hose 18 which includes a one-way valve 37 therein and also has the pressure gauge 15 connected thereto and which is situated in the top panel 13 of the casing 10.
The hose or conduit 19 which is connected to upper radiator adaptor 34 via the hose connection on the end thereof, leads to a first rotary valve 38 and situated in the top panel 13 of the casing.
The aforementioned drain hose 17 is connected to this valve 38 and may be routed to a convenient drain 39 when in use. The conduit 19 also connects to valve 38 and a third conduit 39 extends from this valve to the return conduit 40 leading to the two conduits 18 as indicated by the junction 41 downstream of the one-way valve 37.
A further rotary valve 42 is situated in conduit 40 between junction 41 and downstream of the connection of conduit 39 with conduit 40.
Water supply under pressure through conduit or hose 16 also connects to valve 42 and this water supply is controlled by a valve 43, a back-flow preventer valve 44 and a pressure reduction regulator 45 all of which are conventional.
The valves 38 and 42 are capable of three positions each and these are shown schematically in FIGS. 4 and 5.
Dealing first with valve 38, when in one position, conduit 19 is connected to conduit 39 as indicated by the letter "A" in FIG. 4.
When in the position shown at "B" in FIG. 4, conduit 19 is connected to the drain 17 and when in the position shown in "C" in FIG. 4, this valve closes off all three conduits one from the other.
In FIG. 5, "A" indicates the position of the valve which connects the source of water under pressure via hose 16 to the line 18. When in position "B" in FIG. 5, the water under pressure passes from hose 16 through the valve to the reservoir via line 40 and when in the position shown in "C" in FIG. 5, all three lines are shut off one from the other.
In operation, and dealing first with the power back flush or scrubbing of the chemical scale remover, a conventional corrosive or caustic chemical sold under various names as a radiator flushing liquid may of course be placed within the radiator of the system and the engine run for a predetermined length of time. The heated temperature control inside the car should be turned to the hottest position to ensure flow through the heater radiator core.
The radiator cap is carefully removed and both valves 38 and 42 are placed to the "C" position or the closed position.
The filter basket 35 should be placed within the reservoir ensuring that same is clean and positioned correctly whereupon the device is connected to the source of electrical power through the aforementioned electrical cord (not illustrated). At this point the fluid pump 36 will be "off" as this is controlled by the aforementioned knee switch 12 on the front of the casing.
The water supply line 16 is then connected to a garden hose supply and valve 43 is opened. The adapter 33 is inserted within the hose 21 and line or hose 19 is connected to the upper radiator adaptor 34.
The heater outlet hose 20 is disconnected from water pump 28 and operatively connected to the coolant system supply hose 18. In this connection the open connection left at the water pump should be closed using a short piece of heater hose with a plug and hose clamp.
A short length of garden hose may be connected between the drain hose 17 and the drain 39 and the radiator chemical scale remover is poured into the radiator.
The car engine should be run at idle for some 10 to 15 minutes after which the engine should be switched off.
The back scrubbing or power flushing is undertaken as follows:
Valve 38 should be turned to position "C" i.e. to the off position and valve 42 should be turned to position "B" thus permitting water to flow from the supply to the reservoir 14 which should be filled to approximately half way in order to prime the pump, remove air locks with water and fill the hoses extending from the power scrubber and eliminate any incompletely filled portions of the system. The valve 42 may be turned to position "C" or off.
Valve 38 is then turned to position "A" thus connecting hose 19 with conduit 39 and the fluid pump 36 is actuated by the knee switch 12. This pumps water and chemical from the reservoir 14 along line 18 and into the conduits 20 upwardly through the outlet 29 of the heater radiator core 30 and out through the inlet 31 into hose 32 which leads to the upper side of the engine block 22. It then passes downwardly through all of the coolant passages 25 and out through pump 28 to the conduit 26 and hence to the lower manifold 27 of the engine radiator core. It flows upwardly through the core from the outlet to the inlet header 23 and thence to hose 21 and into line 19, through valve 38 and conduit 39 to conduit 40 and back to the reservoir 14. Straining takes place in basket 35 and this water circulates for approximately 15 to 30 minutes.
The system is then power flushed and the sequence is as follows:
Valve 38 is turned to position "B" thus connecting line 19 to the drain 39 and the reservoir 14 is emptied by pump 36 at which time the fluid pump 36 should be stopped.
Valve 42 is now also turned to position "B" thus connecting the source of water under pressure to line 40 and hence to the reservoir 14. The water should be turned off by valve 42 when the reservoir is approximately half full.
Pump 36 is now started and stopped when the reservoir 14 has been emptied at which time valve 42 should be turned to position "A" and valve 38 to position "B".
Position "A" connects the source of water under pressure to line 18 and position "B" of valve 38 connects line 19 to the drain.
The system is then back flushed with fresh water until it runs clear at the drainline 17 utilizing the pressure of the water system rather than pump 36.
It is advisable to start the car and run same for approximately 5 minutes during the back flush operation to ensure that all of the internal valves are open.
Once water runs clear out of the drain hose 17, valve 38 may be turned to the off position or position "C" thus allowing the mains of water pressure to build up the system pressure to the regulated pressure of approximately 22 PSI at which time valve 42 may be turned to position "C" so that both valves are off and the system is isolated under 22 PSI pressure. The radiator cap normally preset to 15 PSI will reduce the pressure in the system to this 15 PSI.
The pressure test may last for approximately one to five minutes and if no drop occurs then the system would appear to be sound.
At this time the appropriate quantity of antifreeze is added to reservoir 14 depending upon temperature control required and the capacity of the cooling system. At this time valve 38 may be moved to position "B" thus connecting line 19 to the drain and pump 36 may be actuated to pump the antifreeze into the system.
When the reservoir is empty, the pump is closed down, it being understood that the insertion of the required quantity of antifreeze into the system has ejected the equivalent amount of water through line 17 to the drain.
Both valves 38 and 42 are moved to position "C" and the system may be disconnected with the various heater hoses reconnected in the usual way. Upper radiator adaptor 34 may be closed off if it is desired to leave same in circuit with the system.
It will therefore be seen that a relatively simple, efficient power back flush and scrubbing system is provided which is simple in operation and very efficient in use.
Since various modifications can be made in my invention as hereinabove described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without departing 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. | Conventionally, cooling systems are drained and flushed out with a gravity flow of water added through the radiator cup. The present device permits power back scrubbing and flushing through the heater core, through the engine and then through the radiator core thus removing far more scale, rust and sludge than the usual system. It can incorporate a pressure test and then can add the correct amount of antifreeze to the water within the system. | 5 |
FIELD OF THE INVENTION
[0001] The invention relates generally to the field of liquid droplet ejection, for example, inkjet printing, and more specifically to an apparatus for controlling temperature profiles in liquid droplet ejection mechanisms.
BACKGROUND OF THE INVENTION
[0002] The state of the art of inkjet printing, as one type of liquid droplet ejection, is relatively well developed. A wide variety of inkjet printing apparatus are available for commercial purchase from consumer desktop printers that produce general documents to commercial wide format printers that produce huge photographic quality posters.
[0003] A thermal inkjet printer typically comprises a transitionally reciprocating printhead that is fed by a source of ink to produce an image-wise pattern upon some type of receiver. Such printheads are comprised of an array of nozzles through which droplets of ink are ejected by the rapid heating of a volume of ink that resides in a chamber behind a given nozzle. This heating is accomplished through the use of a heater resistor that is positioned within the print head in the vicinity of the nozzle. The heater resistor driven by an electrical pulse that creates a precise vapor bubble that expands with time to eject a droplet of ink from the nozzle. Upon the drop being ejected and the electrical pulse terminated, the ink chamber refills and is ready to further eject additional droplets when the heater resistor is again energized.
[0004] The quality of an ejected droplet from a thermal inkjet printer is dependent upon the precision of the vapor bubble that is produced by the heater resistor, and is therefore dependent upon how uniformly the heater resistor produces heat. Since it is desirable to shape heater resistors to better control the quality and trajectory of the ejected droplet, these shapes can also create design issues of their own. Heater resistors of various shapes are known. More specifically, heaters in the form of rings are known. U.S. Pat. No. 6,588,888 by Jeanmaire et al. teaches that heaters that are disposed within droplet forming mechanisms can be formed in a ring shape or a partial ring shape.
[0005] Inkjet heater resistors by their nature must reside in compact areas, such as within a small printhead. When these resistors are placed within miniature enclosures and are constructed of various curved shapes, current flows through the shortest path that is available. That is to say that if there is a source of current that flows through a conductor, and that conductor provides both a short and a long path to the flow of current, the current will bias itself to take the shorter path. This is defined as current crowding, since more current will flow within the shorter portion of the conductor than the longer portion of the conductor. This being understood, the two paths of current within a conductor will also produce a non-uniform heating profile due to the non-uniform current flow. This is known and addressed in U.S. Pat. No. 6,367,147 by Giere et al., wherein the inventors use current balancing resistors to minimize such effects.
[0006] The ability of a material to resist the flow of electricity is a property called resistivity. Resistivity is a function of the material used to make a resistor and does not depend on the geometry of the resistor. Resistivity is related to resistance by:
R=pL/A
Where R is the resistance (Ohms); p is the resistivity in (Ohms-cm); L is the length of the resistor; and A is the cross sectional area of the resistor. In thin film applications, a property known as sheet resistance (Rsheet) is commonly used in the analysis and design of heater resistors. Sheet resistance is the resistivity of a material divided by the thickness of the heater resistor constructed from that material, the resistance of the heater resistor determined by the equation:
R=R sheet( L/W )
where L is the length of the heater resistor and W is the width of the heater resistor.
[0007] The construction of heater resistors using the CMOS process is desirable and lends particular efficiencies to ink jet printer manufacturing. Moreover, the selective doping of the base polysilicon with elements such as Arsenic, Boron and Phosphorus produce variable sheet resistivities. These resistivities can vary from a minimum of 1 milliohm-cm to 100 ohm-cm. This ability to selectively dope the base sheet resistances allows the construction of heater resistors in the same polysilicon as other necessary structures. Additionally, by adding electronic drivers and the like to the base structure reduces costs and improves process efficiencies by a reducing production steps and the eliminating the need for other materials.
[0008] Inkjet heater resistors constructed of a circular shape are subject to the current crowding effect. Additionally, the doping of polysilicon to create heater resistors is both cost-effective and desirable in the full utilization of the CMOS process to produce inkjet printheads. The present invention is directed towards overcoming one or more of the problems set forth above.
SUMMARY OF THE INVENTION
[0009] According to one feature of the present invention, a heater includes a first material having a circular form and a first sheet resistivity. The first material has a first radius of curvature. The heater has a second material having a circular form and a second sheet resistivity. The second material is positioned adjacent to the first material and has a second radius of curvature. The first radius of curvature is greater than the second radius of curvature and the first sheet resistivity is less than the second sheet resistivity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the detailed description of the preferred embodiments of the invention presented below, reference is made to the accompanying drawings, in which:
[0011] FIG. 1 is a two dimensional view of an inkjet orifice surrounded by a ring heater;
[0012] FIG. 2 is a detail of a non-uniform temperature profile produced by an uncorrected ring heater;
[0013] FIG. 3 is a detail of a corrected temperature profile produced by a corrected ring heater;
[0014] FIG. 4 is a detail of a two dimensional view of an inkjet orifice surrounded by a ring heater and accompanied by its cross-sectional view of it's construction;
[0015] FIG. 5 is a detail of a two dimensional view of an inkjet orifice surrounded by a ring heater and accompanied by its cross-sectional view of it's construction;
[0016] FIG. 6 is a detail of a two dimensional view of an inkjet orifice surrounded by a ring heater and accompanied by its cross-sectional view of it's construction;
[0017] FIG. 7 is a detail of a two dimensional view of an inkjet orifice surrounded by a ring heater and accompanied by its cross-sectional view of it's construction; and
[0018] FIG. 8 is a detail of a corrected temperature profile produced by a corrected ring heater using selective doping.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The present description will be directed in particular to elements forming part of, or cooperating more directly with, apparatus in accordance with the present invention. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art. In the following description and drawings, identical reference numerals have been used, where possible, to designate elements common to the figures.
[0020] Referring to FIG. 1 , drawn is a two dimensional view of the substrate of an orifice plate 10 upon which is disposed an inkjet heater 20 which is arranged about an ejection nozzle 30 . An electrical input conductor 40 and an electrical output conductor 50 supply electrical current to the inkjet heater 20 . The circular or ring-like construction of the inkjet heater 20 by its physical nature allows a shorter current path around the inside path 60 versus the outside path 80 of the inkjet heater 20 . Also shown for means of clarification are an inside portion 70 of the inkjet heater 20 and an outside portion 90 of the inkjet heater 20 . Disposed between the outside portion 90 of the inkjet heater 20 and the ejection nozzle 30 is an unused portion of the base substrate 100 from which the orifice plate 10 is constructed.
[0021] Referring now to FIG. 2 , shown is the detail of a non-uniform temperature profile 110 that will occur in an uncorrected inkjet heater 20 . The application of a specific electrical current across the electrical input conductor 40 and the electrical output conductor 50 (from FIG. 1 ) results in non-uniform heating of the inkjet heater 20 . It should be noted that only ½ of the inkjet heater 20 is detailed for purposes of clarity. It is apparent that, for a given voltage drop, the thermal gradient induced into an uncorrected inkjet heater 20 ranges from 287 degrees Centigrade in the outside path 80 of the inkjet heater 20 to 418 degrees Centigrade in the inside path 60 of the inkjet heater 20 . Thusly, the variation in temperature across the inkjet heater 20 totals 131 degrees Centigrade and cause problems in thermal bubble formation.
[0022] Referring now to FIG. 3 , shown is the detail of a uniform temperature profile 120 that will occur in a corrected inkjet heater 20 when applying one of a variety of possible correction methods of the present invention. Again it should be noted that only ½ of the inkjet heater 20 is detailed for purposes of clarity. It is apparent from the uniform temperature profile 120 that the temperature gradient in a corrected inkjet heater 20 ranges from 484 degrees Centigrade in the outside path 80 of the inkjet heater 20 to 500 degrees Centigrade in the inside path 60 of the inkjet heater 20 . It should also be noted that the same specific voltage drop is applied as in the prior example. Thus the variation in temperature across the inkjet heater 20 is reduced to total only 16 degrees Centigrade and will substantially eliminate undesired effects in thermal bubble formation.
[0023] Referring now to FIG. 4 , a drawing is shown that details a two dimensional view of a orifice plate 10 that comprises an inkjet heater 20 that is arranged about an ejection nozzle 30 . An electrical input conductor 40 and an electrical output conductor 50 supply electrical current to the inkjet heater 20 . The ringed construction of the inkjet heater 20 by nature of physics allows a shorter current path around the inside path 60 versus the outside path 80 of a current flowing through inkjet heater 20 . Additionally FIG. 4 details the construction of the orifice plate 10 in cross-sectional view built upon a base substrate 100 . Establishing a flow of current through input conductor 40 and output conductor 50 that flows through the inkjet heater 20 creates the non-uniform heating profile previously discussed in FIG. 2 . This non-uniform heating is corrected by using a method as shown in the profile drawing of FIG. 4 . In this implementation, the outside portion 90 of the inkjet heater 20 is thicker than the inside portion 70 of the inkjet heater 20 , and their relative widths are equal. This situation establishes a condition wherein the outside portion 90 of the inkjet heater 20 has a larger cross-sectional area than the inside portion 70 of the inkjet heater 20 . A larger cross-sectional area exhibits lower resistance to current flow than a smaller cross sectional area. Thus, the resistance change brought about by a corresponding change in cross-sectional area will normalize the current flow to be uniformly distributed through the inkjet heater 20 . Current that flows by virtue of current crowding through the path of lowest resistance will be denied that ability by making all the current paths through the heater resistor 20 equal to each other. This fact enables an equal flow of current through the heater resistor 20 , and whose temperature profile embodies the uniform temperature profile 120 discussed in FIG. 3 .
[0024] Referring now to FIG. 5 , an additional drawing is shown that details a two dimensional view of a orifice plate 10 that comprises an inkjet heater 20 that is arranged about an ejection nozzle 30 . An electrical input conductor 40 and an electrical output conductor 50 supply electrical current to the inkjet heater 20 . The ringed construction of the inkjet heater 20 by nature of physics allows a shorter current path around the inside path 60 versus the outside path 80 of a current flowing through inkjet heater 20 . Additionally FIG. 5 details the construction of the orifice plate 10 in cross-sectional view built upon a base substrate 100 . Establishing a flow of current through input conductor 40 and output conductor 50 that flows through the inkjet heater 20 creates the non-uniform heating profile previously discussed in FIG. 2 . This non-uniform heating is corrected by using a method as shown in the profile drawing of FIG. 5 . In this implementation, the outside portion 90 of the inkjet heater 20 is wider and has a higher doping than the inside portion 70 . The outside portion 90 of the inkjet heater 20 has a larger cross-sectional area than the inside portion 70 of the inkjet heater 20 . This condition creates a proper normalization. Current that wants to flow by virtue of current crowding through the path of lowest resistance will be denied that ability by making all the current paths through the heater resistor 20 equal to each other. This fact enables an equal flow of current through the heater resistor 20 , and whose temperature profile embodies the uniform temperature profile 120 discussed in FIG. 3 .
[0025] Referring now to FIG. 6 , a drawing is shown that details a two dimensional view of a orifice plate 10 that comprises an inkjet heater 20 that is arranged about an ejection nozzle 30 . An electrical input conductor 40 and an electrical output conductor 50 supply electrical current to the inkjet heater 20 . The ringed construction of the inkjet heater 20 by nature of physics allows a shorter current path around the inside path 60 versus the outside path 80 of a current flowing through inkjet heater 20 . Additionally FIG. 6 details the construction of the orifice plate 10 in cross-sectional view built upon a base substrate 100 . Establishing a flow of current through input conductor 40 and output conductor 50 that flows through the inkjet heater 20 creates the non-uniform heating profile previously discussed in FIG. 2 . This non-uniform heating is corrected by using a method as shown in the profile drawing of FIG. 6 . In this implementation, the outside portion 90 of the inkjet heater 20 is thicker than the inside portion 70 of the inkjet heater 20 , and their relative widths are unequal, inside portion 70 being thinner than outside portion 90 . This situation establishes a condition wherein the outside portion 90 of the inkjet heater 20 has a larger cross-sectional area than the inside portion 70 of the inkjet heater 20 . This condition over-compensates the equalization of the resistance of inkjet heater 20 , and causes excessive current to flow in the outside portion 90 . Selectively doping the inside portion 70 slightly heavier than outside portion 90 will cause a change in the sheet resistivity, making the inside portion 70 more conductive than the outside portion 90 and will normalize the current flow to be uniformly distributed through the inkjet heater 20 . Current that wants to flow by virtue of current crowding through the path of lowest resistance will be denied that ability by making all the current paths through the heater resistor 20 equal to each other. This fact enables an equal flow of current through the heater resistor 20 , and whose temperature profile embodies the uniform temperature profile 120 discussed in FIG. 3 .
[0026] Referring now to FIG. 7 , a drawing is shown that details a two dimensional view of a orifice plate 10 that comprises an inkjet heater 20 that is arranged about an ejection nozzle 30 . An electrical input conductor 40 and an electrical output conductor 50 supply electrical current to the inkjet heater 20 . The ringed construction of the inkjet heater 20 by nature of physics allows a shorter current path around the inside path 60 versus the outside path 80 of a current flowing through inkjet heater 20 . Additionally FIG. 7 details the construction of the orifice plate 10 in cross-sectional view built upon a base substrate 100 . Establishing a flow of current through input conductor 40 and output conductor 50 that flows through the inkjet heater 20 creates the non-uniform heating profile previously discussed in FIG. 2 . This non-uniform heating is corrected by using a method as shown in the profile drawing of FIG. 7 . In this implementation, the outside portion 90 of the inkjet heater 20 is sloped 130 in relation to the inside portion 70 of the inkjet heater 20 , and their relative widths in relation to one another are equal. It should be understood that in keeping with the prior descriptions they can also be unequal, and that the sloped 130 condition can also be an arcuate 140 condition or exhibit some uniform or non-uniform radius of curvature. This configuration establishes a situation wherein the outside portion 90 of the inkjet heater 20 has a larger cross-sectional area than the inside portion 70 of the inkjet heater 20 . A larger cross-sectional area exhibits lower resistance to current flow than a smaller cross sectional area. Thus, the resistance change brought about by a corresponding change in cross-sectional area will normalize the current flow to be uniformly distributed through the inkjet heater 20 . Current that wants to flow by virtue of current crowding through the path of lowest resistance will be denied that ability by making all the current paths through the heater resistor 20 equal to each other. This fact enables an equal flow of current through the heater resistor 20 , and whose temperature profile embodies the uniform temperature profile 120 discussed in FIG. 3 .
[0027] Referring now to FIG. 8 , a drawing is shown that details a two dimensional view of a orifice plate 10 that comprises an inkjet heater 20 that is arranged about an ejection nozzle 30 . An electrical input conductor 40 and an electrical output conductor 50 supply electrical current to the inkjet heater 20 . The ringed construction of the inkjet heater 20 by nature of physics allows a shorter current path around the inside path 60 versus the outside path 80 of a current flowing through inkjet heater 20 . Establishing a flow of current through input conductor 40 and output conductor 50 that flows through the inkjet heater 20 creates the non-uniform heating profile previously discussed in FIG. 2 . This non-uniform heating is corrected by using a method as shown in FIG. 8 . By more heavily doping the outside portion 90 of the inkjet heater 20 than the inside portion 70 of the inkjet heater 20 , a normalization of sheet resistance can also be accomplished. It should be noted that this is detailed in FIG. 8 , by showing a greater density of dots (doping) within outside portion 90 than the density of dots (doping) within inside portion 70 of inkjet heater 20 . This situation establishes a condition wherein the outside portion 90 of the inkjet heater 20 has a lower resistance than the inside portion 70 of the inkjet heater 20 . Thus, the resistance change brought about by a corresponding change in area doping will normalize the current flow to be uniformly distributed through the inkjet heater 20 . Current that wants to flow by virtue of current crowding through the path of lowest resistance will be denied that ability by making all the current paths through the heater resistor 20 equal to each other. This fact enables an equal flow of current through the heater resistor 20 , and whose temperature profile embodies the uniform temperature profile 120 discussed in FIG. 3 . It should be noted here that people skilled in the art will realize that an inkjet heater 20 can be divided into a plurality of correction regions and, for purposes of clarity, the previous discussions have been limited to two regions. Doping of the heater can be varied across an inkjet heater 20 in a multiplicity of rings that can vary in thickness and in width due to individual engineering needs. Additionally, for the corrected results shown in FIG. 3 , the resistivity across the inkjet heater 20 was varied as the square of its radius, when using silicon as a base material. It should be understood by those skilled in the art that the optimum resistivity variation across the inkjet heater 20 will vary as the base material varies, (for example silicon vs. glass) based upon the thermal environment.
[0028] Although the present invention has been described with reference to inkjet printheads, it is recognized that printheads of this type are being used to eject liquids other than inkjet inks. As such, the present invention finds application as a liquid droplet ejector for use in areas other than and/or in addition to its inkjet printhead application.
[0029] The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the invention.
Parts List
[0000]
10 orifice plate
20 inkjet heater
30 ejection nozzle
40 electrical input conductor
50 electrical output conductor
60 inside path
70 inside portion
80 outside path
90 outside path
100 base substrate
110 non-uniform temperature profile
120 uniform temperature profile
130 sloped
140 arcuate | A heater is provided. The heater includes a first material having a circular form and a first sheet resistivity. The first material has a first radius of curvature. The heater also includes a second material having a circular form and a second sheet resistivity. The second material is positioned adjacent to the first material and has a second radius of curvature. The first radius of curvature is greater than the second radius of curvature and the first sheet resistivity is less than the second sheet resistivity. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/462,346 filed on May 2, 2012, which claims the benefit of U.S. Provisional Patent Application No. 61/481,697 filed May 2, 2011, the contents each of which are incorporated herein by reference thereto.
BACKGROUND
[0002] Embodiments of the invention relate generally to an apparatus and method for mounting items on a firearm.
[0003] Numerous accessories are mounted on a standard firearm rail by engaging features of the rail non-limiting examples of such features include but are not limited to telescopic sights, tactical sights, laser sighting modules, Global Positioning Systems (GPS) and night vision scopes. Standard firearm rails include a military standard 1913 rail, Weaver rail, NATO STANAG 4694 accessory rail or equivalents thereof.
[0004] Accordingly, it is desirable to provide a method and apparatus for mounting accessories to a rail of a firearm.
SUMMARY OF THE INVENTION
[0005] In one exemplary embodiment an upper receiver for a weapon is disclosed, the upper receiver having a plurality channels each being oriented in a first direction and wherein each of the plurality of channels intersect an elongated channel extending in a second direction; a modular rail having a pair of securement features configured to be slidably received within a pair of the plurality of channels such that modular rail can slide in the pair of the plurality of channels in the first direction until the pair of features can slide within the elongated channel in the second direction.
[0006] In another embodiment, an upper receiver for a weapon is provided, the upper receiver having: a plurality channels each being oriented in a first direction on opposite exterior sides of the upper received and wherein each of the plurality of channels intersect an elongated channel extending in a second direction; a plurality of modular rails each having a pair of securement features configured to be slidably received within a pair of the plurality of channels such that each of the plurality of modular rails can slid in the pair of the plurality of channels in the first direction until the pair of features can slide within the elongated channel in the second direction.
[0007] Other aspects and features of embodiments of the 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
[0008] Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:
[0009] FIG. 1 is a left side perspective view of a modular rail system in accordance with an exemplary embodiment of the present invention;
[0010] FIG. 2 is a left side perspective view of a modular rail system in accordance with an exemplary embodiment of the present invention with a plurality of rails secured thereto;
[0011] FIGS. 3A-3C are perspective views of a rail configured for use with the modular rail system;
[0012] FIG. 4 is a right side perspective view of the modular rail system without modular rails secured thereto;
[0013] FIG. 5 is a right side perspective view of the modular rail system with modular rails secured thereto;
[0014] FIG. 6 is a top view of a portion of an upper receiver configured for use as a modular rail system;
[0015] FIGS. 7 and 8 are side perspective views of the upper receiver illustrated in FIG. 6 ;
[0016] FIG. 9 is a bottom perspective view of the upper receiver illustrated in FIG. 6 ;
[0017] FIGS. 10 and 11 are perspective views of the upper receiver illustrating two alternative bottom portions;
[0018] FIGS. 12-14 are views illustrating a portion of an upper receiver configured for use with the modular rail system;
[0019] FIG. 15-18 are views of a portion of an upper receiver with a removable rail member secured thereto; and
[0020] FIG. 19 is view of a firearm with the modular rail system in accordance with an exemplary embodiment of the present invention.
DETAILED DESCRIPTION
[0021] Reference is made to the following U.S. Pat. Nos. 6,792,711; 7,131,228; and 7,775,150 the contents each of which are incorporated herein by reference thereto.
[0022] Disclosed herein is an apparatus, method and system for providing a modular rail for a weapon or firearm to provide various options for mounting accessories such as: telescopic sights, tactical sights, laser sighting modules, illumination devices, and vision enhancing devices, Global Positioning Systems (GPS), night vision scopes and grenade launchers to the weapon. This list is not meant to be exclusive, merely an example of accessories that may utilize a modular rail. An accessory is illustrated schematically by box 1 in FIG. 2 . The accessories are removably mounted to the rails in a manner known to those skilled in the related arts by for example, engaging the features of the “Piccatiny Rail” configuration as described in Military Standard 1913 (MIL-STD-1913 (AR).
[0023] Referring now to FIG. 1 , a perspective view of a modular rail or modular rail system 10 of a firearm is provided. Illustrated in the attached FIGS. is a hand guard 12 of an upper receiver 14 . In accordance with an exemplary embodiment of the present invention the hand guard and the upper receiver may be an integral one piece member of unitary construction. In addition and as discussed below, the upper receiver may have a removable bottom portion or bottom hand guard portion.
[0024] Hand guard 12 or a portion of the upper receiver 14 is configured with at least one integral rail such as a “Piccatiny Rail” configuration as described in Military Standard 1913 (MIL-STD-1913 (AR)), which is hereby incorporated by reference herein in its entirety. Other rails will be removably secured to the upper receiver to provide numerous mounting configurations. Of course, other rail configurations are configured to be within the scope of various embodiments of the present invention. The hand guard and rails may be made from any suitable material such as hard coat anodized aluminum as an example.
[0025] As illustrated, in the attached FIGS. the hand guard 12 is provided with an integral upper rail portion 18 and a plurality of modular rail portions 20 . In one embodiment, the modular rail portions 20 can have varying lengths or sizes to provide numerous configurations and/or variations. The hand guard or upper receiver is configured to have a plurality of integral features for removably receiving and engaging the modular rail portions 20 such that user desired configurations can be provided.
[0026] Integrally formed on the left side and right side (e.g., nine o'clock and three o'clock positions) of the hand guard of the upper receiver are a plurality of features 22 . Features 22 are configured to releasably receive appropriately shaped features 24 of the modular rail portions 20 . As illustrated in the attached FIGS., a plurality of channel openings 26 are provided wherein each of the plurality of channel openings 26 is configured to allow the features 24 of the modular rail portion 20 to be inserted into and out of channel openings 26 in a vertical direction illustrated by arrows 28 . As illustrated, each of the plurality of channel openings 26 are configured to be appropriately distanced apart from each other such that the distance between each of the channel openings corresponds to the distance between each of the features 24 of the modular rail portion 20 . Accordingly, a modular rail portion 20 can be inserted into features 22 such that features 24 are now slidably received within a horizontally disposed channel 30 wherein the modular rail portion 20 is now capable of moving horizontally in the directions illustrated by arrows 32 .
[0027] In one non-limiting configuration, channel openings 26 are disposed at either end of horizontal channel 30 pass completely through channel 30 as opposed to the channels 26 located in the middle of the features 22 .
[0028] Features 24 are configured to be slidably received within channel openings 26 during vertical movement of the modular rail when features 24 are received within the channel openings 26 . Once the features are received within the horizontally disposed channel 30 , the modular rail portion 20 is retained to the hand guard or upper receiver by a lower ledge portion 34 and upper ledge portions 36 , each of which has a flange portion that will be received between feature 24 and a surface 38 of the modular rail portion.
[0029] As illustrated in at least FIGS. 3A-3C , features 24 have a portion 40 received within a channel 42 of the modular rail portion 20 . Ear members 44 extend away from portion 40 and are configured to be in a facing spaced relationship with respect to surface 38 such that a gap 46 is provided between ear member 44 and surface 38 . Each of the features 24 are secured to the modular rail portion 20 via a screw or other equivalent member 48 , which in one non-limiting embodiment has a pin or feature 50 secured to a distal end of the screw so that the same cannot be completely withdrawn from the modular rail portion and thus disengaging feature 24 from channel 42 .
[0030] In accordance with one non-limiting embodiment, the screw or other equivalent device threadingly engages a threaded opening of the feature such that the location of ear members 44 can be varied in order to insert the modular rail portion into channel 30 , slide the same horizontally wherein the flange of the lower ledge portion 34 and the flange of at least one upper ledge portion 36 slides in the gap 46 between ear members 44 and surface 38 . Thereafter, the screw 48 is tightened by rotating it in the threaded opening of rail portion 20 to secure the flanges between the surface 38 and ear members 44 by drawing the same towards surface 38 when the screw is tightened. Thus and when the modular rail 20 is secured in place a portion of the flange of the lower ledge and at least one upper ledge is clamped between the ear members 44 and the surface 38 . This allows a user or operator to adjustably mount the modular rail portion 20 and a variety of locations on the hand guard or upper receiver.
[0031] In addition, a plurality of apertures or openings 52 are provided to receive a distal end of the screw proximate to the pin or feature 50 . In one non-limiting embodiment, these openings 52 are provided as locating features for the modular rail 20 as it is slid within channel 30 . Once the modular rail 20 is in the desired location the screws 48 are tightened such that the flange of the lower ledge portion 34 and the flange of at least one upper ledge portion is secured between the ears 44 and the surface 38 of the modular rail. Accordingly and in this embodiment openings 52 are aligned with the positioning of screws 48 in rail 20 .
[0032] In addition and referring now to at least FIGS. 15 and 16 and in one non-limiting alternative exemplary embodiment, the surface of the hand guard integrally formed with the upper receiver has a pair of longitudinally disposed features 54 located at either and of channel 30 . Features 54 provide a raised profile configured to slidably engage channel 42 of modular rail 20 when it is located at either end of channel 30 . Here a portion of the modular rail 20 may extend past channel 30 however the raised profile of feature 54 provides support and engagement to modular rail 20 when it is secured at either end of channel 30 .
[0033] As illustrated in the FIGS., modular rail 20 can have varying lengths such that discreetly located modular rails can be positioned and repositioned on the hand guard for example at the nine o'clock position illustrated in FIG. 2 . Alternatively, a larger or longer modular rail can be provided for example, the modular rail 20 secured at the six o'clock position illustrated in FIG. 2 . FIG. 4 also shows modular rails of varying lengths. The number of features 24 associated with the modular rail will depend on the length of the modular rail. For example, the modular rails secured to the nine o'clock position of the hand guard in FIG. 2 each have a pair of features 24 while the modular rail secured to the three clock position of the hang guard in FIG. 4 has four features 24 .
[0034] Referring now to at least FIG. 10-14 , the hand guard/upper receiver has a removable bottom portion 56 . In one embodiment, the removable bottom portion 56 has an integral lower 6 o'clock rail 58 for different mounting options, such a grenade launcher. One non-limiting example of such a grenade launcher is found in U.S. Pat. No. 7,360,478 the contents of which are incorporated herein by reference thereto.
[0035] In another embodiment, the removable bottom portion is configured to have a plurality of channels 70 which intersect a longitudinally disposed channel 74 wherein modular rails 20 can be secured thereto similar to the configurations provided for in the three and nine o'clock positions. However, and since this is configured for six o'clock mounting positions channels 70 extend completely through channel 74 such that features 24 of a modular rail 20 can be inserted therein from either side of the removable bottom portion. This is in contrast to the elongated ledge 34 which is configured to provide vertical support to the modular rail at the three and nine o'clock positions. This support is desirable since components mounted to the modular rail 20 at the three and nine o'clock positions may have a mass that requires additional support from ledge portion 34 as opposed to a mass secured at the six o'clock position. As used herein, the three, six, nine and twelve o'clock positions correspond with the longitudinal axis of the firearm, rifle or weapon. In other words, the three and nine o'clock positions correspond to left and right while six and twelve o'clock positions correspond to top and bottom.
[0036] In one non-limiting embodiment, the removable bottom portion uses a keyed/key way system or tongue and groove system. Here, the removable bottom portion 56 has a pair of tabs 73 which are inserted into complementary openings 75 of the upper receiver/hand guard and the bottom portion is slid in the direction of arrow 76 until the bottom portion 70 is in its desired location and the same is secured to the upper receiver via fastening means 78 inserted into complementary openings in both the upper receiver and the bottom portion 70 . In addition and while the bottom portion is slid in the direction of arrow 76 another pair of tabs 80 are received within complementary openings 82 . Similarly, fastening means 78 are also inserted in the complementary openings of tabs 80 and openings 82 .
[0037] In order to remove bottom portion 70 , user simply removed the fastening means 78 and slides the bottom portion 70 in a direction opposite to arrow 76 until the tab 72 and 80 are no longer engaging the upper receiver.
[0038] As illustrated, an upper receiver with an integral hand guard is provided wherein modular rails 20 can be discreetly located in various positions on the upper receiver. Thus, the user can locate peripheral devices in particular locations suitable for an individual by merely locating the modular rail in an appropriate location. Moreover and should the user desired to swap out the accessory with a larger or smaller accessory, the modular rail may be removed and replaced with a different size modular rail or alternatively the location of the modular rail may be varied.
[0039] Still further and by providing this modularity a user can also configure the modular rails 20 to be separated by gaps 84 that can be appropriately located for fingers of a user. Accordingly, operator's fingers will not directly contact the ridges of the rails since they will be able to place their fingers within the gaps 84 . Still further, and when no rails are provided vertical channels 26 may also provide a similar function or area for receipt of a user's fingers. Accordingly, gaps 84 and/or channels 26 provide locations for an operator's fingers which prevents them from contacting the features or rails of modular rails 20 , which may cause abrasions or cuts. Moreover and in the event the operator is wearing protective gloves, wear and tear on the gloves is also mitigated by locating the operator's fingers in between the modular rails 20 .
[0040] FIG. 19 illustrates a firearm or weapon 100 with the modular rail system 10 in accordance with one non-limiting exemplary embodiment of the present invention.
[0041] While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the present application. | An upper receiver for a weapon, the upper receiver having a plurality channels each being oriented in a first direction and wherein each of the plurality of channels intersect an elongated channel extending in a second direction; a modular rail having a pair of securement features configured to be slidably received within a pair of the plurality of channels such that modular rail can slide in the pair of the plurality of channels in the first direction until the pair of features can slide within the elongated channel in the second direction. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/532,028, filed Sep. 7, 2011, the contents of which are expressly incorporated by reference thereto in its entirety for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates generally to rechargeable battery cells and, more particularly but not exclusively, to a modified closure assembly (e.g., cell cap) that allows for efficient release of cell contents during thermal events.
BACKGROUND OF THE INVENTION
[0003] The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.
[0004] Batteries can be broadly classified into primary and secondary batteries. Primary batteries, also referred to as disposable batteries, are intended to be used until depleted, after which they are simply replaced with one or more new batteries. Secondary batteries, more commonly referred to as rechargeable batteries, are capable of being repeatedly recharged and reused, therefore offering economic, environmental and ease-of-use benefits compared to a disposable battery.
[0005] Although rechargeable batteries offer a number of advantages over disposable batteries, this type of battery is not without certain drawbacks. In general, most of the disadvantages associated with rechargeable batteries are due to the battery chemistries employed, as these chemistries tend to be less stable than those used in primary cells. Due to these relatively unstable chemistries, secondary cells often require special handling during fabrication. Additionally, secondary cells such as lithium-ion cells tend to be more prone to thermal events, such as thermal runaway, than primary cells, thermal runaway occurring when an internal reaction rate increases to a point that more heat is being generated than can be safely dissipated, leading to a further increase in both reaction rate and heat generation. Eventually the amount of generated heat is great enough to lead to the combustion of the battery, which can lead to further combustion of materials in proximity to the battery. Thermal runaway may be initiated by a short circuit within the cell, improper cell use, physical abuse, manufacturing defects, or exposure of the cell to extreme external temperatures.
[0006] Thermal runaway is of major concern since a single incident can lead to significant property damage and, in some circumstances, bodily harm or loss of life. When a battery undergoes thermal runaway, it typically emits a large quantity of smoke, jets of flaming liquid electrolyte, and sufficient heat to lead to the combustion and destruction of materials in close proximity. If the cell undergoing thermal runaway is surrounded by one or more additional cells as is typical in a battery pack, then a single thermal runaway event can quickly lead to the thermal runaway of multiple cells which, in turn, can lead to much more extensive collateral damage. Regardless of whether a single cell or multiple cells are undergoing this phenomenon, if the initial fire is not extinguished immediately, subsequent fires may be caused that dramatically expand the degree of property damage. For example, the thermal runaway of a battery within an unattended laptop will likely result in not only the destruction of the laptop, but also at least partial destruction of its surroundings, e.g., home, office, car, laboratory, and the like. If the laptop is on-board an aircraft, for example within the cargo hold or a luggage compartment, the ensuing smoke and fire may lead to an emergency landing or, under more dire conditions, a crash landing. Similarly, the thermal runaway of one or more batteries within the battery pack of a hybrid or electric vehicle may destroy not only the car, but may lead to a collision if the car is being driven, or the destruction of its surroundings if the car is parked.
[0007] One approach to overcoming this problem is by reducing the risk of thermal runaway. For example, to prevent batteries from being shorted out during storage and/or handling, precautions can be taken to ensure that batteries are properly stored, for example by insulating the battery terminals and using specifically designed battery storage containers. Another approach to overcoming the thermal runaway problem is to develop new cell chemistries and/or modify existing cell chemistries. For example, research is currently underway to develop composite cathodes that are more tolerant of high charging potentials. Research is also underway to develop electrolyte additives that form more stable passivation layers on the electrodes. Although this research may lead to improved cell chemistries and cell designs, currently this research is only expected to reduce, not eliminate, the possibility of thermal runaway.
[0008] FIG. 1 is a cross-sectional view of a conventional cell and cap assembly commonly used with lithium ion batteries employing the 18650 form-factor. Battery 100 includes a cylindrical case 101 , an electrode assembly 103 , and a cap assembly 105 . Case 101 is typically made of a metal, such as nickel-plated steel, that has been selected such that it will not react with the battery materials, e.g., the electrolyte, electrode assembly, etc. For an 18650 cell, case 101 is often referred to as a can as it is comprised of a cylinder and an integrated, i.e., seamless, bottom surface 102 . Electrode assembly 103 is comprised of an anode sheet, a cathode sheet and an interposed separator, wound together in a spiral pattern often referred to as a ‘jelly-roll’. An anode electrode tab 107 connects the anode electrode of the wound electrode assembly to the negative terminal which, for an 18650 cell, is case 101 . A cathode tab 109 connects the cathode electrode of the wound electrode assembly to the positive terminal via cap assembly 105 . Typically battery 100 also includes a pair of insulators 111 / 113 located on either end of electrode assembly 103 to avoid short circuits between assembly 103 and case 101 .
[0009] In a conventional cell, cap assembly 105 is a relatively complex assembly that includes multiple safety mechanisms. In cell 100 , tab 109 is connected to assembly 105 via a current interrupt device (CID). The purpose of the CID is to break the electrical connection between the electrode assembly and the positive terminal if the pressure within the cell exceeds a predetermined level. Typically such a state of over pressure is indicative of cell overcharging or of the cell temperature increasing beyond the intended operating range of the cell, for example due to an extremely high external temperature or due to a failure within the battery or charging system. Although other CID configurations are known, in the illustrated cell the CID is comprised of a lower member 115 and an upper member 116 . Members 115 and 116 are electrically connected, for example via crimping along their periphery. Lower member 115 includes multiple openings 117 , thus insuring that any pressure changes within case 101 are immediately transmitted to upper CID member 116 . The central region of upper CID member 116 is scored (not visible in FIG. 1 ) so that when the pressure within the cell exceeds the predetermined level, the scored portion of member 116 breaks free, thereby disrupting the continuity between the electrode assembly 103 and the battery terminal.
[0010] Under normal pressure conditions, lower CID member 115 is coupled by a weld 119 to electrode tab 109 and upper CID member 116 is coupled by a weld 121 to safety vent 123 . In addition to disrupting the electrical connection to the electrode assembly during an over pressure event, the CID in conjunction with safety vent 123 are designed to allow the gas to escape the cell in a somewhat controlled manner. Safety vent 123 may include scoring 125 to promote the vent rupturing in the event of over pressure.
[0011] The periphery of CID members 115 / 116 are electrically isolated from the periphery of safety vent 123 by an insulating gasket 126 . As a consequence, the only electrical connection between CID members 115 / 116 and safety vent 123 is through weld 121 .
[0012] Safety vent 123 is coupled to battery terminal 127 via a positive temperature coefficient (PTC) current limiting element 129 . PTC 129 is designed such that its resistance becomes very high when the current density exceeds a predetermined level, thereby limiting short circuit current flow. Cap assembly 105 further includes a second insulating gasket 131 that insulates the electrically conductive elements of the cap assembly from case 101 . Cap assembly 105 is held in place within case 101 using crimped region 133 .
[0013] Elements 115 , 116 and 123 must be fabricated from a material that does not react with the electrolyte used in the electrode assembly. Accordingly, for a conventional lithium ion cell, these elements cannot be fabricated from steel. Typically they are fabricated from aluminum. In contrast, terminal 127 is generally fabricated from steel, thus allowing resistance welding to be used to attach a conductor to the terminal.
[0014] In a conventional cell, such as the cell shown in FIG. 1 , a variety of different abusive operating/charging conditions and/or manufacturing defects may cause the cell to enter into thermal runaway, where the amount of internally generated heat is greater than that which can be effectively withdrawn. As a result, a large amount of thermal energy is rapidly released, heating the entire cell up to a temperature of 900° C. or more and causing the formation of localized hot spots where the temperature may exceed 1500° C. Accompanying this energy release is the release of gas, causing the gas pressure within the cell to increase.
[0015] To combat the effects of thermal runaway, a conventional cell will typically include a venting element within the cap assembly such as that previously shown and described. The purpose of the venting element is to release, in a somewhat controlled fashion, the gas generated during the thermal runaway event, thereby preventing the internal gas pressure of the cell from exceeding its predetermined operating range. Unfortunately in a conventional cell, the cell wall may still perforate (e.g., at site 141 ) due to the size of the vent, the material characteristics of the cell wall, and the flow of hot gas traveling along the cell wall as it rushes towards the ruptured vent. Once the cell wall is compromised, i.e., perforated, collateral damage can quickly escalate, due both to the unpredictable location of such a hot spot and due to the unpredictable manner in which such cell wall perforations grow and affect neighboring cells. For example, if the cell is one of a large array of cells comprising a battery pack, the jet of hot gas escaping the cell perforation may heat the adjacent cell to above its critical temperature, causing the adjacent cell to enter into thermal runaway. Accordingly, it will be appreciated that the perforation of the wall of one cell during thermal runaway can initiate a cascading reaction that can spread throughout the battery pack. Furthermore, even if the jet of hot gas escaping the cell perforation from the first cell does not initiate thermal runaway in the adjacent cell, it may still affect the health of the adjacent cell, for example by weakening the adjacent cell wall, thereby making the adjacent cell more susceptible to future failure.
[0016] One challenge to altering cell design when addressing these issues is that battery cell manufacturers produce enormous volumes of battery cells. Part of the manufacturing process includes “burn-in,” testing, and other operational functions that make use of existing processes and equipment. These processes and equipment depend upon a particular form factor for the battery cell. Even under circumstances when a customer is able to use a second form factor for the battery cell that can address the identified issues during in-field operation, adoption of the second form factor is problematic unless the manufacturer environment is considered and accounted for.
[0017] Accordingly, what is needed is a cell design that can help maintain cell wall integrity during a thermal event by efficiently allowing hot gas and debris to exit the cell via the cap. The present invention provides such a cell design.
BRIEF SUMMARY OF THE INVENTION
[0018] Disclosed is a system and method for a battery cell design that provides a pathway through a predefined region (e.g., the cell cap assembly) for the efficient release of thermal energy that occurs during thermal runaway, thereby reducing the chances of a cell side wall rupture/perforation. Furthermore the disclosed design maintains the functionality of the cell cap as the positive terminal of the cell, thereby having minimal impact on the manufacturability of the cell as well as its use in a variety of applications.
[0019] The following summary of the invention is provided to facilitate an understanding of some of technical features related to controlled ejectment of combustion material from a battery cell near or at thermal runaway, and is not intended to be a full description of the present invention. A full appreciation of the various aspects of the invention can be gained by taking the entire specification, claims, drawings, and abstract as a whole. The present invention is applicable to other cell designs and cell chemistries.
[0020] A battery cell, including an electrode assembly having a cathode and an anode with the electrode assembly constructed of materials that combust under a plurality of combustion conditions to generate a combustion material having a plurality of combustion material properties including a combustion material temperature and a combustion material pressure; a closed case having a base, a crown, and a side wall extending from the base to the crown with the case defining a cavity therein containing the electrode assembly, the case providing a first external electrical contact electrically communicated to the cathode and a second external electrical contact electrically communicated to the anode; wherein a portion of the closed case defines an ejectment structure, responsive to one or more particular combustion material properties of the plurality of combustion material properties, providing an ejectment aperture at a predefined location that directs the combustion material in a predetermined direction.
[0021] A method for ejecting combustion material from a battery cell, including a) enclosing an electrode assembly within a closed case, the electrode assembly having a cathode and an anode with the electrode assembly constructed of materials that combust under a plurality of combustion conditions to generate a combustion material having a plurality of combustion material properties including a combustion material temperature and a combustion material pressure; b) defining an ejectment structure within a portion of the closed case; and c) responding to one or more particular combustion material properties of the plurality of combustion material properties to provide an ejectment aperture at a predefined location that directs the combustion material out of the closed case in a predetermined direction.
[0022] Any of the embodiments described herein may be used alone or together with one another in any combination. Inventions encompassed within this specification may also include embodiments that are only partially mentioned or alluded to or are not mentioned or alluded to at all in this brief summary or in the abstract. Although various embodiments of the invention may have been motivated by various deficiencies with the prior art, which may be discussed or alluded to in one or more places in the specification, the embodiments of the invention do not necessarily address any of these deficiencies. In other words, different embodiments of the invention may address different deficiencies that may be discussed in the specification. Some embodiments may only partially address some deficiencies or just one deficiency that may be discussed in the specification, and some embodiments may not address any of these deficiencies.
[0023] A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention.
[0025] FIG. 1 is a simplified cross-sectional illustration of a cell utilizing the 18650 form-factor;
[0026] FIG. 2 illustrates a ribbed cell cap;
[0027] FIG. 3 illustrates a two part cell cap comprising a top portion and a ring portion;
[0028] FIG. 4 illustrates a crimped plate within the cell cap assembly;
[0029] FIG. 5 illustrates a scored and perforated cell cap;
[0030] FIG. 6 illustrates a cell cap designed to be removed;
[0031] FIG. 7 illustrates a cut-out that may be used with the cell cap shown in FIG. 6 to aid insertion of a tool for cell cap removal;
[0032] FIG. 8 illustrates a cell cap that includes a cross-shaped scoring, thus providing means for easily punching a hole into the cell cap of the cell;
[0033] FIG. 9 illustrates a cell cap that includes a circularly-shaped scoring, thus providing means for easily punching a hole into the cell cap of the cell;
[0034] FIG. 10 illustrates a modified cell cap geometry;
[0035] FIG. 11 illustrates an alternate modified cell cap geometry;
[0036] FIG. 12 illustrates an alternate modified cell cap geometry;
[0037] FIG. 13 illustrates an alternate modified cell cap geometry; and
[0038] FIG. 14 illustrates a perspective view of a cell cap geometry.
DETAILED DESCRIPTION OF THE INVENTION
[0039] Embodiments of the present invention provide a system and method for a system and method for a battery cell design that provides a pathway through a predefined region (e.g., the cell cap assembly) for the efficient release of thermal energy that occurs during thermal runaway, thereby reducing the chances of a cell side wall rupture/perforation. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements.
[0040] Various modifications to the preferred embodiment and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein.
[0041] In a general description of the present invention, an electrode assembly (or other component) within a closed case (as used herein, “closed” includes gas release vents but otherwise sufficiently sealed such that pressure may accumulate) will combust under a set of conditions. The combustion produces a combustion material that is a combination of one or more gases and/or physical debris. The combustion material and internal combustion process includes one or more combustion material properties, such as a combustion temperature, a combustion pressure, and the like. Preferred embodiments provide mechanical response to one or more preselected combustion material properties by defining a special ejectment structure in a portion of the closed case. The ejectment structure responds to the one or more preselected combustion material properties and provides an ejectment aperture. The ejectment aperture permits ejectment of the combustion material from a predetermined location away from the closed case at a predetermined direction.
[0042] One particular implementation includes collections of large numbers of cylindrical battery cells into a battery pack. Efficient packing and electrical contact requirements results in packing the cells into arrays with a side wall of one battery cell adjacent one or more other battery cells, and all the ends of the battery cells exposed because each end typically includes an electrical contact. To simplify the discussion of the present invention, the following description contemplates use of generally cylindrical battery cells such as described in FIG. 1 and with the ejectment structure included as part of a cell cap assembly. In this way, the ejectment structure defines the ejectment aperture at one of the ends and directs the ejectment out of the end and away from other adjacent battery cells. Thus in this context, one or more embodiments of the present invention may utilize (i) a cell cap that clears away during thermal runaway, (ii) a cell cap that is optimized for mechanical removal prior to cell use, and/or (iii) a cell cap geometry optimized for the ejection of runaway gas and matter.
[0043] One embodiment consists of a cell cap constructed of a low melting point electrically-conductive material, such as aluminum, which will melt in the event of thermal runaway (e.g., at temperatures in excess of ˜1000° C.), thereby clearing a wider and lower restriction path for the ejection of gas and/or debris (e.g., combustion material). The side wall is constructed of a higher melting point material (e.g., stainless steel or other). The geometry of this cell cap may be similar to prior art assemblies (for example, as shown in FIG. 1 ), or modified as described below.
[0044] In one embodiment, the cell cap is made from aluminum (or similar material). Preferably in this embodiment the PTC element is eliminated and the cell cap is coined and made thicker in the ring portion, thereby replacing the PTC element. Additionally, the aluminum cell cap may be thinned and ribbed (e.g., FIG. 2 ) to provide additional stiffness and increase ultrasonic bondability while minimizing the amount of material which would need to melt during a runaway event. FIG. 2 illustrates a ribbed cell cap 200 including a side wall 205 , a bonding legs 210 , one or more structural ribs 215 , and one or more vents 220 . Legs 210 are joined to side wall 205 , such as by use of bonding, welding, and other attachment processes.
[0045] In another embodiment illustrated in FIG. 3 , a cell cap 300 includes two pieces, a ring 305 and a top 310 , joined to a side wall 315 . One component, e.g., ring 305 may be made out of a low melting point material, such as aluminum, while the other component, e.g., top 310 , may be made out of a more robust and weldable material, such as steel. The low melting point ring 305 would melt during runaway, releasing steel top 310 . Conversely, top 310 can be made from a low melting point material, while ring 305 is made from a more robust material. In this case, top 310 would melt, clearing a path for ejecting combustion material. Ring 305 can be bonded to top 310 and to side wall 315 by laser welding, ultrasonic welding, friction welding, and the like.
[0046] In a similar embodiment shown in FIG. 4 , a cell cap 400 includes a top plate 405 that is crimped to a body 410 of cap 400 , prior to crimping the cell cap assembly into the battery cell by attachment (e.g., crimping) to a side wall 415 . This embodiment may also include cell cap 400 made from composite materials, some of which may melt during thermal runaway (e.g., top plate 405 or body 410 ) made from a lower melting point material than material used in side wall 415 ). In this embodiment, the attachment mechanism (e.g., crimps) could be pressure responsive to release top plate 405 when a combustion pressure within the cell reaches a predetermined value to limit rupture/perforation of side wall 415 .
[0047] In a modification of the embodiment shown in FIG. 4 , top plate 405 may be configured to snap into the body 410 of the cell cap during manufacturing. This cell cap may then be removed at a subsequent time, for example prior to use in a specific application. Preferably the top plate 405 is reusable. One way to remove top plate 405 would be use of a particular mechanical interface, such as the mechanical interface described below in connection with FIG. 6 - FIG. 8 . This implementation may be considered a form factor adapter, allowing the cell to effectively have two different form factors-one for manufacturing and another for use. In some cases, the adapter may be re-used, either with the battery cell from which it was removed or with a “new” battery cell having a matching (or complementary) form factor.
[0048] In another embodiment illustrated in FIG. 5 , a cell cap 500 is modified so that it will release or hinge out of the way during a thermal runaway event. In this embodiment, preferably cell cap 500 is sealed over a vent plate. Cell cap 500 includes a hole 505 that is sized to allow gas to escape during operation of the cell vent prior to runaway, but is small enough to insure that pressure will build up within cell cap 500 during runaway. Once the pressure within the assembly reaches a predefined value, cell cap 500 breaks away to provide an ejectment aperture with a large path for combustion material to exit the cell. Preferably a scoring 510 is used to insure that a top portion 515 breaks away at the desired location and pressure. Scoring 510 is a mechanical weakness that may be introduced through etching, mechanical scribing, lasing, or other mechanism to selectively pattern the material to a predetermined depth sufficient to mechanically fail at the desired pressure to produce the desired ejectment aperture. In this case, top portion hinges or completely releases from scoring 510 . The disclosed use of materials with dissimilar melting points may also be implemented in this configuration.
[0049] In another embodiment illustrated in FIG. 6 , an end cap assembly 600 includes a cell cap 605 held in place with a plurality of legs 610 . Each leg 610 includes a scoring 615 . This design allows the cell to include a first form factor to be manufactured and processed using current and conventional manufacturing equipment while still providing a simple mechanism for removing cell cap 605 at some later time, the removal could provide a second form factor. Cell cap 605 may be removed by pulling or twisting or other manipulation. Preferably cell cap 605 includes a mechanical interface 620 (e.g., a special shape cut-out of, or otherwise formed in, cell cap 605 ), allowing insertion of a tool that can be used to remove cap 605 . FIG. 7 illustrates a representative shape 705 for interface 620 in cell cap 605 , but other shapes, configurations, orientations are possible, which may be dependent upon providing sufficient removal torque or force to release cell cap 605 .
[0050] Various shapes could be used for mechanical interface, such as an alternative that shown in FIG. 8 . A cap removal tool preferably enters cap assembly 600 via interface 620 (or 705 ) and then either expands or is twisted, thus allowing the tool to grab onto the cap. FIG. 8 illustrates a cell cap assembly 800 that includes a cross-shaped scoring 805 . Scoring 805 provides a mechanism for easily punching a hole into a cell cap 805 of the cell. In cell cap assembly 800 , it is not required that legs 610 and/or scoring 615 be provided as scoring 805 makes it easier to mechanically produce a desired ejectment aperture before the cell is installed for use while preserving manufacturing requirements. Cell cap 810 is scored with scoring interface 805 such that a hole may be punched into or otherwise form with respect to cell cap 810 prior to use, if desired. FIG. 8 illustrates a cross-shaped scoring pattern for scoring 805 and FIG. 9 illustrates a circularly-shaped scoring pattern 905 .
[0051] FIGS. 10-13 provide a top-down view of a cell with four different cap geometries designed to provide improved ejection of gas and debris. These cap geometries may be used alone or in combination with the embodiments described above. In these embodiments, a three-sided contact plate overlies a generally circular ejectment region. The contact plate is so referred to herein as it often provides a desired electrical contact interface. FIG. 10 illustrates a modified cell cap geometry 1000 in which an ejectment region 1005 has an overlying three-sided contact plate 1010 to form three apertures 1015 . Contact plate 1010 includes straight-edges. FIG. 11 illustrates an alternate modified cell cap geometry 1100 having a three-sided contact plate 1105 in which the three edges are arcuate. FIG. 12 illustrates an alternate modified cell cap geometry 1200 similar to FIG. 10 in which a three-sided contact plate 1205 includes an additional circular aperture 1210 centered over ejectment region 1005 . FIG. 13 illustrates an alternate modified cell cap geometry 1300 similar to FIG. 10 in which an ejectment region 1305 is larger, allowing larger ejectment apertures 1310 to be formed by an overlying three-sided contact plate 1315 . In some embodiments, other regular or irregular shapes for the contact plate and/or ejectment region is possible, with use of one or more additional apertures such as additional aperture 1205 (which is not necessarily circular) included in the various geometries. FIG. 14 illustrates a perspective view of a portion of cell cap geometry 1000 shown in FIG. 10 . In one implementation, ejectment region is manufactured of aluminum or other material having a lower melting point than the side wall material. In other implementations, scoring or other ejectment structures as described herein, may be used in ejectment region 1005 .
[0052] Although the preferred embodiment of the invention is utilized with a cell using the 18650 form-factor, it will be appreciated that the invention can be used with other cell designs, shapes and configurations.
[0053] The system and methods above has been described in general terms as an aid to understanding details of preferred embodiments of the present invention. In the description herein, numerous specific details are provided, such as examples of components and/or methods, to provide a thorough understanding of embodiments of the present invention. Some features and benefits of the present invention are realized in such modes and are not required in every case. One skilled in the relevant art will recognize, however, that an embodiment of the invention can be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.
[0054] Reference throughout this specification to “one embodiment”, “an embodiment”, or “a specific embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention and not necessarily in all embodiments. Thus, respective appearances of the phrases “in one embodiment”, “in an embodiment”, or “in a specific embodiment” in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any specific embodiment of the present invention may be combined in any suitable manner with one or more other embodiments. It is to be understood that other variations and modifications of the embodiments of the present invention described and illustrated herein are possible in light of the teachings herein and are to be considered as part of the spirit and scope of the present invention.
[0055] It will also be appreciated that one or more of the elements depicted in the drawings/figures can also be implemented in a more separated or integrated manner, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application.
[0056] Additionally, any signal arrows in the drawings/Figures should be considered only as exemplary, and not limiting, unless otherwise specifically noted. Furthermore, the term “or” as used herein is generally intended to mean “and/or” unless otherwise indicated. Combinations of components or steps will also be considered as being noted, where terminology is foreseen as rendering the ability to separate or combine is unclear.
[0057] As used in the description herein and throughout the claims that follow, “a”, “an”, and “the” includes plural references unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0058] The foregoing description of illustrated embodiments of the present invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed herein. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention, as those skilled in the relevant art will recognize and appreciate. As indicated, these modifications may be made to the present invention in light of the foregoing description of illustrated embodiments of the present invention and are to be included within the spirit and scope of the present invention.
[0059] Thus, while the present invention has been described herein with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of embodiments of the invention will be employed without a corresponding use of other features without departing from the scope and spirit of the invention as set forth. Therefore, many modifications may be made to adapt a particular situation or material to the essential scope and spirit of the present invention. It is intended that the invention not be limited to the particular terms used in following claims and/or to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Thus, the scope of the invention is to be determined solely by the appended claims. | A battery cell design is disclosed that provides a predictable pathway through a portion of the cell (e.g., the cell cap assembly) for the efficient release of the thermal energy that occurs during thermal runaway, thereby reducing the chances of a rupture in an undesirable location. Furthermore the disclosed design maintains the functionality of the cell cap as the positive terminal of the cell, thereby having minimal impact on the manufacturability of the cell as well as its use in a variety of applications. | 7 |
BACKGROUND OF THE INVENTION
The invention relates to a method and apparatus for controlling a rock drill in a drilling machine comprising a frame, a percussion piston provided in the frame and moving in the longitudinal direction thereof, a shank placed on an axial extension of the percussion piston, and at least one piston that is provided in the frame movably in the axial direction thereof, the piston being arranged to act on the shank to push it towards the front of the drilling machine due to a pressure medium acting on the rear surface of the piston, whereupon at least during the drilling the pressure of said pressure medium is such that the combined force of all the pistons acting on the shank and pushing it forward exceeds the feed force acting on the drilling machine during the drilling, so that as the shank rests on all the pistons it is situated at its optimum point of impact, in which method the pressure of said pressure medium acting on the shank is measured.
When holes are drilled in rock with a rock drill, the conditions of drilling vary in different ways. Rock consists of layers of rock material with different degrees of hardness, wherefore the properties affecting the drilling, such as impact power and feed, should be adjusted according to the current drilling resistance. Otherwise the drilling is irregular since the drill propagates rapidly in a soft material and slowly in hard rock. This brings about several problems concerning for example the endurance of the drilling apparatus and the controllability of the drilling process. One example of solving these problems relates to adjusting the impact power of the drilling machine by transferring an impact-transmitting shank forward from the optimum point of impact in the longitudinal direction when a lower impact power is to be transmitted from the percussion piston to the shank. The shank is moved by means of hydraulically operated pistons, which support the shank from behind either directly or via a sleeve. When the pressure of a pressure medium acting in a cylinder space situated behind the pistons is changed, it is possible to adjust the length of movement of the pistons and thus the position of the shank- In this manner, it is possible to transmit a desired amount of capacity via the shank to the drill rod, whereas the rest of the impact is dampened by a damping pad provided at the front end of the percussion piston. Such an arrangement is disclosed in Finnish Patent 84,701.
Finnish Patent Application No. 944,839 discloses a known manner of controlling the drilling capacity of a rock drilling apparatus, wherein the aim is to prevent the occurrence of damage to the drill. The reference discloses that when the drilling machine hits an area where the drilling resistance is smaller and the drill thus penetrates more easily into the rock, the drilling is continued normally except that the operation of the percussion apparatus is stopped completely until the material under operation gets harder and the drilling requires percussion again. The apparatus comprises a piston of a return damper, which moves in the direction of the percussion piston with respect to the frame of the drilling machine and which is able to move forward towards the drill bit when the drilling resistance is temporarily smaller. This leads to a decrease in pressure in the chamber behind the piston, If the pressure falls below a predetermined pressure level, a valve stops the supply of pressure medium to the percussion apparatus, whereupon the percussion piston will not deliver any more blows. When the drill again hits again hard rock and the pressure in the chamber behind the piston exceeds a predetermined pressure limit, the connection to the percussion apparatus is opened and the percussion piston begins to deliver impacts again.
However, the aforementioned prior art arrangements have proved to be insufficient for the efficient and accurate control of drilling machines. They only affect the control of the impact force but they do not provide means for adjusting and controlling the drilling in more various manners. They also cause loss of power, which means that hydraulic pumps, pipes and other hydraulic components must be made unnecessarily large.
The purpose of the present invention is to provide a better and more versatile method and apparatus for controlling the operation of a drilling machine than previously.
SUMMARY OF THE INVENTION
The method according to the invention is characterized in that a pressure sensor measures a return pulse which is reflected back to the drilling apparatus from the rock to be drilled and which results from the impact of the percussion piston, the return pulse being detected as a pressure pulse when the pressure in the space behind the piston is measured by means of the pressure sensor, and that the measurement data of the reflected pressure pulse is used for controlling the operation of the drilling machine.
Further, the apparatus according to the invention is characterized in that a pressure sensor measures a return pulse which is reflected back to the drilling apparatus from the rock to be drilled and which results from the impact of the percussion piston, the return pulse being detected as a pressure pulse when the pressure in the space behind the piston is measured by means of the pressure sensor, and that the measurement data of the reflected pressure pulse is used for controlling the operation of the drilling machine.
A basic idea of the invention is that a pressure sensor is used to measure pressure pulses in a pressure chamber situated behind one or more pistons supporting the shank from behind. When the feed resistance at the drill bit decreases, the point of impact starts to move forward from the optimum point of impact. This means that at least some of the energy of the percussion piston is dampened. Correspondingly, a return pulse that is formed in a softer material is weaker, wherefore the resulting pressure pulse is smaller and possibly shorter than in a normal situation. Instead of two or more pistons, it is also possible to use a single piston, which supports the shank by means of the pressure of the pressure medium. In such a case, measurement is carried out from the pressure chamber of this single annular piston. Absence of pressure pulses or changes in normal values are detected as a situation that deviates from a normal drilling operation by the pressure sensor that is arranged to measure the pressure in the chambers behind the piston(s). The measurement data of the pressure sensor is supplied to the control system of the drilling machine, which then adjusts on the basis of this data the operation of the drill, for example the drilling parameters, which include feed pressure and impact pressure. The power of the drilling is adjusted until the optimum point of impact is reached again.
The invention has an advantage that it is now possible to adjust the impact capacity of the drilling machine and the other drilling parameters in an economical and efficient manner suitably in each situation. The drilling process can now be measured during the drilling and the obtained data can be utilized in several ways to control the drilling. It is also easier to control special situations than previously. The apparatus according to the invention also enables the detection and storage of the properties of different layers of the hole to be drilled in a control unit for later use. On the basis of this data, it is possible, for example, to plan the drilling at the destination and to chart the properties of the rock. It is further possible to use the pressure pulses provided by the pressure sensor to draw conclusions about the condition of the drill bit and to use the measurement data in fault diagnostics. Another advantage is that the arrangement according to the invention decreases the need for power of the drilling apparatus, which in turn decreases the costs. The present arrangement can also be connected to existing devices in a rather simple manner.
BRIEF DESCRIPTION OF DRAWING
The invention will be described in greater detail in the accompanying drawing, in which:
FIG. 1 shows schematically, in a partial section, the front end of a rock drill according to the invention,
FIGS. 2a and 2b show schematically pressure curves measured from a space behind pistons, and
FIG. 3 shows schematically, in a partial section, another embodiment of a drilling machine according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows schematically, in a partial section, the front of a rock drill. The drilling machine comprises a percussion piston 1 and a coaxially positioned shank 2, which receives impacts delivered by the percussion piston. The impact force is transmitted via drill rods, that are usually placed as an extension of the shank, to a drill bit (not shown) that strikes the rock and breaks it. The impact operation of the percussion piston 1 is not discussed in greater detail in this connection since it is generally known in the field and evident to a person skilled in the art. The shank 2 is usually rotated by means of a rotary motor known per se by turning a rotary sleeve that is provided around the shank 2, which is able to move axially with respect to the sleeve. Both the structure and operation of the rotary motor and the rotary sleeve are fully known to a person skilled in the art, wherefore they will not be discussed in greater detail herein.
Further, around the rear of the shank 2 there is a separate supporting sleeve 3 which supports the shank 2 during the drilling. The supporting sleeve 3 supports the shank 2 by means of a sloping support surface 3a, which comes into contact with a corresponding sloping support surface 2a in the shank 2. Behind the supporting sleeve 3 there are several secondary pistons 4a and 4b which are connected to or which act indirectly mechanically on the rear surface of the supporting sleeve 3. Around the supporting sleeve 3 there may also be a stop ring 5, which restricts the movement of the pistons 4a and 4b towards the front of the drilling machine.
The pistons 4a and 4b are situated in cylinder spaces which are formed in a frame 6 or in a separate cylinder section and which are parallel to the axis of the percussion piston 1, and pressure fluid ducts 7a and 7b lead to the cylinder spaces. Such a pressure of the pressure medium is applied at the rear surface of the pistons 4a, 4b at least during the drilling, whereby the combined force of the pistons acting on the shank 2 and pushing it forward exceeds the feed force acting on the drilling machine during the drilling. There are several pistons 4a and 4b in the frame 6 of the drilling machine and they are preferably divided into at least two separate groups which have different lengths of movement towards the front end of the drilling machine. The drilling machine further comprises a conventional absorber 8 at the front of the cylinder space of the percussion piston 1 or over the distance of motion of a piston part 1a of the percussion piston 1 at the front of the drilling machine. The front of the piston part 1a of the percussion piston 1 delivers an impact at this absorber when the percussion piston 1 strikes past its normal optimum point of impact for some reason. Such a structure is known per se and therefore it will not be described in greater detail.
The apparatus further comprises measuring conduits 19a and 19b, which are preferably connected to the ducts 7a, 7b such that a pressure pulse acting behind the pistons 4a can be measured by means of a pressure sensor 20 connected to the measuring conduit 19a. This is the simplest arrangement, but naturally it is also possible to provide a separate bore in the frame 6 for the pressure sensor 20. Measurement data is supplied electrically from the pressure sensor 20 to a control unit 21, where the data can be processed. If required, the control unit 21 transmits a control signal to an actuator 22, which may be, for example, an actuator adjusting the feed or a valve adjusting the pressure of the percussion apparatus, or both. It is possible to supply to the control unit 21 a great deal of different measurement data concerning the drilling process, so that the control unit 21 can control the operation of the drilling machine suitably in each situation on the basis of the data. The FIG. also shows a second pressure sensor 23 which measures the pressure behind the other pistons 4b, the pressure sensor 23 being correspondingly connected to the control unit 21. It is thus possible to measure a pressure pulse either separately from the pistons 4a or 4b, or together from both pistons. It is also possible to use only one pressure sensor 20 or 23, in which case the ducts 7a and 7b of the pistons 4a and 4b would be connected together as shown by a broken line 24, which means that the second pressure sensor 20 or 23 would not be needed. In practice, a pressure pulse can be measured in a relatively simple manner merely from behind the pistons 4a, which means that the pistons 4a and 4b are situated in different pressure circuits. This is based on the fact that since the pistons 4a may move towards the front of the drilling machine only to a position that corresponds to the optimum point of impact of the shank, pressure pulses are only produced when the shank moves towards the rear of the drilling machine at such a force that it moves past its optimum point of impact. When pressure pulses are measured in such a manner, they provide preferably reliable basic information for implementing the control.
FIG. 2a shows schematically a normal pressure curve that has been measured from the space behind the pistons. When the drilling resistance of the rock to be drilled is normal and the pistons have moved the shank to the optimum point of impact, the percussion piston delivers an impact at full force at the shank, from which the impact is transmitted further to the drill rods and thus also to the drill bit. As the drill bit hits the hard rock, it produces a return motion that is reflected backwards and transmitted via the drill rods to the shank. Since the shank is stressed by means of the supporting sleeve 3 and the pistons pushing it forward, the tension that is reflected from the rock is also transmitted to the pistons, which therefore move backwards in their cylinder spaces as a result of this reflected pulse. The backward movement of the pistons produces a rapid increase in pressure, in other words a return pulse, in the space behind the pistons. This can be seen in FIG. 2a as a pressure pulse B, which is clearly distinguishable from the average pressure level. The occurrence of this pressure pulse B in the pressure curve is monitored specifically. The pressure pulses B are always greater than the average pressure level. At least the power, amplitude, rate of rise and frequency of occurrence of the pressure pulse can be utilized for controlling the drilling. Pressure pulses A which are shown in the FIG. and which are smaller than the pressure pulses B result from variations in the pressure of the pressure fluid when the pistons 4a and 4b are subjected to the pressure in the pressure duct of the percussion apparatus. If the pressure fluid supplied to the cylinder space of the pistons to be measured were conveyed from a separate pressure source or via a pressure duct that is separate from the percussion conduit, there would be no pressure pulse A resulting from the impact operation; rather, the average pressure curve would be substantially even.
FIG. 2b, in turn, shows a pressure curve which entirely lacks pressure pulses B. The curve only shows pressure variation A that results from changes in the pressure of the impact circuit. The absence of the pressure pulse B or the weakness of the pulse is due to the fact that the drill bit has penetrated into a soft rock material at a normal drilling power, which means that for a while the drill operates faster than usual. The shank has thus moved forward from the optimum point of impact, wherefore the absorber of the percussion piston receives at least a part of the impact. Since the power of the impact is diminished in this manner, the drill bit does not strike the rock at such a great force nor does it produce a similar recoil as in a normal drilling situation or a resulting return pulse. On the other hand, a soft rock material does not resist an impact to the same extent as a hard material, and therefore it does not cause a similar return pulse in the drilling equipment.
FIG. 3 shows yet another embodiment of the front end of a drilling machine according to the invention in a partial section. The reference numerals correspond to those of FIG. 1. The arrangement shown in the FIG. corresponds otherwise to the arrangement of FIG. 1 except that in FIG. 3 several separate pistons are replaced with sleeve-like pistons, which are placed coaxially around the percussion piston 1. In this case, the pistons 14a and 14b are placed such that the piston 14a is situated in the outermost position and a pressure duct 17a is connected to the piston 14a so that it can push the piston forward all the way to a mating surface 15a. The piston 14b is in turn located coaxially inside the piston 14a, and pressure fluid is supplied behind the piston 14b along a duct 17b . When the piston 14b rests against a mating surface 15b, the shank 2 is pushed forward to a new position that differs from the optimum point of impact. As shown already in FIG. 1, the pressure is measured from the space behind either both the pistons 14a, 14b or only the pistons 14a. The ducts 17a and 17b are connected to a measuring conduit 19a, which is provided with a pressure sensor 20 that measures the reflected pressure pulse. Correspondingly, the duct 17b is connected to a measuring conduit 19b, which is provided with a pressure sensor 23 that measures the reflected pressure pulse. As regards the measurement and use of the pressure pulse, the situation is similar as in FIG. 1. Similarly, it is also possible in this embodiment to measure the pressure pulse with only one sensor, which means that the ducts 17a and 17b are connected to the measuring conduit 19a as shown by a broken line 24, and the pressure sensor 23 is not needed.
The drawing and the related description are only intended to illustrate the inventive idea. The details of the invention may vary within the scope of the claims. For example, the structure of the drilling machine does not have to be identical to the one shown in the figures, but for instance the damping of the percussion piston can be arranged in some other manner. Further, the pistons can be arranged to act directly on the shank, which means that no separate sleeve is necessarily needed between the shank and the pistons. An axial bearing may be provided between the shank and the pistons and it is positioned coaxially with the shank and the percussion piston. The analysis and use of the measurement signal obtained from the pressure sensor may also employ signal processing methods, which enable the extraction of more varied data from the measurement signal concerning, for example, the duration, energy and frequency of the reflected pulse, and this measurement data can then be used to effectively control the drilling machine.
Although the present invention has been described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, modifications, substitutions and deletions not specifically described may be made without departing from the spirit and scope of the invention as defined in the appended claims. | During the drilling of rock by a rock drill bit, percussive impacts are applied to the drill bit by a reciprocating piston which impacts a shank that transmits the impacts to the drill bit. Secondary pistons are provided to push the shank forwardly in response to a pressure medium acting on rear surfaces of the secondary pistons. The secondary pistons push the shank to its optimum point of impact. During a drilling operation, as the piston applies percussive impacts, return pulses are reflected back to the secondary pistons. Pressure sensors detect the return pulses in the form of pressure pulses, which indicate whether the drill bit has encountered weaker or stronger materials. Based upon characteristics of the detected pressure pulses, the operation of the drilling machine, e.g., the feed and/or impact power thereof, is regulated, so that the shank is returned to its optimum point of contact. | 4 |
FIELD OF THE INVENTION
This invention relates to decorative mouldings, and more specifically to a modular moulding system which allows moulding to be installed by a single unskilled person.
BACKGROUND OF THE INVENTION
Conventionally, mouldings such as crown mouldings, chair rails, baseboards, and door frame mouldings have been custom-cut and installed by skilled craftsmen. With the increasing cost of skilled labor, and the increasing interest of homeowners in do-it-yourself home renovation projects, it has become desirable to provide a means for relatively unskilled persons working alone with a minimum of tools to easily install and maintain attractive mouldings in the home.
One of the main problems for the do-it-yourselfer in the installation of mouldings is the need for precise measurement of components to avoid gaps or overlaps. Another is the need for skill in cutting or sawing components to produce true and correctly angled cuts for professional-looking joints and miters. A third problem is the fact that do-it-yourselfers frequently work alone at odd hours and are unable to call upon others to assist in supporting and aligning moulding components during installation.
SUMMARY OF THE INVENTION
The invention overcomes these problems by providing a system in which prefabricated corner pieces, rosettes and/or spacers are first individually positioned and fastened to the wall, ceiling and/or door. These pieces are equipped with retaining slots and tabs of such shape and dimensions that movable runners, rails, headers or casings of approximately appropriate length can be individually inserted and retained therein after the pieces are fixed in place. For this purpose, the retaining slots are deep enough to allow the movable elements to be fully inserted in a fixed element at one of their ends, and then partially withdrawn while being partially inserted into another fixed element at the other end. Once installed, disassembly movement of the movable elements can be prevented by blocking the slots with the aid of nails, screws or pegs. One advantage of the invention is that by making the slot-blocking means removable, the moulding can easily be disassembled for cleaning or painting, or for the replacement of damaged runners.
Guide tabs on the fixed elements may be provided to so interact with corresponding recesses in the movable elements as to guide the movable elements into tight and accurate alignment with the fixed elements during installation, and to help hold them in alignment with the retaining slots prior to insertion where appropriate.
It is also sometimes practical, particularly in connection with rosettes for door frame mouldings, to use the retaining slot system of this invention for the head of the door frame and the twist-lock miter system of copending application Ser. No. 08/521,183, filed 30 Aug. 1995, for the casing of the door frame.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a room illustrating the uses of various embodiments of the invention;
FIG. 2 is a detail plan view of a corner piece;
FIG. 3 is an end elevation of the corner piece of FIG. 2 with a runner inserted;
FIG. 4 is a vertical section of a moulding run along line 4--4 of FIG. 3 showing the runner during assembly;
FIG. 5 is a vertical section similar to FIG. 4 but showing the moulding run after assembly;
FIG. 6 is a bottom perspective view of a door rosette using a twist-lock miter connection for the casing;
FIG. 7 is a front elevation of a door casing assembly for use in a carpeted room; and
FIG. 8 is a front elevation of a door casing assembly for use in a hard-floored room.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As best show in FIG. 1, the system of this invention is designed to enable unskilled persons to easily assemble and attach decorative mouldings to various surfaces of a room 10. For example, the invention may be used for crown mouldings 12, chair rails 14, baseboards 16, or door frame mouldings 18. In the latter case, it may be advantageously adapted to rooms equipped with a carpet 20 or to rooms with a hard floor 22, as hereinafter described. It will be understood that although the elements of the system are shown in the drawings as relatively plain-surfaced, they may be shaped and decorated in any desired manner consistent with their interrelational functioning as described herein.
FIGS. 2 through 5 illustrate the use of the invention in the crown moulding 12. In the plan view of FIG. 2, the corner piece 24 is shown to consist of two pre-assembled corner blocks 26, 28 which are permanently joined at the miter 30. Elongated slots 32, 34 are formed in the rear faces of blocks 26, 28. Guide tabs 36, 38 extending beyond the ends 40, 42 of the blocks 26, 28 are provided on the rear faces of blocks 26, 28 to cooperate with slots 32, 34 and runners 44, 46 for purposes described below.
FIG. 3 shows, in an end view of the block 26, the cross-sectional shape of the slot 32 and the guide tab 36. The front face 48 of the slot 32 is identical in shape to the front face of the runner 44. Preferably, if the runner 44 is not symmetrical in cross section, that shape is sufficiently asymmetrical to make it readily apparent to the user which way is right side up for positioning the runner 44. On its rear face, the runner 44 is provided with a recess 50 which engages the guide tab 36 for alignment and support purposes.
The installation of a crown moulding section in accordance with the invention is shown in FIGS. 4 and 5. First, a pair of end pieces such as the corner piece 24 and the spacer block 52, or corner pieces 24 and 25, are secured in place on the wall and/or ceiling of the room. A runner 44 is then cut to a length just slightly less than the distance between the faces 40 and 54 of the corner piece 24 and spacer block 52, respectively, plus the depth of the slot 32. The accuracy or straightness of the cut is not critical, and even a runner length as much as one or two centimeters shorter than optimum will not cause problems in most instances.
The cut runner is now aligned with, e.g., slot 32 of the corner piece 24 by engaging the recess 50 of the runner 44 with the guide tab 36.
It should be noted that, unless the runner 44 is formed from a flexible material, the thickness of the corner block 26 and/or spacer block 52 between the front face of slot 32 and the front face of the block should be held to a minimum so as to allow placement of the runner (which at this time overlaps the block 52) in as close an alignment as possible with the longitudinal axis of the slot 32.
One end of runner 44 is now inserted into the slot 32 of block 26 as far as it will go. This brings the opposite end of runner 44 out of overlap with block 52 and makes it possible to bring the recess 50 of runner 44 into engagement with the guide tab 56 of block 52. The runner 44 is now aligned with the slot 58 of block 52. By sliding the runner 44 toward block 52 a distance of one-half the depth of slot 32, the runner 44 engages both the slot 58 and the slot 32 and is firmly held in place by them against vertical movement. The assembly can now be completed by using appropriate fasteners, such as pegs, nails or screws to block the slots 32 and 58 adjacent the ends of runner 44, or by actually driving a fastener through the block and runner on at least one end of runner 44.
It will be noted that unless a space is desired between the runner 44 and the ceiling of the room, the highest point of the slot 32 should be at the same neight as the top of corner block 26 and/or spacer block 52.
The same assembly method as described above can be used with chair rails and baseboards, except that in those instances, appropriate corner pieces, spacer blocks and end pieces such as 60 are preferably so designed as to hold the runners flat against the wall rather than at an angle.
FIGS. 6 through 8 illustrate the use of the invention in a door frame moulding. Typically, as shown in FIG. 6, a door frame of this type involves a head 62, corner blocks or rosettes 64 and casings 66. For reasons detailed below, plinth blocks 68 would normally be used on a hard floor (FIG. 7) but are unnecessary on a carpeted floor (FIG. 8).
In the arrangement of FIG. 7, the rosettes 64 and bead 62 are first assembled in the same manner as described above for crown moulding. It may, however, be advantageous, due to the small size of the rosettes 64, to omit the guide tabs of FIGS. 2 through 5 and to rely only on the slots 70 to hold the head 62 against vertical movement.
Because the weight of the casing 66 rests on the plinth block 68, it may be advantageous to make the slot 72 of the plinth block 68 only half as deep as the slot 74 in the rosette. When the casing is inserted first in the rosette 64 and then in the plinth block 68, it will rest on a solid surface without the need for any fasteners.
A somewhat different situation exists in the case where the floor is carpeted. Because the carpet 20 and its pad may be several centimeters thick, difficulties may arise in the absence of a plinth block when the slot type arrangement is used for the casing 66 in the rosette 64. Consequently, it may be advantageous to assemble the rosette 64 with the casing 66 by a twist-lock mechanism 76 (FIG. 6) such as that shown in U.S. Pat. No. 5,603,586 prior to mounting the rosette 64. The twist-lock mechanism 76 holds the casing 66 tightly against the rosette 64, while the lower end of casing 66 will be hidden by the carpet 20 so that the quality and accuracy of its cut is not critical.
Although specific embodiments of the invention have been described herein, it will be apparent to those skilled in the art that many variations, embodiments and combinations of the inventive concept are possible; consequently, the invention is not to be limited except by the scope of the following claims. | A modular moulding system uses slotted blocks which are first individually mounted on a support surface. A length of moulding runner is inserted deeply into the slot of one of the blocks, and then partially withdrawn while being inserted into the slot of the other block. In this manner, moulding can be assembled by one unskilled person working alone, and accuracy of the cut of moulding runners is not critical. | 4 |
CROSS REFERENCE TO RELATED PROVISIONAL APPLICATION
This application is based on Provisional Application Ser. No. 60/231,788 filed on Sep. 12, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is generally related to methods and processes for analyzing well production data and maximizing efficiency of reservoir production therefrom and is specifically directed to the evaluation of multilayer commingled reservoirs using commingled production data and production logging information.
2. Discussion of the Prior Art
Field production performance data and multiple pressure transient tests over a period of time for oil and gas wells in geopressured reservoirs have been found to often exhibit marked changes in reservoir effective permeability over the producing life of the wells. Similarly, the use of quantitative fractured well diagnostics to evaluate the production performance of hydraulically fracture wells have clearly shown that effective fracture half-length and conductivity can be dramatically reduced over the producing life of the wells. A thorough investigation of this topic may be found in the paper presented by Bobby D. Poe, the inventor of the subject application, entitled: “Evaluation of Reservoir and Hydraulic Fracture Properties in Geopressure Reservoir,” Society of Petroleum Engineers, SPE 64732.
Some of the earliest references to the fact that subterranean reservoirs do not always behave as rigid and non-deformable bodies of porous media may be found in the groundwater literature, see for example, “Compressibility and Elasticity of Artesian Aquifers,” by O. E. Meinzer, Econ. Geol. (1928) 23, 263–271. and “Engineering Hydraulics,” by C. E. Jacob, John Wiley and Sons, Inc. New York (1950) 321–386.
The observations of early experimental and numerical studies of the effects of stress-dependent reservoir properties demonstrated that low permeability formations exhibit a proportionally greater reduction in permeability than high permeability formations. The stress-dependence of reservoir permeability and fracture conductivity over the practical producing life of low permeability geopressured reservoirs has resulted in the following observations:
1. Field evidence of reservoir effective permeability degradation with even short production time can often be observed in geopressured reservoirs. 2. Quantitative evaluation of the field production performance of hydraulic fractures in both normal and geopressured reservoirs have resulted in the observation that the fracture conductivity of hydraulically fractured wells commonly decreases with production time. 3. Multiphase fracture flow has been demonstrated to dramatically reduce the effective conductivity of fractures. 4. Pre-fracture estimates of formation effective permeability derived from pressure transient tests or production analyses are often not representative of the reservoir effective permeability exhibited in the post-fracture production performance.
The analysis of production data of wells to determine productivity has been used for almost fifty years in an effort to determine in advance what the response of a well will be to production-stimulation treatment. A discourse on early techniques may be found in the paper presented by R. E. Gladfelter, entitled “Selecting Wells Which Will Respond to Production-Simulation Treatment,” Drilling and Production Procedures, API (American Petroleum Institute), Dallas, Tex., 117–129 (1955). The pressure-transient solution of the diffusivity equation describing oil and gas flow in the reservoir is commonly used, in which the flow rate normalized pressure drops are given by:
( P i −P wf )/ q o , and
{ P p ( P i )− P p ( P wf )}/ q g ,
for oil and gas reservoir analyses, respectively, wherein:
P i is the initial reservoir pressure (psia), P wf is the sandface flowing pressure (psia) q o is the oil flow rate (STB/D) P p is the pseudopressure function, psia 2 /cp and q g is the gas flow rate (Mcsf/D).
While analysis of production data using flow rate normalized pressures and the pressure transient solutions work reasonably well during the infinite-acting radial flow regime of unfractured wells, boundary flow results have indicated that the production normalization follows an exponential trend rather than the logarithmic unit slope exhibited during the pseudosteady state flow regime of the pressure-transient solution.
Throughout most of the production history of a well, a terminal pressure is imposed on the operating system, whether it is the separator operating pressure, sales line pressure, or even atmospheric pressure at the stock tank. In any of these cases, the inner boundary condition is a Dirichlet condition (specified terminal pressure). Whether the terminal pressure inner boundary condition is specified at some point in the surface facilities or at the sandface, the inner boundary condition is Dirichlet and the rate-transient solutions are typically used. It is also well known that at late production times the inner boundary condition at the bottom of the well bore is generally more closely approximated with a constant bottomhole flowing pressure rather than a constant rate inner boundary condition.
An additional problem that arises in the use of pressure-transient solutions as the basis for the analysis of production data is the quantity of noise inherent in the data. The use of pressure derivative functions to reduce the uniqueness problems associated with production data analysis of fractured wells during the early fracture transient behavior even further magnifies the effects of noise in the data, commonly requiring smoothing of the derivatives necessary at the least or making the data uninterpretable at the worst.
There have been numerous attempts to develop more meaningful production data analyses in an effort to maximize the production level of fractured wells. One such example is shown and described in U.S. Pat. No. 5,960,369 issued to B. H. Samaroo, describing a production profile predictor method for a well having more than one completion wherein the process is applied to each completion provided that the well can produce from any of a plurality of zones or in the event of multiple zone production, the production is commingled.
From the foregoing, it can be determined that production of fractured wells could be enhanced if production performance could be properly utilized to determine fracture efficiency. However, to date no reliable method for generating meaningful data has been devised. The examples of the prior art are at best speculative and have produced unpredictable and inaccurate results.
SUMMARY OF THE INVENTION
The subject invention is a method of and process for evaluating reservoir intrinsic properties, such as reservoir effective permeability, radial flow steady-state skin effect, reservoir drainage area, and dual porosity reservoir parameters omega (dimensionless fissure to total system storativity) and lambda (matrix to fissure crossflow parameter) of the individual unfractured reservoir layers in a multilayer commingled reservoir system using commingled reservoir production data, such as wellhead flowing pressures, temperatures and flow rates and/or cumulatives of the oil, gas, and water phases, and production log information (or pressure gauge and spinner survey measurements). The method and process of the invention also permit the evaluation of the hydraulic fracture properties of the fractured reservoir layers in the commingled multilayer system, i.e., the effective fracture half-length, effective fracture conductivity, permeability anisotropy, reservoir drainage area, and the dual porosity reservoir parameters omega and lambda. The effects of multiphase and non-Darcy fracture flow are also considered in the analysis of fractured reservoir layers.
The subject invention is directed to a method of and process for fractured well diagnostics for production data analysis for providing production optimization of reservoir completions via available production analysis and production logging data. The method of the invention is a quantitative analysis procedure for reservoir and fracture properties using commingled reservoir production data, production logs and radial flow and fractured interval analyses. This permits the in situ determination of reservoir and fracture properties for permitting proper and optimum treatment placement and design of the reservoir. The invention provides a rigorous analysis procedure for multilayer commingled reservoir production performance. Production logging data is used to correctly allocate production to each completed interval and defined reservoir zone. This improves the stimulation and completion design and identifies zones to improve stimulation.
The subject invention is a computational method and procedure for computing the individual zone production histories of a commingled multi-layered reservoir. The data used in the analysis are the commingled well production data, the wellhead flowing temperatures and pressures, the complete wellbore and tubular goods description, and production log information. This data is used to construct the equivalent individual layer production histories. The computed individual completed interval production histories that are generated are the individual layer hydrocarbon liquid, gas, and water flow rates and cumulative production values, and the mid-completed interval wellbore flowing pressures as a function of time. These individual completed interval production histories can then be evaluated as simply drawdown transients to obtain reliable estimates of the in situ reservoir effective permeability, drainage area, apparent radial flow steady-state skin effect and the effective hydraulic fracture properties, namely, half-length and conductivity.
Typically, an initial production log is run soon after a well is put on production and the completion fluids have been produced back from the formation. Depending on the formation, the stimulation/completion operations performed on the well and the size and productive capacity of the reservoir, a second production log is run after a measurable amount of stabilized production has been obtained from the well. Usually, additional production logs are run at periodic intervals to monitor how the layer flow contributions and wellbore pressures continue to vary with respect to production time. The use of production logs in this manner provides the only viable means of interpreting commingled reservoir production performance without the use of permanent downhole instrumentation.
The subject invention is directed to the development of a computational model that performs the production allocation of the individual completed intervals in a commingled reservoir system using the fractional flow rates of the individual completed intervals, determined from production logs and the commingled system total well fluid phase flow rates. The individual completed interval flow rate histories generated include the individual completed interval fluid phase flow rates and cumulative production values as a function of production time, as well as the mid-zone wellbore flowing pressures. The computed mid-zone flowing wellbore pressures at the production time levels of the production log runs are then compared with the actual measured wellbore pressures at those depths and time level to ascertain which wellbore pressure traverse model most closely matches the measured pressures.
The identified wellbore pressure traverse model is then used to model the bottom hole wellbore flowing pressures for all of the rest of the production time levels for which there are not production log measurements available. This use of the identified pressure traverse model to generate the unmeasured wellbore flowing pressure is the only assumption required in the entire analysis. It is fundamentally sound unless there are dramatic changes in the character of the produced well fluids or in the stimulation/damage of the completed intervals which is not reflected in the composite production log history, primarily due to inadequate sampling of the changes in the completed intervals producing fractional flow rates. With an adequate sampling of the changing fractional flow rate contributions of the individual completed intervals in a commingled reservoir, this analysis technique is superior to other multi-layer testing and analysis procedures.
The method and process of the subject invention provide a fully-coupled commingled reservoir system analysis model for allocating the commingled system production data to the individual completed intervals in the well and constructing wellbore flowing pressure histories for the individual completed intervals in the well. No assumptions are required to be made as to the stimulation/damage steady-state skin effect, effective permeability (or formation conductivity), initial pore pressure level, drainage area extent, or intrinsic formation properties of the completed intervals in a commingled reservoir system. The method of the invention considers only the actual measured response of the commingled system using production logs and industry accepted wellbore pressure traverse computational models.
The fundamental basis for the invention is a computationally rigorous technique of computing the wellbore pressure traverses to the midpoints (or other desired points) of each completed interval using one or more of a number of petroleum industry accepted wellbore pressure traverse computational methods in combination with the wellbore tubular configuration and geometry, wellbore deviation survey information, completed interval depths and perforation information, wellhead measured production rates (or cumulatives) and the wellhead pressures and temperatures of the commingled multilayer reservoir system performance. The computed pressure traverse wellbore pressures are compared with the measured wellbore pressures of either a production log or a wellbore pressure survey. This permits the identification of the pressure traverse computational method that results in the best agreement with the physical measurements made.
The invention permits the use of information from multiple production logs run at various periods of time over the producing life of the well. The invention also permits the specification of crossflow between the commingled system reservoir layers in the wellbore. The invention evaluates the pressure traverse in each wellbore segment using the fluid flow rates in that wellbore section, the wellbore pressure at the top of that wellbore section, and the temperature and fluid density distributions in that section of the wellbore traverse. The method and process of the invention actually uses downhole physical measurements of the wellbore flowing pressures, temperatures, fluid densities, and the individual reservoir layer flow contributions to accurately determine the production histories of each of the individual layers in a commingled multilayer reservoir system. The results of the analysis of the individual reservoir layers can be used with the commingled reservoir algorithm to reconstruct a synthetic production log to match with the actual recorded production logs that are measured in the well. The invention has an automatic Levenberg-Marquardt non-linear minimization procedure that can be used to invert these production history records to determine the individual completed interval fracture and reservoir properties. The invention also has the option to automatically re-evaluate the initially specified unfractured completed intervals that indicate negative radial flow steady-state skin effects as finite-conductivity vertically fractured completed intervals.
The method and process of the subject invention permits for the first time a reliable, accurate, verifiable computationally rigorous analysis of the production performance of a well completed in a multilayer commingled reservoir system using physically measured wellbore flow rates, pressures, temperatures, and fluid densities from the production logs or spinner surveys and pressure gauges to accomplish the allocation of the flow rates in each of the completed reservoir intervals. The combination of the production log information and the wellbore traverse calculation procedures results in a reliable, accurate continuous representation of the wellbore pressure histories of each of the completed intervals in a multilayer commingled reservoir system. The results may then be used in quantitative analyses to identify unstimulated, under-stimulated, or simply poorly performing completed intervals in the wellbore that can be stimulated or otherwise re-worked to improve productivity. The invention may include a full reservoir and wellbore fluids PVT (Pressure-Volume-Temperature) analysis module.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart of the process of the subject invention.
FIG. 2 is an illustration of the systematic and sequential computational procedure in accordance with the subject invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The subject invention is directed to a computational model for computing the wellbore pressure traverses and individual layer production contributions of the individual completed intervals in a commingled reservoir. Direct physical measurements of the individual layer flow contributions to the total well production and the actual wellbore flowing pressures are recorded and included in the analysis. There are numerous wellbore pressure traverse models available for computing the bottom hole flowing and static wellbore pressures from surface pressures, temperatures and flow rates, as will be well known to those skilled in the art. The selection of the appropriate pressure traverse model is determined by comparison with the actual wellbore pressure measurements. In a commingled reservoir the layer fractional flow contribution to the total well production rate also commonly varies with respect to time. There are many factors that govern the individual layer contributions to the total well production rate with respect to time. Among these are differences in the layer initial pressures, effective permeability, stimulation or damage steady-state skin effect, drainage area, net pay thickness, and the diffusivity and storativity of the different layers. Other factors that are not directly reservoir-controlled that affect the contribution of each of the layers to the commingled reservoir well production are the changing wellbore pressures, completion losses and changing gas and liquid produced fluid ratios with respect to time.
Production logs (PLs) provide a direct means of measuring the wellbore flowing pressures, temperatures, and actual reservoir layer flow contributions at specific points in time, with which to calibrate the computed pressure traverse models. It is preferable to run multiple production logs on wells producing commingled reservoirs to track the variation in the individual completed interval contributions with respect to production time.
It is known that the commingled system total production rate commonly does not equal or even come close to equaling the sum of the individual completed interval isolated flow rates when each interval is tested in isolation from the other completed intervals in the well. There are several factors causing this, including but not limited to (1) invariably higher flowing wellbore pressures present in the commingled system across each of the completed intervals than when they were measured individually, and (2) possible crossflow between the completed intervals.
As more particularly shown in the flowchart of FIG. 1 , the subject invention is directed to a computational model that performs the production allocation of the individual completed intervals in a commingled reservoir system using the fractional flow rates of the individual completed intervals, determined from the production logs and the commingled system total well fluid phase flow rates. This depicts the analysis process for a reservoir with three completed reservoir layers in which the upper and lower reservoir layers have been hydraulically fractured. The middle reservoir completed interval has not been fracture stimulated. The wellbore pressure traverse is computed using the total well commingled production flow rates to the midpoint of the top completed interval. Then the fluid flow rates in the wellbore between the midpoint of the top and middle completed intervals are evaluated using the total fluid phase flow rates of the commingled system minus the flow rates from the top completed interval. The pressure traverse in the wellbore between the midpoints of the middle and lower completed intervals is evaluated using the fluid phase flow rates that are the difference between the commingled system total fluid phase flow rates and the sum of the phase flow rates from the top and middle completed intervals. The individual completed interval flow rate histories generated in this analysis include the individual completed interval fluid flow rates and cumulative production values as a function of production time, as well as the mid-zone wellbore flowing pressures. The computed mid-zone flowing wellbore pressures at the production time levels of the production log runs are then compared with the actual measured wellbore pressures at those depths and time level to ascertain which wellbore pressure traverse model most closely matches the measured pressures.
The identified wellbore pressure traverse model is then used to model the bottomhole wellbore flowing pressure for all of the rest of the production time levels for which there are not production log measurements available. This use of the identified pressure traverse model to generate the unmeasured wellbore flowing pressures is the only major assumption made in the process. It is fundamentally sound unless there are dramatic changes in the character of the produced well fluids or in the stimulation/damage of the completed intervals which is not reflected in composite production log history, primarily due to inadequate sampling of the changes in the completed intervals producing fractional flow rates. With an adequate sampling of the changing fractional flow rate contributions of the individual completed intervals in a commingled reservoir, this analysis technique produces accurate results.
FIG. 2 is an illustration of the systematic and sequential computational procedure in accordance with the subject invention. Beginning at the wellhead 10 , the pressure traverses to the midpoint of each completed interval are computed in a sequential manner. The fluid flow rates in each successively deeper segment of the wellbore are decreased from the previous wellbore segment by the production from the completed intervals above that segment of the wellbore. The mathematical relationships that describe the fluid phase flow rates (into or out) of each of the completed intervals in the wellbore are given as follows for oil, gas, and water production of the j th completed interval, respectively:
q oj ( t )= q ot ( t ) f oj ( t ), q gi ( t )= q gt ( t ) f gj ( t ), q wj ( t )= q wt ( t ) f wj ( t ),
where:
q oj is the j th completed interval hydrocarbon liquid flow rate, STB/D, q of is the composite system hydicarbon liquid flow rate, STB/D, f oj is the j th completed interval hydrocarbon liquid flow rate liquid contribution of the total well hydrocarbon liquid flow rate, fraction, q gi is the j th interval gas flow rate, Mcsf/D j is the index of completed intervals, q gt is the composite system total well gas flow rate, Mscf/D, f gj is the j th completed interval gas flow rate fraction of total well gas flow rate, fraction, q wj is the j th interval water flow rate, STB/D q wt is the composite system total well water flow rate, STB/D f wj is the j th completed interval water flow rate fraction of total well water flow rate, fraction.
The corresponding fluid phase flow rates in each segment of the weilbore are also defined mathematically with the relationships as follows for oil, gas and water for the n th wellbore pressure traverse segment, respectively.
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The flow rate and pressure traverse computations are performed in a sequential manner for each wellbore segment, starting at the surface or wellhead 10 and ending with the deepest completed interval in the wellbore, for both production and injection scenarios. The wellbore flow rate and pressure traverse calculation procedures employed permit the evaluation of production, injection or shut in wells.
The fundamental inflow relationships that govern the transient performance of a commingled multi-layered reservoir are fully honored in the analysis provided by the method of the subject invention. Assuming that accurate production logs are run in a well, when a spinner passes a completed interval without a decrease in wellbore flow rate (comparing wellbore flow rates at the top and bottom of the completed interval, higher or equal flow rate at the top than at the bottom), no fluid is entering the interval from the wellbore (no loss to the completed interval, i.e., no crossflow). Secondly, once the minimum threshold wellbore fluid flow rate is achieved to obtain stable and accurate spinner operation, all higher flow rate measurements are also accurate. Lastly, the sum of all of the completed interval contributions equals the commingled system production flow rates for both production and injection wells.
In the preferred embodiment of the invention, two ASCII input data files are used for the analysis. One file is the analysis control file that contains the variable values for defining how the analysis is to be performed (which fluid property and pressure traverse correlations are uses, as well as the wellbore geometry and production log information). The other file contains commingled system wellhead flowing pressures and temperatures, and either the individual fluid phase flow rates or cumulative production values as a function of production time.
Upon execution of the analysis two output files are generated. The general output file contains all of the input data specified for the analysis, the intermediate computational results, and the individual completed interval and defined reservoir unit production histories. The dump file contains only the tabular output results for the defined reservoir units that are ready to be imported and used in quantitative analysis models.
The analysis control file contains a large number of analysis control parameters that use can be used to tailor the production allocation analysis to match most commonly encountered wellbore and reservoir conditions. | A method for providing production optimization of reservoir completions having a plurality of completed intervals via available production analysis and production logging data provides a quantitative analysis procedure for reservoir and fracture properties of a commingled reservoir system, that includes the steps of measuring pressure for specific zones in a reservoir; selecting a pressure traverse model; computing midzone pressures using the traverse model; comparing the computed midzone pressures with the measured pressures; and modeling the bottomhole pressure of the reservoir based on the traverse model. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to the fabrication of opaque glass-ceramic articles exhibiting an integral beige tint which are eminently useful as culinary ware.
As is well-recognized in the art, glass-ceramic articles are produced through the controlled crystallization of precursor glass articles, the process of manufacture normally consisting of three basic steps: first, a glass forming batch typically containing a nucleating agent is melted; second, that melt is cooled to a temperature below the transformation range thereof and simultaneously shaped into a glass body of a desired configuration; and third, that glass body is exposed to a heat treatment designed to effect the in situ growth of crystals within the glass body. (As is commonly used in the art, the transformation range is defined as the temperature at which a molten material is transformed into an amorphous mass, that temperature being deemed to reside in the vicinity of the annealing point of a glass.)
Quite frequently, the thermally-induced crystallization in situ will be carried out in two general steps: first, the precursor glass body will be heated to a temperature slightly above the transformation range for a period of time sufficient to generate nuclei therein; and second, the nucleated glass is heated to a temperature approaching, and often surpassing, the softening point of the glass to cause the growth of crystals on the nuclei. This two-stage heat treatment commonly yields glass-ceramic articles containing higher levels of crystallization with more uniformly-sized, fine-grained crystals. It will be appreciated that, as the temperature of the nucleated precursor glass article approaches the softening point of the glass, the rate at which the temperature is raised must be regulated to allow time for the sufficient growth of crystallization to resist thermal deformation of the body. Thus, the crystals developed during the heat treatment process are most usually more refractory than the precursor glass, and thereby can provide a structure demonstrating resistance to thermal deformation at temperatures higher than those at which the precursor glass can be subjected. Also, because the crystal forming components will have been removed therefrom, the small percentage of residual glass remaining in the glass-ceramic (customarily less than 50% by volume and frequently less than 10% by volume) will have a very different composition from that of the precursor glass, and most often that residual glass will manifest a higher softening point than that of the precursor glass.
The development of a high concentration of crystals within a glass-ceramic body has a further advantage vis-a-vis the precursor glass body in dramatically enhancing the mechanical strength thereof, usually by a factor of at least two and frequently as much as three times that of the precursor glass. That significant improvement in mechanical strength, coupled with their substantially higher use temperatures and their intrinsic "porcelain-like" appearance, have led to the widespread use of glass-ceramic articles as culinary ware.
Generally, in the absence of added colorants, opaque glass-ceramic articles display a white appearance. For example, Corning Code 9608 glass-ceramic, marketed by Corning Incorporated, Corning, N.Y. for over 30 years under the trademark CORNING WARE® , exhibits a creamy white appearance. Having a composition included within U.S. Pat. No. 3,157,522, that opaque glass-ceramic contains a crystallinity in excess of 90% by volume wherein betaspodumene solid solution constitutes the predominant crystal phase with a minor amount of spinel and rutile also being present. Corning Code 9608 has the following approximate analysis, expressed in terms of weight percent on the oxide basis:
______________________________________SiO.sub.2 69.5 ZnO 1.0 F 0.03Al.sub.2 O.sub.3 17.7 TiO.sub.2 4.7 Fe.sub.2 O.sub.3 0.05Li.sub.2 O 2.7 ZrO.sub.2 0.2 B.sub.2 O.sub.3 0.07MgO 2.6 As.sub.2 O.sub.3 0.6 MnO.sub.2 0.03______________________________________
As might well be expected, colorants known in the glass art have been incorporated into precursor glass compositions which have subsequently been crystallized in situ to glass-ceramic articles. U.S. Pat. No. 4,461,839 (Rittler) and U.S. Pat. No. 4,786,617 (Andrieu et al.) are recent illustrations of that practice.
The former patent discloses the manufacture of opaque glass-ceramic articles containing β-spodumene solid solution as the predominant crystal phase, which can display colors ranging from gray to brown to almond to beige to yellow to blue, that are prepared from precursor glass articles having base compositions essentially free from MgO and consist essentially, in weight percent, of:
______________________________________SiO.sub.2 63.5-69 BaO 0-5Al.sub.2 O.sub.3 15-25 TiO.sub.2 2-3Li.sub.2 O 2.5-4 ZrO.sub.2 0.5-2.5Na.sub.2 O 0.1-0.6 As.sub.2 O.sub.3 0.4-0.8K.sub.2 O 0.1-0.6 Fe.sub.2 O.sub.3 0.05-0.1ZnO 0-2______________________________________
The desired colors are obtained through the use of a "color package" containing about 0.5-3% TiO 2 and up to 0.15% Fe 2 O 3 with 0.3-3% total of at least two oxides in the indicated proportion selected from the group of up to 0.3% V 2 O 5 , up to 3% CeO 2 , up to 2% CaO, up to 1% NiO, up to 1% WO 3 , and up to 1.5% SnO 2 . The total TiO 2 content in the glass will range > 2.5-6% and that of the Fe 2 O 3 content will range 0.05-0.2%.
The latter patent describes the fabrication of opaque glass-ceramic articles containing potassium fluorrichterite and/or a related fluormica as the predominant crystal phase(s) from precursor glass compositions essentially free from Li 2 O and which consist essentially, in weight percent, of:
______________________________________SiO.sub.2 61-70 K.sub.2 O 2.5-5.5Al.sub.2 O.sub.3 2.75-7 Na.sub.2 O + K.sub.2 O <6.8MgO 11-16 F 2-3.25CaO 4.75-9 BaO 0-3.5Na.sub.2 O 0.5-3 P.sub.2 O.sub.5 0-2.5______________________________________
The text of the patent noted that it was possible to incorporate such conventional glass colorants as Fe 2 O 3 , CeO 2 , CaO, Cr 2 O 3 , CuO, MnO 2 , Na 2 O, and V 2 O 5 into the base precursor glass composition in amounts typically less than 1% total. Nevertheless, only the use of Fe 2 O 3 to impart a yellow tint to the glass-ceramic was expressly mentioned.
Corning Incorporated currently markets a line of opal glass tableware under the trademark CORNERSTONE® . That product has a composition included in U.S. Pat. No. 4,331,769 (Danielson et al.) and exhibits a beige tint defined within the polygon bounded by Points ABCDEFA depicted in the appended drawing, which polygon encompasses a plot of the x and y chromaticity coordinates (Illuminant C). The visual appearance of the product is described here in accordance with the standard CIE system utilizing chromaticity coordinates x and y and the tristimulus value Y. Thus, the values are measured under standard conditions, i.e., Illuminant C, with a Hunter Colorimeter and represent the light that diffusely reflects off opaque surfaces. Because the values obtained are readily reproducible, they are commonly employed to facilitate comparisons and to delimit specifications.
The tint is imparted to the CORNERSTONE® tableware through the incorporation of NiO into the base glass compositions. The research leading to the present invention had as its goal the development of an opaque glass-ceramic body demonstrating properties suitable for use as cookware which would exhibit a hue close to and compatible with that of CORNERSTONE® tableware, thereby offering to the consumer market a complete line of dinnerware and cookware of approximately the same tint. Because the glass-ceramics were destined for use as culinary ware, the chemical and physical properties recognized in the art as being necessary in such articles would likewise be required in the tinted articles. For example, the tinted articles would exhibit low linear coefficients of thermal expansion, viz., < 15 and preferably < 13×10 -7 /°C. over the temperature range of 0°-300°C., and good resistance to the chemical attack of food products.
SUMMARY OF THE INVENTION
In view of the fact that Corning Code 9608 was known to manifest the chemical and physical properties to perform well as cookware, additions of known coloring agents, both individually and in various combinations, were made to the base precursor or glass composition therefor in attempts to substantially duplicate the hue of CORNERSTONE® tableware. As a result of those testing experiments, we discovered a very narrow range of precursor base glass compositions containing about 1.5-2.75% CeO 2 as the colorant which could be heat treated to form opaque glass-ceramic articles demonstrating the chemical and physical properties required in glass-ceramics devised for use as culinary ware, and which also display a beige tint close to and compatible with that of CORNERSTONE® tableware. (The incorporation of NiO in the precursor base glass composition of Corning Code 9608 imparts a blue coloration to the glass-ceramic.) Those glass compositions consist essentially, expressed in terms of weight percent on the oxide basis, of
______________________________________SiO.sub.2 66-70 TiO.sub.2 3.5-5.5Al.sub.2 O.sub.3 16.5-19.5 CeO.sub.2 1.5-2.75Li.sub.2 O 2-4 As.sub.2 O.sub.3 0-1.5MgO 1-5 F 0-1.2ZnO 0.5-2 ZrO.sub.2 0-2.5Na.sub.2 O 0-1______________________________________
In like manner to conventional glass-ceramics known to the art, the products of the present invention are prepared in accordance with the following three general steps:
(a) a batch for a glass having a composition within the above ranges is melted;
(b) that melt is cooled to a temperature below the transformation range thereof and simultaneously a glass body of a desired configuration is shaped therefrom; and
(c) the glass body is heat treated in a manner to effect the crystallization in situ thereof.
To assure the development of a highly crystalline article wherein the crystals are uniformly fine-grained, the precursor glass body will be nucleated via exposure for a sufficient period of time to a temperature within the range of about 750°-850°C., and thereafter will be crystallized via exposure for a sufficient period of time to a temperature within the range of about 1025°-1175°C. Whereas an express dwell period within either of those temperature ranges may be used as a matter of convenience, such is not required. It is only necessary that the glass article be within those ranges for a sufficient length of time to accomplish the purpose therefor. As can be appreciated, the time required is dependent in some measure upon the thickness of the glass articles being heat treated to assure temperature equilibration throughout the body thereof.
The inventive glass-ceramics are very highly crystalline, i.e., greater than 75% by volume crystalline and, more desirably, greater than 90% by volume crystalline. The crystals, themselves, are quite uniformly fine-grained, with diameters of less than 1 micron. β-spodumene solid solution (s.s.) constitutes by far the predominant crystal phase with minor levels of spinel and rutile. The cerium-containing minerals loparite (Ce 2 Ti 3 O 8 .7) and perrierite (Ce 2 Ti 2 Si 2 O 11 ) have also been identified via x-ray diffractometry as being present in small amounts.
In summary, to achieve the beige tint displayed by CORNERSTONE® dinnerware, the above-recited composition intervals for the inventive glass-ceramics must be very closely observed. Moreover, care must also be observed in the crystallization heat treatment applied to the inventive precursor glass articles, as will be illustrated hereinafter.
BRIEF DESCRIPTION OF THE DRAWING
The drawing depicts two polygons encompassing plots of reflectance chromaticity coordinates x and y (Illuminant C) measured on CORNERSTONE® tableware and articles of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Table I below lists several precursor glass compositions, expressed in terms of parts by weight on the oxide basis as calculated from the batch, capable of being crystallized in situ to yield opaque glass-ceramic articles, which compositions illustrate the composition parameters of the present invention. Inasmuch as the sum of the individual components closely approximates 100, for all practical purposes the values recorded may be deemed to represent weight percent. Because it is not known with which cation(s) the fluoride is combined, and the amount present to act as a melting aid and as a strengthening agent as disclosed in U.S. Pat. No. 3,148,994 is small, it is merely reported as fluoride in accordance with conventional glass analysis practice. Fe 2 O 3 was not intentionally included in the composition but is present therein as an impurity from the batch materials, particularly in the sand comprising the source of SiO 2 . Because of its severe adverse effect upon color, Fe 2 O 3 will preferably be essentially absent from the compositions and should be held below 0.05% by weight. The actual ingredients employed in preparing the glass forming batch may comprise any materials, either the oxides or other compounds, which, when melted together, will be converted into the desired oxide in the proper proportions. For example, petalite may be used to supply Li 2 O, Al 2 O 3 , and SiO 2 . Sodium silico-fluoride provided the source of fluoride in the two compositions tabulated below. Arsenic oxide was included to perform its conventional function as a fining agent.
TABLE I______________________________________ 1 2 3 4 5 6______________________________________SiO.sub.2 69.60 69.35 69.10 68.85 68.60 68.35Al.sub.2 O.sub.3 17.83 17.83 17.83 17.83 17.83 17.83TiO.sub.2 4.70 4.70 4.70 4.70 4.70 4.70Li.sub.2 O 2.70 2.70 2.70 2.70 2.70 2.70MgO 2.60 2.60 2.60 2.60 2.60 2.60ZnO 1.04 1.04 1.04 1.04 1.04 1.04As.sub.2 O.sub.3 0.52 0.52 0.52 0.52 0.52 0.52Na.sub.2 O 0.37 0.37 0.37 0.37 0.37 0.37F 0.027 0.027 0.027 0.027 0.027 0.027Fe.sub.2 O.sub.3 0.033 0.033 0.033 0.033 0.033 0.033CeO.sub.2 0.50 0.75 1.00 1.25 1.50 1.75______________________________________ 7 8 9 10 11______________________________________SiO.sub.2 68.10 67.60 67.10 68.20 68.38Al.sub.2 O.sub.3 17.83 17.83 17.83 18.80 17.84TiO.sub.2 4.70 4.70 4.70 3.70 4.70Li.sub.2 O 2.70 2.70 2.70 2.90 2.70MgO 2.60 2.60 2.60 2.20 2.60ZnO 1.04 1.04 1.04 1.04 1.04As.sub.2 O.sub.3 0.52 0.52 0.52 0.63 0.63Na.sub.2 O 0.37 0.37 0.37 0.37 0.37F 0.027 0.027 0.027 0.03 0.027ZrO.sub.2 -- -- -- 0.10 --Fe.sub.2 O.sub.3 0.033 0.033 0.033 0.048 0.048CeO.sub.2 2.00 2.50 3.00 1.80 1.86______________________________________
The batch ingredients were compounded, ballmilled together to assist in securing a homogeneous melt, and then discharged into platinum crucibles. The crucibles were moved into a furnace operating at about 1625°C. and the batches melted overnight (˜ 16 hours). the melts were stirred slowly, poured and squeezed through stainless steel rollers to produce glass patties having a width of about 10-15 cm, a length of about 25 cm, and a thickness of 1.5 cm, and those patties were annealed at 700°C. The annealed patties were cut into shapes suitable for testing purposes.
It will be appreciated that the above glass melting and forming processes reflect laboratory practice only. Stated in another way, the above glasses are capable of being melted and formed utilizing commercial, large scale glass melting and forming equipment, and are not limited to laboratory activity. Furthermore, although the compositions of Table I were annealed to room temperature to permit examination of glass quality and to cut test samples from the patties, that action is not required. It is only necessary that the batches be heated sufficiently to produce a homogeneous melt, that melt cooled to a temperature below the transformation range thereof to yield an essentially crystal-free glass, and that glass body then subjected to the nucleation-crystallization heat treatment to convert it into a glass-ceramic.
Table II reports approximate heat treatment schedules which were employed with the glass samples of Table I along with the linear coefficient of thermal expansion (Exp) as measured over the temperature range of 0°-300°C. in terms of ×10 -7 /°C., and the x and y color coordinates with tristimulus value Y utilizing Illuminant C. Temperatures are listed in °C. and time in hours (hr).
TABLE II______________________________________Ex. Heat Treatment Exp x y Y______________________________________1 25-700 at 1000/hr -- 0.3212 0.3315 88.22 700-820 at 265/hr 820-850 at 30/hr 850-1100 at 240/hr 1100 for 1 hr 1100-950 at 400/hr 950-25 at 2500/hr2 25-700 at 1000/hr -- 0.3253 0.3333 85.04 700-820 at 265/hr 820-850 at 30/hr 850-1100 at 240/hr 1100 for 1 hr 1100-950 at 400/hr 950-25 at 2500/hr3 25-700 at 1000/hr -- 0.3253 0.3342 83.64 700-820 at 265/hr 820-850 at 30/hr 850-1100 at 240/hr 1100 for 1 hr 1100-950 at 400/hr 950-25 at 2500/hr4 25-700 at 1000/hr 11.5 0.3268 0.3353 79.66 700-820 at 265/hr 820-850 at 30/hr 850-1100 at 240/hr 1100 for 1 hr 1100-950 at 400/hr 950-25 at 2500/hr5 25-700 at 1000/hr 11.9 0.3286 0.3376 79.0 700-820 at 265/hr 820-850 at 30/hr 850-1100 at 240/hr 1100 for 1 hr 1100-950 at 400/hr 950-25 at 2500/hr6 25-700 at 1000/hr 12.1 0.3306 0.3398 78.46 700-820 at 265/hr 820-850 at 30/hr 850-1100 at 240/hr 1100 for 1 hr 1100-950 at 400/hr 950-25 at 2500/hr7 25-700 at 1000/hr 12.3 0.3335 0.3428 76.77 700-820 at 265/hr 820-850 at 30/hr 850-1100 at 240/hr 1100 for 1 hr 1100-950 at 400/hr 950-25 at 2500/hr8 25-700 at 1000/hr 11.1 0.3336 0.3430 74.58 700-820 at 265/hr 820-850 at 30/hr 850-1100 at 240/hr 1100 for 1 hr 1100-950 at 400/hr 950-25 at 2500/hr9 25-700 at 1000/hr 12.0 0.3368 0.3462 73.13 700-820 at 265/hr 820-850 at 30/hr 850-1100 at 240/hr 1100 for 1 hr 1100-950 at 400/hr 950-25 at 2500/hr10 25-800 at 800/hr 11.5 0.3323 0.3376 63.5 800-830 at 36/hr 830-1070 at 240/hr 1070-1080 at 15/hr 1080-25 at 1050/hr11 25-700 at 1000/hr 13.1 0.3306 0.3377 77.97 700-800 at 215/hr 800-835 at 30/hr 835-1100 at 230/hr 1100 for 1 hr 1100-950 at 400/hr 950-25 at 2500/hr______________________________________
As can be seen from Table II, although no express dwell period within the nucleation range was employed, the rate of temperature increase through the 750°-850°C. range was controlled such that the samples were within that temperature interval for about 1.25 hours. Longer times within the nucleation range can be used without concern with the samples to achieve even greater nucleation, but are unnecessary and are uneconomical from a practical point of view, inasmuch as sufficient nucleation was generated within that period to assure the extensive growth of uniformly-sized, very fine-grained crystals. Hence, exposure periods of about 1-3 hours have been deemed satisfactory.
At temperatures below about 1025°C., growth of crystals is quite slow. On the other hand, crystallization temperatures in excess of about 1175°C. can lead to grain growth of the crystals and thermal deformation of the body. It will be appreciated that, with articles of similar physical dimensions, longer exposure periods to assure the development of a high level of crystallinity will be required at lower temperatures within the crystallization range than at temperatures at the upper extreme thereof. Whereas in the heat treatment schedules listed in Table II the samples remained within the crystallization range for about 1-1.25 hours, longer exposure periods can be utilized without concern, but such longer periods can be uneconomical from a practical point of view in like manner to very extended nucleation periods. Accordingly, crystallization heat treatments of about 1-4 hours have been considered sufficient to achieve the desired extensive growth of uniformly-sized, very fine-grained crystals.
The x and y coordinates for Examples 1-11 are positioned within polygon bounded by Points A'B'C'D'E'F'A', which polygon overlaps the plot of the x and y coordinates encompassed with polygon bounded by Points ABCDEFA and, hence, includes tints not only matching that of CORNERSTONE® tableware, but also hues close to and compatible therewith. As is evident from polygon A'B'C'D'E'F'A', the tints of Examples 1-4, containing CeO 2 concentrations of 0.5%, 0.75%, 1%, and 1.25%, respectively, fall outside of the desired values, and Example 5, containing 1.5% CeO 2 , is at the edge of acceptable color. Accordingly, 1.5% CeO 2 has been deemed a practical minimum limit. At the other extreme, Example 9, containing 2.5% CeO 2 is close to the edge of acceptable color and Example 9, containing 3% CeO 2 is outside of acceptable color. Therefore, 2.75% CeO 2 has been adjudged an appropriate maximum level, with 1.75-2.25% CeO 2 being the preferred range.
To further illustrate the singular behavior of CeO 2 in imparting a beige tint close to and compatible with the hue of CORNERSTONE® tableware, CeO 2 was substituted for SiO 2 in amounts of 1.5%, 2.0%, and 2.5% in the base composition of the CORNERSTONE® tableware. The batches were compounded, ballmilled, melted at 1550°C., poured into 6"×6"×1/2" steel molds, and annealed at 600°C. in like manner to the procedure described in Patent No. 4,331,769. The compositions of those three glasses are recorded below in Table III, expressed in terms of parts by weight on the oxide basis as calculated from the batch. Because the sum of the individual constituents closely approximates 100, for all practical purposes the tabulated values may be deemed to reflect weight percent.
TABLE III______________________________________ 12 13 14______________________________________SiO.sub.2 62.9 62.4 61.7Al.sub.2 O.sub.3 6.28 6.28 6.31Na.sub.2 O 3.04 3.04 3.05B.sub.2 O.sub.3 4.86 4.86 4.89CaO 15.2 15.2 15.3MgO 1.01 1.01 1.01KaO 3.04 3.04 3.05F 3.55 3.55 3.56CeO.sub.2 1.50 2.0 2.51______________________________________
The x and y color coordinates tristimulus values Y (Illuminant C) for those three glasses were measured as follows:
______________________________________Glass 12 x = 0.3201, y = 0.3282, Y = 77.0Glass 13 x = 0.3213, y = 0.3281, Y = 72.5Glass 14 x = 0.3282, y = 0.3342, Y = 67.9______________________________________
As is immediately evident, those values fall far outside of polygon A'B'C'D'E'F'A' and, hence, the hues would not be compatible with the tint of CORNERSTONE® tableware.
The more preferred composition intervals yielding tints not only closely matching that of CORNERSTONE® tableware, but also exhibiting physical and chemical properties rendering them exceptionally suitable for culinary ware, consist essentially, expressed in terms of weight percent on the oxide basis, of
______________________________________SiO.sub.2 68.0 ± 2.0 TiO.sub.2 4.5 ± 0.75Al.sub.2 O.sub.3 18.0 ± 1.5 CeO.sub.2 2.0 ± 0.25Li.sub.2 O 2.75 ± 0.5 As.sub.2 O.sub.3 0.75 ± 0.5MgO 2.5 ± 0.75 F 0.5 ± 0.48ZnO 1.0 ± 0.25 ZrO.sub.2 0 - 0.5Na.sub.2 O 0.5 ± 0.25______________________________________
Example 10 is considered to be the most preferred composition. | This invention relates to the production of opaque, beige-tinted glass-ceramic articles consisting essentially, in weight percent, of
______________________________________
SiO 2 66-70 TiO 2 3.5-5.5Al 2 O 3 16.5-19.5 CeO 2 1.5-2.75Li 2 O 2-4 As 2 O 3 0-1.5MgO 1-5 F 0-1.2ZnO 0.5-2 ZrO 2 0-2.5Na 2 O 0-1______________________________________ | 2 |
FIELD OF INVENTION
This invention relates to an apparatus and method for lifting and depositing bottles having handles. More particularly, this invention relates to an apparatus and method for lifting, conveying and depositing containers by their handles to and from prescribed locations.
BACKGROUND OF THE INVENTION
In the past, a number of prior art devices have been devised for lifting and depositing bottles by the neck or cap of the bottle, even though the bottle to be lifted may have had a handle built into the bottle. Although this has proven to be an acceptable method for handling bottles, it presents the inherent problem that if there is a structural fault in the bottle neck or cap, or if the cap has not been adequately tightened upon the bottle, the bottle can slip and fall out of the handling device.
An example of a handling device which carries a bottle by its cap is disclosed in U.S. Pat. No. 3,604,742, issued Sep. 14, 1971, to Sprague. Sprague disclosed an apparatus for automatically lifting and handling objects having off-center neck portions, such as bottles or other containers, supporting them frictionally by the cap of the bottle. This was accomplished in Sprague through an apparatus having an annular ridge and a plate member which descends upon the bottle or object to be carried, and is moved in a orbital path yieldably passing over the cap of the bottle until it frictionally engages and lifts the bottle, solely by its cap. The bottle is then moved to another location, or placed into a packing box. At the time the bottle is to be released, a plunger mechanism releases the ridge and plate member by which Sprague frictionally held and carried the bottle.
The present invention does away with the necessity of frictionally engaging and carrying a bottle by its off-center neck portion. This invention includes a method and apparatus by which a bottle with an off-center neck portion and a handle is positively engaged and carried by its handle for providing a more efficient, less hazardous, and economical method for lifting or depositing a bottle to or from a platform or packing box.
SUMMARY OF THE INVENTION
Briefly described, the present invention includes a lifting assembly which has a movable support frame, for being initially positioned over the bottle upon the platform. A plurality of guide rods, extending downwardly from a plate of the support frame, align the support frame with the bottle as the support frame is lowered toward the bottle. A plurality of circumferentially spaced, opposed, inwardly extending, handle engaging fingers, respectively pivotally connected to the support frame, converging toward each other so as to pivot upwardly and around the handle, as the frame descends and then pivot toward each other to horizontal positions for carrying the bottle by its handle.
The invention is also provided with adjustable control rods respectively engaging the fingers for permitting each of the fingers to pivot independently upwardly as the fingers pass downwardly around opposite portions of the transverse portions of the bottle handle, while permitting those fingers, the ends of which pass around the handle, to return to their normal positions for lifting the bottle off of the platform as the support frame is raised. Each of the control rods is spring loaded downwardly to permit the fingers to pivot downwardly for releasing the transverse portion of the bottle handle, once a control plate is actuated so that the support frame may then be moved away from the bottle, leaving the bottle in its new position. Thereafter, each of the handle engaging fingers, in conjunction with the control rods and the movable support frame, are returned to their normal positions so that the bottle lifting apparatus can be used for lifting and depositing another bottle.
Accordingly, it is an object of the present invention to provide,an apparatus for transporting bottles, having off-center necks, which will positively support and move them from one place to another.
Another object of the invention is to provide an apparatus and method for automating transporting bottles in packing boxes or for unloading bottles from packing boxes.
It is another object of the invention to provide an apparatus for lifting and depositing bottles which is adaptable for use in commercial applications involving the automatic handling and shipping of bottles, with off-center necks and carrying handles, so that the need for manual labor in handling, transporting and packing the bottles is reduced.
A further object of the invention is to provide an apparatus for lifting and depositing the bottles by their handles which can be quickly, simply and inexpensively installed in industrial or commercial applications, or can be easily and inexpensively retrofitted to existing bottle handling and packaging machines.
Another object of the invention is to provide an apparatus for lifting and depositing bottles which can lift and move upright bottles, having off-center necks and carrying handles regardless of the angular orientation of the handles of the bottles.
Still another object of the present invention is to provide an apparatus and method for transporting containers having handles which apparatus is inexpensive to manufacture, simple and durable in structure, efficient in operation, and requires little maintenance.
Other objects, features and advantages of the present invention will become apparent from the following description when considered in conjunction with the accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an apparatus for lifting and depositing bottles having handles, constructed in accordance with the present invention;
FIG. 2 is a side elevational view, partially in cross section, showing the apparatus for lifting and depositing bottles shown in FIG. 1 and in operative relationship to a bottle having a laterally extending handle, the box for the bottles being depicted in broken lines;
FIG. 3A is a schematic top plan view of a bottle with an off center-neck and a handle and showing the handle engaging fingers of the apparatus of FIG. 1 engaged under the handle of the bottle, the bottle being in a first orientation and being received in a box shown in broken lines;
FIG. 3B is a schematic top plan view similar to FIG. 3A and showing the bottle in a second orientation; and
FIG. 3C is a schematic top plan view similar to FIGS. 3A and 3B and showing the bottle in a third orientation.
DETAILED DESCRIPTION
Referring now in detail to the embodiment chosen for purposes of illustrating the invention, numeral 10 in FIG. 1 denotes, generally, a movable support frame or frame assembly having a flat, rigid, horizontally disposed, rectangular or square base plate 12. An open, rectangular support strap or frame 14 of the frame assembly 10 encompasses the central portion of the base plate 12, the support strap 14 having a pair of horizontally disposed, opposed, complimentary, rectangular, lower and upper panels 14a and 14b, the ends of which are joined by opposed, vertically disposed, end panels 14c and 14d.
Lower panel 14a passes transversely beneath and is fixed to the central portion of base plate 12 so that the ends of the base plate 12 protrude in opposite directions beyond the side edges of panels 14a and 14b.
For lifting and lowering the frame assembly 10, so as to transport the bottle B, from one place to another, a conventional bottle transfer machine is used, the machine including an upright, telescoping, hollow tubular, rectangular transport standard or shaft 16. The lower end of shaft 16 is secured to the central upper surface of panel 14b.
The lower portion of transportation shaft 16, is provided with an idler sheave or pulley 18 rotatably mounted on a transverse shaft 19 within the shaft 16. A belt 20 passes around the lower portion of pulley 18 and thence upwardly on both sides of shaft 16. By taking in one end of the belt 20, the frame or frame assembly 10 is lifted, vertically and by releasing or paying out the belt 20, the frame assembly 10 is lowered.
The shaft 16 is moved laterally to move the frame assembly 10 from one location to another in a conventional manner, by manipulation of shaft 16, so that bottle B can be moved from a first surface, such as a conveyor belt or platform (not shown) and deposited on a second surface, such as the bottom of a crate, or box C, shown in broken lines in FIGS. 2, 3A, 3B and 3C.
Frame 10 includes guide rods 30 protruding downwardly from the corners of the rectangular or square base plate 12. Usually a plurality of four, equally spaced generally parallel, vertically disposed, guide rods 30 are provided. The rods 30 are each flat, straight, steel ribs, the upper or proximal end portions of which are rounded, forming solid cylindrical mounting lugs 30a which are respectively press fitted and fixed within holes in the corner portions of base plate 12. The guide rods 30 are evenly spaced, circumferentially around the vertical axis α of the frame assembly 10, the body 30b of each rod 30, below the lug 30a, being rectangular in cross-section so that the bodies 30b lie generally in radial planes with respect to axis α.
In FIG. 1, it is seen that the straight inner edge portions 30c of rods 30 function as guide edges which pass along the surfaces of the respective side portions of bottle B as the frame assembly 10 is lowered so as to orient the frame assembly 10 over the bottle B. To facilitate the orientation, the lower or distal inner end portions of the rods 30 are provided with outwardly and downwardly diverging cam surfaces or edges 30d.
Intermediate the ends of rods 30 are sidewise protruding pivot pins 32, which respectively pivotally receive and support the proximal end portions of lifting fingers or grippers 35. Each finger 35 is disposed by its proximal end position along one side of its guide rod 30 so that it normally protrudes inwardly from its associated pivot pin 32 to terminate adjacent to axis α. Each lifting finger 35 is a flat straight rod which is rectangular in cross-section, each finger 35 being formed from a straight flat piece of sheet metal, having relatively wide proximal and central portions, which is narrowed toward its tip or distal end portion to provide a straight, upper edge or surface 35a. The function of these lifting fingers or grippers 35 is to cooperate in passing around a lateral portion of handle H at the upper position of the bottle B and then support the bottle B by its handle H as the bottle B is lifted and lowered.
In the present embodiment the lifting fingers 35 are arranged 90° from each other and protrude generally radially inwardly; however, since the fingers 35 are pivoted at the sides of the guide rods 30, the ends of diametrically opposed fingers 35 terminate in slightly offset relationship essentially parallel to each other. The fingers 35 terminate with their inner or distal ends adjacent to axis α.
The fingers 35 are disposed normally in a common horizontal plane and can individually pivot in an arcuate path upwardly or downwardly.
For supporting the fingers 35 in their generally horizontal converging positions, and manipulating the fingers 35, a plurality of individual, straight, rigid, control rods 36 are respectively provided for the lifting fingers 35. Each control rod 36 is provided at its lower end, with a pivot block 37 which receives a transverse pivot pin 38. The pivot pins 38 are respectively parallel to the pivot pins 32 and pass through intermediate portions of the lifting fingers 35. Pins 38 pivotally connect the end of rods 36 to the lifting fingers 35 so that each rod 36, respectively, supports fingers 35 for limited pivotal movement of lifting fingers 35 about pins 32.
Rods 36 extend upwardly and outwardly, passing through holes 39 in the corner portions of the base plate 12 and thence upwardly through holes 40 in a control or actuator plate 45 disposed in parallel relationship normally spaced above plate 12 so that the rods 36 can move axially upwardly and downwardly with the fingers 35.
Helical compression springs 46 respectively coaxially encompass the upper portions of rods 36, below the base plate 12, each rod 6 having a collar or sleeve 43 adjustably fixed to an intermediate portion of the rod 36 and against which the spring 46 reacts. The upper end of each spring 46 abuts a washer 41 below base plate 12 and slideably on rod 36.
All rods 36 terminate above the actuator plate 45, the upper end portions of rod 36 having external threads which threadedly receive nuts 42. Nuts 42 form stops which limit the downward movement of rods 36 and are adjustable to ensure that all fingers 35 are normally in horizontal positions.
The plate 45 is a flat horizontally disposed member which is generally rectangular, i.e., square, and conforms to the shape of base plate 12. Actuator plate 45 is reinforced by central, transversely extending, inverted, U-shaped, channel or rib 48 which extends radially along the central upper surface of plate 45, from one side to the other. Upstanding parallel guide shafts 47, mounted by their proximal ends respectively adjacent to opposite edges on base plate 12, pass through alignment holes in actuator plate 45 and through holes 49 in the top of rib 46, the guide shafts 47 thus guide the plate 45 upwardly and downwardly toward and away from base plate 12.
For controlling the movement of the actuator plate 45, the plate 45 is suspended by an actuator means such as a central piston rod (not shown) carried by a vertically disposed, double acting, pneumatic (fluid operated) cylinder 50 mounted along axis α on the lower side of the upper panel 14b. Fluid, preferably compressed air, is supplied to cylinder 50, via air lines or tubes 51 and valve 52, mounted on the outside surface of the upright end panel 14d. An upstanding spring loaded lever 53 operates valve 52.
Operation
From the foregoing description, the operation of the present invention should be apparent. The frame or frame assembly 10 for lifting and depositing successive bottles B can either be operated to install bottles B in a container or crate C or remove the bottles B from that crate, as desired. In its usual use, the apparatus is employed for picking up successive bottles B from a conveyor and placing those bottles in one or several containers C on another conveyor.
The bottle B is usually prefilled with a liquid and has a cylindrical body B 1 , provided with a neck B 2 , and a cap B 3 and a bottom B 4 . The neck B 2 is offset from the centerline or axis α of the bottle B and a handle H extends laterally from the upper portion of the neck B 2 , across axis α of the body B 1 of the bottle B and, thence, downwardly to connect integrally with the body B 1 , adjacent to the periphery of body B 1 . This handle H therefore, has a transverse portion which defines, with the bottle B, an opening B 5 through which a person's fingers may pass when the person grasps the bottle B. Thus, the opening B 5 has a transverse component and is sufficiently long and wide that it will receive the hand of a person who is lifting the bottle B. Fingers 35 of the apparatus also lift the bottle B by means of the handle H.
The apparatus is lowered onto the bottle B either while the bottle B is stationery on its initial surface or while both the bottle B and frame assembly 10 are moving in the same direction and at the same speed. In any event, the frame assembly 10, after being positioned over bottle B by the telescoping shaft 16, is progressively lowered onto the bottle B so that the guide bars 30 move down around sides of the body B 1 by shaft 16 of bottle B, thereby aligning frame 10 and bottle B along axis α. As the frame 10 is lowered, the lower surfaces of two or more of the distal ends of fingers 35, engage the upper surface of the handle H of bottle B on a first surface, so that, upon further movement of the frame 10 in a downward direction, the distal ends of fingers 35 are progressively moved upwardly in arcuate paths about the pivot pins 32. The fingers 35, therefore, move upwardly with respect to bottle B and outwardly with respect to axis thereby moving the yieldable control rods 36 along their respective axis upwardly through the holes or slots in plates 12 and 45. After the fingers 35 have passed the handle H, they are returned to their horizontal positions by the force of springs 46.
As illustrated in FIGS. 3A, 3B, and 3C, if the handle H is oriented so that the cap B 2 or neck B 3 does not block the full movement of three of the fingers 35, and with the cap B 3 blocking movement of the fourth finger 35, only three of the four fingers 35 will pass over the handle H and then spring back into their normal horizontal positions with their distal end portions beneath handle H, as illustrated in FIG. 3A. If, on the other hand, the handle H is in a position essentially bisecting the angle of two of the fingers 35, then the spout or cap B 3 will be disposed between the other two fingers and, under these conditions, all four of the converging fingers 35 will pass over the handle H and spring together below handle H and protrude into the opening B 4 . This orientation of the bottle B and the fingers 35 is illustrated in 3B.
In FIG. 3C is illustrated an orientation of the bottle B in which the cap B 3 blocks one of the fingers 35 and the handle H is oriented so as to block the diametrically opposed finger 35. In this condition, only the remaining two fingers 35 will pass over the handle H and pivot together below handle H and in opening B 4 . Thus, regardless of the circumferential orientation of handle H, once at least two of the fingers 35, which are in opposition to each other, pass over the handle H and spring back into their horizontal positions, as dictated by the nuts or stops 42 on the ends of rod 36, the bottle B is engaged and can then be lifted in a vertical direction by manipulation of belt 20 and transported laterally in any direction dictated by movement of the shaft 16.
When the shaft 16 positions the frame assembly 10 over the box C or receiving surface the belt 20 is extended so that the fingers 35 are again lowered in a vertical direction. Thus, the bottle B which has been carried by the fingers 35 is progressively lowered into a prescribed compartment in the box C. Upon reaching the appropriate depth, a cam (not shown) actuates the lever 53 so as to open valve 52, thereby feeding compressed air or other fluid into the cylinder 50 so as to cause the cylinder 50 to drive its piston downwardly for moving the control plate 45 in a downward direction toward the base plate 12. This action releases stops 42 and permits the springs 40 to urge the rods 36 downwardly until the nuts or stops 42 permit no further downward movement of the rods 40. As the plate 45 is depressed, this linkage permits the fingers 35 to pivot downwardly to release the handle H as the frame assembly 10 is lifted vertically, leaving the bottle H deposited in container C.
Since the guide rods 30 protrude below the fingers 35 and the pivot pins 32, they guide the apparatus 10 in its upward movement until the fingers 35 are clear of the bottle B. At that time the lever 53 is released, causing air pressure to pass through the other tube 51a to return the piston of cylinder 50 to its original position, moving control plate 45 upwardly to the position shown in FIG. 1. In such a position, the control rods 36 arrange the fingers 35 in their horizontal opposed relationship for an additional cycle for lifting and depositing another the bottle B.
While I have described the operation of a single unit of the apparatus for lifting and depositing bottles, one skilled in the art will understand that a plurality of such apparatuses can be joined together for lifting and depositing a plurality of bottles, simultaneously.
It will be obvious to those skilled in the art that many variations may be made in the embodiment here chosen for the purpose of illustrating the preferred embodiment of the invention, without departing from the scope thereof as defined by the appended claims. | An apparatus and method for lifting and transporting a bottle by its handle from one surface to a second surface and for releasing the bottle at the second surface, the apparatus having a frame with four inwardly converging fingers, pivotally mounted to a frame. Spring loaded control rods hold the fingers in horizontal positions so that the distal ends of the fingers terminate adjacent to each other. The frame is moved downwardly over the bottle so that the distal ends of the fingers pass around the handle and then support the bottle by the handle as the frame lifts and transports the bottle from one surface to another. The rods are pneumatically released when the frame is to move away from the bottle, thereby enabling the fingers to release the handle of the bottle. In different orientations of the bottle, less than all of the fingers protrude beneath the handles for raising and transporting the bottle. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to prepared adhesive bandages for first aid and surgical dressings, and particularly to an improved type for preventing dirt rings while wearing the bandages during work or play.
2. Background of the Prior Art
Adhesive bandages of various types are available in strip, piece, or roll form. Each has a bandage main body and an adhesive surface. Most strip and piece bandages, but not all, have a gauze portion disposed at the center of an adhesive surface. Few roll bandages have a gauze portion, but there are some which do. Heretofore, however, all adhesive bandages have comprised an adhesive surface which completely covered the periphery of the bandage main body.
There have been numerous developments, over the years, directed towards particular drawbacks in the design and/or use of one or more types of adhesive bandages. For example, U.S. Pat. No. 3,973,563 discloses a foamed combination of latex and elastomers to provide a more conformable backing. U.S. Pat. No. 4,285,338 discloses a hollow, rigid, plastic shock-absorbing shell outside the central portion to protect the wound. U.S. Pat. No. 4,334,530 discloses directional markings on the bandage to aid in removal without re-opening or otherwise damaging the wound covered thereby. U.S. Pat. No. 4,393,150 discloses a fiber reinforced adhesive for maintaining attachment to body surfaces over longer periods of time. U.S. Pat. No. 4,530,353 discloses adhesive-coated areas and adjacent pad areas prepared from a single sheet of heat-fusible bandage material. U.S. Pat. Nos. 4,689,044, 4,858,604 and 4,899,739 disclose special adhesive bandages for holding medicinal agents which impregnate the gauze portion when depressed. U.S. Pat. No. 4,726,364 discloses maintaining the gauze portion in a raised position to prevent deleterious contact between the bandage and the scabs that form on wounds covered thereby. U.S. Pat. No. 5,244,523 discloses replaceable dressings on adhesive bandages.
While such prior art adhesive bandages are effective and desirable, there remains a drawback to the use of strip, piece or roll bandages which heretofore has not been overcome. That is, bandages worn during work or play, which are subjected to dust or dirt, will, upon removal, leave a dark, residual ring of dirt/dust, embedded in, or agglomerated with, adhesive material and located at points along the periphery of the area on which the adhesive surface contacted the body. This dirt ring often necessitates intensively washing the surface of the skin, following removal of the bandage, which can have a deleterious effect on a newly healed wound. Furthermore, the buildup of dirt can be caked to the point that it interferes with freely removing the bandage, which can lead to minor bruises on children at points along the bandage periphery.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved adhesive bandage which inhibits formation of such a dirt ring and the problems which ensue upon removal of adhesive bandages.
It is a further object to avoid disaffecting either the bandage application, adherence, or removal. Other objects, features and advantages of the present invention will become apparent from a further reading of the following summary, description, drawings and claims.
The previously described objectives of the present invention are fulfilled by a peripherally-raised, non-adhesive, thin-layer portion on the upper surface of the bandage main body.
The adhesive bandages of the present invention comprise a bandage main body having an adhesive coating on its upper surface but disposed within a peripherally-raised thin wall of non-adhesive material along the periphery of the bandage main body upper surface. This raised wall consists of a thin-layer of non-adhesive which, depending upon the particular type of bandage desired, may not completely surround the adhesive surface. For example, strip-type bandages most often contain a centrally disposed gauze portion on the adhesive surface, which gauze portion longitudinally extends so close to the periphery of the adhesive portion that absence of adhesive at the periphery would risk deleterious exposure of the wound. Accordingly, the adhesive surface of the present invention may be designed to extend completely to that portion of the periphery closely bordering the gauze, and thereby interrupt an otherwise continuous peripheral wall of thin-layer non-adhesive material. Circular piece-type adhesive bandages can be constructed, if desired, to have a continuous thin-layer at the circumferential periphery of the adhesive surface and therefore also surrounding any centrally disposed gauze portion which may be desired. Butterfly configured adhesive bandages and roll-type bandages, which have no gauze portion at all, may be designed which have the peripherally-raised non-adhesive thin-layer wall either completely or intermittently surrounding the adhesive surface.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top perspective view of a two peel sheet strip-type bandage preferred embodiment of the present invention.
FIG. 2 is a top view of said preferred embodiment.
FIG. 3 is a cross-sectional front view through line 3--3 of FIG. 2.
FIG. 4 is a top perspective view of another preferred embodiment strip-type bandage having a single peel sheet.
FIG. 5 is a top perspective view of a circular type bandage of the present invention with its peel sheet intact.
FIG. 6 is a front perspective view of a butterfly-type bandage of the present invention.
FIG. 7 is a top view of a prior art strip-type bandage.
FIG. 8 is a side view of a prior art strip-type bandage.
FIG. 9 is a top view of a strip-type bandage of the present invention with an interrupted peripherally-raised non-adhesive thin-layer portion.
FIG. 10 is a side view of FIG. 9.
FIG. 11 is a top view of a bandage similar to FIG. 9 but having no 14b.
FIG. 12 is an arm showing a dirt ring after removal of the FIG. 11 bandage.
DETAILED DESCRIPTION OF THE INVENTION
The bandage main body may comprise any thin sheet of woven or non-woven fabric, plastic material or like capable of receiving and retaining adhesive of the type normally employed for adhesive bandages. These materials, their dimensions, etc., are well known in the industry.
The upper surface of the bandage main body is coated with an adhesive capable of releasably adhering to human skin. Such adhesive are also well known to those skilled in the art.
Generally disposed at the center of the adhesive-coated upper surface of the bandage main body may be a gauze portion. Preferably, the gauze portion is retained in a raised position above said upper surface.
Peel sheets, comprising one or more sections made of, for example, paper, synthetic resin or the like preferably are permanently affixed along the periphery of the bandage main body upper surface, while being releasably or temporarily affixed to the adhesive surfaces at the center inward from the periphery. With such embodiments, the peel sheet is scored or otherwise designed to allow the releasable portion of said peel sheet to be peeled from the bandage main body prior to use of the bandage, so as to leave a non-adhesive peripherally-raised thin-layer on the bandage main body substantially surrounding the adhesive surface.
Alternatively, the peripherally-raised thin-layer on the bandage main body need not be integrally molded from the same peel sheet. It can, if desired, be separately and freely made of the same or different material from the peel sheet. Such separate material is preferably thin plastic material such as cellophane paper or that used to make Saran Wrap®. It has been found that normal customary peel sheet paper can be applied to cover both the thin peripheral layer or wall and the adhesive surface without taking away from the objects of the present invention.
There are numerous advantages to the novel peripheral thin-layer of the present invention but the most important of which is that such a thin-layer surprisingly inhibits the formation of the dirt ring that often surrounds the wound at the periphery of the surface where the adhesive surface contacts the skin. The peripheral thin-layer also facilitates ease of removal of the bandage from the skin and thus serves to inhibit minor pinching and bruising when removing adhesive bandages from the skin.
With reference to FIGS. 1, 2 and 3, a preferred embodiment of the present invention will be described. Indicated at 1 is an adhesive bandage main body in the form of a rectangular adhesive sheet which is prepared by applying an adhesive 3 to the upper surface 2 of the adhesive bandage main body. A pad 6 of gauze, absorbent cotton, non-woven fabric or the like, all of which herein commonly referred to as the gauze portion, is affixed to the central portion of the main body i on the upper surface thereof.
A peel sheet, generally indicated at 4 on FIG. 2, comprises sections 4a, 4b and 4c depicted in FIGS. 3 and/or 4. Sections 4a and 4b comprise opposing sections of the center of the general peel sheet 4 which are peelable from section 4c of said peel sheet along score line 5. Score line 5 defines the point of separation from section 4c which is permanently affixed as a peripherally-raised thin-layer which is permanently affixed to the upper surface of the bandage main body 1.
Referring to FIG. 4, there is indicated at 7 an alternative embodiment of a single peel sheet member which can take the place of, if desired, sections 4a and 4b of the peel sheet shown in FIGS. 1, 2 and 3.
Referring to FIG. 5, there is shown a circular adhesive bandage having a peel sheet generally shown at 8, whose center section 8b can be peeled away while leaving peripheral section 8a, when peeled along score line 9.
FIG. 6 shows a butterfly configured adhesive bandage having a peel sheet 10 which can be peeled along score line 11, while leaving peripheral thin-layer 10a, when removing center peel section 10b.
FIG. 7 shows a strip-type adhesive bandage main body having only adhesive 12 coated over the bandage main body upper surface and having gauze section 13 centrally disposed.
FIG. 8 is a side view of FIG. 7.
FIG. 9 shows an adhesive bandage main body having adhesive 12 coated on its upper surface and showing peripheral sections 14a and 14b comprised of thin cellophane paper, while the periphery is interrupted so as to have adhesive coating extend all the way to the periphery of the adhesive bandage main body upper surface nearest to gauze section 13.
FIG. 10 is a side view of FIG. 9.
EXAMPLE 1
An adhesive bandage such as that illustrated in FIG. 9, except having only the cellophane paper peripheral section 14a without the accompanying section 14b, is depicted in FIG. 11 and applied to the arm H of a child. The bandage is allowed to be worn by the child continuously for a period of three days. Afterwards, the adhesive bandage is removed, and as can be seen from FIG. 12, a dirt ring 15 is formed around that section of the skin where the adhesive coating 12 was allowed to extend entirely to the periphery of the adhesive bandage, not having section 14b. There is no dirt ring associated with that portion of the arm H where section 14a was applied. | Adhesive bandages having a peripherally-raised non-adhesive thin-layer bordering the adhesive surface of such bandages is disclosed. The non-adhesive thin-layer inhibits formation of dirt rings which would otherwise remain when the adhesive bandage is removed from human skin. | 0 |
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to upholstery fabric intended to cover at least part of the surface of a three-dimensional structure. The invention has particular, but not exclusive, reference to upholstery for an automobile seat, or a seat for other vehicles such as trains, aeroplanes, boats, buses, lorries or other modes of transport. As well as upholstered seats in vehicles or other modes of transport the invention may be used in other upholstered structures in vehicles and modes of transport, such as side cushions for protection or decoration. Further additionally the invention may be used in upholstery for non-transport applications such as seats in houses, offices etc, and upholstered structures generally used for appearance or padding or both.
2. Background Art
The usual method of manufacturing a vehicle seat cover involves converting yarn into woven fabric, cutting out shaped pieces of the woven fabric to make the seat back cover and subsequently sewing these pieces together to form the base and back covers. It is also necessary to provide anchorage devices at the edges of the base and back covers to enable attachment of the covers to respective cushions. Usually these anchorage devices take the form of hollow sewn hems which can be secured to metal rods recessed into the cushions. If the base and/or back cushions comprise bolsters, it is also necessary to provide anchorage devices, usually in the form of open looped flaps, on the undersurface of the cover, in order to conform the cover to the shape of the upper surface of the cushion. Apart from being wasteful in fabric, this method of manufacturing vehicle seat covers is extremely time-consuming and is therefore very costly. Additionally, the amount of time taken to design and produce the warps for weaving; weave the fabric; stenter the fabric; design the patterns; cut and sew, means that design changes in woven seat covers can take eighteen months or more to implement.
Recently, it has been found possible to knit one-piece upholstery fabrics which, without the need for sewing portions together, have the desired shapes to serve as covers for the base and back cushions of a vehicle seat, and incorporate the anchorage devices for the tubes. See UK Patent Application No.2,223,034 A.
An aim of the present invention is to provide such a piece of knitted upholstery fabric with a "mechanical structure" further facilitating its retention on a three-dimensional support, such as a vehicle seat cushion.
SUMMARY OF THE INVENTION
By the present invention there is provided in an upholstered three dimensional structure incorporating an internal core and a knitted fabric cover, the improvement which comprises in the cover a line along which the fabric is less extensible compared to the surrounding fabric, the line being positioned on the fabric such that the line curves over an edge of the core so that on stretching the fabric over the core the less extensible line is displaced from the general plane of the fabric towards the core.
The core may be a foam bun. The line may engage with a recess in the core, or may cut into the core.
The upholstered three-dimensional structure may be a seat, or a part of a seat such as a squab or back.
The line may be formed by knitting the fabric cover such that it is less extensible along the line by virtue of the number, density or type of stitches used. Alternatively at least one reinforcement member may be knitted into the fabric along the line. The reinforcement member may be of a material inherently less extensible than the fabric on knitting. Alternatively, the reinforcement member may be treated after knitting to form the line. The treatment may be heat treatment. The heat treatment may be by steam. The reinforcement member may be a steam shrinkable yarn.
The fabric may be knitted on a flat V-bed machine having independently operable needles. The fabric may be double jersey fabric.
The reinforcement member may be knitted in or inlaid in a course-wise direction. The reinforcement member may be knitted on the rear needles only and may be knitted on only every 2nd, 3rd, 4th, 5th or 6th needle, the reinforcement member being floated over the vacant needles between the beds and therefore between the front and rear of the fabric. There may be a plurality of reinforcement members, each course of reinforcement members picking up the next adjacent needle to the previous course. There may be as many courses as there are sets of knitted-on needles and missed needles, so that, for instance and preferably, if the reinforcement is knitted on one of four needles of a course and floated over three needles, then four courses, or multiples of four courses of reinforcement member would be knitted in. The line is preferably of two to 8 courses, further preferably four or six courses wide when produced in a course wide direction.
The reinforcement material may be an elastomeric thread, but is preferably a heat fusible or heat shrinkable thread. Alternatively combined threads of a heat fusible or shrinkable component together with elastomeric component may be used.
To provide a line in a wale-wise direction, one or two or more needles may be programmed out in the wale-wise direction whilst knitting the fabric, so that there is provided a less extensible line in a wale-wise direction. The line is preferably two to eight wales or further preferably two to four wales wide when knitted in a wale-wise direction.
BRIEF DESCRIPTION OF THE DRAWINGS
By way of example, embodiments of the present invention will now be described with reference to the accompanying drawings, of which:
FIG. 1 is a perspective view of a seat squab in accordance with the present invention,
FIG. 2 is a cross sectional view of a fabric and core,
FIG. 3 is a cross sectional view of an alternative form of fabric and core,
FIG. 4 is a scrap perspective view of a cross section of a fabric in accordance with the present invention,
FIGS. 5A to E are stitch diagrams showing the formation of a course-wise fabric line as shown in FIG. 4,
FIGS. 6A to D are stitch diagrams showing the formation of a wale-wise fabric line, and
FIG. 7 indicates schematically a prior art method of knitting the cover of the seat squab of FIG. 1 without the fabric line featured in this invention.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to FIG. 1, this shows in perspective a seat squab being a typical upholstered three dimensional object in accordance with the present invention. The seat squab comprises a foam core 1 and a fabric outer 2. The fabric outer is shown broken away along the line 3 to reveal the core 1. The foam core or bun is often reinforced with a metal frame. The seat may be provided with a back in a known manner. It will further be appreciated that although there is described herein a vehicle seat, other upholstered products in three dimensions may be manufactured in accordance with the present invention.
The cover 2 is knitted in three dimensions on a flat V-bed machine having independently operable needles. The fabric 2 is of double jersey knit. Because the fabric is knitted in one piece it fits tightly over the foam bun 1. Essentially the seat comprises a base portion 4 with a front portion 5 lying in a plane substantially at right angles to the plane of the base portion 4. A pair of side members one of which is shown at 6 lie substantially in parallel planes at right angles to both the base portion 4 and the front portion 5. The seat is completed by a back portion (not shown but lying substantially parallel to the front portion 5) and a base which preferably includes integrally knitted tubes through which rods can be inserted to retain the seat cover on the foam bun.
FIG. 7 is a diagram showing one way in which a fabric piece similar to the fabric piece 2 of FIG. 1 can be knitted as a one-piece fabric or mainly double jersey structure on a flat V-bed knitting machine provided with a conventional presser foot device and loop holding-down device for holding down the knitted fabric between the opposed needle beds of the machine. The direction of knitting, indicated by the arrow A, is such that wales of the fabric piece 2 extend, as viewed in FIG. 1 in the direction up the side member 6, across the base portion 4, from side to side of the latter, and down the opposite side member.
Referring to FIG. 7, fabric areas 110a and 111a form parts of the front portion 5 and rear portion, respectively, in FIG. 1, the fabric area 108a forms the side member 6 in FIG. 1 and has end portions 110b and 111b which form further parts of the front and rear portions, respectively; the fabric area 106a forms the bolster-covering portion shown but not numbered in FIG. 1 and has end portions 110c and 111c which form further parts of the front and rear portions, respectively; the fabric area 105a forms the upper surface portion 4 in FIG. 1 and has end portions 110d and 111d which form further parts of the front and rear portions, respectively; the fabric area 107a forms a further bolster-covering portion shown but not numbered in FIG. 1 and has end portions 110e and 111e which form further parts of the front and rear portions, respectively; the fabric area 109a forms the other side member in FIG. 1 and has end portions 110f and 111f which form further parts of the front and rear portions, respectively; and the fabric areas 110g and 111g form the final parts of the front and rear portions, respectively.
In FIG. 7, the line BL represents a length of opposed needle beds of the machine on which the fabric piece 2 is knitted. Knitting begins on a few needles in the region of point D of the needle beds to commence formation of the fabric area 110a, more and more needles being brought progressively into action in the directions from D to B and from D to E of the needle beds to define the edges 116 and 117. When all the needles from D to B have been brought into action, needles are progressively made inactive in the direction from B to C as further courses are knitted in the direction of arrow A, to define edge 118, each of the needles made inactive along BC retaining its last knitted loop. When all the needles from D to E have been brought into action, needles are progressively made inactive in the direction from E to C as further courses are knitted in the direction of arrow A, to define the edge 119, each of the needles made inactive along EC retaining its last knitted loop. This completes the knitting of the fabric area 110 a, the portion 112a of which, adjacent to the edge 116, is knitted in the form of a tubular hem, in a manner described hereinafter.
At the same time as the knitting of fabric area 110a is begun, knitting is also begun on a few needles in the region of point K on the needle beds to commence formation of the fabric area 111a. Knitting of this area is performed on needles in the needle bed length HL, in the same way as just described for the fabric area 110a, to define the edges 120- 123 of the area 111a. The portion 113a of the area 111a, adjacent to the edge 121, is also knitted in the form of a tubular hem, in a manner described hereinafter.
When the areas 110a and 111a have been knitted, knitting of the fabric consisting of areas 110b, 108a and 111b is commenced on needles at points C and J of the needle beds. During knitting of the area 110b and part of area 108a, needles previously made inactive between points C and E are progressively re-activated to join edge 119 to edge 124, as indicated schematically by the arrow M. At the same time, other needles are made progressively inactive in the direction from C towards E to define edge 125, each of these last mentioned needles retaining its last knitted loop. When the course designated 126 has been reached, knitting on needles between points C and E is stopped and knitting is commenced on needles between points F and G to begin the edge portion 114 of fabric area 108a up to course 126. The edge portion 114 is knitted as tubular fabric, in a manner described hereinafter. At the same time as the knitting of the area 110b and the left-hand portion of the area 108a are being performed, the fabric area 111b and the right-hand portion of the area 108a are knitted, up to the course 126, in the same way as just described for the area 110a and the left-hand portion of the area 108a. During this stage of the knitting, the edge 123 becomes jointed to edge 127, as indicated schematically by the arrow N and an edge 128 is defined along area 111b.
When the fabric has been knitted up to course 126 in all these areas, knitting of the central portion of the area 108a is completed up to course 129, the needles being made progressively inactive, and retaining their last knitted loops, to define edges 130, 131 and 132.
Knitting of the area comprising portions 106a, 110c and 111c is then commenced, with the progressive reactivation of needles previously rendered inactive to define the edges 133, 134 and 135. During this stage of the knitting the right-hand part of the edge 130 becomes joined to the edge 133, as indicated schematically by the arrow P, edge 132 becomes joined to the edge 134, as indicated schematically by the arrow Q, and the left-hand part of edge 131 becomes joined to the edge 135, as indicated schematically by the arrow R. When the area comprising portions 106a, 110c and 111c has been knitted up to the course 136, knitting is stopped on needles between points S and T and between points U and V of course 136, each of the needles made inactive retaining its last knitted loop. Knitting is continued on selected needles between points T and U to knit the fabric area 137 up to the course 138. At this course 138, the needles previously made inactive at curse 136 are all brought back into action and the knitting of the fabric area comprising portions 105a, 110d and 111d is commenced. During this stage of the knitting, needles previously made inactive during knitting of the edge 125 of the area 110b and the edge 128 of the area 111b are brought back into action progressively to define edges 139 and 140. In the performance of this stage of the knitting, the edge 139 becomes jointed to the edge 125 and the left-hand part of the edge 130, as indicated schematically by the arrow W, and the edge 140 becomes joined to the right-hand part of the edge 131 and the edge 128, as indicated schematically by the arrow X. The edges 139 and 140 are completed when knitting reaches the course 141.
Course 141 represents the transverse center-line of the fabric piece 2 and knitting of the remainder of the piece 2 from the course 141 onwards is performed by a procedure which is substantially the reverse of the procedure outlined above for knitting up to the course 141. During this stage of the knitting, a fabric area 142, similar to the area 137, is knitted between the fabric areas 105a and 107a and a tubular hem 115, similar to the hem 114, is knitted on the area 109a.
In the knitting of the final fabric area 110g and 111g, the needles made inactive along BC and JL during knitting of the areas 110a and 111a are brought back into action progressively to join the edge 118 of the area 110a to the edge 143 of the area 110g, as indicated schematically by the arrow Y, and to join the edge 122 of the area 111a to the edge 144 of the area 111g, as indicated schematically by the arrow Z. During this procedure, the fabric areas 110a and 110g become joined to form part of the front portion 5 (see FIG. 1) with the portions 112a and 112b joined end-to-end to form a tubular hem. At the same time, the fabric areas 111a and 111g become joined to form part of the rear portion (not shown in FIG. 1) with the portions 113a and 113b joined end-to-end to form a further tubular hem.
All areas of the fabric piece 2, apart from the tubular hems 112a, 112b, 113a, 113b, 114 and 115 and the areas 137 and 142 are knitted with a mainly double jersey structure on both beds of the knitting machine.
The hem 115 in FIG. 7 extends between courses 145 and 146. At course 145 the knitting of double jersey structure stops and the knitting of two pieces of single jersey fabric, one on each bed of the machine, continues up to a course situated two courses before the course 146. Double jersey knitting is then resumed on both needle beds for two courses, up to course 146. The result of this is to give the hem 115 a tubular construction. On completion of the course 146, the hem 115 may be cast off the needles and the edge of double jersey fabric sewn to prevent unraveling. Alternatively, one or two courses of fusible yarn may be knitted at the edge of hem 115 after completion of course 146. Subsequent fusion of this fusible yarn prevents unraveling of the two double jersey courses at and adjacent to course 146.
Procedures similar to that just described may be used for knitting the tubular hems 112b and 113b, but since these hems are inclined to the wale directions of the fabric areas concerned, steps must be taken, as knitting proceeds, progressively to reduce the number of needles employed to knit double jersey structure with a corresponding progressive increase in the number of needles employed to knit the two single jersey fabrics.
The tubular hems 112a, 113a and 114 may be knitted using procedures which are substantially the reverse of the procedures described above for knitting the tubular hems 112b, 113b and 115. Thus, for example, the hem 114 is commenced with a double jersey set-up on the two needle beds, which is followed by separate single jersey courses up to course 126. It will, of course, be appreciated that there is no need to take precautions to prevent unraveling of the initial double jersey structure of the hems 112a, 113a and 114.
In the above described knitting of the fabric piece 2, it will be appreciated that the knitting of the course 138 has the effect of joining the fabric areas 105a and 106a and forming the fabric area 137 into a loop projecting from the undersurface of the fabric piece 2. Likewise, the fabric area 142 forms another loop projecting from the undersurface of the fabric piece 2.
When the knitting of the fabric piece 2 has been completed, it has the appearance of the seat base cover shown in FIG. 1. To fit the cover to the foam bun 1 (FIG. 1), the loops are slipped over metallic rods (not shown) recessed into the cushion. The metallic rods are slipped into the tubular hems 112-115 and the rods are secured to the underside of the cushion.
Although the seat cover may be integrally knitted as described above with reference to FIG. 7, there is a danger that it may "shuffle" on the base 4 i.e. the seat cover may move over the surface of the base, and pucker or distort any pattern on the cover. The present invention, by providing a "tight line" in the fabric enables the production of an upholstered product which has a pleasing aesthetic appearance and which has the further advantage of resisting shuffling of the fabric on the foam bun.
Formed integrally into the knitted fabric 2 is a tight line 7. The tight line 7 comprises a line in the fabric of less extensibility than the portion of the fabric on either side of or surrounding the line.
When the fabric is stretched over the bun 1 the tight line does not stretch as much as the remaining portion of the fabric and where the fabric is bent over the edge between the planes of the portions 4 and 5--i.e. over the edge indicated generally by 8--the fabric pulls into the bun as is shown at 9 in FIG. 1.
The effect of the fabric cutting into the foam bun can be seen more clearly in FIG. 2.
In FIG. 2 the fabric 10 is stretched over a core or foam bun 11. Where the fabric passes over an edge (such as the edge 8 in FIG. 1) the tight line such as tight line 12 does not stretch as much as the remainder of the fabric and this causes the fabric in the tight line to be stretched out of the general plane of the fabric towards the centre of the bun 1. The tight line is shown at 12 in FIG. 2.
The tight line will cut naturally into the foam to form a groove for the line. However for further anti-shuffling effect the foam bun may be preformed with a groove such as groove 13 as shown in FIG. 3 so that the tight line 14 in the fabric 15 lies naturally in the groove 13 when the fabric is stretched over the foam core. This register between the tight line and the groove in the foam core of the seat aids assembly of the seat and further assists in an anti-shuffling effect for the fabric on the core.
It will be appreciated that several tight lines may be produced in the fabric to assist in the anti-shuffling effect. The tight lines 7 may be produced by taking a knitted article and producing a seam of lock stitch on a sewing machine. However, although such a seam is easily produced, it does involve an additional machining operation over and above the knitting of the fabric over.
It is preferred, therefore, that the tight line should be produced integrally with the knitting of the fabric cover which surrounds the tight line on both sides. The tight line may be produced by knitting-in, in a course-wise direction, a less extensible material than the yarn used to produce the fabric. As is shown in FIG. 4 the knitted-in structurally reinforcing yarns 16 may produce the tight line effect in the fabric indicated generally by 17, which fabric is a double jersey knitted fabric.
The knitting-in of the tight lines can be carried out by conventional equipment. Knitting techniques useful to the invention will be found in the following works of reference.
"Knitting" by H Wignell, Published by Pitman 1971 Edition, London
"An Introduction to Weft Knitting" by J. A. Smirfitt, Published by Merrow Technical Library, Watford, England, 1975.
"Advanced Knitting Principles" Edited by C. Reichman, Published by National Knitted Outerwear Association, New York, New York, 1964.
"Fully Fashioned Garment Manufacture" by R. W. Mills, Published by Cassell, London, 1965. and
"Knitting Technology" by D. J. Spencer, Published by Pergamon Press, London, 1983.
The knitting may be carried out on a flat bed machine such as:
a Stoll CMS Selectanit machine, for details see Knitting International, May 1990, pages 26-28, or
a Steiger Electra 120FF machine, for details see Knitting International, April 1990, page 96, or
a Shima Seiki SES machine, for details see Knitting International, September 1989, page 60.
The process may be particularly adapted to produce a tight line by the knitting technique illustrated in FIGS. 5A to 5E.
FIGS. 5A to 5D illustrate eight courses of fabric knitted on two sets of needles, an upper set along the line 20 and a lower set along the line 21. It will be seen that the upper set of needles 20 are numbered from 1 to 4 in two sequences. The reason for this will be noted below.
In knitting the double jersey cover for the seat, the front face of the fabric i.e. the face seen by the purchaser of the seat is knitted on the lower row of needles 21. In this particular instance the face side of the fabric is knitted using a polyester yarn 22. The polyester yarn 22 is knitted on all of the needles 21 in the first course of the tight line structure shown in FIG. 5A. On the reverse side of the fabric, however, a contractile thread formed of a low melting point nylon (or low melting point polypropylene) is knitted only on the first needles labelled needles number 1. This contractile thread 23 is therefore knitted on the number 1 needles in each group of four and floats over needles 2,3 and 4 to be picked up again on needle 1. This sequence continues across the entire width of the fabric being knitted. A typical knitted fabric for a vehicle seat cover would use many hundreds of needles and to produce the tight line the first course of the line would knit on every fourth needle.
The next course to be knitted is shown in FIG. 5B. Again the polyester yarn 24 is knitted on all of the line of needles 21 producing the front face of the fabric. This time, however, the contractile thread 25 is knitted only on each number 2 needle in the line of needles 20. The thread is then floated over needles 3,4 and 1 after knitting on needle 2, to be picked up on a second needle 2 as is shown in FIG. 5B. Again this takes place throughout the entire width of the fabric in which the tight line is being knitted.
In FIG. 5C it can be seen that the contractile thread 26 is picked up on only the third in the set of four needles in line 20, whereas the polyester yarn 27 is again knitted on all of the needles of the front face 21.
Finally, in the fourth course of threads the contractile thread 28 is knitted on the fourth set of needles and the thread is then floated over needles 1,2 and 3 as can clearly be seen in FIG. 5D. Once again the polyester yarn 29 is knitted on all of the needles in row 21 to produce the front face of the fabric.
FIG. 5E is a compendium of the FIGS. 5A to D, and it can be seen that each of the row of needles 20 forming the back fabric of the fabric is knitted on in every fourth row whereas the front face needles 21 are knitted continuously. It can be seen, therefore, that the contractile threads are held on every fourth needle but in between the fourth needle they float. Thus after knitting the threads are able, on steaming and shrinking, to shrink down to form a tight line in the fabric to produce the desired effect once the fabric is stretched over the foam bun.
This produces a tight line in a course-wise direction in the fabric. To produce a tight line in a wale-wise direction, the knitting sequence illustrated by means of the stitch diagrams FIGS. 6A to 6D are used.
The wale-wise direction tight line is produced by the repetition of a four course knitting sequence. Thus, FIGS. 6A and 6B are repeated, and FIGS. 6C and 6D show this repeat occurring. In FIG. 6A the needles shown in line 30 correspond to the rear needles producing the rear of the fabric. The needles in row 31 correspond to the front needles producing the front of the fabric. To the left of the diagonal line 32 the structure knitted on needles 30 and 31 is a "bird's-eye backed" ground structure of conventional type. Similarly, to the right of diagonal line 33, again there is knitted the "bird's-eye backed" ground structure.
Between the lines 32 and 33 is knitted the two needle wide sequence which produces the wale-wise tight line structure. The polyester yarn 34 is knitted on needle 35 but is then floated across needle 36 to knit again on needle 37. Similarly, the polyester yarn 38 is floated across needle 39 but is knitted on needle 40 on the front of the fabric. In the next course as shown in FIG. 6B the thread 34 is knitted on needle 36 but is floated over needle 35. Similarly, the thread 38 is knitted on needle 39 but is floated over needle 40. This two needle wide sequence on courses shown in FIGS. 6A and 6B is continuously repeated as shown in FIG. 6C and 6D which represent the next four courses knitted.
It can be seen that the knitting structure shown in FIG. 6C is the same between the lines 32 and 33 as is the structure in FIG. 6A, and the structure in FIG. 6D is the same between lines 32 and 33 as the structure in FIG. 6B. This two needle wide sequence is repeated in two course repetition for as long as is required to make the wale-wise tight line.
Because there are less loops in the structure between the lines 32 and 33, the structure between those lines is less extensible under stress as there is less yarn length to deform between the lines. The structure shown in FIGS. 6A to 6D therefore produces a "tight line" structure which is in a wale-wise direction as the structure is built up in a wale-wise direction by repeated knitting of courses with the floated stitches as illustrated.
It can be seen therefore that the "tight line" structure can be produced in either the course-wise direction or in the wale-wise direction. If it is required to produce a tight line at an angle to the line of courses--for example at an angle of 45° then the structure illustrated in FIGS. 6A to 6D could be used but the floated stitches would be moved one needle to the right or the left for each course to produce the inclined "tight line" structure. | An upholstered three dimensional structure incorporating an internal core and a knitted fabric cover, in which there is provided in the cover a line along which the fabric is less extensible compared to the surrounding fabric, the line being positioned on the fabric such that the line curves over an edge of the core so that on stretching the fabric over the core the less extensible line is displaced from the general plane of the fabric towards the core. | 3 |
CROSS-REFERENCE TO RELATATED APPLICATION
This application is based upon application No. 2000-341822 filed in Japan, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a dental filling instrument and an attachment therefor, and particularly relates to a dental filling instrument used to inject a filler into a tooth cavity in dental treatment and an attachment that can be attached to the dental filling instrument.
2. Description of the Related Arts
Heretofore, various dental filling instruments for injecting a dental filler such as gutta-percha or resin into a tooth cavity (such as a root canal or a defective part of a tooth) have been proposed for dental treatment.
Japanese Examined Laid-Opened Patent Publication No. HEI 1-40621 (International Publication Number: WO82/03761, International Application Number: PCT/US81/00589), for example, discloses a syringe-type filling instrument having a push rod to be thrust forward to extrude a filler in a state softened by heating with a heater from the tip of a needle.
A gun-type filling instrument 2 as shown in FIG. 1 is designed to thrust forward a push rod 4 by means of a ratchet mechanism when a lever 3 is pulled, thereby extruding a filler in a state softened by heating with a heater 5 from a tip 7 a of a needle 7 .
Such conventional filling instruments, however, require application of a large force to the push rod or the lever to extrude the filler. It is therefore not easy to hold the filling instrument so as not to displace the needle tip from a filler-pouring position even when a larger force is applied to the push rod or lever with a finger. For this reason, the user of such a filling instrument is required to become skillful. If the filler is not sufficiently softened, a larger force is required to extrude the filler and, hence, it is difficult to perform the operation of delicately moving the needle tip position as the filler-pouring operation proceeds and the operation of extruding the filler at the same time. Further, at the same time with the operation of extruding the filler, the operator needs to lift the needle tip gradually while sensing a subtle pressure of raising the needle tip received from the filler injected. Thus, the conventional instruments require the operator to perform complicated operations while paying attention to many different points.
When a root canal 8 is to be filled with a filler 9 as shown in FIG. 2 , filler 9 a may overflow from an apical part Ba if the filler is extruded in an excessive amount or abruptly. It is pointed out that such an overflowed filler 9 a leads to unsatisfactory convalescence; for example, filler 9 a causes a pain when the patient is subjected to percussion or it takes a longer time for filler 9 a to be completely absorbed.
If the filler is cooled during the extrusion thereof from the needle, it is possible that the filler cannot be filled closely into a tooth cavity or that the filler adheres to the needle and hence is withdrawn from the tooth cavity along with the needle when the needle is withdrawn from the tooth cavity after the injection of the filler.
In an operating method including an insertion of a solid filler into a root canal, a cut of the filler to a predetermined length and an injection of a softened filler, it is possible that the solid filler is cut by heating with a needle attached to a filling instrument. Such a cutting operation is difficult if the needle is cool.
A root canal filling method has been proposed which includes an insertion of a solid filler in the form of an elongate tapered stick such as a master point or an accessory point into an apical foramen to plug it and a cut off an unnecessary portion of the stick-shaped filler other than the tip portion plugging the apical foramen by instantaneously fusing the filler (for about one second) with a heated leading end of an attachment called “spreader”. There has been proposed another root canal filling method which uses an attachment called “plugger” to press a filler injected into a root canal against the root canal in order to fill the root canal with the filler air-tightly. When such a root canal filling method is used before or after the injection of a filler, an instrument used in one operation needs to be replaced by another to be used in another operation. Such an exchange makes the filling operation cumbersome. Further, if instruments used in respective operations are different in size, shape, weight or the like from each other, a feel or touch in one operation is different from that in another operation, making each operation more difficult.
Still another filling method uses different fillers for different parts of a root canal; for example, a filler of the low-temperature-melting type which melts at a low temperature is used in an apical part requiring tight sealing, while a common filler of the high-temperature-melting type which melts at a high temperature is used in a main root canal portion. In this case, provision of different filling instruments for respective fillers having different properties raises a problem of cost. Further, there is a need for adjusting and operating filling instruments respectively, resulting in a cumbersome and complex operation with low efficiency.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a dental filling instrument capable of filling a tooth cavity with a dental filler more easily and an attachment attachable to the dental filling instrument.
In order to achieve the above object, according to one aspect of the present invention, there is provided a dental filling instrument comprising: a push rod for extruding a dental filler; a push rod driving device for performing a dental filler extruding operation that causes the push rod to travel in a dental filler extruding direction by utilizing power of a power source; and a control device for controlling the dental filler extruding operation of the push rod driving device.
The dental filling instrument is of a type adapted to extrude a dental filler by means of a push rod. The dental filling instrument includes the push rod driving device and the control device. The push rod driving device is capable of performing the dental filler extruding operation that causes the push rod to travel in a dental filler extruding direction by utilizing power of a power source. The control device controls the dental filler extruding operation of the push rod driving device.
In the above construction, the push rod driving device may be appropriately configured in different embodiments. For example, the power of the power source may be transmitted to the push rod either directly or through a power transmission system comprising an appropriate combination of a gear, rack, thread, lever, link mechanism and the like. As the power source may be used any one of various existing actuators or human power, i.e., the operating power of an operator's hand. Examples of suitable actuators include, but not limited to, various motors such as a DC motor, AC motor and pulse motor, hydraulic cylinders using oil or water, pneumatic cylinders, and air turbines. If the push rod driving device is hand-operated, it may be charged with the operating force of a human hand by means of a spring, for example.
With the construction described above, the push rod is moved by the power of the power source and, hence, any operation requiring a large force for extruding the filler (for example, the operation of thrusting the push rod or the lever) becomes unnecessary.
In the above construction, the control device may be of any appropriate configuration for controlling the operation of the push rod driving device. For example, the control device may be configured to control the ON-OFF operation of the power source. Alternatively, the control device may be configured to control a switching mechanism or reduction gear mechanism provided in the power transmission system of the push rod driving device.
According to the construction described above, the traveling of the push rod is controlled by the control device. This feature makes it possible to control the amount of a filler to be injected, filler injection speed and the like without the necessity of adjusting an operator's hand operation of moving the push rod (for example, the operation of thrusting the push rod or the lever), thereby easing the required operations. Thus, the dental filling instrument is capable of realizing easier filling of a dental filler.
Where a dental filler that can be softened by heating (gutta-percha for example) is used in the above construction, heating device is disposed around a cylinder to heat and soften the dental filler and the filler thus softened is extruded by the push rod.
Preferably, the control device includes a traveling speed control section for controlling traveling speed of the push rod.
This feature makes it possible to extrude a filler at a desired speed by controlling traveling speed of the push rod. Thus, it is possible to fill a tooth cavity with a filler at speed suitably adjusted to different conditions including filler characteristic, part to be filled, filling method, and the like.
Preferably, the control device includes a traveling distance control section for controlling distance which the push rod travels.
This feature makes it possible to extrude a filler in a desired amount by controlling the push rod so that it travels appropriate distance. Thus, it is possible avoid excessive filling. For example, in plugging an apical part with a filler, extruding the filler in a required amount makes it possible to avoid overflow of the filler from the apical part or limit the amount of the filler overflowed, thereby minimizing the overflow of the filler. In filling a whole root canal with a filler, it is possible to avoid filling of the filler in an amount greater than necessary, hence, prevent the filler from overflowing from an upper part of the root canal.
Preferably, the control device includes a traveling time control section for controlling traveling time of the push rod.
This feature makes it possible to prevent the filler extruding operation from being performed for a time period longer than a predetermined time period by controlling the push rod so that it travels for a predetermined time period. Thus, the amount of the filler to be extruded will not exceed a fixed amount. Further, since the extrusion time is limited and the filler extruding operation stops automatically, there is no need to perform the operation of stopping the filler extrusion. This advantage allows the operator to concentrate his or her attention to the filling operation.
Preferably, the dental filling instrument includes an injection condition setting device for setting an amount of the dental filler to be injected and setting injection speed of the dental filler. The control device establishes a target value of push rod traveling time based on the amount thereof and the injection speed set by the injection condition setting device, thereby controlling the dental filler extruding operation of the push rod driving device.
With this feature, a target value of push rod traveling time is automatically established based on the injection amount and injection speed set, thereby controlling the push rod traveling time. In the case where the push rod traveling speed is variable, it is possible to establish a target value of traveling time according to varying push rod traveling speed. If the injection amount and injection speed, which usually can be easily determined from a part into which the filler is to be injected or an injecting method employed, are set, optimized injection time and operation time can be established automatically. In this case there is no need to establish the injection time that is found from cumbersome calculation and, hence, the dental filling instrument can be used conveniently.
Preferably, the dental filling instrument includes an injection condition setting device for setting at least one of an amount of the dental filler to be injected, filler injection time and injection speed of the dental filler. The control device controls the dental filler extruding operation of the push rod driving device based on the injection condition set by the injection condition setting device.
This feature makes it possible to control the filler extruding operation so as to meet the injection condition set by the user. Since the injection condition can be changed, the dental filling instrument finds wider application.
Preferably, the dental filling instrument includes an injection condition display device for displaying at least one of an amount of the dental filler to be injected, filler injection time and injection speed of the dental filler.
This feature allows the user to know the injection condition more easily through the injection condition display device.
Preferably, the control device includes an extruding operation switch and a control section responsive to the extruding operation switch. When the extruding operation switch is in an ON state, the control section responsive to the extruding operation switch permits the push rod driving device to perform the dental filler extruding operation. On the other hand, when the extruding operation switch is in an OFF state, the control section forcibly inhibits the push rod driving device from operating.
In the above construction, an arrangement may be employed such that the filler can be extruded only when the extruding operation switch is ON but cannot be extruded when the extruding operation switch is OFF. The control section responsive to the extruding operation switch takes precedence over the traveling distance control section, traveling time control section and the like. This means that when the extruding operation switch is turned OFF, the control section responsive to the extruding operation switch forcibly stops the traveling of the push rod even if the predetermined traveling distance or traveling time is not reached.
This feature makes it possible to start or stop the filler extruding operation in response to the ON-OFF operation of the extruding operation switch, thereby allowing the user to perform the filling operation intuitively. In addition, it is possible to operate the extruding operation switch with a small force. Thus, the filling operation becomes easier.
Preferably, the push rod driving device is capable of performing a push rod returning operation that causes the push rod to travel in a direction opposite to the dental filler extruding direction by utilizing the power of the power source. The control device includes a returning operation switch and a control section responsive to the returning operation switch. When the returning operation switch is in an ON state, the control section responsive to the returning operation switch forcibly inhibits the push rod driving device from performing the dental filler extruding operation while permitting the push rod driving device to perform the push rod returning operation.
This feature makes it possible to return the push rod by merely turning ON the returning operation switch and, hence, it is no longer necessary for the user to return the push rod by hand. Thus, the dental filling instrument with this feature is convenient.
Preferably, the control device includes an extrusion stop control section for causing the push rod driving device to perform the returning operation for a predetermined time period immediately after the dental filler extruding operation of the push rod driving device has been stopped.
Even if the dental filler extruding operation is merely stopped, the dental filler continues to be extruded for a while after the extruding operation has been stopped. With the above feature, however, it is possible to prevent the dental filler from being extruded immediately after the dental filler extruding operation has been stopped. Accordingly, the filling operation is facilitated. Particularly where control is performed to fill a fixed amount of the filler, the accuracy in controlling the filling amount can be advantageously improved.
Preferably, the push rod driving device is capable of performing a push rod returning operation that causes the push rod to travel in a direction opposite to the dental filler extruding direction by utilizing the power of the power source. The control device includes a terminating point detection device, a starting point detection device, and a push rod traveling range control section. The terminating point detection device detects the push rod reaching a first predetermined position in the dental filler extruding direction. The starting point detection device detects the push rod reaching a second predetermined position in a direction opposite to the dental filler extruding direction. The push rod traveling range control section forcibly inhibits the push rod driving device from performing the dental filler extruding operation when the terminating point detection device detects the push rod reaching the first predetermined position. On the other hand, the push rod traveling range control section forcibly inhibits the push rod driving device from performing the push rod returning operation when the starting point detection device detects the push rod reaching the second predetermined position.
This feature enables the push rod to travel between the first predetermined position and the second predetermined position. Thus, it is possible to prevent the push rod from being continuously pushed in the extruding direction or pulled in the returning direction, hence, to prevent the instrument from breaking, whereby safety is ensured.
The dental filling instrument with each of the features described above may comprise a main body from which the filler is extruded, and a separate device connected to the main body through a connection cable. In this case it is possible to dispose each of the push rod driving device, control device, injection condition setting device and injection condition display device in one of the main body and the separate device or both.
Preferably, the dental filling instrument includes a housing shaped to allow a user to hold it with one hand. All the other components (namely, components other than the housing including the push rod driving device, control device, injection condition setting device, injection condition display device and other components) are provided in one of a location which corresponds to an inside of the housing, and a location which corresponds to an outer surface of the housing.
With this feature, the dental filling instrument is wholly rendered compact and has an integral configuration. Since this configuration is a cordless configuration free from any trouble in handling the connection cable or the like, the dental filling instrument can be freely operated as desired by the user holding it and hence offers improved operability.
According to another aspect of the present invention, there is provided a dental filling instrument for extruding a dental filler in a heated state from a tip of a needle attached to a needle fitting portion thereof, comprising: a heating device for heating the needle up to a temperature at which the dental filler is softened, the heating device being disposed at one of the needle fitting portion and a location adjacent to the needle fitting portion; a heating temperature setting device for setting the temperature up to which the needle is heated by the heating device; and a heating control device for controlling a heating operation of the heating device based on the temperature set by the heating temperature setting device.
In the construction described above, the needle attached to the dental filling instrument is heated by the heating device. The heating of the needle is appropriately controlled based on the temperature set by the heating temperature setting device.
In the above construction, the heating device may be variously configured in different embodiments. For example, the heating device may be configured to transfer heat generated by the heating device to the needle or to cause the needle to generate heat based on Joule heat caused by electric current by passing electric current through the needle from the heating device or by applying magnetic flux that is variable with time to the needle to generate eddy current. Though the heating device may be configured to serve also as a filler heating device for softening the dental filler, the heating device is preferably configured to be separate from and independent of the filler heating device. This preferable configuration is capable of controlling the temperature of the needle independently of the heating control for the dental filler, thereby facilitating the heating temperature control for the needle.
In the above construction, the heating temperature setting device may be configured to set a temperature directly or to allow setting of a temperature suited to the type of dental filler selected. In the case where the heating temperature setting device does not set a temperature or a special setting is made, the heating device may be configured not to heat the needle. In this case it is possible that only the dental filler is heated, while the needle is not heated.
This construction makes it possible to heat the needle based on the temperature set according to the softening temperature of a dental filler and inject the dental filler in a sufficiently softened state from the needle into a desired part. Thus, the dental filling instrument enables the filling of the dental filler more easily.
Preferably, the dental filling instrument includes a heating temperature display device for displaying the heating temperature set by the temperature setting device.
This feature allows the user to confirm the set heating temperature at the time of heating temperature setting or during the heating of the needle, thereby affording convenience to the user.
The dental filling instrument with each of the features described above may comprise a main body from which the filler is extruded, and a separate device connected to the main body through a connection cable. In this case it is possible to locate each of the heating device, heating temperature setting device, heating control device and heating temperature display device in one of the main body and the separate device or both.
Preferably, the dental filling instrument includes a housing shaped to allow a user to hold it with one hand. All other components (namely, components other than the housing including the heating device, heating temperature setting device, heating control device, heating temperature display device and other components) are provided in one of a location which corresponds to an inside of the housing, and a location which corresponds to an outer surface of the housing.
With this feature, the dental filling instrument is wholly rendered compact and has an integral configuration. Since this configuration is a cordless configuration free from any trouble in handling the connection cable or the like, the dental filling instrument can be freely operated as desired by the user holding it and hence offers improved operability.
According to still another aspect of the present invention, there is provided a dental filling instrument comprising: a main body; and a needle fitting portion, provided in the main body, for attaching a needle, so as to extrude a dental filler from a tip of the needle, wherein the needle fitting portion is capable of being fitted with an attachment of one of the spreader type and the plugger type.
Namely, the construction thereof allows a spreader- or plugger-type attachment to be fitted to the needle fitting portion of the dental filling instrument. When the spreader-type attachment is fitted to the needle fitting portion, the user becomes capable of cutting a master point or accessory point inserted into a root canal to plug an apical part by fusing an upper portion thereof with the attachment heated at its leading end. Alternatively, when the plugger-type attachment is fitted to the needle fitting portion, the user becomes capable of depressing a plug inserted into a root canal with the leading end of the plugger-type attachment so that the plug adheres to the root canal by pressure.
With this construction the user is allowed to operate the spreader- or plugger-type attachment while holding the dental filling instrument as well as to perform the filling of a dental filler with a touch similar to the spreading or plugging operation. Further, it is possible to reduce the number of appliances to be used by using common appliances in both of these operations, hence, facilitate the choice of appliances. Thus, the dental filling instrument makes it possible to fill the filler more easily.
Preferably, a heater is included in one of the needle fitting portion and a portion adjacent thereto.
This feature makes it possible to heat the attachment fitted to the needle fitting portion of the dental filling instrument without using a burner or the like, thereby affording convenience to the user. Also, heating temperature control is easy. For example, by merely passing electric current through the heater for a given time it is possible that the attachment is heated to a predetermined temperature.
Preferably, the needle fitting portion can be fitted with an attachment having a first end attached to the needle fitting portion and a second end and defining a through-hole extending therethrough from the first end to the second end.
This feature is capable of extruding the dental filler from the second end of the spreader- or plugger-type attachment defining the through-hole fitted to the needle fitting portion. Since the dental filling instrument is capable of performing the spreading or plugging operation as well as the operation of filling the dental filler, it offers improved operating efficiency.
Preferably, the needle fitting portion is capable of being fitted with an attachment formed from a superelastic alloy.
Since the spreader- or plugger-type attachment formed from a superelastic alloy (nickel titanium alloy, for example) exhibits sufficient flexibility, this feature allows the attachment to be easily inserted into a root canal along its curved wall.
The dental filling instrument with each of the features described above may comprise a main body from which the filler is extruded, and a separate device connected to the main body through a connection cable. In this case it is possible to locate each component of the dental filling instrument in one of the main body and the separate device or both.
Preferably, the dental filling instrument includes a housing shaped to allow a user to hold it with one hand. All other components are provided in one of a location which corresponds to an inside of the housing, and a location which corresponds to an outer surface of the housing.
With this feature, the dental filling instrument is wholly rendered compact and has an integral configuration. Since this configuration is a cordless configuration free from any trouble in handling the connection cable or the like, the dental filling instrument can be operated freely as desired by the user holding it and hence offers improved operability.
According to still another aspect of the present invention, there is provided an attachment of one of the spreader type and the plugger type, comprising: a body; and an attaching portion, provided in the body, for attaching to a needle fitting portion of a dental filling instrument adapted to extrude a dental filler from a tip of a needle attached to the needle fitting portion thereof.
With the attachment of the above construction fitted to the dental filling instrument, the user is allowed to perform the operation of cutting a root canal filler or pressure-bonding the filler to the root canal as well as to perform the filling of a dental filler with a touch similar to the cutting or pressure-bonding operation. Further, it is possible to reduce the number of appliances to be used by using common appliances in both of the operations, hence, facilitate the choice of appliances. Thus, it is possible to fill the filler more easily.
Preferably, the attachment has a first end attached to the needle fitting portion and a second end and defines a through-hole extending therethrough from the first end to the second end.
Preferably, the attachment is made of a superelastic alloy.
According to still another aspect of the present invention, there is provided a dental filling instrument comprising: a heating and extruding device for heating a dental filler and extruding the same; and a filler storage device for storing a plurality of dental fillers, each of whish is the dental filler, and for selectively supplying the plurality of dental fillers thus stored to the heating and extruding device.
With this construction, an appropriate one of the plurality of dental fillers stored in the filler storage device can be selected for use. Since there is no need to load the instrument with additional dental filler in the middle of a series of operations using plural dental fillers, it is possible to improve the operating efficiency. Thus, the dental filling instrument makes it possible to fill the dental filler more easily.
The filler storage device may employ various types of filler selective supply system. For example, the filler storage supply device may employ a sliding system. Specifically, the filler storage device includes a plurality of storage sections for storing the dental fillers therein. The filler storage device is slidably supported so that each of the storage sections is selectively located at a communicating position providing communication between each of the storage section and the heating and extruding device.
This feature is capable of selecting a filler to be used by causing the filler storage device to slide so that a storage section storing the desired filler becomes located at the communicating position.
The filler storage device may employ a revolver system. Specifically, the filler storage device includes a plurality of storage sections for storing the dental fillers therein. The filler storage device is rotatably supported so that each of the storage sections is selectively located at a communicating position providing communication between each of the storage section and the heating and extruding device.
This feature is capable of selecting a filler to be used by causing the filler storage device to rotate so that a storage section storing the desired filler becomes located at the communicating position.
The filler storage device may employ another system. Specifically, the filler storage device includes a plurality of storage sections for storing the dental fillers therein, and a communicating section for providing selective communication between each of the storage sections and the heating and extruding device.
This feature allows a storage section storing a desired filler therein to communicate with the heating and extruding device through the communicating section, thereby transferring the desired filler from the storage section to the heating and extruding device. Thus, it is possible to select a filler to be used.
Preferably, each of the storage sections is configured to store a plurality of fillers and to transfer the fillers one by one to the heating and extruding device. This feature makes it possible to reduce the number of times of filler loading, thereby making the filling operation more efficient.
Preferably, the dental filling instrument includes heating and extruding condition setting device for setting at least one of heating and extruding conditions including temperature at which the heating and extruding device heats each of dental fillers, heating time and extruding amount so as to match the dental filler supplied from the filler storage device to the heating and extruding device.
In the dental filling instrument with the above feature, the heating and extruding condition setting device is configured to set the heating and extruding condition for each of the storage sections of the filler storage device, for example.
With this feature, at least one heating and extruding condition is automatically set to match the dental filler to be used and, hence, the filling operation becomes simplified.
Preferably, the dental filling instrument includes a housing shaped to allow a user to hold it with one hand. All other components (namely, components other than the housing including the push rod driving device, control device, injection condition setting device, injection condition display device and other components) are provided in one of a location which corresponds to an inside of the housing, and a location which corresponds to an outer surface of the housing.
With this feature, the dental filling instrument is wholly rendered compact and has an integral configuration. Since this configuration is a cordless configuration free from any trouble in handling the connection cable or the like, the dental filling instrument can be freely operated as desired by the user holding it and hence offers improved operability.
BRIEF DESCRIPTION OF THE DRAWINGS
This and other objects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings.
FIG. 1 is a sectional view showing a conventional dental filling instrument.
FIG. 2 is a schematic view illustrating a root canal treatment using the conventional dental filling instrument.
FIG. 3 is a sectional view showing a dental filling instrument as a first embodiment of the present invention.
FIG. 4 is a sectional view showing a variation of the dental filling instrument shown in FIG. 3 .
FIGS. 5A and 5B are schematic views showing the configurations of other variations of the dental filling instrument shown in FIG. 3 .
FIG. 6 is a sectional view showing a dental filling instrument as a second embodiment of the present invention.
FIG. 7 is an enlarged fragmentary view showing a relevant portion of the dental filling instrument shown in FIG. 6 .
FIGS. 8A , 8 B and 8 C are perspective views showing plugger-type attachments.
FIGS. 9A to 9F are perspective views showing spreader-type attachments.
FIG. 10 is a perspective view showing a dental filling instrument as a third embodiment of the present invention.
FIG. 11 is a perspective view showing a variation of the dental filling instrument shown in FIG. 10 .
FIGS. 12A and 12B are schematic views showing a feature of another variation of the dental filling instrument shown in FIG. 10 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before the description of each of the preferred embodiments according to the present invention proceeds, it is to be noted that like or corresponding parts are designated by like reference numerals throughout the accompanying drawings.
A detailed description is made below upon dental filling instruments and attachments of the preferred embodiments, with reference to FIG. 3 through FIG. 12B .
Referring first to FIG. 3 , it is explained about a dental filling instrument 10 of a first embodiment of the present invention.
The dental filling instrument 10 includes a housing 20 substantially gun-shaped so as to allow the user to hold it with one hand, and a needle 100 having a tip 100 a from which a dental filler, such as gutta-percha, softened by heating, is extruded when an extruding operation switch 30 is turned ON.
More specifically, the housing 20 has an upper portion accommodating therein a heater 36 for heating a filler and an extruding shaft 54 for extruding the filler. For heat insulation the heater 36 of the housing 20 is surrounded by a thermal protector 22 . The extruding shaft 54 is formed with a rack 52 adapted to mesh with a gear 50 (schematically shown). The housing 20 has a lower portion accommodating therein a motor 34 for driving the gear 50 , a control board 32 carrying a control circuit for controlling the heater 36 and the motor 34 , the extruding operation switch 30 that can be turned ON by depressing an exposed portion protruding out of the housing 20 , and a power supply board 26 connected to a power supply cord 24 for supplying electric power to the control board 32 .
The dental filling instrument 10 is loaded with a filler, which in turn is softened by heating with the heater 36 . When the user holding the lower portion of the housing 20 with on hand depresses the extruding operation switch 30 with a finger, the motor 34 starts rotating the gear 50 . The rack 52 meshing with the gear 50 causes the extruding shaft 54 to move the filler in the extruding direction (leftward in FIG. 3 ). Thus, the filler softened by heating is pushed toward the needle 100 and extruded outside from the tip 100 a of the needle 100 .
When a returning operation switch not shown is turned ON, the motor 34 revolves in reverse, causing the extruding shaft 54 to travel in the direction opposite from the extruding direction. Thus, the user is no longer required to pull back the extruding shaft 54 once moved in the filler extruding direction with hand and hence becomes capable of performing the filling operation conveniently.
For the sake of safety, the dental filling instrument 10 has a first limit switch 31 a and a second limit switch 31 b in the housing 20 as shown in FIG. 3 , the first switch 31 a being adapted to detect a leading terminal of the extruding shaft 54 traveling in the extruding direction, the second limit switch 31 b being adapted to detect a rear terminal of the extruding shaft 54 traveling in the returning direction. More specifically, when the motor 34 revolves forward to cause the extruding shaft 54 to travel in the extruding direction (leftward in the drawing) until a shoulder portion 54 s of the extruding shaft 54 is brought into contact with the limit switch 31 a , the motor 34 stops revolving to stop movement of the extruding shaft 54 at the leading terminal in the extruding direction. On the other hand, when the motor 34 revolves in reverse to cause the extruding shaft 54 to travel in the opposite direction (rightward in the drawing) until a detection plate 54 t attached to the extruding shaft 54 is brought into contact with the limit switch 31 b , the motor 34 stops movement of revolving to stop movement of the extruding shaft 54 at the rear terminal in the returning direction.
The dental filling instrument 10 operates in any one of the following operating modes when the extruding operation switch 30 is depressed. It is to be noted that the operating mode of the dental filling instrument 10 may be fixed or may be freely selected.
In a first operating mode, when the extruding operation switch 30 is depressed, the motor 34 revolves at a fixed speed so that the extruding shaft 50 travels at a predetermined speed. Accordingly, the filler is extruded at a constant speed from the tip 100 a of the needle 100 thereby ensuring a stabilized filling operation.
In a second operating mode, when the extruding operation switch 30 is depressed, the motor 34 revolves until a predetermined number of revolutions is reached so that the extrusion shaft 50 travels a predetermined distance. Accordingly, a predetermined amount of the filler is extruded from the tip 100 a of the needle 100 . Since the amount of the filler to be extruded does not exceed the predetermined amount, it is possible to minimize the overflow of the filler even if it occurs as shown in FIG. 2 .
In a third operating mode, when the extruding operation switch 30 is depressed, the motor 30 revolves for a predetermined time period so that the extruding shaft 50 travels for a predetermined time period. Accordingly, the filler is extruded from the tip 100 a of the needle 100 for a limited and predetermined time period. Since the filler is extruded for a limited time period after the extruding operation switch 30 is turned ON, the amount of the filler extruded does not exceed a predetermined amount and, hence, it is possible to minimize the overflow of the filler even if it occurs as shown in FIG. 2 .
In a fourth operating mode, the motor 34 revolves during only a time period for which the extruding operation switch 30 is depressed. When the user stops depressing the extruding operation switch 30 , the motor 34 stops revolving. Since the filler is extruded in response to an operation depressing the extruding operation switch 30 , the user becomes capable of performing the filling operation intuitively.
The fourth operating mode may be combined with any one of the first to third operating modes. In this case, the fourth operating mode should take precedence over any other operating mode. That is, a configuration should be employed such that that the motor 34 stops revolving when the user stops depressing the extruding operation switch 30 even if the condition for terminating the operation in any one of the first to third operating modes is not satisfied.
In any one of the operating modes, the motor 34 revolves forward to extrude the filler. The revolution of the motor 34 is stopped to stop the extrusion of the filler. Since the extruding pressure remains for a while even though the motor 34 stops revolving, the filler continues to be extruded from the tip 100 a of the needle 100 for a while after the revolution of the motor 34 has been stopped.
To stop the extrusion of the filler completely, it is preferred that the motor 34 revolving forward be reversed for a predetermined time period and then stopped. Accordingly, the extrusion of the filler from the tip 100 a of the needle 100 is stopped immediately after the operation of stopping the filling and, hence, the filling operation, as a whole, is facilitated. Further, it is possible to accurately control the amount of the filler used.
Preferably, the returning operation switch takes precedence over the extruding operation switch 30 . That is, when the returning operation switch is turned ON, the extrusion of the filler is stopped even if the extruding operation switch 30 is in an ON state.
Next, description is made on variations (modifications) of the dental filling instrument 10 by focusing the features different from those of the instrument 10 .
As shown in the sectional view of FIG. 4 , a dental filling instrument 11 as a first variation of the dental filling instrument 10 is configured to accommodate a power supply battery 28 in the housing 20 instead of supplying power through the power supply cord 24 . Elimination of the power supply cord 24 facilitates the handling of the dental filling instrument 11 .
A second variation as shown in FIG. 5A comprises a dental filling instrument 12 and a main box 80 , which are connected to each other through a connection cable 25 .
The dental filling instrument 12 is of substantially the same construction as that of the dental filling instrument 10 shown in FIG. 3 , but differs from the instrument 10 in that a control board 33 communicates with a control board 88 located in the main box 80 to be described later through the connection cable 25 . The connection cable 25 serves to supply electric power to the dental filling instrument 12 while transmitting signals between the dental filling instrument 12 and the main box 80 .
The main box 80 includes a display section 86 , a control console 87 and the control board 88 .
Various settings in relation to the operation of the dental filling instrument 12 can be made by appropriately operating switches and volume control buttons on the control console 87 . The console 87 allows appropriate setting of, for example, the filler injecting conditions including filler extruding amount (the amount of the filler to be injected), time (injection time) and speed (injection speed) and the heating conditions including filler heating temperature (heating temperature) and heating time. Such a configuration is possible that the injection speed, calculation of which is cumbersome, is automatically set once the filler injecting amount and injection time, which are easy to predetermine, are set previously.
The display section 86 appropriately displays numerical values or pictures representing various conditions set at the control console 87 (injecting conditions and heating conditions) or the current state of the dental filling instrument 12 (standby state for filler loading, temperature of the filler heated, filler heating terminated state, amount of the filler filled, filler injection terminated state, or the like). For example, the display section 86 displays a schematic illustration of a root canal and shows a varying region in the illustrated root canal shown with varying amount of the filler injected.
A third variation as shown in FIG. 5B is of substantially the same construction as that of the second variation, but differs from the second variation in that a main box 82 is provided with a dental filling instrument rest 84 for a dental filling instrument 13 to rest thereon and the connection cable 25 is eliminated. More specifically, the rest 84 of the main box 82 is provided with a charger terminal and a signal terminal. On the other hand, the dental filling instrument 13 has a chargeable battery 29 and a terminal not shown. The battery 29 is charged while the dental filling instrument 13 rests on the rest 84 of the main box 82 . Communication between a control section 88 of the main box 82 and the control board 33 of the dental filling instrument 13 is possible.
Next, with reference to FIGS. 6 to 9F , a dental filling instrument of a second embodiment of the present invention is described below.
The dental filling instrument 14 according to the second embodiment is of substantially the same construction as that of the dental filling instrument 10 . The features of the instrument 14 different from those of the instrument 10 are focused in the following description.
As shown in the sectional view of FIG. 6 and in the enlarged fragmentary view of FIG. 7 , the dental filling instrument 14 includes a heater 38 adjacent a needle fitting portion 37 . The heater 38 , which is separate from and independent of the heater 36 adapted to heat the filler, is adapted to heat the base end of the needle 100 . The needle fitting portion 37 allows a spreader- or plugger-type attachment (to be described later) to be fitted thereto instead of the needle 100 . It is desirable that the instrument be modified in its outward shape from the substantially T-shaped gun type into a substantially I-shaped hand piece type for improved operability.
It is desirable that the heating temperature of the heater 38 be controlled independently of the heater 36 adapted to heat the filler. This is because the needle or attachment fitted to the needling fitting portion 37 can be easily heated to a desired temperature. In this case the heating temperature of the heater 38 may be set independently of the heater 36 by a temperature setting section not shown. Desirably, the heating temperature of the heater 38 thus set is displayed in a temperature display section not shown.
FIGS. 8A to 8C illustrate examples of plugger-type attachments. These attachments 110 , 120 and 130 define bores 112 , 122 and 132 , respectively, and each can be used as a needle through which a filler is extruded, as well as a plugger.
The attachment 110 shown in FIG. 8A has a flat tip 116 defining a circular opening 114 . The attachment 120 shown in FIG. 8B has a tip 126 cut to form an inclined surface 128 defining a larger opening 124 . The attachment 130 shown in FIG. 8C has a tip 136 cut to form a larger inclined surface 138 defining a much larger opening 134 .
When any appropriate one of these attachments 110 , 120 and 130 is selected and attached to the filling instrument 14 , it is possible to cut a previously inserted root canal plug by burning with the attached attachment heated with the heater 38 and then to fill the root canal with a dental filler. Since the filling operation can be performed without exchanging the attachment or needle attached to the filling instrument 14 , it is possible to perform required operations continuously and efficiently.
FIGS. 9A to 9F illustrate examples of spreader-type attachments. These attachments 210 , 220 and 230 define bores 212 , 222 and 232 , respectively, and each can be used as a needle through which a filler is extruded, as well as a spreader.
The attachment 210 shown in FIG. 9A has a tip 216 formed into a curved surface defining a circular opening 214 as better shown in the enlarged fragmentary view of FIG. 9D . The attachment 220 shown in FIG. 9B has a tip 226 cut to form an inclined surface 228 defining a larger opening 224 as better shown in the enlarged fragmentary view at FIG. 9E . The attachment 230 shown in FIG. 9C has a tip 236 cut to form a larger inclined surface 238 defining a much larger opening 234 as better shown in the enlarged fragmentary view at FIG. 9F .
When any appropriate one of these attachments 210 , 220 and 230 is selected and attached to the filling instrument 14 , it is possible to cut a previously inserted root canal plug by burning with the attached attachment heated with the heater 38 and then fill the root canal with a dental filler. Since the operations of treating the plug and injecting the filler can be performed without exchanging the attachment or needle attached to the filling instrument 14 , it is possible to perform required operations continuously and efficiently.
Next, with reference to FIGS. 10 to 12 , a dental filling instrument of a third embodiment of the present invention is described below.
The dental filling instrument according to the third embodiment is of substantially the same construction as that of the first embodiment, but has a different filler magazine.
Specifically, dental filling instrument 15 shown in FIG. 10 includes a filler magazine 60 slidably supported by an upper portion of the housing 20 . The filler magazine 60 has a filler storage sections 62 and 64 in portions outwardly protruding on opposite sides of the housing. When the magazine 60 slides to the right or left in the direction indicated by an arrow 92 , the filler in the filler storage section 62 or 64 is introduced into the housing 20 and hence becomes ready to be used in the filling operation.
For example, it is possible that a filler for filling apical part is stored in the filler storage section 62 on one side while a common filler for filling whole root canal is stored in the filler storage section 64 on the other side. In this case, it is desirable that the filler storage section 62 be sized to store an amount (0.01 ml for example) of the filler estimated from the volume of an apical part, while the filler storage section 64 be sized to store an amount (0.09 ml for example) of the filler estimated from the volume of a whole root canal. It is also desirable that the filler for filling apical part be of a low-temperature-melting type which melts at 60° C. (degrees Celsius) for example, while the common filler be of a high-temperature-melting type which melts at 160° C. for example.
Once predetermined fillers are stored in respective filler storage sections 62 and 64 , the filler magazine 60 is slid toward the proximal side of the viewer of FIG. 10 to place one filler storage section 62 into the housing 20 . The filler in the filler storage section 62 thus placed in the housing 20 is heated to a temperature previously set (60° C. for example) with the heater. At this time the needle 100 may also be heated with the heater.
Subsequently, the extruding operation switch 30 is turned ON to extrude the filler from the tip 100 a of the needle 100 for an apical part to be filled with the filler.
In turn, the filler magazine 60 is slid toward the opposite side (toward the distal side of the viewer of FIG. 10 ) to place the other filler storage section 64 into the housing 20 . The filler in the filler storage section 64 thus placed in the housing 20 is automatically heated to a temperature previously set (160° C. for example). At this time the needle 100 may also be heated with the heater. Subsequently, the extruding operation switch 30 is turned ON to extrude the filler from the tip 100 a of the needle 100 for a whole root canal to be filled with the filler.
It is desirable that at least one of the extruding and heating conditions including filler heating temperature, heating time and extruding amount be previously set for each of the filler storage sections 62 and 64 . In this case a configuration may be employed such as to allow the heating and extruding conditions to be appropriately set from a control console of a main box (not shown) connected to the dental filling instrument 15 .
In the case where the heating temperature or the heating time for one filler is different from that for another filler, a configuration may be employed such as to notify the user of the termination of filler heating (i.e., the state ready to perform the filling operation) by means of sound or display upon completion of filler heating.
FIG. 11 illustrates a dental filling instrument 16 as a variation (or modification) of the dental filling instrument 15 . The dental filling instrument 16 includes a filler magazine 70 rotatably supported by an upper portion of the housing 20 and having filler storage sections 72 and 74 for storing fillers in a portion protruding on one side of the housing 20 . The filler to be introduced into the housing 20 can be selected by rotating the magazine 70 in the direction indicated by an arrow 94 .
FIG. 12 schematically illustrates a feature of another variation of the dental filling instrument 15 . As shown in FIG. 12A , a filler magazine 300 has two filler storage sections 310 and 320 for storing plural fillers 302 and 304 , a loading section 330 , communicating sections 312 and 322 providing communication between the loading portion 330 and the filler storage sections 310 and 320 , and shutters 314 and 324 disposed in the communicating sections 312 and 322 , respectively. When one shutter 314 is opened as shown in FIG. 12B , the filler 302 in the filler storage section 310 is urged in the direction indicated by an arrow 392 by means of an urging mechanism not shown and transferred to the loading portion 330 along an arrow 390 .
Use of any one of the foregoing dental filling instruments makes it possible to fill a tooth cavity with a filler more easily.
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are also apparent to those skilled in the art.
For example, though in the above description, an explanation about a sealer for improving the adhesion between a root canal and a filler is skipped, the present invention does not inhibit the use of such a sealer but permits appropriate use of such a sealer. It is needless to say that use of a root canal length measuring instrument in cooperation is more desirable.
Dental fillers in the present invention may be used without being heated with the heater of the dental filling instrument. For example, a resin which does not require heating for softening it may be used as a filler, or the dental filling instrument may be loaded with a filler previously softened by heating with a separate heater.
It is possible to employ a configuration to allow the whole heater section to be replaced by another in order to vary the heating temperature. Further, the filler magazine or holder for storing fillers therein may be configured to be replaceable with another one. | A dental injecting apparatus for injecting a dental filler and a dental tool attached to such a dental injecting apparatus. The apparatus includes: an injection rod for injecting a dental filler; an injection rod driver for performing a dental filler injecting operation that causes the injection rod to move in a dental filler injecting direction by using the force of a power source; and a controller for controlling the dental filler injecting operation of the injection rod driver. | 1 |
[0001] This Continuation-in-Part patent application is copending with and claims priority of U.S. patent application Ser. No. 09/694,043, as filed on Oct. 20, 2000, entitled “Swimming Pool Skimming Apparatus.”
BACKGROUND OF THE INVENTION
[0002] The current invention relates to the field of passive devices for the removal of floating waste from the surface of a liquid, and particularly to an improved, stationary apparatus for collecting floating debris in swimming pools having a circulatory current therein.
[0003] There are numerous instances in which impurities or waste must be removed from the surface of a large body of liquid in order to maintain the purity of the liquid or to prevent contamination. Numerous commercial industrial processes, e.g. in the areas of beer making, sanitation systems, water treatment systems, chemical plants, or the food industry, are characterized by the presence of floating debris which is most economically removed by skimming the debris from the open surface of a liquid. In the domestic area, this requirement of debris removal from large bodies of liquid is most often found in swimming pools.
[0004] Cleaning a swimming pool of debris is a common problem among pool owners. Such debris may enter swimming pools from many different sources. Wind and rain carry falling leaves, insects, dust, twigs and other objects onto the surface of the water in the pool where it may float for a period of time before sinking to the bottom. It is desirable to remove such debris before it becomes waterlogged and sinks to the bottom of the swimming pool, since the cleaning of bottom-resident debris by means of vacuum devices is labor intensive and costly.
[0005] The prior art is replete with devices for skimming floating debris. Most such devices have a frame and netting construction. Handheld devices rely on human action to sweep the skimmer along the pool's surface to entrap floating debris, while passive devices are fixed along the edge of the pool and rely upon circular around the perimeter of the pool which are produced by the water jets of the pool filtration pump. These currents may be further enhanced by the Coriolis effect, which in the Northern Hemisphere is manifested by a tendency for objects moving in a straight line to move right, or clockwise. These passive devices are partially submerged in a pool with the inlet or water intake leading to a collection area. The inlet faces into the circulating water current, which flows through the device and exits through an outlet Debris is caught in the netting at the collection area, which is generally colocated with the outlet.
[0006] For example, U.S. Pat. No. 5,849,184 discloses a device having an elongated inlet portion and a similarly elongated collection portion extending the width of the device, the inlet portion being positioned perpendicular to the flow of water.
[0007] U.S. Pat. No. 4,089,074 discloses a triangular-shaped frame supporting a net with the inlet side of the triangle perpendicular to the flow of water and a collection area at the apex opposing the inlet side The current flows through the inlet portion and out through the collection portion, which collects debris in the main current flow.
[0008] U.S. Pat. No. 5,264,122 discloses a floating stationary pool cleaner having a collection portion and an inlet portion but with integral water jets directing the floating debris into the inlet portion As with U.S. Pat. No. 4,089,074, the current flows through the inlet portion and out through the collection portion, which collects debris in the main current flow.
[0009] U.S. Pat. No. 5,173,181 discloses an apparatus for positioning the detachable strainer from a manual pool scoop in an orientation perpendicular to the flow of the water in the pool, by means of a bracket attached to the pool's side. It has an inlet and collection portion as well.
[0010] U.S. Pat. No. 5,279,728 discloses a basket or collection portion to receive debris from the circular flow in a pool. A tube and nozzle arrangement directs a forced flow of water through the basket portion, thus, presumably creating a circular current within the pool.
[0011] U.S. Pat. No. 5,288,414 discloses another supporting device for a collection portion, in which the collection portion for skimming debris is supported by a support member attached to the side of the pool and a float around the neck of the support member.
[0012] U.S. Pat. No. 5,759,388 discloses yet another stationary skimming device floating on the surface of the pool, having an inlet portion perpendicular to the flow of water and a collection portion at the opposing end, similar to that of U.S. Pat. No. 4,089,074.
[0013] U.S. Pat. No. 5,911,878 discloses another passive pool skimmer with an elongated inlet portion and an outlet portion of roughly the same extent. It is non-rigidly secured to the side of the pool and is configured so that it does not present a hazard to swimmers.
[0014] However, all such pool skimmers share the same problem, namely, that debris has a tendency to float out of the skimmer collection area when a certain amount of debris is collected; the debris can thus reenter the swimming pool where it either sinks to the bottom or else is collected again by the skimmer. This phenomenon has been observed to a greater or lesser extent in all such pool skimmers.
[0015] This observed phenomenon is believed to be caused by the following actions The general circular pool current brings debris into the skimmer collection area and flows on through the netting collecting the debris. The current as it flows through the skimmer tends to keep the debris against the netting comprising the outlet portion. As the debris accumulates against the netting, the current flowing through the skimmer from its inlet to its outlet portions is reduced and the force keeping the debris against the netting of the outlet portion is lessened. As the current through the skimmer becomes weaker, the force keeping the debris against the netting of the outlet portion is weakened, thus allowing the trapped debris to float forward towards the inlet portion against the current Eventually the debris escapes the skimmer and is reintroduced into the swimming pool. It is also observed that the netting itself presents resistance to the swimming pool current; this resistance can be increased by using a finer mesh netting or some other permeable material, or decreased by using a coarser mesh. The accumulation of debris at the outlet portion forces pool owners to frequently clean the outlet/collection area in order to keep the circulatory pool current path clear and unimpeded. If the debris could be removed from the collection area before it could accumulate and impede water flow out the outlet area, then the skimmer could operate more efficiently for longer periods.
[0016] In prior art, cleaning the pool skimmer is an tedious task. Most devices use a form of netting as the filter means. The advantage of using a netting for snagging and holding debris also serves as a disadvantage in the cleaning process. Removing the debris from the netting while the netting is attached to the device often is awkward and difficult.
[0017] Thus, it can be seen that there is a need for a pool skimmer which effectively traps increased amounts of debris without allowing the trapped debris to be reintroduced into the swimming pool after capture. The skimmer should also be easily cleaned.
DISCLOSURE OF THE INVENTION
[0018] It is thus an object of this invention to more efficiently collect debris than heretofore.
[0019] It is a further object of this invention to collect debris by altering the circulatory current through a mesh resistance means on the water inlet area of the pool skimmer.
[0020] It is a further object of this invention to provide a removable mesh filter to improve the cleaning and removal of debris.
[0021] It is a further object of this invention to provide a means for collecting floating debris in such a way as to prevent the collected floating debris from inhibiting the current flow therethrough, and thus provide increased capacity and longer intervals between cleaning.
[0022] It is a further object of this invention to provide a commercially viable means for skimming unwanted material from the surface of any vessel containing a liquid exhibiting a current.
[0023] The invention resides not in any one of these features, per se, but rather in the particular combination of all of the herein disclosed and claimed. It is distinguished from the prior art in this particular combination of all of its structures for the functions specified. These and other objects of the invention may be more clearly seen from the detailed description of the preferred embodiment which follows.
SUMMARY OF THE INVENTION
[0024] The present invention consists of a material, such as a net, sieve, or porous ceramic material, supported by a longitudinal frame having a rectangular inlet positioned in a vessel containing a viscous liquid, so that a current urged to flow around the perimeter of the vessel containing the liquid directs debris through the inlet to be caught by the permeable material In addition, the invention features a collection means with an opening, as for example a basket or some other enclosed volume, positioned at one end of the device and including a portion of the inlet but wherein the opening of the collection means is parallel to the current flow through the inlet The collection means is located upstream of the main inlet area and also covered with a material which may be permeable, semi-permeable, or impermeable, depending upon the nature of the liquid contained within the vessel. An unexpected result is observed in this arrangement. The positioning of a collection means upstream of the inlet portion of the device creates an observable secondary cross current flowing across the main current and through the liquid surface area within the collection means, the area immediately upstream of the inlet, and the main portion of the longitudinal frame. This secondary current which is induced by the resistance of the leading edge of the collection means opening and the material on the leading edge of the collection means tends to sweep debris from the main portion of the longitudinal frame and keeps it clear of debris which might inhibit free flow of liquid therethrough. A majority of the floating debris is thus captured within the collection means where it remains until it is removed from the apparatus or until it becomes saturated with the liquid upon which it floats, in which case it sinks to be captured in the portion of the collection means which extends below the surface of the liquid. In this manner, the invention is able to capture increased amounts of debris without clogging, and this increased time results in greater time between cleaning of the apparatus. This apparatus may be used in both commercial and domestic applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1 shows a full three dimensional isometric view of a pool skimmer.
[0026] [0026]FIG. 2 presents an overhead view of a pool skimmer as it is positioned within a swimming pool.
[0027] [0027]FIG. 3 presents a top view of the invention to show how it functions in the presence of a current induced within the liquid within which it is partially submerged.
[0028] [0028]FIG. 4 presents another embodiment of the invention to illustrate an alternative means for positioning the invention within a vessel and an alternative manufacturing method which embodies the principles of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] The simplest embodiment of the invention is given below in order to promote understanding of the principles involved in its use. Referring to FIG. 1 which gives a front perspective view of an embodiment of the invention which is directed towards domestic use, a pool skimmer 20 is shown generally having a proximal end 22 for stationary connection (not shown) with the edge of a swimming pool and a distal end 24 projecting into the interior of the swimming pool. Skimmer 20 is formed of a frame 30 constructed of any light material which can be formed into a frame to support netting.
[0030] The material used for this embodiment and shown in the drawings consists of polyvinyl chloride tubing connected by T- and X-couplings, as is commonly found in swimming pool equipment. Other materials contemplated for this application would be fiberglass or extruded plastic. For swimming pool skimmers, the requirement for a frame is that it be resistant to water corrosion, light, and easily maintained by the owner. As such, frame 30 may be constructed in such a way, as shown, to facilitate easy assembly by untrained personnel or to promote compact packaging. However, frame 30 could also be constructed of continuous extruded and formed material which is held together during use by pins, screws, bolts, or any other semi-permanent connection means which holds the frame in a rigid shape, if disassembly is a goal. Frame 30 could also be assembled with more permanent connection means such as glue, welding, rivets, or integral casting, if more permanent and durable construction is a goal.
[0031] The netting which is referenced in the description of this embodiment may be composed of any permeable material which allows a current of water to flow therethrough; however, a plastic or nylon netting material with a suitable mesh to entrap small particles of debris commonly found around the typical home is typically used. It should be noted that in other commercial processes, additional factors may be present which dictate the choice of netting material, for example, the resistance of the netting material to corrosion by the liquid contained within the vessel, the permeability of the netting with relation to the viscosity of the liquid, the force of current flow which may dictate a stronger netting material, etc.
[0032] In the description that follows, the forward direction is considered to be a direction against the current and a rear direction is considered to be with the current.
[0033] In the embodiment described in FIG. 1, Frame 30 is comprised of an upper frame member 40 and a lower frame member 50 , both extending longitudinally between the proximal end 22 and the distal end 24 . Frame members 40 , 50 are held in constant spaced relation by distal vertical member 80 and proximal vertical member 85 . Vertical members 80 , 85 are connected to the ends of frame members 40 , 50 by L-couplings 107 to form a generally rectangular structure. Rear ribs 60 a , 60 b , 60 c , and 60 d are spaced along the rear side of frame members 40 , 50 and between vertical members 80 , 85 . Rear ribs 60 c , 60 d are positioned towards the proximal end 22 of frame 20 , with the first ends of rear ribs 60 c and 60 d are connected to upper frame member 40 by a standard T-coupling 100 and the second ends of said ribs are connected to lower frame member 50 by a standard T-coupling 100 Rear ribs 60 a , 60 b are positioned towards the distal end 24 of frame 20 Front ribs 70 a and 70 b are spaced distally along the same side of frame members 40 , 50 and oppose rear ribs 60 a and 60 b , respectively. The first ends of ribs 60 a , 70 a and 60 b , 70 b are each connected to upper frame member 40 by a standard X-coupling 105 and the second ends of ribs 60 a , 70 a and 60 b , 70 b are connected to lower frame member 50 by a standard X-coupling 105 .
[0034] Conceptually, the skimmer structure can be described as a frame to which is connected a side-mounted collection basket consisting of front ribs 70 a , 70 b and rear ribs 60 a , 60 b , interconnected by a portion of frame members 40 , 50 and vertical frame member 80 , the open face of which basket is defined by ribs 60 b , 70 b Alternatively, the skimmer structure can be described as a net structure consisting of a netting supported by a frame consisting of rear mounted ribs 60 a - d , upper and lower horizontal members 40 , 50 , and vertical members 80 , 85 , and having a collection scoop mounted at one end of the inlet portion and consisting of the forward mounted frame comprising ribs 70 a , 70 b.
[0035] Skimmer 20 is rigidly attached to a support (not shown) on the side of the swimming by means of proximal horizontal support member 110 and a support means 111 . Any such support means is contemplated, such as by clamps, screws, rings, and the like, wherein the support means rigidly suspends skimmer 20 so that it is half immersed longitudinally beneath the surface of the swimming pool. Optionally, float 108 may be connected to distal end 24 for floating support of skimmer 20 , such connection being accomplished by means of distal horizontal support member 109 attached to an L-coupling 100 along vertical frame member 80 , so as to reduce the supporting requirements for support means 111 .
[0036] Frame 30 supports netting having a fine mesh suitably sized to allow water to pass through but to restrict most small particles of debris. A rear netting portion 150 of generally rectangular shape is attached along the length of upper frame member 40 and is wrapped around rear ribs 60 a -d to attach along the length of lower frame member 50 attachment may be accomplished by any suitable means, and the preferred manner of attachment is by a hook and loop arrangement commonly known to the industry. A front netting portion 155 , also of generally rectangular shape, is attached along upper frame member 40 between front ribs 70 a , 70 b and is wrapped around rear ribs 70 a , 70 b to attach along lower frame member 50 between front ribs 70 a , 70 b . A distal netting portion extends over distal end 24 of pool skimmer 20 , attaching to the distal edges of front netting portion 155 and rear netting portion 150 , conceptually forming a collection basket. A proximal netting portion 170 extends over proximal end 24 of pool skimmer 20 , attaching to the proximal edge of rear netting portion 150 . Note that although the netting covering skimmer 20 has been described as four individual portions, the actual construction of the netting may be as a single piece cut appropriately or as multiple pieces which functionally cover the frame as described.
[0037] The rectangular area defined by upper frame member 40 and lower frame member 50 and between rear ribs 60 b and 60 d define an inlet portion 115 which is unobstructed by netting. The area comprising the rear netting portion 150 is defined as the outlet portion 140 The collection area comprises the netting portion forming a conceptual basket on distal end 24 of skimmer 20 , namely, the area within distal netting portion 160 , forward netting portion 155 , and rear netting portion 150 .
[0038] In another variant of the embodiment as described above is shown FIG. 4, where the frame and netting configuration may be constructed of a series of panels 300 , which are generally rectangular or square, having panel having a rigid frame into which the netting is permanently molded. Two of such panels are connected along their edges and the third panel is connected to a side of one of the two panels which is opposite the connected side, thus forming a C configuration. A plurality of such C configured panels are connected in parallel along their free edges to form a scoop arrangement. To each end of the scoop is attached another panel 301 , 302 to form an enclosed scoop with an inlet area 303 . At one end of the inlet area, another C configuration 304 is attached with its opening opposing the inlet area and enclosed with another panel 305 on its end which is coincident with a previously enclosed scoop end, thus forming the collection area. All panels are connected by a connection means as described previously.
[0039] The generally rectangular configuration of the panels allows a support means to be configured to the apparatus which will allow the apparatus to easily rise and fall with the level of the liquid while maintaining a horizontal attitude. A pool support means is rigidly attached to the edge of the vessel by means of connection points 316 , from which extend two horizontal support bars 314 , 315 which terminate with two horizontally oriented rings 312 , 313 which are permanently attached to support bars 314 , 315 . The rings 312 , 313 loosely encircle two U-shaped vertical support bars 310 , 311 attached to the edges of end panel 301 . A float 317 is attached to the distal end of the apparatus to maintain its orientation with the surface of the liquid and another float (not shown) is optionally connected at the proximal end for similar reasons. It can thus be seen that the apparatus can be positioned perpendicular to the current flow by the arrangement while allowing the apparatus to rise and fall with the level of the liquid surface.
[0040] This method of assembly allows the pool skimming apparatus to be constructed as a series of panels which are easily built and interchangeable with panels of similar size and configuration. This method of manufacture reduces the number of unique parts required to configure a skimmer and thus reduces the cost of manufacture, i.e. tooling, inventory, complexity, etc From this example it can be seen that the design of the pool skimmer apparatus lends itself to numerous ways to reduce part count by judicious engineering.
[0041] Referring to FIG. 2, pool skimmer 20 installed for use in a swimming pool 210 by positioning skimmer 20 adjacent to the edge 210 and supporting skimmer 20 by support means 111 consisting any convenient means on the edge 210 , preferably simple weight lying next to the pool. Skimmer 20 extends towards the interior 206 of the pool 205 and away from edge 210 so that skimmer 20 is partially immersed longitudinally with the water level generally bisecting inlet 115 . The orientation of skimmer 20 is such that the generally circular pool current generated by the force of water emitted from pump nozzle 200 flows into inlet portion 115 along with any debris 220 which may be floating on the pool's surface. The most obvious orientation is for a clockwise current in the Northern hemisphere, although skimmer 20 may be oriented for either counter-clockwise or clockwise currents.
[0042] For commercial applications, the orientation of the skimmer is essentially the same as that of domestic operations. Note also that the collection area of the device may be optionally located at the proximal end if desired. In operation, as seen in FIG. 3, it has been observed that debris collects in collection area 240 and is not returned to the swimming pool 205 , regardless of how full collection area 240 becomes. While the mechanics of this phenomenon are not well understood, it is believed that they act as follows. As the pool current carrying floating debris 220 flows towards inlet portion 115 , the netting at location 227 resists the current sufficiently to create a differential in force of current measured at inlet area 235 and collection area 240 . This differential in current force causes a secondary current which flows around leading point 226 of the frame, through the collection side 225 , and into collection area 240 . Some flow of water continues through the netting at location 227 , and joining the secondary current, continues through collection area 240 into receiving area 250 . The netting at point 228 prevents debris from exiting the collection area 240 and provides sufficient resistance to divert the current back into its original course This differential in current force, thus created, causes a swirling effect to be observed. Some debris which escapes collection area 240 enters receiving area 250 , where the force of the current flowing through inlet 115 causes debris 220 to collect against netting 229 . As debris collects at netting 229 , it begins to impede the force of the current flowing through netting 229 . This causes a lessening of the current force, thereby allowing debris to float free against said current and towards inlet portion 115 . However, this release of debris from the netting 229 reduces the impediment to current flow. Debris floating free from netting 229 is forced by the current flowing through inlet area 235 back through collection side 225 into collection area 240 before it can escape inlet area 235 back into the swimming pool. Eventually, the different forces acting upon the debris reach an equilibrium and the circular secondary current is observed.
[0043] Commercial applications utilizing this process are complicated by differing liquid viscosities, current forces, and temperature, all of which affect the choice of netting and frame material. However, it is believed that the process of debris collection functions as described above.
[0044] While only a preferred embodiment has been illustrated and described, obvious modifications may be made within the scope of this invention and the following claims without substantially changing its functions. Accordingly, the scope of the invention should be determined not by the embodiments illustrated but by the appended claims and their legal equivalents. | An apparatus for skimming floating debris from an enclosed vessel of water wherein a circular current of water occurs, said apparatus comprising a frame defining an inlet portion positioned upstream and an outlet portion covered with netting positioned downstream. A collection area, also covered with netting and located at one end of the inlet portion, extends upstream from and with its open end perpendicular to the inlet portion so that the leading edge of the collection area sufficiently impedes the current along its permeable leading edge. This impediment induces a lateral current internal to the apparatus which causes a substantial portion of the floating debris entering the apparatus to be accumulated in the collection area out of the main flow of the current, rather than accumulating at the netting-covered outlet portion of the apparatus. This lateral collection area with its accompanying lateral current flow improves the ability of the apparatus to prevent debris from leaving the apparatus once captured. | 4 |
FIELD OF THE INVENTION
[0001] The present application relates to a combined metallic pre-embedded anchor slot system used in the construction industry, particularly, a pre-embedded anchor slot system for use in reinforced concrete floor slabs with corrugated steel decking or thin reinforced concrete floor slab.
BACKGROUND OF THE INVENTION
[0002] Designers of modern architectures widely adopt the use of corrugated steel decking with reinforced concrete topping or thin concrete floor slab, with thickness typically ranges from 125 mm to 150 mm. However, due to the reduction of thickness of the floor slab, the embedded anchor slot which relies on attaching to the concrete structure results in a lower loading capacity for external objects.
[0003] In modern high-rise architectures, structural steelwork is typically used as primary structural frame of buildings. Corrugated steel decking with reinforced concrete topping are used to form floor slabs with thickness of mere 125 mm-150 mm. Besides, architects aims to minimize the thickness of floor slabs in order to reduce overall construction costs. In view of the above, the pursuit of combined anchor slot system has become a goal for the construction industry.
SUMMARY OF THE INVENTION
[0004] The present application is directed to a combined pre-embedded anchor slot system to be used in the construction industry.
[0005] The object of the present application is to provide a combined embedded anchor slot system which alleviates the technical difficulties discussed in the prior art, by embedding the system in concrete slab with corrugated steel decking or thin traditional reinforced concrete slab of a concrete structural by utilizing anchor studs and reinforcing steel bars which secured into concrete structure to exert external loads transmitted from the serrated nut.
[0006] There is provided a combined pre-embedded anchor slot system comprising an anchor slot, a linkage bolt, a set nut, a anchor stud, a reinforcing steel bar, and a serrated nut, wherein the said combined embedded anchor slot system further comprises one or more pair of juxtaposed anchor slots, linkage bolt and set nut which are mounted at each end of the anchor slot. The anchor stud is provided at the bottom of the anchor slot and connects to a connection node. A reinforcing steel bar is installed between every two connection nodes forming a combined structure of crossover reinforcing steel bars. One end of the anchor slot is provided with a nut access port and an end cap. The opposite end of the anchor slot is also provided with an end cap and a nut position limiting member which is disposed inside the anchor slot. The serrated nut accesses the anchor slot through the nut access port, wherein one or more serrated nut is installed into the channel rail. The combined pre-embedded anchor slot system forms a frame structure by linking one or more pair of juxtaposed anchor slots together with linkage bolts and a combined body of crossover reinforcing steel bars.
[0007] There is provided a combined pre-embedded anchor slot system wherein the anchor stud is provided at the bottom of the anchor slot, or at the center of the anchor slot.
[0008] There is provided a combined pre-embedded anchor slot system wherein one or more serrated nut is provided inside each anchor slot.
[0009] There is provided a combined pre-embedded anchor slot system wherein the serrated nut is marked with a centre line for aiding the user to carry out positioning of external attachment.
[0010] There is provided a combined pre-embedded anchor slot system wherein a set screw is provided on the serrated nut.
[0011] There is provided a combined pre-embedded anchor slot system wherein the serrated nut is interchangeable with a serrated T bolt.
[0012] There is provided a combined pre-embedded anchor slot system wherein the width of the nut access port of the anchor slot is greater than that of the slot opening.
[0013] There is provided a combined pre-embedded anchor slot system wherein the nut position limiting member is located close to the ends of the anchor slot.
[0014] There is provided a combined pre-embedded anchor slot system wherein adjustments and tightening of the spacing between the pair of anchor slots can be made by adjusting the linkage bolt and set nut.
[0015] The present invention utilizes the above technical features and provides a combined embedded anchor slot system which alleviates the technical difficulties discussed in the prior art, by embedding the system in concrete slab with corrugated steel decking or thin traditional reinforced concrete slab of a concrete structural by utilizing anchor studs and reinforcing steel bars which secured into concrete structure to exert external loads transmitted from the serrated nut. In comparison with the prior art, the combined pre-embedded anchor slot system offers exceptional stability.
[0016] The present invention provides a combined structure of at least a pair of anchor slot embedded in concrete slab. The assembly of anchor studs and longitudinally and laterally arranged reinforcing steel bars enhances the grip between the anchor system and the concrete slab as well as the loading capacity for external constructions. On the other hand, the position limiting member serves to prevent the anchor slot from being pried open under loads, hence avoiding the mounting bolt from being plucked out of the anchor slot which causes the structure to become unstable.
[0017] The combined pre-embedded anchor slot system of the present invention consumes lesser materials, hence is more cost effective and environmentally friendly.
BRIEF DESCRIPTION OF DRAWINGS
[0018] FIG. 1 is a structural representation of a combined pre-embedded anchor slot system of the present application embedded in the concrete slab with corrugated steel decking;
[0019] FIG. 2 is a representation showing a sectional view along line A-A in FIG. 1 ;
[0020] FIG. 3 is a representation showing a front view of FIG. 1 ;
[0021] FIG. 4 is a representation of another embodiment of the present application;
[0022] FIG. 5 is a representation showing a sectional view along line B-B in FIG. 4 ;
[0023] FIG. 6 is a representation showing the side view of a combined pre-embedded anchor system in application;
[0024] FIG. 7 is a representation showing the plan view of FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
Preferred Embodiment of the Present Invention
[0025] The present invention will be described below in detail with reference to the preferred embodiment and the accompanied drawings.
[0026] Referring to FIG. 1 to FIG. 3 , the present invention is aimed to provide a combined pre-embedded anchor slot system for use in the construction industry, which mainly includes an anchor slot 1 , linkage bolts 8 , set nuts 9 , anchor studs 3 and connection nodes 7 , reinforcing steelbars 2 , and serrated nuts 10 . The system is pre-embedded in concrete slab with steel corrugated decking 12 .
[0027] The combined pre-embedded anchor slot system is formed by one or more pair of juxtaposed anchor slots 1 , linked together at the corresponding ends with linkage bolts 8 and set nuts 9 . Anchor studs 3 are provided at the bottom of the anchor slot 1 extending from the web of the anchor slot 1 . As depicted in the figures, the anchor studs 3 are situated on both sides of the web and disposed along the lengthwise direction of the anchor slot 1 . The anchor studs 3 are embedded in the concrete which prevents the anchor slot from being plucked from the concrete under external loads.
[0028] The anchor stud 3 is provided with a connection node 7 . A reinforcing steel bar 2 is installed between two connection nodes 7 along the direction of the anchor slot, as well as in the direction across two anchor slots. As a result, a combined body of crossover reinforcing steel bars 2 is formed by the longitudinally and laterally arranged reinforcing steel bars 2 .
[0029] At one end of the anchor slot 1 , there is provided a nut access port 6 and an end cap 4 . Another end cap 4 is provided at the opposite end of the anchor slot 1 . A nut position limiting member 5 is mounted in proximate to each opposite end of the anchor slot 1 . A serrated nut 10 is inserted into the anchor slot 1 through the nut access port 6 . The number of serrated nut 10 to be fitted into the anchor slot 1 can be one, two or even three. The serrated nuts 10 are mounted inside the anchor slot 1 .
[0030] The serrated nut 10 is marked with a centre line for aiding the user to carry out positioning of external attachment. Set screws 11 are provided on the serrated nut 10 to allow its position to be fixed. The position locking is achieved by driving in the set screws 11 which in turn pushes the serrated nut 10 up against the bottom surface of the foot flange. As a result, the serrations on the serrated nut 10 meshes with the serrations disposed on the bottom surface of the foot flange, therefore, locking the serrated nut 10 in place. The serrated nut 10 may be replaced with serrated T bolts.
[0031] The width of the nut access port 6 is greater than the width of the anchor slot 1 opening for allowing the serrated nut 10 to access through. The anchor slot 1 is also provided with a nut positioning reinforcement member 5 near each opposite end of the anchor slot 1 . The above serves to limit the position range of the serrated nuts 10 and also prevents the anchor slot 1 from being pried open under external loads.
[0032] FIGS. 4 to 5 shows another embodiment of the combined pre-embedded anchor slot system which is primarily formed by the anchor slot 1 , linkage bolt 8 , set nut 9 , anchor stud 9 and connection node 7 , reinforcing steel bar 2 and serrated nut 10 .
[0033] The combined pre-embedded anchor slot system consists of one or more pairs of the aforementioned juxtaposed anchor slots 1 . A linkage bolt 8 and set nuts 9 are mounted on each opposite end of the anchor slot 1 . As shown in the figures, the anchor studs 3 are provided near the opposite ends and also at the centre of the anchor slot 1 , and are disposed on the web and along the lengthwise direction of the anchor slot 1 . The anchor studs 3 are embedded in the concrete which prevents the anchor slot 1 from being plucked from the concrete under external loads.
[0034] The anchor stud 3 is connected to an anchor stud connection node 7 . A reinforcing steel bar 2 is installed between two connection nodes 7 . As shown in the figures, three connection nodes 7 are disposed along the lengthwise direction of anchor slot 1 and are linked by reinforcing steel bars 2 . In addition to the two linkage bolts 8 connecting the two juxtaposed anchor slots 1 , the anchor slots 1 are also linked by two reinforcing steel bars 2 . As a result, a combined body of crossover reinforcing steel bars 2 is formed by the longitudinally and laterally arranged reinforcing steel bars 2 .
[0035] One end of the anchor slot 1 is provided with a nut access port 6 and a sealing cap 4 . Another sealing cap 4 is provided at the opposite end of the anchor slot 1 . A position limiting member 5 is provided inside the anchor slot 1 . A serrated nut 10 is inserted into the anchor slot 1 through the nut access port 6 . As shown in the figures, two serrated nuts 10 inserted in each of the anchor slots 1 .
[0036] The serrated nut 10 is marked with a centre line for aiding the user to carry out positioning of external attachment. Set screws 11 are provided on the serrated nut 10 to allow its position to be fixed. The position locking is achieved by driving in the set screws 11 which in turn pushes the serrated nut 10 up against the bottom surface of the foot flange. As a result, the serrations on the serrated nut 10 meshes with the serrations disposed on the bottom surface of the foot flange, therefore, locking the serrated nut 10 in place. The serrated nut 10 may be replaced with serrated T bolts.
[0037] The width of the nut access port 6 is greater than the width of the anchor slot 1 opening for allowing the serrated nut 10 to access through. The anchor slot 1 is also provided with a nut positioning reinforcement member 5 near each opposite end of the anchor slot 1 . The above setup serves to limit the position range of the serrated nuts 10 and also prevent the anchor slot 1 from being pried open under external loads.
INDUSTRIAL APPLICATION OF THE PRESENT INVENTION
[0038] Referring to FIG. 6 and FIG. 7 , the figures illustrate an application of a combined pre-embedded anchor slot system of the present invention. The combined pre-embedded anchor slot system is embedded in the concrete slab with corrugated steel decking 12 of a concrete structure.
[0039] The combined anchor pre-embedded anchor slot system of the present invention incorporates two or more anchor slots 1 interconnected by linkage rods 8 secured with set nuts 9 , and the longitudinal and laterally arranged reinforcing steel bars 2 to collaboratively form a combined frame structure, which offers superior stability for the whole embedded anchor slot system, particularly for embedding such system in thin concrete slab with corrugated steel decking or thin traditional reinforced concrete slab. By utilizing anchor studs 3 and reinforcing steel bars 2 which secured into concrete structure to exert external loads transmitted from the serrated nut 10 , exceptional stability can be attained.
[0040] The combined pre-embedded anchor slot system of the present invention provides adjustments of the spacing between the juxtaposed anchor slots 1 by adjusting and tightening the linkage bolts 8 and set nuts 9 .
[0041] As described in the foregoing, the combined pre-embedded anchor slot system of the present invention can be embedded in concrete slab with corrugated steel decking or thin traditional reinforced concrete slab of a concrete structural by utilizing anchor studs and reinforcing steel bars which secured into concrete structure to exert external loads transmitted from the serrated nut, the combined pre-embedded anchor slot system offers exceptional stability. In the system, two or more anchor slots are interconnected by linkage bolts secured with set nuts. With the longitudinal and laterally arranged reinforcing steel bars, the system forms a frame structure and the grip between the system and the concrete structure as well as the loading capacity of external loads on the concrete structure can be maximized. The combined pre-embedded anchor slot system of the present invention consumes lesser materials, hence is more cost effective and environmentally friendly.
[0042] Of course, the skilled person in the art would appreciate that the above serves only to illustrate the embodiments but not as limitations to the invention disclosed. Any modification, equivalent, and alternative within the spirits of the invention would fall within the scope of the disclosure as defined by the appended claims. | The present application relates to a pre-embedded anchor system for securing construction elements to concrete slabs. The system comprises at least one pair of juxtaposed elongate anchor slots ( 1 ) connected together by at least two linkage bolts ( 8 ) and an assembly of steel bars ( 2 ) interconnecting a plurality of anchor members ( 3 ) at connection nodes ( 7 ) of the anchor members ( 3 ). The anchor slots ( 1 ) have a plurality of anchor members ( 3 ) extending therefrom. The pair of juxtaposed anchor slots ( 1 ) are interconnected by the linkage bolts ( 8 ) and the assembly of crossover steel bars ( 2 ) to form a frame. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a portable cooking device for use outdoors and more particularly, to a portable gas cooking device having a cooking container, a gas burner, and a gas tank disposed within and stacked up from the top to the bottom of an insulated housing for cooking during transportation thereof without safety and leakage problems.
2. Description of Related Art
Various types of gas cooking devices having a gas burner and a gas source are known in the art. Generally, the gas burner is operated by a gas controlling valve or switch, and the gas burner is provided with container supports for supporting the container disposed over the burner.
Such gas cooking devices are shown in U.S. Pat. No. 3,213,848 to Wei, U.S. Pat. No. 4,082,993 to Oakes, and U.S. Pat. No. 4,726,350 to Steinhauser. However, such gas cooking devices do not disclose an actually portable cooking device containing a pot, a burner, and a gas tank with an automatic igniting system. Also, such cooking devices do not show a cooking device to enable cooking during transportation of the cooking device without safety and leakage problems.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a portable gas cooking device for use outdoors, which eliminates the above problems encountered with conventional gas cooking devices.
Another object of the present invention is to provide a portable gas cooking device including a cylindrical housing, a replaceable gas tank, a gas burner member with an automatic igniting system, and a cooking container with a lid screwed to the cooking container whereby the portable gas cooking device can be effectively operated outdoors even though the weather is bad, and conveniently used during movement/transportation thereof.
Still another object of the present invention is to provide a portable gas cooking device, which is simple in structure, inexpensive to manufacture, durable in use, and refined in appearance.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
Briefly described, the present invention is directed to an improved portable gas cooking device including a cooking container such as a pot or a kettle, a gas burner member, and a gas tank disposed within and stacked within an insulated housing for cooking during transportation thereof without safety and leakage problems.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitative of the present invention, and wherein:
FIG. 1 is a perspective view of a portable gas cooking device according to the present invention containing cut away portions in order to illustrate construction of the device of the present invention;
FIG. 2 is a sectional view of FIG. 1;
FIG. 3 is a bottom plan view of the portable gas cooking device according to the present invention; and
FIG. 4 is an enlarged sectional view of a gas burner member of the portable gas cooking device according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in detail to the drawings for the purpose of illustrating preferred embodiments of the present invention, the portable gas cooking device 10 as shown in FIGS. 1 and 2, includes a housing 11 having a pivotal handle 15 formed at an upper end of the housing 11, a gas tank 14 fit within the housing 11, a gas burner member 23 positioned over the gas tank 14, and a cooking container 13 positioned above the gas burner member 23. The housing 11 is made of insulating materials such as cellular plastics, glass fibers, or polystyrenes and has a cylindrical configuration.
As shown in FIG. 2, the housing 11 is provided with a plurality of stoppers 22 extending from an inner wall of the housing 11 for securely positioning the gas tank, and a plurality of gas tank supports 29 fixed to a bottom peripheral edge of the housing with screws 30 for supporting the gas tank 14 thereon (FIG. 3) so as to enable replacement of the gas tank 14 if necessary. An annular space 20 is formed in a base of the housing 11, preferably within a bottom surface thereof, for inducing fresh air therethrough so as to supply oxygen to the gas burner 23. Also, the housing 11 is further provided with a plurality of openings 18 disposed adjacent an upper end thereof for exhausting of the wasted hot air, smell, and smoke to the atmosphere. A lid 12 covers the upper end of the housing 11 by threadably engaging with an inner threaded portion 19 an opening of the cooking container 13 and an outer threaded portion 19' of the lid 12. The plurality of openings 18 are preferably formed as two parallel lines of openings 18. The lid 12 has a nipple 17 which has a small aperture 17' formed therein for generating whistle while the liquid of the cooking container 13 is boiling so as to indicate the state of cooking of food in the cooking container 13 and maintain the safety of the cooking container 13. A knob 16 or the like is provided on the upper surface of the lid 12 to assist in securement and removal thereof to the container 13.
The cooking container 13 is supported by a plurality of container supports 21 extending from the inner peripheral wall surface at substantially the middle portion of the housing 11 such that the cooking container 13 is disposed over a burner head 37 of the burner 36. The cooking container 13 is preferably a kind of kettle or pot. The cooking container 13 will boil rice or cook various types of soups therewithin even though the portable gas cooking device 10 is transported outdoors, for example, hiking or mountain climbing and the weather is bad such as a windy and/or rainey day.
As shown in FIGS. 1 and 4, the gas burner member 23 includes a gas control valve 24, a burner head 37 having a plurality of gas openings 38, and a burner stem 36 containing a gas pipe 35 operatively communicating with the gas tank 14. The gas control valve 24 is operated by a gas controlling knob 34. Generally, the gas tank 14 contains LPG (liquefied petroleum gas) to be flowed to the plurality of gas openings 38 of the burner head 37 through the gas pipe 35 for transforming the LPG into a flame 39 (FIG. 4). The gas controlling knob 34 is disposed on the exterior of the housing 11.
As shown in FIGS. 1, 2, and 3, a knurled igniting knob 25 disposed on the exterior of the housing 11 and in the vicinity of the gas controlling knob 34 includes a threaded steel member 26 and a knob shaft 31 connected between the knurled igniting knob 25 and the threaded steel member 26. The knob shaft 31 is supported by a C-shaped shaft support 32 fixed to the inner wall of the housing 11. A lighter flint 27 is biased by a spring 28 which is supported by an L-shaped lighter flint support 33 and attached to the upper part of the C-shaped shaft support 32 for igniting fire 39 to the burner head 37, so that it is easy to strike fire a spark.
Accordingly, the gas cooking device 10 for use outdoors according to the present invention can be used in any weather condition, for example, windy or rainy days, can effectively improve heat efficiency, can be conveniently cook even during movement of the cooking device 10, and can guarantee the safety and non-leakage thereof. Also, it is convenient and economical since the exhausted gas tank 14 can be easily replaced with a new one and the cooking device 10 includes an automatic ignition system disposed therewithin, and it is simple in structure, inexpensive to manufacture, durable in use, and refined in appearance.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | A portable gas cooking device for use outdoors, includes a cooking container, a gas burner, and a gas tank disposed within and stacked up from the top to the bottom of an insulated housing for cooking during transportation thereof without safety and leakage problems. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit of United States Provisional Application No. 60/274,387, entitled COUNTER PLATE ELECTRODE WITH SELF ADJUSTING Z-AXIS, filed Mar. 9, 2001 by Mark G. Steele, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
This invention pertains generally to the field of fluid dynamic bearings, and more particularly to etching grooves in a counter plate of a fluid dynamic bearing.
BACKGROUND OF THE INVENTION
Disc drives, including magnetic disc drives, optical disc drives and magneto-optical disc drives, are widely used for storing information. A typical disc drive has one or more discs or platters which are affixed to a spindle and rotated at high speed past a read/write head suspended above the discs on an actuator arm. The spindle is turned by a spindle drive motor. The motor generally includes a shaft having a thrust plate on one end, and a rotating hub having a sleeve and a recess into which the shaft with the thrust plate is inserted. Magnets on the hub interact with a stator to cause rotation of the hub relative to the shaft.
In the past, conventional spindle motors frequently used conventional ball bearings between the hub and the shaft and the thrust plate. However, over the years the demand for increased storage capacity and smaller disc drives has led to the read/write head being placed increasingly close to the disc. Currently, read/write heads are often suspended no more than a few millionths of an inch above the disc. This proximity requires that the disc rotate substantially in a single plane. Even a slight wobble or run-out in disc rotation can cause the disc to strike the read/write head, damaging the disc drive and resulting in loss of data. Because this rotational accuracy cannot be achieved using ball bearings, the latest generation of disc drives utilize a spindle motor having fluid dynamic bearings on the shaft and the thrust plate to support a hub and the disc for rotation.
In a fluid dynamic bearing, a lubricating fluid such as gas or a liquid or air provides a bearing surface between a fixed member and a rotating member of the disc drive. Dynamic pressure-generating grooves formed on a surface of the fixed member or the rotating member generate a localized area of high pressure or a dynamic cushion that enables the spindle to rotate with a high degree of accuracy. Typical lubricants include oil and ferromagnetic fluids. Fluid dynamic bearings spread the bearing interface over a large continuous surface area in comparison with a ball bearing assembly, which comprises a series of point interfaces. This is desirable because the increased bearing surface reduces wobble or run-out between the rotating and fixed members. Further, improved shock resistance and ruggedness is achieved with a fluid dynamic bearing. Also, the use of fluid in the interface area imparts damping effects to the bearing which helps to reduce non-repeat runout.
One generally known method for producing the dynamic pressure-generating grooves is described in U.S. Pat. No. 5,758,421, to Asada, (ASADA), hereby incorporated by reference. ASADA teaches a method of forming grooves by pressing and rolling a ball over the surface of a workpiece to form a groove therein. The diameter of the ball is typically about 1 mm, and it is made of a material such as carbide which is harder than that of the workpiece. This approach and the resulting fluid dynamic bearing, while a major improvement over spindle motors using a ball bearing, is not completely satisfactory. One problem with the above method is the displacement of material in the workpiece, resulting in ridges or spikes along the edges of the grooves. Removing these ridges, for example by polishing or deburring, is often a time consuming and therefore a costly process. Moreover, to avoid lowering yields, great care must be taken not to damage the surface of the workpiece.
A further problem with the above method is due to a recent trend in disc drives toward higher rotational speeds to reduce access time, that is the time it takes to read or write data to a particular point on the disc. Disc drives now commonly rotate at speeds in excess of 7,000 revolutions per minute. These higher speeds require the shaft and the hub to be made of harder material. Whereas, in the past one or more of the shaft, the sleeve or the hub, could be made of a softer material, for example brass or aluminum, now all of these components must frequently be made out of a harder metal such as, for example, steel, stainless steel or an alloy thereof. These metals are as hard or harder than the material of the ball. Thus, the above method simply will not work to manufacture fluid dynamic bearings for the latest generation of disc drives.
Another method for producing the grooves of a fluid dynamic bearing is described in U.S. Pat. No. 5,878,495, to Martens et al. (MARTENS), hereby incorporated by reference. MARTENS teach a method of forming dynamic pressure-generating grooves using an apparatus, such as a lathe, having a metal-removing tool and a fixture that moves the workpiece incrementally in the direction in which a pattern of grooves is to be formed. The metal-removing tool forms the grooves by carrying out a short chiseling movement each time the workpiece is moved. This approach, while an improvement over the earlier one in that it does not produce ridges that must be removed, is also not completely satisfactory. For one thing, this approach like that taught by ASADA is typically not suitable for use with harder metals, which in addition to being more difficult to machine are often brittle and can be damaged by the chiseling action. Moreover, because each groove or portion of a groove must be individually formed and the workpiece then moved, the process tends to be very time consuming and therefore costly. Furthermore, the equipment necessary for this approach is itself expensive and the metal-removing tool is subject to wear and requires frequent replacement.
A final method for producing the grooves involves a conventional etching process as described in U.S. Pat. No. 5,914,832, to Teshima (TESHIMA), hereby incorporated by reference. TESHIMA teaches a process in which the workpiece is covered with a patterned etch resistant coating prior to etching so that only the exposed portions of the workpiece are etched. While this approach avoids many of the problems of the previously described methods, namely the formation of ridges around the grooves and the inability to form grooves in hard metal, it creates other problems and therefore is also not wholly satisfactory. One problem is the time consumed in applying and patterning the etch resistant coat. This is particularly a problem where, as in TESHIMA, the resist coat must be baked to prior to patterning or etching. Another problem is that the coating must be removed after etching. This is frequently a difficult task, and one that if not done correctly can leave resist material on the workpiece surface resulting in the failure of the bearing and destruction of the disc drive. Yet another problem with this approach is that each of the steps of the process requires the extensive use of environmentally hazardous and often toxic chemicals including photo resists, developers, solvents and strong acids.
Accordingly, there is a need for an apparatus and method for forming grooves in a workpiece made of a hard metal to manufacture fluid dynamic bearings suitable for use in a disc drive. It is desirable that the apparatus and method that allows the grooves to formed quickly and cheaply. It is also desirable that the apparatus and method not require expensive equipment or the use of a metal-removing tool that must be frequently replaced. It is further desirable that the apparatus and method not use an etch resistant material during manufacture that could contaminate the workpiece leading to the failure of the bearing and destruction of the disc drive.
As the result of the above problems, electrochemical machining of grooves in a fluid dynamic bearing has been developed as described in the above-incorporated patent application. A broad description of ECM is as follows. ECM is a process of removing material metal without the use of mechanical or thermal energy. Basically, electrical energy is combined with a chemical to form a reaction of reverse electroplating. To carry out the method, direct current is passed between the work piece which serves as an anode and the electrode, which typically carries the pattern to be formed and serves as the cathode, the current being passed through a conductive electrolyte which is between the two surfaces. At the anode surface, electrons are removed by current flow, and the metallic bonds of the molecular structure at the surface are broken. These atoms go into solution, with the electrolyte as metal ions and form metallic hydroxides. These metallic hydroxide (MOH) molecules are carried away to be filtered out. However, this process raises the need to accurately and simultaneously place grooves on a surface across a gap between the electrode and the workpiece, which gaps must be very accurately set. This requires the use of a work holder which can accurately locate and constrain a workpiece within an electrochemical machining process environment (ECM). ECM is used to place grooves on the moving parts of a fluid dynamic bearing. The depth of these grooves has a typical tolerance of ±0.003 mm. Therefore the electrode/workpiece position error must be no greater than this.
In a very commonly used fluid dynamic bearing design, a flat circular plate referred to as a counter plate is used, and must have grooves precisely etched thereon. The invention resulted from the need to accurately locate the distance between a thrust surface type ECM electrode (which defines the groove pattern) and a counter plate (the circular plate used in fluid dynamic motors) within an electro-chemical machining process (ECM). ECM is used to plate grooves on the moving or stationary elements of a fluid dynamic motor. The depth of these grooves has a tolerance of ±0.002-0.003 mm. Therefore the electrode/workpiece maching gap error must be no greater than this. In order to keep the counter plate cost to a relative low, the thickness of the plate has a large size tolerance, typically ±0.025 mm. This shift in plate thickness can alter the machining gap to a point where groove depth consistency is practically unattainable within the specification limits. In addition to the accuracy, the gap adjusting mechanism should be without parts movable while the process is being executed (the salt dissolved in the electrolytes will crystallize and hinder its movement) and be easy to manufacture. The salt dissolved in the electrolyte will crystallize and hinder its movement.
The present invention provides a solution to these and other problems, and offers other advantages over the prior art.
SUMMARY OF THE INVENTION
The present invention relates to a method and apparatus for properly and consistently spacing an electrode from a workpiece while electrochemically etching grooves in a surface of the workpiece to form a fluid dynamic bearing.
Other features and advantages of this invention will be apparent to a person of skill in this field who studies the following detailed description of an embodiment of the invention given in conjunction with the associated drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a disc drive in which a motor incorporating the hydrodynamic bearing whose grooves are formed using the present invention is especially useful.
FIG. 2A is a vertical section of the spindle motor of FIG. 1 .
FIGS. 2B and 2C are vertical and horizontal sectional views of a portion of the motor, especially the shaft and thrust plate, illustrating the grooves which may be formed utilizing the present invention.
FIG. 3 is a perspective view of the diaphragm workholding device of the present invention.
FIG. 4 is a cross section of the device of FIG. 3 shown with the diaphragm deflected.
FIG. 5 is a view along the same section line as FIG. 4 showing the device in its relaxed state with the air pressure removed.
FIG. 6A is a schematic view of the function of the present invention.
FIG. 6B is a vertical sectional view of a preferred embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Other features and advantages of this invention will be apparent to a person of skill in this field who studies the following detailed description of an FIG. 1 is an exploded perspective view a magnetic disc drive for which a spindle motor having a fluid dynamic bearing manufactured by the method and apparatus of the present invention is particularly useful. Referring to FIG. 1 , a disc drive 100 typically includes a housing 105 having a base 110 sealed to a cover 115 by a seal 120 . The disc drive 100 has a spindle 130 to which are attached a number of discs 135 having surfaces 140 covered with a magnetic media (not shown) for magnetically storing information. A spindle motor (not shown in this figure) rotates the discs 135 past read/write heads 145 which are suspended above surfaces 140 of the discs by a suspension arm assembly 150 . In operation, spindle motor rotates the discs 135 at high speed past the read/write heads 145 while the suspension arm assembly 150 moves and positions the read/write heads over one of a several radially spaced tracks (not shown). This allows the read/write heads 145 to read and write magnetically encoded information to the magnetic media on the surfaces 140 of the discs 135 at selected locations.
FIG. 2A is a sectional side view of a spindle motor 155 of a type which is useful in disc drives 100 . Typically the spindle motor 155 includes a rotatable hub 160 having one or more magnets 165 attached to a periphery thereof. The magnets 165 interact with a stator winding 170 attached to the base 110 to cause the hub 160 to rotate. The hub 160 is supported on a shaft 175 having a thrust plate 180 on an end. The thrust plate 180 can be an integral part of the shaft 175 , or it can be a separate piece which is attached to the shaft, for example, by a press fit. The shaft 175 and the thrust plate 180 fit into a sleeve 185 and a thrust plate cavity 190 in the hub 160 . A counter plate 195 is provided above the thrust plate 180 resting on an annular ring 205 that extends from the hub 160 . An O-ring 210 seals the counter plate 195 to the hub 160 .
A fluid, such as lubricating oil or a ferromagnetic fluid fills interfacial regions between the shaft 175 and the sleeve 185 , and between the thrust plate 180 and the thrust plate cavity 190 and the counter plate 195 . One or more of the thrust plate 180 , the thrust plate cavity 190 , the shaft 175 , the sleeve 185 , or the counter plate 195 have pressure generating grooves (not shown in this figure) formed in accordance with the present invention to create fluid dynamic bearings 220 , 225 . Preferably, grooves are formed in an outer surface 215 of the shaft 175 to facilitate inspection of the grooves. More preferably, the grooves in the outer surface 215 of the shaft 175 form one or more fluid dynamic journal bearings 225 having dynamic cushions that rotatably support the hub 160 in a radial direction.
FIGS. 2B and 2C are a vertical sectional view and top plan view, respectively, of a hub and sleeve combination illustrating the grooves which establish the hydrodynamic bearings used to support the sleeve and hub for rotation relative to shaft 175 . In accordance with design principles well known in this field, the sleeve 185 supports on its outer surface a hub 160 which in turn will support one or more discs (not shown) for rotation. The internal surface of the main bore of sleeve 185 includes a pair of sets of grooves 212 , 214 which in cooperation with the surface of the shaft and the intervening fluid (not shown) will form the journal bearings which are used to support the hub 160 for rotation about the shaft 175 .
Typically, such a design also includes a thrust plate supported on one end of the shaft (and shown 180 in FIG. 2 A). A recess 216 is provided for the thrust plate 180 ; a second recess 218 is provided for the counter plate 195 which overlies the thrust plate in the assembled motor and is used to define the hydrodynamic bearing gap with the upper surface of the thrust plate. The lower surface 219 of the counter plate 195 faces an axially outer surface 221 of the thrust plate 180 . Either the thrust plate 180 surface or the surface of the counter plate 195 also includes a set of grooves 222 ( FIG. 2B ) which in this case are in the shape of a succession of chevrons similar to the pattern shown in FIG. 20 and which cooperate with the outer surface 221 of the thrust plate 150 to create a pressure gradient which will support the thrust plate 180 and counter plate 195 for smooth relative rotation. This also prevents tilting of the hub 160 and sleeve 105 relative to the thrust plate 180 and the shaft 175 to which it is affixed so the hub 160 rotates with great stability relative to around the shaft 175 .
It is clear that because of the very small tolerances between the shaft and the thrust plate it supports and the internal surfaces of the sleeve, that the sleeve must be held with great stability in a jig of some sort while the ECM process is carried out; any variation in the gap between the sleeve and the electrode would cause a variation in the depth, spacing and placement of the grooves. As noted above, the fixture must be capable of holding the circular workpiece so that the depth of grooves will have a typical tolerance of ±0.003 millimeters.
To achieve these goals, the work holder or fixture of FIGS. 3 , 4 and 5 was designed, comprising a frame 300 which supports a diaphragm 302 having a plurality of jaw-like workholders 304 facing a common central axis 306 . As shown more clearly in FIG. 4 which should be considered in conjunction with FIG. 3 , as the diaphragm is deflected upward to assume a slightly more spheroidal shape, the jaws 304 are uniformly deflected away from the central axis 306 so that a circular or shaft based workpiece such as shown in FIGS. 2A and 2B can be inserted therein. As the air pressure is withdrawn, the deflected jaws 304 return to their original position as the diaphragm 302 flattens out, capturing the shaft or circular workpiece between the jaws. This operation is more readily apparent from the cross section of FIG. 4 which shows the diaphragm 302 relative to the backing plate 320 . As air is injected through the air inlet 322 , it can be seen that the diaphragm will deflect upwardly along the axis 306 with the upper part of each jaw leaning a little further away from the axis 306 than the lower part. This opening between the jaws 304 allows for the insertion of the shaft or circular workpiece. When the void between the diaphragm 302 and backing plate 320 is depressurized, the diaphragm will snap back to its original position, resting firmly against the backplate. The inner diameter of the generally circular work area defined by the jaws will be reduced, capturing the workpiece with a high level of precision accuracy. FIG. 5 shows these jaws returned to their original position.
So long as the air pressure does not exceed a predefined amount, the maximum bending moment of the diaphragm will not exceed the allowable, allowing substantial repeatability. Further, since the workpiece is consistently held in a repeatably reliable position, with its axial position being defined by the diaphragm, and its radial position accurately fixed by the jaws, an electrode can easily be inserted along the same axis 306 . With the electrode in place, the electrolyte can be applied, and electrical current applied to the system, carrying out the ECM process to form the desired grooves on the workpiece.
The present invention is particularly concerned with providing a work piece holder to be used in conjunction forming a groove pattern such as is shown in FIG. 20 on the surface of counter plate 195 which is to face thrust plate 180 in order to support the counter plate and thrust plate for relative rotation, it is apparent that the same device could be used to support the thrust plate 180 if forming the grooves on that surface is desired.
The invention resulted from the need to accurately locate the distance between a thrust surface type ECM electrode and a counter plate (circular disk used in fluid dynamic motors) within an electro-chemical machining process (ECM). ECM is used to define grooves on the moving or stationary elements of a fluid dynamic motor. The dept of these grooves has a tolerance of ±0.002 to 0.003 mm. Therefore the electrode/workpiece machining gap error must be no greater than this. In order to keep the counterplate cost to a relative low, the thickness of the counterplate or other part has a large size tolerance, typically ±0.025 mm. This shift in plate thickness can alter the machining gap to a point where groove depth consistency is unattainable within the specification limits. In addition to the accuracy, the gap adjusting mechanism preferably should have minimum moving parts and be easy to manufacture. The salt dissolved in the electrolyte will crystallize and hinder movement of moving parts.
Therefore, the present electrode, with a self-controlling machining gap has been designed. The electrode is designed to face the counter plate 195 across a gap 322 as shown schematically in FIG. 6 A. The electrode 310 is made primarily of an electrically conductive material so that the pulsed direct current from the source 320 will pass between the anodic work piece, which in this case is the counter plate 195 , and the cathodic electrode 310 through a conductive electrolyte generally shown at 320 which flows through the gap 322 between anode and cathode. At the anode surface of counter plate 195 , electrons are removed by current flow and the metallic bonds of the molecular structure at the surface are broken. These atoms go into solution with the electrolyte as metal ions and form metallic hydroxides. The MOH molecules are carried away to be filtered out. For this reason, ECM may also be known as “anodic dissolution”. A further element to be noted from FIG. 6A is that the surface 340 of electrode 310 comes the pattern to be formed on the surface of counterplate 195 . This pattern is defined by raised lands of electrically conductive material, usually separated and surrounded by insulating material of equal height. Electrically conductive lands in a pattern as shown at FIG. 2C would produce a pattern on the surface of counter plate 195 which comprises the workplace of that design. While primarily made of a conductive material, the center of the electrode is an electrically inert material such as ceramic 330 .
The electrode 310 shown schematically in FIG. 6A is shown in greater detail in the cross-section view of FIG. 6 B. As shown in this view, the electrode comprises an annular piece 410 of cylindrical cross-section, with a central rod 420 , typically circular in cross-section, which extends ( FIG. 6A 330 ) a short distance in FIG. 6A above the axially end surface 430 of the metallic electrode Thereby defining and establishing the gap spacing 300 . An inlet 440 for electrolyte is provided axially spaced away from the end surface 430 of the electrode, and a gap 445 is defined between the outer surface of the central rod 420 and the inner surface of the conductive cylinder 410 . The electrolyte flows through this gap to reach the axial outer end 430 of the electrode, and then flows radially away between the counter prate 195 which serves as the anode, and the cathodic electrode 430 . This electrolyte as it flows away can then be captured and filtered or simply replaced by fresh electrolyte through the orifice 440 .
As is apparent from both FIG. 6 B and FIG. 6A , the electrically inert center rod 420 is extended a small and very precise set distance above the electrode surface 430 . This sets the gap 350 which as explained above, is a key variable along with time and volume of current flow in establishing groove depth. That is, the center rod 420 establishes and maintains the machining gap in every ECM operation and thus the depth of the grooves formed in counter plate 195 .
Other features and advantages of this invention may be apparent to a person of skill in this art who studies the present invention disclosure. The electrode of this invention can be used to define grooves of a desired depth on any metal surface; it is especially useful to form grooves on a counterplate or similar metallic price adapted to be held by the diaphragm of FIGS. 4 and 5 . Therefore, the scope of the present invention is to be limited only by the following claims. | The present invention relates to a method and apparatus for properly and consistently spacing an electrode from a workpiece while electrochemically etching (ECM) grooves to a precise depth in a surface of the workpiece to form a fluid dynamic bearing. The electrode is especially designed for imparting a grooved pattern to a flat surface, the electrode comprising a surface carrying the pattern to be formed on the flat surface, and a central rod extending a short distance above the electrode surface. The central rod precisely sets the gap between the electrode and the flat surface. The electrode is adapted to be electrically connected to a power supply so that the electrode serves as the cathode, and the flat work piece serves as the anode in an ECM system. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part of U.S. Ser. No. 07/876,828 filed Apr. 30, 1992, and a continuation-in-part of U.S. Ser. No. 07/524,263 filed May 16, 1990, now abandoned. Said Ser. No. 07/876,828 is a continuation of Ser. No. 07/243,092 filed Sep. 12, 1988, now abandoned.
FIELD OF THE INVENTION
The present invention relates to the treatment of autoimmune diseases and graft-versus-host reactions with a Tumor Necrosis Factor (TNF) Binding Protein, herein designated TBP.
BACKGROUND OF THE INVENTION
Tumor Necrosis Factor (TNF) is a multifunctional cytokine involved in the protection of the organism, but when overproduced it can play a major pathogenic role in several diseases. TNF is known to be involved in inflammatory processes and to be a mediator of the damage to tissues in rheumatic diseases (Beutler, B. and Cerami, C. NEJM 316:379-385 (1987)) and of the damage observed in graft-versus-host reactions (Piguet, P. F. et al. J. Exp. Med. 166:1280-89 (1987)).
Two TNF Binding Proteins, designated TBP-I and TBP-II were described in U.S. patent application Ser. No. 07/243,092 filed Sep. 12, 1990 and 07/524,263, filed May 16, 1990, respectively, from the laboratory of the present inventors, and shown to protect cells from TNF toxicity and to interfere with the binding of TNF to cells. Later studies have shown that these two proteins are structurally related to two molecular species of the cell surface TNF receptors (TNF-R) and that, indeed, TBP-I is related to a soluble form of the TNF type I receptor, while TBP-II is related to a soluble form of the TNF type II receptor (Engelmann, H. et al. J. Biol. Chem. 264:11974-11980 (1989); Engelmann, H. et al. J. Biol. Chem. 265:1531-1536 (1990)). Like the cell surface receptors for TNF, the soluble forms of these receptors specifically bind TNF and can thus interfere with its binding to cells, functioning as physiological inhibitors of TNF activity. Although the primary function of the immune system is to protect an individual against infection by foreign invaders such as microorganisms, it may happen that the immune system attacks the individual's own tissues, leading to pathologic states known as autoimmune diseases, which are frequently associated with inflammatory processes. Examples of autoimmune diseases are rheumatoid arthritis, juvenile onset type I diabetes mellitus, systemic lupus erythematosus, thyroiditis and multiple sclerosis. Rheumatoid arthritis is a disease marked by signs and symptoms of inflammation of the joints. Systemic lupus erythematosus (SLE) is characterized by red, scaley patches on the skin, and by malfunction of the kidneys at the advanced stage of the disease, and is associated with inflammatory reactions triggered by deposition of immune complexes in blood vessels, particularly in the kidneys. Multiple sclerosis is a human illness characterized by relapsing, inflammatory conditions that can cause weakness, body tremors and, in extreme cases, paralysis, and is associated with immune system attack of the protective myelin sheath surrounding peripheral nerve cells.
TNF has been associated with inflammatory processes in systemic lupus erythematosus, rheumatoid arthritis and multiple sclerosis. In published European patent applications of the same assignee No. 398327 and 412486, it is disclosed that in SLE patients the serum levels of both TBP-I and TBP-II are significantly elevated and in correlation with the disease activity, indicating that TBP-I and TBP-II may be used as sensitive markers of the disease activity and may be useful in monitoring immune activation related to disease activity in SLE patients as well as in patients with other autoimmune diseases.
SUMMARY OF THE INVENTION
It has now been found, according to the present invention, that Tumor Necrosis Factor Binding Proteins are useful in the treatment of autoimmune diseases and graft-versus-host reactions. It is believed that the TBPs complement the physiological activity of the endogenous soluble TNF receptors, types I and II, whose formation in autoimmune diseases is suggested to constitute a safeguard mechanism against over-response to the damaging effects of TNF.
Accordingly, the present invention provides a method for the treatment of autoimmune diseases and graft-versus-host reactions in a patient, comprising administering to said patient an effective amount of Tumor Necrosis Factor Binding Protein, herein designated TBP, a salt, a functional derivative, a precursor or an active fraction thereof, or combinations of the foregoing.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The TBPs for use in the method of the present invention may be obtained from natural sources, such as human urine (Engelmann, H. et al. J. Biol. Chem. 264:11974-11980 (1989); Engelmann, H. et al. J. Biol. Chem. 265:1531-1536 (1990); Olson, I. et al., Eur. J. Haematol. 42:270-275 (1989); Seckinger, P. et al., J. Biol. Chem. 264:11966-11973 (1989)) or by recombinant techniques (Nophar, Y. et al., EMBO J. 3269-3278 (1990); Schall, T. J. et al., Cell 61:361-370 (1990); Loetscher, H. et al., Cell 61:351-35 (1990)) and then further purified as described in the above-mentioned U.S. patent applications Ser. Nos. 07/243,092 and 07/524,263.
As used herein, the terms "TBPs" "TBP-I" and "TBP-II" refer to all TNF Binding Proteins from natural sources or obtained by recombinant DNA techniques, including but not limited to the TNF Binding Proteins I and II described in U.S. patent application Ser. Nos. 07/243,092 and 07/524,263, as well as to the soluble forms of the cell surface TNF receptors types I and II, and salts, functional derivatives, precursors and active fractions of the foregoing, these last definitions being as defined in U.S. patent application Ser. Nos. 07/243,092 and 07/524,263, the entire contents of each of which are hereby incoporated herein by reference.
In a preferred embodiment, the protein used in the method of the present invention is one having an amino acid sequence substantially corresponding to that of the soluble TNF inhibitory protein of U.S. Ser. No. 07/243,092. The TNF inhibitory protein of U.S. Ser. No. 07/243,092 includes the amino acid sequence: Asp-Ser-Val-Cys-Pro-Gln-Gly-Lys-Tyr-Ile-His-Pro-Gln-X-Asn-Ser, SEQ ID NO: 1 wherein X is an unidentified amino acid residue, said protein having the ability to interact with TNF in such a manner as to (a) inhibit the binding of TNF to a TNF receptor and (b) inhibit the cytotoxic effect of TNF. The complete amino acid sequence for this protein is set forth in Nophar, Y. et al., EMBO J. 3269-3278 (1990).
In another preferred embodiment, the protein used in the method of the present invention is one having an amino acid sequence substantially corresponding to that of the soluble Tumor Necrosis Factor Binding Protein-II of U.S. Ser. No. 07/524,263. Sequence information for this protein is published in Kohno, T. et al., Proc. Natl. Acad. Sci. USA 87:8331-8335 (1990). See also Australian patent 58976/90.
Another preferred embodiment of the protein used in the method of the present invention is one which includes an amino acid sequence substantially corresponding to that of the binding site of the cell surface TNF receptors types I and II.
The terminology "substantially corresponding to" is intended to comprehend proteins with minor changes to the sequence of the natural protein which do not affect the basic characteristics of the natural protein insofar as its ability to bind to TNF is concerned and to thereby inhibit the binding of TNF to a natural TNF receptor in situ.
The term "pharmaceutically acceptable" is meant to encompass any carrier that does not interfere with the effectiveness of the biological activity of the active ingredient and that is not toxic to the host to which it is, administered. For example, for parenteral administration, the TBP may be formulated in a unit dosage form for injection in vehicles such as saline, dextrose solution, normal serum albumin and Ringer's solution. Any mode of parenteral administration may be suitable, including intravenous, intramuscular and subcutaneous administration. Local administration may be preferred, however, if local inflammation is to be treated, e.g., local injection to treat joint inflammation in rheumatoid arthritis, or injection into the cerebrospinal fluid in multiple sclerosis. Besides the pharmaceutically acceptable carrier, the compositions of the invention will also comprise minor amounts of additives, such as stabilizers, excipients, buffers and preservatives.
The term "effective amount" refers to an amount of TBP that is sufficient to affect the course and severity of the autoimmune disease and to improve the patient's condition, leading to reduction or remission of the disease. The effective amount will depend on the route of administration, the disease to be treated and the condition of the patient, but is expected to be within the range of 1 μg-1 g/person/treatment. Determination of the level of TBP-I and TBP-II in the serum or other suitable body fluid of the patient, may help to establish a suitable dose for said patient, considering that the exogenously administered TBP may complement the endogenously formed TBP in neutralizing the TNF deleterious activity.
The invention will be illustrated by the following examples. In some of the examples, animal models of experimental autoimmune diseases are employed (Cohen, I. R. J. Invest. Dermatol. 85:34s-38s (1985)).
EXAMPLE 1
Treatment of Adjuvant Arthritis in Rats
Adjuvant arthritis is an experimental disease characterized by chronic inflammation of the joints, inducible in certain strains of rats by immunization with complete Freund's adjuvant or with fractions of Mycobacterium tuberculosis, and is considered to be a model of human rheumatoid arthritis (Pearson, C. M. Arthritis Rheum. 7:80-86 (1964)). The disease appears about 11-12 days after immunization, and is characterized by mononuclear cell infiltration of the synovia, most prominent in the small joints of the extremities, with panus formation, a process that may progress for months resulting in destruction of bones and ankylosis of joints. Lewis rats are immunized with M. tuberculosis (1 mg) in oil to induce adjuvant arthritis (Pearson, C. M. Proc. Soc. Exp. Biol. Med. 91:95-101 (1956)). Some days later, before or after the onset of overt clinical arthritis, the rats are inoculated subcutaneously with different doses of TBP-I or TBP-II once or daily for several days, and then scored for the development of arthritis on a scale of 0-16 as described (Holoshitz, Y. et al., Science 219:56-58 (1983). Doses that inhibit the appearance or produce a partial inhibition of disease are effective doses. Optimal doses are those administered after onset of the disease that suppress the course and cause a permanent remission of the disease. Suitable doses for human patients can be calculated from these doses. The above-described experiment may readily be carried out by persons of ordinary skill in this art without undue experimentation to determine specific numbers for the optimal doses and suitable human doses.
EXAMPLE 2
Treatment of Experimental Autoimmune Encephalomyelitis (EAE) in Rats
Experimental autoimmune encephalomyelitis (EAE) is an experimental disease inducible in a variety of species: rats, guinea pigs, mice, rabbits, etc., by immunization with white matter of the central nervous system or with the basic protein of myelin or a fragment thereof. It is considered to be a model of multiple sclerosis and, similar to this neurological human disorder, EAE is an autoimmune disorder in which the immune system attacks the protective myelin sheath surrounding peripheral nerve cells. The disease is characterized clinically by acute paralysis and histologically by mononuclear cell infiltrates around blood vessels in the white matter of the central nervous system (Cohen, I. R., supra). Rats are injected with guinea-pig BP or the major encephalitogenic fragment of BP (amino acids 68-88) in a suitable adjuvant such as complete Freund's adjuvant to induce EAE. One day before inoculation and daily for ten days, the rats receive either saline (control) or different doses of TBP-I or TBP-II. The rats are observed for development of paralysis. Doses inhibiting the severity of disease are to be considered effective doses. Suitable doses for human patients can be calculated from these doses. The above-described experiment may readily be carried out by persons of ordinary skill in this art without undue experimentation to determine specific numbers for the optimal doses and suitable human doses.
EXAMPLE 3
Correlation Between Serum Levels of TBP-I and TBP-II and Anti-dsDNA Antibodies in SLE Patients
The levels of TBP-I and TBP-II were determined in the sera of 38 SLE patients and 140 healthy controls by the ELISA method described in published European patent Applications No. 398327 and 412486. The serum concentrations (mean±SD) of TBP-I and TBP-II in the control group were 0.77±0.19 ng/ml and 3.02±0.57 ng/ml, respectively. These values were independent of age and sex. In the SLE patients, significantly higher Concentrations of TBP-I and TBP-II were observed. The mean ±SD concentrations were for TBP-I 1.89±0.89 ng/ml and for TBP-II 7.25±3.89 ng/ml.
The results were compared to the levels of anti-dsDNA antibodies, a parameter considered as a reliable and sensitive indicator of the SLE disease activity. Close examination of the extent of the correlation of the TBPs with the anti-dsDNA antibodies in individual patients revealed 3 distinctive subgroups of patients, as shown in Table 1:
Group 1--Patients with normal levels of anti-dsDNA antibodies and normal concentrations of TBP-I (9 patients) or TBP-II (11 patients).
Group 2--Patients with normal levels of anti-dsDNA antibodies but elevated concentrations of TBP-I (18 patients) or TBP-II (16 patients).
Group 3--Patients with elevation of all three parameters (11 patients).
Although both groups 2 and 3 exhibited increased TBP levels, they differed significantly not only by the extent of increase in antibodies to dsDNA, but also in other parameters of disease activity (Table I). Compared to group 2, group 3 had higher mean disease index (1.7±0.6 vs 2.4±0.8,p<0.02), lower complement C4 levels (9.4±4 vs 30±13 mg/dl, p<0.001) and a higher mean prednisone intake (20.7±17.7 vs 9±9 mg/day, p<0.05).
The enhanced formation of TBP-I and TBP-II, which correspond to the soluble TNF receptors type I and type II, respectively, may constitute an antagonistic mechanism of the organism to antagonize the TNF's damaging effects in the autoimmune diseases. The detection of a sub-group of SLE patients in this study, in which there is significant elevation of the TBPs, yet only marginal increase in disease activity, is consistent with the notion that the TBPs can attenuate progression of this disease and an indication that the TBPs can be used as therapeutic agents in SLE.
EXAMPLE 4
Bioactivity of TBPs in the Sera of SLE Patients--Inhibition of TNF Cytotoxicity
In order to evaluate the bioactivity of the serum TBPs, serum samples were tested by a TNF cytotoxicity assay. The cytocidal activity of TNF was determined using murine A9 cells as targets. The cells were seeded in 96-well microplates at a density of 20,000 cells/well. After 24 hours, the supernatants were decanted. The cells were placed on ice and rhuTNF (5 units/ml, 6×10 7 units/mg protein) was applied alone or together with serum samples with or without added antibodies to the TBPs (described in published European patent applications 398327 and 412486) or with samples of purified TBPs isolated from human urine. After additional incubation on ice for 90 minutes, the samples were decanted and the plates rinsed twice with cold medium at this was followed by addition of Dulbecco's Modified Eagle's Minimal Essential Medium (DMEM) containing 10% fetal calf serum and 25 mg/ml cycloheximide. Cell viability was determined 12 hours later by the neutral red uptake assay.
Serum examples of SLE patients were tested by the above assay and were shown to protect A9 cells from the cytocidal effect of TNF. The extent of inhibition correlated with that observed upon application of the purified TBPs from urine in amounts identical to those present in the sera. Rabbit antisera to the TBPs, which by themselves had no effect on the A9 cytotoxicity assay, blocked the inhibitory effect of the human sera on this assay, thus confirming the assumption that the inhibition of TNF bioactivity observed, was solely due to the bioactivity of the TBPs present in the sera. This indicates that the TBPs may be effective in neutralizing the bioactivity of TBF in vivo, being capable of protecting patients from damages caused by TNF in autoimmune diseases.
TABLE 1______________________________________GROUP 1 2 3TBP Normal Range High HighAnti-dsDNA Ab Normal Range Normal Range High______________________________________TBP-INo. of Patients 9 18 11TBP-I (ng/ml) 0.94 ± 0.14 2.15 ± 0.89 2.17 ± 0.86Anti-dsDNA Ab 10.2 ± 6.62 5.58 ± 6.04 53 ± 25Disease Index 1.33 ± 0.5 1.64 ± 0.6 2.42 ± 0.82Prednison intake 0 9 ± 9 20.7 ± 17.9(mg/day)Complement C3 -- 126 ± 34 67 ± 36Complement C4 -- 30 ± 13.2 9 ± 4.6TBP-IINo. of Patients 11 16 11TBP-II (ng/ml) 3.54 ± 0.75 8.06 ± 1.98 8.57 ± 2.61Anti-dsDNA Ab 10.2 ± 7 5.3 ± 5.9 51 ± 25%Disease Index 1.18 ± 0.4 1.78 ± 0.57 2.41 ± 0.79Prednison intake 0 7.6 ± 9.5 20.7 ± 18.8(mg/day)Complement C3 -- 124.8 ± 32 67 ± 36Complement C4 -- 32.5 ± 12.6 9 ± 4______________________________________
All references cited herein, including journal articles or abstracts, published or corresponding U.S. or foreign patent applications, issued U.S. or foreign patents, or any other references, are entirely incorporated by reference herein, including all data, tables, figures, and text presented in the cited references. Additionally, the contents of the references cited within the references cited herein are also entirely incorporated by reference.
Reference to known method steps, conventional method steps, known methods or conventional methods is not in any way an admission that any aspect, description or embodiment of the present invention is disclosed, taught or suggested in the relevant art.
The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying knowledge within the skill of the art (including the contents of the references cited herein), readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the generic concept of the present invention. Therefore, such adaptations and modifications are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or Phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance Presented herein.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 1(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 16 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(iii) HYPOTHETICAL: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:AspSerValCysProGlnGlyLysTyrIleHisProGlnXaaAsnSer151015 | Tumor Necrosis Factor Binding Proteins (TBPs) are useful in the treatment of autoimmune diseases and graft-versus-host reactions. | 2 |
FIELD OF THE INVENTION
The invention relates to carbon fibers, processes of preparing the carbon fibers and the use of the carbon fibers in various applications.
BACKGROUND OF THE INVENTION
Carbon fibers are generally defined as a fiber containing at least about 92 wt-% of carbon. Carbon fibers containing 99 wt-% or more of carbon are often referred to as graphite fibers. Carbon fibers (CFs) are used in various applications owing to their excellent tensile properties, thermal and chemical stabilities (in absence of oxidizing agents) and thermal and electrical conductivities. The conventional applications of CFs include aircraft frames, turbine blades, automobile panels, sporting goods and industrial components.
Currently, the carbon fiber market is dominated by carbon fiber derived from polyacrylonitrile (PAN), with the balance being made up of fibers from pitch and rayon. CFs with distinct properties result from the processing of different precursor fibers. In a typical process in the art for converting organic polymer fibers into carbon fibers, the organic polymer fiber is first heat-stabilized in air in an oxidation process conducted at a temperature of 200 to 400° C. The thus stabilized precursor fibers then undergo controlled pyrolysis, i.e., a carbonization step, comprising heat-treating in an inert atmosphere such as nitrogen to a temperature of from about 300° C. to about 3000° C., which removes non-carbon elements such as hydrogen, oxygen and nitrogen from the oxidized fiber. It is known in the art that heating at the higher end of the temperature spectrum, e.g., between about 1000° C. and about 3000° C. may achieve higher carbon content, thereby producing CFs with higher Young's modulus values.
For automotive applications, desired mechanical properties for carbon fibers include tensile strength of >1.72 GPa, tensile modulus of >172 GPa and elongation at break of about 1%.
In addition to the limited mechanical properties of conventional CFs, the currently used methods of preparing CFs can be costly. For example, the cost of the precursor fiber amounts to approximately 40% to 50% of the total cost of preparing the carbon fiber. Therefore, there is a need in the art for lower cost precursor fibers that yield carbon fibers of excellent quality would significantly reduce the cost of CFs. An additional benefit would be to enable the expansion of CF applications to industries and markets such as those related to the automotive industry.
Furthermore, it is desirable to provide a source of carbon fibers that derives from a renewable source that does not contribute to global warming.
Polysaccharides have been known since the dawn of civilization, primarily in the form of cellulose, a polymer formed from glucose by natural processes via β(1→4) glycoside linkages; see, for example, Applied Fibre Science , F. Happey, Ed., Chapter 8, E. Atkins, Academic Press, New York, 1979. Numerous other polysaccharide polymers are also disclosed therein.
Only cellulose among the many known polysaccharides has achieved commercial prominence as a fiber. In particular, cotton, a highly pure form of naturally occurring cellulose, is well-known for its beneficial attributes in textile applications.
It is further known that cellulose exhibits sufficient chain extension and backbone rigidity in solution to form liquid crystalline solutions; see, for example O'Brien, U.S. Pat. No. 4,501,886. The teachings of the art suggest that sufficient polysaccharide chain extension could be achieved only in β(1→4) linked polysaccharides and that any significant deviation from that backbone geometry would lower the molecular aspect ratio below that required for the formation of an ordered phase.
More recently, glucan polymer, characterized by α(1→3) glycoside linkages, has been isolated by contacting an aqueous solution of sucrose with GtfJ glucosyltransferase isolated from Streptococcus salivarius , Simpson et al., Microbiology, vol 141, pp. 1451-1460 (1995). Highly crystalline, highly oriented, low molecular weight films of α(1→3)-D-glucan have been fabricated for the purposes of x-ray diffraction analysis, Ogawa et al., Fiber Diffraction Methods, 47, pp. 353-362 (1980). In Ogawa, the insoluble glucan polymer is acetylated, the acetylated glucan dissolved to form a 5% solution in chloroform and the solution cast into a film. The film is then subjected to stretching in glycerine at 150° C. which orients the film and stretches it to a length 6.5 times the original length of the solution cast film. After stretching, the film is deacetylated and crystallized by annealing in superheated water at 140° C. in a pressure vessel. It is well-known in the art that exposure of polysaccharides to such a hot aqueous environment results in chain cleavage and loss of molecular weight, with concomitant degradation of mechanical properties.
Polysaccharides based on glucose and glucose itself are particularly important because of their prominent role in photosynthesis and metabolic processes. Cellulose and starch, both based on molecular chains of polyanhydroglucose are the most abundant polymers on earth and are of great commercial importance. Such polymers offer materials that are environmentally benign throughout their entire life cycle and are constructed from renewable energy and raw materials sources.
The term “glucan” is a term of art that refers to a polysaccharide comprising beta-D-glucose monomer units that are linked in eight possible ways, Cellulose is a glucan.
Within a glucan polymer, the repeating monomeric units can be linked in a variety of configurations following an enchainment pattern. The nature of the enchainment pattern depends, in part, on how the ring closes when an aldohexose ring closes to form a hemiacetal. The open chain form of glucose (an aldohexose) has four asymmetric centers (see below). Hence there are 2 4 or 16 possible open chain forms of which D and L glucose are two. When the ring is closed, a new asymmetric center is created at C1 thus making 5 asymmetric carbons. Depending on how the ring closes, for glucose, α(1→4)-linked polymer, e.g. starch, or β(1→4)-linked polymer, e.g. cellulose, can be formed upon further condensation to polymer. The configuration at C1 in the polymer determines whether it is an alpha or beta linked polymer, and the numbers in parenthesis following alpha or beta refer to the carbon atoms through which enchainment takes place.
The properties exhibited by a glucan polymer are determined by the enchainment pattern. For example, the very different properties of cellulose and starch are determined by the respective nature of their enchainment patterns. Starch or amylose consists of α(1→4) linked glucose and does not form fibers among other things because it is swollen or dissolved by water. On the other hand, cellulose consists of β(1→4) linked glucose, and makes an excellent structural material being both crystalline and hydrophobic, and is commonly used for textile applications as cotton fiber, as well as for structures in the form of wood.
Like other natural fibers, cotton has evolved under constraints wherein the polysaccharide structure and physical properties have not been optimized for textile uses. In particular, cotton fiber is of short fiber length, limited variation in cross section and fiber fineness and is produced in a highly labor and land intensive process.
O'Brien, U.S. Pat. No. 7,000,000 discloses a process for preparing fiber from liquid crystalline solutions of acetylated poly(α(1→3) glucan). The thus prepared fiber was then de-acetylated resulting in a fiber of poly(α(1→3) glucan).
The inventive method described herein, results in carbon fibers meeting these desired mechanical benchmarks and would further reduce the costs making CFs available to additional industrial sectors.
SUMMARY OF THE INVENTION
A process comprising
subjecting one or more filaments of poly(α(1→3) glucan) to a tension below the breaking strength of the one or more filaments at 350° C.; subjecting the thus tensioned one or more filaments to a first thermal exposure by heating said one or more filaments to a temperature in the range of 160 to 200° C. in air for a duration in the range of 5 to 15 minutes; subjecting the thus heated one or more filaments to a second thermal exposure by further heating said one or more filaments at a heating rate, still under tension, from a first temperature in the range of 200 to 250° C. to a second temperature in the range of 300 to 350° C., said heating rate being in the range of 0.1 to 1° C. per minute, thereby preparing one or more thermally stabilized filaments; subjecting said one or more stabilized filaments in a zero tension state to a third thermal exposure by heating said one or stabilized filaments to a temperature in the range of 700 to 1500° C. in an inert atmosphere for a duration in the range of 0.5 to 5 minutes, thereby preparing one or more carbonized filaments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a side view of the fiber spinning apparatus employed in the specific embodiments hereof.
FIG. 2 depicts a side view of the tube furnace arrangement used in the thermal stabilization step of the process hereof as executed in the specific embodiments thereof.
FIG. 3 depicts a side view of the carbonization apparatus used in the specific embodiments hereof.
FIG. 4A depicts a top view, and FIG. 4B depicts a front view of the winding frame used to prepare the filament skeins employed in the specific embodiments hereof.
DETAILED DESCRIPTION OF THE INVENTION
When a range of values is provided herein, it is intended to encompass the end-points of the range unless specifically stated otherwise. Numerical values used herein have the precision of the number of significant figures provided, following the standard protocol in chemistry for significant figures as outlined in ASTM E29-08 Section 6. For example, the number 40 encompasses a range from 35.0 to 44.9, whereas the number 40.0 encompasses a range from 39.50 to 40.49.
As used herein, the term “filament” encompasses a thread-shaped compact unit comprising one or more molecules of a polymer comprising poly(α(1→3) glucan). The filament can further comprise additional polymers added, for example, order to control the morphology of the carbon fiber produced according to the process hereof. Such additives as are commonly employed in the art of carbon fiber production to enhance the properties or processing of organic polymers undergoing solution spinning and subsequent carbonization can also be included.
In the present invention, the term “fiber” and the term “filament” are used interchangeably. The present invention is directed to the preparation of high strength, high modulus carbon fibers from a fiber precursor comprising poly(α(1→3) glucan). Suitable poly(α(1→3) glucan) fibers are in the form of continuous filaments. Staple fibers are not well suited for the practice of the present invention.
According to the present invention a process is provided for the preparation of carbon fiber from a precursor fiber comprising poly(α(1→3) glucan), the process comprising
subjecting one or more filaments comprising poly(α(1→3) glucan) to a tension below the breaking strength of the one or more filaments at 350° C.; subjecting the thus tensioned one or more filaments to a first thermal exposure by heating said one or more filaments to a temperature in the range of 160 to 200° C. in air for a duration in the range of 5 to 15 minutes; subjecting the thus heated one or more filaments to a second thermal exposure by further heating said one or more filaments at a heating rate, still under tension, from a first temperature in the range of 200 to 250° C. to a second temperature in the range of 300 to 350° C., said heating rate being in the range of 0.1 to 1° C. per minute, thereby preparing one or more thermally stabilized filaments; subjecting said one or more stabilized filaments in a zero tension state to a third thermal exposure by heating said one or stabilized filaments to a temperature in the range of 700 to 1500° C. in an inert atmosphere for a duration in the range of 0.5 to 5 minutes, thereby preparing one or more carbonized filaments.
One benefit of the present invention over the known art is that the carbon fiber resulting from the process hereof is a “green” product—that is, it is biologically sourced because the poly(α(1→3) glucan) upon which it is based is produced by fermentation, and not from petroleum.
If the first thermal exposure is conducted at a temperature below 160° C., it may be ineffective. If the first thermal exposure is conducted at a temperature above 200° C., it can cause water molecules trapped within fiber pores to evaporate too quickly and rupture the fiber, causing points of weakness where the fiber can break. The duration of exposure less than 5 minutes is not highly effective. An exposure of greater than 15 minutes is not deleterious, but is unnecessary. In one embodiment of the process hereof, the first thermal exposure is effected at a temperature in the range of 175 to 185° C. for a duration of 7.5 to 12.5 minutes.
Thermal stabilization of the poly(α(1→3) glucan) fiber is effected in a second thermal exposure, which involves heating from a first temperature in the range 200 to 250° C., preferably 230 to 250° C., to a second temperature in the range of 300 to 350° C., preferably 310 to 330° C. At a temperature below 200° C., thermal stabilization does not occur or occurs at a rate that is impractically slow. At a temperature above 350° C., the fiber can melt and break.
In one embodiment of the process hereof, said second thermal exposure is effected in a series of well-defined steps between the first temperature and the second temperature, with a hold period between steps, and a heating rate from step to step in excess of 10° C. per minute.
The first and second thermal exposures are conducted in air or an oxygen containing atmosphere. If the first and second thermal exposures are conducted in an oxygen containing atmosphere other than air, the same sequence of steps will still be operative, but will be modified in detail to accommodate the atmosphere in question.
The third thermal exposure, the carbonization step, is effected in an inert environment. Any inert environment is satisfactory. A heavy nitrogen purge, as described in the specific embodiments infra, has been found to be satisfactory. The third thermal exposure is conducted in the temperature range of 700 to 1500° C., preferably 800 to 1000° C. At a temperature below 700° C., the necessary level of pyrolysis and carbonization does not occur. At temperatures above 1500° C., the resulting carbon fiber can undergo such deleterious changes as loss of integrity, melting and others.
When the third thermal exposure is conducted for a period of time less than 0.5 minutes, insufficient carbonization takes place. For a period of time more than 5 minutes, the resulting carbon fiber may undergo deleterious changes, particularly in the higher range of carbonization temperatures. In one embodiment, the third thermal exposure is effected in the temperature range of 800 to 1000° C. for a period of time of 1 to 2 minutes.
The resulting carbon fiber is strong, very stiff, and tough.
The invention is further described in, but not limited by, the following specific embodiments.
Examples
Materials
MATERIAL
Description
Vendor
Dialysis
Spectrapor 25225-226, 12000
VWR (Radnor, PA).
tubing
molecular weight cut-off
Sucrose
15 wt-% solids aqueous solution
VWR.
(#BDH8029)
Dextran
T-10 (#D9260)
Sigma Aldrich.
Ethanol
Undenatured (#459844)
Sigma Aldrich
Antifoam
Suppressor 7153
Cognis Corporation
(Cincinnati, OH).
All other chemicals were obtained from commonly used suppliers of such chemicals.
Preparation of Glucosyltransferase (gtfJ) Enzyme
Seed Medium
The seed medium, used to grow the starter cultures for the fermenters, contained: yeast extract (Amberex 695, 5.0 grams per liter, g/L), K 2 HPO 4 (10.0 g/L), KH 2 PO 4 (7.0 g/L), sodium citrate dihydrate (1.0 g/L), (NH 4 ) 2 50 4 (4.0 g/L), MgSO 4 heptahydrate (1.0 g/L) and ferric ammonium citrate (0.10 g/L). The pH of the medium was adjusted to 6.8 using either 5N NaOH or H 2 SO 4 and the medium was sterilized in the flask. Post sterilization additions included glucose (20 mL/L of a 50% w/w solution) and ampicillin (4 mL/L of a 25 mg/mL stock solution).
Fermenter Medium
The growth medium used in the fermenter contained: KH 2 PO 4 (3.50 g/L), FeSO 4 heptahydrate (0.05 g/L), MgSO 4 heptahydrate (2.0 g/L), sodium citrate dihydrate (1.90 g/L), yeast extract (Amberex 695, 5.0 g/L), Suppressor 7153 antifoam (0.25 milliliters per liter, mL/L), NaCl (1.0 g/L), CaCl 2 dihydrate (10 g/L), and NIT trace elements solution (10 mL/L). The NIT trace elements solution contained citric acid monohydrate (10 g/L), MnSO 4 hydrate (2 g/L), NaCl (2 g/L), FeSO 4 heptahydrate (0.5 g/L), ZnSO 4 heptahydrate (0.2 g/L), CuSO 4 pentahydrate (0.02 g/L) and NaMoO 4 dihydrate (0.02 g/L). Post sterilization additions included glucose (12.5 g/L of a 50% w/w solution) and ampicillin (4 mL/L of a 25 mg/mL stock solution).
Construction of Glucosyltransferase (gtfJ) Enzyme Expression Strain
A gene encoding the mature glucosyltransferase enzyme (gtfJ; EC 2.4.1.5; GENBANK® AAA26896.1, SEQ ID NO: 3) from Streptococcus salivarius (ATCC 25975) was synthesized using codons optimized for expression in E. coli (DNA 2.0, Menlo Park Calif.). The nucleic acid product (SEQ ID NO: 1) was subcloned into pJexpress404® (DNA 2.0, Menlo Park Calif.) to generate the plasmid identified as pMP52 (SEQ ID NO: 2). The plasmid pMP52 was used to transform E. coli MG1655 (ATCC47076™) to generate the strain identified as MG1655/pMP52. All procedures used for construction of the glucosyltransferase enzyme expression strain are well known in the art and can be performed by individuals skilled in the relevant art without undue experimentation.
Production of Recombinant gtfJ in Fermentation
Production of the recombinant gtfJ enzyme in a fermenter was initiated by preparing a pre-seed culture of the E. coli strain MG1655/pMP52, expressing the gtfJ enzyme, constructed as described infra. A 10 mL aliquot of the seed medium was added into a 125 mL disposable baffled flask and was inoculated with a 1.0 mL culture of E. coli MG1655/pMP52 in 20% glycerol. This culture was allowed to grow at 37° C. while shaking at 300 revolutions per minute (rpm) for 3 hours.
A seed culture, for starting the fermenter, was prepared by charging a 2 L shake flask with 0.5 L of the seed medium. 1.0 mL of the pre-seed culture was aseptically transferred into 0.5 L seed medium in the flask and cultivated at 37° C. and 300 rpm for 5 hours. The seed culture was transferred at optical density 550 nm (OD 550 )>2 to a 14 L fermenter (Braun, Perth Amboy, N.J.) containing 8 L of the fermenter medium described above at 37° C.
Cells of E. coli MG1655/pMP52 were allowed to grow in the fermenter and glucose feed (50% w/w glucose solution containing 1% w/w MgSO 4 .7H 2 O) was initiated when glucose concentration in the medium decreased to 0.5 g/L. The feed was started at 0.36 grams feed per minute (g feed/min) and increased progressively each hour to 0.42, 0.49, 0.57, 0.66, 0.77, 0.90, 1.04, 1.21, 1.41 1.63, 1.92, 2.2 g feed/min respectively. The rate was held constant afterwards by decreasing or temporarily stopping the glucose feed when glucose concentration exceeded 0.1 g/L. Glucose concentration in the medium was monitored using a YSI glucose analyzer (YSI, Yellow Springs, Ohio).
Induction of glucosyltransferase enzyme activity was initiated, when cells reached an OD 550 of 70, with the addition of 9 mL of 0.5 M IPTG (isopropyl β-D-1-thiogalacto-pyranoside). The dissolved oxygen (DO) concentration was controlled at 25% of air saturation. The DO was controlled first by impeller agitation rate (400 to 1200 rpm) and later by aeration rate (2 to 10 standard liters per minute, slpm). The pH was controlled at 6.8. NH 4 OH (14.5% weight/volume, w/v) and H 2 SO 4 (20% w/v) were used for pH control. The back pressure was maintained at 0.5 bars. At various intervals (20, 25 and 30 hours), 5 mL of Suppressor 7153 antifoam was added into the fermenter to suppress foaming. Cells were harvested by centrifugation 8 hours post IPTG addition and were stored at −80° C. as a cell paste.
Preparation of gtfJ Crude Enzyme Extract from Cell Paste
The cell paste obtained above was suspended at 150 g/L in 50 mM potassium phosphate buffer pH 7.2 to prepare a slurry. The slurry was homogenized at 12,000 psi (Rannie-type machine, APV-1000 or APV 16.56) and the homogenate chilled to 4° C. With moderately vigorous stirring, 50 g of a floc solution (Aldrich no. 409138, 5% in 50 mM sodium phosphate buffer pH 7.0) was added per liter of cell homogenate. Agitation was reduced to light stirring for 15 minutes. The cell homogenate was then clarified by centrifugation at 4500 rpm for 3 hours at 5-10° C. Supernatant, containing crude gtfJ enzyme extract, was concentrated (approximately 5×) with a 30 kilo Dalton (kDa) cut-off membrane. The concentration of protein in the gftJ enzyme solution was determined by the bicinchoninic acid (BCA) protein assay (Sigma Aldrich) to be 4-8 g/L.
Enzymatic Synthesis of Poly(α(1→3) Glucan)
Several batches of poly(α(1→3) glucan) polymer were prepared by combining the materials listed in Table 1 in the amounts shown. The pH was adjusted to pH 6.8-7.0 by addition of 10% KOH. De-ionized water was then added to bring the volume up to level specified in Table 1. The buffer concentration in the thus prepared solution was 50 mM.
The thus prepared pH-adjusted solution was then charged with the enzyme extract prepared supra in an amount sufficient to bring the enzyme concentration to 0.30% by weight in each batch. Each thus prepared reaction mixture was then allowed to stand at ambient temperature for 144 hours. The resulting poly(α(1→3) glucan) solids were collected on a Buchner funnel using a 325 mesh screen over 40 micron filter paper. The filter cake was re-suspended in deionized water and filtered twice more as above to remove sucrose, fructose and other low molecular weight, soluble by-products. Finally two additional washes with methanol were carried out, the filter cake was pressed out thoroughly on the funnel and dried in vacuum at room temperature, yielding a white flaky solid in the amounts shown in Table 1.
TABLE 1 Batch KH2PO4 Batch size Sucrose Dextran Buffer Ethanol Number (L) (g) T-10 (g) (mL) (mL) Yield 1 20 1000 4.0 1000 0 120.0 2 20 1000 4.0 1000 0 114.5 3 20 1000 4.0 1000 0 113.0 4 20 1000 4.0 1000 0 86.0 5 3 450 2.4 150 150 47.3 6 3 450 3.0 150 300 32.1 7 3 450 6.0 150 300 49.0 8 3 450 9.0 150 300 56.6
Preparation of 1,3 Alpha Glucan Triacetate
The several batches of poly(α(1→3) glucan) as shown in Table 1 were combined in the amounts shown, respectively, in Table 2 to make three 130 g blends for subsequent acetylation.
The blends were boiled for one hour in deionized water. Each thus boiled blend was then added to a mixture containing 890 mL of methylene chloride, 600 mL of acetic acid and 870 mL of acetic anhydride in a 4 L reaction kettle provided with a nitrogen blanket. Mixing was effected with an egg beater style mixing blade that covered the entire depth of the liquid. The resulting mixture was then cooled to approximately −5° C. Separately, a catalyst mixture was prepared by addition of 9 mL of 70% aqueous perchloric acid to 370 mL of chilled acetic anhydride. The catalyst mixture was then added dropwise to the rapidly stirred reaction mixture at −5° C. Subsequent to catalyst addition, the reaction kettle was immersed in a hot water bath contained in a 2 gallon plastic bucket, and heated to 30° C. When the temperature of the reactants was observed to exceed 32° C., the reaction kettle was removed from the hot water bath and suspended in the air until the reaction temperature was observed to reach 27° C. at which point the reaction kettle was again immersed in the hot water bath. This procedure was continued for a period of 2-4 hours until reaction was complete. The reaction was deemed to be complete when no particulate matter was observed by visual inspection of the translucent reaction mixture.
In small aliquots, the mixture was coagulated in methanol in a Waring blender, the resultant suspension was filtered, washed with methanol twice more, water washed until neutral pH was obtained, and then washed with methanol and dried under vacuum. Yield of the resulting triacetate is shown in Table 2
TABLE 2 Blend Polymer Batches Wt. (g) Triacetate Yield (g) 1 1/2 30/100 190.4 2 3/4 43.7/86.3 204.6 3 5/6/7/8 25/20/40/45 207.94
Spinning Solution
Spinning solutions A and B were prepared from the thus prepared acetylated poly(α(1→3) glucan). 100 parts by weight of trifluoroacetic acid were diluted with 8 parts by weight of water. The thus prepared solution was added to two 1-quart zip-lock bags, each containing 120 g of the respective acetylate poly(α(1→3) glucan) blends, as indicated in Table 3, in an amount sufficient to prepare a 37.5% solids solution in each case. Each bag was then sealed, and was subject to hand kneading to homogenize. The bag was allowed to stand at ambient conditions overnight. In order to dissolve the polymer therein, the mixture of polymer and solvent was first stirred by hand using a stainless steel spatula in order to homogenize the mixture. The homogenized mixture was then pumped back and forth through 13 cycles between two syringes connected by a short length of 3 mm ID stainless steel tubing.
TABLE 3 Spinning Glucan Triacetate Blend Solution # Weight (g) A 1 94 2 26 B 3 120
Fiber Spinning of Glucan Triacetate
The thus prepared spinning solutions were solution-spun into continuous filaments using the spinning apparatus depicted in FIG. 1 . The spinning solution was charged to the cell ( 13 ) that was provided with a piston ( 11 ) connected to ram ( 12 ) which pushed solution through a spin pack containing a screen pack ( 14 ) provided with stainless steel support screens including 100 mesh support screen and a 325 mesh filter screen, and a 20-hole spinneret ( 15 ). Each spinneret hole was characterized by a diameter of 0.005 in. and a length to diameter ratio of 6. The piston ( 11 ) was driven by a drive screw (not shown) that drove the ram at a metered rate. The filaments ( 16 ) emerging from the spinneret ( 15 ) were directed into a coagulation bath ( 17 ) consisting of 100% methanol. The fiber was passed around Teflon guide pins ( 18 ) within the coagulation bath and exiting the bath to a traverse ( 19 ) with a guide pin ( 110 ) distributing the fiber evenly across a width to a windup ( 111 ) where the fiber is collected on a bobbin. The bobbins so prepared were soaked overnight in methanol. Spinning conditions are provided in Table 4. The yarns so produced are herein designated GYA-1 and GYA-2.
TABLE 4 Spin- Jet Wind ning Veloc- Bath Bath Air up Spin Solu- ity Temp length Gap speed Stretch tion (fpm) (° C.) (ft) (in) (fpm) Factor GYA-1 A 17 −1 11.8 0.3 52 3.1 GYA-2 B 22 −19 11.8 0.75 60 2.7
Saponification
0.54 g of sodium methoxide were added to 100 mL of methanol. The bobbin of GYA-2 yarn was placed into the solution so formed for a period of 48 hours to regenerate glucan fiber from the glucan triacetate fiber. The so-treated bobbin was then rinsed with methanol, and soaked for an additional 24 hours in neat methanol, and allowed to air dry. The resulting regenerated glucan fiber yarn is herein designated GY-1.
Oxidation Treatment
Referring to FIG. 2 , a tube furnace ( 21 ) having an entry port ( 22 ) and an exit port ( 22 ′) was equipped with an air supply fan ( 23 ) that flowed air, at rates stated in Table 5, infra, into the entry port ( 22 ) and through the furnace to the exit port ( 22 ′). A skein of fiber ( 24 ) was fed end-wise through the tube furnace. The skein was disposed to pass over a pulley ( 25 ) at each end of the tube furnace. Each end of the skein was formed into a loop ( 26 ), through which a hook ( 27 ) was passed. Affixed to the hook was a weight ( 28 ). The weight employed is stated in the examples, infra. The heated section of the tube inside the tube furnace was a 2 inch schedule 5 tube with an inner diameter of 57 mm and a length of 54 inches. Each specimen was subject to a temperature of 180° C. in air for 10 minutes. The temperature was then increased in a series of steps, as described in the thermal profile provided in the examples, infra. It took less than 1 minute to make the temperature changes between adjacent steps in the thermal profile.
Carbonization Treatment
Referring to FIG. 3 , nitrogen was provided to the tube furnace ( 21 ) at six locations ( 33 ): one at the entry port ( 22 ) and one at the exit port ( 22 ′) of the tube furnace, two at the tubing before the entrance port and two at the tubing before the exit port ( 22 ′). The nitrogen was fed through six flow meters ( 34 ). The oxidized fiber skein ( 35 ) was attached to an Inconel® transport wire 0.9 mm in diameter ( 36 ) using metal crimps ( 37 ) in order to keep the fiber skein in a zero tension state. The Inconel® wire was wrapped around pulleys ( 25 ) located at the entry port ( 22 ) and exit port ( 22 ′) in order to move the fiber skein into and out of the furnace. The fiber skein thus disposed was then subject to heating according to the schedule disclosed in the specific embodiments infra.
Preparation of Filament Skeins.
Referring to FIG. 4 , a skein of filaments having more than 20 ends was prepared by winding the skein around four posts ( 41 ) that were set at the corners of a square ( 42 ), 24 inches apart from each other. A fiber skein was wrapped around the posts until the skein contained the desired number of filaments. The skein was cut at one post, resulting in a length of 8 feet.
Example 1
Two 60-inch skeins, consisting each of 20 filaments of GY-1 were prepared for oxidation as described supra. To each skein, herein designated GY-1-A and GY-1-B, a 3.5-gram weight was affixed at each end as shown in FIG. 2 . Under an air flow rate of 6 standard cubic feet per minute (scfm), each skein was individually heated to 230° C., held for 60 minutes, then heated to 250° C., held for 60 minutes, then heated to 270° C., held for 60 minutes, then heated to 290° C., held for 60 minutes, then heated to 310° C., held for 60 minutes. No breakage had occurred at the end of the five-hour thermal exposure process. The resulting oxidized skeins are herein designated GY-1-AO and GY-1-BO.
The GY-1-AO oxidized skein was prepared for carbonization as described supra. The skein was heated at 800° C. for 90 seconds under a nitrogen purge of 120 scfh. The skein, herein designated GY-1-AC, was removed from the oven and spooled. The skein was black in color, pliable enough to be spooled, but fragile. If the skein was wrapped tightly, filaments would break.
The GY-1-BO oxidized skein was prepared for carbonization as described supra. The skein was heated to 1000° C. for 90 seconds under a nitrogen purge of 120 scfh. The skein was black in color. The filaments seemed stronger than GY-1-AC, but upon removal from the oven, many filaments were caught on the equipment and broken.
Example 2
Referring to FIG. 4 , a 440 filament skein was prepared by wrapping a 20-filament length of GY-1 around the posts 22 times. A second skein was prepared in the same manner. The skeins so prepared were cut at one post, resulting in two lengths of 8 feet each, designated GY-1-C and GY-1-D.
Each of GY-1-C and GY-1-D were prepared for oxidation as described, supra. Each was oxidized separately. To each skein a 50-gram weight was affixed at each end as shown in FIG. 2 . Under an air flow rate of 10 scfm, each skein was heated to 250° C., held for 40 minutes, then heated to 270° C., held for 40 minutes, then heated to 290° C., held for 40 minutes, then heated to 310° C., held for 40 minutes, then heated to 330° C., held for 40 minutes. No breakage occurred at the end of the 200-minute temperature profile. The resulting oxidized skeins are herein designated GY-1-CO and GY-1-DO.
c. Carbonization
Oxidized skein GY-1-CO was prepared for carbonization as described supra. The skein was heated to 800° C. under a nitrogen flow rate of 120 standard scfh for 120 seconds. The thus heated skein, herein designed GY-1-CC, was removed from the furnace. The skein was black in color, pliable, and easy to spool.
Oxidized skein GY-1-DO was treated in a manner identical to that of GY-1-CO except that the temperature was 1000° C. The thus heated skein, herein designed GY-1-DC, was removed from the furnace. The skein was black in color, very pliable, and very easy to spool.
In the thus carbonized skeins fiber diameter was determined by scanning electron microscopy; denier, using a TexTechno Vibromat ME denier testerand (TexTechno H.Stein GMBH & Co.); and, mechanical properties, using an Instron® Universal Testing Machine. Results are shown in Table 5.
TABLE 5
GY-1-CC
GY-1-CD
Diameter (micrometers)
17.0 ± 0.4
19.6 ± 1.7
Denier
3.581 ± 0.789
3.076 ± 0.674
Tenacity (gpd)
1.3 ± 0.5
2.0 ± 1.0
Tensile Strength (MPa)
189 ± 79
203 ± 100
Tensile Modulus (GPa)
28 ± 4
27 ± 6
Comparative Example A
One 60-inch skein consisting of 20 filaments of glucan triacetate GYA-1 was prepared for oxidation as described supra. A 4.5 g weight was affixed to each end of the skein as shown in FIG. 2 . Under an air flow rate of 6 scfm, the bundle was heated to 230° C. After one minute, the skein broke.
Comparative Example B
Two 200 filament skeins were prepared by wrapping the 20-filament glucan triacetate GYA-1 ten times around the posts of the apparatus in FIG. 4 . Each skein was cut at one post, resulting in two lengths of 8 feet.
A 60-inch skein was cut from each of the thus prepared 8 foot lengths, herein designated GYA-1-1 and GYA-1-2. Each 60-inch skein was prepared for oxidation as described supra. Each skein was oxidized separately. A 16 g weight was affixed to each end of the GYA-1-1 skein, and a 40 g weight was affixed to each end of GYA-1-2. The skeins were heated for 10 minutes at 180° C. under an air flow rate of 6 scfm. skeins broke after 10 minutes at 180° C.
Comparative Example C
PANOX® Thermally Stabilized Textile Fiber, an oxidized poly(acrylonitrile) fiber was obtained from The SGL Group, Ross-Shire, UK. Three PANOX fiber skeins, herein designated PANOX-1, PANOX-2, and PANOX-3, consisting of approximately 12,000 filaments per skein were prepared for carbonization as described supra. Three 60-inch length skeins were heated to 800° C. under a nitrogen atmosphere of 120 scfh. PANOX-1 was held for 60 seconds, PANOX-2 was held for 90 seconds, PANOX-3 was held for 120 seconds. PANOX-1 caught on the furnace during removal and was bunched up. No further testing was performed. PANOX-2 was frayed and could not be spooled. PANOX-3 was removed from the oven, herein designed PANOXC-3, and spooled.
A further 12,000 filament 60 inch skein of PANOX, herein designated PANOX-4, was heated to 1000° C. under a nitrogen atmosphere of 120 scfh for 120 seconds. PANOX-4 was removed from the oven, herein designated PANOXC-4 and spooled.
PANOXC-3 and PANOXC-4 were analyzed in the manner of the specimens in Example 2. Results are shown in Table 6.
TABLE 6
PANOXC-3
PANOXC-4
Diameter (micrometers)
8.0 ± 0.3
9.9 ± 0.3
Denier
0.779 ± 0.040
1.111 ± 0.070
Tenacity (gpd)
9.4 ± 2.1
2.7 ± 1.7
Tensile Strength (MPa)
1440 ± 317
387 ± 247
Tensile Modulus (GPa)
85 ± 6
15 ± 8 | A process is provided for preparation of carbon fibers based from fibers of poly(α(1→3) glucan). The method comprises three thermal exposures at progressively higher temperatures to drive off volatiles, thermally stabilize the glucan fiber, and carbonize the thermally stabilized fiber. The carbon fibers prepared according to the process hereof are strong, stiff, tough, and easily handled. | 3 |
FIELD OF THE INVENTION
[0001] The present invention relates to a liquid dispenser and has particular reference to such a dispenser suitable for containing a liquid intended to be poured into a receptacle or reservoir by way of replenishment. The invention has especial, but not exclusive, reference for such a dispenser used for recharging automobile reservoirs with fresh liquids, for example water for the radiator and the engine cooling system, the windshield washer fluid for the appropriate reservoir, and others.
BACKGROUND OF THE INVENTION
[0002] One of the problems associated with conventional dispensers is their use in filling other receptacles or reservoirs without spilling the liquids. Difficulty is generally encountered because of the distance needed to be bridged when upturning the dispenser to align its discharge outlet with the relevant charging reception port. Necessarily spillage occurs even when using a funnel or spout, especially in windy weather conditions or the like, the weight of the dispenser being another contributory factor to the problem.
[0003] It is already known to provide a dispenser with a valving arrangement for its discharge outlet whereby the liquid content is discharged only when the valve is opened following alignment of the discharge outlet with the charging port through which the liquid has to pass for use. U.S. Pat. No. 6,702,160 to Griffith is one example of such a dispenser and discloses a container having a valved dispensing port at one end of the dispenser aligned with a cap at the other end of the container carrying a valve stem with a valve head seating in and sealing the dispensing port. Opening of the cap by unscrewing the same occasions movement of the valve stem and unseating of the valve head thereby releasing liquid form the inside of the container through the dispensing port. Screwing down the cap is intended to reseat the valve and seal it to prevent further egress of liquid. One of the perceived disadvantages of this proposal is the lack of certainty associated with the effective reseating of the valve since continuity of linear movement of the valve stem is not guaranteed, thus giving rise to the possibility of a malfunction of the valve accompanied by undesirable leakage through the discharge outlet of the container.
[0004] Accordingly, there is a need for a liquid dispenser possessing improved features affording a greater degree of reliability of operation than has hitherto been possible with known designs.
SUMMARY OF THE INVENTION
[0005] It is therefore a general object of the present invention to provide an improved liquid dispenser.
[0006] An advantage of the present invention is that the liquid dispenser is of simple construction and easy operation.
[0007] Another advantage of the present invention is that the liquid dispenser gives a more controlled discharge facility, and significantly reduces spillage.
[0008] According to a first aspect of the present invention there is provided a liquid dispenser comprising:
a container defining a liquid holding chamber having two ends, and surrounding walls integral with and interconnecting the said ends; a port defined at one end of the container and a liquid discharge outlet defined at the other end of the container; a tapering spout provided externally of the container and extending therefrom to define the discharge outlet, the spout defining a valve seating section therewithin; a valve stem carrying a valve member for registration within the valve seating section, the valve stem extending from said valve member to the port; a discharge grid disposed fixedly within the spout between the valve seating section and the discharge outlet, the grid being spaced from the valve seating section and providing a guide for the valve stem; a cap provided for the port and adapted to locate and carry the valve stem; and a stop associated with the valve stem to define the extent of movement thereof.
[0016] A recharging inlet for fresh liquid may additionally be provided in the same end as the port.
[0017] The cap is preferably of the screw type engaging a thread formed externally of the port.
[0018] The valve member may advantageously be of frusto-conical shape and provided with a seal, for example an O-ring inset in a groove in its tapered sealing face for mating with the valve seating section in the spout. The O-ring is of elastomeric material.
[0019] The discharge grid may be annular with a cruciform spider defining a central aperture guide for the valve stem. Conveniently, the central apertured boss includes an outwardly tapering aperture for insertion of the stop therethrough.
[0020] The stop is provided on the valve stem, conveniently at a location between the discharge grid and the outlet, whereby abutment of the stop with the grid limits linear movement of both the stem and thus the valve member in relation to the valve seating section of the spout.
[0021] Conveniently, the cap, the valve stem, the valve member and the stop are integrally formed out of one piece.
[0022] In one embodiment, the spout further extends downstream of the grid so as to contain the stop therein when the valve member sits onto the valve seating section of the spout. Conveniently, the spout further tapers when extending downstream of the grid so as to reduce spillage when dispensing liquid from the container.
[0023] The dispenser is advantageously produced from plastics material compatible with the liquids it is intended to contain. Conveniently the dispenser is reusable, and could also be recyclable.
[0024] The container may be formed with an integral carrying handle, which may be hollow and communicate with the rest of the container.
[0025] Other objects and advantages of the present invention will become apparent from a careful reading of the detailed description provided herein, with appropriate reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Further aspects and advantages of the present invention will become better understood with reference to the description in association with the following Figures, in which similar references used in different Figures denote similar components, wherein:
[0027] FIG. 1 is a side view of a liquid dispenser in accordance with an embodiment of the present invention partly cut-away to provide a sectional elevation of the inside of the dispenser, the dispenser being depicted in its normally upright storage position;
[0028] FIG. 2 is a side view of the liquid dispenser partly cut-away to provide a sectional elevation of the inside of the dispenser, the dispenser being depicted in an upended operational position in registration with a reservoir for discharge of its liquid contents; and
[0029] FIG. 3 is a sectional view on the line 3 - 3 of FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] With reference to the annexed drawings the preferred embodiment of the present invention will be herein described for indicative purpose and by no means as of limitation.
[0031] In FIGS. 1 and 2 there is shown a liquid dispenser 1 comprising a container 2 typically molded from a plastics material having two ends 4 , 6 with sides 8 , 10 . The container is provided with an integral hollow handle 12 in at least one of the side walls 10 .
[0032] A discharge outlet 14 is formed at the narrower end of a spout 16 extending from an opening 18 in end 4 of the container 2 . A temporary foil seal 20 is shown covering the outlet 14 and is intended for removal and disposal upon first usage of the dispenser 1 . The spout 16 defines therewithin a valve seating section 22 and also accommodates in fixed manner a discharge grid 24 , which is annular and has a spider 26 with a central apertured boss 28 .
[0033] A valve member 30 is carried on a valve stem 32 extending essentially the full depth of the container 2 . The valve member 30 is typically of frusto-conical discoid form, similar to a drain plug, and is provided with typically an O-ring insert 31 set in a groove 33 for seating on and sealing with the valve seating section 22 , as can be seen in FIG. 1 . The valve stem 32 extends through the aperture 27 of the boss 28 of the spider 26 of the grid 24 and carries at its free end a stop 34 , which in this example is conical. It will be readily understood that the stop 34 is of larger diametral extent than the boss aperture 27 and is intended in use to abut the same thereby to limit the movement of the valve stem 32 and thus the valve member 30 . In order to ease the, typically snapping, insertion of the stop 34 through the aperture 27 from the inside of the container 2 , the aperture 27 typically includes a tapered section 27 ′ substantially outwardly tapering.
[0034] Typically, the screw cap 40 , the stem 32 , the valve member 30 (except the sealing insert 31 ) and the stop 34 could be integrally formed out of one molded piece to easy assembly of the dispenser 1 .
[0035] The valve stem 32 extends from the valve member 30 through the void of the container 2 and is carried by and affixed to a screw cap 40 engageable with a correspondingly externally-threaded necked opening 42 formed in end 6 of the container 2 . A gasket 41 is provided in the cap 40 for sealing engagement with the opening 42 . The necked opening 42 is conveniently recessed into the end 6 as at 44 . A similar externally-threaded necked recharging inlet 46 is also formed in the end 6 and is also recessed therein as at 48 , the inlet 46 being provided with a gasketed closure 49 a shown.
[0036] Typically, the opening 42 is large enough to allow the insertion of the valve member 30 there through.
[0037] In the storage position of the liquid dispenser 1 as shown in FIG. 1 the discharge outlet 14 is presented at the ‘top’ of the container 2 , whilst the screw cap 40 and the inlet 46 are at the base of the container. It will be appreciated that the recessing at 44 and 48 allows the container 2 to assume a stable and upright storage condition on a supporting surface S.
[0038] When it is desired to replenish a reservoir 50 , for example the windshield washer reservoir on a vehicle, the container 2 is inverted as shown in FIG. 2 such as to allow registration of the spout 16 within an inlet 52 on top of the reservoir 50 . Once the spout 16 is positively located for flow communication in the inlet 52 the screw cap 40 is undone and in so doing the valve stem 32 and thus the valve member 30 ascend within the container 2 and the seal between the member 30 and the valve seating section 22 in the spout 16 is broken thus allowing flow of the liquid 60 from the container 2 via the outlet 14 through the inlet 52 into the reservoir 50 . The elevation of the cap 40 allows ingress of air, as shown by arrows 43 , to assist the flow of the liquid 60 which passes over the grid 24 into the frusto-conical section of the spout 16 giving a smooth and controlled flow, thus preventing or at least reducing spillage that could occur, especially because of the presence of the grid 24 . The stop 34 on the valve stem 32 limits the travel of the valve member 30 and the guiding action of the discharge grid 24 with the stem 32 passing through its aperture 27 seeks to ensure linear movement of the stem.
[0039] Once sufficient replenishment of the reservoir 50 has been accomplished without spillage, the valve member 30 is reseated on the seating section 22 by screwing down the cap 40 . The movement of the valve member 30 towards the seating is constrained in linear manner by the interaction of the valve stem 32 and the aperture 27 in the grid 34 as aforesaid and accordingly there is no tendency for the valve stem to wander. The valve member 30 thus seats positively on the seating to seal the discharge outlet 14 to prevent flow of the liquid and any seepage. The grid 24 is spaced from the seating section 22 as can be seen in FIG. 1 to ensure that in use the valve member does not inadvertently bottom on the grid thus giving rise to improper and ineffective seating resulting in leakage. Upon effective sealing of the outlet 14 , the dispenser 1 may then be inverted to its original upright position as shown in FIG. 1 .
[0040] The dispenser 1 may be replenished with fresh liquid through the recharging inlet 46 whilst the container is in the inverted position of FIG. 2 , the closure 49 being securely tightened before the upright position is reassumed.
[0041] The dispenser of the present invention thus constitutes a useful contribution to the art in terms of providing positive guidance for the valve stem and thus the valve member to secure linear movement and therefore effective sealing to prevent seepage. Generally, the invention offers the user a simple means of refilling a reservoir by allowing accurate positioning of the container over the reservoir filling port, thus preventing wasteful and possibly costly spillage.
[0042] Although the opening port 42 is shown to be generally aligned with the discharge outlet 14 , one skilled in the art would understand that the opening port could be offset (unaligned) relative to the discharge outlet, with a shaped stem extending there between, without departing from the scope of the present invention.
[0043] Although the present invention has been described with a certain degree of particularity, it is to be understood that the disclosure has been made by way of example only and that the present invention is not limited to the features of the embodiments described and illustrated herein, but includes all variations and modifications within the scope and spirit of the invention as hereinafter claimed. | A liquid dispenser includes a container having a valved discharge outlet, the valve being actuable remotely by a screw cap of the container, which carries the valve stem. The valve stem is guided in usage during its linear travel between open and closed modes, the guidance being provided in the region of the discharge outlet by an apertured centre boss of a discharge grid. | 1 |
[0001] The present invention relates to an integrated method and system for preventing and solving problems relating to pests of any kind on a site, in a building, in a process, installation or in an area. The system involves complete digitalising and automation of all functions necessary in order to control the pests such as surveillance, registration, alarms, regulation and remedial actions as well as generating reports etc. The aim is to make the overall effort against the pests more effective by means of fully automating all processes to the furthest possible extent.
[0002] The effort against pests is necessary in that pests often pose a threat against the health and welfare of humans and livestock and may impose serious inconveniences as well as large material and cultural losses to society, households and industry.
[0003] The problems relating to pests arise especially when the pests are present in large numbers in forestry, agriculture or gardening. Especially when the pests are present in industry and institutions, in particular in the food stuff, pharmaceutical, health care or other high hygiene demanding sectors as well as in and around our houses.
[0004] The effort against pests must be effective, carried out in a systematic manner and be based on a wide spectre of experience and knowledge.
[0000] The Need for Pest Control in and Around Buildings
[0005] In a large number of establishments and institutions in sectors highly dependent on hygiene and therefore sensitive to pests, the problems of safeguarding against pests are far more complex than they are for plant crops. Besides economic consequences created by the presence of pests in items such as food, food containers, pharmaceuticals and the like, there is a serious risk of diseases being spread. In the industrialized world, pest-control is therefore a part of the statutory demands for, among others, theses lines of businesses. The purpose is to protect the population through among other things, a high degree of food safety.
[0006] This is compounded by a much greater species variation, from rodents, such as rats and mice, to thousands of various flying and crawling insects, a majority of which poses a safety risk. Faeces from rats and mice may, for example, contain as much as a quarter of a million pathogenic bacteria per gram. The risk is serious, if infected foods end up on the dining table. Likewise, many of the highly mobile insects, including flies and wasps, act as carriers of pathogenic microorganisms from for example contaminated drains for food and other high-risk products.
[0007] Pollution prevention requires either the elimination of the source of pollution or the carrier, or the establishment of safe barriers between the source of pollution and sensitive products. The solution to pest problems must necessarily involve all levels of the product chain, i.e. when food is concerned, from farmers to retail stores via the processing industry, transport, storage and handling.
[0008] In many buildings, most of year or the whole year is pest season because a year-round climate, so to speak, is maintained, the easy access to food, water, as well as breeding areas is easy, and many pest species are almost omnivorous. Especially small pests will get in, in spite of all preventive measures, or they are brought in by infected deliveries coming from near or far.
[0009] Ensuring maintenance, cleanliness and tidiness, and, not least, remembering to keep a watchful eye are the key preventive elements.
[0010] Many establishments and institutions, e.g. in the food, health and nursing sectors, must adhere to stringent pest-control requirements, and are at the same time prohibited by law to use chemical pesticides indoors. Requirements regarding traceability and documentation are a key feature of intensified pest control.
[0011] Experience has shown that no preventive efforts will fully remove pest infestations, but by taking immediate action, the damage can be greatly limited.
[0012] In principle, “minute-by-minute” monitoring is needed in order to limit damages caused by pest infestation in an optimal way, whereby the need for more time-consuming and expensive remedies will be curtailed.
[0013] As with all other types of monitoring (e.g., monitoring of production processes and regarding theft and fire prevention), it is important to find means and methods that will increase the safety and unambiguity of collecting monitoring data, and that, on the other hand, will remove or minimize the need for a continuous human presence. Furthermore, when dealing with pest and hygiene control, experience has shown that the need for improving the quality of operations and the integrity of documentation required by authorities and customers is great.
[0014] An examination, analysis and evaluation of the actual situation at the site should precede any pest-control program, as should information about the location, previous pest activity, and users' preferences and requirements, objectives and critical limitations related to pest control.
[0015] In summary, in highly hygiene-dependent and pest-sensitive establishments and institutions, where problems are a lot more complex than in agriculture and gardening, effective pest control will require easy access to a broader span of professional expertise and methods, and making “zero-tolerance,” early warning and immediate relief the key elements, when preparing operations.
STATE OF THE ART
[0016] Anti-pest efforts have generally been conservative. The most prevalent methods are chemical-based. An increasing incidence of resistance in pests has rendered several of the most common chemical agents completely of partially ineffective, and the presence of dead, poisoned animals in inaccessible or hidden places poses a great hazard to health and hygiene.
[0017] Due to low prioritisation and scarce resources, the monitoring of many locations is reduced to a minimum, where a few annual inspections provide only limited safety and control, and only outdated and inadequate information about the current pest situation. This is a poor foundation for an effective pest control, especially for establishments in the food and other sensitive sectors.
[0018] Especially in the industrialized world, there is a generalized and increased aversion towards the use of chemical pesticides that often adversely affect nature in several ways, and can be traced in foods, animal feedstuffs and drinking water.
[0019] Some agents have furthermore been prohibited, while only a few slip through the more stringent approval procedures.
[0020] A more restricted use of chemical agents in favour of biological and ecological methods and agents has put greater focus on such preventive measures that may prevent or minimize the consequences of pest infestations without actually resorting to pest control.
[0000] Pest Control Related to Outdoor Plant Crops
[0021] For outdoor plant crops, pest control runs the gamut of massive, “better-be-safe”, chemical control to assisting plants naturally to resist attacks—for instance by selecting pest-resisting plant varieties, or ensuring healthy, naturally-resistant plants through optimal growth conditions in ecological balance so as to avoid or at least greatly limit actual pest control.
[0022] However, modern, plant-based production in agriculture and gardening is based on monocultures allowing the individual farmer to concentrate on one or a few crop-specific, pest species that may be relevant in relation to his crops. Attacks on “standing” crops will almost always be seasonal and generally occur during short periods (a few days or weeks) depending on the development stage of the crop in question.
[0023] Moreover, the consequences of pest attacks on plant crops will only have an economical dimension.
[0024] US2003/0069697 relates generally to pest-control systems and especially a method for controlling pests using detectors to identify pests and a network-related database, and specifically a method for pest control in crops of one or a plurality of plant growers using different identification sensors combined with computers, analysis and database software, as well as wireless or wired data transfers.
[0025] It mainly provides brief and basic descriptions of the structure, features and contents of the system solution that purportedly solves the significant, general problems raised in the background description of the above mentioned application.
[0026] In summary, these problems can generally be characterized as bottlenecks and poor information processing, for instance, as a result of the following:
Lack of reliable information due to inaccurate detection and interpretation of pest data Slow and delayed dataflow through multiple, manual stages The absence of common standards for critical limits and control measurements
[0030] Besides disclosing a number of general methods and technologies, US2003/0069697, as indicated above, provides no specific instructions in terms of solving the above problems.
[0031] In contrast, U.S. Pat. No. 6,493,363 B1 discloses highly specific instructions for how to count and record insects (flying insects are implied) indoors, however, the solution lacks the very important and often-requested, species-determination option. Furthermore, this solution requires the presence of a high-voltage grid, whose main purpose is to eliminate (kill) flying insects when colliding with the grid. Due to the intensive release of voltage, the insects practically explode, and a profusion of fragments, often carrying germs, scatters over an area of various size, causing a hygiene hazard that is actually greater.
[0032] This solution can therefore be expected to gain less favour, as the use of adhesive plates trapping insects in an intact state and allowing for identification becomes the preferred choice.
DESCRIPTION OF THE INVENTION
[0033] A Through automation, the use of the latest technological achievements, especially within information technology, the present invention aims to optimise quality, safety and reliability of pest control in general, and minimize the need for manpower, overcome bottlenecks in the flow of information, and as a whole solve the problems outlined above.
[0034] The present invention addresses this by providing a pest control system comprising the following components:
one or more detection units, where each unit comprises means for identifying the type of pest and, optionally, the activity of that particular pest and further optional means for sensing physical factors which may correlate to that factor, and means for electronically communicating the collected data to a local server after encryption; a local communication server, where the server comprises means for receiving input from the detection units and means for transmitting said input, optionally after encryption of data, and further optional means for processing and storing said input in an accessible storage medium; a central system server, which may collect and treat data received from one or more discrete and/or remote local communications servers such that the treated data generates an output either as an alarm and/or as a log registration; software modules incorporating self-learning in response to generated data and predetermined responses in view of incoming collected data.
[0039] One embodiment of the present invention relates especially to pest control in establishments and institutions in highly pest-sensitive sectors, such as the food, pharmaceutical, health and care sectors, and as regards residences. This embodiment uses one or more types of detection units.
[0040] The design of the detection units is adapted to the type of pest, the preferred identification data and the physical environment of operation. In some embodiments, the detection unit is attached to a capture unit. The individual detection units incorporate sensor(s) for detecting the activity and condition of pests, and also a microprocessor with software designed to transmit information electronically about detector-ID and detected activities and conditions.
[0041] As the pests may have different life patterns and damaging abilities, the invention in a further advantageous embodiment, when the pest is a rodent, provides that the detection unit comprises one or more of the following detection sensors: infrared temperature and/or movement sensors, mechanical tripping means, and further bait for attracting the particular rodent, optionally optical means in the shape of digital camera techniques as for example CIF, CCD, or VGA technology cooperating with suitable analysis and recognition software.
[0042] In a further advantageous embodiment, when the pest is an insect, the detection unit comprises one or more of the following detection sensors: infrared temperature and/or movement sensors, a plate member comprising a sticky surface arranged such that optical recognition means coupled to a reference database may scan the plate member or, alternatively, the plate member may be placed in a scanner for data collection, or as a further alternative the plate member may be combined with digital camera techniques as for example CIF, CCD, or VGA technology cooperating with suitable analysis and recognition software, a source of UVA blacklight and/or a source of pheromone or a source of bait.
[0043] By the term “insect” all flying and non-flying insects shall be construed which may cause harm as described above.
[0044] The control system, in a further advantageous embodiment, may be provided with means for exterminating pests in the detection unit. As the object is detecting the pest and controlling the pest, it is often advantageous to combine the detection unit with the extermination unit such that the pest is exterminated as it is discovered, and also, for control purposes, it might be advantageous to be able to collect samples of the pest and correlated these with the data collected from the detection unit.
[0045] Besides detecting actual pests, it may be of relevance in many situations to detect traces of the presence of pests.
[0046] The detection units are linked either by wire or wirelessly with a local communication server that acquires, processes and transmit the information from the detection units to a “global” system server with a database.
[0047] The link between the detection units and the local communication server may be wired, however, the preferred embodiment uses some type of wireless link. The communication is done encrypted to prevent interference with other wireless systems at the site. Among the specific technologies for wireless local communication, Wlan (the 802.11 standard) or Bluetooth was used for tasks requiring large bandwidth and 433 Mhz or 866 Mhz radio frequency for jobs requiring a relatively larger operational range.
[0048] The link between the local communication server and the “global” system server, i.e. the central system server, in this preferred embodiment is established via GSM/GPRS and the Internet; but may also be done via LAN and the Internet.
[0049] The above mentioned electronic communication possibilities provide, in a further advantageous embodiment, that the system further comprises means for transmitting a status report on the current status of the detection unit at predetermined time intervals, and, additionally, is capable of transmitting alarm signals if/when action (activity) is detected in the detection unit.
[0050] The access for users and service operators to the “global” system server is mainly done via an Internet link. The “global” system server is equipped with software (established and self-generating decision models) for fully automated control and monitoring of dataflow, including access control, analysis and evaluation of activity and status data, diagnostics, and the emission of alerts and reports.
[0051] The “global” system server is furthermore associated with a database containing, among other things, information about connected users and user locations, service providers and other specialists, as well as “expert-system data”.
[0052] The collection of data in a further advantageous embodiment provides the extra advantage that the central server comprises a database where data from the detection units as well as actions in response to such data is stored, and that the data by means of suitable software may be used in order to predict possible causes of presence of pests, causes of alarm and/or suggest possible actions, and that the collected data is correlated and integrated with the database.
[0053] As already described above, due to the construction of the detection unit as well as the construction of the entire control system, it is important that communication is established between the different locations and also between the different protection unit placed at one location. For this purpose, in a further advantageous embodiment, the communication between the components in the system takes place via wireless means such as for example GSM or GPRS, or via wire, such as for example LAN network, internet, or especially dedicated wiring.
[0054] In a still further advantageous embodiment of the communication set-up, the wireless means may comprise Blue tooth technology, Wlan or traditional wireless transmission of data.
[0055] B Position control. At an individual location, the system may be enhanced by radio-signal-based localisation technology in order to determine and control the positions of the detection units at that location. The majority of the detection units are battery-powered and communicate wirelessly, which may involve a certain risk at some locations of unintended movement away from the positions recorded in the system. Correct location indication for each individual eventactivity/status is critical in order to perform correct analysis and diagnosis, and thus for the automatic responses of the system in the form of e.g. emitting alerts, prevention instructions and other feedback. Position control is done continuously as part of general protection control. accordingly, all detection units should automatically transmit an “alive and well” control message at fixed time intervals.
[0056] For these purposes, the invention in a further advantageous embodiment provides that the one or more detection units, and/or the local communication server, comprise a Local Position System unit or a GPS unit, which LPS or GPS by means of the communication means may convey the components' position.
[0057] C Detection methods. To detect pests or traces after pests and to determine species, their numbers and size, etc., an immense variety of technologies and techniques are being employed. Different types of sensors, each operating on the basis of one or several electrophysical, mecanical, biotechnical and biochemical measuring principles are used individually or in situation-specific combinations. For instance, it is possible to measure light, temperature, smell, sound, weight and length. In relation to the preferred embodiment of the invention, special light and techniques associated therewith (e.g. photocell, IR, UR and diffuse light), computer-supported biochemical and chemical analyses, as well as digital camera technique combined with computer-based image analysis and pattern recognition are used.
1) Activity detection is primarily used for single species in areas with zero tolerance towards the relevant single species, and where immediate automatic or manual prevention efforts are needed. Automatic relief takes place, e.g. when a detection unit is installed in a trap and provides direct capture release, see EP 98919083.0. Activity detection generally uses units that directly measure changed conditions, i.e. changes of a measurable factor, such as light, temperature, weight or similar physical factors used for motion detection. 2) Status Detection detects and records relevant physical, chemical and biological factors to be used in fully or semi-automatic analysis and diagnosis. The status detection is either activity/motion-controlled or time-controlled. More complex tests, e.g. when species determination and number of insects are concerned, require more nuanced situation images. Here, modern digital camera technique is used based on CIF, CCD or VGA technology combined with special image analysis and pattern recognition software, which is known from analyses of complicated biological subjects such as insects and plant seeds, when identifying single individuals through biometric codes.
Multispectral analysis (as disclosed in WO9942900) is used in cases when diagnosis requires recognition of colours or surface structures of pests or traces after pests.
[0061] D The “global” system server may be extended, e.g. in order to ensure optimal access and operational conditions, with an Internet-based network of regional and national communication servers containing the necessary software and databases.
[0062] The “global” system server with associated database contains all the system's information and operation software (including some artificial-intelligence-based, self-generating features) and is shared by all user establishments and service operators making possible a high degree of experience exchanges and common learning and utilization of recent knowledge for the benefit of all that are connected world-wide.
[0063] The self-generating features ensure continuous automatic updating and expansion of the “expert system database”. Continuing correlation analysis are done on all detected data, e.g. in order to reveal new correlations between the occurrence of pest species and control methods, geographic, cultural and national areas, industrial sectors, etc. The system therefore slowly becomes more intelligent, as time progresses.
[0064] E The system includes a series of computer-supported features and activities related to start-up, operation and maintenance of optimum integrated pest control.
1) Status and risk analysis, (Hazard analysis and assessment) which is done at start-up and periodically as part of an integrated pest control program at a location. The analysis comprises a physical review and recording state of all relevant things at the location, a review of the specific requirements of users and authorities, the previous pest burden, etc. 2) A needs evaluation which is done in co-operation with users, comprises a specific risk assessment of the various areas at the location, determination of critical limits for pest activity and the use of chemical agents, as well as the determination of pest-control targets and what's required in terms of individual user efforts. 3) Pest-control planning. Allocating the number and density of detection and capture units, the alert addresses, the number and frequency of continuous and periodical, automatic and manual inspections and reporting. 4) Start-up and running-in the system, including implementation of e-learning programs for those user representatives, who will become involved in the current operation and maintenance of the system. 5) System operations, whereby current (daily) operations are done automatically, and only a few sporadic and periodic activities, wholly or partially, are done manually.
a. Monitoring is done completely automatically, as detection units transmit the relevant information to the pest-control database. Transmission is done in a timer-controlled fashion, or when pest activity is detected, or when the set status level is exceeded, either directly or through a local communications server to the database in the “global” system server. Monitoring also involves a periodical check of all detection units that they are “alive” and in a correct physical position. Monitoring may also involve continuous recording of several physical conditions that may influence the pest activity, e.g. temperature, air humidity, light b. Automatic analysis and diagnosis is done continuously in the “global” server system based on the detected, incoming data. This involves real-time “minute by minute” recordings, making it possible to load a completely updated image of the pest situation and the latest development, e.g. exactly where and when a pest attack began, how it developed, and where its cause may be found at any time. Combining real-time recording of the individual activities and status makes it possible to present an image of the dynamics of pest activity and its association with a number of environmental factors relating to this activity. In order to analyse recorded data, a self-adaptive system is used, which has been taught in advance to “recognize” the most prevalent pest species and pest-occurring situations that can be anticipated, and which continuously expands the collection of known species with new species and situations, as they occur. c. An alert is emitted, if critical limits are exceeded. Alerts are transmitted to one or several pre-dedicated addresses (e.g. www, e-mail, cell phone or landline telephone). As a general rule, an alert is always followed by a report with the relevant corrective instructions and recommendations or detailed queries about the actual, critical situation. d. Reporting, with situational and targeted form and content, is automatically included in an alert message and occurs at fixed intervals or upon request. e. Manual and semi-automatic operational features enable the recording of past inspections and corrective/preventive actions, as well as monitoring data and other results of manual interventions. In addition, any false recordings may be corrected manually, although deletion of previous recordings is not possible. f. Mobile detection and data capture. The system may also comprise mobile units for manual and semi-automatic data capture, as well as communication software that enable secure, mobile determination of species and their numbers through analysis software located in the “global” system server.
6) Expert system and databases are the key elements of the system
[0079] a. General Database
1. Standards and specific expert knowledge related to ensuring detection and elimination of any type of pest. This includes service and a support centre. 2. Decision models 3. Models and other software, including self-adaptive, “artificial intelligence”-based software for the determination of species and their numbers, e.g. using image analysis and pattern recognition. 4. General standards for setting up a system, including risk-classification of locations and determination of risk factors, critical limits and measurements, corrective options, etc.
[0084] b. Individual Databases (for Operators, Users and Locations)
1. Access control 2. Risk/status analyses 3. Protection plans with established risk factors, critical checkpoints, individual measurements and critical limits, etc. 4. Corrective actions in case of critical variations 5. Logs showing inspections, monitor recordings and alerts, as well as corrective/remedial actions, including reports.
[0090] c. Communication Software for Automatic Alert and Data Transfer
[0000] System Description Example
[0000] 1. General System Information
[0000]
GreenTrapOnline presentation
2. Service Operators Room
[0092] 1) Login
[0093] 2) Database and documents frames (standard)
a) Risk and State Analysis in accordance to a Food Safety Standard and/or specific individual demands b) Safety Scheme
i) Plans for risk classified areas including detection and capturing devises ii) Critical Control Points and Risk Faktors iii) Target levels and critical limits iv) Corrective Actions to take in case
c) Logbook
i) Monitoring Critical Control Points ii) Alarms iii) Corrective Actions
[0104] 3) Legislation, Rules and Standards
a) Pest Control b) Food and pharmaceutical Safety etc c) Hygiene
3. Customers Room
[0108] 1) Login
[0109] 2) Database for Each Customer/Location
a) Risk and State Analysis in accordance to a Food Safety Standard and/or specific individual demands b) Safety Scheme c) Safety references (customer specific) d) Plans for risk classified areas including detection and capturing devises e) Critical Control Points and Risk Faktors f) Target levels and critical limits g) Corrective Actions to take in case
i) Logbook ii) Monitoring Critical Control Points iii) Alarms given iv) Corrective Actions taken
3) Knowledge Database
[0121] 4) Login
[0122] 5) Expert System
a) Knowledge about
i) Pests ii) Prevention iii) Buildings and installations techniques iv) Methods, means and remedies v) Food safety standards vi) Pest control standards vii) etc
b) Standard models and programmes
i) Mathematic models and self-learning, “artificial intelligence” based programmes for recognition comparison of patterns and images ii) Programmes for diagnosing and handling incoming data and for dynamic hazard analysis iii) Programmes for handling databases, front pages, dialogue windows etc iv) Programmes for communication v) etc
[0137] Below the system will be further elaborated with reference to the accompanying drawing wherein
[0138] FIG. 1 illustrates a general layout of an exemplified system installed for pest control,
[0139] FIG. 2 illustrates an expanded system comprising an installation for pests in the shape of rodents and further an installation at a bakery where the main pest is in the shape of flying pests,
[0140] FIG. 3 schematically illustrates the communication routes of the system.
SPECIFIC EXAMPLES OF HOW TO SET UP AND OPERATE A GTO SYSTEM
[0141] Since many of the current operational and maintenance issues at the user establishment greatly affect the occurrence of pests at the site and thereby derived harmful effects and risks, all activities related to both implementing and operating a pest-control system are always performed by involving of representatives of the user establishment.
[0000] Setting up
[0000] Status and Risk Analysis (Hazard Analysis and Assessment)
[0142] An inspection and review of all factors and circumstances of relevance for pest protection at the user's establishment must precede the establishment of a pest-protection program. All facts are analysed and a subsequent needs evaluation will produce a specific, useful pest-protection plan.
[0000] Protection Plan
[0143] A pest protection plan involves identified risk areas, critical inspection points, various critical elements (pests, activities and status), as well as determining the number of detection and capture units to install, contents and frequency of ongoing and periodical, automatic and manual inspections, including correction, alerting and reporting procedures.
[0000] Start-Up
[0144] Start-up comprises both the physical set-up and tests, as well as the establishment of user-specific database sections (user folders) with the required access certificates, etc. Further, e-learning programs for user representatives with access via the Internet are established.
[0145] FIG. 1 illustrates a principle pest control solution on a site ( 10 ) e.g. in a building, in a process, installation or in an area.
[0146] Inside and outside the area ( 10 ), an appropriate amount of detection units and capture units ( 21 , 22 , 23 , 25 , 26 ) are placed. They detect pest activity, detection errors and related physical conditions, such as temperature and humidity.
[0147] The units ( 21 , 22 , 25 , 26 ) each transmit, when a critical activity takes place or at fixed time intervals, an encoded message to the “global” system server ( 54 ). The units ( 21 , 22 ) are connected with the “global” system server through a radio link ( 32 ) and a local communication server ( 35 ). The detection and capture unit ( 25 ) is connected ( 31 ) through an incorporated GSM module with the “global” system server ( 54 ) through a GSM link station ( 36 ). The detection units ( 22 , 26 ) are connected via a wired LAN ( 28 )/Internet link ( 33 ) with the “global” system server. The detection unit ( 27 ) is a digital camera/GSM module for mobile data acquisition and supplying data directly to the central server.
[0148] When individually preset critical limits are exceeded or critical conditions occur, the “global” system server emits alert messages to pre-dedicated alert addresses ( 29 ).
Operational Example 1
Rodent Protection for Pharmaceutical Merchants
[0000] Monitoring
[0149] In the specific solution at area ( 10 a ) as illustrated in the left hand part of FIG. 2 , a number of detection units ( 21 , 22 ) as well as capture units with attractant for rodents are set up. The rodent units ( 21 , 22 ) are provided with IR-based motion sensors in order to detect rodent activity, radio emitter/receiver for communicating with the “global” system server ( 54 ), as well microprocessor control. The units ( 21 , 22 ) are programmed to emit an OK (alive) message, three times over a period of 24 hours, and immediately provide a message about “sensed” rodent activity. All messages are accompanied by the relevant unit's ID code.
[0150] The rodent units ( 21 , 22 ) communicate with the “global” system server ( 54 ) through a local communication server ( 35 ) that stores and evaluates received data, which is retransmitted to the “global” system server ( 54 ), when critical limits are exceeded, and/or automatically three times over a 24-hour period. The communication server ( 35 ) is wirelessly connected ( 32 ) with the detection and capture units ( 21 , 22 ) and via an integrated GSM module ( 31 ) with the “global” system server ( 54 ) through a GSM link station ( 36 ).
Operational Example 2
Insect Protection in a Bakery
[0151] At the bakery ( 10 b ), as illustrated in the right-hand part of FIG. 2 , a number of adhesive plate traps ( 23 ) are suspended. Some with UVA blacklight, a special 365 nm light which attracts a broad range of flying insects. Other have a species-specific attractant (pheromone). The insects get caught and remain at the adhesive plate. For each of the insect traps, a programmable combined camera/GMS module ( 25 ) is mounted at a controlled distance. In this solution, the camera/GSM module is set to once over a 24-hour period take a high-resolution image of the whole adhesive plate, and subsequently transmit the image via a GSM link station ( 36 ) as an MMS message to a coded address being the appropriate user's database section in the “global” system server ( 54 ). Here, the image is analysed, compared with the latest previous image taken from the same position, and any newly arrived insects (including their species and number) are recorded.
[0152] In an especially sensitive area, two small adhesive-plate traps ( 23 ) with a pheromone-based attractant for the moth species plodia and ephestia are suspended exclusively for the purpose of detection. They also have a motion-triggered camera/GSM-module ( 24 ) attached, as mentioned above.
[0153] Most insects' development is dependent on the temperature and moisture at the location, which is why room temperature and humidity is measured continuously with the sensors ( 26 ) in every room of the building. Measuring data are transmitted once per hour to the communication server, where it is recorded and transmitted along with the next outgoing data packet to the “global” server ( 54 ). Temperature and humidity data will become part of the total diagnostic basis.
[0154] For mobile acquisition/recording of pest data, a mobile, handheld unit with an integrated camera/GMS module (basically as in 24 ) is placed at the user's location. This mobile unit is used in combination with software in the “global” server for any presence of pests determined sporadically or during routine, manual inspections according to a protection plan.
[0000] Common Features of Operational Examples 1 and 2
[0155] FIG. 2 illustrates the option of a combined system comprising systems with different combinations of detection units ( 21 , 22 , 23 , 24 , 25 , 26 , 27 ) for collecting different data. All manual activities, including routine, periodical inspections and other activities immediately related to pest control, are recorded via Internet access ( 33 ) of the computers ( 11 , 41 ) to the “global” system server ( 54 ). This may involve changes in the physical placement of detection units, switching adhesive plates in insect traps, change of batteries, renewal of baits, emptying rodent traps, and so on.
[0156] In FIG. 3 , a general schematic plan for a system configuration, also indicating different lines of communication, is illustrated.
[0157] Analysis, diagnostic testing, and alerts. The loaded activity and status data are continuously analysed and assessed based on the criteria outlined in the protection plan. If the set critical limits are exceeded, an automatic alert and a corrective instruction are emitted; in full compliance with the protection plan.
[0158] Corrections may be done automatically as a first immediate step in a series of corrective actions. In pest elimination, this is done prior to detection, when insects are concerned, and directly after the detection being triggered, when rodents are concerned.
[0159] Reporting. Reports are automatically printed (recurrently or when an alert goes off), or per request
[0160] Log. All monitoring data, emitted alerts and immediately performed corrections and other corrective actions, as well as reports are compiled in a log.
TABLE 1 10 = Secured against Pest Area 10 a = Secured against Pest Area, Medical Groser 10 b = Secured against Pest Area, Bread Industry 11 = Users Computer 12/42 = Users and operators phone 21 = Detecor Unit for Rodents 22 = Captor Unit for Rodents 23 = Sticky Glueboard Trap for Insects 24 = Digital camera/GSM modul 25 = Combined Glueboard/Camera/GSM Unit 26 = Detector for physical factors (e.g. temperature, humidity) 27 = Mobile digital camera/GSM modul 28 = Cabled network connection (e.g. LAN to Internet) 29 = Alarm address 31 = Global wireless connection (GSW/GPRS) 32 = Local wireless connection (e.g. 433/866 MHz, Bluetooth, WIan) 33 = Internet connection 34 = Cable connectIon 35 = Local Communucatlon server 36 = GSM/GPRS Link 41 = Service Providers Computer 51 = Internet 52 = National Communication, and SystemServer 53 = Regional Communication Network 54 = Central Server 55 = Central Server Network | The present invention relates to an integrated method and system for preventing and solving problems relating to pests of any kind on a site, in a building, in a process, installation or in an area. The system involves complete digitalizing and automation of all functions necessary in order to control the pests such as surveillance, registration, alarms, regulation and remedial actions as well as generating reports etc. The aim is to make the overall effort against the pests more effective by means of fully automating all processes to the furthest possible extent. | 0 |
BACKGROUND OF THE INVENTION
The present invention is directed to a method for inhibiting or preventing fluttering of a paper web passing through the drying section of a paper machine, within the area of a twin-wire draw.
The present invention is also directed to apparatus for carrying out the method, the apparatus including blow or nozzle boxes placed in the pockets formed by the wire-guide rolls and the wires themselves, and extending substantially over the entire transverse width of the web.
Running speeds of paper machine have been constantly increasing in recent years, with speeds being approached of 1500. The fluttering of the web therefore becomes a serious problem, hampering the running quality of the paper machine. The transfer of the web from the press section to the drying section, and the support of the web in an area of a single-wire draw, can be controlled with certain previously-known methods and apparatus. However, in the area of the twin-wire draw, in particular in the third and fourth operating groups of cylinders within a drying section, difficulties have been encountered at high running speed.
As used herein, a single-wire draw is a mode of passing the web over the heated drying cylinders, in which the web runs from one line of cylinders to the other supported by a drying wire, so that the web is between the drying wire and the cylinder surface on one line of cylinders, and on the other line of cylinders, the web is outside and the drying wire is situated between the cylinder surface and the web, with the web being supported by the drying wire in the draws running between the line of cylinders. An advantage of a single-wire draw is that the web is always supported by the drying wire, and there are no open draws at all, or at least no substantially long open draws, which reduces the risk of wrinkles and breaks in the web.
As used herein, a twin-wire draw is a prior-art mode of supporting and passing the web in conjunction with heated drying cylinders, in which an upper wire is used in conjunction with the upper cylinders and a lower wire is used in conjunction with the lower cylinders. These wires are guided by the surfaces of the drying cylinders and by the guide rolls placed between the drying cylinders, so that, on the upper line of cylinders, the web is pressed by the upper wire into direct drying contact with the surfaces of the upper cylinders, and, correspondingly, into drying contact with the surfaces of the lower cylinders, by the lower wire.
In the twin-wire draw, the web has generally had substantially long open draws when running from one line of cylinders to the other. These open draws have been subject to fluttering, resulting in breaks and wrinkles in the web. This drawback has been accentuated in the initial portion of the drying section, where the web is still relatively moist and therefore of low strength, with elastic properties conducive to fluttering.
Attempts have been made to eliminate this drawback by shortening the open draws of the web in the inital portion of the drying section, by placing the imaginary planes passing through the axis of the upper and lower line of cylinders at a distance from one another that is shorter than customary, or shorter than what would be optimal, e.g., in view of the efficiency of drying.
The possibility of providing the third and fourth drying groups of cylinders with a single-wire draw, has also been considered. However, this has been an exigent solution, because it results in a lowered evaporation efficiency and makes the arrangement of air conditioning more difficult.
Attempts have been made to reduce the fluttering of the paper-web in a drying section provided with a twin-wire draw, by shifting the felt guide rolls so that the paper-web runs a shorter distance without support. In U.S. Pat. No. 3,753,298, such a drying section is described. According to the paper "Engineering Consideration for Lightweight Paper Drying in High Speed Machines" (Paper Technology and Industry, July/August, 1978), the positioning of the rolls in accordance with U.S. Pat. No. 3,753,298 has been used in a Swedish paper machine, with which a speed of 853 m/min has been attained. However, fluttering of the web has continued to be a difficulty.
The fluttering of the paper-web has been discussed in the publication "Manufacture of Paper", Textbook and Manual of the Finnish Paper Engineers' Association III, Volume I, pages 699-700, where it is stated that fluttering of the edge of the web is generally not caused by currents of air, which has been a common belief. Under the circumstances, the fluttering of the web cannot be significantly prevented with guiding of air currents in the drying section, which has, however, been frequently attempted.
SUMMARY OF THE INVENTION
Accordingly it is an object of the present invention, to inhibit or prevent fluttering of a running paper web in the drying section of a paper machine.
It is also an object of the present invention to provide for adequate support of a paper web running through the drying section of a paper machine.
It is another object of the present invention to inhibit or prevent breaks and wrinkles from occuring in a paper web running through the drying section of a paper machine.
It is an additional object of the present invention to permit attainment of high running speeds for a paper web through a drying section of a paper machine, with minimal or no chance of fluttering, wrinkles, and or breakage occuring in the running web.
It is a further object of the present invention to provide for suitable support of a paper web running through a twin-wire draw, so that detrimental fluttering is inhibited or eliminated, especially at high running speeds.
These and other objects which will become apparent herein, are attained by the present invention which provides a method in which jets of gas such as air are blown into pockets defined by guide rolls for the wires and the wires themselves. Such jets of gas are directed at the side of the wire run supporting the web between the drying cylinder and the guide roll, in a direction towards or opposite the running direction of the wire. The gas jets are also directed at the free side of the wire guiding roll, i.e. the portion of the guiding roll not contacting the running wire, substantially in the direction of the tangent of the wire guiding roll.
According to a preferred embodiment of the present invention, gas jets such as air are blown into the pockets defined by the free sides of the wire guide rolls and the wires themselves, on the run of the wire that does not support the web, and that passes from a drying cylinder to the guide roll, with these gas jets being directed substantially perpendicular to the wire facing the gas jets.
Additionally, the present invention provides an apparatus including a nozzle or blow box disposed in the pocket formed by the wire guide roll and the wire itself, and extending substantially over the entire transverse width of the web. This nozzle or blow box has at least two nozzle slots disposed transverse to the running web, one of the nozzle slots being placed at the side of the wire supporting the web, and the other nozzle slot being placed at the side of the wire guide roll.
According to a preferred embodiment of this apparatus in accordance with the present invention, the nozzle or blow box includes a third nozzle slot disposed transverse to the running web, along the free run of the wire, i.e. the run of the wire not supporting the web and passing from the drying cylinder to the guide roll.
With the method and apparatus of the present invention, fluttering of the paper web and the disadvantages resulting therefrom, such as wrinkles and breaks in the web, are effectively inhibited or prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in further detail below, with reference to the accompanying drawings, to which the present invention however is not intended to be limited. In the drawings,
FIG. 1 is an illustration of part of a drying cylinder group provided with a twin-wire draw and utilizing the present invention for supporting the web;
FIG. 2 illustrates one pocket defined by a running wire and a wire guide roll, in which apparatus in accordance with the present invention is disposed; and
FIGS. 3 and 4 illustrate a portion of a drying cylinder group provided with a twin-wire draw, in which the wire guide rolls have been shifted in the longitudinal direction of the paper machine, in order to support the running paper web over as long a distance as possible, in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As illustrated in FIG. 1, in the case of a twin-wire draw, the paper web is placed underneath the wires 1,5 both on the upper and on the lower drying cylinders 2,6. The upper wire 1 runs in meandering fashion, as guided by the upper cylinders 2 and by the upper wire guide rolls 4. Correspondingly, the lower wire guide runs as guided by the lower cylinders 6 and by the lower wire guide rolls 8.
Air jets are blown into the pocket T 1 defined by the upper wire 1 and by the wire guide roll 4, the pocket T 1 being open at the top thereof as illustrated. The direction of the air jet S 1 that is blown at the side of the pocket T 1 where the wire 1 supports the web W, is the same as the running direction of the wire 1. Alternatively, as illustrated in FIG. 4 to be discussed further below, the direction of the air jet S 1 blown at the side of the pocket T 1 where the wire 1 supports the web W, may be opposite to the running direction of the wire 1.
The direction of the air jet S 2 that is blown at the side of the wire guide roll 4 as illustrated in FIG. 1, is substantially the same as the direction of the tangent of the roll 4. In both cases, the speed of the air jets S 1 and S 2 is essentially higher than the speed of the moving surfaces facing the jets.
Correspondingly, air jets S 3 and S 4 are blown into the pocket T 2 defined by the lower wire 5 and by the wire guide roll 8, this pocket T 2 being open at the bottom thereof. The air jets S 3 and S 4 are directed in a similar manner corresponding to the air jets S 1 and S 2 that are blown into the pocket T 1 defined by the upper wire 1. Therefore, the direction of the air jet S 3 is the same as, or opposite to (FIG. 4), the running direction of the wire 5 facing the jet. The direction of the air jet S 4 that is blown at the side of the wire guide roll 8, is the same as the direction of the tangent of the roll. In these cases as well, the speeds of the air jets S 3 and S 4 are also greater than the speed of the moving surfaces facing the same.
In addition to the air jets S 1 , S 2 , S 3 , and S 4 , an air jet S 5 may be blown into the pocket T 1 defined by the upper wire guide roll 4 and the wire 1, at the side of the wire 1 that is running free, i.e. not supporting any paper web. In similar fashion, an air jet S 6 may be blown into the pocket T 2 defined by the lower wire guide roll 8 and the wire 5, at the side of the wire 5 that is running free. These air jets S 5 and S 6 are directed substantially perpendicularly to the runs of the respective wires 1 and 5.
Support contact between the respective wire 1, 5 and the paper web W, is improved even further with the air jets S 5 and S 6 .
By way of the generated ejection effect, the air jets S 1 , S 2 , S 3 , and S 4 produce a negative pressure at the side of the wire pocket where the respective wire 1, 5 supports the paper web W. Since the wire fabric 1, 5 is permeable to air, while the paper web is substantially impermeable to air, the negative pressure generated in this fashion improves the supporting contact between the respective wires 1, 5 and the paper web W.
The air blown by way of these air jets S 1 -S 6 gathers at the side of the respective wire pockets T 1 and T 2 where the wire 1, 5 runs alone, i.e. does not contact any web. Thus, a zone of positive pressure is produced in proximity to the wire 1, 5. Additionally, pumping by the moving wire 1, 5 also generates positive pressure within this zone. The pressurized air flows through the wire 1, 5 into the space A as illustrated in FIG. 1, where a positive pressure is also generated. This also improves supporting contact between the wire and the running paper web.
Apparatus in accordance with the present invention is illustrated on an enlarged scale in FIG. 2. The apparatus includes a nozzle or blow box 9, provided with at least two nozzle slots 11 and 12. The nozzle or blow box extends close to the wire guide roll 4 and close to the wire 1, at both sides of the wire pocket T 1 , as illustrated in FIG. 2. The side wall 10 of the blow box 9, situated adjacent to the guide roll 4, is shaped to follow a curved form of the roll 4 as illustrated. The nozzle slot 11, situated at the side of the wire 1 that is supporting the running web W, is situated along this particular run of the wire 1 approximately half way between the guide roll 4 and the upper drying cylinder 2. The nozzle slot 12 which is situated at the free side of the wire guide roll 4, i.e. the portion of the guide roll not contacting any wire 1, is placed near the bottom of the gap (wedge space) formed by the guide roll 4 and the run of the wire 1 that is supporting the web W, as illustrated. Both of the nozzle slots 11, 12 are shaped so that the air jets S 1 and S 2 (denoted in FIG. 1), attain the starting directions described above.
Past the nozzle slot 11, the top wall of the blow box 9 curves gradually towards the free run of wire 1. The curved wall promotes the turning of the air jet S 1 , and the gathering of air at the side of the wire 1 that is running alone, i.e. running free without supporting any running web, in the wire pocket T 1 .
In certain cases, a jet of air may also be blown directly at the side of the wire 1 that is running free. In such a case, a third nozzle slot 13 is disposed as far from the wire guide roll 4 as possible. The nozzle slot 13 is shaped so that the jet S 5 (denoted in FIG. 1), is directed substantially perpendicularly to the free run of the wire 1, as illustrated in FIG. 2.
The blow box 9 disposed proximate to the lower wire guide roll 8 and the lower wire 5, may also be correspondingly provided with a third nozzle slot 13. In such a case, this nozzle slot is also disposed as far as possible from the wire guide 9 roll 8, and is shaped so that the air jet S 6 , blown out thereof, is directed substantially perpendicularly to the free run of the wire 5.
The blow boxes 9 described above, extend over substantially the entire width of the web W in the transverse direction of the paper machine. The blow boxes 9 are provided with closed ends. One or both of these ends may be provided with ducts that are known in and of themselves, through which the air is directed into the blow boxes 9 out from blowing devices also known in and of themselves. Such blowing devices, if necessary, may include means by which pressure level of the air to be blown can be controlled.
The pockets T 1 and T 2 are open at the top when formed in conjunction with the upper cylinders 2, and open at the bottom when formed in conjunction with the lower cylinders 6. If it is desired to increase the pressure level within these pockets T 1 , T 2 , these pockets may be at least partially closed by means of walls or other arrangements, which may be placed, e.g., in the spaces between adjacent cylinders 2 or adjacent cylinders 6, at or proximate to the imaginary plane passing through the axis of these respective upper or lower cylinders.
With the present invention, the air jets S 1 -S 6 may be blown, with the blow boxes 9 being concomitantly used, in all or some of the drying cylinder groups in which a twin-wire draw is used. If a twin-wire draw is used at the final end of the drying section, then the present invention can be advantageously applied in one or some of the first twin-wire draw groups only. The present invention is especially advantageously applied in the third and fourth, and possibly in one or several of the succeeding operating groups, when a single-wire draw is applied in the first and second operating groups of cylinders of a drying section.
In the twin-wire draw illustrated in FIGS. 3 and 4, the wire guide rolls have been shifted in longitudinal direction of the paper machine, i.e. in the running direction of the wire 1 and web W, in order for the paper web W to be supported on the wires 1 or 5, over as long a distance as possible. In the drying sections illustrated in FIGS. 3 and 4, the present invention operates even more efficiently than in the drying section illustrated in FIG. 1. In the drying sections of FIGS. 3 and 4, the negative pressure zone, which improves the supporting contact between the respective wires 1, 5 and the web W, can be made quite long.
In the embodiment of the present invention illustrated in FIGS. 1 and 2, the web W will have free runs as the web passes from the line of upper cylinders 2 to the line of lower cylinders 6, and vice versa. However, it has been possible to make these free runs or draws substantially shorter by appropriately positioning the guide rolls 4 and 8. It is also possible to make the running of the web W more reliable, by means of the jets of air S 1 -S 6 , and the blow boxes 9, in accordance with the present invention.
In the embodiments of the present invention illustrated in FIGS. 3 and 4, the web W runs from the upper line of cylinders 2 to the lower line of cylinders 6, and vice versa, always being supported by one of the drying wires 1 and 5. The web W is shifted from support of one of the wires, e.g. the first wire 1, to support by the second wire 5, and vice versa, at the respective guide rolls 8, 4, within the region denoted by the letter P in FIGS. 3 and 4 respectively.
In FIG. 3, the respective jets of air S 1 , S 3 , are directed in a direction substantially the same as the running direction of the respective wires 1, 5, with the running web W being shifted to a respective wire 1, 5 that is passing about the respective guide roll 4,8 as illustrated. In FIG. 4, the air jets S 1 , S 3 are directed substantially opposite to the running direction of the wire 1 supporting the web W, with the web W being shifted from the respective wire 1, 5 passing about the respective guide roll 4-8, to the other wire 1, 5 as illustrated in FIG. 4. Also, as illustrated in this figure, the jets of air S 2 , S 4 , are blown substantially opposite to the direction of rotation of respective guide rolls 4, 8, unlike the direction of the air jets S 2 , S 4 in the previously illustrated embodiments, which are in the direction of rotation of the respective guide rolls 4, 8.
The preceding description of the present invention is merely illustrative, and is not intended to limit the scope thereof in any way. | A method and apparatus for inhibiting or preventing fluttering in a running paper web in a drying section of a paper machine, such as in the area of a twin-wire draw. Air jets are blown into pockets defined by a wire guide roll and wire itself, such air jets issuing from suitably designed and positioned blow boxes to be directed at the side of the wire supporting the web either in a direction towards or opposite from the running direction of the wire, and also at the side of the wire guide roll not supporting the wire, in a direction of the tangent of the guide roll. An air jet may also be blown into the pocket defined by the wire guide roll and the wire itself, at the side of the wire running free, not supporting any web, such air jet being directed substantially perpendicular to the wire. Fluttering of the paper web and drawbacks resulting from the same, such as wrinkles and breaks in the web, are inhibited or prevented. | 3 |
TECHNICAL FIELD
The present invention relates generally to spur gear trains and more particularly to a gear train assembly which compensates for axial deflections due to deformation of housings or shafts.
BACKGROUND ART
One of the problems encountered with prior spur gear trains operating under load under conditions wherein high radial forces were encountered resulted from shaft deflections and deformations of the housings carrying the gear trains. Such deformations caused malfunctions at tooth engagement due to mutual offset or interference of teeth and produced excessive wear, reduced torque transmission and power loss.
In order to avoid such interference and malfunctions which reduced transmission life and increased load losses, transmissions were employed which were oversized relative to the actual running speeds and torque loads. Not only was this an impractical solution in terms of the transmission cost itself but, in addition, it presented unnecessary continuous no load power losses on the transmission system and thereby decreased operating system efficiencies.
DISCLOSURE OF THE INVENTION
In compendium, the present invention comprises a self-compensating gear system having an input gear and a driven gear coupled to an output shaft. An intermediate ring gear is movably carried on a support hub which includes the driven gear. The ring gear is driven by the input gear through a running tooth system and drives the output gear through a coupling tooth system.
To compensate for deflections of the output shaft, the housing and the gearings due to high radial forces, radial clearance is provided in the coupling tooth system to permit adjustable movement of the ring gear. In addition, axial misalignment of the gearings is also compensated by providing an arcuate, i.e. barrel shaped, axial tooth profile in the coupling tooth system.
Because the radial separating force of the running tooth system is greater than the radial centering force of the coupling tooth system, the ring gear is displaced relative to the center of the support within the limits of the tooth clearance of the coupling tooth system. The peripheral force is transmitted in the coupling tooth system only by a tooth segment lying opposite the point of engagement of the running tooth system. As a result the force required for adjustment of the ring gear is minimized.
A further embodiment of the gear system includes spherically configured rings on the support hub adjacent the teeth of the driven gear and mating spherical surfaces fixed to the ring gear. Suitable clearance is provided between the spherical surfaces. The ring gear is permitted to be axially displaced within the spherical surface clearance, and contact at the spherical surfaces provides the radial force required for adjustment of the ring gear while maintaining radial clearance within the coupling tooth system. The coupling tooth system thus transmits torque forces exclusively and is not required to provide the radial force necessary for adjusting the ring gear.
In order to reduce the forces which affect the position of the gears and provide long term stability of the tooth couplings as well as the mating spherical surfaces (if employed), a lubricating oil is supplied to the coupling tooth system. Sealing discs are provided on both sides of the coupling tooth system to confine the lubricating oil which, due to centrifugal force, forms an oil ring continuously enveloping and lubricating the coupling tooth system and, if present, the spherical surfaces.
In a further embodiment, the driven gear comprises an innal gear and the coupling tooth system includes reduced diameter arcuate tips along the axial tooth profile of the external ring gaer teeth.
From the foregoing summary, it will be appreciated that it is an aspect of the present invention to provide a deflection compensating gear system of the general character described which is not subject to the disadvantages of the background art aforementioned.
A further aspect of the present invention is to provide a deflection compensating gear system of the general character described which is relatively low in cost yet capable of operating under sustained high speed conditions with high torque loads.
A further consideration of the present invention is to provide a deflection compensating gear system wherein deformations of a gear train housing have no adverse effect upon the torque transmission.
A further feature of the present invention is to provide a deflection compensating gear system wherein axial misalignment of gears will not result in tooth interference.
A further feature of the present invention is to provide a deflection compensating gear system of the general character described which is efficient and capable of economical low cost mass production fabrication.
Yet another aspect of the present invention is to provide a deflection compensating gear system of the general character described which is capable of continued operation in the presence of dynamic shaft deformations.
An additional consideration of the present invention is to provide a deflection compensating gear system of the general character described which includes a radially displaceable ring gear for providing compensation for axial misalignment.
Another feature of the present invention is to provide a self-compensating gear system of the general character described which includes a coupling tooth system having arcuate axial tooth profiles for axial deflection compensation.
Yet another feature of the present invention is to provide a deflection compensating gear system of the general character described which includes a radially displaceable ring gear carried on a support and mating spherical surface on the support and the ring gear for providing radial forces necessary to axially adjust the ring gear.
Other features, advantages and aspects of the present invention in part will be obvious and in part will be pointed out hereinafter.
With these features, aspects and considerations in mind, the invention finds embodiment in various combinations of elements and arrangements of parts by which the invention is achieved, all with reference to the accompanying drawings and the scope of which is more particularly pointed cut and indicated in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
With reference to the accompanying drawings wherein some of the various possible exemplary embodiments of the invetnion are shown:
FIG. is a schematized fragmentary axial sectional view through a deflection compensating gear system constructed in accordance with and embodying the invention and showing a movable ring gear carried on a support hub which includes a driven gear having an arcuate axial tooth profile;
FIG. 2 is a fragmentary axial sectional view through an alternate embodiment of the invention with portions deleted and showing a ring gear and wherein a support hub includes spherical surfaces and the ring gear includes mating spherical surfaces for providing radial forces required to axially adjust the ring gear;
FIG. 3 is a fragmentary sectional view through a further embodiment of the invention wherein the support comprises an internally toothed gear.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in detail to FIG. 1 of the drawings, the reference numeral 15 denotes generally a deflection compensating gear system constructed in accordance with and embodying the invention and carried in a housing 17. The gear system 15 includes an input shaft 19 journalled for rotation through a pair of bearings 2, 3 which are seated within apertures of the housing 17. An input pinion 1 is formed of a spur gear fixed to the input shaft 19 and includes a plurality of teeth 14.
The gear system 15 further includes a movable ring gear 4 having a plurality of external teeth 5 and a plurality of internal teeth 6. The ring gear is driven by engagement between the input pinion teeth 14 and the ring gear external teeth 5. Such toothed interrelationship shall hereinafter be referred to as a running tooth system and designated by the reference numeral 16.
The gear system 15 also includes an output shaft 9 journalled for rotation through a pair of bearings 10, 11 which are seated within suitable apertures formed in the housing 17. The output shaft 9 includes an enlarged support hub 12 having a plurality of spur gear teeth 13 formed along its circumference. The support hub 12 and the teeth 13 are driven by the internal teeth 6 of the ring gear 4 and may be considered a driven gear.
The toothed interengagement between the internal teeth 6 of the ring gear 4 and the external teeth 13 of the driven gear will be referred to as a coupling tooth system 18.
Pursuant to the invention, the ring gear 4 is movably carried by the support hub 12 and is radially displaceable relative to the axis of the support hub 12 and its shaft 9. In addition, the axial profile of at least one set of teeth in the coupling tooth system 18, for example the driven gear teeth 13, are arcuate, i.e Due to the spherieal sector configuration of the teeth 13, the teeth 13 of the driven gear are laterally offsettable relative to the output shaft 9 and support hub 12 without encountering interference with the internal teeth 6 of the ring gear 4. Thus, output shaft or housing deflections due to high running radial forces will not impede tooth engagement.
By appropriate tooth dimensions with respect to engagement angle, the teeth 6, 13 of the coupling tooth system 18 are configured so that the separating force of the running tooth system 16, i.e. the radial force component urging the ring gear 4 away from the axis of the input shaft 19 is greater than the centering force of the coupling tooth system 18, i.e. the radial force component due to interengagement of the teeth 6, 13 and urging the ring gear 4 in a radial direction opposite to the separating force.
As a result, under a state of load the ring gear is radially displaced relative to the center of the output shaft 9 a distance limited by the clearance between the top and bottom lands of the teeth 6, 13 respectively. The peripheral force is transmitted only by a tooth segment lying opposite the point of engagement of the running tooth system 16 and thus the force required for adjusting the ring gear 4 is minimized. In addition, the teeth 6, 13 of the coupling tooth system 18 are preferably dimensioned so that by elastic deformation of the teeth in the force transmitting segment region of interengagement, a sufficient number of teeth 6, 13 concurrently participate in torque transmission. Such number is minimized in the region of the running tooth system.
It should be noted that in accordance with the invention it is desirable to maintain continuous lubrication within the coupling tooth system 18. For this purpose a pair of annular sealing discs 7, 8 are secured to the ring gear 4 adjacent the opposite sides of the internal teeth 6. The annular sealing discs 7, 8 preferably extend toward the center of the support hub 12 at least a distance equal to the depth of the teeth 13 to thereby confine a lubricant within the coupling tooth system 18 and maintain an oil ring.
Attention is now directed to FIG. 2 wherein an alternate. embodiment of the invention is shown. This embodiment is similar in configuration to the embodiment previously disclosed and with the drawing omitting portions of the gear system previously disclosed. The reference numeral 20 denotes generally a gear system constructed in accordance with the alternate embodiment. The gear system 20 includes a movable ring gear 24 similar in configuration to the ring gear 4 previously described. The ring gear 24 includes a plurality of external teeth 25 and a plurality of internal teeth 26. Engagement between a drive pinion (not shown) and the external teeth 25 of a running tooth system drives the ring gear.
The gear system 20 also includes a support hub 36 to which is joined an output shaft (not shown). Adjacent the periphery of the support hub 36, a wide web 29 is formed with the web having a plurality of spur gear teeth 38. The support hub 36 is driven by engagement between the teeth 38 and internal teeth 26 formed on the ring gear 24. In a manner similar to that previously described with reference to the prior embodiment, the ring gear 24 is movably carried by the support hub 36 and is radially displaceable about the axis of the support hub.
The tooth engagement between the ring gear teeth 26 and the support hub teeth 38 may be considered a coupling tooth system 23. In accordance with the invention at least one set of teeth of the coupling tooth system 23, for example the support hub teeth 38, are arcuate in axial profile.
The gear system 20 of the present embodiment differs from the gear system 15 of the prior embodiment in that the axial width of the teeth 38 is less than the axial width of the web 29 of the support hub 36. Positioned on the web 29 and extending on both sides of the teeth 38 are a pair of guide rings 42, 44. Similarly positioned on the ring gear 24 are a pair of guide rings 27, 28.
The support guide rings 42, 44 include convex spherical surfaces 46 which may be configured with the same radius of curvature as the arcuate tooth profile of the teeth 38. The convex spherical surfaces 46 engage mating concave spherical surfaces 30 formed on the ring gear guide rings 27, 28. It should be appreciated, however, that the diameter of the concave spherical surfaces 30 is slightly greater than the diameter of the convex spherical surfaces 46 to provide appropriate clearance so that the ring gear 24 with the guide rings 27, 28 can shift axially relative to the axis of the support hub 36 in accordance with the invention.
The ring gear 24 will thus be axially displaced within the limits of the spherical surface clearance and contact between the spherical surfaces 46, 30 provides the radial force required for adjustment of the ring gear. The clearance between the spherical surfaces 46, 30 is less than the clearance between the top and bottom lands of the teeth 26, 38 of the coupling tooth system 23 so that the teeth of the coupling tooth system 23 will not be required to generate radial forces during adjustment of the ring gear 24. As a result, the coupling tooth system 23 will transmit torque forces exclusively.
It should be additionally noted that the gear system 20 also includes a pair of annular sealing discs 32, 34 secured to the ring gear 24 on opposite sides of the guide rings 27, 28 and seated in grooves formed in the ring gear. The sealing discs 32, 34 provide, as with the previous embodiment, an appropriate lubrication confining area 49 to assure proper lubrication of the coupling tooth system 23. In addition, the sealing discs provide proper lubrication confinement for assuring that the guide ring spherical surfaces are also appropriately lubricated with a continuous oil ring.
In order to improve lubrication of the coupling tooth system 23 and spherical surfaces 46, 30, the gear system 20 includes an oil feed nozzle 47 which introduces appropriate lubricating oil into the lubricant confining area 49. In addition, the wide web 29 of the support hub 36 includes suitable oil flow passages 48 to provide oil flow from the confining area 49 to the bottom lands of the teeth 38. Centrifugal force thus assures forced lubrication directly into the coupling tooth system 23. Such forced lubrication also provides suitable lubrication between the spherical surfaces 46, 30 of the guide rings. It should also be noted that the lubricant confining area 49 extends between the sealing discs 32, 34 and the side edges of both the enlarged web 29 and the support hub guide rings 42, 44 to assure proper lubrication of the spherical surfaces 46, 30.
A still further embodiment of the invention is illustrated in FIG. 3. In this embodiment a gear system 53 includes a support hub which carries an internal gear. An input pinion 50 having spur teeth 51 engages internal teeth 54 of a ring gear 52 to provide a running tooth system 63 for driving the ring gear 52. In a manner similar to that described with respect to the prior embodiments, the ring gear 52 is movable.
The ring gear 52 includes external teeth 56 which engage internal teeth 60 of a support hub 55 having an output shaft 59. The external ring gear teeth 56, in engagement with the internal support hub teeth 60, comprise a coupling tooth system 61.
As described with reference to the first embodiment, the ring gear 52 is radially displaceable relative to the output shaft 59 due to the clearance between the top and bottom lands of the teeth 56, 60. Additionally, at least one set of teeth of the coupling tooth system 61 includes an arcuate configuration. It should be noted in this regard that arcuate projections 57 are formed on the tips of the top lands of the external ring gear teeth 56 and the displacement of the ring gear 52 is limited by the clearance between the projections 57 and the bottom lands of the teeth 60.
Thus, it will be seen that there is provided a deflection compensating gear system with radially displaceable ring gear which achieves the various features and aspects of the invention and which is well suited to meet the conditions of practical usage
As various modifications might be made in the invention as above set forth, it is to be understood that all matter herein described or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. | A gear system includes a housing and an intermediate ring gear movably carried on a support hub coupled to an output shaft. The ring gear is driven by an input pinion gear through a running tooth system and drives the support hub through a coupling tooth system. Misalignment of the gearings due to housing, shaft or support deflections under load are compensated by providing an arcuate axial tooth profile and radial clearance in the coupling tooth system. The coupling tooth system includes lubricant confined between a pair of sealing discs. In an alternate embodiment, the ring gear is carried on spherically configured rings of the support and the ring gear includes mating spherically configured rings with suitable clearance between the spherical surfaces. Engagement between the mating spherical surfaces generates the radial force required for adjustment of the ring gear while maintaining radial tooth clearance within the coupling tooth system. As a result, the coupling tooth system transmits torque forces exclusively. | 8 |
CROSS REFERENCE TO RELATED U.S. PATENT APPLICATION
[0001] This patent application relates to U.S. provisional patent application Serial No. 60/328,787 filed on Oct. 15, 2001, entitled OPTICAL SWITCH.
FIELD OF THE INVENTION
[0002] This invention relates generally to optical switches based on quantum interference, and more particularly the present invention relates to great enhancements of optical nonlinearities via the use of quantum Interference, and application of these nonlinearities to optical switches at low light levels (including the single-photon regime and quantum information processing).
BACKGROUND OF THE INVENTION
[0003] Over the past years, a great deal of effort has gone into the search for a practical architecture for quantum computation. It is well known that single-photon optics provides a nearly ideal arena for many quantum-information applications; unfortunately, the absence of significant photon-photon (“nonlinear”) interactions at the quantum level appeared to limit the usefulness of quantum optics to applications in communications as opposed to computation. Therefore, work has focused on NMR, solid-state, and atomic-physics proposals for quantum logic gates, but so far none of these systems has demonstrated all of the desired features such as strong coherent interactions, low decoherence, and straightforward scalability. Typical optical nonlinearities are so small that the dimensionaless efficiency of photon-photon interactions rarely exceeds the order of a part in ten billion.
SUMMARY OF THE INVENTION
[0004] The present invention shows that all optical switching (nonlinearity) may be enhanced by huge factors (e.g., ten orders of magnitude), making it possible for beams of light to control one another even in the extreme low-light-level regime (down to mean photon numbers smaller than 1). Such photon switches constitute novel quantum optical logic gates which may enable new technologies in quantum information processing as well as other low-light-level optical devices.
[0005] The present invention also provides a device which greatly enhances nonlinear optical effects between photon pairs in input laser beams via quantum interference. The device is capable of removing all (or nearly all) photon pairs from the input beams, efficiently converting them to their sum frequency. In an alternative mode, it is capable of changing the phase of all photon pairs in the input beams. The device thus functions as an all-optical switch which may be used as a quantum logic gate. The device can also be used to upconvert photon pairs of only particular polarizations, or to shift the phase of photon pairs of only particular polarizations, by using the appropriate choice of phase-matching. The device works even when there is, on average, less than one photon at a time in each input beam.
[0006] Broad Method
[0007] The method comprises having multiple (“pump” and “probe”) phase-related laser beams impinge on any optically nonlinear medium. One or more pump beam(s) have frequency, polarization, and direction chosen such that they are phase-matched to generate in the nonlinear medium probe beam(s) which are indistinguishable from the probe beams incident on the medium. Quantum interference occurs between the probes incident on the medium and those generated within the medium.
[0008] A Specific Method
[0009] Three phase-related beams are Incident on a crystal with a second order optical susceptibility (2) . The crystal Is phase-matched such that the pump beam is capable of generating pairs of photons, at roughly one-half its frequency, in the probe beams. The sum of the phases of the two input probe beams is set to some difference from the phase of the pump. The medium acts as a conditional phase-switch for photons in the input beams. The photon pair term accumulates an extra, nonlinear, phase shift. The intensity of the two probe beams and the pump beam are fixed to a set ratio depending on the mode of operation. The probability of obtaining a down-converted photon pair is roughly the same (to within a few orders of magnitude) as the probability of obtaining a pair of photons from the input probe beams. The intensity of the pump can be changed to allow the switch to be operated In a low phase-shift mode or a high phase-shift mode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Preferred embodiments of the invention will now be described, by way of example only, with reference to the drawings, in which:
[0011] [0011]FIG. 1 shows a diagrammatic representation of the present invention (a) Local oscillator (LO) beams (shown by dashed lines) are overlapped with the pair of down-converted beams. A coincidence count is registered either if (b) a down-conversion event occurs, or if (c) a pair of laser photons reaches the detectors (SPCMs).
[0012] [0012]FIG. 2 shows an experimental setup: BS 1 and BS 2 are 90/10 (T/R) beam splitters; SHG consists of two lenses and a BBO non-linear crystal for type-1 second-harmonis generation; BG is a colored glass filter; ND is a set of neutral density filters; A/2 is a zero-order half-wave plate; PH is a 25-m diameter circular pinhole; I.F. is a 10-nm-bandwidth interference filter, PBS is a polarizing beam splitter; and Det. A and Det. B are single photon counting modules. The thin solid line shows the beam path of the 810-nm light, and the heavy solid line the path of the 405-am pump light.
[0013] [0013]FIG. 3 shows the coincidence rate and singles rates as functions c the delay time. The coincidence counts (solid circles) demonstrate a phase-dependent enhancement or suppression of the photon pairs emitted from the crystal. The visibility of these fringe is (56.0 1.5)%. The corresponding effects in the singles rate at detectors A (open squares) and detector B (open diamonds) are also shown; the visibilities are 0.83% and 0.78%.
[0014] [0014]FIG. 4. The singles rate at detector A versus the delay for four different polarizer angle settings (labels in upper right corners). At −45o no LOs can pass; at 45o both LOs can pass; at 0o the LO to detector A can pass; at 90o the LO to detector B can pass. The fringes are apparent only for the +45o polarizer setting, and have a visibility of 0.7%. These four data sets show that both horizontally and vertically polarized photons must be present for the effect to occur.
[0015] Figures for Section II:
[0016] [0016]FIG. 1. A cartoon of the experiment. The signal beam, a weak (1) coherent state, is passed through a Mach-Zehnder interferometer in order to measure the phase shift. This shift is imprinted by a x(2) crystal pumped with a strong classical pump (p), only when the control beam (also a weak coherent state with mean photon number 2 1) contains a photon. This conditional phase operation is verified by correlating the MZ output fringes at det. 1 with detection of a control photon at det. 2.
[0017] [0017]FIG. 2. Schematic of the experiment. BS 1 - 4 are 90/10 (T/R) beam splitters; SHG consists of two lenses and a 0.1-mm BBO crystal for type-1 second harmonic generation; A/2 are half-wave plates; S.F. is a spatial filter; I.F. are interference filters; BG is a blue filter; PBS is a polarizing beam splitter; det. 1 and 2 are photon counters. The pump laser at 405 nm is separated from the 810 nm light by using a fused-silica prism, not shown for clarity.
[0018] [0018]FIG. 3. Phase-shifted fringes in the large phase-shift regime. The det. 1 singles rate (open squares, dashed line) and coincidence rate between det. 1 and det. 2 (closed circles, solid line) are shown as a function of the reference delay. The coincidence fringes display the phase of the signal for cased in which a control photon was present; the singles are dominated by cases in which no photon was present. For this particular pump phase, the coincidence counting rate lags the singles rate by (65 8)°.
[0019] [0019]FIG. 4. Phase shift versus pump phase delay. The phase of the pump laser was changed via the pump delay and was estimated using the accompanying modulation in the mean coincidence rate [10]. The phase shift between the coincidence and singles fringes is plotted against the pump phase delay for both the large phase-shift regime (solid circles) and the small phase-shift regime (open circles). The solid and dashed lines show the theoretical predictions for these two cases, respectively, based only on the measured ratio of the individual-path rates, and with no adjustable parameters.
[0020] Figures for Section III:
[0021] [0021]FIG. 2. a) A quantum circuit and b) its optical analogue for the conversion of Bell states to product states. a) This quantum circuit takes a pair of qubits in input modes 1 and 2 and performs a unitary transformation that will convert a Bell state to a product state. b) The optical analogue of the quantum circuit takes a photon pair in a Bell state to a rectilinear product state, provided the photon pair is in the correct superposition with the vacuum.
DETAILED DESCRIPTION OF THE INVENTION
[0022] I—Enhanced Second-Harmonic Generation (2-Photon Switch)
[0023] A. Background
[0024] Nonlinear effects in optics are typically limited to the high-intensity regime, due to the weak nonlinear response of even the best materials. An important exception occurs for resonantly enhanced nonlinearities, but these are restricted to narrow bandwidths. Nonlinear effects which are significant in the low-photon-number regime would open the door to a field of quantum nonlinear optics. This could lead to optical switches effective at the two-photon level (i.e., all-optical quantum logic gates), quantum solitons (e.g., two-photon bound states [1]), and a host of other phenomena. With this device, we demonstrate an effective two-photon nonlinearity mediated by a strong classical field. Quantum logic operations have already been performed in certain systems including trapped ions [2], NMR ([3], and cavity QED [4], but there may be advantages to performing such operations in an all-optical scheme—including scalability and relatively low decoherence. A few schemes have been proposed for producing the enormous nonlinear optical responses necessary to perform quantum logic at the single-photon level. Such schemes involve coherent atomic effects (slow light [5] and electromagnetically induced transparency [6] or photon exchange interactions [7]. We recently demonstrated that photodetection exhibits a strong two-photon nonlinearity [8], but this is not a coherent response, as it is connected to the amplification stage of measurement. While there has been considerable progress in these areas, coherent nonlinear optical effects have not yet been observed at the single-photon level for propagating beams. In a typical setup for the second-harmonic generation, for instance,a peak intensity on the order of 1 GW/cm 2 is required to provide an up-conversion efficiency on the order of 10%. In the device we describe here, beams with peak intensities on the order of 1 mW/cm 2 undergo a second-harmonic generation with an efficiency of about 1%, roughly 11 orders of magnitude higher than would be expected without any enhancement. While this 1% effect in the intensities of the outgoing modes can be described by a classical nonlinear optical theory, the underlying origin of the effect is observable in the correlations of the outgoing modes and requires a quantum mechanical explanation. Furthermore, the effect in the correlations produced by this device was measured to be about 70 times larger than in the intensities and, in theory, 100% of the photon pairs can be up-converted.
[0025] B. Enhanced Two-Photon Absorption/Suppressed Two-Photon Transmission
[0026] Our device relies on the process of spontaneous parametric down-conversion. If a strong laser beam with a frequency 2ω passes through a material with a nonzero second-order susceptibility, x (2) , then pairs of photons with nearly degenerate frequencies, v, can be created. In past experiments, interference phenomena have been observed between weak classical beams and down-converted photon pairs [9-11]. Although spontaneously downconverted beams have no well-defined phase (and therefore do not display first-order interference), the sum of the phases of the two beams is fixed by the phase of the pump. Koashi et al. [10] observed this phase relationship experimentally using a local oscillator (LO) harmonically related to the pump. More recently Kuzmich et al. [11] performed homodyne measurements to directly demonstrate the anticorrelation of the down-converted beams' phases. Some proposals for tests of nonlocality [12] have relied on the same sort of effects. Such experiments involve beating the down-converted light against a local oscillator at one or more beam splitters, and hence have multiple output ports. The interference causes the photon correlations to shift among the various output ports of the beam splitters.
[0027] In contrast, with this device the actual photon-pair production rate is modulated. A simplified cartoon schematic of our device is shown in FIG. 1. A nonlinear crystal is pumped by a strong classical field, creating pairs of down-converted photons in two distinct modes (solid lines). Local oscillator beams are superposed on top of the down-conversion modes through the nonlinear crystal and are shown as dashed lines. A single-photon counting module (SPCM) is placed in the path of each mode. To lowest order there are two Feynman paths that can lead to both detectors firing at the same time (a coincidence event). A coincidence count can occur either from a downconversion event (FIG. 1 b ), or from a pair of LO photons (FIG. 1 c ). Interference occurs between these two possible paths provided they are indistinguishable. Depending on the phase difference between these two paths (φ) we observe enhancement or suppression of the coincidence rate. A phase-dependent rate of photon-pair production has been observed in a previous experiment using two pairs of down-converted beams from the same crystal [13]. By contrast, our device uses two independent LO fields which can be from classical or quantum sources and subject to external control. If the phase between the paths (FIGS. 1 b , 1 c ) is chosen such that coincidences are eliminated, then photon pairs are removed from the LO beams by up-conversion into the pump mode. If, however if one of the LO beams is blocked, then those photons that would have been up-converted are now transmitted through the crystal. This constitutes an optical switch in which the presence of one LO field controls the transmission of the other LO field, even when there is less than one photon in the crystal at a time. This switch does have certain limitations. First, it is inherently noisy because it relies on spontaneous down-conversion, which leads to coincidences even if one or both of the LO beams are blocked. Second, since the switch relies on interference, and hence phase, it does not occur between photon pairs but between the amplitudes to have a photon pair. While this may limit the usefulness of the effect as the basis of a “photon transistor,” a simple extension should allow it to be used for conditional-phase operations (see Section II).
[0028] In order for the down-conversion beams to interfere with the laser beams, they must be indistinguishable in all ways (including frequency, time, spatial mode, and polarization). Down-conversion is inherently broadband and exhibits strong temporal correlations; the LOs must therefore consist of broadband pulses as well. We use a mode locked Ti:sapphire laser operating with a central wavelength of 810 nm (FIG. 2). It produces 50-fs pulses at a rate of 80 MHz. This produces the LO beams, and its second harmonic serves as the pump for the down-conversion. Thus, the down-conversion is centered at the same frequency as the LO, and the LOs and the down-converted beams have similar bandwidths of around 30 nm. To further improve the frequency overlap, we frequency postselect the beams using a narrow bandpass (10 nm) interference filter [14]. As this is narrower than the bandwidth of the pump, it erases any frequency correlations between the down-conversion beams. In addition to spectral indistinguishability, the two light sources must possess spatial indistinguishability. The down-conversion beams contain strong spatial correlations between the correlated photon pairs; measurement of a photon in one beam yields some information about the photon in the other beam. Such information does not exist within a laser beam; since there is only a single transverse mode, the photons must effectively be in a product state and exhibit no correlations. We therefore we select a single spatial mode of the down-converted light by employing a simple spatial filter. The beams are focused onto a 25 micron diameter circular pinhole. The light that passes through the pinhole and a 2-mm diameter iris placed 5 cm downstream is collimated using a 5-cm lens. In order to increase the flux of down-converted photons into this spatial mode, we used a pump focusing technique related to the one demonstrated by Monken et al. [15]. The pump laser was focused directly onto the down-conversion crystal. Since the coherence area of the down-converted beams is set by the phase-matching acceptance angle, the smallest pump area reduced the number of spatial modes being generated at the crystal, improving the efficiency of selection in a single mode. Imaging the small illuminated spot of our crystal onto the pinhole, we were able to improve the coincidence rate after the spatial filter by a factor of 30.
[0029] The final condition necessary to obtain interference is to have a well-defined phase relationship between the LO beams and the down-conversion beams. To achieve this, the same Ti:sapphire source laser is split into two different paths (FIG. 2). The majority of the laser power (90%) is transmitted through BS 1 into path 1, where it is type-I frequency doubled to produce the strong (approximately 10-mW) classical pump beam with a central frequency of 405 nm. This beam is used to pump our down-conversion crystal after the 810-nm fundamental light is removed by colored glass filters. Instead of using down-conversion with spatially separate modes as shown in FIG. 1, we use type-II down-conversion from a 0.5-mm beta-barium borate (BBO) nonlinear crystal. In this process, the photon pairs are emitted in the same direction but with distinct polarizations. The photon pairs are subsequently spatially filtered, spectrally filtered, and then split up by the polarizing beam splitter (PBS). The horizontally polarized photon is transmitted to detector A, and the vertically polarized photon is reflected to detector B. Detectors A and B are both single-photon counting modules (EG&G models SPCM-AQ-131 and SPCM-AQR-13). Path 1 also contains a trombone delay arm which can be displaced to change the relative phase between paths 1 and 2. To create the LO laser beams, we use the 10% reflection from BS 1 into path 2. The vertically polarized laser light is attenuated to the single-photon level by a set of neutral-density (ND) filters, and its polarization is then rotated by 45° using a zero-order half-wave plate, so that it serves simultaneously as LO for the horizontal and vertical beams. After the wave plate, the light may pass through a polarizer, which can be used to block one or both of the polarizations from this path. This is equivalent to blocking one or both of the LO beams. Ten percent of the light from path 2 is superposed with the down-conversion pump from path 1 at BS 2 . The LO beams are thus subject to the same spatial and spectral filtering as the down-conversion and are separated by their polarizations at the PBS. This setup is similar to certain experiments investigating two-mode squeezed light [16]. Rater than investigate the noise characteristics of the output modes, we study the effect of a photon in one LO beam on the transmission of a photon in the other beam.
[0030] In order to maximize the interference visibility, we chose the ND filters so that the coincidence rate from the downconversion path was equal to the coincidence rate from the laser path. The singles rates from the down-conversion path alone were 830/s and 620/s for detectors A and B, respectively, and the coincidence rate was (110±0.3)/s (the ambient background rates of roughly 340/s for detector A and 540/s for detector B have been subtracted from the singles rates, but no background subtraction is performed for the coincidences). The singles rates from the LO paths were 34 560 and 31 350/s for detectors A and B, respectively, and the coincidence rate from this path is (11.6±0.4)/s. The LO intensities need to be much higher than the down-conversion intensities to achieve the same rate of coincidences because the photons in the LO beams are uncorrelated. Nonetheless, the mean number of LO photons per pulse is on the order of 0.01 at the crystal and for this reason the process of stimulated emission is negligible. As the trombone arm was moved to change the optical delay, we observed a modulation in the coincidence rate (FIG. 3). We have explained that this interference effect leads to enhancement or suppression of photon-pair production; naturally, this should be accompanied by a modification of the total photon number, i.e., the intensity reaching the detectors. The visibility of the coincidence fringes is (56.0±1.5)% , and the visibilities in the singles rates are approximately 0.83% and 0.78% for detectors A and B, respectively. In theory, the visibility in coincidences asymptotically approaches 100% in the very weak beam limit for balanced coincidence rates. At the peak of this fringe pattern, the total rate of photon pair production is greater than the sum of the rates from the independent paths. At the valley of the fringe pattern, the rate of the photon-pair production is similarly suppressed. With appropriate device parameters, we have observed coincidence rates drop 16% below the rate from the laser beams alone, an 8 sigma effect. The coincidence and singles fringes are all in phase and have a period corresponding to the 405-nm pump laser. To ensure that the observed oscillations in the coincidence rate were not due to a spurious classical interference effect, we verified that interference was destroyed by insertion of either a blue filter in the LO path or a red filter in the pump laser path, but unaffected by red filters in the LO path or blue filters in the pump path.
[0031] [0031]FIG. 4 shows four sets of singles rate data for detector A, corresponding to four different polarizer settings. Recall that the light is incident upon the polarizer at 45°, so when the polarizer is set to 45°, both of the LO beams are free to pass. When the polarizer is set to 0° or 90°, one of the LO beams is blocked, and when the polarizer is set to −45° both of the LO beams are blocked. The left-hand side of FIG. 4 shows the data for the two orthogonal diagonal settings of the polarizer, −45° (top panel) and 45° (bottom panel); the right-hand side shows the data for the two orthogonal rectilinear settings, 0° (top panel) and 90° (bottom panel). When the polarizer is set to 0°, only the LO going to detector A is allowed to pass; on the other hand, when it is set to 90°, only the LO going to detector B is allowed to pass, so A measures only background plus down-conversion. For the 45° data, the singles rate at detector A shows fringes with a visibility of about 0.7%. This visibility is roughly 70 times smaller than the corresponding visibility in the coincidence rate because only about 1.4% of detected photons are members of a pair, due to the classical nature of our LO beams. The fringe spacing in the singles rate corresponds to that of the pump laser light at 405 nm even though it is the 810-nm intensity that is being monitored. By examining the other three polarizer settings (−45°, 0°, and 90°), it is apparent that in order to observe fringes in the singles rate, both LO paths must be open. This is evidence for a nonlinear effect of one polarization mode on another.
[0032] C. Photon Correlation (The Switch)
[0033] The intensity (singles rates) fringes can be explained by a classical nonlinear optical theory. Although the intensity of the difference-frequency light generated by one LO beam and the pump is negligibly small, its amplitude beats against the other LO to produce a measurable effect in analogy with optical homodyning. However, in a classical picture, the coincidence rate is just proportional to the product of the two singles rates [17]. Therefore, the maximum visibility in the coincidences in a classical theory is just the sum of the visibilities in the singles rates. In out case, that would correspond to a coincidence visibility of only 1.6%. Our 56% visibility can be explained only by a quantum mechanical picture in which the probability for one photon to reach a detector is strongly affected by the presence or absence of a photon in the other beam. A theoretical description of the intensity and coincidence effects has been performed. We have demonstrated a quantum interference effect which is an effective nonlinearity at the single-photon level. We have shown that pairs of photons may be removed from two LO beams, although the system is transparent to individual photons. The phenomenon is closely analogous to second-harmonic generation in traditional nonlinear materials, but is enhanced by the simultaneous presence of a strong classical spectator beam with an appropriately chosen phase. For a different choice of phase, it is be possible to observe an effect analogous to cross-phase modulation between the two weak modes (see section II). Strong nonlinearities at the single-photon level should be widely applicable in quantum optics [19,20]. Overall, effects such as these hold great promise for extending the field of nonlinear optics into the quantum domain.
[0034] References
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[0054] II—Conditional-Phase Switch for Photons
[0055] A. Background
[0056] A great deal of effort has gone into the search for a practical architecture for quantum computation. As was recognized early on, single-photon optics provides a nearly ideal arena for many quantum-information applications [1]; unfortunately the absence of significant nonlinear effects at the quantum level (photon-photon interactions) appeared to limit the usefulness of quantum optics to applications in communications as opposed to computation. (Nevertheless, two recent proposals [2,3] have resurrected the possibility of quantum computation using purely linear optics.) Therefore, work has focused on NMR, [4], solid-state [5], and atomic [6-9] proposals for quantum logic gates, but so far none of these systems has demonstrated all of the desired features such as strong coherent interactions, low decoherence, and straightforward scalability. Typical optical nonlinearities are so small that the dimensionless efficiency of photon-photon interactions rarely exceeds the order of 10 −10 . We have recently used quantum interference to enhance these nonlinearities by as much as 10 orders of magnitude, leading to near-unit-efficiency sum-frequency generation of individual photon pairs. In this application, we demonstrate that a similar geometry can be used to make a conditional phase switch. Our switch is very similar to an enhanced Kerr or cross-phase-modulation effect, in which the presence or absence of a single photon in one mode may lead to a significant phase shift of the other mode. This is also similar to experiments performed in cavity QED [6] (and to theoretical proposals for atomic vapors, in systems relying on atomic coherence effects [11] or photon exchange interactions [12]), but occurs in a relatively simple and robust system relying only on beams interacting in a nonresonant nonlinear crystal.
[0057] The controlled-phase or c-φ gate performs the mapping |m> 1 |n> 2 −>exp(imnφ)|m> 1 |n> 2 , where the subscripts 1 and 2 indicate the two qubits, stored in two distinct optical modes, and m and n can take the values 0 and 1 representing zero- and one-photon states [13]. This shifts the phase of |1> 1 |1> 2 by φ, leaving the other three basis states unchanged. Although in quantum mechanics an overall phase factor is meaningless, this unitary transformation is nontrivial when we consider what happens to superpositions of photon number. The operation induces a relative phase of f between the |0> and |1> states of qubit 2, if and only if qubit 1 is in state |1>. (It is this relative phase which is referred to as the “optical phase” of mode 2 [14].)
[0058] B. The Device
[0059] Since our device relies on interference, its operation is sensitive to the phase and amplitude of the initial state, and we must limit ourselves to a specific set of inputs. In particular, we illuminate our switch with two classical fields in weak coherent states, |Psi>=|a>|b>=[|0> 1 +a|1> 1 ] [|0> 2 +b|1> 2 ], for |a| and |b|<<1 This state includes contributions of all four two-qubit computational basis states. As we show theoretically and experimentally, the lowest-order action of the gate is to shift the phase of only the |1> 1 |1> 2 state, as desired for c-φ operation.
[0060] This gate differs from the canonical c-φ concept in several regards. Principally, the input cannot be in a pure Fock state (e.g., |1> 1 |1> 2 ), or an arbitrary superposition of the computational-basis states, because the appropriate relative phase of |0> 1 |0> 2 and |1> 1 |1> 2 must be chosen at the outset. Nevertheless, the gate produces significant entanglement at the output and may be useful in nondeterministic operation [2]; in other words, it may be possible to postselect the desired value of a given qubit rather than supplying it at the input. Alternatively, such a gate might be used in the polarization rather than the photon-number basis. The interaction can be controlled through phase-matching conditions such that the phase shift is impressed only if both photons have, for example, vertical polarization. Thus, two-photon entangled states as typically produced in down-conversion systems, which are more properly described as |Psi>=|0> 1 |0> 2 +epsilon {w|H>|H>+x|H>|V>+y|V>|H>+z|V>|V>}, could store the amplitudes of the four computational-basis states in the amplitudes w, x, y, and z, with the (small) coefficient epsilon ensuring that epsilon*d exhibits the appropriate phase relationship with the vacuum. Although the vacuum term would dominate, as in most down-conversion experiments, the computation would have the desired effect contingent simply on the eventual detection of a photon pair. Potential contamination due to states outside the computational basis (e.g., states in which two photons are present in the same mode) can be avoided by operating in the low-photon-number regime. Finally, the question as to whether the entanglement produced by these interactions might be useful as a generalized quantum gate in some larger Hilbert space (e.g., higher photon number states) remains open.
[0061] C. Implementation
[0062] Our device can be described as a modified Mach- Zehnder interferometer (MZI) (FIG. 1). The input beam is a weak laser pulse of frequency v (containing much less than one photon per pulse on average) which enters the interferometer and is split into the signal (mode 1) and phase reference (mode 3). Modes 1 and 3 are recombined at a beam splitter after mode 1 passes through a x (2) nonlinear crystal which is simultaneously illuminated by a pump beam at frequency 2v. The output fringes from the MZI serve to measure the relative phase introduced between the two arms by the action of the crystal. Our control beam (mode 2) is another very weak coherent state at v that crosses mode 1 inside the nonlinear crystal. Photon-counting detectors monitor one output of the interferometer and mode 2. In order to demonstrate the conditional phase operation of the device, we measure the phase of the fringes at det. 1 and compare the cases in which the control detector (det. 2) does or does not fire. This “conditional homodyne” measurement is similar to recent studies of “wave-particle correlations” in cavity QED [16].
[0063] A more detailed schematic of the device is shown in FIG. 2. The beam from a Ti:sapphire oscillator (center wavelength 810 nm, rep rate 80 MHz, and pulse duration 50 fs is used to create the four beams used in the device. The phase reference, signal, and control beams are created by separating a small amount of the fundamental beam with beam splitters (BS) 3 and 1 —all beam splitters are 90/10 (T/R). The signal and control beams are made by rotating the polarization after BS 1 and treating the horizontal and vertical components independently. All three of these beams are subsequently attenuated using neutral density filters. The majority of the pump undergoes second-harmonic generation (SHG) in a type-I beta-barium borate (BBO) crystal. With the fundamental removed, this 405-nm pulse serves as the pump laser for parametric down-conversion. The signal and control beams are recombined with the pump laser at BS 4 and all three beams are focused onto a second 0.5-mm BBO crystal phase matched for type-II down-conversion and, therefore, type-II SHG. The spot created on the down-conversion crystal is imaged through a spatial filter to select a single spatial mode. The output from the spatial filter is separated by a polarizing beam splitter (PBS) such that the vertically polarized control beam is sent to detector 2 for direct photodetection, while the horizontally polarized signal beam interferes with the phase reference at BS 2 . Detector 1 measures the output from one port of BS 2 . Both detectors are silicon avalanche photodiodes. Interference filters, with center wavelengths of 810 nm and bandwidths of 10 nm, are placed in front of each detector.
[0064] In previous work, described in section I, we demonstrated that quantum interference leads to a phase-sensitive photon-pair production rate in a similar geometry. The interference can be understood as follows. Initially, modes 1 and 2 contain weak coherent states and mode p contains an intense (classical) pump laser: |Psi>=|p> p [|00>+a|10>+b|01>+ab|11>]. Under the interaction Hamiltonian, H int of the nonlinear crystal, the lowest order action of the pump laser is simply to add an amplitude for a photon pair through parametric down-conversion. The final state becomes |Psi>=|p> p [|00>+a|10>+b|01>+(ab+A DC )|11>], where A DC is the amplitude for downconverion. In the verication of the device described in section I, we observed the modulation in the photon pair production rate by performing direct photon coincidence counting on modes 1 and 2. We changed the phase of the amplitude A DC by changing the delay of the pump laser and, in so doing, changed the value of |ab+A DC| 2 —the probability of producing a photon pair. However, this process also affects the phase of that amplitude, i.e., arg(ab+A DC ), This is the “cross-phase modulation” we study. The absolute phase of a state is never experimentally observable; we therefore study the relative phase between |11> and |01>, contrasting it with the case of no control photon: |10> vs |00>. This relative phase is precisely the optical phase measured by our Mach-Zehnder interferometer. The final state of modes 1 and 2 can be rewritten as follows: |Psi>=(|0> 1 +a |1> 1 )|0> 2 +b[|0> 1 +(a+(A DC /b)|1> 1 ]|1> 2 ]. In this form, it is evident that entanglement is generated between the photon number in mode 2 and the optical phase in mode 1; the conditions that |a|, |b|<<1 limit the state to one of nonmaximal entanglement. Nonetheless, maximal entanglement can be produced in polarization within the coincidence subspace. When |A DC |<<|ab|, (i.e., the down-conversion rate is much less than the “accidental” coincidence rate from the signal and control change in rate. In the opposite limit, when |A DC |>|ab|, the maximum phase shift is 180° and occurs at the point of maximum destructive interference.
[0065] To explore the small phase-shift regime, we adjusted our signal and control beam intensities to obtain, in the absence of interference, a coincidence rate of (256±3)/s between det. 1 and det. 2. Our coincidence rate from downconversion alone was (4.7±0.2)/s. The singles rates at det. 1 (again in the absence of interference) were 88×10 3 /s from the signal beam alone and 79×10 3 /s from the phase reference; det. 2 received a singles rate of 282×10 3 /s from the control beam. This corresponds to several photons per thousand laser pulses. The singles rates due to down-conversion were 400/s at det. 1 and 300/s at det. 2. To demonstrate the device, the phase reference was blocked and pump delay moved in subwavelength steps to observe fringes in the photon pair production rate (described in [10]). The pump delay was then stopped at a fixed phase relative to the maximum of the pair-production fringes. We then scanned over a few Mach-Zehnder interference fringes by stepping the reference delay in 0.04-micron steps and recorded the singles rates at the two detectors and their coincidence rate. Because of the low probability of having a photon in any given control pulse, the interference fringes in det. 1's singles rate are dominated by the case where zero photons are present in the control mode; the coincidence rate shows the phase-shifted fringes when a control photon is detected.
[0066] A sample data set is shown in FIG. 3 for a pump delay of −1.6 fs (about −455°). For clarity, the fringes shown are taken in the large phase-shift regime, with |A DC >|ab|. To achieve this regime, we reduced our coincidence rate from the signal and control beams to (1.1±0.1)/s in the absence of interference; our down-conversion coincidence rate was (5.2±0.2)/s. Det. 1 received about a 700/s singles rate from the signal and 8600/s from the phase reference, det. 2 had a singles rate of 129×10 3 /s from the control beam. The coincidence counts have been averaged over 40-sec intervals due to the considerable shot noise. The fringes were fitted to cosine curves where the period of the coincidence fringes was constrained to equal that of the singles fringes. The phase difference was then extracted modulo 360°.
[0067] D. Verification of Gate Operation
[0068] Relative phases were measured in this way for many different pump phase delays; those values are summarized in FIG. 4. The phase shifts measured for the low phase-shift regime are the open circles (right-hand scale). The dashed line is the theoretical prediction based on the experimentally observed ratio of coincidence rates, with no adjustable parameters. In this regime, the phase shift is limited to approximately |A DC |/|ab| about 8° for the experimental ratio of coincidence rates. The phase shift is approximately sinusoidal in the pump phase for this ratio. The shifts in the large phase-shift regime are shown in FIG. 4 as solid circles (left-hand scale). Theory is shown as a solid line and, again, involves no free parameters. It is clear that in this regime we are able to access any phase shift. In this regime, the phase shift does not follow a sinusoidal modulation but rather increases monotonically with the pump phase, modulo 360°. There is strong agreement between theory and experiment, with slightly reduced phase shifts in the low phase-shift regime possibly attributable to background.
[0069] We have demonstrated the correlation between the photon number in one mode and the optical phase in another in a coherent conditional phase switch. Our theoretical description of the device shows that entanglement between the two modes is generated, but explicit demonstration requires additional measurements. This is a new type of asymmetric entanglement, of the sort required for the quantum c-φ gate. However, our switch differs from the c-φ, since the switch's reliance on quantum interference makes it intrinsically dependent on the optical phase of the input beams While this phase dependence will not allow the gate to operate on Fock states, the gate does act exactly as a c-φ in the coincidence basis in some interesting situations. Devices such as this for of creating and controlling entanglement at the single-photon level are very exciting for the field of nonlinear quantum optics and are promising steps towards all-optical quantum computing.
[0070] References
[0071] [1] C. H. Bennett and G. Brassard, in Proceedings of the IEEE International Conference on Computers, Systems & Signal Processing, Bangalore, India (IEEE, New York, 1984), pp. 175-179; A. K Ekert, J. G. Rarity, and P. P. Tapster, Phys. Rev. Lett. 69, 1293 (1992); A. Muller, J. Breguet, and N. Gisin, Europhys. Lett. 23, 383 (1993); W. T. Buttler et al., Phys. Rev. Lett. 81, 3283 (1998); C. H. Bennett et al., Phys. Rev. Lett. 70, 1895 (1993); D. Bouwmeester et al., Nature (London) 390, 575 (1997). [2] E. Knill, R. Laflamme, and G. Milburn, Nature (London) 409, 46 (2001).
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[0084] III—Quantum Logic (Bell-State Determination)
[0085] A. Background
[0086] The new science of quantum information builds on the recognition that entanglement, an essential but long underemphasized feature of quantum mechanics, can be a valuable resource. Many of the headline-grabbing quantum communication schemes (including quantum teleportation, dense coding, and quantum cryptography) are based on the maximally-entangled two-particle quantum states called Bell states. Using the polarization states of a pair of photons in different spatial modes, the four Bell states are written as: |φ ± >=|HH>±|VV> and |ψ ± >=|HV>±|VH>, where |H> and |V> describe horizontal- and vertical-polarization states. These four states form a complete, orthonormal basis for the polarization states of a pair of photons. In each Bell state, a given photon is completely unpolarized but perfectly correlated with the polarization of the other photon. Photon Bell states were produced in atomic cascades for the first tests of the nonlocal predictions of quantum mechanics. Since that time, parametric down-conversion sources have replaced cascade souces due to their ease of use, high brightness, and the high-purity states they produce. However, down-conversion sources do not deterministically prepare photon Bell states, but rather states in which the Bell state component is in a coherent superposition with a dominant vacuum term; coincidence detection of photon pairs projects out only the two-photon component of the state.
[0087] B. Application of the Device
[0088] While optical Bell state source technology has shown marked improvement, methods of distinguishing these states has proven a difficult challenge. Perhaps the most well-known example of why distinguishing Bell states is important comes from quantum teleportation. A general projective measurement is required for unconditional teleportation; experimental teleportation was originally limited to a maximum efficiency of 25% since only the singlet state, |ψ>, could be distinguished from the other three states. The challenge for distinguishing Bell-states stems from the requirement for a strong inter-particle interaction, which is usually nonexistent for photons. Without such a nonlinearity, only two of the four states can be distinguished. It was realized that a strong enough optical nonlinearity, typically a x (3) nonlinearity, could be used to mediate a photon-photon interaction. Unfortunately, even the nonlinearities of the best materials are far too weak. An experiment using standard nonlinear materials to demonstrate a scheme for unconditional teleportation was limited to extremely low efficiencies (on the order of 10 −10 ). Proposals for extending optical nonlinearities to the quantum level include schemes based on cavity QED, electomagactically-induced transparency, photon-exchange interactions, and quantum interference techniques. Using the latter, we have recently demonstrated a conditional-phase switch, which is similar to the controlled-phase gate in quantum computation (discussed in section II).
[0089] Strong optical nonlinearities are desired so that one can construct a controlled-φ, a specific case of the controlled-phase gate for photons. Such a gate and all one-qubit rotations form a universal set of gates for the more general problem of quantum computation just as the NAND gate is universal for classical computation. One-qubit rotations are simple and easy to perform on photons. Consequently, with our conditional-phase switch one can construct a gate that transforms each Bell-state into a different logical basis state of a two-qubit system. Application of the latter gate and measurement in the logical basis performs a Bell-state measurement. The only unique requirement of this Bell-state measurement the photon pairs are in a known coherent superposition with the vacuum. This follows from the requirements for a functional conditional-phase switch, discussed in section II.
[0090] We disclose a way of implementing a transformation capable of converting the polarization state of a pair of photons from the rectilinear basis to the Bell state basis and vice versa provided the photon pairs are in a known coherent superposition with the vacuum. This transformation relies on a recently reported effective nonlinearity at the single-photon level. Requiring the photon pair to be in a superposition with the vacuum seems unusual, but this type of superposition exists in all down-conversion sources of entangled photons. It is only upon performing a photon-counting coincidence measurement that the maximally-entangled behaviour is projected out. While these down-conversion sources of Bell states exist and are practical in the lab, the creation mechanism does not suggest how one might try to measure those Bell states. In the device discussed here, the Bell state creator and Bell state analyzer look very similar. The creator can essentially be run in reverse to make the analyzer.
[0091] The device discussed herein constitutes a novel way of manipulating the degree of entanglement between a pair of photons, and may find a use in other quantum optics applications. In particular, it can be used for dense coding [1,2] a method of communicating more than one bit of information on a single photon. The ability to entangle and disentangle photon pairs is a crucial step toward building scalable all-optical quantum computers.
[0092] As used herein, the terms “comprises” and “comprising” are to be construed as being inclusive and open ended, and not exclusive. Specifically, when used in this specification including claims, the terms “comprises” and “comprising” and variations thereof mean the specified features, steps or components are included. These terms are not to be interpreted to exclude the presence of other features, steps or components.
[0093] The foregoing description of the preferred embodiments of the invention has been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiment illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed within the following claims and their equivalents.
Appendices Forming Part of the Present Disclosure
[0094] The appendix attached hereto provides mathematical material forming part of the present invention.
[0095] Practical creation and detection of polarization Bell states using parametric down-conversion, K. J. Resch, J. S. Lundeen, and. A. M. Steinberg. To be published in the Solvay Conference Proceedings (2002).
[0096] Electromagnetically induced opacity for photon pairs, K. J. Resch, J. S. Lundeen, and A. M. Steinberg, Journal of Modern Optics, 49,487 (2002).
[0097] References
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[0099] [2] K. Mattle, H. Weinfurter, P. Kwiat, and A. Zeilinger, “Dense Coding in Experimental Quantum Communication,” Phys. Rev. Lett. 76, 4656 (1996). | The present invention shows that all-optical switching (nonlinearity) may be enhanced by huge factors (e.g., ten orders of magnitude), making it possible for beams of light to control one another even In the extreme low-light-level regime (down to mean photon numbers smaller than 1). Such photon switches constitute novel quantum optical logic gates which may enable new technologies in quantum information processing as well as other low-light-level optical devices. The present invention also provides a device which greatly enhances nonlinear optical effects between photon pairs in input laser beams via quantum interference. The device is capable of removing all (or nearly all) photon pairs from the input beams, efficiently converting them to their sum frequency. | 6 |
This application is a division of application Ser. No. 08/617,734, filed Apr. 1, 1996, now U.S. Pat. No. 5,878,783.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an in-pipe vehicle which can carry out an operation within a pipeline, which pipeline may be a gas carrying pipeline.
2. Description of the Background
There have been various activities undertaken concerned with pipeline inspection including remote cameras to enable information on the internal condition of pipelines to be obtained.
SUMMARY OF THE INVENTION
The present invention is concerned with an arrangement which will allow operations to be undertaken from within the pipeline, without the need for external drives, umbilicals or other connections which restrict the movement or utility of such arrangements.
According to the invention there is provided a pipeline vehicle comprising a plurality of linked modules forming a self powered train for travelling within a pipeline, at least one of the modules being capable of carrying out an operation on the pipeline.
Further according to the invention there is provided a method of effecting an operation on a pipeline comprising passing a vehicle consisting of a train of modules through the pipeline to detect the presence of an item to be operated on; and moving the vehicle to align a module with the item to carry out the desired operation.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of example with reference to the accompanying drawings in which:
FIG. 1 shows a main pipeline with a number of service take-offs;
FIG. 2 shows an embodiment of the pipeline vehicle comprising a number of modules.
FIG. 3 shows the control mechanism associated with a module.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A buried cast iron gas main pipeline 1 shown in FIG. 1 carries a polyethylene pipe liner 2 which has previously been inserted through excavation 3 as part of a refurbishment programme.
A number of existing service pipe take-offs 4 each provide the source of gas to individual dwellings or other premises. As part of the refurbishment programme, there is a need to insert a liner in each service pipe and to join this to the main liner 2. In order to achieve this it has been necessary in the past to make an excavation at each service connection 5 (e.g. a screwed pipe connector or a service tee) and penetrate the main liner 2 through the excavation, sealing the take off to the main using a saddle connection, having removed part of the cast iron main in that region.
In the present invention, the need to have individual excavations is avoided as is the need to remove portions of the cast iron main at such excavations. FIG. 2 shows the mechanism now employed.
The in-pipe vehicle 10 of FIG. 2 includes a plurality of dissimilar individual modules 11-16 linked via similar linkage and suspension modules 17. The train of modular elements allows flexibility of operation in that each module provides a specific function which in this embodiment work together to remotely connect polyethylene gas main to service piping inserted into old metal piping (as described below). Other modular configurations would allow further tasks to be effected. The modular arrangement together with the suspension modules allows the degree of serpentine operation needed to negotiate bends in the pipe and to cope with the small diameter of the pipe which can be less than 150 mm.
The first module in the train is the traction module 11 which includes a motor 20 within one of the arms 22, 23 terminating in drive wheels 26 and idler wheels 25 respectively. The moveable arms 22 and 23 allow the wheels to contact closely the inner wall of the pipe through which it traverses and sensors within both the idler and drive wheel detect slippage which causes the traction unit to cause the arm to extend further to increase the traction affect. This can be effected by a motor driven ball screw acting on the lever arm to control the transverse load.
The motor 20 drives the wheels via gearing and feedback on movement, direction and slippage which can be compensated by internal control. Typically the traction unit provides a pushing force for the train of 80 N at a speed of 30 mm/s. Power for the modules including the traction module 11 is provided by the power unit 12 which incorporates a number of rechargeable batteries. Electrical connection to the modules is provided via the suspension unit 17 connectors. The suspension units 17 are provided of common construction and placed between each functional module to give the train flexibility required for small pipes. Each module 17 includes three spring loaded arms 30 terminating in wheels 31. In order to avoid the use of highly preloaded suspension springs, the three lever arms at one end are interconnected via a slider. Thus when the body of the suspension unit is depressed below the pipe centre-line the wheels at the top will be pulled away from the wall to provide no resistance to the upward centralising force. A central shaft 33 through each suspension unit is free to rotate relative to the body. Connectors at each end allow electrical connection between all modules to be effected for power and intercommunication requirements.
The manipulator module 13 includes three re actable extenders 40 which are controlled to extend when required beyond the manipulator's cylindrical body 41 so as to firmly support the module as it becomes wedged in the pipe. A motor with associated gearing (e.g. ring gear) and feedback allows the rear portion of manipulator to rotate relative to the front portion and as the modules are all mechanically linked this causes modules connected to the rear of the manipulator to axially rotate within the pipe so that they can be aligned to a certain portion of the pipe to effect a task when required. A `global` rotational manipulation for all modules has been found effective rather than each module making adjustments themselves, although `local` manipulation may be required in addition for a given module. The rotational manipulation can provide two 210° arcs with the body clamped against the pipe wall. Electrical connection through the rotating interface within the manipulator is provided by use of a coiled cable to avoid slip ring interference and reduce module length.
The sensor module 14 includes a number of magnetic sensors 50 spaced around the periphery of the module. The sensors (typically 40 in number) form part of a variable reluctance magnetic circuit. The detectors can be of the Hall effect type.
As the vehicle moves into the region of a service pipe junction there will be a change in the magnetic field measurement. The hole in the offtake corresponds to the largest loss and indicates its position.
The drill module 15 includes a motorised drill bit 60 capable of drilling a hole through the pipe, but more typically through the pipe liner. A 16 mm hole would be suitable to access a 25 mm service pipe tee.
The fusion module 16 carries a sensor 70 (e.g. a force-sensor with variable resistance when contacted by a guide wire) for detecting the guide wire in the service pipe liner (for reasons described below) and a heater device 71 for effecting a seal between the main liner and the service pipe liner. The manipulator module 13 allows the rotation by 180° of the train including module 16 to allow the sensing and sealing functions to be effected.
A master controller circuit can be located within the power module 12 and individual modules have localised control circuits to effect tasks associated with their particular devices. The master controller and the module controllers can be formed from a common approach using a hierarchical modular organisation of control and monitor process operating on independent communicating modules. The master controller is aware of operations being effected by individual modules and ensures the required tasks are carried out. Each module control arrangement includes a control board sensor and actuators of common hardware design with operation mode selection under software control. Such a module control system is shown in FIG. 3.
Analogue module sensors 80 connect to a programmeable peripheral interface 81 which carries an onboard analog to digital converter (ADC) and digital I/O lines. Digital sensors 89 connect to the digital inputs. Information from the interface is made available to microprocessor 82 which includes associated data storage RAM 83 and program storage ROM 84. A communication link 85 is also available to communicate with other modules. The microprocessor accesses sensor information via interface 81 (e.g. type HD631408) and controls the loads 90, (e.g. motors or other operational devices such as heaters) via decoder 86 and driver circuits 87. Current monitoring feedback is provided via line 88. Power supply regulation block 92 ensures trouble-free power supply requirements.
The microprocessor can be a T225 transputer contains a RISC CPU (16 bit 25 MHZ) and interprocessor communications links. Power for the devices can be high capacity nickel cadmium rechargeable batteries of the `pancake` configuration.
The system can be sufficiently intelligent to carry out the tasks without external control although with a radio link (e.g. 1.394 GHZ) it is possible to send information on operations being effected to an `above ground` station using the pipeline as a waveguide. Return signals could be sent to override or halt tasks if they are detected as being inappropriate. Hence automatic operation to effect an opening in th e main liner would be carried out as follows.
The train of modules is driven by module 11 along the pipe until detector module 14 detects a service tee through the main liner. The aperture will typically be at the highest point in the pipe wall but the actual position is determined by the detectors. The train will then move on until the drill module 15 is at the correct position beneath the tee. The manipulator module 13 then activates its extenders 40 to clamp the module. If the drill is not determined to be in front of the aperture from earlier calculations, the module then rotates in an arc to line up the drill.
Following the drilling operation through the main liner, the manipulator module 13 retracts its extenders and the train moves forwards until the fusion module 16 is determined to be located beneath the service tee.
The manipulator module 13 again activates its extenders and clamps itself to the main pipe. A rotation of the module is effected if it is determined that this is necessary to locate the detector 70 in front of the tee. The hole already drilled in the main liner allows the service pipe liner to be inserted through the service pipe using a very flexible guide wire. The service liner has at its front end a tapered lead component formed from cross-linked polyethylene. The presence of the guide wire confirms to the detector that the correct service tee is being refurbished. Once the lead end is located in the drilled hole, the guide wire is removed, indicating that the jointing step can be effected. Thus the manipulator 13 rotates through 180° to locate the heater device 71 on the fusion module 16 adjacent to the region of the service liner end, within the main liner hole and electric power is applied to the heater to fuse the joint in the liners by raising the temperature to the crystalline melt stage, causing the service liner end-piece to expand and fuse simultaneously to the main liner.
The tasks for this service tee are now complete. The manipulator module contracts its extenders 40 and the train of modules moved on along the pipe until it detects the presence of the next service pipe, when the operations can proceed once again.
Because of the self powered, self controlled nature of the vehicle distances of 100 metres or more can be handled even with bends in the run. | An in-pipe vehicle for carrying out at least one operation in a pipeline. The vehicle comprises a train of modules 11-16 interlinked by suspension units 17 to allow serpentine movement through pipe bends. The vehicle train has its own internal power supply and drive mechanism in respective modules. A detector module 14 determines the presence of a service junction and a manipulative module 13 allows the vehicle to be temporarily wedged in the pipeline whilst providing rotational movement to facilitate the desired operation at the junction. This can include drilling and welding of a service pipe to the main using appropriate modules. | 5 |
BACKGROUND
[0001] This disclosure relates to power distribution systems and, more specifically, to solid state contactors between busses.
[0002] In a typical electrical power distribution system, such as an aircraft electrical power distribution system, a power center includes at least one essential bus for distributing power to various components. A plurality of power sources may communicate power to the essential bus, including any number of AC and DC busses. The power sources are typically coupled to the essential bus using a DC contactor and a diode in series, which undesirably adds size and weight to the system. There is also a significant power loss when standard power diodes are used to conduct current.
SUMMARY
[0003] An example chip on bus bar solid state contactor assembly includes a switching element having a field-effect transistor and a diode in parallel. The switching element is configured to communicate electric current along a current flow path extending from a first bus bar to a second bus bar such that the switching element determines a direction of the electrical current. A control device is configured to selectively communicate current along a portion of the current flow path through the field-effect transistor or the diode of the switching element.
[0004] An example power distribution system for an aircraft includes a first DC bus having a first bus bar. The first DC bus is electrically isolated from a second DC bus having a second bus bar. An aircraft component is electrically connected to the first bus bar. A solid state contactor assembly electrically connects the first bus bar and the second bus bar. The contactor assembly includes a control device and a plurality of switching elements. Each switching element includes a field-effect transistor and diode in parallel. The control device is configured to drive the switching elements to control an electrical current between the first and second bus bars such that the switching elements determine a direction of the electrical current.
[0005] An example method of electrically connecting a first bus bar and second bus bar includes electrically connecting the first bus bar to the second bus bar using a solid state contactor assembly. The solid state contactor assembly has multiple switching elements each having a field-effect transistor and diode in parallel. The direction of current flow between the first bus bar and the second bus bar is controlled using the plurality of switching elements.
[0006] These and other features of the present disclosure can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a schematic view of an aircraft power distribution system including solid state contactor (“SSC”) assemblies.
[0008] FIG. 2A is a schematic view of the SSC assembly shown in FIG. 1 in an OFF state.
[0009] FIG. 2B is a schematic view of the SSC assembly shown in FIG. 1 in the ON state.
[0010] FIG. 2C is a schematic view of the SSC assembly shown in FIG. 1 in another ON state.
DETAILED DESCRIPTION
[0011] Referring to FIG. 1 , an aircraft 10 includes a power distribution system 12 having a first generator 14 , a second generator 16 , and a ram air turbine 18 electrically coupled to an AC bus 20 . The AC bus 20 is electrically coupled to a transformer rectifier unit 22 (“TRU”), which converts AC into DC. The TRU 22 is electrically coupled to an essential DC bus 24 and provides DC to the essential DC bus 24 .
[0012] Essential DC bus 24 includes a bus bar 28 . In addition to being supplied current from the TRU 22 , the essential DC bus 24 can be supplied current by a plurality of secondary DC busses 34 . Each secondary bus 34 is electrically isolated from essential DC bus 24 . Each secondary bus 34 includes a bus bar 36 . A power source 42 , such as a battery, is electrically coupled to each secondary bus 34 and provides power to each secondary bus 34 . Busses 34 , being powered by a battery 42 , are generally a lower voltage than the output of TRU 22 . In one example, SSC assembly 40 is configured so that current from bus 34 will instantaneously power essential DC bus 24 when TRU 22 fails. Additionally, current from TRU 22 is blocked from flowing to battery 42 unless battery charging is needed. The bus bar 36 of each secondary bus 34 is electrically coupled to the bus bar 28 of the essential DC bus 24 through a solid state contactor (“SSC”) assembly 40 . In this example, the SSC assembly is a chip on bus bar SSC assembly 40 such that the components of the SSC assembly 40 are disposed directly on an internal bus bar 87 (shown in FIG. 2A-2C ). However, other SSC assemblies 40 may be used. The essential DC bus 24 is connected to components 44 such that the essential DC bus 24 provides power to the external components 44 .
[0013] In one example, the AC bus 20 and essential DC bus 24 are disposed within electrical power center 26 . In this example, the electrical power center 26 is an emergency electrical power center 26 such that the TRU 22 is conducting about 200 A, and the output of the essential DC bus 24 is about 28V. However, it is within the contemplation of this disclosure to use other electrical power centers having additional components, and different power distribution.
[0014] In operation, the first generator 14 , second generator 16 , or ram air turbine 18 supply power to the AC bus 20 . The AC bus 20 distributes current to the TRU 22 , which converts the AC to DC. TRU 22 provides DC through a switch 46 to the essential DC bus 24 . Essential DC bus 24 can receive alternate DC from the secondary busses 34 through SSC assembly 40 . Essential DC bus 24 distributes power to external components 44 , such as electronics, controls, or other external devices. A power panel control unit 41 selects the power sources 14 , 16 , 18 and controls the logic of the SSC assembly 40 .
[0015] Although only one SSC assembly 40 or 40 ′ is shown, connecting one of the bus bar 36 to the associated one of the bus bar 28 , multiple SSC assemblies 40 , 40 ′ could be used. SSC assemblies 40 , 40 ′ may be located on the bus bars 28 , 36 of any of the essential DC bus 24 or secondary busses 34 . Additionally, any number of secondary busses 34 may be used, depending on system requirements.
[0016] Referring to FIG. 2A-2C , the SCC 40 is disposed on internal bus bar 87 and includes a switching element 60 a and a switching element 60 b . The features of the SSC 40 ′ would be similar to the SSC 40 . Switching elements 60 a , 60 b are in series and each include a diode 64 in parallel with a FET 66 . The diode 64 a of switching element 60 a is directed in an opposite direction from the diode 64 b of switching element 60 b . Switching element 60 a is electrically coupled to the bus bar 36 of the secondary bus 34 while switching element 60 b is electrically coupled to bus bar 28 of essential DC bus 24 .
[0017] Each switching element 60 a , 60 b is electrically coupled to a control device 70 a , 70 b . Control device 70 a includes a comparator 72 a , a gate drive 74 a , and an OR gate 50 a connected to the comparator 72 a and having a control input 52 a controlled by the power panel control unit 41 . Control device 70 b includes a comparator 72 b , a gate drive 74 b , and an OR gate 50 b connected to the comparator 72 b and having a control input 52 b controlled by the power panel control unit 41 . Each comparator 72 a , 72 b has inputs 78 a , 78 b connected on either side of each switching element 60 a , 60 b . The comparator 72 a , 72 b is thus able to read a voltage drop across the connected switching element 60 a , 60 b.
[0018] The comparator 72 a , 72 b uses inputs 78 a and 78 b to compare the voltage drop across connected switching element 60 a , 60 b . When there is a voltage drop from first position 80 b to second position 82 b of switching element 60 b , the gate drive 74 b communicates with the connected gate 76 b of the attached FET 66 b to instruct the FET 66 b to close the gate 76 b and allow flow through the FET 66 b . However, if the comparator 72 b reads a voltage drop from second position 82 b to first position 80 b , there is electric current flowing towards the secondary bus 34 as opposed to the essential DC bus 24 . The comparator 72 b then communicates with the gate drive 74 b , which in turn communicates to open the gate 76 b of the FET 66 b and prevent current flow through the FET 66 b . When the gate 76 b is open, the diode 64 b of the switching element 60 b will block flow towards the secondary bus 34 . After the voltage drop direction is reversed back in the direction of the essential DC bus 24 , the comparator 72 b will again communicate with the gate drive 74 b to order the FET 66 b to close its gate 76 b and allow current to flow through the FET 66 b again. The gate drive 74 a , comparator 72 a , diode 64 a , FET 66 a , and gate 76 a of switching element 60 a operate in substantially the same manner for electrical current that is intended to flow from the essential DC bus 24 towards secondary bus 34 .
[0019] In FIG. 2A , the bus bars 28 , 36 are shown in an OFF state. Therefore, no current is moving through the SSC 40 and there is no flow through either switching element 60 a , 60 b.
[0020] In this example, the FET 66 a , 66 b is a power MOSFET; however, other FETs 66 a , 66 b may be used.
[0021] In FIG. 2B , the bus bar 36 of the secondary bus 34 is in an ON state such the power panel control unit 41 signals electrical current to be available through the SSC assembly 40 to the bus bar 28 of the essential DC bus 24 . Control input 52 a signals OR gate 50 a to close the gate 76 a of the FET 66 a . Control input 52 b is inactive such that the comparator 72 b signals the gate 76 b of FET 66 b to open or close. In this example, during system power up, current moves through the FET 66 a of switching element 60 a and through the diode 64 b of switching element 60 b to establish the direction of the electrical current. In this example, the direction of the electrical current is from secondary bus 34 to essential DC bus 24 . When the essential DC bus 24 is powered by TRU 22 , diode 64 b prevents electrical current from flowing from essential DC bus 24 to secondary bus 34 .
[0022] In FIG. 2C , once the direction of the electrical current is established the bus bar 36 of the secondary bus 34 remains in an ON state and continues to distribute current through the SSC assembly 40 to the bus bar 28 of the essential DC bus 24 . In this example, after the direction is established, switching element 60 b moves current through the FET 66 b instead of the diode 64 b , generating power savings.
[0023] While the current moves through the FET 66 a of switching element 60 a and through the FET 66 b of switching element 60 b to the bus bar 28 of the essential DC bus 24 , the comparator 72 a reads a voltage drop from first position 80 a to second position 82 a for switching element 60 a and the comparator 72 b reads a voltage drop from first position 80 b to second position 82 b for switching element 60 b.
[0024] When the comparator 72 b detects a voltage drop across switching element 60 b from second position 82 b to first position 80 b , the gate drive 74 b is instructed to communicate with the FET 66 b to open the gate 76 b of the FET 66 b . (This position is shown in FIG. 2B .) If current is moving from essential DC bus 24 to secondary bus 34 , the control device 70 a connected to switching element 60 a would work in a similar manner as the control device 70 b connected to switching element 60 b.
[0025] As a result of gate 76 b of switching element 60 b being open, current cannot move through the FET 66 b and instead moves through diode 64 b of switching element 60 b . Because the diode 64 b forces current in a singular direction, the voltage drop direction is reversed. When the comparator 72 b detects a voltage drop from first position 80 b to second position 82 b , it will communicate to the gate drive 74 b to order the gate 76 b closed and current will flow through FET 66 b of switching element 60 b.
[0026] Although the example electric current in FIGS. 2A-2C is shown flowing through the SSC 40 from secondary bus 34 to essential DC bus 24 , flow may move through the SSC 40 in the opposite direction in a the same manner as described above. When power panel control unit 41 signals electric current to flow from essential DC bus 24 to secondary bus 34 , control input 52 a and control input 52 b are reversed such that control input 52 a is inactive and control input 52 b signals OR gate 50 b to close the gate 76 b of the FET 66 b.
[0027] By using SSC assembly 40 , a single assembly 40 is able to implement flow pathways of numerous traditional combinations, such as a contactor, a contactor and diode in parallel, and contactor in series with a diode. By using a FET 66 a , 66 b in parallel with a diode 64 a , 64 b within the assembly 40 , the losses due to voltage drop through diodes are reduced as diodes are only used to determine flow direction. Additionally, by using a single component, the SSC assembly 40 , the size and weight of the electrical power center 26 is minimized.
[0028] Although example embodiments have been disclosed, a worker of ordinary skill in the art would recognize that certain modifications would come within the scope of the claims. For that reason, the following claims should be studied to determine the true scope and content. | An example solid state contactor assembly includes a switching element having a field-effect transistor and a diode in parallel. The switching element is configured to communicate electric current along a current flow path extending from a first bus bar to a second bus bar. A control device is configured to selectively communicate current along a portion of the current flow path through the field-effect transistor or the diode of the switching element. | 7 |
FIELD OF INVENTION
[0001] The invention generally relates to a caddy for holding an item, such as a pen, pencil, cigar, or cigarette by removably or permanently attaching the caddy to an object, such as a golf bag.
BACKGROUND
[0002] Golf originated from a game played on the coast of Scotland during the 15th century. Golfers would hit a pebble instead of a ball around the sand dunes using a stick or club. After 1750, golf evolved into the sport as we recognize it today. During the 1880s, golf bags first came into use.
[0003] During a golf game, a person uses golf clubs to hit a golf ball, may wear cleated golf shoes while “on the green,” may also smoke cigar or cigarettes and/or use a stylus, such as a pen, pencil, or PDA stylus. Over the years, a number of accessories have been designed and marketed to help golfers clean their clubs, balls, shoes and cleats, as well as to cut cigar tips. Unfortunately, these tools take up valuable space in a golf bag or cart and can become easily misplaced.
[0004] As previously stated, golfers may smoke cigarettes or cigars while playing golf When a smoking golfer prepares to take a golf swing or stroke, the golfer typically lays the lighted cigarette or cigar on the ground. This unsanitary practice subjects the cigar or cigarette, and ultimately the golfer, to poisons or injurious chemicals on the ground. The same is true as to placing a pen, pencil or stylus on the ground. In addition, the foregoing items are more susceptible to being lost or forgotten on the green.
[0005] Despite advances in accessories, problems remain. One solution is to use a golf smoke tee, which is a golf tee with a cradle on top for holding objects such as cigars or cigarettes above the ground. One such golf smoke tee is described in U.S. Pat. No. 3,001,529, filed May 9, 1958, issued to Watson. The golf smoke tee disclosed in the Watson patent, however, is described as being about 1″ to 2½″ tall. This may pose problems for golfers who experience back problems. The golfer may need to strain his/her back to bend over and use such a golf smoke tee. An alternative cigar holder is shown in U.S. Design Pat. No. D385,059, filed on Aug. 7, 1996, and issued to Jenkins, which suggests a much taller vertical shank. Jenkin's design patent, however, does not a show or suggest a means for conveniently driving the holder securely into the ground. And, another patent described in U.S. Pat. No. 7,000,617, filed Mar. 18, 2003, issued to Cervantes, discloses a cigar holder with an elongated shaft that is 3-5 feet tall and sticks into the ground. This may pose problems because it adds weight and is a cumbersome tool to carry, especially for golfers who have limited space in their golf bag.
[0006] In light of the foregoing, a need, therefore, exists for an improved device for carrying a cigar, cigarette, pen, pencil, or other stylus, for example, is desirable. It is noteworthy that although the disclosed device may be used by a golfer for attachment to an object, such as a golf bag, the disclosed invention may hold any item that fits into the indentation of the device, and the device may attach to any device permitting an attachment other than just a golf bag.
SUMMARY OF THE INVENTION
[0007] An example embodiments of the invention generally provide a device including a wooden, metal or plastic substrate having at least a back surface, a front surface, and a depth portion located between the back surface and the front surface. Further, the device includes an indentation having a length and a width on the front surface, wherein the length is longer than the width and the length is oriented perpendicular to the depth portion. Further still, the device includes an attachment apparatus connected to the back surface, wherein the attachment apparatus is for attaching the device to another device. Yet further, the device includes an adjustable strap connected to the device and traversing at least the width. Thereby, the device allows one or more items, such as a pen, pencil, cigar or cigarette, to be placed in the indentation and securely held in place by the adjustable strap.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
[0009] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0010] FIG. 1 depicts a front view of the device as discussed herein and in accordance with the disclosed invention.
[0011] FIG. 2 depicts a side, cross-sectional view of the device as discussed herein and in accordance with the disclosed invention.
[0012] FIG. 3 depicts another side view of the device as discussed herein and in accordance with the disclosed invention.
[0013] FIG. 4 depicts a rear view of the device as discussed herein and in accordance with the disclosed invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0014] The following is a detailed description of example embodiments of the invention depicted in the accompanying drawings. The embodiments are examples and are in such detail so as to clearly communicate the invention. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. The detailed descriptions below are designed to make such embodiments obvious to a person of ordinary skill in the art.
[0015] Generally speaking, a device is disclosed that attaches to another object, such as a golf bag, and holds one or more items, such as a cigar or pencil, in an indentation of the device by an adjustable strap, such as an elastomeric band, that is connected to the device. Now, a more detailed description of the invention is disclosed.
[0016] Turning now to a more detailed description and referring the figures, FIG.1 is a frontal view of the device 100 . The substrate's front surface 110 , as well as the entire device 100 , itself may be constructed from wood, metal, and/or plastic. For example, from a decorative and robustness standpoint, the device 100 may be constructed from an aesthetically pleasing hardwood such as oak or cherry. In addition and in the alternative, the device 100 may be constructed from a metallic substance, such as chrome, brass, or steel, and/or a moldable plastic. Although wood may be used, metal and plastic are generally preferable because they are oftentimes stronger and less likely to fracture or splinter.
[0017] FIG. 1 also shows an indentation 120 that traverses the length 135 of the front surface 110 of the device 100 . In example embodiments, the length 135 is three inches and the width 140 of the indentation 120 is one inch; these are just example dimensions, however, and variance from these examples may be as small or large as deemed necessary to meet the purpose of the one or more items 160 to be held in place by the device 100 . As just suggested, the indentation 120 is where one or more items 160 may be stored securely in place by an adjustable strap 150 that traverses at least the width 140 of the indentation 120 . Typically, the indentation 120 is a groove or concavity that is capable of receiving for placement one or more items 160 , such as a cigar, smoking pipe, cigarette, or stylus, e.g., pen, pencil, or PDA stylus. That is, the one or more items 160 are held in place, even when the device 100 is held parallel with the gravitational force, because of the adjustable strap 150 , such an elastomeric band. Finally and although discussed in more detail below, the device 100 may include at least one hole 140 that traverses the depth portion of the device 100 , wherein the depth portion is perpendicular to the length 135 and width 140 . The optionally threaded hole 130 is for a user to adjust a screw or the like that then adjusts a space within the aperture for the attachment apparatus associated device 100 so that it 100 may attach to another object, such as a golf bag.
[0018] Moving on, FIG. 2 shows a cross-sectional side view of the device 200 . This substrate's side 220 of the device 200 shows the part of the attachment apparatus 230 as being countersunk into the device 200 . Specifically, FIG. 2 shows the cross-sectional view of two holes 225 that partly traverse the depth portion 210 . These two holes 225 are for receiving screws or the like in order to securely connect the attachment apparatus 230 to the device 200 . Acceptable dimensions for these holes 225 have been shown to be a quarter to one-half of an inch based on the previously disclosed length 135 of three inches and the width 140 of the indentation 120 being one inch.
[0019] In this example embodiment, the attachment apparatus 230 forms an what is deemed an inverted “J” shape. The linear portion of this inverted “J” shaped attachment apparatus 230 is flush with the back surface 410 as shown in FIG. 4 ; the screws going into holes 225 are countersunk with the substrate's back surface 410 of the device 200 . The hook portion of the inverted “J” shaped attachment apparatus 230 , however, is facing away from the substrate's front surface 110 , which is shown in FIG. 1 . The space of the aperture 240 is adjusted by adjusting the screw into the hole 245 . Screwing it into the depth portion makes the space of the aperture 240 larger; the converse is also true. The aperture 240 should be adjusted so that the resulting aperture 240 through adjusting the screw into the hole 245 renders a removable or permanent attachment of the device 200 to a particular object, such as a golf bag. In this example embodiment, the hook portion of the attachment apparatus 230 may be said to hook onto the object. In alternate embodiments and instead of the inverted J shape shown, the attachment apparatus 230 may be a hook, fastener (e.g., sliding a button located on the attachment apparatus into a button receiving sleeve located on another object, or vice versa; or, a male snap-button located on the attachment apparatus and female snap-button located on another object, or vice versa), or through complimentary Velcro® strips located on both n the attachment apparatus and the object.
[0020] Also depicted in FIG. 2 on this substrate's side 220 of the device 200 is the adjustable strap 250 . In this instance, the adjustable strap 250 surrounds the perimeter of the device 200 , and that is why it is shown in FIG. 2 . It 250 may be held in place by an adhesive substance, or, as shown in FIG. 4 , by tension through its placement between a part of the attachment apparatus 245 and the substrate's back surface 410 as shown on FIG. 4 of the device 200 . Although not depicted, but in other example embodiments, the adjustable strap 250 may be held in place by one or more screws that penetrate through the adjustable strap 250 and partly into the depth portion 210 of the device 200 .
[0021] FIG. 3 shows much of the same parts as found in FIG. 2 ., i.e., one of the substrate's sides 330 , two screw holes 325 for receiving screws to secure the attachment apparatus 330 to the device 300 . Further, it 300 shows screw with a hole 345 , wherein this screw is adjustable to adjust the space of the aperture 340 for attachment of the device 300 to another object. The difference in this FIG. 3 , however, is in the placement of the attachment apparatus 330 and the addition of Velcro® 350 . Here, the attachment apparatus 330 is not countersunk with the substrate's back surface 410 as shown in FIG. 4 . Instead, it 330 is on top of the back surface 410 . In addition, FIG. 3 shows the optional additional of a Velcro® strip to assist in securing the device 300 to another object also having a complimentary Velcro® strip.
[0022] Although not shown in the drawings, the attachment apparatus is shown as being connected to the device through screws or the like. See FIGS. 2 and 3 . Instead, the disclosed device may be formed through the attachment apparatus being integrally connected to the device. That is, the device with the attachment apparatus is a seamless connection, and such may be accomplished most easily through extruded, moldable plastics.
[0023] With reference to FIG. 4 , it shows the substrate's back surface 410 of the device 400 . This view shows the two holes, although it is acceptable to use one or more holes, for receiving screws 420 in order to secure the attachment apparatus 440 to the back surface 410 of the device 400 . Notably, these two holes 420 may be catty-corner with respect to each other as depicted, or they may appear elsewhere on the attachment apparatus 440 . As depicted in FIG. 4 , catty-corner placement may help eliminate torsional strains that the attachment apparatus 430 may undergo.
[0024] FIG. 4 also shows a black box, which represents the hook portion 430 of the inverted-J-shaped attachment apparatus 430 . The hook portion 430 is entirely black because FIG. 4 is a depiction that looks directly at the substrate's back surface 410 of the device 400 ; that is, a straight-on view of the device 400 .
[0025] In another, although non-depicted, example embodiment, a clip, such a small version of a clip used to fasten a bag of potato chips, is used as the attachment apparatus 430 . In such an example embodiment, one half of the clip is affixed, possibly with one or more screws of with an adhesive material, to the substrates' back surface 410 . The other half of the clip may be opened, for example, by squeezing a top located on the clip. After squeezing the clip, a user may place the opened half of the clip onto an object in the created aperture (e.g., 340 in FIG. 3 ), an then release the squeezing so that clip is now held firmly onto object, e.g., a golf bag.
[0026] The adjustable strap 450 is depicted with a portion of the strap 450 being behind the linear portion 430 of the inverted-J-shaped attachment apparatus 430 , and on the substrate's back surface 410 . In additional and alternative example embodiments, a portion of the strap 450 may be screwed or the like into place on any surface of the device 400 , and/or glued into place with an adhesive, such as an epoxy.
[0027] While the foregoing is directed to example embodiments of the disclosed invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims, which may be read in light of the foregoing disclosure, that follow. | A device including a wooden, metal or plastic substrate having at least a back surface, a front surface, and a depth portion located between the back surface and the front surface. Further, the device includes an indentation having a length and a width on the front surface, wherein the length is longer than the width and the length is oriented perpendicular to the depth portion. Further still, the device includes an attachment apparatus connected to the back surface, wherein the attachment apparatus is for attaching the device to an object, such as a golf bag. Yet further, the device includes an adjustable strap connected to the device and traversing at least the width. Thereby, the device allows one or more items, such as a pen, pencil, cigar or cigarette, to be placed in the indentation and securely held in place by the adjustable strap, such as an elastomeric band. | 0 |
BACKGROUND
When working on building structures, it is frequently difficult for the worker to properly position himself for work on particular troublesome areas of the building structure. One of these troublesome areas is near the top of the structure adjacent eaves which project outwardly beyond the side of the building structure. Workman often use ladders to gain access to those portions of the building near the eaves.
It is common practice to use gutters on these eaves. Unfortunately, the structural quality of these gutters is often insufficient to support the weight of a ladder and of the workman. In many situations, the only feasible way of obtaining access to certain areas of the building is to rest the ladder on the gutter. As a result, the gutter is often damaged by the ladder. Further, the instability of the gutters places the worker in a precarious position when his ladder is supported on the gutter. The problems caused by gutters on the eaves of building structures has accentuated in recent years with the widespread use of aluminum gutters.
Moreover, it is also necessary to repair and replace gutters on occassion. This type of gutter repair is extremely awkward when the ladder is rested against the gutter, even when the gutter has sufficient strength to support the ladder. It is thus often necessary to rest the ladder on the side of the building beneath the eave. The distance which the eave extends from the side of the building frequently makes work from this ladder location impractical and time consuming.
In the past, attempts have been made to provide ladder supports which permit the ladder to rest at a location which positions the worker conveniently. For the most part, however, these attempts have not been successful. The prior art ladder supports have generally lacked the requisite stability for secure support of the ladder, or they have been unduly awkward and cumbersome. While some of the more cumbersome supports do support the ladder satisfactorily, their operation has been so time consuming that they have been self defeating from an economic standpoint.
It is accordingly a primary object of the present invention to provide a ladder support which has a minimal set up time and is easy to use.
It is a further object of the present invention to provide a ladder support which has a high degree of stability.
It is yet another object of the present invention to provide a ladder support which will support a ladder adjacent an eave of a building structure without damaging the structure.
It is a further object of the present invention to provide a ladder support which has no moving parts.
SUMMARY OF THE INVENTION
In accordance with the invention, a ladder support is provided which includes a base having a pyramidal configuration. The base includes a plurality of legs converging upwardly to a common junction at the apex of the pyramidal structure. A ladder rest for supporting a ladder is rigidly connected to the legs at this common junction and extends in a direction which is transverse to that of the legs. Ladder stops are provided on opposite ends of the ladder rest for preventing sliding movement of a ladder which is supported upon the ladder rest.
In accordance with a further aspect of the invention, the base of the support includes two pairs of legs. The first set of legs extending for a first predetermined length and the second pair of legs extending for a second predetermined length.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which:
FIG. 1 is a fragmentary side elevational view of a ladder support according to the present invention supporting a ladder adjacent to the eave of a building structure.
FIG. 2 is a bottom view of the ladder support of FIG. 1 taken in the direction of line 2--2 in FIG. 1.
FIG. 3 is a perspective view of the ladder support of FIG. 1 taken in the direction of line 3--3 in FIG. 1.
FIG. 4 is a perspective view of the ladder support of FIG. 1 taken in the direction of line 4--4 in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and to FIG. 1 in particular, a ladder support 10 resting on a roof 12 of a building structure 14 is shown. The ladder support 10 is supporting a ladder 16 in a position which is proximal to, but spaced from, a gutter 18 which is attached to an eave 20 of a building structure 14.
As perhaps seen best in FIG. 2, the ladder support 10 includes a plurality of legs 22, 24, 26, and 28 having a common junction at location 30. Each of the legs 22, 24, 26, and 28 have end caps 22a, 24a, 26a, and 28a on their free ends. The junction 30 also joins the legs 22, 24, 26, and 28 at their ends to a cross bar or ladder support 32 which extends in a direction transverse to that of the legs. Ladder stops 34 and 36 extend perpendicularly from cross bar or ladder support 32 on each end of the ladder support 32. The ladder stops 34 and 36 are approximately two inches in length and have end caps 34a and 36a on their free ends. Each of the end stops 35 and 36 has an adjacent spacer element which extends upwardly from the cross bar 34 approximately one half inch and inwardly from the respective end stops 34 and 36 approximately one half inch. Spacer 40 is adjacent to end stop 34 and spacer 42 is adjacent to end stop 36.
Referring now to FIGS. 3 and 4, it will be noted that the legs 22, 24, 26 and 28 form a pyramidal configuration and converge toward an apex at junction 30, where they are rigidly connected to ladder support 32. Also, the length which ladder support 32 extends is slightly less than the corresponding extension of the free ends of the legs 22, 24, 26 and 28 in the same direction. The transverse extension of the ladder support 32 does, however, approximate that of the transverse extension of legs 22, 24, 26 and 28 in the same direction. These relative dimensions optimize the compactness of the ladder support with the size of the ladder which may be fitted on the ladder support 32 while maintaining stability.
Referring back to FIG. 1, it will be seen that the legs forming the base are dissimilar in length, leg 24 being longer than leg 28. From a combined viewing of FIGS. 2-4, it will be seen that the base is in the form of two sets of legs. A first set of legs is formed by legs 22 and 24 which have a common length while a second set is formed by legs 26 and 28 which also have a common length which is less than the length of the first set formed by legs 22 and 24.
FIG. 1 also shows that the end stops 36 and 38 extend substantially perpendicularly from the crossbar 32 in a direction which is in the plane formed by the first set of legs 24 and 22. It is thus seen that legs 24 and 22 form a set of rear legs while legs 28 and 26 form a pair of front legs. As a result of the dissimilar lengths of the two sets of legs, the ladder support 10 resists sliding upon an angled roof such as that shown by roof 12 as a result of force transmitted to the support 10 by the ladder 16.
The spacers 40 and 42 are optional. They are most helpful when the worker requires heavy materials at his work location. For example, when shingling a roof, it is necessary to transport large bundles of heavy shingles onto the roof. The spacers 40 and 42 prevent the ladder 16 from sliding laterally upon ladder support 32 to the end stops 34 or 36. It is then possible to apply a pulley to ladder support 32 and to use this pulley to transport heavy materials to the work location.
Thus it is apparent that there has been provided, in accordance with the invention, a ladder support that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with a specific embodiment thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and scope of the appending claims. | A ladder support having a pyramidal configuration with a ladder rest at the apex of the pyramid which provides a stable rest for supporting a ladder proximal to eaves of a building structure. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application 61/642,582, filed May 4, 2012, which is incorporated herein by reference.
FIELD OF INVENTION
[0002] The present invention relates to devices such as catheters for the diagnosis and/or treatment of cardiac arrhythmias, such as atrial fibrillation and atrial flutter. In particular the catheter has a two-piece connector for a split handle assembly to provide a means for more easily reusing and reprocessing various portions of the catheter assembly. The catheter handle assembly may also be used for other catheters such as renal ablation catheters.
BACKGROUND OF INVENTION
[0003] Cardiac arrhythmias, such as atrial flutter and atrial fibrillation in particular, persist as common and dangerous medical ailments, especially in the aging population. In patients with normal sinus rhythm, the heart, which is comprised of atrial, ventricular, and excitatory conduction tissue, is electrically excited to beat in a synchronous, patterned fashion. In patients with cardiac arrythmias, abnormal regions of cardiac tissue do not follow the synchronous beating cycle associated with normally conductive tissue as in patients with normal sinus rhythm. Instead, the abnormal regions of cardiac tissue aberrantly conduct to adjacent tissue, thereby disrupting the cardiac cycle into an asynchronous cardiac rhythm. Such abnormal conduction has been previously known to occur at various regions of the heart, such as, for example, in the region of the sino-atrial (SA) node, along the conduction pathways of the atrioventricular (AV) node and the Bundle of His, or in the cardiac muscle tissue forming the walls of the ventricular and atrial cardiac chambers.
[0004] Cardiac arrhythmias, including atrial arrhythmias, may be of a multiwavelet reentrant type, characterized by multiple asynchronous loops of electrical impulses that are scattered about the atrial chamber and are often self propagating. Alternatively, or in addition to the multiwavelet reentrant type, cardiac arrhythmias may also have a focal origin, such as when an isolated region of tissue in an atrium fires autonomously in a rapid, repetitive fashion. Ventricular tachycardia (V-tach or VT) is a tachycardia, or fast heart rhythm that originates in one of the ventricles of the heart. This is a potentially life-threatening arrhythmia because it may lead to ventricular fibrillation and sudden death.
[0005] Another type of arrhythmia is atrial flutter (AFL). Atrial flutter is an abnormal heart rhythm that occurs in the atria of the heart. When it first occurs, it is usually associated with a tachycardia and falls into the category of supra-ventricular tachycardia (SVT). While this rhythm occurs most often in individuals with cardiovascular disease or diabetes it may occur spontaneously in people with otherwise normal hearts. It is typically not a stable rhythm, and frequently degenerates into atrial fibrillation (AF). Therefore, treatment of AFL is desirable. Because of the reentrant nature of atrial flutter, it is often possible to ablate the circuit that causes atrial flutter. This is done in the electrophysiology lab by causing a ridge of scar tissue that crosses the path of the circuit that causes atrial flutter. Ablation of the isthmus, as discussed above, is a common treatment for typical atrial flutter. Physicians now a day utilized tip electrodes perpendicular to the tissue during flutter cases and drag the tip over the tissue to ablate linearly, this invention will allowed the physician to position the tip electrode parallel over the tissue with a single pulling action.
[0006] Atrial fibrillation occurs when the normal electrical impulses generated by the sinoatrial node are overwhelmed by disorganized electrical impulses that originate in the atria and pulmonary veins causing irregular impulses to be conducted to the ventricles. An irregular heartbeat results and may last from minutes to weeks, or even years. Atrial fibrillation (AF) is often a chronic condition that leads to a small increase in the risk of death often due to strokes. Risk increases with age. Approximately 8% of people over 80 having some amount of AF. Atrial fibrillation is often asymptomatic and is not in itself generally life-threatening, but it may result in palpatations, weakness, fainting, chest pain and congestive heart failure. Stroke risk increases during AF because blood may pool and form clots in the poorly contracting atria and the left atrial appendage. The first line of treatment for AF is medication that either slows the heart rate or revert the heart rhythm back to normal. Additionally, persons with AF are often given anticoagulants to protect them from the risk of stroke. The use of such anticoagulants comes with its own risk of internal bleeding. In some patients, medication is not sufficient and their AF is deemed to be drug-refractory, i.e., untreatable with standard pharmacological interventions. Synchronized electrical cardioversion may also be used to convert AF to a normal heart rhythm. Alternatively, AF patients are treated by catheter ablation. Such ablation is not successful in all patients, however. Thus, there is a need to have an alternative treatment for such patients. Surgical ablation is one option but also has additional risks traditionally associated with surgery.
[0007] Diagnosis and treatment of cardiac arrhythmias include mapping the electrical properties of heart tissue, especially the endocardium and the heart volume, and selectively ablating cardiac tissue by application of energy. Such ablation can cease or modify the propagation of unwanted electrical signals from one portion of the heart to another. The ablation process destroys the unwanted electrical pathways by formation of non-conducting lesions. Various energy delivery modalities have been disclosed for forming lesions, and include use of microwave, laser and more commonly, radiofrequency energies to create conduction blocks along the cardiac tissue wall. In a two-step procedure—mapping followed by ablation—electrical activity at points within the heart is typically sensed and measured by advancing a catheter containing one or more electrical sensors (or electrodes) into the heart, and acquiring data at a multiplicity of points. These data are then utilized to select the endocardial target areas at which ablation is to be performed.
[0008] Electrode catheters have been in common use in medical practice for many years. They are used to stimulate and map electrical activity in the heart and to ablate sites of aberrant electrical activity. In use, the electrode catheter is inserted into a major vein or artery, e.g., femoral artery, and then guided into the chamber of the heart of concern. A typical ablation procedure involves the insertion of a catheter having a tip electrode at its distal end into a heart chamber. A reference electrode is provided, generally taped to the skin of the patient or by means of a second catheter that is positioned in or near the heart. RF (radio frequency) current is applied to the tip electrode of the ablating catheter, and current flows through the media that surrounds it, i.e., blood and tissue, toward the reference electrode. The distribution of current depends on the amount of electrode surface in contact with the tissue as compared to blood, which has a higher conductivity than the tissue. Heating of the tissue occurs due to its electrical resistance. The tissue is heated sufficiently to cause cellular destruction in the cardiac tissue resulting in formation of a lesion within the cardiac tissue which is electrically non-conductive. During this process, heating of the electrode also occurs as a result of conduction from the heated tissue to the electrode itself. If the electrode temperature becomes sufficiently high, possibly above 60 degrees C., a thin transparent coating of dehydrated blood protein can form on the surface of the electrode. If the temperature continues to rise, this dehydrated layer can become progressively thicker resulting in blood coagulation on the electrode surface. Because dehydrated biological material has a higher electrical resistance than endocardial tissue, impedance to the flow of electrical energy into the tissue also increases. If the impedance increases sufficiently, an impedance rise occurs and the catheter must be removed from the body and the tip electrode cleaned.
[0009] Electrophysiology catheters used in mapping and ablation procedures are often connected to electroanatomic mapping systems such as the Carto 3® system from Biosense Webster, Inc. Electroanatomic mapping systems are used in conjunction with mapping catheters to determine the anatomy of the endocardial tissue in the heart and where nerve fibers, nodes and bundles appear on that tissue which may be ablated to treat the aforementioned cardiac arrhythmias. U.S. Pat. No. 7,860,553 discloses one such catheter connected to an electroanatomic mapping and/or ablation system the probe connects via a suitable mating connector to an adapter, which in turn connects, via another mating connector, to a console. The probe comprises a sensor and a probe microcircuit, which stores sensor calibration data. The adapter comprises a signal processing circuit for processing a signal that is output by the sensor. The adapter comprises its own microcircuit, which stores calibration data with respect to the signal processing circuit. A microcontroller in the adapter computes combined calibration data based on the data from both of the microcircuits. Signal analysis circuitry in the console receives the processed signal and analyzes this signal using the combined calibration data provided by the probe adapter. U.S. Patent Application No. 2008/0306380 discloses another such catheter and system where a probe adaptor having shielding is used to connect a probe such as a catheter to a console such as an electroanatomic mapping system.
[0010] The handles of electrophysiology catheters for the mapping and ablation of cardiac tissue contain electronic circuitry which converts signals from the tip or ring electrodes near the distal end of the catheter into digital signals that can be communicated to such electroanatomic mapping systems (such as the Carto 3® system from Biosense Webster) and/or an RF generator/ablation system. An electrical connection between the handle and such systems is necessary. This electrical connection is usually accomplished by a “male/female” pin-socket connector such as a Redel™ type connector or other such connector.
[0011] Primarily, these types of catheters are sold as single use only devices due to concerns with the ability to properly clean and sterilize the devices for reuse in addition to concerns that certain electronic circuitry in the devices may be damaged during reprocessing and make such devices less reliable in subsequent reuses.
[0012] There is increased desire to reuse electrophysiology catheters and/or components thereof. A catheter having a design that would facilitate such reuse would be desirable.
SUMMARY OF THE INVENTION
[0013] The present invention is directed to a catheter having a split-handle with a two piece connector that facilities reuse of a portion of the catheter assembly. Electronic circuitry that was typically placed in the operator controlled handle of the device has been moved to a two-piece connector so that the electronic circuitry may be separated from the operator controlled handle for ease of reprocessing. Additionally the two-piece connector for the split-handle design facilities placement of various electrical components in various portions of the connector for flexible design of reprocessed catheters, reuse of various components, EMI shielding and other purposes. Further, the connector design of the present invention provides for each of use with a keyed design and latching mechanisms to secure the pieces together and insure a proper connection.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] These and other features and advantages of the present invention will be better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
[0015] FIG. 1 is an exploded perspective view of the components that comprise the plug port assembly of the two-piece connector.
[0016] FIG. 2 is an exploded perspective view of the components that comprise the receptacle assembly of the two-piece connector.
[0017] FIG. 3 is a plan view catheter attached to the plug assembly of the two-piece connector of the present invention.
[0018] FIG. 4 is a cross-sectional view of the plug assembly of the FIG. 3 through lines A-A.
DETAILED DESCRIPTION OF THE INVENTION
[0019] This invention shown and described herein relates to a catheter having a split handle, i.e. some of the components primarily the printed circuit board (PCB) and associated electronics that would have resided in the operational handle of prior catheter designs are moved to reside in one portion of the two-piece connector. FIG. 1 depicts an exploded perspective view of the components of plug assembly 20 , a first portion of the two-piece connector. Plug assembly 20 comprises plug insulator 22 . Contacts are inserted and held in plug insulator 22 which is designed to hold both pin or socket contacts making plug insulator 22 bi-gender. Plug insulator has sufficient longitudinal length so that contacts do not protrude beyond the front face of the plug insulator 22 . Also, there is a first key 23 and second key on the opposite side (not shown) of different sizes which causes plug insulator to be keyed for one way insertion into the later described plug body 26 . Insulator lead 24 is designed to capture and hold the plug insulator 22 through two snap features 25 a and 25 b. Plug body 26 is the main interface from the plug assembly 20 to the receptacle assembly 40 . The plug insulator 22 and insulator lead 24 are held in place in plug body 26 when the snap features 25 a and 25 b are received in snap receivers 27 a and 27 b (shown in FIG. 4 and disposed opposite 27 a ). Plug body 26 also contains the lock and release button 28 and snap features. Lock and release button 28 engages and disengages the locking mechanism between plug assembly 20 and receptacle assembly 40 . EEPROM recess 33 in body 26 facilitates placement and securing of an EEPROM in the plug assembly. Plug housing 30 captures the plug body 26 when snap features 29 a and 29 b (not shown) of plug body 26 engage with snap receivers 31 a and 31 b (not shown but disposed opposite 31 a ) in the plug housing 30 . Plug housing 30 is the main part of the plug assembly 20 that is visible to the user when plug assembly 20 is connected to receptacle assembly 40 . Strain relief 32 is used to create a transition from the plug housing 30 to the cable 15 and cable insulation 16 (depicted in FIGS. 3 and 4 ). The strain relief shown in FIG. 1 is the cable strain relief. The catheter variant is the same on the connector side and smaller on the catheter side.
[0020] FIG. 2 depicts an exploded perspective view of the receptacle assembly 40 of the present invention. Receptacle insulator 42 is designed to hold both pin or socket contacts making it bi-gender. Contacts are insert and held in place by the insulator lead 44 . Because receptacle insulator 42 is shorter along its longitudinal axis than its companion plug insulator 22 the contacts will always protrude beyond the front face. Also, there is a first key 43 and second key on the opposite side (not shown) of different sizes which causes receptacle insulator to be keyed for one way insertion into the later described receptacle housing component. Insulator lead 44 is designed to capture and hold the receptacle insulator 42 when snap features 45 a and 45 b are engaged in the snap receivers 49 a (shown) and 49 b (not shown). Insulator lead 44 in the receptacle assembly can be substantially identical or identical to insulator lead 24 in the plug assembly to reduce component count although this is not necessary. Receptacle body 48 is the external portion of the interface from the plug assembly 20 to the receptacle assembly 40 . Snap features 50 a (shown) and 50 b (not shown) are received by a further set of snap receivers 47 a and 47 b which reside in receptacle housing 46 . Receptacle body 48 also includes the locking button catch feature 52 which holds the button during engagement and completes the lock between plug and receptacle assemblies. Receptacle housing 46 captures the receptacle body and is the main part of the receptacle assembly 40 that is showing when the plug assembly 20 is connected to the receptacle assembly 40 . Receptacle housing 46 also contains the magnetic shield which is necessary in order to reduce or eliminate external electromagnetic interference (EMI) from various other circuitry and wires present in the typical EP catheter lab environment or other hospital environment. The magnetic shield is preferably comprised of Mu metal although other type of know shielding may be used. Strain relief 54 assures a smooth transition between the receptacle housing 46 and the cable 15 . This end manages the pigtail to connector interface.
[0021] The two-piece connector described above is designed to engage in only one way. This is achieved by visually lining up the different off-center and centered keys 29 on the plug assembly with the related key ways 51 on the receptacle assembly. These different off-center and centered keys and key ways are part of the plug body 26 and the receptacle body 48 respectively. After alignment the halves are pushed together until the plug assembly seats in the receptacle assembly and an audible click is hears which means that the lock and release button 28 has engaged the button catch feature 52 . The two piece connector is now locked together. To disengage the user depresses the lock and release button away from the palm and the two halves are then unlocked.
[0022] The aforementioned components of the plug assembly may be made of numerous types of polymeric materials such as polycarbonate, polyurethane and other thermoplastic materials capable of use in injection molding.
[0023] FIG. 3 depicts a plan view of a catheter having the two piece connector of the present invention. Catheter 10 has an elongated catheter body 11 which is disposed between the operator controlled handle 14 and distal tip 12 where the diagnostic and/or therapeutic electrodes are disposed. The catheter body 11 comprises an elongated tubular construction having a single, axial or central lumen. The catheter body is flexible, i.e., bendable, but substantially non-compressible along its length. The catheter body can be of any suitable construction and made of any suitable material. A presently preferred construction comprises an outer wall made of polyurethane or PEBAX. The outer wall may also comprise an imbedded braided mesh of stainless steel or the like to increase torsional stiffness of the catheter body so that, when the control handle is rotated, the intermediate section of the catheter will rotate in a corresponding manner.
[0024] The outer diameter of the catheter body is not critical, but is preferably no more than about 8 french, more preferably 7 french. Likewise the thickness of the outer wall is not critical, but is thin enough so that the central lumen can accommodate puller members (e.g., puller wires), lead wires, and any other desired wires, cables or tubing such as irrigation tubing. If desired, the inner surface of the outer wall is lined with a stiffening tube to provide improved torsional stability
[0025] Components that extend between the control handle and the deflectable section pass through the central lumen of the catheter body. These components include lead wires for the tip dome electrode and ring electrodes proximal the tip dome electrode on the distal tip 12 , an irrigation tubing for delivering fluid to the distal section (optional), a cable for a position location sensor carried in the distal section (optional), puller wire(s) for causing the proximal and distal deflections and a pair of thermocouple wires to sense temperature at the distal tip section.
[0026] At the distal end of the intermediate section is the distal tip section that includes the tip dome and the aforementioned plurality of lumens, nitinol tube, puller wires, electrically conductive wires to the tip and optional ring electrodes.
[0027] The electrodes are constructed of a biocompatible metal, including a biocompatible metal alloy. A suitable biocompatible metal alloy includes an alloy selected from stainless steel alloys, noble metal alloys and/or combinations thereof. In one embodiment, the tip electrode is a shell is constructed of an alloy comprising about 80% palladium and about 20% platinum by weight. In an alternate embodiment, the shell is constructed of an alloy comprising about 90% platinum and about 10% iridium by weight. The shell can formed by deep-drawing manufacturing process which produces a sufficiently thin but sturdy shell wall that is suitable for handling, transport through the patient's body, and tissue contact during mapping and ablation procedures. In a disclosed embodiment, the shell wall has a generally uniform thickness ranging between about 0.003 in and 0.010 in, preferably between about 0.003 in and 0.004 in, and more preferably about 0.0035 in. While the deep drawn method is well suited to manufacturing the shell with a sufficiently thin wall, it is understood that other methods, such as drilling and/or casting/molding, can also be used.
[0028] Control handle 14 is used by the operator to control the position of the catheter 10 within the body of the patient. Control handle 14 may have disposed thereon various mechanism well known in the art for deflecting the distal tip 12 of the catheter 10 or for varying the radius of a loop at the distal tip. In FIG. 3 the distal tip is depicted as having a loop structure, however, various distal tip structures are known and used in the art.
[0029] Electrical cable 15 connects the electrodes and biosensors (or other location sensing means) as well as any pressure sensing means to plug assembly 20 providing a pathway for electrical signals to travel from the distal tip through conductive leads in elongated catheter body 11 through handle 14 into plug assembly 20 into receptacle assembly 40 and ultimately to the electroanatomic and/ablation or other system.
[0030] FIG. 4 is a cross-sectional depiction of the plug assembly 20 with associated wiring in an embodiment of the present catheter with two-piece connector. Electrical cabling 15 carrying the leads from the electrical elements in the distal tip as well as power from any ablation system to the ablation electrode in the distal tip enters strain relief 32 and the individual leads are connected to a plurality of pins 56 which are arranged in the plug insulator 22 of the plug assembly 20 . An EEPROM 58 is placed in EEPROM recess 33 in plug body 26 depicted in FIG. 1 . The EEPROM is used to store various catheter specific information such as biosensor calibration information, catheter identification information etc. Plug housing 30 functions as described above and is connected to plug body 26 through the snap features. Electrical leads 39 and 49 are connected to the EEPROM via solder connections 38 the EEPROM to two of pins 56 providing an electrical connection to receptacle assembly 40 and ultimately to a console for mapping and/or ablation. As can be seen any number of electrical leads may be connected to one or more pins 56 with the other end of such leads connected to various components such as an EEPROM, a PCB (if desired), diagnostic electrodes in the distal tip 12 , ablation electrodes in the distal tip 12 , magnetic position sensors (biosensors) in the distal tip 12 , pressure sensing mechanisms in distal tip 12 , microelements such as microelectrodes for recording intracardiac ECG, impedance measurements, microthermistors for temperature measurement, etc. The number of elements that may be connected is limited only by the number of pins 56 .
[0031] Pins 56 in plug insulator 22 then provide an electrical connection to the mating connectors (not shown) in receptacle insulator 42 . These mating connectors transfer the electrical sensor to electrical leads located in a cable (not shown) that then route the signals to a console that contains the control circuitry for the ablation and/or diagnostic procedure. A printed circuit board could also be disposed in the receptacle assembly 40 if it is desired to house certain of the electrical circuitry in a location not attached directly to the catheter.
[0032] An operator, such as an interventional cardiologist or electrophysiologist, inserts the catheter of the present invention through the vascular system of a patient so that a distal end of the catheter enters a chamber of the patient's heart. The operator advances the catheter so that the distal tip of the catheter engages endocardial tissue at a desired location or locations. The catheter is typically connected by a suitable connector at its proximal end to console. The console comprises a radio frequency (RF) generator, which supplies high-frequency electrical energy via the catheter for ablating tissue in the heart at the locations engaged by the distal tip, as described further hereinbelow. Alternatively, the catheter and system may be configured to perform ablation by other techniques that are known in the art, such as cryo-ablation, ultrasound ablation or ablation through the use of microwave energy.
[0033] Console may also use magnetic position sensing to determine position coordinates of distal end inside the heart of the patient. For this purpose, a driver circuit in console drives field generators to generate magnetic fields within the body of patient. Typically, the field generators comprise coils, which are placed below the patient's torso at known positions external to the patient. These coils generate magnetic fields in a predefined working volume that contains heart. A magnetic field sensor within distal end of catheter (shown in FIG. 2 ) generates electrical signals in response to these magnetic fields. A signal processor processes these signals in order to determine the position coordinates of the distal end, typically including both location and orientation coordinates. This method of position sensing is implemented in the above-mentioned CARTO system and is described in detail in U.S. Pat. Nos. 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612 and 6,332,089, in PCT Patent Publication WO 96/05768, and in U.S. Patent Application Publications 2002/0065455 A1, 2003/0120150 A1 and 2004/0068178 A1, whose disclosures are all incorporated herein by reference.
[0034] A processor in the system typically comprises a general-purpose computer, with suitable front end and interface circuits for receiving signals from catheter and controlling the other components of console. The processor may be programmed in software to carry out the functions that are described herein. The software may be downloaded to console in electronic form, over a network, for example, or it may be provided on tangible media, such as optical, magnetic or electronic memory media. Alternatively, some or all of the functions of processor 36 may be carried out by dedicated or programmable digital hardware components. Based on the signals received from the catheter and other components of system, processor drives a display to give operator visual feedback regarding the position of distal end in the patient's body, as well as status information and guidance regarding the procedure that is in progress.
[0035] The preceding description has been presented with reference to presently preferred embodiments of the invention. Workers skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in the described structure may be practiced without meaningfully departing from the principal, spirit and scope of this invention. In that regard, it can be understood that the order of the plug assembly and the receptacle assembly may be reversed in use, i.e., the receptacle assembly could be attached (fixedly or releasably) to the catheter handle 14 rather than the plug assembly. Additionally, the position of the snap features and receivers may be reveres as well as the lock and release button and lock catch. Furthermore, the EMI shielding could be placed in the receptacle body, the plug housing and/or the plug body rather than only in the receptacle housing.
[0036] Accordingly, the foregoing description should not be read as pertaining only to the precise structures described and illustrated in the accompanying drawings, but rather should be read consistent with and as support to the following claims which are to have their fullest and fair scope. | A catheter and method for the treatment of a patient having atrial flutter or other arrhythmia comprises an elongated catheter body having an outer wall, proximal and distal ends, and at least one lumen extending therethrough. Further it has a distal tip section comprising a flexible tubing having a proximal end and a distal end and a plurality of lumens extending therethrough. The proximal end of the tip section is fixedly attached to the distal end of the catheter body. The tip section further comprises a nitinol tube having slots formed therein which causes the distal tip section to deflect using the same puller-wire action used to cause the deflectable catheter to deflect at a point proximal to the distal tip section. | 0 |
FIELD OF THE INVENTION
This invention relates generally to card clothing, and is concerned in particular with enhancing the efficiency of fibre transfer to doffers and workers during textile carding.
BACKGROUND ART
A critically important aspect of carding is the efficiency of transfer of fibre from the main cylinder, or swift, to the doffer. Low transfer efficiency leads to excessive recycling of fibre around the swift, which in turn decreases the quality of the product through increased fibre breakage and the incidence of nep in the web. In worsted processing, this increased fibre breakage results in a reduction of the average fibre length or hauteur in the combed wool product. Doffer wire is designed and manufactured specifically to maximise the transfer efficiency by ensuring that the working angles are optimised and that the points of the teeth are sharp. The lifetime of the wire is maximised by appropriate metallurgy and heat treatment of the wire during manufacture.
The workers on cards function in the same way as doffers and the technology described herein, so far as it relates to doffer wire, applies equally to worker wire.
Disclosures of metallic card clothing are to be found in U.S. Pat. Nos. 4,964,195, 5,581,848 and 5,755,012. U.S. Pat. No. 4,964,195 describes a card wire in which, in order to improve the carding action, the teeth are formed to have hooked tips to open up neps. This hooked tip has a flat top and a convex underside to the straight inside edge of the tooth, although the corresponding commercial product has an underside of the tooth that is flat or nearly flat and inclined to the wire base. The flat top is thought to act as a fibre deflecting surface and so reduce the total opening available to receive the fibres between the teeth. U.S. Pat. No. 5,581,848 describes a combing or carding tooth with a second tip in the combing front edge.
Another known wire for carding applications has longitudinal grooves cut on both sides of the teeth. This wire is called “serrated” wire, and its object is to improve the doffing of slippery fibres by providing a notch in the sides of the tooth that prevents the fibres slipping off the pins. Tests by the present applicant have shown that it is of quite limited value for this purpose, even where the grooves are of rectangular cross-section and relatively deep.
FIG. 1 illustrates the successive stages in the transfer of a longer fibre 8 from a swift 4 , indicated at the left, to a doffer 6 . Successive positions of the fibre 8 are depicted at a to g. The arrows 4 a , 6 a , show the directions of rotation. Once a fibre loops around a doffer tooth 7 , it is subsequently straightened (position a) and held under tension by the teeth 5 of the swift 4 because of the much higher surface speed of the swift and the forward angle of the teeth. Given that the fibre on the doffer is under tension, the position evolves to one in which the fibre is normal to the surface of the doffer, provided the doffer tooth can hold the fibre. The actual angle achieved depends on the magnitude of the coefficient of friction between the fibre and the respective metal wires.
Previous analyses of doffer wire efficiency have emphasised the effectiveness of fibre pick-up and have ignored the effect of fibre loss from the pins, which will ultimately determine the level of transfer efficiency. For a doffer operating at equilibrium running conditions, the smaller the transfer efficiency to the doffer, the thicker the layer of recycled fibre on the swift, and the smaller the grip of the teeth of the swift on the fibre held by the doffer. In turn, this reduces the tension in the fibre and increases the chance that the fibre will be retained by the doffer. In effect, doffers rely on recycled fibre to reduce the grip of the pins of the swift so that transfer from the swift can occur. Thus, doffer efficiency is a dynamic function of the design of the doffer wire and the nature of the fibre being processed.
An object of this invention, at least in one application, is to increase the efficiency with which fibres are transferred from the swift to the doffer. The invention also has application to the design of worker wire because workers operate in exactly the same way as doffers.
SUMMARY OF THE INVENTION
The invention essentially entails the concept that enhanced fiber transfer efficiency can be achieve by forming one or more undercuts on the forward or inside face of the overhanging teeth or carding wire on the take-up component in a card transfer stage. The one or more undercut preferably includes a portion substantially parallel to the longitudinal direction of the wire, ie the peripheral surface of the cylindrical structure on which the wire is wrapped.
The invention accordingly provides card clothing comprising a strip of profile wire having a plurality of longitudinally aligned teeth with respective overhanging tips, wherein the edge-face of each tooth under the overhanging tip includes at least one undercut edge-segment spaced along the edge-face from the tip, which undercut edge-segment increases the retention of fibres by said edge-face during carding.
Preferably, there are a plurality of said edge-segments spaced apart and from said tip along said edge-face.
Advantageously, there are multiple undercut edge-segment in said edge-face and the spacing of these edge-segments increases in a direction away from the tip of the tooth.
In an embodiment, each of the edge segments has an extremity in the longitudinal direction of the profile wire, and these extremities of the edge segments and the tip are in alignment.
In one arrangement, the edge-face includes a tip portion adjacent said tip, a base portion adjacent said base, and one or more backset portions between the undercut edge-segment, and wherein said one or more basket portions, said tip portion and said base portion are generally parallel.
In another embodiment the one or more undercut edge-segment is provided by a notch or scallop recess in said edge-face.
The invention also provides a card roll, eg. a doffer or worker, clothed with card clothing according to the invention, and to a card including one or more such rolls.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 illustrates the successive stages in the transfer of a fibre from a swift to a doffer, and is discussed in detail under “background art” above;
FIG. 2 is a magnified isometric view of three adjacent teeth of a profile wire according to a first embodiment of the invention, suitable for use as a doffer wire;
FIG. 3 is a side elevational diagram of one of the teeth shown in FIG. 2;
FIGS. 4 to 6 are views similar to FIG. 3 of respective alternative embodiments: and
FIGS. 7 and 8 are graphs depicting the performance of doffer wire of the form illustrated in FIGS. 2 and 3 .
DESCRIPTION OF PREFERRED EMBODIMENTS
The tooth of a conventional doffer wire has an inside or re-entry inclined edge-face so as to define an overall overhang shape. The inventive concept stems from a realisation that the effectiveness of doffer wire can be significantly increased by making the inside or re-entry edge-face of the tooth, ie the edge-face under the overhang, as parallel as possible to the base of the wire. Prima facie, this involves forming the teeth as highly elongated highly obtuse elements which will improve the grip on the fibre during all stages of transfer from the swift to the doffer.
However, this elongate profile is not the most practical because, firstly, the teeth may be too slender to be sufficiently robust, and, secondly, there is a large reduction in the space available to accommodate the collected fibre. The present invention addresses this difficulty but maintains the essential concept by proposing that one or more, and preferably a plurality of, undercut edge-segments, preferably parallel to the base and longitudinal dimension of the wire, be formed on the inside or re-entry edge-face of each tooth. A simple embodiment of this approach is illustrated in FIGS. 2 and 3. FIG. 2 depicts a 3-tooth segment of profile wire, suitable for use as a doffer wire, in which the inside edge-face 112 of each tooth 110 is punched to provide a small dimension stepped profile consisting of three steps 114 and backset portions or risers 118 . Steps 114 provide undercut edge-segments, and are generally flat and parallel to wire base 113 , and to the longitudinal dimension of the wire. It is believed that this stepped profile counters the tendency for the fibres to slip off the tooth during the critical stages of doffing, eg. at position c in FIG. 1 . It should be noted that the steps 114 will not interfere with stripping of the doffer itself provided the angle of the step is such that the resultant undercut does not form a hook that can trap fibre.
The arrow 120 in FIG. 3 indicates the direction of the stripping motion (whereas arrow 122 is the general direction of pull on the fibre by the swift). It should be noted, however, that increasing the angle of the step will increase the holding angle of the wire and for some specialist uses, the advantages of this may outweigh the greater difficulties for stripping.
The tip region 111 is slightly truncated on top as illustrated at 111 a . Each of the risers 118 is angled to the lie of the original inclined edge-face 112 , which remains unchanged at 112 a adjacent base 113 . In this way, the outer extremity of each step 115 remains on the line of the original edge-face 112 . Riser 118 may be normal to base 113 but is preferably at a small angle to edge-face 112 .
One possible difficulty with the profile illustrated in FIGS. 2 and 3 is that the vertical portions, ie. risers 118 , between the steps, may increase the resistance to pick up of a fibre from the swift. This follows because the force required to push the fibre down the more steeply inclined risers 118 is greater than for the normal tooth. To avoid this difficulty and ensure unimpeded collection of fibre, the modified embodiment 210 shown in FIG. 4 has the risers or backset portions 218 parallel with the lie of the original edge-face 212 . With this arrangement, it is preferable that the successive undercut edge-segments or steps 214 increase in separation in a direction away from tip 211 . Without this, the thickness of the tooth may be significantly compromised towards the tip, potentially shortening its working life. It will of course be appreciated that the exact profile of the inside edge-face can be optimised by careful design, and that many different profiles are possible within the concept of the invention.
In another variation, the steps may be successively deeper, ie wider longitudinally of the wire.
The profile of FIG. 4 has the advantage that it maximises both the collection and retention of fibre by the doffer. Alternative technologies, such as serrated wire or roughening the inside face by abrasion or the deposit of grit-like particles, do not provide a similar combination of benefits. The disadvantage is that since it is just as difficult for fibres to slide down the pins as up, fibres will tend to concentrate at the tips of the pins impeding further transfer of fibre to the doffer. This disadvantage is clearly avoided by the profiles of FIGS. 3 and 4.
Each of the embodiments depicted in FIGS. 2 to 4 has three steps 114 , 214 . FIG. 5 illustrates an alternative design 310 in which the front edge 312 is punched to provide multiple close-spaced steps 314 separated by vertical (ie normal to the surface of base 313 ) risers 318 . Although this design provides multiple undercuts to catch fibres, it is likely that about three steps is sufficient. While studies have shown that fibre density at doffer transfer nips is around one per tooth, which suggests that only one or two steps is necessary, the fibre density can greatly vary locally: if a given tooth had only one or two steps 314 , fibres may not be held because of insufficient step space.
A further embodiment of profile-wire tooth 410 is illustrated in FIG. 6 . Here, the undercut edge-segments 414 are provided by a series of punched out notches or scallop recesses 430 along inside edge-face 412 . It will of course be understood that the generally semicircular shape of the notches 430 depicted in FIG. 6 is simply a matter of convenience and that many other shapes may be possible. Preferably, there is some portion of the undercut that is substantially horizontal or parallel to the base and longitudinal direction of the wire. The angle of the risers 418 also needs to be optimised to provide for the efficient collection of fibre.
Initial trials have indicated that the benefits of the wire profile of the invention are most evident at low swift-doffer draft, ie relatively higher doffer speeds. This arises because, whereas at higher rotational speeds fibres slip off conventional doffer wire teeth back onto the swift, the undercuts of the invention facilitate retention of the fibre and so reduce strip-back off the roller, ie increase the efficiency of transfer. In small-scale experiments with wire having the profile of FIGS. 2 and 3, the .transfer efficiency was estimated to be about 20% higher than that of a control conventional wire, as indicated by a measured faster rate of decay of fibre on the swift. This effect is illustrated in the graph of FIG. 7 .
There was a corresponding observed increase in hauteur, illustrated in FIG. 8, reflecting low retention on the swift and reduced fibre breakage.
The increased efficiency of the inventive wire can be used in two ways: to deliver either an increase in hauteur or an increased production rate. In other words, topmakers can achieve either a longer wool or a higher production rate.
Another way in which benefit might be derived from the invention is to reduce the doffer diameter from conventional values. For example, for worsted cards with single doffers, the diameter of the doffer is typically 1000 mm. It is thought that, by adopting doffer wire according to the invention, the diameter might be reduced to 300 mm or so. There would also be a similar reduction for double-doffer cards.
Although the discussion above has been primarily in relation to doffers, the illustrated or other suitable embodiments of profile wire could also be used in metallic clothing for workers, but in that case there are some other options that could be adopted. Firstly, since there are many more workers on a card, there is the option of grading the extent of the grip on the fibre through the card. This could be done simply by, eg, starting or finishing with workers wrapped with the new wire; various mixes of conventional and new wire are also possible.
The use of the wire is not confined to worsted systems. It may also find use in non-woven carding, especially in those circumstances where neps are a significant problem or the coefficient of friction of the fibre is very low, eg in the carding of PTFE (teflon) fibres. The invention could also be applied to cotton carding, where the invention may be able to displace the practice of automatic doffer wire sharpening to prevent premature dislodgment of the fibre mass from the bottom of the doffer roller.
Profile wire according to the invention could be manufactured by substantially conventional means eg by stamping initially uniform wire on the run. | Card clothing comprises a strip of profile wire having a plurality of longitudinally aligned teeth ( 110 ) with respective overhanging tips ( 111 ). The edge-face ( 112 ) of each tooth under the overhanging tip includes at least one undercut edge-segment ( 114 ) spaced along the edge-face from the tip. This undercut edge-segment increases the retention of fibres by the edge-face during carding. | 3 |
FIELD OF THE INVENTION
The present invention relates to public and industrial warning systems employing multiple remote warning units and more particularly to a method and apparatus for detecting false activation of the remote warning units.
DESCRIPTION OF THE RELATED ART
Outdoor warning sirens are the modern equivalent of what used to be known as civil defense sirens. Outdoor warning sirens are high power voice and siren systems used to notify the public of a potential safety hazard related to severe weather, darn failure, nuclear plant is emergency, chemical plant emergencies or hazardous material spills and the like. A typical outdoor warning system includes a number of warning units dispersed over a geographical area. Each of the warning units includes a high power siren and/or voice warning capability, a power supply with battery backup, a connection to the municipal power grid and a communication interface to link the remote warning units to a centralized base station. The communications link between the remote warning units and the base station typically comprises a one-way or two-way radio frequency (RF) link. In a one-way RF link system, the remote warning units are activated or deactivated by a command transmitted from the base station. Activation and deactivation of warning units operate similarly in a two-way RF link system with the additional feature that the remote warning units can communicate with the base station to relay information regarding status of the warning unit. Status reports may include an alert notifying the base station of some fault in the remote unit, such as failure of the backup power supply.
In a warning siren system, RF communications between the base station and the warning units are typically carried out in either of a dual-tone multi format (DTMF) or frequency shift keying (FSK), although other communications formats are possible.
The base station is typically located in an emergency management center where information and personnel are gathered to evaluate developing threats to public safety. Public safety personnel activate the outdoor warning system from the base station. An activation signal from the base station causes each of the remote warning units to emit a pre-determined tone and/or voice warning alerting the public to the hazard. Different tones and/or voice warnings may be assigned to each hazard and the warning units may store several warning patterns. Thus, there may be several activation commands, depending on the warning siren system configuration.
The term “base station” as used herein refers to that portion of an outdoor warning siren system used to interact with remotely located warning units. The emergency management center is typically equipped with a base radio and antenna. The outdoor warning siren system “base station” therefore typically includes an interface and audio frequency transceiver which allow the siren system to use the existing radio equipment. The “base station” may be a PC-based system or a stand alone unit. Either configuration includes a user-interface permitting emergency personnel to activate and monitor the warning siren system.
A concern raised about such public warning systems is the possibility of a system breach enabling an unauthorized party to generate a false alarm. Such a false activation might be carried out by monitoring the frequency used for communications between the base station and the warning units, recording a coded activation command when transmitted from the base station and replaying the activation command on the correct frequency. This means of false activation is available regardless of whether the activation is coded in the DTMF or FSK format.
One approach to preventing this type of system breach is to provide the base unit and warning units with synchronized clocks and to encode a time along with all system radio communications. The warning units are then programmed to reject or ignore activation command including a time stamp that does not match (or come very close to matching) the time on its clock. This approach increases the maintenance burden by requiring the clocks to be maintained in synchronicity. A particularly severe side effect of this approach is that if the proper maintenance is not performed, the clocks will be out of time and reject even a legitimate warning activation.
Time stamps and other complex data encryption algorithms often require additional, expensive hardware. The additional equipment and complexity may also result in increased maintenance expense.
There is a need in the art for a method and apparatus for detection of a system breach in an outdoor warning siren system. The method and apparatus are preferably capable of distinguishing a valid transmission from an unauthorized transmission.
SUMMARY OF THE INVENTION
The method and apparatus for detection of system breaches in outdoor warning siren systems comprises apparatus and steps for validating encoded RF transmissions used for communications between a base station and remotely located warning units. An aspect of the invention relates to the detection and validation of all command signals that could activate the warning units of an outdoor warning siren system. The invention may be as simple as the addition of computer-implemented steps to the operating software of the base station equipment, although changes to the outdoor warning siren system may be necessary.
A typical outdoor warning siren system has one or more base stations capable of transmitting encoded RF command signals to activate one or more remotely located warning units. In an exemplary embodiment of the present invention, each of the base stations is programmed to monitor the system communication radio frequency (RF). A system with a two-way RF link between the base station and the warning units will necessarily monitor the system communication RF. In a system with a one-way RF link, implementation of the exemplary embodiment of the invention may require the addition of system communication RF monitoring capability. It should be noted that the outdoor warning siren system monitoring function for a particular base station is suspended when that base station is transmitting on the system communication RF.
The present invention may be implemented by adding a security device to the existing base station equipment. The security device is a stand alone unit interfaced with the base station radio and equipped to accept inputs from emergency personnel as well as provide outputs indicating siren system status to emergency personnel. The security device may replicate the base radio interface and audio frequency protocol transceiver to provide the necessary monitoring and transmission capability. In this manner, a siren system using a one-way RF link is upgraded by interfacing the security device with the base station radio and existing alarm activation transceiver.
In an outdoor warning siren system with multiple base stations capable of transmitting an activation command, part of the coded activation command identifies the base station generating the command. An aspect of the invention relates to each base station being provided with a validation procedure. The validation procedure relies on two simple facts. The monitoring function is suspended on a transmitting base station for the brief period of transmission, e.g., a base station does not transmit and monitor at the same time; and a legitimate activation command must be generated by one of the base stations in the outdoor warning siren system. Thus, a legitimate command signal cannot be detected by a base station generating the command signal.
The validation procedure comprises computer-implemented steps of:
monitoring the system communication RF to detect command signals; decoding detected command signals to determine the originating base station; comparing the base station ID of the detected command signal with the detecting base station's ID; and invalidating the command signal if the base station ID included in the detected command signal matches the detecting base station's ID.
Upon detection of an invalid activation command, the outdoor warning siren system may be configured to automatically transmit a command turning off the warning units. The outdoor warning siren system may also be configured to alert relevant personnel to the detection of a system breach. The emergency personnel are then able to deal with the situation accordingly.
An object of the present invention is to provide a new and improved method and apparatus for ensuring the integrity of RF communications in outdoor warning siren systems that is compatible with existing equipment.
Another object of the present invention is to provide a new and improved method and apparatus for ensuring the integrity of RF communications in outdoor warning siren systems that is efficient and reliable.
A further object of the present invention is to provide a new and improved method and apparatus for ensuring the integrity of outdoor warning siren systems that is effective regardless of the format used to encode RF command signals from a base station to the warning units.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional block diagram of a representative security device for implementation of aspects of the method of the present invention;
FIG. 2 is a flow chart of a main routine for a security sub system according to aspects of the present invention;
FIG. 3 is a flow chart of a validate string sub-routine called by the main routine of FIG. 2 ;
FIG. 4 is a block diagram of an exemplary outdoor warning siren system compatible with the method of the present invention; and
FIG. 5 is a block diagram partially illustrating an exemplary outdoor warning siren system in conjunction with a false activation signal.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An exemplary outdoor warning siren system illustrative of several aspects of the present invention is shown in FIGS. 1 through 5 . The illustrated outdoor warning siren system 10 includes one or more base stations 20 and one or more remotely located warning units 30 connected to the base station by an RF link. Each warning unit 30 is includes a sound generating warning device 36 for the generation of tone and/or voice warning signals, a power supply 34 comprising a connection to the local power grid (if available) and a backup power system (usually a battery), microprocessor-based control electronics 32 and RF reception and/or transmission components 24 . In some configurations, solar panels (not illustrated) may be used to charge a battery-type power supply. The control electronics 32 are preferably programmed with alternative tones and/or voice warnings corresponding to different hazards. The control electronics 32 are also equipped with a decoder/encoder for interpreting encoded command signals or encoding status signals sent to the base station 20 . The radio receiver or transceiver 24 is equipped with an appropriate antenna for the reception of and/or transmission of RF signals.
One or more base stations 20 provide emergency personnel with the capability to activate the remotely located warning units 30 by transmission of command signals. FIG. 1 is a functional block diagram of an exemplary embodiment of a security device 20 a for incorporation into or interface with a base station 20 . The security device 20 a primary functional blocks are the microcontroller 40 , a user interface 44 , a radio system 46 , a data system and a power bus 48 . The user interface 44 provides contact closures that may be configured to provide visual indications of the system status and allows emergency personnel to acknowledge a system breach by a contact closure. The radio system 46 includes a base radio interface and an audio frequency protocol (AFP) transceiver 50 in communication with the microcontroller 40 . The AFP transceiver 50 encodes and transmits the command signals to the warning units 30 . The data system 42 includes on-board memory 54 and may also include an interface 56 with an external computer for additional data storage. Power is distributed to the various components from the power bus 48 .
It will be understood that control circuitry of the security device 20 a is preferably implemented using a programmable microcontroller 40 . Alternatively, the security device 20 a user interface 44 , data system 42 and microcontroller 40 may be emulated by software installed on a personal computer (not shown) and interfaced with a radio system 22 . Whatever the physical form of the security device 20 a , it will be understood that the security device is programmable and includes memory for storage of, for example, validation program steps and steps permitting activation of the radio system 22 to transmit a clear command.
The method and apparatus of the present invention may be built into the base station 20 or may be implemented as an add-on security device 20 a as shown in FIG. 5 . The security device 20 a “learns” the base station ID of the base station to which it is attached and uses it in the validation steps as described below. This “plug and play” ease of installation allows the security device to be easily added to existing outdoor warning siren systems without disrupting the system or requiring extensive training of personnel using the system.
New or existing outdoor warning siren systems may be configured as a one-way or two-way system. In a one-way outdoor warning siren system, the remotely located warning units 30 do not have the capability to transmit signals back to the base station equipment. In a two-way outdoor warning siren system 10 as shown in FIG. 4 , each of the remotely located warning units 30 is coupled to the base stations 20 by a two-way RF link. Typically, the outgoing RF link 23 from the base station 20 to the warning units 30 is used for commands from the base station to the warning unit to turn on, turn off, test, or request a status report from the warning units. The incoming RF link 21 from the warning unit 30 to the base station 20 is typically used for regular status reports from the warning unit and may also include requests for maintenance or notifications of a fault from the warning unit to the base station.
In the representative outdoor warning siren system 10 , command signals from the base station 20 to the warning units 30 have a particular format, for example, a ten-digit DTMF string. Returning signals from the warning units 30 to the base station 20 have a different format, for example, a fourteen- to eighteen-digit DTMF string.
An aspect of the invention relates to monitoring the system communication RF and computer implemented steps that validate detected command signals. A security device 20 a in accordance with the present invention includes the monitoring capability even if the existing base station 20 to which it is added does not. In an outdoor warning siren system configured for two way communications, the security device may be implemented without changes to the existing hardware.
In accordance with a further aspect of the present invention, each transmission from a base station 20 includes an encoded portion associating the transmission with the base station that generated it. Each base station 20 or security device 20 a is programmed to monitor the system communication RF. Upon detection of a command signal, the base station 20 or security device 20 a decodes the signal to determine the originating base station ID. If the detected command signal indicates that the detecting base station was the originating base station, the signal is determined to be invalid and indicative of a system breach. If the detected signal contains the base station ID of another of the base stations; the detecting base station ignores the command signal.
A further aspect of the present invention relates to how an outdoor warning siren system improved according to the present invention reacts to detection of an invalid command signal. The base station 20 or security device 20 a may be configured to automatically transmit a command signal turning off any warning units activated by the invalid control signal. This option is indicated at steps 100 (Yes), 102 (Yes) and 104 of FIG. 2 . Another option is to alert authorized personnel to the system breach so that they may deal with the situation as they see fit. This option is indicated at steps 100 (Yes), 102 (No) and 106 . Step 106 corresponds to sending notice to relevant personnel that a system breach has occurred. This may include visual and/or audio alarm indications at the base station. In either case, the invention provides a reliable means for detecting invalid command signals in an outdoor warning siren system.
Data System
The data system 42 is comprised of the EEPRom Data Storage 54 and PC Port Interface 56 functional blocks. The data system 42 provides a means by which an end-user can enter, store, view or change system configuration data.
Configuration data includes system area code, station ID and counter measure scenario, (a counter measure scenario could be audio/visual contact closures and/or automatic sending of a cancel command to siren or system). On power-up the microcontroller 40 loads configuration data into RAM from EEProm 54 at step 110 of FIG. 2 . The operating program of the security device 20 a , including the main routine of FIG. 2 and the Validate String sub-routine of FIG. 3 are run in the microprocessor RAM to detect a system breach. If detected, the main routine deploys a selected countermeasure scenario. A representative countermeasure scenario is illustrated at steps 100 , 102 , 104 , and 106 of FIG. 2 .
The microcontroller 40 has reserved commands for updating data stored in EEPRom Data Storage 54 . When these commands are received, the microcontroller 40 will update the corresponding data field or fields.
Depending on the microcontroller used, the EEPRom Data Storage 54 may be external or internal to the microcontroller. Also, the EEPRom Data Storage 54 is interfaced to the microcontroller 40 serially and that protocol is either I 2 C or polled, depending on the microcontroller used.
The PC Port Interface 56 connects the microcontroller 40 to a PC's serial or USB port. Through the PC Port Interface, commands and data are exchanged-between the microcontroller 40 and a PC (not illustrated).
User Interface
The user interface 44 is comprised of the Audio/Visual Closures and. Breach Acknowledge functional blocks. The user interface 44 is provides contact closures, if configured as part of a counter measure scenario, when a system breach is detected. The term “contact closures” is used to describe the activation of electronic or electromechanical relays to provide control to user-selected devices that may include audio and/or visual signaling devices. An authorized person may disable (open or de-activate) the audio/visual closures by using the breach acknowledge functionality also provided by the user interface. The breach acknowledge is a control input (contact closure) to the security device 20 a.
If the microcontroller 40 detects a system breach and if contact closures are configured as a counter measure, contact closures will move from the “Normally Open” to “Normally Closed” state. Likely external equipment connected to the audio/visual closures might be a flashing light or audible alarm device. Activation of these or similar warning devices signals an operator that a system breach has occurred. A breach acknowledgment from an authorized person will revert the contact closures back to the “Normally Open” state.
Radio System
The radio system 22 includes Audio Frequency Protocol (AFP) Transceiver 50 and Base Radio Interface 52 functional blocks. This provides an electrical interface between the security device microcontroller 40 and the signal handling portions (transmitter/antennae) of the radio system 22 . Functionality for encoding and decoding either the FSK or DTMF audio frequency protocol signals is provided by this system. It will be understood that the security device radio system may duplicate some functions in the existing equipment.
The Audio Frequency Protocol Transceiver 50 monitors all radio and/or landline communications within the outdoor warning siren system 10 . Typically DTMF and/or FSK are the audio frequency protocols (AFPs) being monitored. As each character, as defined by the protocol in use, is detected an interrupt is issued to the microcontroller 40 informing it of the character's presence.
Should the microcontroller 40 require a transmission, the Audio Frequency Protocol Transceiver 50 will convert digital characters from the microcontroller 40 into a format that corresponds to the protocol in use. Several characters together form a string.
The Base Radio Interface 52 provides electrical isolation and signal conditioning between the system's base radio 22 and the microcontroller 40 . To accommodate a variety of radios, configuration options may be provided.
Microcontroller
The microcontroller 40 acts as the “brain” of the base station 20 . The microcontroller 40 interacts with the functional components of the base station 20 through an operating program uploaded from memory on system power up. System variables such as area code and base station ID are retrieved from Eeprom. The microcontroller:
transmits and receives radio frequency characters through the Audio Frequency Protocol Transceiver 50 . The Audio Frequency Protocol Transceiver generates an interrupt to the base station operating program upon reception of a transmission on the system communication RF. transmit and receive PC commands and data through the PC Port Interface. when commanded store data to and on power-up retrieve data from EEPRom Data Storage. following a security breach provide contact closures for any externally connected optional audio/visual alarms. observe and control radio signals i.e. PTT, Squelch and Channel Grant, using the Base Radio Interface. accept a user acknowledgment of a system breach through the user interface 44 .
The microcontroller 40 is programmed to extract the area code and station ID information from any received AFP string. It will then validate that information against system variables retrieved from EEPRom as shown in FIGS. 2 and 3 . If a system breach is detected, then predefined actions, (counter measures) are taken. These actions might be automatic sending of cancel command to the system or siren and/or provide contact closures for external signaling devices to indicate a system breach to relevant personnel.
The software algorithms for the PC Port Interface 56 and Audio Frequency Protocol Transceiver 50 are interrupt driven. The Base Radio Interface 52 and Breach Acknowledge algorithms are polling routines. Sub-routines related to Audio/Visual closures and EEPRom Data Storage 54 are active only when necessary.
The two primary software algorithms relevant to the method disclosed herein are:
the main routine, a relevant portion of which is illustrated in FIG. 2 ; and the validate_string sub-routine illustrated in FIG. 3 .
The main routine is always running and manages polling and general services. FIG. 2 diagrams the functionality of the main routine related to detection and response to a system breach. If the final decision block 300 of the main routine evaluates to Yes, a complete audio frequency protocol (AFP) string has been received, and the Validate_String sub-routine is called, see FIG. 3 . Step 120 of FIG. 3 verifies the length of the string being verified. If the string is of the correct length, e.g., 10 characters, then step 130 verifies that the area code contained in the string is that of the evaluating base station. If the area code corresponds to that of the evaluating base station, then step 140 compares the base ID in the string to its own ID. If the base ID in the string is the same as that of the evaluating base station, then step 150 verifies that the command is valid according to the format and encoding used for the relevant warning system 10 . If the answer to steps 120 , 130 , 140 and 150 are all yes, then a system breach is detected at step 200 . The Validate_String sub-routine delivers a System Breach Yes to the main routine at step 210 . A yes at step 210 of FIG. 2 initiates the countermeasure scenario selected by the outdoor warning system operators. The countermeasure scenario may include activation of the Audio/Visual Closures at step 220 , 222 or automatically clearing the activated warning unit or units at steps 100 , 102 , 104 , 106 .
Power Bus
The Power Buss 48 brings power into the base station and distributes power to the several components. Power from the Power Bus may be distributed to an external signal encoder.
While a preferred embodiment of the foregoing invention has been set forth for purposes of illustration, the foregoing should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention. | Base stations in an outdoor warning siren system monitor the system communication radio frequency to detect the command signals used to activate remotely located warning units. A valid command signal includes a portion identifying the base station generating the signal. When a base station detects a signal bearing its identification, the base station compares the detected signal to its own station ID. If the detected signal matches the detecting station's ID then a system breach is declared. The outdoor warning siren system may respond to a breach by automatically de-activating any alarms activated by the unauthorized signal and/or producing a breach indication to emergency personnel who may respond according to the situation. | 6 |
BACKGROUND OF THE INVENTION
This application is a continuation-in-part of PCT Appln. No. PCT/EP94/00755 filed Mar. 10, 1994 and designating the United States.
1. Field of the Invention
The invention relates to a heating cycle system for a motor vehicle having an interior heat exchanger to receive heated coolant from an internal combustion engine and a circulating pump to deliver coolant as a liquid heat transfer medium. The system includes an independent heating unit to heat the coolant when it is not sufficiently heated by the engine.
2. Description of Related Art
Vehicle heating cycle systems in which a heat transfer medium can be heated by a heating device independent of the engine and circulated selectively either with the inclusion of an internal combustion engine in a large cycle (inline cycle) or by bypassing the latter via a bypass line in a small cycle which comprises only the motor vehicle heat exchanger and the heating device are known, as illustrated by German application DE-A1 40 22 731. In this system, the aforementioned operating modes are controlled by means of a valve which requires an additional electrical drive. This increases the installation cost and also, die to the additional parts, the failure probability of the system.
SUMMARY OF THE INVENTION
A primary object of the invention is to make available in a heating cycle system for a motor vehicle, a simple system for implementing various heat transfer medium cycles.
Another object of the invention is to provide a heating cycle system for a motor vehicle with a circulating pump which is reversible in its direction of rotation and, depending on the direction of rotation, delivers heat transfer medium via one of two separate outlet openings either into a large cycle system through a return line to the internal combustion engine or through a bypass line into a small cycle system which comprises the heating device and the interior heat exchanger. Thus, by simply changing the direction of rotation of the circulating pump which can be easily done by means of a reversible motor, various cycles can be controlled without the need for additional valves operated by means of external energy.
The circulating pump is reversed preferably as a function of a temperature value of the heat transfer medium. This can be done especially easily by means of a thermostatic switch which is preferably located on the intake side of the circulating pump.
A further object of the invention is to provide a heating cycle system for a motor vehicle with a circulating pump wherein each of the outlet openings of the circulating pump is connected to one of two chambers of a valve which are separated from one another in a sealed manner by means of a movable part. One chamber can be connected to the return line to the internal combustion engine and the other can be connected to a bypass line. The delivery pressure of the circulating pump operating for delivery to the bypass line causes the movable part to be moved in the direction of the chamber which leads to the return line to seal access to the return line. For reversed delivery operation of the circulating pump to the return line, the movable part is moved in the direction of the other chamber and seals the access to the bypass line. The movable part can be designed as a membrane and can be used directly to seal the respective line. However, according to another embodiment, on either side of the movable part sealing elements can be provided for engaging or disengaging the bypass or return line. Alternatively to a membrane, the movable part can also be designed as a spring-mounted piston.
A still further object of the invention is to provide a heating cycle system for a motor vehicle having a mode of operation where heat transfer medium delivery takes place both in the direction to the engine and also in the direction to the vehicle heat exchanger, as makes sense for example in the compartment night heating mode of a truck to prevent frequent restarts of the heating device. To accomplish this, in the movable part of a control valve there can be a passage or channel which can be engaged and disengaged by means of an integrated thermostatic valve. To provide a reduced installation cost, the circulating pump and the control valve form a single structural unit which can be attached preferably directly to the heating device.
These and further objects, features and advantages of the present invention will become apparent from the following description when taken in connection with the accompanying drawings which, for purposes of illustration only, show several embodiments in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic representation of the heating cycle system for a vehicle of the present invention with a highly enlarged partial view of a circulating pump and control valve;
FIG. 2 shows a horizontal section along line II-II in FIG. 1;
FIG. 3 shows a second embodiment of a heating device with flange-attached circulating pump and diaphragm valve;
FIG. 4 shows one version of a diaphragm valve; and
FIG. 5 shows another version of a valve.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, an internal combustion engine 1 through which a liquid heat exchange medium flows as a coolant, a pump 2 secured to the engine, a flow line 3, a vehicle interior heat exchanger 4 and a return line 6 form a heating cycle system for heating a vehicle interior when internal combustion engine 1 is operating. Interior heat exchanger 4 through which the heat transfer medium flows in heat exchange with air supplied by a fan 5 gives up thermal energy to a vehicle interior which is not shown. To preheat the vehicle interior with internal combustion engine 1 inoperative or to add heat when internal combustion engine 1 is still cold or in an unfavorable load range, there is a separate heating device 7 in flow line 3. This is a known heating device which is operated by means of liquid fuel, with a heat exchanger through which a liquid heat transfer medium likewise flows. Alternatively to direct placement of heating device 7 in flow line 3, an arrangement of heating device 7 in a branch parallel to flow line 3 is also possible.
Return line 6 and flow line 3 are connected by means of a bypass line 9. The flow line is divided into a first section 3a between internal combustion engine 1 and bypass line 9 and into second section 3b between bypass line 9 and heat exchanger 4. Likewise return line 6 is divided into a first section 6a from heat exchanger 4 and into a second section 6b to the internal combustion engine 1.
In a section of return line 6a is circulating pump 8 which can be operated alternately running clockwise or counterclockwise by means of reversible electric motor 10. Circulating pump 8 is connected on the intake side of first section 6a of return line 6. On the delivery side circulating pump 8, depending on the direction in which pump impeller 11 is turning, is connected either via a first outlet opening 12 to bypass line 9 or via a second outlet opening 13 to second section 6b of return line 6. With the corresponding inclined configuration of pump impeller 11 and the housing of circulating pump 8, this connection can be made directly; in the embodiment described with its simple pump impeller provided with straight blades (FIG. 2) the delivery-side connection to bypass line 9 or return line 6 is made via valve 14. Valve 14 is divided by membrane 15 into first chamber 16 and second chamber 17. First upper angled outlet opening 12 originating from circulating pump 8 empties into first chamber 16 and bypass line 9 discharges from it. Second lower angled outlet opening 13 empties into second chamber 17 and from it discharges into second section 6b of return line 6. Membrane 15 is sealed to the housing of valve 14 and can be moved in the vertical direction within the interior of the housing of valve 14 in FIG. 1. When membrane 15 moves upward, sealing element 18 attached to its upper side comes to rest on valve seat 19 at the outlet to bypass line 9. When membrane 15 moves downward, sealing element 22 attached to it rests against appropriately shaped valve seat 23 at the outlet to return line 6.
Downstream of valve seat 19 at the outlet 20 to bypass line 9 there is check valve 21 in the outlet attached to valve 14. The check valve prevents backflow of heat transfer medium from bypass line 9 into first chamber 16. This check valve 21 can, however, be omitted.
Sealing elements 18, 19 can be attached either directly to membrane 15, or, as shown in FIG. 1, to sleeve-shaped body 29 which extends through membrane 15 and into which a thermostatic valve 27 is integrated. This thermostatic valve opens to open passage channel 28 located in the interior of sleeve-shaped body 29 to second chamber 17 when a certain heat exchange medium temperature is exceeded in first chamber 16.
With internal combustion engine 1 initially off, the function of the heat cycle system shown in FIGS. 1 and 2 will be described below. Depending on whether heat exchange medium from the internal combustion engine 1 is to be included in the preheating operation of heating device 7, the circulating pump begins turning clockwise or counterclockwise. This choice can be made beforehand via a selector switch on the driver's control panel, but it can also be derived from a control device controlling the type of heating device start. For example, operation of the heating device 7 may be initiated by means of a known preselect clock or by means of a radio remote starting means. At the same time, depending on the purpose of heating device 7, a hard-wired preference circuit can be installed either at the plant or by the installation shop. In the following, it is assumed that heating device 7 is designed to preferably first heat up the vehicle interior via heat exchanger 4. Thus the circulating pump begins to operate turning clockwise and due to the upward inclination of the blades of impeller 11, delivers heat transfer medium from the first section of return line 6a via first outlet opening 12 into first chamber 16 of valve 14. By means of the delivery pressure of circulating pump 8 which builds up in first chamber 16 of valve 14, membrane 15 is pressed downward and sealing element 22 attached to it rests on valve seat 23. Second section 6b of return line 6 is blocked thereby and no coolant can reach engine 1 from circulating pump 8. The heat transfer medium is transported via check valve 21 and bypass line 9 to heating device 7, heated there and delivered via second section 3b of flow line 3 to heat exchanger 4.
By bypassing cold engine 1 in which most of the heat transfer medium is located, very fast heat-up of the heat transfer medium, and therefore of the vehicle interior takes place in the small circuit between heating device 7, heat exchanger 4 and circulating pump 8. If in doing so a first heat threshold value of the heat transfer medium is ascertained to have been exceeded by a temperature sensor 30, electric motor 10 is reversed and circulating pump 8 is now operated turning counterclockwise. In this way, due to the inclination of the blades of the impeller 11, the heat transfer medium is now delivered at a lower level through second outlet opening 13 to second chamber 17 of valve 14. By means of the pressure in chamber 17 which is building up, membrane 15 is moved upward, lifting sealing element 22 off valve seat 23, return line 6b is opened and at the same time sealing element 18 comes to rest on valve seat 19, thus blocking bypass line 9. The heat transfer medium is at this point delivered into the large cycle from circulating pump 8 via return line 6b, internal combustion engine 1, flow line 3, heating device 7, heat exchanger 4 and the first branch of return line 6a, and in doing so also preheats internal combustion engine 1 at the same time. Temperature sensor 30 can, as shown, be located in first section 6a of the return line; likewise it can also be integrated in heating device 7.
For an additional operating mode, i.e., preferred interior heating in continuous operation useful, for example, in the heating of a truck driver's compartment during a nighttime stop, the temperature-dependent reversal of electric motor 10 by temperature sensor 30 can be disengaged by the driver via a switch which is not shown. Circulating pump 8 then runs continuously clockwise and delivers the heat exchange medium to first chamber 16. When a predetermined second threshold valve of the temperature of the heat transfer medium which is above the first threshold value is reached, thermostatic valve 27 opens, clears passage channel 28 to second chamber 17 and in doing so lifts sealing element 22 off valve seat 23. In this way some of the delivered heat transfer medium continues to be moved in the small cycle via bypass line 9 and at the same time a smaller part moves in the large cycle via internal combustion engine 1. The second temperature threshold value for opening of thermostatic valve 27 is selected such that it is below the switching value at which a control device (not shown) for heating device 7 causes switchover from partial load operation to a control pause. Thus, in this mode frequent switching of heating device 7, especially restarts associated with noise emissions and additional electrical energy consumption, are prevented and heating device 7 can be continuously operated at the smallest power stage. Thermostatic valve 27 automatically controls this state by the described separation of the flow of heat exchange medium, without noise or consumption of outside energy.
In FIG. 3 one preferred version of the invention is shown in which pump 8 with electric motor 10 and valve 14 is attached directly to housing 24 of heating device 7. The other parts are designated according to their numbering in FIGS. 1 and 2. By means of this integrated construction the installation cost for the heating device is significantly reduced and the line paths are shortened, as is apparent in the example of bypass line 9 which is limited to a very short section behind check valve 21.
FIG. 4 shows a simplified version of a diaphragm valve labelled 14'. In contrast to the previously described embodiment membrane 15' in this case has no separate sealing element on the top or bottom, but itself forms the corresponding sealing element by its upper or its lower side coming to rest against the respective outlet openings of chambers 16' or 17'. The other parts are equivalent to those of the first example and are provided with the same reference numbers with the added prime.
FIG. 5 shows another version of a valve labelled 14" where first chamber 16" and second chamber 17" are separated from one another by means of sealing piston 25 which carries on the top sealing element 18" and on the bottom sealing element 22". The outlet openings of the circulating pump, which is not shown, are labelled 12" or 13" analogously to the first embodiment. Sealing piston 25 is supported by two springs 26 such that in the unpressurized state of chambers 16" or 17", it assumes a neutral middle position. When one of two chambers 16" or 17" receives heat transfer medium, sealing piston 25 moves in the direction of the other chamber 16" or 17" respectively, and of the sealing elements 22" or 18" comes to rest against an appropriately shaped seat of valve 14". Sealing piston 25, like membrane 15 of the first embodiment, suitable for holding thermostatic valve 27. Moreover, versions are conceivable which operate without springs 26 or in which only one spring 26 in chamber 17" provides for bias in the direction of bypass line 9 so that the large cycle is run in the base position of the piston.
By means of the invention, by simply reversing the direction of rotation of a circulating pump reliable control of different operating modes of a heating cycle system is achieved without additional valves controlled by means of outside energy.
While various embodiments in accordance with the present invention have been shown and described, it is understood that the invention is not limited thereto, and is susceptible to numerous changes and modifications as known to those skilled in the art. Therefore, this invention is not limited to the details shown and described herein, and includes all such changes and modifications as are encompassed by the scope of the appended claims. | The invention relates to a heating cycle system of a motor vehicle which includes the vehicle internal combustion engine, a heating device which is independent of the engine, an interior heat exchanger, a circulating pump, and a bypass line which connects a return line to a flow line. According to the invention the circulating pump is driven by a reversible electric motor and is used as a control element for selective operation of a small cycle including only the heating device and the vehicle heat exchanger or a large cycle which also includes the internal combustion engine. The direction of operation of the circulating pump controls a valve which directs fluid to either the small or the large cycle. | 5 |
FIELD
The current application is directed to digital wireless communications. In particular, this application is directed to reducing noise effects related to digital communications.
BACKGROUND
In some communications systems, digital components are used to create the outgoing signal or to deconstruct the incoming signal. This allows the system to perform its function cheaper and with a more efficient use of power. Further, the use of digital components allows the vagaries of analog components to be discarded. Thus, the further use of digital components allows communications to be performed with lower cost and/or lower component counts than used in wholly analog systems, and without huge amounts of analog expertise required.
In some cases, a signal having certain phase or frequency characteristics can be input into a driver stage to be amplified. This is the case in frequency modulation, as well as that employed in combined amplitude modulation/phase modulation systems. In these cases, the conventional systems typically transform the digital signal into an analog signal by outputting the digital data (or derivation thereof) an output of a voltage controlled oscillator (VCO). In this method, the output of the system is then tested against a reference, and the error signal is applied to a loop filter which produces an appropriate correction signal for the system. In this case, control apparatus is usually accomplished with a phase lock loop or a frequency control loop.
However, the signal to noise ratio (SNR) of the system will fall drastically when the clocking speed of the loop filter (or other digital component that drives the VCO) is an integer divisor of the output signal. Thus, when the system operates at output rates that are harmonics or sub-harmonics of the clocking rate of the driver mechanism in a phase lock loop or frequency control loop, that operation can be problematic in a typical communication system. The most pronounced effects on the output of such a system is a frequency that is an integer multiple of the output frequency. In this case, this mode of operation leads to SNR (or other indication of noise) indicating much greater adverse operating characteristics than at the other sub-harmonics.
BRIEF DESCRIPTION
In this description, a communications transmitter is envisioned. The transmitter comprises a signal generator with an input. The signal generator is operable to produce a first signal at a first frequency, with the first signal having an associated first frequency characteristic. The first signal contains frequency-related information and is produced in accordance with a signal received at the input of the signal generator.
An amplification stage is coupled to the signal generator and has an output. The amplification stage is operable to receive the output of the signal generator. The output of the amplification stage is dependant on both the first signal and an incoming amplitude modulating signal.
A detection circuit is coupled to the output of the signal generator. The detection circuit has an output and is operable to detect the first frequency-related characteristic of the output of the signal generator. The detection circuit can generate a signal representative of the first frequency-related characteristic. A comparison circuit is coupled to the detection circuit and has an output. It is operable to compare the signal representative of the first frequency-related characteristic and a signal representative of a second frequency-related characteristic. The output of the comparison circuit is indicative of a difference between the first frequency-related characteristic and the second frequency-related characteristic.
A loop filter is coupled to the comparison circuit and to the signal generator. It is operable to output a signal to the signal generator in response to the output of the comparison circuit, and is operable to be clocked by an input clock at a second frequency. The output of the loop filter provides the input to the signal generator. A clock circuit is coupled to the comparison circuit and to the loop filter, and is used for providing the input clock to the loop filter. The clock circuit is operable to compare the first frequency and the second frequency. The clock circuit can change the second frequency based upon a relationship between the first frequency and the second frequency.
In another aspect, a circuit for producing an output signal based upon an input signal is envisioned. The output signal has an output frequency and an associated output frequency characteristic, and contains frequency-related and amplitude information. The output signal is output to an output port. The input signal is received from an input port and is representative of an expected output frequency characteristic. The circuit comprises a detection circuit for producing a first signal indicative of the output frequency characteristic. A comparison circuit is provided and is coupled to the detection circuit and to the input port. The comparison circuit compares the frequency characteristic as denoted by the first signal and the expected output frequency characteristic, and produces a second signal indicative of a difference between the output frequency characteristic and the expected output frequency characteristic.
A loop filter is coupled to the comparison circuit and outputs a third signal in response to the second signal. The loop filter is operated at least in part by a clock signal operating at a clock frequency. A signal generator is coupled to the loop filter and to the detection circuit. In response to the third signal, the signal generator produces a signal having the output frequency characteristic. An amplification circuit is coupled to the signal generator and to an amplitude modulation circuit. The amplification circuit produces the output signal. The output of the amplification circuit is dependant on both the signal from the signal generator and the signal from the amplitude modulation circuit. In response, it outputs the output signal. A clock circuit is coupled to the loop filter and can produce the clock signal. The clock circuit can dynamically change the clock frequency based upon a comparison of an integer multiple of the clock frequency and the output frequency.
In another aspect, a transmitter is envisioned. The transmitter has an amplifier for producing a signal modulated with both an output amplitude characteristic and an output frequency characteristic. A first circuit is coupled to the amplifier and controls the output frequency characteristic. The first circuit has a clock circuit and a filter coupled to the clock circuit. The filter is actuated by a clock signal with a clock frequency, the clock signal being produced by the clock circuit. A signal generator is coupled to the filter and produces a signal having the output frequency characteristic. The clock frequency is dynamically determined based upon a frequency characteristic associated with the clock signal and the output frequency characteristic.
A method of controlling a transmitter is also envisioned. The transmitter has digital components controlling the generation of an output signal having an output frequency. The digital components are clocked at a first frequency, where the first frequency is derived from a base frequency and a first multiple. The method includes: measuring the output frequency; determining a second frequency such that the second frequency is an integer multiple of the first frequency; determining if the second frequency is within a range about the output frequency; and based on the act of determining, selectively deriving a new first frequency by changing the first multiple to a new multiple, wherein an integer multiple of the new first frequency falls outside the range about the output frequency.
An apparatus for controlling a transmitter is also envisioned. The transmitter has digital components controlling the generation of an output signal having an output frequency. The digital components are clocked at a first frequency, where the first frequency is derived from a base frequency and a first multiplier.
The apparatus has a means for measuring the output frequency and a means for determining a second frequency, where the second frequency is an integer multiple of the first frequency. A means for determining if the second frequency lies within a range about the output frequency is also included. A means for selectively changing the first frequency to a new first frequency is present. The selective change is accomplished by changing the first multiplier to a second multiplier. The means for selectively changing is actuated by an output of the means for determining if the second frequency lies within a range. If a change is called for, an integer multiple of the new first frequency lies outside the range about the output frequency.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more embodiments of the present invention and, together with the detailed description, serve to explain the principles and implementations of the invention.
FIG. 1 is a schematic block diagram of a transmitter employing a dynamically clocked loop filter.
FIG. 2 is a plot detailing typical SNR results of a transmitter operation across a range of frequencies.
FIG. 3 is a frequency diagram of a signal to noise ratio of a signal generated by the transmitter of FIG. 1 .
FIG. 4 is a schematic block diagram of an alternative embodiment of an adjustable clock circuit that is operable to switch amongst a plurality of multipliers to clock the loop filter.
DETAILED DESCRIPTION
Embodiments of the present invention are described herein in the context of an apparatus and method for dynamically clocking a loop filter in a communications device. Those of ordinary skill in the art will realize that the following detailed description of the present invention is illustrative only and is not intended to be in any way limiting. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. Reference will now be made in detail to implementations of the present invention as illustrated in the accompanying drawings. The same reference indicators will be used throughout the drawings and the following detailed description to refer to the same or like parts.
In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will, of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer's specific goals, such as compliance with application- and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure.
In accordance with the present invention, the components, process steps, and/or data structures may be implemented using various types of digital systems, including hardware, software, or any combination thereof. In addition, those of ordinary skill in the art will recognize that devices of a less general purpose nature, such as hardwired devices, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), or the like, may also be used without departing from the scope and spirit of the inventive concepts disclosed herein.
FIG. 1 is a schematic block diagram of a transmitter employing a dynamically clocked loop filter. A communications transmitter 10 outputs a transmitted signal from an amplifier 14 . The amplifier 14 accepts as an input signal from a signal generator having certain phase or a frequency characteristic, such as that provided by a voltage controlled oscillator (VCO) 18 . One will note that many signal generators are able to be implemented, and the VCO is not necessarily unique in accomplishing the task of signal generation for the purposes of this disclosure. This disclosure should be read as inclusive of other apparatuses that produce a signal having frequency, phase, or other frequency characteristic.
The output of the VCO 18 is dependant upon an output of driver mechanism, such as a loop filter 22 . The loop filter 22 accepts as an input a signal representing an error between a desired signal and an actual output signal. Based upon the value of this error signal, the loop filter provides a signal to the VCO 18 to output a higher or lower specific frequency, depending on the circumstances.
In the following discussion, the operation of the system is described in terms of frequency. However, operation based upon general frequency characteristics (including frequency, phase, and other angle-information) may be implemented in a similar manner. Those components described with relation to frequency may also be implemented with phase characteristics, phase derivatives, and the like. Accordingly, this disclosure should be read as contemplating those implementations as well as those specifically and explicitly described. In terms of this disclosure, the frequency, phase, or phase differentials may be measured and compensated for, and this disclosure should be read to encompass such frequency related characteristics.
An output of the VCO 18 is directed to a phase and/or frequency detector 26 . An optional analog to digital converter (ADC) 30 is interposed to convert an analog signal to digital format for the frequency detection circuit 26 . In another embodiment, the frequency detection circuit may directly test an analog signal and output a signal representative of the output of the VCO 18 . The frequency detection circuit may also be embodied as a phase detection circuit.
The output of the frequency detection circuit 26 and a desired signal are compared with one another in a comparison circuit 34 . In turn, the comparison of these signals produce an error signal that is input into the loop filter 22 .
In this manner, the amplifier 14 is driven by the phase lock loop comprising the VCO 18 , the loop filter 22 , the frequency detector 26 , and the comparison circuit 34 . The previous output of the transmitter is then compared to the signal that is wished, and an error signal is generated. The loop filter 22 then produces a signal indicative of an error between the output signal and the wished-for incoming signal. The signal generated by the loop filter 22 drives the VCO 18 to match the input signal. The operation of the loop depicted in FIG. 1 may be one applied not just to frequency matching techniques, but, as indicated supra, to matching frequency-related characteristics techniques as well, and this disclosure should be read as encompassing those as well.
However, digital sampling techniques used by the loop filter 22 may lead to performance shortcomings of the transmitter 10 when operating at certain points. In particular, problems could are prevalent when the operating frequency of the transmitter is at or near integer multiples of the clocking frequency of the loop filter 22 .
Assume that the VCO 18 outputs a signal with a frequency F N . If the loop filter 22 samples at a frequency F L , and the final output of the VCO 18 is or is close to an integer multiple of frequency F L (i.e. F N =kF L , where k is an integer), the signal to noise ratio of the final output may be far less than optimum, as indicated supra and described infra. In these cases of a final output at or near integer multiples of frequency F L may lead to bad signal to noise ratios (SNR) at the final transmitted output due to the sampling characteristics.
FIG. 2 is a plot detailing typical SNR results of a transmitter operation across a range of frequencies. FIG. 2 a shows spikes in the SNR of an output system at various frequencies. As can be seen from the graph, a large decrease in the SNR of the system occurs at integer multiples of the clocking frequency of the loop filter or other loop mechanism. Other portions of the spectrum where SNR is degraded can also occur at multiples of integer reciprocals of the loop clocking frequency F L (i.e. F L /2, F L /3, F L /4, . . . . ) However, these degradations in SNR are not as severe as those seen at the integer multiples, and are not included in this discussion.
In the operation of a wireless communication device, the operation frequency of the output may be at one of several frequencies within a specified spectrum. For example, the GSM operation mode has channel offsets every 200 kilohertz (kHz). Accordingly, depending upon the operation of the base station, the mobile wireless unit may in fact be tasked with operating at a sub-optimum operation point, such as that denoted by point A in FIG. 2 . Thus, when the transmitter's operation is somehow specified to at the frequency denoted by point A, the user of the mobile wireless unit will experience problems in the operation and/or communications using such wireless communications device. The same device operating at point B will encounter much better operation, since point B is a frequency where the noise problems associated with sampling rates will not occur.
It should be noted that the operating (i.e. output) frequency can be set by many different means. The way in which the operating frequency is set is not relevant for the purposes of this disclosure.
Turning back to FIG. 1 , the wireless communications device 10 has an adjustable clock circuit 30 . The adjustable clock circuit 30 is operable to accept a signal representative of the operating frequency of the output, such as that delivered by the frequency detection circuit 26 . The adjustable clock circuit 30 is operable to accept such a signal indicative of the frequency of the output signal, and to determine whether to alter the sampling frequency of the loop filter 22 .
Accordingly, when the communications device 10 determines that the operating frequency of the output and an integer multiple of the clock frequency of the loop filter are too close together, where that the SNR of the output would be degraded (i.e. point A of FIG. 2 ), the adjustable clock circuit 30 can alter the clocking frequency of the loop filter 22 . Such a change in the clock frequency in turn changes the SNR characteristics of the communications device 10 . In practice, the change to the SNR characteristics enables the communications device to operate at the same frequency as before but avoid the SNR problems associated with the previous output.
FIG. 3 is a frequency diagram of a signal to noise ratio of a signal generated by the transmitter of FIG. 1 . This diagram highlights the ability of the present disclosure to change the operational characteristics of the output without any change in frequency.
In FIG. 3 , assume that the operating frequency for the output is a frequency C, and the initial operating point of the system has a signal to noise ratio (SNR) profile of that in the upper graph of FIG. 3 denoted SNR 0. At that frequency, the system is operating at point C 0, which is characterized by a low SNR indicating substantial noise associated with that operation point. At frequency C, it should be noted that the sampling characteristics of the loop leads to such a degradation of the performance due to the proximity of frequency C to an integer multiple of the clocking frequency for the loop filter.
In response to the device operating at point C 0, a transmitter, such as that depicted in FIG. 1 , can determine the operating frequency of the output. If the operating point of the system is at a point that will is associated with less than a predetermined magnitude of signal to noise ratio, or within a predetermined frequency difference from the center frequency of an integer multiple of the clock associated with the loop filter, the transmitter can dynamically change the operating characteristics of the system to compensate for this. In this case, the transmitter alters the operating frequency of the loop filter. Accordingly, the SNR function changes due to the new clock frequency, as denoted by the lower graph in FIG. 3 (SNR 1 .) The frequencies where minimum signal to noise ratio events occur are shifted to integer values of the new clock frequency of the loop filter. Additionally, the width between minima SNR events are either stretched or compacted, depending upon whether the clock rate of the loop filter has increased or decreased, respectively.
In this case, the transmitter has shifted the base clock frequency, thereby shifting the minimal SNR events away from the operating frequency point C. Accordingly, this allows the transmitter to operate in a much more efficient manner at the point on SNR 1 denoted as C 1 . This change can be effected without changing the output of the transmitter.
With reference to FIG. 1 , this is can be operationally performed by the adjustable clock 30 . In FIG. 1 , the adjustable clock circuit 30 changes the clocking of the loop filter 22 , thus changing the SNR characteristics of the transmitter. To effectuate the change, the adjustable clock circuit can change the operating frequency of the loop filter 22 directly, or can initiate a change in the clocking frequency through changing a selectable multiple.
In one case, the output of the VCO 18 is detected by the frequency detection circuit 26 and converted into a format that can be compared with the input signal. An output of the frequency detection circuit 26 is coupled to an input of the adjustable clock circuit 30 . The adjustable clock circuit 30 can determine whether the operational parameters of the current output frequency are sufficient to change the clocking frequency of the loop filter 22 .
As noted before, the determination of when to change the frequency, either through a direct change or through a change of multipliers, can be determined a variety of ways. In one case, a lookup table can be supplied to the system. The operational frequency of the incoming or outgoing signal can then be determined. If the determined frequency lies within a predetermined range from the loop filter clock, or if the decrease in the SNR based upon this effect is within a predetermined range, the system can change the loop filter clock.
In one case, the determination to change the clock frequency may be made based on an absolute difference between the multiple of the clock frequency and the operational frequency. In this case, assume an operational frequency Fz and the clock frequency is Fc. If |Fz−nFc|<=X, the system will implement a clock change. In another cases, the decision may be made based upon a percentage of Fc, or some other function of either Fc or Fz.
In yet another case, the function of the SNR profile will be known, and the determination can be made based upon the value of the SNR profile at the operational frequency. Letting S(Fc) be the SNR profile of the system at the operational frequency Fc, and N(S(Fc), Fz) is the value of the S(Fc) profile at Fz, the decision to switch can be made on this value. For example if N(S(Fc), Fz)<X, then a decision can be made to switch the clock frequency. Other functional values associated with the inverse of the SNR profile can be implemented as well.
In one case, the operational frequencies of the underlying communications mode are known, and the distances between the frequency channels are also known. In this case, a clock frequency can impact at multiple channels. Accordingly, a lookup table can be implemented to tell which clock frequencies should be used with the various channels.
In this manner, a number of relationships can be established between the clocking of the loop filter and the noise in the output. Thus, the system can detect whether such a relationship is present (i.e. noise level, SNR, or relationship between the clocking frequency and the output frequency) and dynamically modify the clocking behavior of the loop filter.
FIG. 4 is a schematic block diagram of an alternative embodiment of a dynamically clocked loop filter in communications device. In this case, the adjustable clock circuit is operable to switch amongst a plurality of multipliers that it can use to clock the loop filter 22 . A base clock is input into an adjustable clock circuit 38 . The detection circuit produces a signal indicative of the frequency at which the VCO is operating. This signal is input into a multiplier determination circuit 42 , which relays to the adjustable clock circuit 38 the base frequency multiplier, or an indication to change the base frequency multiplier. The adjustable clock circuit 38 can, based upon the base clock and the multiplier, produce the loop filter clock. It should be said that the multiplier of the base frequency used to produce the loop filter clock may be an integer, but it could also be any non-integer as well.
If the operation of the system is determined so that the operating frequency (or frequency characteristic) of the system will lead to high noise (based upon the relationship of the clocking rate of the loop filter and the operation point), the adjustable clock circuit can change the clocking of the loop filter in order to reduce the noise effects due to the clocking of the loop filter. In this manner the system can detect whether the transmitter is operating at a point conducive to high signal to noise ratios, and dynamically adapt itself to operate in a lower noise environment.
In one embodiment, a lookup table can be employed to speed the change in the frequency. In this case, the determination of where the operating point of the system is leads to one of the selections in the lookup table being used to obtain a clocking frequency of the loop filter.
FIG. 5 is another implementation of a transmitter using polar modulation technology. In this case, an amplitude modulating signal is concurrently applied to the amplifier 48 to produce a time-varying envelope for the amplified phase or frequency signal.
One should note that the apparatus may also be used in receivers, and is not limited to wireless communications. In fact, many aspects of this description may also be used in other communications devices. Further, the use of the varying clock control of a driver mechanism for a signal generator, such as the loop filter, based upon the relationships to the output and to the accompanying noise may be used in other more general circuits not related to the communications field.
Thus, an apparatus and method for dynamically clocking a loop filter in a communications device is shown and described. Those skilled in the art will recognize that many modifications and variations of the present invention are possible without departing from the invention. Of course, the various features depicted in each of the Figures and the accompanying text may be combined together. Accordingly, it should be clearly understood that the present invention is not intended to be limited by the particular features specifically described and illustrated in the drawings, but the concept of the present invention is to be measured by the scope of the appended claims. It should be understood that various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention as described by the appended claims that follow.
While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art having the benefit of this disclosure that many more modifications than mentioned above are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims. | A transmitter has a signal generator, an amplifier, a detection circuit, a comparison circuit, a loop filter, and an adjustable clock. The signal generator produces a signal. The signal is produced with a first frequency characteristic and contains frequency-related information. The detection circuit detects the first frequency-related characteristic and generates an associated signal in response. A comparison circuit compares the signal from the detection circuit and another signal. It outputs a signal associated with the difference between the two. A loop filter receives the output of the comparison circuit and generates a signal to the signal generator in. The loop filter is clocked at a second frequency by a signal from a clock circuit. The clock circuit can compare the first frequency and the second frequency, and can change the second frequency based upon a relationship between the two frequencies. | 7 |
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present invention relates to erosion control blankets and, more particularly, to a soil erosion control blanket having a synthetic, fibrous filler material which is substantially non-biodegradable. The erosion control blanket of the present invention is designed to prevent soil erosion and runoff, as well as permitting the in-growth of grasses and other vegetation, while retaining a near original state and not degrading significantly over a number of years.
2. History of the Related Art
Erosion control blankets have established commercial acceptance and use worldwide. Erosion control blankets are articles which resemble a form of fibrous matting in which two outer layers of netting or other material are commonly used to form an envelope or covering about a fibrous interior filler layer. These blankets are commonly used to reduce soil erosion and runoff from erosion-prone areas such as highway embankments or water drainage ditches.
Several different styles of erosion control blankets or mats are commonly in use today. One particular style of blanket that does not use a netting material is set forth and shown in U.S. Pat. No. 5,786,281 which is assigned to the assignee of the present invention and incorporated herein by reference. Other styles may include at least two outer netting or facing layers that are filled with a loose fibrous material. For example, one particularly effective erosion control blanket is the CURLEX or excelsior fiber blanket manufactured and sold by the American Excelsior Company of Arlington, Tex. since 1964. This blanket is fabricated in elongated rectangular mat form, from elongated, randomly intertwined wood fibers commonly referred to as excelsior. Prior art erosion control blankets and mats such as these are commonly used in conjunction with commercial or residential construction projects in an attempt to control soil loss and runoff into adjoining areas. The blankets are unrolled along the earth area to be protected against erosion, and are secured along the sides of one another and to the underlying ground area with a series of conventional ground staple members. The ground staple members may be made of steel, wood, plastic or other materials and serve to anchor the mats securely to the covered earth area. Additionally, in some applications, erosion control blankets or mats such as these may be rolled to form a sort of artificial curb or barrier at the edge of a property or construction site.
The netting and loose fiber filler construction permits blankets or mats of this kind to be fairly light in weight and also to permit the ingrowth of grasses and other vegetation into and through the blanket. The netting primarily serves to hold the loose fiber filler together while providing a large number of openings for plant ingrowth. As these blankets will frequently become a fixture in their installment site, it is often desirable to form the inner fibrous layer of the blanket of various types of biodegradable materials. By way of example, recycled paper or fiberized waste paper, wood fibers or excelsior, straw or other naturally fibrous materials such as coconut husks may be used to provide a biodegradable filler material. However, in some erosion-prone areas such as water runoff ditches and the like, it is particularly useful to have an erosion control blanket or mat with a more substantial and permanent filling which will not significantly degrade over long periods of time.
One solution to the problem referenced above is the use of polymeric or other synthetic fibers as filler materials. Some synthetic filler materials which have been suggested include polyethylene, polypropylene or nylon fibers and blends of fibers such as these with organic or biodegradable fibers such as those noted above. Several shortcomings have been noted by end users with these blankets which include synthetic fibers in that the blankets tend to become matted down or thinner over time and tend to lose their loft or three-dimensionality. As blankets become matted down, the fibers in the filler tend to become more tightly packed, and the subsequent in-growth of grasses and other vegetation becomes increasingly difficult. Prior art attempts to resolve fiber matting problems have involved the use of multiple netting layers disposed throughout the filler material and netting which is corrugated or shaped to hold a more three-dimensional structure. However, these solutions may involve significant additional material and labor costs to produce an erosion control blanket. Moreover, synthetic/organic blended fillers tend to degrade over time much like organic-only fillers, and merely do so at a slower rate. Thus, while synthetic-only fillers for erosion control blankets have been suggested, these appear to be somewhat wasteful of natural resources and still suffer from shortcomings in the areas of fiber resiliency and loft.
SUMMARY OF THE INVENTION
The present invention overcomes the shortcoming of the existing designs and satisfies a significant need for a durable erosion control blanket with improved loft and resiliency properties. More specifically, the erosion control blanket of the present invention addresses the need for an erosion control blanket which does not significantly degrade over a number of years and maintains a high degree of resiliency or loft when in use. In one embodiment of the present invention, the erosion control blanket has at least three layers including a top sheet, a filler material and a bottom sheet. The top and bottom sheets generally resemble an open-mesh material or netting. Many of the particular physical characteristics of the erosion control blanket are achieved through the use of a novel synthetic fiber filler material. The filler material for use in the erosion control blanket is a made up of a plurality of crimped polymer fibers which form a three-dimensional matrix between the top sheet and the bottom sheet. Moreover, it is possible to form the crimped polymer fibers from post-consumer polyester fiber material such as polyethylene terephthalate (PET). Although it is to be understood that the synthetic filler is not limited to this particular material, PET is desirable in that it is commonly used to make soda bottles and other translucent packaging containers, and is consequently readily available in post-consumer form. Thus, it is possible to achieve the desired physical and mechanical properties in the erosion control blanket of the present invention while conserving natural resources to some extent by using a readily available post-consumer polymer material.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the erosion control blanket according to the present invention may be obtained by reference to the following detailed description when taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a top plan view of a section of an erosion control blanket constructed in accordance with the present invention;
FIG. 2 is a cut-away side view of a section of an erosion control blanket constructed in accordance with the present invention;
FIG. 3 is a top perspective view of a section of an erosion control blanket constructed in accordance with the present invention; and
FIG. 4 is a block diagram of steps which are carried out to produce an erosion control blanket constructed in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which several preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, the embodiments are provided so that this disclosure is thorough and complete, and fully conveys the scope of the invention to those skilled in the art.
Referring now to FIGS. 1-3 , a section of an erosion control blanket 100 constructed in accordance with the principles of the present invention is set forth and described. Note that each of the drawings have been numbered with like numbers corresponding to like parts. As best seen in FIG. 2 , the erosion control blanket 100 is formed of three layers of material. The first layer is a top sheet 120 of an open-meshed material of natural or synthetic fibers. The second layer is of a loose fiber filler 140 which is arranged to form a three-dimensional matrix and provides the erosion control blanket with a required amount of loft or resiliency. The third layer is a bottom sheet 160 or open-meshed material which generally resembles the top sheet 120 or first layer in construction.
Referring now to FIG. 1 , the top sheet 120 is seen to have a open-meshed material or netting with a high percentage of open area. In one embodiment of the present invention, the openings 130 in this netting material are rectangular in shape with sides ranging form about 0.50 inches to about 1.00 inches in length. The netting itself may be formed of either natural or synthetic materials, and in one preferred embodiment, is of polyethylene (PE), polypropylene (PP), or other suitable polyolefin. It is particularly desirable to make the top sheet 120 or netting of a synthetic material which is both lightweight, strong, and durable enough to resist tearing or rupture of the soil erosion control blanket 100 . The netting material may also include various additives, as known in the art, to improve resistance to ultraviolet (UV) radiation or to impart a particular color. By way of example only, a small amount of carbon black additive, about 0.1% to about 2.5% by weight, may be incorporated into a suitable polymer to impart both a black color and a significant amount of UV resistance into the netting material.
Although not shown in FIG. 1 , the bottom sheet 160 or netting of the erosion control blanket 100 in accordance with the present invention is substantially similar in construction to the top sheet 120 as shown and described. That is, the bottom sheet 160 will also have an open-meshed material with a high degree of open area and be made of very similar materials to that of the top sheet 120 .
Still referring to FIGS. 1-3 , in another embodiment of the present invention, the top sheet 120 and the bottom sheet 160 may be constructed of polymer materials having slightly different mechanical properties. For example, as the top sheet 120 will be exposed to more direct sunlight and UV radiation than the bottom sheet, it may be desirable to use a top sheet 120 which is stronger and heavier than the bottom sheet 160 . In one preferred embodiment, the top sheet 120 is formed of 600 denier, high-tensile, polypropylene material and has a weight of about 10.0 pounds/1000 square feet and a strand count of about 9.0 and about 13.0 strands/10 inches in the machine and transverse directions, respectively. The netting has rectangular openings with sides of about 0.75 inches to about 1.00 inches in length. The top sheet 120 has a break load of about 57.0 pounds/3 inches in the machine direction and about 73.0 pounds/3 inches in the transverse direction. However, in this particular embodiment, the bottom sheet 160 is formed of 600 denier, high-tensile, polypropylene material and has a weight of about 2.87 pounds/1000 square feet and a strand count of about 13.0 to about 14.0 strands/10 inches in both the machine and transverse directions. The netting has rectangular openings with sides of about 0.70 inches to about 0.80 inches in length. The bottom sheet 160 has a break load of about 29.0 pounds/3 inches in the machine direction and about 23.4 pounds/3 inches in the transverse direction.
The filler material 140 of the erosion control blanket 100 of the present invention is an arrangement of crimped polymer fibers 150 to create a three-dimensional matrix having a desired amount of loft and resiliency. Although the polymer fibers 150 may be arranged in various ways, a randomly dispersed loose fiber fill will generally produce a blanket with sufficient loft. In one embodiment of the present invention, the polymer fibers 150 are formed of a post-consumer polyester, namely polyethylene terephthalate (PET). This particular material is commonly used to form soda bottles and other translucent packaging containers, and is readily available in post-consumer form. By way of example only, it is also possible to purchase post-consumer PET which is of a particular color, namely green, which is derived from SPRITE, 7-UP, and other citrus flavored soda bottles. The green-colored, post-consumer PET material is desirable in some applications as it provides the resulting erosion control blanket with a visually attractive green color which tends to blend in with grass and plants.
This post-consumer polyester resin may be recycled into fibers 150 to form the filler material 140 of the blanket 100 according to the present invention. These PET fibers 150 offer a high degree of loft when crimped and tend to be more resilient than other synthetic fibers. In accordance with the present invention, the PET fibers will have a denier size of about 15 to about 500. It is the inventor's belief that the post-consumer PET fibers used in the filler of the erosion control blanket of the present invention are unique in that this particular fiber has a particularly good shape memory. That is, that when a blanket 100 filled with crimped PET fiber materials is compressed and the load is subsequently removed, the crimped fibers 150 and consequently the blanket 100 will tend to spring back to its nearly all of its original dimension. Additionally, the crimped fibers 150 will tend to entangle and cling one-to-another more aggressively than uncrimped fibers do. This particular feature of crimped fibers serves to reduce the migration of fibers out of the blanket and further assures consistent blanket loft with the passage of time. Thus, it is possible to create a erosion control blanket 100 which has a higher degree of loft and is far more resilient than prior art loose fiber filler erosion control blankets.
The recycled polyester fibers 150 used as filler material in the erosion control blanket 100 of the present invention possess a unique combination of mechanical properties. It is notable that the post-consumer PET fibers have a specific gravity greater than 1.0, and do not float in water. However, many other synthetic fibers such as polyethylene, polypropylene and the like have specific gravities of less than 1.0 and will tend to float in water. This is a particularly useful characteristic of the post-consumer PET fibers in that erosion control blankets made in accordance with the present invention may be utilized in high water runoff areas including water drainage channels. Accordingly, it is easier to keep an erosion control blanket in contact with the ground when the fibers which fill the blanket do not float under hydraulic conditions. If an erosion control blanket tends to float, it will be much less effective at reducing soil loss and preventing the washing away of grass seed and other plant matter which is intended to grow through the erosion control blanket. The fiber material may also include various additives, as known in the art, to improve resistance to ultraviolet (UV) radiation or to impart a particular color.
In one embodiment, the post-consumer PET fibers will have denier size of about 15 to about 500, and have a preferred denier size of about 350 to about 450. The post-consumer PET fibers are then crimped using a stuffer-box crimper, not shown, as known in the art. In operation, the stuffer-box crimper receives a large number of semi-molten polymer fibers between a pair of smooth metal nip rolls and forces the fibers into a box or container having fixed dimensions and a variable resistance flapper device on the output opening. It is possible to increase the number of crimps per inch in the fibers by increasing the resistance of the flapper device of the output from the stuffer box. In short, greater resistance on the flapper device results in a higher number of crimps per inch on the fibers coming out of the stuffer-box. The post-consumer PET fiber 150 used in the present invention will normally have crimping in a range of about 1.0 to about 3.0 crimps per inch, with a value of 2.0 crimps per inch being preferred. The crimped PET fibers 150 are cut to lengths ranging from about 5.75 inches to about 6.25 inches, with a length of about 6.0 inches being preferred.
The post-consumer PET fibers 150 used in the present invention have been tested for resistance to compression. The testing procedure begins by first carding an 8.0 to 10.0 gram sample of fibers which are of 2.5 inches maximum length. The carded fibers are then weighed out into a 3.00±0.05 gram sample using an analytical balance. The 3.0 gram carded sample is then placed into the 3.0 inch diameter compression cup of an Instron resistance to compression tester. The compression cup is then sealed and air pressure applied to the fiber sample. The testing apparatus then computes a resistance to compression for the fiber sample in pounds. The crimped, post-consumer PET fibers used as a filler material in the present invention exhibited resistance to compression values ranging from about 4.5 pounds to about 6.0 pounds, with an average value of about 5.2 pounds. This value may also be converted into a resistance to compression value expressed pounds per square inch (psi) per gram of fiber. Thus, for a fiber sample with an average resistance to compression value of about 5.2 pounds, it is possible to calculate a value of about 0.245 psi/gram of fiber.
An additional measure of crimped PET fiber resiliency may be obtained by studying the ability of an amount of filler material to recover its original thickness after the application and removal of a particular load. In one such test, one (1.0) pound of crimped PET fiber loose filler is placed in a circular container having a 6.0 inch diameter and its thickness is measured. A compressive load of 0.5 psi is then applied evenly across the top surface of the loose filler for a period of 5.0 minutes. After the compressive load is removed, the thickness of the loose filler is measured again. A percent recovery is then computed by dividing the thickness after compression by the original thickness and multiplying by 100%. For the crimped, post-consumer PET fibers used as a filler material in the present invention, it was determined that the loose filler had a percent recovery value ranging from about 95% to about 97% of its original thickness.
Referring now to FIG. 4 , a block diagram illustrates, by way of example only, the various steps of a manufacturing process 400 which may be followed to construct an erosion control blanket in accordance with the present invention. In one embodiment, post-consumer plastic materials such as soda bottles and containers are collected and sorted 405 according to polymer types (e.g., polystyrene, polyethylene terephthalate, polybutylene terephthalate, polyethylene, polypropylene, and so forth). These containers are then mechanically shredded 410 and cleaned 415 with high temperature steam to produce post-consumer scrap polymer which is suitable for reprocessing. A fiber manufacturer may then purchase scrap polymer of a particular type, such as PET, pelletize 420 the scrap polymer, melt the polymer 425 in an extruder, and melt spin 430 fibers from the polymer. These fibers may then be crimped 435 using a stuffer-box crimper as described hereinabove and cut 440 to a particular length to produce a crimped loose fiber filler material. An erosion control blanket may then be produced by providing top and bottom sheets of netting material 445 , randomly dispersing 450 the cut, crimped polymer fibers between the top and the bottom sheet, and then stitching 455 the top and bottom sheets together. Once the top and bottom sheets are fastened or stitched together and the loose fiberfill material is secured, it is possible to roll the generally rectangular blankets up into smaller, cylindrical bundles for shipping and handling.
It is thus believed that the operation and construction of the present invention will be apparent from the foregoing description of the preferred embodiments. While the erosion control blanket materials, configurations and designs as shown are described as being preferred, it will be obvious a person of ordinary skill in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention, as defined in the following claims. Therefore, the spirit and the scope of the appended claims should not be limited to the description of the preferred embodiments contained herein. | A durable erosion control blanket featuring a novel synthetic fiber filler is disclosed. The erosion control blanket of the present invention addresses the need for a particularly resilient erosion control blanket through the use of a post-consumer, crimped, polyester fiber filler material. In one embodiment, the post-consumer fiber material is of polyethyleneterephthalate (PET) readily available in post-consumer form from the recycling of soda bottles. In short, a preferred filler material for the blanket of the present invention would utilize recycled soda bottle material which has been converted into a crimped, highly-resilient fibrous filler. It is, thus, possible to achieve the desired physical and mechanical properties in the erosion control blanket of the present invention while conserving natural resources to some extent by using a readily available post-consumer polymer material. | 3 |
GOVERNMENTAL INTEREST
The invention described herein may be manufactured, used and licensed by or for the Government for Governmental purposes without payment to me of any royalties thereon.
FIELD OF USE
This invention relates to an improved burner for use in research.
More particularly, this invention relates to an improved research burner which allows optical access to the pre-combustion and primary reaction zones of flames of combustible mixtures.
PRIOR ART
The study of the reaction chemistry of flames centers on the thin primary reaction zone which is typically on the order of 100 μm thick for a nearstoichiometric flame at atmospheric pressure.
Traditional burners for studying these systems are made by using an array of tubes or the equivalent, sintered porous metal disks, a metal screen or plate, or some other physical barriers to establish a stable flame. Any of these systems result in the extraction of heat from the flame with the amount dependent upon several physical parameters.
In a typical configuration, a stable flame requires that the primary reaction zone by seated very near the burner surface. The latter position makes access to the zone quite difficult at atmospheric pressures. The use of a low pressure chamber to expand the flame zones has been used frequently.
The primary cause of the above difficulty lies in the large index of refraction changes due to temperature and composition differences at the interface between the ambient air and the high temperature flame gases. A laser beam entering the flame is deflected downward into the flame burner surface due to the index of refraction changes at the interface. This causes extensive light scattering which obscures any observation of produced signals such as fluoresence or Raman spactra. In intra-cavity work with CW lasers, the hitting of the surface makes impossible any probing of the flame lower than that distance which allows the beam to pass completely through the flame.
An alternative burner of the art has shown usefulness in probing these low-lying zones but suffers from severe flash-back problems when high flame speed mixtures are used. As a result, such device cannnot be used for these mixtures without excessive dilution of the mixture with an inert gas.
SUMMARY OF INVENTION
It is therefore an object of this invention to provide an improved research burner which allow optical access to the primay combustion regions of flames for research purposes.
A further object is to provide an improved research burner which can produce stable flames of flammable gas mixtures, and which allow optical access to the primary reaction zones.
Other objects and many of the attendant advantages of this invention will become more apparent from a detailed reading of this application when taken with the accompanying drawing, wherein:
FIG. 1 is a full cross-sectional exploded view of the burner of this invention.
DETAILED DESCRIPTION
In general, this invention is a research burner for use with premixed combustible gases. Referring to the FIGURE, the major functional element is a hemispherical center block 11 made of porous sintered metal such as bronze. The top 11A is made with curvature, typically a two-inch radius of curvature serving as a surface for optical access. The hemispherical block 11 is fitted with an internal water-cooling coil 12. The latter coil spirals in the block 11 to carry away the heat that is transferred to the block from the flame. A thin metal septum or shell 13 is affixed to a base 16 and confines the combustible gas mixture to the space below the block 11. An annulus 14 of porous sintered metal such as bronze is provided with a flow of inert gas, and this passes through the metal annulus itself to provide a shroud of gas around the flame, the latter being produced on the upper surface 11A of the head or black 11. The outer shell 15 surrounds the entire assembly and is engaged to the bottom plate 16 and is sealed with a teflon gasket 17.
More specifically, the burner is provided with a base or plate 16, and a septum or shell 13 of hollow construction is secured to the latter base 16. A hemispherical head or block 11 is secured to the open-end of the septum or first shell 13 in a fashion such that the curvature of the block rises above the end of the septum or first shell 13. The upper surface of the head or block 11A provides the base of the flame under study. A metallic outer shell 15 is also secured to the base in spaced relation to the septum a first shell 13 forming a channel 18. An annulus 14 of porous metal is mounted between the upper end of the spectum or first shell and the free end of the second shell 15. The base 16 is provided with an inlet 19 for the combustible gas mixture which communicates with the confined area formed or bounded by the first shell or septum 13 and the hemispherical head or block 11. A second inlet 21 is provided in the base 16 for a shroud gas in communicating relationship to the channel formed by the septum and the second shell 15 in flow relationship to the bottom surface of the annulus of porous metal. This provides, in operation, a shroud of gas around the flame on the upper surface 11A of the head or block 11. A heat-dissipating effect is provided to the head a block 11 by a spiralling coil of copper tubing 12 having an inlet 22 and outlet 23 for the provision of water. The base 16 is adapted to receive the latter inlet and outlet of water.
In operation, water is introduced into the inlet 22 of the base 16, the water flowing in an upwardly fashion to an through the spiraling coil 11 of copper tubing in the hemispherical head or block 11 to the outlet and thence downwardly away from the burner. This flow through the block 11 has a heat-dissipating effect on the block when the combustible mixture is ignited to provide a flame on the upper surface 11A of the hemispherical head or block 11. At this stage, a shroud of gas is introduced through the inlet port 21 of the base 16 to the channel formed by the inner and outer metallic shells 13 and 15 in communicating relationship to the porous annulus 14. The inert gaseous shroud may be argon, nitrogen or helium, and when introduced to the porous annulus 14, flows therethrough to form an annular ring of shroud gas around the upper surface 11A of the block or head 11. At this point, a combustible mixture of flammable gas is introducted to the enclosed area 24 formed by the septum 13 in communicating relationship to the hemispherical head 11. The gaseous mixture flows through the latter porous block 11 to the upper surface 11A thereof and is ignited to produce the flame under study. The cited shroud of inert gas passes through the porous annulus 14 forming an annular boundary around the flame produced by the combustible mixture on the upper surface 11A of the head or block 11.
After a stable flame has been achieved, a laser beam is introduced to the desired zone of the flame, and readings are taken for the temperature and make-up of the contents of the flame.
The research burner of this invention provides a stable flame of gas with extremely wide flame speed range at the upper surface 11A of the block 11. It compares with the stable flame of the conventional devices but with the ability to prove the same flame zone of the double-knife edge burner of the art. It also provides for an inert gas shroud around the flame to minimize the effects of entrained air on the flame properties. This is no propensity to flash-back under high flame speed conditions as there encountered with the double-knife edge burners of the art. The research burner offers the use of a porous metal burner with the capability of optical access to early flame regions without any disadvantage.
In use, a 3507.42 Å line of a Kr + laser was used to measure temperture and species concentration profiles of N 2 , O 2 , and NO on a lean (O=0.47) H 2 /N 2 flame. With the present burner, a researcher can come within a laser beam diameter (0.1 mm.) of the burner surface. The spectral range of the detection system with a Reticon detector allows simultaneous observation of the three species of interest. Raman Q-branch signals were sufficiently large for NO, O 2 and N 2 to allow a determination of temperature as well as the concentration for all three species. The experimental procedure utilized can be found in Vol 2, p 551 of the proceeding of the "First International Specialists Meeting of the Combustion Institute, Bordeaux, France. The only modification to the latter procedure was the use of a Reticon detector, and the present burner of this invention.
The foregoing disclosure and drawing are merely illustrative of the principles of this invention and are not to be interpreted in a limiting sense. I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described because obvious modifications will occur to a person skilled in the art. | A research burner having a water-cooled hemispherical head provided with aurved upper surface adapted as a seat for a flame which is surrounded by a shroud of inert gas. The burner provides for optical access to the various zones of the flame under study for both temperature and concentration of species in a compatible mixture. | 5 |
This is a continuation of co-pending application Ser. No. 296,088 filed on Jan. 11, 1989 now abandoned.
TECHNICAL FIELD
This invention relates to an improved athletic shoe. More particularly, this invention relates to an athletic shoe with improved torsional characteristics. Specifically, this invention relates to an athletic shoe having a horizontal stiffening member with a generally vertical edge flange forming an integral part thereof inserted adjacent to the shoe's midsole region, thereby providing the shoe with enhanced torsional stability.
BACKGROUND OF THE INVENTION
In recent years, individuals have increasingly been made aware of the advantage of vigorous exercise, including its beneficial effect on the heart, as well as nuscle tone in general. As a result of this awareness, long distance jogging, for example, has become very popular, particularly among individuals wishing to be involved in outdoor activities, and at the same time, wanting to enjoy the benefits resulting from strenuous physical exertion.
Many of those engaging in the sport, and other activities requiring prolonged and intense movement of the legs and feet have unfortunately become aware of the fact that such exercise can result in painful injuries and afflictions. For example, "shin splints," painful straining of the extensor muscles in the lower leg resulting from running on a hard surface can be developed. In addition, planter fasciitis, a hurtful inflammation of the tissue on the bottom of the foot can be experienced, as well as a malady involving "jamming" of the large toe, commonly referred to as "turftoe."
As might be imagined, a wide variety of sports equipment has been developed to facilitate running-related activities. This is particular true in the case of athletic footwear such as specially designed running shoes which frequently employ board last, or slip last construction, or combinations thereof to reduce the weight of the shoes. With respect to athletic shoes, the objective has been to make the shoes as light as feasible to minimize the energy required in exercising in them to the extent possible. To further reduce the shoe's weight, lighter-weight construction materials such as ethylene, vinyl acetate, nylon, polyurethane, and various other synthetics have been employed in their fabrication. The shoe designs achieved, however, have necessitated a compromise insofar as the wearer is concerned, inasmuch as while lighter footwear reduces the amount of energy expended, the weight loss has been achieved at the cost of the shoe's structural stability.
Stability of an athletic shoe is a matter of no minor importance since the manipulation of an individual's foot during walking or running places a significant torsional force on the shoe, relative to its longitudinal axis. Unless the twisting thus imposed is resisted, it tends to result in pronation, or supination, i.e., a "rolling in" or a "rolling out" of the shoe and the foot of the wearer. In many cases, such a result tends to exacerbate the physical conditions referred to above. In addition, the excessively flexible construction of the lighter shoes interferes with the rigidity needed to permit efficient propulsive foot movements by the wearer.
The problem of making athletic shoes lighter, and at the same time making them physically sturdy has been recognized for some time, and a variety ways have been proposed for simultaneously achieving both objectives.
One such approach is that described in U.S. Pat. No. 4,484,397, involving the control of a running shoe by means of a horizontal, somewhat "U"-shaped device consisting of an upper flange, for example, partially fitting over a heel wedge member, and connected by an extending sidewall to a lower flange fitting partially between the heel wedge and the lower midsole member. The rigid spacing of the flanges is intended to prevent compression of the heel wedge when the midsole compresses as the runner's foot rolls inward, in a manner intended to prevent pronation. The device suffers from its complexity, however, as well as from the fact that by preventing compression of part of the sole member, a harder foot support results, further aggravating some of the problems referred to.
Another device for reducing pronation and supination is described in U.S. Pat. No. 4,459,765, entailing a resilient heel member bonded to the exterior of the shoe which provides both vertical and longitudinal support and bracing. While the device may be effective with respect to the heel portion of the shoe, the corrective structure involves the drawback that it has minimal, or no effect on the equally important portions of the shoe distal to the heel, and that it provides no torsional reinforcement.
Still another approach suggested is that shown in U.S. Pat. No. 4,759,136 which makes use of a shoe that includes a midsole having a relatively soft central portion, and a peripheral portion of intermediate hardness extending around the central portion in the region of the heel and forward along each side of the shoe to the toe region. Although claiming to avoid overpronation and oversupination, the device makes no provision for torsional reinforcement.
An additional proposal is that disclosed in U.S. Pat. No. 4,625,435, which involves a device for preventing rolling of the heel portion of an athletic shoe. The device consists of an inverted "T" shaped plate whose horizontal inner flange is adapted for insertion between the shoe's upper and the shoe's sole. However, the device is without structure that would prevent torsional twisting, and is configured in a way that would beneficially affect only the heel of the shoe.
U.S. Pat. No. 4,288,929 shows a tray-like roll control device with upwardly sloping walls intended for placement in the heel portion of an athletic shoe. No protection is afforded to the frontal region of the foot, however, and even the torsional reinforcement in the heel area would be relatively marginal.
Other approaches have involved multiple layer midsoles of differing densities, U.S. Pat. No. 4,694,591; multiple component heel members of differing densities U.S. Pat. No. 4,730,402; horseshoe-shaped heel structures, U.S. Pat. No. 4,490,928; shoes with a peripheral sole portion having one density, and an inner sole portion of a different density, U.S. Pat. No. 4,302,892, and a variety of others. While all of the devices are designed to provide support of one type or another, none offer the torsional support provided by the invention disclosed herein, and none are designed to protect the area of the foot which this invention contemplates.
DISCLOSURE OF THE INVENTION
In view of the foregoing, therefore, it is a first aspect of this invention to provide a lightweight athletic shoe with superior torsional resistance.
A second aspect of this invention is to provide an athletic shoe that reduces injuries to wearers thereof caused by undesirable characteristics resulting from the shoe's lightweight construction.
Another aspect of this invention is to provide a lightweight athletic shoe with a reinforcement rigidified by a vertical flange that resists torsional forces acting on the shoe.
A further aspect of this invention is to provide a lightweight athletic shoe reinforcement.
An additional aspect of this invention is to furnish a lightweight athletic shoe that resists both pronation and supination over a substantial part of its length.
A yet further aspect of this invention is to provide a relatively simple, inexpensive device for strengthening lightweight athletic shoes against torsion generated from forces created by the wearer's foot during locomotion.
Still another aspect of this invention is to enhance the propulsive efficiency of lightweight athletic shoes.
The preceding and additional aspects of the invention are provided by an athletic shoe that includes a substantially flat reinforcement plate member, and a substantially vertical flange member, wherein said plate member is disposed substantially parallel to, and below the sole of the wearer's foot, said plate member extending rearwardly across the width of the shoe from a transverse line located behind and adjacent to the wearer's metatarsal/phalangeal joints, at least to a transverse line located substantially adjacent to the front of the heel of said wearer, and wherein except for the transverse edge forward of the shoe's heel-end, said flange member is attached to the edges of said plate member, at least along a substantial part of the lateral edges of said plate member between said lines.
The preceding and additional aspects of the invention are provided by a reinforcement device comprising a substantially flat portion and a flange, said device being configured to conform to that portion of an athletic shoe below and parallel to the sole of a wearer's foot extending from a transverse line located behind and adjacent a wearer's metatarsal/phalangeal joints, at least to a transverse line located substantially adjacent the front of the heel of a wearer, wherein said flange comprises a substantially vertical member which, except for the transverse edge forward of the shoe's heel-end, is attached to the edges of said plate, at least along a substantial part of the lateral edges of said device between said lines.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood when reference is had to the following drawings, in which like-numbers refer to like-parts, and in which:
FIG. 1 is an isometric view of the shoe reinforcement of the invention.
FIG. 2 is a side elevation of an athletic shoe provided with the reinforcement of FIG. 1.
FIG. 3 is a plan view of the reinforced shoe of FIG. 2 along line 3--3 of FIG. 2.
FIG. 4 is an isometric view of the shoe reinforcement of the invention in which the edge flange is segmented.
FIG. 5 is another embodiment of the invention illustrating a lightweight shoe reinforcement.
FIG. 6 is a further embodiment of a lightweight reinforcement of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an isometric view of the shoe reinforcement of the invention, generally 10, illustrating the horizontal base member 12 to which is attacted the rigidifying edge flange 14.
The purpose of the horizontal base 12 is to prevent torsional twisting of the lower portion of the shoe on which the wearer's foot rests; however, by itself, the base member would be insufficient to stiffen the lower part of the shoe sufficiently to successfully resist the twisting forces which cause the objectionable pronation and supination of the wearer's foot. The problem is overcome through the use of edge flange 14 which is anchored against the sides of the lower portion of the shoe, and which is integrally attached to the horizontal base member, forming a reinforced I-beam-like rigid structure.
Preferably, the torsional stabilizer 10 extends from the rear of the heel of the wearer to a line located just behind and adjacent to the wearer's metatarsal/phalangeal joints, as will be explained in greater detail in connection with FIG. 3.
The stabilizers 10 are particularly useful with lightweight athletic shoes, such as running shoes; however, they are equally useful with lightweight shoes intended for other uses, such as tennis shoes, bowling shoes and the like.
FIG. 2 is a side elevation of an athletic shoe, generally 18, provided with a stabilizer of the invention 10. As illustrated, the shoe comprises an outsole 28 fastened to a midsole 26, the latter being attached to the shoe upper 24. The torsional stabilizer 10 is conveniently installed by cementing it in place with an adhesive cement, for example, between the shoe upper and the shoe midsole. Alternatively, the stabilizer may be formed as a part of the shoe's midsole. Whatever its positioning, however, the horizontal base member of the stabilizer is importantly reinforced against torsional twisting by its proximity to, and support gained from the adjacency of the flange 10 to the sides of the shoe components as previously described. In the case of attachment by means of an adhesive cement, any of the cements normally employed in connection with shoe construction may be successfully employed.
FIG. 3 is a plan view of the reinforced shoe of FIG. 2, along line 3--3 of FIG. 2, showing positioning of the torsional stabilizer 10 from a transverse line 22 located behind and adjacent to the wearer's metatarsal/phalangeal joints 20 to the rear of the heel portion of the shoe 18.
Recognizing that the larger the area covered by the stabilizer 10, the greater will be its resistance to torsional forces, it is nevertheless necessary to terminate the stabilizer behind the metatarsal-phalangeal joints to permit full flexion of the wearer's foot. However, it is desirable that the terminal line 22 extend as far forward as possible without interfering with the joints to assure maximum reinforcement of the shoe.
FIG. 4 is an isometric view of the shoe stabilizer or reinforcement device of the invention 10 in which the edge flange 14a, attached to the horizontal base 12, has been segmented. The segmentation provides a further means for desirably lightening the shoe without significantly interfering with the support of the edge flange. As shown in the Figure, the flange segments extending upwardly, alternate with those extending downwardly. While this is a preferred configuration, other alternating segmented sequences might also be employed.
While any of various materials can be used to fabricate the torsional stabilizer of the invention, the use of plastics, particularly thermoplastics such as the polyolefins, e.g., polyethylene, polypropylene, etc., is preferred. Other plastics can also be used, however, such as polyurethanes, reinforced fiberglass, graphite composites and other materials, both plastic and non-plastic.
While the use of a torsional stabilizer whose transverse cross-section, in effect, takes the form of a horizontal "I-beam" is a preferred embodiment of the invention because of the structural stability inherent in an I-beam configuration, modifications of the horizontal base member may be made. For example, the base member can be ergonomically molded to conform to the natural topography of the sole of an individual's foot.
FIG. 5 is another embodiment of the invention illustrating a lightweight reinforcement stabilizer 10a comprising a horizontal base member 12 fabricated as a single piece with the edge flange 14, a preferred method of fabrication, although other methods well-known in the art are possible. As previously indicated, it is desirable that the stabilizer member 10a extend from just behind the metatarsal/phalangeal joints, to the heel-end of the shoe. In some instances, however, in the interest of lightening the shoe still further, the rear end of the stabilizer may be terminated at a transverse line located substantially adjacent to the front of the heel of a wearer. Such a lightened version is illustrated in the Figure.
The dimensions of the stabilizer may be varied within fairly broad limits; however, it is desirable that the walls of the horizontal base member 12 and the edge flange 14 have a thickness of from about 1 millimeter to about 25 millimeters, a thickness of from about 2 millimeters to about 4 millimeters being especially desirable. The lower portion of the edge flange 14 may extend to a point level with the lower surface of the outsole, or even somewhat below such point, to a point above the horizontal base member 12. The overall height of the flange member, however, will normally be from about 1 centimeter to 10 centimeters, at least part of the flange extending above, and part below the horizontal base member 12. In addition, the height of the flange below the base member will typically about equal the height of the flange above the base member, although different heights may be employed if desired.
Of the embodiments described, the preferred embodiment comprehends extension of the stabilizer from the metatarsal/phalangeal joints to the rear of the shoe heel, although as indicated, it may be shortened in the interest of lighter overall weight. In the case of the shortened, lightweight stabilizers, the stabilizer will at least be long enough so that it extends from about 3 to 5 inches behind the metatarsal/phalangeal joints.
FIG. 6 is a further embodiment of a lightweight reinforcement stabilizer of the invention 10 in which the edge flange 14 has been foreshortened in the interest of reducing the weight of the stabilizer. To achieve an additional weight reduction, the stabilizer has also been provided with perforations 16 in the horizontal base member 12, as well as with perforations 16a in the flange 14. The perforations shown have a circular shape in the base plate member, and an elongated shape in the flange portion. Perforations having other shapes may also be used, however, and the distribution of the perforations is not limited to that illustrated in the Figures.
While in accordance with the patent statutes, a preferred embodiment and best mode has been presented, the scope of the invention is not limited thereto, but rather is measured by the scope of the attached claims. | An athletic shoe with a torsional stabilizer incorporated therein comprises a substantially flat horizontal base member extending rearward across the width of the shoe, parallel to the sole of the shoe, from a transverse line located adjacent to and behind the phalangeal/metatarsal joints, at least to a line adjacent to, and forward of the heel portion of the shoe. Except for transverse edges forward of the heel-end, the base member is provided with a substantially vertical flange portion attached to the edges thereof, which serves to stabilize the base member relative to torsional forces acting thereon. | 0 |
BACKGROUND OF THE INVENTION
[0001] In semiconductor device fabrication involving plasma processing to form nanometer-scale feature sizes across a large workpiece, a fundamental problem has been plasma uniformity. For example, the workpiece may be a 300 mm semiconductor wafer or a rectangular quartz mask (e.g., 152.4 mm by 152.4 mm), so that maintaining a uniform etch rate relative to nanometer-sized features across the entire area of a 300 mm diameter wafer (for example) is extremely difficult. The difficulty arises at least in part from the complexity of the process. A plasma-enhanced etch process typically involves simultaneous competing processes of deposition and etching. These processes are affected by the process gas composition, the chamber pressure, the plasma source power level (which primarily determines plasma ion density and dissociation), the plasma bias power level (which primarily determines ion bombardment energy at the workpiece surface), wafer temperature and the process gas flow pattern across the surface of the workpiece. The distribution of plasma ion density, which affects process uniformity and etch rate distribution, is itself affected by RF characteristics of the reactor chamber, such as the distribution of conductive elements, the distribution of reactances (particularly capacitances to ground) throughout the chamber, and the uniformity of gas flow to the vacuum pump. The latter poses a particular challenge because typically the vacuum pump is located at one particular location at the bottom of the pumping annulus, this location not being symmetrical relative to the either the workpiece or the chamber. All these elements involve asymmetries relative to the workpiece and the cylindrically symmetrical chamber, so that such key parameters as plasma ion distribution and/or etch rate distribution tend to be highly asymmetrical.
[0002] The problem with such asymmetries is that conventional control features for adjusting the distribution of plasma etch rate (or deposition rate) across the surface of the workpiece are capable of making adjustments or corrections that are symmetrical relative to the cylindrical chamber or the workpiece or the workpiece support. (Examples of such conventional features include independently driven radially inner and outer source-power driven coils, independently supplied radially inner and outer gas injection orifice arrays in the ceiling, and the like.) Such features are, typically, incapable of completely correcting for non-uniform distribution of plasma ion density or correcting for a non-uniform distribution of etch rate across the workpiece (for example). The reason is that in practical application, such non-uniformities are asymmetrical (non-symmetrical) relative to the workpiece or to the reactor chamber.
[0003] There is, therefore, a need to enable conventional control features for adjusting distribution of plasma process parameters (e.g., distribution across the workpiece of either etch rate, or etch microloading, or plasma ion density, or the like) to correct the type of asymmetrical or non-symmetrical non-uniformities that are encountered in actual plasma process environments.
SUMMARY OF THE INVENTION
[0004] A plasma reactor for processing a workpiece includes a process chamber comprising an enclosure including a ceiling and having a vertical axis of symmetry generally perpendicular to said ceiling, a workpiece support pedestal inside the chamber and generally facing the ceiling, process gas injection apparatus coupled to the chamber and a vacuum pump coupled to the chamber. The reactor further includes a plasma source power applicator overlying the ceiling and comprising a radially inner applicator portion and a radially outer applicator portion, and RF power apparatus coupled to said inner and outer applicator portions, and tilt apparatus capable of tilting either the workpiece support pedestal or the outer applicator portion about a radial axis perpendicular to said axis of symmetry and capable of rotating said workpiece support pedestal about said axis of symmetry. In a preferred embodiment, the reactor further includes apparatus for effecting axially symmetrical adjustments of plasma distribution, which may be either (or both) elevation apparatus for changing the location of said inner and outer portions relative to one another along said vertical axis of symmetry, or apparatus for apportioning the RF power levels applied to the inner and outer applicator portions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 depicts a reactor of a first preferred embodiment.
[0006] FIGS. 2A and 2B depict the operation of a tilt adjustment mechanism in the embodiment of FIG. 1 .
[0007] FIGS. 3A, 3B and 3 C depict successive steps in the operation of the embodiment of FIG. 1 .
[0008] FIGS. 4A, 4B and 4 C depict the etch rate distribution across the surface of a workpiece obtained in the respective steps of FIGS. 3A, 3B and 3 C.
[0009] FIG. 5 depicts a reactor of a second preferred embodiment.
[0010] FIG. 6 depicts a reactor in accordance with an alternative embodiment.
[0011] FIG. 7 is a block flow diagram depicting a first method of the invention.
[0012] FIG. 8 is a block flow diagram depicting a second method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The present invention is based upon the inventors' discovery that spatial distribution across the workpiece surface of a plasma process parameter (such as etch rate) may be transformed from an asymmetrical distribution (relative to the workpiece or to the chamber) to a more symmetrical distribution. Following such a transformation, the distribution (e.g., etch rate distribution) readily may be corrected to a uniform (or nearly uniform) distribution by employing adjustment features that operate symmetrically relative to the workpiece or relative to the chamber. In a preferred embodiment, the spatial distribution of etch rate (for example) across the workpiece is transformed from an asymmetrical distribution to a symmetrical one by tilting an overhead plasma source power applicator relative to the workpiece at such an angle that the etch rate distribution becomes symmetrical with respect to the cylindrical symmetry of the chamber or of the workpiece. For example, the etch rate, which was initially distributed in a non-symmetrical fashion, may be transformed to a center-high or center-low etch rate distribution across the workpiece. The resulting center-high or center-low etch rate distribution is then rendered perfectly uniform (or nearly uniform) by adjusting an inner portion of the overhead source power applicator relative to an outer portion of the overhead source power applicator. In a preferred embodiment, the source power applicator is an inductively coupled source power applicator consisting of (at least) a radially inner symmetrically wound conductor coil and a radially outer symmetrically wound conductor coil concentric with the inner coil. In one implementation, the adjustment of the inner coil relative to outer coil is performed by adjusting the different heights of the inner and outer coils relative to the workpiece.
[0014] Referring to FIG. 1 , a plasma reactor for processing a workpiece consists of a vacuum chamber 100 defined by a cylindrical side wall 105 , a ceiling 110 and a floor 115 . A workpiece support pedestal 120 on the floor 115 can hold a workpiece 125 that is either a semiconductor wafer or a quartz mask (for example). A process gas supply 130 furnishes a process gas at a desired flow rate into the chamber 100 through gas injection devices 135 which may be provided either in the side wall 105 as shown or in the ceiling 110 . A pumping annulus 140 is defined between the workpiece support pedestal 120 and the side wall 105 , and gas is evacuated from the chamber 100 through the pumping annulus 140 by a vacuum pump 145 under the control of a throttle valve 150 . Plasma RF source power is coupled to the gases inside the chamber 100 by an RF plasma source power applicator 160 overlying the ceiling 110 . In the preferred embodiment illustrated in FIG. 1 , the source power applicator 160 consists of an inner RF coil or helical conductor winding 162 and an outer RF coil or helical conductor winding 164 , driven by respective RF source power generators 166 , 168 through respective impedance matches 170 , 172 . RF plasma bias power is coupled to the plasma by an electrode or conductive grid 175 inside the workpiece support pedestal 120 with bias power applied by an RF bias power generator 180 through an impedance match 185 .
[0015] In order to adjust the distribution of plasma process non-uniformities across the surface of the workpiece 125 , the outer coil 164 can be rotated (tilted) about any selected radial axis (i.e., an axis extending through and perpendicular to the chamber's cylindrical or vertical axis of symmetry 190 ). As one advantage of this feature, we have discovered that such a rotation (or “tilt”) of the outer coil 164 , if performed about an optimum radial axis and through an optimum angle, will transform a non-symmetrical non-uniform spatial distribution of a plasma process parameter (e.g., etch rate) to a symmetrical non-uniform distribution (i.e., symmetrical about the vertical or cylindrical axis of symmetry 190 ). The “optimum” radial axis and the “optimum” angle for this tilt rotation depends upon the individual characteristics of the particular reactor chamber, among other things, and are determined empirically prior to processing of a production workpiece, e.g., by trial and error testing.
[0016] Once the etch rate distribution is rendered symmetrical in this manner, its non-uniformities are readily corrected by adjusting the effect of the inner coil 162 relative to the outer coil 164 . In a preferred embodiment, this adjustment can be made by changing the height above the ceiling of one of the coils 162 , 164 relative to the other one. For this purpose, the inner coil 162 is translatable along the cylindrical axis of symmetry 190 relative to the outer coil 164 (and relative to the workpiece 125 and the entire chamber 100 ). If for example the etch rate distribution has been transformed from the typical non-symmetrical distribution to a symmetrical center-high distribution, then the non-uniformity is decreased (or eliminated) by translating the inner coil 162 vertically upward (away from the ceiling 110 ) to decrease plasma ion density over the center of the workpiece 125 . Conversely, if for example the etch rate distribution has been transformed from the typical non-symmetrical distribution to a symmetrical center-low distribution, then this non-uniformity is decreased (or eliminated) by translating the inner coil 162 vertically downward (toward the ceiling 110 ) to increase plasma ion density over the center of the workpiece 125 .
[0017] In an alternative embodiment, adjustment of the effect of the inner coil 162 relative to the outer coil can be made by adjusting the relative RF power levels applied to the different coils 162 , 164 . This can be in addition to or in lieu of vertical translation of the inner coil 162 .
[0018] In the preferred embodiment, the tilt rotation of the outer coil 164 is performed with very fine control over extremely small rotation angles by a pair of eccentric rings 200 , namely a top ring 202 and a bottom ring 204 , best shown in FIGS. 2A and 2B . The outer coil 164 is supported by the top ring 202 and (preferably) rotates with the top ring 202 . The upper and lower rings 202 , 204 may be thought of as having been formed from a single annular ring which has been sliced in a plane 206 that is slanted at some angle “A” relative to the horizontal. As one of the two rings 202 , 204 is rotated relative to the other about the cylindrical axis 190 , the top surface of the top ring 202 tilts from the initial level orientation of FIG. 2A to the maximum rotation of FIG. 2B . For this purpose, the two rings 202 , 204 are rotated independently of one another about the cylindrical axis 190 by respective top and bottom rotation actuators 210 , 215 . Either ring 202 , 204 may be rotated in either direction (clockwise, counter-clockwise) about the axis 190 while the other ring is held still. Or, the two rings may be rotated simultaneously in opposite rotational directions for the fastest change in tilt angle. Also, in order to adjust the orientation of the tilt direction, the two rings 202 , 204 may be rotated simultaneously in unison by the actuators 210 , 215 either before or after a desired tilt angle is established. Thus, a typical sequence may be to establish a desired tilt angle by rotating the rings 202 , 204 in opposite rotational directions until the desired tilt angle is reached, and then establishing the azimuthal direction of the tilt angle (e.g., “north”, “south”, “east” or “west” or any direction therebetween) by rotating the rings 202 , 204 simultaneously in unison—or non-simultaneously—in the same rotational direction until the tilt direction is oriented as desired.
[0019] While in the preferred embodiment of FIG. 1 only the outer coil 164 is coupled to the top ring 202 , in an alternative embodiment both the inner and outer coils 162 , 164 are coupled to the top ring 202 so as to be tilted by the tilt actuators 210 , 215 .
[0020] The axial (vertical) translation (up or down) of the inner coil 162 is performed by a mechanical actuator, such as the screw-drive actuator 220 that is depicted in FIG. 1 . The screw drive actuator 220 may be formed of non-conducting material and may consist of a threaded female rider 222 coupled to the inner coil 162 and a rotatable threaded screw 223 threadably engaged with the rider 222 . The screw 223 is rotated clockwise and/or counter-clockwise by a vertical translation motor 224 . Alternatively, the actuator 220 may be mounted on support structure overlying the coil 162 (not shown).
[0021] In an alternative (but not preferred) embodiment, the top ring 202 supports both the inner and outer coils 162 , 164 , so that the inner and outer coils 162 , 164 tilt simultaneously together.
[0022] FIGS. 3A-3C and 4 A- 4 C depict a basic process of the invention. Initially, the outer coil 164 is essentially level relative to the plane of the ceiling 110 and of the workpiece support 120 , as depicted in FIG. 3A . The etch rate distribution tends to have a non-symmetrical pattern of non-uniformity, as depicted in FIG. 4A . The outer coil 164 is then tilted ( FIG. 3B ) about a particular radial axis by a particular angle that is sufficiently optimum to transform the non-symmetrical pattern of etch rate non-uniformities of FIG. 4A to the symmetrical distribution of non-uniformities of FIG. 4B . Such an axially symmetrical distribution ( FIG. 4B ) reflects an etch rate distribution that is either center-high or center-low (for example). This non-uniformity is reduced or eliminated to produce the perfectly uniform distribution of FIG. 4C by translating the inner coil 162 either up or down along the vertical axis 190 , as indicated in FIG. 3C . Preferably, the inner coil 162 is not tilted with the outer coil 164 . However, if both coils 162 , 164 are tilted together, then the up/down translation of the inner coil 162 may be along a trajectory that is at a slight angle to the cylindrical axis 190 .
[0023] In order to enable a versatile selection of all modes or combinations of all possible rotations of the top and bottom rings 162 , 164 (i.e, for tilting and/or rotation about the cylindrical axis of the outer coil 164 ) and the vertical translation of the inner coil 162 , a process controller 250 independently controls each of the rotation actuators 210 , 215 and the translation actuator 220 , as well as the RF generators 166 , 168 , 180 .
[0024] FIG. 5 depicts another alternative embodiment in which the outer coil 164 is suspended from the bottom of a support 255 coupled to the top ring 202 (rather than resting on the top ring 202 as in FIG. 1 ).
[0025] FIG. 6 depicts another embodiment in which an intermediate coil 260 is introduced that lies between the inner and outer coils 162 , 164 , the intermediate coil being independently driven by an RF source power generator 262 through an impedance match 264 . This embodiment may be employed in carrying out certain steps in a process of the invention in which each of the three coils 162 , 164 , 260 are driven with different RF phases (and possible the same RF frequency) to set up different maxima and minima in the RF power density distribution in the plasma generation region. This in turn is reflected in different patterns in etch rate distribution across s the surface of the workpiece 125 . For example, the intermediate coil 260 may be driven 180 degrees out of phase from the inner and outer coils 162 , 164 .
[0026] Returning now to FIG. 1 , while the preferred embodiments have been described with reference to apparatus and methods in which the outer coil 164 (at least) is rotated (“tilted”) about a radial axis relative to the workpiece 125 and relative to the entire chamber 100 , the converse operation could be performed to achieve similar results. Specifically, the workpiece 125 and workpiece support 120 could be tilted relative to the source power applicator 160 (and relative to the entire chamber 100 ) rather than (or in addition to) tilting the outer coil 164 . For this purpose, a pair of concentric eccentric rings 360 (identical to the rings 162 , 164 of FIG. 1 ), consisting of a top ring 362 and a bottom ring 364 , are provided under and supporting the wafer support pedestal 120 , so that the pedestal 120 can be tilted in the manner previously described with reference to the outer coil 164 . Respective top and bottom actuators 366 , 368 separately control rotation of the top and bottom rings 362 , 364 about the cylindrical axis 190 .
[0027] FIG. 7 is a block flow diagram depicting a first method of the invention. The first step (block 400 ), is to tilt the RF source power applicator 160 (or at least its outer portion or coil 164 ) relative to the chamber 100 or relative to the workpiece 125 so as to transform the non-uniform distribution of a plasma process parameter (e.g., etch rate) from a non-symmetrical non-uniform distribution ( FIG. 4A ) to an axially symmetrical non-uniform distribution ( FIG. 4B ). The second step (block 402 ) is to vertically translate the inner RF source power applicator (e.g., the inner coil 162 ) relative to the outer RF source power applicator (e.g., the outer coil 164 ) or relative to the ceiling 110 or workpiece 125 , so as to transform the axially symmetrical non-uniform distribution of the process parameter (e.g., etch rate) ( FIG. 4B ) to a uniform distribution ( FIG. 4C ).
[0028] FIG. 8 is a block flow diagram depicting another method of the invention that can subsume a number of different versions. The first step (block 404 ) is to rotate (tilt) the RF source power applicator 160 (or at least its outer coil 164 ) about a radial axis. In one version, this step is performed initially, i.e., prior to processing a production workpiece (block 404 a ). This step may be performed to level the source power applicator 160 (or outer coil 164 ) relative to a datum plane of the chamber 100 (block 404 a - 1 ). Or this step may be performed, as discussed previously in this specification, to make the etch rate distribution symmetrical (or at least nearly so) about the cylindrical axis 190 (block 404 a - 2 ). Or, this step may be performed to orient the plane of coil 164 relative to a plane of the workpiece 125 (block 404 a - 3 ). In another version, this step may be performed continuously during processing (block 404 b ). Alternatively, this step may be performed non-continuously or sporadically (block 404 c ).
[0029] In an alternative embodiment, the purpose of the step of block 404 is to tilt the plane of the source power applicator 160 (or at least its outer coil 164 ) relative to the plane of the workpiece 125 , in which case either the coil 164 is tilted (using the rotation actuators 210 , 215 of FIG. 1 ) or the workpiece support 120 is tilted (using the rotation actuators 366 , 368 ). Or, it is possible to simultaneously tilt both the outer coil 164 and the workpiece support 120 until the desired relative orientation of the plane of one relative to the plane of the other one is achieved. As described above, the optimum orientation is one in which the distribution across the workpiece 125 of a plasma parameter such as etch rate is at least nearly symmetrical relative to the vertical axis of symmetry 190 . This enables a symmetrical adjustment in plasma distribution to render the plasma process parameter distribution at least nearly uniform. Such a symmetrical adjustment may be a change in the relative heights of the inner and outer coils 162 , 164 , or a change in the relative RF power levels applied to the two coils, for example, or a change in respective process gas flow rates to the inner and outer portions of the process region overlying the workpiece 125 . Such adjustments are carried out in some of the steps that are described below.
[0030] A next step is to adjust the vertical levels of the inner and/or outer RF source power applicators 162 , 164 relative to one another or relative to the workpiece 125 (block 406 ). This step may be carried out for the purpose of transforming a cylindrically symmetrical non-uniform etch rate distribution across the workpiece 125 to a uniform distribution (or nearly uniform), as discussed above in this specification.
[0031] A next step is to rotate the RF source power applicator 160 (or at least its outer coil or portion 164 ) about the vertical axis during processing (block 408 ). As mentioned previously in this specification, such a step may be carried out by rotating the two eccentric rings 202 , 204 simultaneously in unison. This step may be carried out continuously during processing (block 408 a ). Alternatively, this step may be carried out non-continuously or sporadically (block 408 b ), depending upon the desired effects during processing. Such a step may average out non-uniform effects of the source power applicator 160 across the surface of the workpiece 125 over a number of rotations during a given plasma process step. The rotation of the source power applicator 160 (or at least its outer portion 164 ) may be carried out before, during or after the tilting operation. The difference is that tilting requires relative rotational motion about the axis of symmetry 190 of the top and bottom rings 202 , 204 , whereas pure rotational motion about the axis of symmetry by the outer applicator portion 164 requires rotation in unison of the two rings 202 , 204 with no relative motion between the two rings 202 , 204 . These two modes of motion may be performed simultaneously by combining the two types of relative ring motions. Although the outer applicator portion 164 may already be tilted so that its axis of symmetry does not coincide with the vertical axis 190 , its rotational motion (when the rings 202 , 204 rotate in unison) is nevertheless defined in this specification as occurring about the vertical axis 190 .
[0032] A next step (block 410 ) may be to adjust the respective levels of RF power delivered to the inner and outer coils 162 , 164 independently, in order to control the radial distribution of a plasma processing parameter (e.g., etch rate) or the effective area of the RF source power applicator 160 . As one possible example, this step may be carried out to correct a symmetrical non-uniform etch rate distribution across the workpiece surface. As such, this step may be supplementary to (or in lieu of) the vertical translation of the inner coil 162 referred to above.
[0033] Another step (block 412 ) may be to adjust the RF phase differences between the different (inner/outer) source power applicator portions (e.g., multiple concentric coils 162 , 164 , 260 of FIG. 6 ) to control the radial distribution of a plasma processing parameter (e.g., etch rate). Different RF power distributions may be achieved with different phase relationships between the multiple coils, and some may be optimum for certain desired processing effects in particular instances.
[0034] In a further step that is optional (block 414 of FIG. 8 ), the process gas flow rates from process gas supplies 130 , 131 to inner and outer gas inlets 130 a, 131 a (shown in FIG. 6 ) may be adjusted relative to one another to adjust plasma ion density radial distribution. The adjustments of block 406 (adjusting the relative axial locations of the inner and outer coils 162 , 164 ), block 410 (adjusting the relative RF power levels applied to the inner and outer coils 162 , 164 ) and block 414 (adjusting the relative gas flow rates to the inner and outer gas inlets 131 a, 130 a ) are all symmetrical relative to the vertical axis 190 ( FIG. 1 ) and may be used to render the etch rate distribution (for example) uniform, provided that the etch rate distribution has been transformed to a symmetrical one by the tilting step of block 404 .
[0035] While the invention has been described in detail by specific reference to preferred embodiments, it is understood that variations and modifications thereof may be made without departing from the true spirit and scope of the invention. | A plasma reactor for processing a workpiece includes a process chamber comprising an enclosure including a ceiling and having a vertical axis of symmetry generally perpendicular to said ceiling, a workpiece support pedestal inside the chamber and generally facing the ceiling, process gas injection apparatus coupled to the chamber and a vacuum pump coupled to the chamber. The reactor further includes a plasma source power applicator overlying the ceiling and comprising a radially inner applicator portion and a radially outer applicator portion, and RF power apparatus coupled to said inner and outer applicator portions, and tilt apparatus capable of tilting either the workpiece support pedestal or the outer applicator portion about a radial axis perpendicular to said axis of symmetry and capable of rotating said workpiece support pedestal about said axis of symmetry. In a preferred embodiment, the reactor further includes apparatus for effecting axially symmetrical adjustments of plasma distribution, which may be either (or both) elevation apparatus for changing the location of said inner and outer portions relative to one another along said vertical axis of symmetry, or apparatus for apportioning the RF power levels applied to the inner and outer applicator portions. | 7 |
BACKGROUND OF THE INVENTION
Phthalocyanine pigments of the beta modification are well known in the art as green shade blue pigments used in a wide variety of applications including inks, coatings, plastics, and textiles among the others. Conventional methods for preparing pigments in the beta-form include subjecting the synthesis formed coarse-crystalline material (crude phthalocyanine) to either wet milling in the presence of milling aids and solvents, for example, salt attrition with glycols, or by dry milling without milling aids and with subsequent treatment with solvents or their mixtures with water. Once the pigment from these processes is dried, it can then be dispersed into water or solvent systems by known milling techniques, such as bead milling. Numerous modifications and combinations of these processes are also described in the technical literature. In general, these conventional methods have the disadvantages of being long multi-step procedures and thus very expensive and generating large amounts of wastewater.
U.S. Pat. No. 5,296,034 discloses copper phthalocyanine pigments and pigment preparations in the alpha-phase that are prepared by first wet milling a crude in the form of a water slurry at pH of 7-12 in a stirred bead mill operated at a power density more than 2.5 kW per liter of milling space followed by contact with a non-crystallizing additive and treatment with organic solvents such as alkanols. Despite the fact the process is quite short due to very aggressive wet activation step and the final material has good coloristic properties, the need to regenerate the solvent and isolate the pigment makes the process complex and expensive. To obtain the pigment in 100% beta-modification, the wet milling is carried out in aqueous isobutanol, as is described in U.S. Pat. No. 5,296,033.
U.S. Pat. No. 4,104,277 describes the process of the dry milling of a copper phthalocyanine crude followed by treatment of the activated material with emulsion of water, surfactant, liquid aromatic amine, and resin. The use of highly toxic amines in this process creates serious environmental problems.
Optionally, some esters, such a methyl benzoate, E.P. 0699720 A1, and dimethyl succinate, E.P. 0787775 A2, have been used as a solvent for an activated crude treatment. Upon completion of the pigmentation step, the solvent is hydrolyzed by heating the pigment slurry with caustic.
U.S. Pat. No. 4,158,572 describes a process of producing a β-modification phthalocyanine pigment composition by dry grinding a crude phthalocyanine, stirring the ground material with an aqueous medium containing a non-ionic surfactant and water soluble resin and isolating the pigmentary product. The required isolation in this process is an economic disadvantage, and in the course of the isolation, most of the surfactant is transferred into wastewater thereby creating an environmental problem.
U.S. Pat. No. 6,056,814 and U.S. Pat. No. 6,379,451 disclose pigment compositions that are produced by dry milling a crude phthalocyanine in the presence of a surfactant and a water-soluble resin. The resulting pigment composition is readily dispersed into an aqueous system to obtain aqueous pigment dispersion. Despite the fact the process is simple and the pigment composition easy dispersed, it is limited by systems based on acrylic resins. In addition, the shade of the composition and viscosity are difficult to control and the pigment is not stable against flocculation.
SUMMARY OF THE INVENTION
This invention pertains to a phthalocyanine blue pigment composition and the process of manufacture of phthalocyanine blue pigments and pigment dispersions. More particularly, the process involves dry milling phthalocyanine blue crude, optionally with inorganic fillers, additives, surfactants and resins, to obtain an activated crude composition, followed by processing the resulting activated crude directly into a dispersion with surfactants and/or additives to facilitate conversion to pigmentary form while maintaining a desirable green and clean shade. A polymeric dispersant is incorporated at any stage of the process, that is, in the course of dry milling, pre-mixing activated material with water and other components of the dispersion, milling of the pre-mix, admixing with final dispersion or any combination of thereof. This process results in a product that has excellent coloristic, rheological, and stability properties and is more economical, safer and environmentally acceptable than prior methods, such as milling with inorganic salts and solvents.
The dispersions are suitable for pigmentation of waterborne inks and coatings.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, a phthalocyanine blue crude is processed to form a pigmentary dispersion and this process is modified by the use of a polymeric dispersant.
Thus, the crude is dry milled to obtain an activated pigment composition. Use of salt or similar milling aids is not required. The crude can be any known metal phthalocyanine blue complex or metal free. Preferably, metal free or complexes with Cu, Co, Ni, Al, or Fe are employed. The crude can contain from 0 to about 16%, preferably 0 to about 5%, of halogen, alkyl-, aryl-, oxy-, alkaryl-, carboxy-, carbamido-, sulfo-, cyano-, amino-, sulfonamido-groups, and any combination of thereof, but is not limited to these groups. It can be made by a solvent or solvent-free process. Suitable milling equipment includes, but not limited by, ball mills, attritors, roll mills, vibration mills and the like. Depending on the type of the milling equipment and desired color and other properties, the milling time ranges from 0.5 to 72 hours, preferably 1-24 hours. The temperature of the milling process can be in range from 20 to 140° C., preferably 50-80° C. Depending on the milling composition, milling time and temperature, the resulting activated crude generally contains about 25% to 100% β-phase phthalocyanine.
The activated crude is then mixed with water, surfactants, and optionally resins and/or other additives (such as crystal modifiers, non-flocculating/non-crystallizing agents, humectants, biocides, defoamers and flow and leveling aids), at elevated temperature, generally 15-150° C., and preferably at 90-98° C., for a duration of time necessary for pigmentation and crystal form conversion. Mixing usually is for 1-6 hours, and preferably 2-4 hours. Any type of mixing and homogenizing equipment is suitable for premixing; however, high speed mixers operated at 2,000-12,000 rpm are more preferable. The amount of water should be only that required to form a concentrated premix in which the phthalocyanine concentrations is about 20 to 70%, preferably about 35 to 50%. The amount of surfactants and additives needed for pigmentation and crystal phase conversion is in the range of about 3 to 35%, preferably about 8 to 20%. The pre-mix is then milled for a time sufficient to provide a stable dispersion with desirable characteristics. Mean pigment particle size is in a range 40-400 nm, preferably 80-250 nm. Suitable milling equipment include, but not limited by, horizontal or vertical bead mills, basket mills, attritors, ball mills, vibration mills. Any known type and size of media can be employed, for example, glass, ceramic, sand, polymeric, and metal media. The resulting dispersion can then be mixed with additional surfactants, resins, water, humectants, biocides, extenders and other additives to form a final composition, which can then be used to color inks and coatings.
Optionally, non-flocculating, non-crystallizing and other additives, surfactants, resins, extenders could be incorporated at the dry milling state or at any other stage of the process. The extender can be any known synthetic or natural extenders from the following classes: talc, clay, mica, carbonates, silica, silicates, phosphates and sulfates; or mixtures of same.
The surfactants can be natural or synthetic, and can be of the following classes: anionic, nonionic, cationic or amphoteric, or a mixture thereof. Useable anionic surfactants include, but are not limited to, phosphate esters, carboxylic acids, alkyl-, aryl- and alkaryl-sulfonates and sulfates. The nonionic surfactants include, but are not limited to, alkyl phenol ethoxylates/propoxylates, EO/PO block copolymers, linear or branched alcohol-, amino-, amido-, carboxy-ethoxylates/propoxylates, esters, but are not limited to these only. Non-limiting examples of cationic surfactants are aliphatic, alicyclic and heterocyclic primary, secondary, tertiary and quaternary amines, imides, and imines, but are not limited to these. Natural surfactants include lecithin, fatty acids, glucamides, glycerides, polysaccharides, among others.
Humectants include, but are not limited to, propylene glycol, ethylene glycol, diethylene glycol, polyethylene glycols, sorbitol and glycerine.
Crystal modifiers include, but not limited to, pyrrolidones, alkylpyrrolidones, glycols, dibasic esters, and amines.
Non-crystallizing and non-flocculating additives can be, but are not limited to, phthalimidomethylene phthalocyanine, naphthalimidomethylenes phthalocyanine; salts of phthalocyanine sulfonic acids with primary, secondary, tertiary and quaternary amines or/and etheramines; sulfonamides of phthalocyanine and primary, secondary amines, diamines, polyamines, polyimines or etheramines; amides and esters of phthalocyanine carboxylic acids; linear and branched alkyl-, arylol- or alkanol phthalocyanine; amino-, aminoalkyl-aminoaryl-phthalocyanines; and mixtures thereof.
Other additives include, but are not limited to, biocides, defoamers and flow and leveling aids.
A polymeric dispersant is incorporated at any stage of the process, that is, in the course of dry milling, pre-mixing activated material with water and other components to form the premix, milling of the pre-mix, admixing with materials to form the final dispersion or any combination of thereof. The amount of polymeric dispersant is in a range about 0.5-25.0%, more preferably about 2-10%, based on the weight of the phthalocyanine blue crude. A content of additive less than about 0.5% does not demonstrate desirable dispersion properties and effects, whereas a concentration higher than 25% can be used but does not provide any further advantages and is not economical.
The polymeric dispersant is a poly(oxyalkylene) modified dialkylsuccinyl succinate or phthalocyanine, or a combination thereof.
The poly(oxyalkylene) modified dialkylsuccinyl succinate are the reaction product of a dialkylsuccinyl succinate, i.e., dialkyl-2,5-dioxo-1,4-cyclohexanedicarboxylate, with one or more amines, at least one of which is poly(oxyalkylene) modified. The alkyl groups of the succinate can have 1 to about 18 carbon atoms, and preferably are lower alkyl of 1 to 4 carbon atoms, and most preferably are methyl. The alkyl groups can be straight chained or branched.
The amines generally conform to the formula R—(NH 2) n in which n is 1 or 2, and R is straight, branched or cyclic, saturated or unsaturated group such as alkyl, alkenyl, alkynyl or aryl group or alkaryl or heteroaryl or heterocyclic or ether or ester or ketone or amide or urea or urethane group or combinations thereof, provided that at least one amine is polymeric in that it has a number average molecular weight of at least about 200, preferably at least about 1000.
In general, any alkyl moiety in a R-group has 1 to about 30 carbon atoms, preferably about 1 to 6 carbon atoms, and any cyclic moiety contains about 4 to about 8 carbon atoms, preferably about 5 to 6 carbon atoms.
The R-group can be unsubstituted or substituted by, for instance, with one or more functional groups. Examples of functional groups include, but are not limited to hydroxide, carboxyl, halogen, CN, primary, secondary or tertiary amino, thiol, sulfonate, sulfates, phosphate, phosphonate, and the like. In one preferred embodiment, the R-group is or contains a poly(oxyalkylene) moiety.
Examples of useful amines include, but are not limited to, NH 3 , methylamine, ethylamine, n-propylamine, n-butylamine, n-hexylamine, hydroxyethylamine, hydroxylamine, hydrazine, dimethylaminoethylamine, diethylaminoethylamine, 2-ethylhexylaminoethylamine, stearylaminoethylamine, oleylaminoethylamine, dimethylaminopropylamine, dibutylaminopropylamine, diethylaminobutylamine, dimethylaminoamylamine, diethylaminohexylamine, piperidinomethylamine, piperidinoethylamine, piperidinopropylamine, pipecolinoethylamine, pipecolinopropylamine, imidazolopropylamine, morpholinoethylamine, morpholinopropylamine, 1,2-cyclopentanediamine, 1,2-cyclohexanediamine, aniline, o-phenylenediamine, 2,3- or 1,8-diaminonaphthalene, 2,3- or 3,4-diaminopyridine, 9,10-diaminophenanthrene, N,N-dimethyl-1,4-phenylenediamine and the like.
In the preferred poly(oxyalkylene)-containing amines, each oxyalkylene group contains 1 to about 4 carbon atoms, and preferably about 2 to 3 carbon atoms. The commercially available poly(oxyalkylene) amines generally contain a polyether backbone that is based either on propylene oxide, ethylene oxide or mixed propylene oxide and ethylene oxide. The poly(oxyalkylene) monoamines are prepared by reaction of a monohydric alcohol, followed by conversion of the resulting terminal hydroxyl group to an amine. The poly(oxyalkylene) diamines are commercially available as several types, e.g. diamine-terminated polypropylene glycols, polyether diamines based on a predominantly polyethylene glycol backbone as well as urea condensates of such polyether diamines.
More than one different high molecular weight amines can be employed if desired.
When a difunctional reactant is employed, it can link two dialkylsuccinyl succinate compounds together, thereby forming a polymeric dispersant.
The succinate-amine reaction is effected at a temperature of about 20° to 180° C., preferably at about 100 to 130° C. When two or more amines are used, the reaction can be conducted stepwise. If desired, the reaction can be allowed to continue for a sufficiently long time or sufficiently high temperature for further modification such as oxidation, cyclization, or functional group modification. No solvent is required.
The dispersant of the present invention will generally conform to the formula
or an isomer thereof, or a mixture of them.
In the above formulae, m can be 1 to 10, and R′″ corresponds to the alkyl moieties of the succinate, R 1 , R 2 and R 3 can be the same or different and each corresponds to a straight, branched or cyclic aliphatic saturated or unsaturated group such as alkyl, alkenyl, alkynyl or aryl group or alkaryl or heteroaryl or heterocyclic or ether or ester or ketone or amide or urea or urethane group or combinations thereof, provided that at least one of these R groups is or contains a poly(oxyalkylene) moiety, as described above.
The poly(oxyalkylene) modified phthalocyanine is a material of the formula MPc—[Z(CH 2 CH 3 CHO) X (CH 2 CH 2 O) Y —CH 3 ] n in which Pc is a phthalocyanine radical; M is hydrogen, any metal (preferably copper, cobalt, nickel, iron or aluminum); x is 0 to about 30; y is 0 to about 100; x plus y is at least 3; and n is 0.1-6, preferably 1-3. The Pc radical can be substituted with 0-8 substituents, each of which can be halogen, alkyl-, alkoxy-, alkylthio-, aryloxy-, arylalkyloxy-, sulfo-, sulfamido-, carboxy-, carbamido-, amino-, aminoalkyl-, or cyano-group; Z is —SO 2 NR 1 —, —NCONR 1 —, —NCOO—, —SO 3 N + R 1 R 2 R 3 —, —CH 2 NR 1 —, —CONR 1 —, —COO— group or any combination thereof; R 1 , R 2 , R 3 are hydrogen, substituted or not substituted linear or branched alkyl, aryl, alkylaryl or poly(oxyalkylene) glycol groups.
One of the preferred examples of poly(oxyalkylene) modified phthalocyanine can be prepared by reacting at a temperature of e.g., from about 0° C. to about 100° C., a phthalocyanine compound of the formula Pc—(SO 2 X) n with an amine of the formula HN(R 2 )Y wherein X is selected from Cl, F, Br, or I; and R 2 is hydrogen or unsubstituted or substituted alkyl, cycloalkyl, aryl or Y, and Y is a poly(oxyalkylene) glycol moiety. No solvent is required but if desired reaction media such as water, alcohols or ethers can be used. Acid acceptors, i.e., bases such as alkali metal carbonates, hydroxides or tertiary amines can be helpful to neutralize acid generated during the reaction.
Further details about the poly(oxyalkylene)sulfonamidophthalocyanine dispersants can be found in U.S. Pat. No. 5,177,200, the disclosure of which is incorporated herein by reference.
The present invention results in phthalocyanine pigment dispersions with excellent coloristic properties, and which are produced by an economical manufacturing process without using hazardous acids, solvents, and any waste water.
In order to further illustrate the invention, various non-limiting examples are set forth below. In these, as throughout this specification and claims, all parts and percentages are by weight and all temperatures in degrees Centigrade unless otherwise indicated.
EXAMPLE 1
A ball mill having 6.5 liter capacity was charged with 12,260 parts of 5 cm diameter steel balls. 533.5 parts of a chlorine-free crude phthalocyanine and 16.5 parts of Polymeric Dispersant A were then added and the ball mill rotated for 24 hours at 60° C. The powder was discharged from the mill trough a screen that retained the grinding elements. The yield of activated material was 96.8% and the content of alpha-phase in the activated crude was of about 52%.
Polymeric Dispersant A:
The wavy lines in the formula set forth indicate the polymeric nature of the chain rather than a specific number of carbon atoms.
Then, 258 parts of the activated crude, 48 parts of Igepal CA-887 (Rhodia), 19.8 parts of Vancryl 68 (as 30% solution in water), 2.1 parts of Surfadone LP-100 (ISP), 1.8 parts of a defoaming agent, and 270 parts of water were charged into 2 liter reactor and stirred for 2 hours at 95-97° C. and 5,000 RPM. The uniform slurry was cooled down to the room temperature and milled for 30 min in a horizontal bead mill with 0.7-0.8 mm ceramic media.
Polymeric Dispersant A was obtained by reacting dimethylsuccinyl succinate with a primary amine terminated poly(oxyethylene/oxypropylene) having a number average molecular weight of about 2000 and p-phenylenediamine.
COMPARATIVE EXAMPLE 1
Example 1 was repeated except that during preparation of the activated crude, the polymeric dispersant was omitted and 550 parts of the chlorine-free crude phthalocyanine were used. The yield of activated material was 99.6% and the content of the alpha-phase in the activated crude was about 58%.
EXAMPLE 2
The procedure of Example 1 was repeated, except that 27.5 parts of Polymeric Dispersant A and 522.5 parts of chlorine-free phthalocyanine crude were charged to the ball mill. The yield of activated material was 99.1% and the content of the alpha-phase in the activated crude was about 29%.
EXAMPLE 3
The procedure of Example 1 was repeated, except that 38.5 parts of Polymeric Dispersant A and 511.5 parts of the chlorine-free phthalocyanine blue was charged to the ball mill. Yield of activated material was 96.8% and the content of the alpha-phase in the activated crude was about 15%.
EXAMPLE 4
Charged to a 2 liter reactor were 240 parts of activated crude of Comparative Example 1, 18 parts of Polymeric Dispersant A, 48 parts of Igepal CA-887 (Rhodia), 19.8 parts of Vancryl 68 (as 30% solution in water), 2.1 parts of Surfadone LP-100 (ISP), 1.8 parts of defoaming agent, and 270 parts of water. The reaction mixture was stirred for 2 hours at 95-97° C. and 5,000 RPM. The uniform slurry was cool down to the room temperature and milled for 30 min a horizontal bead mill with 0.7-0.8 mm ceramic media.
EXAMPLE 5
The procedure of Example 1 was repeated, except 38.5 parts of Polymeric Dispersant B and 511.5 parts of chlorine-free phthalocyanine blue was charged to the ball mill. The yield of activated material was 98.4% and the content of the alpha-phase in the activated crude was about 33%.
Polymeric Dispersant B:
Pc—[SO 2 —NH—(CHCH 3 CH 2 O) 10 (CH 2 CH 2 O) 32 —CH 3 ] 2 where Pc is a radical of copper phthalocyanine.
The characteristics of the milled slurries of the foregoing Examples are shown in the following Table:
Color
Mean
Content (%) of
Exam-
strength
particle
α-modification in
ple
%
dA
dB
size, nm
activated material,
Com-
100.00
Standard
Standard
141
58
parative
1
1
105.98
−0.91
−0.36
132
52
2
106.82
−1.02
0.93
138
29
3
102.19
−2.09
2.43
161
15
4
97.25
−0.17
1.32
150
58
5
103.21
−1.58
−0.69
161
33
Various changes and modifications can be made in the invention without departing from the spirit and scope thereof. The various embodiments set forth were for the purpose of illustration only and were not intended to limit the invention. | Phthalocyanine blue pigments and pigment dispersions for water-borne inks and coatings are described. The pigments are produced by dry milling phthalocyanine blue and a polymeric dispersant, optionally with inorganic fillers and other additives, to obtain a material with improved coloristic, rheological, and stability properties. The resulting activated crude is then processed directly into water-based pigment dispersion with additives and/or surfactants to facilitate conversion to pigmentary form while maintaining the desirable green and clean shade. | 2 |
BACKGROUND OF THE INVENTION
This invention relates generally to aerospace vehicle structures and more particularly to materials and designs for improving ice shedding characteristics from such structures.
All aircraft include various “leading edge structures”, i.e. exposed surfaces that face the direction of flight. These surfaces include, for example, parts of the fuselage, wings, control surfaces, and powerplants.
One common type of aircraft powerplant is a turbofan engine, which includes a turbomachinery core having a high pressure compressor, combustor, and high pressure turbine in serial flow relationship. The core is operable in a known manner to generate a flow of propulsive gas. A low pressure turbine driven by the core exhaust gases drives a fan through a shaft to generate a propulsive bypass flow. The low pressure turbine also drives a low pressure compressor or “booster” which supercharges the inlet flow to the high pressure compressor.
Certain flight conditions allow for ice build up on the leading edge structures, and, in particular, the fan and booster flowpath areas of the engine. These areas include the blades, spinner cone, and static vane and fairing leading edges. The FAA requires certification testing at these flight points to demonstrate the ability to maintain engine thrust once the ice sheds from the various components and ingests into the engine.
One particular leading edge structure of interest is the engine's fan splitter. The splitter is an annular ring with an airfoil leading edge that is positioned immediately aft of the fan blades. Its function is to separate the airflow for combustion (via the booster) from the bypass airflow. It is desired for the splitter and other leading edge structures to have mechanical, chemical, and thermal properties such that ice build up and shed volume is minimized during an icing event. This in turn minimizes risk of compressor stall and compressor mechanical damage from the ingested ice.
Prior art turbofan engines have splitters made from titanium, which is known to provide favorable ice shed properties. The downside of titanium is the expense and weight when compared to conventionally treated aluminum. However, aluminum is believed to behave poorly in an aircraft icing environment. Examples of conventional treatments for aluminum include but are not limited to chemical conversion coatings and anodizing.
Leading edge structures can also be protected with known coatings that are referred to as “icephobic” or “anti-ice” coatings, for example, polyurethane paint or other organic coatings. These coatings have the effect of lowering adhesion forces between ice accretions and the protected component. While these coatings can improve ice shedding characteristics, their erosion resistance may be not adequate to protect leading edge structures from the scrubbing effect of airflows with entrained abrasive particles which are encountered in flight.
BRIEF SUMMARY OF THE INVENTION
These and other shortcomings of the prior art are addressed by the present invention, which provides components having icephobic plating that reduces and/or modifies ice adhesion forces to promote ice release and reduce shedding of large ice pieces.
According to one aspect, the invention provides a leading edge structure for use in an aerospace vehicle, including: (a) a body having a flowpath surface which defines a leading edge adapted to face an air flow during operation; and (b) a metallic icephobic plating comprising nickel applied to at least a portion of the flowpath surface.
According to another aspect of the invention, a splitter for a turbofan engine includes: (a) an annular body having a flowpath surface which defines a leading edge adapted to face an air flow during operation; and (b) a metallic icephobic plating comprising nickel applied to a least a portion of the flowpath surface.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be best understood by reference to the following description taken in conjunction with the accompanying drawing figures in which:
FIG. 1 is a perspective view of an aircraft powered by a pair of high-bypass turbofan engines, incorporating icing-resistant components constructed according to an aspect of the present invention;
FIG. 2 is a schematic half cross-sectional view of an engine shown in FIG. 1 ;
FIG. 3 is a half-sectional view of a splitter shown in FIG. 2 ;
FIG. 4 is a view taken from forward looking aft at an alternative splitter;
FIG. 5 is a view taken along lines 5 - 5 of FIG. 4 ;
FIG. 6 is a view taken from forward looking aft at another alternative splitter; and
FIG. 7 is a view taken along lines 7 - 7 of FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings wherein identical reference numerals denote the same elements throughout the various views, FIG. 1 depicts a known type of commercial aircraft 10 which includes a generally tubular fuselage 12 , wings 14 carrying turbofan engines 16 mounted in nacelles 18 , and an empennage comprising horizontal and vertical stabilizers 20 and 22 . Each of these components includes one or more exposed surfaces having a curved or airfoil-like cross-section that faces the direction of flight (in other words, an aerodynamic leading edge). These components are referred to herein as “leading edge structures”. While the present invention will be described further in the context of a gas turbine engine, it will be understood that the principles contained therein may be applied to any type of leading edge structure.
As shown in FIG. 2 , the engine 16 has a longitudinal axis “A” and includes conventional components including a fan 24 , a low pressure compressor or “booster” 26 and a low pressure turbine (“LPT”) 28 , collectively referred to as a “low pressure system”, and a high pressure compressor (“HPC”) 30 , a combustor 32 , and a high pressure turbine (“HPT”) 34 , collectively referred to as a “gas generator” or “core”, various components of the nacelle 18 , and stationary structures of the engine 16 , including a core nacelle 36 , cooperate to define a core flowpath marked with an arrow “F”, and a bypass duct marked with an arrow “B”.
A stationary annular splitter 38 is positioned at the forward end of the core nacelle 36 , between the bypass duct B and the core flowpath F. The splitter 38 may be a single continuous ring, or it may be built up from arcuate segments. While a variety of materials such as metal alloys and composites may be used, the splitter 38 is preferably constructed from an aluminum alloy to reduce weight and expense. For example, an aluminum-alloy splitter may have a lower weight and cost than a comparable titanium splitter. Various aluminum alloys and tempers are known for use in aerospace applications, and the particular alloy used for the splitter 38 is not critical so long as it has acceptable mechanical properties for the particular application (e.g. strength, fatigue resistance, corrosion resistance, etc.) One example of an alloy known to be suitable for constructing the splitter 38 is AL7075.
As shown in FIG. 3 , the flowpath surface 40 of the splitter 38 includes a radially-outward-facing portion 41 and a radially-inward-facing portion 43 . The two portions are demarcated by an aerodynamic leading edge 39 . The splitter 38 is an example of a leading edge structure as described above. At least a portion of the flowpath surface 40 has a metallic plating 42 applied thereto which has “icephobic” properties, that is, very low adhesion forces are generated between the plating 42 and any ice that forms thereon, as compared to the base material of the splitter 38 . The plating 42 is depicted with an exaggerated heavy line solely for the purposes of illustration. In the illustrated example, the splitter 38 has a chord length “C” in the axial direction of about 8.9 cm (3.5 in.). The exact dimensions are not critical and will vary with a particular application. The length of the flowpath surface 40 which is plated is denoted “L” in FIG. 3 . The splitter 38 may be completely plated, in which case the length L would be 100% of the chord length C. However, in operation, ice typically does not cover the splitter 38 to this extent. Accordingly, the plating 42 may be restricted to any shorter length, which need not correspond to the extent of expected ice coverage. A practical example of an expected shorter length L is about 2% to about 20% of the chord length C. The radially inward-facing portion 43 of the flowpath surface 40 may be completely covered regardless of the extent of coverage on the radially-outward facing portion 41 .
An example of a suitable icephobic metallic plating is nickel or a nickel alloy. One example of a known suitable nickel plating process is electroless nickel plating as described in AMS2404. In general, the smoother the surface finish of the plating 42 , the lower the ice adhesion forces are expected to be. Porosity of the plating 42 should be minimized to avoid corrosion and ice adhesion. Addition of phosphorous and/or boron in combined amounts of up to about 25% by weight may be helpful in reducing porosity. Use of a “high phosphorous” plating containing about 10% to about 13% percent by weight is known to minimize porosity of a nickel plating applied to aluminum.
In this example, the finished plating has a thickness of about 0.04 mm (0.0015 in.) to about 0.15 mm (0.0060 in.). The thickness is not critical for icing reduction purposes, so long as the underlying substrate is not exposed (i.e. the plating is continuous) Component testing has demonstrated that nickel plating of this thickness provides erosion resistance comparable to a titanium part, and is suitable for use in a gas turbine engine. The thickness is only important for achieving desired durability and expected service life for the component.
In operation, the engine 10 will be exposed to icing conditions, namely the presence of moisture in temperatures near the freezing point of water. Ice will naturally tend to form on the leading edge structures including the splitter 38 . As the ice mass builds up, it protrudes into the air flow and increasing aerodynamic (drag) forces act on it, eventually causing portions of it to shed from the splitter 38 . With the plating 42 described above, adhesion forces between the ice and the splitter 38 are substantially reduced as compared to conventionally treated aluminum and titanium. The result is that pieces of the ice break off and shed downstream when they are a smaller size than would otherwise be the case. This avoids excessive cooling and foreign object damage in the high pressure compressor 30 .
In addition to lowering overall ice adhesion forces, it is also possible to improve ice shedding properties by varying the ice adhesion forces over the surface of the component. Specifically, by providing different sections of the splitter 38 or other leading edge structure with varying adhesion properties, stresses are generated within the ice itself as aerodynamic forces act on it. This causes the ice to break up into smaller pieces and in a more predictable fashion that if it were to shed naturally.
For example, FIGS. 4 and 5 show an alternative splitter 138 similar in construction to the splitter 38 described above. The flowpath surface 140 is “sectored” into separate surface areas in the circumferential direction. Areas 142 A have a metallic icephobic plating as described above, while the alternate areas 142 B have a coating or surface treatment, or are otherwise prepared so as to present a different ice-adhesion property (i.e. substantially greater or lesser adhesion than the plated areas 142 A). The boundaries between the different areas may be straight or curved, and may have varying alignments. Examples of materials for the alternate areas 142 B would include conventionally treated aluminum, a different metallic plating, organic coatings (e.g. polyurethane or epoxy paints), polytetrafluoroethylene (PTFE), etc. For practical purposes a suitable erosion-protective material should be used. The width “W” of the areas 142 A and 142 B in the circumferential direction may be selected to cause ice to breakup into relatively small pieces.
FIGS. 6 and 7 show another alternative splitter 238 . Like the splitter 138 , the flowpath surface 240 is divided into areas 242 A with metallic icephobic plating as described above, and alternate areas 242 B with different ice adhesion properties. The boundaries between the different areas may be straight or curved, and may have varying alignments. In this example, the flowpath surface 240 is divided in both the circumferential and axial directions. As this example shows, any suitable combination of circumferential, axial, and/or radial sectoring may be used to reduce ice shed size.
The foregoing has described materials and designs for ice shed reduction in aerospace structures. While specific embodiments of the present invention have been described, it will be apparent to those skilled in the art that various modifications thereto can be made without departing from the spirit and scope of the invention. Accordingly, the foregoing description of the preferred embodiment of the invention and the best mode for practicing the invention are provided for the purpose of illustration only. | A leading edge structure for use in an aerospace vehicle includes a body having a flowpath surface which defines a leading edge adapted to face an air flow during operation; and a metallic icephobic plating comprising nickel applied to at least a portion of the flowpath surface. | 1 |
BACKGROUND OF THE INVENTION
This invention relates generally to oxygenation techniques, and more particularly to apparatus for producing a jet of ultrasonically-activated oxygen or other fluids for treating periodontal tissue.
Ultrasonic energy is generated by driving an electro-mechanical transducer with a high-frequency voltage that is converted by the transducer into corresponding mechanical vibrations. The form of the associated electronic circuit is governed by the nature of the application. Thus for ultrasonic cleaning, the power generator is usually of the electronic oscillator-amplifier type providing a continuous wave voltage, whereas for ultrasonic testing, pulsed oscillations are required. The electro-mechanical transducers may be in the form of magnetostrictive or piezoelectric oscillators.
One significant property of ultrasonic energy that renders such vibration especially useful in cleaning, dispersion, emulsification, homogenization and in many other practical applications is cavitation. Cavitation induced by an ultrasonic field at a low energy level acts to degas, whereas at a higher energy level it generates gas bubbles that implode, releasing shock waves of great intensity.
As noted in the text "Ultrasonics" (2nd Edition) by Benson Carlin -- McGraw Hill, ultrasonics has several useful applications in medicine and dentistry. Thus ultrasonic diagnostic equipment is capable of locating tumors, while ultrasonically-actuated surgical tools may be utilized to remove tumors. In the field of dentistry, ultrasonic devices may be used to drill, grind and clean teeth.
The application of ultrasonics to the treatment of periodontal disease is of particular interest. As indicated in the text "Ultrasonic Therapy in Periodontics" by Ewen and Glickstein -- published by Charles C. Thomas, ultrasonic techniques are useful in scaling, root planing, curettage and overhang removal.
In applying ultrasonics to periodontics, use is usually made of a magnetostrictor encased in a cylindrical handpiece having a small applicator or tip projecting therefrom, the magnetostrictor being energized by a high-frequency generator whereby the resultant ultrasonic vibrations are transferred to the tip. This vibratory motion, in the case of a straight tip, is a simple reciprocatory action. More complex motions are obtained by curved or non-linear tips. Such tips, when applied properly to the tooth surface, are able while undergoing vibration to remove calcarous deposits and necrotic accumulations from the surface, to curet or debride the crevicular wall of soft tissue, to flush out the pocket and to cut tissue.
Because of heat generated in magnetostrictive transducers, it is the present practice to provide a constant flow of water or medicated fluid around the transducer in the handpiece, the water flowing through the handpiece and being expelled from an outlet near the end of the tip. This water flow not only dissipates heat developed in the transducer but it also serves for lavage and to provide a medium for cavitation. The ultrasonically-vibrating tip produces cavitation in the fluid, the cavitating water jet reinforcing the mechanical action and acting concurrently to cleanse and wash the area under treatment.
Inasmuch as the present invention makes use of ultrasonic transducers and generators of the type described in the above-identified Ewen and Glickstein text for periodontal applications, the description of such equipment is incorporated herein by reference.
SUMMARY OF THE INVENTION
The main object of this invention is to provide an ultrasonic oxygenation instrument having biological, medical, dental and periodontal applications, the instrument producing an activated jet of oxygen which may be projected toward diseased tissue or any other site requiring treatment or which may be injected therein.
More specifically, it is an object of this invention to provide an instrument of the above-noted type in which a nozzle attached to a hand-held magnetostrictor and rendered vibratory thereby is coupled to a pressurized source of medical oxygen and functions to emit an oxygen jet which may be directed to a site being treated.
The therapeutic value of oxygenation in the treatment of diseased tissue is well recognized. Because the stream of oxygen passing through the nozzle is subjected to vibratory energy in the ultrasonic range, the oxygen is activated thereby to acquire highly-reactive properties comparable to that of nascent oxygen whereby oxygenation is promoted. And because the jet of activated oxygen is pressurized, the stream has a high penetrating force and serves to dislodge debris and to otherwise cleanse the area under treatment in a manner conducive to healing.
Also an object of this invention is to provide an instrument which is adapted selectively to produce an activated jet of pure oxygen or an atomized jet in which oxygen is intermingled with a liquid having therapeutic properties, or a jet of the liquid, per se, whereby the instrument may be set to afford a jet appropriate to the region being treated.
Still another object of this invention is to provide a low-cost instrument which is simple to operate and which functions efficiently and reliably to carry out oxygenation and cleaning procedures.
Briefly stated, these objects are attained in an instrument including a magnetostrictor or other ultrasonic transducer having a nozzle attached thereto, the nozzle being operatively coupled by a flexible tube to a pressurized tank of medical oxygen. The oxygen flow from the tank is regulated to provide a steady stream of oxygen at a predetermined pressure level.
The nozzle which preferably has a form similar to that of a hypodermic needle, is subjected to high-frequency vibration, the vibrations being imparted to the oxygen flowing therethrough to render the emitted jet highly reactive. An atomizer may be interposed between the oxygen regulator and the nozzle to intermingle with the oxygen a liquid having desired therapeutic properties. A control valve is provided to vary the ratio of oxygen to liquid or to restrict the output either to oxygen or to liquid.
OUTLINE OF THE DRAWINGS
For a better understanding of the invention as well as other objects and further features thereof, reference is made to the following detailed description to be read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of an ultrasonic instrument in accordance with the invention;
FIG. 2 is a section of the atomizer taken in the plane as indicated by lines 2--2 in FIG. 1;
FIGS. 3 A, B and C show the three spray configurations which may be produced by the instrument;
FIG. 4 illustrates one manner of using the instrument;
FIG. 5 shows another manner of using the instrument; and
FIG. 6 shows a modified form of nozzle.
DESCRIPTION OF THE INVENTION
Referring now to the drawing and more particularly to FIG. 1, there is shown an instrument in accordance with the invention, the instrument including a hand-held electro-mechanical ultrasonic transducer, generally designated by numeral 10 which is energized by a high-frequency generator 11. Attached to the transducer is a nozzle 12 which is coupled by a flexible tube 13 to a tank 14 containing pressurized medical oxygen, an atomizer 15 being interposed between the nozzle and the tank.
Transducer 10 is preferably in the form of a magnetostrictor enclosed within a cylindrical handpiece 16, the magnetostrictive element having an axial extension 17 which is welded or otherwise attached to one side of nozzle 12. In practice, the magnetostrictor may be water cooled. Nozzle 12 is preferably in the form of a standard stainless steel hypodermic needle which may be of a gauge in the 18 to 23 range. Alternatively, the needle may be in the form of a hull so that as it is moved along a tooth surface, it acts as a debriding instrument as well as a nozzle emitting exploding, imploding and bubble-bursting solutions.
The coil surrounding the magnetostrictive element is connected to generator 11 which is an electronic oscillator operated from a 115 V. 60 cycle power line to produce a high-frequency voltage preferably in a range of 20 to 28 KHz. Commercially-available ultrasonic units may be used for this purpose, such as Cavitron model 660 or Ultrason model 880, the magnetostrictors of the units being modified to include a properly-angled nozzle in lieu of a vibrating tip.
Mounted above high-pressure oxygen tank 14 is a pressure regulator 18 provided with a pressure indicator 19, the output pressure being suitably reduced to provide a steady stream of oxygen, preferably at a pressure of about 30 psi. The oxygen must of course be of a purity acceptable for medical and dental applications.
Atomizer 15 is in the form of a container 20, as shown separately in FIG. 2, having a tube 21 inserted therein, the tube depending from a T-coupling 21 having a control valve providing three operative positions. In one position, the atomizer is by-passed whereby pure oxygen is conveyed to the nozzle whereas in the second position, oxygen flow is blocked and only the liquid drug contained in the atomizer is fed to the nozzle. In the third position, the oxygen is intermingled with the liquid in a dilution depending on the valve setting. Any standard selective valve may be used for this purpose, the details thereof forming no part of the present invention.
FIG. 3 shows the three types of jet sprays emitted by the nozzle. In FIG. 3A, the spray is fluid only, in FIG. 3B the spray is pure oxygen, while in FIG. 3C the fluid and oxygen are intermingled.
As illustrated in FIG. 4, the nozzle may be inserted by the operator in a crevice between the tooth 23 and its adjacent tissue 25 to aerate or oxygenate the crevice, calculus on the surface of the tooth being removed. The gas pressure produced by the jet acts to blow debris and dead tissue out of the crevice and to thoroughly cleanse the area being treated. The activated oxygen delivered to this area reacts with and oxygenates bacteria, spores, protozoa and like material to promote healing at a rapid rate.
The body liquids in the crevice maintain the activated oxygen injected therein in bubble form, the bubbles being minute and separated from each other to optimize their effective surface area. Because of cavitation effects produced by the ultrasonically-activated bubbles, the bubbles burst, releasing shock waves to carry out highly effective cleansing and oxygenation actions. The nozzle, when properly shaped, is capable of also functioning as a vibrating tip and this tip may be applied to the surface of tooth 23, as shown in FIG. 5, to carry out the usual functions of an ultrasonically-vibrated tip as described in the above-identified Ewen and Glickstein text.
The needle, rather then being in the usual hypodermic form, may be constructed as shown in FIG. 6 in the form of a tubular probe 25 of small gauge whose free end is closed but whose sides are foraminated to provide an array of lateral openings from which the oxygen or oxygen-liquid mixture is emitted to create a shower irradiating the site being treated. This shower is useful in cleaning and treating small and normally inaccessible passages and cavities.
The foraminated probe may be made of a sterile rigid plastic of high-strength, such as polycarbonate. It may also be used for delivering oxygen and medications to the internal portions of the bladder, to the penis, or to the interior of the ear.
In the field of periodontics, as noted previously, the instrument is capable of delivering to the site being treated, activated oxygen or an activated liquid medication, or mixtures thereof. The needle-type nozzle makes it feasible to introduce the jet stream within a dental crevice and to move the needle up and down as well as side to side, thereby bathing the entire site under the gum line with fresh oxygen and liquid medication.
In practice, instead of placing the needle outside of the gum to treat the surface thereof, it may be used to pierce the gingiva to inject oxygen directly into the tissue. Where the needle is used for injection, the transducer is provided with a holder thereof which makes it readily possible to remove and replace the needle.
Among the drugs that may be beneficially used in conjunction with oxygen or alone are potassium permanganate which is an oxidizing agent, hydrogen peroxide, sodium hypochlorate or sodium chloride solutions. One can also dissolve antibiotics such as tetracycline in saline solutions and project or spray these ultrasonically-activated atomized solutions into dental crevices. Even when the antibiotic is in insoluble colloidal powder form, it may be dispersed in a suitable liquid carrier for delivery through the nozzle without clogging the nozzle, in that the vibratory action prevents clotting of the powder. The fact that the nozzle, because of the heat developed by the transducer associated therewith runs fairly hot is not a drawback, for the warmth imparted to the jet stream is often helpful in promoting cleansing and oxygenation activity.
Another application for the ultrasonically-vibrating needle-like nozzle is in anesthesia. Current procedures involve either general anesthesia or local infiltration with a hypodermic needle. By the use of an ultrasonically-vibrating needle, one may inject a suitable agent such as xylocaine, procaine or any other acceptable local anesthetic in a dilute solution into the tissue, the vibrating needle facilitating penetration and enhancing the effect of the agent. Similar procedures using an ultrasonically vibrating hypodermic needle may be employed to inject and dissolve clots or to decalcify stones with a decalcifying solution. In all instances the vibrating nozzle serves to produce a jet stream whose constituents are ultrasonically-agitated to render the constituents more effective or reactive.
While there has been shown and described preferred embodiments of an ultrasonic oxygenation instrument in accordance with the invention, it will be appreciated that many changes and modifications may be made therein without, however, departing from the essential spirit thereof. | An ultrasonic instrument having biological, medical, dental and periodontal applications, the instrument producing a jet of oxygen which may be projected toward diseased tissue or any other site in need of cleansing and oxygenation. The instrument includes a hand-held ultrasonic transducer having a nozzle attached thereto, the transducer being energized by a high-frequency generator. The nozzle is coupled by a flexible tube to a tank of pressurized oxygen, the stream of oxygen passing through the vibrating nozzle being ultrasonically activated thereby to produce a highly reactive jet which may be directed toward the site being treated. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to methods and compositions for controlled viscosity reduction of fracturing fluids used in subterranean formations. The method involves both encapsulation and release of viscosity breakers by using microcapsules assembled from charged nanoparticles and polyelectrolytes. During the microcapsule assembly process, breakers such as enzymes, persulphate, aminocarboxylates, etc., are encapsulated into the shell. The encapsulated species are released during the disassembly or deformation of the microcapsules induced by the addition of salt (NaCl, brine, sea water, etc.). The methods and compositions are designed in such a way that the reduction of viscosity is initiated by contacting fracturing fluids with brine solution.
[0002] This method can more generally be utilized for encapsulating water-soluble or water-dispersible materials in microcapsules assembled from nanoparticles and, as such, is useful for the encapsulation and release of a variety of materials. Such materials include, for example, fluorescent dyes, macromolecules, and enzymes. As stated above, this method is particularly useful for the encapsulation of breaker materials used to break fracturing fluids that are employed in the stimulation of subterranean formations.
BACKGROUND OF THE INVENTION
[0003] Description of the Related Art
[0004] Hydraulic fracturing of subterranean formations is done to increase permeability and flow from the formation to a well-bore. The process involves injecting a fracturing fluid into the well-bore at extremely high pressure to create fractures in the rock formation surrounding the bore. The fractures radiate outwardly from the well-bore and extend the surface area from which oil or gas drains into the well. Usually a gel, an emulsion or a foam, having a proppant such as sand or other particulate material suspended therein is introduced into the fracture. The proppant is deposited in the fracture and functions to hold the fracture open after the fluid pressure is released.
[0005] The fracturing fluid typically contains a water soluble polymer, such as guar gum or a derivative thereof, which provides appropriate flow characteristics to the fluid and suspends the proppant particles therein. When the pressure on the fracturing fluid is released, the fracture closes around the propping agent, water is forced therefrom and the water-soluble polymer forms a compact cake. This can prevent oil or gas flow if not removed. To enhance permeability, viscosity breakers may be included in the fracturing fluid and reduce the viscosity of the fracturing fluid by degrading the polymers.
[0006] Currently, breakers are typically either enzymatic breakers or oxidative breakers. Effective use of breakers requires that the onset of either enzymatic hydrolysis or oxidative breakdown of the polymer be controlled. This is needed to prevent any premature degradation of the polymer which may decrease the fluid's ability to fracture the subterranean formations.
[0007] There have been several proposed methods for the breaking of fracturing fluids aimed at eliminating the above problems. The use of capsules to mask, protect, stabilize, delay or control the release of various materials is well known and, in particular, the use of such capsules or microcapsules to encapsulate breaker materials has been described in, e.g., U.S. Pat. Nos. 4,741,401 to Walker et al; 4,919,209 to King; 5,110,486 to Manalastar et al; 5,102,558; 5,102,559; 5,204,183 and 5,370,184 all to McDougall et al; 5,164,099 and 5,437,331 to Gupta et al; and 5,373,901 to Norman et al.
[0008] Typically, the encapsulated breaker material is formed by surrounding the breaker material with an enclosure member that is sufficiently permeable to at least one fluid, generally water, found in a subterranean formation being treated or to a fluid injected with the capsule into the formation and which is capable of releasing the breaker. Generally the breaker is coated or encapsulated by spraying small particles of the material with a suitable coating formulation in a fluidized bed or by suspension polymerization wherein the breaker particles are suspended in a liquid-liquid system containing a monomer which is capable of polymerizing to form a polymeric coating surrounding the breaker particle.
[0009] For example, U.S. Pat. No. 4,506,734 provides a viscosity-reducing chemical contained within hollow or porous, crushable and fragile beads. When a fracturing fluid containing such beads passes or leaks off into the formation or the fluid is removed by back flowing, any resulting fractures in the subterranean formation close and crush the beads. The crushing of the beads then releases the viscosity-reducing chemical into the fluid. This process is dependent upon the pressure of the formation to obtain release of the breaker and is thus subject to varying results dependent upon the formation and its closure rate.
[0010] U.S. Pat. No. 4,741,401 discloses a method for breaking a fracturing fluid comprised of injecting into the subterranean formation a capsule comprising an enclosure member containing the breaker. The breaker is released from the capsule by pressure generated within the enclosure member due solely to the fluid penetrating into the capsule whereby the increased pressure causes the capsule to rupture, releasing the breaker. This method for release of the breaker would result in the release of the total amount of breaker contained in the capsule at one particular point in time. The patent examples disclose the use of the encapsulated breaker at temperatures ranging from room temperature, 65° C. to 85° C.
[0011] Although the foregoing methods appear to provide releasable encapsulated materials, it remains desirable to provide an alternative method and system that is more economical and gives equivalent or superior performance. In addition, there remains a need for a method that provides better control over the release of viscosity breakers, and, subsequently, sharper control of fracturing fluid viscosity.
SUMMARY OF THE INVENTION
[0012] The present invention provides a simple method for encapsulating and releasing various species using nanoparticle-assembled capsules (NACs) having spherical and non-spherical shapes. In preferred embodiments, the present methods for the encapsulation comprise providing a polyelectrolyte having a positive or negative charge, providing an oppositely charged counterion having a valence of at least 2, combining the polyelectrolyte and the counterion in a solution such that the polyelectrolyte self-assembles to form aggregates, adding the compound to be encapsulated, allowing the compound to enter the aggregates, and adding nanoparticles to the solution such that nanoparticles arrange themselves around the aggregates and encapsulate the compound.
[0013] There are numerous water-soluble or water-dispersible compounds that may be encapsulated, including enzymes, organic dyes, sols such as a ferro fluids, magnetic contrast agents, and cosmetics. The method may be carried out at ambient temperature.
[0014] In some embodiments, the final step produces sub-micron or micron-sized organic-inorganic spheres in which the shell consists of nanoparticles and polyelectrolyte molecules that hold the nanoparticles together. The method may further include functionalizing the polyelectrolyte with at least one moiety selected from the group consisting of: organic molecules, organic fluorophores, and biomolecules. Alternatively, or in addition, the nanoparticles may be functionalized.
[0015] A variety of organic and inorganic nanoparticles such as metals, metal oxides, metal-non-oxides, organic particles, linear polymers, biomolecules, fullerenols, and single/multi-walled carbon nanotubes can be used.
[0016] The herein presented method to encapsulate and release breakers and various other species using hybrid microcapsules offers several advantages. The method is extremely simple to carry out, allows huge flexibility in materials composition, and can be made environmentally and economically favorable. The ease of encapsulating a wide variety of compounds makes it viable for a broad spectrum of applications. The one-step method of encapsulation during the assembly of NACs occurs in one pot, and thus there is no need for a large synthesis set-up. NACs can be used to encapsulate both enzymatic and oxidative viscosity breakers. The one-step method of releasing the encapsulate by salt-induced disruption of NACs is simple and does not require any harsh conditions, as opposed to the extreme pH and/or temperature treatments generally employed in other methods. These mild synthesis conditions, which cover a wide pH range, allow the encapsulation of sensitive organic compounds that would otherwise be degraded. And, finally, the present composition and processes can easily be adapted to the procedures for using breaker-containing fracturing fluids currently employed in the stimulation of subterranean formations.
[0017] Thus, the present invention comprises a combination of features and advantages that enable it to overcome various problems of prior methods. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] For a more detailed description of the preferred embodiment of the present invention, reference will now be made to the accompanying drawings, wherein:
[0019] FIG. 1 is a schematic representation of the encapsulation process.
[0020] FIG. 2 is a graph showing the viscosity of guar gel with time at room temperature.
[0021] FIG. 3 is a graph showing the viscosity of guar gel with time at 50° C.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] The present approach involves nanoparticle assembled microcapsules (NACs) designed to carry and deliver breakers. The process herein presented, of polymer self-association in water followed by nanoparticle deposition and creation of (sub)micron-sized colloidal microcapsule structures, can be used to encapsulate water-soluble compounds. Specifically, cationic polyamines form supramolecular spherical aggregates in the presence of multivalent anions through ionic crosslinking, and negatively-charged 12-nm silica nanoparticles electrostatically deposit around the aggregates to form a closed shell. In order to encapsulate water soluble compounds such as enzyme or dye molecules inside these microcapsules, the chosen compounds are added to the polymer aggregates prior to the addition of silica nanoparticles. By electrostatic interaction, the encapsulating compounds penetrate into the aggregates. Upon addition of silica nanoparticles, the enclosing shell formation takes place, encapsulating the desired compounds within. Compounds that can be encapsulated include but are not limited to enzymatic breakers such as β- Mannanase.
[0023] Since the shells of the present microcapsules are made up of nanoparticles and polymer chains held together by electrostatic interaction, the structure can be disassembled or deformed by changing the ionic strength of the aqueous suspension. The addition of a proper amount of NaCl or brine solution, for example, effects the release of the encapsulated materials from the microcapsules. The deformation of the microcapsules was verified using confocal and optical microscopy. The salt-induced release of the encapsulated materials from the microcapsules provides a convenient way to control the release profile, which may lead to wider applications such as oil-field applications, drug delivery, etc.
[0024] Polyamines have been used as the structure-directing agent in the presence of multivalent anions (e.g., sodium sulfate, trisodium citrate). The general steps for carrying out one embodiment of the method for the encapsulation of breakers are discussed in detail below and are shown in FIG. 1 .
[0025] Briefly, a desired concentration of polyamines is dissolved in water. A solution of a desired salt of a multivalent anion is added to the polyamine solution, at which point the counterions mediate the self-assembly of polyamines to form spherical salt-bridged polyamine aggregates. The compound (enzyme or other species) of interest (to be encapsulated) is then added to the polymer-counterion aggregates. The suspension is aged for a certain period, during which time the enzyme or other species penetrates the aggregates. Next, a sol of a preselected type of nanoparticle is added to the same suspension, whereupon these nanoparticles arrange themselves around the polymer aggregates, thus encapsulating the enzyme or other desired molecules. The resulting product is sub-micron/micron-sized organic-inorganic spheres, in which the thick shell consists of nanoparticles and the polyamine molecules.
[0026] The suspension of enzyme-containing NACs can be used as-is or separated from the mother-liquor by centrifugation for their further use. For example, it may be desirable to separate the NACs for use in viscosity reduction in a fracturing fluid. By way of example only, enzyme-containing NACs may be added to a guar gel either at room temperature or elevated temperatures. When desired, a sufficient amount of salt (NaCl or brine) can be added to the mixture of guar gel and enzyme-containing NACs so as to cause the release of enzyme from the NACs.
[0027] To encapsulate the breaker persulfate, its corresponding salt can be used as the anionic species to crosslink the polymer, forming spherical aggregates.
[0028] For the embodiment presented in FIG. 1 , the encapsulated compound is preferably negatively charged in order to ensure effective encapsulation into the polyamine aggregates due to electrostatic interaction with the positive charges on the polymer. The charge on the encapsulated compound can be controlled by changing the pH of the solution.
EXAMPLES
[0029] According to preferred embodiments, one method for preparing nanoparticle assembled microcapsules (NACs) involves poly-L-lysine (PLL) as the polyamine, citrate (cit) as the multivalent anion and silica nanoparticles. β- Mannanase (Megazyme) is used as the enzymatic breaker. For the enzyme encapsulation in NACs, 25 μL of the enzyme solution (9 U/ml β-Mannanase) was mixed with 21 μL of PLL and aged for 25 minutes. The resulting solution was added to a previously aged (25 min) PLL/cit suspension. The suspension was then aged for another 5 minutes. To this, a colloidal sol of silica nanoparticles was added and formed a thick shell surrounding the aggregates.
[0030] Optical brightfield and confocal images of silica microcapsules encapsulating β- Mannanase enzyme show circular microcapsules. The composition comprises: 21 μL PLL-FITC (2 mg/ml, 68.6 kD)+125 μL Na 3 Cit (5.36 mM)+50 μL β- Mannanase enzyme (9 units/ml)+125 μL SiO 2 NP (20 wt %).
[0031] The encapsulation of the enzyme within the resultant NACs was verified by checking its activity in a 0.5 wt % guar solution. The guar solution was prepared by sprinkling 0.25 g of Guar to 49.75 g of DI water. After mixing, the solution was further stirred for 5 minutes and then aged for another 10 minutes without stirring. The enzyme-containing NAC suspension was then added to the guar solution while stirring. Viscosity was measured after specific times using a fans Viscometer (Model 35A). Bob deflection values were obtained at 100, 200, 300 and 600 rpm, which correspond to 170, 340, 511 and 1021 1/sec shear rates, respectively. Viscosity was calculated from the deflection values using instrument conversion factors.
[0032] The stability of enzyme-containing NACs and triggered-release of the enzyme from NACs at room temperature are shown in FIG. 2 . The graph shows the change in viscosity of 0.5 wt % guar gel (with or without containing β- Mannanase enzyme (0.45 Units) encapsulated in NACs) with time. After 7 hours, 4 ml of 5M NaCl was added to the gel. [Composition: 21 μL PLL-FITC (2 mg/ml, 68.6 kD)+125 μL Na 3 Cit (5.36 mM)+50 μL β- Mannanase enzyme (9 units/ml)+125 μL SiO 2 NP (20 wt %)].
[0033] As FIG. 2 , FIG. 3 presents the stability of enzyme-containing NACs and triggered-release of the enzyme from NACs at a temperature of 50° C. The graph shows the change in viscosity of 0.5 wt % guar gel containing the bare or encapsulated enzyme (0.45 Units) in NACs with time at 50° C. After 3 hours, 4 ml of 5M NaCl was added to the gel. [Compositions: (circles) two batches of (21 μL PLL-FITC (2 mg/ml, 68.6 kD)+125 μL Na 3 Cit (5.36 mM)+25 or 50 μL β- Mannanase enzyme (9 units/ml)+125 μL SiO 2 NP (20 wt %)); (triangles) two batches of (42 μL PLL-FITC (2 mg/ml, 68.6 kD)+125 μL Na 3 Cit (5.36 mM)+25 μL β- Mannanase enzyme (9 units/ml)+125 μL SiO 2 NP (20 wt %)].
[0034] The present process can be used to encapsulate and release enzymatic breakers, and oxidizing and chelating agents, thus having potential usage in oil field applications. The method to assemble and disassemble these microcapsules also provides opportunities for applications in areas as diverse as drug delivery, chemical storage, contaminated waste removal, gene therapy, catalysis, cosmetics, magnetic contrast agents (for use in magnetic resonance imaging), and magneto-opto-electronics. It should be emphasized that for many of the above applications the method provides flexibility to meet the required reaction conditions such as pH of the medium, temperature, etc., for specific applications. The present methods are extremely amenable to variations, as discussed below.
Encapsulation of Breakers in NACs
[0035] As described herein, NACs can be assembled from negatively charged polymers and positively charged nanoparticles. Charged polymers having additional functional groups that will provide sites for the breakers to anchor and thereby encapsulate into the NACs can also be employed. The method can involve cationic counterions such as metal ions (e.g., Ca 2+ ) that can have applications in controlling the rate of cement binding in oil-field operations.
[0036] Ethylenediamine tetraacetate, EDTA, can serve as the anionic counteranion, and can also act as a viscosity breaker in the fracturing fluid. Moreover, the polymers may be functionalized with organic molecules, organic fluorophores, or biomolecules before the formation of the encapsulating nanoparticle shell, or the nanoparticles themselves may be functionalized to have active species on the outer surface of the spheres. Salt granules (salts of persulfate, perchlorate, Ca 2+ etc.) can be utilized for encapsulation, and the encapsulation can be performed by assembling charged polymers and then silica nanoparticles on the surface of these granules.
Modification of the NACs
[0037] After formation, the surface of the NACs can be treated with organic molecules for targeting the delivery site, or with nanoparticles for compositional and structural variations.
Alternate Methods for Disassembly or Deformation of the NACs
[0038] The NACs can be disassembled or deformed by various methods, including, but not limited to, changing the ionic strength upon addition of solutions other than NaCl such as brine or sea water, changing the pH of the aqueous suspension, and osmotic pressure.
Modifications of the Method to Encapsulate and Deliver Using NACs
[0039] The method as herein described can be performed at different pH conditions and/or synthesis temperatures, using different solvents, and the synthesis of the microcapsules containing breakers could be carried out in a flow-type reactor, such as microfluidic device and aerosol reactor.
Use of NACs Assembled From NPs Other Than Silica
[0040] Charged NPs include: metal nanoparticles, such as gold, platinum, palladium, copper, silver, rhodium, rhenium, nickel, and iridium having surface positive/negative charge, alloys of metal nanoparticles, such as platinum/iridium having surface positive/negative charge, metal non-oxide nanoparticles, such as II-VI, III-V and IV quantum dots having surface positive/negative charge, metal oxide nanoparticles, such as titanium oxide, zirconium oxide, aluminum oxide, iron oxide, tungsten oxide, cerium oxide, antimony oxide and silicon oxide having surface positive/negative charge, and nanoparticles functionalized with cationic/anionic polymers that can be assembled by adding suitable counterions. Nanoparticles may also be functionalized with molecules to provide a hydrophilic or hydrophobic surface. The use of hydrophobic nanoparticles, such as polystyrene and polypyrrole may be envisioned. Furthermore, nanoparticles may have diameters of 1-100 nm and may have shapes other than spheres, such as rods, triangles, and hexagons. Additionally, combinations of nanoparticles may be employed.
Use of NACs Assembled From Cationic Polymer, Anionic Counterions and Negatively Charged NPs
[0041] Cationic polymers and anionic counterions that can be used in the present invention include but are not limited to: polypeptides and polyamines with different chain lengths with straight or branched structure, anionic counterions with different functional groups, such as carboxylates, phosphates and sulfates (e.g. phosphate and sulfate analogs of citrate and EDTA), and counterions such as peptides, polypeptides, copolypeptides and polymers having negative charge (e.g. aspartic acid and glutamic acid).
Use of NACs Assembled From Anionic Polymer, Cationic Counterions and Positively Charged Nanoparticles
[0042] Likewise, suitable anionic polymers and cationic counterions include: polypeptides and polyacids with different chain lengths with straight or branched structure, cationic counterions such as metal ions (Ca 2+ , Mg 2+ , transition metal ions, etc.), and counterions such as peptides, polypeptides, copolypeptides and polymers having positive charge (e.g. lysine and histidine).
Alternate Polymers
[0043] Other polymers can be utilized, including cationic/anionic polymers functionalized with organic molecules, biomolecules and fluorophores, the blocks of the copolypeptides derived from the 20 natural amino acids (lysine, arginine, histidine, aspartic acid, glutamic acid, glycine, alanine, valine, leucine, isoleucine, methionine, proline, phenylalanine, tryptophan, serine, threonine, asparagine, glutamine, tyrosine, and cysteine), and combinations of polypeptides.
Applications in Other Areas
[0044] The herein disclosed method may find application in other areas, such as the encapsulation of enzymes for biochemical reactions, the encapsulation of organic dyes, the encapsulation of a sol within the interior of the hollow spheres, such as a ferro-fluid, as well as applications in drug delivery, chemical storage, contaminated waste removal, gene therapy, catalysis, cosmetics, magnetic contrast agents (for use in magnetic resonance imaging), and magneto-opto-electronics.
[0045] While preferred embodiments of this invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope of this invention. The embodiments described herein are exemplary only and are not limiting. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims which follow, the scope of which shall include all equivalents of the subject matter of the claims. In the claims that follow, any sequential recitation of steps is not intended as a requirement that the steps be performed sequentially, or that one step be completed before another step is begun, unless explicitly so stated. The disclosures of all patents, patent applications and publications cited herein are hereby incorporated herein by reference to the extent that they describe materials, methods or other details supplementary to those set forth herein. | A method for the encapsulation and triggered-release of water-soluble or water-dispersible materials. The method comprises a) providing an amount of electrolyte having a charge, b) providing an amount of counterion having a valence of at least 2, c) combining the polyelectrolyte and the counterion in a solution such that the polyelectrolyte self-assembles to form aggregates, d) adding a compound to be encapsulated, and e) adding nanoparticles to the solution such that nanoparticles arrange themselves around the aggregates. Release of the encapsulated species is triggered by disassembly or deformation of the microcapsules though disruption of the charge interactions. This method is specifically useful for the controlled viscosity reduction of the fracturing fluids commonly utilized in the oil field. | 0 |
FIELD OF THE INVENTION
The invention relates to an injection-molding system for the processing of casting (molding) resin with at least one pump cylinder, in which a piston is slidable, which piston divides the cylinder into a pump chamber for receiving the casting resin, or a casting-resin component, and a drive chamber for receiving a driving fluid which drives the piston.
BACKGROUND OF THE INVENTION
Casting resins are often mixed with fillers, for example powdered quartz, which are very abrasive. Piston seals, which lie closely to the cylinder wall, can in this case be used only to a limited degree, since the jamming of filler particles between the seal and cylinder wall would lead to a quick destruction of the seal and cylinder wall. A sufficient lifetime is obtained only when a gap is left between piston and cylinder wall, the width of which gap is so great that filler particles cannot be jammed therein. However, certain leakage flows are created by such gaps, which leakage flows are particularly disadvantageous when several components of the casting resin must be mixed together in a specific proportional relationship and subsequently guided to a mold and when during the gelling of the casting resin pressure is supposed to be maintained in the mold. During this pressure maintenance, only small amounts of resin per unit of time are further pressed into the mold, so that different leakages in several pump cylinders result in significant recipe (mixing proportion) adulterations.
Known (from German Pat. No. 27 48 982) is a system, in which the casting resin components are fed by means of dosing pumps to a mixer. Several buffer elements are fed from the mixer. A mold is associated with each buffer element. Said arrangement permits the pressure regulation in several molds to be independent from how long the gelling operation in the individual molds lasts. The buffer elements contain pistons, onto the one end of which acts a pressure medium, while the other piston end presses onto the casting resin and in this manner maintains a specific pressure in the associated mold and also displaces casting resin into the mold in order to compensate for the volume loss which takes place during gelling. The system is complicated, since aside from the dosing pumps also buffer elements are needed.
Further known (from German OS No. 25 54 233) is also a system with two pump cylinders with pistons, the piston rods of which project from the cylinders and are connected to a connecting bridge in order to force a synchronous movement of the pistons. This principle of the dosing is also known otherwise in the dosing technique, for example from German OS No. 23 24 098. The piston rod sides of the pump cylinders according to German OS No. 24 54 233 are loaded by a pressure medium.
Casting resin components which are packed into sacks are introduced into the cylinder chambers on the other end of the piston from the piston rod end. During closing of the cylinder chambers the sacks are slitted. The components are guided together in a spray gun. Nothing is said in the reference concerning the fit of the pistons in the cylinder.
The basic purpose of the invention is to construct an injection-molding system of the abovementioned type so that casting resins, including those with abrasive fillers, can be processed without creating leakages of a damaging degree out of the pump chamber.
This purpose is attained according to the invention by the piston being sealed off relative to the cylinder wall by a gap seal, by the casting resin or the casting resin components being introduceable free of a casing into the pump chamber, by the driving fluid being compatible with the casting resin or the casting resin components and by the active surfaces of the piston which come into contact with the driving fluid and the casting resin or the casting resin components being at least approximately of the same size.
The sealing of the piston by a gap seal makes the pump cylinder, or the pump cylinders, insensitive to abrasive fillers which are contained in the casting resin. Filler particles thus can penetrate into the gap between piston wall and cylinder wall without being jammed there. They therefore also cannot lead to the formation of grooves (scoring) which damage the piston and the cylinder wall. Since there is no seal which lies closely against the cylinder wall, destruction of such a seal cannot occur. Still leakages are practically completely avoided, since the same pressure exists on both ends of the piston, so that there exists no pressure gradients (drops) which could result in leakages. When the driving fluid is, as is preferable, supplied on the piston rod end of the piston, the pressure on the driving end of the piston is, because of the piston rod cross section, slightly greater than on the piston end which presses the casting resin into the mold or toward an outlet. Therefore, at most only small fluid amounts of the driving fluid could penetrate into the casting resin, while in this case by no means does casting resin get into the driving fluid. Due to the use of a driving fluid which is compatible with the casting resin, no disadvantages arise from the two fluids being mixed with one another to a small degree in the area of the gap between piston and cylinder.
The driving fluid preferably comprises at least in part the casting resin or a casting resin component. This, however, is not a condition for the realizing of the invention. The driving fluid can be any neutral fluid, which does not have a damaging influence on the casting resin, that is, does not change same in such a manner that the product is impaired. However, it is advantageous that the driving fluid does not contain any abrasive sedimentating fillers. Also the driving fluid should not harden. However, no fluid may be used as driving fluid which effects an undesired reaction in the casting resin or the casting resin component. For example, one will not use as driving fluid a hardener, if the respective cylinder is supposed to convey a hardness-free casting resin component.
The driving fluid can be pressurized in various ways. Particularly simple for this is the use of a pressurized gas.
In a preferred embodiment of the invention, the capacity of the pump chamber is larger than is needed for the complete filling of a single mold. Such an injection-molding system makes possible the complete filling of a mold and a subsequent pressure maintaining in connection with a follow-up pressure on the casting-resin mass, and thus the pressure regulating mentioned in the beginning, whereby the system has an extraordinarily simple design. The stroke size can also be dimensioned such that several individual portions can be produced with one piston stroke, in order to for example inject one charge of small parts in a vacuum chamber. During the break, which is created by ventilation, loading and evacuation of the casting chamber, the pump cylinder can be loaded anew.
A drive mechanism is advantageously associated with the piston. A loading stroke can be produced with such a drive mechanism, by which loading stroke can be sucked into the cylinder the mass which is to be conveyed later. However, a filling of the cylinder is also possible without such a drive mechanism, when the filling for example occurs under the action of the force of gravity or when a loading pump is provided.
By using several pump cylinders, thus in the case of a system in which several casting resin components are supposed to be mixed together according to a specific recipe (formula), a mechanical connection between the individual pistons is provided. This mechanical connection can in one simple design consist of a rigid connecting piece. Such connecting pieces are actually known, for example from the abovementioned German OS No. 25 54 233, but without a separate guide which is parallel with the cylinder axes. Such known piece has the disadvantage that a cocking of the pistons in the cylinder or the piston rods in their guides can be created, and the piston rods must then be constructed relatively thick, which results in greater pressure differences between the two ends of the piston. However, in the invention, by using a separate guide, thin piston rods can be used, which as a rule need absorb only pulling forces (tensile forces), so that the piston front end and the piston back end are approximately of the same size and thus the pressure difference on both ends of the seal gap is approximately zero. In place of a rigid connecting piece it would also be possible to provide for the mechanical connection a lever, which can pivot about a stationary fulcrum point and which operates several cylinders, which cylinders at their other ends are secured on a base. This permits effecting, with equal cylinder diameters, different volumetric deliveries per unit of time. Such demands are actually known, for example from German OS No. 27 12 610. In the case of a rigid connecting piece different cylinder diameters must be used, if the volumetric deliveries per cylinder are supposed to differ. This is possible without any problems in fitting gap seals, since fitting of elastic seals is not needed.
In a particularly simple construction of an inventive system, the mechanical connection is done by the pistons being parts of a differential piston. Separate connecting pieces are not needed in this case even if several cylinders are provided. In such a device it is advantageous to have close spaced annular chambers which surround sections of the differential piston and connect respective pump chambers to the mold or the like, since in the area of the seal gap noncompatible components leaking from one annular chamber to the other are quickly flushed through due to the constant passage of material through the annular chambers to the mold. The annular chambers may also be directly adjacent, possibly combined to one annular chamber.
The inventive injection-molding system is advantageously equipped with evacuatable storage containers for the casting resin. Qualitatively high-grade workpieces, for example electrical structural parts, like spools, must be created so that no cavities (shrink holes) exist in the injected casting mass. This can only be achieved if the casting resin or its components are carefully degassed prior to casting. The processing of degassed components is reliably possible with the inventive principle.
The inventive system is advantageously equipped with a valve construction by which reliable sealing of the inflow after the filling of the pump cylinder is achieved, even if the casting resin contains abrasive particles. Also, this valve operates according to the principle of the pump cylinders, namely the valve closing force is produced by a driving fluid which is compatible with the casting resin. Also in the closed condition of the valve, with a pump cylinder which is under pressure, there does not exist a pressure difference between the driving fluid and the casting resin or the casting resin component.
Several pump cylinders can be connected to a storage container which contains premixed (ready mixed) casting resin. With this, several injection points can be supplied independently from one another from one storage container.
Casting resin can be ejected in small individual portions with an apportioning means so that for example the filling of several small molds with one piston stroke is possible. The apportioning means can be either a passive device, that is a device which is operated only by the driving fluid, or instead an active, pumplike device. A pressure increase is also possible with an active device.
BRIEF DESCRIPTION OF THE DRAWINGS
Several exemplary embodiments of the invention are schematically illustrated in the drawings, in which:
FIG. 1 illustrates a system for the processing of two components, whereby a mechanical connection of the two pump cylinders is created by a beam;
FIG. 2 illustrates a system with which premixed resin is processed and which thus only has one pump cylinder;
FIG. 3 is a much simplified illustration of a system corresponding with FIG. 2, wherein several processing areas (injection points) are connected to a single storage container;
FIG. 4 illustrates a system, which is designated for the processing of two casting resin components, whereby the mechanical connection of two pump cylinders is effected by a differential piston; and
FIG. 5 illustrates a system which corresponds with FIG. 4, but in addition provides annular chambers.
DETAILED DESCRIPTION
The system A 1 , according to FIG. 1 has two storage containers 1 and 2 for casting resin components. Each of the storage containers is connected to a low-pressure source (not illustrated). The casting resin components 3 and 4 are circulated by means of conveyor worms 5. The resin which is moved up by the conveyor worms spreads out on a discharge chute 6, by which good degassification of the resin is achieved.
A pump cylinder 7 is associated with the storage container 1 and a pump cylinder 8 with the storage container 2. Pistons 7a, 8a are movable in the pump cylinders 7 and 8. Between the pistons 7a, 8a and the associated cylinders 7, 8 there exist gaps 9 which are wide enough that any filler particles in the resin cannot get jammed in such gaps, but are narrow enough to inhibit, as much as possible, the leakage of casting resin therethrough, which gaps 9 thus may be said to define gap seals.
Piston rods 10, 11 are connected to the pistons 7a, 8a, which piston rods project from the cylinders 7, 8. The piston rods 10, 11 are rigidly connected to a beam 12. A guide rod 13 is provided on the beam 12, which guide rod engages a guide member 14 which is provided with a guide bore. Based on the described connection, the two pistons 7a, 8a can move only together with the same speed.
An operating rod 15 engages the beam 12, which operating rod is the piston rod of a piston 16, which is movable in a compressed-air cylinder 17.
The system also includes containers 18 and 19 for receiving the driving fluid 20, 21. The containers 18, 19 are connected to a compressed-air source 22, namely through a valve 23 and lines 24, 25. A pressure-reducing valve 125 is arranged in front of the valve 23. Lines 26, 27 start out from the bottoms of the containers 18, 19, which lines lead to the pump cylinders 7, 8, namely in the area above the pistons 7a, 8a. Valves 28, 29 are built into the lines 26, 27.
A line 30 also leads from the compressed-air source 22 to the compressed-air cylinder 17, namely in the area below the piston 16. A valve 31 is built into the line 30.
The storage container 1 is connected through a large-volume line 32 to the pump cylinder, namely below the piston 7a. A valve 33 is provided at the inlet point, which valve on the one hand can connect the line 32 to the cylinder 7 and on the other hand a simultaneous closure of the mentioned connection and a path from the cylinder 7 to a line 34 which leads to a mixer 35. The cylinder 8 is similarly connected by a valve 37 either through a line 36 to storage container 2 or through a line 38 to the mixer 35.
A valve 39 is provided below the mixer 35, which valve is built into an injection (casting) line 40. The injection line 40 leads to a mold 41, the cavity 41a of which is to be filled with casting mass.
The system A 1 operates as follows. The casting-resin components 3 and 4 are prepared in the storage containers 1, 2, namely are well mixed and simultaneously degassed. When a casting operation is supposed to be initiated, the cylinders 7a, 8a are lifted with the help of the pressure-medium cylinder 17, whereby the valves 33, 37 open the path from the lines 32, 36 into the pump cylinders 7, 8. A condition is illustrated in the drawings, in which condition the pump cylinders 7, 8 are already substantially filled. The driving fluid 20 or 21 which is provided above the pistons 7a, 8a is displaced into the containers 18, 19 with the valves 28, 29 open. Identical movement of both pistons 7a, 8a is effected by the beam 20 which is guided in the guide 13, 14. During the filling of the pump cylinders 7, 8 with mass components 3, 4 the valve 23 is opened such that air can discharge from the containers 18, 19 through an outlet 23a.
After the pump cylinders 7, 8 are filled, the valves 33, 37 are shifted so that the connection to the lines 32, 36 is blocked, but the connection to the lines 34, 38 is opened. When the filling of the mold is supposed to start, compressed air is introduced into the containers 18, 19 with the valve 23 open. The compressed air acts onto the driving fluids which, with the valves 28, 29 open, flow into the cylinders 7, 8 and press the pistons 7a, 8a downwardly, whereby again the guided beam 12 ensures that the movement of the two pistons occurs at the same rate. The two components 3, 4 are brought together in the mixer 35, which causes activated casting resin to be created. With the valve 39 open the activated resin is pressed into the cavity 41a. During the hardening (gelling) of the casting resin, the pressure of the driving fluids 20, 21, and thus also of the pressure of the casting resin components 3, 4 and thus also the pressure of the finish mixed casting resin, is maintained. Also during subsequent very slow further (final) pressing injection of casting resin into the mold the recipe (composition) of the incoming activated resin does not change, because in the absence of a pressure gradient (pressure drop) within the pump cylinders 7, 8 leakages therein are not created. During the pressing of the casting resin components 3, 4 out of the pump cylinders 7, 8, the valve 31 is adjusted so that air displaced by the piston 16 can flow out through the outlet 31a.
The piston rods 10, 11 can be relatively thin, since they need only transmit small forces; the actual discharge force is effected by the driving fluids 20, 21. The thinner the piston rods, 10, 11, the more equal is the pressure above and below the pistons 7a, 8a.
In the system according to FIG. 2, only one single storage container 42 is provided, in which casting resin 43, which is ready for casting is mixed and degassed. The storage container 42 can be constructed principally like the storage containers 1 and 2 according to FIG. 1. A valve 46 is arranged in a discharge line 44, which leads from storage container 42 to a pump cylinder 45.
The valve 46 has a valve seat 47, on which a sealing edge 48a of a valve piston 48 can abut sealingly. The valve piston 48 can slide in a cylinder 49, whereby between the cylinder 49 and the piston 48 there is provided a gap 50 of such a size that filler particles in the casting resin 43 cannot be jammed therein. The valve piston 48 is connected to a driving piston 52 through a piston rod 51, which driving piston 52 is movable in a driving cylinder 53. It is a single-acting cylinder with an inlet 54 and an outlet 55. Compressed air from a compressed-air source 56 can be fed to the driving cylinder 53 through a valve 57. The inlet 54 can with the valve 57 also be connected to an outlet opening 58.
The cylinder chamber above the valve piston 48 can be loaded with a driving fluid 59, which can be fed to the valve-driving cylinder 49 through a line 60 from a storage container 61. A valve 62 is built into the line 60. The space 61a in the storage container 61 can be loaded with compressed air, which also comes from a compressed-air source 56 and is guided through a valve 63. An outlet 64 can also be controlled with the valve 63, through which outlet air can escape from the container 61.
The pump cylinder 45 is in principle constructed like the pump cylinders 7, 8 in the system A 1 . Also in this cylinder there is provided a relatively large gap 65 between the piston 45a and the inner wall of the cylinder 45, in which gap filler particles cannot be jammed. The same driving fluid 59 which acts onto the valve piston 48 also acts on the upper side of the piston 45. The cylinder 45 is for this purpose connected through a line 66 to the storage container 61. A valve 67 is built into the line 66.
A pull-back cylinder 68 is also associated with the pump cylinder 45, the piston 69 of which pull-back cylinder is connected through a piston rod 70 to the piston 45a. The pull-back cylinder 68 is single-acting; it is connected to the compressed-air source 56 through a line 71. A valve 72 is built into the line 71, which valve can also be switched so that the line 71 is instead connected with an outlet 73.
A valve 75 is built into a discharge line 74 of the pump cylinder 45. The line 74 leads to a mold 76, the cavity 76a of which is to be filled with casting resin.
The system A 2 according to FIG. 2 operates as follows. When the pump cylinder 45 is supposed to be filled, the storage container 61 is vented by adjusting the valve 63 so that the outlet 64 is opened. The valve 62 is also open, so that a closing force does not act onto the valve piston 48. The valve 46 is opened by guiding compressed air under the piston 52 by suitable control of the valve 57. The piston 48 is lifted by this, whereby the driving fluid is pressed into the storage container 61 through the open valve 62. The pull-back cylinder 68 is filled with compressed air, by adjusting the valve 72 such that it connects the compressed-air source 56 to the cylinder 68 and closes the outlet 73. The piston 45a is pressed upwardly, whereby corresponding with the arrow 77 casting resin flows through the line 44 into the pump cylinder 45. The valve 75 remains normally closed. In order to assure a reliable opening of the valve 46, compressed air is introduced into the driving cylinder 53, which causes the valve piston 48 to be lifted. The air which is provided above the piston 52 vents through the outlet 55. The driving fluid which is provided above the valve piston 48 is pressed back into the container 61 with the valve 62 open.
When the pump cylinder 45 has been filled, the valve 46 is then closed. The container 61 is pressurized for this purpose by adjusting the valve 63 so that the outlet 64 is closed. The driving fluid is pressed by the compressed air into the valve cylinder 49, which causes the valve piston 48 to be pressed down onto its seat 47. The driving fluid is furthermore pressed into the pump cylinder 45 through the line 66 with the valve 67 open. When now the casting (injection) valve 75 is opened, the mold cavity 76a is filled. The pressure in the mold cavity 76a is maintained, in order to compensate for volume losses due to shrinkage in the casting material during gelling. Since a significant pressure difference between the casting mass 43 and the driving fluid 59 does not exist, leakages of the casting resin 43 are avoided, so that also during long-lasting gelling operations one need not fear having the activated casting resin reach areas of the system where the hardening of the casting resin could do damage.
The valve 46 closes very reliably, since a gap-free seal is provided between valve seat 47 and sealing edge 48A of valve piston 48. The large clearance of the valve piston 48 makes the valve guiding insensitive toward abrasive particles in the casting resin. The driving fluid 59, just like the driving fluids 20 and 21 (of system A 1 ), is made so that its mixing, as it can occur to a very small degree, with the casting resin components (system A 1 ) or with the resin ready to be injected (system A 2 ), is innocuous. For example, the same material can be used as driving fluid as for casting resin or casting resin component, though as a rule without fillers in the driving fluid. However, it is also possible to use, as the driving fluid, substances which at least exist in the casting resin components or in the finish-mixed casting resin.
The system A 3 according to FIG. 3 has a storage container 42, which corresponds with the storage container 42 of the system A 2 . Four output lines 78 to 81 are connected to the storage container. One valve 46 each is provided in each output line, which valve corresponds with the valve 46 of the system A 2 . A pump cylinder 45 is provided behind each valve 46, which pump cylinder 45 corresponds with the pump cylinder 45 of the system A 2 and a casting valve 75 is provided behind each pump cylinder, which casting valve 75 corresponds with the casting valve 75 of the system A 2 . A relatively large mold 82 is fed from the discharge line 78, a smaller mold 83 from the line 89, a casting (injection) nozzle 84 from the line 80 and a further casting nozzle 85 from the line 81. Thus it is possible to supply from one single storage container 42 for finish-mixed resin several injection points.
The system A 4 according to FIG. 4 has two pump cylinders 86 and 87. Said cylinders are coaxial to one another, that is they have a common axis 88. A differential piston 89 is movable in the pump cylinders 86, 87. The differential piston 89 has a thick portion 89a and a thin portion 89b. The thick portion 89a has a gap 90 relative to the cylinder 86, which gap in turn is sufficiently wide that the filler particles cannot be jammed. The thin cylinder portion 89b has a gap 91 relative to the cylinder 87, which gap again is sufficiently large as to prevent jamming of filler particles therein.
A supply line 92 is connected to the pump cylinder 86, into which supply line is built a valve 93. The supply line 92 can lead from a storage container which is constructed like the storage container 1 in the system A 1 . A supply line 95 which is provided with a valve 94 is connected to the pump cylinder 87, which supply line 95 leads from a further storage container like container 2 of FIG. 1.
A line 96 leads from the pump cylinder 86 and a line 97 from the pump cylinder 87 both to a mixer 98. A valve 99 is built into the line 96 and a valve 100 into the line 97. A casting (injection) valve 101 is arranged behind the mixer 21, which casting valve is provided in a casting line 102 which exits from the mixer 98.
A piston rod 103 is connected to the differential piston 89, which piston rod projects into a pull-back cylinder 104. A piston 105 is slidable in the pull-back cylinder 104, which piston is connected fixedly to the piston rod 103. The pull-back cylinder 104 is single-acting and can be loaded through a line 106 with compressed air supplied from a compressed-air source 107. A valve 108 is built into the line 106, which valve can be switched so that the line 106 can be connected to an outlet 109 with simultaneous closure of the line portion which comes from the compressed-air source 107.
A driving fluid 110 can act onto the entire cross section (except for the small cross section of the piston rod 103) of the piston thick portion 89a. The driving fluid comes from a storage container 111, which is connected to the pump cylinder 86 through a line 112. A valve 113 is built into the line 112. Compressed air can be introduced into the space 111a above the level 110a of the driving fluid 110. The compressed air comes also from the compressed-air source 107 and is supplied through a line 114, into which a valve 115 is built. The valve 115 can also be adjusted so that the space 111a can be ventilated through an outlet 116.
The system A 4 operates as follows. When the pump cylinders 86, 87 are supposed to be filled (from the not illustrated storage containers) with casting resin components 123, 124, the valves 93 and 94 are open, while the valves 99 and 100 are closed. The valve 113 is open and the valve 115 is adjusted so that air can escape at 116 from the space 111a. Compressed air is introduced into the pull-back cylinder 104, which compressed air moves the piston 105, and because of its coupling through the piston rod 103 also the differential piston 89, upwardly. Driving fluid 110 is thereby pressed back into the container 111. After ending the filling stroke, the valves 93 and 94, which can be constructed like the valve 46 of the system A 2 , are closed. The driving fluid 110 is thereafter pressurized by introducing compressed air into the container 111. The pressure acts on the differential piston 89. When casting resin is supposed to be mixed and injected, the valves 99, 100 are opened, as is also the casting valve 101.
The driving fluid 110 presses the differential piston downwardly, whereby from the pump cylinder 86 and 87 casting resin components are pressed through the lines 96 and 97 into the mixer 98. In the space 117 below and in the space 118 above the thick piston portion 89a there exist the same pressures, so that a pressure gradient does not exist, due to which mass could flow out of the space 117. Also the pressures in the space 118' below the thin portion 89b of the differential piston and in the space 117 are the same, so that also through the gap 91 no significant flow occurs. This pressure equality exists due to the connection of both spaces 117, 118' through the lines 96, 97 to the mixer 98. Thus the same pressures exist in the three spaces, namely the space 118 above the thick piston portion 89a, in the space 117 below the thick piston portion 89a and in the space 118' below the thin piston portion 89b.
Activated casting mass can be removed as a stream or in discrete portions through the casting valve 101. However, it is also possible to fill a mold and the pressure in the mold can be maintained during the gelling, as was described in the example of the systems A 1 and A 2 .
The embodiment according to FIG. 4 is particularly simple, since a special device for synchronizing the movements of the two pistons is not needed. The use of the differential piston meets the same purpose as the coupling of the pistons 7a, 8a through the beam 12 and the guiding of the beam in the guide device 13, 14 in the system A 1 .
The system A 5 according to FIG. 5 equals substantially the system A 4 . Corresponding parts are characterized with the same reference numerals. Differences from the system A 4 are as follows.
In the system A 5 the discharge line 96' out of the pump cylinder 86 leads to an annular chamber 119, which surrounds the thin piston portion 89'b of the differential piston. The thin piston portion 89'b is constructed longer than the thin piston portion 89b of the system A 4 . The discharge line 95' out of the pump cylinder 87 leads to an annular chamber 120 which is arranged at a small axial distance from the annular chamber 119. The annular chambers 119, 120 are connected through lines 121, 122 to the mixer 98.
Through the arrangement of the annular chambers 119, 120 it is achieved that the casting resin components 123, 124 can come into contact with one another at most in the short space 126 between the chambers 119, 120. With this one avoids the danger that activated resin mass can spread over the greater length of the gap 91, which activated mass could by hardening lead to breakdowns in operation. A constant material change takes place through the annular chambers, which material change keeps the critical area clean. In other respects, the system A 5 operates like the system A 4 , so that further discussions are not necessary.
Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention. | A casting system for the processing of casting resin. From evacuatable storage containers casting resin components are fed to pump cylinders. The movement of the pump cylinders is synchronized through a mechanical connection. The drive of the pistons in the pump cylinders occurs by means of driving fluids which approximately are under the same pressure as the resin components. Leakages across the pistons are avoided due to the pressure equality on both sides of the pistons even when, in consideration of abrasive filler materials, relatively large gaps must be provided between the pistons and their cylinders. | 5 |
REFERENCE TO NON-PROVISIONAL PRIOR APPLICATION
This application is a continuation of prior U.S. application Ser. No. 14/321,489 filed Jul. 1, 2015, which is fully incorporated by reference.
TECHNICAL FIELD
The following disclosure is directed to a wall system for receiving cladding. The wall system offers improved water drainage, and diminished probability of occurrence of mold, mildew and rot formation behind the cladding. The wall system is also inexpensive, and simple to install and use. In addition, the wall system is generally material agnostic, and may be used as an interface between a structural wall (including sheathing, house wraps, gauge-metal framing, and felt), and exterior-façade materials, including, but not necessarily limited to: faux masonry, faux stone, stone, brick, mortar, stucco, and other aesthetic or exterior-façade materials.
The following disclosure is also directed to systems and methods of attaching faux or natural stone, and other artificial or natural aesthetic-façade materials to a wall.
BACKGROUND
Most building codes in the United States require that a water-resistive barrier or non-water-absorbing layer or designed-drainage space be installed before application of a hard-coat stucco or faux stone or other veneer.
Nevertheless, many veneers adhered to the exterior wall (i.e., sheathing, house wraps, metal framing, and felt) still trap moisture behind the veneer. This can lead to damage and rot to the interior structure of a building, and mold issues. In addition, many of these systems often attract wood-destroying insects such as termites, and carpenter ants.
In particular, the advent of faux-stone veneer in recent years, has led to the finding that many of these wall systems were either improperly installed, or had improper water drainage or vapor-permeable barriers between the faux stone, and sheathing or housing wraps.
Consequently, many houses and buildings that use or used faux stone, will experience moisture and insect problems that result in 100% removal of the faux stone, and major structural repairs.
On the other hand, the advantage of not requiring a stone mason to install stone veneer to the side of a building is appealing to the construction industry. Further, because faux stone does not require mortar for their attachment means to a wall, there are less weather and seasonal restrictions to installations. So, faux-stone veneer is desirable to the consumer and building industry, because it is generally less expensive and quicker to install than natural stone. But attaching simulated stone to the sides of walls requires careful attention to water and mold, and requires expertise.
Thus, there remains a need for a simplified wall system for attaching cladding of all types, including faux stone. Such a wall system should offer water drainage, and diminished probability of occurrence of mold, mildew and rot formation behind the cladding.
In addition, there is a need for simplified method and system of attaching individual faux stones to a wall, requiring less time, expertise, and material to install.
SUMMARY
The following disclosure is directed to a wall system for receiving cladding. The wall system offers improved water drainage, and diminished probability of occurrence of mold, mildew and rot formation behind the cladding. The wall system is also inexpensive, and simple to install and use. In addition, the wall system is generally material agnostic, and may be used as an interface between a structural-wall sheathing (including house wraps, gage-metal framing, and felt), and exterior-façade materials, including, but not necessarily limited to: faux masonry, faux stone, mortar, stucco, and other aesthetic or exterior-façade materials.
In one aspect, wall system includes a structural-separation-plane panel, a matrix, and a plurality of spacers. The panel is generally planar, and includes a back surface, and front surface. The front surface may be substantially flat and planar. Alternatively, the front surface may include one or more patterns and shapes.
In one aspect, matrix is a nylon mesh. That is, the matrix includes a mesh of interwoven-nylon strands. The matrix is embedded into the front surface of the panel when the panel is in a liquefied state (such as a mold). But as appreciated by those skilled in the art having the benefit of this disclosure, the matrix may be coupled to the panel by other means such as glue, staples, tacks, or other coupling means. As a whole, the matrix is permeable to both air and water.
The spacers are bumps that protrude from the back surface of the panel. That is, the spacers extend from the back surface of the panel, and form channels for drainage of water when the panel is secured to the wall. That is, spacers are sandwiched between the back surface, and an exterior-most portion of the wall of a building, thereby forming channels for drainage of water. The channels provide open drainage space for water, and do not catch or contain water.
The spacers may include different shapes, and dimensions. In one example, each spacer is approximately ⅛ of an inch thick measured from the back surface of the separation panel extending to a back surface of each spacer. Further, each spacer is molded into, or a part of the back surface of the panel.
Various other examples of wall systems (and constituent parts, shapes, and sizes) for attaching materials are described in the Detailed Description below, and are illustrated in the drawings.
The following disclosure is also directed to systems and methods of attaching faux stone and natural or other man-made materials to a wall.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below. This summary is not necessarily intended to identify key features or essential features of the claimed subject matter, nor is it necessarily intended to be used as an aid in determining the scope of the claimed subject matter.
Reference herein to “example,” “embodiments” or similar formulations means that a particular feature, structure, operation or characteristic described in connection with the example, is included in at least one implementation in this description. Thus, the appearance of such phrases or formulations herein are not necessarily all referring to the same example. Further, various particular features, structures, operations, or characteristics may be combined in any suitable manner in or more examples.
BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The figures are not necessarily drawn to scale.
FIG. 1 is a profile view of a wall-panel system for attachment to a wall of a building in accordance with this disclosure.
FIG. 2 shows a perspective-front view of the system of FIG. 1 , and specifically a front face of a panel of the system in accordance with this disclosure.
FIG. 3A shows a top view a back side of a panel, and an example shape for each spacer in accordance with this disclosure.
FIG. 3B shows a perspective view of a backside of a panel depicted in FIG. 3A .
FIG. 4 is a profile view of another example of a wall-panel system for attachment to a wall of a building in accordance with this disclosure.
FIG. 5A is a profile view of another example of a wall-panel system for attachment to a wall of a building in accordance with this disclosure.
FIG. 5B is a perspective view of the wire mesh depicted in FIG. 5A .
FIG. 6 is a profile view of another example of a wall-panel system for attachment to a wall 102 of a building in accordance with this disclosure.
FIG. 7 shows a top view of one example of a pattern for a roughed version of a front surface of a panel for wall system in accordance with this disclosure.
FIG. 8A is a profile view of another example of a wall-panel system for attachment to a wall of a building in accordance with this disclosure.
FIG. 8B shows a perspective view of the system depicted in FIG. 8A .
FIG. 9 is a profile view of another example of a wall-panel system for attachment to a wall of a building in accordance with this disclosure.
FIG. 10 is a profile view of another example of a wall-panel system for attachment to a wall of a building in accordance with this disclosure.
FIG. 11 is a perspective view of the system depicted in FIG. 10 .
FIG. 12 is a top view of another example system illustrating a back surface of a panel of the system with buttons attached thereto in accordance with this disclosure.
FIG. 13 is a top view of another example of a system having a fabric panel in accordance with this disclosure.
FIG. 14 shows a side view of the system depicted in FIG. 13 with spacers in the form of buttons as depicted in FIGS. 11 and 12 .
FIG. 15 shows an example system for attaching faux stone to a wall in accordance with this disclosure.
FIG. 16 shows another example system for attaching faux stone to a wall in accordance with this disclosure.
FIGS. 17A, 17B, 17C, 17D, and 17E show profile views of example pins used to secure faux stones thereon.
FIG. 18 shows a top view of a faux stone manufactured in accordance with this disclosure.
FIGS. 19-20 show profile views of other example systems for attaching faux stone to a wall.
FIG. 21 shows two example configurations for interconnecting panels.
FIG. 22 shows a profile-focused view of a panel with faux stone pre-attached thereto.
DETAILED DESCRIPTION
FIG. 1 is a profile view of a wall-panel system 100 for attachment to a wall 102 of a building. System 100 includes a structural-separation-plane panel 104 , a matrix 106 , and a plurality of spacers 108 . As depicted in FIG. 1 , wall 102 is typically a non-aesthetic-structural portion of a building, such as a house. In one example, wall 102 is plywood commonly used in home construction. However, wall 102 may be made of any suitable material used in the building industry. In addition, on an attached to wall 102 from the interior is any suitable support system 105 for supporting wall 102 in a vertical position. On the exterior portion of wall 102 is typically an outer material 101 such as sheathing, house wrap, felt or other suitable materials. These materials are not required, but are typically used in the building industry for variety of reasons, including meeting code requirements.
Panel 104 is generally planar, and includes a back surface 110 , and front surface 112 . In one example, panel 104 is fiberglass. However, as will be appreciated by those skilled in the art, after having the benefit of this disclosure, panel 104 may be constructed of other light-weight materials such as polymeric materials, as will be discussed in other examples below.
In one example, panel 104 is approximately 1/16 of an inch thick measured from back surface 110 to front surface 112 , but as will be apparent to those skilled in the art having the benefit of this disclosure, panel 104 may be other suitable thicknesses greater or smaller than 1/16 of an inch, such as, but not necessarily limited to: 1, 3/32, ¼ or ⅛ of an inch thick. Front surface 112 is may be substantially flat and planar. Alternatively, as will be described below, front surface 112 may include one or more patterns and shapes.
In one example, matrix 106 is a nylon mesh. That is, matrix 106 includes a mesh of interwoven-nylon strands 114 . However, matrix 106 may include other suitable waterproof materials, such as but not limited to plastic, polyethylene, or polyester. In one example, matrix 106 is about 3/16 inch to ¼ inch thick, but may include other suitable thickness (greater or less than the aforementioned thicknesses).
In one aspect, matrix 106 is the nylon mesh portion of drainage mats, such as Driwall™ Rainscreen 075-1 mats from Keene company, Mayfiled Heights, Ohio, USA. Alternatively, mesh may also include fused and entangled filaments manufactured by Enka, or Benjamin Obdyke and others.
Matrix 106 is fastened to front surface 112 of panel 104 . In one example, matrix 106 is embedded into front surface 112 of panel 104 , when panel 104 is formed. But as appreciated by those skilled in the art having the benefit of this disclosure, matrix 106 may be coupled to panel 104 by mechanical means such as glue, staples, tacks, or other coupling means. As a whole, matrix 106 is permeable to both air and water.
FIG. 2 shows a perspective-front view of system 100 , and specifically a front face of panel 104 . As depicted in FIG. 2 , there are gaps 202 between strands 114 comprising matrix 106 , thereby revealing front surface 112 of panel 104 . Thus, although strands 114 are generally not permeable to water or air, matrix 106 as a whole is a breathable and vapor-permeable layer. Cladding such as faux stone (not shown in FIG. 2 ) may attached directly to panel 104 with matrix 106 serving as breathable membrane sandwiched between panel 104 and cladding.
Referring back to FIG. 1 , spacers 108 are bumps that protrude from back surface 110 of panel 104 . That is, spacers 108 extend from back surface 110 of panel 104 , and form channels 116 for drainage of water when panel 104 is secured to wall 102 . That is, spacers 108 are sandwiched between the back surface 110 and an exterior-most portion of wall 102 of a building, thereby forming channels 116 .
Spacers 108 may include different shapes, and dimensions. For instance, in one example, each spacer 108 is approximately ⅛ of an inch thick measured from back surface 110 of panel 104 to a back surface 118 of each spacer 108 . Further, each spacer 108 is simply molded into back surface 110 of panel 104 . That is, each spacer 108 is formed when molding panel 104 . Alternatively, one or more spacers 108 may be attached to panel 104 , and may not necessarily be an integral part of panel 104 . For instance, it may be desirable to attach spacers after the panel 104 is formed from a molding process (if a molding process is used).
FIG. 3A shows a top view a backside of panel 104 . In particular, FIG. 3A depicts one example shape for each spacer 108 . That is, each spacer 108 in FIG. 3A is an oblong-oval-shaped bump (similar to the shape of almond). Vertical and horizontal spacers 108 crisscross each other at approximately 45 degree angles forming a pattern. As shown, multiple channels 116 are formed so as to permit drainage and evaporation of water between wall 102 and back surface 110 of panel 104 . Each spacer 108 is approximately one inch in length, and one-to-two inches apart from each other depending on the orientation of the spacer.
However, each spacer 108 may come be of in different sizes and shapes, and distances apart from each other, so as not to catch or retain water as would be appreciated by those skilled in the art. For instance, spacers 108 may be circular, triangular, square, rectangular, star shaped or other suitable shapes as would be appreciated by those skilled in the art, after having the benefit of this disclosure. The water-drainage cavity (i.e. plane) formed on the backside of the separation panel from spacers—or other means such as mesh—is usually between about ⅛ of an inch and about three inches.
In addition, the ratio between spacers and no spacers may vary. So, the shape, depth and size of each spacer may vary, and ratio of spacers to no spacers may vary. Still further, spacers 108 may not crisscross at an angle. Instead, each spacer may be aligned in rows and columns, with each spacer in alignment with the other.
In addition, channels 116 may be formed by other means, such as by ribs, grooves, or other shaped protrusions formed on either back surface 110 of panel 104 or on a major surface of wall 102 (including sheathing, house wrap, felt, etc.).
FIG. 3B shows a perspective view of a backside 110 of panel 104 with spacers 108 and channels 116 .
Referring back to FIG. 1 , panel 104 may be installed against outer material 101 of (i.e., sheathing, house wrap, felt, plywood, etc.) wall 102 by any mechanical fastening means accepted in the industry, and in accordance with national and local ordinances.
In one example, a liquid applied waterproofing air barrier or DuPont's Tyvek® felt may be applied to wall 102 before fastening panel 104 to wall 102 . Panel 104 may be nailed or screwed into plywood at different intervals. In one example, the fasteners 122 are inserted in the middle of each spacer 108 . As would be appreciated by those skilled in the art, fasteners 122 may include nails, screws, staples or other fastening means (such as adhesives in the alternative).
Veneer, such as faux stones 120 , may be fastened to a front face 124 of system 100 by structural (such as screws, nails or other fastening means) or chemical means (such as glue, adhesive, or mortar). Front face 124 faces away from wall 102 . In addition, stucco (in lieu of veneer), and mortar may be adhered directly to matrix 106 .
FIG. 4 is a profile view of another example of a wall-panel system 400 for attachment to a wall 102 of a building. System 400 includes the same panel 104 , matrix 106 (shown in FIG. 4 as 106 ( 1 )) embedded in front surface 112 of panel 104 , as depicted in FIG. 1 . Panel 104 also includes a second matrix 106 ( 2 ) attached to back surface 110 of panel 104 . That is, matrix 106 ( 2 ) is also embedded into back surface 110 of panel 104 , when panel 104 is formed. But as appreciated by those skilled in the art having the benefit of this disclosure, matrix 106 ( 2 ) may be coupled to panel 104 by mechanical means such as glue, staples, tacks, or other coupling means.
Veneer, such as faux stones 120 (see, e.g., FIG. 1 ), may be fastened to panel 104 of system 400 by fastening means such as mortar, glue, adhesive, screws, nails, a combination of the foregoing, or other fastening means. In addition, stucco (in lieu of veneer), and mortar may be adhered directly to matrix 106 ( 1 ).
FIG. 5A is a profile view of another example of a wall-panel system 500 for attachment to a wall 102 of a building. System 500 includes the same panel 104 , and spacers 108 as depicted in FIG. 1 . However, in lieu of a hairy mesh (nylon mesh) for matrix 106 , a fiberglass-wire mesh 506 is embedded into front surface 112 of panel 104 . Mesh 506 may be of various thickness such as ⅛ th or ¼ inch thick. As will be appreciated by those skilled in the art after having the benefit of this disclosure, mesh 506 may also be of different thickness, and comprised of other materials including plastic, nylon, or other suitable materials.
Veneer, such as faux stones 120 , may be fastened to panel 104 of system 500 by fastening means such as mortar, glue, adhesive, screws, nails, a combination of the foregoing, or other fastening means. In addition, stucco (in lieu of veneer), and mortar may be adhered directly to mesh 506 .
FIG. 5B is a perspective view of the wire mesh 506 depicted in FIG. 5A .
FIG. 6 is a profile view of another example of a wall-panel system 600 for attachment to a wall 102 of a building. In this example, panel 104 includes a roughed-up front surface 112 in lieu of a matrix or mesh. That is, surface 112 includes a rough or irregular-hatched pattern that is molded into the surface 112 .
FIG. 7 shows a top view of one example of a pattern for a roughed version of front surface 112 of panel 104 according to the example system 600 . Veneer, such as faux stones 120 (e.g., FIG. 1 ), may be fastened to panel 104 of system 600 by fastening means such as mortar, glue, adhesive, screws, nails, a combination of the foregoing, or other fastening means. In addition, stucco (in lieu of veneer), and mortar may be adhered directly to surface 112 .
FIG. 8A is a profile view of another example of a wall-panel system 800 for attachment to a wall 102 of a building. In the example of FIG. 8 , panel 104 is made of fabric, such as nylon or a related blend. Fabric panel 104 may be about ⅛ of an inch thick, but may have greater or less thickness as would be appreciated by those skilled in the art having the benefit of this disclosure. Here, matrix 106 ( 1 ) and matrix 106 ( 2 ) may be tied into, fastened, or sewn into panel 104 . In this example, if matrix 106 ( 2 ) is used on back surface 110 of panel 104 , spacers 108 may be omitted. Veneer, such as faux stones 120 , may be fastened to panel 104 of system 800 by fastening means such as mortar, glue, adhesive, screws, nails, a combination of the foregoing, or other fastening means. In addition, stucco (in lieu of veneer), and mortar may be adhered directly to matrix 106 ( 1 ).
FIG. 8B shows a perspective view of the system depicted in FIG. 8A .
FIG. 9 is a profile view of another example of a wall-panel system 900 for attachment to a wall 102 of a building. In the example of FIG. 9 , panel 104 is again made of a fabric like as described with reference to FIG. 8 . However, only a matrix 106 ( 2 ) is tied to, fastened, or sewn into back surface 110 of panel 104 . Spacers 108 may be omitted or included.
FIG. 10 is a profile view of another example of a wall-panel system 1000 for attachment to wall 102 of a building. In the example of FIG. 10 , panel 104 is again made of a fabric as describe above. A matrix 106 ( 1 ) is attached to front surface 112 of fabric panel 104 by adhesive, a mechanical fastener, or a combination of attachment means. On back surface 110 of panel 104 , spacers 108 in the form of buttons 1008 are fastened to panel 104 . Buttons 1008 protrude from back surface 110 , and form channels for drainage of water. Buttons 1008 may also serve as a location for mechanically securing panel 104 to a wall of a structure, such as a building. In one example, buttons 1008 are plastic. Buttons 1008 may also be comprised of other materials, such as fiber glass, polymer, rubber, a composite, or various other related materials or combinations thereof. Buttons 1008 may be glued, sewn, or attached by any suitable fastening mechanism. Buttons 1008 may also be of various sizes and thickness, such as 1 inch in diameter, and ⅛ inch thick. In addition, the panel may be fastened to wall 102 by inserting nails or screws (or other fastening means) through buttons 1008 , which act as spacers 108 .
FIG. 11 is a perspective view of example system 1000 depicted in FIG. 10 . Buttons 1008 , matrix 106 ( 1 ), and panel 104 are also depicted in this view.
FIG. 12 is a top view of example 1000 showing back surface 110 of panel 104 with buttons attached thereto. The shapes, patterns, spacing, and density of buttons 1008 used may vary depending on the application, and environment in which the veneer is being installed.
FIG. 13 is a top-perspective view of another example system 1300 having a fabric panel 104 . In the example FIG. 13 , front surface 112 of panel 104 includes a predetermined pattern of diamond-shaped pockets 1302 . Edges 1304 outline each pocket 1302 are approximately a ¼ of an inch above front surface 112 of panel 104 .
FIG. 14 shows a side view of system 1300 with spacers 108 in the form of buttons 1008 as depicted in FIGS. 11 and 12 . As appreciated by those skilled in the art after having the benefit of this disclosures, buttons 1008 may also be other types of spacers 108 fastened to panel 104 . For instance, spacers 108 may be of any suitable dimension, and shape. And may include any water impervious or waterproof material, such as in the form of a grommet, washer, bushing, strip, band, ring, and other suitable configurations as would be appreciated by those skilled in the art with the benefit of this disclosure
FIG. 15 shows an example system 1500 for attaching faux stone 1502 to a wall. System 1500 may include any of the example systems described above such as systems 100 through 1300 . As used herein, “faux stone” refers to manufactured stone, bricks, or other faux veneer. For instance, in one example, the faux stone is made in accordance with materials (or similar or equivalent materials) described in U.S. Pat. Nos. 7,959,991 and 7,198,833 to West, which are hereby incorporated by reference as if fully set forth in this disclosure. In another example, the faux stone is manufactured by Evolve Stone, LLC, and is generally resilient allowing nails to be driven into the stone without chipping or flaking. The stone is also light. For instance, an Evolve Stone LLC's faux stone that is 12 inches×12 inches in height and width, and 1 inch thick weighs about 2.7 lbs. Of course, heavier faux veneer may be used.
Referring to FIG. 15 , each stone 1502 is simply fastened directly through a panel 104 comprising system 1500 , and into wall 102 . That is, a fastener 1504 , such as a nail, pin, screw, stud or similar fasteners may be driven through each stone 1502 , and into wall 102 . Fastener 1504 may also be driven through each stone 1502 , and into panel 104 and not directly to wall 102 .
In addition, a bonding material 1506 , such as cement, mortar and/or glue, may be applied to matrix 106 of system 1500 before each stone 1502 is attached. Next, each stone 1502 may be fastened to wall 102 using a fastener 1504 , thereby holding the stone 1502 in place while bonding material 1506 cures. The fastener 1504 may remain in place after curing, for additional strength. If the fastener 1504 is thin enough, and of similar colors to stone, it cannot generally be seen by a casual observer. For instance, if stainless steel-pin nails are used (slightly countersunk into each stone 1502 ) then a casual observer should not perceive that the stones are secured to a wall by nails.
FIG. 16 shows another example system 1600 for attaching faux stone 1502 ( FIG. 15 ) to a wall 102 . Here, pins 1602 may extend from panel 104 (such as a fiberglass panel shown in FIG. 1 ). Pins 1602 may be made of one or more different materials such as wood, stainless steel, plastic, and fiberglass. The length of pins 1602 may be of a suitable length to receive securely affix stone 1502 to one or more pins by applying pressure to the opposite side 1604 of stone 1502 . That is, an installer will apply force (push or hammer) stone 1502 toward wall 102 , thereby impaling (or embedding) an exposed length of pins 1602 into stone 1502 . It is usually desirable have a pin length that does not exceed the thickness of stone 1502 . In one example, pins 1602 are between ⅛ of an inch to 1 inch long. Gauge or thickness of pins 1602 may vary between 10 and 20. The lengths of pins 1602 (and widths) may also be staggered, with shorter and longer pins dispersed throughout front face 124 system 1600 . Of course, as appreciated by those skilled in the art after having the benefit of this disclosure, other suitable pin lengths and widths may be selected depending on the size of stones 1502 . In addition, pins may be spaced apart every ¼ or ½ inch or greater (or lesser) from each other along front face 124 of system 1600 .
FIGS. 17A-E show profile views of example pins 1602 ( 1 ), 1602 ( 2 ), 1602 ( 3 ), 1602 ( 4 ), and 1602 ( 5 ), respectively, used to skewer and secure stones thereon. Pin 1602 ( 1 ) ( FIG. 17A ) is a straight pin. Each pin 1602 is generally perpendicular to wall 102 , and parallel to the ground. Pin 1602 ( 2 ) ( FIG. 17B ) includes a single barb at the distal end of the pin. Pin 1602 ( 3 ) ( FIG. 17C ) includes a double-bar at the distal end of the pin. Pin 1602 ( 4 ) ( FIG. 17D ) includes a screw/thread pattern. Pin 1602 ( 5 ) ( FIG. 17E ) includes a squiggly pattern. Pins 1602 ( 2 ) through 1602 ( 5 ) generally have a greater ability to lock each stone onto wall 102 than pin 1602 ( 1 ). Pins 1602 are illustrative fasteners, and are limited as to the shape and form of the possible fasteners that may be used to attach stones thereto.
In addition, pins 1602 may have pre-adhesive materials applied to them before each stone 104 is affixed thereto. After each stone 1502 is slid onto one or more pins 1602 , the stones become affixed thereto, pins 1602 are hidden from view. Because each stone is securely attached individually, and held in place by pins 1602 and possibly glue and mortar too, stones 1502 should not fall or become dislodged from wall 102 , even if mortar or glue becomes ineffective over time.
FIG. 18 shows a top view of a faux stone 1502 manufactured in accordance with this disclosure. As depicted in FIG. 18 , stone 1502 includes an abrasive side 1802 that is generally planar for better mechanical attachment to systems 100 through 1600 , and the better mechanical attachment of glue or mortar. The mortar may have plasticizers, or other modifiers added thereto as appreciated by those skilled in the art.
FIG. 19 shows a profile view of another example system 1900 for attaching faux stone 1502 to a wall. System 1900 includes a wire lath 1902 used with conventional brick and stucco. A felt 1904 (such as 15 lb. and 30 lb) may be used in between lath 1902 and wall 102 . CDX, plywood OSB or other exterior materials may also be used as an intermediary between wall 102 , and lath 1902 . Fasteners 1906 may be used to hold each stone 1502 in lieu of pins. Example fasteners 1906 include any suitable mechanical tie back including brick-tie backs. Mortar may be applied directly to lath 1902 .
FIG. 20 shows a profile view of another example system 2000 for attaching faux stone 1502 to a wall 102 . Here modular panels 2002 containing pre-attached faux stone 1502 are attached to wall 102 . Panels 2002 may be used in combination with systems 100 , 400 , 500 , 600 , 8000 , 900 , 1000 , and 1300 described above. Panels 2002 may also incorporate any of the features described with reference to these systems, or other suitable features as would be appreciated by one skilled in the art after having the benefit of this disclosure. Each panel 2002 may be of any suitable size. For instance, panels may be one foot by one foot, or 4′×8′, 8′×16′, or other suitable dimensions greater or smaller than the aforementioned sizes.
At distal edges 2004 (A), 2004 (B) of each panel 2002 there may be a mechanical interconnect system 2006 to fasten panels 2002 to each other. For instance, FIG. 21 shows two example interlocking shape systems 2102 and 2104 for interconnecting panels 2002 . Other suitable shapes and interlocking shape system may be used including Lego® style interlocking systems, peg and hole systems, and other suitable systems as would be appreciate by one skilled in the art after having the benefit of this disclosure. In addition, panels 2002 may have flanges at each distal end or not. And flanges may be non-interlocking configurations.
FIG. 22 shows a profile-focused view 2200 of a panel 2002 with faux stone 1502 pre-attached thereto. As shown, gaps 2202 may be included between stone to permit mortar to be placed between gaps 2202 to permit a builder to customize the cosmetic look and feel of the mortar, such the color therefor. Of course, mortar may or may not come pre-installed as part of panel 2002 . Furthermore, each stone 1502 may be plugged into a panel via pins (as described earlier) or other fastening means. This permits customization of stone look, and allows an installer to break up of shapes and patterns of faux stone, and enhance/customize the cosmetic appearance of each panel.
Exemplary embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. For example, it will be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present.
Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as illustrative forms of implementing the claims. | A wall system for improved water drainage, and diminished probability of occurrence of mold, mildew and rot formation behind cladding attached to the wall system. The wall system is generally material agnostic, and may be used as an interface between a structural-wall sheathing (including house wraps, gage-metal framing, and felt), and exterior-façade materials, including, but not necessarily limited to: faux masonry, faux stone, mortar, stucco, and other aesthetic or exterior-façade materials. The following disclosure is also directed to systems and methods of attaching faux stone to a wall. | 4 |
[0001] This application claims the benefit of priority of U.S. Provisional Patent Application 60/745,806, filed 27 Apr. 2006, and is a continuation-in-part of U.S. patent application Ser. No. 10/672,060, filed 29 Sep. 2003.
FIELD OF THE INVENTION
[0002] The present invention relates to baseball bats and more particularly to tubular baseball bats, constructed of a variety of materials, and more particularly to baseball bats designed to improve player performance. More particularly, baseball bats according to the invention have variable radial stiffness along the barrel length resulting in larger sweet spots, improved batting performance as defined by greater hitting distance, a vibration soft feel, and unique sounds upon contact with a ball while meeting existing, new, or changed performance standards established by regulatory bodies.
BACKGROUND OF THE INVENTION AND PRIOR ART
[0003] Baseball and softball bats, hereinafter referred to simply as “baseball bats” or “bats”, are today typically made solely from aluminum alloys, or aluminum alloys in combination with composite materials (hybrid bats), or most recently solely from composite materials (with the exception of solid wooden bats for the Major Leagues). Such bats are tubular (hollow inside) in construction in order to meet the weight requirements of the end user, have a cylindrical handle portion for gripping, a cylindrical barrel portion for hitting, and a tapered mid-section connecting the handle and barrel portions. Traditionally, such bats have generally had a constant radial stiffness along their barrel portion length, measuring the radial stiffness along the barrel wall as independent annular segments of the barrel wall at any location along the barrel wall length.
[0004] When aluminum alloys initially replaced wooden bats in most bat categories, the original aluminum bats were formed as a single member, that is, they were made in a unitary manner as a single-walled aluminum tube for the handle, taper, and barrel portions. Such bats are often called single-wall aluminum bats and were known to improve performance relative to wooden bats as defined by increased hit distance. More recently (in the mid 1990 's), improvements in bat design largely concentrated on further improving bat performance. This was accomplished primarily by thinning the barrel wall of the single wall bat frame, and adding inner or internal, and or outer or external, secondary members extending along the entire barrel length. These members are often referred to respectively as inserts or sleeves; while the main member is often referred to as a body, shell or frame. Such bats are often called double-wall bats or multi-walled bats in the case of more than two walls resulting from two or more secondary members.
[0005] Such double walled and multi-walled tubular bats generally obtained improved performance in terms of hitting distance by reason of the improved elastic deflection that is characteristic of a multilayer barrel wall. The efficient batting of a ball is maximized by minimizing plastic deformation, both within the bat and within the ball. Ideally, during the collision, the barrel wall of the bat should not deform beyond its elastic limit. Use of a multi-wall two or more member construction along the entire barrel length allows the barrel portion of the bat to elastically deflect or flex more upon ball impact which propels the ball faster and further than prior art single wall bats.
[0006] The scientific principle governing improved bat performance is bending theory. When a ball impacts a bat it has kinetic energy that must be absorbed by the bat in order to stop the ball. The bat stores most of this energy by flexing. The ball as well deforms. After the ball is stopped, the bat returns the energy it has stored by rebounding and sending the ball back towards where it came from. The more the bat barrel or striking portion deforms upon ball impact without failing (denting or breaking) or experiencing plastic deformation, the lower the energy loss and the greater the energy returned to the ball from the bat as the tubular bat barrel portion impacted returns to its original shape.
[0007] To allow the bat barrel portion to deform, requires lowering the radial stiffness of the barrel portion. The prior art double walled and multi-walled tubular bats have traditionally accomplished this by thinning the main member of the barrel portion and adding thin secondary member insert(s) and/or sleeve(s) which are not bonded to the main member, but which generally extend throughout the full length of the barrel portion. Such inserts and sleeves are not coupled to the barrel wall portion of the frame, and these two contacting components may slide with respect to each other in the same manner as leafs within a leaf spring. The resultant lowered radial stiffness along the barrel portion length permits the barrel wall to deflect elastically.
[0008] U.S. Pat. No. 5,415,398 to Eggiman is an example of a multiwalled bat that discloses use of a frame and internal insert of constant thickness running full length of the barrel portion of the bat in a double-wall construction.
[0009] Other similar bat designs are described in U.S. Pat. No. 5,303,917 to Uke which discloses a two member bat of thermoplastic and composite materials and U.S. Pat. No. 5,364,095 to Easton which discloses a two member bat consisting of an external metal tube and an internal composite sleeve bonded to the inside of the external metal tube and running full length of the barrel portion of the bat.
[0010] U.S. Pat. No. 6,251,034 discloses a polymer composite second tubular member running throughout the full length of the barrel portion of the bat with the members joined at the ends only of the barrel portion with the balance of the composite member freely movable relative to the primary member. U.S. Pat. Nos. 6,440,017 and 6,612,945 to Anderson also disclose two member bats with an outer sleeve and inner shell of constant thickness running full length of the barrel portion. Other references include U.S. Pat. No. 6,063,828 to Pitzenberger, U.S. Pat. No. 6,461,760 to Higginbotham; U.S. Pat. No. 6,425,836B1 to Mizuno, and U.S. Patent Pub. 2001/0094882 A1 to Clauzin.
[0011] In all the prior art multi-walled tubular bats cited so far, the bat secondary member, or insert, extends along the entire frame barrel length, have constant diameters and thickness resulting in uniform cross-sectional geometry along the secondary member length. Also, the bat members are not joined, except at their ends, in order to reduce radial stiffness of the barrel portion to improve bat performance. Also, in all cases, the radial stiffness of the barrel portion is uniform or constant full length of the barrel portion of the bats.
[0012] While the prior art single member, and more particularly, double-walled and multi-walled tubular bats have demonstrated improved performance as claimed, various regulatory bodies have raised safety concerns regarding improved performance bats and thus, some have established maximum performance standards for various categories of baseball bats under their jurisdiction. As a result, manufacturers of baseball bats are required to pass various controlled laboratory tests, such as, bbf (batted ball performance), bbs (batted ball speed), etc. Further, for a given bat category (eg. slowpitch softball), there may be two or more regulatory bodies each of which may establish a different standard. Further, any of the regulatory bodies may change their standard from time to time. Such new or changed or varying regulations are extremely problematic, costly, and disruptive for both manufacturers and players.
[0013] It is not generally desirable to lower the performance of a bat by simply increasing the thickness of the barrel wall of one or more of the barrel members along its full length. Lowering the performance of the bat by merely increasing the wall thickness can increase weight such that the finished bat weight standard or objective is exceeded. On the other hand, it is desirable to increase the wall thickness only in the sweetspot, or mid region, of the barrel portion of the bat without significantly increasing the weight.
[0014] Therefore, what is needed is a simple, low cost invention to vary, e.g. decrease, bat performance of tubular bats in a controlled manner, in order to meet lowered or changed bat performance standard requirements without significantly increasing or departing from standard bat weight. Further, in conjunction with causing a decrease in batting performance it would be desirable to improve another bat characteristic such as “sweetspot” size.
[0015] The sweet spot of a bat is generally the portion of the barrel which, with when struck by the ball, provides maximum batting performance. It is the location on the barrel at which the collision occurs with maximum efficiency and with the transmission of minimum vibration through the handle to the hands of a user. While highly subjective, many players would accept that the sweet spot portion on the bat has a dimension of approximately 2 inches, possibly up to 4 inches, in length and is located generally midway along the barrel portion. It is highly desirable to provide improved bats with a predetermined maximum allowable bat performance and a larger sweetspot region than bats of the prior art. This is one of the primary objectives of the present invention. Further, multi-wall bats of the present invention with inventive secondary members with non-uniform cross-sections along their length provide a vibration free soft feel and produce unique sounds upon contact with a ball.
[0016] U.S. published patent application No. 2005/0070384 with patent application filed Sep. 29, 2003, by the inventors of the current application, addresses the larger sweetspot region objective by varying radial stiffness along the barrel length by adding a stiffener, or by changing fibre properties along the barrel length, or by thickening the barrel wall generally in the area of the sweetspot.
[0017] U.S. Pat. No. 6,949,038 issued to Fritzke filed Jan. 21, 2004 also addresses this objective. The Fritzke '038 reference purports to achieve an improved sweet spot characteristic by providing a secondary member, located either inside or outside the barrel of a standard frame, wherein the secondary member has a constant outside diameter with an internal wall whose thickness increases while proceeding from its ends inwardly towards the opposing ends. Generally, this thickening is shown to increase to a maximum around the mid-portion of the length of the secondary member. In one figure, FIG. 12 , this thickness is shown to partially decrease around the mid-portion of the length of the secondary member, providing two laterally placed regions of maximum thickness on either side of the mid-portion.
[0018] While the present inventor's earlier publication and the Fritzke patent represent different means of achieving an enlarged sweet spot of a baseball bat, the present invention includes other means to achieve the same result plus additional benefits regarding performance, feel and sound. Field testing has repeatedly shown that a “soft” feel upon ball impact and/or a “pleasing” sound are both player perceptions which are often favoured by the player over absolute performance as measured by hit distance.
SUMMARY OF THE INVENTION
[0019] Therefore, in view of the foregoing, what is needed is a tubular baseball bat with a specific distribution of variable radial stiffness along their barrel portions in order to vary bat performance along the barrel hitting portion length, to make the bat feel “soft” when striking a ball, and to produce a pleasing sound upon impact with the ball. To achieve these objectives, the bats of the present invention are stiffened in the barrel area of peak bat performance commonly referred to as the sweetspot. Typically, this is an area approximately 2″ to 4″ in width as compared to barrel portion lengths of 4″ to 16″. This is achieved by the presence of an inventive geometric secondary member, or members, with non-constant outside diameters positioned internally within the bat frame, or by independent numerous annular secondary members located along the inner surface of the barrel portion of an external bat frame, or by inserting or adding to the bat a circumferential stiffener in the region of the sweetspot, or by making the barrel wall thicker in the region of the sweetspot, or by having stiffer material in the region of the sweetspot. Such embodiments also can provide variable bat performance along the barrel length, enlarge the sweetspot size, improve bat performance, have a softer feel upon ball impacts, and produce unique pleasing sounds upon ball impact.
[0020] In one embodiment of the present invention, the inventive internal secondary members have a variable outside diameter and constant wall thickness and are characterized by variations in the surface profile on one side of the secondary member wall being reflected by a corresponding profile on the other side of the secondary wall that provide at least two or more contact regions with the internal barrel portion of the frame barrel wall that in turn create at least one functional air cavity that is closed at both ends. In one variant of the invention internal secondary members have constant internal diameters.
[0021] In another embodiment of the present invention, two or more independent annular or ring like, members of generally consistent cross-sectional geometry with variable dimensions and with length less than one-half the barrel portion length are internally located in unbonded contact along the inner wall of the barrel portion of an external bat frame. An additional secondary bat member of length approaching the barrel length may be located internally to the annular secondary members.
[0022] In another embodiment, a short light weight polymer composite circumferential stiffener of the invention as employed adds only minimal weight to a given bat thus allowing the stiffened bat to continued to be used within the required weight requirements set by the relevant governing body. The stiffener of the present invention can be added to previously constructed tubular bats returned from players for modification to meet a changed regulation allowing such previously manufactured bats to meet a changed standard. Though somewhat heavier, a short metallic stiffener could also be employed. An alternative method of varying stiffness, and thus bat performance, along the barrel portion is to vary thickness along the barrel portion.
[0023] Another alternative solution of the present invention for all composite bats is accomplished by engineering calculation considering selection of the composite fiber type, the fibre size, the angles of the fibers, and the thickness of the polymer composite stiffener to be employed to precisely lower the bat performance.
[0024] While tubular bats of the present invention have variable radial stiffness along their barrel portions to achieve a specific predetermined bat maximum bat performance, it is simultaneously possible to achieve a sweetspot which is larger than the sweetspot typically found in tubular bats of the prior art. In the present invention this is accomplished by selectively radially stiffening only the peak performance area (generally the sweetspot area) of the bat to provide a radial stiffness therein which is greater than the radial stiffness of the barrel portion area immediately adjacent on both sides of the sweetspot. The resultant effect can be to approximately double the sweetspot size (that is, the area of the barrel portion which provides maximum bat performance). Further, bats of the present invention with secondary members with a variable outside diameter, with or without thickened end portions have a softer feel upon impact and produce unique impact sounds.
[0025] The foregoing summarizes the principal features of the invention and some of its optional aspects. The invention may be further understood by the description of the preferred embodiments, in conjunction with the drawings, which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 shows a longitudinal cross-section of a typical prior art single wall tubular bat with a singular frame, or member, construction.
[0027] FIG. 1A shows a cross-sectional area taken at any location through the barrel portion of the FIG. 1 prior art tubular bat.
[0028] FIG. 2 shows a longitudinal cross-section of a typical prior art double-wall tubular bat with two separate members, a frame or main member with an internal insert as a secondary member in the barrel area. Both the frame and insert run the full length of the barrel portion and are not joined full length.
[0029] FIG. 2A shows a cross-sectional area taken at any location through the barrel portion of the FIG. 1 prior art tubular bat.
[0030] FIG. 3 shows a longitudinal cross-section of a typical prior art double-wall tubular bat with two separate members, a frame or main member with an external sleeve secondary member in the barrel portion. Both the frame and sleeve run the full length of the barrel portion and are not joined full length.
[0031] FIG. 3A shows a cross-sectional area taken at any location through the barrel portion of the FIG. 3 prior art tubular bat.
[0032] FIG. 4 shows a longitudinal cross-section of one embodiment of the present invention showing a single wall tubular bat in accordance with the present invention showing an internal stiffener generally confined to the sweetspot area of the barrel portion and joined to the barrel portion.
[0033] FIG. 4A shows a cross-sectional area of a barrel location not within the sweetspot area.
[0034] FIG. 4B shows a cross-sectional area within the sweetspot area showing the internal stiffener of the present invention.
[0035] FIG. 5 shows a longitudinal cross-section of a second embodiment of the present invention showing a single wall tubular bat in accordance with the present invention with an external stiffener generally confined to the sweetspot area of the barrel portion and joined to the barrel portion.
[0036] FIG. 5A shows a cross-sectional area at a barrel location not within the sweetspot area.
[0037] FIG. 5B shows a cross-sectional area within the sweetspot area showing an external stiffener of the present invention.
[0038] FIG. 6 shows a longitudinal cross-section of a third embodiment of the present invention showing a single wall polymer composite tubular bat in accordance with the present invention showing a localized area of the fiber type and/or angle change resulting in increased radial stiffness generally confined to the sweetspot area of the barrel portion.
[0039] FIG. 6A shows a cross-sectional area at a barrel location not within the sweetspot area.
[0040] FIG. 6B shows a cross-sectional area within the sweetspot area showing a stiffened area of changed fiber angles and/or type.
[0041] FIG. 6 . 1 shows a longitudinal cross section of a single wall polymer composite tubular bat in accordance with the present invention showing the alternative construction incorporating a thickened barrel wall 21 resulting in increased radial stiffness generally confined to the sweetspot area of the barrel portion.
[0042] FIG. 6 . 1 A shows a cross-sectional area at a barrel location not within the sweetspot area.
[0043] FIG. 6 . 1 B shows a cross-sectional area within the sweetspot area showing a stiffened area with thicker barrel wall.
[0044] FIG. 6 . 2 shows a longitudinal cross-section of an alternative double wall polymer composite bat in accordance with the present invention showing a localized area of the fibre type and/or fibre angle change within the insert resulting in increased radial stiffness generally confined to the sweetspot area of the barrel portion.
[0045] FIG. 6 . 2 A shows a cross-sectional area at a barrel location not within the sweetspot area.
[0046] FIG. 6 . 2 B shows a cross-sectional area within the sweetspot area showing a stiffened area of changed fibre angles and/or type.
[0047] FIG. 6 . 3 shows a longitudinal cross-section of a double wall polymer composite bat in accordance with the present invention with an alternative construction showing a thickened barrel wall 21 within the insert resulting in increased radial stiffness generally confirmed to the sweetspot areas of the barrel portion.
[0048] FIG. 6 . 3 A shows a cross-sectional area of a barrel location not within the sweetspot area.
[0049] FIG. 6 . 3 B shows a cross-sectional area within the sweetspot area showing a stiffened area with thicker barrel wall.
[0050] FIG. 7 shows a longitudinal cross-section of a fourth embodiment of the present invention showing a double-wall tubular bat with two separate members, a frame or main member with an internal insert as a secondary member full length in the barrel portion, and in accordance with the present invention, showing an internal stiffener generally confined to the sweetspot area of the barrel portion and joined to the barrel portion.
[0051] FIG. 7A shows a cross-sectional area at a barrel location not within the sweetspot area.
[0052] FIG. 7B shows a cross-sectional area within the sweetspot area showing the internal stiffener.
[0053] FIG. 8 shows a longitudinal cross-section of a fifth embodiment of the present invention showing a double-wall tubular bat with two separate members, a frame or main member with an external sleeve as a secondary member full length in the barrel portion, and in accordance with the present invention showing an external stiffener generally confined to the sweetspot area of the barrel portion and joined to the barrel portion.
[0054] FIG. 8A shows a cross-sectional area at a barrel location not within the sweetspot area.
[0055] FIG. 8B shows a cross-sectional area within the sweetspot area showing the external stiffener.
[0056] FIG. 9 shows in graphical form the typical relationship between tubular bat performance and barrel location and sweetspot size.
[0057] FIG. 10 shows in graphical form a typical relationship between tubular bat performance of a bat of the present invention and barrel location and sweetspot size.
[0058] FIG. 11A shows a longitudinal cross-section of the barrel portion of a typical prior art single wall tubular bat with a singular frame, or main member. Not shown in FIG. 11A and all following figures is the traditional bat handle portion located at the proximal end of the taper portion.
[0059] FIG. 11B shows a longitudinal cross-section of the barrel portion of a typical prior art single wall tubular bat with a singular frame, or main member, construction wherein the barrel wall is inwardly thickened generally in the area of the sweetspot.
[0060] FIG. 11C shows a longitudinal cross-section of the barrel portion of a typical prior art double wall tubular bat with an external frame and a secondary internal member, or insert.
[0061] FIG. 11D shows a longitudinal cross-section of the barrel portion of a typical prior art double wall tubular bat with an external frame and a secondary internal member, or insert, wherein the insert is inwardly thickened generally in the area of the sweetspot.
[0062] FIG. 11E shows a longitudinal cross-section of the barrel portion of a typical prior art double wall tubular bat with an external frame and a secondary internal member, or insert, wherein both the frame and the insert are inwardly thickened generally in the area of the sweetspot.
[0063] FIG. 12A shows a longitudinal cross-section of the barrel portion of one embodiment of the present invention showing a double wall tubular bat with an external frame and a primary secondary member, or insert, located internally within the frame wherein the primary secondary member has an outer diameter which varies along the length of the member, a constant wall thickness, two contact regions with the frame barrel portion inner surface, and one air cavity that is closed at both ends.
[0064] FIG. 12B shows a variant of the bat of FIG. 12A wherein the primary secondary member has a constant wall thickness, there are two contact regions, and one closed air cavity, wherein the thickness of the air cavity is reduced generally in the area of the barrel mid portion.
[0065] FIG. 12C shows a variant of the bat of FIG. 12A wherein the primary secondary member has a constant wall thickness, there are three contact regions and two closed air cavities.
[0066] FIG. 12D shows a variant of the bat of FIG. 12A wherein the primary secondary member has a constant wall thickness and the outer diameter of the primary secondary member oscillates periodically along its length between a maximum and a minimum diameter, creating multiple contact regions and multiple closed air cavities.
[0067] FIG. 12E shows a variant of the bat of FIG. 12D wherein the period of the oscillation of outside diameter of the primary secondary member increases away from the barrel mid portion.
[0068] FIG. 12F shows a variant of the bat of FIG. 12A with a primary secondary member and an additional secondary member located internally to the primary secondary member wherein both secondary members have outer diameters which vary along the length of the secondary members, have constant wall thicknesses, two contact regions each, and one closed air cavity each.
[0069] FIG. 12G shows a variant of the bat of FIG. 12A wherein the primary secondary member has a constant diameter internal surface, a non-constant diameter external surface, a non-constant wall thickness, two contact regions with the internal frame wall, and one air cavity that is closed at both ends.
[0070] FIG. 12H shows a variant of the bat of FIG. 12G wherein the primary secondary member has two contact regions and one closed air cavity that has a non-uniform cross-section.
[0071] FIG. 12I shows a variant of the bat of FIG. 12G wherein the primary secondary member has three contact regions and two closed air cavities.
[0072] FIG. 12J shows a variant of the bat of FIG. 12D wherein the primary secondary member has a constant diameter internal surface.
[0073] FIG. 12K shows a variant of the bat of FIG. 12E wherein the primary secondary member has a constant diameter internal surface.
[0074] FIG. 12L shows a variant of the bat of FIG. 12F wherein the primary secondary member has a constant diameter internal surface.
[0075] FIG. 13A shows a longitudinal cross-section of the barrel portion of a second embodiment of the present invention showing a double wall tubular bat with an external frame, and six independent annular secondary members, or rings, each of length less than one-half the frame barrel portion length and varying thickness, each internally located side by side, with or without spaces between, along the frame barrel portion length against the barrel portion inner surface of the external bat frame.
[0076] FIG. 13B shows a multi-wall bat variant of the bat of FIG. 13A wherein there are six independent annular secondary members each of length less than one-half the frame barrel portion length, each internally located along the frame inner wall surface, and a tubular additional secondary member with length approaching the frame barrel portion length and located internally to the annular secondary members and in contact with at least one annular secondary member, generally extending co-extensively with the frame barrel portion.
[0077] FIG. 13C shows a variant of the bat of FIG. 13B wherein there are six independent annular secondary members each of length less than one-half the frame barrel portion length, each internally located along the additional secondary member outer wall surface and internally to the external frame inner wall surface.
[0078] FIG. 13D shows a variant of the bat of FIG. 13B wherein there are three independent annular secondary members of constant thickness each internally located between and abutting against the external frame inner wall surface and the additional secondary member outer wall surface forming three closed air cavities.
[0079] FIG. 13E shows a variant of the back of FIG. 13D wherein there are multiple annular secondary members with or without multiple air cavities.
[0080] FIG. 13F shows a longitudinal cross-section of the barrel portion of another embodiment of the present invention showing a multi-wall tubular bat with an external frame, and two annular secondary members, or rings, each of length less than one-half the frame barrel portion length, wherein each annular secondary member is located between the outer frame and an additional secondary member with length approaching the frame barrel portion length, wherein the wall of the additional secondary member is thickest generally in the frame barrel mid portion providing a contact area between the inner surface of the frame and the outer surface of the additional secondary member.
DETAILED DESCRIPTION OF THE INVENTION
[0081] The present invention is directed to providing tubular baseball bats with variable radial stiffness along the length of the barrel or hitting portion 1 , of the bats. Bats of the present invention can have a larger sweetspot size 19 , have a soft feel with substantially reduced vibrations, and produce unique pleasing sounds upon impact with a baseball or softball. Further, such bats can be produced at reasonably low costs.
[0082] Unless otherwise indicated, the term stiffness as used in this disclosure is equivalent to the modulus of elasticity and is a measure of the change in length of a material under loading. For a tubular body, such as a baseball bat, stiffness of the material can be measured in the axial direction, parallel to the longitudinal axis of the tube, or the radial or transverse direction perpendicular to the longitudinal axis of the tube. Radial stiffness is a measure of the force required to depress any given a section of the tube in the radial direction. Radial stiffness is a function of modulus of the material, the tube thickness and the tube diameter. Radial stiffness is measured along the barrel wall as independent annular segments of the barrel wall at each measurement location.
[0083] The prior art bats are shown in FIGS. 1, 2 , 3 , and 11 . FIGS. 1 and 11 A show a single wall tubular bat with main member or frame 16 . FIGS. 2 and 11 C show a double wall tubular bat with an insert or primary secondary member 13 , formed separately from the main member 16 , which is fitted into the entire barrel length 1 of the main member 16 . FIG. 3 shows a double wall tubular bat with a sleeve 14 , formed separately from the main member 16 , which is fitted over the entire barrel length 1 of the main member 16 . FIG. 11B shows a single wall tubular bat with the main member 16 being internally thickened in the barrel mid-section. FIGS. 11D and 11E show double wall tubular bats with an internally thickened secondary member 13 and in the case of FIG. 11E also an internally thickened main member 16 .
[0084] Though not indicated in FIGS. 1 through 8 , and 11 through 14 , bats of the present invention, similarly to bats of the prior art, include a traditional knob at the handle portion end 5 , or proximal end of the bat, and a traditional end cap 21 (not shown in FIGS. 1 through 8 ) at the barrel portion end 4 , the distal end, both of which can be made from a variety of materials.
[0085] Most adult tubular baseball bats of the prior art have maximum outside barrel portion diameter 2 of either 2.625 inches or 2.75 inches. Depending on the taper portion geometry of the mid-section 8 , and the total length of the bat, the barrel length 1 as defined by length of constant maximum diameter 2 , ranges from 4 to 12 inches. Total barrel wall thickness 6 ranges from 0.100 inches to 0.140 inches for aluminum bats and up to 0.220 inches for all composite bats and is measured at any point along the barrel wall as the outside diameter of the frame or member with the largest outside diameter minus the inside diameter of the member with the smallest outside diameter including any gaps, or spaces, between the two extreme diameters.
[0086] Most youth baseball bats and softball bats of the prior art have maximum outside barrel portion diameter 2 of 2.25 inches. Depending on the taper portion geometry of the mid-section 8 , the barrel length 1 ranges from 4 to 16 inches. Barrel wall thickness 6 ranges from 0.060 inches to 0.090 inches for aluminum bats and up to 0.220 inches for all composite bats.
[0087] The bats of the present invention, shown in FIGS. 4 through 8 , and 12 through 14 , have similar dimensions to the foregoing prior art bats shown in FIGS. 1, 2 , 3 , and 11 .
[0088] A first embodiment of the present invention FIG. 4 is a single wall tubular baseball bat consisting of a cylindrical handle portion 7 for gripping, a cylindrical tubular barrel portion 9 for striking or hitting, and a tapered portion 8 connecting the handle 7 and barrel 9 portions, with a thin polymer composite stiffener 18 having a stiffener wall located internally within the barrel portion 9 and extending longitudinally in the mid-section, sweetspot area 19 of the barrel length 1 .
[0089] A polymer composite is a non-homogenous material consisting of continuous fibers embedded in, and wetted by, a polymeric resin matrix whereby the properties of the material are superior to those of its constituent fibers and resin taken separately. Such polymer composites are anistropic materials since they exhibit different responses to stresses applied in different directions depending on how the fibers are aligned or angled within the matrix.
[0090] Other materials commonly used in bat constructions such as aluminum, wood and plastics are not anistropic and are thus limited in controlling bat performance; for example, radial stiffness is equal to longitudinal stiffness and cannot be graduated along the barrel length 1 . However, with composite materials, which are preferred, properties of bats made in accordance with the present invention, such as radial stiffness which determines bat performance can be controlled (i.e. designed to a given requirement) by altering such parameters as the fiber alignments along the barrel length 1 , and/or the type of fibers chosen, their demier or layout density and/or the thickness of the polymer composite structure.
[0091] Generally, the fiber materials used are selected from a group consisting of fiberglass, graphite or carbon, aramid, boron, nylon, or hybrids of any of the foregoing, all of which are commercially available. The resins used to impregnate, wet out, and encapsulate or imbed the fiber materials are generally selected from a group consisting of epoxy, polyester, vinyl ester, urethane, or a thermoplastic such as nylon, or mixtures thereof.
[0092] The first embodiment of the present invention, depicted in FIG. 4 , consists of a thin polymer composite stiffener 18 located internally within the barrel portion 9 generally in the sweetspot area 19 located in proximity to the middle or mid-section area of the barrel length 1 of a single wall tubular bat. The resultant stiffened bat results in a predetermined calculated lower performance, with an enlarged sweetspot 19 , as subsequently explained.
[0093] The sweetspot area 19 of a baseball bat is generally referred to as that area along the barrel length 1 in which bat performance is greatest; that is, a ball struck within the sweetspot area 19 will travel further than a ball struck on either side of the sweetspot area. Typically, the sweetspot area 19 is located around the middle of the barrel length 1 and is in the order of about 2 inches to 4 inches in length when compared to overall barrel lengths 1 which range from approximately 4 inches to 16 inches or more.
[0094] In actual practice, the performance of a baseball bat of the prior art follows a statistical normal distribution along the barrel length 1 , usually centered near the middle of the barrel length 1 in the sweetspot area 19 . FIG. 9 shows a typical bat performance distribution example with a 12-inch barrel length 1 .
[0095] In FIG. 9 , the maximum bbs (one measure of bat performance standard) is 100 while most players would describe the sweetspot as being approximately 2 inch long (that is, the portion of the barrel length equal to or greater than 98 bbs). The bat of this particular sample meets a bat performance factor standard of 100 bbs maximum if so regulated.
[0096] If the applicable regulatory body for the bat in the FIG. 9 example changed the bat performance standard from 100 bbs maximum to say 96 bbs maximum, the bat of the present invention could be provided with a specifically designed 4 inch polymer composite stiffener 18 located in the center of the barrel length 1 . FIG. 10 shows the bbs versus barrel length for this example.
[0097] In FIG. 10 , in an example of the present invention, the combined barrel wall, with the polymer composite stiffener 18 present, is approximately twice as stiff in the center 2 inches of the sweetspot area 19 as in the 1 inch area immediately adjacent to the center or mid-section area on each side of the center area. The polymer composite stiffener 18 fiber type, fiber angles and thicknesses are designed such as to reduce the bbs from 100 to 96 in the center 2 inch area of the barrel length 1 and from 98 to 96 bbs in the 1 inch areas immediately adjacent to the center area. As a result of the present invention, the resultant typical example bat meets the lowered regulatory standard of 96 bbs with a sweetspot area 19 which has been increased in size by 100% (from 2 inches wide to 4 inches wide). At the same time the regions around points A and B have been introduced into the batting performance curve of FIG. 10 that were not present in the curve of FIG. 9 , with the more flattened portion there-between that is characteristic of an enlarged sweet spot.
[0098] Alternatively, thickening the total barrel wall with the same material, the same thickness, and the same location as the stiffener results in the identical reduced bat performance.
[0099] The first embodiment (i.e. as shown in FIG. 4 ) of the present invention is particularly suited to retrofitting used bats returned by players and making them legally playable under a revised standard.
[0100] The thin polymer composite stiffener 18 of the present invention has a stiffener wall which is typically in the order of 0.010 inches to 0.040 inches in thickness, preferably 0.020″ with a length of 2 inches to 6 inches which is typically less than 50% of the barrel length, such as 16⅔% of the barrel length, as is apparent from FIG. 10 . A 4 inch stiffener, as referenced in paragraph [0059], in a 12 inch barrel as referenced in FIG. 10 , would represent 33.3% of the barrel length; a 4 inch stiffener in a 16 inch barrel would represent 25%, and a 2 inch stiffener in a 16 inch barrel would represent 12.5% of the barrel length. The stiffener 18 is preferably bonded, fully or partially, to the main member 16 , or to the secondary member insert 13 of FIG. 7 or to the secondary member sleeve 14 of FIG. 8 , or combinations thereof on either the internal or external barrel walls, as shown in FIGS. 4, 5 , 7 and 8 . Analogous to FIGS. 4, 5 , 7 and 8 an alternative solution (since stiffness is proportional to thickness) to the stiffener 18 is to vary the barrel thickness 6 to the same extent and manner along any portion of the barrel length 1 of any bat according to the invention, including the bat of FIG. 6 in order to vary bat performance. The barrel portion's effective wall thickness in the mid-section can be greater by 8⅓% or more over the thickness of the barrel in the lateral, adjacent portions. Conversely, the barrel wall's thickness beyond its central portion, in the lateral regions proceeding towards the end portions of the barrel, may be at least 8⅓% thinner than the thickness of the barrel wall in the mid-section. Just as the stiffener wall may be typically in the order of 0.005 inches to 0.040 inches in thickness, or 0.010 inches to 0.040 inches in thickness, or 0.015 inches to 0.040 inches in thickness, or 0.015 inches to 0.030 inches, so too the analogous increase in barrel wall thickness along the mid-section may fall within the same ranges.
[0101] A second embodiment of the present invention, as shown in FIG. 5 , is a single wall tubular baseball bat which in accordance with the present invention has a thin polymer composite stiffener 18 located externally to the barrel portion 9 generally in the sweetspot area 19 located in proximity to the middle area of the barrel length 1 . The resultant stiffened bat results in a calculated lower performance, with a bigger (longer) sweetspot 19 , as previously explained.
[0102] A third embodiment of the present invention, as shown in FIG. 6 , is a single wall tubular polymer composite baseball bat which in accordance with the present invention has a localized area of fiber type of greater stiffness and/or angle change 20 resulting in increased radial stiffness generally in the sweetspot area 19 located in proximity to the middle area of the barrel length 1 . This embodiment applies equally well to double-wall and multi-wall (more than two walls) tubular all polymer composite baseball bats and is limited to newly designed polymer composite single wall, double-wall, and multi-walled new bats as opposed to field returned bats. The fiber types, and/or fiber angles, and/or fiber sizes, and/or composite thickness can be designed such as to graduate the radial stiffness of the barrel wall within the barrel portion 1 along its entire length. That is, the radial stiffness could be higher in the peak performance area (generally the sweetspot area 19 ) than in the lateral regions immediately adjacent to the sweetspot area 19 . In fact, by duplicating the increase in radial stiffness in the barrel mid-section as achieved by the stiffener 18 of FIG. 4 or 7 , the exact same bat performance change as shown in FIG. 10 and enlarged in sweetspot size 19 can be achieved by bats of FIG. 6 . Similarly, the alternative solution FIG. 6 . 1 showing a single wall tubular bat with a thickened barrel wall 21 and the alternative solution FIG. 6 . 3 showing a double wall tubular bat with a thickened barrel wall 21 , with the same material, location, and thickness of the stiffener 18 will result in the same bat performance change, as shown in FIG. 10 , and resultant enlarged sweetspot size 19 .
[0103] A fourth embodiment of the present invention, as shown in FIG. 7 , is a double-wall tubular bat showing two separate members, a frame or main member 16 with an internal insert 13 as a secondary member full length in the barrel length 1 and, in accordance with the present invention, a stiffener 18 located internally within the insert 13 generally confined to the sweetspot area 19 , along the barrel length 1 . Though not shown, the stiffener 18 could be located externally to the main member 16 or between the main member 16 and the internal insert 13 . Also, though not shown, in multi-walled bats the stiffener 18 could be located internally, or externally, or between the members, or combinations thereof.
[0104] A fifth embodiment of the present invention, as shown in FIG. 8 , is a double-wall tubular bat showing two separate members, a frame or main member 16 with an external sleeve 14 as a secondary member full length in the barrel length 1 and, in accordance with the present invention, a stiffener 18 , located externally to the sleeve 14 , generally in the area of the sweetspot area 19 along the barrel length 1 . Though not shown, the stiffener 18 could be located internally to the main member 16 and the external sleeve 14 . Also, though not shown, in multi-walled bats, the stiffener 18 could be located internally, or externally, or between the members, or combinations thereof.
[0105] All embodiments of the present invention, as shown in FIGS. 4, 5 , 6 , 7 , 8 , 12 C, 12 I, 13 A, 13 B, 13 C, 13 D, and 13 F, exhibit greater radial stiffness in the mid-section of the barrel length 1 relative to the lateral regions immediately adjacent to the mid-section, resulting in an enlarged sweetspot area 19 .
[0106] Besides an enlarged sweetspot, other objectives of bats of the present invention include providing a user with a “soft feel”, having substantially less vibrations transmitted to the user's hand while striking a ball, unique impact sounds, and higher performance for average or below average players when making contact away from the normal sweetspot. These further objectives are achieved by bats of the present invention with secondary members with a variable outside diameter and by bats with two or more independent annular secondary members internally located along the inside diameter of the external bat frame.
[0107] All bats of the present invention shown in FIG. 12 are characterized by inventive primary secondary members, or inserts 13 , located internally within an external main member, or frame 16 , with frame wall thickness 44 , within the barrel length 1 of the hitting portion of the bat. The primary secondary member 13 has an inner surface 53 , an outer surface 55 , an inner diameter 29 , an outer diameter 25 , a wall thickness 27 , a length 26 , a proximal end 58 , and a distal end 59 . Not shown in the FIGS. 12 and 13 bats is the normal handle portion located adjacent to the taper proximal portion and knob located at the proximal end of the frame 16 traditional bats. A traditional endcap 21 encloses the distal end 49 of the barrel portion 9 . The inventive primary secondary members 13 of the bats of FIG. 12 have outer diameters 25 that vary along the majority of the barrel length 1 . The variations in outer diameter 25 of the inserts 13 in all bats of FIGS. 12 are dimensioned to produce two or more contact areas 30 with the inside surface 45 of the frame 16 . In some variants of the bats of FIG. 12 , the primary secondary member 13 contact areas 30 have substantially flattened portions of constant maximum outer diameter, while in others the contact portions are much smaller. The contact areas 30 create at least one enclosed air cavity 22 with a maximum air cavity thickness 23 of at least 0.010″. The air cavities 22 of the present invention are closed at both ends to produce the desired feel and sound objectives upon ball contact. Varying positioning and quantities of the air cavities 22 , and contact areas 30 , produce bats with different performance levels, feel, and sound upon barrel portion 9 impact with a ball. To produce the desired unique soft bat feel and sound upon impact, the ideal thickness 23 of the air cavities 22 has been found by field testing to be 0.020″ to 0.050″ which is considerably thicker than prior art bats, where any such air spaces exist only due to manufacturing tolerances of the frame 16 and secondary member 13 . The air cavities 22 of the present invention can be filled with an elastomeric material with further performance, feel, and sound effects. Such prior art secondary members 13 do not have variable outer diameters. Due to the variable outer diameter 25 , all bats of FIG. 12 can have variable radial stiffness along the barrel length 1 . However, when the frame 16 and/or the primary secondary member 13 is made with composite materials, fiber types and laminating angles can be manipulated to achieve either constant or variable radial stiffness along the barrel length 1 regardless of dimensional variations.
[0108] As seen in FIGS. 12A through 12F bats of the present invention are further characterized by the inventive primary secondary member 13 having a variable outer diameter 25 and a variable inner diameter 29 . The variable outer diameter 25 of the insert 13 produces variations in the surface profile of the insert 13 which are generally reflected by a corresponding profile on the inner surface 53 of the insert 13 wall. The resulting total bat wall thickness 6 variations along the barrel length 1 vary the performance, feel, and sound of the bats of FIGS. 12A through 12F .
[0109] The bat variant of FIG. 12A has a single annular air cavity 22 where the external frame 16 wall acts independently of the insert 13 wall until the contact force between the ball and the external frame 16 increases enough to deflect the external frame inner surface 45 into contact with the insert's outer surface 55 . At that point, the two members 16 and 13 act together, thus creating a non-linear spring. This decreases the peak contact force between the ball and the bat, which reduces the energy losses in the ball, and therefore improves performance.
[0110] The bat variant of FIG. 12B has an insert 13 outside diameter 25 which increases near the barrel mid-portion 50 , narrowing the air cavity 22 thickness. This reduces the performance improvement due to the effect of the gap, discussed in the previous paragraph, near the mid-portion 50 of the barrel length 1 and therefore gives a more uniform bat performance along the barrel length 1 .
[0111] The bat variant of FIG. 12C is similar to 12 B where the insert 13 makes contact with the frame 16 inner surface 45 near the mid-portion 50 of the barrel length 1 at the insert 13 proximal 58 and distal 59 portions near the barrel ends. This eliminates the performance improvement imparted on the bat by the air cavity 22 at the barrel mid-portion 50 , but creates two independent annular air cavities 22 away from the barrel mid-portion 50 .
[0112] The bat variant of FIG. 12D has an insert 13 where the outside diameter 25 oscillates, or varies periodically along the barrel length 1 . When the period of the oscillations is reduced the insert 13 becomes stiffer and stronger for a given weight, or lighter for a given stiffness. The radial stiffness of the insert 13 increases with increased insert wall thickness 27 , reduced period of oscillation, or increased magnitude of oscillation.
[0113] The bat variant of FIG. 12E has an insert 13 where the outside diameter 25 oscillates, or varies periodically along the barrel length 1 , and where the period of the oscillation increases away from the mid-portion 50 of the barrel length 1 . The resultant reduced radial stiffness away from the sweetspot creates a more uniform performance along the barrel length 1 .
[0114] The bat variant of FIG. 12F is a triple wall version of the bat of FIG. 12A created by an additional secondary member 31 . Though not shown, additional such members could be added to create a multi-wall bat with more than three walls. Similarly, though not shown, additional secondary members 31 of any configuration could be added to the bats of FIGS. 12B, 12C , 12 D, and 12 E.
[0115] FIGS. 12G through 12L depict bats characterized by an inventive primary secondary member 13 with a variable outer diameter 25 and a constant inner diameter 29 along the barrel length 1 . Otherwise, the bat variants of FIGS. 12G through L are similar to the bat variants of FIGS. 12A through F.
[0116] In another embodiment of the present invention, the bats of FIG. 13 have two or more independent annular, or ring-like, secondary members 61 of similar cross-section shape of variable dimensions with individual length 62 , along the barrel portion 19 , less than one-half the barrel portion length 1 and are internally located along the inner surface 45 of the external frame 16 . The annular secondary members 61 have a length 62 , a wall thickness 63 , an inner surface 64 , an inner diameter 65 , an outer surface 66 , and an outer diameter 67 .
[0117] The bat variant of FIG. 13A has the external frame 16 reinforced by a series of independent inner annular secondary members 61 generally in the form of annular rings. The secondary members 61 have a common outer diameter 67 which is equal to or less than the inner diameter 25 of the frame 16 and are generally thicker near the barrel mid-portion 50 of the barrel length 1 and thinner away from it. The rings 61 are generally thicker towards the barrel distal end 49 and thinner towards the barrel proximal end 48 because the bat is moving faster at the distal end 49 . Although not shown, the annular secondary members 61 could be of constant thickness and have varying material properties to accomplish varying radial stiffness and resultant more uniform performance.
[0118] The bat variant of FIG. 13B has an external frame 16 reinforced by a series of independent annular secondary members 61 in the form of annular rings, in combination with an inner additional secondary continuous member 31 extending along the majority of the barrel length 1 . The annular secondary members 61 provide a more uniform bat performance along the barrel length, while the inner additional secondary member 31 supports the impact force.
[0119] The bat variant of FIG. 13C is similar to that of 13 B; however, the annular secondary members 61 have a constant inner diameter 29 .
[0120] The bat variant of FIG. 13D has internal annular secondary members 61 with a uniform inner diameter 29 and outer diameter 25 , which create closed air cavities 22 .
[0121] The bat variant of FIG. 13E has an external frame 16 and axially continuous inner additional secondary member 31 with a series of annular secondary members 61 between the two. One candidate for the intermediate members 61 is a series of elastomeric O-rings with higher stiffness near the barrel mid portion 50 .
[0122] The bat variant of FIG. 13F has an axially continuous inner additional secondary member 31 that is thicker in its mid-portion and could, or could not be, in contact with the external frame 16 near the barrel mid-portion 50 and has a reduced outer diameter at the barrel proximal 48 and distal 49 ends. The bat has two or more annular secondary members 61 located at the barrel portion 9 proximal 48 and diesel 49 ends. In effect, this bat is double walled at the barrel mid-portion 50 and triple walled away from the barrel mid-portion 50 , giving more uniform bat performance along the barrel length 1 resulting in a broadened sweetspot.
[0123] The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
[0000] Conclusion
[0124] The foregoing has constituted a description of specific embodiments showing how the invention may be applied and put into use. These embodiments are only exemplary. The invention in its broadest, more specific aspects, is further described and defined in the claims which now follow.
[0125] These claims, and the language used therein, are to be understood in terms of the variants of the invention which have been described. They are not to be restricted to such variants, but are to be read as covering the full scope of the invention as is implicit within the invention and the disclosure that has been provided herein.
[0126] The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. | A multi-walled, tubular baseball bat has a barrel portion with a mid-section wherein the radial stiffness of the overall barrel wall varies along the barrel length to provide an enlarged sweetspot, improved soft feel and performance, plus unique sounds upon impact. The bat has a frame with a barrel portion of consistent diameter. A secondary member, or members, of tubular form extend internally along the barrel. The secondary member provides the required radial stiffness variation by: 1) variations in the thickness of the wall of the secondary member or by, 2) secondary members with unique geometric external surface profiles or by, 3) the presence of functional air cavities, with or without closed ends, between the main bat frame and the secondary member or members or by, 4) the presence of numerous annular secondary members located side by side less than one-half the length of the barrel portion. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to a method for controlling pressure in a compressed-air accumulator of a level-control system of a motor vehicle.
Methods of the general type under consideration are known, for example, from DE 101 22 567 C1 and DE 101 60 972 C1.
A level-control system for a vehicle is typically provided at each wheel suspension of the vehicle with an air spring bellows to which compressed air can be supplied or from which compressed air can be removed via a valve device. Usually, a compressor is provided to generate the compressed air. To achieve short times for filling and venting the air spring bellows and thus short times for raising and lowering the vehicle body, and to save on the energy required for this purpose, it is advantageous to design such a level-control system as a closed or partly closed system containing a compressed-air accumulator. The compressor is then used primarily to transport compressed air back and forth between the compressed-air accumulator and the air spring bellows. Depending on the operating condition of the vehicle and on external ambient conditions, a variable pressure level in the compressed-air accumulator may be advantageous for achieving short times for filling and venting the air spring bellows and for achieving low energy consumption.
DE 101 60 972 C1 describes how to control the air quantity in a level-control system, while also taking the ambient temperature of the vehicle into consideration via a temperature sensor. For this purpose, a separate temperature sensor for measuring the ambient temperature is necessary.
DE 101 22 567 C1 describes controlling the pressure in the compressed-air accumulator indirectly by determining the air quantity in the level-control system. For simplicity, in determining the air quantity in the level-control system, it is assumed that this quantity is composed of individual air quantities in the air spring bellows and in the compressed-air accumulator and that the individual air quantities in the air spring bellows can be calculated from measured values of pressure and height sensors.
Conventionally, the physical variables relevant for control of the accumulator pressure are taken into consideration not at all or only inadequately. For example, the ambient temperature is not an essential physical variable that determines the efficiency of operation of the level-control system. Even determination of the air quantity does not lead to a physical variable by means of which satisfactory efficiency can be achieved during operation of the level-control system.
Accordingly, the object of the invention is to provide, for control of the pressure in a compressed-air accumulator of a level-control system for a motor vehicle, a method that permits efficient operation of the level-control system. It should be understood that efficient operation of the level-control system is characterized by, for example, low energy consumption, short times for raising and lowering the vehicle body, and the capability of using a compressor designed for the smallest possible delivery capacity.
SUMMARY OF THE INVENTION
Generally speaking, in accordance with the present invention, a new method for controlling the pressure in a compressed-air accumulator of a level-control system of a motor vehicle is provided which improves over prior art methods.
According to a preferred embodiment of the present invention, the relative level and/or load of the vehicle are used as physical variables for control of the accumulator pressure. In the context of level-control systems for motor vehicles, “relative level” refers to the height of the vehicle body relative to the chassis. This variable is therefore a vertical length measure. The term “load” refers to the laden mass in kilograms compared with the mass of the unladen vehicle. Each of these variables independently has a decisive influence on the potential energy stored in the vehicle body (W pot =m*g*h; where m=mass, g=gravitational acceleration, h=height). The relative level is correlated directly with the height h and the load directly with the mass m. If, for example, a change of relative level of the vehicle is demanded by the vehicle user, for example from a low level to a high level, a change of the potential energy stored in the vehicle body is necessary by virtue of the change in height of the vehicle body. This energy change is brought about by the level-control system, which supports the vehicle body via the air spring bellows. During raising or lowering of the vehicle body, not only the compressor but also the potential energy present in the form of stored compressed air in the compressed-air accumulator can provide a contribution to changing the potential energy of the vehicle body, in this case by increasing the potential energy, provided the accumulator pressure has an appropriate value.
Analogously, if the load of the vehicle is increased, as occurs, for example, when further passengers get on board, an increase of the potential energy of the vehicle body takes place and is compensated for by the level-control system in order to keep the relative level constant. In this case, the needed potential energy is again supplied by the compressor as well as by the potential energy stored in the compressed-air accumulator.
According to an advantageous embodiment of the present invention, the level-control system is provided with at least one air spring bellows having variable bellows pressure, and a computing device for automatic determination of the index pressure value which uses at least one parameter map specifying the dependence of bellows pressure on relative level and/or on the load condition for discrete relative levels and/or load conditions. “Bellows pressure” refers to the air pressure in an air spring bellows. Thus, it is possible in simple manner to represent and take into consideration the nonlinear relationships—inherent to the manufacturing process—encountered between bellows pressure and relative level and/or load condition during use of commercial air spring bellows made of rubber. In the normal working range of an air spring bellows, the volume thereof usually increases monotonically both with increasing deflection, or in other words with increasing relative level of the vehicle body, and with increasing pressure. This deflection-dependent volume change depends on the extension of the wall of the air spring bellows, while the pressure-dependent volume change depends on expansion of the lateral wall of the air spring bellows. Typically, the pressure-dependent volume increase becomes greater at larger deflection, since a further extended bellows permits larger cross-sectional expansions. The exact extent of this pressure-dependent and deflection-dependent volume change is specific to each respective bellows and is determined individually, for example by measurement.
According to another advantageous embodiment of the present invention, the computing device determines the load of the vehicle by means of the parameter map. This permits the load to be determined quickly, with high accuracy and with little computational complexity.
According to a further advantageous embodiment of the present invention, a measured value of the relative level of the vehicle is used for automatic determination of the index pressure value. This has the advantage of making it possible to use the signals of existing sensors, such as the relative-level sensors, thus obviating the need for additional sensors.
According to yet another advantageous embodiment of the present invention, a predetermined index value of the relative level is used in addition to or as an alternative to the automatic determination of the index pressure value. As an example, the relative level predetermined by the vehicle user can be used for this purpose. It can be adjusted via a control element in the vehicle. In a level-control system, the actual value of the relative level is usually adapted automatically to the predetermined index value of relative level. Such adaptation of the actual value to the index value is an operation that requires a finite amount of time, during which the actual value gradually changes. Such use of the index value for automatic determination of the index pressure value has the advantage that it is based on the index value, which remains constant after being changed by the vehicle user, and not on the gradually changing actual value, which, under certain circumstances, might lead to unsatisfactory control response during control of the accumulator pressure.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The present invention accordingly comprises the various steps and the relation of one or more of such steps with respect to each of the others, and embodies features of construction, combinations of elements, and arrangement of parts which are adapted to effect such steps, all as exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a schematic diagram of a level-control system for a vehicle in accordance with the present invention;
FIG. 2 is a characteristics map illustrating the dependence of bellows pressure on relative level and vehicle load according to one embodiment of the present invention; and
FIG. 3 is a block diagram depicting an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawing figures, where like reference numerals are used for corresponding elements, FIG. 1 depicts elements of a vehicle level-control system pertinent to the present invention. The level-control system shown in FIG. 1 is provided with a compressed-air delivery device 1 , a valve device 5 , pneumatic lines 7 , 8 for placing compressed-air delivery device 1 in communication with valve device 5 , an atmospheric port 2 in communication with valve device 5 , a compressed-air accumulator 3 , a pneumatic line 10 for placing compressed-air accumulator 3 in communication with valve device 5 and an air spring bellows 4 representative of a plurality of air spring bellows together with associated relative-level sensor, as well as a pneumatic line 9 for placing air spring bellows 4 in communication with valve device 5 . An electronic control unit 6 is also provided which contains a computing device 15 for effecting the method according to the present invention. Electronic control unit 6 is connected via signal lines 11 , 12 , 13 , 14 to compressed-air delivery device 1 , to valve device 5 and to the relative-level sensor of air spring bellows 4 .
Compressed-air delivery device 1 can include, for example, a compressor, which can be driven by an electric motor. The compressor takes in air from pneumatic line 7 and discharges it in the form of compressed air via pneumatic line 8 . Via signal line 11 , the compressor can be turned on and off as appropriate by electronic control unit 6 .
Valve device 5 is used for control of the compressed-air streams between the pneumatic lines 7 , 8 , 9 , 10 and atmospheric port 2 . For this purpose, valve device 5 can be controlled by electronic control unit 6 via a signal line 13 , or, if necessary, via a plurality of signal lines.
Depending on mode of operation of the level-control system, electronic control unit 6 , by transmitting appropriate electrical signals via signal line 13 , can activate valve device 5 such that air is sucked in via atmospheric port 2 by compressed-air delivery device 1 and delivered optionally into air spring bellows 4 or into compressed-air accumulator 3 . In a further mode of operation, compressed air present in the level-control system can be vented via atmospheric port 2 , from air spring bellows 4 or from compressed-air accumulator 3 , for example, and optionally with or without support by compressed-air delivery device 1 . In yet a further mode of operation, compressed air can be directed from air spring bellows 4 to compressed-air accumulator 3 or vice-versa by appropriate adjustment of valve device 5 , optionally with or without support by compressed-air delivery device 1 .
In addition, valve device 5 can include a pressure sensor, with which the prevailing pressure in air spring bellows 4 or the pressure in compressed-air accumulator 3 can be measured. The pressure sensor transmits an electrical signal via signal line 12 to electronic control unit 6 , which processes this pressure signal.
In one embodiment of the present invention, a correlation table specifying a correlation between the index pressure value of the accumulator pressure and the relative level for particular discrete relative levels is stored in electronic control unit 6 .
As an example, the correlation table can have the following structure:
Relative level
Index pressure value
Low level
11 bar
Driving level
8 bar
High level
2 bar
From the relative-level signal transmitted by the relative-level sensor, computing device 15 determines the current relative level of the vehicle body. In practice, the relative-level sensor will transmit, to the electronic control unit, numerical values with which particular relative levels are then correlated in accordance with the foregoing correlation table. In such a case, it is advantageous to provide, in the correlation table, the corresponding numerical values for the respective relative levels.
Computing device 15 then determines the relative level in the correlation table which most closely approaches the transmitted relative level. Thereafter, computing device 15 extracts from the correlation table the index pressure value of accumulator pressure which correlates with this relative level, checks, on the basis of the actual value of accumulator pressure measured by means of the pressure sensor, whether this value deviates from the index pressure value, and raises or lowers the accumulator pressure as needed by outputting activation signals to valve device 5 and compressed-air delivery device 1 .
In another embodiment of the present invention, an expanded correlation table is stored in electronic control unit 6 . This table permits an index pressure value of accumulator pressure to be determined on the basis of the relative level and additionally on the basis of the load. For this purpose, computing device 15 measures not only the relative level as discussed above, but also the load of the vehicle. Measurement of the load can involve, for example, measuring the bellows pressure in air spring bellows 4 , for example via the pressure sensor provided in valve device 5 . In this way, it is possible to measure the load directly and with little complexity. By virtue of the characteristic properties of air spring bellows discussed above, it is advantageous, according to a further embodiment of the present invention, to take these characteristics into consideration in determination of the load.
Referring now to FIG. 2 , the variation of bellows pressure p B typical of air spring bellows 4 is plotted against the deflection Z for various load conditions F 1 , F 2 , F 3 of the vehicle. The deflection Z of air spring bellows 4 takes place parallel to the relative level of that part of the vehicle body which is braced via air spring bellows 4 against the chassis. The deflection Z corresponds, for example, to the relative-level signal transmitted by the relative-level sensor to electronic control unit 6 . The characteristics depicted in FIG. 2 can be determined experimentally. As can be seen from FIG. 2 , the bellows pressure p B is a nonlinear function of the deflection Z. The relationship of the bellows pressure p B to the load F of the vehicle is also nonlinear.
According to another embodiment of the present invention, there is stored in electronic control unit 6 a parameter map that contains discrete values of the characteristics according to FIG. 2 , such as the values 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 .
According to a further embodiment of the present invention, the load of the vehicle is determined by computing device 15 through use of the stored parameter map. For this purpose, computing device 15 first determines the bellows pressure p B as well as the deflection Z on the basis of the signals of the relative-level sensor and pressure sensor. Computing device 15 then locates in the parameter map the characteristic most closely approaching these values. The vehicle load to be determined is equal to the load correlating with this characteristic. For the case where no exactly corresponding values are present in the parameter map for the respective bellows pressure p B or deflection Z, intermediate values are interpolated, for example, by linear interpolation of the closest adjacent values in the parameter map or by another suitable interpolation method, such as, for example, spline interpolation of all values of the parameter map belonging to a characteristic F 1 , F 2 , F 3 .
According to embodiments of the present invention which utilize an expanded correlation table, computing device 15 uses the vehicle load determined in this way in combination with the relative level in order to determine the index pressure value of the accumulator pressure from the expanded, two-dimensional correlation table. As an example, the correlation table can have the following structure:
Index pressure
Index pressure
Index pressure
value at minimal
value at
value at maximal
Index level
load
intermediate load
load
Low level
10 bar
11 bar
12 bar
Driving level
7 bar
8 bar
10 bar
High level
1 bar
2 bar
3 bar
Referring now to FIG. 3 , a control-engineering block diagram of an advantageous embodiment of the present invention for controlling the pressure in compressed-air accumulator 3 is depicted. A block 21 contains the parameter map according to the characteristics of FIG. 2 . Also provided is a block 26 which contains correlation rules for correlation of the index pressure value P S,index with the load B and the deflection Z. The correlation rules can be resident in a form such as a table, a mathematical function or a further parameter map. The correlation rules are preferably stored in electronic control unit 6 .
A further block 28 represents a three-point controller with hysteresis. Advantageously, the hysteresis values can be variably configured and varied as a function of the previously discussed variables or further variables. Three-point controller 28 transmits two switching signals S K , S E which are used by electronic control unit 6 to generate control signals for valve device 5 and compressed-air delivery device 1 in order to raise or lower the accumulator pressure. The switching signals S K , S E are on/off signals, and at any time only one of the signals can have the value “on.”
Also depicted in FIG. 3 are error detectors 23 , 25 which detect malfunctions in the level-control system and trigger appropriate reactions thereto. Examples of such malfunctions are defects in the sensors, such as the pressure sensor or the relative-level sensors. In the event of faulty sensor signals, it may no longer be possible to determine certain of the variables, such as the load B or the actual value Z actual of the relative level of the entire vehicle body, needed for the invention according to FIG. 3 to be fully functional. Upon recognition of such an error, error detectors 23 , 25 therefore cooperate with changeover switches 22 , 24 to change over the signals being used to alternative signals. Thus, in the event of a defect or malfunction of a relative-level sensor, error detector 23 acts via changeover switch 22 to trip changeover of the deflection signal Z from the actual value Z actual of the relative level to the index value Z index of the relative level. In the event of a defect or malfunction of one of the relative-level sensors or of the pressure sensor, the load B of the vehicle can no longer be determined via parameter map 21 . In such a case, error detector 25 acts via changeover switch 24 to trip changeover of the load signal B to a predefined fixed value B v of load.
Error detectors 23 , 25 as well as switches 22 , 24 can be implemented in the electronic control unit in the form of program algorithms to be executed by computing device 15 .
Referring to FIG. 3 , controlling the accumulator pressure preferably operates as described below. From an actual value p B,actual of bellows pressure determined by means of the pressure sensor as well as from the actual value Z actual of the relative level, an actual value B actual of load is determined via parameter map 21 . In the malfunction-free case, this actual value B actual of the load is supplied as the load signal B to block 26 . Concurrently, the actual value Z actual of relative level or, in the error case, the index value Z index of relative level is supplied as the deflection signal Z to block 26 . By applying the correlation rules of block 26 , computing device 15 calculates an index pressure value P S,index for the accumulator pressure. From this index pressure value P S,index, there is subtracted, in a difference calculator 27 , an actual value P S,actual of the accumulator pressure determined via the pressure sensor. The result is supplied as the difference to be corrected to three-point controller 28 , which generates the switching signals S K , S E in the manner discussed above.
Accordingly, the present invention provides a new method for controlling the pressure in a compressed-air accumulator of a level-control system for a motor vehicle wherein the relative level and/or load of the vehicle are used as physical pressure control variables. The present invention permits efficient operation of the level-control system characterized by, for example, low energy consumption, short times for raising and lowering the vehicle body, and the capability of using a compressor designed for the smallest possible delivery capacity.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in carrying out the above method and in the constructions set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. | A method for controlling the pressure in a compressed-air accumulator of a level-control system of a motor vehicle utilizing a pressure-control apparatus constructed and arranged to adjust the accumulator pressure according to a predetermined index pressure value. The index pressure value is automatically determined by a computing device based on the relative level and/or the load of the vehicle. | 1 |
FIELD OF THE INVENTION
The present invention relates to cross-corrugated packing. It is applicable particularly to air distillation columns on board floating oil platforms or on barges.
BACKGROUND OF THE INVENTION
As is well known, cross-corrugated packing is used in certain distillation columns in place of distillation plates, to ensure material and heat exchange between a rising gas and a falling liquid. These cross-corrugated packings are constituted by a superposition of sections. Each section is formed by a stack of corrugated strips each disposed in a ith generally vertical plane, one against the others. The corrugations are oblique and descend in opposite directions from one strip to the next.
The strips generally comprise dense small diameter perforations, with a perforation proportion of about 10l, to permit the liquid to flow on opposite sides of the corrugated strips.
British 1,004,046 and Canadian 1,095,827 disclose such cross-corrugated packings.
A cross-corrugated packing is generally produced from a flat product, namely metallic sheets in the form of strips. The strips are first bent (or folded) so as to form a corrugated metal sheet in a strip whose corrugations are oblique relative to the axis of the strip. The bent strips are then cut off in sections, then stacked alternately reversed. The packing sections thus obtained are often called “packs”.
WO-A-90/10 497 discloses among other things a packing analogous to the mentioned cross-corrugated packings, but perforated in a different way. The term “cross-corrugated packing” used here also comprises such a packing, as well as any analogous packing.
Oil platforms at sea produce residual gases. For economic and environmental reasons, it is becoming more and more necessary to recover these gases, one method consists in their conversion into heavier hydrocarbons, in liquid form and hence more easily transportable, by the Fischer-Tropsch process, which consumes large quantities of oxygen.
SUMMARY OF THE INVENTION
The basic problem that the invention seeks to solve consists in providing an air distillation column capable of operating in satisfactory conditions on board a platform or a barge, which is to say in the presence of oscillations due to swell and whose amplitude is typically comprised between 5° and 10° in all directions. It is thus imperative that the liquid distributed at the head of the column ensures substantially uniform wetting of the packing over all the cross section of the column despite the mentioned oscillations.
To this end, the invention has for its object a corrugated strip for cross-corrugated packing, characterized in that it comprises on its lower edge, in front view, at least one downwardly projecting motif whose contour is such that, if α m and α M indicate the extremes of the algebraic value of the angle that the tangents to the contour form with the horizontal direction, then
−α m >α 0 and α M >α 0 ,
in which ai designates a predetermined angle at least equal to 5°.
The corrugated strip according to the invention can comprise one or several of the following characteristics:
the motif repeats a plurality of times along the lower edge of the strip, the motifs being adjacent each other or separated by substantially rectilinear segments;
each motif is obtained by bending a flat strip according to a corrugation of a height H, an opening angle γ and a radius r at the summit of the bend, with the bend generatrices inclined at an angle δ seen face on, the parameters H,γ, r and δ being selected such that sin δ · tan μ · sin ( γ 2 ) + cos δ 1 + tan 2 μ · sin 2 ( γ 2 ) < cos α 0 , wherein, tan μ = tan δ · [ r · sin ( γ 2 ) + H 2 - r ] + π 180 · ( 90 - γ 2 ) · cos ( γ 2 ) r sin ( γ 2 ) · [ r · sin ( γ 2 ) + H 2 - r ] + cos 2 ( γ 2 ) · r
each motif is obtained by cutting out two recesses in the lower edge of the strip before bending the latter.
The invention also has for its object a cross-corrugated packing section comprising a stack of corrugated strips of which at least one is as defined above, with their corrugations inclined alternately in opposite directions.
The invention also has for its object a distillation column which comprises a superposition of sections of cross-corrugated packing having at least two different angular orientations, at least one of the sections being as defined above, and in which there is at least one direction such that the mean of the cosines of the angles which comprise the assembly of the strips of the section in each direction, the cosines being given an absolute value, is less than 0.5.
When the column is on board a floating structure having a preferred direction of oscillation, which is generally the case with barges, said direction is this preferred oscillation direction.
In particular, in one embodiment, the superposition of the sections is constituted by sections of strips parallel to the preferred direction of oscillation and of sections with strips perpendicular to this direction, the number of these latter being comprised between about ⅔ and ¾ of the total number of sections of said superposed sections.
BRIEF DESCRIPTION OF THE DRAWINGS
Examples of embodiment of the invention will now be described with respect to the accompanying drawings, in which:
FIG. 1 shows schematically, in partial axial cross section, a distillation column according to the invention;
FIG. 2 shows in perspective a portion of a section of cross-corrugated packing;
FIG. 3 shows schematically in perspective an inclined distillation column;
FIG. 4 shows schematically the arrangement of the column of FIG. 1;
FIG. 5 shows a modification, schematically in an analogous manner;
FIG. 6 shows the shape of the corrugation of the cross-corrugated packing of FIG. 2;
FIG. 7 shows a corrugated strip of the packing, seen face on;
FIG. 8 shows on an enlarged scale the lower edge of a strip of the packing; and
FIGS. 9 and 10 show schematically two modifications.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows schematically an air distillation column 1 secured to a barge 2 anchored to the bottom of the sea. This barge, under the influence of swell, oscillates with a preferred direction of oscillation, shown by the double arrow F and contained within the plane of the figure. The angle of inclination to the vertical of the axis X—X of the column can reach a maximum predetermined value α 0 at least equal to 5°, and typically comprised between 5° and 10°. Within this range of oscillation, the column must ensure satisfactory distillation.
FIG. 1 shows schematically the internal arrangement of the upper portion of the column 1 . This upper portion comprises a superposition of stacks 3 of cross-corrugated packing, of which each is in the form of a cylindrical cake occupying all the cross section of the column.
Each pack 3 (FIG. 2) is constituted of a stack of corrugated strips 4 with oblique corrugations 5 , these strips being if desired perforated over all their surface. Each strip 4 comprises a generally vertical plane, all the strips have the same height, and the corrugations are alternately inclined in opposite directions from one strip to the next. Thus, the corrugations of adjacent strips touch at a large it number of points of intersection.
There are provided two types of packs 3 : packs 3 A whose strips 4 A are oriented parallel to the preferred direction of oscillation F, which is to say to the plane of FIG. 1, and packs 3 B whose strips 4 B are oriented perpendicular to the strips 4 A. All the packs 3 have the same number of strips 4 , but the packs 3 B are of greater number than the packs 3 A. In this example, the packs 3 B are twice as numerous as the packs 3 A: the upper pack is a pack 3 A, then, moving downwardly, there are two packs 3 B, a pack 3 A, two packs 3 B, etc . . . Of course, this arrangement can be repeated along the length of the distillation column, which is to say of the low pressure column and of the medium pressure column, when, as in this example, there is a double air distillation column.
Then the liquid, which descends in the column, distributed at the head of the column over all the section of this latter by a distributor 6 , flows for the most part over the perpendicular strips with the direction F, which are effectively opposed to the deflection of the liquid in the direction of inclination. The packs 3 A oppose this deflection less, but their presence is necessary to ensure a redistribution of the liquid perpendicular to the strips 3 A at several levels of the column.
Generally speaking, the number of packs 3 B can be comprised between about ⅔ and ¾ of the total number of packs.
The ability of the packing to resist deflection of the liquid under the influence of oscillation, can be characterized as a value called the “deflection factor of the liquid”, equal to d/i, wherein d designates the mean angle of deflection of the liquid relative to the axis X—X of the column whilst i designates the angle of inclination of this axis to the vertical (FIG. 3 ).
It can be shown that this deflection factor is proportional to the mean M of the cosines of the angles which comprise the assembly of the strips 4 A and 4 B, with the direction F, these cosines being taken at an absolute value. The proportionality factor depends only on the type of packing used.
With the conventional arrangement, with packs 3 A and 3 B in alternation, the mean M is 0.5 when the direction F corresponds to one of the two orientations of the strips, and is greater than 0.5 for any other direction F. For example, M=0.71 for an inclination whose plane makes an angle θ=45° with those of the corrugated strips.
In FIGS. 4 and 5, θ designates the angle of the plane of oscillation with a reference plane, whose trace is superposed horizontally.
FIG. 4 corresponds to the arrangement of two packs 3 B-a pack 3 A described above. θ=0 is the direction of the strips 4 A. In this case, for θ=0, M=0.33; for θ=45°, M=0.71; and for θ=90°, M=0.67. Thus, the deflection factor is reduced when the preferential oscillation direction F is chosen, such that θ=0, or a nearby direction.
As a variant, other arrangements can lead to a reduced deflection of liquid. Thus, in the example of FIG. 5, the packs make alternately an angle x=+60° and x=−60° with the reference direction θ=0. In this case, θ=0 produces M=0.5, θ=30° produces M=0.43 and θ=90° produces M=0.87. It will be seen that the deflection factor is reduced when the preferred direction of oscillation F is selected such that θ=30°, or a close-by direction. There are of course here two directions F which are symmetrical and which are suitable.
There will now be described, with respect to FIGS. 6 to 10 , the construction of the lower edge of the strips 4 A and 4 B.
Seen edgewise (FIG. 6 ), each corrugation has a generally triangular shape, with straight sides 7 symmetrical to the vertical direction D and rounded sides 8 at the peaks of the corrugations. The corrugation is defined by its total height H, measured parallel to the direction D, by its opening angle γ at the peaks, and by the radius r of the curves 8 .
Seen face on (FIG. 7 ), each strip 4 is a rectangle whose corrugations 8 are inclined at an angle δ relative to the horizontal.
When the flat metal starting sheet is bent at the angle δ, by winding on a suitable oblique mandrel, the upper and lower edges have the form of saw teeth, as shown in FIG. 8 for the lower edge. There is thus, seen face on, on the lower edge, a series of protuberances 9 projecting downwardly. Relative to the horizontal direction oriented to the right, the tangent to the contour of the projections evolves between a negative minimum α m and a positive maximum α M .
When the liquid which wets the corrugated strip Sreaches its lower edge, each protuberance 9 constitutes a low point which permits dripping of the liquid on the lower pack and prevents displacement toward the end of the strip. So that this phenomenon will take place no matter what the inclination of the axis of the column, and in no matter what direction, until the angle α 0 , mentioned above is reached (α 0 is equal to or greater than 5°), the parameters H, r, γ and δ are so selected that:
−α m >α 0 and α M >α 0 .
This can be obtained from the following condition: sin δ · tan μ · sin ( γ 2 ) + cos δ 1 + tan 2 μ · sin 2 ( γ 2 ) < cos α 0 , wherein, tan μ = tan δ · [ r · sin ( γ 2 ) + H 2 - r ] + π 180 · ( 90 - γ 2 ) · r sin ( γ 2 ) · [ r · sin ( γ 2 ) + H 2 - r ] + cos 2 ( γ 2 ) · r
As shown in FIGS. 9 and 10, the existence of low points along the lower edge of the strips 4 , for the on-board column, can also be obtained by providing on this lower edge, before bending the metal sheet, a series of recesses 10 each having a suitable profile: arc of a circle or ellipse as shown, but also polygons, etc . . . These recesses 10 , which delimit between them the protuberances 9 , can be separated from each other by rectilinear sections (FIG. 8 ), or adjacent each other (FIG. 9 ).
In the case of FIG. 9, −α m =α M= 45°, and, in FIG. 10, −α m =αM=90°. These values change somewhat after bending the sheet, but remain very much higher than the values α 0 designated for the use in question, which are comprised between about 5 and 10° as indicated above.
As will be understood, the invention is applicable also to fixed distillation columns but whose axis is not exactly vertical. | This corrugated strip comprises on its lower edge, in front view, at least one downwardly projecting motif ( 9 ) whose contour is such that, if α m and α M designate the ends of the algebraic value of the angle that the tangent to the contour forms with the horizontal direction, then
−α m >α 0 and α M >α 0 ,
wherein α 0 designates a predetermined angle at least equal to 5°. The corrugated is particularly useful in air distillation columns on board floating oil platforms or barges. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to an integrated magnetic head suitable for high density recording.
Studies have been made on an integrated magnetic head which separates a recording head and a reproduction head, to accomplish high performance and to improve magnetic recording density. Recording inductive type and reproducing magnetoresistive type heads are made composite. In such a head, one, or both, of the magnetic shield layers are used also as the magnetic pole of the inductive head, as disclosed in a large number of references, such as Japanese Patent Publication No. 35088/1984.
SUMMARY
When the magnetic shield layer serves also as the magnetic pole of the recording head, its dimension in the direction of track width becomes a problem. Generally, the length of the magnetoresistive sensor must be greater than its track width in order to provide anisotropy in the track width direction. In this case, the magnetic shield layer must cover fully the magnetoresistive sensor as a whole in order to suppress the noise that occurs at portions other than the track width. On the other hand, the dimension of the magnetic pole for recording must be in conformity with the track width. In this manner, as to the dimension of the magnetic layer in the track width direction, the conventional heads cannot satisfy simultaneously these two requirements. As a countermeasure, in the separated type head in which the recording head is laminated on the magnetoresistive sensor, a structure is known wherein an upper pole is brought into conformity with the track width while a lower pole has a length such that it can cover the magnetoresistive sensor as a whole. However, the track width of the upper pole does not coincide with that of the lower recording pole, so that side writing is likely to occur at the end portions of the magnetic poles and excellent recording characteristics cannot be obtained easily.
The present invention provides a magnetic layer of a head structure which can satisfy the characteristics of both the magnetic shield layer and magnetic pole layer for recording.
The problems described above can be solved by bringing the combined upper part and lower part of the magnetic layer respectively into conformity with the widths necessary for the shield layer and for the magnetic pole, e.g., specifically, by disposing a taper, or more specifically a step shape, to the section of the magnetic layer to have the dimension of the upper part of the magnetic layer different from that of the lower part. Therefore, in the structure described above, the width of the magnetic layer facing one of the recording magnetic poles can be brought into conformity with the track width. Accordingly, the flux at the time of a write operation concentrates on the track width portion and hence, side writing of the recording head can be reduced. On the other hand, the width of the magnetic head on the opposed side to the magnetoresistive sensor can be extended sufficiently to fully cover the sensor. For this reason, the noise picked up by the magnetoresistive sensor resulting from the signal flux from the adjacent tracks can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects, features and advantages of the present invention will become more clear from the following detailed description of a preferred embodiment, shown in the drawing, wherein:
FIG. 1(a) is a plan view and FIG. 1(b) is an end view of a magnetic head for one embodiment of the present invention;
FIG. 2 is a diagram of experimental data;
FIGS. 3(a), (b), and (c) are a plan view and end views showing different embodiments; and
FIGS. 4 and 5 are end views of further embodiments of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1(a) and (b).
FIG. 1(a) is a plan view of the magnetic head in accordance with the present invention and FIG. 1(b) is a sectional or end view from the surface of a recording magnetic medium. A lower magnetic shield layer 2 is laminated on a head substate 1 and thereafter covered by an insulating layer 3. A magnetoresistive sensor 4 is laminated on the insulating layer 3, and electrode layers 11 are laminated on the sensor 4 and thereafter covered by an insulating layer 5. Subsequently, an upper magnetic shield layer 6 is laminated on the insulating layer 5 and thereafter covered by an insulating layer 8. Furthermore, a conductor layer 9, which is to serve as a coil, is laminated on the insulating layer 8 and thereafter covered with an insulating layer 10. Then an upper magnetic pole 7 is laminated on the insulating layer 10. Width is measured in the track width direction, that is horizontally in FIG. 1(b). The width dimension at the lower part 24 of the upper magnetic shield layer 6 is equal to the width dimension of the lower magnetic shield layer 2, and the width dimension at the upper part 25 of the upper magnetic shield layer 6 is equal to the width dimension of the upper magnetic pole.
The shield layers 2, 6 and the magnetic pole layer 7 are sputtered permalloy in a composition of 82Ni-18Fe, whose film thickness is 2.0 μm. The width dimensions on the end surface facing the medium are 100 μm for the lower shield layer 2, 90 μm at the lower part of the upper shield layer 6 serving also as the lower magnetic pole, 10 μm at the upper part of the upper shield layer 6, and 8 μm at the upper magnetic pole 7. The height of the step 16, as measured perpendicular to the width in FIG. 1(b), that is vertically, of the upper part of the two-stage lower magnetic pole 6 is 0.7 μm. The step can be considered the transition from the lower part 24 to the upper part 25. To provide each layer with lamination margin, the dimension of each layer becomes progressively smaller towards its upper part. Alumina is used for all the insulating layers 3, 5, 8 and 10. The film thickness, measured vertically in FIG. 1(b), at the portions interposed between the magnetic poles 2, 6, 7 is 0.3 μm, 0.4 μm, 0.7 μm and 0.7 μm for the insulating layers 3, 5, 8 and 10, respectively. These insulating layers 3, 5, 8, 10 are made flat by an etch-back method which is employed ordinarily. A 2.0 μm-thick copper film is used for the conductor layer 9 to form a one-turn coil. A 40 nm-thick permalloy composition 82Ni-18Fe film is formed by vacuum deposition for the magnetoresistive sensor 4 and it is 50 μm long (horizontally in FIG. 1(b)) in the track width direction and 10 μm high (vertically in FIG. 1(b)). Electrode layers 11 are disposed at both ends of this sensor and use a two-layered film of Ti of 60 nm-thickness and Au of 150 nm thickness.
A barberpole bias method is employed for the magnetoresistive sensor. Therefore, the end portion of each electrode 11 at the magnetosensitive portion 12 is inclined at 45° as seen in dotted lines in FIG. 1(a). The electrode spacing in the track width direction D is 6 μm and this spacing corresponds to an effective track width. The step due to the magnetoresistive sensor 4 is up to 0.3 μm and this value is smaller than the film thickness of the magnetic shield layer 6 to be formed thereon, that is 2.0 μm. The step on the magnetic pole (0.7 μm) is smaller than the thickness (2 μm) of the coil conductor 9. Accordingly, flattening of the insulator layers is not always necessary.
FIG. 2 shows the off-track overwrite performance curve 22 of the head shown in FIGS. 1(a) and 1(b) and its cross-talk performance curve 23 due to the adjacent tracks. The parameter d/t is the ratio of the thickness d of the step 16 of the lower magnetic pole 6 to the thickness t of the lower magnetic pole. The schematic view of the shape of the poles 6, 7 of the recording head at each of four ratios, as viewed from the surface facing the medium, is illustrated on the diagram. Since the side surfaces of the poles 6 and 7 are tapered during information, the section of each pole is trapezoidal. In the results shown in the diagram, the off-track distance is set to 10% of the track width. The overwrite performance can be improved when the step thickness d increases. This is because the flux at the time of recording concentrates on the recording track width portion with the increase in the step thickness and side recording decreases. The cross-talk performance, also depends on the step thickness d and when the step thickness d becomes greater, the signal to noise ratio S/N drops, which is measured in dB. As d/t becomes greater, the thickness of the shield layer, lower part 24, becomes small and the shield effect drops. When d/t is 1, that is, when the width of the magnetic shield layer 24 is in agreement with the width of the upper magnetic pole 7, the end portion of the magnetoresistive sensor 4 is not shielded so that the S/N drops remarkably. The diagram shows the case where 26 dB is set as the lower limit of the S/N necessary for the operation of the magnetic head. Accordingly, the preferred range of values for the step thickness d, in the case of the 2 μm-thick permalloy in the embodiment is from about 0.6 μm to about 1.4 μm. This range depends on the angle of the taper-like sides 26 of the upper part 25 and lower part 24, in section. In other words, the sharper the taper of the side 26, the greater the decrease of side recording with the result being the improvement in the off-track overwrite performance 22. Furthermore, when the upper magnetic pole 7 is formed by plating, the section side 26 is reversely tapered from that shown, and the side recording can further be reduced. The range described above depends on the magnetic characteristics, e.g., saturated flux density B s , permeability η of the magnetic film used for the magnetic pole 6 and its film thickness.
Another embodiment of the present invention will be described with reference to FIGS. 3(a) and (b).
FIG. 3(a) is a plan view of the magnetic head and 3(b) is an end view as viewed from the surface of a recording medium, to correspond to FIGS. 1(a) and (b). A magnetoresistive sensor 4 is sandwiched between the upper pole 18 and lower pole 13 for recording. The lower magnetic pole 13 for recording functions as a magnetic shield layer and is formed on a substrate 1. Next, an insulating layer 14 is formed and the magnetoresistive sensor 4 is disposed on the insulating layer 14. Next, electrode layers 11 and a conductor layer 9 to function as the coil of the recording head are formed on the insulating layer 14. Afterward an insulating layer 15 is formed on the conductive layer 9 and electrode layer 11, and then a groove 17 corresponding to the recording track width is formed in the insulating layer 15. Subsequently, a magnetic film 18 is laminated as the upper magnetic pole and magnetic shield film. A Co system amorphous alloy having a saturated flux density of 1.3T is used as the magnetic film 18. The thickness of each film is 1.5 μm. The dimension of the lower magnetic pole 13 in the track width direction is 50 μm, the width of the upper magnetic pole 18 is 45 μm and its groove width is 6 μm. Alumina formed by sputtering is used for the insulating layers 14 and 15 of a film thickness 0.4 μm and 0.4 μm between the upper and lower magnetic poles 13, 18 respectively. The magnetoresistive sensor 4 is made of 40 nm-thick permalloy. The barberpole bias method is used as the bias method in the same way as in Embodiment 1. The sensor is 30 μm long and 12 μm high. A 0.2 μm-thick-Al film is used for the electrode layer 11 of the magnetoresistive sensor. The distance between the electrodes in the track width direction, that is, the track width, is 4 μm. The film thickness of the insulating layer 15 must be changed in accordance with the groove depth.
FIG. 3 (c) shows a modification of the embodiment shown in FIGS. 3 (a) and (b), and differs therefrom only in the shape of the magnetic pole piece 13 that also serves as the shield member. In FIG. 3 (c), the magnetic pole piece 13 has a stepped portion 16, the width of which is preferably equal to about the width of the groove piece 17 although it may be of other shapes and dimensions as shown with respect to the similarly shaped piece 6 of FIG. 1 (b).
The off-track overwrite performance of this head and its adjacent track cross-talk performance are evaluated by use of the groove depth as the thickness d of the parameter d/t that is used in FIG. 2. As a result, it was found that a S/N of 26 dB or above can be obtained with the groove depth range of 0.5 μm to 1.0 μm. In this manner, both the off-track overwrite performance and adjacent track cross-talk can be improved by employing the groove of FIGS. 3(a) and (b) as the step in the magnetic shield layer. The magnetic shield layer 13 serving also as the lower magnetic pole in the FIGS. 3(a) and (b) embodiment, could have a step, for example like layer 11 of FIG. 1(b). In this case, too, the effect of the step can be obtained and both the off-track overwrite performance and adjacent track cross-talk can be improved. However, since the magnetoresistive sensor must be made flat, the insulating layer 14 must be made flat by the etch-back method.
The magnetoresistive sensor can use other bias methods. For example, the known dual coupled thin-film self bias, current bias and permanent magnet bias can be employed. Besides the rectangular shape described in the foregoing embodiments, the shape of the sensor may be a picture frame structure having a fine gap.
Though all the foregoing embodiments represent the case where a magnetoresistive sensor having high reproduction efficiency is used as the reproduction head, a conventional inductive head can be used. In this case, off-track overwrite performance and cross-talk between the adjacent tracks can be reduced by making the track width of the recording head great and the track width of the reproduction head small. Accordingly, the head characteristics can be improved by disposing the step on the magnetic pole for both recording and reproduction and bringing the upper and lower dimensions of the step into conformity with the track width, respectively.
Next, another embodiment wherein the specific permeability and saturated flux density differ between the upper and lower parts of the magnetic film for the combined use will be described. In FIG. 4, a magnetic pole 19 for recording is shown laminated on the magnetoresistive sensor type reproduction head. In the reproduction head, the thin film permalloy magnetoresistive sensor 4 is formed between the permalloy shield layers 2 and 6 and the insulating layers 1, 3 and 5 are formed, all in the same way as in Embodiment 1. Next the lower magnetic pole 19 of the recording head is formed on the upper magnetic shield layer 6. In this instance, the magnetic shield consists of a 0.7 μm-thick permalloy. CoTaZr having a saturated flux density of 1.3 T is used as the magnetic pole 19, and the film thickness is 0.8 μm. Thereafter the coil (not shown) is formed and covered by the insulator layer 8, and then the upper magnetic pole 7 is formed on the insulating layer 8. This pole is made of 1.5 μm-thick CoTaZr. The dimension of each magnetic layer in the track width direction is 100 μm for the lower shield layer 2, 90 μm for the upper shield layer 6, 8 μm for the lower magnetic pole 19 and 6 μm for the upper magnetic pole 7. The film thickness of the insulating layers, and the structure of the magnetoresistive sensor and electrode layer 11 are the same as those of the FIGS. 1(a), (b) head.
In this manner, side recording of the recording magnetic field can be limited by increasing the saturated flux density of the magnetic pole 19 on the recording head side relative to the other layers and the recording performance can be improved.
Next, still another embodiment of the invention using an inductive head for both the recording and reproduction heads will be explained with reference to FIG. 5, with other details being the same. First of all as previously described, the lower and upper magnetic poles 19 and 7 for recording are formed on the substrate 1 with the interposition of insulating layer 3. The width of poles 7 and 19, in the direction of the track width at this time is 10 μm and 8 μm, respectively. The film thickness is 3 μm for both poles 7 and 19 and the material used is CoTaZr having a saturated flux density of 1.3 T. Permalloy is laminated on the pole 7 as the magnetic poles 20 and 21 with the interposition of insulating layer 5 for the reproduction head. The lower magnetic pole for reproduction 20 and the upper magnetic pole for reproduction 21 each have a film thickness that is 1 μm. The dimensions of the reproduction head in the track width direction are 5 μm for the lower magnetic film 20 and 4 μm for the upper magnetic pole 21. The specific permeability is 1200 for CoTaZr and 2000 for the permalloy. The film thicknesses of the insulating layers 3 and 5 as the gap layers are 1.5 μm and 0.2 μm, respectively. The number of turns is 8 and 24 turns for the recording head and for the reproduction head, respectively.
As described above, the side recording of the recording magnetic field can be restricted by increasing the saturated flux density of the magnetic pole on the recording head side and increasing the permeability of the magnetic pole on the reproduction head side and the recording characteristics can be improved. Since the flux at the time of reproduction concentrates on the magnetic poles for reproduction, reproduction can be effected efficiently.
Since the present invention can restrict side recording occurring at the end portion of the magnetic pole of the recording head, it can improve the off-track overwrite performance. Since the magnetic shield layer can cover the end portions of the magnetoresistive sensor, cross-talk between the tracks can be reduced.
While a preferred embodiment has been set forth along with modifications and variations to show specific advantageous details of the present invention, further embodiments, modifications and variations are contemplated within the broader aspects of the present invention, all as set forth by the spirit and scope of the following claims. | The magnetic layer of a head structure can satisfy the characteristics of both the magnetic shield layer and magnetic pole layer for recording by bringing the combined upper part and lower part of the magnetic layer respectively into conformity with the widths necessary for the shield layer and for the magnetic pole, e.g., specifically, by disposing a taper or more specifically a step shape to the section of the magnetic layer to have the dimension of the upper part of the magnetic layer different from that of the lower part. The width of the magnetic layer facing one of the recording magnetic poles can be brought into conformity with the track width. Accordingly, the flux at the time of a write operation concentrates on the track width portion and hence, side writing of the recording head can be reduced. On the other hand, the width of the magnetic head on the opposed side to the magnetoresistive sensor can be extended sufficiently to fully cover the sensor. For this reason, the noise picked up by the magnetoresistive sensor resulting from the signal flux from the adjacent tracks can be reduced. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of PPA No. 61/032,952, filed 2008 Mar. 1 by the present inventor, which is incorporated by reference.
FEDERALLY SPONSORED RESEARCH
Not Applicable
SEQUENCE LISTING OR PROGRAM
Not Applicable
BACKGROUND OF THE INVENTION
Field
This application relates to the construction of shelters made of snow or ice crystals, specifically to shelters constructed using slip forms rotated around a horizontal axis to create a surface of revolution.
BACKGROUND
Prior Art
Shelters built from compacted snow or ice crystals serve a variety of important functions. In areas that receive heavy snowfalls, where there are virtually no building materials available other than snow or ice, such shelters provide humans with life-saving insulation from cold or other natural elements. Snow shelters are often used in recreational applications, such as winter camping or ice fishing.
Traditional Igloo Construction Method
FIG. 1 demonstrates the early steps of building a traditional igloo from custom shaped blocks cut from compacted snow. A first row of blocks is placed in a circle on the surface where the igloo is to be built. The blocks are carefully shaped so they fit together tightly. Additional layers of blocks are stacked and fitted on the previous. Each block of each additional layer must be shaped such that the block is canted more towards the center of the igloo than the blocks of the previous layer. As the blocks are stacked in circles of successively smaller diameters, the walls arch inward and the top of the shelter is eventually enclosed. The final block that encloses the top acts as a keystone and strengthens the walls of the igloo. Until the keystone is placed, the inward arching walls are fragile. The finished shelter approximates the shape of a hemisphere.
If there is sufficient snow depth for excavation, the blocks for a traditional igloo are removed from inside the perimeter of the igloo. This creates more interior volume without the work required of creating taller walls.
Problems with the Traditional Igloo Construction Method
Building a traditional igloo shelter is a job that requires a significant amount of skill. Cutting and lifting blocks of compacted snow is difficult. The blocks are heavy and lifting from foot level is required. Many of the blocks must be lifted to shoulder height and above.
In many instances, the snow must be compacted prior to cutting the blocks. One method of compaction is accomplished by repeatedly walking with snowshoes over an area of soft or powered snow until sufficient compaction is achieved. This act requires a significant expenditure of energy.
The shape or size of the shelter is entirely determined by the user, and once a mistake is made, it is difficult to correct the mistake by repositioning the blocks already in place. Inexperienced builders often encounter size or shape problems during construction and may not be able to finish an igloo in a reasonable amount of time.
One typical size problem is inaccurately estimating the initial diameter of the igloo. If the diameter is too large, enclosing the top is extremely difficult due to the height of the structure. If the diameter is too small, there isn't enough interior space.
A typical shape problem involves the inward curvature of the walls. If the inward cant of each block is insufficient, the walls once again become too tall. If the inward cant is too great, the structure may collapse.
The size and shape of the individual building blocks is another source of problems. Ideally, large blocks are used. This speeds up construction and reduces the number of gaps between blocks. However, the difficulty of moving such blocks often causes the builder to cut small blocks to reduce the weight. If the blocks are sized or placed in such a way that reduces the thickness of the wall, the resulting wall may not have sufficient strength and may collapse prior to or after completion. This is especially true when the builder overestimates the appropriate size of the igloo. Larger diameter igloos require thicker walls.
Placing the last few blocks of a traditional igloo is difficult. The builder must place the blocks over his or her head from inside the structure. Due to the keystone nature of the last blocks, the blocks must be shaped precisely and there is a significant risk of the previous rows collapsing prior to installation of the final blocks.
Once a traditional igloo is completed, any defects on the interior and exterior surfaces should be corrected.
One reason for correcting defects is that snow is a thermal insulator. That is how the inside of the igloo can be kept warmer than the outside temperature. If there are gaps between the blocks of snow, the insulation value of the igloo decreases.
A second reason for correcting defects on the interior is the formation of water drops. As the inside temperature rises above freezing, water drops form at the lowest point of each discontinuity and eventually fall on the inhabitants. These drops are annoying and potentially dangerous if the inhabitants are depending on the shelter to keep them dry and warm. A smooth internal surface reduces the chance of water-drop formation.
Manually packing snow into each of the gaps and smoothing out the discontinuities between the blocks is time consuming.
The circular shape of the floor plan is not ideal for modern camping. A typical adult sleeps in a rectangular area, often defined by a rectangular sleeping pad. Since a finite number of such rectangles will fit in a circular floor plan, the floor space is not used very efficiently. Typically, between 50 and 70 percent of the available floor space is used for sleeping. FIG. 2 and FIG. 3 demonstrate how occupants can be positioned in circular igloos. Although the excess area might feel spacious, it represents wasted work due to the additional snow that is required for construction. The excess floor space also implies that there is excess interior volume that must be heated, and extra time was required to complete the large structure.
Traditional Igloo Construction Method Using a Mold to Create Blocks
Molds are found in the prior art and are used to create building blocks by packing a mold with loose snow. These molds provide blocks of consistent shape and size. Molds are generally in the shape of a rectangular or trapezoidal solid. U.S. Pat. No. 4,154,423 (Crock, 1979) teaches such a method.
After forming a block of snow, the builder places and adjusts the block, as is done in the traditional method.
Problems with Mold Method
Molds overcome one problem of the traditional method—cutting an improper size block. However, all of the other disadvantages of the traditional method still exist, plus a few new ones:
If dropped, the weight of the snow packed mold can fracture the mold. Damage to equipment might render it inoperable.
Extra work is also required when using a mold. The builder must gather snow, place snow in mold, compact snow in mold, remove compacted snow from mold, carry block to igloo, and place block on igloo. This requires picking up the same snow at least three times (picking up snow to fill the mold, picking up and inverting the packed mold to empty it, and picking up the formed block). Handling the same snow multiple times slows down the construction process and wears out the builder.
A single shape of block cannot be used to accurately create an igloo. The shape of each block should be modified so that the blocks fit together without gaps. This involves cutting away snow that was previously lifted 3 times and took additional work to form and pack. In other words, work is wasted by modifying the shape of each block.
FIG. 4 demonstrates what occurs if rectangular blocks are stacked without shaping. Because of the uniform shape of the blocks, there will be many gaps in the outer surface of the completed shelter, thus compromising the insulation value of the igloo. Even if the blocks are uniformly wedge shaped, they will not fit at all levels of the igloo. Custom shaping must still occur. To create an igloo that had no voids and required no reshaping of blocks, a different mold would be required for each level of the igloo. Such a set of molds would only create one diameter of igloo.
FIG. 5 shows how a rectangular block in an upper row is placed on two blocks in a lower row. None of the blocks have been custom shaped. The overhanging edge 105 of the upper block is a discontinuity and will likely cause the formation of water drops as previously mentioned.
In Situ Slip Form Construction Methods
A slip form is a mold that is designed to cast a block in situ. After the block is formed, the slip form is moved and the next block is created. The form is normally enclosed on three sides so that as the form is filled, the newly created block is automatically joined to the previous block and to the block or surface below it.
FIG. 6 shows a simplified representation of a slip form known in the art. U.S. Pat. No. 6,210,142 (Huesers et al, 2001) teaches how to use such a slip form to build circular based hemispherical or ellipsoidal structures. Slip form 110 is attached to the end of rigid rod 120 which pivots around fixed center anchor 115 . The building material is deposited in situ block by block.
Slip forms overcome three problems inherent in traditional or mold formed igloos.
1) Slip forms don't leave gaps like mold formed blocks can. Less re-work is required.
2) The wall thickness is well controlled. There is no risk of building a wall that is too thin, as can happen with the traditional method.
3) The size and shape of the igloo is pre-determined. This eliminates the chance for an inexperienced builder to improperly size or shape an igloo.
Problems with Prior Art Slip Forms
The previously mentioned improvements are significant. However, prior art slip forms also introduce new problems or reinforce old problems: they promote wasted work by creating unnecessary internal volume, they promote wasted work because of the small dimensions of the slip form, enclosing the top of the structure becomes more difficult as the height increases, they can require significant practice to become proficient in their use, and they slow down the construction process.
There are several ways that the slip form described by U.S. Pat. No. 6,210,142 limits the rate at which an igloo can be built. In general, the rate is limited by how fast the form can be filled, packed, adjusted and repositioned. These steps are sequential and cannot be performed simultaneously to speed up the construction process
The volume of slip form 110 is a limiting factor on how fast an igloo can be created. A larger volume would allow the user to spend more time filling the form and less time manipulating the form. However, the length of the slip form is limited to a small fraction of the circumference of the penultimate layer of the igloo. This length limitation allows the upper layers to be created, but forces the igloo to be built from a large number of small blocks. The width of the form is limited to the wall thickness, and the height is limited to a practical block height. Thus the volume is constrained. Because slip form 110 is small it must be moved frequently. This frequent movement slows down the building process since blocks cannot be added to the structure during the movement process.
Focusing all labor on the small slip form inevitably causes a production bottle-neck. Two people cannot deliver snow to the form at the same time and snow cannot be delivered during the packing, adjusting, or repositioning steps. One person is dedicated to operating and packing the slip form from inside the igloo. At least one other person must gather snow from outside the perimeter of the igloo and deliver it to the slip form. Thus, at least two people are required to build the igloo, but taking full advantage of more than two people is difficult.
It is almost impossible for a single person to build an igloo using this method since the snow must be gathered from outside the igloo and the slip form must be manipulated and packed from inside the igloo. After the second row of blocks is completed, it becomes very difficult for a person to step over the wall without damaging it. At this point, the wall is too short for a door. In other words, the person manipulating the slip form is stuck inside the perimeter until the wall height becomes sufficient to cut a door.
Most of the snow that fills the slip-form must come from outside the igloo. This implies that more snow is required to create an equivalent interior volume when compared to a traditional igloo where the snow is excavated from the interior of the igloo. The requirement to bring the snow from outside the perimeter is caused by the center pivot point which must not be disturbed during the building process. Also, the interior snow quickly gets trampled down by the operator of the slip form. Once snow is compacted it is difficult to insert and pack into the slip form.
Difficulties are encountered as the height of the igloo wall increases. Functionally, the only open face of the slip form 110 is the top. The snow for each block must be loaded into this opening. The opening is relatively small because of the length and width limitations previously mentioned. Because of the small size of the opening, inserting snow into this opening is relatively difficult when the opening is horizontal. However, as the wall cants inward, the opening in the top of the slip form 110 also cants inward. This inward cant increases the difficulty of filling the slip form. The higher the wall, the more difficult this becomes. This difficulty is amplified because the snow is supplied from outside the perimeter of the igloo. The canted opening faces away from the person loading slip form 110 . Inevitably, a significant amount of snow will miss the opening and fall inside the igloo.
Enclosing the top of the structure is difficult using the method described by U.S. Pat. No. 6,210,142. There are two ways that this can be accomplished, but neither one is very effective. If the slip form is used “as is”, the opening to the form approaches a vertical orientation. The slip form is above the operator's head and is difficult to fill with snow. The other option is to disassemble the slip form and use only the inner surface that is attached to the rigid rod as a snow support. The slip form operator must hold the snow support surface and rod in position and the person outside the igloo must throw snow onto the surface. The person manipulating the remains of the slip form must work with it over his or her head and attempt to pack snow onto the form from a position where he or she cannot see the work in progress. The person delivering the snow must throw it accurately onto the partially disassembled slip form. Snow that misses the slip form will likely end up inside the igloo or fall on the slip form operator and causes wasted work.
U.S. Pat. No. 6,210,142 teaches the use of an adjustable length rigid pole that can be used to create an ellipsoidal shape. As the wall height increases, the length of the pole is increased in a controlled way. Due to the complexities of the adjustable rigid pole, four additional difficulties are encountered: 1) adjusting the rigid pole can be difficult while wearing gloves or mittens, 2) additional practice is required to become proficient at using this feature, 3) the act of adjusting the pole slows the construction process since blocks cannot be built during the adjustment time, and 4) the height of the structure is increased which amplifies the problem of enclosing the top.
Rigid rod 120 that extends from the pivot point creates an obstacle or a trip hazard. Bending, breaking, or otherwise damaging the pole by an operator stepping or falling on it renders the slip form inoperable.
These limitations inherent in the art taught by U.S. Pat. No. 6,210,142 force inefficiencies and imbalance into the build process and generally slow down the construction of an igloo.
Quinzhee Shelter
A quinzhee (or quinzee) is similar to an igloo, but the construction method is vastly different. Snow is gathered and compacted into a large mound. The mound is then hollowed out and the interior snow is discarded. As can be seen, a large amount of time and energy is wasted by gathering the snow, compacting it, and then discarding it. Only a small percentage of the snow gathered is used for finished shelter.
Snow Cave Shelter
A snow cave is similar to a quinzhee except that the snow is naturally deposited and compacted. While there are numerous methods of building a snow cave, they all require that the amount of snow equivalent to the volume of the cave be discarded. Once again, far more snow is moved than that which is required to build a structure such as a igloo. One other problem is finding an appropriate location with adequate snow depth for excavation.
SUMMARY OF PRIOR ART
Traditional igloos were originally created using only a block cutting tool. This was due to the lack of building materials. The only available construction method was to stack the blocks on each other. Many previous improvements in the art have focused on mimicking the same method of building substantially horizontal layers of blocks. Previous inventors have focused on improving various aspects of the individual block method. Removing the barrier of assembling small individual blocks in horizontal layers is a key to making greater improvements in the art. Another key to making improvements over the prior art is moving only the amount of snow that is necessary to build the structure and only moving it once.
The Need for Improvement
There is a great need for a device or method that fills the following requirements:
The device or method aids in the creation of a snow shelter without causing unnecessary or excessive physical effort and thus reduces the work required.
The device or method allows for the snow to be moved or lifted only once.
The device or method is simple and does not require much practice.
The device is easy to assemble, adjust, manipulate, and disassemble while the operator is wearing heavy gloves or mittens.
The device or method accurately and quickly guides the construction of an appropriate sized shelter.
The device or method helps create a shelter of a size and shape that meets to needs of the users and thus reduces the snow required to build the shelter.
The device or method generates a smooth interior surface to reduce rework and reduce the chance of water drops forming.
The device or method generates an exterior surface with few voids to take full advantage of the insulation qualities of the snow.
The device or method enables a single person to build an entire shelter.
The device or method promotes efficiency when multiple people use it simultaneously.
The device or method provides for a large working area and reduces the number of movements of the device.
The device or method does not restrict whether the snow is gathered from inside or outside the perimeter of the shelter.
The device is not a trip hazard or obstacle and thus reduces the chance of damage to equipment or injury to the operator.
The device or method promotes simplicity of construction, including enclosing the top of the shelter.
The device or method promotes rapid completion of the shelter.
The device or method helps ensure that adequate wall thickness is maintained.
The device is easily portable.
SUMMARY
In accordance with one embodiment, a method and apparatus are demonstrated for building a shelter from compacted snow or ice crystals where the basic shape of the shelter is a surface of revolution formed around a horizontal axis.
DRAWINGS
Figures
FIG. 1 is an isometric view of two rows of a traditional igloo (prior art).
FIG. 2 is a floor plan view of a circular igloo (prior art).
FIG. 3 is a floor plan view of a circular igloo (prior art).
FIG. 4 is an isometric view of two rows of an igloo (prior art).
FIG. 5 is an isometric view of three blocks (prior art).
FIG. 6 shows a prior art slip form.
FIG. 7 is an isometric view of a first embodiment of a snow shelter maker in its assembled form.
FIG. 8 shows a snow support assembly.
FIG. 9 shows an exploded view of FIG. 7 .
FIG. 10 shows a section view of a snow support assembly as defined by section line 10 - 10 in FIG. 8 .
FIG. 11 shows an isometric view of a first embodiment of an anchor.
FIG. 12 shows a first embodiment of an angle support.
FIG. 13 is a isometric view of an alternate use of components of a snow support assembly.
FIG. 14 shows the first step in construction of a snow shelter using the first embodiment of a snow shelter maker.
FIG. 15 shows the second step in construction of the shelter.
FIG. 16 shows the third step in construction of the shelter.
FIG. 17 shows the forth step in construction of the shelter.
FIG. 18 shows the fifth step in construction of the shelter.
FIG. 19 shows enlarged detail from FIG. 18 .
FIG. 20 shows the sixth step in construction of the shelter.
FIG. 21 shows the midpoint of the construction of the shelter.
FIG. 22 shows the first step of the construction of the second half of the shelter.
FIG. 23 shows an isometric view of a completed shelter.
FIG. 24 shows an axial view of a completed shelter.
FIG. 25 shows a section view of a shelter as defined by section line 25 - 25 in FIG. 24 .
FIG. 26 shows a section view of a shelter as defined by section line 26 - 26 in FIG. 24 .
FIG. 27 is an isometric view of a variation of a completed shelter.
FIG. 28 is an isometric view of a fortress built with a snow shelter maker.
FIG. 29 shows a view of an alternative embodiment of a completed shelter.
FIG. 30 shows a section view of the shelter defined by section line 30 - 30 in FIG. 29 .
FIG. 31 shows an axial view of the shelter shown in FIG. 29 .
FIG. 32 shows an isometric view of the completed shelter shown in FIG. 29 .
FIG. 33 is an exploded view of an alternative embodiment of a snow support.
FIG. 34 is an isometric view of an alternative embodiment of a snow support.
FIG. 35 is an isometric view of an alternative embodiment of a lower snow support.
FIG. 36 is an isometric view of a back-off mechanism.
FIG. 37 is an exploded view containing a back-off mechanism.
FIG. 38 is an isometric view of a back-off mechanism assembled to a snow support assembly.
FIG. 39 is a alternative embodiment of a snow support assembly.
FIG. 40 is an exploded view of the snow support assembly shown in FIG. 39 .
FIG. 41 is an isometric view of part of a snow support.
FIG. 42 is a detail view of part of FIG. 41 .
FIG. 43 is an isometric view of an alternative embodiment of a snow shelter maker and a partially completed shelter.
FIG. 44 is a cutaway view indicated by section line 44 - 44 in FIG. 43 .
FIG. 45 is an isometric view of a snow retainer assembly attached to the first embodiment of a snow shelter maker.
FIG. 46 is a close-up view of the snow retainer assembly shown in FIG. 45 .
FIG. 47 is an isometric view of a snow retainer assembly during construction of a shelter.
DRAWINGS
Reference Numerals
Overhanging edge 105
Slip form 110
Center anchor 115
Rigid rod 120
Snow support assembly 125
Snow support assembly 125 A
Snow support assembly 125 B
Snow support assembly 125 C
Snow support assembly 125 D
Lower snow support 126
Lower snow support 126 A
Lower snow support 126 B
Upper snow support 127
Apex snow support 128
Anchor 130
Bearing surface 131
Helical rib 132
Snow support retaining feature 133
Removal feature 134
Angle support 135
Cylinder 136
Cylinder 137
Exterior surface 140
Interior surface 145
Lateral surface 150
Lateral surface 150 A
Semi-circular end surface 155
Cylindrical bearing surface 160
Cylindrical bearing surface 160 A
Angle support penetration 165
Apex 167
Radius of curvature 170
Radius of curvature 170 A
Interior surface 171
Axis of rotation 175
Sled connector 181
Sled assembly 182
Snow 185 A
Snow 185 B
Snow 185 C
Snow 185 E
Snow 185 F
Snow 185 G
Flange 190
Back-off mechanism 195
Handle 200
Cylindrical bearing surface 202
Cylindrical bearing surface 205
Lateral pole 210
Lower lateral pole position 210 ′
Lower lateral pole position 210 ″
Lower lateral pole position 210 ′″
Spreader bars 215
Flexible surface member 220
Flexible surface member 220 A
Flexible surface member 220 B
Tubular sleeves 225
Rails 235
Snow retainer assembly 240
Snow retainer assembly 240 A
Tether 245
End cap 250
End cap 250 ′
End cap 250 ″
Straight section 255
Curved section 260
GLOSSARY
The following terms are defined for use in this application:
Curve: A predetermined, continuous, two-dimensional, concatenation of line segments and or arcs that has a beginning point and an end point.
Surface of revolution: A three-dimensional surface created by rotating a curve lying on a plane around a straight line (axis) that lies on the same plane. The term refers to any surface created by a predetermined angular rotation about the axis. The beginning and end points of the curve lie on the axis of rotation.
Horizontal surface of revolution: A surface of revolution formed around an axis of rotation that is generally horizontal.
DETAILED DESCRIPTION
First Embodiment
FIGS. 7 thru 13
FIG. 7 shows an assembled view of a first embodiment of my snow shelter maker. This embodiment includes a snow support assembly 125 , two anchors 130 , and an angle support 135 . FIG. 8 shows various features of the snow support assembly 125 . The snow support assembly 125 forms an elongated, generally convex shape that includes a smooth exterior surface 140 , an interior surface 145 , two lateral surfaces 150 that are generally parallel, and two semi-circular end surfaces 155 that join tangentially with the two lateral surfaces 150 . The semi-circular end surfaces are co-axial. The axis that joins them is axis of rotation 175 . The portions of the exterior surface adjacent to each of the semi-circular end surfaces are planar. The two planar portions are parallel to each other and perpendicular to axis of rotation 175 . There are two cylindrical bearing surfaces 160 that extend perpendicularly from the planar portion of the exterior surface 140 to the interior surface 145 . Each cylindrical bearing surface 160 is co-axial with the axis of rotation 175 . Each cylindrical bearing surface 160 corresponds to bearing surfaces 131 of FIG. 11 . Apex 167 is the point or set of points (i.e. in this embodiment, an arc) farthest from axis of rotation 175 . Near apex 167 there are two angle support penetrations 165 . One angle support penetration is near the upper lateral surface 150 and the other is near the lower lateral surface 150 . Each angle support penetration connects the interior surface 145 to the exterior surface 140 . The snow support assembly forms a structure that is capable of supporting a snow load placed on the exterior surface.
FIG. 9 is an exploded view of FIG. 7 . Snow support assembly 125 comprises two identical lower snow supports 126 and two identical upper snow supports 127 . Each lower support is connected to an upper support and the upper supports are connected together at apex 167 . The method of connection shown is a common peg-and-hole method, but other methods known in the art also work. Each end of the snow support assembly is rotationally connected to one anchor 130 by way of cylindrical bearing surfaces 160 . Angle support 135 is inserted into lower angle support penetration 165 .
FIG. 10 is a section view, defined in FIG. 8 of snow support assembly 125 . The section cut is created by a plane that is perpendicular to the axis of rotation 175 . The radius of curvature 170 of the exterior surface 140 represents the curvature of the exterior surface 140 at all locations of that plane along the axis of rotation 175 unless exterior surface 140 at that location is planar and perpendicular to the axis of rotation.
FIG. 11 shows one embodiment of an anchor. Anchor 130 is embedded in snow and is used to limit the motion of the snow support. Two anchors, placed co-axially, constrain snow support assembly 125 ( FIG. 8 ) to one degree of freedom (i.e. rotation around axis of rotation 175 ). The pair of anchors establishes a generally horizontal axis of rotation.
The diameter of bearing surface 131 is slightly smaller than the diameter of cylindrical bearing surfaces 160 ( FIG. 9 ) in the snow support assembly and rotationally connects the snow support assembly to the axis of rotation and allows for smooth rotational motion.
Anchor 130 has snow support retaining feature 133 to prevent the snow support from becoming detached from the anchor while the anchor is fixed to the snow.
The anchor has a retention feature that holds the anchor in the snow until the operator is ready to remove it. In this embodiment, the retention feature is helical rib 132 formed on a tapered cone. Helical rib 132 prevents the anchor from sliding axially through the snow. In this embodiment, removal features 134 in the snow support retaining feature 133 facilitate removal of the anchor from the snow by creating a feature with which the operator can twist the anchor.
FIG. 12 shows one embodiment of angle support 135 . It comprises two co-axial cylinders of different diameters. The larger diameter cylinder 136 forms a handle that is easy to grasp while the operator is wearing gloves. The smaller diameter cylinder 137 is inserted in the lower of the two angle support penetrations 165 ( FIG. 9 ). The difference in diameter prevents the angle support from being inserted too far. Angle support 135 also serves as a gauge to ensure that adequate wall thickness is maintained. The overall length of the angle support is the minimum acceptable wall thickness (See FIG. 16 ).
FIG. 13 shows sled assembly 182 that can be formed from the pair of lower snow supports 126 . The two lower snow supports are placed side-by-side with exterior surfaces 140 facing down. Sled connector 181 is attached near the semi-circular end surfaces 155 . A second sled connector 181 is attached at the opposite end of the lower snow supports and completes the sled. The method of connection is not shown, but is known in the art. A rope or other similar member (not shown) is attached to sled assembly 182 . The assembled sled aids in transportation of the remaining components of the snow shelter maker and any other gear or items that the operator might wish to place on the sled. Attach points, not shown but known in the art, are envisioned on the lower snow supports 126 and sled connectors 181 to secure the load and prevent the load from departing the sled during transportation.
Operation
First Embodiment
FIGS. 14 thru 23
FIG. 14 shows the first embodiment of the snow shelter maker assembled, positioned on the ground, and ready for construction of a shelter to begin. Angle support 135 is not installed since the snow support assembly is supported by the ground.
FIG. 15 shows the first step in building a shelter using the snow shelter maker. Snow 185 A is firmly packed around the portion of each anchor 130 that protrudes past exterior surface 140 of snow support assembly 125 so as to rigidly fix each anchor to the surface upon which the shelter is to be built. Fixing the anchors constrains the snow support assembly so that it can only rotate around axis of rotation 175 .
FIG. 16 illustrates the next step in the construction process. Snow 185 B is packed along the entire exterior surface of the snow shelter maker, to a height equivalent to the upper lateral surface 150 of the snow support. Angle support 135 is used as a gauge to ensure that adequate thickness of the shelter wall is maintained throughout construction.
FIG. 17 shows the next step in creating the shelter. Snow support assembly 125 is rotated around axis of rotation 175 so that lower lateral surface 150 , at apex 167 is placed approximately where upper lateral surface 150 was previously located. Rotation of the snow support is facilitated because the center of the radius of curvature 170 ( FIG. 10 ) of the exterior surface is coincident with axis of rotation 175 . Snow 185 B does not trap the snow support.
FIG. 18 and FIG. 19 show how angle support 135 is inserted into lower angle support penetration 165 . The portion of angle support 135 that extends beyond exterior surface 140 of the snow support is placed on or embedded in snow 185 B. This prevents rotation of snow support assembly 125 . In other words, angle support 135 sequentially restrains snow support 125 to a series of predetermined angular orientations around axis of rotation 175 .
FIG. 20 shows how snow 185 C is once again piled and packed around the exterior perimeter of the snow support and on top of the previous layer of snow 185 B.
Once the snow is packed to the height of the snow support, angle support 135 is removed and the snow support assembly 125 is moved to its next position and angle support 135 is replaced. This cycle is repeated until the snow support assembly 125 reaches a generally vertical orientation and the first half of the shelter is finished.
FIG. 21 shows the completed first half of the shelter with snow support assembly 125 in a vertical orientation. The completed half of the shelter is called end cap 250
FIG. 22 shows the snow support assembly 125 positioned to begin the second half of the shelter. The steps for completing the first half of the shelter are repeated until the second half of the shelter is complete.
FIG. 23 shows a completed shelter. It is made of two end caps 250 . The door to access the interior of the shelter is not shown, but would normally be cut into the completed first half of the shelter sometime between the steps shown in FIG. 21 and FIG. 23 .
Features of shelters created with the first embodiment of the snow shelter maker— FIGS. 24 thru 28
Some of the features of shelters completed with the first embodiment of the snow shelter maker will be discussed next.
FIG. 24 shows a view along axis of rotation 175 of the completed shelter. This view shows that as long as the anchors are not moved during the construction process and the wall thickness is constant, the exterior shape of this view will be semi-circular. This is because the shelter is a surface of revolution around axis of rotation 175 .
As a result of radius of curvature 170 ( FIG. 10 ) of the snow support assembly, interior surface 171 of the shelter is generally smooth and free of most defects. Thus fewer water drops are likely to form and fall on the occupants.
FIG. 25 is a section view of a shelter as defined by section line 25 - 25 in FIG. 24 . It shows the snow support assembly in a vertical orientation. This view shows that this cross sectional shape of the shelter follows the shape of the snow support. This view of the snow support assembly will be referred to as the profile. As will be shown in later embodiments, the profile of the snow support assembly can vary widely, according to the desired embodiment of the snow support.
When construction is finished, the anchors 130 are removed by rotating the anchors around axis of rotation 175 . Because helical rib 132 ( FIG. 11 ) is formed on a tapered cone, anchor 130 will pull free after several revolutions. Snow support assembly 125 is disassembled, and the snow shelter maker is removed from the interior of the shelter.
FIG. 26 is a section view defined by section line 26 - 26 of FIG. 24 . It shows the floor plan of the shelter. The floor plan will vary according to the profile of the snow support. The representation of occupants shows how this floor plan is tailored to fit the occupants and reduce unusable space.
FIG. 27 is an isometric view of a variation of a shelter built with the same embodiment of the snow support assembly as used to construct the shelter in FIG. 23 . However, the process was varied substantially to create this variation. End cap 250 was created using the steps described in FIGS. 15 thru 21 . However, instead of continuing with the step demonstrated in FIG. 22 , the anchors and snow support assembly were moved a distance equal to the width of the snow support assembly and the snow support assembly was secured in a vertical orientation. Snow was packed around the perimeter of the snow support assembly. The anchors were then moved again as described. These steps were repeated until straight section 255 was created. Curved section 260 was created in a similar manner as straight section 255 except that one anchor was consistently moved less than the width of the snow support assembly and less than the other anchor. This generates a curved section. The curved section was then terminated with end cap 250 ′ as described previously in FIGS. 22 and 23 . (End cap 250 ′ is identical to end cap 250 and is used only for identification purposes within the drawing.)
Straight or curved sections should only be created by this method when the profile of the snow support is a self supporting shape. Profiles that contain large, significantly horizontal, sections should not be used. End cap 250 ″ was created after straight section 255 was created. (End cap 250 ″ is identical to end cap 250 and is used only for identification purposes within the drawing.) This creates a room or alcove off of the structure that it is attached to. The snow shelter maker was placed so as to intersect the existing structure. An aperture (not shown) is cut through the side of straight section 255 to allow access to the interior of 250 B. Snow 185 G might have to be manually placed if the snow support assembly will not rotate far enough to touch portions of the existing structure.
This representation of a shelter demonstrates one of the infinite number of structures that can be created by intentionally moving the anchors during the construction process. Children and youth will likely enjoy building and playing in such unusual structures.
FIG. 28 shows another use. A partially finished structure could be used as a fortress or a defensive structure for snowball fights that children and youth often engage in. A youth is represented in the figure for size comparison.
Description
Alternative Embodiment
FIGS. 29 thru 32
FIGS. 29 thru 32 show four different views of a shelter created with an alternative embodiment of a snow support assembly (not shown). These views demonstrate how a different snow support assembly profile will affect the overall shape of a shelter and its floor plan. The snow shelter maker is not restricted to any particular shape. Instead, different profiles allow the user to choose a snow shelter maker that is optimized for his or her requirements.
FIG. 29 demonstrates a non-traditional profile for a shelter. Notice how the ceiling height is greatest above the head of the occupants. Focusing the volume in this portion of the shelter may be advantageous—this is where an occupant would sit up, enter into a sleeping bag, and do many other activities inside the shelter. Likewise, the volume around the feet of the occupants is reduced. That is the location where very little activity is likely to occur.
FIG. 30 shows the floor plan of the shelter shown in FIG. 29 . Notice how much of the extra floor space is within reach of the occupants. Once again this non-traditional floor plan focuses the space where it is most useable.
FIG. 31 shows the view along axis of rotation 175 . The semi-circular shape reminds the reader that this is a surface of revolution.
FIG. 32 shows an isometric view of the unusual, non-traditional shape of this embodiment of the shelter. The ability to create many different shapes is possible because rotation around a horizontal axis creates a semi-circular cross section ( FIG. 31 ) which is a self supporting shape.
Description
Alternative Embodiment
FIG. 33
FIG. 33 demonstrates how apex snow support 128 can be inserted between the two upper snow supports 127 of snow support assembly 125 ( FIG. 9 ) to create yet a different floor plan. This addition creates snow support assembly 125 A. This embodiment converts a two-person snow shelter maker into a three-person shelter maker. The function of the snow support assembly 125 A is identical to snow support assembly 125 .
Description
Alternative Embodiment
FIG. 34
FIG. 34 shows snow support assembly 125 D, an alternative embodiment of a snow support assembly. Lateral surfaces 150 A of this embodiment are not parallel. They are at maximum separation at apex 167 and transition to minimum separation near the cylindrical bearing surfaces 160 . This embodiment reduces the weight of the shelter maker and facilitates transportation when a method other that the previously mentioned sled is desired. The function of the snow support assembly 125 D is identical to snow support assembly 125 . Snow support assembly 125 D can be disassembled into multiple pieces (not shown) to aid in transportation. The number of pieces is not important. Disassembly is typical of all embodiments of the snow support assembly.
Description
Alternative Embodiment
FIG. 35
FIG. 35 shows an alternative embodiment of a lower snow support. It combines the functions of anchor 130 ( FIG. 11 ) and lower snow support 126 ( FIG. 9 ) into lower snow support 126 A. Lower snow support 126 A is identical to lower snow support 126 except that circular flange 190 has been added and cylindrical bearing surface 160 does not need to be present. Circular flange 190 is concentric with semi-circular end surface 155 . Packing snow around all sides of flange 190 effectively fixes lower snow support 126 A to the ground while still allowing rotation around axis of rotation 175 .
Flange 190 is shown on the interior surface 145 of the lower snow support. However, it is possible to place flange 190 on either the interior or exterior surface, or on both surfaces at once. If flange 190 is placed on the exterior surface, accommodations would have to be made if the lower snow support is to function as a sled. One significant advantage of this embodiment is that fewer parts are required. Reducing the part count reduces the chance of losing a part in the snow. It may also reduce manufacturing costs.
Description
Alternative Embodiment
FIGS. 36 , 37
FIG. 36 shows back-off mechanism 195 . This embodiment comprises two cylindrical, parallel, non-concentric bearing surfaces and a handle 200 for rotating the mechanism. The smaller cylindrical bearing surface 202 is the corresponding bearing surface for anchor 130 ( FIG. 11 ). The larger cylindrical bearing surface 205 is the corresponding surface for cylindrical bearing surface 160 A ( FIG. 37 ) of snow support assembly 125 C ( FIG. 37 ).
FIG. 37 shows an exploded view of how the back-off mechanism is assembled to one embodiment of a shelter maker. Snow support assembly 125 C is the same as snow support assembly 125 ( FIG. 8 ) except that cylindrical bearing surface 160 A in this embodiment is larger in diameter to accommodate larger cylindrical bearing surface 205 . Anchor 130 passes through back-off mechanism 195 and through snow support assembly 125 C.
Operation
Alternative Embodiment
FIG. 38
FIG. 38 shows back-off mechanism 195 assembled to snow support assembly 125 C and anchor 130 . It also shows the motion of the snow support assembly when back-off mechanism 195 is rotated 180 degrees. When anchor 130 is fixed by snow, rotating the back-off mechanism by 180 degrees translates the snow support assembly a distance equal to twice the offset of the two cylindrical bearing surfaces 202 and 205 ( FIG. 36 ). This causes apex 167 (see FIG. 8 ) of the snow support assembly to translate toward or away from the snow that has been packed around the exterior surface of the snow support. This motion allows a snow support assembly to be pulled free from packed snow and rotated to a new position.
Translating the apex 167 toward the snow after rotating the snow support prepares the device for the next layer. Back-off mechanism 195 can be used in conjunction with most embodiments of the snow support assembly but is most useful for those that do not have radius of curvature 170 described in FIG. 10 .
Description
Alternative Embodiment
FIGS. 39 thru 44
FIG. 39 shows another embodiment of a snow support assembly.
FIG. 40 is an exploded view of the snow support assembly shown in FIG. 39 . It comprises two lateral poles 210 , a plurality of spreader bars 215 , a flexible surface member 220 , two lower snow supports 126 B, and tether 245 . Lateral poles 210 could be of the flexible, shock-cord type of poles known in the art of camping tents. They could also be of the rigid form known in the art of camping tents. Spreader bars 215 are compression members that force lateral poles 210 apart which causes flexible surface member 220 to remain in a state of tension. This provides the necessary structural rigidity to support a snow load. Lateral poles 210 are connected to lower snow supports 126 B. Tether 245 is a tension member that connects the two lower snow supports together when flexible lateral poles 210 are used. The tether holds lower snow supports 126 B in the correct relative position until anchors 130 (see FIG. 43 ) can be fixed in snow. After fixing the anchors to the surface, the tether is removed so as not to be a trip hazard.
FIG. 42 is a detail of FIG. 41 and shows how lateral poles 210 are inserted in tubular sleeves 225 that are formed along the lateral edges of flexible surface member 220 . If necessary, additional poles (not shown) could also be integrated into this embodiment to add strength to the structure.
FIG. 43 shows snow support assembly 125 B rotationally connected to back-off mechanism 195 . Back-off mechanism 195 is rotationally connected to anchor 130 . Snow 185 E is packed around snow support assembly 125 B.
FIG. 44 is a section view defined by section line 44 - 44 in FIG. 43 . This view shows how to use a snow support assembly that has an exterior surface that does not conform to the radius of curvature 170 of FIG. 10 . In this embodiment, snow support assembly 125 B has a flexible surface member 220 that does not rigidly conform to radius of curvature 170 . Snow 185 F (a subset of snow 185 E) has been packed around snow support assembly 125 B such that lower lateral pole 210 cannot directly rotate to lateral pole position 210 ′″, as shown by radius of curvature 170 . When back-off mechanism 195 is rotated 180 degrees, snow support assembly 125 B translates such that lateral pole 210 moves to position 210 ′. At this point, radius of curvature 170 A shows that lateral pole position 210 ′ is clear of snow 185 F. Snow support assembly 125 B is rotated such that lateral pole 210 ′ moves to position 210 ″. After rotation of snow support assembly 125 B, back-off mechanism 195 is returned to its original position, which moves lateral pole 210 ″ to position 210 ′″. Construction of the next layer of snow may now continue. The operation of this embodiment is similar to the operation of the first embodiment except that snow support assembly 125 B must be retracted from the packed snow before it can be rotated to a new position. Failure to back-off a snow support that is trapped by snow 185 F can cause cracking of the packed snow. While these cracks in the shelter are often self healing, they can also cause portions of the unfinished shelter to collapse.
When disassembled, the compact nature of this embodiment may be of sufficient benefit to the user to make the additional steps required in building a shelter acceptable.
The inside surface of a shelter created with this embodiment will not have as smooth of a surface as that created by the first embodiment. Once again, the compact nature of this embodiment may outweigh the benefit of having a smoother interior surface.
Description
Alternative Embodiment
FIGS. 45 thru 47
FIG. 45 demonstrates how a snow retainer assembly 240 can be added to snow support assembly 125 .
FIG. 46 shows snow retainer assembly 240 attached to upper snow support 127 . Similar snow retainer assemblies are envisioned surrounding the entire perimeter. This embodiment of snow retainer assembly 240 includes a flexible surface member 220 A attached to rails 235 that are attached to upper snow support 127 . The method of attachment is known in the art.
The function of snow retainer assembly 240 is to contain certain types of snow such as dry power that otherwise might be difficult to compact. The flexible surface member 220 A is attached to rails 235 in such a way that it can be moved to a plurality of positions between two primary positions—parallel to the exterior surface of snow support assembly 125 (as shown in FIG. 45 ) or perpendicular to the exterior surface of the snow support assembly 125 (as shown in FIG. 47 ). These two primary positions are useful during different stages of construction. When the orientation of the snow support assembly is generally horizontal, placing the flexible surface member in the parallel position is desirable ( FIG. 45 ). When snow support assembly 125 approaches a vertical orientation, the perpendicular position for flexible surface member 220 A is desirable ( FIG. 84 ). This keeps the snow from falling over the lateral edge of the snow support assembly until the snow is compacted.
Flexible surface member 220 A would likely include multiple elastomeric cords or other methods known in the art to help it maintain an appropriate shape. In addition to the function of containing powdered snow prior to compaction, snow retainer assembly 240 has the added function of ensuring proper wall thickness.
Rails 235 are removable from snow support assembly 125 and reversible so that the snow retainer assembly can be used on either lateral side of snow support assembly 125 . Snow retainer assembly 240 could be built in individual segments, as shown, or in segments such as snow retainer assembly 240 A that extend over a larger area, including the entire perimeter. Additional flexible surface members 220 B can be added to various locations around the perimeter during stages of construction to better contain loose snow.
Advantages
From the various embodiments of my snow shelter maker and from the method described, the following improvements become evident:
Physical effort is reduced during the construction process. Difficult work positions are avoided and the amount of snow that must be moved is reduced. Snow is moved or lifted only once. The embodiments and method are simple to use and do not require much practice. The embodiments are easy to assemble, adjust, manipulate, and disassemble while the operator is wearing heavy gloves or mittens. The embodiments accurately and quickly guide the construction of an appropriate sized shelter. The shelter is sized and shaped to meet the needs of the users and thus reduces the snow required to build the shelter. The shelter will have a smoother interior surface. Less rework is required and the chance of water drops forming is reduced. The shelter will have an exterior surface with few voids to take full advantage of the insulation qualities of the snow. It is possible for a single person to build an entire shelter. Multiple people can work on a shelter simultaneously. The number of sequential steps is reduced. Most of the work can be performed simultaneously. Snow can be added to the shelter even while the snow support assembly is being rotated. A large working area is provided which reduces the number of movements of the embodiments. Snow may be gathered from inside or outside the perimeter of the shelter. The embodiments reduce trip hazards or obstacles and thus reduce the chance of damage to equipment or injury to the operator. The embodiments and method promote simplicity of construction, including finishing the top of a shelter. The embodiments and method promote rapid completion of a shelter. The embodiment and method help ensure that adequate wall thickness is maintained. The embodiment is easily portable.
CONCLUSION, RAMIFICATIONS, and SCOPE
Thus the reader will see that at least one embodiment of the snow shelter maker provides a faster and easier way to create a snow shelter. The embodiment also requires less work and less experience than prior art methods. Significant variations are envisioned that allow the snow shelter maker to be tailored to the needs and desires of the individual user.
While this apparatus and method are capable of creating a shelter of the traditional igloo shape, it is not limited to that shape but rather it is capable of many other variations and demonstrates many improvements in the art of building snow shelters.
As has been demonstrated, many different embodiments are envisioned. Other embodiments are envisioned in shape, material, color, secondary use, and form.
The components of the snow shelter maker can be made of many different materials and from many different manufacturing methods. For example, a metallic frame structure with a plastic or cloth skin attached functions properly as a snow support. A composite structure made of fiber reinforced plastics encasing foam or other light-weight core material also functions properly as a snow support assembly. The components can be made from injection-molded or blow-molded plastics. Numerous other materials and construction methods known in the art would also function properly.
Desirable qualities of the exterior surfaces include materials or coatings that are hydrophobic. A desirable surface or coating has a low coefficient of friction in relation to snow.
A bright color, such as red or orange, is desirable for all components of the snow shelter maker to help prevent any components from being lost in the snow. Some consumers, however, may prefer camouflage type coloring. Other colors may meet yet other needs of various consumers.
A cloth or plastic cover or envelope is envisioned for uses with the snow support assembly. The combination would function as a tent or shelter in the absence of adequate snow or when time does not allow for the building of a snow shelter.
Various embodiments have been shown for anchor 130 . Others are envisioned that perform equivalent functions even though the physical embodiments vary significantly.
Other embodiments of angle support 135 are envisioned and may include ratcheting devices known in the art that allow the snow support assembly to rotate one direction around the axis of rotation but prevent rotation in the opposite direction. The location of such a ratcheting device could be located near and function in conjunction with an embodiment of an anchor, or, the ratcheting device could be located away from the axis of rotation and react against the previously compacted snow or the surface of construction. Another embodiment involves an extensible pole that would react against the compacted snow. Envisioned embodiments would be easily reversible so that the second half of the shelter could be formed.
Alternative embodiments of back-off mechanism 195 are also envisioned. Embodiments include combining the retraction/extension function in either the anchor or the snow support. If combined as part of a snow support assembly, the back-off function could be used with alternative embodiment of lower snow support 126 A. One way of achieving this would be to incorporate the retraction/extension function of the mechanism at the joints between components of a snow support assembly.
Another envisioned embodiment involves creating a predetermined snow support surface that does not extend from anchor to anchor, but rather it is moved along a support structure that extends from anchor to anchor. The support structure would be rotated around the anchors just as snow support assemblies are in previous embodiments. While this embodiment may be compact, it has the disadvantage of requiring more manipulation by the user and thus slows down the construction process.
The embodiments shown are intended to demonstrate functionality. They have not necessarily been optimized for simplicity, manufacturing ease, manufacturing cost, or any other parameters desirable to the consumer, such as reduced weight. The functionality of each embodiment and components thereof may also be combined or separated in a variety of methods, some of which have been demonstrated.
The relative importance of the different advantages of the various embodiments would be determined by the user.
While my above description contains many specificities, these should not be construed as limitations on the scope, but rather as an exemplification of several preferred embodiments thereof. Many other variations are possible.
Accordingly, the scope should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents. | A method and apparatus for constructing a snow shelter are disclosed. A slip form allows snow or ice crystals to be compacted in situ in large continuous blocks. Each block is built upon the previous as the slip form is rotated incrementally around a generally horizontal axis ( 175 ). The slip form is a convex shape. The convex shape, or profile, is tailored to the size and shape of the shelter desired. The resulting shape of the snow shelter is a surface of revolution of the profile of the slip form around a horizontal axis. Variations of the shelter's shape are explained herein. Various embodiments are described herein. Some of the advantages of the embodiments include: faster and more efficient construction, simple operation, and tailored size and shape of the finished shelter. | 4 |
This application is a continuation in-part of application Ser. No. 216,342, filed Jan. 10, 1972, now abandoned.
BACKGROUND OF THE INVENTION
Conventional circular knitting machines include a rotary needle cylinder which may carry a plurality of magnetically actuable jacks or rocking pressers that transmit motion to the needles. The desired pattern to be manufactured is controlled by a coded punched tape or similar program carrier which outpulses knitting and non-knitting commands in the form of impulses to an actuating electromagnet. In the type of machine of particular interest in the instant application, the magnetic field of such electromagnet cooperates in a differential manner with that of a permanent magnet.
In this arrangement, the permanent magnet normally acts on the magnetic portions of successively engageable rocking pressers, which move close to the permanent magnet by the help of a cam. Said magnet attracts and holds such presser against a restoring force thereby situating such presser in a non-knitting position. When a knitting command is outpulsed from the coded tape, the electromagnet is actuated to weaken the attraction force of the permanent magnet so that the rocking presser can move in the direction of the restoring force to a knitting position to operate the associated needle.
In presently known arrangements of this type, such as disclosed in Ribler U.S. Pat. No. 3,605,448, the coil of the electromagnet is generally wound around one soft iron pole piece of the permanent magnet as well as around the core of the electromagnet so that the fields of the permanent magnet and the electromagnet are strongly coupled. It has been found that this scheme is highly inefficient, since the actuation of the electromagnet not only markedly weakens the magnetic field in the pole pieces of the permanent magnet but also serves to change the point of the non-linear B-H curve of the permanent magnet at which such magnet operates. The result of such change is a significant increase in the reluctance of the composite magnetic circuit of the electromagnet, the permanent magnet and the rocking presser, which in turn increases the amount of magneto-motive force necessary to support an actuating flux level in the jack. Accordingly, an unsatisfactory high degree of loading is imposed on the driving circuitry for the actuator.
SUMMARY OF THE INVENTION
Such unsatisfactory high degree of loading imposed on the driving circuitry for the actuator in presently known arrangements of the above-described type is overcome with the mounting arrangement for the actuator constructed in accordance with the invention for use, e.g., in a circular knitting machine. In general, the electromagnet is provided with a magnetic core separate and apart from the pole structure of the permanent magnet, with the pole structure and the core having individual air gaps.
The permanent magnet normally acts on the magnetic portions of successively engageable rocking pressers, which move close to the permanent magnet with the help of a cam. The permanent magnet attracts and holds such presser against the restoring force thereby situating such presser in a non-knitting position. When a knitting command is out-pulsed from the coated tape, the electromagnet is attracted to weaken the attraction force of the permanent magnet so that the rocking presser can move in the direction of the restoring force to a knitting position to operate the associated needle. The permanent magnet and the electromagnet are disposed with their air gaps mounted coaxially with respect to the line of action of the restoring force acting on the jack. The pole structure of the permanent magnet and the core of the electromagnet are spaced from each other and oriented so that their magnetic fields intersect only in a first portion of the rocking presser, while at any other point they do not affect each other.
The basic difference between FIG. 4 of the above Ribler patent and the present invention lies in that in Ribler the coils directly control the flux generated by the permanent magnet. By way of contrast, the present invention is concerned with two independent magnetic circuits, that is, the field of the permanent magnet and the field of the electromagnet, each acting on a rocking presser.
In the mechanism disclosed in the Ribler U.S. Pat. No. 3,605,448 the coils 5, 5' do not control the flux generated by the permanent magnet 1, nor would this be desirable from the functional point of view. Instead, electromagnetic flux is generated to substitute for the lacking permanent magnetic flux in the area of the air gaps 9, 9', in the area of which the very selection takes place. The principle of the Ribler mechanism differs markedly from that of the present invention wherein the magnetic flux generated by the permanent magnet keeps acting throughout the selecting action and is controlled and displaced from the controlled member by electromagnetic flux.
The resulting relatively low reluctance of each separate magnetic path through the rocking presser lowers the total magnetomotive force required to drive the actuating flux through the rocking presser. The first portion of the rocking presser may be recessed to concentrate the flux passing therethrough, to further reduce the amount of driving force required.
In a first form of the invention, the pole structure of the permanent magnet is mounted within the core of the electromagnet, with the pole structure and the core being aligned and similarly oriented. Such air gaps are mutually spaced in the axial direction of movement of the rocking presser, so that the directions of the magnetic fields of the permanent magnet and the electromagnet within the first portion of the rocking presser are substantially perpendicular.
In a second form of the invention, the permanent magnet is mounted outside the core of the electromagnet with the pole structure and the core being aligned but oppositely oriented. The rocking presser is positioned intermediate the air gaps. If desired, both the rocking presser and the permanent magnet may be mounted on the periphery of the circular bed of the machine, while the electromagnet is situated in radially spaced relation to such periphery.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be further set forth in connection with the following detailed description taken in conjunction with the appended drawing, in which:
FIG. 1 is a perspective view of a permanent magnet of the type used to keep the rocking presser of the circular knitting machine which has been moved close to the magnet with the help of a cam, in a non-knitting position against a restoring force;
FIG. 2 is a diagram partially in side elevation and partially in section, of the first form of mounting arrangement in accordance with the invention for situating the pole structure of the permanent magnet of FIG. 1 within a separate core of a separate electromagnet;
FIG. 3 is a diagrammatic view of a permanent magnet-electromagnet assembly constructed as in FIG. 2 and mounted opposite the periphery of a jack-carrying circular bed of the machine;
FIG. 4 is a diagram similar to FIG. 2, illustrating an alternative means for establishing a minimum separation of the jack from the pole structure of the permanent magnet;
FIG. 5 is a diagram of a second form of mounting arrangement in accordance with the invention, in which the pole structure of the permanent magnet is disposed outside the core of the electromagnet;
FIG. 6 is a diagrammatic view of a permanent magnet-electromagnet assembly constructed in a manner similar to FIG. 5 but with the permanent magnet and the jacks disposed on the moving circular bed of the machine and the electromagnet radially spaced from the periphery; and
FIG. 7 is a view similar to FIG. 2 but showing the north and south poles of the permanent magnet and the electromagnet, and the magnetic fields of the two magnets.
DETAILED DESCRIPTION
As indicated above, the improved mounting means of the invention is useful primarily in the context of the magnetic rocking presser actuator for a circular knitting machine in which the magnetic fields of a normally unexcited electromagnet and a permanent magnet cooperate. The permanent magnet, together with a cam which moves the presser close to the permanent magnet and the restoring force caused by the flexibility of the jack, cooperate to selectively position the presser on the periphery of the machine between a knitting and a non-knitting position.
Since the structure and operation of the rotary needle cylinder of such machine and the manner in which the jacks thereon are selectively positioned by the actuator are well-known to those skilled in the art and form no part of the invention, they will not be described further except where specifically relevant.
The whole assembly, comprising the permanent magnet with pole shoes, the electromagnet with pole shoes and the coil, is embedded in artificial resin so that after hardening and taking out of the mold it constitutes a self-supporting assembly which is placed into the holders in cam blocks associated with the neddle cylinder. Such holders are not part of the invention. For simplicity of illustration the hardened resin of the assembly has been omitted in the various figures of the drawing.
The permanent magnet portion of an actuator of the type just described is shown in FIG. 1. The magnet, designated by the numeral 1, includes a central magnetic member 2 which interconnects a pair of elongated pole pieces 3 and 4 which converge at their forward ends to define a first air gap 5. The magnet 1 exerts an attractive force (designated Pm in FIG. 3) in an axial direction, represented by a line 6, on a jack or rocking presser 7 of magnetically reactive material which may be associated at its forward end (not shown) with a suitable needle on the periphery of the above-mentioned circular knitting machine. The attractive force Pm acts against an oppositely directed axial force Pr which may represent the restoring force caused by the flexibility of the rocking presser which is suitably formed so that it may act as a spring. In normal operation the attractive force Pm is greater than the restoring force Pr so that the rocking presser 7, moved close to the permanent magnet by the help of a cam 18, is normally kept in this position being attracted by the magnet 1 in the absence of suitable constraints of the type described below.
In accordance with the first embodiment of the invention, the permanent magnet 1 is disposed within a separate, generally U-shaped core structure 8 (FIG. 2) of an electromagnet 9 to form the composite magnetic actuator designated generally by 10. The forward ends of the core 8 converge to define a relatively large second air gap 11 through which the rear end of the rocking presser 7 may reciprocate axially. The rear end of the air gap 11 and the front end of the air gap 5 are axially separated by a distance D. As shown, the core 8 and the pole structure 3 and 4 are similarly oriented with respect to the line 6. The respective outer surfaces of the pole structure 3 and 4 and the adjacent inner surfaces of the core 8 are each radially separated by a spacing T.
The electromagnet 9 further includes a coil 12 surrounding the rear end of the core 8. Terminals 12A of the coil 12 may be coupled to conventional driving circuitry (not shown) for the actuator.
The rear end of the rocking presser 7 is provided with a centrally located recess 13 coaxial with the air gaps 5 and 11. The recess 13 defines a third air gap within which the magnetic fields of the electromagnet and the permanent magnet intersect. In order to present impact between the rear end of the rocking presser 7 and the pole pieces 3 and 4, a standoff member 14 which may be made of a relatively hard material such as sapphire extends axially from the air gap 5 in a forward direction in alignment with the recess 13 to limit the rearward motion of the rocking presser 7. The length of the member 14 is chosen to maintain a spacing S between the forward end of the pole pieces 3 and 4 and the rear end of the rocking presser 7. It has been found advantageous to make the distance S less than the distance D between adjacent ends of the air gaps 5 and 11 in order to accelerate the movement of the rocking presser 7 in the forward direction when the force Pr exceeds the attraction force Pm, e.g., upon the excitation of the coil 12 as indicated below. If desired, the member 14 may be provided with a guiding surface for the recess 13 to help center the rocking presser 7 during reciprocation along the line 6.
It will be noted from the above description from FIG. 7 that the permanent magnet 1 and the electromagnet 9 of the magnetic actuator 10 are mutually disposed so that the magnetic fields established in each do not interfere with the magnetic structure of the other. The magnetic fields provided by each of such magnets intersect only within the rocking presser 7 and, in the arrangement shown in FIG. 7, are mutually perpendicular only in the region of intersection. Because the magnetic fields are perpendicular to each other only at every point where they enter into the controlling part of the knitting machine, the driving circuitry for the actuator operates at relatively high efficiency. In the region of encounter the two magnetic fluxes are, of course, parallel, but of opposite directions so that they compensate each other. This permits the driving circuitry for the actuator to operate at relatively high efficiency.
An actuator 10 of the type illustrated in FIG. 2 is shown in FIG. 3 and is disposed radially with respect to the periphery of a rotary needle cylinder bed of a circular knitting machine. It is assumed that the surface of the rotary needle bed with needles and rocking pressers move in the direction of an arrow 17 and that each successive rocking presser is urged by a cam section 18 toward the actuator 10. The rocking presser moves in the same track with the corresponding needle. The part 18, which is shown in FIGS. 3 and 6, is a part of a stationary cam, while the needles and the rocking pressers move with the rotary needle bed. A prior art machine which incorporates this cam and needle cylinder arrangement is disclosed in U.S. Pat. No. 3,771,332 co-assigned to the assignee of the present application.
While the coil 12 remains deenergized, each rocking presser 7 is attracted toward the permanent magnet 1. As the rocking presser reaches the position defined by the line 6, a knit or no-knit decision is made by a suitable program controller 19. If a knit command is outpulsed from the controller 19, the coil 12 will remain unexcitec and the rocking presser will remain attracted to the permanent magnet 1. On the other hand, if a no-knit command is outpulsed from the controller 19, the coil 12 will be excited and the resulting magnetic force in the core 8 will tend to displace the attractive force of the magnet 1 on the rocking presser thereby effectively weakening the attractive force and permitting the restoring force Pr to move the associated rocking presser through the air gap 11 (FIG. 2) in the forward direction into engagement with the periphery of the bed 16 (FIG. 3) to establish the knitting position for the rocking presser. In this embodiment it is to be understood that, as set forth above the force Pr is caused by the springiness of the rocking presser.
FIG. 4 shows a modification of the actuator 10 of FIG. 2 wherein the standoff member of the latter is replaced by a pair of spacers or shims 21 and 22 of hard, non-magnetic material such as sapphire to maintain the desired separation S between the rear end of the rocking presser and the forward end of the permanent magnet 1. The members 21 and 22 extend axially from the rearward end of the air gap 11 to a point near the forward end of the air gap 5, and radially from respectively opposite inner surfaces of the core 8 to points near the outer periphery of the pole structures 3 and 4 of the permanent magnet 1. The spacers 21 and 22 coaxially situate the first and second air gaps with respect to the direction of movement of the presser and space the air gaps in such direction. It will be appreciated that the function of the members 21 and 22 in establishing the spacing S is essentially identical to that of the member 14 of FIG. 2.
It will be understood that the shims 21 and 22 constitute
a. means isolating the core of the electromagnet from the poles of the permanent magnet and
b. means disposing the core of the electromagnet symmetrically with respect to the permanent magnet. Their shape has been chosen so as to provide guidance for the controlled ferromagnetic part and at the same time they protect the surface of the pole shoes and of the core of the electromagnet.
Another form of actuator construction in accordance with the invention is shown in FIG. 5. In this scheme the permanent magnet 1, instead of being disposed within the core 8 as contemplated above, is located outside the core 8. In particular, the air gaps 5 and 11 are each coaxial with the line 6 and are axially aligned to face each other. In this case the jack 7 is supported intermediate the adjacent ends of the respective air gaps 5 and 11. In order to prevent impact between the rocking presser 7 and the adjacent walls of the air gaps 5 and 11, the structure of FIG. 5 is further provided with a pair of standoff members 23 and 24 made from a hard material, such as sapphire. The members 23 and 24 individually extend axially toward each other and overlap the associated air gaps 5 and 11. For this purpose the members 23 and 24 are mounted on corresponding outer surfaces of the permanent magnet 1 and the electromagnet 9. As in the previously described embodiments, the length of the members 23 and 24 may be chosen to maintain a minimum spacing S of the rocking presser 7 from the adjacent magnetic structure on each side. In FIG. 7 the flux path of the electromagnet is designated 14, and the flux path of the permanent magnet is designated 15. The flux strengths of such magnets are designated Qe and Qm, respectively.
FIG. 6 shows an actuator of the general type depicted in FIG. 5 wherein both the permanent magnet 1 and the rocking pressers are located on the periphery of the moving circular bed of the knitting machine. The electromagnet is disposed radially spaced outwardly from the periphery of the circular bed and is mounted on fixed structure (not shown). In this arrangement, the permanent magnet 1 normally keeps each successive rocking presser 7 attracted to the periphery of the machine bed (not shown). When a knit command signal is outpulsed from the controller 19, the coil 12 of the electromagnet is actuated to move the associated rocking presser in a radially outward direction from the periphery to establish the knitting position. In other respects, the arrangement of FIG. 6 functions in a manner similar to that of FIG. 3.
In each of the embodiments described above, the recessed area 13 (FIG. 2) of the rocking presser 7 tends to concentrate the lines of flux passing through the rocking presser from the magnetic circuits of both the permanent magnet and the electromagnet, thereby further lowering the effective reluctance of the magnetic circuit of the actuator and thereby further reducing the load on the driving circuitry.
It will be understood from the above that in the cross section of the controlled element marked 7 (FIG. 4) both magnetic fluxes -- i.e. the magnetic flux excited by the permanent magnet and the magnetic flux excited by the electromagnet -- are parallel to each other, but of opposite directions, so that the flux excited by the permanent magnet is weakened. This results in a weakening of the flux in the air gap between the controlled element and the pole shoes of the permanent magnet and consequently the attractive force P m between the controlled element 7 and the pole shoes of the permanent magnet is reduced. When this attractive force P m decreases so much that the directive force P r affecting the controlled element prevails, the controlled element 7 falls off the pole shoes of the permanent magnet with subsequent selection effect.
The magnetic flux of the driving circuit enters the controlled element perpendicular to the direction of the movement of the element from the shoes of the permanent magnet. This magnetic flux therefore does not affect the directive force which tends to separate the controlled element from the surface of the pole shoes of the permanent magnet. To the contrary, by a suitable shape of the controlled element (see the chamfering in FIG. 2) its falling off the pole shoes can be speeded up.
It will be understood that the above-described embodiments are merely illustrative of the principles of the invention. Numerous other variations and modifications will now occur to those skilled in the art. Accordingly, it is desired that the scope of the appended claims not be limited to the specific disclosure herein contained. | The movement of each of a plurality jacks or rocking pressers of a ferromagnetic material a circular knitting machine between a knitting and a non-knitting position is accomplished by the cooperation of the fields of a permanent magnet and a selectively actuable electromagnet which are magnetically isolated from each other. The portion of the jack where such fields intersect may be recessed to accomplish jack positioning with minimum expenditure of magnetomotive force. The airgap in the pole structure of the permanent magnet and in the separate core of the electromagnet are coaxially disposed, with the electromagnet being suitably located either inside or outside the core of the electromagnet. Where outside mounting is used, the permanent magnet may be disposed on the periphery of the circular bed of the machine along with the jacks, while the electromagnet is radially spaced therefrom. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to farm implements and, more particularly, to a method and apparatus for purging distribution channels for an air seeder of a farm implement.
Agricultural or farm implements that apply seed, fertilizer, or other particulate (granular) matter to a surface (“farm field”) typically have one or more central hoppers or tanks that are loaded with the particulate matter. The hoppers have or are associated with a metering device, which is typically a rotating element, that meters the particulate matter from the hoppers into a set of distribution channels, such as conduits, hoses, etc., that are flow coupled to the individual row units, or seed boxes associated with the individual row units. In many implementations, a blower system provides a turbulent air stream into which the particulate matter is entrained to pass the particulate matter through the distribution channels and ultimately to the individual row units. Such air seeders can take many forms and use various configurations to apportion the correct amount of particulate matter evenly throughout the distribution channels so that the particulate matter is deposited onto the farm field in a uniform and consistent manner.
One type of air seeder uses a large conduit to convey all the metered product to a first hollow distributor or manifold at which the particulate product is divided into a number of secondary streams evenly using evenly sized and spaced outlet ports. The secondary streams are fed to secondary headers, with each secondary header providing additional division and distribution of the secondary streams before the air/product streams are fed to the individual row units.
Another type of air seeder uses a metering roller that is segmented into a number of sections, with each section of the metering roller communicating with a dedicated set of secondary headers. With this type of air seeder, the product is mechanically metered and separated into different streams or runs and each stream is fed to a secondary header that provides additional division and distribution of the air/product streams before being fed to the individual row units.
A third type of air seeder avoids the use of secondary headers and the downstream division that such secondary headers provide. These air seeders use a metering roller that is large enough to feed product to each of the row units directly.
Regardless of the type of air seeder used, due to the increasing cost of seed and fertilizer, the agronomic disadvantage and waste associated with redundant application of seed and fertilizer, and the increasing size of seed drills, efforts have been made to selectively shut off the flow of product to the secondary headers which allows the seed drill to traverse previously seeded land without necessarily reapplying seed or fertilizer while the seed drill is used to apply particulate matter to nearby unseeded land. For air seeders having segmented or direct feed metering rollers, sectional control can be achieved by preventing the flow of product to the metering roller. When starving the roller by mechanically stopping the flow of product by using a gate or similar structure or by not rotating the roller, the roller cannot meter product downstream.
It will thus be appreciated that achieving sectional control is relatively straightforward for air seeders having segmented or direct feed metering rollers. However, for an air seeder that uses a distribution manifold and several downstream secondary headers to distribute particulate matter to the individual row units, sectional control is considerably more difficult. That is, if air flow is stopped to one of the outlet ports of the main header or manifold, the downstream channel may become plugged by the residual product thereby causing an issue when the air flow through the stopped outlet port resumes. If the channel becomes plugged, the application devices that are fed by the plugged channel will not be able to apply product to the field and will result in inconsistent and undesirable application of the seed and/or fertilizer.
SUMMARY OF THE INVENTION
The present invention provides a method and system for sectional control of an air seeding system that uses a main header or distribution manifold to distribute product, such as seed or fertilizer, to a plurality of secondary headers that likewise distribute the product for delivery to application devices, such as row units, or the seed boxes for the row units. The present invention enables sectional control for such an air seeding system by providing an apparatus and method for purging a channel of residual product when air flow to the channel through the header is stopped. In one implementation, the invention provides a plenum of air that provides a purging air flow to a distribution channel that has been shut off from a product air flow. A two position valve is used to selectively flow couple the channel to the primary product air flow and to the purging air flow. In one implementation, the blower that is used to provide the air flow for delivery product is also used to provide a volume of air to the plenum that can be used to purge the closed channel of residual product.
Therefore, in accordance with one aspect of the invention, an apparatus for a product distribution system of a farm implement is comprised of a header having an inlet and a plurality of outlets. The inlet is configured to receive product entrained in an air flow and the plurality of outlets are configured to pass respective portions of the product. A plenum having a volume of air and selectively in fluid communication with the plurality of outlets of the header is provided and is configured to provide a purging air flow to one or more of the plurality of outlets when in fluid communication with the one or more of the plurality of outlets.
In accordance with another aspect of the invention, a product distribution system for a farm implement includes a distribution manifold having a fluid inlet and a plurality of outlets, an entrained fluid flow containing particulate matter entrained in air, and a purging fluid flow free of the particulate matter to which at least one of the plurality of outlets is automatically exposed to when the at least one of the plurality of outlets is fluidly isolated from the entrained fluid flow.
The invention is also embodied in a method of purging a product distribution system of a farm implement. According to one aspect of the invention, the method includes passing entrained product through a manifold for subsequent distribution to a plurality of secondary headers for application of the entrained product onto a farm field. When desired for sectional control, the method includes selectively preventing air flow entrained with product to one of the secondary headers and simultaneously therewith, exposing the one secondary header to an air flow absent of entrained product to substantially purge the product placement devices connected to the one secondary header of product.
It will therefore be appreciated that one object of the invention is to provide a sectional control for a product metering system of a farm implement.
It is another object of the invention to provide a method and apparatus for purging a closed distribution channel of a production distribution system of a farm implement.
Other objects, features, aspects, and advantages of the invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout.
In the drawings:
FIG. 1 is a pictorial view of a farm implement incorporating the principles of the present invention;
FIG. 2 is a schematic view of the product distribution system of the farm implement of FIG. 1 ;
FIG. 3 is an isometric view of a main header and plenum of the product distribution system of FIG. 2 ;
FIG. 4 is a top section view of the main header and plenum of FIG. 3 taken along line 4 - 4 of FIG. 3 ;
FIG. 5 is a section view of the main header and plenum taken along line 5 - 5 of FIG. 3 ; and
FIG. 6 is a section view of the main header and plenum similar to the view shown in FIG. 5 but with exit ports of the main header fluidly exposed to a purging air flow according to one aspect of the invention.
DETAILED DESCRIPTION
Turning now to FIGS. 1 and 2 , an air seeder 10 includes an air hoe drill 12 coupled to a towing tractor 14 in a conventional manner. As known in the art, an air cart 16 is coupled to the air hoe drill 12 , and in the illustrated embodiment, is towed behind the air hoe drill 12 . As also known in the art, the air cart 16 has a large hopper 18 that holds a quantity of particulate matter, e.g., seed and/or fertilizer, and a metering unit 20 that meters the particulate matter from the hopper 18 to the air hoe drill 12 . The size of the hopper 18 may vary, but in one embodiment, the hopper 18 is sized to hold 580 bushels of particulate matter. One exemplary air cart is a Precision Air cart which is commercially available from CNH America, LLC.
In addition to being mechanically linked with the air hoe drill 12 , the air cart 16 and the air hoe drill 12 are interconnected by an air/product hose 22 and an air hose 24 . Air is supplied to both hoses 22 , 24 by a blower assembly 25 generally mounted adjacent the front of the hopper 18 and adjacent the metering unit 20 . Alternately, the blower assembly 25 may be mounted rearward of the hopper or adjacent a side of the hopper. As known in the art, the blower creates a turbulent air flow that forces the particulate matter metered by metering unit 20 into and along air/product hose 22 . The particulate matter is entrained in the air flow created by the blower and communicated from the air cart 16 through hose 22 to a main header or manifold 26 that is mounted to and supported by the air hoe drill 12 . In the illustrated embodiment, the main header 26 is vertically oriented but it is understood that other orientations are possible.
The main header 26 is a hollow conduit fluidly coupled in a conventional manner to hose 22 so that the product/air mixture P passed through hose 22 is delivered to the main header 26 and, more particularly, to a set of outlet or exit ports 28 formed in the main header 26 . The exit ports are equiradially spaced about the upper end of the main header 26 and the openings of the exit ports 28 are equally sized.
In operation, the product/air mixture is fed to the main header 26 and distributed evenly by the main header 26 to a set of primary conduits or hoses 30 that are flow coupled to the outlet ports 28 . The primary conduits 30 are flow coupled to a set of secondary headers 32 . The secondary headers 32 are similar to the main header 26 in that each secondary header 32 has a set of outlets 34 , with each outlet flow coupled to a secondary conduit 36 . Each secondary conduit 36 passes its portion of the air/product mixture to a row unit 38 which is configured in a conventional manner to deposit the particulate matter onto the seeding surface S.
To provide sectional control but also prevent clogging of the conduits downstream of the main header 26 , the present invention provides, in combination, a plenum 40 and a valve arrangement 42 , as shown in FIGS. 4 through 6 . The plenum 40 is mounted adjacently beneath the main header 26 and includes an air inlet 44 that is flow coupled to the air hose 24 . In this regard, the plenum 40 is fed air from the same blower assembly that provides the forced air for passing particulate matter through hose 22 .
In the illustrated example, the valve arrangement 42 includes valves 46 a , 46 b , 46 c , and 46 d and each is configured to selectively expose a respective main header exit port to either the product/air mixture supplied to the main header 26 by hose 22 or to the volume of air contained in the plenum 40 that is fed air via hose 24 . In one implementation, each valve has a gate 48 that is movable between a first position, shown in FIG. 5 , in which the exit port is in fluid communication with the air/product flow P and a second position, shown in FIG. 6 , in which the exit port is in fluid communication with the plenum 40 . It is contemplated that the valves could be activated in a known or to be developed manner, such as by a linear or rotary actuator, generally shown at 47 . Moreover, while a gate 48 is shown, it is understood that any known or to be developed mechanism could be used to selectively expose the exit port to the air/product mixture and the plenum of air. In this regard, when a valve is moved from the first or “open” position to the second or “closed” position, the exit port associated with that valve when will be closed off to the supply of particulate matter in the entrained air flow, as shown in FIG. 6 . As such, the secondary header flow coupled to that exit port will not be supplied product and the row units fed from that secondary header will not be fed product. However, to prevent clogging of the secondary header, the primary conduit that feeds the secondary header, and the secondary conduits, when the valve is moved to the second position, the exit port is exposed to the plenum of air A which functions to purge the downstream components of any particulate matter. When the valve is in the closed position, air only is fed to the row units associated with the closed main header exit port. Thus, the row units will not deposit product thereby enabling the implement operator to selectively control the application of particulate matter onto the seeding surface. This sectional control is believed to be particularly advantageous in avoiding the reapplication of particulate matter to a previously seeded or fertilized area. In another embodiment, the valve arrangement includes tandem pairs of butterfly valves. Other valve types could also be used.
It will be appreciated that the main header described herein may take a form different from that shown and described and thus the present invention is not limited to the specific main header design shown in the figures. Additionally, while the plenum has been described as being mounted beneath the main header, it is understood that other mounting arrangements could be used. It is also understood that other mechanisms could be used to selectively expose outlet ports of the main header to a purging volume of air. Further, it is contemplated that the present invention could be used with one or more of the secondary headers.
Additionally, in a preferred embodiment, the speed or the displacement of the metering assembly is adjusted when any of the exit ports of the main header is closed to the product/air mixture. Adjusting operation of the metering assembly is preferred so that open ports do not receive excess particulate matter when any of the other ports are closed. It is contemplated that a controller (not shown) could receive feedback with respect to the number of closed exit ports and adjust operation of the metering assembly automatically. For example, if twenty percent of the total number of exit ports of the main header is closed to the air/product mixture, the metering assembly is slowed by twenty percent.
Many changes and modifications could be made to the invention without departing from the spirit thereof. The scope of these changes will become apparent from the appended claims. | A method and system enables sectional control for an air seeding system of a farm implement by exposing a main header, or selected ports of the main header, to a purging air flow when product flow through the selected ports is stopped. A plenum of air is fluidly coupled to the main header and provides a purging air flow to any exit port of the main header that has been shut off from product flow. Valves are used to selectively flow couple the exit ports of the main header to the product flow and to the purging air flow. | 0 |
FIELD OF THE INVENTION
A body warming article adapted to be worn around a person's waist.
BACKGROUND OF THE INVENTION
Devices for retaining a person's body heat, often referred to as "body warmers", are well known to those skilled in the art. Thus, by way of illustration, the prior art has disclosed disposable body warmers (see U.S. Pat. Nos. 5,366,492, 5,342,412, 5,046,479, and 4,925,743), body warmers for use under a blanket (see, e.g., U.S. Pat. No. 5,300,100), and a variety of other body warmers of various sizes, shapes, and utilities (see, e.g., U.S. Pat. Nos. 4,846,528, 4,841,646, 4,753,483, 4,282,005, and 4,241,721). The disclosure of each of the United States patents mentioned in this paragraph are hereby incorporated by reference into this specification.
To the best of applicant's knowledge and belief, however, the prior art has not provided a body warmer which is relatively inexpensive to make and use, which can be reused indefinitely, which does not require the addition of chemicals or the use of electricity for its function, and which is washable. It is an object of this invention to provide such a body warmer.
SUMMARY OF THE INVENTION
In accordance with this invention, there is provided an device for retaining body heat which is comprised of two flaps integrally connected to a central body portion. The flaps contain means for removably attaching one to the other. The central body portion is comprised of a cavity in which insulating, fibrous material is present.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully understood by reference to the following detailed description thereof, when read in conjunction with the attached drawings, wherein like reference numerals refer to like elements, and wherein:
FIG. 1 is a perspective view of one preferred embodiment of the body warmer of this invention on the body of a user;
FIG. 2 is a perspective view of the body warmer of FIG. 1 showing its flaps connected to each other;
FIG. 3 is front view of the body warmer of FIG. 1;
FIG. 4 is a back view of the body warmer of FIG. 1;
FIG. 5 is a side sectional view of the body warmer of FIG. 1; and
FIG. 6 is a partial, enlarged sectional view of the body warmer of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The body warmer of this invention is an insulated article of clothing that wraps around the body of a user. Thus, referring to FIG. 1, it will be seen that body warmer 10 is wrapped around the waist of user 12 with body portion 14 of body warmer 10 covering the kidneys (not shown) of the user 12.
Although the body warmer 10 is shown in FIG. 1 contiguous with the skin of user 12, it will be apparent that such body warmer 10 can be worn on the outside of a user's clothes (not shown), or on the inside, like an undergarment.
Although applicant does not wish to be bound to any particular theory, he believes that his body warmer 10 functions effectively because it keeps a user's blood warm as it flows through the body. Approximately twenty-five percent of a person's blood flows through his kidneys ever minute. When the kidneys are kept warm, it is believed that the blood flowing through it also tends to keep warm.
Referring again to FIG. 1, it will be seen that flap 16 is removably attached to flap 18 (not shown in FIG. 1, but see FIGS. 2 and 3). The means for effecting such attachment will be discussed elsewhere in this specification.
Referring to FIGS. 1 and 3, it will be seen that the body portion 14 of body warmer 10 is comprised of an upper section 20 and a bottom section 22 which, for the sake of simplicity of representation, is shown separated by dotted line 24. It will be apparent to those skilled in the art that no such dotted line 24 actually appears in the device.
Referring to FIG. 1, it will be seen that the overall length 26 of body warmer 10 is from about 30 to about 60 inches and, preferably, is from about 39 to about 53 inches.
Referring again to FIG. 1, it will be seen that the lengths 28 and 30 of each of flaps 18 and 16, respectively, will preferably range from about 8 to about 16 inches and, preferably, will be from about 9 to about 13 inches. In one preferred embodiment, each of lengths 28 and 30, which may be the same or be different, will range from about 10 to about 13 inches and, most preferably, will be substantially equal to each other in length.
It is preferred that each of lengths 28 and 30 be at least about twenty-five percent of length 26.
Referring again to FIG. 2, it will be seen that the top portion 20 of body portion 14 preferably has a width which is from about 6 to about 8 inches. The widths 34 and 36 of flaps 18 and 16, respectively, preferably range from about 5 to about 8 inches and, generally, are from about 80 to about 100 percent of width 32 of upper portion 20 of body portion 14. It is more preferred, however, that widths 34 and 36 be from about 6 to about 8 inches and be at least about 90 percent of width 32.
Referring to FIGS. 2 and 3, it will be seen that each of flaps 28 and 30 is comprised of means for releasably fastening one such flap to the other. In the preferred embodiment illustrated in FIGS. 2 and 3, such releasable fastening means comprise "Velcro" separable loop material 38 (see FIG. 3), and Velcro separable hook material 40 (see FIG. 4). As will be apparent to those skilled in the art, when body warmer 10 is wrapped around the waist of a user 10 (see FIG. 1), loop material 38 contacts hook material 40 and releasably attaches the front side 42 of flap 16 (see FIG. 3) to the back side 44 of flap 18 (see FIG. 4).
Any conventional means for releasably attaching flap 16 to flap 18 may be used in the body warmer 10 of this invention. Thus, by way of illustration and not limitation, one may use one or more of the releasable attachment means disclosed in U.S. Pat. Nos. 5,369,852 (mixed hook/loop separable fasteners), 5,357,659 (snap fasteners), 5,328,400 (Velcro fabric fastener), 5,316,294 (hook/loop fastener), 5,287,571 (hook/loop fastener), 5,269,410 (hook/loop strip), 5,267,453, 5,247,182 (complementary fabric fastener means), 5,231,733 (hook/loop separable fasteners), 5,230,333 (snap fasteners), 5,193,549, 5,176,6780 (hook fastener made from polypropylene and loop fastener made from polyester), 5,157,799, 5,152,285, 4,959,265 (adhesive tape fastener), and the like. The disclosure of each of these United States patents is hereby incorporated by reference into this specification.
Referring again to FIGS. 3 and 4, the fastener materials 38 and 40 may be attached to flaps 16 and 18 by conventional means. Thus, by way of illustration and not limitation, they may be sewn onto the flaps 38 and 40, they may be attached by adhesive means, etc. Reference may be had to the aforementioned patents for various conventional means of attachment.
Referring again to FIGS. 3 and 4, it will be seen that the bottom section 22 of body portion 14 of body warmer 10 has a length which decreases from points 46 and 48 (at which points the length of bottom section 22 is substantially equal to the length of top section 20) to points 50 and 52 (at which point the minimum length 54 of bottom section 22 is less the length of the top section 20.
It is preferred that the length 56 of top section 20 (which is also equal to the maximum length of the bottom section 22) be such that the minimum length 54 of bottom section 22 is less than about 90 percent of length 56 and, more preferably, is from about 70 to about 90 percent of length 56. In one preferred embodiment, length 54 is from about 17 to about 21 inches and, more preferably, is from about 18 to about 20 inches; and length 56 is from about 23 to about 29 inches.
It will be apparent to those skilled in the art that, although the reduction of width between points 46 and 50, and 48 and 52, may be accomplished by straight walls (such as, e.g., walls 56 and 58), other shaped walls (such as curved walls) may also be used.
Referring to FIG. 4, it will be seen that the total width of body portion 14 will generally be from about 1.5 to about 2.5 times as great as width 32, and preferably will be from about 1.6 to about 2.0 times as great as width 32
In the embodiment depicted in FIGS. 1-4., the body warmer 10 is comprised of flaps 16 and 18 and body portions 20 and 22 which are made from a fabric material which, preferably, is comprised of cotton.
In one embodiment, the fabric material used is corduroy. As is known to those skilled in the art, corduroy is a cotton, rayon, or other fabric with a cut pile surface of wales; it may be either plain or twill weave. See, e.g., U.S. Pat. Nos. 4,870,727, 4,701,985, 4,180,606, 3,769,816, and the like. The disclosure of each of these United States patents is hereby incorporated by reference into this specification.
In another embodiment, the fabric material used is flannel. Flannel is a loosely woven, generally wool fabric with the wave concealed by a napped surface. See, e.g., U.S. Pat. Nos. 5,287,573, 5,244,625,. 4,916,782, 4,828,914, and the like. The disclosure of each of these United States patents is hereby incorporated by reference into this specification.
Other suitable fabric materials will be readily apparent to those skilled in the art. Thus, e.g., any of the fabric materials referred to in the aforementioned patents on body warmers also may be used.
In the preferred embodiment depicted in the Figures, body warmer 10 is made from two pieces of fabric material, front piece 66 (see FIG. 3), and back piece 68 (see FIG. 4) which are sewn or otherwise joined together at one or more points on either on the sides and/or bottom of such pieces. As will be apparent to those skilled in the art, the use of such a front and back piece will create a chamber between the front and back.
One such chamber is illustrated in FIG. 5. Referring to FIG. 5, chamber 72 is defined between front section 66 of body portion 14, and back section 68 of body portion 14. In the embodiment illustrated, chamber 68 is filled (or substantially filled) with fibrous insulating material.
Any of the fibrous insulating materials known to those skilled in the art may be disposed within chamber 72. Thus, by way of illustration and not limitation, one may use one or more of the fibrous insulating materials disclosed in U.S. Pat. Nos. 5,335,310, 5,297,969, 5,287,674, 5,206,081 (cellulosic fibers), 4,769,194, 4,430,369, 4,360,440, 4,350,001, 3,921,273, and the like. The disclosure of each of these United States patents is hereby incorporated by reference into this specification.
In one preferred embodiment, the fibrous insulating material is fibrous polyester fiberfill such as, e.g., the fiberfill material disclosed in one or more of U.S. Pat. Nos. 5,064,703, 4,869,771, 4,818,599, 4,794,038, 4,783,364, 4,618,531, 4,463,035, and the like. The disclosure of each of these U.S. patents is hereby incorporated by reference into this specification.
In one preferred embodiment, illustrated in FIG. 6, the chamber 72 is formed by an outer layer of fabric 74, and outer layer of fabric 76, and disposed therebetween in chamber 72 an insulating laminated structure 78 comprised of insulating fibrous material 80 bonded to and disposed between sheets of fabric 82 and 84. In one embodiment, polyester fiberfill is the insulating fibrous material, and cotton fabric is used as fabrics 82 and 84.
In the embodiment illustrated in FIG. 6, the laminated structure 78 is from about 0.1 to about 0.4 inches, and the total thickness of the chamber 72 (including its outermost walls) is from about 0.3 to about 0.7 inches.
It is to be understood that the aforementioned description is illustrative only and that changes can be made in the apparatus, in the ingredients and their proportions, and in the sequence of combinations and process steps, as well as in other aspects of the invention discussed herein, without departing from the scope of the invention as defined in the following claims. | A body warmer containing a fabric shell and an interior chamber. The body warmer has a central body and two flaps joined to it; the flaps are adapted to be releasably connected to each other. The shell is preferably made from one piece of fabric which is folded and joined at its periphery. The central part of the shell has a top portion integrally joined to a bottom portion which decreases in length as the bottom of the shell is approached. | 0 |
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