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BACKGROUND OF THE INVENTION
The present invention relates to a device for feeding band-shaped material in sewing machines. The sewing machines may be of a type suitable for sewing band-shaped material (e.g. tape, rubber) to a circular material (e.g. the waist or the crotch of a pair of briefs). More specifically, the present invention is a device for feeding bands in sewing machines selecting one out of a plurality of band-shaped material having different widths, colors, and the like that are disposed around the sewing machine head (e.g. above the head). This selected band of material is interposed between a main and a secondary roller and fed to the sewing section of the sewing machine.
In the prior art, this kind of band feeding device for sewing machines used a single band feeding device comprising a main and a secondary roller arranged near the sewing machine head (e.g. above the head). A band of material out of a plurality of types of bands is selected and set in place to be sewn. This single band is interposed between the main and secondary rollers which feed it to the sewing section.
In this arrangement, where only a single band feeding device is used, it is necessary to reset the band material and reinsert the material between the pair of rollers each time a different band out of a plurality of types of bands is to be sewn to a material. This is complicated for the operator, requires an excessive amount of time, and leads to a decrease in sewing efficiency. In particular, when bands of material are sewn to a single material at different positions (e.g. the waist and crotch), the above procedures must be carried out repeatedly. This interrupts operations frequently and results in significant decreases in efficiency.
In another embodiment of the prior art, a plurality of band feeding devices, each including a main roller and a secondary roller are arranged side by side either laterally or longitudinally near the head of the sewing machine (e.g. above the head). Different types of band materials are set in each of the plurality of band feeding devices, and one of the band feeding devices is selected to perform a feeding operation to the sewing section of the sewing machine. The arrangement of the plurality of band feeding devices laterally or longitudinally increases the bulk of the overall device, and increases the cost.
OBJECTS AND SUMMARY OF THE INVENTION
The object of the present invention is to overcome the drawbacks described above of the prior art.
A further object of the present invention is to provide automatic selection and feeding of a plurality of types of bands without requiring manual procedures such as removing bands from the rollers and resetting the bands. This object is to be achieved while minimizing the number of elements in the device as much as possible and providing a low-cost device.
Another object of the present invention is to decrease the amount of space occupied by the band feeding device and to offer a more compact device.
Yet another object is to provide a substantially fixed tension for the band without applying excessive pull so that the band can be fed to the material and sewn.
Yet another object is to prevent bands that are not supposed to be fed from being fed.
According to an embodiment of the invention, there is provided a band feeding device that feeds a selected one of a plurality of band-type materials (e.g. cloth tape, rubber) to a sewing machine for sewing to a ring-shaped garment such as, for example, the waist or crotch of a pair of trousers or briefs. One of a plurality of secondary rollers is moved to pinch its respective band between itself and a main roller. All other secondary rollers are moved away from the main roller, so that only the selected band is fed. This permits changing the type of band material being fed to the sewing machine without requiring the operator to remove and reinstall band materials each time. The number of elements in the overall device remains small, thus providing an inexpensive and compact device.
According to an embodiment of the invention, there is provided a band feeding device for sewing machines comprising: a main roller, means for rotating the main roller, means for feeding at least first and second bands adjacent a surface of the main roller, at least first and second secondary rollers aligned with the first and second bands, means for urging the first secondary roller toward the main roller such that the first band is pinched therebetween for feeding the first band to the sewing machine, means for urging the second secondary roller toward the main roller such that the second band is pinched therebetween for feeding the second band to the sewing machine, and means for selecting one of the first the second secondary roller for urging toward the main roller, and for moving all other rollers away from the main roller, whereby a selected one of the at least first and second bands is fed to the sewing machine, while all other bands remain inactive.
According to a feature of the invention, there is provided a band feeding device for sewing machines comprising: a main roller, first and second secondary rollers, means for maintaining the first and second secondary rollers a fixed distance apart on opposed sides of the main roller, means for moving the first and second secondary rollers in a generally radial direction of the main roller between first and second positions, means for feeding a first band-type material between the main roller and the first secondary roller, means for feeding a second band-type material between the main roller and the second secondary roller, the first position bringing the first secondary roller into contact with a first side of the main roller, thereby feeding the first band-type material and moving the second secondary roller out of contact with the main roller, thereby preventing feeding of the second band-type material, the second position bringing the second secondary roller into contact with an opposed side of the main roller, thereby feeding the second band-type material, and moving the first secondary roller out of contact with the main roller, thereby preventing feeding of the first band-type material, and means for rotating the main roller in a first direction while the secondary rollers are in the first position, and for reversing rotation of the main roller when the secondary rollers are in the second position, whereby unidirectional feed of the first and second band-type material is provided.
In order to achieve the objects described above, the device for feeding bands to a sewing machine according to the first embodiment of the present invention comprises: a single rotating main roller in contact with a plurality of types of bands to be fed to a sewing section of a sewing machine; a plurality of secondary rollers capable of coming into contact and moving away from the outer surface of fig main roller, and, while in contact with the main roller, capable of supporting a band material and feeding it to the sewing section of the sewing machine; and a secondary roller selection mechanism selecting one out of a plurality of secondary rollers and putting it into contact with the outer surface of the main roller, while moving the other secondary rollers away from the outer surface of the main roller.
With the first embodiment of the present invention configured as described above, one of the plurality of secondary rollers is selected by the secondary roller selection mechanism and pressed against the outer surface of the main roller. The other secondary rollers are moved away from the outer surface of the main roller. This allows one out of a plurality of bands to be automatically selected and interposed between the main and secondary rollers so that it can be fed to the sewing section. Thus, when one out of a plurality of bands is to be sewn onto a material, the need for resetting bands and reinstalling bands between main and secondary rollers is eliminated. This avoids the necessity for excessive manual operations, and allows an overall improvement in the efficiency and ease of operation in sewing. The embodiment also allows a single drive device and main roller to be used no matter which band of material is being fed. This requires fewer elements compared to a configuration involving a plurality of band feeding devices arranged laterally or longitudinally with each having a pair of rollers. Thus, the production costs of the overall device can be lowered.
The second embodiment of the invention is configured as described in the first embodiment of the invention wherein the plurality of secondary rollers is arranged in a row above the main roller along the direction of the axis of the main roller.
With the second embodiment of the invention as described above, the space occupied by the band feeding device is minimized and the overall device can be made more compact.
The third embodiment of the invention is configured as described in the first embodiment further comprising: springs that press against each of the secondary rollers so that they press against the outer surface of the main roller; and cylinders that act against the elastic energy of these springs and move each of the secondary rollers away from the outer surface of the main roller.
According to the third embodiment of the invention as described above, the secondary roller selection mechanism uses the elastic energy of the springs to adapt the holding strength of the main and secondary rollers to different thicknesses in the band material. This provides smooth and reliable feeding of the material.
The fourth embodiment of the invention is configured as described above and further comprises: a sensor for detecting the amount of band material being fed, arranged at a position closer to the band material feed than the main roller; and a control device driving the band material switching to a band material feeding state when the value detected by the sensor is at or below a certain value.
According to the fourth embodiment of the invention as described above, the amount of band material fed is detected by the sensor. When the detected value is equal to, or less than, a certain value, the main roller is driven to feed the band material and the device is switched to a feed state. This prevents excess pull from being applied to the band material, and allows the band material to be fed to the sewing material with a fixed tension.
The fifth embodiment of the invention is configured as described above and further comprises a band material supporting body which acts in response to the secondary roller moving toward and away from the outer surface of the main roller. When the secondary roller is pressed against the main roller, the pressure on the band material is released. When the secondary roller is situated away from the band material, pressure is maintained on the band material.
According to the fifth embodiment of the invention as described above, one of the secondary rollers is pressed against the outer surface of the main roller, while the other secondary rollers are separated from the main roller. The band material for the secondary rollers that are separated from the main roller, i.e. the non-feeding band material, can be held by pressure. This prevents problems involving failure to detect the non-feeding band material by the sensor and therefore cause an unnecessary amount of non-feeding band material to be fed out.
The above, and other objects, features and advantages of the invention will become apparent from the following present description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective drawing of a band feeding device for sewing machines according to an embodiment of the present invention.
FIG. 2 is an enlarged side view of the main elements of the band feeding device of FIG. 1 to which reference will be made describing the operations of this embodiment.
FIG. 3 is an enlarged side view of the main elements for the purpose of describing the operations of the above embodiment.
FIG. 4 is a schematic side view showing the main elements of another embodiment of the invention in which a tape TA is being fed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following is a description of an embodiment of the present invention. The description refers to a case where tape is used as the band material, but of course it is possible to apply the invention to a band material other than tape such as rubber. Also, in this embodiment, the device is arranged behind and above the head of the sewing machine, but the positioning is not limited to this arrangement, and can, for example, involve placing the device to the side of or below the head of the sewing machine.
Referring to FIG. 1, a control box, shown generally at 1, is disposed to the top and to the rear of a sewing machine frame. A band material feeding device 2 is arranged on the side of control box 1. Band material feeding device 2 includes a main roller 3 having an axial length long enough to cover two types of tapes TA, TB. Tapes TA, TB, which may have different widths, are fed from reels 4A, 4B located behind and above main roller 3. Main roller 3 is rotated by a motor (not shown in the drawing) installed in control box 1. Secondary roller supports 5A, 5B are free to pivot freely around a shaft 6 parallel to main roller 3.
Referring to FIG. 2 and FIG. 3, secondary rollers 7A, 7B are rotatably supported at the ends of the secondary roller supports 5A, 5B, respectively, so that they can press against and move away from the outer surface of main roller 3 resulting from up/down motion of secondary roller supports 5A, 5B. Secondary rollers 7A, 7B are arranged in a row in the axial direction above main roller 3. When a secondary roller is pressed against main roller 3, tape TA or TB is supported from above and below while being ted to the sewing section of the sewing machine.
Tape guides. 8A, 8B are pairs of projections separated by an distance corresponding to the width of tapes TA, TB. Tape guides 8a, 8b are arranged on the base end of secondary roller supports 5A, 5B above shaft 6.
A shaft 9, parallel to main roller 3, is fixed to a side of control box 1 below and toward the end of secondary roller supports 5A. A pair of springs 10A, 10B are stretched between shaft 9 and a position toward the ends of secondary roller supports 5A, 5B. The elastic force of springs 10A, 10B urges secondary roller supports 5A, 5B around and below shall. 6 and presses secondary rollers 7A, 7B against the outer surface of main roller 3.
Cylinders 11A, 11B are arranged next to each other on cylinder attachment base 12, which is fixed on a side of control box 1. Cylinders 11A, 11B include shafts 11a and 11b, respectively, which are in contact with the approximate center of the lower surfaces of secondary roller supports 5A, 5B. When cylinder shafts 11a, 11b are extended, secondary roller supports 5A, 5B are moved around shaft 6 against the elastic force of springs 10A, 10B. This results in secondary rollers 7A, 7B being moved away from the outer surface of main roller 3. Cylinder shafts 11a, 11b extend outward or inward in response to a control device (not shown in the drawings) within control box 1. Thus, a secondary roller selection mechanism moves secondary rollers 7A, 7B toward or away from main roller 3 by the opposition of springs 10A, 10B and cylinder shafts 11a, 11b in response to a control device. The rollers are controlled so that when one moves toward the main roller 3, the other moves away from main roller 3.
A tape guide 14, in contact with two tapes TA, TB, is attached to an end of a tape guide base 13. A vertically curved sensor guide groove 15 is formed on the side of control box 1. A sensor 16, in the form of a shaft extending across the feed paths of the tapes of the plurality, is inserted in sensor guide groove 15. Sensor 16 is in contact with tapes TA, TB such that it is moved up and down by increases and decreases in the amount of feed of the tapes. When the feed amount of the tapes detected by sensor 16 is at or below a specific value, i.e. when sensor guide 16 moves up from sensor guide groove by a prescribed amount or greater due to a decrease in the feed of tape TA or TB and an increase in tape tension, the motor in control box 1 increases the speed at which main roller 3 is driven until the amount of tape permits sensor 16 to return to a normal position.
When a change in tape is required, the active secondary roller 7A or 7B moves away from main roller 3, and the previously inactive secondary roller 7A or 7B moves into an active position pinching its respective tape TA or TB against main roller 3. In this way, automatic switching of tape feed is accomplished.
Tape holders 17A, 17B are attached to secondary roller supports 5A, 5B to serve as tape supports. Base ends of tape holders 17A, 17B are attached to shaft 6.
Referring to FIG. 2, when secondary rollers 7A, 7B are positioned down and are feeding the tape in contact with the outer surface of main roller 3, tape holders 17A, 17B move away from the top surface of tape TA, TB to release the pressure on tapes TA, TB between tape holders 17A, 17B and bottom plates 5a, 5b of secondary rollers 5A, 5B.
Referring to FIG. 3, when secondary rollers 5A, 5B are in the up position, and are in a non-feeding state for tapes TA, TB, which are separated from the outer surface of main roller 3, tape holders 17A, 17B are in contact with the upper surface of tapes TA, TB to maintain pressure on tapes TA, TB between tape holders 17A, 17B and bottom plates 5a, 5b of secondary rollers 5A, 5B.
A side cover is attached to the side of band feeding device 2 so that tapes TA, TB do not slide off their feeding paths, but this is not shown in the drawings.
Referring again to FIG. 2, when cylinder 11B is in its retracted condition, the elastic force of spring 10B moves secondary roller support 5B downward around shaft 6. This urges secondary roller 7B, at the end of roller support 5B into contact with the outer surface of main roller 3. Tape holder 17B moves away from the upper surface of tape TB and releases pressure from tape TB between tape holder 17B and bottom plate 5b of secondary roller support 5B.
Returning to FIG. 3, meanwhile, the other cylinder, cylinder 11A is extended. Secondary roller support 5A is moved upward around shaft 6, against the elastic force of spring 10A. Secondary roller 7A, on the end of secondary roller support 5A, is moved to a position away from the outer surface of main roller 3. Tape holder 17A maintained in contact with the upper surface of tape TA, thus maintaining pressure on tape TA between tape holder 17A and bottom plate 5a of secondary roller support 5A.
In this condition, wide tape TB from reel 4B passes through tape guide 8B and is interposed between main roller 3 and secondary roller 7B. With the rotation of main roller 3, tape TB contacts sensor 16, passes through tape guide 14 and is fed toward the sewing section of the sewing machine at a predetermined speed.
While this is being done, a generally constant tension is maintained on tape TB based on the detection by sensor 16 of the amount of tape TB being fed. This detected feed amount is used to control the rotation of main roller 3. Thus, excess tension on tape TB is avoided so that sewing can be done with approximately constant tension.
Similarly, for feeding narrow tape TA, pressure is maintained between tape holder 17A and bottom plate 5a of secondary roller support 5A. The amount of tape TB being fed is detected by sensor 16 to control the rotation of main roller 3. This rotation control prevents unnecessary feeding of tape TB.
With the embodiment described above, two secondary rollers 7A, 7B were arranged side by side above a single main roller 3 along its axis direction.
Referring now to FIG. 4, secondary rollers 7A, 7B are disposed on opposing sides in the radial direction of a single main roller 3. A moving arm 20 is urged upward and downward by a single cylinder 11. Secondary rollers 7A, 7B are maintained a fixed distance apart so that, when one is brought into contact with main roller 3, the other is moved out of contact. In addition to controlling the position of cylinder 11, the control device also reverses the direction of rotation of main roller 3 in order to provide unidirectional drive, regardless of which of secondary rollers 7A and 7B are brought into action.
Also, in the above embodiment, secondary rollers 7A, 7B move away from and toward main roller 3. However, it within the scope of the invention to provide three or more secondary rollers side by side and have one selected to come into contact with the outer surface of main roller 3, while all the other secondary rollers move away from main roller 3. In this case, it may be desirable the control device to respond to manual activation of a selection button. The selection button is pressed by the machine operator to select which of the secondary rollers should come into contact with main roller 3.
Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.
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A band feeding device feeds a selected one of a plurality of band-type materials (e.g. cloth tape, rubber) to a sewing machine for sewing to a ring-shaped garment such as, for example, the waist or crotch of a pair of trousers or briefs. One of a plurality of secondary rollers is moved to pinch its respective band between itself and a main roller. All other secondary rollers are moved away from the main roller, so that only the selected band is fed. This permits changing the type of band material being fed to the sewing machine without requiring the operator to remove and reinstall band materials each time. The number of elements in the overall device remains small, thus providing an inexpensive and compact device.
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TECHNICAL FIELD
[0001] This invention relates to a roof truss connector plate and roof anchor safety system and, in particular, to a connector plate comprising an anchor portion extending therefrom. The anchor portion allows various components of the roof anchor system to be secured to the roof. The truss connector plates are factory installed when the roof truss is formed and provide certifiable anchor capacity to the user.
BACKGROUND OF THE INVENTION
[0002] The need for securing roofing workers on pitched roofs is well known and is now being required by many government regulations. Many safety systems have been developed to secure workers, with the majority involving an anchor attached to either a rafter of a truss or to the surface of the roof. These prior art anchor systems may be temporary or permanent.
[0003] A problem with all of these prior art systems is that they rely on a roofing worker to initially attach the anchor. This often can result in the anchor being attached incorrectly. The potential misconnection of anchor bolts, screws and brackets, and the resulting personal injury, is a serious problem with the prior art safety systems. Additionally, due to the potential liability, building contractors many times retain independent sub-contractors that are expected to provide proper protection, but many times fail to do so. The difficulty and potential for improper installation lead to disastrous results if a roof worker should fall, and the need therefore exists for a simple, integrated approach to provide roof safety to every construction site.
[0004] Accordingly, there is need for providing a roof anchor system that overcomes problems associated with the prior art.
SUMMARY OF THE INVENTION
[0005] The present invention overcomes at least one disadvantage of the prior art by providing a monolithic truss connector plate comprising a first mounting plate portion having a plurality of teeth extending perpendicularly therefrom, and a first anchor portion extending from the mounting plate portion and including a means for attaching at least one safety device. The roof system may therefore have the anchor system as a factory installed product in association with the building materials. This, and other advantages, will be apparent upon a review of the drawings and detailed description of the invention.
[0006] At least one embodiment of the present invention also provides a roof anchor safety system comprising a pair of truss connector plates, each truss connector plate comprising a mounting plate portion having a plurality of teeth extending perpendicularly therefrom and an anchor portion extending from the mounting plate portion, wherein the mounting plate portion of the truss connector plates are attached to opposite sides of a truss such that the anchor portion of each truss connector plate extends beyond an edge of the truss and outward from the truss, and at least one safety device supported by the truss connector plates.
[0007] At least one embodiment of the present invention also provides a method of providing a roof anchor safety system comprising the steps of providing a truss connector plate comprising a mounting plate portion having a plurality of teeth extending perpendicularly therefrom and an anchor portion extending from the mounting plate portion, the anchor including means for attaching a safety device; attaching the mounting plate portion of the truss connector plate to a truss such that the plurality of teeth engage a wooden portion of the truss and the anchor portion extends beyond an edge of the truss and outward away from the truss.
[0008] The roof system may therefore have the anchor system as a factory installed product in association with the building materials. This, and other advantages, will be apparent upon a review of the drawings and detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] This invention will now be described in further detail with reference to the accompanying drawings, in which:
[0010] FIG. 1A is a front view of a peak gusset of a roof anchor system of the present invention and FIG. 1B is a detail perspective view of one of the plurality of teeth of the peak gusset of FIG. 1A ;
[0011] FIG. 2 is a side view of a pair of peak gussets, as shown in FIG. 1 , attached to a truss rafter;
[0012] FIG. 3 is a perspective view of a truss formed with the peak gussets of FIG. 1 and shown with a building structure generally shown in phantom;
[0013] FIG. 4 is a perspective view of a high reach accessory of the roof anchor system of the present invention;
[0014] FIG. 5 is a perspective view of a roof having the roof anchor system of the present invention attached thereto;
[0015] FIG. 6 is a perspective view of a support ferrule insert of the roof anchor system of the present invention;
[0016] FIG. 7 is a front view of a second embodiment of the peak gusset of the present invention shown in a single piece configuration;
[0017] FIG. 8 is a side view of the double gusset of FIG. 7 shown attached to a truss rafter;
[0018] FIG. 9 is a partial perspective view of a truss formed with the double peak gusset of FIG. 7 and a support ferrule of FIG. 6 shown exploded therefrom;
[0019] FIG. 10 is a front view of another embodiment of the peak gusset of the present invention shown in a single piece configuration;
[0020] FIG. 11 is a side view of the double gusset of FIG. 10 shown attached to a truss rafter;
[0021] FIG. 12 is a partial perspective view of a truss formed with the double peak gusset of FIG. 10 and a support ferrule of FIG. 6 shown exploded therefrom;
[0022] FIG. 13 is a perspective view of another embodiment of the high reach accessory of the roof anchor system of the present invention;
[0023] FIG. 14 is a perspective view of a high reach accessory of FIG. 13 shown attached over a portion of a truss using the peak gusset of the present invention;
[0024] FIG. 15 is a partial perspective view of another embodiment of the peak gusset having fold over side reinforcements, shown attached to a plurality of truss rafters and truss webs;
[0025] FIG. 16 is a partial perspective view of another embodiment of the peak gusset having a low profile attachment extension, shown attached to a plurality of truss rafters and truss webs;
[0026] FIG. 17 is a partial perspective view of the peak gusset as shown in FIG. 16 having a plurality of D rings attached thereto for a cable harness hook up;
[0027] FIG. 18 is a front view of a low anchor profile embodiment of the peak gusset of the present invention shown in a single piece configuration;
[0028] FIG. 19 is a side view of the peak gusset of FIG. 18 , shown attached to a truss rafter;
[0029] FIG. 20 is a partial perspective view of a truss formed with the peak gusset of FIG. 18 shown with a metal loop;
[0030] FIG. 21 is a partial perspective view of a truss formed with the peak gusset of FIG. 18 shown with a slide clip;
[0031] FIG. 22 is a front view of a second low anchor profile embodiment of the peak gusset of the present invention shown in a single piece configuration;
[0032] FIG. 23 is a side view of the peak gusset of FIG. 22 , shown attached to a truss rafter;
[0033] FIG. 24 is a partial perspective view of a truss formed with the peak gusset of FIG. 22 .
[0034] FIG. 25 is a front view of another embodiment of the peak gusset of the present invention;
[0035] FIG. 26 is a side view of a the peak gusset of FIG. 25 , shown attached to a truss rafter with an unattached slide-on eyebolt base and eyebolt;
[0036] FIG. 27 is a side view of the peak gusset of FIG. 25 , shown attached to a truss rafter with a slide-on eyebolt base and eyebolt attached to the peak gusset;
[0037] FIG. 28 is a partial perspective view of a truss formed with the peak gusset of FIG. 27 shown with a plurality of support members shown exploded therefrom;
[0038] FIG. 29 is a front view of another embodiment of the peak gusset of the present invention similar to the embodiment of FIG. 25 ;
[0039] FIG. 30 is a side view of the peak gusset of FIG. 29 , shown attached to a truss rafter with an eyebolt attached to the peak gusset;
[0040] FIG. 31 is a partial perspective view of a truss formed with the peak gusset of FIG. 30 shown with a plurality of support members shown exploded therefrom;
[0041] FIG. 32 is a front view of another embodiment of the peak gusset of the present invention utilizing gusset plates with a double fold;
[0042] FIG. 33 is a side view of the peak gusset of FIG. 32 , shown attached to a truss rafter;
[0043] FIG. 34 is a partial perspective view of a truss formed with the peak gusset of FIG. 32 shown with a plurality of support members shown exploded therefrom;
[0044] FIG. 35 is a front view of another embodiment of the peak gusset of the present invention, which is a one-piece version of the gusset plates of FIG. 32 ; and
[0045] FIG. 36 is a side view of the peak gusset of FIG. 35 , shown attached to a truss rafter.
DETAILED DESCRIPTION OF THE INVENTION
[0046] The present invention is directed to an integrated roof safety system wherein successful attachment of this device is assured because it is designed to be installed under ideal and regulated factory conditions. The provision of this device, by the general building contractor, for use by the various hired subsequent subtrades, will create a safe workplace and cause more compliance with existing government regulations. The result will be practical, economical and failsafe product and system. The roof anchor safety system 110 of the present invention will now be described in detail with reference to various embodiments thereof. Referring now to FIG. 1A , a truss connector plate 10 for use at the peak of a truss and referred to herein as a peak gusset 10 is shown and comprises the primary component of the roof anchor safety system 110 . The peak gusset 10 comprises a plate 12 of steel having a plurality of teeth 13 formed from the plate 12 and extending perpendicularly from the plate 12 as best shown in FIG. 1 B . Referring back to FIG. 1A , the exact shape of the plate being unimportant, it is only necessary that the plate be of sufficient size and geometry to resist anticipated pull forces. The peak gusset 10 further comprises an anchor portion 14 extending from the peak side 16 of the gusset 10 . The peak gusset 10 is monolithic such that the anchor portion 14 is an extension of the plate 12 . The anchor portion 14 includes a means for attachment 18 of other safety items, the attachment means shown herein as a pair of apertures 18 in the form of slot 18 . It is noted that other attachment means are contemplated such as an open slot for engaging a stud of the type used for bayonet connection, or other known connection devices. The thickness of the gusset 10 may be of a standard gusset thickness, typically 16-20 gauge, or may be made of a thicker gauge for added strength.
[0047] A peak gusset 10 is attached to either side of a truss peak 22 as shown in FIG. 2 . The plurality of teeth (not shown) are pressed into the wooden truss peak 22 during manufacture of the truss 20 typically using a roll or hydraulic press. Manufacture of the truss is accomplished at the factory under standard environmental conditions to control the quality and strength of the truss. The anchor portion 14 extends outward from the truss peak 22 . At least one aperture 18 provides a connection location for other elements of the roof anchor safety system 110 . Although not shown, it is contemplated that the anchor portion 14 can be formed with vertically extending ribs in a pressed single or multiple wave or corrugated type configuration to add additional strength to the anchor portion 14 of the gusset 10 . Between the manufacture and installation of the truss 20 , the anchor portion 14 may be covered with a protective coating or covering (not shown) such as foam wrap or the like in order to protect the anchor portion 14 as well as workers handling the truss 20 . A wooden piece of scrap material may also be inserted between the anchor portions 14 and temporarily secured to provide additional protection against bending or other damage to the anchor portions 14 during handling and transportation.
[0048] The resulting truss 20 is shown in FIG. 3 with the peak gusset 10 positioned such that the anchor portion 14 of the gusset 10 extends upward from a ridge line 30 formed by the other truss peaks 32 of the roof 34 (shown in phantom). The anchor portion 14 provides an attachment location for D-rings, hooks, cables, and other means of securing a person while working on the roof 34 . It is important to note that, although the peak gusset 10 is shown in the present disclosure solely at the peak of a truss 20 , it is contemplated that the other truss connection plates 36 could be configured with an anchor portion 14 as well.
[0049] The roof anchor system 110 of the present invention further comprises an anchor extension member 40 referred to as a high reach accessory 40 as shown in FIG. 4 . The high reach accessory 40 is essentially an extension bar of a predetermined length that attaches at a first end 42 to the peak gusset 10 . The first end 42 may also include sidewall extensions 43 that extend over the sides of the truss peak 22 to provide additional stability and prevent low-impact side-to-side collapse of the anchor portions 14 of the gussets 10 . The first end 42 fits over the anchor portions 14 and includes an attachment means 44 for securing the high reach accessory 40 to the anchor portions 14 herein shown as apertures in the form of slots 44 . The opposite end 46 of the high reach accessory 40 includes attachment means 48 for attachment of other safety items, the attachment means 48 shown herein as a plurality of apertures 48 .
[0050] The roof anchor safety system 110 of the present invention is shown in FIG. 5 . A truss 20 is shown having peak gussets 10 attached thereto. A high reach accessory 40 is shown attached over the anchor portion 14 (shown as visible even though covered) of the peak gussets 10 . A second high reach accessory 40 is attached to a second peak gusset (not shown) further down the ridge line 30 . A tether line 50 is attached to and extends between the high reach accessories 40 . A harness line 52 is shown slidably attached to the tether line 50 by an attachment ring 54 . An additional truss 20 is shown having peak gussets 10 and is positioned between the two high reach accessories 40 . A harness line is shown attached to the anchor portions 14 of the peak gussets 10 by an attachment ring 54 . Squares of shingles 58 are shown positioned along the ridge line 30 .
[0051] In FIG. 6 , a support ferrule insert is shown for insertion between the anchor portions 14 of the gussets 10 to provide additional support and strength to the anchor portions 14 . The support ferrule 60 includes apertures 62 . The support ferrule 60 is shown as a tubular member or it may be a solid block. The support ferrule 60 is positioned prior to attachment of the high reach accessory 40 . The support ferrule 60 may also include a first end 64 that is formed at an angle to mate with or bridge the peak of the truss 20 and provides additional support to prevent front-to-back low impact collapse of the anchor portions 14 of the gussets 10 .
[0052] When the roof anchor safety system 110 is no longer needed, the harnesses 52 , tether lines 50 , high reach accessories 40 , D-rings 54 and the like, and support ferrule inserts 60 , are removed from the anchor portions 14 and used again as needed. The anchor portions 14 are typically cut near the top of the truss 20 and then folded over the top of the truss 20 . Alternatively, the anchor portions 14 may not need to be cut but rather just be bent over the truss 20 and positioned below the roof. It is also contemplated that the anchor portions 14 may be covered and left in place, with or without a ferrule insert support 60 between the extensions 14 .
[0053] In FIGS. 7-12 , two additional embodiments of the peak gusset 210 , 310 are shown that are manufactured as one piece and then folded prior to attachment to form the truss 200 , 300 . Referring now to FIG. 7 , a double peak gusset 210 is shown having a connection portion 212 between the anchor portions 214 of the double gusset 210 . A plurality of teeth (not shown) extend perpendicularly from each plate portion 216 . The double peak gusset 210 is folded on either end of connection portion 212 and attached to form a truss 200 by the plurality of teeth (not shown) engaging the truss members 202 as shown in FIG. 8 . The attached peak gusset 210 is shown in a partial perspective view in FIG. 9 . The peak gusset anchor portions 214 remain connected by connection portion providing enhanced strength of the anchor portions 214 . A support ferrule insert 220 is shown as insertable between the anchor portions 214 and underneath the connection portion 212 .
[0054] Referring now to FIG. 10 , another embodiment of a double peak gusset 310 is shown having a connection portion 312 between the plate portions 316 of the double gusset 310 . A plurality of teeth (not shown) extend perpendicularly from each plate portion The double peak gusset 310 is folded on either end of connection portion 312 and attached to form truss 300 by the plurality of teeth (not shown) engaging the truss members 302 as shown in FIGS. 11 and 12 . The attached peak gusset 310 is shown in a partial perspective view in FIG. 12 . The peak gusset plate portions 316 remain connected by connection portion 312 . A support ferrule insert 320 is shown as insertable between the anchor portions 314 as shown in previous embodiments.
[0055] A variation of the high reach accessory 140 is shown in FIG. 13 . The high reach accessory 140 is similar to the previous embodiment of the high reach accessory 40 except that it has a rectangular tubular cross-section as opposed to a square cross-section, and apertures 144 at the first end 142 are circular as opposed to slots. The invention is not limited to a particular configuration of the high reach accessory 40 , 140 . As with the previous embodiment, the high reach accessory 140 also may include sidewall extensions that extend over the sides of the truss peak 22 to provide additional stability and prevent low-impact side-to-side collapse of the anchor portions 14 of the gussets 10 as best shown in FIG. 14 . The first end 142 fits over the anchor portions 14 . As with the previous embodiment, the opposite end 146 of the high reach accessory 140 includes attachment means 148 for attachment of other safety items, the attachment means 148 shown herein as a plurality of apertures 148 .
[0056] Another embodiment of the peak gusset 410 is shown in FIG. 15 . The peak gusset comprises a plate 412 of steel having a plurality of teeth (not shown) formed from the plate and extending perpendicularly from the plate 412 . The peak gusset 410 further comprises an anchor portion 414 extending from the peak side of the gusset 410 . The anchor portion 414 includes a means for attachment 418 of other safety items, the attachment means shown herein as a pair of apertures 418 . Gusset 410 includes reinforcing flaps 428 extending from the anchor portion 414 and reinforcing flaps 422 extending from the plate 412 . When a peak gusset 410 is attached to either side of a truss the flaps 412 , 422 of each gusset are folded perpendicular to their respective gussets and provide additional support for the anchor portion 414 . A support ferrule insert (not shown) may still be used, if needed, and is insertable through an opening at the top of the anchor portions 414 of the gussets 410 .
[0057] Another embodiment of the peak gusset 510 is shown in FIGS. 15 and 16 . The peak gusset comprises a plate 512 of steel having a plurality of teeth (not shown) formed from the plate and extending perpendicularly from the plate 512 . The peak gusset 510 further comprises an anchor portion 514 extending from the peak side of the gusset 510 . The anchor portion 514 includes a means for attachment 518 of other safety items, the attachment means shown herein as a pair of apertures 518 . A peak gusset 510 is attached to either side of a truss peak 522 . A support ferrule insert 520 is shown as insertable between the anchor portions 514 as shown in previous embodiments. In FIG. a pair of D-rings 552 are shown attached to the peak gusset 510 .
[0058] The peak gussets 10 , 210 , 310 , 410 , and 510 all have a significant extension of the anchor above the truss. The peak gusset of the present invention may also be configured in a “low profile” configuration. Referring now to FIGS. 18 and 19 , a double peak gusset 610 is shown that is manufactured as one piece and then folded prior to attachment to form the truss 600 . Double peak gusset 610 comprises a connection portion between the anchor portions 614 of the double gusset 610 . A plurality of teeth (not shown) extend perpendicularly from each plate portion 616 . The double peak gusset 610 is folded on either end of connection portion 612 and attached to form a truss 600 by the plurality of teeth (not shown) engaging the truss members 602 as shown in FIG. 19 such that the connection portion 612 forms a cap over the anchor portions 614 . The peak gusset anchor portions 614 only extend a short distance above the peak of the truss 600 and remain connected by connection portion 612 , providing enhanced strength. The attached peak gusset 610 is shown in a partial perspective view in FIG. 20 including a metal loop 630 which provides an attachment location for a harness cable hook up (not shown). Another variation is shown in FIG. 21 wherein a slide clip 640 is used to provide an attachment location for a harness cable hook up (not shown). Slide clip 640 is a U-shaped metal band. Connection portion 612 of the peak gusset 610 is positioned between the legs 644 of the open end 642 of slide clip 640 . Apertures 646 in the legs 644 of clip provide an attachment location for a harness cable hook up. The harness cable hook up and the closed end 648 of slide clip 640 act to secure the slide clip to the peak gusset The low profile of the anchor portions 614 and connection portion 612 make it so they can remain in place and simply be covered by the roof peak vent (not shown), or by ridge shingles. Alternatively, the anchor portions 614 and connection portion 612 can be removed or bent out of the way as in previous embodiments.
[0059] Referring now to FIGS. 22 and 23 , a second embodiment of a low profile double peak gusset 710 is shown. Peak gusset 710 is manufactured as one piece and then folded prior to attachment to form the truss 700 . Double peak gusset 710 comprises a connection portion 712 between the anchor portions 714 of the double gusset 710 . A plurality of teeth (not shown) extend perpendicularly from each plate portion 716 . A plurality of apertures are formed in the anchor portions 714 and/or the connection portion 712 . The double peak gusset 710 is folded on either end of connection portion 712 and attached to form a truss 700 by the plurality of teeth (not shown) engaging the truss members 702 as shown in FIG. 24 . Apertures 725 provide an attachment location for a harness cable hook up. As with the previous embodiment, the low profile of the anchor portions 714 and connection portion 712 make it so they can remain in place and simply be covered by the roof peak vent (not shown) or ridge shingles. Alternatively, the anchor portions 714 and connection portion 712 can be removed or bent out of the way as in previous embodiments.
[0060] Referring now to FIGS. 25-28 , another embodiment of the peak gusset 810 is shown. Peak gusset 810 comprises a plate portion 816 and an anchor portion 814 extending therefrom and having a connection portion 812 . A plurality of teeth (not shown) extend perpendicularly from each plate portion 816 . The gusset plates 810 are attached to form a truss 800 by the plurality of teeth (not shown) engaging the truss members 802 as shown in FIG. 26 . The connection portions 812 are folded outward from the anchor portion of the gusset plates 810 to form a connection flange for a slide-on eyebolt base 830 having an eyebolt 840 attached thereto by a fastener 842 . The eyebolt base 830 is slid over flanges 812 and secured thereto with a plurality of fasteners 832 as shown in FIG. 27 . The attached peak gusset 810 is shown in a partial perspective view in FIG. 28 attached to truss 800 . In order to provide additional strength for the eyebolt connection 840 , a pair of support angles 850 are provided. The support angles 850 each have a leg 852 that engages the top of the rafter 802 and a second leg 854 , perpendicular to leg 852 , which generally spans the width of the anchor portion 814 . The support angles 850 are designed such that the legs 854 nest one under the other. A slot 856 is formed in the legs 854 to allow the shaft of eyebolt 840 to pass through. The support angles 850 are fixed in position by eyebolt 840 and fastener 842 .
[0061] Another variation of this embodiment is shown in FIGS. 29-31 . In the embodiment shown in FIG. 29 the gusset plates 810 ′ have an aperture 818 formed in connection portion 812 ′. As with the previous embodiment, the gusset plates 810 ′ are attached to form a truss 800 by the plurality of teeth (not shown) engaging the truss members 802 as shown in FIG. 30 . However, the connection portions 812 ′ are folded inward from the anchor portions 814 of the gusset plates 810 ′ such that the apertures 818 are aligned to allow the shaft of eyebolt 840 to pass and for the eyebolt 840 to be directly attached to the connection portions 812 ′ by a fastener 842 . The attached peak gusset 810 ′ is shown in a partial perspective view in FIG. 31 attached to truss 800 . In order to provide additional strength for the eyebolt connection 840 , the pair of support angles 850 are provided as previously discussed and shown in FIG. 28 .
[0062] Referring now to FIGS. 32-34 , another embodiment of the peak gusset 910 is shown. As shown in FIG. 32 , a pair of peak gussets 910 each comprises a plate portion and an anchor portion 914 extending therefrom and having a connection portion 922 having at least one aperture 927 and a shoulder portion 912 having at least one aperture 925 . A plurality of teeth (not shown) extend perpendicularly from each plate portion 916 . The gusset plates 910 are attached to form a truss 900 by the plurality of teeth (not shown) engaging the truss members 902 as shown in FIG. 33 . The shoulder portions 912 are folded inward from the anchor portion 914 of the gusset plates 910 and connection portions are folded away from anchor portion 914 such that connection portions 922 and anchor portion 914 are generally parallel to each other. The attached peak gussets 910 are shown in a partial perspective view in FIG. 34 attached to truss 900 . In order to provide additional strength for the anchor portion 912 , a pair of support block wedges 950 are provided. The support blocks 950 each are configured to engage the top of the rafter and the interior of shoulder portion 912 . The support blocks 950 include an aperture that is aligned with aperture 925 of the anchor portion to allow the support block 950 to be fastened to the gusset plates 910 by a fastener (not shown). The apertures 927 in the connection portion 922 provide anchor connection locations for users. It is noted that the support block wedge 950 is shown with open sides and a closed bottom. This allows access such that the hard shaft of the support block fastener can be used as an alternate hook location for the safety line carbiner.
[0063] Another embodiment of the invention is shown in FIGS. 35 and 36 and is a double gusset version of the embodiment shown in FIGS. 32-34 . A double peak gusset 1010 is shown that is manufactured as one piece and then folded prior to attachment to form the truss. Double peak gusset 1010 comprises a pair of shoulder portions 1012 and a pair of connection portions 1022 each having at least one aperture 1027 , between the anchor portions 1014 of the double gusset 1010 . The shoulder portions 1012 are folded inward from the anchor portions 1014 of the double gusset plate 1010 and connection portions 1022 are folded away from anchor portions 1014 such that connection portions and anchor portion 1014 are generally parallel to each other. A plurality of teeth (not shown) extend perpendicularly from each plate portion 1016 . The double peak gusset 1010 is folded and attached to form a truss by the plurality of teeth (not shown) engaging the truss members 1002 as shown in FIG. 36 . As with the previous embodiment, it is contemplated that support blocks 950 could be used to strengthen the anchor portion 1014 .
[0064] Although the present invention has been described above in detail, the same is by way of illustration and example only and is not to be taken as a limitation on the present invention. It is understood that many variations of the illustrated invention are possible without departing from the scope of the present invention. Accordingly, the scope and content of the present invention are to be defined only by the terms of the appended claims.
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A roof truss connector plate is provided comprising a mounting plate portion and an anchor portion extending from the mounting plate portion. The truss connector plate is a portion of a roof anchor safety system. The anchor portion of the truss connector plate allows various safety components of the roof anchor system to be secured to the roof. The truss connector plates are factory installed when the roof truss is formed and provide certifiable anchor capacity to the user.
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[0001] This application is a continuation of and claims priority from U.S. Ser. No. 15/167,984 filed May 27, 2016, entitled “DIRECT POWER COMPACTION METHOD”, which claim priority from U.S. Provisional Application No. 62/167,864 filed on May 28, 2015, entitled ‘Power Compaction Method’ (JAF001/PRO), which are all incorporated herein by reference.
FIELD OF TECHNOLOGY
[0002] This disclosure relates generally to a method of Direct Power Compaction (DPC). In one example embodiment to methods, apparatus, and systems to compact loose ground by vibration and compaction of H piles driven by vibrators (vibro-hammer or pile driver). The DPC method is an efficient and highly economical technique for densifying loose soils. In the procedure piles, with an innovative H pattern structure, are driven in the ground using a combination of downward and vibratory force to move particles of the looses oil closer together and reduce the voids between them. Subsequent backfilling and vibration at the H-pile sites achieves the highest density possible and provides for an improved ground soil structure and load bearing capacity.
BACKGROUND
[0003] Because of the shortage of usable land in industrial areas, especially along waterfront sites, there has been a recent trend towards building large industrial complexes, such as power plants, steel mills, and shipyards on landfill sites or other sites with a loose top soil or soil layer. Additionally, there are several projects presently being planned for construction of large intercontinental airports on landfill sites along the coasts of the United States and the Great Lakes, as well as other sites along other lakes, oceans and rivers around the world.
[0004] In conventional landfill construction projects, the fill is generally provided by depositing relatively solid dry materials along the ocean or water bed, or in the case of swamp land, depositing clean dry fill along the swamp until a firm foundation had been established. Due to the enormous expense of trucking or transporting in fill, and the time and material necessary, the costs involved for conventional land filling have become almost prohibitive when compared to the actual costs of the buildings and facilities constructed on the filled areas, alternative locations and the projected revenue from building in new locations. Thus, there is a need for an invention that converts location specific sub-par land fill or loose soil areas into usable land.
[0005] Recently, new techniques of land filling have been developed involving the hydraulic sand filling of swampy or underwater sites. Generally, this method uses slurry of earth and water from a nearby ocean or lakebed that is hydraulically pumped through a large pipe to the fill site. The slurry is deposited on the fill site and the water drains away, depositing the solid material. With this method it is possible to simultaneously dredge the adjacent river or ocean bed while using the fill area as a depository for the dredged material, of which is a markedly efficient process.
[0006] When hydraulic landfill is used, the material, which is generally granular in nature, must first be compacted prior to commencing any construction thereon. This fill can be compacted by allowing the sand or loose soil to naturally settle over a sufficiently long period of time, usually a matter of months or years, depending on the degree of compaction needed, which in turn is dependent upon the type of material and the weight of any contemplated construction. Alternatively, mechanical means can be used to force the water out of the sand thereby achieving compaction. Generally, this involves large rolling drums, which are rolled back and forth over the material, compacting it as it is deposited of which the rolling drums method, among other prior art methods, takes time, and as mentioned below, are sometimes unfeasible due to environmental circumstances, cost limitations or space limitations.
[0007] When hydraulic landfill is used, continual mechanical compaction is sometimes impossible because of the high fluid consistency of the fill immediately after it is deposited. Even when sufficient drainage has occurred, rolling is time consuming and generally ineffective for sufficient compaction at substantial depths. Natural settlement is unsatisfactory because of the amount of time necessary during which no construction can take place.
[0008] Because hydraulic landfill projects will often require use of up to 20 or 30 feet of fill to form a sufficient base for a foundation, it is necessary that the compaction be uniformly achieved to substantial depths. This becomes especially important in situations where large facilities are to be subsequently constructed. Pounding or rolling the surface to effect compaction will not provide a sufficient degree of compaction more than a few feet below the surface and it becomes necessary to have some sort of soil penetrating device to compact the soil lower down.
[0009] Prior soil compaction systems applicable to hydraulically filled areas and which provide sufficiently deep penetration have employed one of the varying types of penetrating torpedo-type devices which are solid in nature and are lowered down through the soil to some depth. Once lowered, the particular device is set into vibration by a rotating eccentric or other appropriate means, thereby compacting the soil. These prior devices have proven unsatisfactory for certain applications in that they require a separate means for forcing them to a lowered position in the ground, and the hole through which the device is lowered and raised must be back-filled with uncompact fill, once the device is withdrawn.
[0010] It is therefore an object of this invention to provide a device for vibration-compacting a loose ground capable of reducing construction cost by simultaneously improving the ground in a wide range by rod compaction method. Another object of the invention is to provide a method of compacting soil or other granular materials that will provide a relatively high degree of compaction. Another object of the invention is to provide a method of compacting soil or other granular material that will provide a high degree of compaction to relatively large depths. Another object of the invention is to provide a method of compacting soil or other granular material that will not require additional material to backfill holes through which the compacting device is lowered into the soil. Another object of the invention is to provide a method of compacting soil or other granular material, which can be operated, with a minimum expenditure of time and manpower as the invention will provide for an ability to compact soil over a larger footprint than prior art. Another object of the invention is to provide an apparatus for the compaction of soil or other granular materials.
SUMMARY
[0011] Disclosed are methods, apparatus, and systems to provide a device for vibration-compacting a loose soil ground via Direct Power Compaction (DPC). As disclosed herein, a device for vibration-compacting a loose soil ground may be formed by multiple parts. A crane or other structure ay provide a fixed point or a main cable of which the present invention may be attached to. A shock absorber or damper may be fixed to the main cable, of which a vibrator device such as a vibro-hammer or pile driver may be secured under. A rod mounting plate of which may transmit vibration and force to a multitude of rods or piles, may be attached to the bottom output of the vibrator device. A plurality of rods may be vertically fixed to the lower surface of the plate using adapters at specified intervals, such as in a preferred embodiment, four rods may be attached in an H pattern. The vibrator device may be connected to the main wire rope of a crawler crane as to be vertically moved integrally with the rod mounting beam and the rod. The device may also enlist a holding plate position at the bottom section of the rods, wherein the holding plate comprises of a box metal holding body with loosely fitting holes, allowing the vertical movement of the rods through the holes or recesses in the holding plate and maintaining the interval between the rods constant. Each rod may be loosely fitted through the loose insertion hole of each rod formed on the holding body. The holding body may be connected to the auxiliary wire rope of the crawler crane for stability and strength. The compaction strength control also may be possible on an as-needed basis by controlling driving pitch, force and the cycle of compaction, and so forth.
[0012] In this aspect, the method may comprise using the above described H-piles or rods. Vibratory energy may be delivered directly into the ground. The typical configuration may be a quadruple axial DPC rig with a vibro-hammer at the top of each pile wherein the quadruple rods may be position in an H pattern. The extent of the treatment required for optimal densification or compaction may depend on the ground or soil content, grain size/geometry and other factors such as materials, of the soil being compacted. The best results may be realized in sandy soils with low fines content. For loose sands/granular soils, the DPC method yields may result equivalent to those of other densifications/compaction methods, but the simplicity and speed of the DPC method may make it the most efficient and economical solution for improvement of sandy soils.
[0013] Another aspect of the disclosure may include a system in which H shaped piles may first be driven into the ground through a combination of the structure such as the crane lowering the present invention such that the rods may penetrate into the ground along with the effects of the vibrating device, of which enables penetration into the ground, but also vibration of the surrounding soil, helping to minimize the void between the soil materials and compact the soil. When the rods reach the required depth, they may then be pulled up by a distance and inserted again by a distance. The ground may be compacted by the vibration of the vibro-hammer transmitting through the rods while the repetition of driving and withdrawing the rods is repeated. As the area under the rods becomes more compacted, the rods may withdraw more, and drive to a lesser depth every cycle, thus retreating the rods over cycles as the ground becomes compacted, until the rods are retreated to ground level and the entirety of the ground site is compacted. The above process may be executed while backfilling supply sand or another material, such as gravel at the ground surface hence the ground surface would not be lowered by the compaction effect. The lengths of pulling up distance and of the driving in distance may be calculated from the void ratio on the original ground of n value and the design ratio of n value, while the lengths may determine the driving pitch.
[0014] Yet another aspect of the disclosure may include an apparatus for the compaction of granular material comprising an elongated hollow member that is set into vibration by a constant vibrating hammer, the member and hammer being suspended from a crane-like apparatus. While in constant vibration, the member may be lowered into the ground in a substantially vertical position to a predetermined depth, maintained in the lowered position for a period of time, and then withdrawn. The same procedure may be repeated at a plurality of locations.
[0015] In this aspect, such apparatus, and systems may comprise methods to implement the methods described heretofore.
[0016] The methods and systems disclosed herein may be implemented in any means for achieving various aspects. Other features will be apparent from the accompanying drawings and from the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Example embodiments are illustrated by way of example and are not limited to the figures of the accompanying drawings, in which, like references indicate similar elements.
[0018] FIG. 1A-1F are component and detailed representations of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments.
[0019] FIG. 2 is an upward facing vertical schematic view of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments.
[0020] FIG. 3 is component side view of the present invention direct power compacting rig with vibration and driving device mounted on a crane, according to one or more embodiments.
[0021] FIG. 4 shows a step-by-step illustration of the compacting method of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments.
[0022] FIG. 5 is a detailed side view of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments.
[0023] FIG. 6 shows a detailed side view of a construction method of the direct power compacting rig with vibration and driving device, according to one or more embodiments.
[0024] FIG. 7 shows a detailed side view of a construction method of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments.
[0025] FIG. 8 shows a detailed side view a construction method of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments.
[0026] FIG. 9 shows a detailed side view a construction method of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments.
[0027] FIG. 10 shows a graphical representation of a construction method of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments.
[0028] FIG. 11 shows a graphical representation of a construction method of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments.
[0029] Other features of the present embodiments will be apparent from the accompanying drawings and from the detailed description that follows.
DETAILED DESCRIPTION
[0030] Disclosed are methods, apparatus, and systems to compact loose ground soil by vibration and compaction of H rods or piles driven by a vibration and driving device such as a vibro-hammer or other apparatus such as a pile driver. Although the present embodiments have been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the various embodiments. In addition, the components shown in the figures, their connections, couples, and relationships, and their functions, are meant to be exemplary only, and are not meant to limit the embodiments described herein.
[0031] In one or more embodiments, which may be in addition to the above and below embodiments, the present invention may describe a direct power compacting rig.
[0032] In one or more embodiments, which may be in addition to the above and below embodiments, the present invention may describe a direct power compacting rig with one or more rods to be driven into the ground for compaction or solidification purposes.
[0033] In one or more embodiments, which may be in addition to the above and below embodiments, the present invention may describe a direct power compacting rig with one or more rods to be driven into the ground for compaction or solidification purposes and a vibration and driving device such as a vibro-hammer connected to the rods, such that the vibro hammer may vibrate and transmit vibration and force into the ground soil as the rods move to a specific depth.
[0034] In one or more embodiments, which may be in addition to the above and below embodiments, the present invention may describe a direct power compacting rig with one or more rods to be driven into the ground for compaction or solidification purposes and attached to the main cable of a crane. It is noted that the crane maybe substituted for any other structure or machine such as a building, scaffolding structure, etc. The crane or structure may be moveable or mobile, and may be mounted or placed on the ground, or also may be water borne such as on a boat or barge, or moveable by any other method. As well as this it may be noted that the crane or other structure may move the present invention rig in any x, y or z direction in respect to the ground plane so that the point where work is done may be changed by the operator.
[0035] In one or more embodiments, which may be in addition to the above and below embodiments, the present invention may describe a vibration and driving device such as vibro-hammer attached or connected to the main wire cable of a crane or other structure of which in a preferred embodiment, the majority of the rig weight may be placed on the main cable. It is noted that in other embodiments, for other structures, multiple cables or ropes may be used, and in some embodiments, solid mounting points may be preferable, such as a solid mount to an articulating crane structure etc. The structure or crane may be water based such as on a floating barge or ship or land based such as a crawler crane or overhead crane. The structure or crane may be stationery, moving, rotating or of any type, either through the movement of the crane or structure mechanism, such as a tilting or rotating crane structure, or by moving the structure or crane itself to position the present invention over the intended compaction sites.
[0036] In one or more embodiments, which may be in addition to the above and below embodiments, the present invention may describe a vibration and driving device such as vibro-hammer attached or connected to the main wire cable of a crane or other structure of which in a preferred embodiment, the majority of the rig weight may be placed on the main cable and of which the main cable, or cables may lower the rig, and driving rods into the ground, such that either through the weight of the rig, the weight of the rig and the effects of the vibration and driving device, or through the use of other aides in addition, the rods may penetrate into the ground soil to a specific depth. It is noted that the vibration and forces of the rods may be transmitted into the ground, as is known in the art, the loose ground soil, or ground soil may compact, as the force and vibration reduced the voids between the particles of the soil, and thus the soil becomes improved. It is also noted that the force may radiate out from the rods, such that the rods may effect an immediate and proximate area of which may be compacted. Some of these methods may be termed as Direct Power Compaction Method (DPC), but may be among others enabled by the device.
[0037] The crane or structure of which the present invention vibration and driving rig is mounted on may raise and lower the rig through any method, such as on a typical crane, wherein the main cable is retracted via pulleys and motors. Other methods may include raising and lowering the boom of the crane and in turn raising and lowering the rig, a hydraulic ram raising and lower the rig, as well as any other methods
[0038] In one or more embodiments, which may be in addition to the above and below embodiments, the present invention may describe a vibration and driving device attached or connected to a structure or crane of which in between the aforementioned connection between the vibration and driving device and the main wire or mount to the crane or structure, is a shock absorber or vibration reduction device such as a damper shock or shock system. The shock absorber may be connected to the main wire cable or other structure by a hook and loop method, or through any other method. The shock absorbing device may be mounted to the vibration and driving device through any mounting method such as solid mount between the shock absorber and vibration and driving device. In some other embodiments, the connection between the shock absorber and the vibration and driving device may be a movable or pivotable structure such as a hook and eye. The shock absorber or dampening device may be a commonly found industrial damper or shock absorber such as a hydraulic shock absorber. In other embodiments, the damper may be coil spring based, or any other type of absorber or dampener. The shock absorber or dampener may be an active element, including sensor and servos or other pieces, such as using sensors and magnetorheological dampers or other shocks of which can control the amount of vibration travelling from the vibro-hammer and associated rods to the crane or main cable. Additionally, the dampener may provide for active dampening such as a sway control device such as a tuned mass damper or active mass dampener to reduce sway of the device. Also, the shock absorber may also provide for a fundamental absorbing ability for when the entire H-beam structure, vibration and driving device and structure are lowered and raised to reduce shock to the structure, crane and associated devices and structures.
[0039] In one or more embodiments, which may be in addition to the above and below embodiments, the present invention may describe a vibrating device such as a vibro-hammer or pile driver of which is connected to the shock absorber through any method, and of which in turn is connected to the crane main cable through any method.
[0040] In one or more embodiments, which may be in addition to the above and below embodiments, the present invention may describe a vibrating device such as a vibro-hammer or pile driver of which relates to rod compaction equipment. The vibrating or driving device such as the vibro-hammer or pile driver may solidify loose soil such as sandy soil as the rods or piles are impacted and inserted into the ground at the compaction site.
[0041] In one or more embodiments, which may be in addition to the above and below embodiments, the present invention may describe a vibrating or driving device such as a vibro-hammer or pile driver and of which may use magnetic, hydraulic, electrical, steam, diesel or any other lifting or vibrating mechanism. The vibro-hammer may provide for a weight that raises and then is dropped or actively lowered in addition to the force of gravity, such that the hammer pushes a pile, rod or other mechanism or structure into the ground, transferring force into the soil or ground, and thus impacting and compressing the ground to solidify, compact or strengthen the soil or ground. This may be done at any frequency such as 1 time per a second (1 Hz), many times per a second (>1 Hz), or 1 time over many seconds (<1 Hz).
[0042] In another embodiment, the present invention may include an apparatus for the compaction of granular material comprising an elongated hollow member that is set into vibration by a constant vibrating hammer, the member and hammer being suspended from a crane-like apparatus. While in constant vibration, the member may be lowered into the ground in a substantially vertical position to a predetermined depth, maintained in the lowered position for a period of time, and then withdrawn. The same procedure may be repeated at a plurality of locations.
[0043] The mechanism for the vibratory hammer may be a vertical travel lead system, hydraulic hammer, hydraulic press in, vibratory like driver/extractor, or piling rig. The preferred embodiment may use a vibratory pile driver/extractor of which contains a system of counter-rotating weights, powered by hydraulic or electric motors, and designed in such a way that horizontal vibrations cancel out, while vertical vibrations are transmitted into the pile. Vibratory hammers can either drive in or extract a pile. Additionally, any type of hammers may be used with several different vibration rates, such as 1200 vibrations per minute to 2400 vibrations per minute, or over any range. The vibration rate may be chosen based on soil conditions at the site and other factors such as power requirements and purchase price of the equipment and needs of the operator.
[0044] In one or more embodiments, which may be in addition to the above and below embodiments, the present invention may describe a vibro-hammer, of which is connected to a vibration dampener or shock absorber, of which is connected to or hangs from a crane main cable. The vibro-hammer may then pressure, drive or vibrate, such as driving a force into a piles or rods of which then may transfer force into the ground. The present invention may provide the ability to drive multiple rods into the ground through the use of an adapter plate and adapters. The adapter plate may connect through any means to the output of the vibro-hammer and transfer force to connected rods or piles. In a preferred embodiment, this may be four or more rods.
[0045] In one or more embodiments, which may be in addition to the above and below embodiments, the present invention may describe a vibration and driving device of which is connected to a vibration dampener or shock absorber, of which is connected to or hangs from a crane main cable. The vibration and driving device may then pressure, drive or vibrate into a connecting plate, of which provides a provision to mount at least one, and preferably four rods, pile or H beams. The plate may be directly connected to the vibration and driving device, through a direct connection such as with a friction fit or interlocking structures with bolts, welds or by any other method such that a force travels from the vibration and driving device uniformly into the plate and uniformly distributes to the rods or piles. The plate may then transfer the force uniformly through the plate and into the rods, of which may typically be a hollow cylindrical steel pipe. Depending on the particular vibration and driving device and coupling arrangement used, the vibro-hammer can be attached to plate and to the pipe at any position that will enable it to set the pipes or rods into vibration such that they may impact and compact the ground soil. The plate may be of any design, and may be structured as a square plate with a length and width dimension, such that the rods may be mounted at a particular distance from each other, and a height dimension such the plate is strong enough to withstand the impact forces of the vibration and driving device and ground soil. The plate may be made of any material, wherein the material suits the demands of the system for strength, cost and weight and may be of any method such as steel or a honeycomb structure, wherein the structure may be made of any material that can transfer the forces to the rods or piles.
[0046] In one or more embodiments, which may be in addition to the above and below embodiments, the plate, as aforementioned, may be connected to up to four rods, piles or beams of which may transfer force into the ground and compact the loose soil such that the loose soil may be solidified or compacted for a purpose.
[0047] In one or more embodiments, which may be in addition to the above and below embodiments, the rods or beams may be made of any material such as steel, iron, aluminum or any other metal, alloy, composite, or mixture of materials. The beams or rods may be a single piece design, or multi piece design, wherein they may be made of different elements, welded or connected together with each section built to a purpose, such as the bottom driving end made of a stronger or harder material with a wider base such that the surface area of the soil contacting the driver is increased and the strength of the material reduces wear. The middle rod portion may be may be made of a relatively weaker material compared to the impact end, wherein the material still tolerates the forces of the impact, but in the interest of cost, weight and other reasons, does not need to have the strength the bottom impact portion has to withstand contact with the ground or soil. The driving end of each rod may be of any design, such as a wider flat base, or in some circumstances, a cone shape to drive through hard soil layers. These ends may be interchangeable or replaceable to reduce downtime and cost for wear or changing conditions or needs.
[0048] In one or more embodiments, which may be in addition to the above and below embodiments, the rod or pile may be shaped in a fashion wherein the rod, pile or driver fits within a particular dimension or is designed for a purpose such as for shipping or transporting.
[0049] In one or more embodiments, which may be in addition to the above and below embodiments, the rod is shaped in a fashion wherein the rod, pile or driver is structured in particular dimensions to provide for a strength, weight and cost restraint.
[0050] In one or more embodiments, which may be in addition to the above and below embodiments wherein the rods, piles or driver are positioned on the plate in a patterned fashion, and wherein the preferred embodiment may have four rods in a square or H pattern, and wherein each rod is positioned by a set distance from one another.
[0051] In one or more embodiments, which may be in addition to the above and below embodiments, wherein above the ground and surrounding a portion of the lower section of the rods or driver, a holding plate or catch fork is designed and structured, wherein the rods travel through recesses or loosely fitting holes in the holding plate or catch fork such that the rods do not push down or transmit force into or on the holding plate or catch fork, but that the catch fork provides lateral stability to the rods, so that the rods are driven straight into the ground. The catch fork or holding plate may be made of any material, and may provide for friction reduction sleeves where the rods go through the holding plate or catch fork. The catch fork may be connected or otherwise structured or connected to the crane or structure on which the rig is mounted so that the catch fork is stationary in terms of the crane and ground plane. The holding plate or catch fork may also be hung or otherwise supported via auxiliary wires, cables or rope to the boom of the crane or other places on the crane. In one or more embodiments, which may be in addition to the above and below embodiments, the catch fork may be formed in a substantially box-type or any other shape or configuration wherein a rod mounting beam that may be fixed vertically at regular interval or, a plurality of rods may be vertically fixed to the lower surface of the device at specified intervals. Additionally the catch fork or rod mounting beam may be connected to the vibration and driving device and mounting plate. The device also may comprise of a box metal holding body allowing the vertical movement of the rod by maintaining the interval between the rods constant. Each rod may be loosely fitted through an insertion hole or recess in the holding body or catch fork. The holding body may be connected to the auxiliary wire rope of the crane.
[0052] In one or more embodiments, which may be in addition to the above and below embodiments, there also may be a transducer or damper of which may help position, limit or reduce unwanted force transmitted from the catch fork to the crane or structure. The transducer may be of any type such as foam, rubber, coil spring, or any other type of dampening such as a hydraulic damper. The transducer may also move the catch folk to direct the entire rig along with the crane boom or reposition the impact site.
[0053] In one or more embodiments, which may be in addition to the above and below embodiments, the present invention may provide a method to impact the ground soil in any pattern. The pattern may be determined on the needs or purpose of the project and the soil. An embodiment may have a pattern that is based on the soil shape or soil survey wherein specific areas were found to need compaction. The pattern may be to specific distances and depths as set by the operator, and the crane and catch fork may move or position the rods or piles to the specific impact site or sites.
[0054] In some embodiments, which may be in addition to the above and below embodiments, the present invention may provide a method to impact the ground soil with rods or piles. The piles or rods may be inserted to a specific depth in a down stroke by the force provided by the driver or vibration and driving device and the weight of the rig, among other possible sources, which in turn compacts the soil as the rods are driven into the soil. The rods are then retracted to a specific depth in an upstroke. The rods, then may be again inserted or forced down to another specific depth in a down stroke, and in turn compacting or solidifying the soil directly under the rods or piles, as well as the soil surrounding the rods and impact areas. The rods or piles may then be retracted to another specific depth in another upstroke, and then reinserted to another depth in another down stroke. This pattern may be repeated, such that the ground soil may be solidified and compacted to fit the needs of the operator.
[0055] It is noted that in the above cycle, the rods may be inserted first to the lowest depth in a down stroke, and the subsequent upstroke may be to any depth above the lowest depth. The then, subsequent re insertion down stroke, may be higher than the initial lowest depth, as the soil compacts and solidifies below the rod or pile. The subsequent retraction upstrokes and insertion down strokes, may provide for less and less depth, as over the cycles, the soil becomes compacted at less and less depth, and as such the rod or pile compacts soil at a less and less depth. As such, the rod or pile compacts the soil along the entire distance or depth of the initial insertion, until all the soil is compacted from the initial depth, and surrounding area, to the ground level and surrounding area. It is noted that the depths of the upstroke and down stroke, while above described in be in a preferred embodiment, may also provide for changing down stroke depths, of which may be larger than earlier down strokes. As well as this, the upstrokes may or may not retreat the rods out of the soil or ground completely.
[0056] In some embodiments, in addition to the above and below embodiments a material, such as additional soil, or other material, such as solidification material, or other types of soil with desired properties, maybe introduced to the impact site and bores. The material may be introduced as backfill as the rod, driver or pile forces or compacts the existing soil, or may provide for additional material to be compacted, either to provide for more area, or provide or alter the soil with additional or desired characteristics, such as to reduce moisture content for a specific compacted area, or finer or larger grain soil depending on the application. The additional material may be provided through any method, such as a backhoe or tractor, or may be piped or fed through a pressurized line such as in the introduction of concrete. In a preferred embodiment the material is simply pushed into the impact site and bore by a tractor as the piles or rods are retracted, such that the material may provide for backfill as the soil is compacted in a subsequent down stroke, and as such keep the ground plane at the initial height or provide for additional material for compaction.
[0057] An auxiliary note is made that the present invention vibration and driving rig may be power by any means, such as a diesel generator, hydraulic system, or electric system as examples. Also, control of the device may be through any means, whether hydraulic, electric and electronic, or lever based, at the rig site, remotely, over a network, on the crane or from and by any means. The present invention may also include sensors, servos, or other devices in which measurements, effects and surveys may be completed, prior, during or after the process and of which allows the device to manually or automatically be adjusted in any manner. This includes printed readouts, display screens, notification monitors, or any user interface, or computer interface system, of which may automatically or manually require input and adjustment depending on the application.
[0058] FIG. 1A-1F are component and detailed representations of the present invention vibration rig, according to one or more embodiments.
[0059] FIG. 1A is a front view of the present invention direct power compacting rig with a vibration and driving device such as a vibro-hammer. The rig in a preferred embodiment may be connected or hanging from the main cable of a crane over the intended impaction point. A shock absorber or damper 105 may be suspended from the main crane cable wherein, the rig may be suspended below. Attached to the shock absorber or damper 105 , through any means, may be the vibro-hammer 104 of which may be of any design or structure as aforementioned. The hammer may connect directly to the distribution plate 103 , of which may transfer force to the four adapters 102 a, 102 b, 102 c and 102 d, of which 102 a and 102 b are visible in FIG. 1A . These adapters may transmit force into the rods 101 a, 101 b, 101 c, and 101 d, of which 101 a and 101 b are visible in FIG. 1A . These rods may vibrate or move and impact the ground at a specific force and Hz provided by the vibro-hammer, of which may provide for compaction, vibration and ground improvement.
[0060] FIG. 1B provides a rear view of the present invention, which is the same structure of that in front view FIG. 1A . FIG. 1B provides for a view of the adapters 102 c and 102 b and rods 101 c and 101 d of which were not visible in FIG. 1A .
[0061] FIG. 1C provides for a component representation of the present invention direct power compacting rig with vibro-hammer 101 , wherein the plate 103 is visible and connects to the adapters 102 a, 102 b, 102 c, and 102 d of which taper to connect to the rods 101 a, 101 b, 101 c and 101 d.
[0062] FIG. 1D provides for a detail front view of the direct power compacting rig with vibro-hammer 101 of which is the same view as FIG. 1A , but with details of which are missing in the component view.
[0063] FIG. 1E provides the same rear view of the present invention direct power compacting rig with vibro-hammer 101 as FIG. 1B , but further provides details of which are missing in the component view.
[0064] FIG. 1F provides the same bottom view as FIG. 1C but provides further details missing in the component view.
[0065] FIG. 2 is a downward facing vertical schematic view of the present invention direct power compacting rig impact sites, according to one or more embodiments. FIG. 2 provides a preferred embodiment of a pattern of four group impact points, each with four individual impact sites performed by one rig. Site 205 a provides for distance between the four individual impact sites in the y-axis as 282 a and the x-axis as 282 b. The individual impact sites pacing corresponds to the distance the rods are presented and patterned on the rig. The distance may be of any measurement that is suitable to the conditions and needs and may be designed as such. FIG. 2 also presents three other group impact sites of which each have four individual impact sites. The spacing between the group impact sites is dictated the rig's movement, and the grouped impact sites may be measured by distances in the y axis by a distance 281 a, as exampled by between sites 205 a and 205 c and in the x axis by 281 b, as exampled between impact sites 205 c and 205 d . Each group of four individual impact sites may be performed at once by a rig with four rods or drivers. It is also noted that other patterns and schematics may be used wherein there is a different amount of rods or drivers or necessitated by the terrain or soil.
[0066] FIG. 3 is component side view of the present invention direct power compacting rig with vibration and driving device such as a vibro-hammer mounted on a crane, according to one or more embodiments. FIG. 3 presents a crane 315 of which the DPC rig 301 is mounted on. The crane 315 may have a main cable 320 of which may be made of steel braided cable, or any other material. The cable 320 may connect to a shock absorber 305 , of which may connect to the vibration and driving device or vibro-hammer 304 . The hammer may then connect to the adapting plate 303 , of which is connected to the adapters 302 , of which the adapters are connected to the drivers or rods, of which 301 a and 302 b are in view. The rods may run in a square H-pattern formation down to the impact site 301 e. The rods upon impact may be forced or pushed by the impact from the ground, and may pivot or otherwise undesirably move in the x or z axis. Thus, a holding body or plate 306 may extend from the crane, or other structure, and of which may also be further supported by guy wires or other auxiliary cables 321 a, 321 b, and 321 c, of which may connect by any fashion to the crane or another structure and the holding plate 306 . The holding plate 306 may then provide for a recess or loose fitting hole for each respective rod to pass through, and of which the plate may limit the amount of travel the rods may be forced into at any given direction. A transducer or shock absorber 316 may limit the shock impacted into the holding plate and transferred to the crane or structure. The transducer or shock absorber 316 may also aid in the positioning of the rods or drivers and provide further strength.
[0067] FIG. 4 shows the construction method and steps of the present invention direct power compacting rig with vibro-hammer, according to one or more embodiments. FIG. 4 displays an example embodiment with simplified single rod and vibration rig in different steps 481 , 482 , 483 , 484 , 485 , 486 and 487 , of which each step is in various position of compaction. Rod and vibration rig 481 displays the first position, wherein the rod is resting on the ground prior to any work being done. Rod 482 shows the second step being completed, wherein the rod is inserted or penetrated into the ground to a specific depth in a down stroke. A sand, or other material supply may be provided, at point 471 , wherein, the sand may either be stacked around the impact site by a tractor or backhoe, such that when the rod is then later retracted in an upstroke and reinserted or driven down in a down stroke, the material may fall into the bore. It is noted that the rod in upstrokes may be retreated to a point below the ground plane, or may be retracted out of the ground completely, depending on the embodiment and needs of compaction. The introduced material, introduced by a tractor or backhoe piled around the insertion site, then may be used as a backfill to fill the ground as it is compacted so that the ground plane stays level, or may be used as compaction material by falling in the bore and under the rod completely or incompletely and subsequently compacted with the soil material. The material may also be provided through other means, such as through hoses or pipes, wherein the material may be pressured, or introduced at a specific depth. Rod 483 shows the third step completed, wherein the rod is pulled up in an upstroke by a specific distance 491 . Rod 484 shows the fourth step completed wherein the rod is inserted again in a down stroke, by a distance 492 , and wherein the rod compacts the soil with either just the existing ground soil already in the bore or with additional sand or material provided 471 . Rod 485 shows the fifth step completed wherein the rod is pulled up in an upstroke by a depth 493 . Rod 486 shows the sixth step wherein the rod is inserted again in a down stroke, wherein the rod compacts the soil either already in the bore, or with additional material 471 provided. As seen in the seventh step, the vibro-hammer and rod 487 may then be pulled up out of the ground, wherein then the ground is then fully compacted, and wherein the rig may be repositioned to another site. Waves 491 show the compaction of the rod or driver transmitted through the soil, such that the soil becomes compacted. These compaction effects may radiate as shown, but also may radiate to the sides of the rods as both the downward force of the rods is applied, as well as the vibration. The soil, being loose, may have large gaps or distance between individual particles, and the compaction may reduce these gaps, making a tighter, harder and more compact soil. The force and vibration transmitted by the vibration and driving device, and subsequently the rods, may perform the aforementioned compaction. It is noted that there may be intermediary steps between each of the aforementioned steps and the numbering is purely for example purposed. Also, it is noted that the steps may be any order and that the depths may vary due to the needs of the operator. The steps may also be repeated in any plurality and patterned, including additional steps, such as additional compaction cycles after the example sixth step and before the example seventh step.
[0068] FIG. 5 is a detailed side view of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments. FIG. 5 presents a crane 515 of which provides a main cable 506 which connects to the present invention direct power compacting rig with vibro-hammer 504 of which is connected to the adapter plate and adapters 503 , of which connects to rods 501 a and 501 b, of which impact and penetrate the ground. There may be a holding plate 506 of which may limit the movement of the rods, and of which may be connected directly or through a transducer or shock absorber to the crane 515 and further supported by guy wires 507 .
[0069] FIG. 6 shows a detailed side view of a construction method of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments. FIG. 6 shows the example step one wherein the vibration rig 601 is positioned over an impact site 691 , wherein a tractor or backhoe 670 provides sand or other material 671 to the impact site and the rods are retracted above the ground plane.
[0070] FIG. 7 shows a detailed side view of a construction method of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments. FIG. 7 shows the example step two wherein the direct power compacting rig with vibro-hammer 701 is positioned over an impact site 791 , and the rods 702 are inserted or penetrated into the ground at their full depth, or the depth necessary for the current function. A backhoe or tractor 770 may provide sand or another material 771 , of which may flow or fall into the bores, simultaneously or after the rods are inserted.
[0071] FIG. 8 shows a detailed side view a construction method of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments. FIG. 8 shows the example step three wherein the vibration rig 801 is positioned over an impact site 891 , and the rods 802 are retreated or moved to a specific higher depth than the depth in example step 2 . This may provide or create a cavity or bore 895 of which sand or another material 871 , provided by a machine 870 , may have fallen into or placed in by the operators, or of which the cavity may be filled of existing loose ground soil caved in or fallen from the walls of the cavity.
[0072] FIG. 9 shows a detailed side view a construction method of the present invention direct power compacting rig with vibration and driving device, according to one or more embodiments. FIG. 9 shows the example step four wherein the vibration rig 901 is positioned over an impact site 991 , and the rods 902 are inserted or penetrated again to a depth, of which compacts the existing ground soil and possibly the material 971 that has been introduced by a machine 970 . The re-insertion of the rods may compact the soil and material such that the soil becomes compacted and stronger. Area 995 may be represented as a compaction zone wherein the ground soil solely has become compacted, or the ground soil mixed with the material 971 may be compacted. The compaction area also may radiate out from the impact points, creating a larger area wherein the machine may have influenced and provided strength and compaction as the forces and vibration are transmitted throughout the ground. Also, the vibro-hammer at a specific Hz, may further provide positive effects in compaction that radiates throughout the ground soil and material.
[0073] FIG. 10 shows a graphical representation of a construction method of the present invention vibration and driving device, according to one or more embodiments. FIG. 10 graph the depth of the rods changing over time with example depths from a study. For instance in area 1010 , it is seen that for a given time, the rod depth increases from 0 m to 10 m. Then it is seen in area 1020 , the depth increases in an alternating fashion, providing a driving and vibrating motion of up and down strokes, which provides for compaction. For instance, arrow 1021 shows the depth change in a down stroke, while arrow 1022 provides the distance of an upstroke. With an alternating up stroke and down stroke, as the rod is retracted, the ground becomes compacted, as for each upstroke, the rod is retracted and existing or new soil or other material may fill the hole below the driver. On the subsequent down stroke, which is less than the preceding upstroke, the material may be compacted in the area below the rod or driver. The process then repeats, alternating upstrokes and down strokes, such that along the depth of the rod, the ground becomes compacted until the rod fully retreats and the entire depth has been compacted.
[0074] FIG. 11 shows a graphical representation of a construction method of the present invention vibration and driving rig, according to one or more embodiments. FIG. 11 provides for a study improvement of a typical use of the present invention. On the graph the x-axis provides for the SPT N-value which is a standard penetration test and good meter of ground strength and penetration resistance, wherein a higher value is considered to be stronger. The y-axis provides for an indicator of depth and soil type. The results of the study provides the black line with diamond indicators representing the penetration values for the existing unmodified soil such as gravel or sand at the respective depths marked and the grey line with square indicators representing the penetration value for the modified soil. In this example, it may be seen that the gray line with square indicators, which represents the ground soil after being modified by the present invention, may be of a higher value than that of the original soil as the SPT N-value for each specific depth and gravel type after modification was improved over the original values.
[0075] A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the claimed invention. In addition, the methods depicted in the figures do not require the particular order shown, or sequential order, to achieve desirable results. In addition, other steps may be provided, or steps may be eliminated, from the described flows, and other components may be added to, or removed from, the described systems. Accordingly, other embodiments are within the scope of the following claims.
[0076] It may be appreciated that the various systems, methods, and apparatus disclosed herein may be performed in any order. The structures in the figures may be shown as distinct and communicating with only a few specific structures and not others. The structures may be merged with each other, may perform overlapping functions, and may communicate with other structures not shown to be connected in the figures. Accordingly, the specification and/or drawings may be regarded in an illustrative rather than a restrictive sense.
[0077] The structures and modules in the figures may be shown as distinct and communicating with only a few specific structures and not others. The structures may be merged with each other, may perform overlapping functions, and may communicate with other structures not shown to be connected in the figures. Accordingly, the specification and/or drawings may be regarded in an illustrative rather than a restrictive sense.
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The system, method and apparatus described relates generally to a method of Direct Power Compaction (DPC). In one example embodiment to methods, apparatus, and systems to compact loose ground by vibration and compaction of H piles driven by vibrators or drivers (vibro-hammer). The DPC method is an efficient and highly economical technique for densifying loose soils. In the procedure piles, with an innovative H pattern structure, are driven in the ground using a combination of downward and vibratory force to move particles of the loose or sandy soil closer together and reduce the voids between them. Subsequent backfilling and vibration at the H-pile sites achieves the highest density possible and provides for an improvement ground soil structure and load bearing capacity.
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[0001] The present invention relates to a device for overturning mattresses in hemming machines.
BACKGROUND OF THE INVENTION
[0002] As is known, the case that contains mattresses is constituted by two panels which cover the opposite faces of the mattress and by a perimetric band which is joined to the panels with the aid of a tape which is sewn so as to straddle the adjacent edges of the panels and of the band.
[0003] A stationary sewing machine is normally used to sew the tape, and the mattress is pushed and turned manually with respect to the sewing machine on a worktable, with considerable effort on the part of the operator.
[0004] In order to facilitate the work of the operator, the worktable is often constituted by a roller bed, and while the advancement of the mattress occurs by the means of the traction performed by the sewing machine, the rotation of the mattress with respect to the sewing machine in order to hem the perpendicular sides and corners of the mattress is performed by means of an appropriately provided orientation device. A device of this type is disclosed for example in EP 682135 in the name of this same Applicant.
[0005] This patent also discloses a device which allows to overturn the mattress when the sewing of a perimetric hem of one face has ended, so as to perform the perimetric sewing of the opposite face.
[0006] The overturning device disclosed in EP682135, when not active, is accommodated between the rollers that form the worktable and therefore cannot be used in cases in which the worktable is constituted by a moving belt.
[0007] GB 1,144,954, U.S. Pat. No. 3,490,061 also disclose a mattress overturning device for hemming machines which have a worktable constituted by a moving belt. However, such overturning device can be used only in hemming machines of a different concept, in which the mattress, during hemming, remains stationary and the sewing machine moves around it.
SUMMARY OF THE INVENTION
[0008] The aim of the present invention is to provide a device which allows the overturning of the mattress even in hemming machines in which the sewing machine is stationary but at the same time can be used both if the worktable is of the roller type and if it is of the moving belt type.
[0009] Within this aim, an object of the present invention is to provide a device which is structurally simple and therefore cheap and highly reliable in operation.
[0010] This aim and this and other objects which will become better apparent hereinafter are achieved with a device whose characteristics are defined in the claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Further characteristics and advantages of the invention will become better apparent from the following detailed description of a preferred embodiment thereof, illustrated by way of non-limiting example in the accompanying drawings, wherein:
[0012] FIG. 1 is a side view of the overturning device in three distinct operating positions;
[0013] FIGS. 2 , 3 , 4 and 5 are plan views of the device in successive operating positions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] With reference to FIGS. 1 and 2 , the reference numeral 1 generally designates a belt which is closed in a loop around a pair of mutually parallel rollers 2 , 3 , one of which is connected to a motor, which is not shown. An upper portion 4 of the belt 1 constitutes the worktable of the hemming machine on which a mattress 5 is moved, i.e., made to advance and rotate, in order to provide the hem.
[0015] A frame 7 , for supporting and positioning a sewing machine which forms the hem of the mattress and the elements intended to move and orient the mattress, is arranged on a first side of the belt 1 (see FIGS. 2-5 ) where the operator of the hemming machine is generally located and which, for the sake of convenience in description, is referenced hereinafter (and in the appended claims) as the inner side. The “outer side” or second side of the belt 1 (worktable) will be the side opposite to the inner side. Of such frame, which is not shown in full in the drawings since it has a traditional construction, as described and illustrated for example in the already cited EP682135, only a motorized arm 6 is shown and is supported on a column so that it can swing about a vertical axis A and is provided with a pair of pneumatic pressers 8 which are adapted to lock the mattress 5 on the worktable 4 in order to be able to turn it about the vertical axis A when the arm 6 is actuated.
[0016] A shaft 9 is supported on a support 30 located below the worktable 4 , is parallel to the rollers 2 , 3 and protrudes from the outer side of the belt 1 which is arranged opposite the frame 7 . An arm 10 and a sprocket 11 adjacent thereto are jointly connected for rotation on the shaft 9 . A chain 12 meshes with the sprocket 11 and is closed in a loop around a pinion 13 which is keyed to the axis of an actuation motor 14 installed below the belt 1 . The motor 14 is capable of imparting to the arm 10 mutually opposite angular strokes, so as to determine in practice an oscillation of approximately 180° and therefore the overturning of the arm 10 between two final positions which are laterally adjacent to the outer side of the worktable 4 .
[0017] The arm 10 comprises an angled end portion 15 , from which a flat bracket 16 protrudes in a cantilever fashion. The bracket 16 , with respect to the shaft 9 , is at a greater distance than the roller 2 , so that in a final position of the arm 10 it forms a sort of extension of the worktable 4 , while in the other final position it is superimposed on the worktable 4 .
[0018] A hydraulic jack 17 is rigidly coupled to the angled portion 15 and is provided with a stem 18 which extends within a tube 19 , which is guided on a cylinder 20 of the jack and is jointly connected in a cantilever fashion to the end of the angled portion 15 . The jack 17 has an axis which is parallel to the shaft 9 and a distance from the bracket 16 which is greater than the thickness of the mattress 5 , so that the mattress, when the bracket 16 is coplanar with respect to the worktable 4 , can be inserted between the bracket 16 and the tube 19 .
[0019] A second hydraulic jack 21 is fixed below the bracket 16 , is parallel to the preceding one and has a stem 22 which extends toward the arm 10 . A T-shaped member 23 is connected to the end of the stem 22 and by way of the movement of the stem can move along a straight slot 24 of the bracket 16 . A plate 25 is fixed to the T-shaped member 23 , is perpendicular to the stem and can move, acting as a pusher, above the bracket 16 and below the jack 17 between a position for alignment with the outer edge of the belt and a position arranged inside the worktable 4 .
[0020] The operation of the described device is as follows.
[0021] An initial situation is assumed in which hemming of the upper face of the mattress 5 is assumed to have ended. This situation is shown in FIG. 2 , in which the mattress 5 is again arranged with its short side adjacent to the frame 7 for supporting the sewing machine and aligned with the internal edge of the worktable, along which it is made to advance during hemming. During hemming, the arm 10 of the device is overturned in the parking position in which the bracket 16 is coplanar to the worktable 4 and the tube 19 is at a height, with respect to the worktable 4 , which is greater than the thickness of the mattress 5 , so as to allow insertion of the mattress between the bracket 16 and the tube 19 when it is necessary to proceed with the overturning of the mattress. This parking situation is designated by the reference letter B in FIG. 1 . It should be noted that in this situation the pressers 8 are raised with respect to the mattress in order to allow freedom of movement thereof on the worktable, while the jacks 17 and 21 are elongated so that the plate 25 is substantially aligned with the outer edge of the belt 1 that lies opposite the sewing machine and the tube 19 is extended until it interferes with the advancement front of the mattress.
[0022] Once the hemming of one face of the mattress has ended, in order to be able to proceed with the hemming of the opposite face, the operator, either manually or by means of an appropriately provided pusher, moves the mattress away from the sewing machine and positions it until the edge that lies opposite the sewing machine is aligned with the plate 25 , as shown in broken lines in FIG. 2 .
[0023] By way of the actuation of the belt 1 , the mattress 5 is then made to advance until its front end is inserted between the tube 19 and the bracket 16 ( FIG. 3 ). When the rear end of the mattress is at, or has passed beyond, the axis 9 of the arm 10 , the motor 14 is activated and, by means of the transmission 11 - 13 , imparts to the arm 10 a 180° rotation which first produces the straightening in a vertical position (position C of FIG. 1 ) and then the overturning of the mattress 5 on the worktable (position D of FIG. 1 and FIG. 4 ).
[0024] At this point, the jack 21 is activated and, by means of the pusher plate 25 , acts on the edge of the overturned mattress, so as to move the mattress 5 transversely on the worktable 4 and move it closer to the sewing machine, so that the assigned operator can perform hemming of the opposite face of the mattress ( FIG. 5 ).
[0025] It is noted that since in the position D the tube 19 is arranged below the mattress ( FIG. 1 ), the jack 17 is also activated simultaneously with the jack 21 , so that by returning the tube 19 onto the cylinder of the jack 17 the mattress 5 can rest completely on the worktable 4 and allow a regular movement and exact positioning of the mattress with respect to the sewing machine on the part of the operator and the execution of perfect hemming.
[0026] Finally, while final hemming proceeds, the arm 10 is inverted again in the initial position B of FIG. 1 in order to be ready to proceed with the overturning of subsequent mattresses.
[0027] As can be seen, the described device achieves the intended aim and objects. In particular, it allows to overturn mattresses even when the worktable is constituted by a roller bed.
[0028] The described device is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. In particular, in order to ensure better grip of the mattress on the tube 19 during overturning, said tube is provided with a surface covering of friction material.
[0029] Another improvement consists in using on the bracket 16 means which are adapted to form with the tube 19 a sort of clamp which grips and retains the mattress during the overturning step.
[0030] Another improvement of the device provides, in order to actuate the arm 10 , instead of the transmission 11 - 14 , a mechanism which is composed of a lever which is radially jointly connected to the shaft 9 and is associated with a hydraulic actuator so as to impart to the arm 10 the oscillation through approximately 180°.
[0031] The disclosures in Italian Patent Application No. B02007A000320 from which this application claims priority are incorporated herein by reference.
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A device for overturning mattresses in a hemming machine, comprising a worktable which has an inner side and an outer side, a sewing machine to perform the perimetric hemming of the mattress and an assembly for orienting the mattress on the worktable being arranged on the inner side, and further comprising an articulated arm, which is arranged on the outer side of the worktable and is provided with grippers for gripping a mattress, the arm being able to oscillate between a position for gripping the mattress and a position for releasing the mattress after a rotation sufficient to overturn the mattress.
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BACKGROUND
The present disclosure relates to a method of forming a semiconductor structure, and more particularly to a method of forming a semiconductor structure including a transferred semiconductor layer, and structures for effecting the same and formed by the same.
A substrate including a thin silicon layer can be formed by employing a hydrogen-containing cleavage layer. For example, hydrogen ions (protons) can be implanted into a bulk silicon substrate to form a hydrogen-containing layer at a constant depth from a top surface of the bulk silicon substrate. A handle substrate is bonded to the top surface of the bulk silicon substrate, and the bulk silicon substrate is subsequently cleaved at the hydrogen-containing layer so that a thin silicon layer above the hydrogen-containing layer is “transferred” to the handle substrate to form a new substrate, which is an assembly of the handle substrate and the transferred thin silicon layer. The remaining portion of the bulk substrate is planarized by chemical mechanical planarization and re-used to provide another thin silicon layer for another layer transfer process until the thickness of the bulk substrate becomes too thin to be employed for layer transfer purposes.
The method of forming a substrate including a thin silicon layer employing hydrogen implantation is subject to many limitations. First, a hydrogen-containing layer must be formed through hydrogen implantation. Because of inherent depth distribution of the implanted hydrogen ions, a high dose of hydrogen ions must be implanted into the bulk silicon substrate to be able to induce cleavage at the hydrogen-containing layer. Because the vertical distribution range of the hydrogen ions increases with increasing depth of implantation, higher dose of hydrogen ions is needed as the depth of the hydrogen-containing layer increases.
Further, due to the propensity of bulk silicon substrates to cleave along major crystallographic planes, cleavage along only some crystallographic orientations of a silicon crystal produces clean cleavage planes with atomic planarity, while cleavage along other crystallographic orientations can produce cleavage planes that include facets and/or rough surfaces that need to be planarized, for example, by chemical mechanical planarization.
Yet further, the bulk substrate after cleavage needs to be planarized before re-usage. In addition, any modification to the dopant concentration in the transferred layer requires additional processes that include implantation or plasma treatment and dopant activation by a high temperature anneal.
Thus, a process of forming a transferred silicon layer without employing hydrogen ion implantation is desired.
BRIEF SUMMARY
A germanium-containing layer is deposited on a single crystalline bulk silicon substrate in an ambient including a level of oxygen partial pressure sufficient to incorporate 1%-50% of oxygen in atomic concentration. The thickness of the germanium-containing layer may be limited to facilitate some degree of epitaxial alignment with the underlying silicon substrate. Optionally, a graded germanium-containing layer including a graded silicon-germanium alloy can be grown on, or replace, the germanium-containing layer. An at least partially crystalline silicon layer is subsequently deposited on the germanium-containing layer. A handle substrate is bonded to the at least partially crystalline silicon layer. The assembly of the bulk silicon substrate, the germanium-containing layer, the at least partially crystalline silicon layer, and the handle substrate is cleaved within the germanium-containing layer to provide a composite substrate including the handle substrate and the at least partially crystalline silicon layer. Any remaining portion of the germanium-containing layer on the composite substrate is removed.
According to an aspect of the present disclosure, a method of forming a semiconductor structure includes: growing a germanium-containing layer on a single crystalline silicon substrate; growing an at least partially crystalline silicon layer on the germanium-containing layer; bonding a handle substrate to the at least partially crystalline silicon layer; and cleaving an assembly of the handle substrate and the at least partially crystalline silicon layer off the single crystalline silicon substrate along a plane in the germanium-containing layer.
According to another aspect of the present disclosure, a semiconductor structure including a material stack, which includes: a single crystalline silicon substrate; a germanium-containing layer contacting the single crystalline silicon substrate; an at least partially crystalline silicon layer located on the germanium-containing layer; and a handle substrate bonded to the at least partially crystalline silicon layer.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1A-1F are vertical cross-sectional views of a first exemplary semiconductor structure according to a first embodiment of the present disclosure.
FIG. 2A-2F are vertical cross-sectional views of a second exemplary semiconductor structure according to a second embodiment of the present disclosure.
FIG. 3A-3F are vertical cross-sectional views of a third exemplary semiconductor structure according to a third embodiment of the present disclosure.
FIG. 4A-4F are vertical cross-sectional views of a fourth exemplary semiconductor structure according to a fourth embodiment of the present disclosure.
FIG. 5 is a graph of an X-ray diffraction data from a first sample according to the first embodiment of the present disclosure as a function of 2θ.
FIG. 6 is a graph of an X-ray diffraction data from a second sample according to the second embodiment of the present disclosure as a function of 2θ.
FIG. 7 is a graph of an X-ray diffraction data from a third sample including a polysilicon film as a function of 2θ.
FIG. 8 is a graph illustrating data from a secondary ion mass spectroscopy (SIMS) run on the second sample according to the second embodiment of the present disclosure.
FIG. 9 is a scanning electron micrograph (SEM) of a broken portion of the first sample along a vertical cleavage plane without cleaving along the oxygen-containing germanium layer.
FIG. 10 is a scanning electron micrograph (SEM) of a portion of the first sample, which was cleaved along the oxygen-containing germanium layer and includes the bulk silicon substrate and a portion of the oxygen-containing germanium layer.
DETAILED DESCRIPTION
As stated above, the present disclosure relates to a method of forming a semiconductor structure including a transferred semiconductor layer, and structures for effecting the same and formed by the same, which are now described in detail with accompanying figures. Throughout the drawings, the same reference numerals or letters are used to designate like or equivalent elements. The drawings are not necessarily drawn to scale.
As used herein, a “textured crystalline layer” is a polycrystalline layer including grains, in which a predominant portion of the grains have the same set of crystallographic orientations. A “predominant portion” of an element refers to more than 50% in volume of the element. Likewise, as used herein, a “polycrystalline layer” is a more general term that includes both textured crystalline layers and crystalline layers including grains with a mix of crystallographic orientations with no single dominant orientation.
As used herein, an “at least partially crystalline layer” is a layer that is either a single crystalline layer, a textured crystalline layer, or polycrystalline layer.
As used herein, an “at least partially crystalline silicon layer” is an at least partially crystalline layer including intrinsic silicon or doped silicon.
Referring to FIG. 1A , a first exemplary semiconductor structure according to a first embodiment of the present disclosure includes a single crystalline semiconductor substrate 10 . In one embodiment, the single crystalline semiconductor substrate 10 consists of intrinsic silicon or doped silicon. In one embodiment, the single crystalline silicon substrate 10 is a bulk silicon. In this embodiment, the single crystalline silicon substrate 10 is thick enough to allow mechanical handling of the single crystalline silicon substrate 10 without breakage, and can have a thickness from 200 microns to 2,000 microns. In another embodiment, the single crystalline silicon substrate 10 can be attached to another substrate that facilitates handling of the single crystalline silicon substrate 10 . For example, the single crystalline silicon substrate 10 can be attached to an insulating substrate or a conductive substrate. In this embodiment, the single crystalline silicon substrate 10 can have a thickness from 5 microns to 2,000 microns.
The surface normal of a planar top surface of the single crystalline silicon substrate 10 can have any crystallographic orientation. In one embodiment, the surface normal of the planar top surface of the single crystalline silicon substrate 10 can have a “major crystallographic orientation,” which is defined herein as an orientation having a set of Miller indices in which each Miller index in the set of Miller indices has an absolute value that does not exceed 6. In another embodiment, the surface normal of the planar top surface of the single crystalline silicon substrate 10 can have a “non-major crystallographic orientation,” which is defined herein as an orientation having a set of Miller indices in which at least one Miller index in the set of Miller indices has an absolute value that exceeds 6. Thus, the orientation of the surface normal of a planar top surface of the single crystalline silicon substrate 10 is not limited in any way. Non-conventional surface orientations having a “high Miller index,” i.e., a Miller index having an absolute value that exceeds 6, can be provided on the single crystalline silicon substrate 10 by angled polishing on a conventional single crystalline silicon substrate having “low Miller indices,” i.e., Miller indices having absolute values that do not exceed 6.
Referring to FIG. 1B , a germanium-containing layer 20 is grown directly on the top surface of the single crystalline silicon substrate 10 , preferably with at least some degree of epitaxial alignment. The degree of epitaxial alignment between the germanium-containing layer 20 and the single crystalline silicon substrate 10 may be complete or incomplete, depending on embodiments. In one embodiment, the germanium-containing layer 20 is a single crystalline layer having an epitaxial alignment with the single crystalline silicon substrate 10 at an atomic level. In another embodiment, the germanium-containing layer 20 is a textured crystalline layer in which grains are predominantly oriented in a direction providing epitaxial alignment with the single crystalline structure of the single crystalline silicon substrate 10 at an atomic level. In this embodiment, a predominant portion of the grains of the germanium-containing layer 20 has the same set of crystallographic orientations as the single crystalline silicon substrate 10 . In yet another embodiment, germanium-containing layer 20 may be polycrystalline.
The germanium-containing layer 20 is grown in an ambient having an oxygen partial pressure at a level that incorporates oxygen into the germanium-containing layer 20 at an atomic concentration between 1% and 50%, and typically between 2% and 20%. The oxygen partial pressure can be provided by residual gases in a high vacuum environment having a base pressure of 10 −6 Torr to 100 mTorr, and typically from 10 −5 Ton and 10 mTorr. Alternately, the oxygen partial pressure can be provided by supplying an oxygen-containing gas such as oxygen, ozone, or carbon dioxide in an ultrahigh vacuum environment having a base pressure less than 10 −6 Torr. Yet alternately or in addition, the germanium-containing layer 20 can be deposited in an environment having a low oxygen partial pressure such that the germanium-containing layer 20 has an atomic concentration of oxygen less than 1% as deposited. In this case, the germanium-containing layer 20 can be exposed to an oxygen-containing ambient to allow adsorption of oxygen and subsequent incorporation of oxygen into the germanium-containing layer 20 at an atomic concentration between 1% and 50%, and typically between 2% and 20%.
In one embodiment, the germanium-containing layer 20 can have a substantially constant germanium concentration at an atomic concentration from 30% to 99%. The germanium concentration is “substantially constant” because statistical variations in germanium concentration is inherently present due to the statistical nature of composition of the germanium-containing layer 20 . In one case, the germanium-containing layer 20 can include germanium and oxygen, and the sum of the atomic concentration of germanium and the atomic concentration of oxygen is greater than 99%. The germanium-containing layer 20 may consist essentially of germanium and oxygen, and the sum of the atomic concentration of germanium and the atomic concentration of oxygen is greater than 99%. In another case, the germanium-containing layer 20 can include germanium, silicon, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, and the atomic concentration of oxygen is greater than 99%. The germanium-containing layer 20 may consist essentially of germanium, silicon, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, and the atomic concentration of oxygen is greater than 99%. In yet another case, the germanium-containing layer 20 can include germanium, silicon, at least another atom, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, the atomic concentration of the at least another atom, and the atomic concentration of oxygen is greater than 99%. The germanium-containing layer 20 may consist essentially of germanium, silicon, at least another atom, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, the atomic concentration of the at least another atom, and the atomic concentration of oxygen is greater than 99%. The at least another atom can be carbon, a p-type dopant such as boron, gallium, or indium, an n-type dopant such as phosphorus, arsenic, or antimony, any other impurity atoms such as nitrogen, fluorine, hydrogen, or argon, or a combination thereof.
In another embodiment, the germanium-containing layer 20 can include silicon, germanium, and oxygen. The atomic concentration of germanium decreases in the germanium-containing layer 20 with the distance from the single crystalline silicon substrate 10 . Thus, the atomic concentration of germanium in the germanium-containing layer 20 has variable values, which can be in a range from 0% and 99%. In this case, the atomic concentration of germanium in the graded germanium-containing layer 20 has a maximum value that is at least 50%, which occurs at or near the interface with the single crystalline silicon substrate 10 . In one case, the germanium-containing layer 20 can include germanium, silicon, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, and the atomic concentration of oxygen is greater than 99% in each location within the germanium-containing layer 20 . The germanium-containing layer 20 may consist essentially of germanium, silicon, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, and the atomic concentration of oxygen is greater than 99% in each location within the germanium-containing layer 20 . In another case, the germanium-containing layer 20 can include germanium, silicon, at least another atom, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, the atomic concentration of the at least another atom, and the atomic concentration of oxygen is greater than 99% in each location within the germanium-containing layer 20 . The germanium-containing layer 20 may consist essentially of germanium, silicon, at least another atom, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, the atomic concentration of the at least another atom, and the atomic concentration of oxygen is greater than 99% in each location within the germanium-containing layer 20 . The at least another atom can be carbon, a p-type dopant such as boron, gallium, or indium, an n-type dopant such as phosphorus, arsenic, or antimony, any other impurity atoms such as nitrogen, fluorine, hydrogen, or argon, or a combination thereof.
In one embodiment, germanium-containing layer 20 is at least partially epitaxial. The thickness of the germanium-containing layer 20 is maintained not to exceed the critical thickness at which the epitaxial alignment between the single crystalline silicon substrate 10 and the germanium-containing layer 20 is destroyed through stress relaxation. The oxygen content of germanium-containing layer 20 is also kept low (e.g., 1-3%) to help preserve epitaxy. In another embodiment, the thickness of the germanium-containing layer 20 may be less than, the same as, or exceed the critical thickness at which the epitaxial alignment between the single crystalline silicon substrate 10 and the germanium-containing layer 20 is destroyed through stress relaxation. If the thickness of the germanium-containing layer 20 exceeds the critical thickness, the germanium-containing layer 20 may develop dislocations therein.
If the thickness of the germanium-containing layer 20 does not exceed the critical thickness, the thickness of the germanium-containing layer 20 is between 5 nm and 80 nm, and preferably between 10 nm and 60 nm, although lesser and greater thicknesses can also be employed depending on the concentration of germanium provided that at least some epitaxial alignment between the germanium-containing layer 20 and the single crystalline silicon substrate 10 is maintained.
The germanium-containing layer 20 can be deposited by chemical vapor deposition (CVD), vacuum evaporation, or atomic layer deposition (ALD). The deposition temperature is set at a temperature that provides sufficient surface diffusion to germanium atoms and silicon atoms, if silicon is incorporated in the germanium-containing layer 20 , and any other atoms, if any other atoms are incorporated into the germanium-containing layer 20 . For example, the deposition temperature can be 450° C. to 900° C., and typically from 500° C. to 700° C. The pressure of the deposition chamber can vary depending on the deposition process employed. In general, chemical vapor deposition processes employ deposition conditions including a total pressure from 0.1 Torr to 10 Torr, and typically from 0.2 Torr to 5 Torr. A predominant portion of the total pressure is the partial pressure of a carrier gas. If vacuum evaporation or atomic layer deposition is employed, the deposition pressure is typically from 10 −6 Torr to 10 −3 Torr, depending on the base pressure of the deposition system and whether oxygen gas is flowed into the deposition chamber in addition to residual oxygen gases inherently present in any vacuum chamber having a finite (non-zero) base pressure. In case atomic layer deposition is employed, at least one reactant gas and oxygen gas can be alternately flowed into a deposition chamber with optional adjustments to the temperature of the single crystalline silicon substrate 10 to control the amount of oxygen incorporated into the germanium-containing layer 20 .
In case chemical vapor deposition is employed, the single crystalline silicon substrate 10 is placed in a vacuum environment, of which the base pressure can vary as discussed above. Low pressure chemical vapor deposition (LPCVD) process or plasma enhanced chemical vapor deposition (PECVD) may be employed. Energy to decompose one or more reactant gases is provided by thermal energy, whereas energy to decompose one or more reactant gases is provided by plasma energy. A germanium-containing reactant gas, which includes at least one atom of germanium, is flowed into the deposition chamber. Exemplary germanium-containing reactant gases include GeH 4 , GeH 2 Cl 2 , GeCl 4 , and Ge 2 H 6 . If silicon is incorporated into the germanium-containing layer 20 , a silicon-containing reactant gas including at least one atom of silicon, e.g., SiH 4 , SiH 2 Cl 2 , SiHCl 3 , SiCl 4 , and Si 2 H 6 , can be flowed into the deposition chamber. Atomic layer deposition can employ the same reactants and/or dopants as chemical vapor deposition.
If vacuum evaporation is employed, germanium and/or silicon can be evaporated from an evaporation source, which can be an electron beam source or an effusion cell. Typically, the evaporation source is heated at or near the melting temperature of the source material, i.e., the melting temperature of germanium or the melting temperature of silicon. Oxygen can be provided by background level residual oxygen in a vacuum system having a base pressure greater than 10 −6 Torr. Alternatively or in addition, oxygen gas can be continually or intermittently provided into the deposition chamber from an oxygen source such as a mass flow controller connected to an oxygen tank. Alternatively or in addition, oxygen can be provided to the top surface of the germanium-containing layer 20 and incorporated therein by diffusion.
Optionally, the material stack including the single crystalline silicon substrate 10 and the germanium-containing layer 20 may be maintained at an elevated temperature for a period of time to enhance the degree of epitaxial alignment between the single crystalline silicon substrate 10 and the germanium-containing layer 20 and/or to repair crystalline defects in the germanium-containing layer 20 . Because silicon and germanium have the same crystal structures, a crystalline germanium-containing layer 20 would be expected to have a crystallographic orientation epitaxially related to that of the single crystalline silicon substrate 10 .
Referring to FIG. 1C , an at least partially crystalline silicon layer 30 having at least some degree of crystallinity is grown directly on the top surface of the germanium-containing layer 20 . In one embodiment, the at least partially crystalline silicon layer 30 is a single crystalline layer having a complete epitaxial alignment with the germanium-containing layer 20 at an atomic level. In another embodiment, the at least partially crystalline silicon layer 30 is a textured crystalline layer in which grains are predominantly oriented in a direction providing epitaxial alignment with the single crystalline structure of the germanium-containing layer 20 at an atomic level. In this embodiment, a predominant portion of the grains of the at least partially crystalline silicon layer 30 has the same set of crystallographic orientations as the germanium-containing layer 20 . In yet another embodiment, the at least partially crystalline silicon layer 30 is a textured crystalline layer in which grains are predominantly oriented in a direction providing epitaxial alignment with a textured crystalline structure of the germanium-containing layer 20 at an atomic level. In this embodiment, a predominant portion of the grains of the at least partially crystalline silicon layer 30 has the same set of crystallographic orientations as the germanium-containing layer 20 .
The thickness of the at least partially crystalline silicon layer 30 is selected to apply sufficient stress to the germanium-containing layer 20 to cause formation of a plurality of cavities 27 within the germanium-containing layer 20 by the end of deposition of the at least partially crystalline silicon layer 30 . The thickness of the at least partially crystalline silicon layer 30 needed to generate cavities 27 within the germanium-containing layer 20 depends on the thickness of the germanium-containing layer 20 and the germanium content and the oxygen content in the germanium-containing layer 20 . In general, the thickness of the at least partially crystalline silicon layer 30 is at least equal to the thickness of the germanium-containing layer 20 , and is typically greater than twice the thickness of the germanium-containing layer 20 . In case the germanium-containing layer 20 includes silicon in addition to germanium and oxygen, the thickness of the at least partially crystalline silicon layer 30 can be greater than three times the thickness of the germanium-containing layer 20 . Typically, the at least partially crystalline silicon layer 30 has a thickness that is greater than 100 nm. For example, the thickness of the at least partially crystalline silicon layer 30 can be from 100 nm to 500 nm, although lesser and greater thicknesses can also be employed.
The plurality of cavities 27 is formed during the epitaxial growth of the at least partially crystalline silicon layer 30 , i.e., before the completion of deposition of the silicon material of the at least partially crystalline silicon layer 30 . The lateral dimensions of the plurality of cavities 27 is on the same order of magnitude as the thickness of the germanium-containing layer 20 . Typically, each cavity in the plurality of cavities has a maximum lateral dimension less than 200 nm.
The at least partially crystalline silicon layer 30 is grown in a vacuum environment in which oxygen partial pressure is minimal or in an ambient in which oxygen partial pressure is minimized. Any oxygen incorporated in the at least partially crystalline silicon layer 30 is maintained below 5% in atomic concentration, and preferably below 2% in atomic concentration, and most preferably as low as possible.
The at least partially crystalline silicon layer 30 can be deposited by chemical vapor deposition (CVD) or vacuum evaporation. The deposition temperature is set at a temperature that provides sufficient surface diffusion to silicon atoms. For example, the deposition temperature can be from 500° C. to 1,100° C., and typically from 500° C. to 700° C. The pressure of the deposition chamber can vary depending on the deposition process employed. In general, chemical vapor deposition processes employ deposition conditions including a total pressure from 0.1 Torr to 10 Torr, and typically from 0.2 Torr to 5 Torr. A predominant portion of the total pressure is the partial pressure of a carrier gas such as hydrogen gas. If vacuum evaporation or atomic layer deposition is employed, the deposition pressure is typically from 10 −6 Torr to 10 −3 Torr.
In case chemical vapor deposition is employed, the stack of the single crystalline silicon substrate 10 and the germanium-containing layer 20 is placed in a vacuum environment such that the top surface of the germanium-containing layer 20 is exposed. Low pressure chemical vapor deposition (LPCVD) process or plasma enhanced chemical vapor deposition (PECVD) may be employed. A silicon-containing reactant gas including at least one atom of silicon, e.g., SiH 4 , SiH 2 Cl 2 , SiHCl 3 , SiCl 4 , and Si 2 H 6 , is flowed into the deposition chamber. The at least partially crystalline silicon layer 30 can be doped in-situ with p-type dopants or n-type dopants by concurrently flowing dopant gases such as B 2 H 6 , PH 3 , AsH 3 , SbH 3 , or a combination thereof. If vacuum evaporation is employed, silicon can be evaporated from an evaporation source, which can be an electron beam source or an effusion cell.
Optionally, the material stack including the single crystalline silicon substrate 10 , the germanium-containing layer 20 , and the at least partially crystalline silicon layer 30 may be maintained at an elevated temperature for a period of time to enhance the degree of epitaxial alignment between the germanium-containing layer 20 and the at least partially crystalline silicon layer 30 and/or to repair crystalline defects in the at least partially crystalline silicon layer 30 .
Referring to FIG. 1D , a handle substrate 40 is attached to the top surface of the at least partially crystalline silicon layer 30 , for example, by bonding. The handle substrate 40 can include a dielectric material layer, a conductive material layer, a polycrystalline semiconductor material layer, a single crystalline semiconductor material layer, or a combination thereof. In non-limiting exemplary cases, the handle substrate 40 can be a glass substrate or a metal substrate. Any bonding method known in the art may be employed including anodic bonding, in which an electrical bias voltage is applied across the interface between the at least partially crystalline silicon layer 30 and the handle substrate 40 . Typically, the handle substrate 40 is thick enough to allow mechanical handling without significant risk of breakage. For example, the handle substrate 40 can have a thickness from 200 microns to 5 mm, and typically from 500 microns to 1 mm, although lesser and greater thicknesses can also be employed.
Referring to FIG. 1E , the first exemplary semiconductor structure is cleaved along a plane, which is herein referred to as a “cleavage plane,” located within the germanium-containing layer 20 . An upper assembly of the handle substrate 40 and the at least partially crystalline silicon layer 30 and an upper portion of the germanium-containing layer 20 , which is herein referred to as an upper epitaxial germanium-containing portion 27 B, is cleaved off a lower assembly including the single crystalline silicon substrate 10 and a lower portion of the germanium-containing layer 20 , which is herein referred to as a lower epitaxial germanium-containing portion 27 A, along the cleavage plane.
Treatment of the first exemplary semiconductor structure by any chemical treatment, thermal treatment, or ion implantation is not necessary because the germanium-containing layer 20 is under stress induced by the lattice mismatch with the single crystalline silicon substrate 10 and the at least partially crystalline silicon layer 30 . Thus, mechanical shear stress applied to the first exemplary semiconductor structure (i.e., twisting the upper assembly ( 40 , 30 , 20 B) relative to the lower assembly ( 10 , 20 A)) or mechanical tensile stress applied the first exemplary semiconductor structure (i.e., pulling the upper assembly ( 40 , 30 , 20 B) away from the lower assembly ( 10 , 20 A)) can separate the upper assembly ( 40 , 30 , 20 B) from the lower assembly ( 10 , 20 A).
Referring to FIG. 1F , the upper germanium-containing portion 27 B is removed selective to the at least partially crystalline silicon layer 30 by an etch or planarization. The etch can be an isotropic etch such as a wet etch employing hydrogen peroxide that removes germanium or a silicon-germanium alloy with a high atomic percentage of germanium (i.e., at least 30% of germanium in atomic concentration), or a dry etch such as a reactive ion etch that is selective to silicon. Alternately or in addition, chemical mechanical planarization can be employed to remove the upper germanium-containing portion 27 B. The upper assembly at this point includes a stack of the handle substrate 40 and the at least partially crystalline silicon layer 30 .
Referring to FIG. 2A , a second exemplary semiconductor structure according to a second embodiment of the present disclosure includes a single crystalline silicon substrate 10 , which is the same as the single crystalline silicon substrate 10 of the first embodiment.
Referring to FIG. 2B , a stack of a germanium-containing layer 20 and a graded germanium-containing layer 22 are grown on the single crystalline at least partially crystalline silicon layer 10 . Each of the germanium-containing layer 20 and the graded germanium-containing layer 22 can be deposited by chemical vapor deposition, vacuum evaporation, or atomic layer deposition as described in the first embodiment.
The germanium-containing layer 20 includes oxygen at an atomic concentration between 1% and 50%, and typically between 2% and 20%. The germanium-containing layer 20 has a substantially constant germanium concentration at an atomic concentration from 30% to 99%. In one case, the germanium-containing layer 20 can include germanium and oxygen, and the sum of the atomic concentration of germanium and the atomic concentration of oxygen is greater than 99%. The germanium-containing layer 20 may consist essentially of germanium and oxygen, and the sum of the atomic concentration of germanium and the atomic concentration of oxygen is greater than 99%. In another case, the germanium-containing layer 20 can include germanium, silicon, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, and the atomic concentration of oxygen is greater than 99%. The germanium-containing layer 20 may consist essentially of germanium, silicon, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, and the atomic concentration of oxygen is greater than 99%. In yet another case, the germanium-containing layer 20 can include germanium, silicon, at least another atom, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, the atomic concentration of the at least another atom, and the atomic concentration of oxygen is greater than 99%. The germanium-containing layer 20 may consist essentially of germanium, silicon, at least another atom, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, the atomic concentration of the at least another atom, and the atomic concentration of oxygen is greater than 99%. The at least another atom can be carbon, a p-type dopant such as boron, gallium, or indium, an n-type dopant such as phosphorus, arsenic, or antimony, any other impurity atoms such as nitrogen, fluorine, hydrogen, or argon, or a combination thereof.
The graded germanium-containing layer 22 includes silicon, germanium, and oxygen. The atomic concentration of germanium decreases in the graded germanium-containing layer 22 with the distance from the germanium-containing layer 20 . Thus, the atomic concentration of germanium in the graded germanium-containing layer 22 has variable values, which can be in a range from 0% and 99%. The atomic concentration of germanium in the graded germanium-containing layer 22 has a maximum value that is at least 50%, which occurs at or near the interface with the germanium-containing layer 20 . In one case, the graded germanium-containing layer 22 can include germanium, silicon, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, and the atomic concentration of oxygen is greater than 99% in each location within the graded germanium-containing layer 22 . The graded germanium-containing layer 22 may consist essentially of germanium, silicon, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, and the atomic concentration of oxygen is greater than 99% in each location within the graded germanium-containing layer 22 . In another case, the graded germanium-containing layer 22 can include germanium, silicon, at least another atom, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, the atomic concentration of the at least another atom, and the atomic concentration of oxygen is greater than 99% in each location within the graded epitaxial germanium-containing layer 22 . The graded germanium-containing layer 22 may consist essentially of germanium, silicon, at least another atom, and oxygen, and the sum of the atomic concentration of germanium, the atomic concentration of silicon, the atomic concentration of the at least another atom, and the atomic concentration of oxygen is greater than 99% in each location within the graded germanium-containing layer 22 . The at least another atom can be carbon, a p-type dopant such as boron, gallium, or indium, an n-type dopant such as phosphorus, arsenic, or antimony, any other impurity atoms such as nitrogen, fluorine, hydrogen, or argon, or a combination thereof.
In one embodiment, the germanium-containing layer 20 and the graded germanium-containing layer 22 are at least partially epitaxially aligned with silicon substrate 10 . The combined thickness of the stack of the germanium-containing layer 20 and the graded germanium-containing layer 22 is maintained not to exceed the critical thickness at which the epitaxial alignment between the single crystalline silicon substrate 10 and the germanium-containing layer 20 is destroyed through stress relaxation. In general, the thickness of the stack of the germanium-containing layer 20 and the graded germanium-containing layer 22 is between 5 nm and 100 nm, and preferably between 10 nm and 80 nm, although lesser and greater thicknesses can also be employed depending on the concentration levels of germanium in the stack of the germanium-containing layer 20 and the graded germanium-containing layer 22 , provided that the at least partial epitaxial alignment between the germanium-containing layer 20 , the graded germanium-containing layer 22 , and the single crystalline silicon substrate 10 is maintained.
Optionally, the material stack including the single crystalline silicon substrate 10 and the stack of the germanium-containing layer 20 and the graded germanium-containing layer 22 may be maintained at an elevated temperature for a period of time to enhance the degree of epitaxial alignment between the single crystalline silicon substrate 10 and the stack of the germanium-containing layer 20 and the graded germanium-containing layer 22 and/or to cure crystalline defects in the stack of the germanium-containing layer 20 and the graded germanium-containing layer 22 .
Referring to FIGS. 2C , 2 D, 2 E, and 2 F, the processing steps of FIGS. 1C , 1 D, 1 E, and 1 F are performed as in the first embodiment. At the processing step of FIG. 2C , the thickness of the at least partially crystalline silicon layer 30 is selected to apply sufficient stress to the germanium-containing layer 20 to cause formation of a plurality of cavities 27 within the germanium-containing layer 20 by the end of deposition of the at least partially crystalline silicon layer 30 . Depending on the relative germanium concentrations in the germanium-containing layer 20 and in the graded germanium-containing layer 22 and the relative thicknesses of the germanium-containing layer 20 and in the graded germanium-containing layer 22 , the plurality of cavities 27 may be formed solely within the germanium-containing layer 20 or across the germanium-containing layer 20 and the graded germanium-containing layer 22 .
The plurality of cavities 27 is formed during the growth of the at least partially crystalline silicon layer 30 , i.e., before the completion of deposition of the silicon material of the at least partially crystalline silicon layer 30 . The lateral dimensions of the plurality of cavities 27 is on the same order of magnitude as the combined thickness of the germanium-containing layer 20 and the graded germanium-containing layer 22 . Typically, each cavity in the plurality of cavities has a maximum lateral dimension less than 200 nm. While the cleavage plane in FIG. 2E is illustrated as passing only through the germanium-containing layer 20 , it is understood that the cleavage plane may pass through the graded germanium-containing layer 22 in some of the cases where the plurality of cavities 27 is formed across the germanium-containing layer 20 and the graded germanium-containing layer 22 . Remnants of the germanium-containing layer 20 and the graded germanium-containing layer 22 are removed at the processing steps of FIG. 2F employing the same methods as in the first embodiment.
Referring to FIGS. 3A , 3 B, and 3 C, a third exemplary semiconductor structure according to a third embodiment of the present disclosure is the same as the first exemplary semiconductor structure as shown in FIGS. 1A , 1 B, and 1 C, respectively, and can be formed by employing the same processing steps.
Referring to FIG. 3D , a bonding material layer 42 may be employed to bond the at least partially crystalline silicon layer 30 to the handle substrate 40 . The bonding material layer 42 can be a semiconductor oxide layer form on the handle substrate 10 if the handle substrate includes a semiconductor material that can be converted into a semiconductor oxide such as silicon oxide or germanium oxide. Alternately, the bonding material layer 42 can be an adhesive layer that includes resin, polymer, epoxy, or any other material that can be employed as an adhesive.
Referring to FIGS. 3E and 3F , the processing steps of FIGS. 1E and 1F are performed as in the first embodiment.
Referring to FIGS. 4A , 4 B, and 4 C, a fourth exemplary semiconductor structure according to a fourth embodiment of the present disclosure is the same as the second exemplary semiconductor structure as shown in FIGS. 2A , 2 B, and 2 C, respectively, and can be formed by employing the same processing steps.
Referring to FIGS. 4C , 4 D, and 4 F, the fourth exemplary semiconductor structure according to the fourth embodiment of the present disclosure can be formed employing the same processing steps as shown in FIGS. 3A , 3 B, and 3 C, respectively, and can be formed by employing the same processing steps.
Referring to FIG. 5 , a graph of an X-ray diffraction data from a first sample according to the first embodiment of the present disclosure is illustrated as a function of 2θ. Specifically, the first sample includes a stack of a handle substrate 10 and a at least partially crystalline silicon layer 30 as illustrated in FIG. 1F . The handle substrate 10 had an amorphous material (and thereby not contributing any sharp peak to the X-ray diffraction data), and the at least partially crystalline silicon layer 30 had a thickness of 300 nm. To manufacture the first sample, a germanium-containing layer 20 (see FIGS. 1B-1D ) consisting essentially of germanium and oxygen and having a thickness of 30 nm was employed. The single peak at 20 of approximately 69 degrees indicates that the at least partially crystalline silicon layer 30 within the first sample is a single crystalline silicon layer having a (100) surface orientation or a textured crystalline layer in which a predominant portion of grains is aligned along a (100) surface orientation and has a high quality of crystallinity.
Referring to FIG. 6 , a graph of an X-ray diffraction data from a second sample according to the second embodiment of the present disclosure is illustrated as a function of 2θ. Specifically, the second sample includes a stack of a handle substrate 10 and an at least partially crystalline silicon layer 30 as illustrated in FIG. 1F . The handle substrate 10 had an amorphous material (and thereby not contributing any sharp peak to the X-ray diffraction data), and the at least partially crystalline silicon layer 30 had a thickness of 120 nm. To manufacture the second sample, a stack of an germanium-containing layer 20 and a graded germanium-containing layer 22 (See FIGS. 2B-2D ) was employed. The germanium-containing layer 20 consisted essentially of germanium and oxygen and had a thickness of 30 nm. The graded germanium-containing layer 22 consisted essentially of germanium, silicon, and oxygen, and had a thickness of 50 nm. The single peak at 20 of approximately 69 degrees suggests that the at least partially crystalline silicon layer 30 within the second sample is a single crystalline silicon layer having a (100) surface orientation or a textured crystalline layer in which a predominant portion of grains is aligned along a (100) surface orientation and has an even higher quality of crystallinity than the first sample of FIG. 5 .
For illustrative purposes, an X-ray diffraction data from a third sample including a polysilicon film as a function of 2θ is shown in FIG. 7 . The polysilicon film of the third sample provided multiple peaks corresponding to various crystallographic orientations in the grains of the polysilicon film.
Referring to FIG. 8 , a graph illustrates data from a secondary ion mass spectroscopy (SIMS) run on the second sample of FIG. 6 prior to cleavage, i.e., the second sample according to the second embodiment of the present disclosure at the step of FIG. 2C . The atomic concentrations of germanium, silicon, and oxygen are shown by three curves labeled “Ge,” “Si,” and “O,” respectively. The graph in FIG. 8 is divided into portions corresponding to the various structural elements in the first exemplary semiconductor structure of FIG. 2C , and each portion is labeled with the corresponding reference numeral in the first exemplary semiconductor structure of FIG. 2C .
Referring to FIG. 9 , a scanning electron micrograph (SEM) is shown of a broken portion of the first sample along a vertical cleavage plane at a step corresponding to FIG. 1C , i.e., prior to attaching a handle substrate 10 or cleaving along the oxygen-containing germanium layer 20 . This SEM shows, from bottom to top, a vertical surface of a single crystalline silicon substrate 10 as cleaved for SEM preparation, a vertical surface of an oxygen-containing germanium layer 20 as cleaved for SEM preparation, and a vertical surface of an at least partially crystalline silicon layer 30 as cleaved for SEM preparation, and a top surface of the at least partially crystalline silicon layer 30 . A plurality of cavities is shown in the oxygen-containing germanium layer 20 in dark color.
Referring to FIG. 10 , a scanning electron micrograph (SEM) is shown of a portion of the first sample, which was cleaved along a plane in the oxygen-containing germanium layer 20 at a step corresponding to FIG. 1E . This portion of the first sample includes a bulk silicon substrate 10 and a portion of the oxygen-containing germanium layer 22 , i.e., a lower germanium-containing portion 27 A. This SEM shows, from bottom to top, a vertical surface of the single crystalline silicon substrate 10 as cleaved for SEM preparation, a vertical surface of the lower germanium-containing portion 27 A as cleaved for SEM preparation, and a top surface of the lower germanium-containing portion 27 A. A plurality of cavities is shown on the top surface of the lower germanium-containing portion 27 A in dark color.
While the present disclosure has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details can be made without departing from the spirit and scope of the present disclosure. It is therefore intended that the present disclosure not be limited to the exact forms and details described and illustrated, but fall within the scope of the appended claims.
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A germanium-containing layer is deposited on a single crystalline bulk silicon substrate in an ambient including a level of oxygen partial pressure sufficient to incorporate 1%-50% of oxygen in atomic concentration. The thickness of the germanium-containing layer is preferably limited to maintain some degree of epitaxial alignment with the underlying silicon substrate. Optionally, a graded germanium-containing layer can be grown on, or replace, the germanium-containing layer. An at least partially crystalline silicon layer is subsequently deposited on the germanium-containing layer. A handle substrate is bonded to the at least partially crystalline silicon layer. The assembly of the bulk silicon substrate, the germanium-containing layer, the at least partially crystalline silicon layer, and the handle substrate is cleaved within the germanium-containing layer to provide a composite substrate including the handle substrate and the at least partially crystalline silicon layer. Any remaining germanium-containing layer on the composite substrate is removed.
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FIELD OF THE INVENTION
[0001] The invention relates to a rolling body guide cage which is produced as such under the influence of forming production steps from at least one ring element and several guide structures arranged in succession in the circumferential direction and in each case provided to guide rolling bodies. The invention furthermore also relates to a method for manufacturing such a rolling body guide cage.
BACKGROUND
[0002] DE 1 625 540 A1 discloses a ball bearing cage which is composed of two axially profiled ring elements. The two ring elements are of identical design and are axially profiled in such a manner that they form spherical cap pockets which are arranged in succession in the circumferential direction and which are connected in each case via bridge portions. The two ring elements are composed in such a manner that they contact one another via their bridge portions, wherein the in each case corresponding spherical cap pockets which face one another then jointly form ball guide pockets into which in each case a ball can be inserted. The two ring elements which contact one another via the bridge portions are welded to one another in the region of the bridge portions by spot weld points. In order to manufacture the ring elements, these are punched out from a sheet metal material and formed in a forming tool such that they obtain the axial profiling required to form the ball guide pockets.
[0003] It is disadvantageous in the case of this ball bearing cage that a relatively large amount of waste material is generated when punching out the ring elements from the sheet metal material.
SUMMARY
[0004] Proceeding from the disadvantages set out of the known prior art, the object on which the invention is based is therefore to indicate solutions by means of which it is possible to reduce the production costs which arise during manufacture of rolling body guide cages.
[0005] According to the invention, this object is achieved by a rolling body guide cage with a ring element which is produced from a sheet metal material and has an axial profiling formed by forming techniques and several rolling body guide structures which are arranged in succession in the circumferential direction, the ring element being composed of at least two flat material ring segments which are joined to one another in succession in the circumferential direction and are connected, in particular welded, to one another in a production step which precedes the formation of the axial profiling.
[0006] As a result of this, it is advantageously possible to significantly reduce the cutting waste in the manufacture of rolling body guide cages produced by forming techniques in a manner which can be achieved at relatively low-cost from a process engineering perspective. The invention has been shown to be particularly advantageous in particular in the manufacture of rolling body guide cages with an internal diameter of more than 140 mm since the process costs associated with the formation of three weld joints are, at this diameter, already substantially below the material costs of the cutting waste which has hitherto arisen.
[0007] According to one particularly preferred embodiment of the invention, the flat material ring segments placed in succession with one another in the circumferential direction are put together across an engagement zone and in this engagement zone are welded along edge regions which face one other therein. The flat material ring segments are connected to one another according to a particular aspect of the present invention in the region of the engagement zones across positively engaging joint contours. These joint contours form an undercut geometry which as such preliminarily couples the ring elements to one another in the circumferential direction. The geometric profile of the joint contours is preferably selected such that adequate coupling of the ring segments is produced with as short as possible a weld seam length. The joint contours are furthermore preferably configured such that the weld seams taper both towards the ring element inner circumferential edge and towards the ring element outer circumferential edge with as obtuse an angle as possible.
[0008] The flat material ring segments are cut out, in particular, punched out according to the invention from a sheet metal material. A relatively high material saving can be achieved according to the invention in that the flat material ring segments are formed as 120° ring segments. Only three weld points are then required for joining together a ring element from such flat material ring segments. The 120° segments can be punched out in close succession from a sheet metal strip. In the case of this punching-out step, the circular arc-like inner and outer edges as well as the joint geometries can be cut out in one step.
[0009] The concept according to the invention of the production of the rolling body guide cage from a welded ring segment is suitable both for the manufacture of radial bearing cages and for the manufacture of axial bearing cages, in particular cages of groove and angular ball bearings. Particularly in the case of the manufacture of rolling body guide cages for groove and angular ball bearings, the rolling body guide cage can be structured such that it is composed of a first ring element and a structurally identical second ring element positioned in mirror-symmetry. The per se structurally identical ring elements are preferably put together in such a manner that the weld points formed between the ring segments of the ring elements of both ring elements are offset with respect to one another in the circumferential direction, i.e. a weld point is overlapped by an unwelded point.
[0010] In terms of the method, the object indicated above is also achieved according to the invention by a method for manufacturing a rolling body guide cage from a ring element which is produced from a sheet metal material and obtains an axial profiling in the context of a forming step, wherein the rolling body guide cage forms several rolling body guide structures arranged in succession in the circumferential direction and wherein, in the context of a method step which precedes the forming step, the ring element is composed of at least two flat material ring segments which are joined to one another in succession in the circumferential direction.
[0011] According to a particularly preferred embodiment of the method according to the invention, these flat material ring segments are welded to one another in the region of a joint formed by these flat material ring segments.
[0012] The formation of the weld point is preferably performed by laser welding. As a result of this, a high-strength weld point is produced with a low degree of welding distortion. Alternatively to this, it is also possible to this end to form the weld point as a pressure welding point. To this end, it is possible to retain local accumulations of material in the region of the weld point which are formed, for example, by bead portions which can be generated when punching out the ring elements.
[0013] The ring segments can be produced in such a manner that they initially have a slight oversize and are initially further cut and where necessary calibrated after welding in the context of a contouring step. However, the ring segments can in principle also be cut to their final dimensions in terms of their material width and are subsequently only formed and where necessary punched internally.
[0014] It is possible to punch out the ring segment from a sufficiently wide strip material and thereby push by means of the punching die directly into a positioning device, for example an annular groove of a rotary plate. The rotary plate is pivoted by a corresponding degree of angle of e.g. 120° after insertion of the ring segment and the next ring segment is punched out from the strip material and pushed back into the annular groove of the rotary plate, wherein said ring segment comes into engagement with the connection geometry of the ring element which already lies in the annular groove. After a further rotation of the rotary plate, the third ring segment is punched from strip material and is inserted into the free annular groove portion, wherein said ring segment now comes into engagement with the two ring elements which already lie in the annular groove. Even prior to the introduction of the third ring segment, the ring segments already located in the annular groove can be welded in the rotary plate. After the third ring segment has been inserted and thus a complete ring element lies in the annular groove, the two remaining weld points can be formed. The finished welded ring element is then ejected from the annular groove of the rotary plate and the process is continued again. The punching and welding steps can be carried out such that these overlap chronologically. During the formation of the last two weld points on the respective ring element, strip material can be supplied and where necessary also be punched, wherein the ring segment formed in this manner is moved into the annular groove either only after emptying of the rotary plate or a further rotary plate is supplied. The welding is preferably carried out by a laser beam guided in a path-controlled manner. The welding can where necessary be carried out with the addition of welding material, in particular via a welding wire. The weld seam is, however, preferably formed by only local fusing of the material along the joint edges.
[0015] It is thus possible to still join together the ring segments in the context of the workpiece movement to be attributed to the punching process to form a ring segment. In the context of this joining process, the ring segments can also initially be put together only positively in the rotary plate and then lifted out of the rotary plate and moved as prejoined ring elements into a welding station.
[0016] It is furthermore possible to join together the initially punched out or otherwise cut out ring segments with alignment of the edges to form a stack or ring segment block and then supply this to a welding station in which the ring segments are inserted, for example, again into an annular groove of a rotary plate and thereby come into engagement with one another via their head and tail geometries.
[0017] A particularly high-quality design of the weld connection points can be achieved in that, prior to the punching out of the ring segment or during punching out, a material bead close to the edge is generated which then provides in the context of carrying out the welding process a material volume which enables a complete filling out of the weld seam so that no chamfer is formed in the region of the weld point or any other cross-sectional weakening is produced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The rolling body guide cage formed according to the invention is explained in greater detail below in several preferred embodiments with reference to the enclosed drawings. In these drawings:
[0019] FIG. 1 shows a sketch in order to illustrate a ring element used according to the invention to form a rolling body guide cage, which ring element is composed of several ring segments which are welded to one another;
[0020] FIG. 2 shows a sketch in order to illustrate the structure of a ring segment used to form the ring element according to FIG. 1 ;
[0021] FIG. 3 shows a perspective illustration of a cage part, which is produced in the context of a forming step from a ring element according to FIG. 1 , of a two-part ball bearing cage;
[0022] FIG. 4 shows a perspective illustration of an axial needle bearing cage which is produced in the context of a forming step from a ring element according to FIG. 1 ;
[0023] FIG. 5 shows a perspective illustration of a cage, which is produced in the context of a forming step from a ring element according to FIG. 1 , for an axial ball roller bearing;
[0024] FIG. 6 shows a sketch in order to illustrate a further variant of the joint contour produced, preferably welded over between two ring segments;
[0025] FIG. 7 shows a sketch in order to illustrate an exemplary embodiment in which an accumulation of material is formed along the edges to be welded by plastic forming;
[0026] FIG. 8 a shows a first sketch in order to illustrate an exemplary embodiment in which, by local plastic forming, axial securing of the ring segments which are positively interlocked in one another in the circumferential direction can also be achieved;
[0027] FIG. 8 b shows a second sketch in order to illustrate an exemplary embodiment in which, by local plastic forming, axial securing of the ring segments which are positively interlocked in one another in the circumferential direction can also be achieved;
[0028] FIG. 9 shows a sketch in order to illustrate the cut position of the ring segments punched out according to the invention from a strip material in order to form a joined together ring element for a rolling body guide cage.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] FIG. 1 shows in the form of a top view a ring element which as such is further processed in the context of the following working steps, in particular a forming step to form a rolling body guide cage, wherein the ring element then in the context of the forming step obtains an axial profiling and in general a geometry in which it forms several rolling body guide structures arranged in succession in the circumferential direction.
[0030] The ring element shown here is produced from a sheet metal material and is composed of at least three flat material ring segments S 1 , S 2 , S 3 which are joined to one another in succession in the circumferential direction. Said flat material ring segments S 1 , S 2 , S 3 are joined together and here furthermore welded together via joints F 1 , F 2 , F 3 .
[0031] Flat material ring segments S 1 , S 2 , S 3 which are apparent here and which are placed in succession with one another in the circumferential direction are welded along the edge regions which face one another within joints F 1 , F 2 , F 3 . Flat material ring segments S 1 , S 2 , S 3 are configured in the region of joints F 1 , F 2 , F 3 such that said joints F 1 , F 2 , F 3 form engagement zones within which flat material ring segments S 1 , S 2 , S 3 are connected to one another via joint contours which engage positively in one another. These joint contours form, as is apparent here, an undercut geometry which as such at least preliminarily couples flat material ring segments S 1 , S 2 , S 3 to one another in the circumferential direction. The geometric profile of the joint contours is concretely selected here so that adequate coupling of flat material ring segments S 1 , S 2 , S 3 is produced.
[0032] FIG. 2 illustrates the structure and the component geometry of an individual flat material ring segment S 1 . Flat material ring segment S 1 is cut out from a sheet metal material in such a manner that this ring segment forms a 120° ring segment. Only three weld points are required for joining together a ring element composed of such flat material ring segments, as is apparent in FIG. 1 . The 120° segments can be punched out from a sheet metal strip in close superficial succession. In the case of this punching out step, the circular arc-like inner and outer edges and the joint geometries are cut out in one step. Flat material ring segment S 1 forms a head portion S 1 K and a head insert portion S 1 E. The outer contour of head portion S 1 K and the inner contour of the head insert portion are matched to one another so that both flat material ring segments sit in one another under slight elastic tension during insertion of head portion S 1 K of an adjoining flat material ring segment into head insert portion S 1 E. In so far as the joined together flat material ring segments are welded, it is possible to begin with the formation of the weld seam at a point which makes it possible that, during the weld seam formation, the ring segments to be connected to one another come closer to one another as a result of elastic pretensioning or also as a result of thermal influences. The pretensioning can also be selected such that it prevents a thermal moving part of the edge regions to be welded. In the case of the exemplary embodiment shown here, it is in particular possible to begin with the formation of the weld seam at the inner region of the joint contour, i.e. at the edge of tongue tip Z of the head portion, and form the weld seam in two steps from the inner region towards the outer or inner edge of the ring element.
[0033] FIG. 3 shows a ring element for a rolling body guide cage which is produced by forming from a composed ring element according to FIG. 1 . Weld points W 1 , W 2 , W 3 are indicated in the ring element shown here, along which weld points W 1 , W 2 , W 3 individual ring segments S 1 , S 2 , S 3 are welded to one another in a forming step which precedes the plastic forming. This ring element is put together with a further ring element of an identical design to form a cage for a groove ball bearing. The ring element shown here forms several spherical cap pockets K which are arranged in succession in the circumferential direction and then form ball guide pockets in interaction with a ring element of identical design arranged in mirror-symmetry. The connection of the two combined ring elements can be carried out depending on the design of the ball bearing before or also only after the insertion of the balls into the path space formed between bearing inner ring and bearing outer ring. In the case of a groove ball bearing, the connection of the two ring elements is typically only carried out after insertion of the balls into the path space.
[0034] FIG. 4 shows a further embodiment of a ring element according to the invention for a rolling body guide cage which is produced in a similar manner to the variant according to FIG. 3 by forming from a combined ring element according to FIG. 1 . In the ring element shown here, weld points W 1 , W 2 , W 3 are in turn indicated along which individual ring segments S 1 , S 2 , S 3 are welded to one another in a forming step which precedes plastic forming. The rolling body guide cage shown here is formed as an axial cylinder roller guide cage. This rolling body guide cage forms several rolling body guide windows F which are arranged in succession in the circumferential direction and are separated from one another by guide webs B. Guide webs B are axially profiled and form a middle stage B 1 and connecting bridges B 2 , B 3 . Outer edge region R 1 of the rolling body guide cage forms an angle profile in the axial section. Inner edge region R 2 of the rolling body guide cage also forms an angle profile in the axial section. It is possible, by forming, to enclose an additional wire ring element in the inner and/or outer edge region R 1 , R 2 of the ring element, which wire ring element increases the mechanical strength of the ring element, in particular also in the region of weld points W 1 , W 2 , W 3 .
[0035] FIG. 5 shows a third embodiment of a ring element according to the invention for a rolling body guide cage which is produced in a similar manner to the variants according to FIGS. 3 and 4 also by forming from a combined ring element according to FIG. 1 . In the ring element shown here, weld points W 1 , W 2 , W 3 are in turn indicated along which individual ring segments S 1 , S 2 , S 3 are welded to one another in a forming step which precedes plastic forming. The rolling body guide cage shown here is formed here as a ball guide cage for an axial ball bearing. This ball guide cage forms several rolling body guide windows F which are arranged in succession in the circumferential direction and are in turn separated from one another by guide webs B. Rolling body guide windows F are punched into the ring element formed by forming techniques in a machining step which follows the forming. Outer edge region R 1 of the ball guide cage forms, in a similar manner to the variant according to FIG. 4 , an angle profile in the axial section. Inner edge region R 2 of the rolling body guide cage also forms an angle profile in the axial section. It is also possible here, by forming, to enclose an additional wire ring element in inner and/or outer edge region R 1 , R 2 of the ring element, which wire ring element increases the mechanical strength of the cage and bridges weld points W 1 , W 2 , W 3 . FIG. 6 illustrates, in the form of a top view of a portion of a ring element, an alternative joint contour by which two ring segments S 1 , S 2 arranged in succession can be connected to one another. This contour is characterized by a small widening of the gap during the welding process and requires a small amount of material in the circumferential direction. The joint contour forms two engagement tongues Z 1 , Z 2 which are anchored positively in a corresponding complementary contour. The run-out of the joint edges to the inner or outer edge is relatively obtuse, it being almost 90° here.
[0036] FIG. 7 illustrates in the form of a cross-sectional sketch how, by forming beads 2 , 3 on the sheet metal material, a certain degree of material accumulation can be retained which makes it possible, after fusing thereof, in particular by laser welding, to generate a substantially flat weld point. Beads 2 , 3 can be formed in the context of the punching process or a preceding embossing step by plastic material forming.
[0037] FIGS. 8 a and 8 b also illustrate in the form of a cross-sectional sketch how axial securing of ring segments S 1 , S 2 can be achieved by local material forming. Beads 2 a, 2 b can be formed, for example, along head edge K 1 of ring segment S 1 by a preceding embossing step and in each case depressions 3 a, 3 b can be formed at foot edge F 2 of adjoining ring segment S 2 . After joining together of ring segments S 1 , S 2 , beads 2 a, 2 b are rolled over and deformed into the state shown in FIG. 8 b . In this state, both ring segments S 1 , S 2 are axially secured with respect to one another. The connection point formed in this manner can where necessary be welded over.
[0038] FIG. 9 shows by way of example how a ring segment S 1 can be punched out of a strip material SM in close succession. Punched out ring segments can joined together directly after the punching step to form a ring element and then welded. In the case of the exemplary embodiment shown here, ring segment S 1 forms a segment angle W of 120°. In so far as the ring element is formed from three segments S 1 punched out from strip material SM in direct succession, it is ensured that substantially the same material properties are ensured within a ring element. This is particularly advantageous for a uniform formation of the weld points.
LIST OF REFERENCE NUMBERS
2 a Bead
2 b Bead
3 a Depression
3 b Depression
B Guide web
[0039] B 2 Connecting bridge
B 3 Connecting bridge
F 1 Joint
F 2 Joint
F 3 Joint
[0040] K Spherical cap pocket
K 1 Head edge
R 1 Outer edge region
R 2 Inner edge region
Flat material ring segment
S 2 Flat material ring segment
S 3 Flat material ring segment
S 1 K Head portion
S 1 E Head insert portion
W Segment angle
W 1 Weld points
W 2 Weld points
W 3 Weld points
SM Strip material
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A rolling element guide cage having a ring element which is made from a sheet material and has an axial profiling produced using forming techniques and forms a plurality of successive rolling element guide structures in the circumferential direction. The ring element is composed of at least two flat material ring segments joined to one another successively in the circumferential direction, said segments being joined together in a manufacturing step which precedes the formation of the axial profiling.
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[0001] The invention relates to automotive parking methods and devices having multi storied parking structure with number of floors along which a hoisting appliance is movable, wherein the hoist way links parking floors situated one above the other in several levels.
BACKGROUND
[0002] It is found that in highly inhabited commercial and industrial cities space to park automotives is insufficient. It results the continuation of illegal parking on streets and obstruction of traffic. Recently, automatic multi-storey car parks are appearing as a solution to this problem. However, the cost of the mechanical equipments added to the building cost overweight the advantages of such parking facilities. Also such parking devices operated by hydraulic or cables on vertical direction to haul up and bring back to owner, consumes lot of energy making these methods becoming extremely expensive.
SUMMARY
[0003] The method introduced is a multi storied parking system less sophisticated with less maintenance and operational cost to provide a multi storied parking facility that could be constructed economically.
[0004] New method introduces a multi-storied car park combined with an inclined hoist way. The hoist way takes shape, across the multiple of parking floors forming an opening on each slab to provide the access for the hoist way to travel hoisting appliance. The opening at any floor and elevator platform is made in such a way that when the platform of the elevator reaches any floor, the floor and platform creates a drive way for the hoisted automobile to drive in to the desired floor. Moreover, the hoist way comprises a pair of rails held on two structural beams at same inclination, connected with the building structure. Therefore the elevator travels along the rail track extending though multiple of parking floors between top most and the lowest parking floor including the loading station.
[0005] The elevator is driven on wheels along rails, so that, the weight of the elevator and load will be distributed on rails, while the elevator is driven due to traction imparted by the cables secured to the top of the elevator. The cables passes over the traction pulley in the upper station and carries the counter weight hanged on another pulley and returns the cable end to a stationary grip at a higher level. The counterweight is located in a vertical hoist-way and rides a separate rail system. So that, the counter weight travels in opposite direction at half the speed of elevator, which is travelling along the inclined track. As the platform goes up, the counterweight goes down, and vice versa. This manner the weight of the elevator is balanced by the counterweight which is typically higher than the weight of the elevator platform. This action is powered and controlled by the traction machine which is an electrical motor or power generator.
[0006] The elevator is having the platform of rigid surface maintained in horizontal position, so that the automobiles from any floor could be driven in and out the elevator by the driver, when it reaches the designated floor. A close tolerance is maintained between the elevator platform sill and the sill of open space of the floor in hoist way at any floor, serving as a drivable access to parking spaces on the required floor.
[0007] Advantageously the elevator is constructed as a multi-deck elevator in a manner two or more compartments located one above the other, in order to haul number of vehicles at a time.
[0008] Further more, each hoist way has a pair of guide rails that run parallel to one another, keeping the elevator and counterweight from swaying or twisting during their travel, and they also work with the safety system to stop the elevator in an emergency. The rail track, on which the elevator travel also can be utilize as the guide rail for the elevator in any method of operation. Advantageously, traction motor directed by the controller, typically a relay logic or computerized device that directs starting, acceleration, deceleration and stopping of the elevator platform.
[0009] The inclined vehicle conveyance also provided with suitable braking systems and safeties that grab onto the rail when the car moves too fast and whenever required to stop, like any other traction cable elevator system operates. The bottom of the shaft of elevator and balance weight are mounted with heavy-duty shock absorber systems to soften the elevator system landing. Advantageously, the platform of the elevator and the loading floor are held together while the parking vehicle drives in and out of the elevator.
[0010] The parking structure may comprise with a stair way, elevator or escalator to allow the driver to return to ground station after loading the vehicle to the parking floor and vice versa.
[0011] The loading and unloading bay is arranged in a motorable floor either on ground floor or closer, with entrance and departure station is provided. Advantageously underground floors may provide to increase the number of parking floors to facilitate more parking spaces.
[0012] Similarly, such parking conveyance can be adapted to a multipurpose building where in the building structure is a combination of shopping malls apartments or any other utilities.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] These features and advantages of the present invention as well as others will be fully understood when the following description is read in light of the accompanying drawings, in which:
[0014] FIG. 1 —is a longitudinal section of the parking structure along the hoist way with elevator at loading station.
[0015] FIG. 2 —is a longitudinal section of the parking structure along the hoist way with elevator at top most floor station.
[0016] FIG. 3 —is the lay out plan at loading and delivery floor while elevator deck in loading floor, as shown in FIG. 1 .
[0017] FIG. 4 —is the lay out plan at topmost parking floor while elevator deck is in the same floor, as shown in FIG. 2 .
[0018] FIG. 5 —is a sectional view at G-G of FIG. 01 , showing the details of the parking floor entrance and loading station
[0019] FIG. 6 —is a sectional view across the hoist way for the counter weight.
[0020] FIG. 7 —is a side view of elevator with two compartments one above the other.
[0021] FIG. 8 —is a sectional view of the elevator shown in FIG. 07 .
[0022] FIG. 9 —is a layout plan at over head machine room consisting traction motor, traction drum with sheaves, deflection sheaves and cable system.
[0023] FIG. 10 —is detailed view of the elevator platform.
[0024] FIG. 11 —is details at rail track and guide rails
[0025] FIG. 12 —is details of another way of connecting guide rails
[0026] FIG. 13 —is a detail view of Safeties connected to cross head of the elevator.
[0027] FIG. 14 —is details of rail track and wheel base.
[0028] FIG. 15 —is a sectional view inside the elevator
[0029] FIG. 16 —is an instance illustrating when one of traction cable broken the plug and socket disengage to send a signal to emergency brake
[0030] FIG. 17 —is an instance illustrating how safety breaks takes place when entire cable system collapses.
[0031] FIG. 18 —is another method of construction of the elevator where vehicle is loaded at lateral direction to the inclined hoist way.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] The FIG. 1 shows the typical section along the elevator, at A-A as shown in layout plan FIG. 4 , at A-A.
[0033] The hoist motor 15 is installed in machine room at upper level, powering the drive drum 10 with large sheaves. The grooves of sheaves grip the multiple of traction cables 8 that runs from the elevator 1 , up and around a drive drum attached to the hoist motor and passing over the deflection sheave 11 to suspend counter weight 13 on another pulley 12 down and ultimately fitted to a permanent grip 14 at an upper level.
[0034] The track wheels 6 attached on either side of elevator 1 are typically flanged and ride on top of the rail 7 thereby easily guided on rails resting on rail track, while it guide and support the elevator 1 up the inclination. So when the electric motor rotates the sheave and the cables move too, providing enough force to pull the elevator 1 during travel.
[0035] According to this design the elevator 1 is a multi deck type, having two compartments 2 , 3 located one above the other. The structure consists of a rigid frame having a cross head 4 to which the main frame 5 is braced to hold platforms in position. Vehicle compartments are constructed with horizontal platforms secured to the elevator structure. The elevator 1 is connected to a set of traction cables 8 that link the power driven rolling drum with pulley 10 connected to the motor 15 . The elevator 1 and the counterweight each run in their own sets of guide rails.
[0036] The hoist way is centrally built in relation to two beams stretched out from top to bottom on which elevator 1 can move along the rail inside the hoist way that formed as an open way at an inclined profile across the multiple of floor slabs. The platforms of elevator 1 is made to a close tolerance of the floor slab opening to move smoothly along the rail track, enabling to align with any floor when it reach the designated level.
[0037] The hoisting elevator compartments are comprised of electrically operated doors, closed while hoisting. The elevator compartments 2 are having control panels with intercommunication system to operate by the person in the cradle during an emergency.
[0038] The hoist way doors in floors are motor controlled remotely or controlled by the control panel fitted on wall. Alarm buttons, and emergency telephones are fixed next to the doors. The electromechanical door inter locks are installed in order to prevent the elevator 1 from operating if the door is not completely closed and to protect the driver inside the parking vehicle, from being trapped by the closing door. The same door interlocks also prevent the outer doors on each floor from opening if the elevator 1 is not approached.
[0039] In the operation, when a vehicle is driven near to the hoist way in to the loading station, the hoist operator will control the elevator mechanisms to bring the elevator 1 to its loading station in alignment with the floor. The platform of the elevator 1 will be in level with the floor of the loading station.
[0040] The hoist door is opened and the car is driven on to the platform situated on the hoist way. Then the hoist is elevated with platform maintained in horizontal position and lifted to the desired parking floor with the driver inside the car. When it reaches in level with a selected floor the door of the access is opened and the drive is allowed to drive the car to the required location on the floor.
[0041] After the car is parked at designated location the driver leaves the car and able to reach the ground, using the access provided by the passenger lift 24 . The access for passenger can be a staircase or an escalator.
[0042] This operation is reversed when the car is required to bring back to the ground floor retrieved for departure.
[0043] The process is directed by the controller, typically a relay logic or computerized device that directs starting, acceleration, deceleration and stopping of the elevator platform.
[0044] As the car approaches its destination, a switch near the landing signals the controls to stop the car at desired floor level. Access is provided in the shaft way to install limit switches to monitor over travel conditions. It detect the over speed conditions and activate safeties. The safeties will grip the guide rails and stop the elevator 1 .
[0045] Like many other elevators inclined conveyance for vehicle parking equipped with primary safety mechanisms such as a governor which controls the elevator speed by controlling the speed of the cable pulleys, an emergency brake which consists of jaws that grip the elevator 1 to guide rails in the event the cables break. The speed governor is integrated with the traction drum. In the event of excessive speed of elevator 1 , the governor activates the emergency brake jaws which grip the guide rails and slow the elevator 1 to a stop.
[0046] The elevator 1 may consist of a multiple of cables for traction so that even if one cable snapped, the remaining cables would hold the elevator 1 up.
[0047] A new safety device is introduced in this elevator 1 to prevent movement unintentionally, due to cable failure. As shown in FIG. 13 the set of cables are connected to the cross head and each cable fitted with a plug and socket held by an extended arm at a reasonable distance from the cross head. During engagement of socket in the plug electric circuit is formed and prevent emergency brake jaws grip the guide rails imposing brake. If the cable is slack as shown in FIG. 16 , the plug will leave the socket and circuitry is disengaged. Therefore the electrical current floor will stop that prevent brake on hold, allowing the system to apply brakes.
[0048] Another cable safety method is adopted as shown in FIG. 13 and FIG. 17 , by linking the cross head to cable scheme by a spring loaded arm. If the cable set fails the bar attached to cable scheme will trend to come closer towards the cross head, turning the leverage of brakes to clamp the guide rails.
[0049] At the bottom of each hoist way a shock absorber typically a piston mounted in an oil-filled cylinder, works like a cushion to soften the elevator landing.
[0050] Also the elevator 1 is having an automatic brake system near the top and bottom of the elevator shaft. If the elevator car moves too fast in either direction, the brake brings it to a stop
[0051] In addition to these elaborate emergency systems, the inclined elevator system may be equipped with any other versatile methods to make the system safety and reliable.
[0052] In this design the guide rails and wheels supporting rail track are functioning as separate members, but it would be apparent from the design that the wheels supporting rail track can use as the guide rail at the same time. Further more the guide rail can fix along the beam as shown in FIG. 12 as well.
[0053] It would be noticeable another inclined conveyance could be constructed by arranging the drive way lateral to the inclined hoist way as shown in FIG. 18 .
[0054] With respect to the above description, 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.
[0055] 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.
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Automobiles parking method and apparatus comprising a multi storied building with an inclined hoist way located diagonally along the vertical profile linking all parking floors in order to park and retrieve automobiles carried by the elevator lifted along rails situated in the inclined hoist way by means of over head traction cables powered by motor. During parking process automobile is driven in to horizontally positioned platform of the elevator brought down to loading station, so that the elevator is moved along rails on wheels by overhead traction cables to desired parking floor for automobile to drive in to desired parking place and vice versa.
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The invention refers to a method for the autostereoscopic production of three-dimensional image information from scanned subpixel extracts from at least a left and a right image view on a matrix screen having colour-assigned subpixels in scanning lines with an optical separating raster, wherein the periodicity of the separating elements in horizontal direction corresponds to a) four or b) six subpixels and the separating elements extend obliquely in relation to the matrix of the screen with an inclination corresponding to the small side ratio of the subpixels, as well as to an arrangement for implementing said method.
PRIOR ART
In the autostereoscopic representation methods as they are usable for multiple purposes e.g. for information and communication technology, medical engineering and computer and video engineering in both, public and private domains, the entire L-R-aligned stereoscopic separation is performed in the method and in the implementing system itself; additional personal user hardware, as for example glasses, are not required, which essentially increases the user comfort. The principle of autostereoscopic representation methods (cf. for example Publication I of S. Pastoor “3D-Displays: Methoden und Stand der Technik”, Handbuch der Telekommunikation, Vol. 4, Chapter 4, supplementary delivery June 2002, Fachverlag Deutscher Wirtschaftsdienst GmbH & Co KG, Cologne, ISBN 3-87156-096-0) is based on a scanning of different image views on a screen and an optical separation of these scanned views in direction towards the eyes of a viewer so that each eye will only see parts of a single image view in an optical context that are joined together into a perspective view. For that purpose, the separating raster includes many adjacently arranged separating elements, e.g. slots, cylindrical lenses or prisms. Depending on the number of the discrete image views represented, a stereoscopic view can be generated with a single perspective (two discrete image views that are usually taken with interocular distance) or a parallax view with several individual perspectives (three or more discrete adjacent image views). While for a stereoscopic view, a relatively fixed viewing position or an optical tracking of the image output is required for enabling stereoscopic vision, a movement of the head leads to reaching another individual perspective in case of a parallax view. Preferably, the viewing zones for the individual perspectives adjoin seamlessly to one another. In known methods using parallax reproduction, however, the occurring crosstalk reduces the usable image depth. With an increasing image depth (disparity), the visibility and disturbing effect of the crosstalk increase. In a matrix screen designed as a direct viewing screen, the pixel number available for N individual perspectives is reduced to 1/N of the pixels of the matrix screen used. In commercially available flat screens (LCD, plasma displays, OLED, etc.), every pixel consists of three subpixels of the colours red, green and blue, the intensity value of which can be controlled.
For avoiding scan-effects and for achieving a nearly symmetrical resolution in horizontal and vertical screen directions, the optical separating raster therefore can be arranged turned by an angle in relation to the pixel raster in such kind of screens (“Slanted Raster Method”, c. for example WO 99/05559 A1 or Publication II of van Berkel et al.: “Characterisation and Optimisation of 3D-LCD-Module Design” Proc SPIE vol 3012 pp 179-187, 1997). However, a basic disadvantage of that approach, apart from the strongly reduced individual image resolution, is the fact that the individual perspectives cannot be perfectly separated. That crosstalk of the adjacent stereo channels affects the spatial impression and reduces the image quality e.g. by blurring, multiple ghosting, contrast reduction and colour errors.
In order to achieve highest possible image quality with a high image resolution for an individual viewer, there have been described two-channel (“stereo channel”, scanning of a left and a right image view) autostereoscopic methods that adapt, with the help of mechanical and/or electronic means, the viewing areas on the screen to the current position of the viewer's eyes (“tracking method”, cf. for example EP 0 354 851 A2). The position of the eyes or pupils or of another detail of the head or eyes can be measured in a contactless and almost instantaneous manner with the help of known video methods. In that known two-channel method, the separating raster placed in front is arranged orthogonally to the pixel raster so that the resolution in the one (for example horizontal) direction is reduced to the half while it remains unchanged in the other (accordingly vertical) direction. For reducing the requirements on the exactness and response time of the tracking procedure for the eye position, it was proposed to introduce pixel reserves in the left and right image columns of the respectively scanned stereo pair (cf. for example DE 197 36 035 A1). That way, there is achieved a certain tolerance with regard to head movements of the viewer, but with the disadvantage that the already halved resolution in the one direction is further reduced. In autostereoscopic methods using quick electronic tracking, adjustment to the current eye position of the user is achieved by an electronic shifting of the scanned image content on the matrix screen; with a mechanical and therefore rather expensive and delayed tracking, the tracking is done by a relative movement of screen and/or separating raster in relation to the viewer (cf. for example DE 102 46 941 A1). It is inherent in the methods with asymmetrical image resolution that either a part of the originally available image information is not used for the representation on the matrix screen or that intermediate pixels must be interpolated in the direction to the higher resolution. For example according to DE 102 46 941 A1, every second image column of the left and right stereo half-image is left out for matrix screens, which causes disturbing scan-effects.
The nearest prior art that this invention uses as a starting point is described in Publication III of K. Mashitani et al.: “Step barrier system multi-view glass-less 3-D display” (SPIE-IS&T Vol 5291, 2004, pp. 265-268). For the parallax view with a plurality of individual views, for example four or seven, there is described a “thinning-out method” (cf. FIG. 6 ibid.), wherein, for four image views, a subpixel from every pixel of an image view is selected and taken over into the current subpixel extract, maintaining its address. However, the loss of resolution is accordingly high. In a “loss-free” method, all pixels are taken over into the current subpixel extract, but most of the pixels are readdressed (cf. FIG. 7 ibid.), which requires high computing capacity. The subpixels are arranged obliquely with an offset of one subpixel each over three scanning lines along a stepped barrier raster the overall width of which in individual steps for example covers four or seven subpixels and by which the respectively newly sorted subpixels are optically joined together again into one pixel for the viewer. Taking into account all subpixels, however, there is required a not commercially available, cost-intensive screen with a very high pixel number (cf. FIG. 8 ibid.). In a hybrid method of both methods, there is made an attempt to find a compromise between the advantages and disadvantages of both methods (cf. FIG. 9 ibid.). However, in both methods, there is always selected the same number of subpixels from a pixel and taken over into the subpixel extract, which results in a systematic error. Due to the used multi-view method offering different individual perspectives, there is moreover not used a tracking procedure for image tracking. That way, several viewers may be present, but an individual viewer will not receive a stable undistorted individual perspective according to his/her natural head movements as it would be required for medical applications for example.
Problem and Solution
It is the problem to be solved by the invention to provide a method of the above-described generic kind that, taking into account the basic aspect of increasing the comfort for the viewer/s, can autostereoscopically produce a three-dimensional information with the highest possible resolution that has an approximately symmetric image resolution in horizontal and vertical directions. In that connection, quality-reducing effects, such as crosstalk, shading by separating lines between the pixels and electronic components and jumps, shall be avoided to a large extent and the method shall be carried out in a fault-tolerant manner. Moreover, the method shall allow for an autostereoscopic image reproduction for the individual viewer with sufficient margin for movements of the head. The optical tracking of the image output for the left and the right eye of the viewer shall be floating, without perceivable switching-effects, without need for a mechanical movement of components of an arrangement implementing the method. The arrangement itself shall use commercially-available components, in particular a commercially available matrix screen of landscape format, and shall be easy to operate, not susceptible to failure and cost-effective.
The solution to that problem according to the invention can be gathered from the following summary.
In the method according to the invention (in the following briefly referred to as “Multiplex-Track-Method”—MTV), a coloured subpixel extract of a stereoscopic view is generated from two discrete image views (right and left image view) on a commercially available matrix screen in landscape format and is electronically tracked for at least one viewer. For that purpose, the addresses of the subpixels of the right image view are stored in a right memory and the addresses of the subpixels of the left image view are stored in a left memory first. Then, the current eye position of the viewer is determined. Depending on that determined current eye position, a current subpixel extract is formed and displayed on the matrix screen. It is an essential feature of that subpixel extract that all subpixels included have maintained their original address from the R- or L-memory. That way, computing capacity and computing time for each subpixel extract can be considerably reduced. Moreover, every subpixel is at its correct content-related place from the individual view so that an image reproduction true to the original can also be ensured under the scanning required for autostereoscopy. The multiplex scheme of the formation of the subpixel extract consists of the progressive scanning-line arrangement of two (or three) neighbouring subpixels from the right image view directly and continuously beside two (or three) neighbouring subpixels from the left image view. Between the individual scanning lines, there is always observed an offset by one subpixel so that there results a subpixel overlapping of one (or two) subpixels for the same eye between neighbouring scanning lines and a crosstalk between both image views is reduced. The offset is oriented along the inclination of the separating raster so that always two pixel pairs are arranged under a separating element. The arrangement of two or three adjacent subpixels from an image view depends on whether the individual separating element covers four subpixels (in which case subpixel pairs from equal image views are arranged side by side and the obliquely extending covering between subpixel pairs from the same image view adjacent in scanning lines has a width of one subpixel) or six subpixels (in which case subpixel triples from equal image views are arranged side by side and the obliquely extending covering between subpixel triples from the same image view adjacent in scanning lines has a width of two subpixels).
The writing of the subpixel addresses into the current subpixel extract according to the multiplex scheme depends on the determined current eye position of the viewer. In its normal (nominal) position, the assignment preferably starts directly on the top left subpixel of the matrix screen. Due to the spatial L-R-aligned assignment of the subpixels to the viewer's eyes, there is started with the first two (or three) subpixels from the right memory. There follow two (or three) subpixels from the left memory that are stored there in the first scanning line on places 3 and 4 (or 4 , 5 and 6 ) and the entire scanning line is accordingly assigned in an alternating manner in the right and left memory, maintaining the original subpixel addressing. Due to said address-maintaining, in case of subpixel pairs, there are alternatingly selected one or two subpixels from an original pixel, i.e. the selection is made asymmetrically. From the prior art, there is exclusively known a symmetrical selection (the same number of subpixels is selected from every pixel), which leads to systematic errors. In the invention, that system is broken so that the systematic error is significantly reduced. Moreover there is alternated, under a separating element covering four subpixels, between an assignment of three subpixels from the one memory and one subpixel from the other one and two subpixels from each memory, which leads to a further reduction of the systematic error. In case of a covering of six subpixels by a separating element, the assignment for the normal original position of the viewer is symmetrical. A complete pixel from the R memory and one from the L memory are alternatingly written. But already with a lateral offset of one subpixel due to a lateral movement of the viewer's head, an alternating asymmetry of the subpixel selection occurs here as well.
Depending on a lateral or vertical movement of the viewer, the subpixel extract is updated subpixel by subpixel. Since the subpixel assignment on the matrix screen is fixed (division into red, green and blue image gaps), it is necessary, maintaining the address, to select other subpixels of the fitting colour from the two image views when the viewer looks at the screen and therefore at other subpixels of other colours from a changed position. Depending on the viewer's movement, the writing of the current subpixel extract then starts on the second, third or fourth subpixel of the top scanning line of the matrix screen. If the viewer looks at the screen even more from the side, the representation switches back to the first subpixel and starts from the beginning. Individual subpixels in the edge region of the matrix screen are filled up according to the multiplex scheme or remain unassigned since they cannot be seen by the viewer anyway. Further explanations of the structure of the current subpixel extract can be gathered from the specific part of the description.
The MTV is based on the objective to make use of the basic advantages of the inclined position of the separating raster (resolution as symmetrically as possible in both image directions, blurring of interferences by regular, visible structures on the matrix screen) and of the introduction of an image reserve (more freedom of movement of the viewer without crosstalk, tolerance to errors of the method for determining the eye position) in connection with the advantage of the higher image resolution of a two-channel stereo method. The reduction of the resolution of the two image views to half the resolution of the matrix screen that is required for the MTV, too, however, has an effect on the subpixels only. That way, the visibility of interferences caused by scanning-effects can be clearly reduced. Unlike in the stereo method known from prior art, the MTV uses, in tracking the viewing areas, position-related new subpixel extracts from the composition of the two partial stereo images. The MTV ensures that the two image views available in the resolution of the matrix screen are represented on its subpixel raster with a symmetrical resolution. The crosstalk of the individual views known from the inclination of the separating raster in multiview systems is avoided by that special subpixel arrangement and by the design of the separating raster.
In summary, the special advantages of the MTV according to the invention are as follows:
applicable in the usual landscape screen format with a nearly symmetrical stereoscopic image resolution in horizontal and vertical directions; almost floating, fully electronic tracking of the image content depending on the current position of the viewer (no visible switching-over with intermediate shadow zone as in an orthogonal arrangement of the separating raster, no mechanically moved parts); less restrictions in the use of modern LCD displays with conductor tracks, transistors and other visible structures within the pixel aperture (as in wide-angle LCD displays with Multi-Domain Vertical Alignment), therefore investment security in modifications of the subpixel structure of the matrix screen; reduced crosstalk in the obliquely extending separating raster due to buffer areas with image reserve (always two or three adjacent horizontal subpixels are used for one image perspective).
In a special form of execution of the MTV, there can be used a subpixel multiplex scheme that is technically very easy to realise and is very favourable with regard to the requirements on electronic tracking. For avoiding repetitions, reference is made to the specific part of the description.
Another essential feature of the MTV is the electronic tracking of the current autostereoscopic image information to the current position of the viewer's eyes. The current eye position can be advantageously determined by involving a preferably video-based tracking procedure for finding the head or eye details of the at least one viewer. Tracking procedures are generally known and reliably developed. They are able to work without further strain on the viewer, such as e.g. by markings on the viewer's head, and that way will not reduce the user comfort. On the contrary, they increase it because the electronic tracking in the MTV allows the viewer to move the head without leaving the stereoscopic area of an image perspective. Video-based tracking procedures work with video cameras for capturing the current head or eye details that are analysed accordingly. With video cameras, it is also possible to capture the two separate image views for the right and the left eye of the viewer. Other tracking procedures without video capturing of the viewer are technically mature and usable, too. In the tracking procedure, it is of advantage to dynamically change the capturing setting for the image views depending on the current eye position determined by the tracking method. Apart from an autostereoscopic representation of static image scenes, it is also possible to represent autostereoscopic moving images. For that purpose, a dynamic storage of the image views is of advantage. Standard video formats can be used and analysed for addressing the subpixels. Furthermore, an automatic adaptation of the image views to the resolution of the matrix screen is of advantage (format conversion) as it is for example integrated in the software of customary computer operating systems.
Moreover, it is possible, by means of a adjustable distance of the separating raster to the matrix screen, to change the representation geometry of the scanning and thereby the size of the stereoscopic areas and that way respond to changes in depth of the distance of the viewer to the screen. Electronic tracking can only compensate for lateral and vertical changes in the eye position. Changes in the representation can also be made e.g. by addressing the separating raster for activating or blocking the individual separating elements. That way, the separating raster can be switched off in part or fully. In case it is completely switched off, only monoscopic image information can be represented on the screen. But there can also be switched off certain areas while other ones are maintained so that there results a hybrid screen that shows monoscopic as well as stereoscopic image information. But it is for example also possible to switch off every second raster column so that the distance between the individual separating elements is doubled. By such a measure, there can be selected for example a different viewing mode as described below.
A modification of the MTV provides for a division of the right image view into a first right and a second right image view and a division of the left image view into a first left and a second left image view, a storage of the addresses of the subpixels of the first and second right image views in a first and second right memory and of the first and second left image views in a first and second left memory, a formation of the current subpixel extract by a progressive arrangement alternatingly line by line of two adjacent subpixels of both right or both left image views and an involvement of a tracking procedure for detecting the head or eye details of two viewers, assigning to each viewer a right and a left image view, respectively. With that modification, the essential advantages of the MTV, in particular the reduced crosstalk in the obliquely arranged separating raster and the maintenance of the original pixel addressing, are preserved and it becomes also possible to provide two viewers simultaneously with an autostereoscopic information each—however with an again halved resolution and increased crosstalk. For that purpose, two left and two right partial stereo images are stored in respective memory means. Now the subpixel pairs are not selected from one and the same partial stereo image anymore, but from two closely adjacent ones so that the reserve function of multiple subpixel selection is maintained and the effect of crosstalk is reduced. Also with this modification, the individual autostereoscopic image contents are tracked in relation to the respective viewer. Thus, two tracking systems are used both of which access the same screen so that two viewers receive simultaneously a similar (or equal when the two stereoscopic views are simply doubled) autostereoscopic image information also when moving their heads. The same applies analogously to three viewers with three tracking systems when three right and three left image views are stored. In that case, however, the image resolution is divided by three compared with a use by one viewer.
Such a division among two or three viewers is suitable when they are at a medium distance to the screen. For a viewer at a short distance to the screen, there should be used the highest possible resolution and therefore only provided one right and one left image view in a single perspective. Since, however, the number of viewers and their distance to the screen may change, it is of advantage when the tracking procedure can be switched over, either manually or automatically, between a tracking of one, two or three viewers depending on the distance of the front viewer to the matrix screen. Finally, there may be provided an additional mode for a tracking-free multiview representation from N image views as it is known from prior art. That mode can be sensibly chosen when a large number of viewers is present at a larger distance to the screen. When the separating elements are switchable, for example eight neighbouring image views can be combined into seven different view perspectives as parallax view. Advantageously, it will be possible, depending on the number of viewers and their distance to the screen, to switch over between the tracked stereoscopic view for one, two or three viewers or the untracked multiple view for more than three viewers depending on the distance of the front viewer to the screen. Further switching possibilities comprise the switching over to a monoscopic image content or to a hybrid image content with stereoscopic and monoscopic view areas.
The MTV is relatively easy to realize with commercially available components. Preferably, there may be used an arrangement with a matrix screen having colour-assigned subpixels in scanning lines and an optical separating raster, wherein the periodicity of the separating elements in horizontal direction corresponds to a) four or b) six subpixels and wherein the separating elements are arranged obliquely in relation to the matrix of the screen with an inclination corresponding to the small side ratio of the subpixels. Moreover, there are provided at least a right memory and a left memory as well as a multiplex memory for storing the currently formed subpixel extract, a data processing unit for forming the current subpixel extract and for controlling the process flow and the individual components of the arrangement and at least one preferably video-based tracking system for detecting head or eye details of a viewer. According to the viewing mode, there may also be provided, subject to the number and distance of the viewers, two or three tracking systems for detecting head or eye details of two or three viewers. If they do not only move laterally and horizontally, but also in their distance to the screen, it is of advantage when the separating raster is variable in its distance to the screen or removable. The change of the distance can be made manually or electrically, individually or automatically. Removing the separating raster allows for a normal two-dimensional viewing mode on the conventional matrix screen. In the separating raster, the separating elements may have the form of slots or stripes (barriers) or prisms, cylindrical lenses, however, being preferred. Thus, the separating raster is preferably designed as a lenticular raster with obliquely arranged cylindrical lenses as separating elements. Such a separating raster is easy to manufacture and provides for a constantly high optical reproduction quality.
An even more fine-stepped tracking is possible when an addressable separating raster having alternative separating-element combinations offset by half a subpixel in relation to the subpixel raster of the matrix screen is used. For such sub-subpixel tracking, there is advantageously used alternating addressing between the separating elements in the defined periodicity and further separating elements with the same periodicity laterally offset from the defined periodicity by half the width of a subpixel. For that purpose, it is of advantage to use a separating raster with separating stripes the activation of the separating elements of which is addressable, wherein the individual separating stripes are arranged in two groups having the same periodicities with an offset of half the width of a subpixel to one another. Both, a mechanical and an electronic sub-subpixel tracking can be realised, the latter being preferable in the technical development. The stripes can opened and closed merely electronically. A mechanical shifting of two stripe plates arranged on top of one another, however, is possible, too.
The rectangular form of the subpixels is an idealised description. In practice, the subpixels often deviate from that form with areas in the corners being covered. That way, the areas where control elements are integrated are covered up. By a skilful rearrangement of these areas, the crosstalk in the subsequent view can be reduced. Especially with a bevelling of the subpixels on both sides, an optimum adjustment of the subpixels to the oblique separating raster is achieved and that way the crosstalk is reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
The Multiplex Track Method MTV and a preferred arrangement for its implementation according to the invention are explained below in more detail for their further understanding on the basis of the schematic figures. In respective image details, the figures show the following:
FIG. 1 a subpixel extract for a perpendicular (nominal) viewing angle;
FIG. 2 the change of the subpixel extract for a variable viewing angle;
FIGS. 3A to 3D four multiplex schemes for 4 subpixels behind a separating element;
FIGS. 4A to 4F six multiplex schemes for 6 subpixels behind a separating element;
FIG. 5 the subpixel distribution for 4 subpixels behind a separating element;
FIG. 6 the subpixel distribution for 6 subpixels behind a separating element;
FIG. 7 a subpixel extract with several right and left image views;
FIG. 8 a block diagram of an arrangement for implementing the MTV;
FIG. 9 an addressable separating raster for sub-subpixel tracking;
FIG. 10 an addressable separating raster for single- and multiple-user utilisation;
FIG. 11 a bevelled subpixel design.
DESCRIPTION OF PREFERRED EMBODIMENTS
As an exemplary embodiment of the MTV (Multiplex Track Method), FIG. 1 schematically shows a detail of a matrix screen MB covered with a scanned subpixel extract SPA for the reproduction of autostereoscopic information. On the matrix screen MB (LCD, plasma display), there are simultaneously reproduced, in a scanned manner, a left (L) and a right (R) image view (stereoscopic view, stereo semi-image), which means the views for the left an the right eye of the viewer, respectively. The matrix screen MB has vertical colour stripes of blue subpixels SP (in FIG. 1 shown hatched ascending to the right), green subpixels SP (in FIG. 1 shown horizontally hatched) and red subpixels SP (in FIG. 1 shown hatched descending to the right). The subpixels SP are arranged in horizontal scanning lines BZ. A pixel P of an image information is composed of a blue, a green and a red subpixel SP. The colour value of the pixel P results from the superimposition of the intensities of the three subpixels SP (colour mixing takes place in the viewer's eye). In the separating raster TR arranged obliquely in relation to the matrix of the matrix screen MB, respective colour subpixels SP along the inclination belong to one pixel P. The assignment of the subpixels SP from both image views L, R in the scanned image view on the matrix screen MB is described by a multiplex scheme MUX i . A separating raster TR placed in front of the matrix screen MB is fixed in a position turned by an angle α in relation to the vertical axis of the matrix screen MB (Slanted Raster Principle). The angle is calculated as α=arctg b/a, b being the narrow side and a the broad side of a subpixel SP. Thus, the (negative) slope of the separating raster TR corresponds to the small side ratio of the subpixels SP. With a ratio of b:a=1:3, there results an angle α of 18.43° for the inclination of the separating raster TR. In the exemplary embodiment shown, the separating raster TR has cylindrical lenses ZL as separating elements TE. The lens width LB (pitch) is chosen in such a manner that a cylindrical lens ZL has about the width of four subpixels SP in horizontal direction. A covering of six subpixels SP by a separating element TE is also possible, the lens width LB being respectively larger in that case, the slope of the separating raster TR does not change.
For the optical addressing of the two eyes of a viewer, a tracking procedure is used. Upon movements of the viewer's head, the viewing areas for the left and the right eye is tracked by a respective selection or adjustment of the multiplex scheme MUX i (electronic tracking). FIG. 2 exemplarily shows the lateral shifting of the image content on the matrix screen MB for the right eye R of the viewer when the latter moves out of the nominal normal position ( 1 ) to the positions ( 2 ), ( 3 ), ( 4 ) or ( 5 ), wherein position ( 5 ) again corresponds to position ( 1 ). One can see the lateral change of the image content by one subpixel SP each time to other subpixels SP of respective other colours so that other subpixels SP must be respectively selected from the two image views L, R for the subpixel extract SPA in order to track the image content correctly according to the eye movement.
In the nominal normal view of the viewer (perpendicular to the screen surface, see FIG. 1 ), always two horizontally adjacent subpixels SP belong to the same left or right image view (L or R). The pairs of two subpixels SP from the left image view LL and two right subpixels SP from the right image view RR are alternatingly continued line by line and that way the entire matrix screen MB is filled. Due to the distance D between the separating raster TR and the matrix screen MB (cf. FIG. 2 ), there results a parallax effect: with a respective dimensioning of the matrix screen MB with the separating raster TR placed before it, the viewer, depending on the current position of his/her head, sees with the left eye L essentially a certain selection of the subpixels SP of the matrix screen MB (SP-Set L, cf. FIGS. 3A and 4A , for reference not explained see FIG. 1 ) and with the right eye R essentially sees a certain selection of the remaining subpixels SP (SP-Set R, cf. FIGS. 3A and 4A ). For bringing about the stereoscopic effect, the subpixels SP of the left and right stereoscopic views L, R are assigned to the respective subpixel sets (SP-Set L, SP-Set R) by an image multiplexer, the addresses of the subpixels SP remaining unchanged. Since the screen coordinates of the two subpixel sets (SP-Set L, SP-Set R) depend on the current eye position (more exactly: the 3D coordinates of both pupils) of the viewer in relation to the screen, the application of a tracking procedure is required. In the following it is assumed by way of simplification that the arrangement of matrix screen MB and separating raster TR shall be designed for a fixed nominal viewing distance of the viewer; i.e. an adjustment of the addressing of the subpixels SP is only made depending on the horizontal and vertical movements of the viewer's head. Such simplification is admissible because the viewing areas have an extension also in direction towards the matrix screen MB that is sufficient for practical applications. The viewing areas for the autostereoscopic MTV described here are rhomb-shaped areas with maximum horizontal and vertical extensions at the place of the nominal viewing distance.
Embodiment of Subpixel Multiplexing
In the following, the multiplexing is described for the exemplary raster arrangement shown in FIG. 1 . In a specific embodiment of the Multiplex Track Method MTV, there can be used a subpixel multiplex scheme that is technically very easy to realise and supports the requirements on electronic tracking very well. It is assumed that the two image views exist in the form of two prefabricated bitmaps (e.g. image pair of a stereoscopic camera) or may be generated by a special computer program depending on the viewer's perspective. As long as conventional user interfaces (API), such as Open GL or DirectX do not allow for direct access to the addressing of the subpixels of a graphics adapter, a modified hardware-specific graphics driver is required for subpixel multiplexing.
It is further assumed that the bitmaps of both image views are kept as a whole or in part in two memory means, the left memory L-Buffer and the right memory R-Buffer. The multiplex software reads individual subpixels SP or pairs of adjacent subpixels SP at certain addresses out of the two memory means L-Buffer, R-Buffer and writes the video values under the corresponding addresses into a multiplex memory MUX-Buffer. A special advantage of the MTV is based on the fact that only a maximum of four (in case of a separating element TE covering four subpixels SP) or six (in case of a separating element TE covering six subpixels SP) multiplex schemes need to be implemented in the driver software of the graphics adapter for addressing the multiplex memory MUX-Buffer depending on the horizontal and vertical viewer position (cf. FIGS. 3 and 4 ). Then, a respective driver software of the tracking system used only needs to select the required multiplex scheme MUX depending on the respective pupil position of the viewer (taking into account the optical and geometric parameters of the matrix screen MB and of the separating raster TR that are assumed to be known) and fill the matrix screen MB accordingly.
For forming the subpixel extract on the matrix screen MB, two different variants can be used. In the first variant, a) four or b) six different multiplex schemes MUX i , starting with the first to the a) fourth or b) sixth subpixel SP in the first scanning line can be firmly defined in the multiplex software. Depending on the specific current eye position, the fitting multiplex scheme MUX i is accessed and the multiplex memory MUX-Buffer is respectively filled. There exist four (cf. FIGS. 3A to 3D ) or six (cf. FIGS. 4A to 4F ) different multiplex schemes MUX i because the viewer can look at each of the four or six subpixels SP under the separating element TE that then is quasi assigned as the “first” subpixel SP for the right eye R. The subpixels SP lying before the “first” subpixel SP up to the edge of the matrix screen MB are filled up in a respective alternating manner and show the difference in the different multiplex schemes MUX i . In the course of FIGS. 3A to 3D or FIGS. 4A to 4F , respectively, the “first” subpixel SP for the right eye R jumps one subpixel SP to the right each time so that there do always occur different subpixel constellations in front of it. Only the fifth or seventh offset by one subpixel SP again shows exactly the first multiplex scheme MUX.
In the second variant that is not presented in detail in the figures, only three different multiplex schemes MUX i , starting with the first, second or third subpixel SP in the first scanning line, and an integral pixel jump nP are defined, depending on the certain current eye position. The subpixel extract starting for the fourth (or seventh subpixel SP or the tenth subpixel SP etc.) subpixel SP for four subpixels SP under a separating element TE then results from the first multiplex scheme MUX shifted by an entire pixel P (or two pixels 2 P for the seventh subpixel SP or three pixels 3 P for the tenth subpixel SP etc.). Analogously, the subpixel extract for the fifth subpixel SP results from the second multiplex scheme MUX shifted by one pixel P and the subpixel extract for the sixth subpixel SP results from the third multiplex scheme MUX shifted by one pixel P. Then the assignment rule repeats itself with a pixel jump of 2P etc. For six subpixels SP under a separating element TE, there result analogous conditions, there are accordingly shifted the three first multiplex schemes MUX i by an integral pixel number nP.
The first variant involving a direct reading of the different multiplex schemes MUX i will always be applied advantageously when the image information to be reproduced is smaller than the matrix screen MB. Upon shifting the content, subpixels SP on the edge may remain unassigned because a viewing is not possible for the viewer there. The second variant can be advantageously used when the image to be reproduced is larger than the matrix screen MB. Also the shifted image will always fill the entire matrix screen MB completely.
The distribution of the subpixels SP in relation to the viewer's eye is shown in FIG. 5 for a cylindrical lenses ZL with four covered subpixels SP (variant a: LB=4SP). Moreover, the inclination of the cylindrical lens ZL by the angle α is shown; the horizontal pixel distribution with three subpixels SP red, green, blue each is indicated by the eye-assignment R, L. It is visible that every horizontal pixel P comprising three subpixels SP of different colours is always composed of two subpixels SP of the one and one subpixel SP of the other image view (numbers 2 - 1 ). Under the cylindrical lens ZL, there is moreover positioned one subpixel SP from the next left pixel P. It is visible that, from the pixels P of the two image views, alternatingly one or two subpixels SP are taken over into the subpixel extract SPA. Due to that alternating multiplex scheme MUX used in the MTV with an offset by one subpixel SP line by line resulting in an obliquely arranged covering of one subpixel SP, on the one hand, the subpixels SP along the obliquely arranged cylindrical lens ZL are optimally arranged so that there is no crosstalk and, on the other hand, they are combined into one pixel P in an colour-related optimum way so that the viewer does not perceive any jumps in the content even though the systematic error was considerably reduced by the mixing from different pixels P.
FIG. 6 shows the analogous distribution of the subpixels SP for a cylindrical lens ZL covering six subpixels SP (variant b: LB=6SP). In the first multiplex scheme MUX I, the selection of three subpixels SP from one image view each corresponds to the pixels P under the cylindrical lens ZL (numbers 3 - 3 ). With an offset by one subpixel SP (multiplex scheme MUX II), the following asymmetric distribution is visible: two subpixels SP from the first right pixel P, one subpixel SP from the second right pixel P, two subpixels SP from the first left pixel P, one subpixel SP from the second left pixel P (numbers 2 - 1 - 2 - 1 ). This alternating sequence is changed between the image views in the following multiplex scheme MUX III (numbers 1 - 2 - 1 - 2 ). Also with an arrangement of six subpixels SP under a cylindrical lens ZL it is therefore guaranteed that, alternatingly, always three, two or one subpixel/s SP from the pixels P are/is taken over into the current subpixel extract SPA and the above-mentioned advantages are maintained.
FIG. 7 shows a subpixel extract SPA, when a first and a second right image view R 1 , R 2 and a first and a second left image view L 1 , L 2 are used, for the case of variant a) that four subpixels SP are located under a separating element TE. The application of the different multiplex schemes MUX i with an offset line by line by one subpixel SP along the obliquely arranged separating raster TR applies analogously, just like the maintenance of every subpixel address from the storage memory to the video memory. For two right and two left image views R 1 /R 2 , L 1 /L 2 , two right and two left memory means for pixel storage are provided accordingly. The formation of pairs of two right subpixels SP and their direct arrangement beside two left subpixels SP are maintained, too. In contrast to the use of only two image views R, L, in this variant, however, the two right or left subpixels SP do not come from the same image view R, L, but from two different even though very closely neighbouring right and left image views R 1 /R 2 , L 1 /L 2 . With that modification, either two or (in case of six subpixels SP under one separating element TE) three viewers can be simultaneously tracked and receive an individually tracked image perspective of two related right and left image views (R 1 /R 2 , L 1 /L 2 ) respectively or, when the tracking is deactivated, more than two or three viewers can view different image perspectives without image tracking just like in a conventional multiview system. It is possible to switch over between the different modes as required. An analogous subdivision into three right and three left image views for variant b) with six subpixels under one separating element TE is possible, too. By means of three tracking systems, three viewers can be separately provided with a trackable individual perspective each. By using the subpixels SP from only one image view, there can be realized a locally restricted or full-area monoscopic image reproduction; maybe with a (local) deactivation of the separating raster TR.
FIG. 8 shows a block diagram of an arrangement for implementing the MTV. A 3-D application captured for example with a stereo video camera SVK having a right image view R and a left image view L is loaded, via a conventional user interface API into a right memory R-Buffer and a left memory L-Buffer on a graphics adapter GK. By means of a preferably video-based tracking system TS for detecting head or eye details of a viewer, for example a pupil tracker PT, the current eye position of the viewer is determined. The tracking system TS is addressed depending on the currently reproduced camera signal KS. The different multiplex schemes MUX I-IV/VI are stored in the graphics software of the graphics driver GT. The graphics driver GT comprises a computing unit RE for controlling the process flow and for selecting the mode. Depending on the respective viewer position determined, a multiplex scheme MUX i is selected and the current subpixel extract SPA is created and stored in a multiplex memory MUX-Buffer. It is displayed on the matrix screen MB with a separating raster TR in front of it.
FIG. 9 shows a section view of a separating raster TR in front of the matrix screen MB with oblique separating stripes TRS and a covering of four subpixels SP in three different switching states. The separating raster TR is electronically addressable with regard to the currently addressed and opened separating stripes TRS. The view on the top shows the separating raster TR with an activation of the separating stripes TRS with the period for an autostereoscopic operation for a single user. The view in the middle shows the same arrangement with an activation of an equal period of separating stripes TRS that, however, is offset by half the width of a subpixel SP in relation to the structure of the subpixels SP of the matrix screen MB (double arrow). By that measure, the fine tracking is continued up into the sub-subpixel area. The correct assignment of the image content is achieved by using the correct subpixel extract SPA. The selection is maintained when the user makes no or only very slight movements of the head. If it is necessary to compensate for a movement of the head in the opposite direction, another subpixel extract is to be selected. The view on the bottom again shows the activation of the original raster according to the left view of FIG. 9 . But the right and the left viewing areas were shifted further to the right. For that purpose, there were used a subpixel extract SPA in which the subpixels SP of the left and right images are shifted by one subpixel position. References not explained can be gathered from the preceding figures.
FIG. 10 shows a separating raster TR with separating stripes TRS where, in the view on the top, the separating stripes were realised for operation by a single user. In the lower view, however, every second separating stripe TRS is closed. In that mode, it is possible to realise, behind the remaining opened separating stripes TRS, a parallax viewing from various image views for several users according to the number of existing subpixels SP that in turn corresponds to the number of the individual views. Every subpixel SP contains a colour information from views having a lateral disparity between each other, the address of the subpixel SP on the matrix screen MB corresponding to that one from the subpixel extract SPA of the respective view.
FIG. 11 shows subpixels SP with a double bevel AS at the corners along the oblique separating raster TR. The bevels AS in the subpixels SP were regrouped in part in order to reduce the crosstalk between the subpixel sets (SP-Set L, SP-Set R). The optimum adjustment of the double-bevelled subpixels SP to the oblique separating raster TR is well visible.
LIST OF REFERENCES
α slope angle of TR
a broad side of SP, variant a with 4 SP
API user interface
AS bevel
b narrow side of SP, variant b with 6 SP
BZ scanning line
D distance TR-MB
GK graphics adapter
GT graphics driver
KS camera signal
L left image view, left eye
LB lens width
L-Buffer left memory
MB matrix screen
MTV Multiplex Track Method
MUX i multiplex scheme
MUX-Buffer multiplex memory
nP number of integral pixels
P pixel
PT pupil tracker
R right image view, right eye
R-Buffer right memory
RE computing unit
SP subpixel
SPA subpixel extract
SP-Set L left subpixel set
SP-Set R right subpixel set
SVK stereo video camera
TE separating element
TR separating raster
TRS separating stripe
TS tracking system
ZL cylindrical lens
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A method for autostereoscopically producing three-dimensional image information from scanned subpixel extracts uses a multiplex track method (MTV) having a separating raster (TR) obliquely extended with respect to a matrix screen (MB) and an electronic tracking (TS) of viewing areas ibased on two separated image views (L, R), that adjacently disposes two or three subpixels (SP) of each pixel (P) of the two image views (L, R) in the actual subpixel extraction (SPA), continuously and alternatingly preserving each subpixel address and disposes said subpixels (SP) in an overlapping manner on each other with an offset, whereby the resolution loss effects the subpixels (SP) only. The crosstalk resulting from the inclination of the separating raster (TR) is reduced by a special structure of the subpixel extraction (SPA), wherein the resolution homogenisation in two directions of the screen is simultaneously preserved. The formation of the actual subpixel extraction (SPA) is carried out according to multiplex schemes (MUX i ) predetermined according to an observer actual position. One or several observers can be electronically tracked subject to the distance thereof from the matrix screen (MB), and the image representation can be adapted therefor.
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BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention relates to a process for producing tubular shaped fibrous articles.
2. STATEMENT OF THE PRIOR ART
Rod shaped fibrous articles used as a core for belt-tip pens*, filters, etc. have heretofore been prepared by cutting fulled felts of wool or felts of chemical fibers or synthetic fibers obtained by employing a binder or through mechanical entanglement, to predetermined shaped and sizes. (* felt-tip pens: the core, the end portion of which is felt-tip, is made from compact fibrous materials). Further, in the case of tobacco filters and the like, use has been made of a process comprising the steps of depositing triacetin onto crimped tows to plasticize it and shaping the resulting products into rods. Still further, in recent years, various shaped fibrous articles have been obtained with the use of hot-melt-adhesive composite fibers. For instance, U.S. Pat. No. 4,270,962 disclosed a process for producing rod-form shaped fibrous articles by heat treating a fibrous bundle containing at least 20% by weight of adhesive fibers by introducing the fibrous bundle into a heating zone through an elongated transport zone consisting of a single hollow pipe that is surrounded by said heating zone, imparting heat to the exterior portion of said fibrous bundle by directing heat against the exterior of said transport zone and imparting heat throughout the interior of said fibrous bundle by directing heated gas outwardly through the interior of said transport zone in a direction opposite to the inward movement of said fibrous bundle through said transport zone. With this process, however, it is possible to obtain solid rod-form shaped fibrous articles, but it is impossible to obtain hollow ones.
U.S. Pat. Nos. 4,100,009 and 4,197,156 specifications teach a method for producing a hollow-cylindrically shaped fibrous article stabilized by hot adhesion, which comprises passing a web of gathered fiber layer carried on a conveyor belt through a heating zone, heating said web in such a way that a lower-melting component of composite fiber contained in the lower part of said web contacting the conveyor belt is not in the molten state and a lower-melting component contained in the upper part of said web is in the molten state, while separating said web from the conveyor belt, winding up said web on a take-up rod or tube in such a way that the upper surface thereof occupies the inner side of the winding, while heating the web further, cooling the wound up article and drawing out the take-up rod or tube from the shaped product, and an apparatus for carrying out the same. However, this method provides only shaped articles which are hard as well as of larger diameter and thickness, and involves relatively complicated steps.
SUMMARY OF THE INVENTION
As a result of intensive and extensive studies made of a process for producing tubular shaped fibrous articles of small diameter, the desired object has been achieved by the provision of a process for producing tubular shaped fibrous articles by heating and cooling a fibrous bundle containing at least 20 weight % of hot-melt-adhesive composite fibers, wherein the improvements comprise:
using a shaping apparatus including an injecting chamber, an injecting hole formed in the wall of said chamber, a fibrous bundle outlet provided with a nozzle of a desired shape in cross-section, a fibrous bundle-introducing cylindrical pipe, which has a cross-sectional area larger than that of said outlet and is located at a position opposite to said fibrous bundle outlet and projects toward said fibrous bundle outlet and terminates in said injecting chamber, and a core pipe which is open at its base on the outside of said injecting chamber and has its one end inserted through said fibrous bundle-introducing cylindrical pipe and extends into said nozzle through said injecting chamber and has vents in its portion exposed within said injecting chamber, and
passing said fibrous bundle through between said fibrous bundle-introducing cylindrical pipe and said core pipe to said fibrous bundle outlet, while injecting a hot compressed gas through said injecting hole, thereby to heat to and to shape said fibrous bundle to and at its hot-melt-adhesive temperature. The present invention has been accomplished on the basis of such findings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become apparent from the following detailed description with reference to the accompanying drawings, which are given for the purpose of illustration alone, and in which:
FIG. 1 is a schematical view showing one example of the shaping apparatus according to the present invention,
FIG. 2 is two sectional views taken along the line A--A of FIG. 1,
FIG. 3 is two enlarged views showing a part encircled at B in FIG. 1, and
FIG. 4 is a general view showing one embodiment of the process according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As the hot-melt-adhesive composite fibers to be used in the present invention, use may be made of any composite component fibers wherein there is a difference of 10° C. or higher in melting point between the composite components, and a low-melting component forms at least a part of the surface of each fiber and exhibits hot-melt adhesiveness. In an advantageous embodiment, however, preference is given to the composite fibers having a melting-point difference of 20° C. or higer and a side-by-side or sheath-core structure wherein the fiber circumferential proportion, in cross-section, of a low-melting component amounts to 50 to 100%. The combinations of composite components to be mentioned include (polyproplene/polyethylene), (polypropylene/ethylene-vinyl acetate copolymers or their saponified products or mixtures thereof with polyethylene), (polyester/polypropylene), (nylon 6/nylon 66), and the like. Heating is carried out at the hot-melt-adhesive temperature, a temperature between the melting points of both composite components, whereby the low-melting component melts and adheres together, while its fibrous form remains unchanged. The fineness of fibers used may optionally be selected from a wide range of 0.5 D/F (abbreviation of "denier per filament") to 200 D/F inclusive. The degree of crimping is preferably in a range of 3 to 30 crimps per inch. Crimp may be of either the mechanical or the steric type. The fibrous bundles used may be in the form of tows, filament yarns, slivers, spun yarns, etc. Other fibers to be mixed with the composite fibers may include natural fibers, bast fibers, chemical fibers, synthetic fibers, etc.
The hot compressed gases used usually include air or steam, but other gases such as nitrogen may be used. Steam is superior in the conduction of heat to air, and the use of steam makes the shaping apparatus more compact and the shaping speed higher. Where moisture is undesired, air is preferred. In order to conduct an amount of heat to the fibrous bundle as fast as possible, the heated gas is previously compressed to a higher pressure, then passed deeply through within the fibrous bundle, and is finally discharged under reduced pressure to the atmosphere. A main pressure of 1 to 5 Kg/cm 2 (gauge) is preferred to this end. The gas may be heated by either passing it through a heating device heated by a sheath heater element, or applying external heat to a pipe through which it is passed.
Further explanation will be made together with one preferable apparatus used in the process of the present invention.
Referring now to the drawings, reference numeral 1 stands for an injecting chamber, 2 an injecting hole, 3 a shaping apparatus, 4 a nozzle, 5 a fibrous bundle outlet, 6 a fibrous bundle-introducing cylindrical pipe, 7 a core pipe, 8 a vent, 9 a fibrous bundle-introducing inlet, 10 an opening in the base end of the core pipe, 11 a fibrous bundle, 12 a tubular shaped fibrous body, 13 a take-up means, 14 a cutter, and 15 a product.
The fibrous bundle 11 is drawn through the fibrous bundle-introducing inlet 9 (hereinafter simply called the introducing inlet 9), pre-shaped in the tubular form while it passes in between the core pipe 7 and the fibrous bundle-introducing cylindrical pipe 6 (hereinafter simply called the introducing pipe 6) consisting of funnel-like portion and cylindrical portion, and is drawn through the nozzle 4 to the outside of the shaping apparatus 3. In order that the fibrous bundle 11 is uniformly pre-shaped in the shaping apparatus 3, it is preferably divided into plural, more preferably at least three portions, and is fed through a same plurality of introducing inlets 9 as said portions into the introducing pipe 6 where such portions are pre-shaped as an integrated piece. When the hot compressed gas is injected through the injecting hole 2, it heats the introducing pipe 6 from the outside, and tends to leave through the introducing pipe 6 and the fibrous bundle outlet 5 (hereinafter simple called the outlet 5) to the outside air. Then, since the cross-sectional area of the introducing pipe 6 is larger than that of the outlet 5 and the fibrous bundle 11 passes through the portion left by subtracting the cross-sectional area of the core pipe 7 from each cross-sectional area of the introducing pipe 6, the density of fibers in the introducing pipe 6 is lower than that in the outlet 5. In other words, the gaps between the fibers in the introducing pipe 6 is larger than that in the outlet 5. Hence, even if the introducing pipe 6 is increased in length, a larger amount of the injected hot gas escapes through the introducing pipe 6, rather than through the outlet 5, to the outside air. By further reason of the vents 8 provided along the surface of the core pipe 7, a portion of the injected hot gas passes through the fibrous layer, and is then sent out of the vents 8 to the outside through the interior of the core pipe 7 and teh opening 10, whereby the core pipe 7 per se is heated. Accordingly, while the fibrous bundle 11 moves from the introducing pipe 6 to the nozzle 4, it is pre-shaped in the tubular form and, at the same time, is heated from the outside and inside of it. Combined with the fact that the hot gas passes through the gaps between the fibers, such heating makes it possible for the fibrous bundle to be heated uniformly to its depth in an extremely short period of time, whereby the composite fibers are put into a hot-melt-adhesive state. If the core pipe 7 were neither hollow nor vented at 8, heating of the core pipe 7 would become insufficient so that insufficient adhesion takes place on the inner surface of the shaped body, with the cracking, surface roughening and the like occurring as a result.
In accordance with the present invention, while the fibrous bundle 11 passes through the introducing pipe 6, it is uniformly heated even to its depth in a relatively low density state; hence, where the fibrous bundle is thermally deformable, development of latent crimps and shrinkage occur uniformly. Thus, the form of the shaped body shaped by the subsequent nozzle 4 is stabilized without any deformation.
If the cross-sectional area between the introducing pipe 6 and the core pipe 7 is too large, too much release of the hot gas through the introducing inlet 9 then takes place so that difficulty is encountered in heating of the fibrous bundle 11. If that area is too small, then the fibers are press-bonded or nonuniformly adhered together. In an extreme case, it is impossible to draw the fibrous bundle 11 out of the nozzle 4. The cross-sectional area between the introducing pipe 6 and the core pipe 7 should preferably be 1.2 to 4 times as large as that between the nozzle 4 and the core pipe 7.
The length of the introducing pipe 6 should preferably be such that it extends with a length between the extremity of the introducing pipe 6 and the nozzle 4 corresponding to 1/10 to 3/10 of the overall length of the injecting chamber in order to directly heat the outer periphery of the fibrous bundle by the hot gas for a while and provides an inlet for the introducing pipe 6 and the core pipe 7.
In order to apply uniform heating to the fibrous bundle 11, the vents 8 to be formed in the core pipe 7 may be comprised of a number of small holes arranged in a zigzag and multi-stage manner, or a multi-stage arrangement of circumferential slits.
The shaped body leaving the nozzle 4 is cooled and solidified, taken up by the take-up means 13, and is cut to a desired length by the cutter 14. Cooling may be carried out in the conventional manners in which that body is passed through a pipe cooled as by air or water. Air cooling may usually be applied to the shaped body, while it leaves the nozzle 4 and reached the take-up means 13. For drawing, slight nipping may be applied to the shaped body with a grooved roll. The thus drawn body is cut into the product 15 by the cutter 14.
The present invention has the following effects.
(1) The obtained tubular shaped fibrous articles have the fibers sufficiently and uniformly adhered together on not only the outside face but also on the inside face, and thus excel in dimensional stability.
(2) The tubular shaped fibrous articles can bery easily be produced at a high speed, with the required apparatus being of a compact size.
(3) The obtained tubular shaped fibrous articles have the fibers sufficiently and uniformly hot-adhered together even to the depth with a controlled fiber bulk density selected from the considerably wide range of 1 to 40%.
(4) The obtained tubular shaped fibrous articles include fine and uniform voids formed by point-adhesion among the hot-melt-adhesive composite fibers, which voids are uniformly and finely distributed throughout the overall fibrous layer, and provide high-quality filters for gases or liquids.
EXAMPLE 1
To each introducing inlet 9 shown in FIG. 2(2-1) was fed a fibrous bundle 11 having a total fineness of 80,000 deniers, which consisted of highly crimpable hot-melt-adhesive composite fibers having a fineness of 3 D/F and composed of a low-melting component (with a M.P. of 110° C.) of an 1:3 blend of an ethylene-vinyl acetate copolymet (abbreviated as EVA, and having a vinyl acetate content of 20%) and polyethylene and a high-melting component (with a M.P of 165° C.) of polypropylene, said low-melting component having a circumferential proportion in cross-section of 80%. In this manner, a total fineness of 240,000 deniers of fibrous bundles were drawn to prepare a tubular shaped fibrous body 12. The shaping apparatus used includes a introducing pipe 6 having a total length of 28 cm and comprising a cylindrical portion of 12 mm in inner diameter and 13 cm in length and a funnel-like portion of 5 cm in length, a core pipe 7 of 3.6 mm in inner diameter, 6 mm in outer diameter and 26 cm in total length [having a total of 20 (five per one stage) of vents 8 in its portion extending from the introducing pipe 6], and a circular nozzle 4 of 10 mm in inner diameter and 20 mm in total length. While 2 Kg/cm 2 (gauge) of superheated steam were injected through the injecting hole 2, said fibrous bundles were passed at a rate of 30 cm/min for heating and shaping, thereby to obtain a tubular shaped fibrous body 12 of 10 mm in outer diameter and 6 mm in inner diameter. After air cooling, that body was cut into products 15 of 10 cm in length. The thus obtained shaped fibrous body 12 is found to be free from any fuzzing and cracking on the outer and inner faces thereof, and have a uniform thickness. To determine the resistance to water permeation of the wall of that body, it was attached to a housing for a cartridge filter. As a result, that body was found to have a resistance to water permeation of 0.11 Kg/cm 2 (gauge) at a water flow rate of 250 l/h, and be suitable for use as a water filter.
Comparison Example 1
A tubular shaped fibrous body was obtained in the same manner as in Example 1, provided that a core pipe having no vent was used. The obtained shaped body was found to be considerably fuzzed on the inner face, and was judged to be poor in adhesion. The resistance to water permeation was 0.04 Kg/cm 2 (gauge), and the shaped body was found to be crakced after measurement.
EXAMPLE 2
Thirty (30) % by weight of highly crimpable heat-adhesive composite fibers having a fineness of 3 D/F and a length of 102 mm and consisting of a sheath component of polyethylene (M. P.: 135° C.) and core component of polypropylene (M. P. : 165° C.) were blended with 70% by weight of highly crimpable acetate fibers having a fineness of 4 D/F and a length of 102 mm, and the resulting blended fibers were opened by carding into slivers, each of 7 g/m. The sliver was fed to each introducing inlet 9 shown in FIG. 2 (2-2) to draw a total of 28 g/m of fibrous bundles into a tubular shaped fibrous body 12 of 6 mm in inner diameter and 10 mm in outer diameter. The shaping apparatus used was the same as that of Example 1, except for the introducing inlet 9, and was operated at a shaping speed of 30 cm/min, while heating was carried out at 170° C. with 3 Kg/cm 2 (gauge) of superheated steam. A tubular shaped fibrous body 12 air-cooled and cut afterward to a length of 10 cm was found to be free from any fuzzing on both inner and outer faces, has a uniform thickness, and shows a resistance to water permeation of 0.10 Kg/cm 2 (gauge).
Comparison Example 2
A tubular shaped fibrous body was prepared in the same manner as in Example 2, provided that a core pipe having no vent was empolyed. The obtained body was found to be fuzzed even on the inner face, and uneven in thickness. This body was easily deformable between fingers, had a resistance to water permeation of barely 0.03 Kg/cm 2 (gauge), and was found to be unsuitable for use as a filter.
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In a process for producing tubular shaped fibrous articles of small diameter by heating and cooling a fibrous bundle containing at least 20 weight % of hot-melt-adhesive composite fibers, the improvements comprise using a shaping apparatus including an injecting chamber, an injecting hole formed in the wall of the chamber, a fibrous bundle outlet provided with a nozzle of a desired shape in cross-section, a cylindrical pipe for introducing the fibrous bundle, which has a cross-sectional area larger than that of the outlet, is located at a position opposite to the outlet and projects toward the outlet and terminates in the injecting chamber, and a core pipe which is open at its base on the outside of the injecting chamber, has its one end inserted through the cylindrical pipe and extending into the nozzle through the injecting chamber, and having a vent in its portion exposed within the injecting chamber, and passing the fibrous bundle through the cylindrical pipe to the outlet, while injecting a hot compressed gas through the injecting hole, thereby to heat and shape the fibrous bundle to and at its hot-melt-adhesive temperature.
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BACKGROUND OF THE INVENTION
The invention relates to the discovery that 2-descarboxy-2-(tetrazol-5-yl)-11-desoxy-16-aryl-ω-tetranor prostaglandins of the E series are able to stimulate bone reformation. Their synthesis and structure are disclosed in U.S. Pat. No. 3,932,389.
Bone, characteristically, is the main organ of the body that stands against the stress and strain of movement and work done by the body. This function requires both strength and rigidity of the bone and necessitates constant rebuilding of bone tissue. The result is a dynamic balance of formation, resorption and maintenance of the materials composing the tissue so that the bone strength is projected along the stress vector caused by external force on the bone.
The bone as living tissue is composed of cells, osteoid which is the extracellular organic matrix and osteominerals which are complex inorganic salts. The cells do all the work of formation, resorption and maintenance in the bone while the osteoid and the osteominerals provide the resiliency and strength characteristic of the bone. Morphologically the cells are divided into osteoblasts, osteoclasts and osteocytes which perform the functions of formation, resorption and maintenance of bone respectively. Collagen and ground substance form the two parts of the organic matrix called the osteoid. The former consists of cross-linked protein while the latter consists of glycol proteins functioning as cementing material. The osteominerals exist in both the amorphous and crystalline states and form a bed around the osteoid. Of the many complex minerals present, the most important and plentiful is calcium phosphate.
The osteoblasts and osteocytes control the metabolism of collagen, glycol proteins and minerals while the osteoclasts, which are multinuclear in nature cause resorption of collagen by enzymatic lysing action. The laying down of bone by the osteoblasts is regulated indirectly by two hormones, parathyroid hormone and thyrocalcitonin. Their secretion is a response to changes in the serum calcium level and their effect is to normalize the serum calcium level. The result is the use of bone by the body as a reservoir for removal or deposition of calcium in response to this hormone stimulation. The most important growth factor, however, is external stress without which there can be no stimulation of bone growth.
When the dynamic balance between bone resorption and bone formation is upset, the usual result is loss of bone density. The osteoblasts and osteocytes fail to maintain the regular growth of bone while the osteoclasts continue to lyse and dissolve bone. The result is a loss of collagen and osteominerals thus providing a thin shell of brittle bone in a poor condition to withstand stress.
There are many causes of the disruption of the dynamic balance resulting in loss of bone density. They are: osteopenia which includes such diseases as post menopausal osteoporosis and senile osteoporosis, osteomalacea, cystica fibrosa, osteogenic carcinomas and tumors, osteolysis and peridontal disease. Bone fracture also disrupts the normal dynamic balance between bone growth and resorption but it doesn't result in a loss of bone density. The usual treatment for bone wasting includes exercise and a diet rich in protein and calcium. However, it usually doesn't cure but simply arrests the ultimate debilitation. Obviously, osteogenic carcinomas and tumors have additional requirements for their treatment. In addition to exercise and diet, traditional treatment of bone wasting disorders has also relied upon the efficacy of such drugs as estrogens and anabolic hormones.
While some types of prostaglandins are reported to cause an increase in bone deposition, that affect is not a general phenomenon. U.S. Pat. Nos. 4,000,309, 3,982,016 and 4,018,892 all describe the bone deposition effects resulting from the administration of 16-aryl-13,14-dihydro-PGE 2 p-biphenyl esters to animals. However, the usual effect exhibited when prostaglandins are administered is not stimulation of bone deposition but bone resorption. The natural prostaglandins, PGE, PGF, PGA and PGB, of the one and two series all are reported to stimulate bone resorption in vitro (J. W. Dietrick, et al Prostaglandins, 10,231 (1975)). It is, thus, highly unlikely that any particular synthetic prostaglandin will exhibit bone deposition activity.
In view of the bone resorption characteristics of natural prostaglandins and the independent structures of the prostaglandins used in the present invention compared to those used in the U.S. patents supra describing a method of deposition, it has been suprisingly found that 2-descarboxy-2(tetrazol-5-yl)-11-desoxy-16-aryl-ω-tetranor prostaglandins may be used to cause increased bone deposition in animals.
SUMMARY OF THE INVENTION
In accordance with the present invention, a method for the treatment of bone disorders has been discovered which utilizes the administration of a prostaglandin to increase the amount of both the osteomineral deposit and the osteoid present within the bone. The prostaglandins producing this effect have the structure ##STR1## and the pharmacologically acceptable salts wherein: A is ethylene or cis-vinylene;
M is oxo, ##STR2## R is hydrogen or methyl; and Ar is phenyl or monosubstituted phenyl, said monosubstituent being fluoro, chloro, bromo, trifluoromethyl, methyl, methoxy and phenyl.
The preferred prostaglandins to be used in the treatment of bone wasting disorders are 2-descarboxy-2-(tetrazol-5-yl)-11-desoxy-13,14-dihydro-16-phenyl-ω-tetranor-prostaglandin E 2 , 2-descarboxy-2-(tetrazol-5-yl)-11-desoxy-16-phenyl-ω-tetranor-prostaglandin E 0 , the corresponding C-15 epimers, the corresponding C-15 keto isomers and the magnesium salts of the preferred compounds.
Especially preferred are the magnesium salts of 2-descarboxy-2-(tetrazol-5-yl)-11-desoxy-16-phenyl-ω-tetranor prostaglandin E 0 and 2-descarboxy-2-(tetrazol-5-yl)-11-desoxy-15-keto-16-phenyl-ω-tetranorprostaglandin E 0 .
The method is especially useful when the bone disorder to be treated is osteopenia, including osteoporosis, osteomalacia, osteitis, fibrosa cystica, osteolysis, a pathological change in the dynamic balance of the blood serum calcium and bone calcium levels, peridontal disease, bone fracture and bone loss associated with primary bone tumors.
The preferred routes of administration include oral tablets or capsules and injection. For oral administration the prostaglandin may be given in a suspension or solution with water, ethyl alcohol or vegetable oil or administered orally in a tablet or capsule form alone or in combination with excipients and solid diluents such as corn starch, talc, gum arabic, acacia, polyvinylpyrrolidone, clay, sucrose or dextrose at doses containing 2 microgram /kg. to 0.2 mg./kg. of the prostaglandin with up to 5 doses per day. For injection, the prostaglandin may be given intravenously, intramuscularly or subcutaneously in a sterile mixture or solution with such diluents as normal saline or water and ethyl alcohol at doses containing 0.5 micrograms/kg. to 50 micrograms/kg. of the prostaglandin with up to 5 doses per day.
DETAILED DESCRIPTION OF THE INVENTION
The structure and prostaglandins used in this invention as well as method for their synthesis have been disclosed and the compounds claimed in U.S. Pat. No. 3,932,389. Briefly, they are synthesized using the well-known Corey prostaglandin synthesis route and employing 2- 5α-hydroxy-2β-formyl-cyclopent-1α-yl!acetic acid γ-lactone, dimethyl 2-oxo-3-arylpropyl or butyl phosphonate wherein the aryl group is defined as above and 4-(tetrazol-5-yl)-n-butyl!triphenylphosphonium bromide as starting materials for the cyclopentyl nucleus and the bottom and top side chains.
In addition to the isolated prostaglandins themselves, physical compositions of the prostaglandins used for this invention consist of a variety of pharmacologically acceptable salts. These useful salts are formed by the combination of the prostaglandins described supra and pharmacologically acceptable metal hydroxides, methoxides and ethoxides, ammonium hydroxide, amines and quaternary ammonium halide salts. Methods to form these salts are well-known in the art. Especially preferred metal cations to be used in the combinations are those derived from alkali metals such as lithium, sodium and potassium and from alkaline earth metals such as magnesium and calcium, although cationic forms of other metals such as aluminum, zinc and iron are within the scope of this invention. Pharmacologically acceptable amine cations to be used in the combination are those derived from primary, secondary and tertiary amines. Examples of suitable amines are methyl amine, dimethyl amine, triethyl amine, ethyl amine, benzyl amine, alpha phenylethyl amine, beta phenylethyl amine as well as heterocyclic amines such as piperidine, morpholine, pyrrolidine and piperazine. Other amines include those containing water solubilizing or hydrophilic groups such as mono, di and tri ethanol amine, galactamine, n-methyl glucosamine, ephedrine, phenylephedrine, epinephrine, procaine and the like. Examples of suitable pharmacologically acceptable quaternary ammonium cations to be used in the combination are tetramethylammonium, tetraethylammonium, benzyltrimethylammonium phenyltriethylammonium and the like. Examples of excipients and binders which can be used to form tablets or capsules with the prostaglandins or their salts used in this invention include polyvinylpyrrolidone, sodium citrate, calcium carbonate, dicalcium phosphates, starch, alginic acid, complex silicates, milk sugar (lactose) gelatin, acacia, gum arabic corn starch, talc, sucrose, dextrose and the like. A typical formulation is composed of the desired amount of prostaglandin or its salt and from 5 to 20% corn starch and from 75 to 95% lactose compressed into tablet form.
The prostaglandins used for this invention can be administered in a variety of pharmaceutical preparations as described above. Although the particular dose formulation and route of administration are dependent upon each patient's unique condition and the wisdom of his attending physician, the guidelines set forth infra for the 2-descarboxy-(tetrazol-5-yl)-11-desoxy-16-aryl-ω-tetranor-prostaglandins and their pharmacologically acceptable salts describe the method of treatment of bone wasting disorders according to the present invention. For deposition of the bone tissue, the prostaglandins or their salts used in this invention may be administered orally in tablet or capsule form in formulations as described supra at doses containing 2 microgram/kg. to 0.2 mg/kg. of the prostaglandin with up to 5 doses per day. The prostaglandins may also be administered by injection intramuscularly, intravenously or subcutaneously in a sterile mixture or solution with diluents such as normal saline or water and ethyl alcohol at doses containing 0.5 microgram/kg. to 50 micrograms/kg. of the prostaglandin with up to 5 doses per day.
The following example describes the efficacy of the prostaglandins used in this invention in causing bone deposition in various species of animals. It is meant to be illustrative only and in no way limits the scope of the claims.
Twelve male and 12 female cynomolgus monkeys were assigned to four groups of three males and three females each. Three of these groups were given the test compound, the magnesium salt of 2-descarboxy-2-(tetrazol-5-yl)-11-desoxy-15-keto-16-phenyl-ω-tetranor PGE o , in gelatin capsules at dose levels of 0.5, 0.25 and 0.1 mg./kg. once daily for 98 days. The test compound was administered as a 1% cornstarch-lactose blend containing 10% cornstarch, 89% lactose and 1% test compound. The three dose groups therefore were given 50, 25 and 10 mg. of this blend /kg./day respectively. The fourth group serving as controls received empty gelatin capsules only. Five of six high dose level animals exhibited bilateral, diaphyseal thickening of the long bones (humerus, radius, ulna, femur, tibia, fibula). Histologically, this lesion is characterized by periosteal new bone formation; and, concomitant lysis of cortical and periosteal new bone. Withdrawal of the drug for a short period of time did not cause complete reversion of the bone to its original state. Other clinical chemistry appeared to be within the normal range for the cynomolgus monkey.
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Bone deposition in animals is produced by administration of 2-descarboxy-2-(tetrazol-5-yl)-11-desoxy-16-aryl-ω-tetranor prostaglandins of the E series, their C-15 keto isomers, and the pharmaceutically acceptable salts thereof.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is directed to rubber compositions cabable of adhesion to both polymeric and metallic materials. Such composition is useful generally for adhesive bonding of a thermoplastic resin to a metallic material and particularly for firm attachment of a metal fitting to a hose construction. The invention further relates to a method of jointing a coupler on to a hose.
2. Description of the Prior Art
Polymeric materials have of late found application to a wide variety of industrial sectors and household commodities. This trend has lent an impetus to the production of composite polymer materials in which a polymer and a metal are bonded together into an integral structure and further to the development of adhesive compositions for polymer-to-metal bonding.
Prior adhesive compositions are applicable for instance to automotive hoses for air-conditioning and fuel-transporting use. As refrigerants a family of gases known as chlorofluorocarbons (CFCs) have been employed among which dichlorodifluoromethane (CFC 12) is typified. CFC 12, however, is reported to rise into the stratophere and erode the ozone layer that screens out dangerous solar rays and thus induce cutaneous cancer in some cases. The world's industrial nations are required to phase out the use of such ozone-depleting chemical. 1,1,1,2-Tetrafluoroethane (HFC 134a) is considered to be one safe substitute.
An urgent need has arose, in addition to safety examination of HFC 134a by experts, for means ensuring leak proof, maintenance-free transport of that gas as a refrigerant.
Various hoses have been proposed for use in transporting or otherwise handling refrigerants and fuels. One such hose is constructed with a core tube formed from a acrylonitrile-butadiene rubber (NBR) or chlorosulfonated polyethylene (CSM) for its good oil-resistance and refrigerant- and fuel-impermeable properties. To further improve impermeability, another hose has assembled a combination core including an inner peripheral wall of a thermoplastic resin such as a nylon and an outer peripheral wall of a rubbery material such as NBR, CSM or butyl rubber (IIR). Either type of hose is usually provided at each of its opposite ends with an aluminum joint fixed by the use of an adhesive composition for connection to the companion part.
The last-mentioned, laminated-cored hose has a drawback in that on prolonged exposure to a temperature exceeding a working temperature, say from 140° to 160° C., it gets flattened at the inner resinous wall under stresses originating from the joint. In such instances the hose is susceptible to leakage at a lower pressure than a working pressure usually of from 15 to 30 kgf/cm 2 and even at the working temperature. This is evidenced by the following performance tests in which the hose has been examined for air tightness after aging at varying temperatures for different lengths of time.
______________________________________temperature (°C.) time (hr) pressure (kgf/cm.sup.2)______________________________________120 168 not leaked at 40140 168 leaked at less than 5150 168 leaked at less than 5160 24 leaked at less than 5______________________________________
The foregoing hose of a combination core type is wholly unsatisfactory as it is prone to leak only under appreciable stress particularly where it is by sheer accident subject to a higher temperature for a longer period of time. This is literally responsible for laborious maintenance and often for hazardous operation.
The above problems have been coped with by the use of metal joints constituted of a nipple and a socket, the nipple being structured in a trapezoidally channeled, serrated or voluted shape and the socket formed to suit wavy or flat clamping. None of these attempts works to satisfaction from the leakproofness point of view. Alternatively, it is known that a hose body and a metal fitting can be clamped with an O-ring or sleeve interposed therebetween. In this mode of clamping, the packing is objectionably displaceable and difficult to position in place while in interengagement of the hose with the fitting.
To attain integral bonding between a composite hose and a metal joint, it has been proposed that a chlorinated rubber cement be used as an adhesive. This cement tends to adversely affect the resinous material constituting an inner wall of the hose core, rendering the resultant hose assembly sensitive to stress crack and hence fluid leak.
SUMMARY OF THE INVENTION
With the existing situation of the prior art in view, the present invention seeks to provide a novel rubber composition which is adhesively bondable to polymeric and metallic materials, sufficiently durable against severe vibration and repetitive pressurization and rather inert to thermosetting and thermoplastic resins.
Another object of the invention is to provide a method of intergrally jointing a composite hose with a metal coupler with the use of such rubber composition.
The rubber composition according to the invention contemplates particular utility in automobile hoses, contributing to leak-proof, maintenance-free transport of refrigerants such as CFC 12 and HFC 134a and a fuel such as gasoline.
The above and other objects and features of the invention will become better understood from the following description taken in conjunction with the accompanying drawings.
More specifically, one aspect of the invention provides a rubber composition for use in bonding a polymer and a metal into an integral structure, which comprises (a) a base rubber, (b) at least one inorganic or organic filler, the inorganic filler having a hydrochloric acid-soluble content of not more than 3 percent, the filler totalling at an amount of from 30 to 300 parts by weight per 100 parts by weight of the base rubber, (c) a silane coupling agent in an amount of greater than 2 parts by weight per 100 parts by weight of the base rubber and (d) a vulcanizing agent whereby the composition has a minimum viscosity of from 45 to 120 as determined at 125° C. on a Mooney viscometer.
According to another aspect of the invention, these is provided a method of integrally attaching a composite hose to a metal joint, the hose comprising an inner tube, a reinforcing layer and a cover superimposed in the order mentioned, the core tube including an inner peripheral wall formed of a polymeric material and an outer peripheral wall formed of a rubbery material, which method comprises (e) disposing a rubber composition peripherally over the hose at an end thereof and in a predetermined area, (f) mounting the joint on the hose end having the composition carried thereon and (g) subsequently clamping the joint into fixed relation to the hose end, the rubber composition comprising (a) 100 parts by weight of a base rubber, (b) at least inorganic or organic filler, the inorganic filler having a hydrochloric acid-soluble content of not more than 3 percent, the filler totalling at an amount of from 30 to 300 parts by weight per 100 parts by weight of the base rubber, (c) a silane coupling agent in an amount of greater than 2 parts by weight per 100 parts by weight of the base rubber and (d) a vulcanizing agent whereby the composition has a minimum viscosity of from 45 to 120 as determined at 125° C. on a Mooney viscometer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, segmentally seen and partly cut away, of a hose construction to which the principles of the present invention are applied.
FIG. 2 is a partly enlarged, cross-sectionally taken view showing the manner in which the hose of FIG. 1 has been assembled at its one end with a metal joint.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, there is shown a typical example of a composite hose designated at 10 and adapted to be used in the present invention. The hose 10 is built with an inner tube 20, a reinforcing layer 30 and a cover 40 superimposed in the order mentioned. The tube 20 is generally of a two-layered structure having an inner peripheral wall 20a formed of a thermoplastic material and an outer peripheral wall of a rubbery material. Labeled at 50 is a metal fitting made up of a socket 50a and a nipple 50b and arranged to hold one end of the hose 10 in clamped relation, as illustrated in FIG. 2, for engagement with the corresponding part intended.
A rubber composition according to the invention is disposed as an adhesive agent 60 in a region defined between the inner wall 20a of the tube 20 and the nipple 50b of the fitting 50 as viewed in FIG. 2 in a warpwise direction and between a front end 70 of the socket 50a and a rear end 80 of the nipple 50b as seen in a weftwise direction.
The rubber composition, provided in accordance with one preferred embodiment of the invention, is comprised of a base rubber, one or more inorganic fillers having a specified hydrochloric acid-soluble content, or an organic filler, a silane coupling agent and a vulcanizing agent. Thus the composition is designed to have a viscosity of from 45 to 120 as determined at 125° C. on a Mooney viscometer. Such a rubber composition is highly capable of exhibiting superior bondability to polymers and to metals, thus ensuring sufficient impermeability to gases and to oils on application to automotive hoses in particular.
Polymers used for purposes of the invention may be selected from thermoplastic resins such as polyethylenes, polyvinyl chlorides, polyamides typified by nylon-6, nylon-66, nylon-8, nylon-10, nylon-11, nylon-12, nylon-666, nylon-610 and the like, polyamide-polyether copolymers in which polyamide segments are taken from nylon-6, nylon-11, nylon-12, nylon-666, nylon-612 and the like and polyether segments from polytetramethylene glycol, polypropylene glycol, polyethylene glycol and the like, polyacrylates and the like, elastomers such as natural and synthetic rubbers and thermosetting resins such as phenolic resins, polyesters, epoxy resins, urethane resins and the like. The nylons now listed are commonly accepted in the art, and no explanations will be believed necessary of their physicochemical properties.
Suitable metals typically include aluminum, iron and the like.
As base rubbers there may be used natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), acrylonitrile-butadiene rubber (NBR), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), chloroprene rubber (CR), ethylene-propylene-diene rubber (EPDM), butyl rubber (IIR), chlorobutyl rubber (CI-IIR), bromobutyl rubber (Br-IIR), epichlorohydrine rubber (CHR, CHC), acrylic rubber and the like. CSM, IIR, CI-IIR and Br-IIR are particularly preferred which may be employed either alone or in combination with other different rubbers.
In one specific example CSM is a rubber derived by incorporating chlorine and sulfur dioxide into a high-pressure polyethylene and graded usually as having a chlorine content of 25 to 43% and a sulfur content of 0.9 to 1.3%. This rubber excels not only in weather resistance, ozone resistance, chemical resistance, flame retardance and mechanical strength but also in durability against adverse vibration and repetitive pressurization.
Specific examples of fillers include inorganic fillers such as carbon black, white carbon, e.g. anhydrous or hydrous silicic acid, calcium silicate, aluminum silicate or the like, clay, talc, titanium oxide, calcium carbonate, magnesium carbonate, barium sulfate, alumina hydrate and the like either alone or in combination and organic fillers such as phenolic resin, styrene-rich SBR resin and the like. The inorganic filler should not exceed 3% in hydrochloric acidsoluble content for reasons which will follow.
The solubilization quality denotes the content of a metal ion in a given filler component, the ion including Zn 2+ , Ca 2+ , A1 3+ , Fe 2+ , Fe 3+ , Co 2+ and the like. Too much of the metal ion results in a polymer assembly involving stress cracks; that is, the metal ion readily reacts with free chlorine generating for instance from a CSM rubber and thus forms a metal chloride that tends to invite cracking on stress of thermoplastic resins, particularly of nylons such as nylon-6.
The filler should range in amount from 30 to 300 parts by weight, preferably 40 to 270 parts, per 100 parts by weight of the base rubber. Less than 30 parts would not be effective for viscosity buildup to a desirable extent, and more than 300 parts would make the resulting composition inadequately viscous.
Silane coupling agents include for example vinyl type silanes such as vinyltrichlorosilane, vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane and the like, methacryloxy type silanes such as γ-(methacryloxypropyl)trimethoxysilane and the like, epoxy type silanes such as β-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane, γ-glycydoxypropylmethyldiethoxysilane, γ-glycydoxypropyltrimethoxysilane and the like, amine type silanes such as N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane and the like, sulfur-containing type silanes such as γ-mercaptopropyltrimethoxysilane, e.g. one tradenamed KBM 803 and manufactured by ShinEtsu Silicone Co., bis-(3-triethoxysilylpropyl)tetrasulfide, e.g. one tradenamed Si 69 and manufactured by Degussa GmbH, and the like, and halogenated alkyl type silanes such as γ-chloropropyltrimethoxysilane and the like. Particularly preferred are sulfur-containing silanes among which Si 69 is most recommended. The silane compound has a role to improve adhesion between the nipple of the metal fitting and the inner wall of the inner tube.
The coupling agent should be added in an amount of greater than 2 parts by weight, preferably from 3 to 50 parts, based on 100 parts by weight of the base rubber. Less than 2 parts would fail to give sufficient adhesion. More than 50 parts would produce no better results, entailing cost burdens.
Vulcanizing agents depend on the nature of base rubbers, and they include metal oxides, metal peroxides, organic acids and the like for use in CSM. Specific examples include metal oxides such as magnesium oxide, lead oxide, tribasic lead maleate and the like, metal peroxides such as lead peroxide and the like and organic metal salts of resinous acids such as hydrogenated rosin, abietic acid and the like and of fatty acids such as stearic acid, lauric acid and the like. For IIR there may be utilized modified phenol resin, quinone dioxime, alkyl phenol-formaldehyde resin, p-quinone dioxime, p,p'-dibenzoylquinone dioxime, tetrachloro-p-benzoquinone and the like.
The rubber composition of the invention may if necessary be blended with plasticizers, lubricants, antioxidants, vulcanization accelerators, softeners, tackifiers, peptizers, dispersants, processing aids and the like. For instance, plasticizers may be chosen from dibasic acid esters, glycol derivatives, glycerine derivatives, paraffin derivatives and epoxy derivatives in which are included trimellitate ester, dioctyl phthalate, di-n-butyl sebacate and the like. Lubricants typically include stearic acid, metal soap thereof, wax, polyethylene and the like.
Importantly, the composition of the invention should have a minimum viscosity of 45 to 120, preferably 50 to 100, which results from determination at 125° C. on a Mooney viscometer. The viscosity defined herein is generally taken as a magnitude of plasticity of a rubber composition in an unvulcanized state.
Minimum viscosities if lower than 45 would make the after-cure rubber mix insufficiently bondable to both a polymer and a metal and hence liable to leak a fluid in a metal-fitted hose. Lower viscosities would also cause a rubber mix to become too soft and less workable, leading to a much deposit on a blender or roll and eventually to poor productivity and irregular quality. Minimum viscosities if higher than 120 would generate heat while in blending or rolling that develops premature crosslinking, i.e. scorching.
On exposure to a higher temperature than 125° C., the composition of the invention gets readily crosslinkable, mechanically strong, adequately bondable to polymeric and metallic materials and rather resistant to strain. Even at below 80° C. at which crosslinking usually initiates, the composition can produce adhesion force and strain resistance to an acceptable extent at a viscosity of not lower than 45 at 125° C.
The composition according to the invention may suitably be interposed between a polymer and a metal and in the form of a cement treated with an organic solvent or a sheet formed by rolling or pressing. The cement is feasible in a concentration usually of about 5 to 50% by weight with the use of toluene, xylene, methyl ethyl ketone, ethyl acetate, hexane or the like. Cementing is convenient in that uniform coating of small thickness is possible with minute adjustments, whereas sheeting facilitates handling and environment qualities.
Where it is used particularly for hose-joint attachment, the composition of the invention may be cemented to a dry thickness of 0.05 to 0.2 mm. At smaller thicknesses than 0.05 mm the cement would be held in diplaced relation at a locally stressed portion on the hose body during clamping of a socket. Proper insertion of the hose into the joint would be difficult to attain at thicknesses larger than 0.2 mm. The thickness requirement equally applies to the case with the sheet.
In accordance with another preferred embodiment of the invention, there is provided a method of integrally bonding a metal joint on to a composite hose with the use of a rubber composition. Details as regards the construction and materials of the hose and the structure and materials of the joint are described in connection with the first embodiment, together with the components of the composition, and illustrated in FIGS. 1 and 2.
As viewed in FIG. 1, the hose 10 is built with a laminated tube 20, the inner wall 20a of the inner tube being formed form the polymers specified hereinabove. Any rubbery materials and polymeric fibers in common use are suitable for the formation of the outer wall 20b of the core tube, the reinforcement layer 30 and the cover 40.
The method according to the invention may be accomplished by disposing the rubber composition, in cement or sheet form, on one end of the hose in a specified area and by mounting the joint on the hose end on which the cement or sheet has been carried, followed by clamping of the joint into fixed relation to the hose end. Clamping is attainable in a conventional manner.
The area of the composition to be applied should be preferably in the range of 15 to 85% within an overall hose region defined between the front end 70 of the socket 50a and the rear end 80 of the nipple 50b as seen from FIG. 2. A vacant region in an area of 15% should importantly be left adjacent to the front end of the socket.
Areas below 15% would be too small for bonding between a hose and a joint. Larger areas than 85%, narrower vacant region, would produce acceptable proofness to leak but to an extent to bring the composition into contact with and even into elution in a gaseous fluid, leading to fluid discoloration and often to operation failure.
Either one of the cement-like and sheet-like compositions is feasible in a thickness of 0.05 to 0.2 mm.
The invention will now be described by way of the following examples which are provided for purposes of illustration. In all formulations the numerical figures are expressed in part by weight unless otherwise noted.
EXAMPLES 1 TO 13 AND COMPARATIVE EXAMPLES 1 TO 5
1) Preparation of Cement
Different rubber compositions were prepared as formulated in Table 1. Minimum viscosity measurement was made at 125° C. on a Mooney viscometer by the procedure of JIS K-6300. Each of the composition was treated with toluene to give a test cement having a solid content of 30% by weight.
2) Preparation of Hose
A nylon-6/nylon-11/polyolefin resin was extruded on a thermoplastic extruder around a mandrel to form a tubular inner wall having a thickness of 0.15 mm. The mandrel was one formed of nylon-11 and treated with a releasing agent and having an outside diameter of 10.6 mm. The inner wall-carrying mandrel was thereafter passed through a rubber extruder so that an outer wall of IIR was laminated in a thickness of 2.0 mm over the inner wall. The inner tube thus formed was reinforced by braiding with fibrous polyester around which a cover of CI-IIR was then extruded in a thickness of 1.5 mm.
The resulting hose was cured under pressure at 150° C. for 60 minutes, followed by pulling of the mandrel out of the vulcanizate.
3) Attachment of Joint to Hose
An aluminum joint of a conventional type was used which was made up of a socket and a nipple. The test cement was applied in a dry thickness of 0.05 mm onto the nipple in an area of 85% within an overall joint region. The hose was allowed to insert into the nipple after which the socket was clamped at a pressure of 60 kgf/cm 2 .
Performance evaluation was made of the resulting assembly under the conditions given below and with the results shown in Table 2.
4) Aging Test
Aging was done at 160° C. for 24 hours and at 140° C. for 24 hours. The hose after being aged with heat was examined for air tightness, adhesion and resin deterioration.
4-1) Air Tightness
The hose on aging with heat was cooled at room temperature and let to stand in water with the internal pressure held at 50 kgf/cm 2 . Leakage was adjudged by naked inspection.
The symbol "∘" denotes no leak and "x" leak.
4-2) Adhesion
The aged hose was cooled at room temperature and divided at a joint-fitted portion and in a longitudinal direction into two segments. One such segment was forced to delaminate out of the nipple at an angle of 90°.
"P" means peeling between the cement and the nipple and "F" fracture in which the cement fractured and adhered to the nipple and to the hose. "RD" is taken as resin deterioration in which measurement was made impossible.
4-3) Resin Resistance to Deterioration
The deterioration resistance was evaluated to the inner resinous wall of the hose. The hose subjected to the adhesion test was examined with naked eye for cracking on the inner wall.
"∘" shows no crack, "Δ" less crack and "x" much crack.
5) Vibration Test
The hose of 215 mm in length, held at a horizontal position, was pressurized at an internal pressure of 40 kgf/cm 2 and vibrated diametrically at a width of 1.6 mm, at a frequency of 30 Hz and at a cycle of 10 9 . Subsequent testing involved air tightness and resin deterioration.
5-1) Air Tightness
The procedure of 4-1 was followed except that the internal pressure was varied in the range of 30 to 50 kgf/cm 2 .
5-2) Resin Resistance to Deterioration
Evaluation was made by the procedure of 4-3.
6) Impulse Test
The hose was allowed to curve in a U shape of 60and exposed to impact at 150° C., at a reciprocal pressure up to 30 kgf/cm 2 and at a cycle of 20 4 per 35 cycles per minute.
Determination was made of the procedures of 5-1) and 5-2).
As is evident from Table 2, the rubber compositions according to the invention are highly satisfactory in respect of all the test properties. Nil or less silane coupling agent has been found unacceptable in adhesion force and impulse resistance as evidenced by Comparative Examples 1 and 2. Hydrochloric acid-soluble contents falling outside the scope of the invention, Comparative Examples 3 to 5, showed a sharp decline in resin resistance to deterioration.
EXAMPLES 14 TO 20 AND COMPARATIVE EXAMPLES 6 TO 8
7) Preparation of Cement
Ten rubber compositions were prepared according to the recipe shown in Table 3 and admixed on a mixing roll at 60° C. for 15 minutes. Minimum viscosity was measured at 125° C. with the use of a Mooney viscometer.
Each of the compositions was dissolved in an organic solvent into a cement with a solid content of 30% by weight. The solvent was toluene in Examples 14 to 19 and Comparative Examples 6 to 8 and n-hexane in Example 20. Coating was done in two varied thicknesses on a dry basis, one being at 0.05 mm and the other at 0.1 mm.
8) Production of Hose
The method of Example 1-1 was followed in producing different hoses.
A known aluminum-made joint was used which was constituted by a socket and a nipple. The nipple was coated with the cement obtained above and also wound with a sheet formed separately. Sheeting was effected at 0.05, 0.1 and 0.2 mm in thickness. On insertion of the hose into the joint thus treated, the socket was clamped at 60 kgf/cm 2 . A joint-fitted hose was provided in which the cement or sheet was interposed between the nipple and the inner resinous wall of the core tube.
10) Air Tightness Test
The procedure of Example 1-4-1 was followed except that the internal pressure was varied. The results are shown in Tables 3 to 5.
Evaluation was made as in Example 1-4-1. In Comparative Example 8 the symbol "S" is interpreted to mean that measurement was made impossible due to scorching.
EXAMPLES 21 TO 25 AND COMPARATIVE EXAMPLES 9 TO 11
The procedure of Example 14-10 was followed except for the temperature, time and pressure conditions. Tested were the same cements as in Examples 14 to 18 and Comparative Examples 6 to 8. A control was used in which no adhesive composition was added. The results are shown in Table 6.
EXAMPLES 26 TO 28 AND COMPARATIVE EXAMPLES 12 TO 14
Coat areas were varied as shown in Table 7 with the use of the same cement as in Example 16. This area was taken as a ratio of coat area to hose-nipple bond area. The cement was coated on the nipple in a predetermined area and in a direction from the rear end of the nipple toward the front end of the socket. The resulting hose assembly was examined for air tightness by the procedure of Example 14-10.
Further evaluation was made of aging after oil filling and delamination on nipple attachment under the conditions indicated hereunder and with the results shown in Table 7.
11) Oil-Filled Aging Test
JIS K-6349 7.4(2) was followed at 120° C. for 168 hours. After completion of the treatment, the oil used was taken out of the hose for naked inspection of discoloration.
12) Delamination Test
The joint-fitted hose was divided longitudinally into two segments at a portion above the nipple. The appearance of the cement on the nipple was adjudged by naked inspection.
By the symbol "∘" is meant no discoloration or no delamination and "Δ" partial delamination. "x" denotes that the oil discolors severely, or the cement delaminates successively.
As appears clear from Table 3, Examples 14 to 18 and Comparative Examples 6 to 8 show the correlation between the viscosity and the impermeability. Too low viscosities, Comparative Examples 6 and 7, revealed leak even at from 20 to 40 kgf/cm 2 . Comparative Example 8 is different from Example 5 in that no plasticizer is present with too high a viscosity with the result that the comparative composition was susceptible to scorching while in mixing. Example 19 is directed to the use of CSM combined with carbon black and Example 20 to an IIR-carbon black combination. Both compositions are acceptable in all the test properties.
Examples 21 to 25 and Comparative Examples 9 to 11 demonstrate the criticality of minimum viscosities at 125° C. as against temperatures and pressures. The inventive compositions are sufficiently impermeable at from 80° to 160° C. The higher the minimum viscosity at 125° C., the greater pressure resistance as is apparent from Table 6. This means that the viscosity characteristics according to the invention exhibit notable benefits. Comparative Examples 9 and 10 using lower viscosities revealed leak even at above 120° C. It has now been confirmed that the minimum viscosity should be set at 125° C.
Examples 26 to 29 and Comparative Examples 12 to 14 represent the effects of cement positioning and coat area not only on leak proofness and fluid inertness but also on cement delamination. Comparative Example 12 was unacceptable in impermeability which was attributable to the coat area being too small. Too large coat areas, though sufficiently resistant to leak, were readily susceptible to fluid discoloration and cement delamination as is evident from Comparative Examples 13 and 14. It will be noted therefore that the cement or sheet should be positioned with a blank hose region in an area of 15% left adjacent to the front end of the joint and that the overall coat area should be set at from 15 to 85%.
TABLE 1__________________________________________________________________________ HCl- Soluble Comparative Comparative Content Examples Examples ExamplesFormulation (%) 1 2 1 2 3 4 5 6 3 4 5__________________________________________________________________________CSM.sup.1) 100 100 100 100 100 100 100 100 100 100 100white carbon.sup.2) <0.1 45 45 45 45 45 45 45 45 45 45 45barium sulfate.sup.3) <0.1 60 60 60 60 60 60 60 60 60 60 60titanium dioxide.sup.4) <0.1 50 50 50 50 50 50 50 50 50 50 50Mistron Vapor.sup.5) 0.2 60Silkalite.sup.6) 2.8 60talc.sup.7) 4.2 60talc.sup.8) 8.9 60Lithopone.sup.9) 18.0 60stearic acid 2 2 2 2 2 2 2 2 2 2 62trimellitate ester.sup. 10) 25 25 25 25 25 25 25 25 25 25 25litharge, yellow no. 1 10 10 10 10 10 10 10 10 10 10 10dibenzothiazyl- 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5disulfide.sup.11)dipentamethylenethiruram- 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7tetrasulfide.sup.12)silane coupling agent.sup.13) 0 1 3 10 15 30 30 30 30 30 30minimum viscosity (125° C.) 70 70 68 68 65 65 92 95 80 70 65__________________________________________________________________________ HCl- Soluble Content ExamplesFormulation (%) 7 8 9 4 10 11 12 13__________________________________________________________________________CSM.sup.1) 100 100 100 100 100 100 100 100white carbon.sup.2) <0.1 45 45 45 45 45 45 45 45barium sulfate.sup.3) <0.1 0 0 30 60 70 80 80 80titanium dioxide.sup.4) <0.1 0 50 50 50 50 50 50 50Mistron Vapor.sup.5) 0.2 60 60Silkalite.sup.6) 2.8talc.sup.7) 4.2talc.sup. 8) 8.9Lithopone.sup.9) 18.0stearic acid 2 2 2 2 2 2 2 2trimellitate ester.sup.10) 25 25 25 25 25 25 25 25litharge, yellow no. 1 10 10 10 10 10 10 10 10dibenzothiazyl- 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5disulfide.sup.11)dipentamethylenethiruram- 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7tetrasulfide.sup.12)silane coupling agent.sup.13) 30 30 30 30 30 30 30 30minimum viscosity (125° C.) 46 55 60 65 70 75 104 111__________________________________________________________________________
TABLE 2__________________________________________________________________________ Com- parative Comparative Examples Examples Examples ExamplesProperties 1 2 1 2 3 4 5 6 3 4 5 7 8 9 4 10 11 12 13__________________________________________________________________________Aging Test160° C. × 24 hr air tightness (50 kgf/cm.sup.2) ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ adhesion P F F F F F F F RD RD RD F F F F F F F F resin resistance ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ x x x ∘ ∘ ∘ ∘ ∘ ∘ ∘ x140° C. × 24 hr air tightness (50 kgf/cm.sup.2) ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ adhesion P P F F F F F F RD RD RD F F F F F F F F resin resistance ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ Δ x x ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘Vibration Test air tightness (30 kfg/cm.sup.3) ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ air tightness (40 kfg/cm.sup.3) ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ air tightness (50 kfg/cm.sup.3) x ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ x ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ resin resistance ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ x x x ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘Impulse Test air tightness (30 kfg/cm.sup.3) ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ air tightness (40 kfg/cm.sup.3) x ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ x ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ air tightness (50 kfg/cm.sup.3) x x ∘ ∘ ∘ ∘ ∘ ∘ ∘ x x x x ∘ ∘ ∘ ∘ ∘ ∘ resin resistance ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ x x x ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘__________________________________________________________________________
TABLE 3__________________________________________________________________________ Examples Comparativwe ExamplesFormulation/Properties 14 15 16 17 18 6 7 8__________________________________________________________________________CSM.sup.1) 100 100 100 100 100 100 100 100white carbon.sup.2) 45 45 45 45 45 45 45 45Mistron Vapor.sup.5) 60 60 60 60 60 60 60 60titanium dioxide.sup.4) 50 50 50 50 50 50 50 50stearic acid 2 2 2 2 2 2 2 2trimellitate ester.sup.10) 50 40 30 25 10 100 60 0litharge, yellow no. 10 10 10 10 10 10 10 10 10accelerator DM.sup.11) 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5accelerator TRA.sup.12) 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7minimum viscosity (125° C.) 45 53 71 92 120 20 35cement coating S(160° C. × 24 hr)coat thickness (mm) 0.05 0.1 0.05 0.1 0.05 0.1 0.05 0.1 0.05 0.1 0.05 0.1 0.05 0.1air tightness 5 ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘(kgf/cm.sup.2) 10 ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ 20 ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ x ∘ ∘ ∘ 30 ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ -- x x ∘ 40 ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ -- -- -- x 50 x ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ -- -- -- --sheet covering(160° C. × 24 hr)sheet thickness (mm) 0.1 0.2 0.1 0.2 0.1 0.2 0.1 0.2 0.1 0.2 0.1 0.2 0.1 0.2air tightness 10 ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘(kgf/cm.sup.2) 20 ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ 30 ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ x ∘ ∘ ∘ 40 ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ -- x x ∘ 50 ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ -- -- -- ∘__________________________________________________________________________
TABLE 4______________________________________Formulation/Properties Example 19______________________________________CSM.sup.1) 100carbon black.sup.14) 80AC polyethylene 3trimellitate ester.sup.10) 10litharge, yellow no. 10 10accelerator TRA.sup.12) 2minimum viscosity (125° C.) 70cement coating(160° C. × 24 hr)coat thickness (mm) 0.05 0.1air tightness 5 ∘ ∘(kgf/cm.sup.2) 10 ∘ ∘ 20 ∘ ∘ 30 ∘ ∘ 40 ∘ ∘ 50 ∘ ∘sheet covering(160° C. × 24 hr)sheet thickness (mm) 0.1 0.2air tightness 10 ∘ ∘(kgf/cm.sup.2) 20 ∘ ∘ 30 ∘ ∘ 40 ∘ ∘ 50 ∘ ∘______________________________________
TABLE 5______________________________________Formulation/Properties Example 20______________________________________IIR.sup.15) 100carbon black.sup.16) 65AC polyethylene 10stearic acid 3softener.sup.17) 8phenol resin.sup.18) 6minimum viscosity (125° C.) 61cement coating(160° C. × 24 hr)coat thickness (mm) 0.05 0.1air tightness 5 ∘ ∘(kgf/cm.sup.2) 10 ∘ ∘ 20 ∘ ∘ 30 ∘ ∘ 40 ∘ ∘ 50 ∘ ∘sheet covering(160° C. × 24 hr)sheet thickness (mm) 0.1 0.2air tightness 10 ∘ ∘(kgf/cm.sup.2) 20 ∘ ∘ 30 ∘ ∘ 40 ∘ ∘ 50 ∘ ∘______________________________________
TABLE 6__________________________________________________________________________ Examples Comparative ExamplesFormulation/Properties Control 21 22 23 24 25 9 10 11__________________________________________________________________________CSM.sup.1) 100 100 100 100 100 100 100 100white carbon.sup.2) 45 45 45 45 45 45 45 45Mistron Vapor.sup.5) 60 60 60 60 60 60 60 60titanium dioxide.sup.4) 50 50 50 50 50 50 50 50stearic acid 2 2 2 2 2 2 2 2trimellitate ester.sup.10) 50 40 30 25 10 100 60 0litharge, yellow no. 10 10 10 10 10 10 10 10 10accelerator DM.sup.11) 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5accelerator TRA.sup.12) 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7minimum viscosity (125° C.) 45 53 71 92 120 20 35cement coating Scoat thickness (mm) -- 0.05 0.1 0.05 0.1 0.05 0.1 0.05 0.1 0.05 0.1 0.05 0.1 0.05 0.1air tightness 5 x ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘(160° C. × 24 hr) 10 -- ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ 20 -- ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ x ∘ ∘ ∘ 30 -- ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ -- x x ∘ 40 -- ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ -- -- -- x 50 -- x ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ -- -- -- -- 60 -- -- x x x x x x x x x -- -- -- --air tightness 10 x ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘(140° C. × 24 hr) 20 -- ∘ ∘ ∘ ∘ ∘ ∘ ∘ 30 -- ∘ ∘ ∘ ∘ ∘ x ∘ 40 -- ∘ ∘ ∘ ∘ ∘ -- x 50 -- ∘ ∘ ∘ ∘ ∘ -- -- 60 -- x x x ∘ ∘ -- -- 70 -- -- -- -- x x -- --air tightness 40 ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘(120° C. × 24 hr) 50 x ∘ ∘ ∘ ∘ ∘ ∘ ∘ 60 -- ∘ ∘ ∘ ∘ ∘ x x 70 -- x x x x x -- --air tightness 50 ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘(100° C. × 24 hr) 60 x ∘ ∘ ∘ ∘ ∘ ∘ ∘ 70 -- ∘ ∘ ∘ ∘ ∘ ∘ x xair tightness 50 ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘(80° C. × 24 hr) 60 x ∘ ∘ ∘ ∘ ∘ ∘ ∘ 70 -- ∘ ∘ ∘ ∘ ∘ x x__________________________________________________________________________
TABLE 7______________________________________ Com- parative Comparative Examples ExamplesProperties Example 12 26 27 28 13 14______________________________________coat area (%) 10 15 50 85 90 100air tightness(50 kgf/cm.sup.2 after160° C. × 24 hr)coat thickness (mm) 0.05 x ∘ ∘ ∘ ∘ ∘ 0.1 ∘ ∘ ∘ ∘ ∘ ∘aging after oil filling ∘ ∘ ∘ ∘ x x(120° C. × 168 hr)delamination on nipple ∘ ∘ ∘ Δ x xinsertion______________________________________
______________________________________Notes to TablesMaterial Maker Nature______________________________________1) Hypalon 40 DuPont2) Nipsil AQ Nippon Silica silicon dioxide3) No. 100, precipitated Sakai Chemical4) Tiepake R-820 Ishihara Sangyo5) Mistron Vapor Nippon Mistron magnesium silicate6) Silkalight Takehara Chemical aluminum silicate- magnesium silicate7) Talc F Nippon Talc magnesium silicate8) Talc SP 50A Fuji Talc magnesium silicate9) Lithopone D Sachtleben zinc sulfide- barium sulfate10) Witmol 218 Dynamite Nobel plasticizer11) Sunceller DM-PO Sanshin Chemical accelerator12) Sunceller TRA Sanshin Chemical accelerator13) Si 69 Degussa14) Asahi No. 50 Asahi Carbon SRF15) Exxon Butyl 268 Exxon isobutylene- isoprene16) Showblack N220 Showa Cabot ISAF17) Machine Oil 22 Fuji Kosan paraffinic oil18) Tackyroll 250-T Taoka Chemical brominated alkylphenol- formaldehyde resin______________________________________
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Rubber compositions are disclosed for integral attachment of polymeric and metallic materials. Improved bondability is attributed to the use of a selected base rubber blended with a selected class of inorganic or organic fillers, silane compounds and vulcanizing agents such that the finished composition is provided with a specified range of Mooney viscosities. Also disclosed is a method of hose-metal fitting connection by the application of the composition. Gas- and oil-impermeability characteristics are greatly enhanced.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application 60/926,021 filed on Apr. 23, 2007, the contents of which are incorporated herein by reference in their entirety.
STATEMENT OF GOVERNMENT INTEREST
[0002] The U.S. Government has certain rights in this invention pursuant to Grant No. EEC0310723 awarded by National Science Foundation.
FIELD
[0003] The present disclosure relates to coils. More in particular, it relates to a foldable polymer-based coil structure and a method for fabricating such coil. The coil structure of the present disclosure is suitable for radiofrequency (RF) operation.
BACKGROUND
[0004] Inductive coupling between a pair of coils is a very promising technology for wireless power and data transmission to implantation components in many biomedical applications. For a retinal prosthesis specifically, a receiving coil with high self-inductance and low series resistance (i.e., high Q) is needed to optimize the efficiency of the system. However, thin film coils made by existing conventional planar micromachining technology cannot achieve this requirement due to geometrical restrictions. Some techniques, such as electroplating and suspended structures (see, for example, Jae Y. Park and Mark G. Allen, High Q spiral - type microinductors on silicon substrates, IEEE Transactions on Magnetics, Vol. 35, NO. 5, (1999) 3544-3546), have been developed to make high-Q coils, but the processes are usually expensive, complicate, and unreliable.
[0005] FIG. 1 shows the concept of a telemetry system used for biomedical applications by way of an equivalent circuit of an electromagnetically coupled system. The primary coil (L 1 ) is outside the human body, and thus has fewer design constraints such as physical sizes and power consumption. Therefore, the power transfer efficiency of this system mainly depends on the intrinsic characteristics of the receiving coil (L 2 ). The intrinsic characteristics of a planar circular coil, i.e., the self-inductance L s and series resistance R s , can be calculated by its geometrical factors, as shown in equation (1) and (2).
[0000]
L
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=
2
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2
×
10
-
9
[
(
ln
4
d
t
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(
1
+
t
2
24
d
2
…
)
-
1
2
+
43
t
2
288
d
2
…
]
(
Henries
)
,
(
1
)
R
s
=
ρ
L
A
c
(
Ohm
)
(
2
)
[0006] Where L s is the self-inductance, N is the number of turns, d (in cm) is the mean diameter of the coil, t (in cm) is the coil width, R s is the series resistance, ρ is the metal resistivity, L is the total wire length, and A c is the cross section area of the metal wire. See, for example, Herbert Dwight, Electrical Coils and Conductors, McGraw Hill Book Company, 1945, ch 31, p 267. With these known parameters, the intrinsic Q-factor, which represents the efficiency of an inductor, is defined by the following formula, where ω is the angular resonant frequency of the AC signal (i.e., 2π×1 MHz for the current system),
[0000]
Q
t
=
ω
L
s
R
s
(
3
)
[0007] Theoretically, the higher the Q-factor, the more efficiently the coil performs. That means the power transfer efficiency of the system can be improved significantly by both increasing the self-inductance and lowering the series resistance of the receiving coil. Therefore, multiple layers of metal and thick metal are more desirable, but in reality this is difficult to fabricate using conventional micromachining techniques.
[0008] Y. C, Tai, F. Jiang, Y. Xu, M. Liger, S. Ho and C. M. Ho, Flexible MEMS skins: technologies and applications. Proceedings, Pacific Rim MEMS Workshop, Xiamen, China, 2002 describes a shear-stress sensors array integrated on a flexible polymer thin film, fabricated with a parylene/metal thin film technology.
SUMMARY
[0009] According to a first aspect, a foldable polymer-based coil structure is provided, comprising: a metal wiring arrangement comprising coils and at least one interconnection between the coils; and a polymer coating embedding the coils and the at least one interconnection, wherein the at least one interconnection and a portion of the polymer coating embedding the at least one interconnection define at least one foldable region configured to be folded to obtain a folded layered structure where the coils overlap each other,
[0010] According to a second aspect, a method for fabricating a foldable polymer-based coil structure is provided, comprising: providing a first polymer layer; depositing a first metal layer on the first polymer layer; patterning the first metal layer to form at least one metal interconnection; depositing a second polymer layer on the patterned first metal layer; patterning the second polymer layer to open the at least one metal interconnection; depositing a second metal layer on the patterned second polymer layer, the second metal layer contacting the opened at least one interconnection; patterning the second metal layer to form conductive wires; depositing a third polymer layer on the patterned second metal layer; and patterning the third polymer layer to define an embedded coil structure, the embedded coil structure comprising the conductive wires connected though the at least one interconnection.
[0011] According to a third aspect, a polymer-based coil stack comprising a plurality of coil structures stacked on each other is provided, each coil structure comprising: a metal wiring arrangement comprising a coil; a horizontal interconnection via connected with coil; a metal contact connected with the horizontal interconnection via; a polymer coating embedding the coil and the horizontal interconnection via; and a vertical interconnection via for connection to other coil structures of the stack.
[0012] Further embodiments of the present disclosure are provided in the written specification, drawings and claims.
[0013] A first advantage of the device and method of the present disclosure is that of providing high-Q coils with multiple layers of metal that can be fabricated without using electroplating technology.
[0014] A second advantage of the present disclosure is that the skins obtained in accordance with the present disclosure can be folded or stacked, and bonded together using a post fabrication thermal bonding process.
[0015] A third advantage is that the devices fabricated in accordance with the present disclosure are flexible and foldable, which can help to prevent any undesired degradation or mechanical damage in the region of implantation.
[0016] Additionally, according to some of its embodiments, the overall device is sealed by parylene, which makes it biocompatible. Moreover, although the device is specifically designed for intraocular retinal prostheses, it can be used in other biomedical applications which use wireless power and data transmission, such as micro stimulators for paralyzed muscle stimulation.
[0017] The device can be completely made using micromachining steps, which has many advantages over traditional fabrication approaches for bioimplantable coils, such as smaller size, precise dimensional control, and feasibility for system integration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 , already described above, shows an equivalent circuit of an electromagnetically coupled telemetry system used for biomedical applications,
[0019] FIG. 2 shows a top view of a polymer/metal thin film skin before folding and bonding.
[0020] FIG. 3 shows a perspective view of the skin of FIG. 2 when folded into two layers.
[0021] FIG. 4 shows a top view of the skin when fused into one piece after bonding.
[0022] FIG. 5 is a cross-sectional view showing an example of vertical interconnect or interconnection via suitable with the present disclosure.
[0023] FIG. 6 is a top view showing a three-layered structure, where FIG. 6( a ) shows the structure before folding, while FIG. 6( b ) shows the structure after folding.
[0024] FIGS. 7( a ) to 7 ( i ) show cross sectional views of fabrication steps of the foldable polymer-based coil.
[0025] FIG. 8 shows perspective exploded views of a guiding and holding device (jig) for aligning and bonding layers of a multilayer coil.
[0026] FIG. 9 shows a perspective exploded view of a stackable coil.
[0027] FIG. 10 shows a cross-sectional view of a vertical interconnection via with reference to a first layer and a second layer of a stacking coil.
[0028] FIG. 11 shows a top sectional view of FIG. 10 .
DETAILED DESCRIPTION
[0029] FIGS. 2-4 provide views of the foldable polymer-metal device according to the present disclosure to be used as an RF (radiofrequency) coil, which is targeted to solve the above discussed problem encountered in current high-Q coil manufacturing. Preferably, a parylene-based skin is provided, comprising two buried layers of metal made using parylene/metal thin film technology. Parylene is the generic name for members of a polyxylene polymer series. The basic member of this series, called parylene N, is poly-para-xylylene. Parylene C is produced from the same monomer modified only by the substitution of a chlorine atom for one of the aromatic hydrogens. Parylene C has very unique properties, including flexibility (an elongation break of about 200%) and mechanical strength (Young's modulus about 4 GPa), chemical inertness. United States Pharmacopoeia (USP) Class VI biocompatibility, and lower water permeability compared with other materials, such as polymide. Moreover, parylene C deposition is conformal, room temperature CVD coating. With a given thickness, parylene—and in particular parylene C—has better flexibility and mechanical strength than other common used polymers, such as polymide and PDMS.
[0030] FIG. 2 shows a top view of a parylene/metal thin film skin structure ( 10 ) comprising parylene C ( 20 ), metal coils ( 30 ) and metal contacts ( 40 ). The preferable thickness range is from 1 micron to 30 microns. The term “skin” indicates a very thin, flexible and biocompatible polymer-based film. As better shown later in FIGS. 7( a )- 7 ( i ) and in particular in FIG. 7( i ), the parylene coating embeds the metal wires ( 30 ) with the metal contacts ( 40 ) opened. Turning to FIG. 2 , thin film skin structure ( 10 ) also comprises coil interconnection vias ( 50 ) to connect the metal coils ( 30 ) with each other and contact, interconnection vias ( 60 ) to connect each coil ( 30 ) to a respective metal contact ( 40 ).
[0031] The metal structure ( 10 ) shown in FIG. 2 is a two-layered metal structure, where one layer of metal is for building the inductor conductive wires ( 30 ) and a second layer of metal is used for making the interconnections ( 50 ) between the conductive wires ( 30 ) and for forming the return leads or contact interconnection vias ( 60 ) to other components by way of the metal contacts ( 40 ).
[0032] The structure shown in FIG. 2 is symmetrical, so that it can be folded to form a two-layered structure. FIG. 3 shows a perspective view of the structure ( 10 ) of FIG. 2 when folded. This thin film skin can be easily folded into two layers thanks to the flexibility of parylene C (Young's modulus about 4 GPa).
[0033] FIG. 4 shows a top view of the skin when fused into one piece after thermal bonding. In particular, a post fabrication heat treatment is applied to the folded skin to bond together the separate layers into a whole piece. By varying the geometrical design, this technology can be easily extended to multiple layers. For example, before folding, vertical interconnects can be designed together with in-plane coils with alternating orientations between adjacent layers. After folding, all conductive wires will follow the same direction. Multi-layered structures allow to obtain higher values of L 2 ( FIG. 1 ) as needed.
[0034] FIG. 5 is a cross-sectional view showing an example of vertical interconnect or interconnection via suitable with the present disclosure. A top layer of metal ( 70 ) is located above a bottom layer of metal ( 72 ). In regions not corresponding to the vertical interconnection vias, a parylene insulating layer ( 74 ) is present between layers ( 70 ) and ( 72 ). On the other hand, a vertical interconnection via ( 76 ) is created by contacting the top layer of metal ( 70 ) with the bottom layer ( 72 ) as shown in the figure.
[0035] FIG. 6 is a top view showing an example of three-layered structure. In particular, FIG. 6( a ) shows the structure before folding, while FIG. 6( b ) shows the structure after folding. The structure of FIG. 6( a ) is folded along lines ( 80 ) and ( 82 ) of FIG. 6( a ).
[0036] FIGS. 7( a ) to 7 ( i ) show cross sectional views of fabrication steps of the foldable parylene-based coil shown in FIGS. 2 to 4 .
[0037] FIG. 7( a ) shows a first step where a silicon wafer ( 110 ) is provided and sacrificial layer of photoresist ( 100 ) is spin coated on the silicon wafer ( 110 ). Other substrates, such as glass substrates, can also be used.
[0038] FIG. 7( b ) shows a second step where a first layer of polymer such as parylene ( 120 ) is deposited on the photoresist ( 100 ).
[0039] FIG. 7( c ) shows a third step where metal layer, such as a Ti/Au multilayer (a layer of Ti, e.g. a 20 nm Ti layer, serving as adhesion layer, followed by a layer of Au), is deposited on the parylene layer ( 120 ) and then patterned to form metal interconnections and return leads ( 130 ). Patterning of the metal can occur by way of wet etching. The metal interconnections and return leads ( 130 ) correspond to the first metal layer of the two-layered structure discussed with reference to FIG. 2 . In particular, they correspond to the interconnections ( 50 ) and leads ( 60 ) shown in FIG. 2 .
[0040] FIG. 7( d ) shows a fourth step where a second parylene layer ( 140 ) is deposited above the structure of FIG. 7( c ) to provide insulation between the two layers of metal of the present disclosure, i.e. 1) the layer of metal to build the interconnections and leads ( 130 ) and 2) the layer of metal to build the coil wires ( 160 ) and ( 30 ), see also FIG. 7( f ).
[0041] FIG. 7( e ) shows a fifth step where pattern transfer is performed on the parylene layer and the parylene layer ( 140 ) is etched to open interconnection vias ( 150 ) between the metal layers. Etching can occur, for example, by way of O 2 plasma etching using a photoresist mask. Pattern transfer refers to a technique in which a photoresist mask is coated and patterned on top of parylene to protect selective areas when etching down into parylene. With this technique, the patterns on the photoresist can be transferred into parylene.
[0042] FIG. 7( f ) shows a sixth step where a second layer of metal, such as Ti/Au, is deposited and patterned to form the conductive wires ( 160 ) of the coil. Patterning can occur, for example, by wet etching. The second layer of metal corresponds to the layer of metal for building the inductor conductive wires ( 30 ) of FIG. 2 .
[0043] FIG. 7( g ) shows a seventh step where a further parylene coating ( 170 ) is provided, to seal the whole structure.
[0044] FIG. 7( h ) shows an eighth step where the parylene is patterned ( 180 ) to define the coil profile, for example by way of transfer pattern. Etching can occur, for example, by way of O 2 plasma etching. The person skilled in the art will understand that the geometry of the coils can be varied to meet the specification of different applications. The structure shown in FIG. 7( h ) represents a whole piece. The two central voids ( 180 ) represent the inner holes of the coils of FIG. 2 . The step described in FIG. 7( h ) first removes excess parylene to define the coil shape. In addition, it creates the contact openings—see the two side voids ( 180 )—by removing parylene on top of the contacts. Because plasma cannot penetrate metal, it will not etch the parylene under the metal contacts.
[0045] FIG. 7( i ) shows a ninth step where the device is released from the silicon substrate ( 110 ), for example by dissolution of the photoresist sacrificial layer ( 100 ) in acetone or other solvents.
[0046] Many different metals and conductive polymers can be used as the electrically conducting material. Other parylenes, polymers or plastics, can be used as the insulating material instead of parylene C. Moreover, the thickness of the insulating layer can be varied for different application environments. The thickness of the metal layers can he any kind of thickness, e.g., 20 nm to 4 μm. The thickness of each polymer layer can range, for example, from 2 μm to 20 μm.
[0047] After the parylene-based skin is released from the substrate, the structure is folded, and then a thermal bonding process is performed in a vacuum oven to fuse the separate layers together. The vacuum oven is used to prevent the oxidation of parylene C, which could make parylene very fragile. The bonding temperature should be below the melting point of parylene C (typically about 290° C.), for example 200° C. for 2 days. Other mechanisms can be used to heat up parylene skins instead of the thermal method, such as microwave.
[0048] According to an embodiment of the disclosure, the coil shown so far can be specifically designed for intraocular retinal prostheses. A particular case of such embodiment provides for a coil having 28 turns of metal wires, and being 10 mm in outer diameter. The metal can be encapsulated by 9 μm of parylene C.
[0049] As already mentioned above, the person skilled in the art will understand that the techniques shown so far can also be used for coils having a number of layers greater than, two. In this case, alignment between layers during folding could become an issue if too many layers are made with this technique.
[0050] In applications with a large number of such layers, a special jig (i.e. a guiding and holding device or mold for aligning and holding) matching the size of the coil can help to ensure good alignments. Good alignment is desired to achieve the maximum theoretically possible self-inductance (L 2 ). Such self-inductance will drop down in presence of misalignment. FIG. 8 shows an example of such jig ( 200 ), which comprises a top metal piece ( 210 ) and a bottom metal piece ( 220 ) to allow the parylene skins to be aligned and sandwiched in between during the thermal bonding process. For example, the jig can be made of aluminum which does not stick to parylene C at high temperature, and allows the device to be easily peeled off after thermal bonding. Alternatively, the jig can be made of Teflon®. Additionally, to improve the thermal bonding process, clamping force or pressure can be applied on the jig. Alignment can occur through the presence of alignment holes ( 340 ) (see FIG. 1 ) adapted to match alignment poles ( 330 ) provided in the jig,
[0051] Stackable coils can be an alternative approach for making high-Q coils with multiple layers of metal. FIG. 9 shows a perspective schematical view of a stackable coil ( 300 ), in accordance with a further embodiment of the present disclosure. In this embodiment, each layer ( 310 ) of coil is fabricated individually with vertical interconnection vias ( 320 ) precisely positioned and fully opened. Then the parylene/metal skins are aligned and stacked together with the assistance of a matching jig ( 210 ), ( 220 ). Also in this case, small (e.g., 500 microns diameter) poles ( 330 )—see also FIG. 8 —can be built on the jig, to match the alignment holes ( 340 ) on the periphery of the coils ( 310 ). The parylene/metal skins ( 310 ) can be aligned by feeding the poles ( 330 ) through the holes ( 340 ). After that, a similar thermal treatment process in vacuum oven is used to bond the layers ( 310 ) together. Finally, silver paste can be filled into the open vias to build the interconnections between layers, while the top opening is sealed with biocompatible epoxy or parylene to render an implantable final device. Instead of silver paste, other conductive materials, such as conductive epoxy and solder can be used for making the contacts between layers.
[0052] FIG. 10 shows a cross-sectional view of a vertical interconnection via ( 320 ) with reference to a first layer ( 400 ) and a second layer ( 410 ) of a stacking coil. The structure is similar to that shown in FIG. 5 , with a top metal layer ( 420 ), a bottom metal layer ( 430 ) and a parylene insulating layer ( 440 ), with the difference that this time a through hole ( 450 ) is present. Element ( 460 ) represents the soldering material (e,g., silver paste) that is used to fill the through holes ( 450 ) of the layers of the stack for forming electrical contact.
[0053] FIG. 11 shows a top sectional view of FIG. 10 , where element ( 460 ) is not being shown for clarity purposes.
[0054] In summary, according to some of the embodiments of the present disclosure, a polymer-based foldable coil employing a multilayer polymer/metal thin film is shown. According to such embodiments, the device is completely made using microfabrication technologies, which are compatible with the existing processes developed for other system components, such as multi-electrode arrays. Microfabrication refers to processes for building miniature structures, with sizes in micron-scale and smaller, such as photolithography, chemical vapor deposition (CVD), E-beam evaporation, oxygen plasma etching, and wet etching process. Because of the flexibility of parylene or some similarly flexible polymer, this thin film skin can be folded and bonded together to form a multiple layer structure using a post fabrication heat treatment. The geometry of the coil shown in such embodiments is determined by the dimension of the human eyeball, and this can be varied for other applications.
[0055] Accordingly, what has been shown is a foldable polymer-based coil structure and a method for fabricating the same. While the coil and the method have been described by means of specific embodiments and applications thereof, it is understood that numerous modifications and variations could be made thereto by those skilled in the art without departing from the spirit and scope of the disclosure. It is therefore to be understood that within the scope of the claims, the disclosure may be practiced otherwise than as specifically described herein.
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A foldable polymer-based coil structure and a method for fabricating the same are disclosed. The coil structure has metal wirings and interconnections between the wirings. The wirings and connections are embedded by a polymer. The coil structure is foldable in two or more layers. In the folded condition, coils of one layer overlap the coils of another layer. A stackable structure and jigs for aligning the foldable and stackable structures are also disclosed.
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CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation of application of application Ser. No. 07/711,167 filed Jun. 5, 1991, now abandoned.
FIELD OF THE INVENTION
The present invention pertains to the field of arrowheads for use with arrow shafts, and in particular to a high-penetration, high velocity arrowhead with self alignment capabilities and weight adjustability for front to rear arrow balance.
BACKGROUND OF THE INVENTION
Current arrowheads are fraught with limitations which become particularly acute when the arrowheads are used for hunting. Broadheads, usually preferred for hunting arrows, typically vary in weight and may not necessarily balance any particular arrow shaft. As a result the arrow shaft does not properly track, or follow the head in flight. A broadhead typically has a set of blades which extend outward from the ferrule of the arrowhead and render an arrow difficult to draw past the riser because the blades interfere with the bow's riser unless the arrowhead is properly aligned. Once the arrow has been shot, its penetration into its target is limited by the excess size of the ferrule, improper blade angle, and the difficult transition from the broadhead point to the blades.
SUMMARY OF THE INVENTION
The present invention allows the weight of the arrowhead to be precisely adjusted to ensure that the shaft properly tracks, follows the head for maximum accuracy, arrow flight and range. The arrowhead, once mounted to the shaft, can be rotated with respect to the riser to obtain perfect alignment with the bow riser. The ferrule has a reduced cross section past the broadhead point to reduce ferrule drag when entering the target. The blades are set at precisely the right angle of entry for maximum penetration of the target, and the leading edges of each blade are preceded by a primary leading edge on the arrowhead point which serves to ease the entry of the blade cutting edge into the target. The secondary facet assures the penetrating surface to be taut for maximum penetration.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects of the invention will be more fully understood by referring to the following detailed description and the accompanying drawings, wherein:
FIG. 1 is a side elevation view of an arrow incorporating an arrowhead constructed according to the present invention;
FIG. 2 is an exploded view of the arrowhead and a portion of the shaft of FIG. 1;
FIG. 3 is a cross-sectional view of the arrowhead and a portion of the shaft of FIG. 1;
FIG. 4 is a cross-sectional view of the arrowhead of FIG. 3 taken along line 4--4;
FIG. 5 is a cross-sectional view of the arrowhead of FIG. 3 taken along line 5--5;
FIG. 6 is a front elevational view of the arrowhead of FIG. 1;
FIG. 7 is a side elevation view of the front portion of the arrowhead of FIG. 1 with a side blade taken directly above a secondary facet of the point; and
FIG. 8 is an alternative embodiment of an arrowhead constructed according to the present invention in a view similar to that of FIG. 7.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates primarily to a broadhead arrowhead for use in hunting. However, many of the advances of the present invention can be incorporated into other kinds of arrows for target shooting and the like. While it is presently preferred that the present invention be incorporated into a broadhead, many aspects of the invention may also be used in other types of arrowheads, regardless of the use of the arrowhead.
A typical arrow has a long shaft 10 (shown broken in FIG. 1) with an arrowhead 12 at one end and arrow tail 14 at the other. The tail has a set of feathers 16 and a nock 18 at its end. The nock is adapted to engage a bow string when the arrow is shot in a bow. For typical broadhead arrows, the arrowhead can be unscrewed from the shaft 10.
Referring to FIG. 2, a broadhead constructed according to the present invention has an elongated ferrule 20 to which a set of blades 22 is connected. The blades have a cutting edge 24 and a mounting edge 26. The cutting and mounting edges meet at a junction 28, and the cutting edge then diverges away from the mounting edge at an angle. The cutting edge ends at a perpendicular support 30 which also connects to the mounting edge. At the junction between the mounting edge and the perpendicular support is a retaining tab 32. Each blade, including the tab 32, fits into a groove 34 in the ferrule. At the front end of the ferrule is a point 36, and the groove preferably extends from the point back to a location near the rear end of the ferrule. A retaining ring 38 slides over the rear end of the ferrule, and encircles the tabs 32 of all of the blades to hold the rear ends of the blades in place. The front ends of the blades at the junction 28 are held in place by the point as described below.
The rear end of the ferrule has a male threaded connection 40 which is inserted into a central bore 42 in the arrow shaft (the insert is glued into the end of the hollow arrow shaft). Inside the bore is a female threaded connection 44 which the male threaded connection on the arrowhead screws into. A flange 46 at the opening of the arrow shaft bore contacts the retaining ring 38 so that when the arrowhead is screwed into the arrow shaft, the flange butts up against the retaining ring and holds the retaining ring in place against the perpendicular supports of the blades.
In addition, a weight rod 48 is provided. The weight rod has a retaining end 50 and a weight end 52. The retaining end is inserted into an axial bore 54 through the center of the ferrule, as best seen in FIG. 3. At the end of the retaining end of the rod is a seat 56 which seats against a seat 58 at the end of the ferrule bore. In addition, a shoulder 59 midway along the weight rod seats against a shoulder 60 in the ferrule bore near the ferrule's male threaded connection. The weight rod is inserted into the ferrule simply by pushing it into the ferrule bore. Pressure applied to the weight end of the weight rod, toward the seat and shoulder, wedges the rod into place. The tolerances between the weight rod and the ferrule bore are preferably close enough that the weight rod can be wedged into place and will stay there reliably during use. However, for greater security, a small amount of adhesive can be applied to the end of the weight rod to glue it onto its seat. When installed the weight end of the weight rod extends in the opposite direction out of the ferrule bore, into the axial bore 42 in the arrow shaft, see, e.g., FIG. 3.
Since arrow shafts are typically hollow throughout their entire length, the weight rod can be quite long. For a typical 80 cm long arrow with a 6.5 cm broadhead measured from the point to the end of the threads, it is presently preferred that the weight rod measure approximately 15 cm long. The weight rod is preferably cylindrical, with a set of coined grooves 62 on its weight end dividing the weight end of the rod into scored increments. The weight of the rod can be adjusted by breaking off portions of the weight rod at the grooves. Since the weight rod can be quite long, the range of adjustment can be quite great.
In use, the broadhead is assembled with the weight rod onto the end of the arrow shaft, and the arrow is then shot at a target. For maximum range, speed and accuracy, it is preferred that the arrow shaft track, i.e., follow the path of the arrowhead in flight. This is usually achieved when the arrow has a 60% to 40% front to rear weight balance. However, the precise weight distribution depends on the type of arrow shaft, and the relative weights of the shaft, feathers and nock. The weight rod is preferably initially too heavy for all commonly available arrow shafts. Therefore, after a first test flight, the excess heaviness of the arrowhead can be judged. The tester first observes the flight attitude of the arrow in a test flight and then breaks off one or more of the increments of the weight rod and retests the arrow by again shooting it toward a target for another test flight. If the arrowhead is still too heavy, then more increments of the weight rod are broken off. After perfect balance has been achieved, the arrow shaft-arrowhead combination is ready for actual use.
For use with typical hunting shafts, it is presently preferred that the arrowhead without the weight rod weigh approximately 82 grain, and that each increment on the weight rod weigh approximately 3 grain. The weight rod is preferably constructed of 316 full hard stainless steel with a diameter of about 2.3 mm so that each increment is about 6.3 mm long. The weight rod can be used with a variety of different types of arrowheads other than the broadhead shown in the drawings. In addition, the weight rod can be attached permanently to, or formed integrally with, the ferrule. It is presently preferred that the weight rod extend all the way into the ferrule and seat against a seat which is as close to the point as possible. This helps to transfer the weight of the weight rod upon impact directly to the point where it is most needed. It is also preferred that the weight rod be removable so that if too many increments are broken off in an attempt to adjust the weight of the weight rod, the weight rod can be replaced with a longer weight rod without discarding the ferrule.
Referring to FIG. 3, the ferrule has a preferably rigid 304 full hard stainless steel core 66 with a 258,000 psi tensile strength. Making the core hollow reduces its weight and allows the weight-adjusting rod to be seated at the point. Preferably, the point is metal injection molded of 440C stainless steel and has annular seat built directly into its core that is directly press fitted onto the forward end 68 of the hollow ferrule core and has an interior 45° incline surface 64 which allows the leading edge of the blades to back into when the blades are in place and the head is tightened. The stainless steel core is then surrounded with a deformable thermoplastic polycarbonate resin sleeve 70, for example, the resin sold under the trademark Lexan. This sleeve is injection molded over the core.
While the core has a cylindrical exterior, the sleeve provides the grooves 34 which hold the blades. The grooves are molded into the outer surface of sleeve and extend along its axis from the interior surface 64 of the point to the flange 46 at the end of the arrow shaft. When the blades 22 are placed into the grooves 34, the front tip of the blade cutting edge, where it joins the mounting edge, meets the inclined surface 64 on the interior edge of the point. When the arrowhead is screwed onto the arrow shaft this inclined surface forces the cutting edge of the blade downward as the blade is pushed forward in the groove by the arrow shaft flange 46.
The mounting edge of the blades rests against a set of spaced apart lands 74 at the bottom of the grooves in the sleeve. FIG. 4 shows the mounting edge of a blade resting on a land, while FIG. 5 shows the mounting edge suspended over a space between lands. The lands hold the mounting edge up away from the stainless steel core. The tabs 32 on the blades extend underneath the retaining ring 38. After the blades are inserted into the grooves and the retaining ring is slipped around the rear end of the ferrule and the tabs, the ferrule can be screwed on to the end of the shaft. As the ferrule is rotated into the arrow shaft threads, the retaining ring 38 butts against the flange 46 at the end of the arrow shaft. At some point, the core is screwed sufficiently far into the insert of the arrow shaft that the retaining ring holds the blade ends wedged against the interior surface and prevents the blades from wobbling or vibrating significantly in flight or from becoming removed upon impact with a target.
However, to obtain a full draw when shooting the arrow, the blades must be properly aligned with the nock at the opposite end of the arrow shaft. Typically, the nock is not adjustable and determines the position of the arrow shaft in the bow because of its connection with the bow string. If the blades are not properly aligned with the nock, then upon a full draw, the blades will interfere with the riser of the bow, preventing the arrow from being able to be drawn all the way on the arrow rest. Either the draw must be reduced to keep the blades away from the riser, or the blades must be realigned. In the present invention, since the ferrule sleeve is made from a deformable material, the arrowhead can be rotated beyond the point of initial tightness. As the arrowhead is further screwed into the arrow shaft to align the blades, the point is driven further toward the arrow shaft flange 46. The blades, held by the retaining ring, are then wedged further downward by the inclined surface on the point, compressing the lands on the ferrule sleeve. Thus, these lands provide the "give" to permit the broadhead to be rotated relative to the nock while the parts of the broadhead remain firmly held together. Because of the spaces between the lands, the lands deform and expand into the spaces under pressure. The spaces between lands can extend through the entire depth of the sleeve to the core, as shown in the drawings, or only part of that depth so that there is some sleeve material between lands. Using the stainless steel and Lexan construction described above and a conventional thread pitch, the arrowhead can be rotated a full turn beyond the point of initial tightness. This allows the blades easily to be aligned with the notch for a full draw of the bow string when shooting.
The blades are preferably also constructed of 440C stainless steel for a durable, easy-to-clean, hard edge. The point, as best seen in FIGS. 4 and 5, has a six-faceted design, the facets of which are precisely aligned with the leading edges of the blade cutting edges. In the preferred three-blade embodiment shown in the drawings, the point has a set of three primary facets 76 which initially meet the target. Between each facet is a first set of leading edges 78. It is these facets which initially contact the target and create an opening in the target through which the arrowhead will penetrate. The three primary facets lead into a set of three secondary facets 80 which begin midway along the leading edge 78 between each of the three primary facets. The secondary facets are spaced apart rearward from the front tip of the point, and have leading edges 82 on either side. The secondary facets are aligned with the blades 22 so that the initial portion of the cutting edge of each blade is directly behind the center of a secondary facet. The leading edges 82 of the secondary facets spread the target material, holding it taut for the entry of the blade. This allows the blade to enter more smoothly and cleanly into the target for better penetration. Once the blade has smoothly entered the target, the cutting edge continues through into the target to its maximum penetration depth. Any number of first and secondary facets may be provided, preferably one of each per blade.
In some arrows, the feathers are designed to rotate the arrow in flight. Some of this rotational force still exists after the point impacts the target. In other words, the arrow continues to rotate even after the point has penetrated the target. As a result, in such arrows, the blade must be offset from the center of the secondary facet in order for the blade to enter between the two leading edges on either side of the secondary facet directly in front of it. The amount of offset will vary depending on the anticipated amount of arrow rotation as the tip pierces the target with existing hunting arrows on offset of between 30 and 50 degrees around the circumference of the ferrule is preferred. Such an offset blade configuration for a rotating arrow is shown in FIG. 8.
To further enhance penetration of the broadhead, the ferrule diminishes in cross section immediately behind the point. The ferrule can also be straight or parallel to the axis. As shown in the preferred embodiment, the ferrule is elongated and substantially cylindrical. Accordingly, a cross section taken perpendicular to the ferrule's axis of elongation will be circular (see, e.g., FIG. 4). The area of this circle, however, varies along the length of the ferrule, and in particular, the ferrule sleeve. At the point, the ferrule has the same cross-sectional area as the rear end of the point. However, from there, the cross-sectional area decreases with distance from the point. This reduces the drag of the ferrule through the target and allows the blades to be more effective. Toward the rear end of the ferrule, the cross-sectional area again increases rapidly to match that of the retaining ring 38 and the arrow shaft. This provides a smooth transition to the arrow shaft so that the arrow, if it has sufficient momentum, can penetrate into the target past the ends of the blades and the end of the ferrule. Such aerodynamic details can also lengthen the arrow's range through the air.
The broadhead arrow penetration can also be affected significantly by the shape of the blades. As best seen in FIG. 2, the cutting edges of the blades extend outward, away from the mounting edge and toward the rear of the ferrule. The cutting edge and the mounting edge are both substantially straight, and preferably form an angle at their junction of 27.5°. If the blade angle is too great, then the broadhead does not penetrate deeply enough into the target. If the blade angle is too little, the blades do not cut the target. With the proper blade angle, maximum penetration and effectiveness is obtained. While exactly 27.5° is not essential, it is preferred that the angle be between 25° and 20°. For the 6.5 cm ferrule discussed above, a blade mounting edge of 3.5 cm including the tab and a blade cutting edge of about 3 cm can form the proper 27.5° angle when the perpendicular support extends perpendicularly from the rear end of the cutting edge to the mounting edge. This is known as the perfect angle of entry.
While only a few embodiments have been discussed above, it will be understood by those skilled in the art that a great variety of modifications and adaptations may be made to those embodiments without departing from the spirit and scope of the present invention. Different materials may be substituted for those which are presently preferred. The number and orientation of blades may be varied to suit particular applications. The blades may be removed entirely, and a different type of point used to suit different types of targets or different bows. It is not intended to limit the scope of the present invention to the embodiments described above, but only by the claims below.
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A high penetration arrowhead with an adjustable alignment and weight screws onto the end of a hollow arrow shaft. The arrowhead has a hollow ferrule covered by a grooved resin sleeve. A point at the forward end of the ferrule presents an interior inclined surface at the forward end of each groove. A blade with an inclined cutting edge fits into each groove so that the cutting edge contacts the inclined surface pressing the blade into the bottom of the groove. A retaining ring at the rear end of the groove encircles tabs on the blades and drives the blades forward to hold the blades in place as the arrowhead is screwed onto the shaft. Deformable lands on the groove bottom allow the arrowhead's adjustable alignment to be adjusted while maintaining pressure on the blades. The point has a secondary facet directly in front of each cutting edge to enhance penetration and the ferrule has a narrowing cross section behind the point for the same reason. A weight rod fits inside the hollow ferrule and seats against the point. The weight rod is scored so that pieces can be broken off to adjust its weight. The point also has a seat for the structural tube to be pressed into so on impact the tube cannot spread thus creating all forces to be dispersed equally throughout the arrow shaft.
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BRIEF SUMMARY
This invention relates to the textile industry and is directed to a method and a device for spinning by means of revolving rings.
In conventional continuous-spinning frames, the yarn-guide traveler slides on a fixed ring, thus causing rapid wear of the travelers and relatively high tension of the yarn, which has the effect of setting a limitation on the spindle speed.
In order to overcome these disadvantages, it has already been proposed to make use of revolving rings, especially rings mounted on air-film fluid bearings. A spinning ring of this type has been described, for example, in German Pat. No. 1,195,207 in which the ring is driven in rotation solely by the traveler. By means of an arrangement of this type, the speed of rotation of the ring after an initial period of start-up and acceleration under the action of friction of the traveler becomes equal to the speed of rotation of the traveler by virtue of the practically zero friction of the fluid bearing, with the result that there is no further relative motion between the traveler and the ring. In order to obtain a reduction in yarn tension which permits a high spindle speed and in order to eliminate problems relating to wear of travelers, the need to ensure that the traveler and the ring both rotate at the same speed had accordingly been recognized. For example, in French Pat. No. 74 41 171 which related to a revolving ring rotatably mounted on an aerodynamic fluid bearing, it was even proposed to fix the traveler on the ring.
However, the present Applicant has observed that, although the use of rings rotatably supported on fluid bearings does offer some of the advantages which are sought (namely a very appreciable increase in spindle speed, a reduction in yarn breaks, elimination of wear of travelers), there appeared on the other hand certain disadvantages which are inherent in this type of ring, especially harmful instability of tensile stress on the thread which in turn gave rise to instability of the "balloon".
Although formal reasoning led to the acknowledged conclusion that the relative velocity between traveler and ring should be zero (that is to say, during operation of the spindle and of course after the periods corresponding to start-up), the present Applicant has come to the conclusion, on the contrary, that this synchronization between traveler and ring should be avoided.
The invention has for its object a method of ring-frame spinning, and especially a method in which each spinning ring is rotatably supported on a fluid bearing, which consists in intentionally producing a difference in velocity Δω between the revolving ring and the spindle.
Preferably, a difference in velocity Δω within the range of 4 to 16% of the spindle speed is thus produced.
A first embodiment of the method according to the invention consists in intentionally increasing the resisting torque of the ring. In particular, provision can be made on the ring for projecting portions such as fins, for example, which produce an aerodynamic braking action on the ring and accordingly prevent this latter from attaining a speed at which it rotates in synchronism with the traveler.
In a second embodiment of the method according to the invention, use is made of a traveler having a portion which is applied against the ring with a very low coefficient of friction so that the traveler always slides on the ring and is not capable of bringing the ring up to the speed of synchronization with the spindle in spite of the low values of friction within the fluid bearing of the ring.
The two embodiments of the method can be applied conjointly.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
A more complete understanding of the invention will be gained from the following detailed description and from the accompanying drawings in which a number of embodiments of the invention are illustrated by way of example without any limitation being implied, and in which:
FIG. 1 is a comparative experimental graph of yarn tensions as a function of ring speeds in the case of a conventional ring rotatably supported on a fluid bearing and of a revolving ring for the application of the present invention;
FIG. 2 is a part-sectional view in elevation showing a revolving ring provided with the improvements according to the invention;
FIG. 3 is a theoretical comparative graph in which the method of spinning with a conventional revolving ring is compared with the method according to the invention;
FIG. 4 illustrates a revolving ring in accordance with another embodiment of the invention;
FIG. 5 is a curve showing the resisting torque of the ring of FIG. 4 as a function of its speed of rotation;
FIG. 6 is a part-sectional view in perspective showing a spinning ring with a traveler in which a portion of the traveler is applied against the ring with a low coefficient of friction;
FIG. 7 is a graph showing the yarn tensions as a function of the ring speeds in respect to different spindle speeds.
DETAILED DESCRIPTION
In FIG. 1, the curves A-B-C-D show the variations in yarn tension in grams as a function of the speed of the ring in the case of a revolving ring of the fluid bearing type which operates in the conventional manner, that is to say in which the speeds of the ring and of the traveler are synchronized after the start-up period. The curves A and B relate to a spindle speed of 10,000 rpm whilst the curves C and D relate to a speed of 8,000 rpm. The curves A and C indicate the tensions when the yarn is wound onto the small diameter of the bobbin whilst the curves B and D indicate the tensions when the yarn is wound onto the large diameter of the bobbin.
It is apparent from curves A and B that the yarn tension increases at a uniform rate during the start-up period, then at a higher rate above approximately 6,000 rpm and finally reaches a maximum value (of approximately 45 grams during the test) when the ring practically attains the speed of synchronism. The progressive increase in tension arises from the fact that the coefficient of friction of the pair constituted by traveler and steel ring tends to increase when Δω tends to zero at the same time as it proves necessary to accelerate the ring. At this moment, there takes place a sudden reduction in yarn tension (from 45 g to 25 g or 21 g, depending on whether the yarn is wound onto the small diameter or the large diameter of the bobbin) since the tension again falls to a minimum value when the acceleration is zero.
In the case of a spindle speed of 8,000 rpm (curves C and D), the phenomenon is identical and the yarn tension suddenly drops when synchronism is attained at a ring speed of 8,000 rpm, from 29 g to 15 g. This phenomenon arises from the fact that the traveler must no longer supply the necessary energy for acceleration of the ring but only in order to overcome the low values of friction of the ring within its air-film bearing. Since the speed of the ring and the speed of the traveler are synchronized, the friction force applied by the traveler on the ring is practically zero, with the result that the tension exerted on the yarn falls to a minimum.
This sudden reduction in yarn tension which takes place in synchronism has a disadvantage in that it produces an adverse effect on the balloon which becomes unstable.
One of the means in accordance with the invention for preventing the ring from attaining the speed of synchronism consists in providing on said ring either hollow or projecting portions disposed substantially in a radial direction or with at least one radial component.
In FIG. 2, there is shown by way of example a revolving ring supported on a fluid bearing of the type which is fed by an external supply of compressed air.
The ring 2 comprises a cylindrical tubular skirt 4, a peripheral annular flange 6, a traveler rail 8 and a traveler 10. In accordance with known practice, the ring is centered and lifted with respect to a stator 12 provided with a manifold 14 for the admission of compressed air and nozzles 16-18 for the discharge of compressed air into the leakage gap between the stator and the ring.
In accordance with the invention, provision is made for a plurality of fins 20 (three or six fins, for example) which are fixed on the ring. The design function of said fins is to set up an aerodynamic resistance which increases substantially with the square of the speed of rotation of the ring.
In FIG. 1, the shaded zones E and F indicate the operating zones (respectively for winding of the yarn onto the small diameter and onto the large diameter of the bobbin) of a spinning ring in accordance with the invention, said ring being provided with three fins such as those illustrated in FIG. 2.
In the zones E and F aforesaid, the points 21, 21'-22, 22'-23, 23'-24, 24' correspond respectively to spindle speeds of 10,000, 12,000, 13,000 and 14,000 rpm. It is apparent from FIG. 1 that the yarn tension progressively increases but is not attended by the sudden reduction in tension which is observed in the case of known rings.
The present invention makes it possible not only to prevent sudden variations in yarn tension during transient periods but also to improve the stability of the balloon during operation. This result is illustrated in FIG. 3, in which the curve 26 indicates, as a function of the speed of rotation, the resisting torque of the traveler with respect to the ring (CRC) and the curve 28 indicates the resisting torque of the ring (CRA) in the case of a conventional fluid-bearing spinning ring. The operating point 30 is plotted in respect of a ring speed in the vicinity of the spindle speed Ω (synchronism). By virtue of the fact that the curves 26 and 28 intersect at a small angle α, it is apparent that the operating point will have low stability and that small random variations in CRC or CRA will give rise to substantial variations in ring speeds.
On the contrary, in accordance with the present invention, the resisting torque of the ring is a function of the square of the speed by virtue of the presence of the fins as shown by the curve 32 which intersects the curve CRC at an angle β which is much larger than the angle α at a point of equilibrium 34 corresponding to a speed ω 0 of the ring which is appreciably lower than the speed of synchronism Ω, thereby achieving enhanced stability of operation.
In FIG. 4, there is shown an alternative embodiment of the invention in which the ring is provided with grooves 36 in addition to the fins, said grooves being formed in the skirt 4 of the ring. The resisting torque of a ring of this type is represented by the curve 38 in FIG. 5, the curvature of which is similar to that of the curve 32 of FIG. 3. It should be noted that, in the case of low speeds of rotation, the resisting torque of the ring is negative by reason of the orientation and arrangement of the grooves 36 within the leakage gap of the fluid bearing.
A suitable choice of the number, size and shape of the fins 20 and even of the grooves 36 makes it possible to obtain the most favorable relative velocity Δω between traveler and ring while remaining sufficiently far from synchronism to avoid the problems of instability which were mentioned earlier.
In another embodiment of the invention, use is made of a traveler 10' (shown in FIG. 6) having a frictional contact portion 38 formed of material having a very low coefficient of friction, for example a synthetic material of the type which is marketed under the trade-names of "Teflon", "Delrin", low-friction loaded "Nylon".
In the case of revolving rings mounted on fluid bearings in which the ring is driven in rotation solely by the traveler, that is to say by the thread 40 which passes through said traveler, it had been considered preferable up to the present time to employ travelers which had a relatively low capacity for sliding with respect to the ring. It had in fact been found desirable to drive the ring by frictional contact as rapidly as possible up to the speed of synchronism and it had even been proposed to fix the traveler on the ring. On the contrary, the present Applicant has reached the conclusion that, with a traveler having a very low degree of friction, said traveler was incapable of pulling the ring up to the speed of synchronism and that there therefore always existed a difference in speed between the ring and the spindle.
Since there exists a relative speed Δω, the traveler performs frictional work which results in yarn tension and prevents the sudden variations in tension which were mentioned earlier in the description.
FIG. 7 shows the results obtained with a 30 mg traveler having a frictional-contact portion of synthetic material which has a very low coefficient of friction. The ring employed is not provided with fins. The shaded zone G corresponds to winding of the yarn onto the small diameter of the bobbin whilst the zone H corresponds to winding of the yarn onto the large diameter of the bobbin. The speeds of the ring in rpm have been plotted as abscissae and the yarn tensions in grams have been plotted as ordinates.
The points 42--42', 44--44', 46--46', 48--48' have been plotted respectively in respect of spindle speeds of 10,000, 12,000, 13,000 and 14,000 rpm. The results recorded in FIG. 7 are as follows:
______________________________________Spindle speed Ring speed Δω______________________________________10,000 rpm. 9,520 rpm. 480 rpm.12,000 11,500 50013,000 11,600 1,40014,000 11,700 2,300______________________________________
The relative speeds which produce the best results are within the range of 4% to 16% of the spindle speed. It is worthy of note that the yarn tension increases progressively without ever showing a tendency towards a sudden reduction which would result in instability.
As can readily be understood, both embodiments of the invention can be employed conjointly on the same spinning ring such as, for example, a finned ring and a traveler having a low coefficient of friction, the characteristics of the fins and of the traveler being chosen so as to obtain the desired relative speed.
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Each revolving ring of a continuous-spinning frame for textile yarn is mounted on a fluid bearing and driven in rotation by a ring traveler. The resisting torque of the ring is intentionally increased by means of hollow or projecting portions such as fins formed on the ring in order to produce a difference in speed between the normal speed of rotation of the spindle and the speed of rotation of the ring. The result thereby achieved is to ensure uniform tension of the yarn and to improve operating stability of the spinning frame.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of provisional patent application Ser. No. 61/849,882 filed on Feb. 5, 2013.
FIELD OF THE DISCLOSURE
The present disclosure relates generally to pet carriers and more specifically to carriers for cats.
BACKGROUND
Pet carriers are portable enclosures for temporarily housing and/or transporting small domestic animals, such as cats and dogs. Unlike dogs, birds and other pets, cats have a unique combination of characteristics that can make them particularly difficult to handle and control. Cats usually are very alert, have quick reflexes, have a good sense of balance, are extremely agile and can be rather skittish under certain circumstances. These qualities in combination with a cat's sharp claws can render general purpose pet carriers unsuitable for handling cats. At times, it can be difficult to safely transfer unwilling cats to or from conventional pet enclosures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front end view of an example cat carrier constructed in accordance with the teachings disclosed herein.
FIG. 2 is a right side view of FIG. 1 .
FIG. 3 is a perspective view of the cat carrier shown in FIG. 1 with the carrier's front panel in an attached-inserted position.
FIG. 4 is a perspective view similar to FIG. 3 but showing the carrier's front panel is an attached-extended position.
FIG. 5 is an exploded perspective view similar to FIG. 4 but showing the carrier's front panel in a removed position.
FIG. 6 is a perspective view of an example insert used in example cat carriers constructed in accordance with the teachings disclosed herein.
FIG. 7 is a cross-sectional end view show the roller portion of the insert shown in FIG. 6 .
FIG. 8 is a side view similar to FIG. 2 but showing the cat carrier open.
FIG. 9 is a side view showing a cat being lowered onto the floor of the container's insert.
FIG. 10 is a side view similar to FIG. 9 but showing the cat standing upright on the insert's floor.
FIG. 11 is a side view similar to FIG. 10 but showing the cat crouching down in reaction to the insert being slid into the carrier's outer housing.
FIG. 12 is a cross-sectional side view similar to FIG. 9 but showing the cat being lowered onto the insert floor of another example cat carrier constructed in accordance with the teachings disclosed herein.
FIG. 13 is a cross-sectional side view similar to FIG. 12 but showing the cat standing upright on the insert's floor.
FIG. 14 is a cross-sectional side view similar to FIG. 13 but showing the cat crouching down in reaction to the insert being slid into the carrier's outer housing.
FIG. 15 is a cross-sectional side view similar to FIGS. 10 and 13 but showing the cat standing upright on the insert floor of another example cat carrier constructed in accordance with the teachings disclosed herein.
FIG. 16 is a cross-sectional side view similar to FIG. 15 showing the cat's potential reaction to the roof sliding over a relatively stationary insert rather than the insert sliding underneath a relatively stationary roof.
FIG. 17 is a cross-sectional side view similar to FIG. 15 but showing the cat standing upright on the insert floor of another example cat carrier constructed in accordance with the teachings disclosed herein.
FIG. 18 is a cross-sectional side view similar to FIG. 17 showing the cat's potential reaction to the roof tipping over a relatively stationary insert.
FIG. 19 is a block diagram illustrating an example cat carrier method that can be used with at least one of the example cat carriers disclosed herein.
DETAILED DESCRIPTION
FIGS. 1-14 illustrate example carriers and associated methods for confining, sheltering and/or transporting cats. Some example carriers and methods involve the use of a translating floor to safely transfer cats in and out of the carriers. Sliding a floor out from within an outer housing provides unobstructed access to the cat. Sliding the floor into the housing mildly destabilizes the cat's footing such that the cat tends to crouch down into the carrier rather than jumping out of it.
In the example shown in FIGS. 1-11 , a cat carrier 10 comprises an insert 12 with a floor 14 that can be slid within an outer housing 16 . In this example, outer housing 16 comprises an upper shell 16 a and a lower shell 16 b. In some examples, shells 16 a and 16 b are integrally combined as a unitary seamless piece. In the illustrated example, however, shells 16 a and 16 b are individual pieces that are connected at a joint 18 held together by a series of conventional fasteners 20 . Lower shell 16 b includes a bottom 22 and two lower side walls 24 extending up from bottom 22 . Lower shell 16 b also has and a lower back wall 26 extending up from bottom 22 and extending laterally between lower side walls 24 .
Upper shell 16 a, in this example, includes a roof 28 and two upper side walls 30 extending down from roof 28 . For portability, a fold-down carrying handle 32 , in some examples, is attached to roof 28 . Roof 28 extends from a front edge 28 a to a rear edge 28 b. Upper shell 16 a also has an upper back wall 34 that extends down from the roof's rear edge 28 b and extends laterally between upper side walls 30 . When shells 16 a and 16 b are together, outer housing 16 provides a chamber 36 defined by bottom 22 , roof 28 and walls 30 , 34 , 24 and 26 .
Insert 12 can be slid in and out of chamber 36 . The term, “slid” and derivatives thereof refer to translating motion that in some examples is assisted by one or more rollers 38 interposed between insert 12 and housing 16 , as shown in FIG. 7 . In some examples, rollers 38 are mounted to insert 12 , as shown in FIG. 6 . FIGS. 1-3 show insert 12 in an inserted position within chamber 36 , and FIGS. 4 , 5 and 8 - 11 show insert 12 in an extended position relative to outer housing 16 .
In the illustrated example, insert 12 has a pet receptacle 40 defined by floor 14 , two side panels 42 , a front panel 44 , an impassable back panel 46 and an impassable rear barrier 48 . In some examples, the various parts of insert 12 are integrally combined to render insert 12 as a unitary seamless piece. In some examples, just two or more of the insert's parts are integrally combined while the remaining parts are connected. In the illustrated example, back panel 46 , floor 14 and side panels 42 are integral extension of each other while conventional fasteners 50 attach rear barrier 48 to back panel 46 . In other examples, rear barrier 48 is a seamless integral extension of back panel 46 , whereby barrier 48 and panel 46 are combined as a seamless unitary piece.
In some examples, front panel 44 serves as an optional door that is movable selectively to a removed position ( FIG. 5 ), an attached-extended position ( FIG. 4 ), and an attached-inserted position ( FIG. 3 ). FIG. 5 is an example of front panel 44 being open with respect to side panels 42 , and FIGS. 3 and 4 are examples of front panel 44 being closed with respect to side panels 42 . In the illustrated example, conventional fasteners 52 selectively attach front panel 44 to a forward protruding flange 54 of side panels 42 while lower protrusions 56 extending down from front panel 44 extend into holes 58 in flange 54 to help hold front panel 44 in place.
Some examples of front panel 44 have an actuator 60 with a dual purpose handle 62 . When handle 62 is in the position shown in FIGS. 1-3 , rods 64 of actuator 60 extend laterally into holes 66 to hold front panel 44 closed. When handle 62 is rotated to the position shown in FIGS. 4 and 5 , rods 64 retract out from within holes 66 to unlatch front panel 44 . Once unlatched, handle 62 provides a convenient means for pulling insert 12 out from within outer housing 16 , as shown in FIG. 4 .
Cat carrier 10 can be used according to the example sequence shown in FIGS. 9 , 10 and 11 . FIG. 9 shows cat carrier's outer housing 16 set upon a stationary base 70 (e.g., table, countertop, floor, etc.) with insert 12 extended. The term, “stationary” means fixed relative to Earth. Arrow 72 represents a veterinarian assistant 74 lowering a cat 76 down onto the insert's floor 14 . Upon doing so, cat 76 passes through an open-air space 78 that provides a generally unobstructed passageway from above roof 28 down to floor 14 .
In some examples, roof 28 is at a first height 80 above base 70 , an uppermost edge 82 of insert side panel 42 is at a second height 84 (upper edge height), and open-air space 78 is at a third height 86 . Third height 86 is greater than first height 80 to facilitate lowering cat 76 onto the insert's floor 14 , and second height 84 is less than 75 percent of first height 80 to provide cat 78 (once lowered onto floor 14 ) with a calming, unrestricted side view. The open grate of front panel 44 might further help cat 76 feel less confined. With the freedom to look around, cat 76 is perhaps less likely to jump out once cat 76 is standing comfortably on the insert's floor 14 , as shown in FIG. 10 .
While the relative heights 80 , 84 and 86 can be important, a height 88 of rear barrier 48 can play an important role as well. If side panel height 84 and rear barrier height 88 were both significantly less than roof height 80 , cat 76 could possibly jump over rear barrier 48 from receptacle 40 into chamber 36 and land in a trapped area 90 between the insert's back panel 46 and the outer housing's lower back wall 26 . This can create two problems: one, subsequently inadvertently forcing the unoccupied insert 12 back into housing 16 could crush cat 76 in trapped area 90 , and two, it might be very difficult and hazardous to reach in and remove cat 90 out from within trapped area 90 . Consequently, some examples of rear barrier 48 have barrier height 88 slightly less than roof height 80 (less than 3 inches between heights 88 and 80 ) and have barrier height 88 significantly greater than side panel height 84 . In some examples, front panel 44 extends above side panel 42 so that front panel 44 can effectively close and contain cat 76 . The term, “height,” as used throughout this patent, is a vertical distance measured with reference to a cat carrier's lowermost surface intended for resting upon base 70 .
Next in the sequence of use, assistant 74 pushes insert 12 into outer housing 16 , as shown in FIG. 11 . Sliding motion 92 of the insert's floor 14 mildly destabilizes the cat's footing such that cat 76 tends to crouch down to perhaps regain its balance, as shown in FIG. 11 . This places cat 76 in the perfect position for sliding insert 12 completely into outer housing 16 .
FIGS. 12-14 show a similar example cat carrier 94 and sequence of use, wherein FIGS. 12 , 13 and 14 correspond to FIGS. 9 , 10 and 11 , respectively. In this example, cat carrier 94 comprises an insert 12 ′ that can be manually slid underneath a stationary roof 28 ′. Insert 12 ′ comprises a front panel 44 ′, a back panel 46 ′ with an integral rear barrier 48 ′, a floor 14 ′ and two side panels 42 ′. FIG. 12 shows assistant 74 lowering cat 76 onto floor 14 ′, FIG. 13 shows cat 76 standing on floor 14 ′, and arrows 96 and 98 of FIG. 14 represents assistant 74 sliding the insert's floor 14 ′ underneath roof 28 ′ while cat 76 is on floor 14 ′ and roof 28 ′ is kept relatively stationary. The terms, “relatively stationary” and “substantially stationary” as they pertain to an outer housing or a roof means that the housing and/or roof move less than an insert or floor as the insert or floor is being slid underneath the roof. Roof 28 ′ can be kept stationary by any suitable or convenient means. Examples of such means include, but are not limited to, manually holding roof 28 ′ still and/or supporting roof 28 ′ by an outer enclosure, side wall or other structure that is resting on top of base 70 .
FIGS. 15 and 16 show an alternate example cat carrier 100 that is similar to cat carrier 94 but with subtle yet key structural and functional differences. FIGS. 15 and 16 correspond to FIGS. 13 and 14 , respectively. Structurally, an insert 102 of cat carrier 100 has significantly higher side panels 104 that can disconcertingly obstruct the cat's side view, thereby perhaps making cat 76 feel more confined and want to escape. Functionally, instead of sliding insert 102 underneath a roof 106 that is relatively stationary, roof 106 is slid 108 across the top of insert 102 and toward cat 76 . In this example, since cat 76 retains a firm footing on stationary floor 14 ′, cat 76 might have a natural tendency to simply jump out to avoid the approaching roof 106 , as shown in FIG. 16 .
FIGS. 17 and 18 show an example cat carrier 110 that is similar to cat carrier 100 with FIGS. 17 and 18 corresponding to FIGS. 15 and 16 , respectively. Instead of sliding roof 106 over the top of insert 102 , as shown in FIG. 16 , a roof 112 pivots down over insert 102 , as shown in FIG. 18 . In this example, since cat 76 retains a firm footing on stationary floor 14 ′, cat 76 might have a natural tendency to simply jump out to avoid the descending roof 112 .
FIG. 19 illustrates an example cat carrier method 114 , wherein block 116 represents selecting base 70 that is substantially stationary. Block 118 represents positioning roof 28 ′ at a substantially stationary location relative to base 70 such that roof 28 ′ is at first height 80 above base 70 . Block 120 represents providing floor 14 ′ of insert 12 ′ that is movable relative to roof 28 ′. Block 122 represents extending insert side panel 42 ′ up from floor 14 ′ such that uppermost edge 82 ′ of insert side panel 42 ′ is at second height 84 above base 70 , wherein second height 84 is less than 75 percent of first height 80 . Block 123 represents providing open-air space 78 extending continuously upward from floor 14 ′ to third height 86 that is greater than first height 80 . And blocks 124 and 126 represents lowering cat 76 down through open-air space 78 onto floor 14 ′ of insert 12 ′. Block 128 represents sliding floor 14 ′ underneath roof 28 ′ while cat 76 is on floor 14 ′ and roof 28 ′ is substantially stationary.
Although certain example methods, apparatus and articles of manufacture have been described herein, the scope of the coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.
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A portable cat carrier has a sliding floor that momentarily and mildly destabilizes a cat's footing to facilitate transferring the cat in and out of the carrier. The floor is the bottom portion of a movable insert that has a receptacle for receiving the cat. The insert has relatively low side panels to provide the cat with a calming, unrestricted side view. After the cat is lowered into the receptacle, the insert is slid horizontally into an outer housing for containing the cat. When the insert is fully inserted within the housing, a front panel of the insert closes the housing's access opening to prevent the cat from escaping. A back panel of the insert has an elevated impassable rear barrier that prevents the cat from jumping into a trapped area between the insert and the outer housing.
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BACKGROUND OF THE INVENTION
This invention relates generally to crop harvesting and threshing machines, more commonly known as combines, and more particularly, to the apparatus used to control the unloading auger by which cleaned grain is unloaded from the grain tank to a receiving vehicle. Specifically, the invention is directed to a control mechanism which allows the combine operator to activate the unloading auger by momentarily engaging the unloading auger control, permitting the auger to rotate off of the auger switch and then releasing the control, thereby having the unloading auger swing from the fully inboard or storage position to a predetermined outboard position automatically for the unloading of grain. This invention is applicable to all types of combines which utilize some type of grain unloading tube that must move between predetermined positions of non-operation and operation.
Traditionally combines utilize a grain storage system that has the threshed and cleaned grain transported by means of a collection trough and auger to an elevator which carries the cleaned grain upward into a receiving receptacle or grain tank. The grain is continuously fed into the grain tank during the operation of the combine as it harvests and threshes crop material in the field. The continuous field operation of a combine is generally limited by the capacity of the grain tank to store the clean grain. When the grain rank is full, the combine operator must normally cease the harvesting and threshing operation to unload grain from the grain tank to a receiving vehicle. Occasionally, this unloading operation is conducted simultaneously with the continued harvesting and threshing by having a receiving vehicle move alongside the combine as it progresses down the field. The receiving vehicle may either be a wagon towed behind a tractor or a large grain truck. These receiving vehicles haul the unloaded grain to appropriate storage areas generally remote from the field. This procedure is repeated continuously during the harvesting and threshing of the crop material.
Combine operators normally activate the unloading system by engaging a lever or a switch which requires that the operator continue its engagement during the entire time that it takes the unloading tube to swing from its inboard to its outboard position. Should the unloading operation be conducted while the combine continues to harvest and thresh crop material this requires the operator to direct his attention to several functions at one time. The operator must continually monitor the crop material which is being harvested to the front of the combine as it moves across the field, scan the numerous monitors displayed on the combine control panel and observe the movement of the unloading tube from the inboard to the fully outboard position which is utilized for unloading. Since the operator must continue to steer the combine during this time, this means that the operator must remove one of his hands from the steering wheels and simultaneously conduct at least two operations. Obviously this is a difficult and distracting procedure which could inadvertently cause the operator to vary from his desired path across a field. At the least, the continuous engagement of the unloading tube control mechanism is an inconvenience. The foregoing problems are solved in the design of the machine comprising the present invention by permitting the combine operator to engage the unloading tube control momentarily, thereby activating a system which will permit the unloading tube to automatically swing from the full inboard to the fully outbaord position without any further operator involvement.
SUMMARY OF THE INVENTION
It is a principal object of the present invention to provide in a combine an improved control means for the grain tank unloading means which upon manual activation for a period of time substantially less than that required for the unloading means to move from a first position of non-operation to a second position in which unloading is performed, the control means is effective to automatically move the unloading means from the first position to the second position.
It is a further object of the present invention to provide a relatively simple mechanism that will reduce the amount of operator involvement required in the unloading operation of the grain from the grain tank of a combine.
It is a feature of the present invention that the control means includes a hydraulic fluid directional control valve with a multi-grooved spool that is positionally controlled by the combined operation of a solenoid and a plurality of electrical switches as a part of a hydraulic circuit that is self-contained within the combine.
It is another feature of the instant invention that the unloading means comprises an unloading auger within an unloading tube that is pivotally movable or swingable between an inboard storage position and an outboard unloading position by a hydraulic cylinder that is controlled by the flow of hydraulic fluid through the hydraulic fluid directional control valve.
It is another feature of the instant invention that the unloading auger and tube are automatically stopped in their outboard movement by the engagement of a contact plate with an additional switch which is remotely mounted from the hydraulic valve.
It is another feature of the present invention that the control means has an inherent safety that prevents the unloading auger from being inadvertently activated to move from the inboard to the outboard position upon starting of the combine.
It is an advantage of the present invention that the unloading of the grain tank while the combine continues to operate across a field is made easier because of the reduced operator involvement in the operation.
It is another advantage of the present invention that the automatic movement of the unloading auger between the first and second positions is manually overrideable at any point therebetween.
These and other objects and advantages are obtained by providing apparatus in a crop harvesting and threshing machine that will permit the unloading auger and tube to be automatically moved from at least an inboard first position to an outboard second position by the momentary engagement of the control means for substantially less time than that required for the unloading auger and tube to move from the first position to the second.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages of this invention will become apparent upon consideration of the following detailed disclosure of the invention, especially when it is taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a side elevational view of a crop harvesting and threshing machine with the improved control means shown in phantom lines;
FIG. 2 is an enlarged top plan view taken along the lines 2--2 of FIG. 1 showing the unloading auger tube hydraulic circuit and the fluid control valve controlling the flow of hydraulic fluid to the hydraulic cylinder which moves the unloading auger tube between the inboard and outboard positions;
FIG. 3 is an enlarged top plan view taken along the lines 3--3 of FIG. 1 showing the unloading auger tube ring and hydraulic cylinder with the ball switch and contact plates attached thereto;
FIG. 4 is an enlarged side elevational view of the ball switch on the unloading auger tube ring taken along the line 4--4 of FIG. 3;
FIG. 5 is an enlarged side elevational view of the contact plate and its mounting bracket which fastens to the unloading tube ring taken along the line 5--5 of FIG. 3;
FIG. 6 is an end elevational view of the contact member and mounting bracket shown in FIG. 5;
FIG. 7 is an enlarged plan view of the hydraulic fluid directional control valve with the spool extension attached thereto taken along the lines 7--7 of FIG. 1;
FIG. 8 is a side elevational view of the hydraulic valve showing the relationship of the two interconnected spools, the centering spring, the solenoid controlled detent ball and the electrical ball switch taken along the lines 8--8 of FIG. 7; and
FIG. 9 is a diagrammatic illustration of the electro-hydraulic circuit utilized in the improved control means for the unloading auger tube of the combine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a combine indicated generally by the numeral 10 in a side elevational view with the critical portions of the instant invention shown partially in detail in phantom lines and partially in solid lines at reduced scale. As can be seen, the combine 10 has a mobile frame mounted to a pair of primary driving wheels 11 in the front and a pair of smaller steerable wheels 12 in the rear. It is powered by an engine (not shown) which is usually deisel fuel consuming. The engine is mounted to the upper portion of the combine in a suitable fashion and, by means of drive belts or sprocket chains, is drivingly connected to the operational components of the combine.
The combine 10 generally has a header (not shown) and an infeed housing 14 mounted at its front, as seen in FIG. 1. The combine 10 has a main frame or housing indicated generally by the numeral 15, that internally supports a threshing and separating means (not shown), as well as the operator's cab 16 and the grain tank 18. The operator's cab 16 extends forwardly over the front of the main frame 15 and is atop the infeed housing 14. The cab 16 has a ladder 19 which provides access for the operator to the cab and extends outwardly and downwardly therefrom. Housings 20 and 21 enclose the engine and the discharge beater and discharge grate assembly (both of which are not shown), respectively.
The structure thus far has been described generally since it is old and well known in the art. This structure and the interrelationships between the various operating components of the combine are described in greater detail in U.S. Pat. Nos. 3,626,472, issued Dec. 7, 1971; 3,742,686, issued July 3, 1973; and 3,995,645, issued Dec. 7, 1976; all to Rowland-Hill, hereinafter specifically incorporated by reference in their entirety, insofar as they are consistent with the instant disclosure.
Best seen in FIG. 2, a grain tank has along its bottom most portion a horizontal grain tank unloading auger 22 contained within an elongate, open-topped trough 23. As seen in FIG. 1, the grain tank 18 has a pivotal unloading auger tube 25 within which is contained a rotatable auger (not shown). Tube 25 is fastened to the grain tank via elbow housing 26, which is in turn appropriately fastened to unloading auger ring 28. A horizontal auger tube extension 24 connects into elbow housing 26 at the outboard end of horizontal grain tank unloading tube 25. Elbow housing 26 is joined to unloading auger tube 25 via elbow housing flange 35 and unloading auger tube flange 36 by a suitable number of nuts and bolts.
Double acting hydraulic cylinder 29, seen also in FIGS. 2 and 3, is connected to the unloading auger ring 28 at the rod end 31 of the cylinder 29 via a mounting bracket 32 and double arm bracket 38. On its opposing end hydraulic cylinder 29 is fastened via bracket 30 to the combine frame. Rod-like fasteners 39 fasten the cylinder 29 to bracket 30 and also via double arm bracket 38 to bracket 32, thereby movably connecting the cylinder 29 to the bracket 32. Hydraulic lines 40 and 41 of FIG. 3 lead into opposing ends of the cylinder of hydraulic cylinder 29. Hydraulic cylinder 29, upon activation, pivotally moves the unloading auger tube 25 with its auger from an inboard storage or transport position illustrated as A in FIGS. 1 and 2 to an outboard unloading position illustrated as B. Tube 25 at its outboard end has a discharge opening 27 through which crop material passes into a receiving vehicle when the tube is is in the outboard position and it is desired to unload the grain tank 18.
Unloading auger ring 28 is best illustrated in and understood from viewing FIGS. 3 and 4. Bracket 32, which moves in response to the extension of the rod end 31 of hydraulic cylinder 29, is fastened to the ring 28 by a series of bolts and locking nuts and washers which are indicated generally by the numerals 44 in FIG. 4. As seen in FIG. 4, the bolts and locking nuts and washers 42 and 44 extend through suitably sized apertures in the L-shaped portion 33 of ring 28 and its annular covering plate 34. Bolts and locking nuts and washers 42 and 44 help securely fasten the annular covering plate 34 to the L-shaped portion 33 of the ring 28 which extends upwardly and outwardly from elbow housing 26. The lower portion of ring member 28 adjoins elbow housing 26. Rotatably seated within the L-shaped portion 33 of ring member 28 and beneath the annular covering plate 34 is the annular flange extension 45 of horizontal auger tube extension 24 leading from the grain tank. Auger tube extension 46 is functionally connected to horizontal grain tank unloading auger tube 23. None of the bolts and locking nuts and washers 42,44 pass through this annular flange portion 45. Flange portion 45 remains stationary and the L-shaped portion 33 and annular covering plate 34 of unloading auger ring 28, therefore, rotate about flanged portion 45 when the hydraulic cylinder 29 is activated.
Also fastened to the unloading auger ring 28 and the annular covering plate 34 are a pair of mounting plates 48 and 49, best shown in FIGS. 3 and 4. Mounting plate 48 is fastened to the annular covering plate 34 by bolts and locking washers and nuts 44. Welded to the underside of mounting plate 48 is contact plate 53 which is sloped on its sides so as to form opposing ramps. Contact plate 53 is best shown in FIGS. 5 and 6. Mounting plate 49 has a contact plate 50 which is identical in structure and mounting to contact plate 53 and is best shown in FIGS. 3 and 4.
The fluid directional control valve 55 is best shown in isolated detail in FIGS. 7 and 8. Valve 55 is also shown integrated within the entire operating circuit, including the operational apparatus of the unloading auger tube control means, in FIG. 2. Valve 55 in FIG. 7 generally consists of a main valve housing 59 having multiple ports for the ingress and egress of hydraulic fluid. Hydraulic lines 40 and 41 each permit the two way flow of hydraulic fluid into the valve 55 during the operation of the double acting hydraulic cylinder 29. An adaptor 62 fastens appropriately to the end of housing 59 and, with connector 63, serves to join extension housing 64 therewith. On the end of the extension housing 64 distant from the main housing 59 a cap 65 is appropriately fastened. The cap contains a breather vent 66 with a breather screen plug 68 on its extreme end. Alternately, extension housing 64 could equally well be joined to the main valve housing 59 by only the use of adaptor 62 and a set screw in extension housing 64 to hold the extension housing 64 onto the adaptor 60.
As seen in FIG. 8 there is a first spool 69 within valve housing 59 which is movable within the linear central bore 70. On its forward and exteriorly projecting end spool 69 is connected to link 71 via a double arm bracket 72 and a locking pin 74. O-ring housing 75 seals the front portion of bore 70 in housing 59 and has an appropriately sized aperture through which the portion of spool 69 which connects to link 71 projects. Link 71 pivots about link support and pivot point 77 of FIG. 7 in response to the manual activation of the lever 76 within the operator's cab 16, briefly see FIG. 1, to linearly slide the spool 69 within bore 70. Levers 71 and 76 are movably interconnected by connecting link 78.
As shown in FIG. 8, spool 69 on its interior side abuts against a washer 79 which sets against one end of the centering spring cavity 80. A centering spring 81 is mounted about a rod member 82. On the opposing end of the rod from washer 79 is another washer 84 mounted about the rod member 82. Spool 85 abuts against washer 84 and is linearly movable within bore 86. The compression of spring 81 and washer 79 and 84 against the opposing lips in the centering spring cavity limits the linear movement of spools 69 and 85. Rod member 82 is detachably fastened to spool 69 and is preferably an extension of spool 85. Spool 85 has three grooves 88, 89 and 90 which allow spool 85 and spool 69, through rod member 82 and spring 81, to be retained in predetermined positions to selectively permit the flow of hydraulic fluid in either of two working directions through the hydraulic circuit or to permit a nonworking flow of fluid to pass through the control valve 55 while the spools are in the center neutral position illustrated in FIG. 8.
Extension housing 64 has removably mounted to the top a solenoid detent mechanism 91 and a ball switch 92. The solenoid detent mechanism 91 is fastened to a bracket 94 by a clamping bracket 95 near the top of the solenoid 91. Bracket 94 is appropriately fastened to the top of the housing 64, such as by welding or a screw. An electrical conducting wire 96 connects solenoid detent mechanism 91 and ball switch 92. The solenoid detent mechanism 91 includes a locking ball 87 and a spring 93 which is compressed when the electrical circuit is closed to permit ball 87 to ride up and out of either groove 88 or 89 in spool 85. Ball switch 92 has a ball 97 movably mounted within its housing so that it seats in groove 90 when the spools 69 and 85 are in the center neutral position, but which rides upwardly into contact with wires 107 when the hydraulic circuit is working by directing hydraulic fluid to hydraulic cylinder 29. Thus the solenoid detent mechanism 91 serves to control the linear movement and positioning of spool 85 and, through the centering spring 81 and rod member 82, the positioning of spool 69. Since the control of the flow of the hydraulic fluid in the hydraulic circuit is accomplished within the main valve housing 59, this arrangement effectively controls the flow of hydraulic fluid through the hydraulic circuit. The structure of the main valve housing 59 and the spool 69 has been described only generally since that structure is old in the art and is commercially available from the Fluid Power Division of Cessna Corporation as Part No. 315352-AAE.
The channeling within that portion of the valve housing assembly 59 where spools 69 and 85 are located will be described briefly. As shown in FIG. 8 hydraulic lines 40 and 41 connect to reversible flow ports 98 and 99, respectively. The reversible flow ports 98 and 99 lead into reversible flow chambers 100 and 10, respectively. When the spool 69 is in the neutral portion, the hydraulic fluid flows from inlet flow port 116, see briefly FIG. 7, to inlet chamber 102 and then directly to return chamber 104 from where the fluid is returned via the outlet flow port 118 of FIG. 7 to the reservoir 105, briefly seen in FIG. 9. Alternate flow or inlet chamber 109 receives the hydraulic flow from the inlet flow port 116 of FIG. 7 when the spool is positioned to move the unloading auger tube 25 to the inboard position. When the tube 25 is being moved from the inboard to the outboard position the spools 69 and 85 are positioned so hydraulic fluid flows from inlet flow port 116 to inlet chamber 102 and reversible flow chamber 100. The return flow of hydraulic fluid enters flow port 99, chamber 101 and chamber 108 and then proceeds via outlet flow port 118 (FIG. 7) to the reservoir 105 when the unloading auger tube 25 is being moved to the outboard position when the tube 25 is moved to the inboard position the fluid return flow enters flow port 98, chamber 100 and chamber 106 and exits via outlet flow port 118 to the reservoir 105.
The electro-hydraulic circuit is diagrammatically illustrated in FIG. 9. Battery 110 is connected to starter switch 111. Starter switch 111 is electrically connected by line 112 to the solenoid detent mechanism 91. Solenoid detent mechanism 91 is connected by wire 96 to normally open ball switch 92, which in turn connects with the normally open ball switch 51 on the auger tube ring 28 via wire 56. Wire 58 runs from the auger tube ring ball switch 51 back to the battery. The starter or ignition switch must be on for the circuit to be operational and for the solenoid detent mechanism 91 and ball switch 92 to control the flow of hydraulic fluid through the fluid directional control valve 55. The hydraulic fluid is pumped from the reservoir 105 through pump 115 about the hydraulic circuit. Pump 115 brings the hydraulic fluid into the fluid control valve 55 via inlet flow port 116, best shown in FIG. 7 and carries it out via outlet flow port 118 generally as described above.
In operation, the operator drives the combine 10 across the field harvesting the crop material. When the grain tank 18 is filled with grain, the operator engages the lever 76 within the operator's cab. Lever 76, through connecting link 78 and link 71, causes the double arm bracket 72 connected to spools 69 and 85 to move rearwardly by pivoting link 71 about link support and pivot point 77. This causes the hydraulic fluid, which has been entering the fluid directional control valve 55 via inlet flow port 116 and the neutral position inlet chamber 102 and exiting via the neutral position return chamber 104, to be redirected from inlet chamber 102 into chamber 100. The hydraulic fluid is then routed out through flow port 98 to hydraulic cylinder 29. The hydraulic fluid is carried from flow port 98 to the base end of hydraulic cylinder 29 via hydraulic line 40. The flow of fluid then forces the rod end 31 of hydraulic cylinder 29 outwardly causing the unloading auger ring 28 to rotate and ball switch 51 to break contact with contact plate 50.
This breaks the electrical circuit causing the solenoid detent mechanism 91 to stop compression of the spring 93 and allows the ball 87 to be forced downwardly as the spring 93 extends to engage the groove 88 of spool 85. Locked in this position the spool 69 permits the flow of hydraulic fluid to pass through directional control valve 55 so as to continue moving the unloading auger tube 25 and the auger contained within from the inboard position to the outboard position without the need for the operator to continue to engage lever 76. Spool 69 also compresses the centering spring 81 within the centering spring cavity.
When the unloading auger tube 25 and the auger contained within have swung to a sufficiently outboard position for the contact plate 53 on the unloading auger ring 28 to engage the normally open ball switch 51 the electrical circuit is then again completed. This causes the flow of current to go from the battery to the solenoid detent mechanism 91 and compress the spring 93. The current then continues through ball switch 92 and completes the circuit back to switch 51. The compression of the spring 93 within solenoid detent mechanism 91 allows the locking ball 87 to disengage from groove 88 to permit the centering spring 81 to return the spools 69 and 85 to the neutral center position shown in FIG. 8. This stops the flow of hydraulic fluid through the cylinder 29 and again directs the fluid from the reservoir 105 through the pump 115 into the directional control valve 55 via inlet flow port 116 and inlet chamber 102. The fluid continues out of the valve 55 through return chamber 104 and outlet flow port 118 back to the reservoir 105. Thus, the electro-hydraulic circuit has positioned the unloading auger in the fully extended or outboard position shown as B in FIGS. 1 and 2.
When the operator desires to return the unloading auger tube 25 and its auger to the inboard position, shown as A in FIGS. 1 and 2, the operator reengages the lever 76 moving the connecting link 78 so that link 71 pivots about link support and pivot point 77 to move the spools 69 and 85 forwardly. This forward movement of the spool 69 allows the hydraulic fluid to flow from the pump 115 into the fluid directional control valve 55 via inlet flow port 116 and inlet chamber 109. Hydraulic fluid then passes through flow chamber 101, flow port 99 and exits the control valve 55 via hydraulic line 41 enroute to the hydraulic cylinder 29. The fluid causes the rod end 31 of cylinder 29 to retract, thereby commencing the pivoting of the unloading auger ring 28 and the unloading auger tube 25 from the outboard position toward the inboard position. As soon as the contact plate 53 has broken contact with the normally open ball switch 51, the electrical circuit is broken. This again causes the pressure within solenoid detent mechanism 91 to stop the compression of spring 93 and permits the locking ball 87 to engage groove 89 of spool 85. This positioning of spool 85 locks spool 69 into position to permit the flow of hydraulic fluid to continue without the need for the operator to continue to engage lever 76 so that the fluid leaves hydraulic cylinder 29 and returns via hydraulic line 40 to flow port 98. The hydraulic fluid then passes through flow chamber 100 and into the return chamber 106 from which it is directed to the hydraulic reservoir 105 via outlet flow port 118 to complete the fluid circuit. When the unloading auger tube 25 has returned sufficiently inboard to permit contact plate 50 to reengage ball switch 51 the electrical circuit is again completed and spring 93 within solenoid detent mechanism 91 is compressed, allowing the locking ball 87 to ride upwardly out of groove 89 in spool 85. The centering spring 81 then again repositions the spools 69 and 85 in the center neutral position, directing the flow of hydraulic fluid through the directional control valve 55 via inlet flow port 116, inlet chamber 102, return chamber 104 and outlet flow port 118. The spools 69 and 85 are retained in their center position by centering spring 81. In the centering position the ball 97 within the normally open switch 92 enters the groove 90 of spool 85 breaking the electrical circuit so there is no flow of current when spools 69 and 85 are in the neutral position.
Should the lever 76 inadvertently be engaged by the operator while the unloading auger tube 25 and its auger are in either the inboard or outboard positions prior to having started the combine, the surge of electricity through the circuit upon starting will always cause the solenoid to compress the solenoid spring 93, thereby permitting the ball 87 to ride upwardly out of either groove 88 or 89 and allowing the centering spring 81 to position the spools 69 and 85 in their neutral center position. Thus, the unloading auger tube 25 and its auger will never be accidentally swung from the outboard to the inboard position or vice versa upon engaging the ignition switch or starter. The latter possibility would be especially dangerous should the combine 10 be stored within a closed building with obstructions in the path of movement of the unloading auger tube 25 that could cause damage to either the combine, the structure or both in the event of such an accidental activation.
Should the operator desire to stop the unloading auger tube 25 at any point intermediately of the first fully inboard position and the second fully outboard position the automatic movement therebetween is manually overrideable by simply engaging the control lever 76 to cause connecting link 78 and link 71 to move in the appropriate direction to cause spools 69 and 85 to return to the center neutral position. As described previously, this cuts off the flow of fluid to the hydraulic cylinder 29 and stops the rotation of the unloading auger tube 25.
Additionally, it should be noted that spool 85 and housing 64 with its solenoid detent mechanism 91 and ball switch 92 could be adapted to control the positioning of other hydraulically controlled components, both on combines and other machinery. For example, with the appropriate electro-hydraulic circuits such apparatus could be used to raise and lower combine headers between predetermined positions or to control the positioning of buckets or scoops on earth working machinery between a fully extended dump position and a second scooping position. Also on earth working machine during a leveling operation it is difficult for an operator to physically see when his bucket is level. With an arrangement similar to that utilized on the instant invention, the bucket would automatically be level each time it is positioned in the scooping position, thereby relieving the operator of this normally manually controlled and imprecise operation.
While the preferred structure in which the principles of the present invention have been incorporated is shown and described above, it is to be understood that the invention is not to be limited to the particular details thus presented, but in fact, widely different means may be employed in the practice of the broader aspects of this invention. The scope of the appended claims is intended to encompass all obvious changes in the details, materials and arrangements of parts which will occur to one of ordinary skill in the art upon a reading of this disclosure.
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In a crop harvesting and threshing machine there is provided apparatus that will permit the unloading auger and tube to be automatically moved from at least an inboard first position to an outboard second position by the momentary manual engagement of the control apparatus for substantially less time than that required for the unloading auger and tube to move from the first position to the second position.
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CROSS-REFERENCE TO OTHER APPLICATIONS
This application claims the benefit of U.S. provisional patent application No. 61/761,269, filed on 6 Feb. 2013, entitled Swung Implement with Educating Feedback.
BACKGROUND OF THE INVENTION
A great amount of time and energy has been expended in the pursuit of training techniques, training devices and training aids to help sports enthusiasts, in particular golfers and tennis players and to a lesser extent baseball players and fly fishers, improve their swings and strokes. Although the equipment continues to improve, such as metal woods for golfers and graphite rods for fly fishers, to some extent these improvements have merely increased what is generally considered a basic level of competence in a particular sport. Therefore sports enthusiasts continue to look for ways to improve their skills.
BRIEF SUMMARY OF THE INVENTION
An example of a golf swing training aid is positionable along the shaft of a golf club. The golf club has a club head at a distal end of the shaft, the club head having a striking face extending between a heel and a toe of the club head. The training aid includes a housing and a light beam generator carried by the housing. The light beam generator is placeable in an on state to generate inside and outside light beams directable towards inside and outside positions corresponding to the heel and toe of the club head as the golf club is swung during a golfing stroke. Examples of the golf swing training aid can include one or more the following. The housing can be removably mountable to a golf club shaft or can be an integral portion of the golf club shaft. The light beam generator can include a laser light source. The inside and outside light beams can be oriented to be directed along paths forward of the striking face of the club head. The light beam generator can generate a second light beam directed generally parallel to the shaft and away from the club head.
An example of a golf swing training club includes a golf club and a golf swing training aid. The golf club has a shaft with a distal and proximal ends, a grip at the proximal end, and a club head at the distal end. The club head has a striking face extending between a toe and a heel of the club head. The golf swing training aid includes a light beam generator along the shaft. The light beam generator is placeable in an on state to generate inside and outside light beams directed towards inside and outside positions corresponding to the head and toe of the golf club head as the golf club is swung during a golfing stroke. In some examples the light beam generator can generate a second light beam directed generally parallel to the shaft and away from the club head.
An example of a method for improving the golf club swinging motion of a golfer is carried out as follows. A golf swing training club is accessed. The golf swing training club includes a golf club and a golf swing training aid. The golf club has a shaft with distal and proximal ends, a club head at the distal end, and a grip at the proximal end. The club head has a striking face extending between a toe and a heel of the club head. The golf swing training aid has a light beam generator along the shaft. Inside and outside light beams are generated by the light beam generator, the light beams being directed towards inside and outside positions corresponding to the heel and toe of the club head as the golf club is swung during a golfing stroke. A golfing stroke is executed over a surface using the golf swing training club. The paths of the inside and outside light beams along the surface are observed during the golfing stroke. This method can be carried out to include one or more the following. The method can further comprise placing a golf ball on the surface and striking the golf ball with the striking face of the club head during the golfing stroke. The paths observing step can include determining the locations of the paths relative to the golf ball. The paths observing step can include determining the orientation of the striking face of the club head relative to the golf ball. The light beams generating step can be carried out so that the inside and outside light beams are directed in front of the striking face. The method can also include generating a second light beam generally parallel to the shaft and away from the club head, and observing the path of the second light beam along the surface during a backswing portion of the golfing stroke.
Other features, aspects and advantages of the present invention can be seen on review of the drawings, the detailed description, and the claims which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of a first example of a golf swing training club.
FIG. 2 is a view in section of the golf swing training aid within the grip of the golf club of FIG. 1 .
FIG. 3 is a view of a second example of a golf swing training club generating inside and outside, downward extending light beams.
FIG. 4 is a view of a third example of a golf swing training club in which inside and outside, downward extending light beams emanate from the central portion of the shaft of the golf club.
FIG. 5 is a schematic view in section of a golf swing training aid within the shaft of the golf club of FIG. 4 .
FIG. 6 is a view of a fourth example of a golf swing training club in which inside and outside, downward extending light beams emanate from the shaft of the golf club adjacent to the grip.
FIG. 7 is a schematic illustration showing various electronic components of the golf swing training club of FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
The following description will typically be with reference to specific structural embodiments and methods. It is to be understood that there is no intention to limit the invention to the specifically disclosed embodiments and methods but that the invention may be practiced using other features, elements, methods and embodiments. Preferred embodiments are described to illustrate the present invention, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize a variety of equivalent variations on the description that follows. Unless otherwise stated, in this application specified relationships, such as parallel to, aligned with, or in the same plane as, mean that the specified relationships are within limitations of manufacturing processes and within manufacturing variations. When components are described as being coupled, connected, being in contact or contacting one another, they need not be physically directly touching one another unless specifically described as such. Like elements in various embodiments are commonly referred to with like reference numerals.
The invention may be embodied in various shapes and forms to various devices or implements that require a user to make a precise swinging motion of the device or implement. Preferred embodiments provide feedback to a user to facilitate education of the user, thereby permitting the user to achieve a desired swing. Desirably, the education process afforded by an embodiment of the instant invention causes faster and/or more complete progress toward mastering a swing than achievable with currently available and conventional training.
FIG. 1 illustrates a first example of a golf swing training club 10 adapted to provide learning feedback for the swinger of a golf club. The training club 10 in FIG. 1 includes a golf club 12 and a golf swing training aid 14 . Golf club 12 includes a shaft 16 having a grip 18 at its proximal end and a club head 20 at its distal end. Club head 20 has a striking face 22 for striking a golf ball 24 during a golfing stroke. Golf swing training aid 14 includes a light source and battery assembly 26 housed within grip 18 as shown in FIG. 2 . Assembly 26 includes a light source 27 , typically a laser source 27 , adapted to extend a light beam 28 , commonly referred to as laser beam 28 , aligned with the axis of shaft 16 , and propagating away from the club head 20 through a window 31 at the proximal ends of shaft 16 and grip 18 . Preferably, the laser propagates co-linearly with the central axis of the club shaft.
The laser beam 28 paints a laser beam path 30 on the ground 32 as the golfer makes a swing. At the top of the swing, the laser beam 28 is pointing almost directly at the ball 24 . The golfer can observe the laser beam path 30 during the backswing and can ascertain whether or not the backswing is staying in the proper swing plane. Also, as the golfer begins the stroke to impact, the golfer can see whether or not the club remains in the proper plane. If it does, the laser beam 28 will trace an overlapping arc shape on the backswing and downstroke. Further, the arc, or an extension of the arc, should pass approximately or actually through the ball.
A laser type light source 27 is currently preferred for use in generating light beam 28 to provide visual feedback to the user, due to the high visibility of commercially available, low cost, red laser beams. Therefore, the light source 27 of assembly 26 will generally be referred to as a laser, although other light sources are not excluded.
One way to provide a laser in association with a golf club is illustrated in FIG. 2 , where laser and battery assembly 26 is structured to be carried inside the grip 18 of the club 12 . Positioning of the assembly 26 may be made by removing a grip end-cap, and sliding the assembly along the inner shaft of the grip to a desired installed position. Gripping structure, such as one or more illustrated O-rings 36 , may be employed in compression to hold the assembly 26 at the desired position. Certain structure, e.g. for recharging the battery, removing the assembly, and details of the window, are not illustrated, being well within the capability of one of ordinary skill to construct. Alternative arrangements are within contemplation, including structuring a laser assembly as one or more add-on module that may be coupled with a commercially available golf club.
By observing the projected light beam's impingement on the surface 32 on which a target golf ball 24 rests before, during and after a golf stroke, the user gets immediate visual feedback regarding the path of the club with respect to a target ball. This feedback is beneficial in ensuring proper backswing, proper backswing positioning at its apex, and proper swing path through the swing plane, and proper finish to the golf stroke.
FIG. 3 illustrates a second example of a golf swing training club 10 in which golf swing training aid 14 is an add-on module that may be coupled with a commercially available golf club 12 . In the illustrated example, golf swing training aid 14 attaches to the approximate mid-shaft of a golf club 12 , and includes an attachment mechanism, a light source 27 (e.g., a laser source 27 ), a pair of light beams, generally referred to as inside laser beam 38 and outside laser beam 40 , and an adjustable component which allows the beams to be projected down in front of the club striking face 22 an arbitrary (and desirably selectable) distance in front of the club striking face 22 . In a preferred embodiment, the assembly 26 is as light as possible so that it minimally affects club performance. Also, the attachment mechanism preferably holds the device rigidly in place at the club shaft's center of percussion.
The pair of laser beams 38 , 40 may be provided from a cost-effective single laser source 27 by way of fiber optic cables, one or more lens, or an angularly variable beam splitter, such as beam splitter 44 shown in FIG. 5 . Desirably, the spacing between inside and outside laser beams 38 , 40 is adjustable, as indicated by γ. A preferred device permits positioning the two beams to straddle a golf ball that is disposed at the sweet spot in the club head's striking face 22 . Also, it is preferred for the line 46 defined between the projected beams 38 , 40 to be adjustable relative to the striking face, as indicated by β.
When the club is moved through the golf stroke, the split beams 38 , 40 pass on both sides of the ball 24 before the club face 22 impacts the ball. The beams 38 , 40 are positioned such that they provide immediate visual feedback regarding club face position, whether open, closed, or perpendicular to the swing path, at the moment of impact, allowing the golfer to make swing adjustments for the purpose of addressing hooking or slicing or desired fade or draw. The beams 38 , 40 also enable the golfer to observe where the club face 22 strikes the ball 24 (i.e., toe 48 , center, heel 50 ) and make appropriate adjustments to addressing and stance.
A third example is illustrated in FIGS. 4 and 5 and may combine one or more selected aspects contained in both of FIGS. 1 and 3 . Assembly 26 is constructed to create the laser beam 28 extending away from club head 20 and a second laser beam 29 -generally towards the club head. Laser beam 29 is transformed into inside and outside laser beams 38 , 45 beam splitter 44 . An aperture 52 in the club shaft 16 may be provided as an alternative way to permit projecting the laser beams 38 , 40 from a propagation location inside the club shaft. Alternatively, an aperture may be provided at the area of handle-to-shaft junction. The assembly 26 illustrated in FIG. 5 may be disposed inside the grip 18 or at any desired position along the shaft 16 . Since certain components, such as a battery, necessarily adds some weight (and mass), it is sometimes preferable to dispose the assembly 26 inside the grip 18 to minimize change in club response due to inclusion of one or more feed-back devices. Fiber optic cables may be used to advantage to route an interior beam through the wall of the club shaft 16 at a location that reduces reduction of structural integrity of the shaft (e.g., through the larger-diameter shaft near/inside the grip 18 ). A pair of such cables may be employed to split and orient direction of propagation of a beam from a single laser source 27 .
The examples illustrated in FIGS. 1 , 3 and 4 provide only visual feedback to the golfer. The embodiment illustrated in FIGS. 6 and 7 may include none, or any one or more of the aspects illustrated in FIGS. 1 , 3 and 4 , and also provide additional feedback to a user of the golf club. In addition to potentially including one or more visual feedback arrangements, the embodiment in FIGS. 6 and 7 includes one or more data acquisition transducers 56 , a central processing unit (CPU) 58 , and one or more feedback modules. Data acquisition transducers 56 within contemplation include accelerometers and gyroscopes, especially such transducers that are embodied as micro versions. A feedback module 60 may provide physical feedback (such as vibration) or audible feedback (such as a tone). A battery module 62 provides power for assembly 26 . A charging/communication port 68 can be used to charge battery module 62 and to permit stored data to be downloaded.
The embodiment in FIGS. 6 and 7 includes as integral parts: a CPU 58 , one or more micro-accelerometers, and/or micro-gyroscope transducers 56 , and a feedback module 60 to provide tactile and/or audible feedback. Such components work together to provide the golfer immediate physical feedback as to the correctness of the golf stroke during the backswing, downswing and follow-through.
A tactile or audible feedback may be provided by one or more feedback modules 60 , such as a vibrator. An operable vibrator may include an eccentric weight spun by a motor, similar to the vibrator of a cellular telephone. An audible feedback may be provided by a feedback module including a speaker, or other sound producing element. The audio feedback could be selected to be heard by anyone in the area as it emanates from the golf club 12 or training aid 14 . In addition or alternatively, the audio feedback could be transmitted to an earpiece via Wi-Fi or other wireless transmission protocol. Providing the audio feedback only to an earpiece allows the feedback to be available only to one or more of the user, instructor or other third party.
Certain transducers 56 , such as accelerometers and/or gyroscopes, may be located in the club 12 such that the relative speeds and positions of the club face 22 , shaft 16 and grip 18 are continuously detected through the entire stroke sequence. The CPU 58 typically monitors these respective positions throughout the stroke sequence. If the stroke is executed properly, no tactile or audible feedback may be provided to the golfer. If, at any point in the stroke sequence, the relative speeds and positions of club face 22 , shaft 16 , and grip 18 depart from an acceptable and proper swing plane and swing motion, the CPU 58 may be programmed to instantly signal one or more feedback module to provide a selected sensation to the golfer. The golfer learns to avoid this sensation, and therefore more quickly develops a proper stroke sequence. The frequency and/or intensity of the vibrational feedback can be made to vary. For example, a high frequency and more intense vibration can be used to indicate a larger departure from the desired swing plane, tempo, etc. Similarly, the pitch and/or volume of an audible tone can made to vary according to the accuracy of the golf stroke.
The educating feedback provided by embodiments structured according to certain principles of the instant invention can be incorporated into wedges, irons, hybrid clubs, woods, and drivers, among other applications. The sensing and feedback system can generally be turned off or on at will by the golfer. The clubs can be used on practice ranges or on the course. The clubs can be used by the golfer alone, or with the assistance of golf pros or coaches. The technology is designed to be as unobtrusive to the clubs' performance as possible, such that they perform identically to similar clubs not incorporating the technology.
Desirably, a particular base-line, or “desired” swing for the golf club's CPU 58 is obtained, e.g., programmed with the use of heuristics; e.g., professional golfers could swing the clubs hundreds to thousands of times to create a “profile swing” typical of that golfer. Swing deviation boundaries will be established to trigger actuation of the feedback system. A user can potentially select the professional golfer's profile most appealing to them. (E.g., the “Bubba Watson” or the “Stacy Lewis” stroke profile). The CPU's firmware will typically be re-programmable so that a user can experiment with a variety of different professional stroke profiles to determine which profile is most suitable. For back swings, impact swings and follow-through, different tones can be generated to indicate to the user that the golfing stroke is, for example, inside, outside, high, or low relative to an ideal path. This provides the user additional information about what is necessary to correct the swing path. Nine fundamental full swing strokes, including straight, draw, and fade strokes, each selectable for low, medium, and high loft, can be user selectable by the user according to which stroke user wishes to practice.
It is within contemplation that an alternative embodiment of a golf club may include data acquisition transducer(s) 56 and a communication module 68 . For communicating individual or average swing performance to a remote CPU 64 for swing evaluation. An associated display 66 may be used to provide the golfer with a rigorous printout detailing the specific area(s) of departure of a user's swing from a desired swing. An on-board memory module may be provided to store data related to one or more swing. Swing data may be uploaded on demand to the remote processing/display device by way of a communication protocol, including wired and wireless. An exemplary wired communication protocol includes micro-USB cable. An exemplary wireless communication protocol includes Bluetooth. Preferred embodiments of the invention may therefore allow a golfer to not only obtain real-time feedback in the course of each swing, but also enable later review for additional learning (e.g., consistent swing errors) and improvement.
In any case, a club may be programmed by having a professional golfer swing it many, many, times to create an “average” perfect swing in the style of “big name” pros, perhaps even an actual “big name” professional may perform the swinging. By virtue of the instrumentation recording many such strokes, the club may be programmed heuristically to note the preferred path and allowable departures from it within an arbitrarily assigned value. Specific departure values may have to be empirically determined by watching the flight path of the struck balls and correlated to each particular stroke, potentially for each individual user. The golfer can see the result of each ball strike to see what the problem(s) is and can alter subsequent swings accordingly. This is what is done anyway without instrumentation, but with additional feedback inculcation of muscle memory is accelerated. Heuristically derived swing patterns can be adjusted to allow arbitrarily larger or smaller deviations by the user. In this way a less experienced golfer can increase the allowable departure tolerance compared with a more refined and experienced golfer.
It is envisioned that a golf club with integrated technology according to certain aspects of the invention will be purchasable as single units. Retrofit kits may also be available to allow golfers to have their existing clubs equipped with the technology.
The instantaneous visual feedback afforded by certain golf-related embodiments of the invention helps beginning golfers more rapidly obtain proper mechanics of the entire stroke sequences for a variety of different golf strokes. It provides reinforcement to other visual, physical, and kinesthetic feedback to enhance and accelerate establishment of muscle memory for optimal stroke mechanics. It can help more advanced golfers isolate issues with their swing mechanics and correct defects correspondingly. The device can be used by the golfer alone, or it can be used as a coaching aid by golf professionals providing instruction. A device structured according to any of FIGS. 1 , 3 , 4 , 6 and 7 , can be used off the course, at driving ranges, or during actual play to maintain high awareness of stroke mechanics and consequences of specific variations from proper club head motion and positioning throughout the entire stroke sequence.
Embodiments according to certain aspects of the instant invention may be applied to other swung implements. For one non-limiting example, casting in fly fishing includes a timing element that is dependent on amount of line out. A fly rod embodiment of the invention may include one or more sensors adapted to detect proper amount of bending after a back cast (rod loading) before the front cast is initiated. Vibration of the grip if the front cast is started too soon would be a powerful teaching aide. Feedback if the fly fisher fails to maintain the rod in a plane (e.g., perhaps for distance casts) could be also. It is within contemplation that a laser could also have some sort of aiming benefit, and if the beam extends too far in front of you, you know your tip went too low on the back cast.
Desirably, the inclusion of the feedback-generating equipment according to preferred embodiments of the invention is effected in such a manner that it interferes minimally (or not at all) with proper use and swinging of the implement by the user. That is, the combination of feed-back generating equipment and an associated implement is desirably weighted and balanced such that the feedback-generating equipment has minimal interference with proper use and swinging of the implement.
It is within contemplation to include means to provide discontinuous output of a laser to avoid causing harm to any bystanders during use of an embodiment of the invention. For example, the laser may be shut off, or its emission path interrupted, under certain circumstances, such as if the beam would not normally contact the ground. As a non-limiting example, one or more on-board data acquisition sensor may be used as one way to provide feedback to a golf club control system effective to regulate laser output and provide a safety over-ride mechanism to resist unsafe laser emissions. One alternative includes a mechanical switch, such as a mercury switch, which only permits laser operation during a “safe” arc of club travel.
Desirably, certain embodiments of the invention will include a way to initiate implement response (e.g. tell a golf club to pay attention and prepare to evaluate a swing). That is, the user may provide an input that signals to an implement's control system that a swing is imminent. One potential such signal includes tapping an implement on the ground one or more times to turn the processing system on and prepare to receive and process a swing input. One or more of the on-board data acquisition transducers can provide an initiation signal based on ground-contact induced shock. An alternative includes permitting the user to “waggle” an (e.g. golf club-type) implement a few times (as is the warm-up custom of many golfers). Even a simple contact switch that is actuated by grasping an implement, such as by properly holding the grip of a golf club, may be employed in another variation to communicate initiation of a stroke to the control system.
It is contemplated that certain embodiments of the invention may be applied to any and/or all swung implements, whether in sports, industry, military applications, video gaming, and so on. For examples, but without limitation, embodiments of the invention may be applied to baseball bats, tennis racquets, cricket paddles, swords, epees, racquetball racquets, lacrosse sticks, hockey sticks, etc. In each application the utility of each aspect of the invention(s) (i.e., which sensors and feedback mechanisms, CPU, memory) would be evaluated and applied as appropriate. For example, use of light emitting feedback components may have little utility with an epee, but, may have applicability to hockey sticks. In many cases the use of micro triaxial accelerometers or micro gyros may be useful in conjunction with tactile or audible feedback mechanisms. Heuristic programming of the algorithms controlling feedback may have utility with many implements. For example, heuristically derived tennis swing patterns, for example backspin swings, fore spin swings or lob swings, can be adjusted to allow arbitrarily larger or smaller deviations by the user. In this way a less experienced tennis player can increase the allowable departure tolerance compared with a more refined and experienced tennis player. The ability to record through use of on board memory, for example, all of the swings of a tennis racquet in the course of a game, set, or match, may provide the user with substantial information to understand and enhance the learning process. Similarly, the use of transducers and audible and tactile feedback in an instrumented baseball bat, along with recording all swings in the course of a game or practice session for later analysis may have substantial utility, for example regarding the swing path of the bat, or timing of the users “wrist breaking”.
The above descriptions may have used terms such as above, below, top, bottom, over, under, et cetera. These terms may be used in the description and claims to aid understanding of the invention and not used in a limiting sense.
While the present invention is disclosed by reference to the preferred embodiments and examples detailed above, it is to be understood that these examples are intended in an illustrative rather than in a limiting sense. It is contemplated that modifications and combinations will occur to those skilled in the art, which modifications and combinations will be within the spirit of the invention and the scope of the following claims. For example, various examples could include structure for selecting one or more of audio on/off, vibration on/off, light source 27 on/off.
Any and all patents, patent applications and printed publications referred to above are incorporated by reference.
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A golf swing training club includes a golf club, with a shaft, a grip and a club head, and a golf swing training aid, with a light beam generator along the shaft placeable in an on state to generate inside and outside light beams directed towards inside and outside positions corresponding to the head and toe of the club head. A golfing stroke can be executed over a surface so that the paths of the inside and outside light beams along the surface can be observed during the golfing stroke. A second light beam can be generated generally parallel to the shaft and away from the club head; the path of the second light beam along the surface can also be observed during a backswing portion of the golfing stroke.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a device for dispensing and applying a strip of decorative material in a circular pattern.
2. Description of the Prior Art
Dispensers are known for applying strips of tape along a surface to be decorated or to apply tape to mask a surface during painting of an adjacent surface. Dispensers for masking or for applying strips of tape have utilized a guide member which is positioned to one side or forwardly of the tape applicating roller. These dispensers however have not been satisfactory for applying a narrow strip of a pressure-sensitive decorative tape to form a circle on a planar surface or slightly conical circular surface.
SUMMARY OF THE INVENTION
The present invention provides a dispenser for use in applying a strip of decorative tape onto a surface in a circular configuration. The dispenser of the present invention comprises a dispenser having a frame with a mandrel for rotatably supporting a roll of tape, guide means for directing the tape from the roll to an applicating roller, cutting means for cutting the tape adjacent the applicating roller, an arm pivotally connected to the frame of the dispenser and pivotal about an axis which is generally perpendicular to the axis of the mandrel supporting a strip of tape. Means are provided for adjusting the position of arm with respect to the dispenser to move the same between a position generally parallel to the axis of the mandrel and a position generally perpendicular to the axis of the mandrel. Adjustably supported along the arm is a cross arm which is provided with a pair of guide rollers to provide two guide points at circumferentially spaced positions with respect to the applicating roller to define the circular path of the applicating roller during application of the strip of tape. The guide rollers are rotatably supported on axes which are generally perpendicular to each other at opposite ends of the cross arm which is adjustably mounted with respect to the support arm to define the diameter of the circle to be formed by the tape.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will be further defined hereinafter with reference to the accompanying drawing wherein:
FIG. 1 is a vertical sectional view of a wheel of an automobile with the dispenser of the present invention positioned thereon for applying a strip of tape to a circular generally flat surface on the wheel;
FIG. 2 is a right side view of the wheel of FIG. 1 showing the dispenser of the present invention positioned thereon;
FIG. 3 is a detailed view of the applicating roller and cutter of the dispenser;
FIG. 4 is a view of the tape dispenser with one cover removed to show the interior portions of the dispenser;
FIG. 5 is a detail view of the dispenser and the pivotal arm for positioning the dispenser on the surface to be striped; and
FIG. 6 is a detail view of the guide wheel on the cross arm.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides a tape dispenser and fixture for applying a narrow, i.e. 1/8 inch (0.03 mm) to 1/2 inch (0.13 mm) wide, strip of tape and preferrably of the decorative film such as that sold under the tradename "SCOTCHCAL" colored vinyl film tapes having a pressure-sensitive adhesive and available from Minnesota Mining and Manufacturing Company (3M) of St. Paul, Minn. U.S.A. The dispenser permits the application of this decorative film on circular surfaces which are flat or generally concial such as the application of a stripe of decorative film on an automobile wheel or other area where a narrow strip of tape is desirable on a circular surface. The dispenser incorporates a unique film tracking system and tape cut-off system. The cutting system severs the tape in a position that facilitates starting a new application without handling the tape. The cut-off system provides for the cutting of the tape automatically. The cutting system works to cut the tape upon withdrawing the tool from the application surface while continuing the forward motion of the dispenser.
The dispenser 10 and fixture is illustrated for applying the narrow decorative film strip uniformly about a circular surface such as the rim 11 of the wheel, generally designated 12, having a felly 13 for supporting the tire. The dispenser 10 comprises a frame 15. Means are provided for adjusting the position of the frame with respect to the tape receptor surface. The frame 15 is pivotally mounted to an arm 16 of the fixture for movement with respect thereto about an axis defined by a pin 17. The pin 17 extends through one end of the arm 16 and through a hole in a gusset plate 18 fixed to the frame 15 of the dispenser 10. The gusset plate 18 is also provided with an arcuate slot 20 receiving a set screw 21 extending from the arm 16. The set screw 21 permits the arm 16 to be positioned with respect to the frame 15 from a position which is generally parallel to the frame 15 and a position which is at an angle to the frame 15.
The fixture further includes a cross arm 22 which is slidably mounted on the arm 16 and is positionable along the length of the arm 16 by a set screw 24. The cross arm 22 has a pair of guide rollers 25 rotatably supported at each end to stabilize the cross arm at two circumferentially spaced points from the dispenser 10. The rollers 25 are formed with bevelled surfaces and are each mounted on an axis which is angularly positioned with respect to the longitudinal axis of the cross arm 22. The axis of each of the guide rollers is generally perpendicular to each other. The rollers 25 thus rotate with respect to the guiding surface or the edge of the felly adjacent the surface 11 to permit an applicating roller 30 of the dispenser 10 to position the strip of decorative film about the rim 11. The axis of the applicating roller is generally perpendicular to the axis of pin 17.
The dispenser 10 is adapted for use with a linerless pressure-sensitive adhesive coated decorative film or with the conventional decorative film utilizing a liner over the adhesive.
The dispenser comprises a support mandrel 31 for supporting a roll of tape 32 which may be formed with a removable liner 33. The tape 32 is drawn from the periphery of the roll over a first tape guide such as an idler roller 35 and then to and around a second guide roller 36 where the liner is stripped from the adhesive. The liner 33 is directed through an opening in the frame 10 away from the applicating roller 30. The tape goes from guide roller 35 over a third guide roller 37 to a knurled roller 38 which directs the tape onto the applicating roller 30. The roller 30 has a resilient coating to aid in pressing the tape against the surface, which may have some irregularlarity.
The cutting means on the dispenser 10 comprises a U-shaped knife support 40 which is pivotally mounted about a pin 41 at one end and the opposite end projects outside of the frame 15 and supports the cutting knife 42. The support 40 is biased by a spring 44 toward the applicating roller 30. The support 40 urges the tape into contact with the knurled roller 38 to brake the tape and to aid in tensioning the tape during the cutting motion. FIG. 4 illustrates the normal position of the knife support 40 during application and a roller 45 rolls on the tape to buff the tape with the aid of the bias spring 44 and lifts the support 40 away from roller 38. When the application of the strip is completed the operator can raise the dispenser from the applicating surface and continue the movement of the dispenser. The support 40 can move the knife 42 toward the position shown in FIG. 3 where it will cut through the tape closely adjacent the surface of the applicating roller 30. When the dispenser is raised the tape is tensioned between the application surface and the applicating roller 30 and easily cut by the knife to make a good butt joint at the joining ends of the tape strip completing the circular pattern.
The adjustable set screw 21 permits the dispenser 10 to be positioned perpendicular to the surface of the rim 11 upon which the strip is to be applied and the adjustment of the cross arm 22 with respect to the support arm 16 permits the exact positioning of the dispensing applicating roller 30 to maintain its path around the rim 11 by rotation of the dispenser and arm with respect to the axis of the wheel. The guide rollers 25 are formed to guide the cross arm around the outer edge of the felly of the wheel 12 or may engage an inner edge of the wheel 12, depending on the position of the surface 11 to which the strip is to be applied. The device can suitably be used to apply a strip to wheel covers as well as to the rim of the wheel.
Certain changes may be made in the construction of the dispenser of the present invention, but, all such modifications are contemplated as come within the scope of the appended claims.
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A dispenser for a decorative tape to apply the same in a circular pattern and a fixture connected to the dispenser to guide the same along a circular path. The fixture comprising a rod pivotally connected to the dispenser on an axis perpendicular to the tape applicating roller and having a cross arm adjustable to the rod with guide rollers at each end thereof to define the circular pattern.
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This is a division of application Ser. No. 753,767 filed Dec. 23, 1976, now U.S. Pat. No. 4,076,510.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the coating of filamentary articles. In particular continuous filaments are uniformly and concentrically coated.
2. Description of the Prior Art
In the field of optical glass fibers, it is desirable to coat a continuous glass fiber filament with a coating material in order to protect and strengthen the filament. In the prior art such continuous glass fiber filaments are coated by the extrusion of plastic as set forth in U.S. Pat. No. 3,960,530, which issued to R. Iyengar on June 1, 1976. That patent discloses a closed vertical cylinder charged with plastic coating material. The cylinder has a die aperture in the lower end thereof and an axial core tube terminating in the die aperture to form an annular orifice, the plastic being liquified to pass through the die orifice. The glass fiber filament is drawn from a source of molten glass coaxial with the core tube, continuously through the core tube. Pressurized gas is introduced into the upper portion of the cylinder to force the liquified plastic through the annular orifice and onto the filament as it leaves the axial core tube.
Such extrusion application of the plastic coating induces undesirable stresses in the coating material as it passes through the die orifice and, in addition, the drawing speed of the glass fiber filament is limited due to the relatively slow application speed of the extrusion process.
SUMMARY OF THE INVENTION
The instant invention overcomes the foregoing problems with a method and apparatus for uniformly and concentrically distributing flowable material on a continuous filament by forming a vortex of the material and drawing the filament through the center of the vortex, in contact with the material, to uniformly and concentrically distribute the material thereon.
The vortex of flowable material is formed by drawing the filament through a material distributor means comprised of an open-ended cage having the geometry of a hyperboloid of rotation.
The filament does not make physical contact with the distributor means, but only contacts the flowable material. Advantageously, this precludes undesirable scraping or abrading of the filament.
Also, by using an open ended cage having the shape of a hyperboloid of rotation to distribute the previously applied material, a vortex is formed which centers the filament in the throat portion of the cage. Also, by using a cage there is substantially no back pressure at the throat portion resulting in substantially no stress being applied to the coating material.
Furthermore, the open ended cage has a variable throat diameter which, advantageously, can accommodate a wide range of filament thicknesses and can control the thickness of the flowable material applied thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a coating material being applied to a filament in accordance with the instant invention;
FIG. 2 is a partial view of the filament passing through a rotating body of the coating material;
FIG. 3 is a side view of the rotating body of coating material with the filament being drawn therethrough in the direction of rotation of the material;
FIG. 4 depicts a filament being drawn through the rotating material and through an open ended material distribution cage to distribute the material on the filament;
FIG. 5 is a cross-sectional view of the open ended distribution cage mounted within a housing;
FIG. 6 is an isometric view of the distribution cage;
FIG. 7 is an isometric view of the distribution cage wherein one end has been rotated to form a hyperbolic cross section;
FIG. 8 is a cross-sectional view through the throat of the distribution cage in a plane perpendicular to the axis thereof;
FIG. 9 is an isometric view of a modified distribution cage;
FIG. 10 is an isometric view of a modified distribution cage housing; and
FIG. 11 is a cross-sectional view of the instant material applicator.
DETAILED DESCRIPTION
The instant invention is related to a method and apparatus for distributing a flowable material on a filament and is herein described in relation to the application of a protective coating of material to a glass fiber filament. However, it should be understood that such description is exemplary only and is for the purposes of exposition and not for purposes of limitation. It will be readily appreciated that the inventive concept as described is equally applicable for applying and distributing flowable material to any filament such as metallic wire, string, yarn, or the like.
The instant coating apparatus is generally designated by the numeral 10 in FIG. 1. A laser 11 or any other kind of heat source such as resistance or induction furnace is used to melt a portion of a glass preform 12 and a continuous glass fiber filament 13 is then drawn from the melt zone onto a rotatable take-up reel 14. The filament 13 passes through a substantially planar rotating body of flowable material 16 which is formed by an applicator, generally designated by the numeral 17.
The applicator 17 is comprised of a rotatable conical member 18 having an apex 19 in juxtaposition to a planar plate 26. The flowable material 16 is fed into the volume bounded by the surface of the plate 26 and the rotatable conical member 18 through a conduit 27. The apex 19 projects slightly into, but does not make contact with the end of the conduit 27, as can best be seen in the enlarged partial cross-sectional view of FIG. 11. The rotatable conical member 18 is rotated under the control of a variable speed motor 28 via a shaft 29.
In operation, the motor 28 is activated to rotate the conical member 18 as the flowable material 16 is introduced between the conical member and the plate 26, via the conduit 27, to fill the volume therebetween. As the conical member 18 rotates, the viscous force of the flowable material 16, balanced with the centrifugal and gravitational forces, holds the flowable material between the conical member and the plate 26. For a small angle between the surface of the conical member 18 and the plate 26, of 3 degrees or less, the rotating body of flowable material 16 is substantially planar in shape and in a specific embodiment has been operated in a vertical plane. Although the vertical positioning of the flowable material 16 has been found to be most advantageous it is contemplated that any plane including the horizontal may be used depending upon the particular application.
Once the flowable material 16 has been rotated to form the substantially planar body of material the laser 11 is activated and directed at the optical glass preform 12 is form a melt zone from which the optical fiber filament 13 is drawn. The glass fiber filament 13 passes through the substantially planar body of flowable material 16 without making contact with either the plate 26 or the rotatable conical member 18 as can best be seen in the enlarged partial plan view of FIG. 2.
FIG. 3 depicts a cross-sectional view in elevation of the rotating body of flowable material 16 with arrows indicating the direction of movement of the material. The filament 13 is shown passing through the flowable material 16 in the same direction as the movement of the material. Advantageously, this permits application of the material 16 to the filament 13 at high drawing speeds since the material can be made to move at substantially the same velocity as the filament. This was not possible using the prior art extrusion techniques.
In a particular working embodiment of the instant invention, the glass fiber filament 13 was an optical fiber having a diameter ranging from approximately 70 to 200 micrometers and the coating applied was approximately 50-100 micrometers thick.
The material 16 used was a "hot melt" plastic which is raised to its melting temperature prior to being fed to the applicator 17 via the conduit 27. The use of such "hot melt" plastics may require that the conduit 27 and/or the plate 26 be heated during operation. In particular, the "hot melt" plastic used was Ethylene-Vinyl Acetate (EVA) having a melting temperature of 180° C. and a viscosity in the neighborhood of 150 poise. Once the material 16 has been applied to the filament 13, it becomes hardened as it travels between the applicator 17 and the take-up reel 14 due to cooling of the material to ambient temperature.
The plate 26 was circular in shape with a diameter of 10 centimeters and made of aluminum. The surface of the conical member 18 formed an angle of 3 degrees with the plate 26 and was rotated at a tangential velocity of approximately 0.2 meters per second as the optical fiber filament 13 was drawn at a speed of approximately 0.75 meters per second for the EVA material. The viscosity level of the coating material used is one of the governing factors determining the maximum drawing speed.
FIG. 4 depicts the coating apparatus 10 shown in FIG. 1 with the addition of distribution apparatus 41 and a curing apparatus 42 positioned in tandem with the applicator 17.
It should be noted that although the applicator 17 advantageously applies the coating material 16 to glass fiber filament 13, the coating may be non-uniform in thickness. Thus, the purpose of the distribution apparatus 41 is to uniformly and concentrically distribute the flowable material 16 which was previously applied to the glass fiber filament 13. Although FIG. 4 depicts an embodiment in which the flowable material 16 was applied by the applicator 17, such apparatus is not required. Any apparatus which can apply the flowable material 16 such as that shown in the above-referred to Iyengar patent or the like may be used. All that is required is that the flowable material 16 be, in some fashion, applied to the fiber 13 prior to passing through the distribution apparatus 41.
The distribution apparatus 41 schematically shown in FIG. 4 is shown in detail in FIGS. 5, 6 and 7. FIG. 5 is a cross-sectional view of the distribution apparatus 41 fully assembled and which comprises a cylindrical housing 43 having a distribution cage 44 therein which can best be seen in FIGS. 6 and 7. The cylindrical housing 43 has upper and lower shoulders 46 and 47, respectively. The upper shoulder 46 has a plurality of upwardly projecting spring biased pins 48--48.
The distribution cage 44 is comprised of a first circular plate 49, having a first central aperture 50, which is spaced from and aligned with a second circular plate 51 having a second central aperture 52. Both plates 49 and 51 have a plurality of holes 53--53 arranged in a circular array about the first and second central apertures 50 and 52, respectively. A strand 54 is threaded through the holes 53--53 of the plates 49 and 51 to form the distribution cage 44 connected by substantially parallel sections of the filament 54 as can best be seen in FIG. 6. The filament 54 may be fine wire, nylon or the like having a melting point above the melting point of the flowable material 16.
The distribution cage 44 is shown assembled within the cylindrical housing 43 in FIG. 5. The second cylindrical plate 51 is seated in the lower shoulder 47 of the housing 43 and is held fixedly in place by a set screw 61. A downwardly extending section 62 of the first circular plate 49 is seated within the upper shoulder 46 on the spring biased pins 48--48.
Prior to the distribution operation, the first circular plate 49 is rotated using a pair of outwardly extending arms 63--63 as shown in FIG. 7. As the first circular plate 49 is rotated, it simultaneously moves downward, urging the spring biased pins 48--48 down into the cylindrical housing 43. As the first circular plate 49 is rotated the normally parallel filaments 54--54 (see FIG. 6) now become skewed as shown in FIG. 7 forming a hyperboloid of rotation with a throat 64 (see FIG. 8) that can be varied as a function of the angular rotation of the first circular plate 49. Once the desired diameter of the throat 64 has been obtained the first circular plate 49 is maintained in the position with the spring biased pins 48--48 which are held in place by the frictional contact between the plate and the pins. Accordingly, the throat 64 can be varied to accommodate a wide variety of filament diameters by rotating the first circular plate 49 to provide the desired diameter in the throat. Additionally, by varying the diameter of the throat 64 the thickness of the coating material 16 on the fiber 13 can be controlled. The wider the diameter of the throat 64 the thicker the coating will be.
FIGS. 9 and 10 depict a modified distribution cage 44' and distribution apparatus 41', respectively. The distribution cage 44' has a first radial slot 66 formed in the first circular plate 49 and is aligned with a second radial slot 67 formed in the second circular plate 51 when in the unoperated position. FIG. 10 shows the distribution apparatus 41' assembled within a modified cylindrical housing 43' having a longitudinal opening 71 therein. Prior to the rotation of the first circular plate 49 as hereinbefore described, the first and second slots 66 and 67 are aligned with the longitudinal opening 71 to provide radial access for the continuous optical fiber filament 13 to the central portion of the distribution cage 44'.
In operation, as can best be seen in FIG. 4, once the flowable material 16 has been applied by the applicator 17 (or other applying means) to the optical fiber filament 13, the filament is drawn through the distribution apparatus 41. The coated filament 13 is threaded axially through the central apertures 50 and 52 when using the distribution cage 44 depicted in FIG. 6 or the filament may be inserted radially through the slots 66 and 67 and the aligned longitudinal opening 71 when using the distribution apparatus 41' shown in FIG. 10.
As the optical fiber filament 13 is drawn through the distribution apparatus 41 the flowable material 16 on the filament 13 contacts the sections of skewed strand sections 54--54 which tends to move the material in a spiral direction, along the path of the filaments (see FIG. 8) forming a vortex of the flowable material terminating at the throat 64 of the cage 44. As the filament 13 is pulled through this vortex, it is automatically centered within the throat 64 of the distribution cage 44 by the movement of the flowing material 16 causing the material to be uniformly distributed to concentrically coat the filament 13. Additionally, by forming the throat 64 with a plurality of strand sections 54--54 there is substantially no back pressure at the throat, resulting in a stress-free coating.
Once the filament has been uniformly and concentrically coated with the flowable material 16 it is wound about take-up reel 14. The curing apparatus 42 is used to cure the flowable material 16 coating the filament 13 prior to take-up when curing is required.
The material 16 can be a material having a low enough viscosity to flow into the volume between the plate 26 and the rotatable conical member 18 and sufficiently high viscosity to be held within that volume as the rotatable conical member is rotated. An example of such a material which can be used at normal room temperatures would be any curable materials such as a resin or epoxy which is flowable at room temperatures. Such materials generally require use of the curing apparatus 42 to cure the material prior to being rolled onto the take-up reel 14. Such curing may be accomplished by heat curing (i.e., infra-red or the like) or by polymerization (i.e., ultra-violet or the like) depending on the selection of materials.
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A glass fiber is drawn through a rotating body of flowable coating material to apply the material thereon and then is further drawn through a throat section of an open ended cage formed by a plurality of wire strands forming a hyperboloid of rotation. As the glass fiber is drawn through the throat section the previously applied flowable material contacts the wire strands causing a vortex of material which centers the fiber in the throat and distributes the material uniformly and concentrically thereon.
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BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to a system for controlling pollution. More particularly, the present invention relates to a system that systematically controls a PCV valve assembly that recycles engine fuel by-products, reduces emissions and improves engine performance.
[0002] The basic operation of standard internal combustion (IC) engines vary somewhat based on the type of combustion process, the quantity of cylinders and the desired use/functionality. For instance, in a traditional two-stroke engine, oil is pre-mixed with fuel and air before entry into the crankcase. The oil/fuel/air mixture is drawn into the crankcase by a vacuum created by the piston during intake. The oil/fuel mixture provides lubrication for the cylinder walls, crankshaft and connecting rod bearings in the crankcase. The fuel is then compressed and ignited by a spark plug that causes the fuel to burn. The piston is then pushed downwardly and the exhaust fumes are allowed to exit the cylinder when the piston exposes the exhaust port. The movement of the piston pressurizes the remaining oil/fuel in the crankcase and allows additional fresh oil/fuel/air to rush into the cylinder, thereby simultaneously pushing the remaining exhaust out the exhaust port. Momentum drives the piston back into the compression stroke as the process repeats itself. Alternatively, in a four-stroke engine, oil lubrication of the crankshaft and connecting rod bearings is separate from the fuel/air mixture. Here, the crankcase is filled mainly with air and oil. It is the intake manifold that receives and mixes fuel and air from separate sources. The fuel/air mixture in the intake manifold is drawn into the combustion chamber where it is ignited by the spark plugs and burned. The combustion chamber is largely sealed off from the crankcase by a set of piston rings that are disposed around an outer diameter of the pistons within the piston cylinder. This keeps the oil in the crankcase rather than allowing it to burn as part of the combustion stroke, as in a two-stroke engine. Unfortunately, the piston rings are unable to completely seal off the piston cylinder. Consequently, crankcase oil intended to lubricate the cylinder is, instead, drawn into the combustion chamber and burned during the combustion process. Additionally, combustion waste gases comprising unburned fuel and exhaust gases in the cylinder simultaneously pass the piston rings and enter the crankcase. The waste gas entering the crankcase is commonly called “blow-by” or “blow-by gas”.
[0003] Blow-by gases mainly consist of contaminants such as hydrocarbons (unburned fuel), carbon dioxide or water vapor, all of which are harmful to the engine crankcase. The quantity of blow-by gas in the crankcase can be several times that of the concentration of hydrocarbons in the intake manifold. Simply venting these gases to the atmosphere increases air pollution. Although, trapping the blow-by gases in the crankcase allows the contaminants to condense out of air and accumulate therein over time. Condensed contaminants form corrosive acids and sludge in the interior of the crankcase that dilutes the lubricating oil. This decreases the ability of the oil to lubricate the cylinder and crankshaft. Degraded oil that fails to properly lubricate the crankcase components (e.g. the crankshaft and connecting rods) can be a factor in poor engine performance. Inadequate crankcase lubrication contributes to unnecessary wear on the piston rings which simultaneously reduces the quality of the seal between the combustion chamber and the crankcase. As the engine ages, the gaps between the piston rings and cylinder walls increase resulting in larger quantities of blow-by gases entering the crankcase. Too much blow-by gases entering the crankcase can cause power loss and even engine failure. Moreover, condensed water in the blow-by gases can cause engine parts to rust. Hence, crankcase ventilation systems were developed to remedy the existence of blow-by gases in the crankcase. In general, crankcase ventilation systems expel blow-by gases out of a positive crankcase ventilation (PCV) valve and into the intake manifold to be reburned.
[0004] PCV valves recirculate (i.e. vent) blow-by gases from the crankcase back into the intake manifold to be burned again with a fresh supply of air/fuel during combustion. This is particularly desirable as the harmful blow-by gases are not simply vented to the atmosphere. A crankcase ventilation system should also be designed to limit, or ideally eliminate, blow-by gas in the crankcase to keep the crankcase as clean as possible. Early PCV valves comprised simple one-way check valves. These PCV valves relied solely on pressure differentials between the crankcase and intake manifold to function correctly. When a piston travels downward during intake, the air pressure in the intake manifold becomes lower than the surrounding ambient atmosphere. This result is commonly called “engine vacuum”. The vacuum draws air toward the intake manifold. Accordingly, air is capable of being drawn from the crankcase and into the intake manifold through a PCV valve that provides a conduit therebetween. The PCV valve basically opens a one-way path for blow-by gases to vent from the crankcase back into the intake manifold. In the event the pressure difference changes (i.e. the pressure in the intake manifold becomes relatively higher than the pressure in the crankcase), the PCV valve closes and prevents gases from exiting the intake manifold and entering the crankcase. Hence, the PCV valve is a “positive” crankcase ventilation system, wherein gases are only allowed to flow in one direction—out from the crankcase and into the intake manifold. The one-way check valve is basically an all-or-nothing valve. That is, the valve is completely open during periods when the pressure in the intake manifold is relatively less than the pressure in the crankcase. Alternatively, the valve is completely closed when the pressure in the crankcase is relatively lower than the pressure in the intake manifold. One-way check valve-based PCV valves are unable to account for changes in the quantity of blow-by gases that exist in the crankcase at any given time. The quantity of blow-by gases in the crankcase varies under different driving conditions and by engine make and model.
[0005] PCV valve designs have been improved over the basic one-way check valve and can better regulate the quantity of blow-by gases vented from the crankcase to the intake manifold. One PCV valve design uses a spring to position an internal restrictor, such as a cone or disk, relative to a vent through which the blow-by gases flow from the crankcase to the intake manifold. The internal restrictor is positioned proximate to the vent at a distance proportionate to the level of engine vacuum relative to spring tension. The purpose of the spring is to respond to vacuum pressure variations between the crankcase and intake manifold. This design is intended to improve on the all-or-nothing one-way check valve. For example, at idle, engine vacuum is high. The spring-biased restrictor is set to vent a large quantity of blow-by gases in view of the large pressure differential, even though the engine is producing a relatively small quantity of blow-by gases. The spring positions the internal restrictor to substantially allow air flow from the crankcase to the intake manifold. During acceleration, the engine vacuum decreases due to an increase in engine load. Consequently, the spring is able to push the internal restrictor back down to reduce the air flow from the crankcase to the intake manifold, even though the engine is producing more blow-by gases. Vacuum pressure then increases as the acceleration decreases (i.e. engine load decreases) as the vehicle moves toward a constant cruising speed. Again, the spring draws the internal restrictor back away from the vent to a position that substantially allows air flow from the crankcase to the intake manifold. In this situation, it is desirable to increase air flow from the crankcase to the intake manifold, based on the pressure differential, because the engine creates more blow-by gases at cruising speeds due to higher engine RPMs. Hence, such an improved PCV valve that solely relies on engine vacuum and a spring-biased restrictor does not optimize the ventilation of blow-by gases from the crankcase to the intake manifold, especially in situations where the vehicle is constantly changing speeds (e.g. city driving or stop and go highway traffic).
[0006] One key aspect of crankcase ventilation is that engine vacuum varies as a function of engine load, rather than engine speed, and the quantity of blow-by gases varies, in part, as a function of engine speed, rather than engine load. For example, engine vacuum is higher when engine speeds remain relatively constant (e.g. idling or driving at a constant velocity). Thus, the amount of engine vacuum present when an engine is idling (at say 900 rotations per minute (rpm)) is essentially the same as the amount of vacuum present when the engine is cruising at a constant speed on a highway (for example between 2,500 to 2,800 rpm). The rate at which blow-by gases are produced is much higher at 2,500 rpm than at 900 rpm. But, a spring-based PCV valve is unable to account for the difference in blow-by gas production between 2,500 rpm and 900 rpm because the spring-based PCV valve experiences a similar pressure differential between the intake manifold and the crankcase at these different engine speeds. The spring is only responsive to changes in air pressure, which is a function of engine load rather than engine speed. Engine load typically increases when accelerating or when climbing a hill, for example. As the vehicle accelerates, blow-by gas production increases, but the engine vacuum decreases due to the increased engine load. Thus, the spring-based PCV valve may vent an inadequate quantity of blow-by gases from the crankcase during acceleration. Such a spring-based PCV valve system is incapable of venting blow-by gases based on blow-by gas production because the spring is only responsive to engine vacuum.
[0007] U.S. Pat. No. 5,228,424 to Collins, the contents of which are herein incorporated by reference, is an example of a two-stage spring-based PCV valve that regulates the ventilation of blow-by gases from the crankcase to the intake manifold. Specifically, Collins discloses a PCV valve having two disks therein to regulate air flow between the crankcase and the intake manifold. The first disk has a set of apertures therein and is disposed between a vent and the second disk. The second disk is sized to cover the apertures in the first disk. When little or no vacuum is present, the second disk is held against the first disk, resulting in both disks being held against the vent. The net result is that little air flow is permitted through the PCV valve. Increased engine vacuum pushes the disks against a spring and away from the vent, thereby allowing more blow-by gases to flow from the crankcase, through the PCV valve and back into the intake manifold. The mere presence of engine vacuum causes at least the second disk to move away from and therefore vent blow-by gases from the engine crankcase. The first disk in particular typically substantially covers the vent whenever the throttle position indicates that the engine is operating at a low, constant speed (e.g. idling). Upon vehicle acceleration, the first disk may move away from the vent thereby venting more blow-by gases when the throttle position indicates the engine is accelerating or operating at a constant yet higher speed. The positioning of the first disk is based mostly on throttle position and the positioning of the second disk is based mostly on vacuum pressure between the intake manifold and crankcase. But, blow-by gas production is not based solely on vacuum pressure, throttle position, or a combination. Instead, blow-by gas production is based on a plurality of different factors, including engine load. Hence, the Collin's PCV valve also inadequately vents blow-by gases from the crankcase to the intake manifold when the engine load varies at similar throttle positions.
[0008] Maintenance of a PCV valve system is important and relatively simple. The lubricating oil must be changed periodically to remove the harmful contaminants trapped therein over time. Failure to change the lubricating oil at adequate intervals (typically every 3,000 to 6,000 miles) can lead to a PCV valve system contaminated with sludge. A plugged PCV valve system will eventually damage the engine. The PCV valve system should remain clear for the life of the engine assuming the lubricating oil is changed at an adequate frequency.
[0009] As part of an effort to combat smog in the Los Angeles basin, California started requiring emission control systems on all model cars starting in the 1960's. The Federal Government extended these emission control regulations nationwide in 1968. Congress passed the Clear Air Act in 1970 and established the Environmental Protection Agency (EPA). Since then, vehicle manufacturers have had to meet a series of graduated emission control standards for the production and maintenance of vehicles. This involved implementing devices to control engine functions and diagnose engine problems. More specifically, automobile manufacturers started integrating electrically controlled components, such as electric fuel feeds and ignition systems. Sensors were also added to measure engine efficiency, system performance and pollution. These sensors were capable of being accessed for early diagnostic assistance.
[0010] On-Board Diagnostics (OBD) refers to early vehicle self-diagnostic systems and reporting capabilities. OBD systems provide current state information for various vehicle subsystems. The quantity of diagnostic information available via OBD has varied widely since the introduction of on-board computers to automobiles in the early 1980's. OBD originally illuminated a malfunction indicator light (MIL) for a detected problem, but did not provide information regarding the nature of the problem. Modern OBD implementations use a standardized fast digital communications port to provide real-time data in combination with standardized series of diagnostic trouble codes (DTCs) to establish rapid identification of malfunctions and the corresponding remedy from within the vehicle.
[0011] The California Air Resources Board (CARB or simply ARB) developed regulations to enforce the application of the first incarnation of OBD (known now as “OBD-I”). The aim of CARB was to encourage automobile manufacturers to design reliable emission control systems. CARB envisioned lowering vehicle emissions in California by denying registration of vehicles that did not pass the CARB vehicle emission standards. Unfortunately, OBD-I did not succeed at the time as the infrastructure for testing and reporting emissions-specific diagnostic information was not standardized or widely accepted. Technical difficulties in obtaining standardized and reliable emission information from all vehicles led to an inability to effectively implement an annual testing program.
[0012] OBD became more sophisticated after the initial implementation of OBD-I. OBD-II was a new standard introduced in the mid 1990's that implemented a new set of standards and practices developed by the Society of Automotive Engineers (SAE). These standards were eventually adopted by the EPA and CARB. OBD-II incorporates enhanced features that provide better engine monitoring technologies. OBD-II also monitors chassis parts, body and accessory devices, and includes an automobile diagnostic control network. OBD-II improved upon OBD-I in both capability and standardization. OBD-II specifies the type of diagnostic connector, pin configuration, electrical signaling protocols, messaging format and provides an extensible list of DTCs. OBD-II also monitors a specific list of vehicle parameters and encodes performance data for each of those parameters. Thus, a single device can query the on-board computer(s) in any vehicle. This simplification of reporting diagnostic data led to the feasibility of the comprehensive emissions testing program envisioned by CARB.
[0013] Thus, there exists a significant need for an improved PCV valve system that optimally regulates the flow of engine blow-by gases from the crankcase to the intake manifold. Such a pollution control device should include an electrically controllable PCV valve capable of regulating air flow from the crankcase to the intake manifold, a controller electrically coupled to the PCV valve for regulating the PCV valve, and a set of sensors for measuring engine performance such as engine speed and engine load. Such a pollution control device should decrease the rate of fuel consumption, should decrease the rate of harmful pollutant emissions, and should increase engine performance. The present invention fulfills these needs and provides further related advantages.
SUMMARY OF THE INVENTION
[0014] The pollution control system disclosed herein includes a controller coupled to a sensor monitoring an operational characteristic of a combustion engine. The sensor may include an engine temperature sensor, a spark plug sensor, an accelerometer sensor, a PCV valve sensor or an exhaust sensor. In one embodiment, the controller monitors engine combustion rate via the engine temperature sensor to gauge the quantity of blow-by gas product. The controller may include a wireless transmitter or a wireless receiver for sending and/or receiving data associated with the information collected by the sensors. In this regard, the controller may include a pre-programmed software program, a flash-updatable software program, or a behavior-learning software program. In a preferred embodiment, the software program operating the controller is accessible wirelessly through the transmitter and/or the receiver. Information such as customized operating conditions developed by the behavior-learning software program may be retrieved from the controller and subsequently used to more efficiently operate the pollution control system.
[0015] The pollution control system further includes a PCV valve having an inlet and an outlet adapted to vent blow-by gas out from a combustion engine. Preferably, the PCV valve is a two-stage check valve. A fluid regulator associated with the PCV valve and responsive to the controller is used in the pollution control system to selectively modulate engine vacuum pressure to adjustably increase or decrease the fluid flow rate of blow-by gas venting from the combustion engine. The controller adjustably positions the fluid regulator to vary the degree of engine vacuum based, in part, on measurements taken from one or more of the aforementioned sensors. In a preferred embodiment, the PCV valve inlet connects to a crankcase and the PCV valve outlet connects to an intake manifold of an internal combustion engine. The controller decreases the engine vacuum pressure during periods of decreased blow-by gas production in the internal combustion engine, thereby decreasing the fluid flow rate through the PCV valve, and increases the engine vacuum pressure during periods of increased blow-by gas production in the internal combustion engine, thereby increasing the fluid flow rate through the PCV valve.
[0016] The controller may activate and/or deactivate the fluid regulator under any one of a plurality of different conditions. For instance, the controller activates and/or deactivates the fluid regulator at an engine frequency (e.g. a resonant frequency) or a set of engine frequencies. Alternatively, the controller may further couple to an engine RPM sensor having a window switch. The fluid regulator is selectively positionable based on a predetermined engine RPM or multiple engine RPMs set by the window switch. In another alternative embodiment, the controller may include an on-delay timer that sets the fluid regulator to preclude fluid flow for a predetermined duration after activation of the combustion engine. The predetermined duration the fluid regulator precludes fluid flow may be a function of time, engine temperature or engine RPM.
[0017] In another alternative embodiment, the pollution control system may further include a supplemental fuel fluidly coupled to the PCV valve and to the air flow regulator. A one-way check valve electronically coupled to the controller selectively modulates release of the supplemental fuel to the PCV valve and the fluid regulator. The supplemental fuel may include a compressed natural gas (CNG) or a hydrogen gas. Preferably, the hydrogen gas is made on-demand by a hydrogen generator coupled to and regulated by the controller. The controller increases hydrogen gas production with increased vacuum pressure and the corresponding increase in fluid flow rate, and decreases hydrogen gas production with decreased vacuum pressure and the corresponding decrease in fluid flow rate. Modulation of the vacuum pressure and the fluid flow rate may be based on measurements from combustion engine operational characteristics that might include engine temperature, a quantity of engine cylinders, a real-time acceleration calculation, or engine RPM.
[0018] Other features and advantages of the present invention will become apparent from the following more detailed description, when taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings illustrate the invention. In such drawings:
[0020] FIG. 1 is a schematic illustrating a controller operationally coupled to numerous sensors and a PCV valve;
[0021] FIG. 2 is a schematic illustrating the general functionality of the PCV valve with a combustion-based engine;
[0022] FIG. 3 is a perspective view of a PCV valve for use with the pollution control system;
[0023] FIG. 4 is an exploded perspective view of the PCV valve of FIG. 3 ;
[0024] FIG. 5 is a partially exploded perspective view of the PCV valve, illustrating assembly of an air flow restrictor;
[0025] FIG. 6 is a partially exploded perspective view of the PCV valve, illustrating partial depression of the air flow restrictor;
[0026] FIG. 7 is a cross-sectional view of the PCV valve, illustrating no air flow;
[0027] FIG. 8 is a cross-sectional view of the PCV valve, illustrating restricted air flow; and
[0028] FIG. 9 is another cross-sectional view of the PCV valve, illustrating full air flow.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] As shown in the drawings for purposes of illustration, the present invention for a pollution control system is referred to generally by the reference number 10 . In FIG. 1 , the pollution control system 10 is generally illustrated as having a controller 12 preferably mounted under a hood 14 of an automobile 16 . The controller 12 is electrically coupled to any one of a plurality of sensors that monitor and measure the real-time operating conditions and performance of the automobile 16 . The controller 12 regulates the flow rate of blow-by gases by regulating the engine vacuum in a combustion engine through digital control of a PCV valve 18 and a flow control orifice 19 . The controller 12 receives real-time input from sensors that might include an engine temperature sensor 20 , a spark plug sensor 22 , a battery sensor 24 , a flow control sensor 25 , a PCV valve sensor 26 , an engine RPM sensor 28 , an accelerometer sensor 30 , an exhaust sensor 32 , and a gas/vapor injection sensor 33 . Data obtained from the sensors 20 , 22 , 24 , 25 , 26 , 28 , 30 , 32 , 33 by the controller 12 is used to regulate the PCV valve 18 and the flow control orifice 19 , as described in more detail below.
[0030] FIG. 2 is a schematic illustrating operation of the PCV valve 18 and the flow control orifice 19 within the pollution control system 10 . As shown in FIG. 2 , the PCV valve 18 is disposed between a crankcase 34 , of an engine 36 , and an intake manifold 38 . In operation, the intake manifold 38 receives a mixture of fuel and air via a fuel line 40 and an air line 42 , respectively. An air filter 44 may be disposed between the air line 42 and an air intake line 46 to filter fresh air entering the pollution control system 10 , before mixing with fuel in the intake manifold 38 . The air/fuel mixture in the intake manifold 38 is delivered to a piston cylinder 48 as a piston 50 descends downward within the cylinder 48 from the top dead center. This creates a vacuum within a combustion chamber 52 . Accordingly, an input camshaft 54 rotating at half the speed of the crankshaft 34 is designed to open an input valve 56 thereby subjecting the intake manifold 38 to the engine vacuum. Thus, fuel/air is drawn into the combustion chamber 52 from the intake manifold 38 .
[0031] The fuel/air in the combustion chamber 52 is ignited by a spark plug 58 . The rapid expansion of the ignited fuel/air in the combustion chamber 52 causes depression of the piston 50 within the cylinder 48 . After combustion, an exhaust camshaft 60 opens an exhaust valve 62 to allow escape of the combustion gases from the combustion chamber 52 out an exhaust line 64 . Typically, during the combustion cycle, excess exhaust gases slip by a pair of piston rings 66 mounted in a head 68 of the piston 50 . These “blow-by gases” enter the crankcase 34 as high pressure and temperature gases. Over time, harmful exhaust gases such as hydrocarbons, carbon monoxide, nitrous oxide and carbon dioxide can condense out from a gaseous state and coat the interior of the crankcase 34 and mix with the oil 70 that lubricates the mechanics within the crankcase 34 . But, the pollution control system 10 is designed to vent these blow-by gases from the crankcase 34 to the intake manifold 38 to be recycled as fuel for the engine 36 . This is accomplished by using the pressure differential between the crankcase 34 and intake manifold 38 . In operation, the blow-by gases exit the relatively higher pressure crankcase 34 through a vent 72 and travel through a vent line 74 , the PCV valve 18 , a return line 76 , the flow control orifice 19 , and finally through an auxiliary return line 76 ′ and into the relatively lower pressure intake manifold 38 coupled thereto. Accordingly, the quantity of blow-by gases vented from the crankcase 34 to the intake manifold 38 via the PCV valve 18 and the flow control orifice 19 is digitally regulated by the controller 12 shown in FIG. 1 .
[0032] The PCV valve 18 in FIG. 3 is generally electrically coupled to the controller 12 via a pair of electrical connections 78 . The controller 12 at least partly regulates the quantity of blow-by gases flowing through the PCV valve 18 via the electrical connections 78 . In FIG. 3 , the PCV valve 18 includes a rubber housing 80 that encompasses a portion of a rigid outer housing 82 . The connector wires 78 extend out from the outer housing 82 via an aperture therein (not shown). Preferably, the outer housing 82 is unitary and comprises an intake orifice 84 and an exhaust orifice 86 . In general, the controller 12 operates a restrictor internal to the outer housing 82 for regulating the rate of blow-by gases entering the intake orifice 84 and exiting the exhaust orifice 86 .
[0033] FIG. 4 illustrates the PCV valve 18 in an exploded perspective view. The rubber housing 80 covers an end cap 88 that substantially seals to the outer housing 82 thereby encasing a solenoid mechanism 90 and an air flow restrictor 92 . The solenoid mechanism 90 includes a plunger 94 disposed within a solenoid 96 . The connector wires 78 operate the solenoid 96 and extend through the end cap 88 through an aperture 98 therein. Similarly, the rubber housing 80 includes an aperture (not shown) to allow the connector wires 78 to be electrically coupled to the controller 12 ( FIG. 2 ).
[0034] In general, engine vacuum present in the intake manifold 38 ( FIG. 2 ) causes blow-by gases to be drawn from the crankcase 34 , through the intake orifice 84 and out the exhaust orifice 86 in the PCV valve 18 ( FIG. 4 ). The air flow restrictor 92 shown in FIG. 4 is one mechanism that regulates the quantity of blow-by gases that vent from the crankcase 34 to the intake manifold 38 . Regulating blow-by gas air flow rate is particularly advantageous as the pollution control system 10 is capable of increasing the rate blow-by gases vent from the crankcase 34 during times of higher blow-by gas production and decreasing the rate blow-by gases vent from the crankcase 34 during times of lower blow-by gas production, as described in more detail below. The controller 12 is coupled to the plurality of sensors 20 , 22 , 24 , 25 , 26 , 28 , 30 , 32 , 33 to monitor the overall efficiency and operation of the automobile 16 and operates the PCV valve 18 in real-time to maximize recycling of blow-by gases according to the measurements taken by the sensors 20 , 22 , 24 , 25 , 26 , 28 , 30 , 32 , 33 .
[0035] The operational characteristics and production of blow-by is unique for each engine and each automobile in which individual engines are installed. The pollution control system 10 is capable of being installed in the factory or post production to maximize automobile fuel efficiency, reduce harmful exhaust emissions, recycle oil and other gas and eliminate contaminants within the crankcase. The purpose of the pollution control system 10 is to strategically vent the blow-by gases from the crankcase 34 into the intake manifold 38 based on blow-by gas production. Accordingly, the controller 12 digitally regulates and controls the PCV valve 18 and the flow control orifice 19 based on engine speed and other operating characteristics and real-time measurements taken by the sensors 20 , 22 , 24 , 25 , 26 , 28 , 30 , 32 , 33 . Importantly, the pollution control system 10 is adaptable to any internal combustion engine. For example, the pollution control system 10 may be used with gasoline, methanol, diesel, ethanol, compressed natural gas (CNG), liquid propane gas (LPG), hydrogen, alcohol-based engines, or virtually any other combustible gas and/or vapor-based engine. This includes both two and four stroke IC engines and all light, medium and heavy duty configurations. The pollution control system 10 may also be integrated into immobile engines used to produce energy or used for industrial purposes.
[0036] In particular, venting blow-by gases based on engine speed and other operating characteristics of an automobile decreases the quantity of hydrocarbons, carbon monoxide, nitrogen oxide and carbon dioxide emissions. The pollution control system 10 recycles these gases by burning them in the combustion cycle. No longer are large quantities of the contaminants expelled from the vehicle via the exhaust. Hence, the pollution control system 10 is capable of reducing air pollution by forty to fifty percent for each automobile, increasing gas mileage per gallon by twenty to thirty percent, increasing horsepower performance by twenty to thirty percent, reducing automobile engine wear by thirty to fifty percent (due to low carbon retention therein) and reducing the number of oil changes from approximately every 5,000 miles to approximately every 50,000 miles. Considering that the United States consumes approximately 870 million gallons of petroleum a day, a fifteen percent reduction through the recycling of blow-by gases with the pollution control system 10 translates into a savings of approximately 130 million gallons of petroleum a day in the United States alone. Worldwide, nearly 3.3 billion gallons of petroleum are consumed per day, which would result in approximately 500 billion gallons of petroleum saved every day.
[0037] In one embodiment, the quantity of blow-by gases entering the intake orifice 84 of the PCV valve 18 is regulated by the air flow restrictor 92 as generally shown in FIG. 4 . The air flow restrictor 92 includes a rod 100 having a rear portion 102 , an intermediate portion 104 and a front portion 106 . The front portion 106 has a diameter slightly less than the rear portion 102 and the intermediate portion 104 . A front spring 108 is disposed concentrically over the intermediate portion 104 and the front portion 106 , including over a front surface 110 of the rod 100 . The front spring 108 is preferably a coil spring that decreases in diameter from the intake orifice 84 toward the front surface 110 . An indented collar 112 separates the rear portion 102 from the intermediate portion 104 and provides a point where a rear snap ring 114 may attach to the rod 100 . The diameter of the front spring 108 should be approximately or slightly less than the diameter of the rear snap ring 114 . The rear snap ring 114 engages the front spring 108 on one side and a rear spring 116 on the other side. Like the front spring 108 , the rear spring 116 tapers from a wider diameter near the solenoid 96 to a diameter approximately the size of or slightly smaller than the diameter of the rear snap ring 114 . The rear spring 116 is preferably a coil spring and is wedged between a front surface 118 of the solenoid 96 and the rear snap ring 114 . The front portion 106 also includes an indented collar 120 providing a point of attachment for a front snap ring 122 . The diameter of the front snap ring 122 is smaller than that of the tapered front spring 108 . The front snap ring 122 fixedly retains a front disk 124 on the front portion 106 of the rod 100 . Accordingly, the front disk 124 is fixedly wedged between the front snap ring 122 and the front surface 110 . The front disk 124 has an inner diameter configured to slidably engage the front portion 106 of the rod 100 . The front spring 108 is sized to engage a rear disk 126 as described below.
[0038] The disks 124 , 126 govern the quantity of blow-by gases entering the intake orifice 84 and exiting the exhaust orifice 86 . FIGS. 5 and 6 illustrate the air flow restrictor 92 assembled to the solenoid mechanism 90 and external to the rubber housing 80 and the outer housing 82 . Accordingly, the plunger 94 fits within a rear portion of the solenoid 96 as shown therein. The connector wires 78 are coupled to the solenoid 96 and govern the position of the plunger 94 within the solenoid 96 by regulating the current delivered to the solenoid 96 . Increasing or decreasing the electrical current through the solenoid 96 correspondingly increases or decreases the magnetic field produced therein. The magnetized plunger 94 responds to the change in magnetic field by sliding into or out from within the solenoid 96 . Increasing the electrical current delivered to the solenoid 96 through the connector wires 78 increases the magnetic field in the solenoid 96 and causes the magnetized plunger 94 to depress further within the solenoid 96 . Conversely, reducing the electrical current supplied to the solenoid 96 via the connector wires 78 reduces the magnetic field therein and causes the magnetized plunger 94 to slide out from within the interior of the solenoid 96 . As will be shown in more detail herein, the positioning of the plunger 94 within the solenoid 96 at least partially determines the quantity of blow-by gases that may enter the intake orifice 84 at any given time. This is accomplished by the interaction of the plunger 94 with the rod 100 and the corresponding front disk 124 secured thereto.
[0039] FIG. 5 specifically illustrates the air flow restrictor 92 in a closed position. The rear portion 102 of the rod 100 has an outer diameter approximately the size of the inner diameter of an extension 128 of the solenoid 96 . Accordingly, the rod 100 can slide within the extension 128 and the solenoid 96 . The position of the rod 100 in the outer housing 82 depends upon the positioning of the plunger 94 due to the engagement of the rear portion 106 with the plunger 94 as shown more specifically in FIGS. 7-9 . As shown in FIG. 5 , the rear spring 116 is compressed between the front surface 118 of the extension 128 and the rear snap ring 114 . Similarly, the front spring 108 is compressed between the rear snap spring 114 and the rear disk 126 . As better shown in FIGS. 7-9 , the front disk 124 includes an extension 130 having a diameter less than that of a foot 132 . The foot 132 of the rear disk 126 is approximately the diameter of the tapered front spring 108 . In this manner, the front spring 108 fits over an extension 130 of the rear disk 126 to engage the planar surface of the diametrically larger foot 132 thereof. The inside diameter of the rear disk 126 is approximately the size of the external diameter of the intermediate portion 104 of the rod 100 . This allows the rear disk 126 to slide thereon. The front disk 124 has an inner diameter approximately the size of the outer diameter of the front portion 106 of the rod 100 , which is smaller in diameter than either the intermediate portion 104 or the rear portion 102 . In this regard, the front disk 124 locks in place on the front portion 106 of the rod 100 between the front surface 110 and the front snap ring 122 . Accordingly, the position of the front disk 124 is dependent upon the position of the rod 100 as coupled to the plunger 94 . The plunger 94 slides into or out from within the solenoid 96 depending on the amount of current delivered by the connecting wires 78 , as described above.
[0040] FIG. 6 illustrates the PCV valve 18 wherein increased vacuum created between the crankcase 34 and the intake manifold 38 causes the rear disk 126 to retract away from the intake orifice 84 thereby allowing air to flow therethrough. In this situation the engine vacuum pressure exerted upon the disk 126 must overcome the opposite force exerted by the front spring 108 . Here, small quantities of blow-by gases may pass through the PCV valve 18 through a pair of apertures 134 in the front disk 124 .
[0041] FIGS. 7-9 more specifically illustrate the functionality of the PCV valve 18 in accordance with the pollution control system 10 . FIG. 7 illustrates the PCV valve 18 in a closed position. Here, no blow-by gas may enter the intake orifice 84 . As shown, the front disk 124 is flush against a flange 136 defined in the intake orifice 84 . The diameter of the foot 132 of the rear disk 126 extends over and encompasses the apertures 134 in the front disk 124 to prevent any air flow through the intake orifice 84 . In this position, the plunger 94 is disposed within the solenoid 96 thereby pressing rod 100 toward the intake orifice 84 . The rear spring 116 is thereby compressed between the front surface 118 of the solenoid 96 and the rear snap ring 114 . Likewise, the front spring 108 compresses between the rear snap ring 114 and the foot 132 of the rear disk 126 .
[0042] FIG. 8 is an embodiment illustrating a condition wherein the vacuum pressure exerted by the intake manifold relative to the crankcase is greater than the pressure exerted by the front spring 108 to position the rear disk 126 flush against the front disk 124 . In this case, the rear disk 126 is able to slide along the outer diameter of the rod 100 thereby opening the apertures 134 in the front disk 124 . Limited quantities of blow-by gases are allowed to enter the PCV valve 18 through the intake orifice 84 as noted by the directional arrows therein. Of course, the blow-by gases exit the PCV valve 18 through the exhaust orifice 86 . In the position shown in FIG. 8 , blow-by gas air flow is still restricted as the front disk 124 remains seated against the flanges 136 . Thus, only limited air flow is possible through the apertures 134 . Increasing the engine vacuum consequently increases the air pressure exerted against the rear disk 126 . Accordingly, the front spring 108 is further compressed such that the rear disk 126 continues to move away from the front disk 124 thereby creating a larger air flow path to allow escape of the additional blow-by gases. Moreover, the plunger 94 in the solenoid 96 may position the rod 100 within the PCV valve 18 to exert more or less pressure on the springs 108 , 116 to restrict or permit air flow through the intake orifice 84 , as determined by the controller 12 .
[0043] FIG. 9 illustrates another condition wherein additional air flow is permitted to flow through the intake orifice 84 by retracting the plunger 94 out from within the solenoid 96 by altering the electric current through the connector wires 78 . Reducing the electrical current flowing through the solenoid 96 reduces the corresponding magnetic field generated therein and allows the magnetic plunger 94 to retract. Accordingly, the rod 100 retracts away from the intake orifice 84 with the plunger 94 . This allows the front disk 124 to unseat from the flanges 136 thereby allowing additional air flow to enter the intake orifice 84 around the outer diameter of the front disk 124 . Of course, the increase in air flow through the intake orifice 84 and out through the exhaust orifice 86 allows increased venting of blow-by gases from the crankcase to the intake manifold. In one embodiment, the plunger 94 allows the rod 100 to retract all the way out from within the outer housing 82 such that the front disk 124 and the rear disk 126 no longer restrict air flow through the intake orifice 84 and out through the exhaust orifice 86 . This is particularly desirable at high engine RPMs and high engine loads, where increased amounts of blow-by gases are produced by the engine. Of course, the springs 108 , 116 may be rated differently according to the specific automobile with which the PCV valve 18 is to be incorporated in a pollution control system 10 .
[0044] In another aspect of the pollution control system 10 , the flow control orifice 19 , as shown in FIG. 2 , is disposed between the PCV valve 18 and the intake manifold 38 . The flow control orifice 19 regulates the quantity of air flow through the return line 76 during engine operation and may be used with any of the embodiments described herein. Specifically, a set screw 138 resides in a line block 140 disposed between the PCV valve 18 and the intake manifold 38 . The set screw 138 and the line block 140 are designed to regulate the vacuum pressure between the crankcase 34 and the intake manifold 38 . Increasing and/or decreasing the vacuum pressure with the flow control orifice 19 affects the rate blow-by gases vent from the crankcase 34 to the intake manifold 38 . For example, blow-by gases exiting the PCV valve 18 through the exhaust orifice 86 enter into the return line 76 . The return line 76 is pressure sealed to the line block 140 . As shown by the directional arrow in FIG. 2 , the set screw 138 may screw into or out from the line block 140 . The set screw 138 is used in this manner to regulate air flow through the line block 140 . The purpose of the set screw 138 is to function as an air flow restrictor between the return line 76 and the auxiliary return line 76 ′. Inserting the set screw 138 into the line block 140 restricts air flow between the return line 76 and the auxiliary return line 76 ′. Accordingly, the set screw 138 builds up back pressure in the return line 76 that counters the engine vacuum. Thus, the quantity of blow-by gases vented from the crankcase 34 into the vent line 74 and into the PCV valve 18 decreases. When the pollution control system 10 endeavors to increase the quantity of blow-by gases vented from the crankcase 34 into the intake manifold 38 , the controller 12 retracts the set screw 138 out from within the line block 140 to decrease the back pressure on the engine vacuum. This allows the passage of more blow-by gases from the return line 76 to the auxiliary return line 76 ′. The set screw 138 is digitally electrically controllable by the controller 12 and the positioning of the set screw 138 may be dependent on measurements taken by the controller 12 via any one of the sensors 20 , 22 , 24 , 25 , 26 , 28 , 30 , 32 , 33 or any other data received or calculated by the controller 12 .
[0045] The set screw 138 includes a plurality of threads 142 that engage a similar set of threads (not shown) in the line block 140 . An electronic system coupled to the set screw 138 may screw or unscrew the set screw 138 within the line block 140 according to the instructions provided by the controller 12 . A person of ordinary skill in the art will readily recognize that there may be many mechanical and/or electrical mechanisms known in the art capable of regulating the air flow between the return line 76 and the auxiliary return line 76 ′ in the same manner as the set screw 138 coupled to the line block 140 . In general, any mechanism capable of regulating air flow between the intake manifold 38 and the crankcase 34 comparable to the flow control orifice 19 is capable of being substituted for the set screw 138 and the line block 140 .
[0046] As described above with respect to FIGS. 1-2 , the controller 12 governs the air flow rate between the return line 76 and the auxiliary return line 76 ′ with the set screw 138 and governs the air flow rate through the PCV valve 18 with the plunger 94 . These features work together to govern the vacuum pressure within the pollution control system 10 and consequently govern the rate of air flow between the crankcase 34 and the intake manifold 38 . The controller 12 may include one of or more electronic circuits such as switches, timers, interval timers, timers with relay or other vehicle control modules known in the art. The controller 12 operates the PCV valve 18 and/or the flow control orifice 19 in response to the operation of one or more of these control modules. For example, the controller 12 could include an RWS window switch module provided by Baker Electronix of Beckley, W. Va. The RWS module is an electric switch that activates above a pre-selected engine RPM and deactivates above a higher pre-selected engine RPM. The RWS module is considered a “window switch” because the output is activated during a window of RPMs. The RWS module could work, for example, in conjunction with the engine RPM sensor 28 to modulate the air flow rate of blow-by gases vented from the crankcase 34 .
[0047] Preferably, the RWS module works with a standard coil signal used by most tachometers when setting the position of the set screw 138 in the flow control orifice 19 or setting the position of the plunger 94 within the solenoid 96 . An automobile tachometer is a device that measures real-time engine RPMs. In one embodiment, the RWS module may activate the flow control orifice 19 to position the set screw 138 to block air flow from the return line 76 to the auxiliary return line 76 ′. Here, the PCV valve 18 does not vent any blow-by gas from the crankcase 34 to the intake manifold 38 . In another embodiment, the RWS module may activate the plunger 94 within the solenoid 96 at low engine RPMs, when blow-by gas production is minimal. Here, the plunger 94 pushes the rod 100 toward the intake orifice 84 such that the front disk 124 seats against the flanges 136 as generally shown in FIG. 7 . In this regard, the PCV valve 18 vents small amounts of blow-by gases from the crankcase to the intake manifold via the apertures 134 in the front disk 124 even though engine vacuum is high. The high engine vacuum forces blow-by gases through the apertures 134 thereby forcing the rear disk 126 away from the front disk 124 , compressing the front spring 108 . At idle, the RWS module activates the solenoid 96 to prevent the front disk 124 from unseating from the flanges 136 , thereby preventing large quantities of air from flowing between the engine crankcase and the intake manifold. This is particularly desirable at low RPMs as the quantity of blow-by gas produced within the engine is relatively low even though the engine vacuum is relatively high. Obviously, the controller 12 can regulate the PCV valve 18 and the flow control orifice 19 simultaneously to achieve the desired vacuum pressure in the pollution control system 10 to set the air flow rate of blow-by gases vented from the crankcase 34 .
[0048] Blow-by gas production increases during acceleration, during increased engine load and with higher engine RPMs. Accordingly, the RWS module may activate the flow control orifice 19 to partially or completely remove the set screw 138 out from within the line block 140 . This effectively increases the air flow rate from the crankcase 34 to the intake manifold 38 due to the higher engine vacuum therein. Moreover, the RWS module may turn off or reduce the electric current going to the solenoid 96 such that the plunger 94 retracts out from within the solenoid 96 thereby unseating the front disk 124 from the flanges 136 ( FIG. 9 ) and allowing greater quantities of blow-by gas to vent from the crankcase 34 to the intake manifold 38 . These functionalities may occur at a selected RPM or within a given range of selected RPMs pre-programmed into the RWS module. The RWS module may reactivate when the automobile eclipses another pre-selected RPM, such as a higher RPM, thereby re-inserting the set screw 138 within the line block 140 or re-engaging the plunger 94 within the solenoid 96 .
[0049] In an alternative embodiment, a variation of the RWS module may be used to selectively step the set screw 138 out from or into the line block 140 depending on the desired air flow rate from the crankcase 34 to the intake manifold 38 . In this embodiment, the set screw 138 may be disposed twenty-five percent, fifty percent or seventy-five percent within the line block 140 to selectively partially obstruct air flow between the return line 76 and the auxiliary return line 76 ′. Alternatively, the RWS module may be used to selectively step the plunger 94 out from within the solenoid 96 . For example, the current delivered to the solenoid 96 may initially cause the plunger 94 to engage the front disk 124 with the flanges 136 of the intake orifice 84 at 900 rpm. At 1700 rpm the RWS module may activate a first stage wherein the current delivered to the solenoid 96 is reduced by one-half. In this case, the plunger 94 retracts halfway out from within the solenoid 96 thereby partially opening the intake orifice 84 to blow-by gas flow. When the engine RPMs reach 2,500, for example, the RWS module may eliminate the current going to the solenoid 96 such that the plunger 94 retracts completely out from within the solenoid 96 to fully open the intake orifice 84 . In this position, it is particularly preferred that the front disk 124 and the rear disk 126 no longer restrict air flow between the intake orifice 84 and the exhaust orifice 86 . The stages may be regulated by engine RPM or other parameters and calculations made by the controller 12 and based on readings from the sensors 20 , 22 , 24 , 25 , 26 , 28 , 30 , 32 , 33 .
[0050] The controller 12 can be pre-programmed, programmed after installation or otherwise updated or flashed to meet specific automobile or on-board diagnostics (OBD) specifications. In one embodiment, the controller 12 is equipped with self-learning software such that the switch (in the case of the RWS module) adapts to optimally position the set screw 138 within the line block 140 and also adapts to the best time to activate or deactivate the solenoid 96 , or step the location of the plunger 94 in the solenoid 96 , to optimally increase fuel efficiency and reduce air pollution. In a particularly preferred embodiment, the controller 12 optimizes the venting of blow-by gases based on real-time measurements taken by the sensors 20 , 22 , 24 , 25 , 26 , 28 , 30 , 32 , 33 . For example, the controller 12 may determine that the automobile 16 is expelling increased amounts of harmful exhaust via feedback from the exhaust sensor 32 . In this case, the controller 12 may remove the set screw 138 from the line block 140 or activate withdrawal of the plunger 94 from within the solenoid 96 to vent additional blow-by gases from within the crankcase to reduce the quantity of pollutants expelled through the exhaust of the automobile 16 as measured by the exhaust sensor 32 .
[0051] In another embodiment, the controller 12 is equipped with an LED that flashes to indicate power and that the controller 12 is waiting to receive engine speed pulses. The LED may also be used to gauge whether the controller 12 is functioning correctly. The LED flashes until the automobile reaches a specified RPM at which point the controller 12 changes the positioning of the set screw 138 or the current delivered to the solenoid 96 via the connector wires 78 . In a particularly preferred embodiment, the controller 12 maintains the position of the set screw 138 or the amount of current delivered to the solenoid 96 until the engine RPMs fall ten-percent lower than the activation point. This mechanism is called hysteresis. Hysteresis is implemented into the pollution control system 10 to eliminate on/off pulsing, otherwise known as chattering, when engine RPMs jump above or below the set point in a relatively short time period. Hysteresis may also be implemented into the electronically based step system described above.
[0052] The controller 12 may also be equipped with an On Delay timer, such as the KH1 Analog Series On Delay timer manufactured by Instrumentation & Control Systems, Inc. of Addison, Ill. A delay timer is particularly preferred for use during initial start up. At low engine RPMs little blow-by gases are produced. Accordingly, a delay timer may be integrated into the controller 12 to delay activation of the set screw 138 or the solenoid 96 and corresponding plunger 94 . Preferably, the delay timer ensures that the air flow between the return line 76 and the auxiliary return line 76 ′ remains completely blocked at start-up by disposing the set screw 138 all the way within the interior of the line block 140 of the flow control orifice 19 . Additionally, such an on-delay timer may, after opening the flow control orifice 19 , ensure that the plunger 94 remains fully inserted within the solenoid 96 such that the front disk 124 remains flush against the flanges 136 thereby limiting the quantity of blow-by gas air flow entering the intake orifice 84 . The delay timer may be set to activate release of either one of the disks 124 , 126 from the intake orifice 84 after a predetermined duration (e.g. one minute). Alternatively, the delay timer may be set by the controller 12 as a function of engine temperature, measured by the engine temperature sensor 20 , engine RPMs, measured by either the engine RPM sensor 28 or the accelerometer sensor 30 , or from measurements received from the spark plug sensor 22 , the battery sensor 24 or the exhaust sensor 32 . The delay may include a variable range depending on any of the aforementioned readings. The variable timer may also be integrated with the RWS switch.
[0053] In another alternative embodiment, the controller 12 may automatically sense the number and type of cylinders in the engine via the spark plug sensor 22 . In this embodiment, the spark plug sensor 22 measures the delay between spark plug firings among the spark plugs in the engine. A four-cylinder engine has a different sequence of spark plug firings than a six-cylinder, eight-cylinder or twelve-cylinder engine, for example. The controller 12 can use this information to automatically adjust the PCV valve 18 or the flow control orifice 19 . Having the capability of sensing the quantity of valves in an automobile engine allows the controller 12 to be automatically installed to the automobile 16 with minimal user intervention. In this regard, the controller 12 does not need to be programmed. Instead, the controller 12 automatically senses the quantity of valves via the spark plug sensor 22 and operates the PCV valve 18 or the flow control orifice 19 according to a program stored in the internal circuitry of the controller 12 designed for the sensed engine.
[0054] The controller 12 preferably mounts to the interior of the hood 14 of the automobile 16 as shown in FIG. 1 . The controller 12 may be packaged with an installation kit to enable a user to attach the controller 12 as shown. Electrically, the controller 12 is powered by any suitable twelve volt circuit breaker. A kit having the controller 12 may include an adapter wherein one twelve volt circuit breaker may be removed from the circuit panel and replaced with an adapter (not shown) having multiple connections, one for the original circuit and at least a second for connection to the controller 12 . The controller 12 includes a set of electrical wires (not shown) that connect one-way to the connector wires 78 of the PCV valve 18 so a user installing the pollution control system 10 cannot cross the wires between the controller 12 and the PCV valve 18 . The controller 12 may also be accessed wirelessly via a remote control or hand-held unit to access or download real-time calculations and measurements, stored data or other information read, stored or calculated by the controller 12 .
[0055] In another aspect of the pollution control system 10 , the controller 12 regulates the PCV valve 18 or the flow control orifice 19 based on engine operating frequency. For instance, the controller 12 may activate or deactivate the plunger 94 as the engine passes through a resonant frequency. Alternatively, the controller 12 may selectively position the set screw 138 in the line block 140 based on sensed engine frequencies. In a preferred embodiment, the controller 12 blocks all air flow from the crankcase 34 to the intake manifold 38 until after the engine passes through the resonant frequency. This can be accomplished by positioning the set screw 138 all the way within the line block 140 thereby blocking air flow from the return line 76 to the auxiliary return line 76 ′. The controller 12 can also be programmed to regulate the PCV valve 18 or the flow control orifice 19 based on sensed frequencies of the engine at various operating conditions, as described above.
[0056] Moreover, the pollution control system 10 is usable with a wide variety of engines, including unleaded and diesel automobile engines. The pollution control system 10 may also be used with larger stationary engines or used with boats or other heavy machinery. The pollution control system 10 may include one or more controllers 12 , one or more PCV valves 18 and/or one or more flow control orifices 19 in combination with a plurality of sensors measuring the performance of the engine or vehicle. The use of the pollution control system 10 in association with an automobile, as described in detail above, is merely a preferred embodiment. Of course, the pollution control system 10 has application across a wide variety of disciplines that employ combustible materials having exhaust gas production that could be recycled and reused.
[0057] In another aspect of the pollution control system 10 , the controller 12 may modulate control of the PCV valve 18 and the flow control orifice 19 . The primary functionality of the flow control orifice 19 is to control the amount of engine vacuum between the crankcase 34 and the intake manifold 38 . The positioning of the set screw 138 within the line block 140 largely dictates the air flow rate of blow-by gases traveling from the crankcase 34 to the intake manifold 38 . In some systems, the flow control orifice 19 may simply be an aperture through which selected air flow is configured such that the system does not fall below a certain force according to the original equipment manufacturer (OEM). In the event that the controller 12 fails, the pollution control system 10 defaults back to OEM settings wherein the PCV valve 18 functions as a two-stage check valve. A particularly preferred aspect of the pollution control system 10 is the compatibility with current and future OBD standards through inclusion of a flash-updatable controller 12 . Moreover, operation of the pollution control system 10 does not affect the operational conditions of current OBD and OBD-II systems. The controller 12 may be accessed and queried according to standard OBD protocols and flash-updates may modify the bios so the controller 12 remains compatible with future OBD standards. Preferably, the controller 12 operates the PCV valve 18 in conjunction with the flow control orifice 19 to regulate the engine vacuum between the crankcase 34 and the intake manifold 38 , thereby governing the air flow rate therebetween to optimally vent blow-by gas within the system 10 .
[0058] In another aspect of the pollution control system 10 , a gas/fuel vapor source 144 ( FIG. 2 ) may couple to the vent line 74 by a check valve 146 . The controller 12 regulates the vapor source 144 and the check valve 146 . The vapor source 144 preferably includes a source of hydrogen that is selectively injected into the vent line 74 for return back into the intake manifold 38 to supply additional fuel for combustion within the engine 36 . Accordingly, the controller 12 selectively operates the check valve 146 to subject the vapor source 144 to the engine vacuum. The engine vacuum draws fuel from the vapor source 144 when the controller 12 opens the check valve 146 . The controller 12 may modulate the opening and/or closing of the check valve 146 depending on the operation of the pollution control system 10 and the feedback received from any of the plurality of sensors 20 , 22 , 24 , 25 , 26 , 28 , 30 , 32 , 33 . The vapor source 144 may include, for example, a source of compressed natural gas (CNG) or may include a hydrogen generator that creates hydrogen on-the-fly in proportion to the quantity desired to be supplied to the vent line 74 to optimally aid in the combustion of the blow-by gas and fuel mixed within the intake manifold 38 . For example, the hydrogen generator relies on electrical energy to produce hydrogen. At idle, the hydrogen demand may be low due to low engine RPMs and thereby the controller 12 sets the vapor source 144 to produce small quantities of hydrogen at a low voltage. At higher engine RPMs, it is desirable to increase the quantity of hydrogen supplied to the vent line 74 . The controller 12 may then increase production of hydrogen at the vapor source 144 by, e.g., increasing the voltage supplied therein. The quantity of fuel supplied through the check valve 146 via the vapor source 144 better optimizes the recycling and combustion of the blow-by gases within the engine 36 .
[0059] In another aspect of the pollution control system 10 , the controller 12 may modulate activation and/or deactivation of the operational components, as described in detail above, with respect to the PCV valve 18 , the flow control orifice 19 or the vapor source 144 . Such modulation is accomplished through, for example, the aforementioned RWS switch, on-delay timer or other electronic circuitry that digitally activates, deactivates or selectively intermediately positions the aforementioned control components. For example, the controller 12 may selectively activate the PCV valve 18 for a period of one to two minutes and then selectively deactivate the PCV valve 18 for ten minutes. These activation/deactivation sequences may be set according to pre-determined or learned sequences based on driving style, for example. Pre-programmed timing sequences may be changed through flash-updates of the controller 12 .
[0060] Although several embodiments have been described in some detail for purposes of illustration, various modifications may be made to each without departing from the scope and spirit of the invention. Accordingly, the invention is not to be limited, except as by the appended claims.
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The pollution control system includes a controller coupled to a sensor monitoring an operational characteristic of a combustion engine, such as engine RPM. A PCV valve having an inlet and an outlet is adapted to vent blow-by gas out from the combustion engine. A fluid regulator associated with the PCV valve and responsive to the controller selectively modulates engine vacuum pressure to adjustably increase or decrease a fluid flow rate of blow-by gas venting from the combustion engine. The controller selectively adjustably positions the fluid regulator to vary the degree of vacuum pressure to optimize the recycling of blow-by gases.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a power supply circuit of a television receiver used in an automobile, and in particular to a power supply circuit of a television receiver which enables two different voltages from two kinds of storage batteries for an automobile to be used in common.
2. Description of the Prior Art
Recently, it has become more popular than ever to watch TV in a car as the number of cars increases. In general, a storage battery of 12 volts is used in small cars while one of 24 volts is used in large cars so that there is a disadvantage that a separate power supply device is required for driving a TV set in compliance with the respective battery used in the car.
Accordingly, it is an object of the invention to provide a power supply circuit which outputs a constant voltage whether it is output from the storage battery of 12 volts or from that of 24 volts thereby effecting stable operation of a TV set.
SUMMARY OF THE INVENTION
In accordance with the invention, a power supply circuit of a TV receiver used in a car comprises a switching circuit which switches on a first constant voltage circuit in the case of a 12 volt storage battery and switches on a second constant voltage circuit in the case of a 24 volt storage battery, the output voltage of the said first constant voltage circuit driving a booster circuit simultaneously with the driving of a horizontal drive circuit to have the booster voltage therefrom applied to a horizontal output circuit and the output voltage from the said second constant voltage circuit driving the horizontal drive circuit and at the same time being applied to the horizontal output circuit as it is.
BRIEF DESCRIPTION OF THE DRAWING
The construction, operation and the effect of the invention will be described with reference to the accompanying drawing, wherein:
The sole drawing is a circuit diagram of the power supply circuit according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawing, the output terminal O 1 of a storage battery 1 is connected to the inputs of a switching circuit 2, comprising a Zener diode ZD 1 , resistors R 1 and R 2 and a transistor TR 1 ; a first constant voltage circuit 3 comprising a resistor R 3 , a capacitor C 1 , a Zener diode ZD 2 ; and a transistor TR 2 and of a second constant voltage circuit 4 comprising a resistor R 4 , a capacitor C 2 , a Zener diode ZD 3 , and a transistor TR 3 , respectively. The collector of transistor TR 1 which is the output side of the switching circuit 2 is connectected to the base of transistor TR 2 and the emitter of transistor TR 2 which is the output side of the first constant voltage circuit 3 is connected via diode D 2 to a center tap C of the primary coil of a high voltage transformer FBT. The emitter of transistor TR 3 which is the output side of the second constant voltage circuit 4 is connected through diode D 1 to a capacitor C 4 and to one terminal a of the primary coil of the transformer FBT to constitute the booster circuit 5. The output sides of the first and second constant voltage circuits 3 and 4 are respectively connected through diode D 3 and resistor R 5 to the horizontal oscillatory power supply terminal I 1 of the horizontal drive circuit 6 with the output thereof connected to the base of transistor TR 4 of a horizontal output circuit 7, and the other terminal b of the primary coil of the transformer FBT is connected to the collector of transistor TR 4 of the horizontal output circuit 7, a capacitor C 5 , diode D 4 and in common to a deflection yoke DY and a capacitor C 6 connected in series with each other. Further, one terminal d of the secondary coil of the transformer FBT is connected through diode D 5 to the high voltage input terminal 8 source and the other terminal e of the secondary coil is connected through a rectifying circuit formed of a diode D 6 and a capacitor C 7 , to the rectified power input terminal 9.
Assume here that the voltage output from the output terminal O 1 of the storage battery 1 is 12 volts (hereinafter called "a first voltage") or 24 volts (hereinafter called "a second voltage"), the Zener voltage from the Zener diodes ZD 1 and ZD 3 is set lower than the second voltage but higher than the first voltage and the Zener voltage from the Zener diode ZD 2 is set lower than the first voltage.
The operation of the power supply circuit of the invention will now be described in detail.
Assume that the output voltage from output terminal O 1 of the storage battery 1 is the second voltage. Since Zener voltage of the Zener diode ZD 1 is set lower than the second voltage, the Zener diode ZD 1 , is switched on to apply bias voltage to the transistor TR 1 and accordingly the transistor TR 1 is turned on with the collector voltage dropping to lower potential so that the transistor TR 2 of the constant voltage circuit 3 is turned off with the result that no voltage is output from the emitter of the transistor TR 2 . However, since the second voltage is applied via resistor R 4 of the second constant voltage circuit 4 to Zener diode ZD 3 and the Zener voltage from the Zener diode ZD 3 is set lower than the second voltage as described above, the Zener diode ZD 3 is on and the Zener voltage therefrom is applied to the base of the transistor TR 3 . Thus the transistor TR 3 is on and the emitter thereof outputs a constant voltage. The constant voltage output from the second constant voltage circuit 4 as described above is applied to the horizontal oscillatory power supply terminal I 1 through resistor R 5 , so the horizontal drive circuit 6 performs horizontal oscillation to output an oscillation signal to the transitor TR 4 of the horizontal output circuit 7.
The constant voltage output from the second constant voltge circuit 4 is also applied to the terminal a of the primary coil of the transformer FBT via diode D 1 and the first constant voltage circuit 3 does not operate, thus no voltage is applied to the center tap C of the primary coil of the transformer FBT so that there is no boosting action of the booster circuit 5.
Accordingly, as only the constant voltage applied to terminal a of the transformer FBT through diode D 1 is applied to the horizontal output circuit 7 via the primary coil of the transformer FBT, the transistor TR 4 of the horizontal output circuit 7 repeats on and off operations by the oscillatory signal output from the horizontal drive circuit 6 and the horizontal output circuit 7 normally operates.
Assuming that the voltage output from the output terminal O 1 of the storage battery 1 is the first voltage, the Zener diodes ZD 1 and ZD 3 are off to turn off the transistors TR 1 and TR 3 because the Zener voltages of Zener diodes ZD 1 and ZD 2 are set higher than the first voltage. Therefore, there is no output voltage from the second constant voltage circuit 4 but since the first voltage output from the output terminal O 1 of the storage battery is applied through resistor R 3 to the Zener diode ZD 2 and the Zener voltage of the Zener diode ZD 2 is set lower than the first voltage as described above, the Zener diode ZD 2 is on and the Zener voltage thereof is applied to the base of the transistor TR 2 .
Thus the transistor TR 2 is on and the emitter thereof which is the output side of the first constant voltage circuit 3, outputs a constant voltage. As the constant voltage from the circuit 3 is applied to the horizontal oscillatory power supply terminal I 1 of the horizontal drive circuit 6 through diode D 3 , the horizontal drive circuit 6 operates to output a oscillatory signal to the base of the horizontal output circuit 7. Moreover, since the constant voltage output from the first constant voltage circuit 3 is applied to the horizontal output circuit 7 via the coil between the center tap C and the other terminal b of the primary coil of the transformer FBT, the transistor TR 4 of the horizontal output circuit 7 repeats on and off operations.
However, when the transistor TR 4 of the horizontal output circuit 7 is in the off condition, the output voltage from the first constant voltage circuit 3 applied to the center tap c of the primary coil of the high voltage transformer FBT is charged through the coil between the center tap c of the primary coil and the terminal a of the transformer FBT to the capacitor C 4 and thereby operates the booster circuit 5 so that the booster voltage, which is by far higher than the voltage applied to the center tap c of the primary coil of the transformer FBT, is charged to the capacitor C 4 , and when the transistor TR 4 of the horizontal output circuit 7 is in the on condition, the booster voltage charged to the capacitor C 4 is discharged through the primary coil of the transformer to the horizontal output circuit 7 to render the transistor TR 4 conductive.
Since the booster voltage of the booster circuit 5 is determined by the number of turns of the coil between terminal a and the center tap c of the transformer FBT, the horizontal output circuit 7 operates in the same manner as when the voltage is output from the second constant voltage circuit 4, by adjusting the booster voltage to be the same as that output from the second constant voltage circuit 4 and applied to terminal a of the transformer FBT.
As described above, the voltage induced from the secondary coil of the transformer FBT is constant because the voltage applied across the primary coil of the transformer is constant regardless of the first or the second voltage, thus the voltage induced at one terminal of the secondary coil of the transformer FBT is applied through diode D 5 to the high voltage input terminal 8, and the voltage induced at the other terminal e of the secondary coil is rectified by a diode D 6 and a capacitor C 7 and then applied to the rectified voltage source input terminal 9 in a TV set.
As can be appreciated, in case the output voltage from the storage battery is the first voltage, the first voltage is boosted up to a constant voltage corresponding to the second voltage by the operation of the booster circuit and then applied to the horizontal output circuit through the primary coil of the high voltage transformer, and in case the output voltage from the storage battery is the second voltage, the second voltage which is constant is directly applied to the horizontal output circuit through the primary coil of the transformer without being boosted. Therefore, the horizontal output circuit is stably operative regardless of whether the first or the second voltage is present from the storage battery, and the voltage induced from the secondary coil of the high voltage transformer is also kept constant regardless of the voltage of the battery.
Consequently, the power supply circuit according to the invention makes it possible to drive a TV receiver used in a car stably whether the storage battery of 12 volts or that of 24 volts is used in the car. Moreover, the voltage induced from the secondary coil of the high voltage transformer may be used as a stable power source for other electric apparatus in a car.
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A power supply circuit for a television receiver used in an automobile having either a 12 volt or 24 volt storage battery. The power supply circuit outputs a constant voltage whether connected from a storage battery of 12 volts or 24 volts thereby effecting stable operation of a TV set. A first constant voltage source is activated by an input of 12 volts and the output therefrom is boosted by a booster voltage circuit. A switch means is activated by an input of 24 volts and functions to disable the first voltage source means. A second voltage source means is activated by an input of 24 volts and outputs a constant voltage directly to a horizontal output circuit.
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FIELD OF THE INVENTION
The present invention relates to a method for soldering, and more particularly to a fluxless soldering method which eliminates the need for post-soldering cleaning.
BACKGROUND OF THE INVENTION
In the area of electronic circuit fabrication, it is necessary to bring discrete devices into electrical contact. For example, integrated circuits (or "chips") are often mounted on printed wiring boards, or other such devices, which may be generally referred to as substrates. The contact between the chip and substrate must have physical, chemical and electrical integrity and stability.
One method for physically and electrically connecting microelectronic devices employs the fabrication of metal pads on the top or exposed surface of various substrates. These metal pads are often formed with a top layer of solder; i.e., a low melting point alloy, usually of the lead-tin type, used for joining metals at temperatures around 450° F. The solder pads are brought into contact with a metal structural element often referred to as a "metallurgy"--typically a metal pad--that will wet with liquid solder when heat is applied to join the solder and the metal pad and thereby form the electrical connection.
At present, most soldering processes comprise three basic steps: (1) pre-cleaning and deoxidation of surface oxides; (2) solder reflow and/or reflow joining; and (3) post-soldering cleaning. The pre-cleaning step is performed with different flux materials to prepare the surfaces for the soldering step by removal of contaminants and metal oxides from the solder surface. The solder joining step can occur only after the oxide coating is removed because the high melting point oxides will prevent the wetting of the two surfaces to be joined by reflow of the solder. Solder reflows into its characteristic spherical shape when heated, and joins the surfaces in contact with the solder. The third step, post-soldering cleaning, removes any flux residue remaining from the first step.
The post-soldering step has become more difficult to perform effectively as the size of electronic components shrink, making it much more difficult for the post-soldering cleaning agents to penetrate the smaller gaps between the components and the substrate. The post-soldering step becomes even more difficult when Surface Mount Technology (SMT) is employed.
Inefficient fluxing will result in defective bonding and inefficient post-soldering cleaning will reduce the long term reliability of the whole assembly. A high investment in cleaning equipment, materials, and processes can solve some of the problems, but undesired effects on the environment caused by cleaning solvents are generated.
A dry or fluxless soldering process can replace the pre-cleaning step and totally eliminate the post-soldering cleaning step. Since the main reason for using flux while reflowing solder joints is to break the high melting point and rigid oxide that covers the solder, a gas phase reaction that will remove this layer can replace the commonly used liquid fluxes that necessitate the post-soldering cleaning step.
Various attempts at fluxless soldering have been made; however, these attempts have suffered from limitations that made them applicable only to a small number and very specific applications.
For example, Moskowitz and Yeh in "Thermal Dry Process Soldering," J.VAC.SCI.TECHNOL.A, Vol. 4, No. 3, May/June 1986, describe a dry soldering process for solder reflow and bonding of Pb/Sn solder. This process uses halogen containing gases, CF 2 , CL 2 , CF 4 , and SF 6 for the reduction of the surface oxide to enable solder reflow at temperature above the solder melting point. The activation energy needed for the oxide reduction by these gases is lowered by the use of a catalyst (Pt mesh) in a vacuum chamber. Yet the temperature needed for successful reflow bonding is 350° C. This temperature is well above the typical soldering temperature for most electronic applications, i.e., 220° C., and can damage the components, the substrate, and generate defects due to thermal mismatch between different materials.
Another attempt at fluxless soldering is disclosed in IBM Technical Disclosure Bulletin Vol. 27, No. 11, April, 1985, entitled, "Dry Soldering Process Using Halogenated Gas." The IBM bulletin discloses the use of halogenated gases in an inert carrier gas at elevated temperature to produce a reduction of solder oxide by the reactive gas and to allow solder reflow. Again, for the more common low temperature applications, thermal damage may result. Moskowitz and Davidson in "Summary Abstract: Laser-Assisted Dry Process Soldering," J. VAC.SCI.TECHNOL.A., Vol. 3, No. 3, May/June, 1985, describe a laser-assisted fluxless soldering technique for solder reflow. This technique uses laser radiation to excite an otherwise non-reactive gas in the presence of pre-heated solder surface. This technique requires direct access of the laser radiation to the solder surface, thus limiting the applications as well as resulting in a low throughput process.
Other attempts to remove surface oxides have employed sputtering. The sputtering methods, however, are extremely inaccurate and can damage the substrates and components while removing oxides, and are very limited in penetration distances, making sputtering unsuitable to applications like solder reflow.
In summary, the use of high temperatures in the available fluxless soldering methods may often have deleterious effects on the printed circuit boards and the components being joined. Laser assisted soldering methods have also proven inadequate for commercial use, because laser beams do not penetrate to unexposed areas, and thus cannot be applied to solder joining. In addition, being based on a localized beam, it is a time consuming process.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved soldering process.
It is another object of the present invention to provide an improved fluxless soldering process.
It is yet another object of the present invention to provide a soldering process without the need for the post-soldering cleaning step.
It is yet another object of the present invention to provide a pre-soldering process for improved solder reflow.
It is yet another object of the present invention to provide an improved fluxless soldering reflow process without the need for laser or thermal excitation.
It is yet another object of the present invention to provide an improved fluxless soldering process which occurs at a low temperature.
It is still another object of the present invention to provide an improved removal of surface compounds such as oxides from the solder surface.
These and other objects of the present invention are accomplished by supplying the activation energy for the removal of the solder surface oxides through a plasma process. For example, in a plasma treatment using fluorinated gases (e.g., SF 6 , CF 4 , or other fluorinated gases), the tin oxide may be converted to tin fluoride. It has been found that tin fluoride does not prevent the wetting of the two surfaces to be joined during the solder reflow step as does tin oxide.
One or more surfaces to be joined by the solder can be coated with solder to aid in the wetting of the solder. The solder is then treated with a plasma-assisted reaction to form the tin fluoride, which may be stored and reflowed later in an inert atmosphere or vacuum. This method has the advantages of improved wetting of the surfaces to the solder without the need for a fluxing agent during the solder reflow, and/or reflow joining step.
According to the present invention, converting the tin oxide to tin fluoride through a plasma process occurs at a low temperature. Typically, the temperature is about 34° C. to 50° C. The plasma treatment time is short (i.e., approximately 1/2-3 minutes) and can occur at low or high pressures (i.e., 5 m Torr to 1 Torr). The solder reflow occurs in a non-oxidizing atmosphere. Preferably, the plasma treatment and reflow and/or reflow joining occur in an unbroken vacuum, to encourage the formation of higher quality solder wetting. A high throughput, reliable soldering process is thus provided, which does not damage the chip or substrate to be soldered.
DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention and the manner in which same are accomplished will be more completely understood with reference to the detailed description and to the drawings in which:
FIGS. 1A-E show a fluxless plasma pretreatment and solder reflow joining method of the invention.
FIGS. 2A-E show another fluxless plasma reflow joining method of the present invention.
FIGS. 3A-E show a fluxless plasma pretreatment and solder reflow method of the invention.
FIGS. 4A-E show another fluxless plasma reflow method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein; rather, applicants provide this embodiment so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
Like characters refer to like elements throughout. For greater clarity, the thickness of layers has been exaggerated.
FIGS. 1A-E and 2A-E show a fluxless plasma pretreatment and reflow joining of the present invention. FIGS. 3A-E and 4A-E show a fluxless plasma pretreatment and solder reflow of the present invention. Similar numbers represent similar elements.
Referring now to both FIGS. 1 and 3, in FIG. 1A, the first surface 10 to be soldered is shown. Surface 10 may be a substrate, for example, a printed circuit, SMT board, or surface 10 maybe another solder bump.
Referring now to FIG. 1B, solder 20 is deposited on the first surface 10. The solder 20 can be of any appropriate soldering material such as tin, lead tin, and lead-tin based alloys. Applicants used the eutectic 63% lead, 37% tin material (melting point 183° C.). Surface oxides 25 form on the exposed portion 40 of the solder 20 through exposure to oxygen in the ambient. The presence of surface oxides prevents the solder reflow or the wetting of the surfaces to be solder joined and must therefore be removed.
Referring now to FIG. 1C, the first surface 10 and solder 20 with surface oxides 25 are placed in a reaction chamber 30. Within the vacuum of the reaction chamber, the plasma solder treatment process is performed. The plasma excitation is of a fluorinated gas (i.e., SF 6 , CF 4 ). The plasma treatment may occur at room temperature (34°-50° C.). The plasma process is preferably very short in duration (i.e., 1/2-3 minutes). The treatment may occur in relatively high pressure (for example, 1 Torr) or low pressure (for example, 5 m Torr). Power level, gas flow, gas mixture and other typical plasma process conditions may vary according to the reactor configuration and the nature of the assembly to be treated.
Surface oxides prevent wetting of the surfaces to be soldered and must therefore be removed. Applicants believe that fluorinated gases will remove the surface oxides during the plasma process because of the higher electronegativity of fluorine or due to instability in the fluorine structure.
While applicants do not wish to be bound to a particular theory, it is believed that the activation energy needed for converting the oxides is supplied by excited fluorine radicals in the plasma which diffuse and hit the surface oxide 25, resulting in formation of a fluorine compound 45 on the solder surface. The fluorine plasma process is performed until the surface oxide 25 is substantially removed from the solder surface and a compound of the solder material 20 and fluorine forms on the solder surface.
Referring to FIG. 1D, the compound 45 formed during the plasma process is shown on the exposed surface 40 of solder bump 20. The plasma is a fluorinated gas (for example, SF 6 or CF 4 ), resulting in a tin fluoride compound 45. FIG. 1D illustrates the removal of the surface oxide layer 25 from the surface and the formation of a tin fluoride compound on the solder surface.
Referring now to FIG. 1E, in the first embodiment of the method of the present invention, the substrate and solder are removed from the plasma pretreatment reaction chamber 30. The solder is then reflowed in a non-oxidizing ambient to form either a solder bump 60 or to reflow and join the second 50 surfaces. Second surface 50 may be a component or another solder bump. The reflow or reflow joining conditions are the same typical conditions used with conventional wet flux methods. While applicants do not wish to be bound to a particular theory, it is believed that during reflow, the surface fluoride in the compound 45 either dissolves into the solder 20 or breaks up into colloidal-type particles. FIGS. 3A-E illustrate the same process except no joining of the solder to another object occurs; only solder reflow occurs.
Referring now to FIGS. 2A-E and 4A-E, a preferred embodiment of the present invention is shown. In this embodiment, reflow or reflow joining of the solder occurs in the vacuum of the reaction chamber 30 in a continuous mode with the plasma treatment, thereby creating a higher quality joint since exposure to the ambient is prevented. In FIG. 2A, a first substrate 10 is shown. As in FIG. 1B, FIG. 2B shows a first surface 10 having a solder 20 deposited thereon. Surface oxides 25 form on the exposed surface 40 of the solder 20. The oxides 25 prevent the solder reflow or the wetting by the solder of the two surfaces to be joined.
Referring now to FIG. 2C, the structure of FIG. 2B is placed within a reaction chamber 30 whereupon the same plasma process as described in connection with FIG. 1C is performed.
Referring now to FIG. 2D, the post-plasma treatment structure devoid of surface oxides is shown. Solder bump 20 now has a surface compound 45 consisting of solder and fluorine in such quantities sufficient to allow solder reflow or wetting of the solder bump 20 to a second surface to occur.
Referring now to FIG. 2E, in the continuous mode of operation, the solder bump 20 on the first surface 10 is reflowed or reflow joined to surface 50. The performance of the plasma treatment and reflow in a continuous mode within the reaction chamber creates a much higher quality solder surface because risk of reoxidation is eliminated by not exposing the solder surface to the ambient. FIGS. 4A-E illustrate the same process, except no joining of the solder to another object occurs; only solder reflow occurs.
In another alternative embodiment of this invention, the plasma process treatment and the reflow process may occur simultaneously and/or the second surface 50 may be brought in contact with the solder 20 during reflow. In yet another alternative embodiment of the invention, either or both of the surfaces 10 and 50 to be joined by the solder can be coated with a layer of the solder material or other known materials (i.e., gold) which improve the wetting of the solder to the surfaces to be joined. Both solder surfaces are then treated in a pressure-assisted reaction to form the tin fluoride and then reflowed with even higher bond integrity.
In another alternative embodiment of this invention, prior to the fluorine plasma treatment, an oxygen plasma treatment, as commonly known in the industry, can be performed. The oxygen plasma treatment will remove--by oxidation--any organic residue from the surface and eliminates any need for pre-solder cleaning. Organic residue can prevent complete removal of the surface oxides and replacement by fluorides through the fluorine plasma treatment. The oxygen plasma treatment occurs at similar conditions to the fluorine plasma treatment as described earlier. The oxygen plasma treatment may, however, occur at higher pressures. This step can replace the pre-soldering cleaning and will further improve solder reflow or wetting.
In the drawings and specification, there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.
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A method of soldering without the need for fluxing agents, high temperature, hydrogen, laser excitation or sputtering techniques. The method uses plasma excitation to remove surface oxides from solder surfaces, thereby eliminating the need for post-soldering cleaning in an accurate and efficient manner, resulting in a higher quality and long term reliability solder joint. In addition, serious environmental problems caused by cleaning solvents are avoided.
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FIELD OF THE INVENTION
The invention relates to devices that close the surgical wounds, especially the small wounds from laparoscopic surgery (laparoscopic trocar sites), incorporating various tissue layers except the skin in the closure.
BACKGROUND
Laparoscopic surgery (also known as key-hole surgery or minimally invasive surgery) utilizing small surgical incisions has become a widely popular procedure of choice for many diseases and conditions involving various organ systems in recent years, as it has been shown to provide decreased perioperative patient morbidity. Laparoscopic cholecystectomy (gall bladder removal), appendectomy (appendix removal), hysterectomy (uterus removal), and nephrectomy (kidney removal) are some of the examples. The laparoscopic surgical wounds, although small in size, generally require suture closure to prevent the formation of hernia, in which an intra-abdominal structure such as bowel protrudes through and can be entrapped at the wound site. The incidence of hernia at unclosed laparoscopic wound sites has been reported to be up to 5-6% in the medical literature, and these hernia cases have been often associated with bowel complications requiring reoperation. Even if there is no associated discomfort or bowel entrapment, hernias generally require surgical closure to minimize the risk of potential bowel emergency. Consequently, closure of the laparoscopic trocar wounds, especially those ≧10 mm in size, is generally recommended.
In the closure of the laparoscopic wound sites (from laparoscopic trocar puncture), it is important to close the fascial layer defect, which is located below the skin and subcutaneous fatty layer. The fascia provides most of the strength to the body wall and is the most important layer to close. Peritoneum (the inner most layer of abdominal wall and comes in direct contact with intra-abdominal structures such as bowel) is also important to close as there are reported cases of bowel hernia in obese patients after fascial closure alone. Incorporating the fascial layer and the peritoneal layer in the wound closure constitutes a full-thickness closure, which is the optimal method.
Small surgical wounds from laparoscopic trocar sites are typically closed via open surgical techniques (by directly identifying and hand suturing of the body tissue layers using the conventional open surgical instruments) or via certain medical devices such as Carter-Thomason Suture Passer/CloseSure Device (from Inlet Medical), various double-headed needle-tip suture threading and capture devices, and various single-headed needle-tip suture passing and capture devices (See U.S. Pat. Nos. 5,953,734, 5,496,335, 6,183,485, 7,320,693, 5,562,688, 5,281,234, 5,222,508, 5,503,634, 5,336,239, 5,507,755, 5,320,629, 5,281,237, 5,817,112, 5,499,991, 5,468,251, 5,439,469, 5,350,385, 5,403,328, 5,653,717, 5,387,227, 5,149,329, 5,433,722, 5,462,560, 5,374,275, 5,368,601, 5,320,632, 5,403,329, 5,458,609, 5,626,558, 5,507,757, 5,368,601, 6,500,184, 6,066,146, 5,085,661, 5,626,614, 5,041,129, 5,354,298, 6,488,691, 5,391,182 and published patent application number 20050043746A1, 20040249412A1, 20040087978A1). Open surgical closure is often difficult and time-consuming due to the small size of the incisional opening and the significant depth of the incision. The various medical devices for laparoscopic wound closure listed above were designed to reduce the efforts and closure time needed. Of these, Carter-Thomason system is the most popular. However, full thickness closure (incorporating different body wall layers including the peritoneum and fascial layer except the skin) in a timely manner is often unreliably or inconsistently achieved clinically. In addition, some of the devices may be expensive to manufacture. None of these clinically available devices describe or suggest the present invention. Furthermore, none of the wound closure devices patented previously yet not used clinically describe or suggest the present invention.
There is clearly a long-felt need for devices and methods that provide reliable full-thickness tissue closure at the small surgical wounds such as those in laparoscopic surgery. There is a need for such devices and methods to provide small surgical wound closure in a safe and fast manner. There is a need for such devices that are simple and inexpensive to manufacture, that are simple to use and robust in use, and that can be used with a variety of wound sizes, configurations, and depths. The present invention provides such devices and methods of using them.
Exemplary embodiments of the invention are described in detail by the figures and by the description below.
THE FIGURES
Like all preceding and following discussions, the first variation of the invention will be considered as synonymous with the “outside-in” variation, and the second variation of the invention will be considered as synonymous with the “inside-out” variation.
FIG. 1A illustrates the center piece of the first variation of the device (“outside-in” variation) showing the center piece body ( 1 ), its distal end ( 2 ) to be inserted into the wound site, its proximal end ( 3 ), its 2 ring-like wings ( 4 and 5 ), its wing portions with hollow space or lumen ( 6 and 7 ), and wing portions without lumen ( 8 and 9 ). The wings may be attached to the center piece body via mechanical (such as pivots, rods, joints, rubber or elastic flaps), electrical, electromagnetic, or other means, and a rod/pivot/hinge mechanical attachment mechanism ( 11 ) is illustrated in the present embodiment. The wings may move or rotate in relation to the center piece at the attachment site (see the 2 inset figures showing the directions of wing rotation indicated by the arrows). The 2 wings may move or rotate in a manner independent of each other. A rail or groove ( 10 ) may be present in some embodiments but absent in certain embodiments. Alternatively, guide or guides based on a protruding design (not shown) may be present in certain embodiments.
FIG. 1B illustrates the top view of the embodiment in FIG. 1A , showing the proximal end of the center piece ( 3 ), the wing portions without lumen ( 8 and 9 ), and a rod-pivot hinge mechanical joint between each wing and center piece body ( 11 ). A rail or groove ( 10 ) may be present in certain embodiments but absent in others.
FIG. 1C illustrates the center piece of the first variation of the device (“outside-in” variation) showing the center piece body ( 1 ), its distal end ( 2 ) to be inserted into the wound site, its proximal end ( 3 ), its 2 wings ( 4 and 5 ), its wing portions with hollow space or lumen ( 6 and 7 ), and wing portions without lumen ( 8 and 9 ). The wings may be attached to the center piece body via mechanical (such as pivots, rods, joints, rubber or elastic flaps), electrical, or other means, and a rod/pivot/hinge mechanical attachment mechanism ( 11 ) is illustrated in the present embodiment. The wings may move or rotate in relation to the center piece at the attachment site (see the 2 inset figures in FIG. 1A , showing the directions of wing rotation indicated by the arrows). The 2 wings may move or rotate in a manner independent of each other. A rail or groove ( 10 ) may be present in some embodiments but absent in certain embodiments. Alternatively, guide or guides based on a protruding design (not shown) may be present in certain embodiments.
FIG. 1D illustrates the top view of the embodiment in FIG. 1C , showing the proximal end of the center piece ( 3 ), the wing portions with lumen ( 6 and 7 ), a rod-pivot hinge mechanical joint between each wing and center piece body ( 11 ), and wing lumen ( 12 ). A rail or groove ( 10 ) may be present in certain embodiments.
FIG. 2A is a top view of the ring piece of the first variation of the device (“outside-in” variation), with ring body ( 13 ), ring lumen or hollow space ( 14 ) that accommodates the proximal end of center piece (not shown), and 2 suture passer tunnels ( 15 and 16 ). A guide or guides ( 17 ), which may be based on a protrusion design into the ring lumen that is accommodated by the groove, slit, or rail of proximal center piece ( 10 in FIGS. 1A and 1C but not shown in FIG. 2A ), may be present in some embodiments. Alternatively, such guide or guides may be absent in certain embodiments. Alternatively, rails, grooves, or other concave design may (not shown) may replace such protruding guide or guides in other embodiments.
FIG. 2B is a cross-sectional side view of the ring piece of the “outside-in” variation of the device, with ring body ( 13 ), ring lumen ( 14 ), and 2 suture passer tunnels ( 15 and 16 ). Indentation on the side wall of the ring piece (indicated by the solid arrows) may be present in certain embodiments to provide ergonomic finger grasping of the ring piece. Note that the suture passer tunnels align with the hollow spaces (lumen) of the wings associated with the center piece (not shown). Such alignment allows direct passage of a suture passer through a suture passer tunnel of the ring piece into the lumen of a wing.
FIG. 2C is a cross-sectional side view of the ring piece of the “outside-in” variation of the device, with ring body ( 13 ), ring lumen ( 14 ), and 2 suture passer tunnels ( 15 and 16 ). Indentation on the side wall of the ring piece (indicated by the solid arrows) may be present in certain embodiments. The top and bottom entrances to the ring lumen ( 14 ) may have different dimensions, and the “slanted” configuration of the ring lumen on the cross-sectional side view is indicated by the 2 thin arrows in the figure. Note that the suture passer tunnels align with the hollow spaces (lumen) of the wings associated with the center piece (not shown). Such alignment allows direct passage of a suture passer through a suture passer tunnel of the ring piece into the lumen of a wing.
FIG. 2D is a three-dimensional view of an alternative embodiment of the device. In such embodiment, the ring piece and the center piece of the device may be physically integrated as a single entity as the ring lumen slides along the elongated center piece body yet cannot be detached or removed from the center piece body.
FIG. 3A is a cross-sectional side view of the distal end of the suture passer, with center rod body ( 18 ), center rod needle tip ( 19 ), center rod concavity ( 20 ), outer sheath ( 21 ), outer sheath opening ( 22 ), jaw ( 23 ), and attachment of the jaw to center rod ( 24 ). The center rod concavity accommodates the jaw within the outer sheath lumen when the jaw is pushed into a closed position by sliding the outer sheath wall over the jaw. The jaw may be attached to the center rod via mechanical (such as pivots, rods, joints, rubber, elastic flaps . . . etc), electrical, electromagnetic, or other means. Flexible materials with memory such as Nitinol may be used in certain embodiments (see inset picture), in which a bent Nitinol piece replaces the need for a mechanical hinge associated with a spring/rod/pivot mechanism.
FIG. 3B is a cross-sectional side view of the distal end of the suture passer, with center rod body ( 18 ), center rod needle tip ( 19 ), center rod concavity ( 20 ), outer sheath ( 21 ), outer sheath opening ( 22 ), jaw ( 23 ), and attachment of the jaw to center rod ( 24 ). The jaw moves or rotates away from the center rod and protrudes through the outer sheath opening ( 22 ) by sliding the outer sheath opening over the jaw. In such orientation, the jaw is in the “open” position. The jaw may be attached to the center rod via mechanical (such as pivots, rods, joints, rubber, elastic flaps . . . etc), electrical, electromagnetic, or other means. Flexible materials with intrinsic memory such as Nitinol may be used in certain embodiments (see inset picture), in which a bent Nitinol piece (bent in its resting state) replaces the need for a mechanical hinge associated with a spring/rod/pivot mechanism. Note that the jaw opening points away from the needle tip ( 19 ).
FIG. 3C illustrates that a raised edge or protrusion design may be present at the tip of the jaw, to prevent escape of the surgical suture strand captured by the jaw.
FIG. 3D illustrates a different embodiment of the distal end of suture passer, in which the jaw opens to a different direction compared to the embodiments described in FIGS. 3A-3C . Note that the jaw opening points toward the needle tip ( 19 ). Center rod body ( 18 ), center rod needle tip ( 19 ), center rod concavity ( 20 ), outer sheath ( 21 ), outer sheath opening ( 22 ), jaw ( 23 ), and attachment of the jaw to center rod ( 24 ) are also shown. The jaw may be attached to the center rod via mechanical (such as pivots, rods, joints, rubber, elastic flaps . . . etc), electrical, electromagnetic, or other means. Flexible materials with intrinsic memory such as Nitinol may be used in certain embodiments, in which a bent Nitinol piece replaces the need for a mechanical hinge associated with a spring/rod/pivot mechanism.
FIG. 3E illustrates a variation of the proximal end of suture passer, in which the outer sheath (not shown) movement is controlled by sliding a pad or knob. The control may be achieved via mechanical, electrical, electromagnetic, or other means.
FIG. 3F illustrates a variation of the distal end of suture passer much different from the earlier illustrations ( 3 A- 3 E), in which the outer sheath is a hollow needle with lumen ( 25 ) with a sharp needle-like distal end ( 26 ). Along the distal end of the outer sheath shaft ( 27 ), there is a slit of various dimension ( 28 ) to accommodate the surgical suture (not shown) as the suture is secured to the suture passer. Within the lumen of the outer sheath ( 25 ), wire-like jaws ( 29 ) with various angulation/curvature design to secure the surgical suture are present. Each jaw may have a hook or protrusion element at its distal tip ( 30 ) to facilitate suture capturing. The number of the jaws may vary from 1 to more than 3 to 4. The jaws expand outward away from the axis of the outer sheath as they are advanced beyond the distal tip of outer sheath ( 26 ), but they are sufficiently flexible to be retracted within the outer sheath lumen during resting state or during suture capturing state, the latter of which involves suture entrapment with the jaws. The jaws may be made of any material. The deployment mechanism of the jaws (advancement beyond the outer sheath distal end and retraction within the outer sheath lumen) may involve the use of springs and may be based on any mechanical, electrical, or other means.
FIGS. 4A-4N illustrate one possible method of using the invention (“outside-in” variation) to close a trocar wound site.
FIG. 4A is a cross-sectional view of the trocar wound site of the abdominal wall, showing skin (S), subcutaneous tissue layer (ST), external layer of fascia (F) providing strength to body wall, muscle (M), and peritoneum (P). The abdominal cavity space (AC) is below the level of peritoneum (P). These labels apply to the remaining figures under FIG. 4 .
FIG. 4B shows the placement of the center piece of the device (“outside-in” variation) into the trocar wound site, with the dark arrow indicating the direction of device insertion towards the abdominal cavity space (AC). Proximal center piece body ( 3 ), distal center piece body ( 2 ), its 2 wings with portions without lumen ( 8 and 9 ), and wings portions with lumen ( 6 and 7 ) are shown.
FIG. 4C shows the rotation of the wings at their attachment sites to the center piece body so that the wing portions with lumen ( 6 and 7 ) are to be placed within the subcutaneous tissue layer (ST), between the skin (S) and fascia (F). Proximal center piece body ( 3 ), distal center piece body ( 2 ), its 2 wings with portions without lumen ( 8 and 9 ), and wings portions with lumen ( 6 and 7 ) are shown. The direction of rotation of the wings in relation to the center piece is indicated by the dark solid arrows.
FIG. 4D shows the center piece of the device with its wings (portions with lumen— 6 and 7 ) positioned within the subcutaneous tissue layer (ST). Proximal center piece body ( 3 ), distal center piece body ( 2 ), its 2 wings with portions without lumen ( 8 and 9 ), and wings portions with lumen ( 6 and 7 ) are shown.
FIG. 4E shows the attachment of the ring piece body ( 13 ) of the device to the proximal center piece ( 3 ) with the wing portions without lumen ( 8 and 9 ). The ring lumen ( 4 ) accommodates both the proximal center piece ( 3 ) and the wing portions without lumen ( 8 and 9 ). The ring lumen ( 14 ) may fit or engage the proximal center piece ( 3 ) and its wing portions without lumen ( 8 and 9 ) via a design involving grooves/slits/rails (such as 10 in FIG. 1A and 17 in FIG. 2A ), which is not shown in the present figure, and such design is intended to prevent rotation of the ring piece in relation to the center piece. Proximal center piece body ( 3 ), distal center piece body ( 2 ), its 2 wings with portions without lumen ( 8 and 9 ), wings portions with lumen ( 6 and 7 ), and suture passer tunnels of the ring piece ( 15 and 16 ) are shown.
FIG. 4F shows the completion of the attachment of the ring piece body ( 13 ) of the device to the proximal center piece ( 3 ) with the wing portions without lumen ( 8 and 9 ). The ring lumen (not labeled) now accommodates both the proximal center piece ( 3 ) and the wing portions without lumen ( 8 and 9 ). The ring lumen may fit or engage the proximal center piece ( 3 ) and its wing portions without lumen ( 8 and 9 ) via various designs such as that involving grooves/slits/rails (such as 10 in FIG. 1A and 17 in FIG. 2A ), which is not shown in the present figure, and such design is intended to prevent rotation of the ring piece in relation to the center piece. Proximal center piece body ( 3 ), distal center piece body ( 2 ), its 2 wings with portions without lumen ( 8 and 9 ), wings portions with lumen ( 6 and 7 ), and suture passer tunnels ( 15 and 16 ) of the ring piece are shown.
FIG. 4G shows the insertion of the suture passer with a suture strand secured to its distal tip (as the suture strand is entrapped by the closed jaw of the suture passer) into one of the 2 suture passer tunnels of the ring piece of the device ( 15 in the present figure). Proximal center piece body ( 3 ), distal center piece body ( 2 ), its 2 wings with portions without lumen ( 8 and 9 ), wings portions with lumen ( 6 and 7 ), ring piece body ( 13 ), suture passer tunnels ( 15 and 16 ) of the ring piece, needle tip of suture passer ( 19 ), center rod of suture passer ( 18 ), outer sheath of suture passer ( 21 ), and jaw of suture passer ( 23 ) are shown.
FIG. 4H shows the suture strand is being released into the abdominal cavity space from the suture passer distal tip by sliding the outer sheath over the jaw, thereby opening the jaw. Proximal center piece body ( 3 ), distal center piece body ( 2 ), its 2 wings with portions without lumen ( 8 and 9 ), wings portions with lumen ( 6 and 7 ), ring piece body ( 13 ), suture passer tunnels ( 15 and 16 ) of the ring piece, outer sheath of suture passer ( 21 ), and jaw of suture passer ( 23 ) are shown. Note that in certain embodiments, the outer sheath ( 21 ) protrudes beyond the limit of the needle tip of the suture passer (not shown) as the jaw ( 23 ) is open, thereby preventing injury to the intra-abdominal organs or structures from the sharp needle tip. Note that the suture passer penetrates through all layers of the body wall (from skin to peritoneum) as well as the lumen of one wing of the device ( 6 ).
FIG. 4I shows that one end of the suture strand has been left inside the abdominal cavity space (AC) after the removal of the suture passer from the surgical site. Proximal center piece body ( 3 ), distal center piece body ( 2 ), its 2 wings with portions without lumen ( 8 and 9 ), wings portions with lumen ( 6 and 7 ), ring piece body ( 13 ), and suture passer tunnels ( 15 and 16 ) of the ring piece are shown. Note that the suture strand travels through all the layers of the abdominal wall, from skin (S) to peritoneum (P).
FIG. 4J shows that the suture passer jaw is open and ready to secure the suture strand end inside the abdominal cavity, after its insertion through the second suture passer tunnel of the ring piece ( 16 ), all tissue layers of the abdominal wall (from skin to peritoneum), as well as the wing portion with lumen of the device ( 7 ). Proximal center piece body ( 3 ), distal center piece body ( 2 ), its 2 wings with portions without lumen ( 8 and 9 ), wings portions with lumen ( 6 and 7 ), ring piece body ( 13 ), suture passer tunnels ( 15 and 16 ) of the ring piece, outer sheath of suture passer ( 21 ), and jaw of suture passer ( 23 ) are shown. Note that in certain embodiments, the outer sheath ( 21 ) protrudes beyond the limit of the needle tip of the suture passer (not shown) as the jaw ( 23 ) is open, thereby preventing injury to the intra-abdominal organs or structures from the sharp needle tip.
FIG. 4K shows the suture strand path at the wound site following the removal of the suture passer (not shown), which is used to capture the intra-abdominal suture suture strand end in FIG. 4J and pull the strand end out of the abdominal cavity to the space outside the skin. Proximal center piece body ( 3 ), distal center piece body ( 2 ), its 2 wings with portions without lumen ( 8 and 9 ), wings portions with lumen ( 6 and 7 ), ring piece body ( 13 ), suture passer tunnels ( 15 and 16 ) of the ring piece are shown. Note that the suture travels through one suture passer tunnel of the ring piece ( 15 ) and all layers of the abdominal wall (from skin to peritoneum), enters the abdominal cavity space, exits the abdominal cavity space, travels through all layers of the abdominal wall and the second suture passer tunnel of the ring piece ( 16 ), and returns to the space outside the skin.
FIG. 4L shows the device and suture assembly at the wound site after the removal of the ring piece (not shown). Proximal center piece body ( 3 ), distal center piece body ( 2 ), its 2 wings with portions without lumen ( 8 and 9 ), wings portions with lumen ( 6 and 7 ) are shown. Note that the suture travels through all layers of the abdominal wall (from skin to peritoneum), enters the abdominal cavity space, exits the abdominal cavity space, travels through all layers of the abdominal wall, and returns to the space outside the skin.
FIG. 4M shows the removal of the center piece of the device away from the wound site while the suture strand is being left behind. Proximal center piece body ( 3 ), distal center piece body ( 2 ), its 2 wings with portions without lumen ( 8 and 9 ), wings portions with lumen ( 6 and 7 ) are shown. Note that the suture travels through all layers of the abdominal wall (from skin to peritoneum), enters the abdominal cavity space, exits the abdominal cavity space, travels through all layers of the abdominal wall, and returns to the space outside the skin. Also note the suture strand portions outside the skin are pulled into the subcutaneous tissue (ST) and the lumen of the wound site during the center piece removal.
FIG. 4N shows the path of the single suture strand at the wound site after the removal of the device. Note that the suture travels through all layers of the abdominal wall below the skin level (including fascia and peritoneum), enters the abdominal cavity space, exits the abdominal cavity space, and travels through all layers of the abdominal wall below the skin level (including peritoneum and fascia). The 2 ends of the suture strand can then be tied to each other for wound closure. Note that skin is not incorporated into the wound closure.
FIG. 4O illustrates one variation of the present device, in which the proximal end of center piece ( 3 ), distal end of center piece ( 2 ), wings with lumen ( 6 and 7 ), wings without lumen ( 8 and 9 ), ring piece body ( 13 ) with suture passer tunnels ( 15 and 16 ) are shown. In this variation, the center piece has a lumen that accommodates a tubular rod with a proximal end ( 31 ) and a distal end that is composed of 2 wings ( 32 and 33 ). In diagram (A), the distal end of the central tubular rod is retracted within the lumen of distal center piece ( 2 ), thereby allowing the 2 wings ( 32 and 33 ) of the distal end of the central tubular rod to be brought in proximity to each other and to provide a smooth, tapered contour to the distal end of the device. In diagram (B), the distal end of the central tubular rod is pushed (distally) out of the distal center piece ( 2 ) lumen, thereby allowing the 2 wings ( 32 and 33 ) of the distal end of the central tubular rod to be separated from each other. In diagram (B), the 2 wings ( 32 and 33 ) are connected to the distal end of central tubular rod ( 35 ) via a connection mechanism ( 34 ), which may be of any mechanical, electromagnetic, or any other means or design. Use of spring may be involved in such mechanism ( 34 ). Diagram (C) illustrates various types of possible mechanical design of the connection ( 34 ), which is located between the distal end of central tubular rod ( 35 ) and the 2 wings ( 32 and 33 ). Please note that the angle (Z) between the 2 wings in separated position may be variable, from 1 degree to 359 degrees, but it is designed preferably in the range of 90 to 180 degrees. Diagram (D) illustrates the 3-dimensional view of the 2 wings ( 32 and 33 ) of the distal central tubular rod. In one variation of such wings, each wing has a slit that can capture/secure one terminal end of the suture strand. In one variation, each wing may be hollow (shell-like), in which the body of the suture strand can be stored or housed. In another variation, each wing may be solid, and the contact surface of the 2 wings may be flat or grooved. It should be noted that the suture strand terminal ends may be reversibly attached to/captured by the wings ( 32 and 33 ) via any type of design or means, including slits, clips, jaw . . . etc.
FIG. 4P illustrates the different types of possible deployment of the specific variations (of the present device) described in FIG. 4O . One possible deployment method is shown in diagram (A), in which the 2 wings ( 32 and 33 ) of the distal end of tubular rod are secured to and carry the 2 terminal ends of the suture strand through the wound into the body cavity. The mid-portion of the suture strand is outside the wound (that is, not within the abdominal cavity). Note that distal center piece ( 2 ), proximal center piece ( 3 ), ring piece ( 13 ) with its 2 suture passer tunnels ( 15 and 16 ), wings without lumen ( 8 and 9 ), wings with lumen ( 6 and 7 ), distal end of tubular rod ( 35 ) that is well retracted within lumen of center piece are shown. Again, skin (S), subcutaneous tissues (ST), fascia (F), muscle (M), peritoneum (P), and abdominal cavity (AC) are shown. Another possible deployment method is shown in diagram (B 1 ), in which the 2 wings ( 32 and 33 ) of the distal end of the tubular rod are secured to and carry the 2 terminal ends of the suture strand into the body cavity. The body (including mid-portion) of the suture strand is stored/housed within the hollow cavity of the wings ( 32 and 33 ), as described in FIG. 4O diagram (D). When the distal tubular rod is pushed distally, as in diagram (B 2 ), the 2 wings ( 32 and 33 ) become separated from each other, allowing the suture strand body to be dropped into/placed within abdominal cavity, while the terminal ends of the suture strand remain secured to the 2 wings ( 32 and 33 ).
FIGS. 4Q-X illustrate one possible method of using the invention (“outside-in” variation) to close a trocar wound site. The specific variation of the invention described in FIG. 4O and FIG. 4 P(A) is illustrated.
FIG. 4Q shows the same cross-sectional view of the trocar wound site of the abdominal wall, showing skin (S), subcutaneous tissue layer (ST), external layer of fascia (F) providing strength to body wall, muscle (M), and peritoneum (P). The abdominal cavity space (AC) is below the level of peritoneum (P). The different components of the invention, including distal center piece ( 2 ), proximal center piece ( 3 ), wings without lumen ( 8 and 9 ), wings with lumen ( 6 and 7 ), ring body ( 13 ) with its suture passer tunnels ( 15 and 16 ), proximal central tubular rod ( 31 ), and the 2 distal wings of the central tubular rod ( 32 and 33 ) in retracted position/partially positioned within lumen of distal center piece ( 2 ) are shown. These labels apply to the remaining FIGS. 4Q-X ). Note that the wings with lumen ( 6 and 7 ) have been positioned within the subcutaneous tissue layer (ST). Note that the ring piece ( 13 ) has locked the wings without lumen ( 8 and 9 ) in place so that the wings with lumen ( 6 and 7 ) are anchored within the ST layer without movement. Note that the 2 terminal ends of the suture strand are secured to the 2 distal wings of the central tubular rod ( 32 and 33 ) while the body/mid-portion of the suture strand is outside the abdominal cavity (AC).
FIG. 4R illustrates the separation of the 2 distal wings of the central tubular rod ( 32 and 33 ) by pushing the proximal central tubular rod ( 31 ) distally towards the abdominal cavity. Note that the 2 terminal ends of the suture strand remain secured to the 2 distal wings of the central tubular rod ( 32 and 33 ).
FIG. 4S illustrates the placement of the suture needle passer through one of the suture passer tunnels of the ring piece ( 15 ), full thickness abdominal wall (layers S, ST, F, M, P) into abdominal cavity (AC) to capture the first terminal end of the suture strand. One variation of the suture passer described previously ( FIG. 3F ) is shown, with its wire-like jaws ( 29 ) protruding from its distal sheath with sharp end ( 26 ). The jaws ( 29 ) of suture passer are used to capture the first terminal end of suture strand and detach it from the distal wing of central tubular rod ( 32 ).
FIG. 4T illustrates that the first terminal end of the suture has been brought through the full-thickness abdominal wall and the suture passer tunnel of ring piece ( 15 ). This is achieved by withdrawing the suture passer proximally away from the abdominal cavity (AC) with the captured first terminal end of suture strand. The first terminal end of suture strand is now outside the abdominal cavity (AC).
FIG. 4U illustrates the placement of the suture needle passer through the opposite suture passer tunnel of the ring piece ( 16 ), full thickness abdominal wall (layers S, ST, F, M, P) into abdominal cavity (AC) to capture the second terminal end of the suture strand. One variation of the suture passer described previously ( FIG. 3F ) is shown, with its wire-like jaws ( 29 ) protruding from its distal sheath with sharp end ( 26 ). The jaws ( 29 ) of suture passer are used to capture the second terminal end of suture strand and detach it from the distal wing of central tubular rod ( 33 ).
FIG. 4V illustrates that the second terminal end of the suture has been brought through the full-thickness abdominal wall and the suture passer tunnel of ring piece ( 16 ). This is achieved by withdrawing the suture passer proximally away from the abdominal cavity (AC) with the captured second terminal end of suture strand. The second terminal end of suture strand is outside the abdominal cavity (AC). Note that the suture travels through one suture passer tunnel of the ring piece ( 15 ) and all layers of the abdominal wall (from skin to peritoneum), enters the abdominal cavity space, exits the abdominal cavity space, travels through all layers of the abdominal wall and the second suture passer tunnel of the ring piece ( 16 ), and returns to the space outside the skin.
FIG. 4W illustrates the removal of the invention from the wound site while the suture strand is being left behind. Note that the suture travels through all layers of the abdominal wall (from skin to peritoneum), enters the abdominal cavity space, exits the abdominal cavity space, travels through all layers of the abdominal wall, and returns to the space outside the skin. Also note the suture strand portions outside the skin are pulled into the subcutaneous tissue (ST) and the lumen of the wound site during the removal of the invention.
FIG. 4X shows the path of the single suture strand at the wound site after the removal of the device. Note that the suture travels through all layers of the abdominal wall below the skin level (including fascia and peritoneum), enters the abdominal cavity space, exits the abdominal cavity space, and travels through all layers of the abdominal wall below the skin level (including peritoneum and fascia). The 2 ends of the suture strand can then be tied to each other for wound closure. Note that skin is not incorporated into the wound closure.
FIG. 5 ( 5 A-K) illustrates another embodiment of the first variation of the invention (“outside-in” variation).
FIG. 5A illustrates the rod portion of the device, with its distal end associated with a wing with hollow space (lumen). The wing may be of any dimension, material, configuration, or design. The rod may be made from any material, dimension, or design.
FIG. 5B shows that the hollow wing of the distal rod is inserted into the subcutaneous tissue (ST) at the trocar wound site. Skin (S), subcutaneous tissue (ST), fascia (F), muscle (M), peritoneum (P), and abdominal cavity space (AC) are also shown. These labels apply to the remaining figures under FIG. 5 .
FIG. 5C shows that a suture passer with its distal end secured to a suture strand has been inserted through all tissue layers of the abdominal wall (from skin to peritoneum) into the abdominal cavity space (AC). The suture passer may or may not be identical to that described in FIG. 3A-E .
FIG. 5D shows that after the removal of the suture passer, the suture travels through the skin, subcutaneous tissue, lumen of the wing at distal end of the rod, fascia, muscle, and peritoneum into the abdominal cavity space.
FIG. 5E shows that the suture strand portion outside the skin is pulled into the subcutaneous tissue layer and lumen of the wound while the wing of the distal rod is being removed from the wound site.
FIG. 5F shows that the suture travels from outside the skin, through all layers of body wall (except skin), and into the abdominal cavity space. The rod device with hollow wing has been removed.
FIG. 5G shows that the hollow wing of the rod of the device is placed into the subcutaneous tissue layer on the opposite side of the wound lumen.
FIG. 5H shows that the suture passer has been placed through all abdominal wall layers (from skin to peritoneum), through the wing lumen of the distal rod, and into the abdominal cavity space. The suture passer is then used to secure the end of the suture strand previously left inside the abdominal cavity. The jaw of the suture passer is shown to be open, ready to entrap the suture end.
FIG. 5I shows that the suture travels through the subcutaneous tissue layer/fascia/muscle/peritoneum, enters abdominal cavity space, exits abdominal cavity space, travels through all body wall layers (peritoneum/muscle/fascia/subcutaneous tissue/skin), and exits into the space outside the skin. Note that the suture also travels through the lumen of the wing of the device.
FIG. 5J shows that suture strand portion outside the skin is pulled into the subcutaneous tissue layer and the wound lumen while the wing of the distal rod is being removed from the wound site.
FIG. 5K shows the path of the suture strand: it travels from outside the skin, through wound lumen, through subcutaneous tissue/fascia/muscle/peritoneum, into abdominal cavity, through peritoneum/muscle/fascia/subcutaneous tissue, into wound lumen, and into space outside the skin. The 2 ends of the suture can then be tied to each other to provide wound closure without incorporating the skin.
FIG. 6A illustrates the center piece of the second variation of the invention (the “inside-out” variation). It consists of a pair of J-shaped or U-shaped (inverted) hooks ( 1 and 2 ) whose sharp distal ends ( 3 and 4 ) can be attached to the ends of a suture strand. The shafts of the 2 hooks ( 1 and 2 ) may be accommodated within the lumen of a elongated shell ( 5 ). (Note that the shell may be absent in certain embodiments.) The shell may have a tapered distal end ( 6 ), which may have a slit or other types of suture strand carrying mechanism ( 7 ). The suture strand carrying mechanism may be a simple slit at one side of the distal shell wall (shown in the present figure), clip, hole, spring-loaded grasper, . . . etc, encompassing any type of mechanical, electromagnetic, electrical, or other means and any type of dimension and design. This suture carrying mechanism may be located at any part of the center piece of the device. Rotation (clockwise or counter clockwise) of the proximal ends of the hooks ( 8 and 9 ), associated with the proximal end of the shell in the present embodiment, leads to the rotational movements of the hooks (that is, rotation along their respective longitudinal axis—therefore, the distal ends of the hooks may be positioned inside or outside the shell lumen by rotating their respective proximal ends). In FIG. 6A , the distal needle ends of the hooks ( 3 and 4 ) are rotated outward and 180 degrees away from each other and, therefore, are outside the shell ( 5 ). Note that the 2 hooks and the shell may be of any length, dimension, material, and design. Note that the 2 hooks may be of different lengths/heights. Note that the bent portions of the hooks may be at different levels or the same level. Note that the distal needle ends of the 2 hooks may be at different levels or the same level. Note that the proximal ends of the 2 hooks may be controlled or rotated or locked or unlocked by any mechanical, electromagnetic, electric, or other means or any design. These proximal controls may be rotated or controlled independently or dependently of each other.
FIG. 6B illustrates the center piece of the second variation of the invention (the “inside-out” variation). It consists of a pair of J- or U-shaped (inverted) hooks ( 1 and 2 ) whose sharp distal ends ( 3 and 4 ) can be attached to the ends of a suture strand. The shafts of the 2 hooks ( 1 and 2 ) may be accommodated within the lumen of a elongated shell ( 5 ). The shell may be absent in other embodiments. The shell may have a tapered distal end ( 6 ), which may have a slit (shown in the present embodiment) or other types of suture strand carrying mechanism ( 7 ). The suture strand carrying mechanism may be a simple slit at one side of the distal shell wall, clip, hole, spring-loaded grasper, . . . etc, encompassing any type of mechanical, electromagnetic, electrical, or other means and any type of dimension and design. This suture carrying mechanism may be located at any part of the center piece of the device. Rotation (clockwise or counter clockwise) of the proximal ends of the hooks ( 8 and 9 ), associated with the proximal end of the shell, leads to the rotational movements of the hooks (that is, rotation along their respective longitudinal axis—therefore, the distal ends of the hooks may be positioned inside or outside the shell lumen by rotating their respective proximal ends). In FIG. 6B , the distal needle ends of the hooks ( 3 and 4 ) are rotated inward towards each other and, therefore, are inside the shell ( 5 ). Note that the 2 hooks and the shell may be of any length, dimension, material, and design. Note that the 2 hooks may be of different lengths/heights. Note that the bent portions of the hooks may be at different levels or the same level. Note that the distal needle ends of the 2 hooks may be at different levels or the same level. Note that the proximal ends of the 2 hooks may be controlled or rotated or locked or unlocked by any mechanical, electromagnetic, electric, or other means or any design. These proximal ends may be controlled or rotated independently or dependently of each other.
FIG. 6C illustrates the rotational movements of one of the hooks. By rotating the proximal end of hook shaft ( 2 ) along its longitudinal axis, its distal end ( 4 ) is rotated away from the other hook shaft ( 1 ) and becomes outside of shell wall ( 5 ). Rotating the same hook shaft ( 2 ) along its longitudinal axis in the opposite direction allows its distal end ( 4 ) to return to the lumen of the shell. The 2 hooks may be rotated independently of each other in some embodiments (as shown in FIG. 6C ) but may be rotated synchronously via a central control mechanism in other embodiments.
FIG. 6D illustrates the rotational movements of one of the hooks. By rotating the proximal end of hook shaft ( 1 ) along its longitudinal axis, its distal end ( 3 ) is rotated away from the other hook shaft ( 2 ) and becomes outside of shell wall ( 5 ). Rotating the same hook shaft ( 1 ) along its longitudinal axis in the opposite direction allows its distal end ( 3 ) to return to the lumen of the shell. The 2 hooks may be rotated independently of each other in some embodiments (as shown in FIG. 6D ) but may be rotated synchronously via a central control mechanism in other embodiments.
FIG. 6E is a 3-dimensional illustration of the center piece of the “inside-out” variation of the invention. It consists of a pair of J- or U-shaped (inverted) hooks ( 1 and 2 ) whose sharp distal ends ( 3 and 4 ) can be attached to the ends of a suture strand. The shafts of the 2 hooks ( 1 and 2 ) may be accommodated within the lumen of a elongated hollow shell ( 5 ). The shell may be absent in certain embodiments. The shell may have a tapered distal end ( 6 ), which may have a slit (shown in the present figure) or other types of suture strand carrying mechanism ( 7 ). The suture strand carrying mechanism may be a simple slit at one side of the distal shell wall, clip, hole, spring-loaded grasper, . . . etc, encompassing any type of mechanical, electromagnetic, electrical, or other means and any type of dimension and design. This suture carrying mechanism may be located at any part of the center piece of the device. Rotation (clockwise or counter clockwise) of the proximal ends of the hooks ( 8 and 9 ), associated with the proximal end of the shell, leads to the rotational movements of the hooks (that is, rotation along their respective longitudinal axis—therefore, the distal ends of the hooks may be positioned inside or outside the shell lumen by rotating their proximal ends). The proximal controls of the hooks ( 8 and 9 ) may be based on any mechanical, electromagnetic, electrical, or other design or means, and they may be rotated or controlled independently or dependently. In FIG. 6E , the distal needle ends of the hooks ( 3 and 4 ) are rotated outward and 180 degrees away from each other and, therefore, are outside the shell ( 5 ). The figure also illustrates a protruding ridge or guide ( 10 ) associated with the exterior surface of the center piece shell wall ( 5 ). This protruding design may be present in some embodiments but absent in others, and this may be accommodated by the slit of the outer shell component of the invention (see FIG. 7 )—to prevent the rotation of the center piece within the lumen of the outer shell component. Note that rather than having a protruding design, other embodiments may have a concave design such as groove or slit. The inset pictures illustrate various methods and designs involved in the attachment of a suture strand end to the distal end/needle tip of a hook of the center piece. Slits, holes, double-hook with slit, . . . etc and any type of mechanical, electromagnetic, electrical, and other means and design may be used to attach the end of a suture strand to the distal end of each of the 2 hooks in the invention.
In certain embodiments without the shell (present and shown in 6 A- 6 D), the needle rotational directions may be different from those illustrated in FIGS. 6C-6D . One such embodiment is shown in FIG. 6F . This variation consists of a pair of J-shaped or U-shaped (inverted) hooks ( 1 and 2 ) whose sharp distal ends ( 3 and 4 ) can be attached to the ends of a suture strand. The shafts of the 2 hooks ( 1 and 2 ) may be accommodated within the lumen of an elongated cylindrical shell ( 5 ). (Note that the shell may be absent in certain embodiments.) The bottom surface of the hooks are connected to a suture-carrying (or storage) entity ( 7 ) with a tapered distal end ( 6 ), and the suture strand carrying mechanism may be of any type or design. The suture-carrying entity ( 7 ) may be hollow (to house or store suture strand) or solid in nature. When the hooks are rotated in such a way that the needle points ( 3 and 4 ) are within the boundary of outer shell ( 5 ), as in diagram (A), the 2 halves of the suture-carrying entity ( 7 ) come together to provide a housing compartment for suture strand storage. When the hooks are rotated in such a way that the needle points ( 3 and 4 ) are 180 degrees away from each other and are outside the boundary of the outer shell ( 5 ), as in diagram (B), the 2 halves of the suture-carrying entity ( 7 ) are separated from each other, allowing the housed suture strand to be detached from the suture-carrying entity ( 7 ). Note that the 2 hooks and the shell may be of any length, dimension, material, and design. Note that the 2 hooks may be of different lengths/heights. Note that the bent portions of the hooks may be at different levels or the same level. Note that the distal needle ends of the 2 hooks may be at different levels or the same level. Note that the proximal ends of the 2 hooks ( 8 and 9 ) may be controlled or rotated or locked or unlocked by any mechanical, electromagnetic, electric, or other means or any design. These proximal ends may be controlled or rotated independently or dependently of each other. These 2 ends may be controlled via a central dial or mechanism to facilitate the use of the present invention. Diagram (C) illustrates the rotational movements of the hooks. By rotating the proximal end of hook shaft ( 2 ) along its longitudinal axis, its distal end ( 4 ) is rotated away from the other hook shaft ( 1 ) and becomes outside the boundary of shell wall ( 5 ). By rotating the proximal end of hook shaft ( 1 ) along its longitudinal axis, its distal end ( 3 ) is rotated away from the other hook shaft ( 2 ) and becomes outside the boundary of shell wall ( 5 ). Rotating the same hook shaft ( 2 ) along its longitudinal axis in the opposite direction allows its distal end ( 4 ) to return to the luminal boundary the shell ( 5 ). Rotating the same hook shaft ( 1 ) along its longitudinal axis in the opposite direction allows its distal end ( 3 ) to return to the luminal boundary of the shell ( 5 ). The 2 hooks may be rotated independently of each other in some embodiments (as shown in FIG. 6F ) but may be rotated synchronously via a central control mechanism in other embodiments.
FIG. 7A illustrates one variation of the 3-dimensional and cross-sectional views of the outer shell component of the “inside-out” variation of the invention. The shell body ( 11 ) has a lumen ( 12 ) and a slit along its longitudinal axis ( 13 ). The slit may be absent in certain embodiments. There are 2 wings attached to its distal end ( 14 and 15 ). The wings have portions without hollow space or lumen ( 16 and 17 ). The 2 wings also have portions with lumen ( 18 and 19 ). The 2 wings are attached to the distal portion of the outer shell, and the attachment may be achieved via any mechanical, electrical, electromagnetic, or other means or any design. In the figure, there are slits in the flaps ( 22 and 23 , which represent the continuation of the outer shell wall) at the distal portion of the outer shell, and these 2 slits accommodate the body of the wings. Any component of the outer shell component and its associated parts may be of any material, dimension, configuration, or design. In one preferred embodiment, the outer shell component is flexible enough to allow compression towards its central lumen as its side walls are squeezed with manual pressure.
FIG. 7B illustrates that the portions of the wings without lumen ( 16 and 17 ) may be attached to the exterior wall of the outer shell component of the invention ( 11 ). Such attachment may be achieved via any mechanical, electrical, electromagnetic, or other means or any design. In the figure, the flaps with slits ( 22 and 23 , with 22 not shown) accommodating the wings are bent or folded so that the portions of the wings without lumen ( 16 and 17 ) are attached to the exterior wall of the outer shell. (In this orientation, the portions of wings with lumen— 18 and 19 —are turned outward 180 degrees away from each other and become perpendicular to the longitudinal axis of the outer shell component). Inset 1 shows that the attachment is achieved via a male-female connection: with a protruding component located on exterior wall of outer shell ( 20 ) that can be accommodated by and locked into a hole on the each of the portions of the wings without lumen ( 16 and 17 , with 17 not shown). Inset 2 shows that the attachment is achieved via a ring external to the outer shell ( 11 ), accommodating the outer shell circumference as well as both wings (at the level of the portions of wings without lumen— 16 and 17 , with 17 not shown). Alternatively, in some embodiments, there may be a rigid (such as c) ring that is integrated as part of the outer shell wall and has attachment means (any type) for the portions of wings without lumen, which is not shown in the figure. (Such rigid ring may ensure that the 2 wings are positioned symmetrically at the same level in relation to the outer shell component.) Note that any component of the outer shell component (such as the shell wall and the wings) may be of any dimension, configuration, material, and design. In one preferred embodiment, the outer shell is flexible enough to be compressed against its lumen ( 12 ) as its side walls are squeezed with manual pressure.
FIG. 7C illustrates another variation of the component described in FIG. 7B , in which the portions of the wings without lumen ( 16 and 17 ) may be attached to the exterior wall of the outer shell component of the invention ( 11 ). In this variation ( 7 C), the slit ( 13 ) is absent and is replaced by a groove (G) along the inner wall of the outer shell component ( 11 ). The labels that are used in FIG. 7B , such as 12 , 20 , 16 , 23 , 18 , and 19 , also apply to FIG. 7C .
FIG. 8A illustrates an obturator (or a guide) that can be accommodated by the hymen of the outer shell component of the invention (the “inside-out” variation). It can also be accommodated by the lumen of a laparoscopic trocar. The obturator may be of any dimension, configuration, material, or design. In one preferred embodiment, its body ( 24 ) is hollow and compressible (towards its lumen as the side walls are squeezed by manual pressure). However, such feature may be absent in certain embodiments, in which the body ( 24 ) is rigid (or even non-compressible) and may be solid in nature. It may have a tapered distal end to facilitate its insertion into the trocar wound site ( 25 ).
FIG. 8B illustrates that the obturator is placed within the lumen of the outer shell component in a 3-dimensional view. Obturator body ( 24 ), obturator distal end ( 25 ), outer shell body ( 11 ), outer shell slit ( 13 ), outer shell flaps with slits accommodating the wings ( 23 and 22 , with 22 not shown), 2 wings with portions without lumen ( 16 and 15 ) and portions with lumen ( 18 and 19 ). Note that a protruding mechanism (male part) is present on the outer shell side wall ( 20 , with its counterpart 180 degrees away and not shown), which can be accommodated by and locked into the “locking hole of the wing” (located at the portion of the wing without lumen on each side). Note that the obturator ( 24 ) can be accommodated with the lumen of the outer shell component ( 11 ), and these 2 structures may be locked (and unlocked) to each other via any mechanical, electromagnetic, electrical, or other means and any design. Furthermore, there may be valves or other gas-leak prevention means or design for the outer shell and/or obturator to minimize the risk of gas leak during the removal of the obturator from the outer shell lumen (see FIG. 9F below).
FIG. 9 ( 9 A- 9 L) illustrates one possible method of deploying the second variation (the “inside-out” variation) of the invention to close a trocar wound.
FIG. 9A is a cross-sectional view of the trocar wound site of the abdominal wall, showing skin (S), subcutaneous tissue layer (ST), external layer of fascia (F) providing strength to body wall, muscle (M), and peritoneum (P). The abdominal cavity space (AC) is below the level of peritoneum (P). These labels apply to the remaining figures under FIG. 9 . A laparoscopic trocar (T) is also shown at the trocar wound site.
FIG. 9B illustrates the placement of the obturator into the lumen of the trocar (T). Proximal part of the obturator body ( 24 ) is outside the trocar, and the tapered distal end of the obturator ( 25 ) is associated with the distal end of the trocar.
FIG. 9C illustrates the removal of the trocar from the wound site while the obturator ( 24 ) is left in place.
FIG. 9D illustrates the insertion of the outer shell component of the device along the obturator towards the wound opening. Outer shell body ( 11 ) with its lumen accommodates the body of the obturator ( 24 ). Distal obturator end ( 25 ), the portions of wings without lumen ( 15 and 16 ), and the portions of wings with lumen ( 18 and 19 ) are also shown. (Note that in certain embodiments, the obturator ( 24 ) may be inserted through the lumen of the outer shell body ( 11 ) first before the removal of the trocar from the wound site. In this alternative method with the obturator-outer shell assemble—in which the steps illustrated in FIGS. 9B-9D are not applicable—the obturator tapered end ( 25 ) is first placed into the wound site after trocar removal. The outer shell component of the device is then placed along the obturator into the wound opening.)
FIG. 9E illustrates the rotation of the wings at their attachments to the outer shell distal portion so that the portions of the wings with lumen ( 18 and 19 ) are inserted into the subcutaneous tissue layer. Note that the portions without lumen are locked to the exterior wall of the outer shell ( 11 ) at specific sites ( 20 ). In the present figure, the male-female locking mechanism is shown, with a protruding mechanism on the exterior wall of outer shell ( 20 ). Obturator ( 24 ) is still inside the outer shell ( 11 ).
FIG. 9F shows the same setup as that in FIG. 9E , except that the obturator has been removed from the surgical site. The labels used in FIG. 9E also apply to the present figure.
FIG. 9G shows the insertion of the center piece of the device into the lumen of the outer shell component ( 11 ). Note that the center piece is loaded with a strand of suture attached to the distal needle ends of the hooks ( 3 and 4 ). The 2 hooks ( 1 and 2 ) turned towards each other and accommodated within the lumen of its shell, their distal sharp ends ( 3 and 4 ) carrying the ends of the suture strand, proximal controls of the hooks ( 8 and 9 ), distal tapered end of central piece ( 6 ) with suture securing/carrying mechanism ( 7 ), the portions of wings without lumen ( 15 and 16 ), and the portions of wings with lumen ( 18 and 19 ) are also shown. The wings are also locked to the exterior wall of the outer shell component via a locking mechanism ( 20 ).
FIG. 9H shows that the 2 hooks ( 1 and 2 ) are rotated outward and become 180 degrees away from each other (by rotating their respective proximal controls— 8 and 9 ), now with their distal tips ( 3 and 4 ) outside its center piece shell. Note that the center piece is loaded with a strand of suture attached to the distal needle ends of the hooks ( 3 and 4 ). The outer shell component wall ( 11 ), the proximal controls of the hooks ( 8 and 9 ), distal tapered end of central piece ( 6 ) with suture securing/carrying mechanism ( 7 ), the portions of wings without lumen ( 15 and 16 ), and the portions of wings with lumen ( 18 and 19 ) are also shown. The wings are also locked to the exterior wall of the outer shell component via a locking mechanism ( 20 ).
FIG. 9I shows that the center piece device with its 2 hooks ( 1 and 2 , pointing 180 degrees away from each other and carrying the ends of a suture strand) is pulled up against the abdominal wall, leading to full-thickness penetration of all layers of the abdominal wall (from peritoneum to skin) by the 2 hook needle ends ( 3 and 4 ) attached to the ends of a suture strand. The outer shell component wall ( 11 ), the portions of wings without lumen ( 15 and 16 ), and the portions of wings with lumen ( 18 and 19 ) remain in the same position at the wound site while the center piece is being pulled upward towards the body wall to deliver the 2 ends of the suture strand to the space outside the skin. The wings are locked to the exterior wall of the outer shell component via a locking mechanism ( 20 ). Distal tapered end of central piece ( 6 ) with suture securing/carrying mechanism ( 7 ) are also shown. Note that the needle tips of the 2 hooks ( 3 and 4 ) also travel through the hollow spaces (lumen) of the 2 wings ( 18 and 19 ) positioned in the subcutaneous layer during this step.
FIG. 9J shows the suture path after the removal of the center piece of the device. Following step in FIG. 9I , the 2 ends of the suture strand are detached from the needle tips of the 2 hooks and secured outside the skin. The center piece device is then reinserted back into the abdominal cavity, after which the hooks are rotated towards each other via their proximal controls, followed by the removal of the center piece of the device. The suture path is now as follows: the suture originates from the space outside the skin, travels through all layers of the abdominal wall (from skin to peritoneum) as well as the lumen of the first wing of the device ( 19 ), enters abdominal cavity, exits abdominal cavity, travels through all layers of abdominal wall (from peritoneum to skin) and the lumen of the second wing of the device ( 18 ), and enters the space outside the skin. The wings are locked to the exterior wall of the outer shell component ( 11 ) via a locking mechanism ( 20 ).
FIG. 9K shows the removal of the remaining device from the wound site. During this maneuver, the portions of the suture strand outside the skin are pulled into the subcutaneous tissue layer and the lumen of the wound.
FIG. 9L shows the path of the single suture strand at the wound site after the removal of the device. Note that the suture travels through all layers of the abdominal wall below the skin level (including fascia and peritoneum), enters the abdominal cavity space, exits the abdominal cavity space, and travels through all layers of the abdominal wall below the skin level (including peritoneum and fascia). The 2 ends of the suture strand can then be tied to each other for wound closure. Note that skin is not incorporated into the wound closure.
DETAILED DESCRIPTION OF EMBODIMENTS
Various embodiments are shown in the figures attached. There are 2 main variations of the present invention. The first variation—the “outside-in” variation—is shown in the earlier figures ( FIGS. 1-5 ). The second variation—the “inside-out” variation—is shown in the latter figures ( FIGS. 6-9 ).
The fundamental principle shared by all variations and embodiments of the present invention is that there is at least 1 ring (equivalent to “wing portion with lumen” in all the figures illustrated for the invention) placed into the subcutaneous tissue layer (between skin and fascia) so that suture passage through all layers of the abdominal wall (including skin, subcutaneous tissue layer, fascia, muscle, and peritoneum), regardless of the direction of passage (from the space outside the skin towards abdominal cavity space or from the abdominal cavity space towards the space outside the skin), allows capture of all tissue layers of the abdominal wall except the skin following the removal of the ring from the subcutaneous tissue layer. This is due to the fact that the portion of the suture strand outside the skin is pulled into the subcutaneous tissue layer and the lumen of the wound site during the removal of the ring from the wound site. (In other words, the result is that the suture strand travels through the subcutaneous tissue layer, fascia, muscle, and peritoneum, into the abdominal cavity space, exits the abdominal cavity space via the lumen of the wound). When a single ring is used on both sides of the wound lumen (asynchronously—shown in FIG. 5 ) or when 2 separate rings are used for the wound site synchronously (shown in FIGS. 4 and 9 ), suture closure incorporating all body wall layers (other than the skin) can be achieved.
In one preferred embodiment, the first variation of the device consists of 3 main components: a center piece with its 2 wings, a ring piece, and a suture passer. Any part of each of the 3 components may be made from any material, dimension, and design. Any of the 3 components may be integrated into another component(s) in other embodiments. In another preferred embodiment, the center piece has a lumen that accommodates a tubular rod with 2 distal wings (as in FIGS. 4O and 4P ) that carry 2 terminal ends of the suture strand.
The details of some of the embodiments of the first variation of the device have been described in FIGS. 1-5 .
In one preferred embodiment, the second variation of the device consists of 3 main components: a center piece with its 2 inverted hooks (carrying the 2 ends of a suture strand), an outer shell with its 2 wings, and an obturator. Any part of each of the 3 components may be made from any material, dimension, and design. Any of the 3 components may be integrated into another component(s) in other embodiments.
The details of some of the embodiments of the second variation of the device have been described in FIGS. 6-9 . The detailed discussion of the major steps involved in the device deployment is shown in FIG. 9 . Note that in certain embodiments, the obturator ( 24 in FIG. 9 ) may be inserted through the lumen of the outer shell body ( 11 in FIG. 9 ) first before the removal of the trocar from the wound site. In this alternative method with the obturator-outer shell assembly—in which the steps illustrated in FIGS. 9B-9D are not applicable—the obturator tapered end ( 25 in FIG. 9 ) is first placed into the wound site after trocar removal. The outer shell component of the device is then placed along the obturator and inserted into the wound opening
In certain embodiments the device (including both “outside-in” and “inside-out” variations) is designed to have disposable elements or to be entirely disposable. Disposability is really a function of cost in relation to expense of sterilization. Heat and chemical sterilization is a relatively inexpensive process, but it may damage certain or the more delicate elements of an apparatus. Any component of the device (including variations) may be made disposable or reusable. In other embodiments, the entire device may be disposable, dispensing with the need for sterilization altogether.
Any component and any associated part of the 2 variations of the invention may be made from any material, with any dimension, configuration, rigidity or flexibility, and design. The attachment and association means between and among the different components or parts may be achieved mechanically, electromagnetically, electrically, or any other method.
The invention is designed primarily to close lap aroscopic trocar wound sites. It may also be used for other types of applications in surgery (such as hernia repair) or body systems including the chest cavity. The principle of a strand of suture or string passing through a ring outlined above may be applicable to other medical and non-medical fields, all of which should be encompassed by the present invention.
It should be also be noted that in the first variation of the device (“outside-in” variation), the center piece may have one or more associated wings. Two wings represent one preferred embodiment, although other embodiments may have 1, 3, 4, or more wings.
It should also be noted that in the second variation of the device (“inside-out” variation), the outer shell component may have one or more associated wings with lumen. Two wings represent one preferred embodiment, although other embodiments may have 1, 3, 4, or more wings.
It should also be noted that in the second variation of the device (“inside-out” variation), the center piece component may have one or more associated hooks with lumen. Two hooks represent one preferred embodiment, although other embodiments may have 1, 3, 4, or more wings. It should also be noted that the inverted hook may have a configuration other than inverted U (which is one preferred embodiment), although J, L, . . . etc and other variations at various angles (relative to the longitudinal axis of the hook shaft) to allow the needle tip point towards the proximal control of the respective hook may be present in other embodiments.
In any of the wings with lumen (in both first and second variations of the invention), the wing tips may be sharp, blunt, tapered, or others in design and configuration. The dimension of each wing lumen may be of any design. The wings may be of any material, dimension, and design.
In all parts of the present document including claims, the wings with lumen (present in both the “inside-out” and “outside-in” variations of the invention) through which the suture passer or needle carrying the suture strand travels through should be considered as a form of rings (defined as a element with circumferential enclosure and central lumen allowing passage of other elements). In other words, the wings with lumen are specific forms of rings.
The present invention provides various advantages over the prior art devices and methods. It provides full-thickness closure of a small laparoscopic wound site, capturing all body wall tissue layers, except the skin, on both sides of the wound lumen. It provides such closure in a simple, easy-to-use, reliable, and fast manner. The second variation of the invention (“inside-out” variation), in fact, allows the surgeon to complete wound closure without much of the assistant's help—the assistant only needs to control the laparoscope and help the surgeon visualize the trocar wound site from the intra-abdominal perspective. Additionally, the present invention is simple and inexpensive to manufacture, simple to use and robust in use, and can be used with a variety of wound dimensions and depths.
It will be readily appreciated that various adaptations and modifications of the described embodiments can be configured without departing from the scope and spirit of the invention and the above description is intended to be illustrative, and not restrictive, and it is understood that the applicant claims the full scope of any claims and all equivalents.
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The invention encompasses devices and methods used to provide wound closure based on rings positioned within the tissue layers of the wound opening (with the rings regionally separate the wound depth tissue layers into 2 compartments), followed by suture transport through the rings and full-thickness tissue layers of both compartments. Upon suture transport via synchronous or asynchronous manner and device removal, wound closure is achieved by tying the 2 ends of the suture without incorporating tissue above the level of the rings such as skin. When the device is applied to abdominal or chest wall wound opening, all tissue layers except the skin are incorporated in the suture closure of the wound. The closure process can be performed in a simple, reliable, and expeditious manner.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to railway air system air dryers and, more particularly, to an air dryer having a heating control system for preventing freezing of valves.
2. Description of the Related Art
A typical “twin-tower” desiccant-type air dryer includes two drying circuits that are controlled by valves. Wet inlet air flows through one circuit to remove water vapor, while dry product air counter flows through the other circuit to remove the accumulated water and regenerate the desiccant. Inlet and outlet valves for each pneumatic circuit are responsive to controlling electronics to switch the air flow between the two circuits so that one circuit is always drying while the other is regenerating. The air dryer may include a pre-filtration stage with a water separator and/or coalescer positioned upstream of the drying circuits. The pre-filtration stage removes liquid phase and aerosol water and oil that can accumulate in air supply system as a result of the compression of ambient air by the locomotive air compressors. A pre-filtration stage includes a drain valve that is used to periodically purge any accumulated liquid. For example, a typical pre-filtration drain valve actuation cycle might command a purge (open) for two seconds every two minutes.
The air dryer valves, including any pre-filtration drain valve, are constantly subjected to wet air and thus prone to freezing at low temperatures. In order to counteract this problem, a heater element may be provided to warm the valves sufficiently to prevent freezing. Unfortunately, it takes time to sufficiently warm the valves when the air supply system is powered up from a cold temperature. If any of the valves are commanded open before they are sufficiently warmed, the valves can freeze in the open position. If a valve remains in an open position when it should otherwise be closed, there is a risk of an uncontrollable venting of the compressed air from the locomotive air supply system. Further, due to the high volume of air flowing through the frozen valve, the heater may not have sufficient power to thaw the frozen valve, if it is frozen open. Thus, there is a need for a heating control system that ensures that the valves are sufficiently warmed before they are operated so that they do not freeze.
BRIEF SUMMARY OF THE INVENTION
The present invention comprises an air dryer having an inlet for receiving compressed air, a series of valves positioned in a valve block for controlling the movement of the compressed air through a desiccant, a heater configured to warm the valve block, a temperature sensor for outputting a signal indicating the temperature of at least a portion of the air dryer, and a controller piloting the series of valves. To prevent a risk of the valves freezing when operated, the controller is programmed to inhibit operation of the series of valves until the signal received from the temperature sensor indicates that the series of valves are warm enough that they will not freeze when operated. The series of valves may include a pair of inlet valves and a pair of exhaust valves associated with a twin-tower desiccant air dryer. The series of valves may also include a drain valve associated with a pre-filtration stage. The temperature sensor is preferably positioned to determine the temperature of air flowing through the air dryer, but may be installed in the valve block or positioned to detect the outside temperature.
The present invention also comprises a method of preventing frozen air dryer valves that involves the use of an air dryer comprising an inlet for receiving compressed air, a series of valves positioned in a valve block for controlling the movement of the compressed air through a desiccant, a heater configured to warm the valve block, a temperature sensor for outputting a signal indicating the temperature of at least a portion of the air dryer, a controller piloting the series of valves. The signal indicating the temperature in the air dryer is received by the controller from the temperature sensor, and then the controller inhibits operation of the series of valves if the signal received from the temperature sensor indicates that any of the series of valves could freeze when operated.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic of a locomotive air supply system having an air dryer having a heated valve block according to the present invention;
FIG. 2 is a schematic of an air dryer with integral pre-filtration stage and a heated valve block according to the present invention;
FIG. 3 is a schematic of a heated valve block of an air dryer with pre-filtration state according to the present invention; and
FIG. 4 is a flowchart of a heater control process for an air dryer having a heated valve block.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, wherein like reference numerals refer to like parts throughout, there is seen in FIG. 1 a locomotive air system 10 having an air compressor 12 , aftercooler 14 , first and second main reservoirs MR 1 and MR 2 , and a two-tower desiccant air dryer 16 having heater control according to the present invention, as more fully described below. Second main reservoir MR 2 is coupled to the braking system 18 and a check valve 20 is positioned between the first and second main reservoirs MR 1 and MR 2 . A pre-filtration stage 22 is associated with air dryer 16 and includes a drain valve 24 that is operated according to a drain valve purge cycle time.
Referring to FIG. 2 , two-tower desiccant air dryer 16 comprises an inlet 28 for receiving air from first main reservoir MR 1 . Inlet 28 is in communication with pre-filtration stage 30 , shown as comprising a water separator 32 , a coarse coalescer 34 , and a fine coalescer 36 . Any accumulated liquids in water separator 32 , coarse coalescer 34 , and fine coalescer 36 are expelled through drain valve 24 . A pair of inlet valves 42 and 44 are positioned downstream of pre-filtration stage 30 for diverting incoming air between one of two pathways, each of which is associated with one of two dessicant towers 46 and 48 . A temperature sensor 50 is positioned upstream of inlet valves 42 and 44 and downstream of pre-filtration stage 30 . Optionally, the temperature, or a second temperature sensor may be located in the valve block housing the series of valves. The first pathway downstream of first inlet valve 42 leads to an exhaust valve 52 and first desiccant tower 46 . The second pathway downstream of second inlet valve 44 leads to a second exhaust valve 54 and second desiccant tower 48 . The first pathway further includes a first check valve 58 and first bypass orifice 62 downstream of first desiccant tower 46 , and the second pathway further includes a second check valve 60 and bypass orifice 64 downstream of second desiccant tower 48 . A single outlet 66 is coupled to the end of the first and second pathways, and a humidity sensor 68 is positioned upstream of outlet 66 . Inlet valves 42 and 44 and outlet valves 52 and 54 are piloted by controller 40 . Controller 40 operates inlet valves 42 and 44 and outlet valves 52 and 54 so that compressed air provided at inlet 28 is directed through one of desiccant towers 46 or 48 for drying. The other of desiccant towers 46 or 28 may be regenerated by allowing dried air to reflow through bypass orifice 62 or 64 and out of exhaust valve 52 or 54 as needed. Controller 40 is also in communication with temperature sensor 50 and humidity sensor 68 . A heating element 70 may also be coupled to controller 40 and positioned in air dryer 16 to warm drain valve 24 , inlet valves 42 and 44 and outlet valves 52 and 54 if the temperature is below freezing.
As seen in FIG. 3 , the air dryer pathways seen in FIG. 1 are arranged so that drain valve 24 , inlet valves 42 and 44 , and outlet valves 52 and 54 are commonly located along with heater element 70 in a valve block 72 . As explained above, air dryer 16 includes temperature sensor 50 for determining the approximate temperature of valve block 72 and thus drain valve 24 , inlet valves 42 and 44 , and outlet valves 52 and 54 . Temperature sensor 76 is shown as being positioned to detect the temperature of air passing through air dryer 16 , but may be positioned to detect the temperature of valve block 72 , the temperature of the inlet air, the temperature of ambient air, or some combination of the above.
Referring to FIG. 4 , air dryer controller 40 is programmed to implement a heater control process 80 to ensure that valve block 72 is sufficiently heated to a temperature that avoids the likelihood that drain valve 24 , inlet valves 42 and 44 , or outlet valves 52 and 54 can become frozen. First, controller 40 reads the temperature 82 such as by using temperature 76 positioned in valve block 72 . Next, a check 84 is performed to determine whether the temperature is below freezing (or any other predetermined temperature selected to be indicative of a risk that drain valve 24 , inlet valves 42 and 44 , or outlet valves 52 and 54 will become frozen). If the temperature is below the threshold at check 82 , controller 40 inhibits valve operation 86 , such as by inhibiting the operation of drain valve 24 , inlet valves 42 and 44 , and/or outlet valves 52 and 54 until such time as the temperature has risen above the threshold. Thus, if air dryer 16 is turned on after an extended cold soak at low temperature, controller 40 will affirmatively inhibit actuation of drain valve 24 , inlet valves 42 and 44 , and/or outlet valves 52 and 54 until heater element 70 has warmed valve block 72 sufficiently to prevent any of drain valve 24 , inlet valves 42 and 44 , and outlet valves 52 and 54 from freezing in an open position and causing an undesired venting of compressed air from locomotive air supply system 10 . Preferably, inlet valves 42 and 44 are normally open and exhaust valves 52 and 54 are normally closed in the unpowered state, so that compressed air may flow through air dryer 16 to MR 2 when all valves are in an unpowered state. By using closed loop temperature feedback to control inhibit the operation of the series of valves, the start-up time for a cold air dryer is proportional to the starting temperature. Alternatively, a simple system which uses a fixed time delay calculated to allow the valve block to warm to above freezing for the worst case condition may be provided.
The same sensor and controller may be used to turn off the heater, when the temperature of the valve block is at or above the target temperature, thus regulating the temperature of the valve block to a temperature above freezing when the ambient temperature is below freezing; and turning the heater off completely when the ambient temperature, as indicated by the temperature of the valve block, is above freezing.
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An air dryer having a heater element associated with its valves to prevent freezing at cold temperatures. The air dryer includes a temperature sensor and an electronic controller that reads the temperature sensor and inhibits actuation of the valves whenever the temperature of valves is below freezing or a predetermined temperature that indicates a risk for freezing until the valves have been sufficiently warmed by the heater to avoid freezing during operation.
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BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to packaging of electrical or electronic components.
It is desirable to package electrical or electronic components within containers and/or on racks of certain standard sizes and that electrical or electronic components and hardware therefor should be of certain standard sizes to be receivable within containers and/or on racks.
With this in mind a number of companies have devised modular units and, recently, certain sizes have been agreed upon as being desirable standards.
In particular, reference is made to an I.E.C. document which is referred to as I.E.C. TC - 13-217. The standards suggested therein are now coming to be accepted.
One undesirable consequence of the standards specified by I.E.C. is that in certain situations it is necessary to use sheets of metal of thickness of about 1.4 mm and width of about 450 mm which are supported at their sides but not across their width. Such sheets are too thin to support their own weight and often sag. Whilst thickening the unsupported edge or securing it to a cross-member would give the desired strength and stiffness, so doing would probably result in the container, racking or other electronic component support means of which the sheet formed part ceasing to comply with these I.E.C. standards.
Since these solutions to the problem are unacceptable, this invention has an object the stiffening of such sheets without causing non-compliance with I.E.C. standards.
SUMMARY OF THE INVENTION
The present invention provides, in a packaging for electrical or electronic components, for instance a racking system, a module, a housing, a component mounting, a mounting frame or a housing, a sheet unsupported along an edge and, in its own right, tending to bow along said edge under its own weight or under component loads and wherein said edge is stiffened by a stiffener member hingedly attached to said edge and wherein said stiffener can be hingedly swung between first and second positions in which it respectively does not project beyond the plane of one surface and the opposite surface of said sheet.
PREFERRED ASPECTS
It is particularly preferred that the stiffener member is such as to stiffen said edge in all hinged orientations thereof. To this end the stiffener member may be made of a material having substantially greater stiffness than said sheet at said edge. However, it is particularly preferred that the stiffener member is of substantially greater cross-sectional thickness relative to said sheet at said edge and measured in a plane perpendicular to the sheet at said edge in all of said hinged orientations. In this last aspect it is preferred that the cross-sectional thickness as aforesaid of the stiffener member is at least 3 times, more preferably 5 times, that of the sheet at said edge.
As it is likely that in some circumstances two such sheets will be placed parallel and in contiguity it is preferred that the stiffener members of the two sheets are so shaped that in such circumstances both stiffener members may be hingedly swung between first and second positions so as, respectively, not to project beyond the plane of the surface of one sheet most remote from the other sheet and the plane of the surface of said other sheet most remote from said one sheet. Further, it is preferred that the stiffener members of the two sheets are so shaped as not to project towards the respective sheets beyond a plane, which plane being perpendicular to the aforesaid planes and passing through said edge of each of the two sheets, when in the first and second positions. However, given that the dimensions of the stiffener members are not such as to take up a significant area of the sheets such projection may be permissible in certain instances.
In another instance where there are two such sheets in parallel and contiguity it may only be necessary to use one stiffener member. In this respect, if it is desired to stiffen both sheets it may be necessary that they be secured to one another.
The preferred form of the stiffener member is a longitudinally extending angle, solid member or box section. The use of a box section rather than a solid section will give greater stiffness per unit of weight but manufacturing sensibilities may dictate the use of solid sections.
It is preferred that the cross-sectional shape of the solid member or box section is that of a right angle triangle having 45° as the other angles or an equilateral triangle. A quadrant is also a desired cross-sectional shape. When the solid member or box member has the cross-sectional shape of a right angle triangle having 45° as the other angles it is preferred that the hinged attachment thereof to the sheet is at one of the 45° angles rather than at the right angle and where two sheets with two stiffener members are in parallel and contiguity it is particularly desirable that the hypotenueses of those triangles are adjacent to one another.
Although in many instances it would be undesirable that the stiffener member or members should project as aforesaid, such projection can be of use to support another such sheet which is not provided with a stiffener member.
The sheet may be made of metal or synthetic plastics material; the former being more probable.
The present invention has particular application to sheets of thickness 0.5 to 3 mm, preferably about 1.4 mm, width measured along said edge of 200 to 1000 mm, preferably about 450 mm and of indeterminate length.
The stiffener member preferably has a maximum cross-sectional thickness, measured radially of the axis of hinging, of at least 5 mm, more preferably at least 10 mm and preferably not more than 100 mm, more preferably not more than 50 mm and still more preferably not more than 20 mm and most preferably about 10.0 mm.
The hinged attachment of the stiffener member to the sheet is unlikely, except in rare circumstances, to be achievable by securing a strap of a hinge to said sheet as so doing, in the context of electronics packaging, is likely to unacceptably increase the thickness of the sheet.
However, in one instance the hinged attachment is provided by a thin flexible material extending between the sheet and the stiffener member. In a particular instance of this the sheet, thin flexible material and stiffener are integrally formed such as by extrusion or by pressing an extruded member to form the thin flexible material.
When the sheet is to be of metal it is preferred that said edge is formed to constitute one part of the knuckle of the hinge, the other part of the knuckle being attached to or formed with a stiffener member and there is a hinge pin joining the two knuckle parts. This last is currently the most preferred construction.
The present invention also provides such a sheet having such a stiffener member hingedly attached thereto.
Specific constructions in accordance with this invention will now be described with the aid of the accompanying drawings.
BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWINGS
FIG. 1 is a perspective view of a known racking system,
FIG. 2 is a fragmentary cross-sectional view on line II--II in FIG. 1,
FIG. 3 is a perspective view of a sheet and a stiffener member in accordance with this invention but in disassembled condition,
FIG. 4 is a perspective view of the sheet and a stiffener member of FIG. 3 but in assembled condition,
FIG. 5 is a side elevation showing two sheets and a stiffener member in accordance with this invention of FIG. 4 in alternative configurations,
FIG. 6 is a side elevation of the sheets and a stiffener member shown in FIG. 5 but in alternative configurations,
FIG. 7 is a side elevation showing two alternative stiffener members in accordance with this invention,
FIG. 8 is a side elevation showing an alternative stiffener member in accordance with this invention,
FIG. 9 is a side elevation showing an alternative stiffener member in accordance with this invention, and
FIG. 10 is a perspective detail of a part shown in FIG. 9.
DETAILED DESCRIPTION
In FIG. 1 is shown a known racking system comprising vertical side stiles 1 and 2 which support containers comprised of sides 3 and 4 and top and bottom sheets 7 and 6 of about 1.4 mm thickness, 450 mm width and indeterminate depth. Facing members 8 are also provided but, if sufficiently thick and attached to the sheets 6 and 7 to provide adequate reinforcement, may make the aperture "a" unacceptably small.
Since the sheets 6 and 7 will tend to sag under their own weight and under loading, there is a problem which can at least in part be overcome as shown in FIGS. 3 - 6 where sheets 16 and 17 have hinge knuckle parts 18 and stiffener members 19 and 20 have hinge knuckle parts 21 and which hinge knuckle parts are connected by a hinge pin 22.
The stiffener members 19 and 20 are box sections and will stiffen the sheets 16 and 17. Further, the stiffener member can be oriented as shown in full or dash lines in FIG. 6 where they respectively do not extend above and below sheets 16 and 17 and thus in no way affect the location of electronic components or enter the containers. When access to the containers is not required the location in intermediate positions as shown in FIG. 5 is permissible.
The constructions shown in FIGS. 7 - 10 differ from that of FIGS. 3 - 6 in that differently shaped stiffener members are used and that the stiffener members are solid.
In the constructions shown in FIGS. 8 and 9 the stiffener members are shaped so that when the upper one or part thereof is oriented to lie in the same plane as the upper surface of the sheet 16 the other or another part thereof will enter the container. Given that the amount of entrance does not exceed about 15 mm this is not deleterious and permits the stiffener to also locate components or restrict movement of components by means of the end 23 as shown in FIG. 8 and FIG. 9.
It is to be noted in respect of FIG. 8 that only the top sheet 16 is provided with a stiffener and that the bottom sheet 17 is unstiffened. This will be satisfactory in gravity load only situations but, if desired, the sheets 16 and 17 can be secured to one another so that sheet 17 derives its stiffness from sheet 16.
Referring now to FIGS. 9 and 10, the stiffeners 19 and 20 are provided with a plate 24 having lands. These lands can serve to locate components and restrict them against sideways movement if those components have projections which can be received between the lands. In an alternative to the plate 24 the stiffeners 19 and 20 may be provided with upstanding projections such as pins received within holes in the stiffeners 19 and 20.
Modifications and adaptations may be made to the above described without departing from the spirit and scope of this invention which includes every novel feature and combination of feature disclosed herein.
The claims form part of the disclosure of this specification.
The standards prescribed in I.E.C. TC - 13 - 217 have recently been republished by the International Electro-technical Commission (I.E.C.) as Publication Nos. 297 and 473.
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A device for stiffening a rack for electrical or electronic components having an unsupported sheet includes a stiffener member hingedly attached to an edge of the unsupported sheet. The stiffener may be formed as a box section or as a solid member.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to use of low molecular weight polymers (oligomers) as insolubilizers for binders in paper coating compositions.
2. Description of the Prior Art
Polymers have been used as insolubilizers for binders in paper coating compositions.
U.S. Pat. No. 3,869,296--Kelly, Jr. et al., issued Mar. 4, 1975, describes paper coating compositions containing a pigment, starch as binder for the pigment and a insolubilizing agent for the binder, being the reaction product of glyoxal and urea at a mole ratio of 1.0 mole glyoxal to from about 0.5 mole to about 0.75 mole of urea. These compositions cure at low temperatures, are stable and provide coatings which possess high wet-rub resistance.
U.S. Pat. No. 3,917,659--Glancy et al., issued Nov. 4, 1975, describes dry, solid glyoxal-urea products obtained by drying the reaction product of 1.0 mole glyoxal to from 0.25 mole to 0.9 mole of urea. These products are useful in paper coating compositions.
U.S. Pat. No. 4,343,655--Dodd et al., issued Aug. 10, 1982, describes paper coating compositions containing at least one pigment, at least one binder and as an insolubilizer for the binder an alkylated product of the reaction of glyoxal and a cyclic urea at a mole ratio of about 0.5 to about 2.0 mole glyoxal to 1.0 mole of cyclic urea.
SUMMARY OF THE INVENTION
It has been found unexpectedly that when glyoxal and urea are reacted at temperatures between about 40 and about 50° C. for several hours using a very narrow molar ratio of glyoxal to urea, with the preferred ratio being about 3 moles of glyoxal to about 1 mole of urea, the resulting product contains 95-96% of a polymeric material having a low molecular weight, a water soluble oligomer which is a highly efficient formaldehyde-free paper coating composition insolubilizer. Any substantial deviation from the 3:1 ratio results in a highly decreased performance when used as a paper coating insolubilizer.
DETAILED DESCRIPTION
Polymers produced by the prior art could not successfully compete with melamine-formaldehyde resins due to their higher cost and poor performances when compared on a cost basis. The polymers produced by the present invention have numerous advantages over prior art polymers even when used in a fraction of the amount required for the melamine-formaldehyde resins to produce high wet-rub resistance deemed to be satisfactory in paper coating applications.
The present invention relates to production of an oligomer of glyoxal and urea. This oligomer is obtained by condensation of an aqueous solution containing about 3 moles of glyoxal and about 1 mole of urea at about 40 to about 50° C. for several hours.
The water soluble oligomer may be added in the form of an aqueous solution to paper coating compositions containing binders, pigments, preservatives, lubricants, defoamers and other additives. Coating compositions may contain starches such as natural starches, oxidized starches or enzyme converted starches having functional groups such as hydroxyl, carbonyl, amido or amino groups, proteins such as casein, latices such as styrene-butadiene resins or the like. Pigments, which may be present in coating compositions, include clays, titanium dioxide, calcium carbonate, carbon blacks, ultramarine blue or the like. Preservatives such as bactericides, fungicides, silimicides or the like may also be present in coating compositions.
Total solids content of the coating compositions may be within the range of about 40 to about 70% depending on the method of application and product requirements. In these coating compositions, the amount of binder is based upon the amount of pigment; the ratio varies with the amount of bonding desired and with the adhesive characteristics of the particular binder employed. The amount of binder may be from about 10 to about 25%, and preferably from about 12 to about 18% based on weight of the pigment. Amount of insolubilizer varies with the amount and properties of the binder and the amount of insolubilization desired; in general it is about 2% to about 15% by weight and preferably from about 5 to about 10% based on the weight of the binder. These coating compositions may be applied to paper or paper-like substrates by any known and convenient means.
For a fuller understanding of the nature and advantages of this invention, reference may be made to the following examples. These examples are given merely to illustrate the invention are not to be construed in a limiting sense. All quantities, proportions and percentages are by weight and all references to temperature are °C.
EXAMPLE I
435.0 parts by weight of a 40% by weight aqueous glyoxal solution containing 3.0 moles of glyoxal were charged into a glass lined reactor. Temperature of the charge was 23° C. and the pH 2.16. 60.0 parts by weight of urea containing 1.0 mole of urea were added to the agitated glyoxal solution. After 15 minutes, a uniform solution was obtained, the condensation temperature fell to 16° C. and the pH rose to 2.89. Low heat was applied and the temperature gradually increased over one hour's time to 45° C. The pH of the condensation solution dropped to 2.33. The condensation mixture was held at a constant temperature of 45° C. for the next 2.5 hours. At the end of this period, the pH of the condensation solution fell to 2.17. After 2 more hours at 45° C., no further change in pH was noted and the condensation mixture was cooled to 20° C. A mixture of 0.85 parts by weight sodium hydroxide 50% and 3.5 parts by weight water was prepared and added slowly under agitation. The resulting product, a pale-yellow, clear liquid having 46.9% by weight solids, a pH as is of 6.9 and a freezing point of -7° C., contained an oligomer. The molar ratio of glyoxal to urea in the oligomer was 3 moles of glyoxal to 1 mole of urea. The oligomer was analyzed by the following methods:
A total of 30.0 grams of the product was added to 600 grams of acetone, stirred with a glass rod for 10 minutes to obtain a white precipitate. The white precipitate, the oligomer, was transferred quantitatively to a weighed filter paper, washed 2 times with 200 grams acetone, dried in a vacuum dessicator and then overnight in an oven at 90°-100° C. The weight of the recovered oligomer was 13.44 grams.
30.0 grams at 46.9% solids=14.07 grams
Recovered oligomer=13.44 grams
oligomer yield=95.5%
A 40% water solution of the recovered oligomer had a reduced viscosity at 30° C. ηsp/c=0.089 as measured by the Cannon-Fenske instrument.
Structure of the oligomer was unknown but it is assumed to be:
6 moles of glyoxal+2 moles of urea ##STR1##
Attempts to determine residual glyoxal remaining in the oligomer or the terminal CHO groups by simple alkalimetric method where excess of alkali is used to convert the glyoxal to glycolic acid by the Cannizzaro reaction were fruitless because under strong alkali conditions the oligomer was split resulting in formation of excess of glycolic acid groups and giving completely erroneous results.
The preferred method for determination of free glyoxal and terminal CHO groups, a method based on a kinetic study by the Department of Chemistry, University of Turku, Finland, was used. This method is based on addition of excess sodium bisulfite to glyoxal in a phosphate buffer system in order to effect a rapid addition reaction, after which the excess bisulfite is titrated with standard iodine solution under acid conditions in order to prevent the decomposition of the glyoxal-bisulfite adduct during the titration.
Following are the details of the method:
Apparatus
Erlenmeyer flasks, 250 ml; burette 25 ml;
Volumetric flasks, 1000 ml; 200 ml;
Automatic pipettes, 20 ml; 10 ml; 5 ml.
Reagents
0.05 Molar glyoxal solution=7.25 grams glyoxal 40%/liter
0.01 Normal sodium bisulfite solution=10.4 grams/liter (freshly prepared)
0.01 Normal iodine solution
Buffer solution, 71 grams Na 2 HPO 4 +17 grams KHPO 4 /liter
1 Normal HCl solution
Starch indicator solution
Procedure
1. Add to a 250 ml Erlenmeyer flask exactly 20 ml 0.1 Normal sodium bisulfite solution. 10 ml buffer solution, 5 ml 1 Normal HCl solution. Titrate with 0.1 Normal iodine solution. Record the number of ml required=X.
2. Add to a 250 ml Erlenmeyer flask exactly 5 ml 0.05 molar glyoxal solution, 20 ml 0.1 Normal sodium bisulfite solution. Leave standing for 3 minutes time. Add 5 ml 1 Normal HCl solution. Titrate with 0.1 Normal iodine solution. Record the number of ml required=Y.
3. Dissolve exactly 5.8 grams of the tested liquid sample or 2.0 grams of the solid sample in a 200 ml volumetric flask with distilled water. Fill to the mark and shake well to get a uniform solution. Add 5 ml of the solution to a 250 ml Erlenmeyer flask followed by 10 ml buffer solution and 20 ml of 0.1 Normal sodium bisulfite solution. Leave standing for a 3 minute period. Add 5 ml 1 Normal HCl solution. Titrate with 0.1 Normal iodine solution. Record the number of ml required=Z.
Calculation
% free glyoxal+CHO terminal groups
5.8 grams sample: ##EQU1## 2.0 grams sample: ##EQU2##
Sample from Example I as is 5.8 grams was analyzed by the bisulfite method and gave the following results:
X=31.0
Y=11.6
Z=15.6 ##EQU3##
Acetone precipitated sample weighing 2 grams was analyzed by the bisulfite method and gave the following results:
X=37.8
Y=18.1
Z=28.9 ##EQU4## % solids in the liquid polymer=46.9 13.1×0.469=6.14% CHO terminal groups in liquid material
% free glyoxal 7.94-6.14=1.8%
The 13.1% CHO terminal groups in the dry polymer correspond to about 2 terminal CHO groups in the assumed structure of the oligomer.
EXAMPLE II
406.0 parts by weight of a 40% aqueous glyoxal solution containing 2.8 moles of glyoxal were charged into a glass lined reactor. The temperature was 22° C. and the pH was 2.16. 60.0 parts by weight of urea (1.0 mole) were added to the glyoxal solution under agitation. After 15 minutes, a uniform solution resulted. The temperature dropped to 15° C. and the pH rose to 2.9. Low heat was applied and the temperature rose gradually within one hour's time to 46° C. The reaction mass was kept at a constant temperature of 46° for a four hour period. The reaction mass was then cooled to 20° C. and 4 parts of 10% by weight sodium hydroxide solution was added slowly. The final product appeared as a pale-yellow, clear liquid having 47.3% solids and a pH of 6.0.
The molar ratio of glyoxal to urea in Example II was 2.8 moles of glyoxal to 1 mole of urea.
EXAMPLE III
464.0 parts by weight of a 40% aqueous glyoxal solution containing 3.2 moles of glyoxal were charged into a glass lined reactor. The temperature was 20° C. and the pH was 2.16. 60.0 parts by weight of urea (1.0 mole) were added to the glyoxal solution under agitation. After 18 minutes time a uniform solution resulted, the temperature dropped to 12° C. and the pH rose to 2.8. Low heat was applied and the temperature rose gradually within one hour's time to 44° C. The reaction mass was kept at constant 44° C. for 4 hours. The reaction mass was then cooled to 20° C. and 4 parts by weight of 10% by weight sodium hydroxide solution was added slowly. The final product appeared as a pale-yellow, clear liquid having 46.5% solids and a pH of 6.0.
The molar ratio of glyoxal to urea in this Example III was 3.2 moles of glyoxal to 1.0 mole of urea.
EXAMPLE IV
261.0 parts by weight of a 40% aqueous glyoxal solution containing 1.8 moles of glyoxal were charged into a glass coated reactor. The temperature was 23° C. and the pH was 2.17. 60.0 parts by weight of urea (1 mole) were added to the glyoxal solution under agitation. After 15 minutes time a uniform solution resulted, the temperature dropped to 12° C. and the pH rose to 2.9. Low heat was applied and the temperature rose gradually within one hour to 45° C. and was kept constant at 45° C. for a four hour period. After cooling to 20° C., 4 parts by weight of 10% by weight sodium hydroxide solution was added slowly. The final product was a pale-yellow, clear liquid having 50.5% solids and a pH of 6.0.
The molar ratio of glyoxal to urea in this example was 1.8 mole of glyoxal to 1.0 mole of urea.
EXAMPLE V
217.5 parts by weight of a 40% aqueous glyoxal solution containing 1.5 moles of glyoxal were charged into a glass coated reactor. The temperature was 22° C. and the pH was 2.7. 60 parts by weight of urea (1 mole) were added to the glyoxal solution under agitation. After 15 minutes time a uniform solution resulted, the temperature dropped to 12° C. and the pH rose to 2.9. Low heat was applied and the temperature rose gradually within one hour's time to 45° C. The reaction mass was kept at constant temperature of 45° C. for the next 4 hours, then cooled to 20° C. 4 parts of sodium hydroxide 10% was added slowly. The final product appeared as a pale-yellow, clear liquid having 52% solids and a pH of 6.0.
The molar ratio of glyoxal to urea in Example V was 1.5 moles of glyoxal to 1.0 mole of urea.
Comparative Performance Tests
A test coating formula was prepared as follows:
100.0 parts Ultragloss 90 clay
8.0 parts Penford gum 280 starch
7.0 parts Polysar 55E SB latex
0.1% TSPP on clay (tetrasodium polyphosphate)
55.0% total solids
10% insolubilizer on binder, solids basis (about 3%)
pH 7.0
The following materials were added as insolubilizers:
No. 1. A commercial melamine formaldehyde resin, solids 62%.
No. 2. A commercial glyoxal-ehylene urea resin, solids 45%.
No. 3. Example No. 1, glyoxal-urea resin, solids 46.9%.
No. 4. Example No. 2, glyoxal-urea resin, solids 47.3%.
No. 5. Example No. 3, glyoxal-urea resin, solids 46.5%.
No. 6. Example No. 4, glyoxal-urea resin, solids 50.5%.
No. 7. Example No. 5, glyoxal-urea resin, solids 52%.
______________________________________Sample 1 Minute Cure 120°C. 2 Minutes Cure 120°C.______________________________________Wet Rub Results According to TAPPI UM463Blank 2 2No. 1 4 10No. 2 3 4No. 3 9 15No. 4 9 15No. 5 9 15No. 6 1.5 2.5No. 7 1.8 3.8Comparative Efficiency of the MaterialsAgainst Example No. 1 as 100Blank 22 13No. 1 45 67No. 2 34 27No. 3 100 100No. 4 100 100No. 5 100 100No. 6 17 17No. 7 10 26______________________________________
The above tests show that the materials prepared according to the process of the invention with ratios glyoxal to urea in the range of 2.8-3.2 moles of glyoxal to 1.0 mole urea are at least 50% better than the standard melamine formaldehyde resin (Sample No. 1) and at least 3 times better than the commercial glyoxal-ethylene urea products (Sample No. 2).
When the molar ratio of glyoxal to urea is outside of the claimed optimum range, the performance of the materials drops drastically as to between 17-26% of the performance of the optimum ratio materials.
Three pigmented coatings formulas were used to evaluate the performance of different insolubilizers for wet-rub resistance using the Adams Wet Rub Tester.
______________________________________ Coating Formula (Parts)Components No. 1 No. 2 No. 3______________________________________Clay No. 2 100 100 100S.B. Latex -- 3 8Oxidized starch 17 13 8______________________________________
0.1% antifoam, 0.1% dispersant and 1% lubricant were added to all 3 formulations. 3% of insolubilizer were added to the formulas. pH=7.0.
Coatings were applied using the rod applicator (No. 8 rod) on the Keegan coater and sheets were continuously dried using two infra-red driers on the Keegan. Coat weights were approximately 8-10 lb/3300 square feet and were controlled as closely as possible. Adams wet rub tests were run 24 hours after coating application. The procedure as supplied by the Testing Machines, Inc., the equipment suppliers, was modified to obtain the highest possible test accuracy. Whereas the procedure called for running one test strip and using a filtration technique with filter paper and drying the filter paper with residue, in the modified procedure 3 test strips (1 each from 3 different coated sheets) were used and the water was evaporated in aluminum dishes that contained the water used during the test sequence. The modified procedure adds to test accuracy because the filtration step is omitted and the inherent inaccuracies of filter papers with milligram differencies in residue weight are eliminated. Beside this, the residue weights are tripled by the use of 3 times greater surface area of coated paper. Each weight was divided by 3 for reporting to conform to the original procedure as supplied by the Testing Machines, Inc.
Summary of the Tests Using the Adams Wet-Rub Tester
______________________________________ Adams Brookfield ViscosityInsolubilizer Residue Grams in cps at 10 RPM______________________________________ Coating No. 1Blank 0.0160 3200Commercial MF resin 0.0050 3200Commercial glyoxal- 0.0037 4000ethylene urea resinCommercial formalde- 0.0040 6000hyde-free resinExample No. 1 0.0020 3600Example No. 2 0.0021 3700Example No. 3 0.0020 3000Example No. 4 0.0117 3000Example No. 5 0.0076 3000 Coating No. 2Blank 0.0098 3600Commercial MF resin 0.0027 3000Commercial glyoxal- 0.0017 4600ethylene urea resinCommercial formalde- 0.0026 8200hyde-free resinExample No. 1 0.0013 3600Example No. 2 0.0013 4200Example No. 3 0.0012 4800Example No. 4 0.0076 3000Example No. 5 0.0050 3000 Coating No. 3Blank 0.0024 2600Commercial MF resin 0.0061 2400Commercial glyoxal- 0.0015 2600ethylene urea resinCommercial formalde- 0.0021 3000hyde-free resinExample No. 1 0.0010 2600Example No. 2 0.0010 2400Example No. 3 0.0010 2400Example No. 4 0.0059 2200Example No. 5 0.0038 2200______________________________________
Comparative Efficiency of the Materials Against Example No. 1 as 100
______________________________________ CoatingSample No. No. 1 No. 2 No. 3______________________________________Blank 12 13 41Commercial MF resin 40 48 16Commercial glyoxal-ethylene 54 76 66urea resinCommercial formaldehyde-free 50 50 48resinExample No. 1 100 100 100Example No. 2 95 100 100Example No. 3 100 108 100Example No. 4 17 17 17Example No. 5 26 26 26______________________________________
The above tests show that the materials made according to the process of invention are 2-6 times better than the MF resins and 1.3-2 times better than the commercial formaldehyde-free formulations, depending on coating compositions.
While the invention has been described with reference to certain specific embodiments thereof, it is understood that it is not to be so limited since alterations and changes may be made therein which are within the full intended scope of the appended claims.
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A highly efficient formaldehyde-free coating composition insolubilizer is prepared by reacting about 3 moles of glyoxal with 1 mole of urea resulting in a formation of a low molecular weight oligomer in a yield of 95-96%. The molar ratio of glyoxal to urea is very critical in obtaining the highest efficiency and is kept within narrow limits. The coating compositions of the present invention possess 2 till 4 times higher wet-rub resistance than the prior art compositions.
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BACKGROUND
The present invention relates to suture passers and graspers and more particularly to such instruments and methods for their use wherein provision is made to eject the suture therefrom.
Within the field of medical surgery, there are times when a suture needs to be passed through soft tissue, but direct access to the tissue is not possible (e.g. during arthroscopy). Generally, this passage of suture is performed either anterograde or retrograde. In anterograde passing an instrument called a suture passer grasps a strand of suture and is forcibly driven through the soft tissue. Then, the suture is disengaged from the passer and the passer removed from the tissue. Retrograde passing involves driving an empty passer through the soft tissue and then manipulating it such that it captures a length of suture already inside the body. The passer is then removed from the soft tissue and pulls the suture through with it. In both of these cases, one major drawback of the suture passer is that it can be quite difficult to disengage the suture from the jaws of the passer. This is particularly true for the anterograde technique and is mainly due to the fact that the passer jaws open into a fairly large cavity. The surgeon must manipulate the tip of the passer to cause the suture to move sufficiently out of the open jaws that closing the open jaws will no longer cause the suture to become re-trapped by the passer. This process of manipulation can lead to trauma to the surrounding soft tissue up to and including the suture passer ripping through the soft tissue, foiling the repair intent of the suturing and forcing the surgeon to pursue alternate courses of repair of patient treatment. The cavity frequently also is provided with a lip or other structure to assist in the process of capturing the suture, but such features can add difficulty when the surgeon later attempts to expel the suture.
SUMMARY OF THE INVENTION
A suture passing mechanism according to the present invention comprises an elongated delivery member having a suture capture fitting at a distal end thereof. The suture capture fitting comprises a recess for receiving a length of suture. The recess has a proximal wall and a lateral opening leading therein. An expeller at the recess is adapted to expel suture out of the recess through the lateral opening.
Preferably, the expeller comprises a surface movable across the recess toward the lateral opening whereby to push the suture out of the lateral opening. In one embodiment, the expeller comprises a line affixed adjacent the lateral opening. It is received within the recess and spaced apart from the opening in a first position and adjacent the lateral opening in a second position. In one aspect of the invention, the line is biased into the first position and tension applied to the line moves it into the second position. Alternatively, axial compression applied to the line moves it into the second position. It can also be moved into the second position by removing tension applied to the line or removing compression applied to the line.
A method according to the present invention provides for passing suture through tissue. The method comprises the steps of: capturing a suture into a recess in a suture capture fitting on a distal end of an elongated delivery member; passing the suture through the tissue via the delivery member; and expelling the suture out of the recess through a lateral opening into the recess via an expeller in the recess.
In one aspect of the invention, a surface on the expeller is moved across the recess toward the lateral opening to push the suture out of the lateral opening. The expeller can comprise a line affixed adjacent the lateral opening and received within the recess so that it is spaced apart from the opening in a first position and adjacent the lateral opening in a second position such that the line is moved from the first position to the second position to expel the suture out of the lateral opening. The method can further comprise the step of biasing the line into the first position. The method can further comprise the step of applying, removing, increasing, or decreasing tension or compression to the line to move it into the second position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of a suture passer according to the present invention;
FIGS. 2A to 2C are side elevation views of a suture grasping mechanism with an expelling feature at a distal end of the suture passer of FIG. 1 ;
FIGS. 3A to 3C are side elevation views of a further suture grasping mechanism according to the present invention with an alternative expelling feature;
FIG. 4 is a side elevation view of a further suture grasping mechanism according to the present invention with an alternative expelling feature;
FIG. 5 is a side elevation view of an alternative suture grasping mechanism for a suture passer according to the present invention;
FIGS. 6A to 6C are side elevation views of a further suture grasping mechanism according to the present invention;
FIGS. 7A to 7C are side elevation views of a further suture grasping mechanism according to the present invention; and
FIGS. 8A to 8C are side elevation views of a further suture grasping mechanism according to the present invention.
DETAILED DESCRIPTION
FIG. 1 illustrates a suture grasper 10 according to the present invention. It comprises in gross an elongated shaft 12 having a distal grasping mechanism 14 and a proximal scissor handle 16 . The grasping mechanism 14 comprises a suture capture recess 18 having a lateral opening 20 and an articulating jaw 22 . The handle 16 comprises a fixed arm 24 and an articulating arm 26 connected to the articulating jaw 22 via a rod or wire 28 whereby articulation of the arm 26 translates into articulation of the jaw 22 .
Turning also now to FIGS. 2A to 2C , the shaft 12 optionally terminates with a sharp distal tip 30 for passing a portion of the shaft 12 and the grasping mechanism 14 through tissue (not shown) to grab or release a suture 32 . The suture 32 is captured in the recess 18 ( FIG. 2A ). It can then be manipulated in a procedure such as being pulled back through the tissue. To release the suture 32 the jaw 22 is opened ( FIG. 2B ).
To assist in releasing the suture 32 from the recess 18 an expeller wire 34 is bowed outwardly toward the opening 20 to push the suture 32 out of the opening 20 ( FIG. 2C ). The expeller wire 34 is preferably a flexible but stiff wire that will bow when put into compression. It could be formed from a superelastic material such as NITINOL, but the invention need not be limited thereto. Other suitable materials include nylon, stainless steel, polyesters and elastomeric materials. The wire 34 preferably terminates in a ball 36 received within a cup 38 within the recess 18 . The cup 38 can be open or partially enclosed so as to retain the ball 36 therein while allowing rotation. Preferably, the cup 38 opens toward the opening 20 to encourage the wire 34 to rotate and bow in such direction when placed into compression. The wire 34 extends along the shaft 12 and terminates at the handle 16 in a button 40 or other mechanism to allow a user to apply compressive force thereto. Alternatively, the wire 34 could also be connected to the articulating arm 26 of the handle 16 so that a single action by a user would open the jaw 22 and activate the expeller wire 34 to expel the suture 32 from the recess 18 .
Other configurations for the wire 34 are possible. It can be pre-bent in the direction of the opening 20 to encourage it to bow in that direction under compression. This feature can be incorporated into the wire 34 along with the ball 36 and cup 38 or with some other attachment of the wire 34 , such as the wire simply being welded to the wall of the recess 18 . Rather than terminate in a ball 36 the wire 34 could terminate in a cylinder (not shown) received in a transverse bore adjacent the recess 18 with the wire 34 movable in a closed ended slot open toward the opening 20 thereby promoting rotation of the cylinder and wire toward the opening upon compression of the wire 34 . The compression applied is relative to any force on the wire 34 when it is in the position within the recess shown in FIG. 2A . For instance, if an open cup 38 is employed the wire might be biased toward the cup 38 to hold it in place and then when additional compressive force is applied the wire 34 will bow outwardly toward the opening 20 .
Turning also now to FIGS. 3A to 3C an alternative embodiment of a suture grasper 50 is shown wherein tension force applied to an expeller wire 52 initiates the expelling action. The grasper 50 comprises a grasping mechanism 54 on a distal end 56 of a shaft 58 and having a recess 60 with a lateral opening 62 enclosed by an articulating jaw 64 across the opening 62 ( FIG. 3A ). The wire 52 terminates in a distal, transverse cylinder 66 which rotates in a transverse bore 68 adjacent to the recess 60 . A closed end slot 70 is open toward the opening 62 to encourage the cylinder 66 and wire 52 to rotate toward the opening when tension is applied to the wire 52 . The wire 52 is pre-bent to normally bow outwardly away from the opening 62 leaving the recess 60 open for receipt of a suture 72 ( FIG. 3B ). A groove 74 in the wall of the recess 60 adjacent the jaw 64 allows the wire 52 to follow a path into the recess 60 without obstructing the recess 60 . When tension force is applied to the wire 52 it straightens and moves toward the opening 62 to eject the suture 72 from the recess 60 ( FIG. 3C ). A slot 76 in the jaw 64 allows the wire 52 to take this configuration unimpeded by the jaw 64 . The term “tension” is used here relative to the state of the wire 52 as shown in FIGS. 3A and 3B in which the wire could be put into less compression to encourage it to bow outwardly away from the opening 62 than it was in FIG. 3A .
FIG. 4 illustrates a further embodiment of a suture grasper 80 having a recess 82 with a lateral opening 84 and an articulating jaw 86 enclosing the opening 84 . The recess 82 is C-shaped and forms a distal lip 88 . This feature aids in capturing suture (not shown in FIG. 4 ) into the recess 82 but can impair release of suture from the recess 82 . A first end 90 of an expeller rod 92 attaches to the lip 88 adjacent the opening 84 and is received within a groove 94 in the wall of the recess 82 which extends partially therealong from the lip 88 . An actuating rod or wire 96 attaches to a second end 98 of the rod 92 to control its articulation from position received within the groove 94 leaving the recess 82 fully open to a position as shown in FIG. 4 where it is moved partially toward the opening 84 to bridge the overhang of the lip 88 and to thereby reduce or eliminate the ability of the lip 88 to entrap suture in the recess 82 . It does not fully expel the suture but allows it to more easily move out of the recess 82 unimpeded by the lip 88 . The rod 92 can be formed of a resilient material to encourage it to bow into the groove 94 . Alternatively, a wire as in the previous embodiments could be substituted for the rod 92 and be oriented similarly to operate to diminish the effect, when desired, of the lip 88 . Another option would be to form an effective lip with the wire such as with a living hinge point.
FIG. 5 illustrates a further embodiment of a suture passer 100 according to the present invention. It comprises an elongated shaft 102 terminating in a sharp distal tip 104 for penetrating tissue (not shown) with a grasping mechanism 106 immediately proximal thereto. The penetrating mechanism 106 comprises a recess 108 formed of a wall 110 and having a distal overhanging lip 112 . It further comprises a lateral opening 114 which can be spanned by an articulating jaw 116 pivotable about an axis 118 . An ejector arm 120 connects to and articulates in unison with the jaw 116 . When the jaw 116 is in a closed position, spanning and closing the opening 114 , the ejector arm 120 is received deeply within the recess 108 . A groove (not shown) can be provided in the wall 110 to receive the ejector arm 120 to minimize or eliminate its obstruction of the recess 108 in this position. When the jaw 116 is pivoted outwardly away from the opening 114 the ejector arm 120 pivots outwardly away from the wall 110 forming the recess 108 , preferably connecting to the lip 112 . If suture (not shown in FIG. 5 ) is received within the recess 108 it will now be possible to slip the suture out of the recess 108 without it getting caught up on the lip 112 . The jaw 116 and ejector arm 120 form a V-shaped opening in this position suitable for suture capture. To enhance capture employing the lip 112 to snag a suture a user can place the jaw 116 and ejector arm 120 into an intermediate position in which the opening 114 is not closed by the jaw 116 and the lip 112 is not completely obstructed by the ejector arm 120 . Alternatively, the jaw 116 and ejector arm 120 can be adapted for independent articulation.
FIGS. 6A to 6C illustrate a further embodiment of a suture grasper 200 according to the present invention. It comprises a shaft 202 having a suture capture recess 204 having a lateral opening 206 and an articulating jaw 208 . An expeller wire 210 at the recess 204 is placed in tension during capture of a suture 212 to hold the wire 210 out of the path of the suture 212 into the recess 204 ( FIG. 6A ). The jaw 208 is closed to hold the suture 212 in the recess 204 and preferably the expeller wire 210 is maintained in tension during this time ( FIG. 6B ). When it is desired to expel the suture 212 the articulating jaw 208 is opened and tension is released on the expeller wire 210 ( FIG. 6C ). The expeller wire 210 has a preformed curvature 214 which when the tension is released expels the suture 212 from the recess 204 . Preferably the expeller wire is formed of a superelastic material.
FIGS. 7A to 7C illustrate a further embodiment of a suture grasper 220 according to the present invention. It comprises a shaft 222 having a suture capture recess 224 having a lateral opening 226 and an articulating jaw 228 . An expeller wire 230 is affixed adjacent the opening 226 and when under no or reduced tension has a preformed shaped which forms a lip 232 at the recess 224 and also a curvature 234 into the recess 224 . Suture 236 is captured into the recess 224 with the assistance of the lip 232 ( FIG. 7A ) and then retained therein by closure of the jaw 228 ( FIG. 7B ). To eject the suture 236 the jaw 228 is opened and tension applied to the expeller wire 230 to straighten it thereby eliminating, or substantially reducing, the curvature 234 and the lip 232 thus pushing the suture 236 out of the recess 224 .
FIGS. 8A to 8C illustrate a further embodiment of a suture grasper 250 according to the present invention. It comprises a shaft 252 having a suture capture recess 254 having a lateral opening 256 and an articulating jaw 258 . An ejector 260 having a curvature 262 is positioned within the recess 254 . Preferably it comprises a wire. The ejector 260 is rotatable such that during capture of a suture 264 ( FIG. 8A ) the curvature 262 is away from the opening 256 to allow entry of the suture 264 into the recess 254 . The jaw 258 is then closed to hold the suture 264 in the recess 254 . To eject the suture 264 the jaw 258 is opened and the ejector is rotated to swing the curvature 262 toward the opening 256 thereby pushing the suture 264 out of the recess 254 .
While the invention has been particularly described in connection with specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and that the scope of the appended claims should be construed as broadly as the prior art will permit.
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A suture passing mechanism is disclosed having an elongated delivery member and a suture capture fitting at a distal end of the delivery member. The suture capture fitting includes a recess for receiving a length of suture. The recess is bounded by a proximal wall and a lateral opening leads therein. An expeller at the recess is adapted to expel suture out of the recess through the lateral opening.
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FIELD OF THE INVENTION
[0001] The invention relates to an infant drinking device, comprising a teat, a reservoir for holding a liquid, the reservoir being detachably connected to the teat by a connector of the infant drinking device, and an aerator, or alternatively indicated as a vent valve, such as a duckbill valve, the aerator thereto comprising a deformable opening, for example a slit, such that an internal/external pressure differential during use of the device is reduced in an open position of the opening by allowing air to enter through the opening into the reservoir and such that leakage of fluid from an inside of the drinking device to an outside of the drinking device is hindered in a closed position of the opening, wherein the aerator is included in the connector or the teat.
BACKGROUND OF THE INVENTION
[0002] Infant drinking devices are generally known. Such devices often include an aerator. This allows the entry of atmospheric air back into the bottle, as the infant drinks fluid from the device and creates an underpressure inside the reservoir. The underpressure inside the reservoir causes the aerator or valve to open. The aerator thereto has an opening, which is for instance created by cutting a slit in flexible material of the aerator through which opening air can pass to overcome the effects of negative pressure inside the reservoir. On the one hand the opening should ensure that air can pass to the inside of the reservoir as explained here before, but on the other hand leakage of fluid from the reservoir to the outside of the device should be avoided as much as possible. Another known problem of such drinking devices is that the aerator may become stuck quite easily, thereby compelling the caretaker to intervene and clear up the aerator. This may be a rather tiresome clean-up chore, especially when the reservoir is still filled and the inside of the teat being moisturized with liquid. The intervention of the caretaker may also influence the hygienically prepared milk or other fluid negatively. Besides it is inconvenient for the baby who cannot extract milk or any other fluid from the bottle anymore, as air inflow in the bottle is prevented by the stuck valve and as the teat has to be removed from his mouth thereafter by the caretaker to clear up the aerator. When the teat blocks or is removed from the baby's mouth, many babies start crying. This makes parents often nervous.
[0003] EP 1 863 427 A1 discloses a teat for a feeding bottle having a one-way valve located in the skirt of the teat to allow to enter the feeding bottle to replace liquid sucked out of the bottle through the nipple while preventing liquid from leaking from the bottle.
SUMMARY OF THE INVENTION
[0004] It is an object of the invention to provide an infant drinking device of the kind as set forth in the opening paragraph having a more reliable aerator.
[0005] According to the invention this object is realized in that a temporary deformation of the opening of the aerator into the open position is enforced by the geometrical and/or material properties of the teat-connector combination during assembly of the teat, connector and reservoir.
[0006] The problem which is addressed by the invention is that the slit may become stuck occasionally with residue left from the previous feeds. Such may occur for instance when the device was not cleaned properly or after storage. The opening usually has faces of silicone such as LSR that touch each other in a disassembled state of the drinking device. The faces may be stuck together for instance when dried-in baby instant or milk powder is left between the faces thereby sticking the faces together such that the faces of the opening cannot clear when reduction of the pressure difference is required during drinking. Also it may be possible that the faces are affixed to each other by cohesion forces caused by the material itself.
[0007] Well then, a minimally defined deformation of the opening causes the dried-in residues to crumble or causes the stuck faces to loosen, thereby setting free the opening. If such a deformation is systematically brought about, every time that the teat, the connector and the reservoir are assembled, the aerator can function more reliable. After assembly the drinking device starts off with a cleared aerator, regardless if the opening was stuck or not before assembling the device. This mechanism of systematically clearing the opening considerably avoids disassembling the teat, the connector and the reservoir to a great extent.
[0008] On assembly of the drinking device, the connector tightly holds the reservoir and the teat together. Under influence of the assembly forces the teat and/or the connector will deform. The aerator is included in the teat or in the connector. The material and geometrical properties of the teat and the connector determine the deformation that is provided and required for assembly. By adapting the geometry of the combination of connector and teat such, that the opening of the aerator also deforms during assembly, the aerator is reset thus ensuring good performance from the teat and feeding bottle system.
[0009] In an advantageous embodiment of the drinking device the aerator is included in the teat wherein the connector is more rigid than the teat, wherein the connector contributes to prevention of leakage through the aerator by accommodating the aerator sufficiently close to the connector in an assembled state of the drinking device. The teat is in contact with the mouth of the drinking infant at the outside and liquid is in contact with the inside of the teat. Therefore, it is of utmost hygienic importance that the teat is properly cleaned after every use. The aerator may likely get in contact with the liquid during use as a part of its function is to avoid leakage of said liquid. By including the aerator in the teat, the aerator will be cleaned with the same frequency as the teat. By arranging the connector close to the aerator the stiffness properties of the aerator may be attuned in assembled state to obtain a sufficiently reliable and stable aerator with a good anti-leakage behavior.
[0010] In an advantageous embodiment according to the invention the aerator is monolithically included in the teat and the teat has a zone of reduced stiffness in which zone the aerator is accommodated. Under the action of the forces which are present during assembly of the teat, the connector and the reservoir, the zone of reduced stiffness will deform relatively more in relation to other parts of the teat. This deformation of the zone of reduced stiffness better enables a transfer deformation to the opening of the aerator. The teat and the aerator can be manufactured for instance by injection molding. The geometry of the monolithic teat can be designed to create the zone of reduced stiffness for instance by accommodating the aerator in or near a zone of reduced wall thickness. The skilled person will know other ways to provide a decrease in local stiffness of the zone.
[0011] In a very advantageous embodiment of the drinking device according to the invention the teat has a suction portion which is suitable for entering into the mouth of an infant for feeding, and a connector portion which is suitable for interacting with the connector and/or the reservoir for assembly of the teat to the reservoir, wherein the aerator is arranged outside the suction portion. By arranging the aerator outside the suction portion, the teat can be moved around by the infant or parent during feeding, while its function is not affected.
[0012] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
[0014] FIG. 1 is a schematic side view of an infant feeding bottle according to the present invention;
[0015] FIG. 2A schematically shows a side view of the exemplary embodiment of the teat and the connector shown in FIG. 1 ;
[0016] FIG. 2B schematically shows a combination of a side view of the exemplary embodiment of the teat and a cross-sectional view of the connector shown in FIG. 2A ;
[0017] FIG. 3A schematically shows a bottom perspective view of the isolated exemplary embodiment of the teat shown in FIG. 1 ;
[0018] FIG. 3B schematically shows a detail of the bottom perspective view shown in FIG. 3A ;
[0019] FIG. 3C is a cross section of a detail of FIG. 3B ;
[0020] FIG. 4A schematically shows a cross-section of the embodiment according to the previous figures.
[0021] FIG. 4B shows a detail of the cross-section of a state of the art valve
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] FIG. 1 depicts a schematic side view of an infant feeding bottle 1 according to the invention. The bottle 1 has a reservoir 60 , a connector 50 , and a resilient teat 10 . The reservoir 60 can hold a liquid for instance infant food. The reservoir includes an upper portion provided with an outer screw thread onto which the connector can be attached in a manner which is known to the skilled person. The teat 10 and the reservoir 60 are connected by the connector 50 .
[0023] FIG. 2A schematically shows a side view of the embodiment of FIG. 1 prior to assembling the teat 10 , connector 50 and reservoir 60 . The teat has a top 11 , a bottom 12 , a suction portion 13 on which the baby sucks or moves its mouth to extract milk from the infant feeding bottle 1 and a connection portion 14 which is designed for connecting the teat to the connector 50 and subsequently to the reservoir 60 . When the teat 10 is connected to the reservoir 60 , a skirt 22 of the teat 10 fits over an upper rim 64 of the reservoir 60 . The connector 50 has an inner thread 51 which corresponds to an outer thread 66 of the reservoir 60 . The teat 10 has an annular groove 24 configured to receive a rim 53 of the connector 50 fitting sealingly together as is known per se by the man skilled in the art. When screwing the connector 50 top the reservoir 60 , the connector rotates around a rotational axis L. An arrow A indicates the direction wherein the teat 10 , the connector 50 and the reservoir 60 are assembled together. First the teat 10 is pulled into the connector 50 in the direction of the arrow A, thereby deforming the teat 10 to force the rim 53 over the top side of the groove 24 . Subsequently the connector is screwed onto the top part 64 of the reservoir 60 by means of threaded portions 51 and 66 . A top face 62 of the reservoir 60 is pressed against a sealing face 16 of the teat 10 in the assembled state to prevent leakage of fluid from the reservoir 60 . The force which is required for the sealing of face 68 against face 16 is provided by tightening the connector 50 by means of the threaded portions 51 and 66 .
[0024] The skilled person will understand that other rotational configurations of the teat 10 and the reservoir 60 may be applicable, such as an oval shape of teat and reservoir or octagonal symmetries while yet using a round shape at the connection interface. Alternatively, instead of threaded portions, the clamping force may be provided by other means such as a snap fit connection or by means of external clamping mechanisms which are all per se known to the skilled person. The connector 50 has an inner passage 52 to allow liquid to pass through the connector 50 to the top 11 of the teat 10 . FIG. 2B shows the teat 10 and the connector 50 in assembled state.
[0025] FIGS. 3A schematically shows a bottom perspective view of the teat 10 as described here above and according to FIGS. 1 and 2 . Rectangle 100 indicates a portion of the teat 10 wherein an aerator 31 is accommodated. An enlargement of the portion indicated in rectangle 100 is given in FIG. 3B . The aerator 31 has a duckbill valve 38 accommodated into a frame 39 of the aerator. The frame 39 is shaped as a thickened portion of frame 36 of the teat 10 and has a circumference similar to a guitar without a neck. The frame 36 is locally weakened by an upper recessed portion or recess 41 and a lower recess 42 . Between the upper recess 41 and the lower recess 42 is accommodated a dam section 37 in the frame 39 . The dam section has an opening in the form of a slit 35 . The dam section 37 comprising the slit 35 form the duckbill valve of the aerator 31 . Air from outside the bottle can enter to compensate a pressure difference between the inside and the outside of the bottle during use. A top face 32 and a bottom face 33 of the dam section 37 delimit the dam section 37 against both recesses 41 and 42 (see FIG. 3C ).
[0026] FIG. 3C is a cross section of a detail of FIG. 3B . The duckbill valve 38 and its slit 35 are is a configuration wherein the faces of the slit make contact in a zone of contact 34 . This is the closed state of the duckbill valve 38 . When an internal/external pressure differential is absent the slit 35 is closed and the top face 32 and its underlying material and the bottom face 33 and its underlying material abut against each other in the zone of contact 34 of the slit 35 . When a baby sucks on the teat an internal/external pressure differential starts to be created by the removal of the milk from the bottle. Then the air outside the bottle forces the two faces 32 , 33 of the duckbill valve to deform and move apart thereby clearing the zone of contact 34 of slit 35 . Normally a threshold is present to the extent that the internal/external pressure differential has to exceed a specific value before the two faces 32 , 33 are separated thereby causing disconnection in the zone of contact 34 to create a hole which allows the aerator 31 to vent the inside of the bottle, thus reducing the internal/external pressure differential.
[0027] To further explain the pressure compensation mechanism a cross-sectional view of the detail presented in FIG. 3B is shown in FIG. 4B . In FIG. 4B the teat 10 comprising the duckbill valve 31 in the lower portion 14 are indicated. The duckbill valve 31 comprises the top face 32 , the bottom face 33 and the opening in the form of the slit 35 . The top face 32 and the bottom face 33 are separated by the slit and come together or abut at contact portion 34 (see FIG. 4C ). As can be derived from FIG. 3A , the slit 35 of the duckbill valve 31 is oriented perpendicular to the longitudinal axis L.
[0028] When an internal/external pressure differential is absent the slit 35 is closed and the top face 32 and the bottom face 33 abut against each other and may connect at the internal faces or contact portion 34 of the slit 35 . When a baby sucks drinks from the bottle an internal/external pressure differential is created by the removal of the milk from the bottle. Then the air outside the bottle forces the two faces 32 , 33 to disconnect. When the internal/external pressure differential exceeds a specified value, the two faces 32 , 33 are separated such that they disconnect thereby causing the opening 35 to create a hole which allows the aerator 31 to vent the inside of the bottle, thus reducing the internal/external pressure differential.
[0029] The faces 32 , 33 of a silicone duckbill valve 31 have a tendency to stick to each other, mainly caused by the material properties of the material, silicone, and/or by residue from the previous feeds left between the two sidewalls. To overcome the sticking force the faces 32 , 33 have to be enforced to separate. This can be done manually by, pressing for example a pencil between the two faces 32 , 33 , but this may introduce new bacteria or dirt into the hygienically prepared milk. Instead of pressing the two faces apart, they can also be pulled apart by applying a force perpendicular to the contact portion 34 , i.e. in the direction of the longitudinal axis L. When connecting the teat 10 to the connector 50 a force perpendicular to the contact portion 34 , i.e. along the longitudinal axis L, of the duckbill valve 31 is applied: the second clamp portion 26 of the teat 10 remains behind the connector 50 while first clamp portion 25 moves through the connector 50 and away from the connector 50 . As can be seen from FIG. 2B , the diametrical dimensions of the connector 50 and the annular groove 24 match in an assembled state. However, when assembling the teat 10 to the connector 50 , the teat 10 has to deform to allow the upper clamp portion 25 to pass through the connector 50 . The specific deformation of the teat 10 is among others dependent from the geometrical and material properties of the teat. In this specific embodiment the arrangement of the aerator 31 is such that a folding deformation is enforced in the thickened portion around the aerator 31 by means of the upper and lower recesses 41 and 42 . The recesses 41 , 42 now function as weakening means to enforce deformation. As a result the contact portion 34 of the slit moves apart thereby clearing the duckbill valve 31 . This is an important advantage over the currently available teats.
[0030] FIG. 4A schematically shows a cross-sectional view of the teat 10 according to the previous figures and according to the invention. Prior to explaining the execution of the aerator of FIG. 4A first a state of the art aerator will be explained which state of the art aerator is depicted in FIG. 4B .
[0031] In FIG. 4B a rectangle R is indicated. The material of the teat extends into the rectangle R and the frame 36 is stiffened by the presence of material in rectangle R. The material inside the rectangle R contributes to the stability of the valve. This prevents leakage of fluid from inside the bottle. In the arrangement according to FIG. 4A the material inside the rectangle R depicted in FIG. 4B has been removed. The frame in which the duckbill valve is arranged is weakened which contributes to a better clearance of the valve according to an object of the invention. This stability of the valve—which is required to prevent leakage—is now further improved by the connector rim 5 by accommodating the duckbill valve sufficiently close to the rim 53 of connector 50 in an assembled state of the drinking device 1 .
[0032] The amount of material removed in the embodiment according to FIG. 4A is such that no material is present between face 33 and the top face 62 of the reservoir. The skilled person will understand that less material can be removed to the extent that the clearance behavior of the aerator is sufficient according to an object of the invention. The skilled person will understand that for instance also the material can be removed up until half of the distance between the top face of the reservoir and the bottom face 33 of the duckbill valve and that a better execution will be reached if this level is decreased to one third of said distance or one fourth. If all the material is removed the clean ability of the valve is increased because there are less edges available where fluid food may be caught. When removing more material the rim of the connector has to be arranged more closely towards the weakened portion to restore the stiffness of the frame which is needed to stabilize the valve to prevent leakage during use.
[0033] It will be appreciated that the term “comprising” does not exclude other elements or steps and that the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to an advantage. Any reference signs in the claims should not be construed as limiting the scope of the claims.
[0034] The skilled person will appreciate that the present invention is not limited to the specific embodiments. For example the connection portion may also be weakened around the aerator, causing the connection portion to deform in a longitudinal direction rather than in a folding like pattern when a longitudinal force is applied. This may likewise cause a clearance of the aerator during assembly.
[0035] Although claims have been formulated in this application to particular combinations of features, it should be understood that the scope of the disclosure of the present invention also includes any novel features or any novel combinations of features disclosed herein either explicitly or implicitly or any generalisation thereof, whether or not it relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as does the parent invention. The applicants hereby give notice that new claims may be formulated to such features and/or combinations of features during the prosecution of the present application or of any further application derived therefrom.
[0036] Other modifications and variations falling within the scope of the claims hereinafter will be evident to those skilled in the art.
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To provide a drinking device with a more reliable aerator the invention relates to an infant drinking device ( 1 ), comprising a teat ( 10 ),a reservoir( 60 ) for holding a liquid, the reservoir ( 60 ) being detachably connected to the teat ( 10 ) by a connector ( 50 ) of the infant drinking device ( 1 ), and an aerator ( 31 ), such as a duckbill valve, the aerator thereto comprising a deformable opening, for example a slit, such that an internal/external pressure differential during use of the device ( 1 ) is reduced in an open position of the opening ( 35 )by allowing air to enter through the opening ( 35 ) into the reservoir ( 60 ) and such that leakage of fluid from an inside of the drinking device ( 1 ) to an outside of the drinking device ( 1 ) is hindered in a closed position of the opening ( 35 ), wherein the aerator ( 31 ) is included in the connector ( 50 ) or the teat ( 10 ), wherein during assembly of the teat ( 10 ), connector ( 50 ) and reservoir ( 60 ), a minimally defined deformation of the opening ( 35 ) of the aerator ( 31 ) is enforced by the geometrical and/or material properties of the teat-connector combination.
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FIELD OF THE INVENTION
This invention relates to an open-end spinning machine having a number of spinning units and at least one movable maintenance device which is equipped with means for displacing thread monitoring sensors, one of which is arranged in a thread draw-off path of each spinning unit.
DESCRIPTION OF THE PRIOR ART
German Patent Specification No. 2,350,840 discloses an open-end spinning machine having a movable maintenance device which can intermittently interrupt the spinning process of the individual spinning units. This deliberate interruption, which is followed by cleaning of the spinning unit and subsequent resumption of spinning, is for the purpose of maintaining consistent operating conditions as far as possible, to avoid differences in yarn quality. Otherwise, such differences can arise after a certain operating time during which dirt can be deposited in the spinning unit, particularly in its open-end spinning rotor. After a certain operating time not only does the quality of the yarn deteriorate, but the frequency of thread breakages increases; this can also be prevented by timely cleaning.
It is usual for each spinning unit machine to be equipped with a thread monitoring sensor, that is, a sensor which monitors the presence of the thread. The sensor is held in its operating position by the thread tension. On breakage of the thread, it switches over and interrupts operation of a device which feeds fibre lap to the spinning unit. In order to bring about a thread breakage deliberately, the thread monitor can be moved into the position which indicates a breakage in the thread, where it switches off the supply of fibre lap. This is envisaged for the known maintenance device. However, how this is to be carried out in practice is left open and in fact difficulties can arise if the thread monitoring sensor is switched from the movable maintenance device. The thread monitoring sensor must be very sensitive so that it can respond to the relatively light tension of the thread. The construction of mechanical actuating means which will not cause damage to the thread monitoring sensor even after long operating times, and will continue to switch reliably, presents considerable difficulties.
SUMMARY OF THE INVENTION
It is an object of the invention to provide, in an open-end spinning machine, the possibility of deliberate displacement of the thread monitoring sensor, without danger of damaging the sensor.
According to this invention there is provided in an open-end spinning machine comprising a plurality of spinning units, a thread monitoring sensor associated with the thread draw-off path of each spinning unit, at least one movable maintenance device, the maintenance device having means for displacing a respective thread monitoring sensor, the improvement wherein the said deflecting means provides for indirect, non-contacting displacement of the sensor. By use of the invention, mechanical elements are excluded from contact with the thread monitoring sensor, which could lead to overloading and damage.
In one embodiment of the invention, the maintenance device is equipped with means for deflecting a running thread and for lifting the thread from its associated monitoring sensor. With such means, the maintenance device slackens off the thread tension in the vicinity of the monitoring sensor sufficiently for a breakage in the thread to be simulated, to interrupt the supply of fibre lap and cause an actual breakage in the thread.
The maintenance device may have a blade which can be moved up to the running thread of a spinning unit. This embodiment is based on the fact that the thread end which is produced when the fibre lap suppy is cut off is not suitable for resumption of spinning as the thread end tails off due to the interrupted delivery of fibre. If however the running thread is cut off, a better thread end is produced rejoining the thread, and having a shape which corresponds to the rest of the thread.
In another embodiment of the invention provision is made for the maintenance device to have a magnet which can be brought up to a respective thread monitoring sensor, all the sensors each having a magnetic part. This embodiment also prevents the thread monitoring sensor from being damaged by forcible mechanical switching off.
In another embodiment the maintenance device has means for opening part of the housing of the spinning unit, which part bears the relevant thread draw-off channel, whilst the thread monitoring sensor of the spinning unit is mounted in stationary manner. In this embodiment the running thread is deflected by opening the housing so that the thread monitoring sensor is released sufficiently for it to interrupt the supply of fibre lap.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic section through part of an open-end spinning machine with a first embodiment of maintenance device;
FIG. 1A is a schematic view of a thread cutting device of the FIG. 1 maintenance device;
FIG. 2 is similar to FIG. 1, showing another embodiment;
FIG. 3 is similar to FIG. 1, showing another embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is seen an open-end spinning unit 1, a number of which are usually arranged in a row one beside another, the unit having a yarn draw-off channel 2, whence a thread 3 is drawn by a pair of draw-off rollers 6, 7 and fed to a spooling device, not shown. The thread 3 is guided with a small deflection as shown, and thus under slight tension, over a thread monitoring sensor 4 which is connected to a switch 5 to cut off the supply of a fibre lap to the unit 1, the switch 5 being in an electrical circuit (not shown). The switch is operated by the sensor 4 when the latter is not held in its operating position by the thread 3. The operating position is indicated in full lines. The sensor has a spring which swings it out of its operating position if the thread tension is not present. The driven draw-off roller 6 is preferably a shaft running lengthwise through the whole spinning machine. The draw-off roller 7 is a pressure roller and is pivotally mounted by an arm 8 on an axle 9 fixed in the machine.
A maintenance device 10, which is only shown schematically, can be moved over the whole length of the machine. This device 10 can comprise in known manner devices for cleaning the spinning unit 1 and/or devices for joining a broken thread 3 and/or for changing spools. The device 10 has means for interrupting the thread 3 by contact-free actuation of the sensor 4. In the embodiment of FIG. 1 a lever arm 11 is mounted for pivoting about an axis 12 and against a compression coil spring 14, in the direction of the arrow, by an actuator in the form of a solenoid 13. Transversely of the lever 11 is a projection 15 which can deflect the thread 3 to the position 3a indicated in dot-dash lines. The lever 11 and projection 15 then assume positions 11a and 15a. On deflection of the thread to its position 3a, it is lifted off the sensor 4, so that the tension is removed therefrom and so that the sensor moves to its position 4a, i.e. into its thread-broken position, in which it causes interruption of the supply of fibre lap.
In this way, and without need of any other provision, a thread end is produced which is drawn through the draw-off rollers 6, 7 and finally wound onto the winding spool, not shown. This thread end would be somewhat attenuated and therefore would not be favourable for resumption of spinning. For this reason, a cutting device 16 is also provided on the movable maintenance device 10, so that at this point a thread end of correct shape is produced. FIG. 1A schematically depicts cutting device 16 with a movable blade B, guided in guide G, for cutting thread 3. The thread end which is not drawn off is sucked into a container 19 by a suction device 17 connected to a reduced pressure source 18.
It is possible for the thread end 3a to be removed in other ways, for example by means of a spinning rotor at low pressure located in the unit 1 which sucks the thread end into unit 1 from where it can be further sucked out by a suction line or the like.
FIG. 2 shows an embodiment for contact-free actuation of the thread monitoring sensor 4 of a spinning unit, of which, other than the sensor 4 itself, only the switch 5, the yarn draw-off channel 2 and a part of the operative run of thread 3 are shown. The movable maintenance device 10 in this embodiment also has a lever 11 which can be deflected around an axis 12, and which is fitted at its end with a magnet 20. The magnet 20 is movable as indicated by the arrow into the vicinity of the sensor 4 and can deflect the sensor from its operating position. Either a permanent magnet or an electromagnet can be used. When required, the lever 11 is moved back, drawing the sensor magnetically with it. For this purpose the sensor 4 contains a bar of magnetic material. In this way spinning can be interrupted.
Both the above-described embodiments exhibit interruption of spinning by displacement of a thread monitoring sensor 4 without the latter coming into mechanical contact with the actuating element. In this way the sensor 4 is protected and its operation not prejudiced.
FIG. 3 shows another embodiment, in which spinning is interrupted simply by opening the spinning unit 1. A housing 21 is movable, about a stationary axis 22 at each spinning unit, to the dash-dot line position 21a. As the yarn draw-off channel 2 is also swung away with it, the thread path 3 assumes a new position, as indicated by dash-dot lines and in this way the sensor 4, which does not move with the housing 21, is released to move into its position 4a and thus cuts off the supply of fibre lap.
To bring about this movement of the housing 21 actuating elements 23 to 26 are provided on the movable maintenance device 10, and they take the form of a pivot arm which can be deflected about an axis 23 as indicated by the double arrow 30. They form a telescopically extensible unit. This unit comprises a piston rod 25 which can be moved as indicated by the double arrow 29 in a cylinder 24. The piston rod 25 has on its end a ball 26 seated in a guideway 27 on the housing 21. During opening this ball moves to the position 26a, thereby moving the housing 21 to its position 21a.
As it is advantageous to open the spinning unit in any case for cleaning, the embodiment of FIG. 3 provides a simple appliance for interrupting spinning. It is only necessary not to arrange the thread monitoring switch 5 and the thread monitoring sensor 4 on the housing 21 (as is often normal practice) but on a stationary point somewhat removed from the housing 21, so that the thread 3 can be lifted from the sensor 4.
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An open-end spinning machine has a number of spinning units and a movable maintenance device. The maintenance device has means for deflecting the thread monitoring sensors of the spinning units, there being a sensor associated with the thread draw-off path of each unit. The deflecting means provides for indirect, non-contacting deflection of a thread monitoring sensor.
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BACKGROUND OF THE INVENTION
The technical area of the present invention is that of measuring devices, and in particular to a process and device for rapid measuring of thickness or mass of a fiber sliver in a draw-frame or card (so-called "regulation"), as well as a linearized influencing process for measured (as yet) non-linear signals.
In the above-mentioned machines processing fiber slivers, the presented slivers consisting of several fiber slivers generally run through a measurement indicator consisting of a rotatably mounted pair of scanning rollers. One of these two scanning roller is furthermore movable and is moved more or less relative to the fixed scanning roller by the fluctuations of the sliver mass, i.e. the thickness of the fiber sliver running through the scanning rollers while the width of the nip remains constant. These excursion movements are detected through a contact-less sensor and can be translated into an electrical measuring signal (a movable "target" is measured without contact for its distance from a fixed "distance indicator"). By means of this measuring signal, the card, for example, is influenced in its drafting zone in such a manner that the rollers (input roller, central roller) of the card are given different speeds when the different sliver mass reaches the drafting zone (between central roller and delivery roller). In practice this takes place over a changing running time (so-called "electronic memory") which transmits the measured value with appropriate delay to a desired-value step.
The above-mentioned measurements must be carried out rapidly at the high sliver velocities (e.g. in the range of 15 km/h< vL< 50 km/h), so that a high scanning frequency for the sliver thickness (mass) to be measured may be made available. Since a considerable amount of calculations usually follow the measurements, high-performance micro-calculators, micro-computers or signal processors, and if necessary floating-point computing chips must be made available.
OBJECTS AND SUMMARY OF THE INVENTION
A principal object of the invention is to accelerate the measuring process in a drafting apparatus and at the same time to maintain, or even improve, the precision of the measurement. Additional objects and advantages of the invention will be set forth in the following description, or may obvious from the description, or may be learned through practice of the invention.
The objects are attained by the invention if the primary measuring signal which originates with the measurement indicator is modified during operation on the basis of a previously stored characteristic line which is based on a relationship measured by points between a defined thickness on the measurement indicator and the primary measuring signal. The device which is suitable for this process contains a "circuit" (software technology or hardware-specific) in which a stored curve (function) or stored data words are contained which modify the measuring signal of the measurement indicator in such a manner that the output signal of the circuit is linear (with thickness changeable in a linear manner) even though the output signal of the measurement indicator and thereby the input signal of the circuit is non-linear. The stored contents of the circuit are based on a learning phase or steps preceding operation, which has been carried out for several thicknesses (so-called "test measurements", e.g. 3 mm, 4 mm, 5 mm and 6 mm). In these learning steps, the calculating-time-intensive computations have been carried out for which sufficient time is available in the pre-operation phase; the results of the computations only are stored and these are merely read out during operation, without it being necessary to make the computations again in the operating phase of the measuring device, when the machine is in operation and the fiber sliver is moved through the measuring device.
The pre-operation phase may occur one single time, until all necessary data words, or the curve which constitutes them, are obtained. Thereafter the measuring system is calibrated for any situation in operation, even without pre-operation phase, and must be brought again into a pre-production phase only when parts of the measuring system or of the measurement indicator are replaced or modified. In addition it is possible to re-calibrate if the user has doubts as to the measured magnitudes.
By scheduling the computation of the measuring signals before the actual operation phase ("in advance") and the production phase only carries out measurements which can be converted very rapidly through a table with respect to an offset or an upgrade, the invention makes it possible to accelerate and at the same time to linearize the measurement.
For these linearized measured values no expensive components are required, and conventional logic building blocks, if necessary an ASIC, are sufficient. Further treatment of the linearized measured values for programming purposes is simplified.
The precision with which the invention is achieved includes also the analog/digital transformer which is connected downstream of the measurement indicator and which makes the measuring signal available in digital form. Its characteristic line and its non-linearities are taken into consideration already in the computation of the data words in the pre-operation phase.
Multiplication and division is no longer required in real time and mathematical co-processors or signal processors for rapid handling of this multiplication and division while maintaining high precision can be dispensed with.
The linearity of the measurement indicator (e.g. "Target" and "distance indicator") which makes the analog measuring signal available, need not be paid special attention since its non-linearity is compensated for in any case through the fact that the circuit constitutes its reverse, so that the transmission function overall, starting from the thickness at input d(t) until the output signal u 2 (t) of the circuit which may be digital or analog, is linear.
The invention is explained and completed below through several examples of embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a representation of a fiber sliver movement for a draw-frame in which a scanning-roller pair 1a, 1b, roller 1b being movable, measures the thickness d of the presented sliver 20 which is composed of several individual fiber slivers 19. With the thickness measurement d(t) the mass m(t) of the fiber sliver (per length segment or time unit) is also known, because it is possible to base the calculation on a known specific weight and a known (or measurable) sliver speed.
FIG. 2 is an enlargement of the circuit 10 shown in FIG. 1, with its analog or digital element, as well as with a pulse generator 14.
FIG. 3 shows a non-linear transmission function K1 as u 1 =f(d), where d is parallel with x and perpendicular to the direction of the sliver speed. The output signal is generated by the measured-value indicator 1 of FIG. 1, whether the dependent variable is angle a or whether it is the electrical output signal u 1 ' of an damping-measuring probe 2b. FIG. 3 shows also the linearized function M such as it appears for the overall measuring device with respect to the function u 2 =f(d) with the addition of the circuit of FIG. 1.
FIG. 4 shows the "regulating area" shown from the side in FIG. 1, with intake area 22 and drafting area 23 in a top view, the switching elements of FIG. 2 being shown.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the presently preferred embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used on another embodiment to yield still a further embodiment. It is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents.
FIG. 4 clarifies the surrounding field in which the invention is to be explained through a diagram according to FIG. 2, although it is obvious that the hardware example of FIG. 2 can also be realized through programming if the control of logic operation is a program segment or a sub-program which operates with interrupt control and if the RAM or ROM 12 is a detail of a larger data memory of the processor.
FIG. 4 shows the draw frame area between the central roller M which rotates at a speed v 2 (circumferential speed) in operation and the delivery roller L which rotates at the speed v 3 (circumferential speed) and feeds the fiber sliver drafted in the drafting area 23 at a much higher speed from the draw frame in the form of fiber sliver 24 into a sliver storage. A flat fiber fleece as shown at 22 is supplied to the drafting area 23, it is fanned out by an input roller E rotating at a speed v 1 (circumferential speed) and which spreads out the fibers from a fiber bundle 21 for the central roller. Before the inlet roller is a scanning element 1a, 1b consisting of two rotating disks or rollers 1a, 1b facing each other which bundle together the combined fiber sliver composed of several fiber slivers 19 with great force and which make it possible to determine the thickness d, and thereby the fiber sliver mass. Following the scanning rollers 1a, 1b the fiber sliver is fanned out and formed to the width--under the action of the input roller E of the drafting area--which is fed to the central roller M and to the drafting area 23.
The scanning rollers 1a, 1b are shown as examples. Other measuring elements may be used here. Both scanning rollers 1a, 1b rotate, but one roller can be moved so that its distance from the other roller changes, as shown schematically in FIG. 1, and indicates its excursion via a lever arm 3 (characterizing the principle) through swivel articulation 23a to a target 2a the distance of which from an inductively functioning distance indicator 2b is set.
The output signal of the distance indicator 2b is transmitted to a measured-value memory 11a via a signal converter which may be a proportional element 9, said measured-value memory 11a then sets a predetermined time delay to the currently measured thickness signal d(t 1 ) in order to change the speed v 2 of the central roller M and at the same time that of the input roller E via a desired-value step R, the servo drive 15, and a planetary gear 16 so that the desired drafting takes place at a predetermined drafting point within the area 23. The main motor H drives the delivery roller L at the speed v 3 , it also drives the planetary drive at that speed, so that the changes in thickness measured by means of the scanning roller 1b influence the speeds v 2 , v 1 only as differential number via the servo drive 15 and the planetary gear 16, while the stationary state is adjusted so that the speed v 3 is a multiple of the speed v 2 , v 1 but is stationary at an unchanged fiber thickness 19.
Because of imprecision and non-linearities in the signal path between the fiber sliver thickness d at the scanning rollers 1a, 1b and up to desired value step R, it is necessary to work with non-linear signal processing in order to control the regulation of the draw frame (the pre-control of speeds v 2 and v 1 ). Non-linearities affect the precision of regulation, they require long computation times and the installation of high performance computations during operation.
For this reason, the circuit 10 is provided as shown in FIG. 1, making linear thickness measuring possible with a still conventional measured-value indicator 1a, 3, 3a, 2a, 2b (hereinafter simply: 1, 2) and at a greater speed and with lower installed computation capability.
The change in measured value as per functional block 10 occurs e.g. in a model based on hardware technology as shown in FIG. 2. The still non-linear measuring signal u 1 (t) is transmitted to an A/D transformer 11 which emits an 8-bit signal for instance, interpreted as an address signal. With the address signal A 1 which is bit-parallel, the memory 12 which is a RAM or an EEPROM or a ROM buffered with a battery, is read out. It emits data words D1 which need not necessarily have the same bit width as the input bit width, but they can also be selected with 8 bits. The digital signal u 2 (t) is a time-discrete signal. The measured values from the memory 12 are read out by controls 14, which are controlled either with a fixed pulse or are synchronized with the rotational speed v 3 of the delivery roller L or the rotational speed v 1 of the input roller E or at the rotational speed v 2 of the central roller M. As a result, an operating mode is achieved which is length-oriented, with the interrupt-time of the computer depending on the speed of the fleece.
The data memory 12 contains data values which were determined before the actual operation of the draw frame serving here as an example in the explanation.
FIG. 3 shows how the contents of memory 12 are determined. A normally non-linear transmission function K1 results in part from the mechanical structure of the measured-value indicator 1, 2 (e.g. if a linear thickness change d of the bundled fiber sliver is not equal to a corresponding linear change in the distance between the target 2a and the distance indicator 2b, or if a linear change of in the distance between the target 2a and the inductively operating distance indicator 2b does not lead to a corresponding linear signal change u 1 ), and in part due to missing adjustment. To these non-linearities are also added offsets which may be due to thermic reasons, but which are unavoidable because of the structure, just as offsets which affect the A/D converter 11 itself. These non-linearities of which only examples are cited here, are represented in the non-linear characteristic line K1.
FIG. 3 shows the linearized characteristic line M which represents the entire transmission function, from the change in input thickness d of the sliver at the measured-value indicator 1, 2 to the output signal u 2 , i.e. the transmission function M=F u 2 (t)/d(t)}. The reverse of the non-linear function K1 is thus stored in the data memory 12 in order to result again in a linear output u 2 (t) with a non-linear input which characterizes a linear change in the measured value d(t).
The data words in memory 12 are ascertained in a pre-operation phase, when individual test measurements are put in the measured-value indicator 1, 2 and the corresponding output signal u 1 ' is then found. Since it is known with the test measurements which output values are desired via the adaptation curve, the corresponding (still non-linear) measured value u 1 can be stored so that a computation basis is constituted in the pre-operation phase in order to determine in the memory 12 the function which leads to the linear output magnitude u 2 (t). This function has previously been designated as the "reverse" function, and "reverse" also contains an offset correction as well as an incrementation correction if the non-linear measured value u 1 ' may be affected by all these errors.
As test measurements which are regularly supplied as a set for the start-up of a machine, dimensions of 3 mm, 4 mm and 6 mm are suitable, but a greater number of dimensions may be contained in this set, however these must be very precise in their dimension.
From the individual points, the system is able to calculate the data values of the memory 12 in the pre-operation phase, and these data values merely need to be read out in operation, since they already contain the non-linearities and are thus able to rapidly carry out linearization and conversion.
Insofar as only a few points are measured in the pre-operation phase (e.g. four) the system itself is able to form a form or curve by points with much higher resolution on basis of a linearization function if the sections or individual points are only known. For this, the program in the pre-operation phase uses linearization methods or offset compensation methods in order to obtain a reverse defined by points or a reverse defined by sections.
If a definition by points is selected, a corresponding data zone D 1 must be available over the entire address zone A 1 . Although the resolution is high, so is the volume of the memory. If a reduced volume is selected with maintenance of sufficient precision, the sections of the address zone A 1 which are respectively associated with a data word D 1 can be combined. This may be accomplished by cutting off the bits of the address zone A 1 with the lowest value (representing the measuring signal u 1 ').
The circumference calculations which takes place before the actual operation phase of the machine can be solved without time problems, since a high interrupt-frequency is not required before the actual operation of the machine. The computation time can thus be extended substantially, and processors can be used which do not require the high computation capabilities that would be required by a processor if it had to transform in operation the currently measured (non-linear) measured values u 1 ' into linearized measured values or if it even had to transform the measured values taken from the distance indicator 2b only on the basis of known relationships (division and multiplication) into a measuring signal.
With the embodiment of this example, it is possible to place the conversion of the measured values based in the mechanism of the indicator as well as the linearization of these measured values before the operation of the machine. During operation, the system only has to read out the previously stored data points or sections (address zones) in order to provide the linearized and rapidly found measured signal u 2 (t).
In computing in advance the contents of the data memory 12, it is necessary, in order to achieve a high degree of precision, that one (or several) measured values be used first in order to first take the offset into account. Following this, the gradient can be calculated from the different measured values, with gradient and offset having both been taken into account. Several measurements or iteration processes can be used in order to calculate as precise a characteristic line as possible and store it in the memory 12 before the machine starts its actual operation. Before the operation of the machine, the computation capability and computation time are nearly unlimited, so that the measuring process is not subject to any restrictions in this respect.
The changes of the data stored in the data memory 12, which may either be an external memory or a storage area within the system, occur only very rarely, e.g. when a new scanning system is built in or if it is suspected that the distance measurement contains a software or hardware error. A distance measuring system which has once been built in (the indicator 1, 2 with its scanning roller 1b, for example) is found again, individualized with the appertaining elements 2a, 2b, 9 and A/D transformer 11 in the function (the "reverse") in memory 12. Only when a measured-value indicator is newly installed is it necessary to readjust this function which is then found before start-up of the machine with the new distance measuring system in the manner described above.
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 and spirit of the invention. It is intended that the present invention cover such modifications and variations.
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The invention relates to a process for rapid measurement of thickness or mass of a fiber sliver in a draw-frame or card (so-called "regulation"). The object of the invention is to accelerate the process of measuring according to the state of the art while maintaining measuring precision and even improving it. For this, a process for rapid measuring of the thickness or mass of a fiber sliver in a machine processing fiber slivers, such as a draw-frame or card, in which the primary measuring signal (u 1 , u 1 ') of the measurement indicator is taken via a signal-influencer which modifies the primary signal by segment or point before transmission in the form of measuring signal (u 2 , u 2 '); the modification is predetermined by a characteristic line stored previously by segment or point which is based on a relationship (K1) measured by point between defined predetermined thicknesses at the measurement indicator and the primary measurement signal (u 1 u 1 ') measured at that moment.
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TECHNICAL FIELD
[0001] This invention relates to a glass sheet forming system that has versatility in use for economically forming different glass sheet jobs of different sizes and shapes.
BACKGROUND
[0002] Glass sheet forming systems conventionally include a furnace for heating glass sheets for forming, a forming station that cyclically receives the heated glass sheets from the furnace to provide the forming and a cooling station located downstream from the forming station to provide cooling that may be slow cooling for annealing, faster cooling for heat strengthening or rapid cooling for tempering. The most efficient operation of such glass sheet forming stations takes place with the least possible downtime between switching from one job to another. Such job switching was originally accomplished by changing one or more molds utilized to provide the glass sheet forming, but such mold switching changes require significant downtime, four to six hours or more, that necessarily increases the cost of each formed glass sheet produced. To reduce the downtime, a pair of forming stations that can be moved sideways along the length of the glass sheet forming system for use of one or the other have also more recently been utilized, which is more economical than having two systems because the cost of the forming stations relative to the cost of the furnaces and cooling stations is much less and reduces the downtime since any mold changing can be performed when another production job is being performed.
[0003] Prior art glass sheet forming systems are disclosed by: U.S. Pat. No. 6,573,484 Bennett et al. which discloses that the furnace can also include a roll bending station with inclined rollers that preform the glass sheet prior to conveyance to the forming station for further forming; U.S. Pat. No. 6,543,255 Bennett et al. which discloses a roll bed having detachable drive wheel assemblies that permit a lower press ring of varying shapes to be utilized in the forming; and U.S. Pat. No. 6,513,348 Shetterly et al. which discloses cooling of a formed glass sheet after the forming, all three of which patents are assigned to the assignee of the application and are hereby incorporated by reference.
SUMMARY
[0004] An object of the present invention is to provide an improved glass sheet forming system that has versatility in use in performing different glass sheet jobs of different sizes and shapes with reduced downtime so as to provide economy and thus cost reduction of the formed glass product.
[0005] In carrying out the above object, a glass sheet forming system constructed according to the invention includes a pair of glass sheet forming lines extending alongside each other along a direction of conveyance of the forming system. Each of the forming lines includes: a heating furnace for heating glass sheets; a forming location downstream along the direction of conveyance from the furnace which cyclically supplies heated glass sheets to the forming location; and a cooling station located downstream along the direction of conveyance from the forming location to cyclically receive formed glass sheets therefrom for cooling. The forming system also includes three forming stations any two of which can be respectively positioned at the forming locations of the pair of forming lines. Three communication assemblies of the forming system are respectively associated with the three forming stations and each includes: an upwardly extending stanchion having an upper end; a horizontal beam having an elongated length including a distal end having a pivotal connection to its associated forming station; a bearing assembly that mounts the horizontal beam on the upper end of the stanchion for pivotal movement about an associated vertical axis and for horizontal movement along its length; and a looping type wire bundle connected to its associated forming station at the distal end of the horizontal beam and extending therefrom to the stanchion to provide control of the forming station. A control system of the forming system is connected to the wire bundles to operate the pair of forming lines including the heating furnaces, the selected two forming stations respectively in the forming locations, and the cooling stations.
[0006] As disclosed, the forming station includes a pair of storage locations at either of which any one of the forming stations not being used can be stored and at which any two of the forming stations not being used can be stored.
[0007] As also disclosed the upper end of the stanchion of one of the communication assemblies is located higher than the upper ends of the stanchions of the other two communication assemblies so the horizontal beam of the one communication assembly is movable above the horizontal beams of the other two communication assemblies during forming station movement.
[0008] Additionally, the forming station includes a rail assembly having rails and a turntable on which the forming stations are movable within the forming system. The stanchions of two of the communication assemblies are disclosed as respectively located upstream and downstream from the turntable along the direction of conveyance of the forming lines, and the stanchion of the other communication assembly is located adjacent the stanchion of one of those two communication assemblies. More specifically, the stanchions of the two communication assemblies located upstream and downstream from the turntable are aligned with the turntable along the direction of conveyance and the stanchion of the other communication assembly is located laterally relative to the direction of conveyance to one side of the stanchion of one of those two communication assemblies and the upper end thereof is higher than the upper ends of the stanchions of the two communication assemblies so the horizontal beam thereof is movable above the horizontal beams of the two communication assemblies during forming station movement. Also, the pair of storage locations are located upstream and downstream from the turntable along the direction of conveyance of the forming lines to provide for storage of one or two of the forming stations not being used.
[0009] The glass sheet forming system as disclosed has a control system including first and second PLCs (i.e. programming logic controllers) for respectively operating the pair of forming lines, a control panel connected to the associated wire bundle of each forming station to control its operation, and a third PLC for operating the three forming stations through their respective control panels in respective cooperation with the forming lines.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic top plan view of a glass sheet forming system constructed according to the present invention to include a pair of glass sheet forming lines extending alongside each other and also including three forming stations any two of which can be utilized with the two forming lines at any given time, three communication assemblies used in the operation of the forming stations, and a control system that operates the forming lines.
[0011] FIG. 2 is a schematic perspective view of the communication assemblies that operate the forming stations of the forming system
[0012] FIG. 3 is a more detailed perspective view of the communication assemblies.
[0013] FIG. 4 is a somewhat schematic view of one of the communication assemblies shown with a horizontal beam thereof in an extended position connected to the associated forming station at a remote location from an associated stanchion of the assembly.
[0014] FIG. 5 is a view similar to FIG. 4 but with the horizontal beam in a retracted position extending from the stanchion to the associated forming station at a closer position.
[0015] FIG. 6 is a schematic view taken along the direction of line 6 - 6 in FIG. 5 to illustrate a bearing assembly on the upper end of the stanchion for supporting the horizontal beam for horizontal and pivotal movement.
DETAILED DESCRIPTION
[0016] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
[0017] With reference to FIG. 1 of the drawings, a glass sheet forming system embodying the present invention is generally indicated by 10 and includes a pair of glass sheet forming lines 12 extending alongside each other along a direction of conveyance C of the forming system which forms glass sheets G in a cyclical manner. Each forming line 12 includes: a heating furnace 14 for heating glass sheets, a forming location 16 located downstream along the direction of conveyance C from the furnace 14 , and a cooling station 17 located downstream along the direction of conveyance C from the forming location 16 to cyclically receive formed glass sheets therefrom for cooling. It should be noted that the furnace 14 may provide flat glass sheets to the forming location or may include a roll forming end for preforming the glass sheets as disclosed by the previously mentioned U.S. Pat. No. 6,573,484 Bennett et al. which has been incorporated herein by reference, and it should also be mentioned that the cooling station 17 may perform slow cooling for annealing, faster cooling for heat strengthening or rapid cooling for tempering of the formed glass sheets.
[0018] With continuing reference to FIG. 1 , the glass sheet forming system 10 also includes three forming stations 18 any two of which can be respectively positioned at the forming locations 16 of the pair of forming lines 12 . These forming stations 18 are preferably press bending stations as disclosed by the 6,573,484 Bennett et al. patent which has herein been incorporated by reference. Three communication assemblies 20 of the forming system 10 are respectively associated with the three forming stations 18 . Each of the communication assemblies 20 includes an upwardly extending stanchion 22 which, as shown in FIG. 3 , has an upper end 24 located above the factory floor 26 . A horizontal beam 28 of each communication assembly 20 has an elongated length including a distal end 30 having a pivotal connection 32 to its associated forming station 18 as shown in FIGS. 4 and 5 , and each communication assembly 20 also includes a bearing assembly 34 that, as schematically illustrated in FIGS. 4 and 5 , mounts the horizontal beam 28 on the upper end 24 of the associated stanchion 22 for pivotal movement about an associated vertical axis and for horizontal movement along its length between the extended position shown in FIG. 4 and the refracted position shown in FIG. 5 . A looping type wire bundle 36 of each communication assembly 20 is connected to its associated forming station 18 at the distal end 30 of the horizontal beam 28 and has a convention bendable support that limits bending at the bend 38 . At the other horizontal beam end 39 , the wire bundle 36 in its bendable wire support extends around a turn 40 back to the stanchion 22 to provide control of the forming station while still permitting movement of the forming station between different positions in the system closer and farther away from the stanchion. The wire bundles 36 include wires for providing electrical communication and any necessary vacuum or gas pressure tubes for operating the forming station during the glass forming operation.
[0019] With reference back to FIG. 1 , a control system 42 of the forming system 10 is connected to the wire bundles 36 described above to operate the pair of forming lines 12 including the heating furnaces 14 , the selected two forming stations 18 respectively in the forming locations 16 , and the cooling stations 17 .
[0020] As shown in FIG. 1 , the glass sheet forming system 10 also includes a pair of storage locations 44 at either of which any one of the forming stations not being used can be stored and at which any two of the forming stations not being used can be stored.
[0021] As illustrated in FIGS. 2 and 3 , one of the stanchions 22 whose upper end is identified by the reference numeral 24 in FIG. 2 is higher than the upper ends of the other two stanchions 22 so the horizontal beam 28 of that communication assembly is movable above the horizontal beams 28 of the other two communication assemblies 20 during movement of the forming stations 16 , which allows any two of the forming stations to be positioned in either forming line with the other forming station in one of the storage positions 16 while still having communication through the wire bundles described above to provide operation of the forming stations in both forming lines. It should be mentioned that it is also possible for only one of the forming lines 12 to be operated at any given time with the two other forming stations in the storage locations and located so there is no interference between their communication assemblies 20 .
[0022] The forming station includes a rail assembly 46 having rails 48 and a turntable 50 on which the forming stations are movable within the forming station between the forming locations 16 of the forming lines 12 and the storage locations 44 . Each forming station 18 has power driven wheels 49 ( FIGS. 4 and 5 ) for movement thereof along the rails 48 .
[0023] The stanchions 22 of two of the communication assemblies 20 are respectively located upstream and downstream from the turntable 50 along the direction of conveyance of the forming lines as shown and the stanchion of the other communication assembly is located adjacent the stanchion of one of those two communication assemblies. More specifically, stanchions 22 of the two communication assemblies 20 upstream and downstream from the turntable 50 are aligned along the direction of conveyance C with the turntable 50 and the stanchion 22 of the other communication assembly 20 is located laterally relative to the direction of conveyance C to one side of the stanchion of one of the two communication assemblies aligned with the turntable and the upper end thereof is higher than the upper ends of the other two stanchions such that the horizontal beam of the higher upper ended stanchion is movable above the horizontal beams of the other two communication assemblies during forming station movement to permit the movement to the different positions as described above. This construction permits any two of the forming stations 18 to be respectively used in the two forming lines 12 with communication by the control system for operation. Furthermore, the pair of storage locations 44 are located upstream and downstream from the turntable 50 along the direction of conveyance of the forming lines to provide for storage of one or even two of the forming stations not being used.
[0024] As illustrated in FIG. 1 , the control system 42 of the forming system 10 includes first and second programmable logic controllers 52 (PLCs) for respectively operating the pair of forming lines 12 and also includes control panels 54 respectively connected to the associated wire bundles of each forming station 18 to control its operation under the control of a third PLC 55 through wire bundles 56 for operating the three forming stations through their respective control panels in respective cooperation with the forming lines.
[0025] As illustrated in FIG. 6 , the upper end 24 of each stanchion 22 includes a pivotal support 58 that mounts an inverted U shaped frame 60 having lower support rollers 62 that mount the horizontal beam 28 and having upper rollers 64 that provide lateral guiding. Both sets of rollers 62 and 64 can be provided at spaced positions along the length of the horizontal beam so as to facilitate its support and guided movement.
[0026] By the construction of the forming station as described above with the communication assemblies, any two glass sheet forming jobs can be performed while a third forming station has its molds changed in order to reduce the time of job switching from one job to another at one of the forming lines. Thus, scheduling of the glass sheet forming jobs to be conducted timewise can reduce switchover time and thereby reduce the cost of each formed glass sheet produced.
[0027] While an exemplary embodiment is described above, it is not intended that this embodiment describes all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.
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A glass sheet forming system ( 10 ) has two parallel forming lines ( 12 ) that can utilize any two of three forming stations ( 18 ) to provide versatility in use for forming different glass sheet jobs of different sizes and shapes while reducing switchover time from one job to the next.
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TECHNICAL FIELD
[0001] The present invention relates to a microsphere vascular embolizing agent comprising anti-tumor drug, the preparation method and the use thereof. The present invention especially relates to a targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib, the preparation method and the use thereof.
BACKGROUND TECHNOLOGIES
[0002] Sorafenib is a novel diaryl urea, under the chemical name of 4-{4-[3-(4-chloro-3-trifluoro-phenyl)-ureido]-phenoxyl}-pyridine-2-carboxylic methylamine, whose molecular weight is 464.8 g/mol. The sorafenib used in clinic is its tosylate salt. The molecular formula of sorafenib tosylate is C 21 H 16 C 1 F 3 N 4 O 3 .C 7 H 8 O 3 S, the molecular weight is 637.0 g/mol and the chemical formula is shown below:
[0000]
[0003] The melting point of sorafenib tosylate is 225-235° C., and is a kind of tasteless solid, intermediate between white and brown. It is heat-stable and nonabsorbent; its solubility is low in aqueous solution and becomes higher a little bit under the strongly acid condition. It is slightly soluble in alcohol but can be dissolved in polyethylene glycerol 400. Sorafenib is a multi-target tumor-targeting therapeutic drug, which was co-developed by Bayer and ONYX during their collaboration since 1994. It is the first tumor-targeting drug approved by the U.S. Food and Drug Administration (FDA), for the treatment of metastatic renal cancer. Sorafenib was officially approved by U.S. FDA in December 2005 for use in the treatment of advanced renal cancer and it therefore became the first commercially available oral multikinase inhibitor. It was authorized to be marketed in China in End November of 2006.
[0004] Sorafenib acts as tyrosine kinase inhibitor, angiogenesis inhibitor, as well as vascular endothelial growth inhibitor. The survival, growth and metastasis of tumor are dependent on the effective cell proliferation and angiogenesis of tumor. Ras (GTP binding protein)/Raf signal transduction is a key pathway involved in tumor cell proliferation and angiogenesis. Raf is a serine/threonine (Ser/Thr) protein kinase and is the downstream effector enzyme of Ras protein. Once Raf is activated, mitogen-activated protein kinase (MEK) 1 and 2 are both triggered, which in turn cause extracellular signal-regulated kinase (ERK) 1 and 2 to be activated by phosphorylation and then translocated to nucleus. Transcription initiation and translation activation pathways are therefore triggered, resulting in cell proliferation. So this signal transduction pathway plays a direct role in regulating tumorigenesis and tumor developement in various human tumor tissues. On one hand, sorafenib inhibits RAS/RAF/MEK/ERK signal transduction pathway by inhibiting the activity of RAF so as to inhibit tumor cell growth directly. On the other hand, sorafenib interrupts neovascularization of tumor and also cuts off the nutrition supply of tumor cells by inhibiting the activity of several tyrosine kinase receptors involved in neovascularization and development of tumor, including vascular endothelial growth factor receptor 2 (VEGFR-2), REGFR-3, platelet derived growth factor receptor β (PDGFR-β) and proto-oncogene C-kit, so as to inhibit the growth of tumor cells indirectly. Thus, sorafenib has a dual anti-tumor function.
[0005] Sorafenib is mainly metabolized in liver through CYP3A4 enzyme oxidative metabolism and UGTIA9 glucuronic acid metabolism. Eight of metabolic products have been identified and five of them have been measured in blood. The predominant metabolic product pyridine N-Oxide, accounting for 9%˜16% of all metabolic products, plays a similar role to sorafenib in vitro. When orally taking a single dose of a solution containing 100 mg sorafenib, 77% of sorafenib is excreted in the faeces within 14 days, where 15% is excreted unchanged; while 19% of sorafenib is excreted as glucuronic acid metabolic products in urine. Sorafenib is the first drug allowed to enter clinical trials among congeneric compounds. The preliminary results of the clinical studies suggest that sorafenib has anti-tumor effects on solid tumors such as renal cancer, liver cancer, melanoma, non-small cell lung cancer, gastric cancer, ovarian cancer and the like.
[0006] The common side effects of sorafenib include skin redness, rash, itching, hair loss or patchy hair loss, frequent diarrhea and/or enterokinesia relaxation, nausea or vomiting, oral ulcer, fatigue, appetite loss (decrease), high blood pressure, hand-foot syndrome and the like. Among the common side effects of sorafenib, dermal toxicity and gastrointestinal responses are the main reasons for decreasing dosage or halting medication. During the treatment with oral administration of sorafenib, the most common side effects are the ones caused in gastrointestinal track, wherein 95% is gastrointestinal response, 58% is diarrhea, 30% is nausea, 24% is vomiting, and 47% is indigestion accompanied by appetite loss.
[0007] The potential side effects announced by the U.S. FDA include birth defect or death of fetus. Thus, any methods of birth control should be adopted for both male and female during the treatment and for two weeks after stopping taking sorafenib. The potential side effects such as redness, pain, swelling or blistering in palm and thenar may be observed as well. Blood pressure should be checked every week during the first six weeks of the treatment. If high blood pressure is caused while taking the medication, it should be treated in time. If patient has any potential heart problems, doctors should be informed before medication, since some side effects in heart may be caused during the treatment.
[0008] A number of genes and kinases are involved in tumorigenesis and tumor development, so targeted therapy has become one of the hottest research fields nowadays. Based on the further disclosure of the molecular biology mechanism of tumorigenesis, sorafenib was developed successfully as a novel drug possessing a unique multi-target anti-tumor activity. Its successful application in clinic inaugurated a new era of biological targeted therapy on tumors. In the aspects of the mechanism of action as well as the clinical trial results, sorafenib is different from chemotherapeutic drugs as it works mainly by inhibiting growth of tumor cells instead of via cytotoxic effects. The clinical trial results have verified that the second-line treatment of advanced renal cell carcinoma with sorafenib can prolong PFS, OS and TTP markedly. There are no doubts that the biggest concerns at the clinical trial stage nowadays are how to further enhance therapeutic effects of sorafenib and how to seek available markers to predict its therapeutic effects. Sorafenib is a novel multi-kinase inhibitor, which can inhibit not only RAF-MEK-ERK pathway but also tyrosine kinase receptors so as to result in the inhibition of tumor growth and angiogenesis. The Phase I clinical trial showed that it is tolerated and effective to take 400 mg orally twice a day and the most common side effects caused are diarrhea and skin lesion. The Phase II clinical trial suggested that sorafenib has anti-tumor activities on liver cancer and renal cancer, respectively. The Phase III clinical trial on advanced renal cancer has proved that the tumor in most of patients was shrunk markedly and the median survival time was prolonged dramatically too. Currently, a number of Phase III clinical trials, such as the Phase III clinical trial of treating liver cancer with sorafenib in China, are still underway. Thus, it is believed that more inspiring outcomes will come up and new hope of treating tumors may also arise. While holding up hopes, it should be noted that a great many problems are pending to be resolved, for example, the fact that it is difficult for drugs to penetrate tumor tissues during medication. Further clinical trials should be performed to overcome the difficulty for drugs of reaching tumor tissues and resolve the problem of treating with low concentration.
[0009] A Phase II study carried out by Ghassan et al. on the treatment of liver cancer with sorafenib has shown that the monotherapy with sorafenib has some therapeutic effects on liver cancer. Although the researchers deem that the monotherapy with sorafenib is not very effective, the effect of sorafenib is close to that of combined chemotherapy. The mechanism of action as well as the lower toxicity of sorafenib also allows it to be combined with other anti-cancer drugs to further enhance therapeutic effects. This study is a multi-center Phase III clinical trial in the Asian-Pacific area focusing on middle or advanced liver cancer cases where the patients are unable or unwilling to undergo surgery. As the nosogenesis of liver cancer is being disclosed and new molecular targeted drugs are being studied, patients suffering from advanced liver cancer may be offered an opportunity to receive targeted therapy. Most of liver cancer is descended from hepatocirrhosis so the patients with liver dysfunction and in poor physical condition benefit very little from chemotherapy and radiotherapy. Rapid advances in molecular targeted drugs provide alternative methods to treat liver cancer. In a word, molecular targeted therapy with good targets and low toxicity shows a broad prospect of treating advanced liver cancer. Thus, this kind of drug is probably one of the most potential and promising methods to treat liver cancer in the future.
[0010] Primary carcinoma of liver is an extremely malignant tumor. Although excision may be the first therapy, around 70% of patients are already in the middle or terminal stage while diagnosed. At that time, broad lesions or even metastasis has is already happened, which is usually accompanied by hepatocirrhosis, so that the tumor cannot be excised surgically in those cases. Transcatheter arterial chemoembolization (TACE) is one of the key therapies to treat middle and advanced liver cancer and it works by utilizing chemotherapeutic agents as well as embolism. Since 90%-95% of the blood supply of liver cancer is from hepatic artery, infusion of chemotherapeutic agents and embolism through hepatic artery may cause ischemic necrosis of tumors by blocking their blood supply, which allows high-dose agents work particularly on tumors for a longer time so as to improve therapeutic effects eventually. Additionally, treating with TACE before liver cancer surgery may lead to necrosis, absorption and fibrosis of tumor tissues and formation of thick fibrous capsule, all of which will reduce the amount of bleeding in the operation and prevent tumor cells from spreading that may be caused by surgical procedures or extrusion. Furthermore, the activities and toxicities of some drugs will be decreased in liver, which can hardly be reached by intravenous injections.
[0011] Tumors are one of world's deadliest diseases nowadays. The clinical treatments such as surgery, radiotherapy, chemotherapy and the like are effective methods to remove tumor mass. However, surgical resection can only be applied to visible tumors but have no effects on invisible subclinical focuses, tumor cells spreading to the surrounding normal tissues through the lymphatic system or bloodstream, or tumor cells infiltrating the surroundings directly. Radiotherapy is a treatment via local radiation so it is unable to kill the tumors outside the radiation area and has no effects on those insensitive tumor cells either. Chemotherapy is a systematic treatment which has poor selective inhibition effects on tumor cells and even has no effects on dormant tumor cells. For those reasons, several new methods and techniques have been developed to treat tumors in the recent years. Among them, molecular targeted therapy turns out to be a hotspot and even a trend of current researches. On the basis of tumor molecular biology, the molecular targeted therapy works by utilizing specific agents or drugs of targeted molecules to target the specific molecules associated with the cancer. This kind of treatment that targets diseased cells possesses sweeping “permanent” effects on tumors, in comparison with those three traditional therapies, surgery, radiotherapy and chemotherapy. However, the causes of tumors are various, so the treatment strategy should be designed from different aspects. The targeted therapy is the new technology applied in the current treatments of tumors and can eliminate tumors by inhibiting tumorigenesis and tumor development through various mechanisms.
[0012] So far, it has not ever been reported in either China or other countries around the world that the microsphere made from sorafenib and sodium alginate can be applied to the treatment of liver cancer, renal cancer, non-small cell lung cancer, gastric cancer, ovarian cancer, prostate cancer, head and neck tumor, melanoma and other solid tumors with local vascular embolism in target region.
[0013] Thus, how to maximize sorafenib's effects on treating tumors has become an urgent technical problem of the field to be resolved.
DISCLOSURE OF THE INVENTION
[0014] One objective of the present invention is to provide a targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib.
[0015] The above-mentioned objective can be achieved via the technical solution described below:
[0016] A targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib, comprising natural carrier sodium alginate and anti-tumor drug sorafenib, where the sorafenib is encapsulated by sodium alginate and the weight ratio of the sorafenib to the sodium alginate is 1:1˜1:30.
[0017] Another objective of the present invention is to provide a method for preparing the targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib.
[0018] The above-mentioned objective can be achieved via the technical solution described below:
[0019] A preparation method of targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib, the steps of which are listed below:
[0020] (1) Preparation of carrier solution
[0021] Sodium alginate is dissolved in physiological saline or water for injection proportionally to prepare a 1 wt %˜7 wt % sodium alginate carrier solution.
[0022] (2) Preparation of solidifying solution
[0023] Calcium lactate or calcium chloride is weighted proportionally and dissolved in physiological saline or water for injection to obtain a 1 wt %-10 wt % calcium lactate or calcium chloride solution.
[0024] (3) Preparation of drug solution
[0025] Sorafenib is weighted proportionally and then dissolved in polyethylene glycerol 400 or dimethyl sulfoxide (DMSO) to obtain a sorafenib drug solution.
[0026] (4) Preparation of mixture of carrier solution and drug solution
[0027] The sorafenib drug solution of Step (3) is mixed with the sodium alginate carrier solution of Step (1) by a high-speed mixer to obtain a mixture solution.
[0028] (5) Preparation of targeted sustained-release sodium alginate microsphere containing sorafenib
[0029] The mixture solution obtained in Step (4) is reacted with the solidifying solution of Step (2) via a high-voltage electrostatic multihead microsphere generating device to obtain microspheres (or micro gel beads).
[0030] A preferred technical solution, characterized in that the high-voltage electrostatic multihead microsphere generating device in Step (5) comprises high-voltage generator, multiplepoint electrode, micro-infusion pump, syringe, tailor-made needle, lifting platform, and sterile glass collector.
[0031] A preferred technical solution, wherein the preparation procedure of Step (5) is described below:
[0000] 1) A 10˜60 ml syringe is fitted with a tailor-made needle and then 10˜60 ml of the mixture solution obtained in Step (4) is aspirated into the syringe;
2) The syringe of Step 1) is fixed in the syringe pushing slot of the micro-infusion pump;
3) The positive interface of the high-voltage electrostatic generator is connected to the tailor-made needles of 2˜12 syringes via multiplepoint electrode; while the negative interface of the high-voltage electrostatic generator is connected, via multiplepoint electrode, to the extensions of 2˜12 b-shape stainless steel rings soaking in the solidifying solution of Step 2); the tailor-made needles are hung above the sterile glass collector which is placed on the lifting platform; the distance between the tip of the tailor-made needle and the surface of liquid in the sterile glass collector is adjusted to 5-20 cm; and once pressing start buttons on the high-voltage electrostatic generator and the micro-infusion pump, the sodium alginate mixture solution containing sorafenib is dropped into the solidifying solution in the sterile glass collector to obtain microspheres (or micro gel beads) called wet beads.
[0032] A preferred technical solution, characterized in that the tailor-made needle is made from stainless steel with blunt end.
[0033] A preferred technical solution, characterized in that the obtained microspheres (or micro gel beads) are subjected to centrifuge washing or precipitation washing and then stored in a preserving solution to obtain the sodium alginate microspheres (or micro gel beads) containing sorafenib; and the microspheres retain intact without sorafenib leaking during storage.
[0034] A preferred technical solution, characterized in that the preserving solution is prepared as described below:
[0035] Calcium chloride or calcium lactate is weighted proportionally and dissolved in water for injection to prepare a 3 wt %-15 wt % preserving solution.
[0036] A preferred technical solution, characterized in that the particle size range of the microspheres (or micro gel beads) stored in the preserving solution is 50˜100 μm, 70˜150 μm, 100˜200 μm, 100˜300 μm, 150˜450 μm, 300˜500 μm, 500˜700 μm, or 700˜900 μm.
[0037] A preferred technical solution, characterized in that the obtained microspheres or micro gel beads are dried via freeze drying (or oven drying) to obtained dry beads, whose particle size range is 20˜60 μm, 30˜75 μm, 50˜100 μm, 70˜150 μm, 80˜250 μm, 150˜300 μm, 250˜500 μm or 500˜700 μm.
[0038] A further objective of the present invention is to provide the use of the targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib.
[0039] The above-mentioned objective can be achieved via the technical solution described below:
[0040] The use of the targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib for the manufacturing of medicament for the treatment of liver cancer, lung cancer, ovarian cancer, prostate cancer, head and neck tumor, melanoma and other solid tumors.
[0041] The application procedure is described below:
[0042] A catheter is inserted into the artery supplying the target organ via interventional radiolography or interventional ultrasonography and then arteriography is performed. The above-mentioned targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib is chosen according to the arteriogram. When superselecting embolism, microcatheter is preferred and should be manipulated aseptically. The preserving solution in the bottle of the sodium alginate microspheres (wet beads) containing sorafenib is discarded by using syringe. The microspheres are washed with the same amount of physiological saline for 3 times, or are firstly transferred to a sterile bowl from the bottle and then washed with 50˜100 ml physiological saline for 1˜3 times. After discarding the washing fluid, an appropriate amount of contrast agent or the diluted contrast agent is added and mixed with the microspheres to make the microspheres fully suspend in the contrast medium, which is then injected into the focus slowly, in accordance with specific conditions, through the catheter under fluoroscopic control. When the flow of the contrast medium slows down apparently, the embolization is completed. Arteriography is performed once again to evaluate the effectiveness of embolization.
[0043] If dry beads are applied, the mircrospheres cannot be used until turning back into wet beads by being soaked in physiological saline half an hour in advance of application.
Beneficial Effects
[0044] By altering the dosage form as well as changing the route of administration, the targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib of the present invention enables the targeted drugs to be directed to the target region and then to have a rapid, long and focused effect on the cancer tissue. So its advantages lie in good targets, excellent therapeutic effects, negligible harm to normal tissues while killing cancer cells, low toxicity, small amount of required drugs and low treating cost.
[0045] The targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib enhances therapeutic effects by utilizing new techniques to facilitate sorafenib to reach the target region rapidly, to be released sustainably and focused around cancer cells, which reduces the cycle of the drugs, required doses, damage of normal cells and toxicity.
[0046] Currently, there are some problems associated with oral administration of sorafenib, including low bioavailability, large doses required, and high toxicity, all of which cause that the medical cost is too high to be acceptable to either doctors or patients. The combination of anti-cancer drug and embolizing agent results in a combined effect when positioning the target region; while the separate normal administrations of these two drugs at the same time have no such an effect. The microsphere encapsulating the targeted drug sorafenib and the arterial vascular embolizing agent allows the concentration of drugs to be maintained in the local tissues for a longer time. The targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib results in a focused effect by avoiding the first-pass effect whereby the drug is damaged and excreted via systemic circulation and in liver, kidney and other organs, reducing the probability of failure that drug binds to plasma proteins, prolonging the functioning time of the drug, all of which may conquer the defects of oral administration, intravenous chemotherapy and simple drug infusion, including is short retention time in tumor tissues, fast clearance from tumors and inadequate exposure of drug to tumor cells. The clinical pharmacokinetics studies suggests that the quantity of killed cancer cells is increased by 10 to 100 times and the therapeutic effect is doubled when the concentration of anti-cancer drug is doubled within a certain range in the local tissue. Since the targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib has been developed successfully, the traditional routes of drug administration will be changed and patients would therefore enjoy efficiency, comfort and convenience which are brought by the new-type agent. It will also play an indispensable role in treating solid tumors.
[0047] The inventors of the present invention found that the 2˜12 micro-infusion devices in the high-voltage electrostatic multihead microsphere generating device allows more uniform microspheres to be prepared, the yield to be increased, and the microspheres of difference particle size to be produced at the same time.
[0048] Hereinafter, the present invention will be further described in the following embodiments. However, these embodiments are not intended to restrict the scope of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Example 1
1. Preparation Before Encapsulating
[0049] Treatment of glass wares: The clean glass wares were dried out in the air and then baked in high-temperature oven at 260° C. for 3 hours to kill bacteria and remove pyrogens.
2. Preparation of Reagents
[0050] (1) Preparation of anti-tumor drug sorafenib solution
[0051] 10 mg of commercial sorafenib was weighted and added into the above-mentioned glass ware. An appropriate amount of polyethylene glycerol 400 was then dropped till the sorafenib was fully dissolved to obtain 20 ml of sorafenib solution.
[0052] (2) Preparation of sodium alginate solution
[0053] 3 L of 2 wt % sodium alginate solution was prepared by adding physiological saline into sodium alginate while stirring till sodium alginate was fully dissolved.
[0054] (3) Preparation of solidifying solution
[0055] Adequate calcium chloride was weighted and dissolved in physiological saline to prepare a 3 wt % calcium chloride solution.
[0056] (4) Preparation of preserving solution
[0057] Adequate calcium chloride was weighted and dissolved in water for injection to prepare a 3 wt % calcium chloride solution, i.e. the preserving solution.
[0058] (5) 20 ml of the above-mentioned sorafenib drug solution was mixed with 3 L of the alginate solution by a high-speed mixer to obtain the mixture solution containing sodium alginate and sorafenib.
3. Preparation of Sodium Alginate Microsphere Containing Sorafenib
[0059] (1) Two 10 ml syringes were fitted with tailor-made needles, respectively, and then the mixture of sorafenib solution and sodium alginate solution was aspirated into the syringes in at least 151 times, respectively.
[0060] (2) The syringes mentioned in Step (1) of the preparing process of microsphere were fixed in the syringe pushing slot of the micro-infusion pump.
[0061] (3) The positive interface of the high-voltage electrostatic generator was connected to the tailor-made needles of the 2 syringes via multiplepoint electrode; while the negative interface of the high-voltage electrostatic generator was connected, via multiplepoint electrode, to the extensions of the two b-shape stainless steel rings soaking in the solidifying solution of Step (2); the tailor-made needles were hung above the sterile glass collector which was placed on the lifting platform; the distance between the tip of the tailor-made needles and the surface of liquid in the sterile glass collector was adjusted to 12 cm; and once pressing the start buttons of the high-voltage electrostatic generator and the micro-infusion pump, the sodium alginate mixture solution containing sorafenib was dropped into the solidifying solution in the sterile glass collector to obtain microspheres (or micro gel beads) called wet beads. The tailor-made needle was made from stainless steel with blunt end.
[0062] (4) Washing: the obtained microspheres (or micro gel beads) were subjected to centrifuge washing or precipitation washing and then stored in the 3 wt % preserving solution. During storage, the microspheres retain intact without sorafenib leaking.
[0063] (5) The particle size of the microspheres (or micro gel beads) stored in the preserving solution ranged from 70 to 150 μm.
[0064] (6) The obtained sodium alginate microspheres or micro gel beads containing sorafenib were dried out via freeze drying to obtain dry beads, whose particle size ranged from 30 to 75 μm.
[0065] The mircrospheres can be used right after turning back into wet beads by being soaked in physiological saline half an hour in advance of application.
4. Application to Treating Patients Via Targeted Vessel Embolisation
[0066] For the patient suffering from liver cancer, a catheter was inserted into the artery supplying the target organ via interventional radiolography or interventional ultrasonography and then arteriography was performed. The above-mentioned targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib is chosen according to the arteriogram. When superselecting embolism, microcatheter would be preferred and should be manipulated aseptically. The calcium chloride solution in the bottle of the sodium alginate microspheres (wet beads) containing sorafenib was discarded by using syringe. The microspheres were washed with the same amount of physiological saline for 3 times, or were firstly transferred to a sterile bowl from the bottle and then washed with 50˜100 ml physiological saline for 1˜3 times. After discarding the washing fluid, an appropriate amount of contrast agent or diluted contrast agent was added and mixed with the microspheres to make the microspheres fully suspend in the contrast medium, which was then injected into the focus slowly, in accordance with specific conditions, through the catheter under fluoroscopic control. When the flow of the contrast medium slowed down apparently, the embolization was completed. Arteriography was performed once again to evaluate the effectiveness of embolization.
Example 2
1. Preparation Before Encapsulating
[0067] Treatment of glass wares: The clean glass wares were dried out in the air and then baked in high-temperature oven at 260° C. for 3 hours to kill bacteria and remove pyrogens.
2. Preparation of Reagents
[0068] (1) Preparation of anti-tumor drug sorafenib solution
[0069] 0.62 g of commercial sorafenib was weighted and added into the above-mentioned glass ware. An appropriate amount of dimethyl sulfoxide (DMSO) was then dropped till the sorafenib was fully dissolved to obtain 500 ml of sorafenib solution.
[0070] (2) Preparation of sodium alginate solution 45 L of 1 wt % sodium alginate solution was prepared by adding physiological saline into sodium alginate while stirring till sodium alginate was fully dissolved.
[0071] (3) Preparation of solidifying solution
[0072] Adequate calcium lactate was weighted and dissolved in physiological saline to prepare a 1 wt % calcium lactate solution.
[0073] (4) Preparation of preserving solution
[0074] Adequate calcium chloride was weighted and dissolved in water for injection to prepare a 8 wt % calcium chloride solution, i.e. the preserving solution.
[0075] (5) 500 ml of the above-mentioned sorafenib solution was mixed with 45 L of the sodium alginate solution by a high-speed mixer to obtain the mixture solution containing sodium alginate and sorafenib.
3. Preparation of Sodium Alginate Microsphere Containing Sorafenib
[0076] (1) Twelve 60 ml syringes were fitted with tailor-made needles and then the mixture of sorafenib solution and sodium alginate solution was aspirated into the syringes in at least 63 times.
[0077] (2) The syringes mentioned in Step (1) of the preparing process of microsphere were fixed in the syringe pushing slot of the microinfusion pump. The parameters of the pump were also adjusted.
[0078] (3) The positive interface of the high-voltage electrostatic generator was connected to the tailor-made needles of the 12 syringes via multiplepoint electrode; while the negative interface of the high-voltage electrostatic generator was connected, via multiplepoint electrode, to the extensions of the 12 b-shape stainless steel rings soaking in the solidifying solution of Step (2); the tailor-made needles were hung above the sterile glass collector which was placed on the lifting platform; the distance between the tip of the tailor-made needles and the surface of liquid in the sterile glass collector was adjusted to 5 cm; and once pressing the start buttons of the high-voltage electrostatic generator and the micro-infusion pump, the sodium alginate mixture solution containing sorafenib was dropped into the solidifying solution in the sterile glass collector to obtain microspheres (or micro gel beads) called wet beads. The tailor-made needle was made from stainless steel with blunt end.
[0079] (4) Washing: the obtained microspheres (or micro gel beads) were subjected to centrifuge washing or precipitation washing and then stored in the 8 wt % preserving solution. During storage, the microspheres retain intact without sorafenib leaking.
[0080] (5) The particle size of the microspheres (or micro gel beads) stored in the preserving solution ranged from 300 to 500 μm.
[0081] (6) The obtained sodium alginate microspheres (or micro gel beads) containing sorafenib were dried out via freeze drying (or oven drying) to obtain dry beads, whose particle size ranged from 150 to 300 μm.
[0082] The mircrospheres can be used right after turning back into wet beads by being soaked in physiological saline half an hour in advance of application.
4. Application to Treating Patients Via Targeted Vessel Embolisation
[0083] For the patient suffering from renal cancer, a catheter was inserted into the artery supplying the target organ via interventional radiolography or interventional ultrasonography and then arteriography was performed. The above-mentioned targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib is chosen according to the arteriogram. When superselecting embolism, microcatheter would be preferred and should be manipulated aseptically. The calcium chloride solution in the bottle of the sodium alginate microspheres (wet beads) containing sorafenib was discarded by using syringe. The microspheres were washed with the same amount of physiological saline for 3 times, or were firstly transferred to a sterile bowl from the bottle and then washed with 50˜100 ml physiological saline for 1˜3 times. After discarding the washing fluid, an appropriate amount of contrast agent or diluted contrast is agent was added and mixed with the microspheres to make the microspheres fully suspend in the contrast medium, which was then injected into the focus slowly, in accordance with specific conditions, through the catheter under fluoroscopic control. When the flow of the contrast medium slowed down apparently, the embolization was completed. Arteriography was performed once again to evaluate the effectiveness of embolization.
Example 3
1. Preparation Before Encapsulating
[0084] Treatment of glass wares: The clean glass wares were dried out in the air and then baked in high-temperature oven at 260° C. for 3 hours to kill bacteria and remove pyrogens.
2. Preparation of Reagents
[0085] (1) Preparation of anti-tumor drug sorafenib solution
[0086] 6.9 mg of commercial sorafenib was weighted and added into the above-mentioned glass ware. An appropriate amount of dimethyl sulfoxide (DMSO) was then dropped till the sorafenib was fully dissolved to obtain 30 ml of sorafenib solution.
[0087] (2) Preparation of sodium alginate solution
[0088] 2,000 ml of 7 wt % sodium alginate solution was prepared by adding physiological saline into sodium alginate while stirring till sodium alginate was fully dissolved.
[0089] (3) Preparation of solidifying solution
[0090] Adequate calcium lactate was weighted and dissolved in water for injection to prepare a 10 wt % calcium lactate solution.
[0091] (4) Preparation of preserving solution
[0092] Adequate calcium lactate was weighted and dissolved in water for injection to prepare a 15 wt % preserving solution.
[0093] (5) 30 ml of the above-mentioned sorafenib solution was mixed with 2,000 ml of the sodium alginate solution by a high-speed mixer to obtain the mixture solution containing sodium alginate and sorafenib.
3. Preparation of Sodium Alginate Microsphere Containing Sorafenib
[0094] (1) Ten 50 ml syringes were fitted with tailor-made needles and then the mixture of sorafenib solution and sodium alginate solution was aspirated into the syringe in at least 4 times.
[0095] (2) The syringes mentioned in Step (1) of the preparing process of microsphere were fixed in the syringe pushing slot of the microinfusion pump.
[0096] (3) The positive interface of the high-voltage electrostatic generator was connected to the tailor-made needles of the 10 syringes via multiplepoint electrode; while the negative interface of the high-voltage electrostatic generator was connected, via multiplepoint electrode, to the extensions of the 10 b-shape stainless steel rings soaking in the solidifying solution of Step (2); the tailor-made needles were hung above the sterile glass collector which was placed on the lifting platform; the distance between the tip of the tailor-made needles and the surface of liquid in the sterile glass collector was adjusted to 5 cm; and once pressing the start buttons of high-voltage electrostatic generator and the micro-infusion pump, the sodium alginate mixture solution containing sorafenib was dropped into the solidifying solution in the sterile glass collector to obtain microspheres (or micro gel beads) called wet beads. The tailor-made needle was made from stainless steel with blunt end.
[0097] (4) Washing: the obtained microspheres (or micro gel beads) were subjected to centrifuge washing or precipitation washing and then stored in the 15 wt % preserving solution. During storage, the microspheres retain intact without sorafenib leaking.
[0098] (5) The particle size of the microspheres (or micro gel beads) stored in the preserving solution ranged from 500 to 700 μm.
[0099] (6) The obtained sodium alginate microspheres (or micro gel beads) containing sorafenib were dried out via oven drying to obtain dry beads, whose particle size ranged from 250 to 500 μm.
[0100] The mircrospheres can be used right after turning back into wet beads by being soaked in physiological saline half an hour in advance of application.
4. Application to Treating Patients Via Targeted Vessel Embolisation
[0101] For the patient suffering from lung cancer, a catheter was inserted into the artery supplying the target organ via interventional radiolography or interventional ultrasonography and then arteriography was performed. The above-mentioned is targeted sustained-release sodium alginate microsphere vascular embolizing agent containing sorafenib is chosen according to the arteriogram. When superselecting embolism, microcatheter would be preferred and should be manipulated aseptically. The calcium chloride solution in the bottle of the sodium alginate microspheres (wet beads) containing sorafenib was discarded by using syringe. The microspheres were washed with the same amount of physiological saline for 3 times, or were firstly transferred to a sterile bowl from the bottle and then washed with 50˜100 ml physiological saline for 1˜3 times. After discarding the washing fluid, an appropriate amount of contrast agent or diluted contrast agent were added and mixed with the microspheres to make the microspheres fully suspend in the contrast medium, which was then injected into the focus slowly, in accordance with specific conditions, through the catheter under fluoroscopic control. When the flow of the contrast medium slowed down apparently, the embolization was completed. Arteriography was performed once again to evaluate the effectiveness of embolization.
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A targeted sustained-release microsphere vascular embolizing agent, the production method and the use thereof are disclosed. The microsphere comprises sodium alginate as the carrier and sorafenib as the targeted anti-tumor medicine and sorafenib is encapsulated by sodium alginate. The weight ratio of sorafenib to sodium alginate is 1:1˜1:30. The microspheres are used for manufacturing medicament for the treatment of solid tumors with advantages including high medicine concentration in the target regions with reduced systemic dosage and toxic and side effects.
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[0001] This application claims the priority benefit under 35 U.S.C. §119 of Japanese Patent Application No. 2005-060246 filed on Mar. 4, 2005, which is hereby incorporated in its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a semiconductor light emitting device, and particularly relates to a semiconductor light emitting device that can include a modified electrode structure.
[0004] 2. Description of the Related Art
[0005] An opaque pad electrode whose rear surface is wire bonded can be employed in conventional type semiconductor light emitting devices. Even if light is emitted, the light is shielded or absorbed by the pad electrode. Light emissions cannot be efficiently produced on the rear surface area and the luminous efficiency drops with respect to the applied electrical power.
[0006] In order to solve this problem, a device called a current confined path type light emitting diode can be used. This type of LED is provided with a pad electrode locally formed on the topmost layer of semiconductor layers and a linear electrode with an approximate mesh shape part of which makes contact with the pad electrode. Furthermore, a Schottky contact is formed between the pad electrode and the topmost layer of semiconductor layers, thereby preventing the leakage of current and the emission of light at areas covered by the pad electrode as well as preventing decreases in the quantity of light emitted with respect to the applied electrical power.
[0007] FIG. 1 and FIG. 2 show examples of the configuration of this type of conventional current confined path type light emitting diode 90 (for example, see Japanese Patent Laid-Open Publication No. 2004-296979, which is hereby incorporate in its entirety by reference). As shown in the cross section in FIG. 1 , this light emitting diode 90 includes a P-type semiconductor layer 92 , an active layer 93 , an N-type semiconductor layer 94 , and a topmost semiconductor layer 95 formed of n-AlGaInP.
[0008] As shown in FIG. 2 , on the topmost semiconductor layer 95 a linear electrode 96 is provided made of a metal such as An/Sn/Ni. The linear electrode 96 has a shape like a spider web that can evenly supply electrical current over a wide range of the topmost semiconductor layer 95 . The topmost semiconductor layer 95 and the linear electrode 96 are thermally alloyed to form an ohmic contact therebetween.
[0009] An electrode used for a pad 97 is formed at the center of the linear electrode 96 so as to make contact with both the topmost semiconductor layer 95 and the linear electrode 96 . Metal material, such as Ti/Au/Pt, that has work functions larger than the electron affinity of the topmost semiconductor layer 95 is selected for the electrode used for a pad 97 at this time. Then, a bonding wire 98 is connected to the electrode used for a pad 97 to allow power to be supplied from an external source.
[0010] According to this configuration, an ohmic contact is formed between the topmost semiconductor layer 95 and the linear electrode 96 . An ohmic contact is also formed between the linear electrode 96 and the electrode used for a pad 97 , and only a Schottky contact is formed between the topmost semiconductor layer 95 and the electrode used for a pad 97 .
[0011] Therefore, the electrical power supplied to the bonding wire 98 is transmitted to the topmost semiconductor layer 95 from the electrode used for a pad 97 through the linear electrode 96 and electrical current is not supplied to the topmost semiconductor layer 95 from the electrode used for a pad 97 (Schottky connected). Because of this, light does not irradiate from the area under the electrode used for a pad 97 and there is no ineffective electrical power consumed.
[0012] In the configuration of the conventional current confined path type light emitting diode 90 described above, the irradiation of light from the area under the electrode used for a pad 97 can surely be prevented, although a problem occurs in which a metal such as Ge or Zn, which is added to the linear electrode 96 in order to improve the ohmic contact between the topmost semiconductor layer 95 and the linear electrode 96 , deposits on the electrode used for a pad 97 during the thermal alloying, thereby weakening the bonding strength of the bonding wire 98 .
[0013] When the linear electrode 96 is laid out, the position of the linear electrode 96 should be taken into consideration because the linear electrode 96 may also shield the light irradiation. To cope with this problem, it is possible to thinly form the electrode in a range in which a sufficient amount of electrical power will be provided to the LED chip 91 . However, a phenomenon easily occurs in which Ge or Zn, which is added to the linear electrode 96 as described above, concentrate at one area during the thermal alloying and, for example, the resistance value of the linear electrode 96 thereby increases. Due to this, there is a limit of approximately 5 μm on the width, and the electrode cannot be thinly formed. Consequently, although the configuration is complicated, a problem also occurs wherein the light gathering efficiency is not improved.
SUMMARY
[0014] As a specific method to solve the conventional problems mentioned above and other problems, one aspect of the subject matter described herein provides a semiconductor light emitting device that can include: a substrate; at least one semiconductor layer formed on the substrate, having a topmost semiconductor layer; a pad electrode formed from a plurality of layers provided on the topmost semiconductor layer; and a linear electrode provided on the topmost semiconductor layer covering the topmost semiconductor layer except for an area occupied by the pad electrode, making contact with part of the pad electrode, and forming an ohmic contact with the topmost semiconductor layer. In this device, the pad electrode can include, as one of the plurality of layers, a barrier metal layer that covers part of or all of an upper surface and a sidewall of the linear electrode at a contact area between the linear electrode and the pad electrode.
[0015] In the semiconductor light emitting device according to the above aspect, the pad electrode may form a Schottky contact with the topmost semiconductor layer.
[0016] In the semiconductor light emitting device according to the above aspect, a bonding layer may be provided between the barrier metal layer within the pad electrode and the topmost semiconductor layer and/or the linear electrode at the contact area between the linear electrode and the pad electrode.
[0017] In the semiconductor light emitting device according to the above aspect, at least one layer among the plurality of layers of the pad electrode may be a bonding layer that makes contact with the topmost semiconductor layer, and the bonding layer may be formed from a material that has a barrier function.
[0018] In the semiconductor light emitting device according to the above aspect, the linear layer may comprise a plurality of layers, at least one of which is a barrier metal layer.
[0019] In the semiconductor light emitting device according to the above aspect, the linear electrode can have a mesh type shape, a spider web shape, a radial pattern shape, a grid pattern shape, or other shape.
[0020] In addition, the pad electrode can be provided for wire bonding in like manner to the electrode used for a pad of the conventional technique described above, and functions to supply power to the linear electrode as well as has enough surface area for at least a wire bond.
[0021] According to an aspect of the described subject matter, the conventional problems mentioned above as well as other problems can be solved by the linear electrode that forms an ohmic contact with the topmost semiconductor layer and by preventing diffusion migration of the component that constitutes the linear electrode, through the connection portion of the pad electrode. In other words, the bonding strength of the gold wire and the Schottky characteristics of the pad electrode can be maintained by preventing diffusion migration of the linear electrode component to the topmost surface of the pad electrode. In addition, the Schottky characteristics of the pad electrode can be maintained by preventing diffusion migration of the linear electrode component to the bottom surface (Schottky contact surface) of the pad electrode when the pad electrode is Schottky connected with the topmost semiconductor layer.
[0022] Secondly, a barrier metal layer can be provided within the layer structure of each of the pad electrode and the linear electrode which forms an ohmic contact with the topmost semiconductor layer. This can prevent the deposition of Ge or Zn onto the electrode surface due to diffusion or migration in any of the process steps of the thermal alloying process in the element manufacturing process. This can produce flexibility in the procedures for manufacturing the elements.
[0023] In addition, components such as Ge or Zn do not concentrate at one area within the linear electrode with any loss in the conductivity of the linear electrode. The linear electrode that conventionally has an approximate limit of 5 μm on the width can also be thinly produced up to approximately 2 μm. This results in a device that can effectively extract the quantity of light conventionally shielded by this linear electrode to the outside, leading to an effect that allows an even brighter LED to be produced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] These and other characteristics, and features will become clear from the following description with reference to the accompanying drawings, wherein:
[0025] FIG. 1 is a cross-sectional view showing a conventional example;
[0026] FIG. 2 is a top view showing the conventional example of FIG. 1 ;
[0027] FIG. 3 is a plan view showing an embodiment of a semiconductor light emitting device made in accordance with principles of the invention;
[0028] FIG. 4 is a cross-sectional view taken along the line A-A of FIG. 3 ;
[0029] FIG. 5 is an explanatory view showing a first process of a manufacturing process of an embodiment of a semiconductor light emitting device made in accordance with principles of the invention;
[0030] FIG. 6 is an explanatory view showing a second process of the manufacturing process of the semiconductor light emitting device of FIG. 5 ;
[0031] FIG. 7 is an explanatory view showing a third process of the manufacturing process of the semiconductor light emitting device of FIG. 5 ; and
[0032] FIG. 8 is an explanatory view showing a completed state of the semiconductor light emitting device of FIG. 5 .
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0033] Next, embodiments shown in the drawings will be described in detail. The embodiments relate to a configuration and manufacturing method for a light emitting diode 1 which is a type of a current confined path type light emitting diode.
[0034] In order to prevent diffusion migration of the linear electrode elements in the upward direction and/or the lateral direction towards the pad electrode in the light emitting diode, a barrier metal layer can be provided on the top of the linear electrode as well as on a portion or all of the sidewall thereof at the contact area between the linear electrode and the pad electrode. A bonding layer can also be provided between the barrier metal layer and the topmost semiconductor layer and/or between the barrier metal layer and the linear electrode construction. The bonding layer can also have a barrier function.
[0035] TiWN, TaN, WN, Ni, or NiV can be used as the material of the barrier metal layer provided at the contact area between the linear electrode and the pad electrode. However, materials with similar effect can be used, and there is no limitation for selecting the material of the barrier metal layer.
[0036] FIG. 3 and FIG. 4 show an embodiment of a semiconductor light emitting diode 1 . FIG. 3 is a plan view and FIG. 4 is a cross-sectional view showing portions of the pad electrode 3 and the linear electrode 2 . Both the pad electrode 3 and the linear electrode 2 can be provided in a bonded state on the surface of the topmost semiconductor layer 1 a . The linear electrode 2 and the pad electrode 3 can be partly bonded with each other.
[0037] When the topmost semiconductor layer 1 a is composed of an n-type semiconductor, examples of the material used for the linear electrode 2 that can form an ohmic contact with the topmost semiconductor layer 1 a include a metal such as Au, Ge, Sn, Ni, and Zn and their eutectic alloys. The linear electrode 2 can be substantially any shape and supply electrical current in the surface direction of the semiconductor layer. Examples of shapes include a mesh type, a spider web shape, a radial pattern, a grid pattern, and the like.
[0038] In the conventional example, the compositional elements of the linear electrode 2 such as Ge or Zn may migrate towards the pad electrode 3 via the top of the linear electrode 2 or the contact area between the linear electrode 2 and the pad electrode 3 producing negative effects on the electrode characteristics, the electrode shape, and the like. In order to prevent this, barrier metal layers 2 b and 3 b can be formed within the layer structure of the linear electrode 2 and the layer structure of the pad electrode 3 , respectively.
[0039] In more detail, due to diffusion migration of the compositional elements of the linear electrode 2 in the upward direction and the longitudinal direction, the linear electrode 2 may be cut, the Schottky contact characteristics between the topmost semiconductor layer 1 a and the pad electrode 3 may become disturbed, or the bonding strength between the Au wire 4 of the pad electrode 3 may deteriorate. In order to prevent these issues, the barrier metal layer 2 b can be provided within the layer structure of the linear electrode 2 and the barrier metal layer 3 b can be provided within the layer structure of the pad electrode 3 .
[0040] The barrier metal layer 3 b can be provided making contact with the sidewall of the linear electrode 2 and can also be provided through another layer such as a first bonding layer 3 a (described in more detail below).
[0041] There is also a possibility that the diffusion migration of the compositional elements of the linear electrode 2 in the upward direction will result in variations in the linear electrode shape or surface. This is especially apparent with a linear electrode 2 that has a thickness less than 5 μm, and in the worst case the linear electrode 2 may be cut. The linear electrode 2 can also be formed without any divisions at 2 μm by providing the barrier metal layer 2 b within the layer structure that comprises the linear electrode 2 .
[0042] Hereupon, the function of each layer in the layer structure of the linear electrode 2 will be described with reference to FIG. 4 . If the layer on the side making contact with the topmost semiconductor layer 1 a is described as the first layer, this first layer can be considered the linear electrode first ohmic layer 2 a that forms an ohmic contact with the topmost semiconductor layer 1 a . Examples of the material suitable for this layer 2 a include AuGe, and the layer 2 a is formed at a film thickness of 300 nm in this embodiment.
[0043] The linear electrode barrier metal layer 2 b can be formed at a film thickness of 200 nm on the upper surface of the linear electrode ohmic layer 2 a using TaN in order to prevent upward diffusion of the compositional elements of the linear electrode ohmic layer 2 a . A linear electrode bonding layer 2 c made of Ta can be formed on the linear electrode barrier metal layer 2 b at a film thickness of 50 nm. Furthermore, a linear electrode second ohmic layer 2 d made of Au can be formed on the surface of the linear electrode 2 at a film thickness of 200 nm.
[0044] Next, the configuration of the pad electrode 3 will be described. If the layer on the side making contact with the topmost semiconductor layer 1 a is described as the first layer in like manner to the linear electrode 2 , the first layer is a first bonding layer 3 a . The material for the first bonding layer 3 a is Ta, for example, and the layer 3 a is formed at a film thickness of 50 nm, for example. The pad electrode first bonding layer 3 a can function to bond the linear electrode second ohmic layer 2 d and the pad electrode barrier metal layer 3 b at the bonding area between the linear electrode 2 and the pad electrode 3 . Since the linear electrode 2 makes contact with the pad electrode 3 partly on the sidewall of the linear electrode 2 and is conductive by that area, the adhesiveness can be high.
[0045] In this embodiment wherein the first bonding layer 3 a is formed so as to cover the sidewall of the connection portion between the linear electrode 2 , part of the first bonding layer 3 a can also function as a barrier metal layer to prevent diffusion migration of the compositional elements of the linear electrode ohmic layer 2 a in the lateral direction towards the pad electrode 3 . Because of this, there may be little or no negative effects on the Schottky contact between the first bonding layer 3 a and the topmost semiconductor layer 1 a . Incidentally, the first bonding layer 3 a , or Ta layer, can form a Schottky contact with the topmost semiconductor layer.
[0046] The second layer of the pad electrode 3 can be formed by TiWN at a film thickness of 200 nm and can function as the pad electrode barrier metal layer 3 b to prevent diffusion migration of Ge, Zn (or other compositional elements of the linear electrode 2 ). A second bonding layer 3 c of Ta at a film thickness of 50 nm can be formed as the third layer, for example, over the pad electrode barrier metal layer 3 b . Furthermore, a bonding pad layer 3 d of Au at a film thickness of 600 nm can be formed as the fourth layer, for example.
[0047] The second bonding layer 3 c of Ta (the third layer) can bond the pad electrode barrier metal layer 3 b (the second layer) and the bonding pad layer 3 d of Au (the fourth layer). By making it possible to prevent diffusion of the compositional elements of the linear electrode 2 to the pad electrode 3 , the Schottky characteristics between the pad electrode 3 and the topmost semiconductor layer 1 a and the bonding strength of the wire in the bonding pad layer 3 d can be maintained.
[0048] The fact that the pad electrode first bonding layer 3 a (first layer of the pad electrode 3 ) also functions as a barrier layer is said to prevent lateral migration diffusion of the compositional elements of the linear electrode 2 in a direction towards the pad electrode 3 . When migration diffusion of the compositional elements of the linear electrode 2 towards the pad electrode 3 occurs, the Schottky contact between the pad electrode 3 and the topmost semiconductor layer 1 a may fail. Because of this, a phenomenon may be seen in which the light emission around the periphery of the pad electrode 3 becomes very noticeable when injecting electrical current.
[0049] As shown in FIG. 4 , when the pad electrode first bonding layer 3 a is formed from Ta, the above phenomenon may not be seen at all. Therefore, it could also be confirmed that this pad electrode first bonding layer 3 a functions as a barrier metal layer as well. Other than Ta mentioned above, Ni or Ti can be used as materials that have a combined function of bonding layer and barrier layer to form the pad electrode first bonding layer 3 a.
[0050] The results of trial production and test lighting performed by the inventors when forming a current confined path type light emitting diode verified that it is possible to narrow the line width of the linear electrode 2 from 5 μm to 2 μm compared to a conventional configuration depending on whether or not there is a layer structure as described above, including providing the barrier metal layer 2 b as described above. If simply calculated, this means that the surface area of the linear electrode 2 that occupies the light emitting surface of the LED chip can be made 1/2.5 and the brightness as measured on the basis of the entire device increased by that amount.
[0051] The above described semiconductor device is only an exemplary embodiment. It should be understood that the invention is not limited to the specific structures and alternatives described above, and can be modified and combined in many different ways. In particular, the pad electrode 3 can be configured in different ways to maintain the Schottky characteristics of the Schottky contact with the topmost semiconductor layer 1 a . Even in a configuration in which the pad electrode 3 has no Schottky contact with the topmost semiconductor layer 1 a , many benefits are evident such as maintaining the bonding strength between the pad electrode 3 and the wire 4 electrode by preventing diffusion migration of the compositional elements of the linear electrode 2 in the lateral direction and the upward direction.
[0052] Since no light is emitted directly under the pad electrode 3 when the pad electrode 3 is formed using an ohmic electrode, it is possible to reverse the conductivity type of a p-type clad layer, to form an electrical current prevention layer on the p-type clad layer, or the like corresponding to the position where the pad electrode 3 is formed. In addition, an insulation layer, such as SiO 2 , can also be formed while making contact with the topmost semiconductor layer 1 a . In this type of configuration, the bonding strength between the bonding wire can be maintained by forming a barrier metal layer within the layer structure of the pad electrode 3 .
[0053] The first bonding layer 3 a and the second bonding layer 3 c can be appropriately introduced as necessary. In the embodiment described above, the pad electrode 3 can also be formed as the two layer structure of the barrier metal layer 3 b and the bonding pad layer 3 d . For example, the pad layer can be formed to have a two layer structure including a 300 nm Ta barrier layer and a 600 nm Au bonding pad layer. Since the Ta film is hard, when thickly laminated, there is a high possibility that separation will occur at the boundary between other metal films. Consequently, it is possible to use the lamination structure in the embodiment described above to alleviate the stress or provide compatibility with the suitable barrier properties and adhesiveness by selecting materials.
[0054] Even further, when the first bonding layer 3 a is provided, it is not always necessary to form the layer in the same region as the barrier metal layer 3 b . It can be partially formed to cover only the upper surface and side wall of the linear electrode or only the topmost semiconductor layer. In addition, it can be partially formed using a different material. As described above, a high-quality semiconductor light emitting device can be provided.
[0055] Next, a method of forming an n-type topmost semiconductor layer 1 a of the semiconductor light emitting device 1 will be described with reference to FIG. 5 to FIG. 8 in order. The linear electrode 2 is patterned using the resist R as roughly illustrated at the side of the topmost semiconductor layer 1 a of the substrate 1 c as shown in FIG. 5 . At first, a resistance heating method is used to deposit AuGe at a film thickness of 300 nm as the linear electrode first ohmic layer 2 a.
[0056] Next, sputtering is conducted to deposit TaN at a film thickness of 200 nm as the barrier metal layer 2 b . Then, Ta is deposited at a film thickness of 50 nm as the linear electrode bonding layer 2 c , and lastly Au is successively vacuum deposited at a film thickness of 200 nm to form the linear electrode second ohmic layer 2 d . Thereafter, the resist R is removed by lift-off process (refer to FIG. 6 ).
[0057] Continuing, patterning for the pad electrode 3 (refer to FIG. 7 ) is performed using the resist R 2 on the topmost semiconductor layer 1 a . Sputtering is then conducted to deposit Ta at a film thickness of 50 nm to form the pad electrode first bonding layer 3 a . Next, TiWN is deposited at a film thickness of 200 nm to form the pad electrode barrier metal layer 3 b.
[0058] Next, Ta is deposited at a film thickness of 50 nm to form the pad electrode second bonding layer 3 c , Au is vacuum deposited at 100 nm, and lastly a resistance heating is conducted to vacuum deposit Au at 500 nm. This results in the bonding pad 3 d with a total thickness of 600 nm. Thereafter, the resist is removed by lift-off and a dicing street is formed by mesa etching. Alloying is then performed at 400° C. (refer to FIG. 8 ) to complete this exemplary embodiment of a method for manufacturing a semiconductor light emitting device 1 . The pad electrode 3 is formed by lamination on one area on the linear electrode. In particular, the first bonding layer 3 a and the barrier metal layer 3 b are formed so as to cover without exposing the side wall of the portion (overlapping the pad electrode 3 ) of the ohmic electrode.
[0059] Hereupon, conditions will be illustrated for the pad electrode 3 to form a Schottky contact with the topmost semiconductor layer 1 a . The barrier height, qφn, occurring due to contact between the metal and an n-type semiconductor (the topmost semiconductor layer 1 a ) can be solved using the equation q(φm−χ). Herein, φm is the work function of the metal and χ is the electron affinity of the semiconductor. Therefore, when forming the pad electrode 3 on an n-type semiconductor, a metal material can be selected that has a work function larger than the electron affinity of the semiconductor.
[0060] In more detail, when n-AlGaInP with an electron affinity of approximately 4.1 eV is used as the n-type semiconductor that constitutes the topmost semiconductor layer 1 a , Ti (4.33 eV), Pt (5.65 eV), Ni (5.15 eV), Al (4.28 eV), or Ta (4.25 eV) which has a work function greater than the above value should preferably be used. Incidentally, in the foregoing embodiments, the topmost semiconductor layer 1 a serving as a current diffusion layer and the semiconductor layer 1 b are formed on or above the substrate 1 c . The semiconductor layer 1 b other than the topmost semiconductor layer 1 a may be a buffer layer, a p-type clad layer, an active layer, an n-type clad layer, or the combination thereof. They are formed directly on the substrate 1 c in this order, or alternatively, separately formed layers may be adhered onto the substrate 1 c.
[0061] The materials used for the various layers and structures described above are not limited to those literally disclosed with respect to the exemplary embodiments. Specifically, other known materials can be used that serve the various functions of the layers and structures as set forth above. In addition, the method described above should not be limited by the particular disclosure of layer sequencing or the functional description of the layers with respect to the exemplary method described.
[0062] While there has been described what are considered to be exemplary embodiments of the invention, it will be understood that various modifications may be made thereto, and it is intended that the appended claims cover all such modifications as fall within the true spirit and scope of the invention.
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A semiconductor light emitting device can be configured to prevent diffusion migration of components constituting a linear electrode. The semiconductor light emitting device can include a substrate, at least one semiconductor layer formed on the substrate and having a topmost semiconductor layer, a pad electrode formed from a plurality of layers provided on the topmost semiconductor layer, and a linear electrode provided on the topmost semiconductor layer. The linear electrode can be configured to overlap the topmost semiconductor layer except for an area occupied by the pad electrode. The linear electrode can also be configured to make contact with part of the pad electrode, and form an ohmic contact with the topmost semiconductor layer. The pad electrode can include, as one of the plurality of layers, a barrier metal layer that covers part of or all of an upper surface and/or a sidewall of the linear electrode at a contact area between the linear electrode and the pad electrode.
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[0001] The present application is a divisional application of U.S. patent application Ser. No. 13/813,806 filed Apr. 15, 2013, which is a U.S. National Phase filing of International Application No. PCT/CN2011/077896, filed Aug. 2, 2011, designating the United States of America and claiming priority to Chinese Patent Application No. 201010242472.X, filed Aug. 2, 2010. The present application claims priority to and the benefit of all the above-identified applications, and all the above-identified applications are incorporated by reference herein in their entireties.
TECHNICAL FIELD
[0002] The present invention relates to a substituted pyridazine derivative or a pharmaceutically acceptable salt or hydrate thereof, a pharmaceutical composition comprising the same, and use thereof as a medicament for combating picornavirus infections in the prevention and/or treatment of a viral disease caused by a picornavirus.
BACKGROUND ART
[0003] The Picornaviridae is the smallest animal RNA virus known in the art, and it has 7 genera, i.e., rhinovirus genus, enterovirus genus, aphthovirus genus, cardiovirus genus, hepatovirus genus, double ECHOviruses (enteric cytopathic human orphan viruses) genus, and some unclassified picornaviruses. Picornaviruses can induce diseases in many systems, such as respiratory diseases, hand-foot-mouth diseases, meningitis/encephalitis, acute poliomyelitis, cardiovascular diseases, hemorrhagic conjunctivitis, and hepatitis.
[0004] In the late 1980s, virology developed greatly. Several important events in viral life cycle have been well described, and many molecular targets are confirmed. In recent years, the appearance of many novel antiviral drugs also promotes the development of virology. The activities of picornavirus inhibitors are studying. These inhibitors act on targets including viral capsid protein 1 (VP1), a relatively conservative capsid structure for mediating viral absorption/uncoating process. VP1s of viruses of different serotypes are of highly conservative structure, but are very important for replication of viruses, and inhibitors acting on this target could be drugs for combating picornaviruses, among which Pirodavir is a typical representative (ANTIMICROBIAL AGENTS and CHEMOTHERAPY, 36(4), 727-732), and this compound exhibits significant activity against rhinovirus (HRV) in vivo and in vitro. Bioorg Med Chem. 2009, 17: 621-624 discloses a series of compounds with good inhibition activity to HRV, among which the compounds 4-{2-[N-(3-chloropyridazin-4-yl)piperidin-4-yl]ethoxyl}benzoic acid ethyl ester (5f) and 3,6-dichloro -4-{4-[2-(4-ethoxylphenoxy)ethyl]piperazin-1-yl}pyridazine (5c) have an activity comparable to Pirodavir, but have a relatively low toxicity, and a relatively high index of selectivity.
[0005] However, there is still need to develop an antiviral agent having a novel structure, effectiveness, and optionally one or more physiological and/or physicochemical advantages.
DESCRIPTION OF THE INVENTION
[0006] The object of the present invention is to discover and develop a novel small molecule compound acting on VP1 of a picornavirus, which can block the adhesion and uncoating of the virus, has an inhibition activity on a picornavirus, and thereby accomplishes the goals of the prevention and/or treatment of a disease caused by a picornavirus.
[0007] After extensive studies, the present inventors have found that a compound of the following Formula I can act on VP1 of picornavirus to block the adhesion and uncoating of the virus, and thus may be used for the prevention and/or treatment of a disease caused by a picornavirus. The present invention is thus accomplished on the basis of the above findings.
[0008] The first aspect of the present invention provides a compound of Formula I:
[0000]
[0009] or a pharmaceutically acceptable salt or hydrate, in which:
[0010] R1, R2 and R3 are each independently selected from the group consisting of hydrogen and halogen (such as fluorine, chlorine, bromine or iodine, preferably fluorine or chlorine);
[0011] n is an integer of 2 to 5 (such as an integer of 3 to 5, an integer of 3 to 4, an integer of 2, 3, 4 or 5, preferably an integer of 3 to 5, an integer of 3 to 4, or 2, 3 or 4); and
[0012] R4, R5 and R6 are each independently selected from the group consisting of hydrogen, halogen (such as fluorine, chlorine, bromine or iodine), a straight or branched C1-C8 alkyl (such as a straight or branched C1-C8 alkyl, a straight or branched C1-C6 alkyl, a straight or branched C1-C4 alkyl, methyl, ethyl, n-propyl, isopropyl, n-butyl or tert-butyl), —COOR7 and —OR8; wherein
[0013] R7 and R8 are each independently selected from the group consisting of hydrogen, a straight or branched C1-C6 alkyl (such as a straight or branched C1-C4 alkyl, methyl, ethyl, n-propyl, isopropyl, n-butyl or tert-butyl).
[0014] The compound according to the first aspect of the present invention is a compound of Formula Ia:
[0000]
[0015] or a pharmaceutically acceptable salt or hydrate, wherein:
[0016] R1 is selected from the group consisting of hydrogen, fluorine, chlorine, bromine and iodine (preferably fluorine and chlorine);
[0017] n is an integer of 2 to 5 (such as an integer of 3 to 5, an integer of 3 to 4, an integer of 2, 3, 4 or 5, preferably an integer of 3 to 5, an integer of 3 to 4, or 2, 3 or 4); and
[0018] R4 is selected from the group consisting of hydrogen, halogen (such as fluorine, chlorine, bromine, or iodine), a straight or branched C1-C8 alkyl (such as a straight or branched C1-C8 alkyl, a straight or branched C1-C6 alkyl, a straight or branched C1-C4 alkyl, methyl, ethyl, n-propyl, isopropyl, n-butyl or tert-butyl), —COOR7 and —OR8; wherein
[0019] R7 and R8 are each independently selected from the group consisting of hydrogen, a straight or branched C1-C6 alkyl (such as a straight or branched C1-C4 alkyl, methyl, ethyl, n-propyl, isopropyl, n-butyl or tert-butyl).
[0020] The compound according to the first aspect of the present invention is a compound of Formula Ia:
[0000]
[0021] or a pharmaceutically acceptable salt or hydrate, in which:
[0022] R1 is selected from the group consisting of fluorine and chlorine;
[0023] n is an integer of 3 to 5 (preferably an integer of 3 to 4, or 3 or 4); and
[0024] R4 is selected from the group consisting of halogen (such as fluorine, or chlorine), a straight or branched C1-C6 alkyl (such as a straight or branched C1-C4 alkyl, methyl, ethyl, n-propyl, isopropyl, n-butyl or tert-butyl), —COOR7 and —OR8; wherein
[0025] R7 and R8 are each independently selected from the group consisting of hydrogen, a straight or branched C1-C4 alkyl (such as methyl, ethyl, n-propyl, isopropyl, n-butyl or tert-butyl).
[0026] The compound according to the first aspect of the present invention is a compound of Formula Ia:
[0000]
[0027] or a pharmaceutically acceptable salt or hydrate, in which:
[0028] R1 is chlorine;
[0029] n is 3 or 4; and
[0030] R4 is selected from the group consisting of a straight or branched C1-C6 alkyl (such as a straight or branched C1-C4 alkyl, methyl, ethyl, n-propyl, isopropyl and n-butyl), —COOR7 and —OR8; wherein
[0031] R7 and R8 are each independently selected from the group consisting of hydrogen and a straight or branched C1-C4 alkyl (such as methyl, ethyl, n-propyl, isopropyl and n-butyl).
[0032] The compound according to the first aspect of the present invention is selected from the group consisting of:
[0033] 3-{4-[3-(4-ethoxylphenoxy)propyl]piperazin-1-yl}-6-chloropyridazine,
[0034] 3-{4-[3-(4-methylphenoxy)propyl]piperazin-1-yl}-6-chloropyridazine,
[0035] 3-{4-[3-(4-ethylphenoxy)propyl]piperazin-1-yl}-6-chloro-pyridazine,
[0036] 3-{4-[3-(4-isopropylphenoxy)propyl]piperazin-1-yl}-6-chloropyridazine,
[0037] 4-{3-[4-(6-chloropyridazin-3-yl)piperazin-1-yl]propoxy}benzoic acid methyl ester, and
[0038] 4-{3-[4-(6-chloropyridazin-3-yl)piperazin-1-yl]propoxy}benzoic acid ethyl ester, or a pharmaceutically acceptable salt or hydrate.
[0039] The second aspect of the present invention provides a pharmaceutical composition comprising a therapeutically and/or preventively effective amount of the compound according to the first aspect of the present invention or a pharmaceutically acceptable salt or hydrate thereof, and optionally one or more pharmaceutically acceptable carrier or excipient.
[0040] The third aspect of the present invention provides use of the compound according to the first aspect of the present invention or a pharmaceutically acceptable salt or hydrate thereof, or the pharmaceutical composition according to the second aspect of the present invention in the manufacture of a medicament for treating and/or preventing a disease or disorder associated with viral infections. In one embodiment of the third aspect of the present invention, the virus is a picornavirus. In one embodiment of the third aspect of the present invention, the picornavirus is selected from the group consisting of: rhinoviruses, enteroviruses, aphthoviruses, cardioviruses, hepatoviruses, dual ECHOviruses. In one embodiment of the third aspect of the present invention, the disease or disorder associated with viral infections is selected from the group consisting of: respiration diseases (including but not being limited to: common cold (such as summer cold), pharyngitis, tonsillitis and croup), hand-foot-mouth diseases, meningitis/encephalitis, acute poliomyelitis, cardiovascular diseases, hemorrhagic conjunctivitis, and hepatitis.
[0041] The fourth aspect of the present invention provides use of the compound of the first aspect of the present invention or a pharmaceutically acceptable salt or hydrate thereof or the pharmaceutical composition of the second aspect of the present invention as a medicament for combating a disease or disorder associated with viral infections. In one embodiment of the fourth aspect of the present invention, the virus is a picornavirus. In one embodiment of the fourth aspect of the present invention, the picornavirus is selected from the group consisting of: rhinoviruses, enteroviruses, aphthoviruses, cardioviruses, hepatoviruses, dual ECHOviruses. In one embodiment of the fourth aspect of the present invention, the disease or disorder associated with viral infections is selected from the group consisting of: respiration diseases (including but not being limited to: common cold (such as summer cold), pharyngitis, tonsillitis and croup), hand-foot-mouth diseases, meningitis/encephalitis, acute poliomyelitis, cardiovascular diseases, hemorrhagic conjunctivitis, and hepatitis.
[0042] The fifth aspect of the present invention provides a method for treating and/or preventing a disease or disorder associated with viral infections in a subject in need thereof, comprising administering to the subject a therapeutically and/or preventively effective amount of the compound according to the first aspect of the present invention or a pharmaceutically acceptable salt or hydrate thereof, or the pharmaceutical composition of the second aspect of the present invention. In one embodiment of the fifth aspect of the present invention, the virus is a picornavirus. In one embodiment of the fifth aspect of the present invention, the picornavirus is selected from the group consisting of: rhinoviruses, enteroviruses, aphthoviruses, cardioviruses, hepatoviruses, dual ECHOviruses. In one embodiment of the fifth aspect of the present invention, the disease or disorder associated with viral infection is selected from the group consisting of: respiration diseases (including but not being limited to: common cold (such as summer cold), pharyngitis, tonsillitis and croup), hand-foot-mouth diseases, meningitis/encephalitis, acute poliomyelitis, cardiovascular diseases, hemorrhagic conjunctivitis, and hepatitis.
[0043] The sixth aspect of the present invention provides the compound according to the first aspect of the present invention or a pharmaceutically acceptable salt or hydrate thereof for treating and/or preventing a disease or disorder associated with viral infections. In one embodiment of the sixth aspect of the present invention, the virus is a picornavirus. In one embodiment of the sixth aspect of the present invention, the picornavirus is selected from the group consisting of: rhinoviruses, enteroviruses, aphthoviruses, cardioviruses, hepatoviruses, dual ECHOviruses. In one embodiment of the sixth aspect of the present invention, the disease or disorder associated with viral infection is selected from the group consisting of: respiration diseases (including but not being limited to: common cold (such as summer cold), pharyngitis, tonsillitis and croup), hand-foot-mouth diseases, meningitis/encephalitis, acute poliomyelitis, cardiovascular diseases, hemorrhagic conjunctivitis, and hepatitis.
[0044] The various aspects and features of the present invention are further described as follows.
[0045] All cited references are incorporated herein by their full texts, and if the meaning of an expression in these references is inconsistent with that in the present invention, the meaning of the expression in the present invention should be used. In addition, the terms and phrases used in the present invention have common meanings known by those skilled in the art, unless they are defined otherwise. If the meaning of a term or phrase defined in the present invention is inconsistent with that well known in the art, the meaning defined in the present invention should be used.
[0046] As used herein, by the term “pharmaceutically acceptable”, for example, when used in “a pharmaceutically acceptable salt”, it mans that the salt is not only physiologically acceptable in a subject, but also a substance having pharmaceutical value.
[0047] As used herein, the term “alkyl” comprises a straight and branched saturated hydrocarbonyl with the designated number of carbon atoms. As used herein, the term “C 1-6 alkyl” refers to an alkyl having the designated number of carbon atoms, which is a straight or branched alkyl, and may comprise its subgroups, such as C 1-4 alkyl, C 1-3 alkyl, C 1-2 alkyl, C 2-6 alkyl, C 2-4 alkyl, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, tert-butyl, pentyl, or hexyl.
[0048] As used herein, the term “halogen”, “halogen atom”, “halogenated” represents fluorine, chlorine, bromine or iodine, especially fluorine, chlorine or bromine.
[0049] As used herein, the term “effective amount” refers to a dose that can achieve the treating and/or preventing of the disease or disorder as defined in the present invention in a subject.
[0050] As used herein, the term “pharmaceutical composition” refers to a “composition”, which can achieve the treating and/or preventing of the disease or disorder as defined in the present invention in a subject, especially a mammal.
[0051] As used herein, the term “subject” may refer to a patient or an animal, especially human, dog, monkey, bovine, or equine, which is administered with the compound of Formula I of the present invention or a pharmaceutical composition thereof to treat and/or prevent the disease or disorder as defined in the present invention.
[0052] As used herein, “%” refers to a weight/weight percentage, especially in a situation of describing solid substance, unless it is specifically indicated otherwise. Of course, when it is described for a liquid substance, the “%” may refer to a weight/volume percentage (in the case of a solid being dissolved in a liquid), or a volume/volume percentage (in the case of a liquid being dissolved in a liquid).
[0053] One embodiment of the present invention relates to a method for the prevention and/or treatment of a disease associated with an infection caused by a picornavirus, comprising administrating a therapeutically and/or preventively effective amount of at least one of the compound of Formula I or a pharmaceutically acceptable salt or hydrate thereof to a patient in need of such treating and/or preventing of the disease associated with an infection caused by a picornavirus.
[0054] According to the present invention, the compound of Formula (I) or a pharmaceutically acceptable salt or hydrate thereof is preferably selected from the group consisting of the following compounds:
[0055] 3-{4-[3-(4-ethoxylphenoxy)propyl]piperazin-1-yl}-6-chloropyridazine,
[0056] 3-{4-[3-(4-methylphenoxy)propyl]piperazin-1-yl}-6-chloropyridazine,
[0057] 3-{4-[3-(4-ethylphenoxy)propyl]piperazin-1-yl}-6-chloro-pyridazine,
[0058] 3-{4-[3-(4-isopropylphenoxy)propyl]piperazin-1-yl}-6-chloropyridazine,
[0059] 4-{3-[4-(6-chloropyridazin-3-yl)piperazin-1-yl]propoxy}benzoic acid methyl ester, and
[0060] 4-{3-[4-(6-chloropyridazin-3-yl)piperazin-1-yl]propoxy}benzoic acid ethyl ester
[0061] According to the present invention, the compound of the present invention may be prepared as an example by a process of the following reaction scheme:
[0000]
[0062] For example, N-piperazine carboxylic acid ethyl ester is reacted with a compound of Formula II in the presence of potassium carbonate in acetonitrile as the solvent at room temperature to generate a compound of Formula III, the compound of Formula III is heated for refluxing in the presence of 10% sodium hydroxide aqueous solution in ethanol as the solvent to generate a compound of Formula IV, a compound of Formula V is reacted with the compound of Formula IV in the presence of sodium carbonate in chloroform, acetone, dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide (preferably N,N-dimethylacetamide) as the solvents at room temperature to generate a compound of Formula VI, and the compound of Formula VI is reacted with a compound of Formula VII in the presence of triphenylphosphine and diethyl azodicarboxylate in tetrahydrofuran as the solvent at room temperature to generate a compound of Formula I.
[0063] According to the present invention, the term “pharmaceutically acceptable salt” of the compound of the present invention comprises acid salts formed with the compound of the present invention and pharmaceutically acceptable inorganic or organic acids, or alkali salts formed with the compound of the present invention and pharmaceutically acceptable alkalis, in which the acid salt include but are not limited to: hydrochloride, hydrobromide, hydroiodide, nitrate, sulfate, bisulfate, phosphate, biphosphate, acetate, propionate, butyrate, oxalate, trimethylacetate, adipates, alginate, lactate, citrate, tartrate, succinate, maleate, fumarate, picrate, aspartate, gluconate, benzoate, mesylate, esylate, besylate, tosilate, and pamoate; and alkali salts include but are not limited to ammonium salt, alkali metal salts such as sodium and potassium salts, alkaline earth metal salts such as calcium and magnesium salts, organic alkali salts such as dicyclohexylamine and N-methyl-D-glucosamine, and amino acid salts such as arginine and lysine salts.
[0064] According to the present invention, the pharmaceutical composition of the present invention comprises an effective amount of the compound of Formula (I) of the present invention or a pharmaceutically acceptable salt or hydrate and one or more suitable pharmaceutically acceptable carriers. These pharmaceutically acceptable carriers include but are not limited to: ion exchangers, alumina, aluminum phosphate, lecithin, serum proteins such as human serum protein, buffering substances such as phosphates, glycerol, sorbic acid, potassium sorbate, partial glycerides of saturated vegetable fatty acids, water, salt or electrolyte, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, zinc salts, colloidal silica, magnesium trisilicate, polyvinylpyrrolidone, cellulose substances, polyethylene glycol, carboxymethylcellulose sodium, polyacrylic esters, beewax, polyethylene-polyoxypropylene block polymer, and lanolin.
[0065] The compounds of the present invention are a group of potent inhibitors for a picornavirus, and such compounds are highlighted in the both prevention and treatment of a disease caused by a picornavirus. The disease caused by a picornavirus includes but is not limited to respiratory diseases, hand-foot-mouth diseases, meningitis/encephalitis, acute poliomyelitis, cardiovascular diseases, hemorrhagic conjunctivitis, or hepatitis.
[0066] The respiratory diseases include but are not limited to: common cold (such as summer cold), pharyngitis, tonsillitis and croup. These diseases are usually caused by rhinoviruses of the picornavirus family.
[0067] According to the present invention, the pharmaceutical composition of the compound of the present invention may be administered via any one of the following manners: oral administration, spray inhalation, rectal administration, nasal administration, bucca administration, vagina administration, topic administration, parenteral administration, such as subcutaneous, intravenous, intramuscular, intraperitoneal, intrathecal, intraventricular, intrasternal, and intracranial injection or infusion, or administration with the help of an explanted reservoir, in which oral, intraperitoneal or intravenous administration is preferred. In addition, in order to allow the compound of the present invention to effectively treat central nervous system disorders, intraventricular administration is preferred to overcome the possible low blood-brain barrier permeability.
[0068] For oral administration, the compound of the present invention may be processed in any acceptable forms for oral administration, including but not being limited to tablets, capsules, water solutions or water suspensions. The tablets use a carrier generally comprising lactose and maize starch, additionally comprising a lubrimayt such as magnesium stearate. The capsules use a diluent generally comprising lactose and dry maize starch. The water suspensions usually use a mixture of an active component and suitable emulsifying agent and suspending agent. If necessary, the above oral dosage forms may further comprise some sweetening agents, flavoring agents or coloring agents.
[0069] For rectal administration, the compound of the present invention is usually processed to form a suppository, which is prepared by mixing the drug with a suitable unstimulated excipient. This excipient is of solid state, and melts at rectal temperature to release drug. This excipient comprises cocoa butter, bee wax and polypropylene glycol.
[0070] For local administration, especially in treatment of neurogenic disease of a readily accessible affected surface or organ such as eye, skin or inferior part of intestinal tract by local external application, the compound of the present invention may be processed into different dosage forms for local administration according to different affected surfaces or organs, which are illustrated as follows:
[0071] For local administration to eyes, the compound of the present invention may be processed in a dosage form of micronized suspension or solution, in which the used carrier is isotonic sterile saline with a certain pH, wherein a preservative such as chlorobenzylalkanol salt may be added or not be added. For the eye use, the compound may be processed into ointment form, such as Vaseline ointment.
[0072] For local administration to skin, the compound of the present invention may be processed in suitable dosage forms such as ointments, lotions or creams, wherein the active component is suspended or dissolved in one or more carriers. The carriers usable in ointments include but are not limited to: mineral oil, liquid paraffin, white Vaseline, propylene glycol, polyethylene oxide, polypropylene oxide, emulsified wax and water; the carriers usable in lotions or creams comprise but are not limited to: mineral oil, sorbitan monostearate, Tween 60, hexademaye ester wax, hexadecylene aromatic alcohol, 2-octyldodemayol, benzyl alcohol and water.
[0073] For local administration to lower intestinal tract, the compound of the present invention may be processed to form the above rectal suppository or suitable enema, and may be processed to form topic transdermal patches.
[0074] The compound of the present invention may further be administered in dosage form of sterile injections, including water or oil suspensions for sterile injection, or sterile injection solutions. The usable carriers and solvents include water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile nonvolatile oil may also be used as the solvent or suspending medium, such as monoglyceride or diglyceride.
[0075] It is further pointed out that the dose and usage method of the compound of the present invention depend on many factors, including age, body weight, gender, natural health status, nutritional status, activity of compound, administration time, metabolic rate, severity of disease and subjective judgment of diagnostic doctor. The preferred dose used in the present invention is between 0.01 and 100 mg/kg bodyweight/day.
EXEMPLARY MODES FOR CARRYING OUT THE INVENTION
[0076] The present invention is further illustrated with the following examples, but the scope of the present invention is not limited to the following examples. Those skilled in the art would understand that the present invention may be changed and modified in many ways without departing from the spirit and scope. The present invention describes in general and/or in details the materials and experimental methods used in experiments. Although many materials and operation methods used for fulfilling the objective of the present invention are well known in the art, they are still described in the present invention in details as much as possible.
[0077] As for all of the following examples, standard operations and purification methods known in the art may be used. Unless other stated, all temperatures are represented with ° C. (Celsius degree). The structures of the compounds are determined by nuclear magnetic resonance (NMR) or mass spectrum (MS). Melting point of compound is measured by RY-1 type melting point instrument, thermometer is not calibrated, and m.p. is expressed in ° C. 1 H NMR is measured by JNM-ECA-400 type nuclear magnetic resonance. Mass spectrum is measured by Agilent 5875 (EI). All solvents used in reactions are subjected to a standard pretreatment, unless specifically indicated otherwise.
Example 1
Synthesis of 3-{4-[3-(4-ethoxylphenoxy)propyl]piperazin-1-yl}-6-chloropyridazine
[0078] 1.1 Synthesis of 4-(3-hydroxypropyl)piperazinylcarboxylic acid ethyl ester
[0079] N-piperazine carboxylic acid ethyl ester (25.50 g, 161.39 mmol), 3-bromo-1-propanol (22.43 g, 161.39 mmol), potassium carbonate (55.68 g, 403.48) and anhydrous acetonitrile (200 mL) were placed in a 500 mL round bottom flask, heated for refluxing and stirred overnight. The reaction was cooled down to room temperature, filtered, concentrated and subjected to a column chromatography (eluting agent: dichloromethane/methanol/triethylamine system, v/v/v 100:1:0.5) to obtain a light yellow oily substance, 26.60 g, yield 76.3%, which was directly used in the next step of reaction.
[0080] 1.2 Synthesis of 1-(3-hydroxypropyl)piperazine
[0081] 4-(3-hydroxypropyl)piperazinylcarboxylic acid ethyl ester (14.06 g, 65.09 mmol), 10% sodium hydroxide aqueous solution (150 mL) and ethanol (150 mL) were placed in a 500 mL round bottom flask, heated for refluxing and stirred overnight. The reaction was cooled down to room temperature, distilled under a reduced pressure to remove the solvent to obtain a light yellow oily substance, which was added with 200 mL saturated saline, and the resulting mixture was extracted with dichloromethane (5×200 mL), dried (Na 2 SO 4 ), filtered, concentrated to obtain a light yellow oily substance, 7.56 g, yield 80.7%, which was directly used in the next step of reaction.
[0082] 1.3 Synthesis of 3-[4-(6-chloropyridazin-3-yl)piperazin-1-yl]propan-1-ol
[0083] 3,6-dichloropyridazine (14.90 g, 100 mmol), sodium carbonate (10.60 g, 100 mmol) and DMA (80 mL) were placed in a 250 mL three-necked bottle, and the solution of 1-(3-hydroxypropyl)piperazine (14.4 g, 100 mmol) in DMA (20 mL) was added slowly in dropwise within 30 min under an ice-bath condition. The mixture was stirred at room temperature overnight, distilled under a reduced pressure to remove the solvent to obtain a brown solid, which was subjected to a column chromatography (gradient elution: petroleum/acetone system, v/v 2:1 to acetone) to obtain a white solid, 13 g, yield 50.8%.
[0084] 1.4 Synthesis of 3-{4-[3-(4-ethoxylphenoxy)propyl]piperazin-1-yl}-6-chloropyridazine
[0085] 3-[4-(6-chloropyridazin-3-yl)piperazin-1-yl]propan-1-ol (0.77 g, 3 mmol), p-ethoxylphenol (0.41 g, 3 mmol), triphenylphosphine (0.79 g, 3 mmol) and anhydrous THF (20 mL) were placed in a 100 mL three-necked bottle, and DEAD (0.52 g, 3 mmol) was added slowly in dropwise within 10 min under an ice-bath condition. The mixture was stirred at room temperature overnight, subjected to a column chromatography (eluting agent: petroleum/ethyl acetate, v/v 3:2) to obtain a white solid, 0.27 g, yield 23.9%. mp: 125-127° C.; 1 H-NMR(400 MHz, CDCl 3 , δppm) δ1.39(t, 3H, J=7.2 Hz), 2.00(m, 2H), 2.61(br, 6H), 3.67(br, 4H), 3.98 (m, 4H), 6.83(s, 4H), 6.90(d, 1H, J=9.6 Hz), 7.21(d, 1H, J=9.6 Hz); EI-MS(m/z): 376.2[M+H] + .
[0086] The following compounds may be prepared by referring to the procedures in step 1.4 of Example 1, replacing p-ethoxyphenol in step 1.4 by different reactants (various substituted phenol).
Example 2
Synthesis of 3-{4-[3-(4-methylphenoxy)propyl]piperazin-1-yl}-6-chloropyridazine
[0087] By referring to the procedures in step 1.4 of Example 1, p-methylphenol was used to replace p-ethoxylphenol to obtain the titled compound as a white solid, yield 35.7%. mp: 129-131° C.; 1 H-NMR(400 MHz, CDCl 3 , δppm) δ2.00(m, 2H), 2.29(s, 3H), 2.59(br, 6H), 3.65(br, 4H), 4.02 (t, 2H, J=6.0 Hz), 6.81(d, 2H, J=8.8 Hz), 6.90(d, 1H, J=9.2 Hz), 7.08(d, 2H, J=8.4 Hz), 7.21(d, 2H, J=9.6 Hz); EI-MS(m/z): 346.1[M+H] + .
Example 3
Synthesis of 3-{4-[3-(4-ethylphenoxy)propyl]piperazin-1-yl}-6-chloropyridazine
[0088] By referring to the procedures in step 1.4 of Example 1, p-ethylphenol was used to replace p-ethoxylphenol to obtain the titled compound as white solid, yield 33.3%. mp: 123-125° C.; 1 H-NMR(400 MHz, CDCl 3 , δppm) δ1.21(t, 3H, J=7.2 Hz), 2.01(m, 2H), 2.59(m, 8H), 3.66(br, 4H), 4.02 (t, 2H, J=6.0 Hz), 6.83(d, 2H, J=8.4 Hz), 6.90(d, 1H, J=9.2 Hz), 7.08(d, 2H, J=8.4 Hz), 7.21(d, 2H, J=9.6 Hz); EI-MS(m/z): 360.2 [M+H] − .
Example 4
Synthesis of 3-{4-[3-(4-isopropylphenoxy)propyl]piperazin-1-yl}-6-chloropyridazine
[0089] By referring to the procedures in step 1.4 of Example 1, p-isopropylphenol was used to replace p-ethoxylphenol to obtain the titled compound as white solid, yield 17.1%. mp: 125-127° C.; 1 H-NMR(400 MHz, CDCl 3 , δppm) δ1.22(d, 6H, J=7.2 Hz), 2.01(br, 2H), 2.60(br, 6H), 2.86(m, 1H), 3.66(br, 4H), 4.03(t, 2H, J=8.8 Hz), 6.84(d, 2H, J=8.4 Hz), 6.90(d, 1H, J=9.2 Hz), 7.14(d, 2H, J=8.8 Hz), 7.21(d, 1H, J=9.6 Hz); EI-MS(m/z): 374.2 [M-H] + .
Example 5: Synthesis of 4-{3-[4(6-chloropyridazin-3-yl)piperazin-1-yl]propoxy} benzoic acid methyl ester
[0090] By referring to the procedures in step 1.4 of Example 1, p-hydroxybenzoic acid methyl ester was used to replace p-ethoxylphenol to obtain the titled compound as white solid, yield 23.9%. mp: 128-130° C.; 1 H-NMR (400 MHz, CDCl 3 , δppm) δ2.04(t, 2H, J=6.4 Hz), 2.60(br, 6H), 3.66(br, 4H), 3.89(s, 3H), 4.11 (t, 2H, J=6.0 Hz), 6.91(m, 3H), 7.21(d, 1H, J=9.6 Hz), 7.99(d, 2H, J=8.8 Hz); EI-MS(m/z): 390.2 [M-H] + .
Example 6
Synthesis of 4-{3-[4-(6-chloropyridazin-3-yl)piperazin-1-yl]propoxy}benzoic acid ethyl ester
[0091] By referring to the procedures in step 1.4 of Example 1, p-hydroxybenzoic acid ethyl ester was used to replace p-ethoxylphenol to obtain the titled compound as white solid, yield 28.5%. mp: 125-127° C.; 1 H-NMR (400 MHz, CDCl 3 , δppm) δ1.38(t, 3H, J=7.2 Hz), 2.05(br, 2H), 2.61(br, 6H), 3.66(br, 4H), 4.11(t, 2H, J=6.0 Hz), 4.35(m, 2H), 6.91(m, 3H), 7.20(d, 1H, J=9.6 Hz), 7.99(d, 2H, J=8.8 Hz); EI-MS(m/z): 404.2 [M-H] + .
Experiment Example 1
Activity of Combating Picornavirus in an in Vitro Model
[0092] Experimental Materials:
[0093] Host cells: HeLa cells (self-stored in the present laboratory)
[0094] Virus: rhinovirus 3 (HRV-3) (ATCC: VR-1113)
[0095] Positive compounds: see, Bioorg Med Chem. 2009, 17: 621-624, the preferred compounds therein, 4-{2-[N-(3-chloropyridazin-4-yl)piperidin-4-yl]ethoxyl}benzoic acid ethyl ester (5f) and 3,6-dichloro-4-{4-[2-(4-ethoxylphenoxy)ethyl] piperazin-1-yl}pyridazine (5c) were separately used as positive control 1 (hereinafter referred to as Control 1) and positive control 2 (hereinafter referred to as Control 2).
[0096] 1) Determination of the Maximum Nontoxic Dose of the Compound
[0097] The drug was dissolved in DMSO, diluted with cell maintenance medium by 20 times, then diluted stepwise by 2 times to form working solutions with different concentrations. HeLa cells were inoculated on 96-well plate in an amount of 10,000 (0.1 mL) per well, added with 0.1 mL maintenance medium, incubated at 37° C. in adherence manner, sucked to remove maintenance medium, replaced it with 0.2 mL of compound working solution, and maintenance medium was used as control. The growth of cell was observed each 24 h, for 3 days. The lowest dilution times which did not cause pathological change was used to determine the nontoxic limit of drug (maximum nontoxic dilution).
[0098] 2) Prophylactic Administration
[0099] Principle: drug was mixed with virus and incubated in advance to block the procedure of viral uncoating and invasion into cell. Method: the drug in a concentration of 100 ng/ml was added to a 12-well plate, then added with a viral dose with TCID 50 value of about 100, after 0.5 h, 500,000 cells were added to each well, incubated at 33° C., 3 days later, when virus control group showed 100% cytopathic effect (CPE), the effects of drug on preventing cells from phagocytosis were observed, and expressed in cell protection rate (%). The results of prophylactic administration show that various compounds have protection effects in different extents in preventing phagocytosis; in which Control 1, Control 2 and the compounds obtained in various examples all have good protection effects.
[0100] 3) Therapeutic Administration
[0101] The compounds exhibiting better effects in prophylactic administration were further screened for therapeutic administration. 500,000 cells were added to each well, incubated at 33° C. overnight for adherence, then added with a viral dose with TCID 50 TCID 50 value of about 100, sucked to remove culture medium after 30 min, drug in a concentration of 100 ng/mL was added to the 12-well plate, the total reaction volume was 2 mL, 48 h later, when the virus control group showed 100% phagocytosis (CPE), the effects of drug on preventing cells from phagocytosis were observed, and expressed in cell protection rate (%). 4) Half Effective Concentration of Compound, Inhibition Index of Compound and Maximum Viral Inhibition Concentration
[0102] On the basis of primary screening, half effective concentration of compound, inhibition index of compound and maximum viral inhibition concentration were determined.
[0103] Measurement of half effective concentration (therapy): 100,000 cells were added to each well of a 24-well plate, incubated at 33° C., then added with virus with 50 μL TCID 50 value of about 100, compound was diluted by 5 times in gradient manner and added stepwise to the 24-well plate, 48 h later, when virus control group showed 100% phagocytosis (CPE), the concentration of compound that could prevent 50% cells from phagocytosis was determined (expressed in ng/ml). In the meantime, the lowest effective dose of compound was determined.
[0104] Measurement of inhibition index of compound: 2 times stepwise dilution was performed from the drug concentration with 100% inhibition effects as determined in the primary screening, and the highest dilution times of drug without showing viral pathology was recorded. The inhibition index of drug was calculated: inhibition index=highest dilution times of viral inhibition/nontoxic limit dilution times.
[0105] Maximum viral inhibition concentration: the concentration of compound was set as 100% inhibition of virus titer (TCID 50 value of about 100), then virus was added stepwise in doubling manner, and the maximum of viral concentration that could be inhibited at the designated compound concentration was determined.
[0106] 5) Experimental results
[0107] According to the above experimental method, positive controls Control 1, Control 2 and the compounds as prepared in the examples were tested, and their therapeutic activity data were shown in Table 1. The results show that under therapeutic administration condition, Control 1, Control 2 and the compounds as prepared in examples all have good protection effects, and under the same inhibition index condition, some of the compounds of the present invention exhibit activity superior to that of the control compounds.
[0000]
TABLE 1
Screening data of therapeutic activity of the compounds
Cell protection
Maximum
Maximum
rate
Half effective
inhibition virus
nontoxic dose
(100 ng/mL,
concentration
Inhibition
titer
No.
(μg/mL)
TCID 50 100)
(ng/mL)
index
TCID 50
Control 1
3.9
100%
50
1/39
Not tested
Control 2
31.3
100%
25
1/625
≦200
1
7.8
100%
<3.2
1/625
>1600
2
7.8
100%
25
1/78
≦100
3
7.8
100%
25
1/156
≧800
4
15.6
100%
6.25~12.5
1/625
≧400
5
7.8
100%
6.25
1/625
≦400
6
7.8
100%
6.25~12.5
1/312
≧400
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Disclosed are pyridazine derivatives represented by Formula I or pharmaceutically acceptable salts or hydrates thereof, pharmaceutical compositions comprising the compounds, methods of treating and/or preventing diseases or disorders associated with viral infections in patients using the compounds, and the use of the compounds in preparing the medicaments for treating and/or preventing diseases or disorders associated with viral infections. The compounds represented by Formula I have antiviral activity, especially anti-microRNA viral activity. Symbols in the compounds represented are described in the specification.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to devices used to interconnect and transfer forces between structural members such as the walls of a building and its roof framing system, and more particularly, to a strut system for providing direct, simplified and cost effective seismic connections that can articulate in three planes while transferring both tension and compression forces from the walls of new and existing concrete, concrete “tilt-up” and concrete block buildings to their diaphragm continuity elements.
2. Description of the Prior Art
Tilt-up buildings generally consist of those types of structures that are constructed with precast concrete wall panels that are precast horizontally on the ground, cured, and then tilted up into place. Concrete block walls are similar in character, but are built up block by block. Other concrete walls are typically cast in place.
The timber roof framing systems of older concrete, concrete tilt-up and concrete block buildings (hereinafter referred to generally as “concrete buildings”) that were built between the early to mid 1960's were generally constructed with longspan timber roof trusses and timber roof joists. The timber trusses in these buildings were typically oriented to span the short direction of the building. Spacing between these trusses generally varies between 16 and 24 feet. The roof joists generally consist of 2×8's, 2×10's, or 2×12's spaced at 24″ o.c., and span between the timber trusses. At the perimeter of the building the roof joists span between the timber trusses and the walls, where they are typically framed onto a timber ledger that is bolted to the wall. Roof sheathing for these buildings typically consists of ⅜″ or ½″ plywood.
After the mid 1960's, the roof timber framing systems of most concrete as well as other types of buildings were generally constructed with glulam beams, instead of longspan timber trusses, and used a “panelized” roof framing system instead of roof joists. These modifications to the roof framing systems were typically made for economic reasons.
A “panelized” roof framing system consists of timber purlins, timber sub-purlins (also known as stiffeners), and roof sheathing. The roof sheathing typically consists of 4′×8′ sheets of ⅜″ or ½″ plywood, and spans between the sub-purlins. These sub-purlins are generally 2×4's or 2×6's, and span between the purlins. The purlins typically consist of 4×12's or 4×14's and span between the glulam beams (or in some cases longspan timber trusses). The plywood sheathing is typically oriented with it's long dimension parallel to the sub-purlins, or perpendicular to the purlins. The sub-purlins are generally spaced 24″ apart. The purlins are typically spaced 8 feet apart to accommodate the length of the plywood sheathing. The glulam beams are typically spaced 20 to 24 feet apart. Sections of the panelized roof are typically fabricated on the ground and raised into place with a crane or forklift.
In buildings with timber framed roof diaphragms, the major roof framing elements, such as beams, girders, and trusses, are used as diaphragm continuity elements to form a plurality of spaced continuity lines that extend across the length and width of a building, i.e., a diaphragm continuity system. The purpose of a diaphragm continuity system is to provide a discrete structural system that provides for the transfer of seismic, wind, or other forces from the walls of a building into the roof diaphragm, and eventually to the structural elements intended to resist such forces. Forces from the walls are typically transferred to the diaphragm continuity elements through a sub-diaphragm. A sub-diaphragm is generally taken to be a localized area of the roof diaphragm that spans between diaphragm continuity elements and extends into the diaphragm a certain distance. This distance is dependent on the shear capacity of the sub-diaphragm and the forces that are to be transferred through the sub-diaphragm.
In areas subject to high seismicity, the connection between the walls of most older concrete buildings and their timber roof framing system is inadequate per the currently established seismic design standards for such buildings. Generally, this connection consists of only the nailing between the roof sheathing and the timber ledger that is bolted to the wall. This type of connection relies on a mechanism that subjects the ledgers to “cross grain bending”, a mechanism that is highly vulnerable to failure. The deficiencies associated with this type of connection were responsible for numerous failures and collapses of concrete buildings during the 1971 San Fernando Earthquake. As a result, this type of connection has been specifically disallowed since the 1973 Edition of the Uniform Building Code. It is generally recommended that concrete buildings with such deficiencies be retrofitted with new connections per the currently established seismic design standards and/or recommendations for such buildings.
In some buildings constructed prior to the 1973 Edition of the uniform Building Code, and in most constructed afterwards, the walls of concrete, concrete tilt-up, and concrete block buildings are attached to the roof diaphragm, or sub-diaphragms, with discrete walls ties. Such wall ties generally consists of timber blocks or struts that are interconnected with metal straps, rods, holddown type connection devices, such as those disclosed in U.S. Pat. No. 5,249,404, or a combination thereof, and are only designed to resist tension forces, or may consist of the recently developed wall tie system disclosed in U.S. Pat. No. 5,809,719. These “conventional” wall tie systems generally consist of many individual components that can take a significant amount of time to install, especially when the roof diaphragm is sloped (as is generally required for drainage, sometimes significantly) and the walls are not orthogonal to the diaphragm continuity elements. In many buildings, particularly older buildings with unblocked joisted non-panelized roof diaphragms, the sub-diaphragm shear capacity may be very limited, and require that those wall tie systems that rely on sub-diaphragms be extended from the wall into the roof diaphragm a significant distance in order to increase the depth of the sub-diaphragm, and hence reduce the sub-diaphragm shear stresses to within acceptable limits. Such conventional wall tie systems can be very costly.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a simplified and cost effective seismic connection mechanism for transferring both tension and compression forces from the walls of buildings to their diaphragm continuity elements.
Another object of the present invention is to provide a seismic connection of the type described for connecting the walls of concrete buildings to diaphragm continuity elements consisting of the major roof framing elements such as beams, girders and trusses.
Yet another object of the present invention is to provide a seismic connection of the type described which is capable of transferring both tension and compression forces from building walls into the overall roof diaphragm through the beams, girders and/or trusses thereof.
Still another object of the present invention is to provide a seismic connection of the type described that eliminates dependence on the sub-diaphragm as a means of preserving wall to diaphragm integrity.
Briefly, a preferred embodiment of the present invention includes either a single or a plurality of strut pairs, each forming an assembly for transferring force between a wall and a roof diaphragm continuity element. Each assembly is comprised of two elongated strut elements, or load transfer members, each including a member at one end that allows longitudinal adjustment and rotation thereof, a first end connector assembly for facilitating connection of one end of the strut element to a wall, and a second end connector assembly for facilitating attachment of the other end of the strut element to a diaphragm continuity element connection assembly, the latter assembly being adapted to combine with a corresponding connection assembly and sandwich the continuity element therebetween. Each strut element is adapted to angularly intersect both the engaged wall and the diaphragm continuity element at angles which are determined by the particular buildings design.
An important advantage of the present invention is that it provides a reliable load transfer mechanism for use in structurally attaching the walls of new or existing tilt-up, concrete or concrete block wall buildings to their major roof framing elements.
Another advantage of the present invention is that it provides a simplified connection mechanism that can be used to connect walls and roof framing elements intersecting each other at any angle, either horizontally, vertically or both.
A further advantage is that it includes relatively lightweight components that can be manually installed without the use of heavy lifts, jacks, etc.
These and other objects and advantages of the present invention will no doubt become apparent to those skilled in the art after having reviewed the following detailed description of the preferred embodiments illustrated in the several figures of the drawing.
IN THE DRAWING
FIG. 1 is a bottom plan view illustrating a flare strut assembly in accordance with the present invention.
FIG. 2 is an elevational view showing one strut of the assembly illustrated in FIG. 1 .
FIGS. 3 and 4 illustrate alternative embodiments of a strut member.
FIG. 5 is a plan view showing a wall connection end connector assembly.
FIG. 6 is an elevational cross-section taken along the lines 6—6 of FIG. 5 .
FIG. 7 is a plan view of a continuity member connection end connector assembly.
FIG. 8 is an elevational view partially sectioned along the lines 8—8 of FIG. 7 .
FIG. 9 is an elevational view illustrating a strut member engaging a block wall at an oblique angle.
FIG. 10 is a partially broken plan view schematically showing use of the flare strut stem of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 of the drawing wherein a bottom plan view of a segment of a concrete wall 10 and building roof 12 are depicted, it will be appreciated that the panelized roof structure consists of main supporting beams or trusses 14 that form diaphragm continuity members that span between the walls and rest upon support columns or posts 16 either formed integral with or attached to the adjacent wall. In this case, the illustrated continuity member 14 is a large glulam beam (See FIG. 2 ). Spanning between adjacent beams are purlins 16 , and spanning between the purlins 16 or a purlin and a ledger beam 18 , are sub-purlins 20 . And finally, attached to and spanning between subpurlins are rectangular sheets 22 of roof sheathing.
Mounted to the wall and roof structure, typically at each junction of continuity beam and wall, are flare strut assemblies 23 , including first and second struts 24 and 26 , and their associated end fastening subassemblies 28 and 30 .
The Flare Strut System of the present invention provides an alternate to conventional wall tie systems that might consist of strap and block systems, rod and block systems, strap and strut systems, rod and strut systems, or the recently developed DS Dragline System (developed for “tilt-up” buildings with panelized roof framing systems, (See U.S. Pat. No. 5,809,719). These conventional wall tie systems generally consist of many individual components that can take a significant amount of time to install, especially when the roof diaphragm is sloped (as is required for drainage, sometimes significantly) and the walls are not orthogonal to the diaphragm continuity elements, and rely on a subdiaphragm (a localized area of the roof diaphragm that spans between diaphragm continuity elements) to transfer forces from the walls to the diaphragm continuity elements. In many tilt-up” type buildings, particularly older buildings with unblocked joisted (non-panelized) roof diaphragms, the subdiaphragm shear capacity may be very limited, and require that those wall tie systems that rely on subdiaphragms be extended from the wall into the roof diaphragm a significant distance in order to increase the depth of the subdiaphragm, and hence reduce the subdiaphragm shear stresses to within acceptable limits. Such wall tie systems can be very costly. Since the present invention provides for a direct connection between the walls of a “tilt-up” or other concrete walled building and its diaphragm continuity elements, the subdiaphragm is bypassed, and any capacity related problems associated with that subdiaphragm are eliminated. Furthermore, since the strut assemblies of the present invention install simply and quickly, the installation costs associated therewith can be significantly less than those associated with conventional systems.
As indicated above, the preferred embodiment of the FS Flare Strut System is comprised of a combination of struts 24 , 26 designated “Flare Strut (FS)”, a first end connector assembly 28 designated “End Connection Type 1 (EC- 1 )” which provides for the attachment of the Flare Strut to the wall, and a second end connector assembly 30 designated “End Connection Type 2 (EC- 2 )”, which provides for the attachment of the flare strut to a roof framing element (beam, girder, or truss). A Shear Transfer Plate (STP) for both EC- 1 and/or EC- 2 , may be included as required.
As depicted in FIG. 3, the flare strut consists of a Strut Element (SE), an Interface Plate (IP), a Pipe Element (PE), and a Coupler Element (CE). The SE generally may consist of either a structural steel pipe (round) or tubular (square or rectangular) section. Generally, square rectangular tubing will most often used for the SE, as it is readily available, and typically lighter than an equivalent pipe section. The SE is attached to the IP by welding or brazing. The IP consists of either a square (typically), round, or multi sided steel plate, and is then welded or brazed to the PE, serving to attach the SE to the PE. The PE consists of a steel pipe section (that may also be solid round stock or threaded rod) with external (or internal) right hand (or left hand) threads, and is threaded into (or onto) the CE. The CE consists of a steel pipe section (that may also be solid round stock or threaded rod if provided with external threads) with internal (or external) right hand (or left hand) threads. The threaded connection between the PE and the CE allows the FS to freely rotate about the longitudinal axis of the FS, thus providing the FS System with one degree of articulation, as well as allowing the overall length of the FS to be adjusted for field fit-up.
Both the SE and CE of the flare strut may be attached to either EC- 1 or EC- 2 type connectors since both EC- 1 and EC- 2 are attached to the strut ends with a single pin bolt passed through the bores. This provides the FS System with a second degree of articulation. As shown in FIGS. 1 and 2, both the EC- 1 (wall) connector 28 and the EC- 2 connector 30 (diaphragm continuity element) are attached to their designated building element with a single connection bolt. This provides the FS System with a third degree of articulation.
As an alternate, the FS may be modified as shown in FIG. 4 with the addition of an Interface Sleeve (IS) to form a Flare Strut Head (FSH). This head configuration allows for either a bolted connection or an aligned and welded connection between the SE and the Flare Strut Head (FSH) and thus permits an installer to combine the FSH with a field cut and drilled SE to readily accommodate strut length variations or changes in the field.
The EC- 1 connector is illustrated in detail in FIGS. 5 and 6 and consists of a base plate 40 and two connection plates 42 welded thereto. The plates 42 have matching holes 43 for receiving a connection bolt or pin (not shown). The base plate may be square, rectangular, round, or multi sided, and is provided with at least one hole 44 for receiving a connection bolt or pin (not shown). The connection plates may be square, rectangular, or otherwise shaped to provide the installer and inspector with a visual reference as to the allowable limits the strut to be attached thereto may be skewed relative to the EC- 1 connector. Both the base plate and the connection plate may be modified as required to minimize the eccentricity between the line of action LAS along the strut and the line of action LAB along the connection bolt 46 , and/or minimize the bearing pressure that the base plate might exert upon the building element to which it is to be attached.
If the shear capacity of the connection bolt 46 attaching the EC- 1 connection to the building element is inadequate, then additional shear capacity can be derived with the installation of a Shear Plate (SP). The shear plate may consist of a square, rectangular, round, or multi-sided steel plate that is provided with holes 48 and 50 for concrete (or masonry) anchors 52 and 54 , and perhaps additional holes (not shown) for nails, screws or lag bolts.
The EC- 2 connector is illustrated in detail in FIGS. 7 and 8 and consists of a base plate 60 and two connection plates 62 welded thereto. The plates 62 have matching holes 63 for receiving a connection bolt or pin. The base plate may be square, rectangular, round, or multi-sided, and is provided with a least one hole 64 for receiving a connection bolt or pin (not shown). The connection plates may be square, rectangular, or otherwise shaped to provide the installer and inspector with a visual reference as to the allowable limits the strut to be attached thereto may be skewed relative to the EC- 2 connector. Both the base plate and the connection plate may be modified as required to minimize the eccentricity between the line of action LAS along the strut and the line of action LAB along the connection bolt and/or minimize the bearing pressure that the base plate might exert upon the building element to which it is to be attached.
If the shear capacity of the connection bolt attaching the connection EC- 2 connection to the building element is inadequate, then additional shear capacity can be derived with the installation of a Shear Plate (SP). The shear plate may consist of a square, rectangular, round or multi-sided steel plate that is provided with holes for nails, screws, lag bolts or bolts.
Momentarily returning to FIG. 1, it will be noted that the connector assemblies 30 on each side of beam 14 are connected together by a common bolt 31 that is extended through the holes 64 (FIGS. 7 and 8) as well as through a hole drilled through beam 14 . If shear plates SP are, used, they may be either independently by nailing, screwing, etc., or may be joined by bolts extending through bolt holes (not shown) formed in the beam and plates SP. Ideally, the assemblies 30 will be aligned.
But, in some cases, they can be staggered so long as provisions are made to resolve the unbalanced forces. The angle at which each strut intersects beam 14 is a matter of engineering design.
In FIG. 9 an installation of the present invention to a concrete block building having a steeply sloped roof is depicted in partial cross-section to illustrate that the subject strut assembly can accommodate an angular connection angled at acute angles in more than one plane. This is permitted by rotation of the strut in one place, about its connecting pin and rotation of the strut in a second plane by rotating the connector about its attachment bolt.
FIG. 10 is a plan view depicting an exemplary installation of the FS System in a building having two orthogonally disposed walls 70 and 72 and two walls 74 and 76 that are at least in part non-orthogonally oriented relative to the other walls. As shown, a strut assembly 80 is installed at each intersection of a beam or other roof diaphragm continuity element 82 . Note that the non-orthogonal wall segments 77 and 78 are accommodated by simply shortening the length of one of the struts in each strut assembly.
The walls 72 and 76 , and wall segments 77 and 78 are interconnected in this drawing using the apparatus and techniques disclosed in U.S. Pat. No. 5,813,181.
Although the present invention has been described in terms of specific embodiments it is anticipated that alterations and modifications thereof will no doubt become apparent to those skilled in the art. It is therefore intended that the following claims be interpreted as covering all such alterations and modifications as fall within the true spirit and scope of the invention.
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A Flare Strut System including a plurality of strut pairs, each forming an assembly for transferring force between wall and a roof continuity element. Each assembly is comprised of two elongated strut elements, or load transfer members, each including a longitudinal rotation and adjustment member at one end thereof, a first end connector assembly for facilitating connection of one end of the strut element to a wall, and a second end connector assembly for facilitating attachment of the other end of the strut element to a continuity element connection assembly, the latter assembly being adapted to combine with a corresponding connection assembly and sandwich the continuity element therebetween. Each strut element is adapted to angularly intersect both the engaged wall and the continuity element at acute angles which are determined by the particular buildings design.
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BACKGROUND OF INVENTION
[0001] 1. Field of Invention
[0002] This invention relates to packaging for holding and displaying frangible items such as holiday ornaments.
[0003] 2. Discussion of Related Art
[0004] Decorative items such as holiday ornaments are customarily packaged in boxes that enable the ornaments to be only partially viewed without removing them from the packaging. Typically, the packaging includes a base, tray and cover. In some prior art packaging of this type, the base and cover are made of one piece of opaque material such as cardboard. Typically, the cover has a transparent plastic window, and the ornaments are supported on a tray inside the base. In other such prior art packaging, the base and cover are separately fabricated, and the cover made of a transparent material extends over the side walls of the base so that the ornaments inside the packaging can only be viewed through the top of the cover. In both forms of prior art described, the trays are made of opaque material, and the trays are provided with recesses that receive the ornaments in a position which leaves half or more of the surface of the ornament hidden from view.
SUMMARY OF INVENTION
[0005] In accordance with one aspect of this invention, the packaging enables substantially all of each ornament in the package to be viewed through the cover as the tray which supports the ornaments is made of a transparent material and the inner surface of the base is light reflective or mirror-like. In accordance with another aspect of this invention the ornaments sit in a relatively high position above the top of the side wall of the base, and the cover enables the ornaments to be viewed through the side as well as the top of the packaging. The elevated position of the ornament and the light properties of the materials from which the various components are made allow substantially all sides of the ornaments to be viewed through the cover without opening or removing the ornaments from the packaging.
BRIEF DESCRIPTION OF DRAWINGS
[0006] The accompanying drawings, are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:
[0007] FIG. 1 is a perspective view of ornament packaging embodying the present invention;
[0008] FIG. 2 is a cross-sectional view of the packaging taken along section line 2 - 2 of FIG. 1 ;
[0009] FIG. 3 is an exploded perspective view of the base and tray of one embodiment of the packaging,
[0010] FIG. 4 is a perspective view of a partially erected base in accordance with one embodiment of this invention;
[0011] FIG. 5 is a plan view of the blank from which the base of FIG. 4 is made;
[0012] FIG. 6 is a perspective view of one embodiment of the cover in accordance with the present invention, and
[0013] FIG. 7 is a plan view of the blank from which the cover of FIG. 6 is made.
DETAILED DESCRIPTION
[0014] This invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” “containing”, “involving”, and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
[0015] The packaging of the present invention includes three major elements, namely, a base 10 , cover 12 and tray 14 . The tray has one or more recesses 16 that receive the ornaments to be displayed in the packaging. As broadly described, packaging composed of a box, cover and tray are well known in the art. However, the packaging of the present invention includes modifications of several parts that markedly enhance the display of the glass ornaments or other products placed in the packaging.
[0016] In accordance with one aspect of the present invention, the inner surfaces 17 of the base of packaging 10 are dark, and preferably black, and are light reflective, that is, they have a mirror-like quality that will reflect the ornaments or other items disposed before the surface. The base may be made of heavy paper, cardboard or other sheet product that preferably possesses enough stiffness to maintain the side walls of the box in a generally perpendicular position with respect to the base bottom wall.
[0017] In accordance with one embodiment of the invention, the base 10 is made of cardboard cut as a single sheet in the configuration shown in FIG. 5 . The base blank shown has a pair of opposite side walls 18 attached to the bottom wall 20 along fold lines 22 , and flaps 24 extend from each end thereof at fold lines 26 . On the other two opposite sides of the bottom wall 20 are additional side walls 28 attached to those sides along fold lines 30 . This second set of opposite side walls 28 are formed so as to fold up and over the flaps 24 on the first pair of side walls and extend downwardly along their inner faces, and a flange 32 is provided at the edge of each of the second pair of side walls to frictionally engage the upper surface 17 of the bottom wall 20 when the box is erected. This particular configuration of the box is free of adhesive or other material which would detract from the clean unadorned box surfaces and add to its manufacturing costs.
[0018] The tray 14 is made of transparent material such as PVC plastic and preferably is thermoformed. The tray is sized to fit within the base 10 and is complementary shaped so as to just fit within the base. The tray has side walls 36 whose lower edges 38 preferably rest on the base bottom wall 20 and flanges 32 , and the side walls are of a height to support the top wall 40 of the tray at or just below the rim 42 of the base. The wells 16 are shaped to complement the shape of the ornaments 44 or other items to be displayed in the package, and in the embodiment shown, as the ornaments are essentially round, the wells 16 are approximately hemi-spherical in shape. In the specific embodiment shown, as the wells are designed to receive decorative ornaments 44 that include a spherical body 46 and a short cylindrical collar 48 carrying the rings 50 by means of which the ornaments are hung, the wells 16 have generally semi-cylindrical extensions 52 that receive the collars. It is to be appreciated that while three wells are shown in the drawings, essentially any number may be provided, depending only on the size of the packaging and the size of the ornaments to be contained therein.
[0019] In accordance with another aspect of the present invention, the ornaments 44 extend above the rim 42 of the base 10 . The portions of the ornaments extending above the tray 14 and base 10 are, however, enclosed by the cover 12 .
[0020] In accordance with yet another aspect of the invention, the cover 12 is in the form of a sleeve (see FIG. 6 ) that fits snugly over the bottom 20 and side walls 18 and 28 of the base, but the top wall 60 of the cover is spaced substantially above the rim 42 of the base 10 and the top wall 40 of the tray 14 , so as to enclose the portions of the ornaments that extend above the tray. In accordance with one embodiment of the invention, the cover is made of a transparent material such as PVC. In the embodiment shown, the plastic from which the cover is made is formed as a sheet (see FIG. 7 ) and is provided with fold lines shown in broken lines in FIG. 7 , that define the top wall 60 and bottom walls 62 , opposite side walls 64 , and opposite end walls 66 , the latter each being composed of a pair of inner flaps 68 and a pair of outer flaps each composed of a female 70 and male 72 . The inner flaps 68 , two at each end of the cover, are integral with the side edges of the side walls 64 . The outer pair of flaps 70 and 72 are connected to the end edges 74 of the top and bottom walls 60 and 62 of the cover and in turn overlap one another and enclose the inner flaps 68 when the cover is erected. The outer flaps are releasably held in the cover forming configuration by means of tongues 76 , two carried on each of the male outer flaps 72 and threaded through a pair of slots 78 in the other outer flaps 70 . The assembly of the various end flaps is shown in FIGS. 1 and 2 . Obviously, other forms of closure may be used as well, such as single tongue and slot, interengaging slits, etc.
[0021] In accordance with the embodiment of cover shown in FIGS. 6 and 7 , the cover is erected by bending the various walls along the fold lines (shown as broken lines) that connect them to adjacent walls of the cover blank. A narrow flange 80 is provided along the edge 82 of the lower wall 62 which is cemented to the one side wall 64 so as to permanently form the cover into a sleeve when the inner and outer pairs of flaps 68 , 70 and 72 are opened. Obviously such a flange could alternatively be provided along the edge 84 of the side wall 64 . In the configuration of an open ended sleeve, the sub-assembly of base 10 , tray 14 and ornaments 44 may be slipped within the cover through either end, and when the ends of the sub-assembly are aligned with the end edges of the top and bottom walls, the inner and outer end flaps may be detachably locked in the manner described. It will be appreciated that when the cover is assembled in that fashion on the sub-assembly of base, tray and ornaments with the end flaps closed, a secure package is formed that will not accidentally or unintentionally open and allow the contents of the cover to spill out. And when the cover is closed, with the base, tray, and ornaments disposed within the cover, all sides of each ornament may be readily viewed because of the transparency of the cover and tray and the light reflective quality of the inner surfaces of the base. Thus, when the package is on display, for example, in a store, display room or other facility, a potential customer viewing the package may quickly appreciate the full beauty of the ornaments on display by seeing all of their sides through the transparent cover and without opening the package. As is evident in FIGS. 1 and 2 , the ornaments may be viewed through the top wall 60 or the portions of the side walls 64 or of the end walls 66 of the cover that are disposed above the upper edges 42 of the side walls 18 and 28 of the base 10 as indicated by the reflected images 44 ′ and lines of sight 86 .
[0022] While the preferred embodiment of the cover has been described in detail, it should be appreciated that other embodiments of covers made of transparent material may be used and achieve many of the advantages of the preferred embodiment described.
[0023] For example, if the cover is of the same shape in plan view as the base and is sized to slip over a portion or all of the side and end walls of the base, and if this embodiment of cover is made of a transparent material, at least with respect to that portion of the cover which lies above the rim of the base, and further if the side walls of the cover extend above the top edges of the side walls of the base, the ornaments packaged therein will be easily viewed just as is described in connection with the preferred embodiment. However, such a cover would not provide a degree of protection provided by the preferred embodiment, and it may be too easy for a customer to open the box and handle the ornaments, and upon deciding to purchase the product, he/she may select another box as opposed to that which the customer opened.
[0024] Alternative constructions are also available for the base. While in the preferred embodiment, the base is very conveniently erected without the use of any adhesive material. More conventional constructions may be employed with separate end and side walls on all sides thereof with such walls being cemented together. It is however, important that the inner surfaces of the walls including the bottom wall be mirror-like to enhance the visibility of the ornaments.
[0025] It is also most advantageous to have the side walls of the tray made of a transparent material so as not to diminish the light reflecting quality of the inner surfaces of the base. However, as an alternative, the inner surfaces of the side walls of the tray may be made of a mirror-like material so as to substitute for the reflective qualities of the side walls of the base that are covered by the tray side walls.
[0026] Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.
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Packaging for enclosing and displaying frangible items has a base, tray and cover. The base has bottom and side walls that are opaque with their inner surfaces being mirroro-like. A tray sits in the base and is made of a transparent material and has recesses for supporting the items in a position wherein they extend above the side walls of the base. A cover extends beyond the side walls of the tray and extends over the tops of the items and is made of a transparent material enabling the items to be substantially fully viewed through the cover by virtue of the transparent cover, transparent tray and light reflecting side walls of the base.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of international application number PCT/EP2008/001623 filed on Feb. 29, 2008, which claims the benefit of German application number 10 2007 011 606.5 of Mar. 2, 2007, which are each incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a non-woven fiber fabric, also, in particular, in the form of a flat material or as part of a flat material, a method for its production as well as various uses of the non-woven fiber fabric.
[0003] The invention is aimed, in particular, at non-woven fiber fabrics which can be used as a biodegradable material in medicine, in particular, as implants or carrier materials for living cells (tissue engineering) but also at non-woven fiber fabrics which may be used in food technology in a variety of applications, in particular, as preliminary products for foods.
BRIEF SUMMARY OF THE INVENTION
[0004] For this purpose, a new non-woven fiber fabric is suggested in accordance with the invention which contains fibers which consist of a gelatin material and have a thickness of, on average, 1 to 500 μm, wherein the non-woven fiber fabric has a plurality of areas, at which two or more fibers merge into one another without any phase boundary. The special feature of the non-woven fiber fabrics according to the invention is to be seen, in particular, in the fact that the linking of the fibers in the non-woven fiber fabric can be attributed to the areas, at which two or more fibers form a point of connection, at which no phase boundaries are apparent and, therefore, material conditions which are universally the same can be observed at the points of connection.
[0005] These areas are not, therefore, formed by any adhesion or welding of fiber surfaces which are adjacent to one another but rather the special feature is to be seen in the fact that the fiber surfaces disappear when the point of connection is formed.
[0006] Particularly for the purposes of the application in medicine and, in this case, in particular, for the purposes of tissue engineering, average fiber thicknesses in the range of 3 to 200 μm, in particular, in the range of 5 to 100 μm are recommended. The preferred fiber thicknesses allow, in particular, a simple colonization of the non-woven fiber fabric with living cells for the formation of implants.
[0007] The non-woven fiber fabrics according to the invention may be easily produced with the open pore structure desired for the cell colonization and offer a very large, specific surface for this purpose.
[0008] At the same time, the non-woven fiber fabrics according to the invention form, when observed macroscopically, a carrier material which is beneficial for a homogenous cell distribution following the colonization. The interconnecting pore structure of the non-woven fiber fabrics according to the invention, which is superior to that of porous sponge structures, is particularly advantageous for the subsequent growth of cells.
[0009] The non-woven fiber fabrics according to the invention may also be achieved with a sufficient form stability which is also adequately maintained in the wetted state. This may be ensured, in particular, by an adequate number of individual fibers which have a large diameter.
[0010] The resorption of the carrier structure of the non-woven fiber fabric in the case of implants is also ensured on account of the biological tolerance of the gelatin material.
[0011] The gelatin material in the fibers is biodegradable in a simple manner and for controlling the degradation behavior of the fibers of the non-woven fiber fabric it is advantageously provided for the gelatin material of the fibers to be cross-linked at least partially. The degradation behavior may be controlled via the degree of cross-linking and also the strength of the non-woven fiber fabric influenced in a moist to completely wetted or swollen state.
[0012] In a particularly preferred embodiment of the present invention, the gelatin material of the fibers is predominantly amorphous. This has the advantage that a gelatin material of the fibers in the amorphous state can easily be wetted. This is particularly the case when the gelatin material of the fibers is present in an amorphous state to 60% by weight or more.
[0013] This may also be expressed as initial wettability with pure water which is intended to be 1 minute or less. This specification of time is measured in accordance with the time which is required for the absorption of a drop measuring 50 μl by a non-woven fiber fabric with the weight per unit area of 150 g/m 2 . The good initial wettability is expressed, for example, by the fact that a sample of the non-woven fiber fabric placed on a surface of water will be wetted, as it were, instantaneously and by absorbing water will sink into the water.
[0014] The capillary suction effect may be used to characterize the structure of the non-woven fiber fabric, in particular, its cavity structure. In the case of preferred non-woven fiber fabrics with pure water, this should generate a height of rise of the water of 15 mm or more within 120 seconds.
[0015] In a further, preferred embodiment of the invention, the maximum water absorption capacity of the non-woven fiber fabric, which is brought about by or is co-dependent on, in particular, a swelling of the gelatin material used for the fibers, is at least four times the dry weight of the non-woven fiber fabric, i.e., preferably 4 g or more, in particular, 10 g or more per gram of non-woven fiber fabric.
[0016] Non-woven fiber fabrics according to the invention preferably have a surface energy of 25 mN/m or less, in particular, 10 mN/m or less. This facilitates the initial wetting of the non-woven fiber fabric.
[0017] The tear resistance, which is preferably 0.15 N/mm 2 or more at a specific weight per unit area of the non-woven fiber fabric in the range of 140 to 180 g/m 2 in the dry state, is of particular importance for the non-woven fiber fabrics according to the invention, wherein a breaking elongation in the hydrated state (state of maximum water absorption due to swelling) of the non-woven fiber fabric is, in addition, preferably 150%, in particular, 200% or more.
[0018] Such non-woven fiber fabrics are excellent to handle, in particular, in the case of medical applications in the dry state and also offer an adequate strength in the hydrated, i.e., swollen state and so they may be adapted very easily to the conditions of the body at the implant site when used as implant carrier materials. In particular, a satisfactory suturing strength is also achieved for fixing the implants.
[0019] Preferred non-woven fiber fabrics of the present invention have an open pore structure with a permeability of the non-woven fiber fabric to air of 0.5 l/min×cm 2 or more, wherein this parameter is determined in accordance with German Standard 9237. Non-woven fiber fabrics are particularly preferred, with which the gelatin material of the fibers is present in a partially cross-linked gel form, which means that the stability of the non-woven fiber fabric at the body temperature of a patient is sufficient, on account of the cross-linking, even in the swollen state, for it to be handled without the non-woven fiber fabric thereby tearing or being damaged in another way.
[0020] In this respect, those non-woven fiber fabrics are of importance, in particular, which form a closed-pore fibrous gel structure in a hydrated state. This means that the non-woven fiber fabrics, which can and should certainly have an open pore structure in the dry state, lose their open porosity on account of the considerable amounts of water absorbed by the gelatin parts and the swelling following therefrom and then form a closed-pore, fibrous gel structure. This is of particular significance when the tissue areas to be covered by an implant bleed profusely and the implant is also intended to be used at the same time as a cover for open wounds or for the purpose of stopping bleeding.
[0021] The non-woven fiber fabric of the present invention has, in particular, fibers consisting of gelatin material which are produced with a rotor spinning process and at least some of the fibers have an intertwined structure.
[0022] Preferred gelatin materials as starting materials for the production of fibers for the non-woven fiber fabric according to the invention have a gel strength of 200 Bloom or more.
[0023] Additional, preferred embodiments of the present invention relate to non-woven fiber fabrics of the type described above, with which the non-woven fiber fabric contains at least one additional type of fibers which are formed from an additional material different to the gelatin material.
[0024] Such additional materials, from which the additional type of fibers can be formed, are, in particular, chitosan, carrageenan, alginate, pectin, starch and starch derivatives, regenerated cellulose, oxidized cellulose and cellulose derivatives, such as, for example, carboxy methyl cellulose (CMC), hydroxy propyl methyl cellulose (HPMC), hydroxy ethyl cellulose (HEC) and methyl cellulose (MC). In addition, synthetic biocompatible polymers are suitable, such as, for example, polylactic acid and polylactate copolymers, polydihydroxysuccinic acid, polycaprolactons, polyhydroxybutanoic acid and polyethylene terephthalate. In addition, gelatin derivatives are suitable, such as, for example, gelatin terephthalate, gelatin carbamate, gelatin succinate, gelatin dodecyl succinate, gelatin acrylate (cf., for example, EP 0 633 902), as well as gelatin copolymers, such as, for example, gelatin polylactide conjugate (cf. DE 102 06 517).
[0025] The invention relates, in addition, to a flat material, containing a non-woven fiber fabric according to the invention which has already been explained in detail in the above. Such flat materials can contain one or several layers of the non-woven fiber fabric according to the invention.
[0026] The flat materials according to the invention contain a membrane extending parallel to the non-woven fiber fabric for certain application purposes.
[0027] The membrane can, in this respect, serve as a carrier layer for the non-woven fiber fabric and so very low weights per unit area can, in particular, be realized in the case of the non-woven fiber fabric.
[0028] Alternatively or in addition, the membrane can form a barrier layer which inhibits the proliferation of cells and so an undisturbed growth of the cells which are desired or have been introduced into the implant is possible, in particular, with the use as a carrier material for tissue engineering applications. In this connection, it is also advantageous when the membrane is permeable for cell nutrients.
[0029] The invention relates, in addition, to a flat material of the type described above, wherein the non-woven fiber fabric is colonized by living cells, in particular, chondrocytes or fibroblasts.
[0030] With these applications, fiber diameters of, in particular, on average 3 μm or more are used and so the cell colonization is simple to configure. In this respect, pore sizes of, on average, approximately 100 μm to approximately 200 μm are preferred.
[0031] The invention relates, in addition, to the use of the non-woven fiber fabric described above as well as the flat material likewise described above as a cell colonization material.
[0032] The invention relates, in addition, to the use of the non-woven fiber fabric described above as well as the flat material described above as a medical wound cover.
[0033] The invention relates, in addition, to the use of the non-woven fiber fabric described above as well as the flat material described above as a medical implant.
[0034] The invention relates, in addition, to the use of the non-woven fiber fabric described above as a food.
[0035] The non-woven fiber fabrics according to the invention and the flat materials according to the invention can also be used for the production of depot medicines. In this respect, it may also be provided for the gelatin material of the fibers to contain a pharmaceutical substance.
[0036] Optionally, in addition or alternatively, the non-woven fiber fabric according to the invention and the flat material according to the invention can serve as a carrier for a pharmaceutical substance.
[0037] A preferred pharmaceutical substance, in particular, for the use as a material for covering wounds is the substance thrombin.
[0038] In addition or alternatively, the pharmaceutical substance can contain cell growth factors, in particular, a peptide pharmaceutical, in particular, growth modulators, such as, for example, BMP-2, BMP-6, BMP-7, TGF-β, IGF, PDGF, FGF.
[0039] The invention relates, in addition, to a method for producing non-woven fiber fabrics of the type described above, wherein the method includes the steps of:
(a) providing an aqueous spinning solution which contains a gelatin material; (b) heating the spinning solution to a spinning temperature; and (c) processing the heated spinning solution in a spinning device with a spinning rotor; (d) and, optionally, an additional treatment of the non-woven fiber fabric obtained by adding property-changing additions in a fluid or gaseous state of aggregation.
[0044] The method according to the invention operates as a rotation spinning method, with which the fibers or filaments generated by the spinning rotor are collected as non-woven fiber fabrics on a suitable collection device.
[0045] A suitable collection device is, for example, a cylinder wall which is arranged concentrically to the spinning rotor and which can, possibly, likewise be driven for rotation. A further possibility is the horizontal collection of the filaments on a base surface, for example, a perforated metal sheet which is arranged beneath the spinning rotor.
[0046] The flight time of the fibers or filaments can be predetermined via the distance between the exit openings of the spinning rotor and the collection device and this time is selected such that an adequate solidification of the spinning solution discharged in fiber form is made possible and so the fiber form is retained when impacting on the collection device.
[0047] This is aided, on the one hand, by the cooling of the fiber or filament materials during the flight time, on the other hand, by the gel formation of the gelatin and, in addition, by an evaporation of water or of the solvent.
[0048] The fibers or filaments generated by the spinning rotor may easily be collected in a state, in which points of connection between two or more fibers are formed in a plurality of areas of the non-woven fiber fabric and the fibers merge into one another at these points without any phase boundary.
[0049] In the optional additional treatment step (d), the non-woven fiber fabric according to the invention may be adapted to specific applications in a plurality of characteristics.
[0050] By cross-linking the gelatin material, the mechanical and, in particular, chemical properties can be modified. For example, the resorption properties for medical application purposes can be specified via the degree of cross-linking of the gelatin material.
[0051] The non-woven fiber fabric of the present invention, which is regularly highly flexible, may be stiffened in subsequent treatment steps, for example, in order to improve the form stability and to make the introduction into a target area easier.
[0052] The non-woven fiber fabrics according to the invention may be saturated and/or coated with liquid media in subsequent treatment steps. Other biodegradable polymer materials or also wax-like materials can, in particular, be considered for this purpose.
[0053] The non-woven fiber fabrics of the present invention, with which a fiber thickness of on average from 1 to 500 μm is generated, may be generated by means of the method according to the invention and described above, in particular, in a simple manner and wherein, in addition, the areas characteristic for the invention are formed, at which two or more fibers are connected or, as it were, melt into one another without any phase boundary. A spinning solution, with which the proportion of gelatin is in the range of approximately 10 to approximately 40% by weight, is preferably used for the method according to the invention.
[0054] The gel strength of the gelatin is, in this respect, preferably approximately 120 to approximately 300 Bloom.
[0055] The spinning solution is preferably heated to a spinning temperature in the range of approximately 40° C. or more, in particular, in the range of approximately 60 to approximately 97° C. These temperatures enable, in particular, a simple formation of the characteristic areas of the non-woven fiber fabrics, at which two or more fibers are connected to or merge into one another without any phase boundaries.
[0056] The spinning solution is preferably degassed prior to the processing in step (c) and so long fibers with a very homogeneous fiber thickness are obtained in the non-woven fiber fabric.
[0057] The degassing will preferably be carried out by means of ultrasound.
[0058] Preferably, a cross-linking agent will already be added to the spinning solution to generate partially cross-linked gelatin materials in the fibers. Cross-linking may, however, also be brought about and in addition in the case of the fibers already spun by bringing them into contact with a cross-linking agent, whether gaseous or in solution.
[0059] The method according to the invention can be carried out particularly reliably when the rotor is heated to a temperature of approximately 100 to approximately 140° C. This temperature is particularly suitable for processing the aqueous spinning solutions, which contain gelatin materials, in the rotation spinning method.
[0060] A further cross-linking will preferably be carried out on the non-woven fiber fabric which is already finished and this determines the final degree of cross-linking of the gelatin material in the non-woven fiber fabric and, therefore, its biodegradability.
[0061] Various methods are available for the cross-linking, wherein enzymatic methods, the use of complexing agents or chemical methods are preferred.
[0062] In the case of the chemical cross-linking, the cross-linking will be carried out by means of one or more reactants, in particular, with aldehydes, selected from formaldehyde and dialdehydes, isocyanates, diisocyanates, carbodiimides, alkyl dihalides and hydrophilic dioxiranes and trioxiranes, such as, for example, 1.4 butanediol diglycidether and glycerin triglycidether.
[0063] It is recommended, in particular, in the case of the medical application to remove surplus cross-linking agent from the non-woven fiber fabric or the flat material following the cross-linking.
[0064] As described above, it is preferable for a cross-linking agent to already be added to the spinning solution and for a further cross-linking to then be carried out on the finished non-woven fiber fabric, so-to-speak in a second step, until the desired degree of cross-linking is reached.
[0065] The non-woven fiber fabrics of the present invention can be produced, in particular, as extremely flexible flat materials, are thereby elastic and are very easy to shape. In addition, the non-woven fiber fabrics can be regarded as structures which are completely open in comparison with sponge structures which have likewise already been used as a carrier material for tissue engineering and are likewise porous but have cell walls.
[0066] In this respect, very small filament thicknesses may be produced, in particular, with the spinning rotor spinning method suggested in accordance with the invention, wherein the gelatin need be subjected to higher temperatures during the entire spinning process only for a very short time, i.e., the temperature burden on the gelatin material can be limited to a considerable extent with respect to time and leads to fibers consisting of a gelatin material which corresponds essentially to the initial gelatin material in its molecular weight spectrum.
[0067] Non-woven fiber fabrics according to the invention can have an essentially uniform average fiber thickness.
[0068] Alternatively, non-woven fiber fabrics can, within the scope of the present invention, have a proportion of fibers, the average fiber thickness of which differentiates them from the other fibers. They can, in particular, have a larger average fiber thickness. By using two or more fiber fractions in the non-woven fiber fabric which differ as a result of their average fiber thickness, its mechanical strength values can be influenced in a targeted manner.
[0069] Alternatively or in addition, two or more layers of non-woven fiber fabric can, on the other hand, be combined to form a flat material, wherein the individual layers can have fibers of different, average fiber thicknesses. It is, of course, also possible in the case of these flat materials to use layers of non-woven fiber fabric with fibers of an essentially uniform, average fiber thickness together with layers of non-woven fiber fabric with several fiber fractions having different, average fiber thicknesses.
[0070] Non-woven fiber fabrics with fiber fractions having different, average fiber thicknesses, e.g., approximately 7 μm together with approximately 25 μm may be realized with the method according to the invention in that a spinning rotor is used, in which spinning nozzles with nozzle openings of different sizes are provided during the spinning procedure.
[0071] When the non-woven fiber fabric according to the invention is used as a carrier material for living cells, the non-woven fiber fabric has a great advantage over sponge structures or woven fabric structures in that very varied cavities are offered for the storage of the cells and so the cells can find the storage locations which are ideal for them. This already applies for non-woven fiber fabrics which have a uniform, average fiber thickness.
[0072] These and further advantages of the present invention will be explained in greater detail in the following on the basis of the drawings as well as examples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0073] FIG. 1 shows a schematic illustration of a device for carrying out the method according to the invention;
[0074] FIGS. 2 a to c show micrographs of a non-woven fiber fabric according to the invention in different enlargements;
[0075] FIG. 3 shows a graph of height of rise/time for different materials;
[0076] FIGS. 4 a to c show a schematic illustration of a device for calculating the heights of rise illustrated in FIG. 3 ; and
[0077] FIGS. 5 a and b show tension/elongation results for conventional cell carrier materials and those according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Example 1
Production of a Non-woven Fiber Fabric
[0078] A 20% aqueous solution of a pork rind gelatin (300 Bloom) is produced by mixing 20 g of gelatin and 80 ml of distilled water at room temperature. After the gelatin has swollen for a period of approximately 60 minutes, the solution is heated for one hour to 60° C. and subsequently degassed with ultrasound.
[0079] This solution is then processed with a spinning device 10 , as shown schematically in FIG. 1 . Spinning devices of the type described in DE 10 2005 048 939 A1 are also suitable and reference is made to the content of this publication in full.
[0080] The spinning device 10 includes a spinning rotor 12 which can be caused to rotate about a vertical axis of rotation 16 by a drive unit 14 .
[0081] The spinning rotor 12 has a container 18 for accommodating the aqueous gelatin spinning solution which can be supplied continuously during the spinning procedure from a supply channel 22 via a funnel 20 .
[0082] The container 18 has at its outer circumference a plurality of openings 24 , via which the spinning solution is discharged in a filament form due to centrifugal force.
[0083] A collection device 26 in the form of a cylinder wall is provided at a predetermined distance a from the openings 24 and collects the spinning solution shaped to form filaments or fibers. On account of the flight time predetermined via the distance a at a specific rotational speed of the spinning rotor 12 , the spinning solution forming the filaments or fibers will be solidified to such an extent that the filament form is essentially retained when impinging on the collection device 26 ; on the other hand, the areas, in which two or more fibers or filaments melt, as it were, into one another and create points of connection, at which the phase boundaries of the fiber sections abutting on one another are removed (cf., in particular, FIG. 2 b ), can still be formed.
[0084] The spinning rotor 12 together with the drive unit 14 and the collection device 26 are arranged in a housing 28 which separates a spinning chamber from the surroundings.
[0085] In the present example, the spinning rotor 12 is driven at a rotational speed of 2,000 to 3,000 U/min. The rotor 12 is heated to a temperature of 130° C. The gelatin solution is heated to 95° C. and supplied to the rotor 12 so that a continuous generation of filaments can be carried out. The filaments are collected on the collection device 26 as fleece by means of suction. The distance a is approximately 20 cm and, therefore, defines a flight time of approximately 0.01 m/sec.
[0086] The average diameter of the filaments or fibers obtained may be influenced via the size of the openings 24 of the container 18 of the spinning rotor 12 , the rotational speed of the spinning rotor 12 as well as the concentration of gelatin in the spinning solution. In the present example, the diameter of the openings 24 is approximately 0.9 mm.
[0087] In the example specified above, filaments with a filament thickness in the range of 2.5 to 14 μm (average fiber thickness 7.5 μm±2.6 μm) are obtained. An example of a non-woven fiber fabric which can be obtained with the method according to the invention is illustrated in FIGS. 2 a to c in different enlargements.
[0088] The relatively loose non-woven fiber fabric as shown in FIG. 2 a can, of course, also be obtained with a higher filament or fiber density but non-woven fiber fabrics with the density as shown in FIG. 2 a can also be connected, when several are placed one on top of the other, to form a self-supporting sheet material in the form of a fleece or, however, be placed on carrier materials, such as, for example, membranes or films.
[0089] FIG. 2 b shows, in a scanning electron micrograph, the non-woven fiber fabric 30 according to the invention which can be obtained with the method according to the invention with a plurality of fibers 32 consisting of a gelatin material and, in particular, the areas 34 which distinguish the invention and in which two or more fibers 32 are connected to one another without a phase boundary.
[0090] In FIG. 2 c , the effect of the intertwining of the individual filaments 36 is made visible in a light micrograph in polarized light, wherein the intertwining sections are visualized by way of light-dark areas 38 .
Example 2
Production of a Cell Carrier Material
[0091] Predetermined pieces of material are punched from the non-woven fiber fabric obtained in Example 1 and placed in layers on top of one another until a fleece with a desired weight per unit area, for example, in the range of approximately 20 to approximately 500 g/m 2 is achieved.
[0092] In the present Example, a multi-layered fleece, formed with a weight per unit area of 150 g/m2, is produced and, subsequently, partially cross-linked with the aid of gaseous formaldehyde. The cross-linking conditions in detail were as follows:
[0093] The non-woven fiber fabric is incubated in a gas atmosphere for approximately 17 hours over a formaldehyde solution of 10% by weight. Subsequently, the non-woven fiber fabric is slow cooled in a refrigerator for 48 hours at approximately 50° C. and 70% relative humidity. The cross-linking reaction is hereby completed and the surplus amount of formaldehyde (cross-linking agent) which was not used will be removed.
[0094] Samples were punched from fleeces produced in this manner and compared in their water absorption properties as well as mechanical properties with conventional cell carrier materials in the form of porous gelatin sponges as well as a material consisting of oxidized cellulose.
[0095] The width of the sample was 1 cm each time.
[0096] FIG. 3 shows the height of rise of pure water plotted against the time for these three materials, wherein the curve designated with the letter A corresponds to the fleece according to the invention as a multi-layered non-woven fiber fabric, the curve B a conventional gelatin sponge and the curve C the conventional cellulose material which is commercially obtainable.
[0097] It is obvious from the comparison of the absorption of water over the unit of time that gelatin materials are clearly superior to the cellulose materials such as those used in sample C.
[0098] The sample of fleece from the non-woven fiber fabric according to the invention and according to curve A is, again, clearly superior to the gelatin material in a sponge form (curve B) in its water absorption capacity per unit of time, as is apparent from FIG. 3 .
[0099] The practical advantage of this speed of water absorption, which is increased considerably, is to be seen in the fact that liquids, such as, for example, blood, can be absorbed more quickly and to a greater extent and, in the case of wounds which are to be treated, this leads to an improved staunching of the bleeding.
[0100] In FIGS. 4 a to c , the principle for measuring the height of rise per unit of time is illustrated schematically. The prepared sample 40 is clamped via a holding device 42 so as to hang freely downwards and placed over a basin 44 with temperature-controlled water (25° C.). At the beginning of the measurement, the basin with the water is moved upwards to such an extent that the sample dips into the supply of water to a depth of 2 mm. Subsequently, the height of rise which is generated via capillary forces is registered as a function of time and then entered in the graph according to FIG. 3 . A measuring stick 46 applied to the sample 40 makes the reading of the height of rise easier.
[0101] Tension/elongation measurements were also carried out on the samples described above with a width of 15 mm and a thickness of approximately 1 mm, namely in the dry state ( FIG. 5 a ). Only the two samples based on gelatin were compared, i.e., on the one hand, the fleece produced in accordance with the invention and, on the other hand, the conventional sponge sample with the same dimensions.
[0102] It is apparent from FIG. 5 a that the gelatin fleece in accordance with the present invention has a considerably higher specific tensile strength in comparison with the gelatin sponge in the dry state (water content approximately 10% by weight) and, in addition, allows a considerably greater elongation in the dry state, as well. Whereas the tension/elongation curve for the gelatin sponge sample (curve B) already breaks off after an elongation of approximately 7 to 8%, i.e., the sample tears, the fleece sample according to the invention may be stretched by approximately 17% before any tearing of the sample is observed. In this respect, a considerably higher tensile strength in comparison with the sponge sample is also ascertained.
[0103] In the completely hydrated state of the samples ( FIG. 5 b ), i.e., in a state, in which the cross-linked gelatin material of the sponge or of the fleece according to the invention are completely swollen, even greater and more significant differences are obtained. The water content is, in this case, more than 100% by weight in relation to the gelatin material.
[0104] A standard sponge in the size 80×50×10 mm as well as the fleece according to the invention in the size 80×50×1 mm were used for the comparison. The sponge has a dry weight per unit area of 120 g/m 2 , the fleece one of 180 g/m 2 .
[0105] In this case, tearing of the sample is observed for the sponge sample after an elongation of just about 75% (curve B) whereas the fleece sample according to the invention may be stretched to 400% (curve A) before it finally tears. In the hydrated state, as well, the fleece (with 2.6 N tensile force) achieves a higher strength than the sponge.
[0106] This is of quite particular significance for the use of the fleece materials as carriers for cell implants since this gives the attending physician the possibility of deforming, stretching and adapting the cell implant to the conditions of the wound of the patient to be treated almost as required.
Example 3
Production of Sugar-Free Candy Floss
[0107] Analogous to Example 1, a 20% by weight aqueous spinning solution is produced with the following composition:
[0000] 15 g of gelatin type A, 260 Bloom, edible quality
15 g of gelatin hydrolysate type A, average molecular weight 3 kD
70 g of water
[0108] Coloring matter (e.g., raspberry) and aromas (e.g., vanilla-cola) can be added according to the producer's specifications.
[0109] The spinning solution is heated to 70° C. and spun in the spinning rotor.
[0110] The product collected has the consistency and sensory perception of candy floss.
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In order to provide a non-woven fiber fabric, in particular, in the form of a flat material or as part of a flat material which can be used as a biodegradable material in medicine, in particular, as an implant or carrier material for living cells (tissue engineering) but also a non-woven fiber fabric which can be used in food technology in a variety of applications, in particular, as a preliminary product for foods, a non-woven fiber fabric is provided containing fibers consisting of a gelatin material, wherein the thickness of the fibers is on average 1 to 500 μm and wherein the non-woven fiber fabric has a plurality of areas, at which two or more fibers merge into one another without any phase boundary.
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FIELD OF THE INVENTION
The present invention relates generally to medical devices and more particularly to intraurethral bladder control devices. Specifically, the invention relates to devices adapted to initiate urine flow in intraurethral devices and, more specifically, capable of initiating urine flow in users unable to generate sufficient bladder pressure due to atonic bladder disorder.
BACKGROUND OF THE INVENTION
The use of sphincter and bladder control devices is wide spread in the field of the present invention. See, for example, commonly assigned U.S. Pat. Nos. 5,512,032; 5,701,916; 5,701,916; and 5,722,932, herein incorporated by reference. Many existing intraurethral devices seek to duplicate the function of normal urinary sphincter control. This usually involves opening a valve in response to a user initiated stimulus, for example, an initial moment of high bladder pressure generated by the user of the device. In some devices, once begun, flow can be maintained without requiring continuing high bladder pressure.
There exists a class of potential users of these devices that cannot generate even a moment of sufficiently high bladder pressure to initiate flow through the aforementioned devices. Some users cannot generate pressure due to atonic bladder disorder. These individuals could maintain urination through some of the intraurethral devices, if the device could be initially opened to flow without requiring high bladder pressure. What has not been provided are devices and methods for initiating urine flow in devices in cases where the users can maintain flow through the devices, but cannot initiate urine flow.
SUMMARY OF THE PRESENT INVENTION
Devices and methods according to the present invention give a large number of people, previously unable to use intraurethral devices, the ability to deal with urinary incontinence using such devices. In particular, the present invention allows users of a class of intraurethral devices to initiate urine flow through the devices without having to generate high bladder pressure. One class of intraurethral devices within the scope of the present invention includes a substantially cylindrical housing having a wall, a proximal end having a proximal retainer, a distal end having a distal retainer, a valve therein, and a lumen therethrough. The proximal retainer is adapted to fit against the bladder wall and the distal retainer is adapted to fit against the urethral meatus.
The valve in a preferred device includes a stopper slidably disposed within the housing lumen and biased in a proximal direction so as to normally preclude urine flow. The stopper can typically rest proximally and tightly against a valve seat when closed and distally on standoffs against a retaining ring when open, leaving channels around the stopper for fluid flow. Once initiated, flow through the channels is of sufficiently high velocity so as to create a negative pressure on the stopper through the Bernoulli effect. In users not having significant bladder pressure problems, the user can initiate flow by forcing the stopper into a distal, open position with an initial moment of high bladder pressure. In users having significant problems, other methods and actuating devices according to the present invention can be used.
One system according to the present invention includes an intraurethral device as described above and a suction actuating device. One suction device includes a plunger having an end adapted to fit snuggly within the intraurethral device lumen, such that inserting the plunger within the lumen and rapidly withdrawing it generates a vacuum, causing the stopper to be pulled distally into the open position. Another suction device includes a syringe having an orifice adapted to mate to the intraurethral device lumen, such that forcing the syringe orifice against the intraurethral distal end and retracting the syringe plunger creates a negative pressure, thereby moving the stopper into the open position. Yet another suction device includes a squeezable bulb having an orifice adapted to mate to the intraurethral device distal end. The bulb can be squeezed or collapsed, the orifice can be forced against the intraurethral device distal end, and the bulb released, thereby generating suction and pulling the stopper into an open position.
One system according to the present invention includes an intraurethral device similar to that described above, but having a magnetically responsive stopper. A magnet can be included in the actuating device, such that the magnet can be used to force the stopper into the open position. In one system, the magnet is used to pull the stopper distally to open the valve.
In another system according to the present invention, an elongate member is disposed within the intraurethral device housing and coupled to the stopper. In one intraurethral device, the elongate member includes a flexible string or tape region, such that pulling on the elongate member causes tension in the elongate member and operates to force the stopper into the open position. In another intraurethral device, the elongate member includes a rod member capable of transmitting a compression force.
In use, the actuating device can be brought within an effective range of the intraurethral device and operated to force the stopper into the open position and allow urine flow to commence. Once urine is flowing within the device, high velocity flow through a channel of the valve generates a negative pressure through the Bernoulli effect. The negative pressure acts on the stopper to keep the stopper in the open position. Once urine flow drops below a certain threshold or stops altogether, the stopper, being biased to remain in the closed position, closes.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a perspective view of a bladder control device for insertion in a female urethra;
FIG. 2 is cutaway, fragmentary side view of the bladder control device of FIG. 1 disposed in a female urethra, between the bladder and urethral meatus;
FIG. 3 is a cutaway, perspective view of the bladder control device of FIG. 1 having a urine flow lumen and a valve stopper in a proximal, closed position;
FIG. 4 is a cutaway, perspective view of the bladder control device of FIG. 3 having the valve stopper in a distal, open position;
FIG. 5 is a cutaway, side view of the device of FIG. 1 in closed position, having a plunger actuator in the process of being positioned in the flow lumen;
FIG. 6 is a cutaway, side view of the device of FIG. 6 in open position, after the plunger has been withdrawn and urine flow initiated;
FIG. 7A is a cutaway, side view of a bladder control device in closed position having a housing wall including a lumen therein, and an elongate actuating member disposed within the wall lumen;
FIG. 7B is a cutaway, side view of the bladder control device of FIG. 7A, having the elongate member distally moved, causing the valve stopper to open;
FIG. 8A is a cutaway, side view of a bladder control device in a closed position having a housing wall including a lumen therein, and an elongate member disposed within the wall lumen;
FIG. 8B is a cutaway, side view of the bladder control device of FIG. 8A, having the elongate member proximally pushed, causing the valve stopper to open;
FIG. 9 is a cutaway, side view of a bladder control device having a magnetically responsive valve stopper and an actuator magnet capable of forcing the stopper into an open position;
FIG. 10 is a cutaway, side view of a bladder control device inserted into a female urethra, having a suction device orifice mated to the flow control device distal end;
FIG. 11 is a fragmentary, perspective view of the distal end of a bladder control device and a suction device tube adapted to be inserted within the bladder control device lumen; and
FIG. 12 is a fragmentary, perspective view of the distal end of a bladder control device and a suction device tube adapted to abut the flow control device distal end.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a bladder control device 20 having a proximal end 22 and a distal end 24 , extending from a proximal retainer 26 through a housing 34 to a distal retainer 28 . Proximal retainer 26 can include a plurality of leafs springs 30 , preferably terminating in hemispheric safety pads 32 . Housing 34 includes a urine lumen 36 extending therethrough, and a valve within. FIG. 2 illustrates bladder control device 20 disposed within a female bladder 38 and a urethra 42 , extending between a bladder wall 40 and urethral meatus 43 . Proximal retainer 26 prevents bladder control device 20 from migrating out of the body, while distal retainer 28 prevents migration into the body.
Referring now to FIG. 3, bladder control device 20 is illustrated in greater detail, showing a flow control valve 44 in a closed position. Valve 44 including a valve seat 46 , a stopper 48 , and a spring 50 . In the embodiment shown, spring 50 biases stopper 48 against valve seat 46 , thereby closing valve 44 and precluding urine flow through lumen 36 . A spring mounting ring 52 retains spring 50 distally and a blind lumen 56 within stopper 48 bounds spring 50 proximally. A stopper retaining ring 54 limits the stopper distal travel and provides flow channels for urine between stopper 48 and stopper retaining ring 54 . Valve seat 46 has a narrowing shoulder portion 58 and a narrower, constricted portion 60 , leading to a lumen throat region 62 . Stopper 48 has a stopper shoulder region 64 and a stopper proximal nose region 66 . In the embodiment shown, in the closed position, stopper nose 66 fits snuggly within valve seat constricted region 60 and stopper shoulder 64 presses against valve seat shoulder 60 .
Referring now to FIG. 4, bladder control device 20 is shown having valve 44 in open position, with stopper 48 near stopper retaining ring 54 . Urine in flows through a channel 68 between stopper 48 and retaining ring 54 . Standoffs 70 may be seen keeping stopper 48 nominally centered, away from the walls of housing 34 , and away from retaining ring 54 allowing flow around the stopper, between the standoffs. As the cross sectional area available for flow is less than the area of throat 62 , the fluid velocity is greater in channels 68 than in throat 62 . The higher speed flow creates a negative pressure on stopper 48 through operation of the Bernoulli effect, acting to pull stopper 48 proximally, keeping valve 44 open. While open, valve stopper 48 has both nose 66 and shoulder 64 exposed to hydrostatic pressure. The greater amount of surface area exposed while open also serves to keep valve stopper 48 in open position.
In device users able to generate sufficient bladder pressure, an initial amount of bladder pressure is applied, bringing fluid pressure to bear on stopper 48 , forcing stopper 48 proximally against spring 52 and moving the stopper axially downward to rest on retaining ring 54 . The higher flow rate around stopper 48 between standoffs 70 and in channels 68 creates sufficient negative pressure on stopper 48 to hold valve 44 in the open position, even without any user applied bladder pressure. When the flow stops or decreases below a threshold, the negative pressure is no longer sufficient to oppose spring 50 and spring 50 forces stopper 48 to the closed position. Thus, while high bladder pressure is required to initially open valve 44 , normal flow is sufficient to hold valve 44 open.
In device users having an atonic bladder disorder, it may not be possible to generate bladder pressure sufficient to open valve 44 . Referring now to FIG. 5, bladder control device 20 is again illustrated. Device 20 includes a distal lumen region 74 having housing wall 76 and an inside diameter indicated by “D”. An actuator device in the form of a plunger 100 is inserted within distal lumen region 74 , fitting snuggly against wall 76 . In the embodiment shown, plunger 100 includes a head 102 having resilient outer edges 104 . Attached to head 102 is an elongate central member 106 secured to plunger head 102 . Elongate member 106 has a proximal portion 108 . In one embodiment, elongate member 106 is a rigid, capable of pushing plunger head into lumen 74 . In another embodiment, elongate member 106 is a flexible string or tape, secured to proximal portion 108 which is preferably rigid. In this tape embodiment, a finger or other member can be used to insert plunger head 102 within lumen region 74 .
After insertion, when urine voiding is desired, elongate member 106 can be grasped and pulled in a distal direction, away from bladder control device 20 . This action is illustrated in FIG. 6 . This action causes plunger head 102 to slide out of lumen region 74 , creating a suction or negative pressure. This suction causes stopper 48 to move axially and distally toward retaining ring 54 , allowing urine to flow past stopper 48 , thereby initiating the Bernoulli effect and the resultant negative pressure. The flow caused negative pressure should then be sufficient to maintain stopper 48 in open position until urine flow decreases below a threshold or stops. After urine voiding is complete, the previous plunger or a fresh plunger can be inserted.
Referring now to FIG. 7A, another embodiment is illustrated in a bladder control device 220 . Device 220 includes a housing 234 , a housing wall 235 , and a lumen 236 disposed within housing wall 235 . An actuator device in the form of an elongate member 238 is slidably disposed within lumen 236 . Elongate member 238 includes a distal portion 241 and a proximal portion 240 . Proximal portion 240 includes an arcuate, U-shaped portion 242 which includes a tip 243 which can be brought to bear on stopper 48 . In one embodiment, elongate member 238 is formed of a rigid material capable of bearing tension and compression forces without significant buckling. In another embodiment, U-shaped portion 242 can bear compression force while distal portion 241 is a string or tape which can transmit only tension force.
Referring now to FIG. 7B, use of bladder control device 220 and actuator elongate member 238 is illustrated. When urine voiding is desired, the externally accessible portion of member distal portion 241 can be grasped by the wearer and pulled away from device 220 . In one embodiment, lumen 236 includes a proximal, wide, slotted region 237 , allowing arcuate portion 242 some travel in a proximal-distal direction. Arcuate portion 242 is thereby pulled distally, brining tip 243 to bear on stopper 48 , thereby forcing stopper 48 away from valve seat 46 and toward retaining ring 54 , thereby opening the valve and initiating urine flow. Once urine flow commences, the forces previously discussed serve to keep stopper 48 in the open position until flow sufficiently decreases or stops. The coupling force between the grasped member and stopper 48 thus includes both tension and compression in the embodiment illustrated in FIG. 7 B.
Referring now to FIG. 8A, another embodiment is illustrated in a bladder control device 520 . Device 520 includes housing 234 , housing wall 235 , and lumen 236 disposed within housing wall 235 . An actuator device in the form of a pushable elongate member 538 is slidably disposed within lumen 236 . Elongate member 538 includes a distal portion 541 and a proximal portion 540 . Proximal portion 540 includes an arcuate, U-shaped portion 542 which includes a tip 543 which can be brought to bear on stopper 48 . In one embodiment, elongate member 538 is formed of a rigid material capable of bearing compressive forces without significant buckling. In particular, the portion of elongate member 538 near tip 543 should be capable of bearing compressive forces without buckling.
Referring now to FIG. 8B, use of bladder control device 520 and elongate actuator member 538 is illustrated. When urine voiding is desired, the externally accessible portion of member distal portion 541 can be grasped by the user and pushed into device 520 . Arcuate portion 542 is thereby subject to compression, forcing member 538 to slide through lumen 236 and forcing tip 543 to bear on topper 48 , thereby forcing stopper 48 away from valve seat 46 . In this embodiment, over most of its length, elongate member 538 is supported against buckling by lumen 236 .
Referring now to FIG. 9, another bladder control device 320 is illustrated. Device 320 uses a magnet 322 as an actuator and magnetic force as a coupling force. In device 320 , a magnetically responsive stopper 348 is included in the device. As used herein, “magnetically responsive” means capable of being attracted or repelled by a magnetic force. In one embodiment, stopper 348 if formed of a magnetically responsive material. In one embodiment, a magnetically responsive material is enclosed in a protective, polymeric layer. In another embodiment, a magnetically responsive material is embedded in a polymeric material. In yet another embodiment, a magnetic member is operably secured to the stopper. One class of magnetic materials suitable for use in a magnetic embodiment includes ferromagnetic materials.
In use, magnetic actuator 322 can be brought within its effective range, sufficiently close to exert an attractive force on stopper 348 . Magnet 322 can then be moved alongside or “swiped” over device 320 , substantially parallel to the longitudinal axis. The magnetic force acting on the stopper pulls the stopper away from valve seat 46 and toward retaining ring 54 . In another method, magnet 322 is disposed near distal end 24 , with the magnet having sufficient effective range to pull stopper 348 into an open position. After flow has been initiated, magnet 322 can be removed, and urine flow continues.
Referring now to FIG. 10, another bladder control device 420 is illustrated. Device 420 includes a distal end 428 in fluid communication with a urine flow lumen. An actuator in the form of a suction device 421 is illustrated, having a squeezable bulb 430 in communication with an inlet tube 440 and, preferably, an outlet tube 444 . The coupling force between bulb 430 and the bladder device is a negative pressure or suction. Inlet tube 440 has an orifice 442 adapted to mate to bladder device distal end 428 . Suction bulb 430 has an inlet end 432 and an outlet end 434 . Inlet end 432 has a one way valve 436 , and outlet end 434 also has a one way valve 438 . Inlet one way valve 436 allows fluid into the bulb and outlet valve 438 allows fluid out of the bulb into outlet tube 444 .
In use, inlet tube 440 can be mated to device distal end 428 . Bulb 430 can be squeezed, partially collapsing the bulb and forcing air out through outlet valve 438 while inlet valve 436 remains shut. When released, bulb 430 expands, outlet valve 438 is pulled shut by the vacuum, directing the vacuum through now open inlet valve 436 . Once urine flow is initiated, the urine can flow through bulb 430 and outlet valve 438 , through outlet tube 444 . In one embodiment, outlet valve 438 closes in the presence of vacuum in bulb 430 , but remains open in the absence of suction pressure. Outlet tube 444 can lead to a reservoir for holding urine. Suction device 421 is suitable for use in institutions in general, and for bed-ridden patients in particular.
Referring now to FIG. 11, bladder control device distal end 428 is further illustrated, having an inlet 429 adapted to receive a tip 431 of tube 442 within. In one embodiment, tip 431 has a plurality of ribs to secure tip 431 within device end 428 . Referring now to FIG. 12, another tip 443 is illustrated, having a pair of wings 445 for wrapping around a lip 447 on device distal end 428 . Wings 445 are preferably formed of an elastomeric, resilient material adapted to receive lip 447 . Tip 443 can be fit over lip 447 for the duration of the urine voiding and subsequently removed.
Numerous characteristics and advantages of the invention covered by this document have been set forth in the foregoing description. It will be understood, however, that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size and ordering of steps without exceeding the scope of the invention. The invention's scope is, of course, defined in the language in which the appended claims are expressed.
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A system for initiating urine flow in intraurethral bladder control devices having a housing, a flow lumen, a valve biased to close, a distal end disposed near the urethral meatus, and a proximal end disposed near the bladder. The system includes an actuator device to open the valve. One intraurethral bladder control device has a higher velocity flow region near the valve distal end, such that the Bernoulli effect generates a negative pressure on the valve, keeping the valve in an open position once urine flow commences. One valve includes a spring biased stopper in the urine flow lumen. One actuator device is a suction device adapted to mate to the intraurethral device distal end and capable of pulling the stopper into the open position. Suction devices include plungers, syringes, and squeezable bulbs. Another actuator device includes a magnet capable of moving a magnetically responsive stopper. Yet another actuator device includes an elongate member disposed within the device housing and operably coupled to the stopper. Grasping and manipulating a free distal end of the elongate member causes the stopper to open and initiate urine flow.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Application Ser. No. 60/758,234 filed on Jan. 12, 2006, U.S. Application Ser. No. 60/759,620 filed on Jan. 18, 2006, U.S. Application Ser. No. 60/762,534 filed on Jan. 27, 2006, U.S. Application Ser. No. 60/787,193 filed on Mar. 30, 2006, U.S. Application Ser. No. 60/818,274 filed on Jul. 5, 2006, U.S. Application Ser. No. 60/830,087 filed on Jul. 12, 2006, U.S. Application Ser. No. 60/830,328 filed on Jul. 14, 2006, Korean Application No. 10-2006-0004956 filed on Jan. 17, 2006, Korean Application No. 10-2006-0027100 filed on Mar. 24, 2006, Korean Application No. 10-2006-0037773 filed on Apr. 26, 2006, Korean Application No. 10-2006-0110337 filed on Nov. 9, 2006, and Korean Application No. 10-2006-0110338 filed on Nov. 9, 2006, each of which is incorporated herein by reference.
This application is related to U.S. application Ser. No. 11/622,591 titled “PROCESSING MULTIVIEW VIDEO”, U.S. application Ser. No. 11/622,592 titled “PROCESSING MULTIVIEW VIDEO”, U.S. application Ser. No. 11/622,611 titled “PROCESSING MULTIVIEW VIDEO”, U.S. application Ser. No. 11/622,709 titled “PROCESSING MULTIVIEW VIDEO”, U.S. application Ser. No. 11/622,675 titled “PROCESSING MULTIVIEW VIDEO”, U.S. application Ser. No. 11/622,803 titled “PROCESSING MULTIVIEW VIDEO”, U.S. application Ser. No. 11/622,681 titled “PROCESSING MULTIVIEW VIDEO”, each of which is being filed concurrently with the present application, and each of which is also incorporated herein by reference.
BACKGROUND
The invention relates to processing multiview video.
Multiview Video Coding (MVC) relates to compression of video sequences (e.g., a sequence of images or “pictures”) that are typically acquired by respective cameras. The video sequences or “views” can be encoded according to a standard such as MPEG. A picture in a video sequence can represent a full video frame or a field of a video frame. A slice is an independently coded portion of a picture that includes some or all of the macroblocks in the picture, and a macroblock includes blocks of picture elements (or “pixels”).
The video sequences can be encoded as a multiview video sequence according to the H.264/AVC codec technology, and many developers are conducting research into amendment of standards to accommodate multiview video sequences.
Three profiles for supporting specific functions are prescribed in the current H.264 standard. The term “profile” indicates the standardization of technical components for use in the video encoding/decoding algorithms. In other words, the profile is the set of technical components prescribed for decoding a bitstream of a compressed sequence, and may be considered to be a sub-standard. The above-mentioned three profiles are a baseline profile, a main profile, and an extended profile. A variety of functions for the encoder and the decoder have been defined in the H.264 standard, such that the encoder and the decoder can be compatible with the baseline profile, the main profile, and the extended profile respectively.
The bitstream for the H.264/AVC standard is structured according to a Video Coding Layer (VCL) for processing the moving-image coding (i.e., the sequence coding), and a Network Abstraction Layer (NAL) associated with a subsystem capable of transmitting/storing encoded information. The output data of the encoding process is VCL data, and is mapped into NAL units before it is transmitted or stored. Each NAL unit includes a Raw Byte Sequence Payload (RBSP) corresponding to either compressed video data or header information.
The NAL unit includes a NAL header and a RBSP. The NAL header includes flag information (e.g., nal_ref_idc) and identification (ID) information (e.g., nal_unit_type). The flag information “nal_ref_idc” indicates the presence or absence of a slice used as a reference picture of the NAL unit. The ID information “nal_unit_type” indicates the type of the NAL unit. The RBSP stores compressed original data. An RBSP trailing bit can be added to the last part of the RBSP, such that the length of the RBSP can be represented by a multiple of 8 bits.
There are a variety of the NAL units, for example, an Instantaneous Decoding Refresh (IDR) picture, a Sequence Parameter Set (SPS), a Picture Parameter Set (PPS), and Supplemental Enhancement Information (SEI), etc.
The standard has generally defined a target product using various profiles and levels, such that the target product can be implemented with appropriate costs. The decoder satisfies a predetermined constraint at a corresponding profile and level.
The profile and the level are able to indicate a function or parameter of the decoder, such that they indicate which compressed images can be handled by the decoder. Specific information indicating which one of multiple profiles corresponds to the bitstream can be identified by profile ID information. The profile ID information “profile_idc” provides a flag for identifying a profile associated with the bitstream. The H.264/AVC standard includes three profile identifiers (IDs). If the profile ID information “profile_idc” is set to “66”, the bitstream is based on the baseline profile. If the profile ID information “profile_idc” is set to “77”, the bitstream is based on the main profile. If the profile ID information “profile_idc” is set to “88”, the bitstream is based on the extended profile. The above-mentioned “profile_idc” information may be contained in the SPS (Sequence Parameter Set), for example.
SUMMARY
In one aspect, in general, a method for decoding a video signal comprises: receiving a bitstream comprising the video signal encoded according to a first profile that represents a selection from a set of profiles that includes multiple profiles for single view video signals and at least one profile for a multiview video signal, and profile information that identifies the first profile; extracting the profile information from the bitstream; and decoding the video signal according to the determined profile.
Aspects can include one or more of the following features.
The method further comprises extracting from the bitstream configuration information associated with multiple views when the determined profile corresponds to a multiview video signal, wherein the configuration information comprises at least one of view-dependency information representing dependency relationships between respective views, view identification information indicating a reference view, view-number information indicating the number of views, view level information for providing view scalability, and view-arrangement information indicating a camera arrangement. For example, the configuration information can be extracted in response to determining that the profile corresponds to a multiview video signal.
The profile information is located in a header of the bitstream.
The view-dependency information represents the dependency relationships in a two-dimensional data structure.
The two-dimensional data structure comprises a matrix.
The view level information corresponds to a plurality of levels assigned to views according to a hierarchical view prediction structure among the views of the multiview video signal.
Multiple portions of a given picture pictures of a given view are associated with respective identifiers indicating a corresponding level.
The multiple portions correspond to independent slices of the given picture.
Each slice corresponds to a full picture.
Pictures of a view assigned a given level are predicted from pictures of a view assigned a level lower than the given level.
Pictures of a single view assigned the lowest level are not predicted from pictures of another level.
The hierarchical view prediction structure includes a single base view and multiple auxiliary views, wherein pictures in a first level view are predicted on the basis of pictures in the base view and pictures in a given higher level view are predicted on the basis of views in lower levels than the level of the given higher level view.
In another aspect, in general, a method for decoding a multiview video signal comprises: receiving a bitstream comprising the multiview video signal encoded according to dependency relationships between respective views, and view-dependency information representing the dependency relationships in a two-dimensional data structure; extracting the two-dimensional data structure and determining the dependency relationships from the extracted data structure; and decoding the multiview video signal according to the determined dependency relationships.
Aspects can include one or more of the following features.
The two-dimensional data structure comprises a matrix.
The method further comprises extracting from the bitstream configuration information comprising at least one of view identification information indicating a reference view, view-number information indicating the number of views, view level information for providing view scalability, and view-arrangement information indicating a camera arrangement.
The view level information corresponds to a plurality of levels assigned to views according to a hierarchical view prediction structure among the views of the multiview video signal.
Multiple portions of a given picture pictures of a given view are associated with respective identifiers indicating a corresponding level.
The multiple portions correspond to independent slices of the given picture.
Each slice corresponds to a full picture.
Pictures of a view assigned a given level are predicted from pictures of a view assigned a level lower than the given level.
Pictures of a single view assigned the lowest level are not predicted from pictures of another level.
The hierarchical view prediction structure includes a single base view and multiple auxiliary views, wherein pictures in a first level view are predicted on the basis of pictures in the base view and pictures in a given higher level view are predicted on the basis of views in lower levels than the level of the given higher level view.
In another aspect, in general, for each respective decoding method, a method for encoding a video signal comprises generating a bitstream capable of being decoded into the video signal by the respective decoding method. For example, in another aspect, in general, a method for encoding a bitstream comprises: forming the bitstream according to a first profile that represents a selection from a set of profiles that includes multiple profiles for single view video signals and at least one profile for a multiview video signal, and profile information that identifies the first profile. In another aspect, in general, a method for encoding a bitstream comprises: forming the bitstream according to dependency relationships between respective views, and view-dependency information representing the dependency relationships in a two-dimensional data structure.
In another aspect, in general, for each respective decoding method, a computer program, stored on a computer-readable medium, comprises instructions for causing a computer to perform the respective decoding method.
In another aspect, in general, for each respective decoding method, image data embodied on a machine-readable information carrier is capable of being decoded into a video signal by the respective decoding method.
In another aspect, in general, for each respective decoding method, a decoder comprises means for performing the respective decoding method.
In another aspect, in general, for each respective decoding method, an encoder comprises means for generating a bitstream capable of being decoded into a video signal by the respective decoding method.
In another aspect, in general, a method for encoding a multiview sequence comprises: generating a bitstream by encoding images acquired at several views (i.e., multiview), wherein if the number of the multiview (m) is set to 2 n−1 <m≦2 n , the bitstream includes a single base-view bitstream and N hierarchical auxiliary-view bitstream.
In another aspect, in general, there is provided a method for encoding a multiview sequence comprising: generating a bitstream by encoding images acquired at two-dimensional (2D) several views (i.e., 2D multiview), wherein if the number (m) of the 2D multiview on a horizontal axis is set to 2 n−1 <m≦2 n , and the number (p) of the 2D multiview on a vertical axis is set to 2 k−1 <p≦2 k , the bitstream includes a single base-view bitstream and (n+k) hierarchical auxiliary-view bitstreams.
In yet another aspect, in general, there is provided a method for decoding a multiview sequence comprising: receiving an encoded bitstream of images acquired at several views (i.e., multiview), wherein if the number of the multiview (m) is set to 2 n−1 <m≦2 n , the bitstream includes a single base-view bitstream and n hierarchical auxiliary-view bitstream, and selectively decodes the base-view stream and/or the n hierarchical auxiliary-view bitstream according to the received bitstream.
In yet another aspect, in general, there is provided a method for decoding a multiview sequence comprising: receiving a bitstream by encoding images acquired at two-dimensional (2D) several views (i.e., 2D multiview), wherein if the number (m) of the 2D multiview on a horizontal axis is set to 2 n−1 <m≦2 n , and the number (p) of the 2D multiview on a vertical axis is set to 2 k−1 <p≦2 k , the bitstream includes a single base-view bitstream and (n+k) hierarchical auxiliary-view bitstreams, and selectively decodes the base-view bitstream and/or the (n+k) hierarchical auxiliary-view bitstreams according to the received bitstream.
In yet another aspect, in general, there is provided a method for encoding a multiview sequence comprising: generating a bitstream by encoding images acquired at m views (i.e., multiview of m), wherein the bitstream includes a single base-view bitstream and at least one auxiliary-view bitstream, both ends of the multiview are set to first views, respectively, a center view from among the multiview is set to a second view, views successively arranged by skipping over at least one view in both directions on the basis of the second view are set to third views, respectively, the remaining views other than the first to third views are set to fourth views, respectively, and any one of the first to third views is set to a base-view for independent encoding, and the remaining views other than the base-view are set to auxiliary-views for predictive coding.
In yet another aspect, in general, there is provided a method for encoding a multiview sequence comprising: generating a bitstream by encoding images acquired at m views (i.e., multiview of m), wherein the bitstream includes a single base-view bitstream and at least one auxiliary-view bitstream, a location of the base-view is set to a view located at a center part of the multiview, locations of a second auxiliary-view are set to views located at both ends of the multiview, and locations of a first auxiliary-view are successively arranged by skipping over at least one view in both directions on the basis of the base-view.
In yet another aspect, in general, there is provided a method for decoding a multiview sequence comprising: receiving an encoded bitstream of images acquired at m views (i.e., multiview of m), wherein the bitstream includes a single base-view bitstream and at least one auxiliary-view bitstream, a base-view image from among the received bitstream is recovered by independently decoding data of a center view from among the multiview, an image of a first auxiliary-view is recovered using the base-view image from among the received bitstream, the first auxiliary-view being views successively arranged by skipping over at least one view in both directions on the basis of the base-view, and an image of second auxiliary-views is recovered using the base-view image from among the received bitstream, the second auxiliary-views being views located at both ends of the multiview.
In yet another aspect, in general, there is provided a method for decoding a multiview sequence comprising: receiving an encoded bitstream of images acquired at m views (i.e., multiview of m), wherein the bitstream includes a single base-view bitstream and at least one auxiliary-view bitstream; reading out location information of a base-view from the received bitstream, recognizing the locations of the base-view and the auxiliary-view through the location information, and recovering images of the base-view and the auxiliary-view, wherein the location information of the base-view is indicative of any one of a first view located at both ends of the multiview, a second view located at the center of the multiview, and a third view successively arranged by skipping over at least one over in both directions on the basis of the second view.
In yet another aspect, in general, a method for encoding a video sequence comprises: selecting at least one profile from among several profiles when a bitstream is generated; and including at least one configuration information associated with a video sequence in the profile.
In yet another aspect, in general, there is provided a method for decoding a video sequence comprising: extracting at least one profile information from a received bitstream; extracting at least one configuration information contained in the profile on the basis of the extracted profile information; and decoding the bitstream using the extracted configuration information.
In yet another aspect, in general, there is provided an apparatus for encoding a video sequence comprising: means for selecting at least one profile from among several profiles when a bitstream is generated; and means for including at least one configuration information of the received video sequence in the selected profile.
In yet another aspect, in general, there is provided an apparatus for decoding a video sequence comprising: means for extracting at least one profile information from a received bitstream; means for extracting at least one configuration information contained in the profile on the basis of the extracted profile information; and means for decoding the bitstream using the extracted configuration information.
Aspects can have one or more of the following advantages.
The method for encoding/decoding a multiview sequence can effectively encode the multiview sequence. During the decoding of the multiview sequence, individual views can be hierarchically displayed during the decoding of the multiview sequence. The method establishes a prediction structure of individual-view images during the encoding of the multiview sequence. Therefore, although the multiview number increases and the array is extended, the method can extend the prediction structure in the same manner as in the above-mentioned preferred embodiments. In addition, the method performs a view scalability function of the multiview using a hierarchical structure, such that it can perform the encoding/decoding process to be suitable for a variety of displays contained in the reception end, resulting in the implementation of an effective encoding/decoding system.
The method for encoding/decoding a video sequence transmits the “num_views” information indicating the number of views to the encoder and the decoder when handling a multiview sequence captured by several cameras. The encoding/decoding method can designate a reference view acting as a base of the entire view. The reference-view sequences can be encoded without referring to another-view sequence, independent of each other. The encoding/decoding method can effectively perform the encoding/decoding processes according to individual arrangements by referring to “view_arrangement” information.
The encoding/decoding method can identify the profile type, can add a variety of configurations associated with a video sequence, and can effectively perform the encoding/decoding processes using the added information.
Other features and advantages will become apparent from the following description, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 is an exemplary decoding apparatus.
FIG. 2 is a structural diagram illustrating a sequence parameter set RBSP syntax.
FIG. 3A is a structural diagram illustrating a bitstream including only one sequence.
FIG. 3B is a structural diagram illustrating a bitstream including two sequences.
FIGS. 4A-4C are diagrams illustrating exemplary Group Of GOP (GGOP) structures.
FIG. 5 is a flowchart illustrating a method for decoding a video sequence.
FIGS. 6A-6B , 7 A- 7 B, and 8 are diagrams illustrating examples of multiview-sequence prediction structures.
FIGS. 9A-9B are diagrams illustrating a hierarchical prediction structure between several viewpoints of multiview sequence data.
FIGS. 10A-10B are diagrams illustrating a prediction structure of two-dimensional (2D) multiview sequence data.
FIGS. 11A-11C are diagrams illustrating a multiview sequence prediction structure.
FIG. 12 is a diagram illustrating a hierarchical encoding/decoding system.
DESCRIPTION
In order to effectively handle a multiview sequence, an input bitstream includes information that allows a decoding apparatus to determine whether the input bitstream relates to a multiview profile. In cases that it is determined that the input bitstream relates to the multiview profile, supplementary information associated with the multiview sequence is added according to a syntax to the bitstream and transmitted to the decoder. For example, the multiview profile ID can indicate a profile mode for handling multiview video data as according to an amendment of the H.264/AVC standard.
The MVC (Multiview Video Coding) technology is an amendment technology of the H.264/AVC standards. That is, a specific syntax is added as supplementary information for an MVC mode. Such amendment to support MVC technology can be more effective than an alternative in which an unconditional syntax is used. For example, if the profile identifier of the AVC technology is indicative of a multiview profile, the addition of multiview sequence information may increase a coding efficiency.
The sequence parameter set (SPS) of an H.264/AVC bitstream is indicative of header information including information (e.g., a profile, and a level) associated with the entire-sequence encoding.
The entire compressed moving images (i.e., a sequence) can begin at a sequence header, such that a sequence parameter set (SPS) corresponding to the header information arrives at the decoder earlier than data referred to by the parameter set. As a result, the sequence parameter set RBSP acts as header information of a compressed data of moving images at entry S 1 ( FIG. 2 ). If the bitstream is received, the profile ID information “profile_idc” identifies which one of profiles from among several profiles corresponds to the received bitstream.
The profile ID information “profile_idc” can be set, for example, to “MULTI_VIEW_PROFILE)”, so that the syntax including the profile ID information can determine whether the received bitstream relates to a multiview profile. The following configuration information can be added when the received bitstream relates to the multiview profile.
FIG. 1 is a block diagram illustrating an exemplary decoding apparatus (or “decoder”) of a multiview video system for decoding a video signal containing a multiview video sequence. The multiview video system includes a corresponding encoding apparatus (or “encoder”) to provide the multiview video sequence as a bitstream that includes encoded image data embodied on a machine-readable information carrier (e.g., a machine-readable storage medium, or a machine-readable energy signal propagating between a transmitter and receiver.).
Referring to FIG. 1 , the decoding apparatus includes a parsing unit 10 , an entropy decoding unit 11 , an Inverse Quantization/Inverse Transform unit 12 , an inter-prediction unit 13 , an intra-prediction unit 14 , a deblocking filter 15 , and a decoded-picture buffer 16 .
The inter-prediction unit 13 includes a motion compensation unit 17 , an illumination compensation unit 18 , and an illumination-compensation offset prediction unit 19 .
The parsing unit 10 performs a parsing of the received video sequence in NAL units to decode the received video sequence. Typically, one or more sequence parameter sets and picture parameter sets are transmitted to a decoder before a slice header and slice data are decoded. In this case, the NAL header or an extended area of the NAL header may include a variety of configuration information, for example, temporal level information, view level information, anchor picture ID information, and view ID information, etc.
The term “time level information” is indicative of hierarchical-structure information for providing temporal scalability from a video signal, such that sequences of a variety of time zones can be provided to a user via the above-mentioned temporal level information.
The term “view level information” is indicative of hierarchical-structure information for providing view scalability from the video signal. The multiview video sequence can define the temporal level and view level, such that a variety of temporal sequences and view sequences can be provided to the user according to the defined temporal level and view level.
In this way, if the level information is defined as described above, the user may employ the temporal scalability and the view scalability. Therefore, the user can view a sequence corresponding to a desired time and view, or can view a sequence corresponding to another limitation. The above-mentioned level information may also be established in various ways according to reference conditions. For example, the level information may be changed according to a camera location, and may also be changed according to a camera arrangement type. In addition, the level information may also be arbitrarily established without a special reference.
The term “anchor picture” is indicative of an encoded picture in which all slices refer to only slices in a current view and not slices in other views. A random access between views can be used for multiview-sequence decoding.
Anchor picture ID information can be used to perform the random access process to access data of a specific view without requiring a large amount of data to be decoded.
The term “view ID information” is indicative of specific information for discriminating between a picture of a current view and a picture of another view. In order to discriminate one picture from other pictures when the video sequence signal is encoded, a Picture Order Count (POC) and frame number information (frame_num) can be used.
If a current sequence is determined to be a multiview video sequence, inter-view prediction can be performed. An identifier is used to discriminate a picture of the current view from a picture of another view.
A view identifier can be defined to indicate a picture's view. The decoding apparatus can obtain information of a picture in a view different from a view of the current picture using the above-mentioned view identifier, such that it can decode the video signal using the information of the picture. The above-mentioned view identifier can be applied to the overall encoding/decoding process of the video signal. Also, the above-mentioned view identifier can also be applied to the multiview video coding process using the frame number information “frame_num” considering a view.
Typically, the multiview sequence has a large amount of data, and a hierarchical encoding function of each view (also called a “view scalability”) can be used for processing the large amount of data. In order to perform the view scalability function, a prediction structure considering views of the multiview sequence may be defined.
The above-mentioned prediction structure may be defined by structuralizing the prediction order or direction of several view sequences. For example, if several view sequences to be encoded are given, a center location of the overall arrangement is set to a base view, such that view sequences to be encoded can be hierarchically selected. The end of the overall arrangement or other parts may be set to the base view.
If the number of camera views is denoted by an exponential power of “2”, a hierarchical prediction structure between several view sequences may be formed on the basis of the above-mentioned case of the camera views denoted by the exponential power of “2”. Otherwise, if the number of camera views is not denoted by the exponential power of “2”, virtual views can be used, and the prediction structure may be formed on the basis of the virtual views. If the camera arrangement is indicative of a two-dimensional arrangement, the prediction order may be established by turns in a horizontal or vertical direction.
A parsed bitstream is entropy-decoded by an entropy decoding unit 11 , and data such as a coefficient of each macroblock, a motion vector, etc., are extracted. The inverse quantization/inverse transform unit 12 multiplies a received quantization value by a predetermined constant to acquire a transformed coefficient value, and performs an inverse transform of the acquired coefficient value, such that it reconstructs a pixel value. The inter-prediction unit 13 performs an inter-prediction function from decoded samples of the current picture using the reconstructed pixel value.
At the same time, the deblocking filter 15 is applied to each decoded macroblock to reduce the degree of block distortion. The deblocking filter 15 performs a smoothing of the block edge, such that it improves an image quality of the decoded frame. The selection of a filtering process is dependent on a boundary strength and a gradient of image samples arranged in the vicinity of the boundary. The filtered pictures are stored in the decoded picture buffer 16 , such that they can be outputted or be used as reference pictures.
The decoded picture buffer 16 stores or outputs pre-coded pictures to perform the inter-prediction function. In this case, frame number information “frame_num” and POC (Picture Order Count) information of the pictures are used to store or output the pre-coded pictures. Pictures of other view may exist in the above-mentioned pre-coded pictures in the case of the MVC technology. Therefore, in order to use the above-mentioned pictures as reference pictures, not only the “frame_num” and POC information, but also view identifier indicating a picture view may be used as necessary.
The inter-prediction unit 13 performs the inter-prediction using the reference pictures stored in the decoded picture buffer 16 . The inter-coded macroblock may be divided into macroblock partitions. Each macroblock partition can be predicted by one or two reference pictures.
The motion compensation unit 17 compensates for a motion of the current block using the information received from the entropy decoding unit 11 . The motion compensation unit 17 extracts motion vectors of neighboring blocks of the current block from the video signal, and obtains a motion-vector predictor of the current block. The motion compensation unit 17 compensates for the motion of the current block using a difference value between the motion vector and a predictor extracted from the video signal and the obtained motion-vector predictor. The above-mentioned motion compensation may be performed by only one reference picture, or may also be performed by a plurality of reference pictures.
Therefore, if the above-mentioned reference pictures are determined to be pictures of other views different from the current view, the motion compensation may be performed according to a view identifier indicating the other views.
A direct mode is indicative of a coding mode for predicting motion information of the current block on the basis of the motion information of a block which is completely decoded. The above-mentioned direct mode can reduce the number of bits required for encoding the motion information, resulting in the increased compression efficiency.
For example, a temporal direct mode predicts motion information of the current block using a correlation of motion information of a temporal direction. Similar to the temporal direct mode, the decoder can predict the motion information of the current block using a correlation of motion information of a view direction.
If the received bitstream corresponds to a multiview sequence, view sequences may be captured by different cameras respectively, such that a difference in illumination may occur due to internal or external factors of the cameras. In order to reduce potential inefficiency associated with the difference in illumination, an illumination compensation unit 18 performs an illumination compensation function.
In the case of performing illumination compensation function, flag information may be used to indicate whether an illumination compensation at a specific level of a video signal is performed. For example, the illumination compensation unit 18 may perform the illumination compensation function using flag information indicating whether the illumination compensation of a corresponding slice or macroblock is performed. Also, the abovementioned method for performing the illumination compensation using the above-mentioned flag information may be applied to a variety of macroblock types (e.g., an inter 16×16 mode, a B-skip mode, a direct mode, etc.).
In order to reconstruct the current block when performing the illumination compensation, information of a neighboring block or information of a block in views different from a view of the current block may be used, and an offset value of the current block may also be used.
In this case, the offset value of the current block is indicative of a difference value between an average pixel value of the current block and an average pixel value of a reference block corresponding to the current block. As an example for using the above-mentioned offset value, a predictor of the current-block offset value may be obtained by using the neighboring blocks of the current block, and a residual value between the offset value and the predictor may be used. Therefore, the decoder can reconstruct the offset value of the current block using the residual value and the predictor.
In order to obtain the predictor of the current block, information of the neighboring blocks may be used as necessary.
For example, the offset value of the current block can be predicted by using the offset value of a neighboring block. Prior to predicting the current-block offset value, it is determined whether the reference index of the current block is equal to a reference index of the neighboring blocks. According to the determined result, the illumination compensation unit 18 can determine which one of neighboring blocks will be used or which value will be used.
The illumination compensation unit 18 may perform the illumination compensation using a prediction type of the current block. If the current block is predictively encoded by two reference blocks, the illumination compensation unit 18 may obtain an offset value corresponding to each reference block using the offset value of the current block.
As described above, the inter-predicted pictures or intra-predicted pictures acquired by the illumination compensation and motion compensation are selected according to a prediction mode, and reconstructs the current picture.
A variety of examples of encoding/decoding methods for reconstructing a current picture are described later in this document. FIG. 2 is a structural diagram illustrating a sequence parameter set RBSP syntax.
Referring to FIG. 2 , a sequence parameter set is indicative of header information including information (e.g., a profile, and a level) associated with the entire-sequence encoding.
The entire compressed sequence can begin at a sequence header, such that a sequence parameter set corresponding to the header information arrives at the decoder earlier than data referring to the parameter set. As a result, the sequence parameter set (RBSP) acts as header information associated with resultant data of compressed moving images at step S 1 . If the bitstream is received, “profile_idc” information determines which one of profiles from among several profiles corresponds to the received bitstream at step S 2 . For example, if “profile_idc” is set to “66”, this indicates the received bitstream is based on a baseline profile. If “profile_idc” is set to “77”, this indicates the received bitstream is based on a main profile. If “profile_idc” is set to “88”, this indicates the received bitstream is based on an extended profile. A step S 3 uses the syntax “If (profile_idc)==MULTI_VIEW_PROFILE)” to determine whether the received bitstream relates to a multiview profile.
If the received bitstream relates to the multiview profile at step S 3 , a variety of information of the multiview sequence can be added to the received bitstream.
The “reference_view” information represents a reference view of an entire view, and may add information associated with the reference view to the bitstream. Generally, the MVC technique encodes or decodes a reference view sequence using an encoding scheme capable of being used for a single sequence (e.g., the H.264/AVC codec). If the reference view is added to the syntax, the syntax indicates which one of views from among several views will be set to the reference view.
A base view acting as an encoding reference acts as the above-mentioned reference view. Images of the reference-view are independently encoded without referring to an image of another-view.
The number of views (num_views) may add specific information indicating the number of multiview captured by several cameras. The view number (num_views) of each sequence may be set in various ways. The “num_views” information is transmitted to an encoder and a decoder, such that the encoder and the decoder can freely use the “num_views” information at step S 5 .
Camera arrangement (view_arrangement) indicates an arrangement type of cameras when a sequence is acquired. If the “view_arrangement” information is added to the syntax, the encoding process can be effectively performed to be appropriate for individual arrangements. Thereafter, if a new encoding method is developed, different “view_arrangement” information can be used.
The number of frames “temporal_units_size” indicates the number of successively encoded/decoded frames of each view. If required, specific information indicating the number of frames may also be added. In more detail, provided that a current N-th view is being encoded/decoded, and a M-th view will be encoded/decoded at the next time, the “temporal_units_size” information indicates how many frames will be firstly processed at the N-th view and the M-th view will be then processed. By the “temporal_units_size” information and the “num_views” information, the system can determine which one of views from among several views corresponds to each frame. If a first length from the I slice to the P slice of each view sequence, a second length between the P slices, or the length corresponding to a multiple of the first or second length is set to the “temporal_units_size” information, the “temporal_units_size” information may be processed at only one view, and may go to the next view. The “temporal_units_size” information may be equal to or less than the conventional GOP length. For example, FIGS. 4B˜4C show the GGOP structure for explaining the “temporal_units_size” concept. In this case, in FIG. 4B , the “temporal_units_size” information is set to “3”. In FIG. 4C , the “temporal_units_size” information is set to “1”.
In some examples, the MVC method arranges several frames on a time axis and a view axis, such that it may process a single frame of each view at the same time value, and may then process a single frame of each view at the next time value, corresponding to a “temporal_units_size” of “1”. Alternatively, the MVC method may process N frames at the same view, and may then process the N frames at the next view, corresponding to a “temporal_units_size” of “N”. Since generally at least one frame is processed, “temporal_units_size_minus1” may be added to the syntax to represent how many additional frames are processed. Thus, the above-mentioned examples may be denoted by “temporal_units_size_minus1=0” and “temporal_units_size_minus1=N−1”, respectively, at step S 7 .
The profiles of the conventional encoding scheme have no common profile, such that a flag is further used to indicate compatibility. “constraint_set*_flag” information indicates which one of profiles can decode the bitstream using a decoder. “constraint_set0_flag” information indicates that the bitstream can be decoded by a decoder of the baseline profile at step S 8 . “constraint_set1_flag” information indicates that the bitstream can be decoded by a decoder of the main profile at step S 9 . “constraint_set2_flag” information indicates that the bitstream can be decoded by a decoder of the extended profile at step S 10 . Therefore, there is need to define the “MULTI_VIEW_PROFILE” decoder, and the “MULTI_VIEW_PROFILE” decoder may be defined by “constraint_set4_flag” information at step S 11 .
The “level_idc” information indicates a level identifier. The “level” generally indicates the capability of the decoder and the complexity of bitstream, and relates to technical elements prescribed in the above-mentioned profiles at step S 12 .
The “seq_parameter_set_id” information indicates SPS (Sequence Parameter Set) ID information contained in the SPS (sequence parameter set) in order to identify sequence types at step S 13 .
FIG. 3A is a structural diagram illustrating a bitstream including only one sequence.
Referring to FIG. 3A , the sequence parameter set (SPS) is indicative of header information including information (e.g., a profile, and a level) associated with the entire-sequence encoding. The supplemental enhancement information (SEI) is indicative of supplementary information, which is not required for the decoding process of a moving-image (i.e., sequence) encoding layer. The picture parameter set (PPS) is header information indicating an encoding mode of the entire picture. The I slice performs only an intra coding process. The P slice performs the intra coding process or the inter prediction coding process. The picture delimiter indicates a boundary between video pictures. The system applies the SPS RBSP syntax to the above-mentioned SPS. Therefore, the system employs the above-mentioned syntax during the generation of the bitstream, such that it can add a variety of information to a desired object.
FIG. 3B is a structural diagram illustrating a bitstream including two sequences.
Referring to FIG. 3B , the H.264/AVC technology can handle a variety of sequences using a single bitstream. The SPS includes SPS ID information (seq_parameter_set_id) in the SPS so as to identify a sequence. The SPS ID information is prescribed in the PPS (Picture Parameter Set), such that which one of sequences includes the picture. Also, the PPS ID information (pic_parameter_set_id) is prescribed in the slice header, such that the “pic_parameter_set_id” information can identify which one of PPSs will be used.
For example, a header of the slice # 1 of FIG. 3B includes PPS ID information (pic_parameter_set_id) to be referred, as denoted by {circle around ( 1 )}. The PPS# 1 includes the referred SPS ID information (SPS=1), as denoted by {circle around ( 2 )}. Therefore, it can be recognized that the slice # 1 belongs to the sequence # 1 . In this way, it can also be recognized the slice # 2 belongs to the sequence # 2 , as denoted by {circle around ( 3 )} and {circle around ( 4 )}. Indeed, the baseline profile and the main profile are added and edited to create a new video bitstream. In this case, two bitstreams are assigned different SPS ID information. Any one of the two bitstreams may also be converted into a multiview profile as necessary.
FIG. 4A shows an exemplary Group Of GOP (GGOP) structure. FIG. 4B and FIG. 4C shows a GGOP structure for explaining a “temporal_units_size” concept. The GOP is indicative of a data group of some pictures. In order to effectively perform the encoding process, the MVC uses the GGOP concept to perform spatial prediction and temporal prediction.
If a first length between the I slice and the P slide of each view-sequence, a second length between the P slices, or a third length corresponding to a multiple of the first or second length is set to the “temporal_units_size” information, the “temporal_units_size” information may be processed at only one view, and may go to the next view. The “temporal_units_size” information may be equal to or less than the conventional GOP length. For example, in FIG. 4B , the “temporal_units_size” information is set to “3”. In FIG. 4C , the “temporal_units_size” information is set to “1”. Specifically, in FIG. 4B , if the “temporal_units_size” information is denoted by “temporal_units_size>1”, and one or more views begin at the I frame, (temporal_units_size+1) frames can be processed. Also, the system can recognize which one of views from among several views corresponds to each frame of the entire sequence by referring to the above-mentioned “temporal_units_size” and “num_views” information.
In FIG. 4A , individual frames are arranged on a time axis and a view axis. Pictures of V 1 ˜V 8 indicate a GOP respectively. The V 4 acting as a base GOP is used as a reference GOP of other GOPs. If the “temporal_units_size” information is set to “1”, the MVC method processes frames of individual views at the same time zone, and then can re-process the frames of the individual views at the next time zone. Picture of T 1 ˜T 4 indicate frames of individual views at the same time zone. In other words, the MVC method can firstly process the T 1 frames, and then can process a plurality of frames in the order of T 4 →T 2 →T 3 → . . . . If the “temporal_units_size” information is set to “N”, the MVC method may firstly process N frames in the direction of the time axis within a single view, and may process the N frames at the next view. In other words, if the “temporal_units_size” information is set to “4”, the MVC method may firstly process frames contained in the T 1 ˜T 4 frames of the V 4 GOP, and then may process a plurality of frames in the order of V 1 →V 2 →V 3 → . . . .
Therefore, in the case of generating the bitstream in FIG. 4A , the number of views (num_views) is set to “8”, the reference view is set to the V 4 GOP (Group Of Pictures) The number of frames (temporal_units_size) indicates the number of successively encoded/decoded frames of each view. Therefore, if the frames of each view are processed at the same time zone in FIG. 4A , the “temporal_unit_size” information is set to “1”. If the frames are processed in the direction of the time axis within a single view, the “temporal_unit_size” information is set to “N”. The above-mentioned information is added to the bitstream generating process.
FIG. 5 is a flow chart illustrating a method for decoding a video sequence.
Referring to FIG. 8 , one or more profile information is extracted from the received bitstream. In this case, the extracted profile information may be at least one of several profiles (e.g., the baseline profile, the main profile, and the multiview profile). The above-mentioned profile information may be changed according to input video sequences at step S 51 . At least one configuration information contained in the above-mentioned profile is extracted from the extracted profile information. For example, if the extracted profile information relates to the multiview profile, one or more configuration information (i.e., “reference_view”, “num_views”, “view_arrangement”, and “temporal_units_size” information) contained in the multiview profile is extracted at step S 53 . In this way, the above-mentioned extracted information is used for decoding the multiview-coded bitstream.
FIGS. 6A-6B are conceptual diagrams illustrating a multiview-sequence prediction structure according to a first example.
Referring to FIGS. 6A-6B , provided that the number (m) of several viewpoints (i.e., multiview number) is set to 2 n (i.e., m=2 n ), if n=0, the multiview number (m) is set to “1”. If n=1, the multiview number (m) is set to “2”. If n=2, the multiview number (m) is set to “4”. If n=3, the multiview number (m) is set to “8”. Therefore, if the multiview number (m) is set to 2 n−1 <m≦2 n , the bitstream includes a single base-view bitstream and n hierarchical auxiliary-view bitstreams.
Specifically, the term “base view” is indicative of a reference view from among several viewpoints (i.e., the multiview). In other words, a sequence (i.e., moving images) corresponding to the base view is encoded by general video encoding schemes (e.g., MPEG-2, MPEG-4, H.263, and H.264, etc.), such that it is generated in the form of an independent bitstream. For the convenience of description, this independent bitstream is referred to as a “base-view bitstream”.
The term “auxiliary view” is indicative of the remaining view other than the above-mentioned base view from among several viewpoints (i.e., the multiview). In other words, the sequence corresponding to the auxiliary view forms a bitstream by performing disparity estimation of the base-view sequence, and this bitstream is referred to as “auxiliary-view bitstream”.
In the case of performing a hierarchical encoding process (i.e., a view scalability process) between several viewpoints (i.e., the multiview), the above-mentioned auxiliary-view bitstream is classified into a first auxiliary-view bitstream, a second auxiliary-view bitstream, and a n-th auxiliary-view bitstream.
The term “bitstream” may include the above-mentioned base-view bitstream and the above-mentioned auxiliary-view bitstream as necessary.
For example, if the multiview number (m) is set to “8” (n=3), the bitstream includes a single base-view and three hierarchical auxiliary-views. If the bitstream includes the single base-view and n hierarchical auxiliary-views, it is preferable that a location to be the base-view from among the multiview and a location to be each hierarchical auxiliary-view are defined by general rules. For reference, square areas of FIGS. 6A-6B indicate individual viewpoints. As for numerals contained in the square areas, the number “0” is indicative of a base-view, the number “1” is indicative of a first hierarchical auxiliary-view, the number “2” is indicative of a second hierarchical auxiliary-view, and the number “3” is indicative of a third hierarchical auxiliary-view. In this example of FIGS. 6A-6B , a maximum of 8 viewpoints are exemplarily disclosed as the multiview video sequence, however, it should be noted that the multiview number is not limited to “8” and any multiview number is applicable to other examples as necessary.
Referring to FIG. 6A , respective base-views and respective auxiliary-views are determined by the following rules. Firstly, the location of the base-view is set to a 2 n−1 -th view. For example, if n=3, the base-view is set to a fourth view. FIGS. 6A-6B shows an exemplary case in which the beginning view is located at the rightmost side. A specific view corresponding to a fourth order from the rightmost view 61 is used as the base-view. Preferably, the base-view location may be located at a specific location in the vicinity of a center view from among the multiview or may be set to the center view from among the multiview, because the base-view may be used as a reference for performing the predictive coding (or predictive encoding) process of other auxiliary-views.
For another example, the leftmost view is always set to the beginning view, and the number (m) of viewpoints (i.e., the multiview number) may be arranged in the order of m=0→m=1→m=2→m=3, . . . . For example, if n=3, the 2 n−1 -th multiview number (i.e., m=4) may be set to the base-view.
The first hierarchical auxiliary-view location may be set to a left-side view spaced apart from the abovementioned base-view by a 2 n−2 -th magnitude, or a right-side view spaced apart from the above-mentioned base-view by the 2 n−2 -th magnitude. For example, FIG. 6A shows an exemplary case in which a viewpoint spaced apart from the base view in the left direction by the 2 n−2 -th view (i.e., two viewpoints is case of n=3) is determined to be the first hierarchical auxiliary-view. Otherwise, FIG. 6B shows an exemplary case in which a viewpoint spaced apart from the base view in the right direction by the 2 n−2 -th view is determined to be the first hierarchical auxiliary-view. In the above-mentioned example, the number of the first hierarchical auxiliary-view is set to “1”.
The second hierarchical auxiliary-view location may be set to left-side view spaced apart from the base-view by a 2 n−2 -th magnitude, or a right-side view spaced apart from the first hierarchical auxiliary-view by the 2 n−2 -th magnitude. For example, the above-mentioned case of FIG. 6A generates two second hierarchical auxiliary-views. Since the above-mentioned case of FIG. 6B has no view spaced apart from the first hierarchical auxiliary-view in the right direction by 2 n−2 -th magnitude, a viewpoint spaced apart from the base-view in the left direction by the 2 n−2 -th magnitude is determined to be the second hierarchical auxiliary-view.
A viewpoint spaced apart from the second hierarchical auxiliary-view in the left direction by the 2 n−2 -th magnitude may also be determined to be the second hierarchical auxiliary-view 63 . However, if the viewpoint corresponds to both ends of the multiview, the abovementioned viewpoint may be determined to the third hierarchical auxiliary-view. One or two second hierarchical auxiliary-views may be generated in the case of FIG. 6B .
Finally, the third hierarchical auxiliary-view location is set to the remaining viewpoints other than the above-mentioned viewpoints having been selected as the base-view and the first and second hierarchical auxiliary-views. In FIG. 6A , four third hierarchical auxiliary-views are generated. In FIG. 6B , four or five third hierarchical auxiliary-views are generated.
FIGS. 7A-7B are conceptual diagrams illustrating a multiview-sequence prediction structure according to a second example.
The second example of FIGS. 7A-7B is conceptually similar to the above-mentioned first example of FIGS. 6A-6B , however, it should be noted that FIGS. 7A-7B show that the beginning-view for selecting the base-view is located at the leftmost side, differently from FIGS. 6A-6B . In other words, a fourth view spaced apart from the leftmost side 65 is selected as the base-view. In FIGS. 7A-7B , the remaining parts other than the above-mentioned difference are the same as those of FIGS. 6A-6B .
FIG. 8 is a conceptual diagram illustrating a multiview-sequence prediction structure according to a third example.
The third example of FIG. 8 shows an exemplary case in which the multiview number (m) is set to 2 n−1 <m≦2 n . In more detail, FIG. 8 shows a variety of cases denoted by m=5, m=6, m=7, and m=8. If m=5, 6, and 7, the multiview number (m) does not satisfy the condition of m=2 n , such that the system has difficulty in implementing the abovementioned first example of FIGS. 6A-6B and the abovementioned second example of FIGS. 7A-7B without any change. In order to solve the above-mentioned problem, the system applies a virtual-view concept, such that the abovementioned problem is obviated by the virtual-view concept.
For example, if 2 n−1 <m<2 n , 2 n −m virtual-views are generated. If the multiview number (m) is an odd number, (2 n −m+1)/2 virtual-views are generated at the left side (or the right side) of the multiview arrangement, and (2 n −m−1)/2 virtual-views are generated at the right side (or the left side) of the multiview arrangement. If the multiview number (m) is an even number, (2 n −m)/2 virtual-views are generated at the left side and the right side of the multiview arrangement, respectively. And then, the abovementioned prediction structure can be applied with the resultant virtual views in the same manner.
For example, if the multiview number (m) is set to “5”, the multiview of m=8 is virtually formed by adding one or two virtual-views to both ends of the multiview, respectively, and the base-view location and three hierarchical auxiliary-view locations are selected. As can be seen from FIG. 8 , two virtual-views are added to the end of the left side, and a single virtual-view is added to the end of the right side, such that the base-view and the first to third hierarchical auxiliary-views are selected according to the above-mentioned example of FIG. 6A .
For example, if the multiview number (m) is set to “6”, the multiview of m=8 is virtually formed by adding a single virtual-view to both ends of the multiview, and the base-view location and three hierarchical auxiliary-view locations are selected, respectively. As can be seen from FIG. 8 , the base-view and the first to third hierarchical auxiliary-views are selected according to the abovementioned example of FIG. 6A .
For example, if the multiview number (m) is set to “7”, the multiview of m=8 is virtually formed by adding a single virtual-view to any one of both ends of the multiview, and the base-view location and three hierarchical auxiliary-view locations are selected, respectively. For example, as shown in FIG. 8 , a single virtual-view is added to the end of the left side, such that the base-view and the first to third hierarchical auxiliary-views are selected according to the abovementioned example of FIG. 6A .
FIGS. 9A-9B are conceptual diagrams illustrating a hierarchical prediction structure between several viewpoints of multiview sequence data. For example, FIG. 9A shows the implementation example of the case of FIG. 6A , and FIG. 9B shows the implementation example of the case of FIG. 7A . In more detail, if the multiview number (m) is set to “8”, the base-view and three hierarchical auxiliary-views are provided, such that the hierarchical encoding (or “view scalability”) between several viewpoints is made available during the encoding of the multiview sequence.
Individual pictures implemented by the abovementioned hierarchical auxiliary-view bitstreams are estimated/predicted on the basis of a picture of the base-view and/or a picture of an upper hierarchical auxiliary-view image, such that the encoding of the resultant pictures is performed. Specifically, the disparity estimation is generally used as the above-mentioned estimation.
For example, the first hierarchical auxiliary-view 92 performs the estimation/encoding process between viewpoints (i.e., estimation/encoding process of the multiview) by referring to the base-view 91 . The second hierarchical auxiliary-views ( 93 a and 93 b ) perform the estimation/encoding process between viewpoints by referring to the base-view 91 and/or the first hierarchical auxiliary-view 92 . The third hierarchical auxiliary-views ( 94 a , 94 b , 94 c , and 94 d ) perform the estimation/encoding process between viewpoints by referring to the base-view and the first hierarchical auxiliary-view 92 , and/or the second hierarchical auxiliary-views ( 93 a and 93 b ). In association with the above-mentioned description, the arrows of drawings indicate progressing directions of the above-mentioned estimation/encoding process of the multiview, and it can be recognized that auxiliary streams contained in the same hierarchy may refer to different views as necessary. The above-mentioned hierarchically-encoded bitstream is selectively decoded in the reception end according to display characteristics, and a detailed description thereof will be described later with reference to FIG. 12 .
Generally, the prediction structure of the encoder may be changed to another structure, such that the decoder can easily recognize the prediction structure relationship of individual view images by transmission of information indicating the relationship of individual views. Also, specific information, indicating which one of levels from among the entire view hierarchy includes the individual views, may also be transmitted to the decoder.
Provided that the view level (view_level) is assigned to respective images (or slices), and a dependency relationship between the view images is given, even if the prediction structure is changed in various ways by the encoder, the decoder can easily recognize the changed prediction structure. In this case, the prediction structure/direction information of the respective views may be configured in the form of a matrix, such that the matrix-type prediction structure/direction information is transmitted to a destination. In other words, the number of views (num_view) is transmitted to the decoder, and the dependency relationship of the respective views may also be represented by a two-dimensional (2D) matrix.
If the dependency relationship of the views is changed in time, for example, if the dependency relationship of first frames of each GOP is different from that of other frames of the remaining time zones, the dependency-relationship matrix information associated with individual cases may be transmitted.
FIGS. 10A-10B are conceptual diagrams illustrating a prediction structure of two-dimensional (2D) multiview sequence according to a fourth example.
The above-mentioned first to third examples have disclosed the multiview of a one-dimensional array as examples. It should be noted that they can also be applied to two-dimensional (2D) multiview sequence as necessary.
In FIGS. 10A-10B , squares indicate individual views arranged in the form of a 2D, and numerals contained in the squares indicate the relationship of hierarchical views.
For example, if the square number is configured in the form of “A-B”, “A” indicates a corresponding hierarchical auxiliary-view, and “B” indicates priority in the same hierarchical auxiliary-view.
As for numerals contained in the square areas, the number “0” is indicative of a base-view, the number “1” is indicative of a first hierarchical auxiliary-view, the number “2-1” or “2-2” is indicative of a second hierarchical auxiliary-view, the number “3-1” or “3-2” is indicative of a third hierarchical auxiliary-view, the number “4-1”, “4-2” or “4-3” is indicative of a fourth hierarchical auxiliary-view, and the number “5-1”, “5-2”, or “5-3” is indicative of a fifth hierarchical auxiliary-view.
In conclusion, in the case of generating a bitstream by encoding images acquired from the two-dimensional (2D) multiview, if the 2D multiview number (m) on a horizontal axis is 2 n−1 <m≦2 n and the 2D multiview number (p) on a vertical axis is 2 k−1 <p≦2 k , the above-mentioned bitstream includes a single base-view bitstream and (n+k) hierarchical auxiliary-view bitstreams.
In more detail, the above-mentioned (n+k) hierarchical auxiliary-views are formed alternately on the horizontal axis and the vertical axis. For example, a first hierarchical auxiliary-view from among the (n+k) hierarchical auxiliary-views in FIG. 10A is positioned at the vertical axis including the base-view. A first hierarchical auxiliary-view from among the (n+k) hierarchical auxiliary-views in FIG. 10B is positioned at the horizontal axis including the base-view.
For example, as shown in FIG. 10A , if the multiview number of the horizontal axis (m) is set to “8” (i.e., n=3), and the multiview number of the vertical axis (p) is set to “4” (i.e., k=2), the bitstream includes a single base-view and five hierarchical auxiliary-views. In association with the above-mentioned description, FIG. 10A shows that the hierarchical auxiliary-views are selected in the order of “vertical axis→horizontal axis→vertical axis→ . . . ”. A method for determining locations of the base-view and the auxiliary-views will hereinafter be described as follows.
Firstly, the base-view location is determined in the same manner as in the above-mentioned one-dimensional array. Therefore, the base-view location is determined to be a specific view corresponding to a 2 n−1 -th location in the direction of the horizontal axis and 2 k−1 -th location in the direction of the vertical axis.
The first hierarchical auxiliary-view location is determined to be a top-side view or bottom-side view spaced apart from the base-view location in the direction of the vertical axis by the 2 k−2 -th magnitude, as denoted by {circle around ( 1 )}. The second hierarchical auxiliary-view locations are determined to be left-side views, as denoted by {circle around ( 2 )} or right-side views spaced apart from the base-view location and the first hierarchical auxiliary-view in the direction of the horizontal axis by the 2 n−2 -th magnitude. The third hierarchical auxiliary-view locations are determined to be the remaining views contained in the vertical axes including not only the first and second hierarchical auxiliary-views but also the base-view. The fourth hierarchical auxiliary-view location is determined to be a left-side view or right-side view spaced apart from the first to third hierarchical auxiliary-views and the base-view in the direction of the horizontal axis by the 2 n−2 -th magnitude. Finally, the fifth hierarchical auxiliary-view locations are determined to be the remaining views other than the base-view and the first to fourth hierarchical auxiliary-views.
For example, as can be seen from FIG. 10B , if the multiview number of the horizontal axis (m) is set to “8” (i.e., n=3), and the multiview number of the vertical axis (p) is set to “4” (i.e., k=2), the bitstream includes a single base-view and five hierarchical auxiliary-views. In association with the above-mentioned description, FIG. 10B shows that the hierarchical auxiliary-views are selected in the order of “horizontal axis→vertical axis→horizontal→ . . . ”. A method for determining locations of the base-view and the auxiliary-views will hereinafter be described as follows.
Firstly, the base-view location is determined in the same manner as in the above-mentioned one-dimensional array. Therefore, the base-view location is determined to be a specific view corresponding to a 2 n−1 -th location in the direction of the horizontal axis and 2 k−1 -th location in the direction of the vertical axis.
The first hierarchical auxiliary-view location is determined to be a left-side view or right-side view spaced apart from the base-view location in the direction of the horizontal axis by the 2 n−2 -th magnitude, as denoted by {circle around ( 1 )}. The second hierarchical auxiliary-view locations are determined to be top-side views, as denoted by {circle around ( 2 )} or bottom-side views spaced apart from the base-view and the first hierarchical auxiliary-view in the direction of the vertical axis by the 2 k−1 -th magnitude. The third hierarchical auxiliary-view locations are determined to be left- and right-direction views spaced apart from the base-view and the first to second hierarchical auxiliary-views in the direction of the horizontal axis by the 2 n−2 -th magnitude. The fourth hierarchical auxiliary-view locations are determined to be the remaining views contained in the vertical axes including not only the first to third hierarchical auxiliary-views but also the base-view. Finally, the fifth hierarchical auxiliary-view locations are determined to be the remaining views other than the base-view and the first to fourth hierarchical auxiliary-views.
FIGS. 11A-11C are conceptual diagrams illustrating a multiview-sequence prediction structure according to a fifth example. The fifth example of FIGS. 11A-11C has prediction-structure rules different from those of the above-mentioned first to fourth examples. For example, the square areas of FIGS. 11A-11C indicate individual views, however, numerals contained in the square areas indicate the order of prediction of the views. In other words, as for numerals contained in the square areas, the number “0” is indicative of a first predicted view (or a first view), the number “1” is indicative of a second predicted view (or a second view), the number “2” is indicative of a third predicted view (or a third view), and the number “3” is indicative of a fourth predicted view (or a fourth view).
For example, FIG. 11A shows decision formats of the first to fourth views in case the multiview number (m) is denoted by m=1˜m=10. The first to fourth views are determined by the following rules.
For example, both ends of the multiview are set to the first view ( 0 ), and the center view from among the multiview is set to the second view ( 1 ). Views successively arranged by skipping over at least one view in both directions on the basis of the second view ( 1 ) are set to the third views ( 2 ), respectively. The remaining views other than the first to third views are set to the fourth views ( 3 ), respectively. If the first to fourth views are determined as described above, there is a need to discriminate between the base-view and the auxiliary-view. For example, any one of the first view, the second view, and third view is set to the base-view, and the remaining views other than the base-view may be set to the auxiliary-views.
Provided that the base-view is not determined by the prescribed rules described above and is arbitrarily selected by the encoder, identification (ID) information (i.e., “base_view_position”) of the base-view location may be contained in the bitstream.
FIG. 11B shows another example of the decision of the second view ( 1 ). In more detail, FIG. 11B shows another example different from the example of FIG. 11A , such that it shows an exemplary case in which the remaining views other than the first view ( 0 ) are set to even numbers. In other words, if m=4, m=6, m=8, or m=10, the second view ( 1 ) of FIG. 11B may be different from the second view ( 1 ) of FIG. 11A as necessary. For another example, in the case of determining views located after the second view ( 1 ), upper views may be determined by sequentially skipping over a single view on the basis of the leftmost first view ( 0 ).
In association with the above-mentioned description, FIG. 11C shows an exemplary case in which the multiview number (m) is 10 (i.e., m=10), and the base-view from among the multiview is denoted by “base_view_position=‘1’ view” (corresponding to a sixth view) by the base-view ID information. For example, as can be seen from FIG. 11C , the first hierarchical auxiliary-view is set to the third view ( 2 ), the second hierarchical auxiliary-view is set to the first view ( 0 ), and the third hierarchical auxiliary-view is set to the fourth view ( 3 ).
In association with the above-mentioned description, in FIGS. 11A-11B , the base-view may also be set to the first view ( 1 ) as shown in FIG. 11C . The reason is that if the base-view is located at a specific location in the vicinity of the center part of the multiview, or is located at the center part of the multiview, the estimation/encoding process of other auxiliary-views can be effectively performed. Therefore, the base-view location and the auxiliary-view location can be determined according to the following rules.
In other words, the base-view location is set to the center view ( 1 ) of the multiview, the second auxiliary-view location is set to both-end views ( 0 ) of the multiview, and the first auxiliary-view location is set to the view ( 2 ) successively arranged by skipping over at least one view in both directions on the basis of the base-view. The remaining views ( 3 ) other than the above-mentioned views are all set to the third auxiliary-views.
In association with the above-mentioned description, if the multiview number (m) is equal to or less than “7” (i.e., m≦7), only two or less views are arranged between the base-view ( 1 ) and the second auxiliary-view ( 0 ), all the views arranged between the base-view ( 1 ) and the second auxiliary-view ( 0 ) are set to the first auxiliary-views ( 2 ), respectively.
If the multiview number (m) is equal to or more than “8” (i.e., m≧8) and only two or less views are arranged between the second auxiliary-view ( 0 ) and the first auxiliary-view ( 2 ), all the views arranged between the second auxiliary-view ( 0 ) and the first auxiliary-view ( 2 ) are set to the third auxiliary-views ( 3 ), respectively.
For example, as depicted in FIGS. 11A-11B , if m=8, m=9, and m=10, it can be recognized that one or two views located between the second auxiliary-view ( 0 ) and the first auxiliary-view ( 2 ) are set to the third auxiliary-views ( 3 ), respectively.
For another example, if only two or less views are located between the base-view ( 1 ) and the second auxiliary-view ( 0 ), all the views arranged between the base-view ( 1 ) and the second auxiliary-view ( 0 ) may be set to the third auxiliary-views ( 3 ), respectively. For example, as shown in FIGS. 11A˜11B , if m=8, it can be recognized that two views located between the base-view ( 1 ) and the second auxiliary-view ( 0 ) are set to the third auxiliary-views ( 3 ), respectively.
Using the base-view and the auxiliary-views determined by the above-mentioned method, the view scalability between views (or viewpoints) can be performed.
For example, if the multiview number (m) is equal to or less than “7” (i.e., m≦7), a single base-view stream and two hierarchical auxiliary-view bitstreams are generated. For example, the second auxiliary-view ( 0 ) can be set to the first hierarchical auxiliary-view, and the first auxiliary-view ( 2 ) can also be set to the second hierarchical auxiliary-view.
For example, if the multiview number (m) is equal to or higher than “8” (i.e., m≧8), i.e., if m=8, m=9, or m=10, a single base-view bitstream and three hierarchical auxiliary-view bitstreams are generated. For example, the first auxiliary-view ( 2 ) is selected as the first hierarchical auxiliary-view, the second auxiliary-view ( 0 ) is selected as the first hierarchical auxiliary-view, and the third auxiliary-view ( 3 ) is selected as the third hierarchical auxiliary-view.
FIG. 12 is a conceptual diagram illustrating a hierarchical method of encoding/decoding a multiview sequence.
Referring to FIG. 12 , the encoder of a transmission end performs the view scalability function of the multiview sequence using modified methods which may be predicted by the first through fifth embodiments and methods shown in the first to fifth examples, for generating a bitstream, and transmits the bitstream to the reception end.
Therefore, the decoding method or apparatus receives the bitstream formed by the above-mentioned characteristics, decodes the received bitstream, and generates decoded data for each hierarchy. Thereafter, according to the selection of a user or display, a variety of displays can be implemented, using data decoded by each hierarchy.
For example, a base layer 121 for reproducing data of only the base-view is appropriate for the 2D display 125 . A first enhancement layer # 1 ( 122 ) for reproducing data of the base-view and data of the first hierarchical auxiliary-view together is appropriate for a stereo-type display 126 formed by a combination of two 2D images. A second enhancement layer # 2 ( 123 ) for reproducing data of the base-view, data of the first hierarchical auxiliary-view, and data of the second hierarchical auxiliary-view together is appropriate for a low multiview display 127 for 3D-reproduction of the multiview sequence. A third enhancement layer # 3 ( 124 ) for reproducing data of the base-view and data of all hierarchical auxiliary-views together is appropriate for a high multiview display 128 for 3D-reproduction of the multiview sequence.
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Decoding a multiview video signal comprises receiving a bitstream comprising the multiview video signal encoded according to dependency relationships between respective views, and view-dependency information representing the dependency relationships in a two-dimensional data structure; extracting the two-dimensional data structure and determining the dependency relationships from the extracted data structure; and decoding the multiview video signal according to the determined dependency relationships.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a power transmission device. More particularly, the present invention relates to a power transmission device capable of transmitting an input power to a next-stage member (including an attachment), which can be suitably used for driving a robot wrist.
[0003] 2. Description of the Related Art
[0004] A power transmission device disclosed in Japanese Patent Laid-Open Publication No. 2002-61720 is conventionally known. This power transmission device has an output shaft in the shape of a flange and can be directly attached to a next-stage member (e.g., an attachment of an industrial robot).
[0005] FIGS. 4A, 4B , and 4 C show a power transmission device 290 having approximately the same structure as the aforementioned conventional power transmission device disclosed in Japanese Patent Laid-Open Publication No. 2002-61720. FIG. 4A is a front view of the power transmission device 290 , FIG. 4B is a cross-sectional view thereof, taken along the line IVB-IVB in FIG. 4A , and FIG. 4C is a rear view thereof.
[0006] The power transmission device 290 includes an input shaft 260 , an eccentric body 240 that is rotated in an eccentric manner by rotation of the input shaft 260 , a bearing 230 for the eccentric body that transmits the eccentric rotation of the eccentric body 240 , an external gear 238 that is fitted with the bearing 230 , and an internal gear 234 in which the external gear 238 is inscribed. The internal gear 234 and the external gear 238 engage with each other. There is a small difference between the number of teeth of the internal gear 234 and that of the external gear 238 . The internal gear 234 also serves as a casing 250 .
[0007] The external gear 238 has a plurality of inner pin holes 238 a . An inner pin 236 and an inner roller 232 are freely inserted into each of the inner pin holes 238 a.
[0008] The inner pin 236 is fitted into a first output flange 200 and a second output flange 202 . The first output flange 200 and the second output flange 202 are connected to each other via a carrier bolt 228 .
[0009] The reference numeral 270 in FIG. 4A denotes a mounting hole used for mounting an attachment (not shown) of a robot onto the power transmission device 290 .
[0010] When the input shaft 260 rotates around a shaft center O 4 , the eccentric body 240 provided on an outer circumference of the input shaft 260 also rotates. The rotation of the eccentric body 240 tries to cause oscillating rotation of the external gear 238 around the input shaft 260 . However, the rotation of the external gear 238 is constrained by the internal gear 234 . Therefore, the external gear 238 makes an oscillating movement almost only, while being in contact with the internal gear 234 .
[0011] The oscillating movement component of the oscillating rotation of the external gear 238 is absorbed by the inner pin hole 238 a and the inner pin 236 (and the inner roller 232 ). Only the rotation component generated by the difference between the number of teeth of the external gear 238 and that of the internal gear 234 is transmitted to the attachment via the first output flange 200 .
[0012] When the above-described power transmission device is used especially in an industrial robot, a next-stage member such as an attachment to be mounted onto the power transmission device (hereinafter, simply referred to as an attachment or the like) is inevitably different depending on the purpose of the industrial robot, e.g., welding, transport, or assembly. Thus, the power transmission device should be able to transmit a power to various types of attachment or the like.
[0013] Therefore, when a mounting hole (e.g., a tap) is formed in the output flange of the power transmission device and the attachment or the like is mounted by means of a mounting screw or the like, if another member (e.g., the inner pin or the carrier bolt) is fitted into the output flange, it is inevitably necessary to form the mounting hole at a position other than a position of the other member. Thus, the position of the mounting hole and the number of mounting holes that can be formed are limited (see FIG. 4A ).
[0014] In other words, for some types of attachment or the like to be mounted, the mounting hole cannot be formed while sufficient mounting strength is ensured. Thus, in some cases, it is necessary to use a separate joint flange for connection, or a problem is caused that the power transmission device or a mounting portion of the attachment or the like to be mounted has to be redesigned.
SUMMARY OF THE INVENTION
[0015] In view of the foregoing problems, various exemplary embodiments of this invention provide a power transmission device including an output flange that has a high degree of freedom of design for a mounting hole used for attaching an attachment or the like to the power transmission device, thereby allowing a wider variety of attachment or the like to be directly attached to the power transmission device without using a separate joint flange or redesigning the power transmission device and the like.
[0016] Various exemplary embodiments of the present invention provide a power transmission device for driving a robot wrist. The power transmission device includes an internal gear and an external gear that is inscribed in the internal gear and engages with the internal gear, and can transmit an input power to an attachment. The power transmission device further includes: an inner pin for bringing out a relative rotation component between the internal gear and the external gear; and an output flange connected to the inner pin. In this configuration, the inner pin and the output flange are integrally formed as one member, and a mounting hole for connecting the output flange to the attachment is formed in a surface of the output flange that is opposite to the inner pin.
[0017] According to various exemplary embodiments of the invention, the inner pin and the output flange are integrally formed. Thus, it is possible to avoid a problem in which the mounting hole for attaching the attachment or the like has to be designed at a position other than a position of the inner pin. Therefore, the mounting hole for attaching the attachment or the like can be designed more freely.
[0018] The present invention can be applied to a reducer in which the inner pin is supported at both ends. Moreover, the present invention can be applied to a reducer in which the inner pin projects from the output flange while being supported at one end, as in the aforementioned example, as well as an exemplary embodiment described later. Incidentally, in the reducer in which the inner pin is supported at both ends, the use of a carrier bolt is not denied. However, the inner pin according to various exemplary embodiments of the present invention is integrated with the output flange and has strength that is sufficient to serve as the carrier bolt. Thus, an operation of the present invention can be more significantly achieved by completely eliminating the carrier bolt and making all the pins serve as inner pins.
[0019] In this description, a side closer to a working portion (attachment) in an industrial robot is referred to as a “next stage.”
[0020] According to various exemplary embodiments of the present invention, it is unnecessary to use a separate joint flange in accordance with the attachment or the like or change design of the power transmission device and the like. Furthermore, the power transmission device that is compact, has a good balance of rotation, and has high strength can be designed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a partial cross-sectional view of a whole power transmission device 190 attached to a robot wrist according to an exemplary embodiment of the present invention;
[0022] FIGS. 2A and 2B show the whole power transmission device according to the exemplary embodiment of the present invention,
[0023] FIG. 2A being a front view thereof, and FIG. 2B being a cross-sectional view thereof, taken along the line IIB-IIB in FIG. 2A ;
[0024] FIGS. 3A and 3B show the power transmission device shown in FIGS. 2A and 2B in which a mounting hole for a next-stage member is provided, FIG. 3A being a front view thereof, and FIG. 3B being a cross-sectional view thereof, taken along the line IIIB-IIIB in FIG. 3A ; and
[0025] FIGS. 4A, 4B , and 4 C show a whole power transmission device of a conventional example, FIG. 4A being a front view thereof, FIG. 4B being a cross-sectional view thereof, taken along the line IVB-IVB in FIG. 4A , and FIG. 4C being a rear view thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] An exemplary embodiment of the present invention is now described with reference to the accompanying drawings. In the description and the drawings, components that are the same or similar as/to those in the aforementioned conventional example are labeled with reference numerals in which last two digits are the same as those in the conventional example, and the description of those components is omitted in an appropriate manner. That is, only a difference between the exemplary embodiments of the present invention and the conventional example is described.
[0027] FIG. 1 is a partial cross-sectional view showing a whole power transmission device according to an exemplary embodiment of the present invention. The power transmission device is attached to a robot wrist. In the following description, the robot wrist means a portion including the fourth one of a plurality of axes included in a robot and all the following portions. More specifically, the robot wrist means a portion including an arm portion of the robot formed by basic three axes, i.e., a pivot axis, a back-and-forth axis, and a vertical axis and the following portion (a portion arranged more closely to the attachment).
[0028] A wrist including three joints J 4 , J 5 , and J 6 is provided in a robot arm 154 extended from the arm portion. An attachment 176 is attached to an end of the robot arm 154 . FIG. 1 only shows a part of the attachment 176 . Although three joints are provided in the wrist in the present exemplary embodiment, the number of the joints is not limited thereto. Four or more, or two or less, joints may form the wrist. Each of those joints J 4 , J 5 , and J 6 includes a power transmission device. More specifically, the joint J 4 includes a power transmission device 190 , the joint J 5 includes a power transmission device 490 ( FIG. 1 only shows an appearance thereof), and the joint J 6 includes a power transmission device 390 . The joint J 4 is arranged to be rotatable in an X-direction around a shaft center O 1 , the joint J 5 is arranged to be rotatable in a Y-direction around a shaft center O 2 , and the joint J 6 is arranged to be rotatable in a Z-direction around a shaft center O 3 . According to this structure, cooperating rotation of those joints J 4 , J 5 , and J 6 enables the attachment 176 to be freely manipulated three-dimensionally.
[0029] The power transmission devices 190 , 390 , and 490 respectively included in the joints J 4 , J 5 , and J 6 have the same structure basically, although they are different in detail.
[0030] Next, the power transmission device 190 will be described as a representative of the power transmission devices 190 , 390 , and 490 with reference to FIGS. 2A and 2B . The other power transmission devices 390 and 490 have approximately the same structure as the power transmission device 190 . Therefore, the same or similar components in the power transmission devices 390 and 490 as/to those in the power transmission device 190 are labeled with reference numerals that are the same in last two digits as those in the power transmission device 190 , and redundant description is omitted. FIGS. 2A and 2B show the whole power transmission device 190 . FIG. 2A is a front view thereof, and FIG. 2B is a cross-sectional view thereof, taken along the line IIB-IIB.
[0031] In the present exemplary embodiment, an inner pin 136 and a first output flange (output flange) 100 are integrally formed as one member. Herein, the phrase “be integrally formed as one member” does not mean that a plurality of parts are integrated by fixing them by press fitting, adhesion, or the like but means that they are originally formed with integrity by forging or the like.
[0032] The first output flange 100 integrally formed with the inner pin 136 is connected and fixed to a second output flange 102 (second output flange) via the inner pin 136 by means of a bolt 128 screwed from a side of the second output flange 102 that is opposite to the inner pin 136 . No carrier bolt is used in this arrangement. A first output flange surface 100 a is secured on the first output flange 100 on a side opposite to the inner pin 136 , as shown with hatching in FIG. 2A . The first output flange surface 100 a has nothing formed thereon and is flat. Therefore, a mounting hole can be freely formed in the first output flange surface 100 a in advance or in accordance with a hole position in a next-stage member 131 later. FIGS. 3A and 3B show an example of formation of an exemplary mounting hole 170 .
[0033] An operation of the present exemplary embodiment will now be described. In the following, redundant description is omitted and only a difference between the present exemplary embodiment and the conventional example is described.
[0034] Since the inner pin 136 for transmitting a rotation component of an external gear 138 is formed integrally with the first output flange 100 , the first output flange surface 100 a is secured on the side of the first output flange 100 that is close to the next-stage member 131 (i.e., on the side opposite to the inner pin 136 ) as shown with hatching (see FIG. 2A ). In the exemplary embodiment shown in FIGS. 3A and 3B , screw holes 170 are formed in the first output flange surface 100 a at similar positions to those in FIG. 4A for the sake of convenience. However, the position at which the screw hole 170 is formed is not limited thereto, as is apparent from comparison between FIG. 3A and FIG. 4A . This is because an end face of the inner pin 236 or the carrier bolt 228 that was conventionally located on the first output flange surface 100 a is not located on the first output flange surface 100 a in the present exemplary embodiment.
[0035] Therefore, even if the next-stage member is changed, there are few needs of using a separate joint flange or changing design of the power transmission device in accordance with the next-stage member.
[0036] Especially, in the case of a power transmission device attached and used in a wrist of an industrial robot, it is preferable to make the power transmission device as light and small as possible in order to precisely control the robot (position the robot), secure a wide work range, and save an electric power.
[0037] Therefore, it is highly significant that the degree of freedom of determining the position at which the mounting hole 170 is processed is improved without increasing the weight or the like, as in the present exemplary embodiment.
[0038] Moreover, in the present exemplary embodiment, the first output flange 100 and the second output flange 102 are connected to each other by means of the inner pin 136 only without using a carrier bolt conventionally used. However, the first output flange is integrated with the inner pin 136 and the second output flange is tightly connected to the first output flange by means of the bolt 128 . Therefore, each of the inner pins 136 can sufficiently fulfill a connecting function of the carrier bolt conventionally used.
[0039] In addition, all the inner pins 136 can contribute to power transmission. Therefore, a load applied to each inner pin 136 is reduced because the inner pin 136 is also arranged at a position at which the carrier bolt is conventionally arranged.
[0040] Furthermore, the inner pin 136 and the bolt 128 are arranged evenly in a radial direction. Therefore, the power transmission device that has a good balance of rotation during an operation can be achieved.
[0041] In the present exemplary embodiment, a top end of the inner pin 136 is supported by the second output flange 102 . Alternatively, another arrangement may be employed in which the second output flange is omitted and the inner pin 136 projects from the first output flange 100 while being supported at one end. That is, the arrangement around the top end of the inner pin 136 (the side close to the second output flange in the above exemplary embodiment) is not specifically limited.
[0042] Moreover, the external gear is formed of three pieces in the present exemplary embodiment. However, the structure of the external gear is not necessarily limited thereto. The number of pieces forming the external gear may be selected in accordance with a transmission capacity (e.g., one or two).
[0043] The most significant effect of the present invention can be achieved when the present invention is applied to a power transmission device attached to a wrist of an industrial robot, as described in the exemplary embodiment. A servomotor may be connected with the power transmission device. However, it is apparent that the present invention can be also applied to another type of power transmission device for transmitting a power to another machine.
[0044] The disclosure of Japanese Patent Application No. 2005-86971 filed Mar. 24, 2005 including specification, drawing and claim are incorporated herein by reference in its entirety.
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The power transmission device includes an internal gear and an external gear that is inscribed in the internal gear and engages with the internal gear, and can transmit an input power to an attachment. The power transmission device further includes: an inner pin for bringing out a relative rotation component between the internal gear and the external gear; and an output flange connected to the inner pin. In this configuration, the inner pin and the output flange are integrally formed as one member, and a mounting hole for connecting the output flange to the attachment is formed in a surface of the output flange that is opposite to the inner pin.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the use of specific heterocyclic hydrogen phosphonates as antiwear additives in functional fluids, and the compositions thereby obtained. More particularly, the invention relates to the use of spiro-bis-hydrogen phosphonate and cycloneopentyl glycol hydrogen phosphonate and related products. The functional fluids are particularly synthetic lubricants and/or water-based fluids (rather than petroleum-based products).
2. Prior Art
The use of antiwear additives in functional fluids is extremely old in the art. Spiro-bis-hydrogen phosphonate and cycloneopentyl glycol hydrogen phosphonate are both known in various physical forms. However, neither compound is now known to have been actually used as an antiwear additive in a non-petroleum based functional fluid.
Spiro-bis-hydrogen phosphonate (hereinafter "Compound A") is indexed by Chemical Abstracts Service (CAS) under the name pentaerythritol diphosphite and Register No. 2723-44-6. CAS has apparently indexed only three references, according to a computer search. These are discussed below.
Russian Pat. No. 476,267 describes spiro-bis-hydrogen phosphonate as being a useful intermediate for insecticides and flame-proofing agents. The patent includes a method of preparation that is quite similar to the method used herein. It gave a 100% yield of a white crystalline powder melting at 90°-95° C. (in contrast to about 170° C. in Examples 1B-1D hereinafter).
The CAS reference CA65:10719c is apparently a miscite.
"Pentaerythritol Phosphite Condensation Polymers" by L. Friedman and H. Gould in Am. Chem. Soc., Div. Polymer Chem., Preprints 4(2), 98-101(1963)(Eng) is primarily directed to polymers intended for flame retardant applications. In general, "many of these polymers have interesting properties but were too unstable towards moisture to be effective as materials of construction". However, "they are quite effective as additives in stabilizing other polymer systems, such as polyethylene . . . against oxidative and thermal degradation". All of the polymers were prepared from raw materials including diphenyl pentaerythritol diphosphite, rather than pentaerythritol diphosphite. At least three of the references cited by Friedman and Gould are of interest. In particular, see U.S. Pat. No. 3,053,878 (Friedman and Gould); U.S. Pat. No. 3,047,608 (Friedman and Gould); and U.S. Pat. No. 2,847,443 (Hechenbleikner and Lanoue). However, they do not appear to disclose or suggest the invention claimed hereinafter.
Cycloneopentyl glycol hydrogen phosphonate (hereinafter "Compound B") is old in the art. Three U.S. Patents are discussed below.
U.S. Pat. No. 3,152,164 (Oswald) relates to the preparation of compounds such as Compound B by transesterification of a phosphite diester with a glycol. Oswald suggests that the cyclic organic phosphorus compounds of his invention will be of particular advantage due to their increased thermal and hydrolytic stability as petroleum additives themselves or can be used as starting materials for the preparation of additives (see Col. 2, lines 65-69).
U.S. Pat. No. 2,916,508 (McConnell) describes the preparation of Compound B (shown at Col. 2, line 10). The proposed enduses are merely insecticides, stabilizers for polyesters and artificial resins, fungicides, and other related uses.
U.S. Pat. No. 2,899,455 (Coover et al.) concerns derivatives of Compound B obtained by addition-type reactions. The derivatives are described as being useful as pesticides, plasticizers, solvents, flame-proofing agents and intermediates.
Essentially, nowhere does the now-known aforementioned prior art disclose or suggest that Compound A or Compound B or closely related compounds have utility in water-based functional fluids or synthetic functional fluids.
SUMMARY OF THE INVENTIOn
In contrast to the aforementioned prior art it has now been discovered that certain species of hydrogen phosphonate are eminently suitable for use as additives in water-based functional fluids. Some of the species suitable for water-based applications are also suitable for synthetic functional fluid applications. The broadest aspects of the invention are described in the independent claims hereinafter.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the invention are shown in the claims hereinafter. They are illustrated by the Examples below contrasted to both the prior art and the Comparatives Examples below.
The process of this invention reduces the wear in apparatus having moving parts separated by a functional fluid that is at least 90 percent by weight a non-petroleum base stock, B. It comprises dispersing in B up to 10 percent by weight of an additive comprising a first heterocyclic compound, C1, or a second heterocyclic compound, C2, or mixtures thereof.
Numerous non-petroleum base stocks may be used in this invention. Numerous heterocyclic compounds C1 and/or C2, likewise may be used. It is normally required that the additive C1 and/or C2 be capable of dissolving in B, since this simplifies dispersion.
Preferred variants of B include neat water-based systems; phosphate ester bases; and mixed polyalphaolefin/polyol ester bases.
A preferred variant of C1 is spiro-bis-hydrogen phosphonate (Compound A) which has the following structural formula: ##STR1##
A preferred variant C2 of cycloneopentyl glycol hydrogen phosphonate (Compound B) having the following structural formula: ##STR2##
In general, C1 has the following structural formula: ##STR3## wherein: Y is oxygen or sulfur;
W is hydrogen or an alkali metal; and
m, n, and m plus n, all have values of 0, 1, 2, 3 or 4.
In general, C2 has the following structural formula: ##STR4## wherein: Y, W, m, and n are as defined for C1; and
R 1 -R 6 are individually selected from hydrogen and saturated hydrocarbyl radicals containing from one to 10 carbon atoms.
Methods for preparing Compound A and Compound B are given in the Examples below. Method for preparing other variants of C1 and C2 respectively may be obvious variants of the foregoing method of preparing Compound A and Compound B, as indicated below.
Compounds wherein Y is sulfur rather than oxygen may be prepared by substituting 1 mole of P 2 S 5 for each 2 moles of PCl 3 and using an appropriate catalyst.
Compounds wherein W is an alkali metal such as sodium or potassium, rather than hydrogen, may be prepared by reacting Compound A and/or Compound B with the appropriate metal hydride.
Compounds wherein m, n, and m plus n have values of 1, 2, 3, or 4, may be prepared by replacing pentaerythritol by the corresponding tetrahydroxyl compound.
Compounds wherein R 1 -R 6 are saturated hydrocarbyl radicals rather than hydrogen may be prepared according to the process for preparing Compound B except that 2,2-dimethyl-1,3-propanediol is replaced by the corresponding dialkyl-1,3-propanediol.
The preferred combined amount of C1 and C2 in this invention is a maximum of 5 weight percent. More preferably, it is in the range from 0.5 to 2.5 weight percent. Optimum values within these ranges will depend upon the remaining constituents of the functional fluid.
It should be noted that both Compound A and Compound B hydrolyze slowly in the presence of water. Accordingly, when B is water, it will be necessary to replenish or replace the functional fluid periodically. In practice, this does not pose a problem for many applications.
Preparation of Compounds A and B
Compound A was prepared in a manner similar to that given in the CAS abstract of aforementioned Russian Patent No. 476,267. The synthesis involved esterification of pentaerythritol with PCl 3 to form the spiro-bis chloro phosphite in near quantitive yield. The esterification was run in CHCl 3 solvent with a catalytic quantity of pyridine. The intermediate chlorophosphite was not isolated but treated with t-butanol at 25° C. to give a near quantitative yield of the hydrogen phosphonate. The product was merely filtered from the reaction solution and dried. An earlier experiment under similar conditions indicated that the hydrogen phosphonate was an off-white powder with a m.p. of 172°-175° C. (in contrast to 92°-95° C. as reported in the Russian patent). 31 P-NMR analysis indicated one phosphorus environment. H-NMR indicated P-H and ring protons in a 1:4 ratio respectively. IR showed no OH absorption but a strong P-H bond at 2440 cm -1 . Titration for P III indicated 98.3% of theory.
Compound B was prepared essentially according to aforementioned McConnell's U.S. Pat. No. 2,916,508, Example 2.
Solubility of Compound A and B
Compounds A and B were evaluated for solubility in various functional fluids at room temperature. Compound A was found to be soluble in water, but insoluble in petroleum based oil. Compound B was found to be insoluble in paraffinic oil; but soluble in phosphate ester, polyol ester (short chain), polyalphaolefins, and water.
Comparative Antiwear and Load Bearing Trials
Four comparative trials were performed. Within each trial of several experiments, (1) Compound A or Compound B or a possible competing compound was conventionally dissolved in a given base stock; and (2) the resultant solutions were evaluated for antiwear properties by ASTM D-2266 and/or extreme pressure properties by ASTM D-2783 and/or oxidation corrosion data by Federal Test Method Procedure 791B (Method 5308.6). The base stocks used in these trials were as follows:
(i) Neat High Water Based System
PLURASAFE P 1200 Hydraulic Fluid Concentrate was obtained from BASF Wyandotte Corporation. According to BASF's Technical Bulletin (dated 1983 or earlier) PLURASAFE P 1200 Hydraulic Fluid may be made by adding 1 part of the concentrate to 9 parts of tap water, and stirring with a Lightnin' Mixer or other comparable device. This was done except that distilled water was used. The technical Bulletin states that the so-diluted concentrate is a thickened high water hydraulic fluid ready to use. It has undefined vapor-phase corrosion protection, lubricant additives and anti-corrosive additives as part of its formulation. PLURASAFE P 1200 Hydraulic Fluid is stated to overcome the deficiencies of unthickened high water fluids which are due to low viscosity. Unthickened fluids tend to exhibit low efficiency at high pressure, high leakage rates, and the wire-draw type of erosion.
Typical characteristics of ready-to-use PLURASAFE P 1200 Hydraulic Fluid include the following:
______________________________________Specific Gravity, 100° F. 0.999Viscosity at 100° F., SUS 200 ± 50Freezing Point, °F. 32Boiling Point °F. 212pH at 25° C. 9.8 ± 0.2Reserve Alkalinityml 0.1 N HCl/10 ml sample 5.6(ml 0.IN HCl/50 ml sample) 25-30Flash Point NoneColor Hazy blueOdor Fruity odor______________________________________
The Technical Bulletin also indicates that the optimum temperature for use of PLURASAFE P 1200 Hydraulic Fluid is 100° F. However, any temperature between 80° F. and 120° F. is acceptable.
(ii) Phosphate Ester Base
The phosphate ester base was essentially t-butylphenyldiphenyl phosphate (Stauffer Chemical Company's SOA-8478).
(iii) Mixed Polyalphaolefin/Polyol Ester Base
This base was prepared by conventionally blending four parts of poly-alpha-decene (obtained from Mobil Corporation as a 6 cst fluid) with one part by weight of trimethylolpropane triheptanoate (Stauffer Chemical Company's Base Stock 704).
TRIAL 1
Compound A/Neat High Water Based System
In Examples 1A (Comparative), 1B, 1C, and 1D, respectively, Compound A was dissolved in the neat high water based system at concentrations of 0; 0.5; 1.0; and 2.0 weight percent. The wear preventive characteristics (four ball method) were determined under ASTM D 2266 procedures at 40 kg load, room temperature, for 1 hour, at speeds of (i) 600 RPM and (ii) 1800 RPM. The wear scars obtained are shown in Table 1 below.
TABLE 1______________________________________ Compound A Wear Scar (mm) Wear Scar (mm)Ex. No. (wt. %) at 600 RPM at 1800 RPM______________________________________1A (Comp) 0 0.84 1.141B 0.5 0.75 0.881C 1.0 0.65 0.941D 2.0 0.65 1.04______________________________________
The weld point of Example 1A (Comp) was only 80 kg in contrast to 126 kg of Example 1C (as tested in accordance with ASTM D-2783).
TRIAL 2
Compound B/Neat High Water Based System
Trial 2 was similar to Trial 1 except that Compound B was substituted for Compound A. The wear preventive characteristics are shown in Table 2.
TABLE 2______________________________________ Compound B Wear Scar (mm) Wear Scar (mm)Ex. No. (wt. %) at 600 RPM at 1800 RPM______________________________________2A 0.0 0.84 1.142B 0.5 0.75 0.872C 1.0 0.70 0.902D 2.0 0.70 0.94______________________________________
TRIAL 3
Compound B/Phosphate Ester Base
Compound B was compared with three prior art compounds as an additive in the phosphate ester base, as shown in Table 3 below. The wear scar test was carried out according to ASTM D 2266 at 600 RPM, 40 kg, for three sequential 30 minute runs.
TABLE 3______________________________________ Wear Scar (mm)Ex. No. Additive 200° F. 400° F. 500° F. 550° F.______________________________________3A(Comp) None .63 .73 .93 .813B 1 wt % cpd. B .58 .62 .62 1.23C(Comp) 1 wt % Dibutyl .60 .75 1.2 1.4 Phosphite3D(Comp) 1 wt % Diphenyl .63 .88 1.3 1.2 Phosphite3E(Comp) 1 wt % Zinc .49 .73 .87 1.3 Dialkyl Dithiophosphate______________________________________
TRIAL 4
Compound B/Mixed Pao/Polyol Ester
Compound B was compared with two prior art compounds as an antiwear additive in the mixed polyalphaolefin/polyol ester base. The wear test was carried out under ASTM D 2266 at 600 RPM, 40 kg load, for one hour at the temperatures indicated in Table 4A below.
TABLE 4A______________________________________ Wear Scar (mm)Ex. No. Additive 225° F. 275° F. 300° F.______________________________________4A(Comp) None .55 .60 .464B 1 wt. % Cpd. B .48 .47 .414C(Comp) 1 wt % Dibutyl .52 .55 .57 Phosphite4D(Comp) 1 wt % Zinc .45 .49 .49 Dialkyl Dithio- phosphate______________________________________
The blends were also tested according to ASTM D-2783 for Last Non Seizure Point (LNS); Weld Point (WP); and Load Wear Index (LWI). The results are shown in Table 4B below.
TABLE 4B______________________________________Ex. No. LNS WP LWI______________________________________4A(Comp) 20 100 11.14B 32 160 32.44C(Comp) 20 126 34.74D(Comp) 32 126 20.9______________________________________
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Certain heretocyclic hydrogen phosphonates are disclosed as having utility in functional fluids, particularly synthetic lubricants and/or water-based functional fluids. Antiwear characteristics and other properties are improved by the blending of additives such as spiro-bis-hydrogen phosphonate and cycloneopentyl hydrogen phosphonate with non-petroleum base stocks such as water, phosphate esters, and mixed polyalphaolefins/polyol esters. Preferred formulations are disclosed.
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TECHNICAL FIELD OF THE INVENTION
The present invention relates generally to mining shovels and more particularly to an automatic lubrication system for mining shovels.
BACKGROUND OF THE INVENTION
Mining shovels are used to move overburden and minerals in the mining process. Many mining shovels have dipper assemblies to scoop, contain and move this material. The dipper assembly contains a door which can be opened to deposit the contained material into a truck or other receptacle for transportation. For example, such an arrangement is shown in U.S. Pat. No. 4,509,895, which is incorporated herein for all purposes.
Mining shovels require proper levels of lubrication to key locations throughout the machine for maximum operating efficiency and long component life. Improper lubrication can lead to metal-to-metal contact, resulting in premature component failure and the necessity to cease operation of the entire mining shovel. Each component has specific needs as to frequency and volume of lubrication.
One past practice of providing lubrication was to manually apply lubrication to components while the mining shovel was inactive. Such a procedure contributes unfavorably to machine productivity, and leads to less than optimum distribution of lubrication to all machine components.
In an attempt to address inconsistencies of the manual method of lubrication, various gravity feed and simple accumulator systems have been developed. These systems operate without manual intervention, except to refill the associated reservoir with the lubricant during scheduled stoppages of the mining shovel. One disadvantage of these systems is the continued application of lubrication whether the machine is operating or idle. Additionally, the volume of lubricant dispensed is not consistent in the accumulator systems. As the pressure in the chamber decreases, the flow rate is typically diminished.
Another automatic system has been developed utilizing pumps, a method of metering, and a timed sequence for operation. Refinement of the timing control provides lubrication to only those locations in need, and limited the operation only to times the mining shovel was fully operational and requiring lubrication. A disadvantage of this system is the need for pneumatic or electric power to operate the pumps, and electric supply for the timer function. Additionally, the output of this system cannot readily be routed to all portions of the machine, particularly the dipper assembly and its associated components.
SUMMARY OF THE INVENTION
Therefore a need has arisen for an automatic lubricating system for mining shovels that eliminates or reduces the disadvantages of previous lubricating systems. According to an aspect of the present invention, an automatic lubricating system for mining shovels having a dipper assembly is provided. The system includes an actuator associated with movement of a portion of the dipper assembly and a pump mechanism pressurized by movement of the actuator. Additionally, the system may include a lubricant supply subsystem coupled to the pump mechanism for supplying lubrication to a selected location in response to pressurization of the pump mechanism.
According to another aspect of the present invention, a method for automatically lubricating a mining shovel is provided. That method includes providing a lubricant supply system for dispensing a lubricant; providing an actuator on the shovel such that a first portion of the actuator will move under the influence of gravity, the movement of the first portion being relative to the shovel and in response to movement of the shovel; activating a second portion of the actuator through movement of the first portion; and delivering lubricant from the lubricant supply subsystem to a selected site in response to activation of the second portion.
The invention has numerous technical advantages; some examples follow. A technical advantage of the present invention is that the lubrication is applied based on the lubrication requirements of the lubricated parts. Another technical advantage of the present invention is that an electrical source is not necessarily required. Yet another technical advantage of the present invention is that lubricant is not constantly applied regardless of whether lubricant is required. Another technical advantage of the present invention is that a consistent amount of lubrication can be applied.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following written description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a left side elevation of a mining shovel for which the present invention is particularly suited;
FIG. 2 is a left side elevation view in detail showing the dipper, door, and crowd handle;
FIG. 3 is a left side elevation of the dipper door snubber mechanism, located midway between left and right extremes of the door width;
FIG. 4 is a rear elevation view of the dipper door snubber mechanism, with principle components mounted symmetrically about the centerline of the dipper assembly and crowd handle;
FIG. 5 is a schematic diagram of one embodiment of the present invention;
FIG. 6 is a diagram of a typical pin joint within the dipper assembly, and the internal passages for lubricant;
FIG. 7 is a schematic diagram of a second embodiment of the present invention;
FIG. 8 is a schematic diagram of a third embodiment of the present invention; and
FIG. 9 is a schematic diagram of a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiments of the present invention and its advantages are best understood by referring to FIGS. 1-9 of the drawings, like numerals being used for like and corresponding parts of the various drawings.
Referring to FIG. 1, a mining shovel 10 is provided for which the present invention is particularly suited. One such mining shovel is the Marion Power Shovel 351M Version Mining Shovel. Mining shovel 10 includes a crawler unit 12 and an upper frame 14. Pivotally connected to upper frame 14 at connection point 15 is a boom structure 16. On one end of boom structure 16 is hoist sheave assembly 18, which supports a hoist rope 20. Hoist rope 20 runs above boom 16, and on to side of dipper handle 22.
Pivotally connected to boom structure 16 and supported in part by hoist rope 20 is a dipper handle 22. A dipper 24 is connected to dipper handle 22 through dipper connection pins 26 and 28. Pivotal about a line coaxial with dipper connection pins 28 is a dipper door 30, which couples with dipper 24 through dipper door connection pins 29. Dipper door 30 can be opened through release of a dipper latch 34. Hoist rope 20 helps to support dipper handle 22 at a bail sheave pin 37.
Referring to FIG. 2, there is shown an expanded view of dipper 24 and dipper door 30. When dipper 24 is full of earth or other material and the operator desires to empty the dipper, dipper latch 34 is released and dipper door 30 pivots about a line coaxial with dipper connection pins 28 and dipper door connection pins 29, shown as dipper door pivot line 27. Also shown in FIG. 2 is one possible placement of a lubricant reservoir or accumulator 56, and one possible placement of a pump cylinder 48, which may be used to pump lubricant. The components are described further below.
Referring to FIGS. 3 and 4, axis line 25 denotes the axis through which first door-snubber connection pins 32 are aligned. Also coaxial with dipper door pivot line 27 is a tensioning bolt 42 on snubber assembly 38. Snubber assembly 38 provides resistance to dipper door 30 to accommodate forces about dipper door pivot line 27, which result from the great weight of dipper door 30. Snubber assembly 38 may include a series of disks 40, which operate similar to a disk brake system in an automobile, and are connected in alternating fashion to snubber connection pin 33 and door-snubber connection pin 32. Disks 40 rotate about dipper door pivot line 27. The snubber assembly may also include a series of guide pins 45 and compression springs 44.
Referring now to FIG. 5, one embodiment of the present invention is shown. This embodiment includes an actuator 51, which in this instance is cam 46 and cam follower 50. The embodiment also includes a lubricant supply subsystem 53 and a pump 48.
Cam 46 is pivotal about axis 27 and may include one of the snubber disks 40. Cam 46 is also connected to first door-snubber connection pin 32 as shown best in FIG. 3. First door-snubber connection pin 32 is coaxial with axis line 25, shown in FIGS. 2, 3, and 4. Linkage 62 connects cam 46 at first door-snubber connection pin 32 to dipper door 30 at second door-snubber connection pin 36. Actuator 51 interfaces or is associated with lubricant supply subsystem 53 by the linking of cam follower 50 with pump cylinder 48.
With reference to FIG. 5, lubricant supply subsystem 53 will be described in more detail. A plurality of hoses or conduits interconnects much of subsystem 53. Fluidly connected to pump cylinder 48 is a hose 82A which extends to a pressure relief by pass valve 54. Intermediate bypass valve 54 and pump cylinder 48 is an intersection 83 providing fluid contact between hose 82A and hose 82B. Hose 82B extends between a check valve 58 and a flow control valve 60. Hose 82C extends from pressure relief bypass valve 54 to lubricant reservoir or accumulator 56 and to a tank-fill port 72. Intermediate pressure relief by pass valve 54 and lubricant reservoir 56 is hose 82D, which extends into check valve 58. Opposite of where hose 82B connects to flow control valve 60 is hose 82E.
Hose 82E is fluidly connected to sequence lubricator block 52. Sequence lubricator block 52 is connected to a first lubrication point 64 by hose 74. Sequence lubricator block 52 is connected to a second lubricator point 66 by hose 76. A third lubrication point is connected to sequence lubricator block by hose 78. Finally, sequence lubricator block 52 is connected to a fourth lubrication point by hose 80. Hoses 74, 76, 78 and 80 may in fact be formed by a plurality of smaller hoses bundled together. Furthermore, it is understood that while the specific embodiment shown in FIG. 5 includes four lubrication points 64, 66, 68 and 70, more or less lubrication points could be utilized.
An expanded view of pin lubrication point 64 is shown in FIG. 6 for lubricating a pin 65. It is to be understood that sequence lubricator block 52 could contain any number of pin supply ducts 69 for providing lubricant to pin lubrication channels 71, 73, and 75 through pin lubrication supply channels 77, 79, and 81.
A number of flow control devices are used in this embodiment of subsystem 53. Check valve 58 only allows flow in the direction from hose 82D towards 82B. Flow control valve 60 allows flow only in the direction from hose 82B towards 82E. A pressure relief bypass valve 54 operates to prevent excessive system pressure buildup. Sequence lubricator block 52 may be a Manzel Series-Flow Type Feeder. Pump cylinder 48 may be mounted on dipper 24 proximate the handle 22, as shown in FIG. 2, or on handle 22 proximate to dipper 24, or at any other convenient location.
When pump cylinder 48 is compressed and thereby pressurized, a lubricant is forced through a flow control valve 60 into sequence lubricator block 52. If the lubricant pressure is excessive, a portion of the lubricant will flow through a relief valve 54 into an accumulator 56, which stores the lubricant. When dipper door 30 closes, the pump cylinder may return to a neutral position, with lubricant drawn through a check valve 58 to allow the return of, and may assist in, the return of pump cylinder 48 to a neutral position, thereby recharging the pump. One commercially available pump that is appropriate for use with the embodiment shown in FIG. 5 of the present invention is a Doering Cartridge Pump Series 241.
Accumulator 56 may be a pressurized tank. As discussed above in the context of the check valve 58, the pressurized lubricant returning through the check valve 58 may accommodate the return of pump cylinder 48 to a neutral position. Accumulator 56 could be placed in handle 22, as shown best in FIG. 2, dipper 24, dipper door 30, or a variety of other positions. Accumulator 56 may be sized to have sufficient capacity to require filling only at normal maintenance intervals. Tank fill port 72 may be located remote from other elements of the lubrication system to provide easy maintenance access.
In normal operation, when dipper door 30 is opened, linkage 62 causes cam 46 to rotate as reflected by the cam in position 47 of FIG. 5. Rotation of cam 46 causes cam follower 50 of actuator 51 to move pump cylinder 48 to cause lubricant therein to flow into hose 82A through joint or juncture 83 and further through flow control valve 60 and finally arriving at sequence lubricator block 52 by means of hose 82E. Sequence lubricator block 52 provides metered lubricant flow over several cycles of the machine in order to provide sufficient but not excessive flow of lubricant. When the lubricant arrives at sequence lubricator block 52, the lubricant is transmitted through hose 74 to a pin lubrication point 64. The next time cam 46 is activated and pump cylinder 48 is compressed, sequence lubricator block 52 will transmit lubricant through second hose 76 to pin lubrication point 66. A similar sequence is performed for lubrication points 68 and 70. For a sequence lubricator block with four hoses, each lubrication point 64, 66, 68, 70 will preferably receive lubricant approximately every two minutes.
Various changes may also be made to the lubricant supply subsystem; for example, pump unit 48 in FIG. 5 could be replaced with a ratcheting rotary type rather than the plunger actuated cylinder type shown. In the ratcheting type pump, for example, a shaft could be connected along dipper door pivot line 27. Opening of dipper door 30 would cause the shaft to rotate the ratcheting type rotary pump. Thus, lubrication as described above could occur at intervals that are a function of the opening of dipper door 30.
Various changes may be made to actuator 51; for example, another embodiment of the present invention is shown in FIG. 7 that includes actuator 151. In the embodiment shown in FIG. 7, cam 46 and spring returned cam follower 50 have been removed. In this embodiment, dipper door 30 is directly connected to a pump cylinder 148. This connection could occur at the first snubber-door connection pin 32 or a variety of other points. The operation of the embodiment shown in FIG. 7 is substantially similar to that shown in FIG. 5 except that when dipper door 30 opens, pump cylinder 148 is directly compressed rather than actuated through the rotation of cam 46 and the resulting motion of cam follower 50.
Referring now to FIG. 8, a third embodiment of the present invention includes another alternative actuator 251. In this embodiment, rather than pivoting about dipper door pivot line 27, cam 292 pivots about any mounting point such as first snubber-door connection pins 32 or second snubber-door connection pins 36, or another convenient pivot linkage. When dipper 24 changes position, gravity will maintain dead weight 290 parallel to the ground. When dipper 24 moves to a more horizontal position, cam 292 will pivot relative to dipper 24. Thus, the pivoting of cam 292 relative to dipper 24 causes actuation of cam follower 250 and pump 248. In this embodiment, cam follower 250 and pump 248 could be mounted anywhere within dipper 24 or dipper handle 22. The operation of lubricator supply subsystem 253 shown in FIG. 8 is substantially similar to the automatic lubrication systems discussed in previous embodiments.
Modifications or alternatives may be used in both the actuator and the lubricant supply subsystem in combination. For example, a fourth embodiment of the present invention is shown in FIG. 9 with actuator 351 and lubricant supply subsystem 353. In this embodiment, actuator 351 includes a dead weight 390 having a pivot linkage 392. Dead weight 390 is connected to dipper 24 at a convenient pivot linkage point 392. Dead weight 390 is pulled by gravity towards the ground. Therefore, when the dipper is positioned to a more horizontal position, dead weight 390 will pivot relative to dipper 24 about pivot linkage point 392 in a similar fashion to dead weight 290 as described above.
Lubricant supply subsystem 353 is analogous in most respects to the previously described lubricant supply subsystems 53, 153, and 253, but pump 48, 148, and 248 has been replaced by valve 394. Valve 394 is arranged such that rotation of dead weight 390 about pivot point 392 causes valve 394 to open and then when the relative angle between valve 394 and dead weight 390 is restored, valve 394 will close. When valve 394 is opened by the pivoting or relative movement of dead weight 390 with respect to valve 394, valve 394 releases lubricant from the accumulator 356 to sequence lubricator block 352 through hose 382. The operation of the remainder of lubricant supply subsystem 353 shown in FIG. 9 is analogous to the automatic lubrication system discussed in the previous embodiments.
In addition to providing lubrication based on the opening and closing of dipper door 30 as well as having relative position to dipper 24, the present invention may also utilize other motion of mining shovel 10 to coordinate lubrication of lubrication points with their use. Furthermore, the lubrication system of the present invention may be utilized for other connections and lubrication points on mining shovel 10.
Although the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.
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A mining shovel (10) is provided with an automatic lubricant system controlled by movement of a portion for the mining shovel (10). The automatic lubrication system includes an actuator (51, 151, 251, 351) and a lubrication supply subsystem (53, 153, 253, 353). The lubrication supply subsystem (53, 153, 253, 353) delivers lubricant to a selected site in response to movement of the actuator (51, 151, 251, 351).
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[0001] This application claims priority to U.S. Provisional Patent Application No. 60/903,495 filed Feb. 26, 2007 and to PCT Application No. PCT/US2008/002364 filed Feb. 22, 2008. The instant invention is in the field of combustion gas analysis and more specifically the instant invention is in the field of tunable diode laser spectroscopic analysis of combustion gases. Tunable diode laser spectroscopic analysis of combustion gases is known and described in the prior art, for example, by: Lackner et al., Thermal Science, V.6, p 13-27, 2002; Allen, Measurement Science and Technology, V.9, p 545-562, 1998; Nikkary et al., Applied Optics, V.41(3), p 446-452, 2002; Upschulte et al., Applied Optics, V.38(9), p 1506-1512, 1999; Mihalcea et al., Measurement Science and Technology, V.9, p 327-338, 1998; Webber et al., Proceedings of the Combustion Institute, V.28, p 407-413, 2000; Ebert et al., Proceedings of the Combustion Institute, V.30, p 1611-1618, 2005; Nagali et al., Applied Optics, V.35(21), p 4027-4032, 1996; and U.S. Pat. Nos. 7,248,755 7,244936 and 7,217,121.
BACKGROUND OF THE INVENTION
[0002] Despite the significant advances in the prior art, problems related to poor sensitivity, background interferences and temperature interferences remain as significant problems for the application of tunable diode laser spectroscopic simultaneous analysis of combustion gas for carbon monoxide, gaseous water and gaseous hydrocarbon.
SUMMARY OF THE INVENTION
[0003] The instant invention is a solution to the above-stated problems for the simultaneous analysis of carbon monoxide, gaseous water and gaseous hydrocarbon in combustion gas by tunable diode laser spectroscopy. The sensitivity of analysis is improved by operating the tunable diode laser in a wavelength range of from 2 to 2.5 micrometers. Multivariate processing techniques for manipulating the spectral data allow the simultaneous determination of carbon monoxide, gaseous water and gaseous hydrocarbon even though only a single tunable diode laser is used. More specifically, the instant invention is a chemical analysis method for determining the concentration of carbon monoxide, gaseous water and gaseous hydrocarbon in a combustion gas, comprising the steps of: (a) directing wavelength modulated light from a single tunable diode laser at a wavelength in the range of from 2 to 2.5 micrometers through the combustion gas to a light detector to produce an absorption profile of the combustion gas (b) digitizing the adsorption profile of the combustion gas; (c) storing the digitized adsorption profile in a digital computer; (d) processing the digitized adsorption profile in the digital computer to produce an output from the computer indicative of the concentration of carbon monoxide, gaseous water and gaseous hydrocarbon in the combustion gas.
[0004] In a related embodiment, the instant invention is a method for monitoring and controlling a combustion driven thermal processing system to meet efficiency, environmental and operational safety goals, the combustion driven thermal processing system producing a combustion gas, comprising the steps of: (a) determining the concentration of oxygen in the combustion gas; (b) determining the temperature of the combustion gas; and (c) determining the concentration of carbon monoxide, gaseous water and gaseous hydrocarbon in a combustion gas, by a method comprising the steps of: (i) directing wavelength modulated light from a single tunable diode laser at a wavelength in the range of from 2 to 3 micrometers through the combustion gas to a single light detector to produce an absorption profile of the combustion gas; (ii) digitizing the adsorption profile of the combustion gas; (iii) storing the digitized adsorption profile in a digital computer; (iv) processing the digitized adsorption profile in the digital computer to produce an output from the computer indicative of the concentration of carbon monoxide, gaseous water and gaseous hydrocarbon in the combustion gas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a schematic drawing of a hydrocarbon processing heater or furnace;
[0006] FIG. 2 shows the relationship between key combustion parameters for the heater or furnace of FIG. 1 ;
[0007] FIG. 3 a is a schematic drawing of the heater or furnace of FIG. 1 employing a tunable diode laser gas analysis system;
[0008] FIG. 3 b is a schematic drawing of the heater or furnace of FIG. 1 employing two tunable diode laser gas analysis systems and a pair of zirconia oxygen sensors;
[0009] FIG. 4 is a more detailed drawing of the tunable diode laser gas analysis system;
[0010] FIG. 5 shows the infrared spectrum for oxygen in the 759 to 779 nm wavelength region;
[0011] FIG. 6 shows the infrared spectrum for carbon monoxide in the 2280 to 2630 nm wavelength region;
[0012] FIG. 7 shows the infrared spectrum for carbon monoxide in the 1550 to 1680 nm wavelength region;
[0013] FIG. 8 shows HITRAN spectra of CO, H 2 O and CH4 from 2324 to 2328 nm;
[0014] FIG. 9 shows HITRAN spectra of CO, H 2 O and CH4 from 2301.9 to 2302.4 nm; and
[0015] FIG. 10 shows absorption spectra of CO and H 2 O collected across a long path at 1,100° C.
DETAILED DESCRIPTION
[0016] The measurement of gas species in a combustion system is important for safe, environmentally responsible, and efficient operation. While not limited thereto, the instant invention has particular importance to hydrocarbon processing furnaces and heaters.
[0017] The specific gas species and condition measurements used in this invention are, Oxygen (O 2 ), Carbon Monoxide (CO), Combustion Gas Temperature, Water (H 2 O) and hydrocarbons (C—H) such as methane (CH 4 ).
[0018] Referring now to FIG. 1 , therein is shown schematic drawing of a hydrocarbon processing heater or furnace 10 such as an ethylene cracker, a petroleum refinery heater, a petroleum refinery hydrocracker, a petroleum refinery fluidized catalytic cracker and an electrical power generation steam boiler. The heater or furnace 10 is comprised of an enclosure or wall 11 , a pipe 16 carrying, for example, a stream of hydrocarbon to be heated, by the flames 14 and 15 from burners 12 and 13 .
[0019] Referring now to FIG. 2 , therein is shown a plot of concentration v. percent excess burner air for the relationship between key combustion parameters for the heater or furnace of FIG. 1 . The primary operational concerns addressed by the instant invention are, efficiency of the burners (optimum air/fuel ratio), emissions from the combustion system (CO, CO 2 , NOx, etc.), and safety monitoring (flame loss, fuel rich burner conditions, leak or rupture of the product tube).
[0020] Combustion efficiency requirements can be generally summarized as optimizing the air/fuel ratio to the burners with the lowest amount of excess air in the combustion by-products. Fuel feed to the burners is typically determined by the firing rate required for processing (amount of heat required). Air feed to the burners must be high enough to allow complete combustion without the production of excess emissions (CO, etc.) and unburnt fuel (hydrocarbons). Excess air will be heated by the flame, consuming some of the heat which then is not available for the primary purpose of the combustion system (such as cracking feedstock). Excess air to a burner will also generate NOx emissions. FIG. 2 illustrates the relationship between efficiency, safety and emissions.
[0021] Emissions requirements are determined by the operator or the governmental authority. In many cases an industrial plant or the individual furnace/heater has a limit on the amount of pollutants and greenhouse gases that can be emitted. Primary pollutants are carbon monoxide (CO), NOx (nitric oxide+nitrogen dioxide) and carbon dioxide (CO 2 ). In some cases the firing rate of the burners (production rate) can be limited by the need to remain below mandated emissions limits. Measurement of the pollutants, or the conditions required to generate the pollutants can be used to control and reduce emissions reduction.
[0022] Safe operation of combustion systems requires that explosive mixtures are not present in the combustion system. These explosive mixtures can occur under three common conditions. First, if the burner(s) are not supplied with enough air, unburnt fuel will be present in the burner(s). This unburnt fuel can be ignited if excess air is then introduced into the system, from the burner air feed or from air leaks into the system. Second, if the burner(s) flame goes out (flameout, liftoff) the air/fuel feed to the burner will enter the combustion chamber, any subsequent ignition source can ignite this mixture. Third, if the furnace/heater is used for processing hydrocarbons, a leak in the product tube can introduce unburnt hydrocarbons to the combustion chamber. If excess air is present, along with an ignition source an explosion can occur. Measurement of the presence of the explosive mixture along with other conditions can both indicate the un-safe condition and the source of the safety breach.
[0023] Referring now to FIG. 3 a , therein is shown a schematic drawing of the heater or furnace of FIG. 1 employing a tunable diode laser gas analysis system comprising a tunable diode laser sending unit 17 and a detector 18 . Referring now to FIG. 4 , therein is shown a more detailed drawing of the tunable diode laser gas analysis system. The tunable diode laser gas analysis system includes a laser module 37 containing the tunable diode laser. A control unit 31 contains the central processing unit programmed for signal processing (to be discussed below in greater detail) as well as the temperature and current control for the tunable diode laser and a user interface and display. Alignment plate 29 and adjustment rods 30 allow alignment of the laser beam 41 . Dual process isolation windows 28 are mounted in a four inch pipe flange 40 . The space between the windows 28 is purged with approximately 25 Liters per minute of nitrogen at ten pounds per square inch gauge pressure. The flange 40 is mounted through the wall of the furnace.
[0024] Referring still to FIG. 4 , the laser beam 41 is passed through the combustion gas and then through dual process isolation windows 33 to a near infrared light detector 38 . The windows 33 are mounted in a four inch pipe flange 39 . The space between the windows 33 is purged with approximately 25 Liters per minute of nitrogen at ten pounds per square inch gauge pressure. The flange 39 is mounted through the wall of the furnace. Alignment plate 34 and adjustment rods 35 allow alignment of the detector optics with the laser beam 41 . Detector electronics 36 are in electrical communication with the control unit 31 by way of cable 37 a . The control unit 31 is also in electrical communication (by way of electrical cables 38 a ) with a process control system 32 for controlling the furnace 10 . The system shown in FIG. 4 is commercially available from Analytical Specialties of Houston, Tex.
[0025] The system shown in FIG. 4 operates by measuring the amount of laser light at specific wavelengths, which light is absorbed (lost) as it travels through the combustion gas. Carbon monoxide, gaseous water and hydrocarbons each have a spectral absorption of infrared light that exhibits unique fine structure. The individual features of the spectra are seen at the high resolution of the tunable diode laser 37 .
[0026] Referring now to FIG. 3 b , therein is shown a schematic drawing of the heater or furnace of FIG. 1 employing two tunable diode laser gas analysis systems 17 , 18 , 19 and 20 , and a pair of zirconia oxygen sensors 21 and 22 . The system shown in FIG. 3 b is a preferred embodiment of the instant invention. The oxygen measurement can be performed a number of ways. Two common methods are zirconia oxide probes, tunable diode laser (TDL) spectroscopy, or a combination of both. This application will include a description of a combination of zirconia oxide probes with tunable diode laser spectroscopy in relation to FIG. 3 b . The TDL oxygen analyzer 19 , 20 at a wavelength in the range of from 759 to 779 nanometers provides a path average oxygen concentration to avoid errors due to the uneven oxygen distribution across the firebox. By measuring two oxygen absorption peaks, Gas Temperature can be calculated and provided as an output from the analyzer. The zirconia oxygen probes provide a point measurement of oxygen which can be used to diagnose localized inefficiencies in multi-burner systems.
[0027] CO measurement is also possible using a number of analysis methods such as, solid state sensors, non dispersive infrared and tunable diode laser. The preferred embodiment of this invention is the use of TDL spectroscopy to measure the CO in the combustion gas. With proper absorption line selection in the wavelength range of from 2 to 2.5 micrometers it is also possible to measure H 2 O and hydrocarbons (methane and others) with a single tunable diode laser system. It is also possible to use multiple lasers to provide single species measurement per laser or combinations of single and multiple species measurements per laser.
[0028] Referring still to FIG. 3 b two individual diode lasers systems 17 , 18 , 19 and 20 are used to provide measurements of, O 2 , CO, H 2 O, gas temperature, and unburnt hydrocarbons including but not limited to methane (CH4). TDL is an optical measurement. The measured gas absorbs the laser light at a specific wavelength. The amount of light absorbed is a function of gas concentration, pressure, temperature and optical path length. The process heater/furnace also has single or multiple burners 12 and 13 , that are used to provide the heat for the thermal processing. These burners are supplied with air and fuel, both of which are controlled to provide the desired heat, control efficiency, reduce emissions and ensure safe operation. There are a number of potential operating conditions, some of which will be outlined below, where the gas species measurements may be used to meet the goals of maximum heat capacity, efficient operation (lowest burner fuel costs), safe operation (avoiding explosive mixtures in the furnace), and reducing emissions.
[0029] Referring still to FIG. 3 b , under normal operating conditions where the burners 12 and 13 are lit and the product being processed is contained in the product tube 16 , the key operational parameter is minimizing excess air, while providing the desired heat, minimizing unburnt fuel, and staying within emissions limits. The gas measurements listed above may be used as follows. Oxygen and CO measurements will indicate the efficiency of the burner(s), minimum oxygen concentration without significant levels of CO can indicate optimum overall furnace fuel efficiency. The combination of path average and point source oxygen measurements can indicate localized burner efficiency if multiple burners are present in the system. Gas temperature measurement can indicate the amount of heat available for product processing. CO can also be used as a pre-cursor to fuel rich conditions where burner fuel (combustibles) is not burned and present in the combustion chamber. C—H measurement can be used to indicate the presence of unburnt fuel from the burners. H 2 O measurement can be used to calculate efficiency. A combination of oxygen and CO measurement can be used to predict or calculate the pollutant emissions such as CO 2 and NOx since both of these pollutants increase as air and fuel levels to the burners increase. For example NOx is produced from the nitrogen and oxygen present in the air supplied to the burner(s), increased excess air (above the minimum level required) will lead to increased NOx formation.
[0030] Under conditions produced by a burner flame loss or flame-out, the gas measurements may be used as follows. Oxygen levels will rise since oxygen present in the burner air feed is not being consumed by the combustion process. Gas temperature levels will fall rapidly upon the loss of the heat source (flame). Gas H 2 O levels will fall rapidly since they are produced as a combustion by product. Methane and other hydrocarbon levels will increase in large amounts. By providing and monitoring each of these gas measurements a loss of burner flame can be inferred.
[0031] Under conditions produced by a product tube leak, where the product tube contains hydrocarbons, the following conditions may be monitored. Hydrocarbon levels will increase in the combustion chamber as the product from the tube enters the combustion chamber. If steam is also present in the product tube, H 2 O levels will increase as the steam enters the combustion chamber. Oxygen levels, gas temperature and CO levels may also change under these conditions and potentially be used for diagnostics and control.
[0032] Under conditions produced by a product tube leak, where the product tube contains steam but no hydrocarbons, the following conditions may be monitored. H 2 O levels will increase as the steam enters the combustion chamber. Oxygen levels, gas temperature and CO levels may also change under these conditions and potentially be used for diagnostics and control.
[0033] The preferred embodiment of this invention uses tunable diode laser spectrometer(s) to measure oxygen, carbon monoxide, hydrocarbons such as methane, water vapor and temperature. These measurements can be utilized in many combustion driven thermal processing systems, one example being refinery process heaters.
[0034] TDL spectroscopy uses a tunable diode laser as the light source. This laser is typically controlled at a constant temperature to establish the course wavelength position, the laser is then modulated using a current ramp from the control electronics, modulation results in a wavelength scan over a repeated range (i.e. 760 nm to 761 nm for oxygen). The modulated laser light passes through beam shaping optics, and then a first process isolation window, through the gas being measured where if the gas being measured is present it absorbs a portion of the infrared light transmitted across the process, another process isolation window, to an appropriate light sensitive detector selected for the wavelength being used for measurement. The detector signal is sampled by an appropriate data acquisition system, the results are then processed by the analyzer digital central processing unit (CPU). One example of such a device is the TruePeak Tunable Diode Laser analyzer available from Analytical Specialties, Inc of Houston, Tex.
[0035] Each of the gases used for measurement have a unique absorption of infrared light. One example of this is shown in FIG. 5 , this is the infrared absorption spectra for oxygen. By selecting one or more of the specific absorption peaks, inputting the distance the laser light transmits across the process along with gas temperature and pressure, a path average concentration can be calculated and reported. This path average concentration basically counts the number of molecules of the gas being measured that are in the beam of laser light. One advantage of a path average measurement versus a point source measurement (as with zirconia oxygen sensors) is that all of the analyte is measured, point sensors only measure a small portion of the process, if the analyte is distributed throughout the process a point measurement may not be representative of the entire system. In some cases both a path average and one or more point source measurements may be desirable, for example to diagnose burner malfunctions. If path and point measurements are desired a combination of both types of measurements may be employed as shown in FIG. 3 b.
[0036] Oxygen measurement can be made with this type of analytical device by selecting any suitable absorption peak shown in FIG. 5 , from 759 to 779 nm.
[0037] It is also possible to infer the gas temperature by scanning the laser over two suitable oxygen peaks, for example 760.55 nm and 760.56 nm. The oxygen absorption peak strength is strongly related to the gas temperature, if two lines are selected that have sufficiently different line strength vs. temperature, measuring both and comparing the line strength allows the inference of gas temperature. This same approach may be used with other analytes (moisture as an example), this embodiment uses the oxygen peaks for temperature measurement.
[0038] Measurement of carbon monoxide (CO) is performed in a similar method. FIGS. 6 & 7 show the absorbing CO peaks at two different wavelength regions. Depending on the sensitivity requirements for the CO measurement and the cost of the diode laser either wavelength region may be selected.
[0039] The preferred embodiment of this invention uses the CO peaks in the wavelength range of 2290 to 2580 nm. Two specific examples will be outlined as they are particularly well suited for combustion analysis requirements at high temperatures. Measurement of CO close to the burners themselves has an advantage in that the CO levels are typically higher closest to the burners, making the measurement and control simpler. As the combustion gases travel further from the burner system they continue to react, this reaction results in lower CO levels further from the burner(s) at lower temperature zones. In addition the measurement response time is reduced.
[0040] FIG. 8 shows HITRAN absorption spectra of CO, H 2 O and CH4 from 2324 to 2328 nm. This wavelength region is one example where a single diode laser can be wavelength modulated to cover the absorption wavelengths for CO, H 2 O and multiple hydrocarbons, methane being the example used here.
[0041] FIG. 9 shows HITRAN absorption spectra of CO, H 2 O and CH4 from 2301.9 to 2302.4 nm. This wavelength region is another example where a single diode laser can be wavelength modulated to cover the absorption wavelengths for CO, H 2 O and multiple hydrocarbons, methane being the example used here.
[0042] FIG. 10 shows absorption spectra, collected across a long path at 1100 C, in approximately the same wavelength range as FIG. 9 (2301.9 to 2302.4 nm) wherein the plain curve relates to CO plus H 2 O while the triangle marked curve relates to H 2 O. As can be seen by comparing standard HITRAN spectra with the measured spectra from a operating furnace, the background H2O absorption pattern is different than expected. This is primarily due to the fact that HITRAN was originally designed for atmospheric monitoring applications and it isn't very accurate for high temperature condition. Because of long path (20 meters), background H2O absorbance interference with CO absorbance is significant. Concentration prediction based on a simple peak height measurement or peak area integration is not possible (or at least very difficult) while maintaining measurement integrity.
[0043] CLS (classical least squares) signal processing is a preferred solution to this problem in the instant invention. Preferably, the signal processing is done by a digital computer, preferably a general purpose digital computer programmed to perform one of the following types of analysis of the signal(s) stored in the digital computer. CLS is a type of multivariate analysis which uses a mathematical model to predict concentration level of each component. Multivariate analysis includes classical least square (CLS), principal components regression (PCR) and partial least squares (PLS). CLS is probably the simplest. It requires calibration to get all the spectra of each component, and then build a mathematical model for future mixture measurement. Calibration is the process of constructing a mathematical model to relate the output of an instrument to properties of samples. Prediction is the process of using the model to predict properties of a sample given an instrument output. For example, the absorbance at a given wavelength can be related to the concentration of an analyte. To construct the model, instrument responses from samples with known concentration levels are measured and a mathematical relationship is estimated which relates the instrument response to the concentration of a chemical component(s). This model may be used to predict the concentration of a chemical component in future samples using the measured instrument response(s) from those samples. Many instrumental responses can be considered, and a number of sample properties can be predicted. In many applications, one response from an instrument is related to the concentration of a single chemical component. This is referred to as univariate calibration because only one instrument response is used per sample. Multivariate calibration is the process of relating multiple responses from an instrument to a property or properties of a sample. The samples could be, for example, a mixture of chemical components in a process stream, and the goal is to predict the concentration levels of the different chemical components in the stream from infrared measurements.
[0044] Scanning the laser wavelength across individual absorption peaks for CO, H 2 O and specific hydrocarbons such as CH4, allows the measurement and reporting of these components. Multivariate models may be required and used to enhance the measurement.
[0045] The following specific wavelengths (in nanometers) are specifically recommended when the combustion gas has a temperature of about 1,100° C.: 2302.1; 2303.9; 2319.1; 2323.6; 2325.2; 2326.8; 2331.9; 2333.7; 2335.5; 2342.8; 2346.8; 2348.2; 2356.1; 2363.1; and 2373.1. The following specific wavelengths (in nanometers) are specifically recommended when the combustion gas has a temperature of about 300° C.: 2307.8; 2320.6; 2323.6; 2331.9; 2339.3; 2353.9; 2360.8; 2368.0; 2373.1; 2389.3; and 2401.0. Thus, there are a number of possible wavelengths that permit the simultaneous determination of CO, H 2 O and hydrocarbon (such as CH 4 ). The selection of the best wavelength is application dependent and determined by a reasonable degree of experimentation. Factors such as the desired sensitivity, the optical pathlength (furnace size) and combustion gas temperature are important variables.
[0046] The central feature of the preferred embodiment of the instant invention is the monitoring of oxygen, temperature, carbon monoxide, water vapor and/or hydrocarbons in a single analytical system. The combination of these measurements along with an understanding of the process conditions that affect these gas measurements allows not only combustion efficiency optimization, emissions reduction and safety monitoring, but also allows the discrimination between conditions. One embodiment of this invention allows discrimination between air rich or fuel rich conditions along with discrimination between unsafe conditions such as product tube leaks and burner flame out. Another embodiment of this invention which includes additional point oxygen measurements allows localized diagnostics in multiple burner systems.
CONCLUSION
[0047] In conclusion, it should be readily apparent that although the invention has been described above in relation with its preferred embodiments, it should be understood that the instant invention is not limited thereby but is intended to cover all alternatives, modifications and equivalents that are included within the scope of the invention as defined by the following claims.
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A chemical analysis method for determining the concentration of carbon monoxide, gaseous water and gaseous hydrocarbon in a combustion gas. The method includes the following steps: (a) directing wavelength modulated light from a single tunable diode laser at a wavelength in the range of from 2 to 2.5 micrometers through the combustion gas to a light detector to produce an absorption profile of the combustion gas (b) digitizing the adsorption profile of the combustion gas; (c) storing the digitized adsorption profile in a digital computer; (d) processing the digitized adsorption profile in the digital computer to produce an output from the computer indicative of the concentration of carbon monoxide, gaseous water and gaseous hydrocarbon in the combustion gas.
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This application is a continuation-in-part of U.S. application Ser. No. 10/756,002 filed Jan. 13, 2004 now abandoned, which claims the benefit of U.S. Provisional Application No. 60/523,031, filed Nov. 18, 2003.
BACKGROUND OF THE INVENTION
The present invention relates to retention clips mountable to wall panels to improve the ease with which these panels can have insulation or related structure mounted thereto.
Wall panels are some of the basic components of building structures, and come in various configurations, including pre-formed and assembled-on-site versions. One type of wall panel that has been used extensively in modern building structures involves the use of tilt-up, precast, cast-in-place, and other similar construction techniques, where uncured material (such as concrete) is introduced into a form and cured such that a panel in the shape of the form is produced. As used herein, a precast panel includes any panel that is formed from a cast material that upon curing hardens up, thereby allowing the panel to be subsequently placed in a desired (typically vertical) location within a building structure. A tilt-up panel is a particular type of precast panel that is formed on a horizontal surface and tilted up into place upon curing of the cast material. A need exists for securing insulation to these and related panels in a quick, inexpensive and repeatable fashion.
SUMMARY OF THE INVENTION
The present invention comprises a clip that includes sealed retention channels, such that when the clips are connected to precast wall panels (generally), tilt-up wall panels (specifically) or any other type of wall or surface to be insulated, they can hold insulation securely to the wall panel in such a way as to maximize the insulative properties of the wall. The clips are configured such that close tolerances, coupled with knife-edge seals, promote a secure fit with the insulation material and improved insulative properties of the wall panel-insulation material combination. The clips of the present invention can be disposed both horizontally and vertically on the wall panel, the former to support the weight of the insulation and the latter to adjoin adjacent insulation panels or enclose the edge of the insulation.
According to a first aspect of the invention, a retention clip is disclosed. The clip includes a panel engaging portion and a retention portion, where the panel engaging portion and retention portion together define at least one retention channel between them. The retention portion further includes at least one seal extending along a longitudinal dimension of the retention channel. The seal is configured such that it defines a channel entrance along the retention channel's longitudinal dimension; this channel entrance defines a throat-like channel access dimension that is smaller (or restrictive) relative to a parallel dimension of a remaining portion of the retention channel.
According to another aspect of the invention, a clip for securing insulation to a panel is disclosed. In the present context, it will be understood that insulation comes in various forms, and that any such form that includes rigid sheet or fibrous-based rolls (such as fiberglass) is envisioned as being compatible with the present invention. In addition, any generally planar sheet material with a thickness dimension properly engageable with the clip described herein would qualify as insulation by virtue of its ability to measurably reduce the transfer of heat to or from the panel relative to no sheet being present. The clip includes a panel-engaging portion with a corresponding panel-engaging surface, and a retention portion, configured to engage the insulation, coupled to the panel-engaging portion. The retention portion is made up of numerous walls that together define at least one retention channel, and one or more seals configured such that upon placement of the insulation into the channel, the seal engages the insulation.
In one form, the placement of the insulation into the channel causes the seal to be biased against the insulation to effect a secure fit between them. Moreover, the seal can be situated on a substantially distal end of the retention portion. In another option, the panel-engaging surface is substantially planar, while in yet another, the clip is of unitary construction. The panel-engaging portion is elongate relative to the retention portion in at least one dimension such that an attachment-receiving tab is defined therein. The attachment-receiving tab can accept adhesives thereon or fasteners therethrough, such as screws, nails, rivets or the like. In the relatively elongate configuration, the tab extends such that a substantially outward-facing normal projection from a surface on the tab does not intersect the plurality of walls of the retention portion, thereby facilitating substantially unimpeded access of a fastener to the clip to retain the clip on the panel. The tab may additionally include an aperture to facilitate the receipt of a fastener therethrough.
The clip can be configured such that the retention portion defines a substantially T-shaped (or I-shaped) cross-section or where the entirety of the clip defines a substantially J-shaped cross-section. In the T-shaped configuration, the plurality of walls define two retention channels, whereas in the J-shaped configuration, they define one channel. In the T-shaped configuration, a seal can be disposed at the substantial distal end of each of the retention portions. In addition, each of the two retention channels of the T-shaped clip are configured to secure substantially equal-sized parts of the insulation. The clip may further include one or more springs disposed along one of the plurality of walls. These springs can be formed in either of both of the panel-engaging portion or the channels. For example, a spring may be disposed along one of the walls that extends substantially parallel to the panel-engaging portion. The T-shaped clip can be made as either a one-piece (unitary) construction, or from multiple-piece construction; in the latter, at least one of the plurality of walls makes up a first piece, while another of the walls makes up a second piece. For the multiple-piece configuration, a locking mechanism may be included to facilitate a snap-fit between the first and second pieces. The locking mechanism may include a plurality of complementary teeth on respective surfaces of the first and second pieces.
The clip may be made from a variety of materials, including plastic, such as polyvinyl chloride (PVC) or related extrudable plastics. The seal may be made from a material that is pliant (flexible) relative to the material making up the remainder of the clip. This promotes a more secure fit with reduced likelihood of gap formation, especially when the insulation against which the seal engages is rigid. The position of the seal is such that when the insulation is placed within the clip, the seal is biased against the insulation, substantially eliminating the aforementioned gap and consequent airflow between the seal and insulation. In situations where the seal is made from a different extrudable material than the remainder of the clip, it may be configured such that it can be co-extruded with a corresponding one of the walls.
According to another aspect of the invention, an insulative assembly is disclosed. The assembly includes a panel, a layer of insulation configured to cover at least a portion of the panel, and first and second clips to secure the insulation to the panel. The first clip includes a first panel-engaging portion and a first retention portion coupled to the first panel-engaging portion similar to those described in the previous aspect. The second clip includes a second panel-engaging portion and a second retention portion, also similar to that previously described. Optionally, and as before, the panel is substantially planar. In addition, the first clip can be made substantially J-shaped, while the retention portion of the second clip can be made substantially T-shaped. At least one of the first clips can be attached to the panel such that its longitudinal dimension extends along a substantially horizontal dimension of the panel. In such case, two of the first clips can be placed such that one is disposed above the other on the panel. Moreover, the retention channels of the two first clips may be disposed in a facing relationship to one another, thereby forming a frame-like enclosure at the upper and lower end of the insulation. In addition, the first clips can also be placed with its longitudinal dimension along a substantially vertical dimension of the panel; such use of the first clips can promote lateral support of the insulation, especially in corners or endwalls formed by the panels. At least one of the second clips can be disposed on the panel with its longitudinal dimension along a substantially vertical dimension of the panel. In another option, the thickness of the second clip is slightly less than the first clip, thereby allowing the former to fit inside the latter.
According to yet another aspect of the invention, a method of forming an insulated panel is disclosed. The method includes providing a panel, attaching at least one clip to the panel, and placing insulation in a retention channel of the clip such that the insulation engages a seal defined in the channel. As previously discussed, the clip includes a panel-engaging portion defining a panel-engaging surface thereon and a retention portion coupled to the panel-engaging portion and configured to engage the insulation. By placing the insulation in the clip, a bias is effected between the seal and the insulation such that a secure fit between the two is formed. Also as previously discussed, the clip can be secured to the panel by adhesive, fasteners or related attachment schemes. As with the previous aspect, numerous clips may be used to secure the insulation to the panel. For example, the plurality of clips may include at least one substantially J-shaped clip and at least one clip with a substantially T-shaped retention portion.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The following detailed description of the preferred embodiments of the present invention can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
FIG. 1 illustrates a side view of an embodiment of a first clip according to an aspect of the present invention;
FIG. 2 illustrates the clip of FIG. 1 mounted to a wall panel and supporting a piece of insulation material;
FIG. 3A illustrates a top view of an embodiment of a second clip;
FIG. 3B illustrates a top view of an alternate embodiment of the second clip of FIG. 3A ;
FIG. 4 illustrates an exploded view of the second clip of FIG. 3B ;
FIG. 5 illustrates a wall panel with an insulation sheet mounted to it using both the first and second clips according to an aspect of the present invention; and
FIG. 6 illustrates a variation on the second clip depicted in FIG. 3A , including springs disposed in various channel walls.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1 , a clip 100 is substantially J-shaped such that it can support a workpiece (such as a piece of insulation) against a wall or related panel. Clip 100 defines a retention portion 110 (also known as a trough) to engage the workpiece, and an extending panel-engaging portion 120 for engagement of the support clip 100 to the wall. Retention portion 110 is made up of walls 112 , 114 and connected to a portion of panel-engaging portion 120 at a proximal end 116 of retention portion 110 to define a retention channel 110 A therebetween. The panel-engaging portion 120 extends beyond retention portion 110 with an extension 127 to facilitate connection of clip 100 to a wall surface. The elongate nature of the panel-engaging portion 120 with extension 127 is such that a user can easily insert a fastener 1 (such as a screw, nail, wall anchor, rivet or the like) through an optional aperture 125 defined in extension 127 . Preferably, clip 100 is of one-piece construction, and is made of an easily-formable material, such as plastic. More preferably, the plastic is an extruded plastic. A seal 130 is disposed at the distal end of the trough, as shown by the end of wall 112 such that when the workpiece is placed inside retention channel 110 A, the workpiece forms a close fit with the panel-engaging portion 120 , the lower wall 114 , and the edge formed by the seal 130 . The seal 130 promotes a relatively tight fit between the workpiece and the clip 100 so that the flow of air between the workpiece and the generally planar surface to which the clip is mounted is significantly reduced. Efficacy of the seal 130 is enhanced when the workpiece is generally planar and relatively rigid. In a preferable (although not necessary) form, seal 130 is made of a material that is more pliant than that of the remainder of clip 100 . For example, both could be made of plastic, where the plastic of seal 130 is more flexible than that of the panel-engaging portion or the remainder of retention portion 110 . Clip 100 includes a substantially constant cross-section, such that it is amenable to rapid, low-cost production techniques, including extrusion. The seal 130 may be made from the same material as the remainder of clip 100 , or made from a different material such that the two can be co-extruded.
Regardless of the nature of the material used to form the seal 130 , the seal 130 is configured such that it defines a restricted channel entrance 132 along a longitudinal dimension of the retention channel 110 A. More specifically, as is clearly illustrated in FIG. 1 , the channel entrance 132 defines a channel access dimension a that is restricted relative to a parallel dimension b of a remaining portion of the retention channel 110 A, such that (b-a) represents an extension distance t 1 of the seal 130 which, as is illustrated in FIG. 2 , exceeds the spacing S that is defined between the insulation 300 and the wall panel 400 . The I-shaped and T-shaped clips described below also define corresponding extension distances t 2 that exceed the spacing s, as is clearly illustrated in FIGS. 3A , 3 B, 4 , and 6 . The insulative characteristics of a sheet of insulation held by the clip 100 are thus enhanced because the seal either defines a discrete contact surface with the insulative sheet or at least restricts the size of any gap between the clip 100 and the insulative sheet at the channel entrance 132 .
Referring next to FIG. 2 , the relative engagement of insulation 300 , support clip 100 and the wall panel 400 is shown, where the wall panel 400 is shown in a preferably vertical orientation. The connection between the clip 100 and wall panel 400 can be by any known means, such as adhesives or fasteners. In the event a fastener is used, the relatively exaggerated surface of panel-engaging portion 120 provides a suitable location through which the fastener may be placed. Seal 130 is preferably oriented such that defines a knife-edge along the seal's longitudinal dimension. As can be seen from the figure, the size of the clip 100 relative to the insulation 300 , as well as the inwardly-projecting seal 130 is such that seal 130 forms a snug fit against a corresponding surface of the insulation 300 . This snug fit further improves the insulative properties of the wall/insulation combination, as it cuts down on airflow around the insulation 300 that could otherwise lead to drafting and related circulation problems. By having the seal 130 be relatively compliant, it can be more conformally shaped against the insulation 300 to further reduce the likelihood of formation of gaps or related airflow passages. Support of insulation 300 along a downward direction is provided by trough 110 , specifically its lower wall 114 . Referring to FIG. 5 , as clearly illustrated in the Figure, the plurality of insulation panels 300 have a major surface parallel to a surface of the wall 400 .
Referring next to FIGS. 3A , 3 B and 6 , variations 200 and 250 on a second clip are shown. Referring with particularity to FIG. 3A , one variation defines a substantially T-shaped retention portion 210 made up of a pair of retention channels 210 A, 210 B. In this variation, the clip 200 comprises a unitary structure where retention portion 210 is integrally formed with an elongate panel-engaging portion 220 along an S-shaped spring 240 . In the present context, a structure is considered “unitary” when it is of one-piece construction. By way of example, a one-piece molded or extruded plastic component would be considered to exhibit unitary construction. Similarly, if the part includes co-extruded seals 230 A, 230 B (collectively seals 230 ), it is still of unitary construction, as the finished part has no components that are separately attached after the forming process. The inclusion of spring 240 allows the retention channels 210 A, 210 B to be elastically bent during insertion of the insulation, then snapped back into place afterwards. As with the J-shaped support clip 100 , seals 230 disposed at the ends of each respective channel 210 A and 210 B are used to facilitate a snug fit between the insulation (not presently shown) and the clip 200 . In addition, panel-engaging portion 220 includes an extension 227 that forms a base that can be mounted to a wall panel in a manner similar to that of support clip 100 . Referring with particularity to FIG. 6 , a further variation is shown on the unitary construction of the second clip, where panel-engaging portion 520 together with retention portion 510 (defined by channels 510 A, 510 B) makes up clip 500 . In addition to previously shown and described spring 240 (shown presently as spring 540 A) disposed on a generally vertical wall of retention portion 510 , a second spring 540 B is included on the generally horizontal wall that carries the and seals 530 A, 530 B. The addition of the second spring 540 B provides additional clip compliance, further enabling insertion of a layer of insulation into the channels 510 A, 510 B.
Referring with particularity to FIG. 3B , another variation 250 of the second clip is substantially I-shaped such that it defines a retention portion 260 made up of a pair of retention channels 260 A, 260 B. Unlike the unitary construction of clip 200 , adjoining clip 250 is of two-piece construction, where connection 290 between them is defined by a T-shaped male member 294 that can be secured to a substantially T-shaped female member 292 . Panel-engaging portion 270 of female member 292 defines a base that is mountable to the surface of the wall panel (not presently shown). As with the previously-discussed variation, clip 250 includes seals 280 (shown corresponding to each respective channel as 260 A and 260 B) that are used to facilitate a snug fit between the insulation (not presently shown) and clip 250 . Referring to FIG. 5 , as clearly illustrated in the Figure, the co-extruded seals (not shown) of the I-shaped clip 250 engage a major face of the plurality of insulation panels 300 .
Referring next to FIG. 4 , the engagement of retention channels 260 A, 260 B to the panel-engaging portion 270 for clip 250 is shown. While the insertion of male member 294 into female member 292 could be effected by various means (such as a frictional pressing into place of the former to the latter), a more permanent connection can be established by using numerous prismatic retention members 293 disposed on corresponding surfaces of the members 294 , 292 such that the prismatic retention members 293 are configured to define complementary snap-fit connection surfaces. The prismatic retention members 293 would resist separation from the complementary engaging surface once joined. Prismatic retention members 293 could be made from any suitable shape, of which triangular, saw-tooth or trapezoidal forms are examples. Preferably, but not necessarily, the relationship between the prismatic retention members 293 is such that a permanent lock can be formed. In the present context, a locking arrangement is considered “permanent” where the connection between two members is such that they cannot be separated without severely curtailing or disabling their subsequent connective properties.
Examples of dimensions of the clips 100 , 200 and 250 (of which the latter is shown in FIG. 4 ), while capable of being adapted to any predetermined size (based on the application), are described in conjunction with FIG. 4 . Overall width W 1 of the top of the retention portion 260 is approximately two inches, with an overall height H 1 of approximately seven-eights of an inch. The overall height H 2 of the male member 294 is approximately thirteen-thirty seconds of an inch with the height H 3 of each individual prismatic retention member 293 approximately three thirty-seconds of an inch. Furthermore, each individual prismatic retention member 293 has a width W 2 of approximately three thirty seconds of an inch at its outer dimension, and a width W 3 of approximately one-sixteenth of an inch at its inner dimension. The top of the retention portion 260 is angled A 1 relative to a horizontal plane by approximately one degree. Seals 280 A, 280 B are angled A 2 relative to the same horizontal plane by between one hundred and thirty five and one hundred and forty degrees. Height of the seals 280 A, 280 B is approximately five thirty-seconds of an inch, and includes an approximately thirteen degree taper angle A 3 with a thickness at its narrow end of approximately one-thirty second of an inch. The panel-engaging portion 270 has an overall height H 4 of approximately one and one-thirty second of an inch, with a thickness B of the horizontally-oriented base 271 of approximately one-sixteenth of an inch. The outer dimension width W 3 of the female member 292 is approximately three-sixteenths of an inch, with an inner dimension width of the portion that receives the prismatic retention members 293 ranging from approximately one-sixteenth of an inch for the inner dimension W 4 , to approximately three-thirty seconds of an inch for the outer dimension W 5 . The angle A 4 with which the opening of female member 292 makes with the horizontal plane is between sixty-five and seventy degrees, shown specifically in the figure as approximately sixty-nine degrees.
Referring to FIG. 5 , in conjunction with FIGS. 1 , 3 A and 3 B, it will be appreciated that the relative thickness dimensions T 1 of first clip 100 and T 2 of second clips 200 , 250 is such that T 1 is slightly greater than T 2 . Thus, in placing the clips onto wall panel 400 , the second clips 200 , 250 can be placed within first clip 100 . The flexible nature of the material (such as the aforementioned PVC) making up clips 100 , 200 and 250 facilitates the relative overlapping relationship between the clips. It will also be appreciated that while first clips 100 are shown in a generally horizontal orientation, they are also suitable for generally vertical mounting as shown such that they can substantially enclose the vertical edge of the insulation 300 that would otherwise be left exposed.
Referring to FIG. 5 , as clearly illustrated in the Figure, the trough of one of the J-shaped clips 100 is provided on a bottom portion of the plurality of insulation panels 300 and the trough of another one of the J-shaped clips 100 is provided on a top portion of the plurality of insulation panels 300 . A side portion of the insulation panel 300 is provided within one retention portion of the I-shaped clip 250 . In one configuration, both ends of the I-shaped clip 250 extend vertically into the opposing trough portion of the at least two J-shaped clips 100 .
Referring to FIG. 5 , as clearly illustrated in the Figure, the co-extruded seal 130 of the J-shaped clips 100 engage the major face of the plurality of insulation panels 300 .
Having described the invention in detail and by reference to preferred embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. More specifically, although some aspects of the present invention are identified herein as preferred or particularly advantageous, it is contemplated that the present invention is not necessarily limited to these preferred aspects of the invention.
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An insulated wall assembly including a plurality of pre-cast panels, a plurality of insulation panels, at least two J-shaped clips, and at least one I-shaped clip is provided. The precast panels may be oriented such that the adjacent vertical edges are in an abutting relationship to form a wall, and the J-shaped clips comprise a trough portion and a wall engaging portion. The I-shaped clip comprises two wall engaging portions and a two retention portions, and the wall engaging portions of the J-shaped clips each define a substantially planar wall-engaging surface capable of attaching to the wall. The wall-engaging portions of the I-shaped clip each define a substantially planar wall-engaging surface capable of attaching to the wall. The trough portion of the J-shaped clip comprises at least one pliant integral co-extruded seal extending away from a distal edge of the trough portion in an angled configuration, and each retention portion of the I-shaped clip includes at least one pliant integral co-extruded seal extending away from a distal edge of the retention portion in an angled configuration.
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FIELD
[0001] This disclosure relates to Handicapping Services.
BACKGROUND
[0002] Professional sports handicappers monitor and collect information to predict outcomes on particular aspects of sporting events. Subscribers to the resulting plays often receive updates when they seek them rather than receiving notifications about changes in circumstances which change the predictions.
[0003] Handicappers sometimes use existing technologies such as websites, emails, and instant messages, but on an ad hoc basis.
SUMMARY
[0004] The instant application discloses, among other things, techniques to provide handicappers a simplified interface to distribute items, which may include predictions and other information in more reliable, consistent, and faster ways. Handicappers may provide predictions (or “picks”) for sporting events, share prices in a stock market, weather, or any other topic. Items may include picks, news, observations, or other insights to subscribers, with updates distributed regularly, for example on an hourly basis, or on an irregular timetable, for example news as it happens. One skilled in the art will recognize than many different events may trigger distribution of items.
[0005] A subscriber may be a person (“user”) or a device capable of receiving notifications, predictions or other types of information from one or more handicappers, via a way supported by Handicapping Services.
[0006] A combination of hardware and software may be used to allow a subscriber to select which items the subscriber will receive, as well as how the information will be delivered. For example, a user may choose to receive predictions about professional football games on a particular day, and that the user wishes to receive the information via instant messages. Another user may wish the same information delivered via a microblog site such as TWITTER™ or email. Many different types of items and methods of delivery may be integrated into the hardware and software.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is an example of a system on which Handicapping Services may be implemented according to one embodiment.
[0008] FIG. 2 is a block diagram of creating predictions for Handicapping Services according to one embodiment.
[0009] FIG. 3 is a block diagram illustrating input to a Handicapping Services server according to one embodiment.
[0010] FIG. 4 is a block diagram illustrating output from a Handicapping Services server according to one embodiment.
[0011] FIG. 5 is a flow chart for one embodiment of Handicapping Services.
[0012] FIG. 6 is a flow chart for another embodiment of Handicapping Services.
[0013] FIG. 7 illustrates a component diagram of a computing device according to one embodiment.
DETAILED DESCRIPTION
[0014] A more particular description of certain embodiments of Handicapping Services may be had by references to the embodiments shown in the drawings that form a part of this specification, in which like numerals represent like objects.
[0015] FIG. 1 is an example of a system on which Handicapping Services may be implemented. A handicapper may input items on Handicapper's Device 110 , and transfer the items to Server 130 by using Network 120 . A user may receive items from Server 130 on Subscriber's Device 140 via Network 120 .
[0016] Network 120 may include Wi-Fi, cellular data access methods, such as 3G or 4GLTE, the Internet, local area networks, wide area networks, or any combination of these or other means of providing data transfer capabilities.
[0017] Server 130 may include one or more computers, and may serve a number of roles, including, but not limited to, storing and retrieving: content, configuration information, subscribed user lists, user preferences, and credentials for both users and handicappers.
[0018] Subscriber's Device 140 may be a desktop computer, a laptop, a tablet, a smartphone, a cell phone, a specialized device for this application, or any other type of device capable of receiving notifications.
[0019] One skilled in the art will recognize that Handicapper's Device 110 , Subscriber's Device 140 , and Server 130 may be of many different designs and may have different capabilities.
[0020] FIG. 2 is a block diagram of creating Predictions 240 for Handicapping Services according to one embodiment. Predictions 240 , also known as picks, may be created by a handicapper, and may pertain to any types of information subscribers may wish to have experts or professionals assist in predicting, for example, but not limited to, sports competition outcomes, weather, or stock market prices. Predictions 240 based on Analysis 230 of Knowledge 210 and Research 220 . Research 220 may include reading news stories, having discussions with others, watching sports, seeing how players are performing, hearing of industry news, sky-watching, or any other way of obtaining information. One having skill in the art will recognize that research for predicting events may take many different forms depending on a topic, may vary from handicapper to handicapper, and may vary from time to time.
[0021] Predictions 240 may change over time as Knowledge 210 , Research 220 , or Analysis 230 are updated, which may happen multiple times per day. A handicapper may wish to share any of Knowledge 210 , Research 220 , Analysis 230 , or Predictions 240 with subscribers.
[0022] FIG. 3 is a block diagram illustrating input to a Handicapping Services server according to one embodiment. A handicapper may use Handicapper's Device 110 to enter Items 350 , which may include Predictions 240 and Information 330 of interest to subscribers. Items 350 may then be transferred via Network 120 to Server 130 , where it may be stored as Items 360 , and may include Predictions 340 and Information 335 .
[0023] Handicapping Services Application 300 may be software running on Server 130 , or on a combination of servers, networks, and other devices. Handicapping Services Application 300 may be running as one monolithic application, or as components running in a distributed fashion. It may provide various services, including but not limited to, receiving, storing, and distributing Items 360 , authenticating subscribers, determining and using communication channels, and distributing notifications. Handicapping Services Application 300 may provide a consistent interface for handicappers to communicate with subscribers.
[0024] Server 130 may contain a Subscriber Database 310 . Subscribers may be people who receive items from the handicapper. Subscriber Database 310 may include information about subscribers including names, account information, preferences for ways of communicating, billing information, or other information relating to subscribers. One having skill in the art will recognize that Subscriber Database 310 may be made up of one or more physical databases, and that many different storage and file formats may be used. In another embodiment, different information may be stored, or other storage techniques may be implemented.
[0025] Configuration Information 320 may include account information for Handicapping Services to distribute Predictions 240 . For example, information relating to TWITTER™, email, text messaging, or other forms of communication may be stored, which may allow Server 130 to post or send information so that subscribers may receive it.
[0026] Information 335 may include information entered as Information 330 on Handicapper's Device 110 , as well as information from other Handicappers or from other sources. This information may be news updates, analyses made by a Handicapper, stock price updates, weather observations, or any other information that may be of interest to subscribers or other handicappers.
[0027] Predictions 340 may include a copy of Predictions 240 . Predictions 340 may also include additional predictions from other handicappers, and may include various types of predictions depending on a subject matter of the predictions. For example, Predictions 340 may include predictions from several sports handicappers who have predicted outcomes from various sporting events, and from a meteorologist predicting weather. One having skill in the art will recognize that many different storage methods may be used to store and retrieve these types of information.
[0028] FIG. 4 is a block diagram illustrating output from a Handicapping Services server according to one embodiment. Server 130 may directly or indirectly send one or more notification of Items 360 , which may include Predictions 340 or Information 335 , to a Subscriber's Device 140 via Network 120 . A selection of which notifications to be sent and how they may be sent may be based upon information in Subscriber Database 310 , Configuration Information 320 , and Items 360 . As an example, one subscriber may receive notifications of predictions made by a particular handicapper via an SMS message, while another subscriber may receive notifications of updates of stock prices. Information to allow determining how to send notifications and which subscribers should receive them may be obtained from data contained in one of or a combination of Subscriber Database 310 , Configuration Information 320 , and Items 360 , which may include Predictions 340 and Information 335 .
[0029] Various communications techniques and applications (“channels”) may be used to transmit notifications to Subscriber's Device 140 , including but not limited to TWITTER®, email, SMS, a dedicated software application, a mobile application, a web page, FACEBOOK®, or other social networks. One having skill in the art will recognize that many communication channels and formats may be used, and that a subscriber may use one or more of these options.
[0030] Notification 440 may include one or more notifications of Items 360 , and may be displayed or stored on Subscriber's Device 140 .
[0031] FIG. 5 is a flow chart for one embodiment of Handicapping Services. A handicapper may Enter Item 510 on a Handicapper's Device 110 . The Item may be Sent 520 to Handicapping Services, over Network 120 . Handicapping Services may perform a process to Review Subscriber Information 530 to Determine a Subscriber 540 to receive a notification of the Item. This may be based upon Subscriber Database 310 , Item 360 , and Configuration Information 320 . Handicapping Services may review Configuration Information 320 and Determine a Channel to Use 550 to deliver a notification. Handicapping Services may then Send Notification Using Determined Channel 560 . For example, if the determined subscriber requested delivery of Items via email, Handicapping Services may use an email service to send the notification. In one embodiment, the sent notification may include a link which may allow authentication of a subscriber and allow the subscriber to obtain the prediction or information. In another embodiment, the notification may include the prediction or information.
[0032] FIG. 6 is a flow chart for another embodiment of Handicapping Services. A handicapper may Enter Item 510 on a Handicapper's Device 110 . The Item may be Sent 520 to Handicapping Services, over Network 120 . Handicapping Services may Distribute Notification 630 broadly. For example, followers of the Handicapper may receive a notification via TWITTER®, others may receive FACEBOOK® status updates, emails, SMS messages, or any other communication channel to indicate a new item is available. Handicapping Services may then Receive Request for Item 640 from a subscriber, indicating a subscriber wishes to read the item. Handicapping Services may then Authenticate Subscriber 650 and Determine a communications Channel to Use 550 based upon the handicapper, the item, the Subscriber Database 310 , and the Configuration Information 320 . Handicapping Services may then Send Item Using the Determined Channel 560 . For example, if the determined subscriber requested delivery of Items via email, Handicapping Services may use an email service to send the notification. In one embodiment, the sent notification may include a link which may allow authentication of a subscriber and allow the subscriber to obtain the prediction or information. In another embodiment, the notification may include the prediction or information.
[0033] One having skill in the art will recognize that there are many possible implementations to provide a similar functionality of Handicapping Services.
[0034] FIG. 7 illustrates a component diagram of a computing device according to one embodiment. The Computing Device ( 1300 ) can be utilized to implement one or more computing devices, computer processes, or software modules described herein, including, for example, but not limited to a Handicapper's Device 110 , a Subscriber's Device 140 , or a Server 130 . In one example, the Computing Device ( 1300 ) can be utilized to process calculations, execute instructions, receive and transmit digital signals. In another example, the Computing Device ( 1 300 ) can be utilized to process calculations, execute instructions, receive and transmit digital signals, receive and transmit search queries, and hypertext, compile computer code as required by a Handicapper's Device 110 , a Subscriber's Device 140 , or a Server 130 . The Computing Device ( 1 300 ) can be any general or special purpose computer now known or to become known capable of performing the steps and/or performing the functions described herein, either in software, hardware, firmware, or a combination thereof.
[0035] In its most basic configuration, Computing Device ( 1300 ) typically includes at least one Central Processing Unit (CPU) ( 1 302 ) and Memory ( 1 304 ). Depending on the exact configuration and type of Computing Device ( 1 300 ), Memory ( 1304 ) may be volatile (such as RAM), non-volatile (such as ROM, flash memory, etc.) or some combination of the two. Additionally, Computing Device ( 1300 ) may also have additional features/functionality. For example, Computing Device ( 1300 ) may include multiple CPU's. The described methods may be executed in any manner by any processing unit in computing device ( 1300 ). For example, the described process may be executed by both multiple CPU's in parallel.
[0036] Computing Device ( 1300 ) may also include additional storage (removable and/or non-removable) including, but not limited to, magnetic or optical disks or tape. Such additional storage is illustrated in FIG. 5 by Storage ( 1306 ). Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Memory ( 1304 ) and Storage ( 1 306 ) are all examples of computer storage media. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by computing device ( 1300 ). Any such computer storage media may be part of computing device ( 1 300 ).
[0037] Computing Device ( 1300 ) may also contain Communications Device(s) ( 1312 ) that allow the device to communicate with other devices. Communications Device(s) ( 1312 ) is an example of communication media. Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, radio frequency (RF), infrared and other wireless media. The term computer-readable media as used herein includes both computer storage media and communication media. The described methods may be encoded in any computer-readable media in any form, such as data, computer-executable instructions, and the like.
[0038] Computing Device ( 1300 ) may also have Input Device(s) ( 1 310 ) such as keyboard, mouse, pen, voice input device, touch input device, etc. Output Device(s) ( 1308 ) such as a display, speakers, printer, etc. may also be included. All these devices are well known in the art and need not be discussed at length.
[0039] Those skilled in the art will realize that storage devices utilized to store program instructions can be distributed across a network. For example, a remote computer may store an example of the process described as software. A local or terminal computer may access the remote computer and download a part or all of the software to run the program. Alternatively, the local computer may download pieces of the software as needed, or execute some software instructions at the local terminal and some at the remote computer (or computer network). Those skilled in the art will also realize that by utilizing conventional techniques known to those skilled in the art that all, or a portion of the software instructions may be carried out by a dedicated circuit, such as a digital signal processor (DSP), programmable logic array, or the like.
[0040] While the detailed description above has been expressed in terms of specific examples, those skilled in the art will appreciate that many other configurations could be used. Accordingly, it will be appreciated that various equivalent modifications of the above-described embodiments may be made without departing from the spirit and scope of the invention.
[0041] Additionally, the illustrated operations in the description show certain events occurring in a certain order. In alternative embodiments, certain operations may be performed in a different order, modified or removed. Moreover, steps may be added to the above described logic and still conform to the described embodiments. Further, operations described herein may occur sequentially or certain operations may be processed in parallel. Yet further, operations may be performed by a single processing unit or by distributed processing units.
[0042] The foregoing description of various embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification, examples and data provide a complete description of the manufacture and use of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
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The instant application discloses, among other things, techniques to allow analysis, predictions, or other observations made by a professional, for example a sports handicapper, a weather forecaster, or a stock analyst, to be obtained by subscribers through various communication options.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2008-322133 filed Dec. 18, 2008.
BACKGROUND
1. Technical Field
The present invention relates to a liquid droplet ejecting head and a liquid droplet ejecting apparatus and particularly to a liquid droplet ejecting head and a liquid droplet ejecting apparatus that eject a high-viscosity liquid as a liquid droplet.
2. Related Art
Water-based inkjet printers that are known as liquid droplet ejecting apparatus and are currently commercially available use dye-based liquids and pigment-based inks with a viscosity generally around 5 cps or 10 (or slightly larger than 10) cps at most. For reasons such as preventing liquid-bleeding when the liquid lands on a medium, increasing optical color density, suppressing expansion of the medium resulting from water content reduction and drying the medium in a short amount of time, and/or increasing the degree of freedom when totally designing such a high-quality liquid, it is known that printing performance can be improved by increasing ink viscosity.
In the ejection of the high-viscosity liquid, it is easy for problems to occur, in comparison to a low-viscosity liquid, such as the stability of the ejected liquid falls and variations in the ejected liquid droplets per nozzle increase. Particularly in a case where, counter to excessive flow path resistance of the high-viscosity liquid, back pressure is applied in order to supply the liquid to the vicinity of the nozzle, it becomes even more difficult to maintain a uniform meniscus (problem of dripping from the nozzle may also arise), and the above-described problems are promoted.
SUMMARY
A liquid droplet ejecting head of an aspect of the present invention includes: a nozzle that ejects a liquid droplet; a liquid flow path member at which a liquid flow path that supplies a liquid toward the nozzle is formed; a back pressure generating unit that applies back pressure to the liquid in the liquid flow path toward the nozzle; a beam member joined together with the liquid flow path member or including the liquid flow path member, that deforms so as to become concave in a liquid droplet ejection direction, thereafter undergoes buckling reverse deformation so as to become convex in the liquid droplet ejection direction, and applies inertia to the liquid in the vicinity of the nozzle in the ejection direction, to cause the liquid in the vicinity of the nozzle to be ejected from the nozzle as a liquid droplet; an opening that is disposed on an opposite side of the liquid flow path member to a side in the ejection direction and is communicated with the external atmosphere; a suction path whose suction opening is directed toward the vicinity of the nozzle; and a negative pressure generating unit that generates negative pressure in the suction path.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention will be described in detail with reference to the following figures, wherein:
FIG. 1A is a side view showing the structure of a liquid droplet ejecting head pertaining to the invention, FIG. 1B is a cross-sectional view showing the structure of the liquid droplet ejecting head pertaining to the invention, and FIG. 1C and FIG. 1D are perspective views showing the structure of the liquid droplet ejecting head pertaining to the invention;
FIG. 2 is a side view showing operations of the liquid droplet ejecting head pertaining to the invention;
FIG. 3 is a side view showing operations of the liquid droplet ejecting head pertaining to the invention;
FIG. 4 is a side view showing operations of the liquid droplet ejecting head pertaining to the invention;
FIG. 5A is a perspective view showing the structure in the vicinity of a nozzle of the liquid droplet ejecting head pertaining to the invention, and FIG. 5B is a cross-sectional view showing the structure in the vicinity of the nozzle of the liquid droplet ejecting head pertaining to the invention;
FIG. 6A and FIG. 6B are cross-sectional views showing the structure in the vicinity of the nozzle of a liquid droplet ejecting head pertaining to a second exemplary embodiment of the invention;
FIG. 7A to FIG. 7C are perspective views showing a process of manufacturing the liquid droplet ejecting head pertaining to the invention;
FIG. 8A is a cross-sectional view showing the structure in the vicinity of the nozzle of a liquid droplet ejecting head pertaining to a third exemplary embodiment of the invention, and FIG. 8B is a cross-sectional view showing the structure in the vicinity of the nozzle of a liquid droplet ejecting head pertaining to a fourth exemplary embodiment of the invention;
FIG. 9A and FIG. 9B are perspective views showing the structure in the vicinity of the nozzle of a liquid droplet ejecting head pertaining to a fifth exemplary embodiment of the invention;
FIG. 10A to FIG. 10C are cross-sectional views showing the relationship between the size of an opening and a meniscus in the liquid droplet ejecting head pertaining to the invention;
FIG. 11A to FIG. 11E are cross-sectional views showing the relationship between the size of the opening and a meniscus in the liquid droplet ejecting head pertaining to the invention; and
FIG. 12 is charts showing the relationship between a positional relationship between the opening and the nozzle and ejection performance in the liquid droplet ejecting head pertaining to the invention.
DETAILED DESCRIPTION
In FIG. 1A to FIG. 1D , there is shown the basic structure of a liquid droplet ejecting head 10 pertaining to exemplary embodiments of the invention.
The liquid droplet ejecting head 10 shown in FIG. 1A and FIG. 1B has a structure where a hollow tubular flow path member 12 having a liquid flow (supply) path 13 and a suction path 42 (mentioned later) inside and a nozzle 16 in a substantial center in its length direction and a beam member 14 that supports the flow path member 12 are joined together in a columnar shape and where support members 18 support both ends.
Further, in the left side portion of the liquid droplet ejecting head 10 with respect to the nozzle 16 in FIG. 1B (at the side of another rotary encoder 20 B which will be mentioned later), a piezo element 30 is joined to the beam member 14 , and a signal electrode 32 is joined to the piezo element 30 , such that an actuator 36 is configured by the beam member 14 , the piezo element 30 and the signal electrode 32 . The beam member 14 also serves as a common electrode of the piezo element 30 , and the piezo element 30 is sandwiched between the beam member 14 and the signal electrode 32 . An electrode pad 33 is disposed on one end of the signal electrode 32 and is connected to an unillustrated switching IC by an unillustrated wire 34 . The piezo element 30 is driven by a signal from this switching IC such that control as to whether to cause the beam member 14 to make flexure (bend) or not to make flexure (bend) is performed.
The flow path member 12 is capable of flexure in a liquid droplet ejection direction (upward in FIG. 1A and FIG. 1B ) and in the opposite direction and ejects, by inertia in the ejection direction as liquid droplets, a liquid L that has been supplied from a liquid pool 24 through the liquid flow path 13 to reach the nozzle 16 .
At this time, the liquid L, to which back pressure has been applied by a back pressure generating component 200 , is supplied to the liquid flow path 13 from the liquid pool 24 disposed in one rotary encoder 20 A, is fed from a longitudinal direction end to the vicinity of the nozzle 16 , and is ejected from the nozzle 16 as liquid droplets 2 .
Moreover, as shown in FIG. 1B , on the opposite side of the ejection direction with respect to the nozzle 16 , an opening 116 is disposed in the beam member 14 and the actuator 36 , and opens to the atmosphere. Thus, the liquid L that has been fed from the liquid flow path 13 temporarily stays in a liquid pool 100 formed in the vicinity of the opening 116 disposed in the beam member 14 .
As shown in FIG. 1B , a liquid suction pool 124 disposed in another rotary encoder 20 B is communicated with a suction component (a negative pressure generating component 300 ) such that negative pressure is applied to the liquid suction pool 124 . The suction path 42 is disposed in the flow path member 12 on the opposite side of the nozzle 16 with respect to the liquid flow path 13 in the longitudinal direction, and is communicated with the liquid suction pool 124 . For this reason, the suction path 42 sequentially sucks out and removes the liquid L that stays in the liquid pool 100 in the vicinity of the opening 116 .
In the right side portion of the liquid droplet ejecting head 10 with respect to the nozzle 16 in FIG. 1B (at the side of the one rotary encoder 20 A), as shown in FIG. 1D , a flow path member 40 is disposed on one side of the beam member 14 , such as on the opposite side in the ejection direction, for example, and a blowing path 44 is formed inside the flow path member 40 . The blowing path 44 is communicated with a blowing component 400 such that air that has been pressurized is fed through the blowing path 44 . At this time, a filter may be disposed inside the blowing path 44 to filter the air, or a humidifying component may be disposed inside the blowing path 44 to humidify the air with solvent component of the liquid L.
The support members 18 are pressed from both sides in positions that are offset from rotation centers of the rotary encoders 20 (hereinafter, “rotary encoder 20 A and rotary encoder 20 B” will be merely recited as “rotary encoders 20 ”), or force is applied in a bend direction to the support members 18 , such that the flow path member 12 that is joined to the beam member 14 is made flexure in the ink liquid ejection direction or in the opposite direction. The support members 18 may have a rod-like structure that is long in the front-to-back direction of the page surface of FIG. 1A , for example, or may have a ladder-like structure where plural flow path members 12 are disposed in the support members 18 .
Further, in the case of a liquid droplet ejecting head that jets the liquid droplets 2 collectively from the plural nozzles 16 , it is not necessary for the suction path 42 to be disposed for each nozzle 16 ; for example, one suction path 42 may be formed with respect to two nozzles 16 (liquid flow paths 13 ). It is not necessary for the liquid flow path 13 and the suction path 42 to have the same shape, and the suction path 42 may have a larger (fatter, wider, higher) cross section than that of the liquid flow path 13 .
<Buckling Reverse Ejection>
In FIG. 2 and FIG. 3 , there is shown the relationship between buckling reverse and the flexure direction of the beam member and the flow path member of the liquid droplet ejecting head pertaining to the exemplary embodiments of the invention. All of these drawings shown deformation focusing on one flow path member in a liquid droplet ejecting head with a structure where plural flow path members are disposed in a ladder-like manner in the support members.
In a case where the liquid droplet ejecting head 10 is controlled so as to not eject the liquid droplet 2 , first, as shown in (A) in FIG. 2 , the rotary encoders 20 reversely rotate (rotate in the direction where they stretch the flow path member 12 ) such that the rotary encoders 20 straightly stretch the flow path member 12 which is in a state of having a convex shape in the ejection direction in an initial state.
Next, as shown in (B) in FIG. 2 , when slackening stretching the flow path member 12 , the actuator 36 is not driven because a signal instructing ejection is not sent to the flow path member 12 , and the flow path member 12 remains in the state where it is made flexure so as to be convex in the ejection direction.
Further, when the rotary encoders 20 continue to be forwardly rotated in the ejection direction as shown in (C) and (D) in FIG. 2 , the flexure amount increases in the state where the flow path member 12 is made flexure so as to be convex in the ejection direction, but this does not lead to ejection of the liquid droplet 2 from the nozzle 16 because deformation of the flow path member 12 in the ejection direction resulting from buckling reverse does not occur.
On the other hand, in a case where the liquid droplet ejecting head 10 is controlled so as to eject the liquid droplet 2 , first, as shown in (A) in FIG. 3 , the rotary encoders 20 reversely rotate (rotate in the direction where they stretch the flow path member 12 ) such that the rotary encoders 20 straightly stretch the flow path member 12 which is in a state of having a convex shape in the ejection direction in an initial state, and place the flow path member 12 in a state where there is no flexure.
Next, as shown in (B) in FIG. 3 , a signal instructing ejection is sent to the flow path member 12 from the unillustrated switching IC, the actuator 36 is driven, and the flow path member 12 is made in a flexure state so as to be concave in the ejection direction.
Moreover, when the rotary encoders 20 are forwardly rotated in the direction of the arrows shown in (C) in FIG. 3 , the flexure direction of the flow path member 12 changes, from near the rotary encoders 20 (that is, from both end sides in the longitudinal direction), such that the flow path member 12 becomes convex in the ejection direction (upward in the drawing).
When this change approaches the center from both end sides, the flow path member 12 (or the beam member 14 ) undergoes a steep buckling reverse at a certain point and abruptly deforms convex in the liquid droplet ejection direction (upward in the drawing) as shown in FIG. 3D .
Because the nozzle 16 is disposed in the substantial center of the flow path member 12 in the length direction of the flow path member 12 , the liquid L that is supplied through the inside of the flow path member 12 and reaches the nozzle 16 is ejected as the liquid droplet 2 from the nozzle 16 in accompaniment with the convex deformation of the flow path member 12 in the ejection direction resulting from this buckling reverse.
Moreover, after the flexure amount reaches a maximum in FIG. 3D and the rotary encoders 20 stop, the rotary encoders 20 reversely rotate to flatten the flow path member 12 ((A) in FIG. 3 ) and thereby return the flow path member 12 to the initial position shown in (A) in FIG. 3 .
In FIG. 4 , there is shown another structure of the liquid droplet ejecting head pertaining to the exemplary embodiment of the invention. That is, one longitudinal direction end of a beam member 14 is fixed to a support member 18 that is held in a rotary encoder 20 B, and the other longitudinal direction end as a fixed end is held in a support member 18 B that is fixed.
Further, a liquid flow path 13 is disposed at the support member 18 B side in a flow path member 12 that is disposed on the beam member 14 , a liquid L is fed toward a nozzle 16 that is disposed in the vicinity of the longitudinal direction center, and the liquid L is ejected from the nozzle 16 .
As shown in (A) in FIG. 4 , from an initial state where the half of the beam member 14 on the rotary encoder 20 B side is concave on the ejection side and where the half of the beam member 14 on the other end side is convex on the ejection side, the liquid L is fed through the inside of the liquid flow path 13 from the end of the beam member 14 (the flow path member 12 ) and is fed to the nozzle 16 as shown in (A) in FIG. 4 .
Moreover, as shown in (B) in FIG. 4 , when the rotary encoder 20 rotates in the ejection direction, the beam member 14 begins to deform so as to become convex in the ejection direction starting from the one end of the beam member 14 that is held by the support member 18 , and, as shown in (C) in FIG. 4 , the portion of the beam member 14 in the vicinity of the nozzle 16 (near the center in the longitudinal direction) undergoes buckling reverse in the ejection direction, and the liquid L is ejected as the liquid droplet 2 from the nozzle 16 .
In FIG. 5A and FIG. 5B , there are shown details of the structure in the vicinity of the nozzle of the liquid droplet ejecting head pertaining to a first exemplary embodiment of the invention.
The liquid L is fed, in a state where back pressure is applied, through the inside of the liquid flow path 13 formed by the flow path member 12 , so the liquid L is always supplied to the liquid pool 100 that is formed in the vicinity of the opening 16 . At this time, the liquid pool 10 temporarily holds the liquid L, which is supplied in a larger quantity than the liquid quantity that is lost by ejection, so as to not become supply-deficient, and the surplus portion of the liquid L is sucked out and discharged by the suction path 113 to which negative pressure is applied. Thus, the liquid L in the pool 100 forms a free surface, shear resistance of the liquid L that obstructs inertia ejection of the liquid droplets 2 is suppressed, and the liquid droplet ejecting head is given a configuration where, in comparison to a structure where the opposite side in the ejection direction (back side of the nozzle) is tightly closed, it is difficult to be obstructed for ejection even when the liquid L has a high viscosity.
As shown in FIG. 5A and FIG. 5B , the flow path member 12 of the liquid droplet ejecting head 10 is equipped with the liquid flow path 13 that penetrates the inside of the flow path member 12 in its longitudinal direction and the nozzle 16 that is disposed in the flow path member 12 , and the opening 116 that is formed by perforating the beam member 14 is disposed on the back side (opposite side in the ejection direction) of the nozzle 16 .
The flow path member 40 is disposed on the opposite side of the beam member 14 in the ejection direction (the back side of the beam member 14 ), and the blowing path 44 is formed between the flow path member 40 and the beam member 14 . The blowing path 44 is communicated with the blowing component such that air that has been pressurized is fed through the blowing path 44 as indicated by arrow 43 .
A filter 48 is disposed as a filtering component inside the blowing path 44 and filters the air that is fed through the blowing path 44 . Moreover, a humidifying component 46 such as a sponge that is capable of holding a liquid is disposed inside the blowing path 44 and humidifies the air that is fed through the blowing path 44 with solvent component of the liquid L. Some of the air that has been fed as indicated by arrow 43 proceeds toward the suction path 113 as indicated by arrow 45 in the liquid pool 100 and is sucked out and removed together with the surplus liquid L as indicated by arrow 41 .
By configuring the liquid droplet ejecting head 10 in this manner, the liquid droplet ejecting head 10 has a configuration where, in comparison to a configuration where the liquid pool 100 merely opens to the atmosphere, there is little incorporation of dirt and foreign matter because air that has been filtered by the filter 48 is fed to the liquid pool 100 and it is difficult for the liquid L in the vicinity of the nozzle 16 to dry because air that has been humidified by solvent is fed.
Second Exemplary Embodiment
In FIG. 6A and FIG. 6B , there are shown details of the structure in the vicinity of the nozzle of a liquid droplet ejecting head 11 pertaining to a second exemplary embodiment of the invention.
The place where an opening 116 is disposed and which had been open to the atmosphere in the first exemplary embodiment is sealed by a flexible thin film 102 of a polyimide or epoxy resin with a thickness of about 5 μm, for example, such that the liquid L in a liquid pool 100 that has been formed is prevented from contacting the outside air.
That is, the opening 116 is disposed in a beam member 14 on the opposite side of the nozzle 16 in the ejection direction to form the liquid pool 100 , and the opposite side of the liquid pool 100 in the ejection direction is sealed by the thin film 102 , so that when the liquid L is fed, in a state where back pressure is applied, through the inside of a liquid flow path 13 formed by a flow path member 12 , the thin film 102 expands as shown in FIG. 6A due to the back pressure that is applied to the liquid L.
The liquid L is always supplied to the liquid pool 100 , so the liquid pool 100 that the expanded thin film 102 seals temporarily holds the liquid L, which is supplied in a larger quantity than the liquid quantity that is lost by ejection, and the surplus portion of the liquid L is sucked out and removed by a suction path 113 to which negative pressure is applied. Thus, in the liquid pool 100 , a surface is formed by the flexible thin film 102 , and shear resistance of the liquid L that obstructs inertia ejection of a liquid droplet 2 is suppressed.
The liquid droplet ejecting head 11 has a structure where, at the time of ejection of the liquid droplet 2 , as shown in FIG. 6B , the thin film 102 deforms in the direction of the nozzle 16 (ejection direction), so it is difficult for the liquid L inside the liquid flow path 13 to be restrained. Accordingly, at the time of ejection of the liquid droplet 2 , the liquid droplet ejecting head 11 has a configuration where, in comparison to a structure where the opposite side in the ejection direction (back side of the nozzle) is tightly closed by a rigid member, it is difficult to be obstructed for ejection even when the liquid L has a high viscosity.
<Manufacturing Process>
In FIG. 7A to FIG. 7C , there is shown an example of a process of manufacturing the liquid droplet ejecting head pertaining to the exemplary embodiments of the invention. First, an SUS plate with a thickness of about 20 μm is etched (slit-etched) in rows with blank therebetween with a slit width of about 70 μm, and a PI (polyimide) film 14 B is heat-sealed to the ejection surface back side to form the beam member 14 .
As shown in FIG. 7A , an SUS plate with a thickness of about 10 μm where a PI (polyimide) film 12 B has been heat-sealed to the ejection surface back side is slit-etched with a slit width of 70 μm as a flow path member 12 A. Next, the opening 116 is perforated by a YAG laser 50 or the like from the ejection surface back side to form a void (space) where the liquid pool 100 will be formed.
Next, as shown in FIG. 7B , a PI film 12 C is heat-sealed to the ejection surface side of the flow path member 12 A. The nozzle 16 is perforated by the YAG laser 50 or the like, and the beam member 14 that has been disposed in parallel in the longitudinal direction of the support member 18 is divided. Further, at the same time, the liquid pool 24 that communicates with the slits (=the liquid flow paths 13 ) that have been disposed in the flow path member 12 A is disposed by removing the PI film 12 C. At this time, slit-etching is performed beforehand with respect to the beam member 14 and the flow path member 12 B, so just the PI film 12 C on the surface is removed by laser ablation.
Moreover, the piezo elements 30 on which the signal electrodes 32 have been formed beforehand are joined in a region up to half in the longitudinal direction at the ejection back surface. A supply port 25 through which the liquid is supplied from an unillustrated liquid feed pump is connected to the liquid pool 24 disposed inside the support member 18 , and the liquid droplet ejecting head 10 is formed.
Third Exemplary Embodiment
In FIG. 8A , there is shown a cross-sectional view of the vicinity of a nozzle 16 of a liquid droplet ejecting head 110 pertaining to a third exemplary embodiment of the invention. In the liquid droplet ejecting head 110 , a flow path member 12 is disposed on a beam member 14 whose one end is held in a support member 18 , and a liquid flow path 13 is disposed in the longitudinal direction inside the flow path member 12 .
As shown in FIG. 8A , the flow path member 12 of a liquid droplet ejecting head 110 is provided with the liquid flow path 13 that penetrates the inside of the flow path member 12 in its longitudinal direction and the nozzle 16 that is disposed in the flow path member 12 , and an opening 116 that is formed by perforating the beam member 14 is disposed on the back side (opposite side in the ejection direction) of the nozzle 16 .
A flow path member 40 is disposed on the opposite side of the beam member 14 in the ejection direction (the back side of the beam member 14 ), and a blowing path 44 is formed between the flow path member 40 and the beam member 14 . The blowing path 44 is communicated with the blowing component such that air that has been pressurized is fed through the blowing path 44 as indicated by arrow 43 .
A filter 48 is disposed as the filtering component inside the blowing path 44 and filters the air that is fed through the blowing path 44 . Moreover, a humidifying component 46 such as a sponge that is capable of holding a liquid is disposed inside the blowing path 44 and humidifies the air that is fed through the blowing path 44 with solvent component of the liquid L.
The liquid flow path 13 becomes a suction path 113 after passing the nozzle 16 and is communicated with the suction component such that negative pressure is applied thereto. Some of the air that has been fed as indicated by arrow 43 proceeds toward the suction path 113 as indicated by arrow 45 A in a liquid pool 100 and is sucked out and removed together with the surplus liquid L as indicated by arrow 41 .
On the other hand, some of the air does not proceed from the liquid pool 100 toward the suction path 113 but is returned back to the blowing component through an air circulation path as indicated by arrow 45 B. Moreover, the air is fed from the blowing component to the blowing path 44 and is again sent to the liquid pool 100 as indicated by arrow 43 . By configuring the liquid droplet ejecting head 110 in this manner, the liquid droplet ejecting head 110 has a configuration where, in comparison to a configuration where the liquid pool 100 merely opens to the atmosphere, there is little incorporation of dirt and foreign matter because air that has been filtered by the filter 48 is always fed. Further, drying of the liquid in the vicinity of the nozzle 16 can be suppressed.
Fourth Exemplary Embodiment
In FIG. 8B , there is shown a cross-sectional view of the vicinity of the nozzle 16 of a liquid droplet ejecting head 111 pertaining to a fourth exemplary embodiment of the invention. In the liquid droplet ejecting head 111 , a flow path member 12 is disposed on a beam member 14 whose one end is held in a support member 18 , and a liquid flow path 13 is disposed in the longitudinal direction inside the flow path member 12 .
As shown in FIG. 8B , the flow path member 12 of the liquid droplet ejecting head 111 is provided with the liquid flow path 13 that penetrates the inside of the flow path member 12 in the longitudinal direction and a nozzle 16 that is disposed in the flow path member 12 , and an opening 116 that is formed by perforating the beam member 14 is disposed on the back side (opposite side in the ejection direction) of the nozzle 16 .
A flow path member 40 A is disposed on the opposite side of the beam member 14 in the ejection direction (the back side of the beam member 14 ), and a blowing path 44 A is formed between the flow path member 40 A and the beam member 14 . The blowing path 44 A is communicated with the blowing component such that air that has been pressurized is fed through the blowing path 44 A as indicated by arrow 43 A.
A filter 48 A is disposed as the filtering component inside the blowing path 44 A and filters the air that is fed through the blowing path 44 A. Moreover, a humidifying component 46 A such as a sponge that is capable of holding a liquid is disposed inside the blowing path 44 A and humidifies the air that is fed through the blowing path 44 A with solvent component of the liquid L.
The liquid flow path 13 becomes the suction path 113 after passing the nozzle 16 and is communicated with the suction component such that negative pressure is applied thereto. Air that has been fed as indicated by arrow 43 A proceeds toward the suction path 113 as indicated by arrow 45 in a liquid pool 100 and is sucked out and removed together with the surplus liquid L as indicated by arrow 41 A.
Further, a flow path member 40 B is disposed on the ejection direction side of the beam member 14 (the front side of the beam member 14 ), and a blowing path 44 B is formed between the flow path member 40 B and the beam member 14 . The blowing path 44 B is also communicated with the blowing component such that air that has been pressurized is fed through the blowing path 44 B as indicated by arrow 43 B.
Moreover, a suction path 42 B is formed between the flow path member 40 B and the flow path member 12 on the downstream side of the nozzle 16 in the blowing direction, and the suction path 42 B sucks out air that has been fed thereto. This suction path 42 B is communicated with the negative pressure generating component (a suction pump or the like) such that negative pressure is applied thereto, so the suction path 42 B sucks out and removes air and the liquid L that has spilled over in the ejection direction in the vicinity of the nozzle 16 , as indicated by arrow 41 B.
An opening 416 that is larger than the nozzle 16 as seen from the ejection direction is disposed in the flow path member 40 B and does not obstruct the ejection of the liquid droplet 2 from the nozzle 16 . Moreover, a filter 48 B is also disposed as the filtering component inside the blowing path 44 B and filters the air that is fed through the blowing path 44 B. Moreover, a humidifying component 46 B such as a sponge that is capable of holding a liquid is also disposed inside the blowing path 44 B and humidifies the air that is fed through the blowing path 44 B with solvent component of the liquid L.
By configuring the liquid droplet ejecting head 111 in this manner, the liquid droplet ejecting head 111 has a configuration where, in comparison to a configuration where the liquid pool 100 merely opens to the atmosphere, there is little incorporation of dust and foreign matter because air that has been filtered by the filter 48 A is always fed, and, drying of the liquid in the vicinity of the nozzle 16 can be suppressed. Moreover, it is difficult for the liquid L to adhere in the vicinity of the nozzle 16 .
Fifth Exemplary Embodiment
In FIG. 9A and FIG. 9B , there is shown a liquid droplet ejecting head 112 pertaining to a fifth exemplary embodiment of the invention.
The liquid droplet ejecting head 112 pertaining to the fifth exemplary embodiment of the invention has a structure where, as shown in FIG. 9A , a hollow tubular flow path member 12 having a liquid flow path 13 inside and a nozzle 16 in a substantial center in its length direction and a beam member 14 that supports the flow path member 12 are joined together in a columnar shape and where support members 18 support both ends. Further, on the opposite side of the nozzle 16 in the ejection direction, an opening 116 is disposed and a liquid pool 100 is formed in the beam member 14 , which is the same as in each of the preceding exemplary embodiments.
FIG. 9B shows a cross-section along line A-A of FIG. 9A . As shown in FIG. 9B , in the liquid droplet ejecting head 112 , the hollow flow path member 12 is disposed on the ejection surface side (front side) of the beam member 14 , and the liquid flow path 13 is formed inside the flow path member 12 . Further, a flow path member 40 C is disposed on the opposite side (back side) of the ejection surface, and a suction path 42 C is formed inside the flow path member 40 C.
The suction path 42 C is communicated with a suction component such that negative pressure is applied thereto. The suction path 42 C opens in the vicinity of the liquid pool 100 that is formed on the opposite side of the nozzle 16 in the ejection direction, and the suction path 42 C sucks out and removes the surplus liquid L. By configuring the liquid droplet ejecting head 112 in this manner, the liquid L can be supplied from both end sides of the liquid flow path 13 toward the nozzle 16 . Further, in this configuration, when the liquid L is supplied only from one end side of the liquid flow path 13 toward the nozzle 16 , the suction path 42 C can be disposed on the ejection surface side (front side) and on the opposite side of the ejection surface (back side), which is superior in terms of the dischargeability of the surplus liquid L in comparison to each of the preceding exemplary embodiments.
<Opening Position>
In FIG. 10A to FIG. 10C and FIG. 11A to FIG. 11E , there are shown examples of the relationship between the liquid surface (meniscus) and the distance from the end of the opening to the center of the nozzle in the liquid droplet ejecting head pertaining to the exemplary embodiments of the invention.
In a case where the opening size of the nozzle 16 is 50 μm, when a size d 1 of the opening 116 is equal to or less than 100 μm, as shown in FIG. 10A , the liquid film in the nozzle 16 is easily destroyed and it becomes difficult for the liquid film to form. When a size d 2 of the opening 116 is about 150 μm, as shown in FIG. 10B , the liquid film in the nozzle 16 is thin and becomes unstable, such as occurrence of pulsation due to suction by the suction path 113 . When a size d 3 of the opening 116 is about 200 to 400 μm, as shown in FIG. 10C , the problems that accompany suction described above do not arise.
In a case where the opening diameter of the nozzle 16 is 25 μm, when suction is not performed and the liquid L is capillary-supplied without back pressure being applied thereto, there are no problems in terms of ejectability only in a case where, as shown in FIG. 11A , the size of the opening 116 is 50 μm, and when the size of the opening 116 is about 100 to 150 μm, it becomes difficult for the liquid film to be formed in the nozzle 16 , such as the liquid L moves to the opening 116 and flows out as shown in FIG. 11B . Further, in a case where back pressure is applied to the liquid L and suction is performed by the suction path 113 , liquid spilling, moistening, and ejection variations in the nozzles 16 occur regardless of the size of the opening 116 .
In a case where back pressure is applied to the liquid L and suction is performed by the suction path 113 , when the size of the opening 116 is equal to or less than 100 μm, as shown in FIG. 11C , it becomes easy for the liquid film in the nozzle 16 to be destroyed by suction from the suction path 113 and ejection variations occur.
When the size of the opening 116 is about 150 μm, as shown in FIG. 11D , the liquid film in the nozzle 16 becomes thin and it becomes difficult to maintain the liquid film because the distance from the liquid flow path 13 becomes large, and ejection variations occur. The above-described examples are all results of cases where the centers of the nozzle 16 and the opening 116 coincide as seen from the ejection direction. In this cases where the centers of the nozzle 16 and the opening 116 coincide, it is difficult to obtain sizes of the opening 116 and the nozzle 16 such that proper nozzle ejection performance and the like is obtained.
Thus, the charts in FIG. 12 show results where the distance (d in) from the back pressure side (supply side) end of the opening 116 to the center of the nozzle 16 and the distance (d out) from the suction side (downstream side) end of the opening 116 to the center of the nozzle 16 are varied and ejection performance is visually determined.
As shown in FIG. 12 , ejection performance is excellent when the distance from the back pressure side (supply side) of the opening 116 to the center of the nozzle 16 is within 3 times the diameter of the nozzle 16 , and ejection performance is excellent when the distance from the suction side (downstream side) end of the opening 116 to the center of the nozzle 16 is in the range of 3 times to 10 times the diameter of the nozzle 16 .
<Other>
The present invention is not limited to the preceding exemplary embodiments. For example, in each of the preceding exemplary embodiments, there has been exemplified a configuration where the suction path 113 and the blowing path 44 are disposed for each of the nozzles 16 , but the present invention is not limited to this and may also be configured such that the suction path 113 and the blowing path 44 are disposed for each plurality (e.g., two or four) of the nozzles 16 . At this time, as long as the nozzles 16 are disposed evenly with respect to the suction path 113 and the blowing path 44 , it is easy for the liquid film to be made uniform.
Further, the liquid droplet ejecting head in the exemplary embodiments has been described by way of an inkjet recording head, but the liquid droplet ejecting head is not invariably limited to recording characters and images on recording paper using ink. That is, the recording medium is not limited to paper, and the liquid that is ejected is also not limited to ink. For example, it is possible to apply the present invention to all liquid droplet jetting apparatus that are used for industrial purposes, such as apparatus that eject a liquid onto polymer film or glass to create color filters for displays or apparatus that eject liquid-solder onto a substrate to form bumps for mounting parts.
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A liquid droplet ejecting head of an aspect of the invention includes: a nozzle ejecting a liquid-droplet; a liquid flow path member in which a liquid is supplied toward the nozzle; a back-pressure generating unit applying back-pressure to the liquid in a liquid-flow-path toward the nozzle; a beam member joined together with or including the liquid flow path member, deforming to become concave in a liquid-droplet ejection direction, thereafter undergoing buckling reverse deformation to become convex in the ejection direction, and applying inertia to the liquid near the nozzle in the ejection direction, to cause the liquid near the nozzle to be ejected; an opening disposed on an opposite side of the liquid flow path member in the ejection direction and communicated with the atmosphere; a suction path whose suction opening is directed toward near the nozzle; and a negative-pressure generating unit generating negative-pressure in the suction path.
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BACKGROUND OF THE INVENTION
The present invention relates generally to an apparatus for making a non-woven web from fibers of substantial length (say from 1/2" to 31/2") and/or from synthetic fibers, and more particularly to a subassembly for trimming the edge of one or both edges of the web during its formation stage.
With the advent of synthetic fibrids adaptable for use in the art of forming sheet-like structures, as distinguished from the common wood pulps, it has been determined that the dispersion problem now dictates techniques different from those normally used in order to insure optimum operating performance at the forming area and to provide for the desired balance of physical properties in the final product.
Long fibers offer one particularly annoying problem in that they cannot be wet trimmed by the conventional and known means. Trim showers produce ragged or feather edges which offer a tendency to cause breaks.
In this prior art apparatus, it has been traditional to employ trim squirts or wet trim rolls for the purpose of trimming the edge of edges of the formed web in order to best attain a web of the desired width, with the trimmed edge or edges being reverted to recycling processes.
As the art of papermaking machines, has developed and is developing, with pickup and transfer fabrics being employed, it has been obvious that, therewith, with the resultant absence of open draws, the known trim devices are no longer practical for use.
SUMMARY OF THE INVENTION
The present invention stems from the conclusion that, if it is possible to accommodate a so-called trim board configured to cover the length of the forming area and placed beneath the forming wire, it should be possible to interrupt and prevent sheet formation along that length. Thus it should be possible to define what would be called a "split mat" with the main body portion of the forming web being split or separated from the edge portion thereof at the edge or edges thereof.
Of course, the trim board arrangement would be made adjustable in the across-the-machine direction so as to vary the width of the forming web or vary the width of the trimmed edge, as preferred, and, if desired, the arrangement would be disposed at each opposite side of the machine so as to trim both edges of the forming web or at one side of the machine so as to trim but one edge of the forming web.
By way of exemplification, assume a trim board width on the order of 2" and further assume a disposition of that trim board 10" away from the inside headbox wall. Such would allow an edge mat of approximately 10" width which can be disposed of by running same into the couch pit for recycling while the main portion of the forming web continues in its progress for eventual transfer to the next following machine section.
It is significant that by not forming for a certain width along the length of the trim board area, the flow is not disrupted so as to upset look-through, tensile ratio, or other sheet properties.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a fragmentary diagrammatic view in top plan of the left side of the inclined wire section of the forming machine with the headbox removed and with certain portion of the forming wire removed for purposes of clarity;
FIG. 2 is a sectional view on the line 2--2 of FIG. 1 and including a schematic fragmentary showing of the respective left side wall of the headbox; and
FIG. 3 is a fragmentary diagrammatic sectional view of the left side of the wire section shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring firstly to the embodiment as illustrated in FIG. 3, it will be seen that reference numeral 10 identifies a receptacle conventionally known as a headbox having an inlet 12 and an outlet 14 spaced from and forwardly of the inlet.
The inlet 12 is connected in known manner via a supply conduit (not illustrated) with a source of an aqueous suspension of synthetic fibers, for instance glass fibers.
As indicated by arrow a, this suspension flows forwardly in the direction of the arrow and through the outlet 14.
A pond regulator 16 such as identified in my U.S. Pat. No. 3,384,537 serves the function of controlling the flow of the suspension. The pond regulator cooperantly with the headbox walls defines an area therewithin in which the stream of liquid slurry is confined and aids in the control of the discharge of the slurry onto the upwardly-inclined run of the forming wire or screen 20. Means are provided for adjusting the position of the pond regulator with respect to the headbox and of course to the forming wire, but same are not part of this invention and are not shown in detail.
Suffice to say that the pond regulator facilitates the accommodation within the headbox of a large volume of a free-draining aqueous suspension of fibers known as a slurry or pond and designed to allow regulation of the linear velocity of the slurry without permitting loss of the turbulence required to attain optimum dispersion thereof, all so as to achieve herewith the laying down of a layer of stock upon an upwardly-travelling inclined section of the forwardly-moving run of the wire.
Extending across the outlet 14 is the inclined section of an endless forming wire 20 which is entrained about transporting rollers such as 22, 24 et al. Additional non-illustrated rollers may be provided, certain of which may be driven in order for the forming wire to travel in clockwise direction, as viewed in FIG. 1, and as indicated by arrow b.
The term "forming wire" identifies the screen-like belt or the like which is water permeable.
Arranged beneath that inclined run of the forming wire 20 which extends across the outlet 14 are a series of suction boxes 26 or other suction devices which are each provided with outlet conduits 28 wherefor the degree of vacuum along various parts of the run may be controlled.
As the suspension issues from the outlet 14, the aqueous component of the suspension runs off through the forming wire 20, aided by the suction which exists beneath the latter, and this water is then carried away via the conduits 28 for the usual recycling portion of the stock preparation program.
The solid component of the suspension, that is the fibers, becomes deposited on the upper surface of the forming wire to form the non-woven fibrous web, that is a fleece-like mat 30 which travels away from the outlet 14 on the advancing inclined run of the forming wire 20 and is largely freed of water due to the suction effect of the suction boxes 26.
The trim device constitutes a drainage control unit and is constituted into as many spaced trim boards or masks 40 as practical to accommodate to the particular length of the forming area of the papermaking machine upon which installation is made.
The trim boards or masks, while individually and selectively movable, will be arranged in echelon so as to be aligned with each other in the direction of the advance of the forming wire.
The trim boards 40, each of a width in the order of say 2", are disposed beneath the forming wire, and are alignable as to each other in the direction of the advance of the forming wire. Adjacent trim boards are separated by a key 42 extending transversely across the machine width, the trim boards being mated with the respective keys in such as a tongue-and-groove manner wherefor the trim boards may be moved inwardly or outwardly relative to the tending side of the machine in directions as indicated by arrows c.
Each keyway is disposed immediately above a respective line of joinder between respective adjacent suction devices.
In practice the trim boards will be arranged at the desired distance inboard of the inside wall 11 of the headbox 10.
As can be appreciated by reference to FIG. 2, the trim boards can be moved laterally toward or away from the table rail R of the papermaking machine.
The trim boards function in the manner of sliding valves so that the suspension on the wire may be held back from flowing through the wire along the defined length and thereby not only stop its flow through the wire but also preclude the deposition of fibers along that length.
The term trim is normally used to mean cut, but in papermaking the term trim is used to mean separating an edging from a main body portion of a web being formed. Cutting in such instance is not involved.
By the aligning of the trim boards along the axis of the movement of the wire, a width of, in the described exemplification, 2" along the entire mat forming length is provided, in which width drainage through the wire is precluded wherefor disposition of fibers is precluded. Mat formation being there prevented, a split mat is provided with a main portion 50 proceeding forwardly in the usual manner and the split of edge portion 52 proceeding to the recycling system.
From the foregoing it will be understood that the present invention is possessed of unique advantages. However, such modifications and equivalents of the disclosed concepts such as readily occur to those skilled in the art are intended to be included within the scope of this invention and thus the scope of this invention is intended to be limited only by the scope of the claims such as are, or may hereafter be, appended hereto.
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In a papermaking machine, a drainage interrupting mask of a certain width is disposed between a continuously moving endless Fourdrinier wire and respective suction box therebelow for interrupting web formation through the said certain width and along the length of the forming web and providing a dividing of the web with that portion of the web outboard of the mask being recycled for subsequent reuse as pulp slurry while the remainder of the forming web continues forwardly for the usual papermaking functions.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a paper feeding device that is used in a printer, which prints and issues a receipt, ticket, or the like using a sheet of a paper roll, and feeds the sheet of the paper roll to a printing device.
2. Description of the Related Art
As such a paper feeding device, for example, there is known a paper feeding device disclosed in Patent Document JP 05-345429 A.
However, in the paper feeding device disclosed in Patent Document JP 05-345429 A, a paper roll holder which bearing-supports the paper roll accommodates only one kind of paper roll, in other words, only, for example, a paper roll having 4 inches diameter in an unused (new) state. Thus, when a user intends to change to a paper roll having a larger diameter (paper roll having 6 inches diameter, for example) in response to usage condition or the like, the paper roll having the larger diameter cannot be mounted to the paper roll holder, thereby causing a problem of bad usability.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above-mentioned circumstances, and therefore has an object to provide a paper feeding device in which a plurality of paper rolls having different diameters in an unused (new) state can be mounted freely according to a choice of a user, and can increase convenience for a user.
In order to solve the above-mentioned problem, the present invention adopts the following means.
A paper feeding device according to the present invention is a paper feeding device that feeds a sheet of a paper roll to a printing device and includes two side plates vertically arranged along both side surfaces of the paper roll, each of the side plates including a plurality of notches which are capable of bearing-supporting paper rolls having different diameters in an unused state, one of the side plates including: a near end sensor that detects a remaining amount of the paper roll; and a linear groove that causes the near end sensor to slide in two directions moving close to and away from the paper roll bearing-supported by each of the notches.
In the paper feeding device according to the present invention, there are provided the plurality of notches which are capable of bearing-supporting the paper rolls having the different diameters in the unused (new) state, and hence the paper rolls having the different diameters in the unused (new) state can be mounted freely according to a choice of a user, whereby it is possible to increase the convenience for a user.
Further, even in a state where the paper roll is bearing-supported by any notches, the near end sensor is caused to slide along the linear groove, whereby the near end sensor can be easily moved to a direction close to or a direction away from the paper roll and can be easily arranged in a position suitable for detecting the remaining amount of the paper roll.
In the paper feeding device, it is more suitable that the groove is formed so that a longitudinal axis of the groove passes through a midpoint of a straight line connecting a rotation center of a paper roll bearing-supported by one notch of the plurality of notches and a rotation center of a paper roll bearing-supported by another notch of the plurality of notches and is placed on another straight line which is vertical to the straight line.
According to the paper feeding device described above, in the case where a diameter of a paper tube which is set (fixed) to a center portion of the paper roll bearing-supported by the one notch and rotates together with the paper roll and a diameter of a paper tube which is set (fixed) to a center portion of the paper roll bearing-supported by the another notch and rotates together with the paper roll are equal (or substantially equal) to each other, a sensor portion of the near end sensor detects that a remaining amount of the paper roll set in the one notch and a remaining amount of the paper roll set in the another notch are equal (or substantially equal) to each other.
Therefore, even in the case where a paper roll having other diameter (different diameter) is set in the one notch or the another notch, when a remaining amount of a paper roll to be detected is not changed, the near end sensor can be left as it is without being caused to move, whereby it is possible to further increase the convenience for a user.
In the paper feeding device described above, it is more suitable that the groove is formed so that the near end sensor can be moved close to and away from a paper roll bearing-supported by a notch other than the one notch and the another notch.
According to the paper feeding device described above, the near end sensor can be moved close to and away from the paper roll bearing-supported by any notch, whereby it is possible to increase the convenience for a user.
A printer according to the present invention includes the paper feeding device which is capable of freely mounting the paper rolls having the different diameters in the unused (new) state according to the choice of a user, thereby increasing the convenience for a user.
According to the present invention, the plurality of the paper rolls having the different diameters in the unused (new) state can be mounted freely according to the choice of a user, thereby attaining an effect of increasing the convenience for a user.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a side view of a printer provided with a paper feeding device according to an embodiment of the present invention;
FIG. 2 is an enlarged view of one side plate of the paper feeding device illustrated in FIG. 1 ;
FIG. 3 is a sectional view taken along an arrow A-A of FIG. 2 ; and
FIG. 4 is an enlarged view of one side plate of a paper feeding device according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Hereinafter, an embodiment of a paper feeding device according to the present invention is described with reference to FIGS. 1 to 3 .
FIG. 1 is a side view of a printer provided with the paper feeding device according to this embodiment. FIG. 2 is an enlarged view of one side plate of the paper feeding device illustrated in FIG. 1 . FIG. 3 is a sectional view taken along an arrow A-A of FIG. 2 .
As illustrated in FIG. 1 , a printer 1 includes a printing device 4 that prints various kinds of information on a thermal printing layer of a sheet of a paper roll (thermal paper, for example) 2 a ( 2 b ) fed from a paper feeding device 3 in a conveying direction of the sheet of the paper roll 2 a ( 2 b ), a cutting device (paper cutting device) 5 that cuts the sheet of the paper roll 2 a ( 2 b ) printed by the printing device 4 , and a paper discharging device 6 that takes out (discharges) the sheet of the paper roll 2 a ( 2 b ) cut by the cutting device 5 from a bezel (paper outlet) (not shown).
The printing device 4 is a so-called thermal printer, and includes a thermal head (not shown) for heating the thermal printing layer of the sheet of the paper roll 2 a ( 2 b ) and a platen roller (not shown) pressed to the thermal head. The printing device 4 performs printing while pinching the sheet of the paper roll 2 a ( 2 b ) fed from the paper feeding device 3 between the thermal head and the platen roller, and conveys the same.
The cutting device 5 includes, for example, a pair of disk-like rotating blades (not shown) for cutting the sheet of the paper roll 2 a ( 2 b ) taken out from the printing device 4 to a desired length, and conveys the cut sheet of the paper roll 2 a ( 2 b ) to the paper discharging device 6 .
Further, the paper feeding device 3 , the printing device 4 , the cutting device 5 , and the paper discharging device 6 are combined through a main body frame 7 .
As illustrated in FIG. 1 , the paper feeding device 3 according to this embodiment includes a paper holder 8 and a near end sensor 9 .
The paper holder 8 includes a bottom plate 8 a having a substantially rectangular shape in plan view extending in the conveying direction and a width direction of the sheet of the paper roll 2 a ( 2 b ), and two side plates 8 b extending upward in a vertical direction from side edges of the bottom plate 8 a.
In each side plate 8 b of the paper holder 8 , there are provided, for example, a first notch 11 which is set (fixed) to a center portion of the paper roll 2 a having 6 inches diameter and bearing-supports a paper tube (core: rotating shaft) 10 rotating together with the paper roll 2 a , and, for example, a second notch 13 which is set (fixed) to a center portion of the paper roll 2 b having 4 inches diameter and bearing-supports a paper tube (core: rotating shaft) 12 rotating together with the paper roll 2 b . The first notch 11 and the second notch 13 are formed so that a front end (end portion on the printing device 4 side) 14 of an outer peripheral surface of the unused (new) paper roll 2 a having 6 inches diameter when the paper roll 2 a is set in the first notch 11 through the paper tube 10 , and a front end (end portion on the printing device 4 side) 15 of an outer peripheral surface of the unused (new) paper roll 2 b having 4 inches diameter when the paper roll 2 b is set in the second notch 13 through the paper tube 12 are positioned in the same vertical plane.
Further, a groove 16 is provided in one side plate 8 b of the paper holder 8 (near-side side plate 8 b of FIG. 1 , in this embodiment) The groove 16 guides protrusions 9 a (see FIG. 3 ) protruding from a back surface of the near end sensor 9 (inner-side surface of FIG. 1 ) and serves as an opening which is required for a sensor portion 9 b arranged on the back surface of the near end sensor 9 to detect a remaining amount of the paper roll 2 a ( 2 b ).
As illustrated in FIG. 2 , the groove 16 is a long hole which is formed so that a central axis (longitudinal axis) thereof passes through a midpoint of a straight line L 1 connecting a central axis (rotation center) C 1 of the paper tube 10 and a central axis (rotation center) C 2 of the paper tube 12 and is placed on a straight line (vertical bisector) L 2 which is vertical to the straight line L 1 . In other words, the groove 16 is formed so that a distance between the sensor portion 9 b of the near end sensor 9 and the central axis C 1 of the paper tube 10 when the near end sensor 9 is moved closest to the paper tube 10 set in the first notch 11 , and a distance between the sensor portion 9 b of the near end sensor 9 and the central axis C 2 of the paper tube 12 when the near end sensor 9 is moved closest to the paper tube 12 set in the second notch 13 are equal to each other, and that the distance between the sensor portion 9 b of the near end sensor 9 and the central axis C 1 of the paper tube 10 when the near end sensor 9 is moved farthest away from the paper tube 10 set in the first notch 11 and the distance between the sensor portion 9 b of the near end sensor 9 and the central axis C 2 of the paper tube 12 when the near end sensor 9 is moved farthest away from the paper tube 12 set in the second notch 13 are equal to each other.
As illustrated in FIG. 3 , the protrusions 9 a protruding from the back surface of the near end sensor 9 are formed to be fitted into the groove 16 so as not to generate backlash therewithin, and formed to move smoothly without drag from one end of the groove 16 to the other end thereof.
Further, in the near end sensor 9 , a screw 17 is loosened to generate clearances (gaps) between end surfaces of the protrusions 9 a and a surface of a presser plate 18 , whereby the near end sensor 9 can be caused to slide integrally with the screw 17 and the presser plate 18 while keeping that condition along the groove 16 to a desired position. At the same time, the screw 17 is fastened at a desired position to sandwich the one side plate 8 b between the end surfaces of the protrusions 9 a and the surface of the presser plate 18 , whereby the near end sensor 9 can be set (fixed) to a desired position.
In the paper feeding device 3 according to this embodiment, the first notch 11 and the second notch 13 are provided on each side plate 8 b of the paper holder 8 , and hence any one of the two paper rolls 2 a , 2 b having the different diameters in the unused (new) state is mounted freely according to a choice of a user, whereby it is possible to increase the convenience for a user.
Further, when the paper roll 2 a having 6 inches diameter or the paper roll 2 b having 4 inches diameter in the unused state is mounted to the first notch 11 or the second notch 13 , the first notch 11 and the second notch 13 are formed so that the front ends 14 , 15 of the outer peripheral surfaces of the paper rolls 2 a , 2 b are positioned in the same vertical plane, whereby it is possible to stably feed a paper sheet to the printing device 4 in the case of using any one of the paper rolls 2 a , 2 b.
Moreover, in the paper feeding device 3 according to this embodiment, the groove 16 forming of a long hole is provided in the one side plate 8 b of the paper holder 8 . Accordingly, a user can set the near end sensor 9 to a desired position easily and rapidly in accordance with the diameter of the paper roll 2 a ( 2 b ) selected appropriately as needed.
Note that, adjusting the position of the near end sensor 9 can be performed by merely sliding along the groove 16 , and hence anyone can perform it easily.
Still further, in the paper feeding device 3 according to this embodiment, the groove 16 is formed so that the central axis thereof passes through the midpoint of the straight line L 1 connecting the central axis C 1 of the paper tube 10 and the central axis C 2 of the paper tube 12 and is placed on the straight line L 2 which is vertical to the straight line L 1 . Accordingly, in the case where the diameter of the paper tube 10 and the diameter of the paper tube 12 are equal (or substantially equal) to each other, the sensor portion 9 b of the near end sensor 9 detects that the remaining amount of the paper roll 2 a set in the first notch 11 and the remaining amount of the paper roll 2 b set in the second notch 13 are equal (or substantially equal) to each other.
Therefore, even in the case where the paper roll 2 b or a paper roll having a diameter other than that of the paper rolls 2 a , 2 b is set in the first notch 11 , or a paper roll having a diameter other than that of the paper rolls 2 a , 2 b is set in the second notch 13 , when a remaining amount of the paper roll to be detected is not changed, the near end sensor 9 can be left as it is without being caused to move, whereby it is possible to further increase the convenience for a user.
On the other hand, a manufacturer which manufactures and sells the paper feeding device 3 does not need to prepare paper holders corresponding to respective paper rolls having the different diameters in the unused (new) state, and hence the number of components can be reduced. Further, it is possible to reduce the manufacturing cost and to realize the simplification of parts control.
Further, the printer 1 provided with the paper feeding device 3 according to the present invention includes the paper feeding device 3 which can mount the paper rolls 2 a , 2 b having the different diameters in the unused (new) state freely according to the choice of a user, whereby it is possible to increase the convenience for a user.
Note that, the present invention is not limited to the embodiment described above, and variation or modification can be effected appropriately as needed without departing from the technical idea of the present invention.
For example, in the embodiment described above, the paper holder 8 provided with the two notches 11 , 13 has been described. However, the present invention is not limited thereto and can employ a paper holder 25 provided with three notches 21 , 22 , 23 and a circular hole (notch) 24 as illustrated in FIG. 4 .
The notches 21 , 22 , 23 and the circular hole 24 are each provided in each of the side plates 8 b of the paper holder 8 and bearing-support paper tubes 26 , 27 , 28 , 29 which are set to center portions of paper rolls (not shown) and rotate together with the paper rolls. The notches 21 , 22 , 23 and the circular hole 24 are formed so that a straight line L 3 connecting a central axis (rotation center) C 3 of the paper tube 26 and a central axis (rotation center) C 4 of the paper tube 29 passes through a midpoint of a straight line L 4 connecting a central axis (rotation center) C 5 of the paper tube 27 and a central axis (rotation center) C 6 of the paper tube 28 and is placed on straight line (vertical bisector) which is vertical to the straight line L 4 .
Further, a groove 30 is provided in the one side plate 8 b of the paper holder 8 . The groove 30 guides the protrusions 9 a (see FIG. 3 ) protruding from the back surface of the near end sensor 9 (see FIGS. 1 and 2 ) and serves as an opening which is required for the sensor portion 9 b (see FIG. 2 ) arranged on the back surface of the near end sensor 9 to detect a remaining amount of a paper roll.
Then, as illustrated in FIG. 4 , the groove 30 is a long hole which is formed so that a central axis (longitudinal axis) thereof passes through the midpoint of the straight line L 4 connecting the central axis (rotation center) C 5 of the paper tube 27 and the central axis (rotation center) C 6 of the paper tube 28 and is placed on the straight line (vertical bisector) L 3 which is vertical to the straight line L 4 . In other words, the groove 30 is formed so that a distance between the sensor portion 9 b of the near end sensor 9 and the central axis C 5 of the paper tube 27 when the near end sensor 9 is moved closest to the paper tube 27 set in the notch 22 and a distance between the sensor portion 9 b of the near end sensor 9 and the central axis C 6 of the paper tube 28 when the near end sensor 9 is moved closest to the paper tube 28 set in the notch 23 are equal to each other, and that the distance between the sensor portion 9 b of the near end sensor 9 and the central axis C 5 of the paper tube 27 when the near end sensor 9 is moved farthest away from the paper tube 27 set in the notch 22 and the distance between the sensor portion 9 b of the near end sensor 9 and the central axis C 6 of the paper tube 28 when the near end sensor 9 is moved farthest away from the paper tube 28 set in the notch 23 are equal to each other.
Further, the groove 30 is also formed so that the sensor portion 9 b can detect a near end of a paper roll (not shown) having the paper tube 26 when the near end sensor 9 is slid (positioned) to an end (upper end of FIG. 4 ) of the groove 30 , and can detect a near end of a paper roll (not shown) having the paper tube 29 when the near end sensor 9 is slid (positioned) to another end (lower end of FIG. 4 ) thereof.
Effects and actions of the paper feeding device provided with the paper holder 25 are the same as those of the paper feeding device according to the embodiment described above. Accordingly, a description thereof is omitted here.
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A paper feeding device that feeds a sheet of a paper roll to a printing device includes two spaced-apart side plates having opposed first notches for rotatably bearing-supporting a first paper roll and opposed second notches for rotatably bearing-supporting a second paper roll that may have a different diameter in an unused state from that of the first paper roll. A near end sensor for detecting the remaining amount of the paper rolls is slidably positioned in a linear groove formed in one of the side plates. The linear groove having a longitudinal axis that passes through a midpoint of a straight line connecting a rotation center of a first paper roll bearing-supported in the first notches and a rotation center of a second paper roll bearing-supported in the second notches. When first and second paper rolls of different sizes are used, if both paper rolls are wound on paper tubes of the same size, the position of the near end sensor need not be changed, which is a great convenience for the user.
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Recreational vehicles and motor homes may be supplied with three different power sources, namely a landline, which is connected to the recreational vehicle with 120 volt AC power, a motor generator which is carried by the vehicle, and an inverter which converts the 12-volt DC vehicle battery power to 110 volt AC power.
Often, the recreational vehicles and motor home relies the 120-volt AC power for a number of applications including exterior awnings, electric doors, electric shades, air conditioning, and powered patio extensions.
It should be clear that many, if not all, of these accessories are restricted to use when the vehicle is parked, i.e. a stationary condition.
The present invention provides for an alternating current power interlock (ACPI) for providing a disablement of 120-volt AC circuit when recreational vehicles or motor homes are about to be moved and moving. A disablement of 12-volt circuits may also be enabled.
SUMMARY OF THE INVENTION
An AC power system in accordance with the present invention for a recreational vehicle generally includes an input circuit receiving alternating current and at least one output circuit providing alternating current voltage. The output circuit may be utilized for exterior awnings, electric doors, electric shades, air conditioning, and powered patio extensions, as hereinabove noted.
Park brake circuitry provides a brake signal deactivation signal upon parking brake deactivation. Ignition circuitry provides an ignition signal when the vehicle engine ignition is activated.
Interlock circuitry, in accordance with the present invention, interconnected with the hereinabove referenced circuitry disables the AC power output circuit in response to at least one of the brake signals and/or the ignition signal.
The system may include a plurality of output circuits and a plurality of input circuits with the park brake circuitry and ignition circuitry along with the interlock circuitry operating in a manner hereinabove noted. Additional interlocks may be applied such as door switches, pressure switches, security sensor switches and the like.
In addition, a switch circuit may be provided which temporarily disables the output circuit and thereafter restores the output circuit, as will be hereinafter described in greater detail.
The interlock circuitry may also include a circuit disabling the output circuit in response to a combination of the brake signal and ignition signal.
The input circuitry may provide an AC signal upon interruption of alternating current receipt and the interlock circuitry may include circuitry to delay the enabling of the output circuit in response to an absence of the AC signal.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be more clearly appreciated when taken in conjunction with the accompanying drawings in which:
FIGS. 1A and 1B in combination provide a schematic drawing of the AC power system in accordance with the present invention; and
FIG. 2 is a block diagram of a connector panel illustrating input and output corresponding to the schematic diagram, as shown in FIGS. 1A and 1B .
DETAILED DESCRIPTION
An AC powered interlock system 10 in accordance with the present invention is shown schematically in FIGS. 1A , 1 B and FIG. 2 illustrates a block diagram of connections thereto.
The system 10 prevents AC accessory operation when the vehicle is moving or when the AC power is interrupted. This is mandatory since many accessories (not shown) are controlled by wall switches or hand held rf remotes (not shown) that are accessible from the interior of the coach. For safety purposes, it is mandatory to prevent accidental or unwanted operation the switches or remote controls when the vehicle is in motion. The AC interlock system 10 in accordance with the present invention provides a safety interlock and prevents inadvertent operation of the AC accessories in unsafe conditions.
As shown in FIGS. 1A , 1 B, the ACPI 10 is a “smart power switch” that has a single 120-volt input and four 120-volt outputs. There is a switch that may be electromechanical or electrical that interrupts the phase lead whenever the coach is in motion. It provides a way to disable 120-volt AC circuits in motor homes when the vehicle is in an unsafe condition. This system is also usable for 240-volt AC or DC. A two pole switch may be used to interrupt both phase and neutral power wires.
The basic unit contains a three-pin AC power connector with phase, neutral, and ground output. This input circuit is from the inverter or AC distribution panel.
Depending on the current carrying capacity of the switching the ACPI 10 example output circuits are each capable of 3 or 5 amps. These circuits typically go to awning motors but may be used for any of the AC circuits that must be protected from being used when the vehicle is in an unsafe condition.
Current generation environmental control units (awnings, shades, blinds) (not shown) are provided with remote controls that operate the units from a hand set. The ACPI 10 will disable AC power and therefore render the remote control inoperative when the vehicle is moving. This safety feature can be offered on any device that is AC powered.
There are four low level input and signal wires identified as +12 volts, (+12 Volt) ground, ignition, and park brake. These signals are commonly available on a recreational vehicle and may be obtained directly or indirectly from the vehicle. Three conditions are identified which will interrupt the AC input: ignition on, park brake off, or AC power intermittent. So, for example, if the ignition switch is on, or if the park brake is disengaged, the AC will be interrupted and any motor or other device on any one of the four output circuits will be rendered inoperative. If the vehicle driver decides to use the park brake only as an interlock and does not hook up the ignition, then the power will be disabled only if the park brake is disengaged. A similar condition exists if the ignition input is used and the park brake is not hooked up.
Once all of the conditions: park brake engaged, ignition is off, and the AC power is stable, the 120-volt AC input will be switched onto the (four) output circuits after a delay of approximately (20) seconds. This time may be changed to suit the required conditions.
The above description refers to a power control circuit that has one input and several outputs. It is possible to have almost any number of input and output circuit combinations. The description defines a low cost version that requires only one relay or equivalent (AC) interpreter.
An important feature of the above circuit is that all of the conditions must be stable for N seconds before the AC power is switched. Another feature is the capability to switch the power at the zero crossing point. Although this is a well-known technique to prevent large switching currents from being switched by the relay or its equivalent, using this provides greater reliability and less stress on the AC switching components.
The AC input wiring is connected to J 1 and the AC circuits to motors are on J 2 , J 3 , J 4 , and J 5 . There are three wires per circuit. For the AC to be switched on, the ignition must be off and the park brake must be engaged. If these conditions are met, then the AC J 1 will be connected to J 2 , J 3 , J 4 , and J 5 after the conditions are stable for (20) seconds. If a remote control is available, it will operate the motors used in the awnings or shades. If for any reason the AC should be momentarily interrupted, the phase wire of the input will be disconnected from the outputs and remain disconnected until the AC is stable.
If the unit is used for rf motors, (motors with built-in rf controls) it may be used to separately reprogram motors to accept the rf channel(s). This is done using the four phase interrupt switches, PJ 1 , PJ 2 , PJ 3 , and PJ 4 . For example, if the motor connected to the circuit on J 1 needs to be reprogrammed, PJ 1 is set “on” and switch SW 1 is depressed and switches PJ 2 , PJ 3 , and PJ 4 are set to off. This must be done within one minute of pressing SW 1 . When SW 1 is pressed a second time, the power on J 1 will be cycled and the motor will be reset. If the switch is not pressed within the minute, the system will revert to normal operation. SW 1 provides a way to interrupt the AC for one minute if pressed only once not more often than every two minutes. The LED (D 3 ) will indicate whenever the AC is active.
Modes of Operation
1. Disable AC on deactivation of park brake.
2. Disable AC on activation of ignition.
3. Disable AC for twenty seconds on momentary “glitch” of AC.
4. Allow AC “program cycle” when SW 1 pushed once. If pushed again within one minute, AC will perform “program cycle” and stay on.
Although there has been hereinabove described a specific AC power interlock system for homes in accordance with the present invention for the purpose of illustrating the manner in which the invention may be used to advantage, it should be appreciated that the invention is not limited thereto. That it is, the present invention may suitably comprise, consist of, or consist essentially of the recited elements. Further, the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein. 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 present invention as defined in the appended claims.
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An AC power system for recreational vehicle includes an input circuit for receiving alternating current and at least one output circuit providing alternating current to devices. A park brake circuit is provided for producing a vehicle brake signal, deactivation signal, and an ignition circuit provides a vehicle engine ignition signal. An interlock provides for disabling the output circuit in response to at least one of the brake signal and ignition signals.
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This is a continuation of application Ser. No. 455,493, filed Jan. 4, 1983, now abandoned, and the benefits of 35 USC 120 are claimed relative to it.
BACKGROUND OF THE INVENTION
The present invention relates to a method for the production of patterned nonwoven fabric by sheet formation under hydraulic pressure treatment with high velocity water streams serving to cause fiber entanglement, and more particularly to such method for production of patterned nonwoven fabric comprising the steps of subjecting fibrous web to the hydraulic pressure treatment with high velocity fine water streams on water-impermeable supports to cause sufficient fiber entanglement in said fibrous web to form a sheet and then of subjecting this sheet to the similar treatment with high velocity fine water streams without deterioration of a strength of said sheet so that the entangled fibers may be reoriented by this last treatment to give the sheet a desired pattern.
It is well known to produce nonwoven fabrics by high energy treatment with water streams at unusually high pressure for fiber entanglement into a fibrous web. However, a mass production on a industrial scale has been difficult with this well known method, because only nonwoven fabric of unsatisfactory properties has been obtained with poor productivity and at a relatively high cost. In view of this situation, the inventors of the present invention have previously developed the effective method to improve the above-mentioned well known method and disclosed it in Japanese Patent Application No. 55-114151, U.S. patent application Ser. No. 293512 (now abandoned), GB Patent Application No. 8125263, West Germany Patent Application No. P31 32 792.3 and French Patent Application No. 81.16036. The invention thus disclosed in the applications in various countries was based on conditions that the supports for fibrous web should have a water-impermeability and a surface hardness of 50° or higher as defined by JIS (the Japanese Industrial Standards)-K 6301 Hs; that each of the orifices adapted to jet the water streams at high pressure should have a vertical section comprising a diameter downwardly tapered portion and a linear small diameter portion, L/D, a ratio of the length L and the diameter of the former portion, being less than 4/1; that each of the water streams should be supplied transversely with respect to each of said supports at a flow rate of 40 cc/sec.cm or lower; that the pressure at which the water streams are jetted through the associated orifices should be lower than 35 kg/cm 2 ; and that a basic weight of the fibrous web to be treated should be between 15 and 100 g/cm 2 .
It is also well known to produce patterned nonwoven fabric by a similar high energy treatment with water streams at high pressure. Such method also has drawbacks similar to those encountered by the above mentioned method.
In view of this situation, the inventors have developed an improved and novel method for production of patterned nonwoven fabric comprising continuous steps of the sheet formation by the fiber entangling treatment according to the previous invention of the inventors and of patterning. More specifically, the present invention is characterized by that, in the previously proposed method in accordance with said previous invention, there is provided as the fibrous web support of the final stage a support provided on its surface with a relief pattern so that the nonwoven fabric may be thereby correspondingly patterned.
The method according to the present invention thus enables patterned nonwoven fabrics of excellent properties to be produced at higher productivity and lower cost compared to the method of the prior art. The nonwoven fabrics obtained by the method of this invention have the bulkiness improved by the relief patterns and the surface gloss so matted that they look as if they are cotton fabrics. Thus, the cushiony, soft and warm touch of the product is remarkably improved. The relief pattern presents high density areas and low density areas so that the spot absorption capacity for liquid is also improved. The patterned nonwoven fabrics according to the present invention will find advantageous applications in a series of goods which are used in direct contact with the skin of the human body, for example, the surface material of a sanitary napkin or a disposable diaper.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a method for the production of patterned nonwoven fabric substantially comprising the steps of subjecting a fibrous web which has a basic weight of 15 to 100 g/m 2 to a fiber entangling treatment, on a plurality of supports each consisting of a water-impermeable roll having a substantially smooth surface and arranged at intervals along a path of the fibrous web, by fine water streams supplied at high velocity from orifices of nozzle means arranged so as to cooperate with the associated supports or rolls; and subjecting the fibrous web having its fibers entangled by the foregoing step, on a support consisting of a roll or endless belt having a relief pattern on its surface and arranged downstream of the last support for the previous step, to similar treatment by fine water streams supplied at high velocity from orifices of nozzle means arranged so as to cooperate with the last-mentioned support so that the fibers in said fibrous web may be effectively reoriented by this treatment to give the sheet the corresponding relief pattern.
BRIEF DESCRIPTION OF THE DRAWING
Preferred embodiments of the present invention will be described in reference with the accompanying drawing in which:
FIG. 1 is a schematic side view showing an apparatus used for realization of a method according to the present invention;
FIG. 2 is a perspective view showing a water-impermeable belt serving as the first support for a fibrous web;
FIG. 3 is a perspective view showing a water-impermeable roll serving as the second support for a fibrous web;
FIG. 4 is a perspective view showing a water-impermeable roll serving as the third support for a fibrous web;
FIG. 5 is a diagram illustrating a principle on which the high velocity fine water streams act upon a fibrous web;
FIGS. 6 to 9 are plan views showing by way of example various relief patterns which may be carried by the surface of the third roll;
FIGS. 10 to 13 are plan views showing the nonwoven fabrics obtained by the patterning treatment on the supports as shown by FIGS. 6 to 9, respectively;
FIGS. 14(A) through 14(D) show by way of example various configurations of each orifice formed in the bottom of each nozzle means in vertical sections; and
FIG. 15 is a perspective view showing another example of relief patterns which may be carried by a plurality of cord like endless belts suspended among each of a plurality of rolls as the third support for a fibrous web.
DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 1, a water-impermeable and substantially smooth-surfaced endless belt 1 as the first support is suspended between a pair of rolls 2, 3, and at the left hand thereof as seen in FIG. 1, there are provided three water-impermeable and substantially smooth-surfaced rolls 4a, 4b and 4c as the second supports. At the left hand thereof, there is provided a water-impermeable roll 5 carrying on its surface a relief pattern as the third support. There are provided nozzle means 6a, 6b, 6c, 6d, 6e above the belt 1, the rolls 4a, 4b, 4c and the roll 5, respectively (see FIGS. 2, 3 and 4). At the left hand of the roll 5 as seen in FIG. 1, a pair of squeeze rolls 8 is provided to remove any excess water from the fibrous web 7. The respective nozzle means 6a, 6b, 6c, 6d, 6e are connected via associated pressure regulating valves 9 and pressure gauges 10 to a distributing reservoir 11. The distributing reservoir 11 is connected via a pipe 12 to a filter reservoir 13 which is, in turn, connected to a pressure pump 15 driven by a motor 14. The pump 15 is connected via a pipe 16 to a reservoir 17. Under the belt 1, the rolls 4a, 4b, 4c, the roll 5 and the rolls 8, there is arranged a tray-like recovery reservoir 18 which is connected via a pipe 19 and a filter box 20 reservoir 17. A quantity of water within the reservoir 17 is pressurized by the pressure pump 15 to an adequately high level, filtered by the filter reservoir 13, then supplied to the distributing reservoir 11, distributed by said reservoir 11 to the respective nozzle means 6a, 6b, 6c, 6d, 6e, and finally jetted through the respective orifices formed in the bottoms of the respective nozzle means at desired pitches unto the belt 1, the rolls 4a, 4b, 4c, and the roll 5, respectively, in the form of high velocity fine water streams (see FIGS. 2, 3 and 4).
In the apparatus as has been described just above, a fibrous web 7 introduced in the direction as shown by an arrow 21 onto the belt 1 and transported in the direction shown by arrow 22 is subjected first to a preliminary fiber entangling treatment on the belt 1 with high velocity water streams supplied through the orifices of the nozzle means 6a so that the fibrous web 7 may be bestowed with an appropriate interlacing cohesiveness of fibers as said fibrous web is transported along the path defined by the belt 1 and the rolls 4a, 4b, 4c without any conspicuous deformation or damage of the web due to a high pressure of the high velocity water streams jetted from the orifices of the respective nozzle means 6b, 6c, 6d. The fibrous web having the fibrous interlacing cohesiveness reinforced in this manner to some degree is then subjected to the fiber entangling treatment in stages and in a full scale under action of the high velocity water streams jetted from the orifices of the respective nozzle means 6b, 6c, 6d as said fibrous web 7 is transported over the respective rolls 4a, 4b, 4c. During this step, the substantially complete sheet in the form of nonwoven fabric having a desired strength is obtained. This nonwoven fabric or the fibrous web 7 having fibers entangled to a desired degree is then treated, on the roll 5, with the high velocity water streams jetted from the orifices of the associated nozzle means 6e and has its fibers reoriented thereby so that a pattern corresponding to the relief pattern carried on the surface of said roll 5 is imparted to the nonwoven fabric. Then, substantially the whole quantity of water contained in the nonwoven fabric is removed by the squeeze rolls 8 and thereafter the nonwoven fabric is transferred to a subsequent process of drying.
FIG. 5 illustrates the principle on which the high velocity water streams behave when the fibrous web is subjected to the fiber entangling treatment on the belt 1 and the rolls 4a, 4b, 4c. The water streams 23 penetrate the thickness of the fibrous web 7, then strike the belt 1 and the rolls 4a, 4b, 4c and rebound thereon upwards so as to act upon the fibrous web 7. Thus, the fibrous web 7 is really subjected to a fiber entangling treatment by reciprocal effect of the water jet streams 23 and their rebounding streams 24, and, in consequence, individual fibers in the fibrous web 7 are displaced in three-dimensional directions so that the fibrous web attains complicated, cohesive and efficient fiber entanglement. The water streams of which the initial energy has been consumed for the fiber entangling treatment now drip off along the supports and partially along the side edges of the travelling fibrous web 7, and finally are recovered by the reservoir 18. Such behaviour of the water streams that these high velocity water streams rebound on the surfaces of the respective supports and the rebounding streams contribute again to the fiber entangling treatment is possible only on the assumption that the respective supports should have an adequately high surface hardness. According to the present invention, therefore, the belt 1 serving as the first support and the rolls 4a, 4b, 4c serving as the second support have their surface hardnesses of 50° or higher, preferably of 70° or higher in accordance with JIS (the Japanese Industrial Standards )-K 6301 Hs. So far as the respective supports have such surface hardnesses and sufficient strengths to resist the pressure of the high velocity water streams, said belt 1 and rolls 4a, 4b, 4c may be exclusively made of metal, rubber or plastic, or of multilayered construction comprising a combination of these materials. Diameters of said rolls 4a, 4b, 4c are preferably selected between 50 mm and 300 mm in order that sufficient strength to resist the pressure of said high velocity water streams may be obtained and the drainage may be facilitated.
FIGS. 6 to 9 show by way of example various relief patterns which can be carried on the roll 5 serving as the third support. Said fibrous web or the nonwoven fabric already fiber entangled to form a stabilized sheet is now subjected to the patterning treatment on the roll 5 and thereby given a pattern corresponding to the relief pattern 25 carried on said roll 5. Such patterning of the nonwoven fabric is achieved due to a fiber reorientation in that the fibers lying on the projection areas 25a of said relief pattern 25 are partially driven by the pressure of the high velocity water streams into the recess areas 25b. It is important, therefore, the orifices of said nozzle means 6e should be arranged so as to direct the water streams jetted from the respective orifices accurately to the projection areas 25a and, to enable it, the orifices each having a diameter of 0.05 to 0.2 mm should be arranged at a pitch less than 2 mm. When the recess areas 25b of the relief pattern 25 are shallower than 0.1 mm, on one hand, the fiber displacement under the pressure of the water streams would be insufficiently small to form a distinct pattern on the nonwoven fabric, and when the recess areas 25b are 1.0 mm or deeper, on the contrary, it would be difficult to peel the nonwoven fabric off from the roll 5 and the pattern once formed on the nonwoven fabric would be disturbed during this operation of peeling off, although such relatively deep recess areas 25b certainly permit a distinct pattern to be formed on the nonwoven fabric. It should be understood here that the high velocity water streams behave on the roll 5 in the same manner as described in connection with FIG. 5 and therefore the fiber entanglement occurs also on the roll 5, but the desired water entanglement has already been achieved before the roll 5. Namely, the step of the method according to the present invention which is accomplished on this roll 5 is exclusively for the patterning treatment of the nonwoven fabric.
The relief pattern 25 may be directly engraved in the surface of the roll 5, or a separate member provided with the relief pattern engraved in the surface thereof may be mounted on the surface of the roll 5 (not shown). Furthermore, a plurality of cord-like members 31 may be stably suspended at intervals among the rolls 5a, 5b, 5c and 5d above which the nozzle means 6e, 6f, 6g, 6h, respectively, are disposed, as shown in the FIG. 15, or a separate mesh-like member may be mounted on the surface of the rolls 5a-5d (not shown). Just like said belt 1 and rolls 4a, 4b, 4c, the rolls 5, 5a, 5b, 5c, 5d also may be exclusively made of metal, rubber or plastic, or of multilayered construction comprising a combination of these materials. Diameter of this roll 5 also is preferably selected between 50 mm and 300 mm in order that the sufficiently high strength to resist the pressure of said high velocity water streams may be obtained and the drainage may be facilitated. It should be noticed here that the roll 5 may be replaced by an endless belt although the latter is not shown.
FIGS. 10 to 12 show the nonwoven fabrics 26 respectively subjected, on the relief patterns 25 carried by the respective rolls 5, to the patterning treatment and having obtained the patterns 27 corresponding to the particular patterns 25 of the associated rolls 5. The pattern 27 formed on each nonwoven fabric 26 has a low density in the area 27a corresponding to each projection area 25a and a high density in the area 27b corresponding to each recess area 25b of said relief pattern 25.
FIG. 14 shows by way of example various configurations of each orifice 28 formed in the bottom of each nozzle means 6a, 6b, 6c, 6d, 6e in vertical sections. The orifice 28 may have a diameter of 0.05 mm to 0.2 mm and, as shown by FIGS. 14(A), (B), (C) and (D) in vertical section, comprise a downward tapered portion 29 and a linear portion 30 at a ratio L/D less than 4/1, preferably less than 3/1 where L represents a length and D represents a diameter of said portion 30. Such configuration of the orifice 28 reduces a pressure loss due to the water stream resistance possibly occurring in said orifice 28. When the orifice 28 is cylindrically formed with an invariable diameter and said ratio L/D is 4/1 or higher, said pressure loss due to the water stream resistance will increase and result in a negligible inconvenience in economic aspects.
Flow rate of the high velocity water streams to be jetted from the nozzle means 6a, 6b, 6c, 6d, 6e provided with such orifices 28 onto the respective supports is less than 40 c.c./sec.cm and preferably less than 30 c.c./sec.cm. The term "transverse average flow rate" means a value F/W where F represents a total flow jetted onto each support, i.e., each of the belt 1, the rolls 4a, 4b, 4c, and the roll 5 as shown by FIGS. 1 to 4 and W represents an effective width of each nozzle means 6a, 6b, 6c, 6d, 6e. Said transverse average flow rate of 40 c.c./sec.cm or higher would result in that the high velocity water streams jetted onto the belt 1, the rolls 4a, 4b, 4c or the roll 5 can not be satisfactorily drained and, in consequence, the fibrous web is flooded. As a result, the energy of the high velocity water streams acting upon the web would be sharply reduced and the fiber entangling effect as well as the patterning effect would be deteriorated or disturbance appearing in the fibrous web would impair the stability of the treatment's result.
A jet pressure of the high velocity water streams or, more strictly, a back pressure in each nozzle means 6a, 6b, 6c, 6d, 6e is less than 35 kg/cm 2 , and preferably 10 to 30 kg/cm 2 . Said back pressure of 35 kg/cm 2 or higher would result in that the individual fibers in the fibrous web are displaced too far to maintain a desired stability of said fibrous web and thereby the fiber entanglement becomes uneven. A back pressure lower than 7 kg/cm 2 would make it impossible to produce the nonwoven fabric of excellent property at a high productivity, even when the fibrous web is subjected for an excessively long period to the treatment with the high velocity water streams or even when said nozzle means are arranged close to the surface of the fibrous web.
As material for the fibrous web, every kind of fibers conventionally used for woven or nonwoven fabrics may be used in the form of tandem web, parallel web or cross web. In view of the fact that the endless belt and/or the rolls having water impermeable surfaces are used as the supports for the fibrous web to be treated, as previously described, the fibrous web of which the basic weight is 15 to 100 g/m 2 and preferably 20 to 60 g/m 2 must be used in order that the energy of the high velocity water streams effectively act on the fibrous web. When the basic weight is less than 15 g/m 2 , the fibrous web would become uneven and, in consequence, it would be impossible to obtain a practically uniform nonwoven fabric. When the basic weight is 100 g/m 2 or higher, use of the water impermeable supports would be in vain.
EXAMPLE
Fibrous web having a basic weight of 38 g/cm 2 and comprising 50% of polyester fibers (1.4 d×51 mm) by weight and 50% of rayon fibers (1.5 d×51 mm) by weight was treated and several samples of nonwoven fabric were produced. The inventors used the apparatus as shown by FIG. 1, in which the jet pressure was 30 kg/cm 2 , the nozzle means each having the orifices arranged at a pitch of 0.5 mm were selected, and the rolls provided with the relief patterns directly engraved in their surfaces as well as the rolls provided with the relief patterns in the form of wire meshes mounted on their surfaces were used as the third support. The recess depths of the recess area in the relief pattern carried on each roll, and the basic weights, the strengths and the pattern qualities of the obtained nonwoven fabric samples are shown in the following table.
TABLE______________________________________Support B.W. of Recess nonwoven TensileSample depth fabric strength PatternNo. Surface (mm) (g/cm.sup.2) (kg/cm.sup.2) Quality______________________________________1 Engraved 0.1 35.2 3.5 Indistinct2 " 0.5 33.1 3.6 Distinct3 " 2.0 35.2 3.3 "4 Wire -- 37.5 3.4 Indistinct mesh (100 mesh)5 Wire -- 34.2 3.3 Distinct mesh (30 mesh)______________________________________
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A method for production of patterned nonwoven fabric from a fibrous web which is subjected to high energy treatment with high velocity water streams not only for fiber entangling but also for patterning of said fibrous web, wherein the fiber entangling treatment is performed on a plurality of non-porous supports arranged in multistaged manner at regular intervals along the path of the fibrous web and the patterning treatment is performed on a separate non-porous support arranged downstream of the previously mentioned non-porous supports and provided on a peripheral surface with a relief pattern.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national stage application (under 35 U.S.C. §371) of PCT/EP2008/002008, filed Mar. 13, 2008, which claims benefit of German application 10 2007 012 623.0, filed Mar. 16, 2007.
BACKGROUND OF THE INVENTION
The invention relates to a packaging with foodstuffs and/or articles of daily use that are sterilized or disinfected for hygienic reasons. The invention also relates to a method for the sterilization, disinfection or partial disinfection of packaged goods.
As long as anyone can remember, sunlight has been credited with the power to counteract diseases or the spreading of infections. Later research showed that the bactericidal effect emanates from the invisible portion of the solar radiation below 320 nm. Therefore, already at the end of the 19th century, the first artificial UV radiation sources were developed and used. An effective disinfection method without chemical agents or the use of high temperatures was hence available.
In the process of the gentle production of foodstuffs and medicinal products, efficient packaging becomes more and more important. Because of changed products and consumer behavior, partially disinfected or aseptic packaging are filled with increasing frequency in order to optimally preserve the quality, prevent premature spoilage and the multiplication of disease-producing germs and hence overall extend the storage life. For the partial disinfection of packaging materials in particular, UV irradiation is a method that is used in practice. However, in many cases it is not sufficient to use disinfected packaging material since the products themselves are frequently contaminated by viruses and bacteria. For a hygienically acceptable packaging unit, the sterilization of the products is therefore necessary in addition. Nevertheless, the possibility that re-germination has occurred by the time the filling or actual packaging of the products takes place cannot be excluded. In any case, several process steps are necessary and high demands on hygiene and cleanliness have to be met when packaging and filling in order to produce a packaging unit that is as hygienically acceptable as possible.
For example, UV treatment of the wash and transport water with the help of which the foodstuffs are pre-purified takes place first. Subsequently, an additional UV treatment of the product to be packaged is required. For this, the different foodstuffs or goods pass through a section in which they are subjected to the UV radiation for a certain period of time in order to achieve a certain disinfection rate. The goal is to kill 90% of the germs residing on the surface and subsequently package the product under sterile conditions.
UV irradiation to disinfect products becomes more and more important since this method has many advantages compared to sterilization methods with peroxides or superheated steam. The methods are easy to apply, the properties of the product are not affected and the disinfection is very effective. During treatment, residues, corrosive or harmful substances are not formed, the smell and taste of the foodstuffs is not altered and the purchase and maintenance costs of the systems are low.
UVC rays have a shorter wavelength and are more energy-rich than UVA and UVB rays. They comprise the largest portion of the entire UV range and exhibit a strong germ-killing (bactericidal) effect. Just like the visible wavelengths of light, UVC rays only travel in a straight line and their intensity decreases with increasing distance from the source. As a matter of principle, UVC rays do not penetrate any material, including window glass.
UVC radiation is technically produced by mercury lamps, the primary radiation of which of 254 nm is very close to the maximum of the bactericidal action. Low-pressure lamps, high-pressure lamps or medium-pressure lamps are optionally used. The efficiency of low-pressure tubes with an efficiency factor of more than 90% in the bactericidal wavelength range is unsurpassed to this day. The remaining radiation of a low-pressure tube is distributed over secondary emissions such as light (above 400 nm) and heat.
The germicidal action of UVC rays is based on the following effects. The short-wave and energy-rich UVC rays are absorbed in certain sections of the genetic material (DNA). As a result, photochemical changes occur in certain sections of the helix, for example linkage reactions of adjacent functional groups. These sections become useless for the copying process of the helix strand operating by the template principle. The necessary passing-on of information does not happen. The cell can no longer multiply.
If the number of disruptions exceeds a level specific to each species, the cell dies without multiplying. As a consequence of this principle of action, germs are not killed in the proper sense! They are, in fact, inactivated and hence are prevented from building up a critical potential by cell division.
BRIEF SUMMARY OF THE INVENTION
The invention was based on the object to provide an improved method for producing sterile, packaged products.
This object is solved by a method for disinfecting products in which the products are enclosed with a packaging material and in the packaged state are irradiated with UVC radiation, the packaging material being permeable to UVC rays.
In prior art, as yet no packaging materials are known that are sufficiently permeable to UVC rays. Hence, as yet it has never been proposed to perform the UV disinfection of the products in the packaged state.
Surprisingly, within the scope of the present invention packaging materials were found that are permeable to UVC rays, contrary to the preconception of prior art. For this reason, according to the invention it is possible to first package products and to then sterilize or disinfect them. The method according to the invention has the extraordinary advantage that the products are disinfected in their packaging or together with the packaging material by means of UVC radiation. For this reason, recontamination after disinfection of the products on the way to packaging is practically completely eliminated.
Surprisingly, within the scope of the present invention UVC permeability was found for polymers of polylactic acid.
DETAILED DESCRIPTION OF THE INVENTION
The packaging material can consist of an unstretched (cast film), a monoaxially oriented or a biaxially oriented polyhydroxycarboxylic acid film comprising one or more layers. Other suitable packaging forms are containers, bowls or similar shapes. The main component of these packaging materials is a polymer made of at least one aliphatic hydroxycarboxylic acid. The packaging material or the film generally comprises at least 70-100% by weight of polymer made of aliphatic polyhydroxycarboxylic acid, preferably PLA (polylactic acid). Embodiments of 80-99% by weight, preferably 85-95% by weight, of the mentioned polymers, each based on the weight of the packaging material, are preferred.
Single-layered or multi-layered films of polyhydroxycarboxylic acid, preferably PLA, are preferably used as packaging material. Both single-layered and multi-layered films of aliphatic polyhydroxycarboxylic acid are suitable for the invention. Multi-layered films are generally composed of a thick base layer which has the largest layer thickness and accounts for 60 to 100% of the total thickness of the film. This base layer is optionally provided with covering layer(s) on one side or both sides. In further embodiments, additional interlayers or coatings on the outer surface of the single-layered or multi-layered film are possible whereby four-layered or five-layered, coated or uncoated, films are obtained. The thickness of the covering layer is generally in a range of 0.5 to 20 μm, preferably 0.5-10 μm, most preferably 1 to 5 μm. According to the invention, the total thickness of the film is in a range of 20 to 150 μm, preferably 25 to 100 μm, most preferably 30 to 100 μm. The covering layers are the layers that form the outer layers of the film. Interlayers are disposed by nature between the base layer and the covering layers. The explanations below regarding the layers of the film apply analogously in similar manner to single-layered embodiments of the film.
The layer(s) of the film comprise(s) 70 to about 100% by weight, preferably 80 to 98% by weight, of a polymer made of at least one aliphatic hydroxycarboxylic acid, below also referred to as PHC or polyhydroxycarboxylic acid. Homopolymers or mixed polymers that are composed of polymerized units of aliphatic hydroxycarboxylic acids are meant hereby. Among the PHC suitable for the present invention are in particular polylactic acids. These are referred to as PLA (polylactic acid) below. Here as well, the term PLA means both homopolymers, which are composed only of lactic acid units, and mixed polymers, which contain predominantly lactic acid units (>50%) in combinations with other aliphatic hydroxylactic acid units.
As monomers of aliphatic polyhydroxycarboxylic acid (PHC), aliphatic mono-, di-, or trihydroxycarboxylic acids or dimeric cyclic esters thereof are particularly suitable, among which lactic acid in its D- or L-form is preferred. Such polymers are known per se in prior art and are commercially available. The production of polylactic acid is also described in prior art and occurs via catalytic ring opening polymerization of lactide (1,4-dioxane-3,6-dimethyl-2,5-dione), the dimeric cyclic ester of lactic acid; PLA is therefore often referred to as polylactide. In the following publications, the production of PLA is described—U.S. Pat. No. 5,208,297, U.S. Pat. No. 5,247,058 or U.S. Pat. No. 5,357,035.
Polylactic acids composed solely of lactic acid units are preferred. PLA homopolymers comprising 80-100% by weight of L-lactic acid units, corresponding to 0 to 20% by weight of D-lactic acid units, are particularly preferred. To reduce the crystallinity, even higher concentrations of D-lactic acid units as comonomer may also be included. Optionally, the polylactic acid can additionally comprise aliphatic polyhydroxycarboxylic acid units different from lactic acid as comonomer, for example glycolic acid units, 3-hydroxypropionic acid units, 2,2-dimethyl-3-hydroxypropionic acid units, or higher homologs of hydroxycarboxylic acids having up to 5 carbon atoms.
Lactic acid polymers (PLA) having a melting point of 110 to 170° C., preferably from 125 to 165° C., and a melt flow index (measured according to DIN 53 735 at 2.16 N load and 190° C.) of 1 to 50 g/10 min, preferably from 1 to 30 g/10 min, are preferred. The molecular weight of the PLA is in a range of at least 10,000 to 500,000 (number average), preferably 50,000 to 300,000 (number average). The glass transition temperature Tg is in a range from 40 to 100° C., preferably 40 to 80° C.
Each of the individual layers of the film comprises 70 to about 100% by weight of the polymers described above, preferably 80 to 98% by weight, and optionally additionally additives such as neutralizing agents, stabilizers, slip agents, antistatic agents and other additives, provided they do not interfere with the UVC permeability.
Advantageously, they are already added to the polymer or the polymer mixture prior to melting. Phosphorous compounds, such as phosphoric acid or phosphoric acid esters, for example are used as stabilizers. In principle, the individual layers can have the same or different composition(s) with regard to the polymer and added additives. Generally, the composition of the base layer is different from the composition of the remaining layers. In particular, additives such as antiblocking agents or slip agents are added to the covering layers. Neutralizing agents and stabilizers are generally present in all layers, each in effective quantities. However, structure and composition of the individual layers of the film can in principle vary within wide limits.
It was found that transparent embodiments without vacuoles are particularly suitable for the application according to the invention.
Optionally, the film can be coated to optimize further properties. These coatings can be based on the PHC polymers described above or should on their part be permeable to UVC rays. Typical coatings are adhesion-promoting, slip-improving or dehesive-acting layers. Optionally, these additional layers can be applied by means of in-line coating using aqueous or non-aqueous dispersions prior to transverse stretching or they can be applied off-line.
The PHC film is produced by the extrusion or coextrusion method known per se. Within the scope of this method, the melt(s) corresponding to the layers of the film are coextruded through a flat film extrusion die; the single-layered or multi-layered film thus obtained is taken off on one or more roller(s) for solidification. For oriented or biaxially oriented embodiments, the film is subsequently mono- or biaxially stretched (oriented), the stretched film is heat-set. Optionally, the films are corona-treated or flame-treated on one side or both sides on the surface layer provided for treatment.
Biaxial stretching is generally performed sequentially. Preferably, stretching occurs first in the longitudinal direction (i.e. in the machine direction=MD) and subsequently in the transverse direction (i.e. perpendicular to the machine direction=TD). This results in an orientation of the molecular chains. Stretching in the longitudinal direction preferably occurs by means of two rollers running at different speeds in accordance with the desired stretch ratio. For transverse stretching, an appropriate tenter frame is generally used. Optionally, biaxial stretching can also occur simultaneously, for example by means of LISIM® technology. Further description of the film production follows using the example of a flat film extrusion with subsequent sequential stretching.
The melt(s) are pressed through a flat film extrusion die (slot die), and the pressed out film is taken off on one or more take off rollers at a temperature of 10 to 100° C., preferably 20 to 80° C., whereupon it cools and solidifies.
The film thus obtained is then stretched longitudinal and transverse to the extrusion direction. Longitudinal stretching is preferably performed at a roller temperature of the stretching roller of 40 to 130° C., preferably 50 to 100° C., advantageously by means of two rollers running at different speeds in accordance with the desired stretch ratio, and transverse stretching is preferably performed at a temperature of 50 to 130° C., preferably 60 to 120° C., by means of an appropriate tenter frame. The longitudinal stretch ratios can be varied in the range of 1.5 to 8, preferably 1.5 to 4. The transverse stretch ratios are in the range of 3 to 10, preferably 4 to 7.
The stretching of the film is followed by the heat setting (heat treatment) thereof, the film being kept convergently for about 0.1 to 10 s at a temperature of 60 to 150° C. (convergence of up to 25%). Subsequently, the film is wound up in customary fashion by means of a winding device.
Besides the films, other forms of the packaging material can also be used. For example, containers, bowls, bottles or other forms are also suitable. These receptacles are produced from the polyhydroxycarboxylic acids described above, preferably PLA, as described above in connection with the films. If necessary, the rheological properties of the polymer have to be adapted to the respective processing method; the production of injection molded or blow molded containers requires for example a different melt flow index of the PLA as film raw material. Those skilled in the art will readily select suitable raw materials from the PLA polymers known per se.
To pack or package the products, any common packaging technology and filling process can be used, for example film wrapping on HFFS or VFFS packaging machines. After packaging of the products, the disinfection, partial disinfection or sterilization by means of UV radiation according to the invention occurs. For this, the packaged product is subjected to UV radiation, which comprises the wavelength range of 254 nm (UVC), in a suitable manner in the packaging. This UV-C radiation is technically produced by mercury lamps, for example by low-pressure lamps, optionally also by high-pressure or medium-pressure lamps. The UV lamps generally consist of a housing with a quartz glass window as exit window for the radiation and the actual mercury discharge lamp. Low-pressure tubes are preferred since they are very effective with a very high efficiency factor of more than 80% in the bactericidal wavelength range of about 254 nm. Typically, these lamps also emit radiation at other wavelengths, for example in the range of 200 to 280 nm, but they have the highest intensity in the relevant range of about 254 nm. Advantageously, high-powered mercury low-pressure radiators, which are provided with a cooling device, are used. The cooling prevents heating-up and the shift of the spectrum associated therewith. These lamps are characterized by a very high and constant power output. In principle, the radiant power of the UV lamps used can vary within a broad range, for example between 50 and 250 W, preferably between 100 and 150 W. The power supply, control and monitoring of the operating parameters can occur via a ballast. The intensity of the irradiation can be individually tuned to the respective sterilization or disinfection process, or the goods to be filled. The intensity of the irradiation specifies the radiant power per surface area and is for example 10 to 200 mW/cm 2 , preferably 50 to 150 mW/cm 2 . To irradiate the packaged goods, they run through the UV section, moved by a conveyor system, for example by means of a conveyor belt that is passed under the UV lamp. The irradiation time and hence the radiation dosage can be regulated via the speed of the belt. Optionally, with constant web speed dosing can also occur via appropriate filters that affect the transmission of the produced UV radiation. For optimum disinfection of the products, all three parameters should be adjusted and optimized with regard to the best efficiency possible. The radiation dosage in particular can be adjusted via both the irradiation time and the intensity of the irradiation.
Optionally, the goods to be filled can also be pre-purified or disinfected in advance by processes known per se and subsequently treated using the sterilization or disinfection method according to the invention. In principle, all types of goods to be filled can be disinfected or sterilized using the process according to the invention, for example individually packaged goods, goods to be filled, powders, grains, liquids and water, for example bottled. All products which require disinfection and sterile storage, for example foodstuffs, other perishable goods, medicinal products such as disposable syringes, dressing material or implants are possible as products. The method according to the invention utilizes all advantages of the UV sterilization or UV disinfection known per se and avoids recontamination of the products on the way from disinfection to packaging or until they are used as intended since the packaging reliably protects against said recontamination after disinfection. This disinfection system is therefore extraordinarily effective and simple to use. The product properties are not affected and residues, side effects or side products are not produced. The method leads in a single process step to a sterilely packaged good, which ensures quality preservation and suitability for storage in a very simple manner.
The packaging according to the invention is generally not provided with an imprint or any other application that might interfere with the passage of UV irradiation. Small-area imprints, such as for example data or bar codes, that do not cover the product in an interfering manner are of course possible. Optionally, after disinfection the sterile packaging with its content can be provided with an additional outer packaging or labels, which then on their part have decorative or informative elements, for example wrap-around labels, adhesive labels, a print covering the whole surface or part of it, or a metal layer for protection against gas or steam transmissions or the action of light. This outer packaging does not have to meet any special requirements with regard to sterility and therefore can be selected, depending on the application, from the variety of packaging materials known per se based on functionality or visual appearance.
For the characterization of the raw materials and films, the following measured values were used:
Below, the invention is explained by means of exemplary embodiments
Example 1
A transparent three-layered PLA film having a thickness of about 30 μm was produced by extrusion and subsequent stepwise orientation in the longitudinal direction and transverse direction. The base layer consisted to nearly 100% by weight of a polylactic acid having a melting point of about 160° C. The layer additionally comprised stabilizers and neutralizing agents in customary quantities. The two sealable covering layers were essentially composed of an amorphous polylactic acid, this polylactic acid having an L/D ratio of about 40/60. Each of the covering layers comprised in addition 0.1% by weight of SiO 2 -based particles as antiblocking agent. Each of the covering layers had a thickness of 2.5 μm.
The production conditions in the individual process steps were:
extrusion:
temperatures:
170-200° C.
temperature of the
60° C.
take-off roller:
longitudinal
temperature:
68° C.
stretching:
longitudinal stretch ratio:
2.0
transverse
temperature:
88° C.
stretching:
transverse stretch
5.5
ratio (effective):
setting:
temperature:
75° C.
convergence:
5%
A bag packaging was made from the film. The bag packaging was filled with strawberries and sealed. Subsequently, the filled packaging closed by sealed seams was placed for 30 sec under a low-pressure mercury lamp and subsequently stored at a temperature of about 10° C. for 7 days.
Example 2
A bag packaging was made from the film according to Example 1. The bag packaging was filled with strawberries and sealed. The packaging was stored at a temperature of about 10° C. for 7 days without prior UV disinfection.
Example 3
A transparent three-layered polypropylene film having a symmetrical structure and a total thickness of 20 μm was produced by coextrusion and subsequent stepwise orientation in the longitudinal and transverse direction. Each of the covering layers had a thickness of 0.6 μm. The base layer consisted of a propylene homopolymer having a melting point of 166° C. and a melt flow index of 3.4 g/10 min and N,N-bis-ethoxyalkylamine as antistatic agent. The covering layers consisted of random ethylene-propylene copolymers having a C 2 content of 4.5% by weight and 0.33% by weight of SiO 2 as antiblocking agent having an average particle size of 2 μm and 0.90% by weight of polydimethylsiloxane.
The production conditions in the individual process steps were:
extrusion:
temperatures base layer:
260° C.
covering layers:
240° C.
temperature of the
20° C.
take-off roller:
longitudinal
temperature:
110° C.
stretching:
longitudinal stretch ratio:
5.5
transverse
temperature:
160° C.
stretching:
transverse stretch ratio:
9
setting:
temperature:
140° C.
convergence:
20%
A bag packaging was made from the film. The bag packaging was filled with strawberries and sealed. Subsequently, the filled packaging closed by sealed seams was placed for 30 sec under a low-pressure mercury lamp and stored at a temperature of about 10° C. for 7 days.
As a result, the strawberries that had been packaged and UV disinfected according to Example 1 did not show any signs of putrefaction or mold infestation, whereas without UV disinfection (Example 2) or with oPP film despite UV disinfection (Example 3) signs of spoilage were easily detectable.
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The present invention relates to a method for the disinfection, partial disinfection or sterilization of a product by means of UV radiation. A product is enclosed with a UV permeable packaging material made of polyhydroxycarboxylic acid and subsequently disinfecting, partially disinfecting or sterilizing in the packaged state by means of irradiation with UV radiation.
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BACKGROUND OF THE INVENTION
The invention concerns a turning device for sludge and/or deposits and a solar drier having a turning device. Sludge or deposits are often dried on a stable floor or in flat pools. In order to increase the drying efficiency, the product to be dried is turned over when the uppermost layer is dry and moisture transport from the lower sludge layers into the air is impaired.
In a conventional turning device categorizing the invention (DE OS 4315321 A1), the device extends across the entire width of the drying surface and is guided and driven at the sides thereof. This turning device has the disadvantages of having substantial structural difficulty and expense, of being limited by the width of the drying surface, of requiring guiding means on both sides of the drying surface as well as of requiring a drive device on at least one side thereof. In addition, this complicated and expensive device is not efficiently utilized. The entire product to be dried is turned during one single passage of the turning device over the drying surface. Since the drying proceeds slowly, the inactive time of the turning device is long in comparison to the active time.
The invention also concerns a solar drier having a turning device. In view of the limited amount of natural resources, increased efforts have been made in recent times to utilize solar energy for drying processes of various kinds. This is attractive from an economical point of view when no particular requirements are made for the drying speed and for high temperatures. In this manner, deposits or other sludge can often be dried using solar means, resulting in low operational costs for the drying procedure and conservation of natural resources in an environmentally sound fashion.
A device and a method for solar drying of sludge and soiled liquids is described in a solar drier of conventional construction categorizing the invention (DE OS 4315321 A1) with which the sludge is transported into a precipitation pool, wherein a portion of the water is removed using a drainage pipe. A turning and transport device, extending across the entire width of the pool and of the adjacent drying surface, is then used to transport the somewhat thickened sludge from the precipitation pool onto the drying surface. The sludge is disposed at this location in the form of a relatively thin layer and is dried by an opposing stream of air. The drying speed is increased using a greenhouse structure erected over the drying surface and the precipitation pool. The incident solar radiation heats the sludge and the air located within the greenhouse leading to the above mentioned increase in drying speed. The required convection within the greenhouse is produced by a chimney installed, as seen in the flow direction of the air, on the rear end of the greenhouse. In the event that natural convection is insufficient, an electrically driven fan can increase the draft in the chimney. This conventional solar dryer for solar drying of sewage sludge has the disadvantage of being associated with a relatively high degree of structural difficulty and expense related to the chimney, the complicated and expensive turning and transport device, the precipitation pool, a pressurized installation, an external solar collector as well as dehumidifying devices.
SUMMARY OF THE INVENTION
In contrast thereto, the turning device in accordance with the invention has the advantage that the degree of structural difficulty and expense is substantially reduced, wherein use of a smaller and flexibly controllable turning device not only saves substantial investment and operation costs but allows the turning device to be operated in a manner which is adapted to the product being dried. In addition, the efficiency of use of the turning device is increased by a plurality of passages through the product to be dried and the drying device can be loaded to an increased extent and thereby utilized in a more efficient manner due to the intense mixing of the product to be dried.
In accordance with an additional advantageous configuration of the invention, the distribution tool is fixed to a frame so that the penetration depth of the distribution tool into the sewage sludge can be easily adjusted.
In accordance with an additional advantageous configuration of the invention, the distribution tool is motor-driven so that mixing of dried and moist sludge layers is intensified.
According to an additional advantageous embodiment of the invention associated therewith, the processing speed and the processing direction of the distribution tool can be regulated and controlled in dependence on the consistency of the sludge and the driving mechanism.
In accordance with an additional advantageous embodiment of the invention, the drive device and, optionally, the distribution tool are electrically powered so that the drive mechanism requires little maintenance, is economical and is robust.
In accordance with an additional advantageous embodiment of the invention associated therewith, the turning device is provided with electrical energy via a tracking device disposed on the building and a power cable so that the motors can be operated with power from the mains, leading to low power loss. In addition, electrical energy coming from the mains is regularly available end-user energy, which is relatively inexpensive.
In accordance with an additional advantageous embodiment of the invention, the turning device is supplied with electrical energy via storage batteries so that the turning device can be operated in an isolated fashion.
In accordance with an additional advantageous configuration of the invention, the drive device and, optionally, the distribution tool are at least indirectly driven by a combustion engine so that high drive power is possible with low weight.
In accordance with an additional advantageous configuration of the invention, the direction of motion and the speed of the turning device are controlled by a shifting system disposed on the turning device which is actuated by at least one delimiting device disposed on the edge of the floor.
In accordance with an additional advantageous configuration of the invention, the path of the turning device is determined in a stochastic fashion via the collision between the turning device and the delimiting device so that an even mixing is also guaranteed in the edge regions of the floor.
In accordance with an additional advantageous configuration of the invention, the path of the turning device is adjusted by an actuator disposed between portions of the frame to move the turning device along predetermined paths.
In accordance with an additional advantageous configuration of the invention, the turning device moves along fixed paths so that the path length or the efficiency of the turning device can be optimized.
In accordance with an additional advantageous embodiment of the invention associated therewith, the path is determined by a stationary ultrasonic or infrared transmitter in conjunction with a receiver disposed on the turning device, the receiver controlling the direction of motion of the turning device via appropriate actuators to easily adapt control to differing external boundary conditions.
In accordance with an additional advantageous configuration of the invention, the paths are defined by induction loops disposed in the floor so that the control of the turning device on predetermined paths is robust and insensitive to soiling.
In accordance with an additional advantageous configuration of the invention, the path control of the turning device is effected with the assistance of a satellite navigation apparatus so that no devices are required in addition to the turning device.
In accordance with an additional advantageous configuration of the invention, the active width of the distribution tool is substantially smaller than the length or the width of the floor, to thereby improve efficiency of use of the distribution tool and to reduce investment costs.
In addition, the solar drier in accordance with the invention has the advantage that its drying efficiency is high despite the simple and economical structure.
In accordance with an additional advantageous embodiment of the invention related thereto, the floor has precipitation sections and drying sections so that a portion of the moisture can flow-off through the precipitation sections.
In accordance with an additional advantageous configuration of the invention related thereto, the precipitation section consists essentially of single grain concrete and the liquid draining through the precipitation section is collected in a container so that a portion of the liquid contained in the sludge or deposit is drained-off to thereby increase the drying efficiency of the solar drier.
In accordance with an additional advantageous configuration of the invention, the delimiting sides of the precipitation sections extend substantially parallel to the outer edges of the floor so that moisture pockets do not form in the edge regions of the floor.
In accordance with an additional advantageous configuration of the invention, the floor can support farming machines so that turning and removal of the dried substrate can be effected in a rapid fashion using available machines and apparatus.
In accordance with an additional advantageous configuration, the solar drier comprises a turning device in accordance with the invention.
In accordance with an additional advantageous embodiment of the invention, the delimiting device is up to 3 meters in height so that the solar drier can also be used as a temporary storage unit.
In accordance with an additional advantageous embodiment of the invention, the building enclosure has an air inlet and an air outlet to increase drying efficiency.
In accordance with an additional advantageous embodiment of the invention associated therewith, the air inlet and air outlet are regulated in order to further increase the drying power.
In accordance with an additional advantageous embodiment of the invention associated therewith, the exhaust is suctioned off and an exhaust filter is disposed on the air outlet so that the entire exhaust is guided through the exhaust filter to effect a slight partial pressure within the building.
In accordance with an additional advantageous embodiment of the invention, a dehumidifier is disposed within the building enclosure so that there is no exchange of air between the inside of the building and the surrounding environment to prevent unpleasant odors from escaping out of the drier.
In accordance with an additional advantageous embodiment of the invention, plants grow on the sludge or deposit (reeds or the like) so that the drying efficiency is increased by the increased drying surface. In addition, this measure leads to an increase in the caloric content of the dried sewage sludge or deposits, including the plants, compared to the caloric content of the dried sewage sludge or deposit only.
Further advantages and advantageous configurations of the invention can be extracted from the subsequent description, the drawings and the claims.
An embodiment in accordance with the invention is shown in the drawings and more closely described below.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a cross section through a solar drier having a turning device,
FIG. 2 shows a side view of the turning device,
FIG. 3 shows a plan view of the turning device in straight travel,
FIG. 4 a shows a first plan view of the turning device in curved travel,
FIG. 4 b shows a second plan view of the turning device in curved travel,
FIG. 5 a shows a first view of the drive roller,
FIG. 5 b shows a second view of the drive roller,
FIG. 6 a shows a first view of the hacking roller,
FIG. 6 b shows a second view of the hacking roller.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a building 1 having the conventional construction of a greenhouse. The building enclosure 2 consists essentially of a transparent heat insulating plastic, such as e.g. a PE insulating air cushion sheet, which is permeable to solar radiation. Sewage sludge 3 is located on the floor 6 of the building 1 . Solar radiation incident on this sewage sludge 3 leads to warming thereof. Since the warmed sewage sludge 3 radiates heat having longer wavelength than that of sunlight and since the building enclosure 2 absorbs light of these longer wavelengths, only a small fraction of this radiation can escape from the building enclosure 2 . The floor 6 of the building, consisting essentially of the precipitation sections 4 and drying sections 5 , can be seen within the building enclosure 2 . Delimiting devices, in the form of side walls 7 can also be seen. The delimiting deices can contain the sludge and prevent it from sinking into the surrounding earth and can also steer the turning device 8 . The precipitation sections 4 consist essentially of single grain concrete and allow a portion of the liquid contained in the sludge 3 to pass through, whereas the solid components of the sludge are blocked. The collecting device for the drained liquid is not shown. Since the precipitation sections 4 are large compared to the overall floor 6 , the single grain concrete absorbs solids at a slow rate. Should the concrete become clogged with solids, it can be cleaned using water. The turning device 8 travels back and forth in or on the sewage sludge 3 and effects a mixing of dry and moist sewage sludge layers using a distribution tool 17 (schematically shown). In order to illustrate the manner of operation of the turning device 8 , we assume that it is travelling towards a side wall 7 in FIG. 1 . As soon as the turning device 8 touches the wall 7 , a turning device 8 shifting system is triggered, as a result of which it changes its direction and curvature of motion to move away from the edge of the base surface 6 . Approach and retraction of the turning device 8 from the side walls 7 is effected along differing paths. The turning device 8 is supplied with energy by means of a power cable 9 attached to a tracking device 11 extending in the longitudinal direction of the hall. This tracking device 11 allows the turning device 8 to travel across the entire base surface 6 without damaging the power cable 9 .
FIG. 2 shows a side view of the turning device 8 . A frame 12 connects the drive device 16 , consisting essentially of a motor 13 , a transmission element 14 and a drive roller 15 to the distribution tool 17 in a hinged fashion. The ability of the drive device 16 and the distribution tool 17 to change their position relative to each other via the hinge 18 in the frame 12 , permits the turning device 8 to travel through curves having differing radii. In the embodiment shown, the distribution tool 17 is driven by a motor 19 .
FIG. 3 shows a plan view of the turning device 8 . One clearly sees that the hinge 18 is not centered in the drive direction. A connecting element 21 is located on the side of the frame 12 opposite to the hinge 18 , to increase the stiffness of the frame 12 and reduce the relative motion between the two frame portions 21 , 22 . Should the turning device 8 travel along predetermined paths, the connecting element 20 can be configured as a control cylinder. When the turning device 8 is incident on a side wall 7 or another encumbrance, the drive direction of the drive device 16 and of the distribution tool 17 change. The angle between the frame portions 21 , 22 changes simultaneously. This change in angle is effected by a reversal in drive direction, a collision between the turning device 8 and an obstacle, or by means of an actuator (electrical or pneumatic cylinder) 20 . The turning device 8 thereby travels away from the side wall 7 or the obstacle along a path which differs from that along which it was incident thereon. Practical experiments have shown that a stochastic path control can be achieved in this fashion to cover the entire base surface, wherein the required path length for the turning device 8 is approximately 3 times the quotient between the base area and the active width of the turning device 8 . Longer turning device 8 paths intensify mixing of the sewage sludge 3 .
FIGS. 4 a and 4 b show plan views of the turning device 8 in curved travel.
FIGS. 5 a and 5 b show a drive roller 15 from the front, in section. The drive roller 15 consists essentially of two disc wheels 25 disposed on a shaft 24 between which a plurality of spokes 26 , which do not project beyond the disc wheels 25 , are disposed in a plurality of planes. The spokes 26 have drive means 27 extending parallel to the longitudinal axis of the drive roller 15 to improve the positive and frictional engagement between the drive roller 15 and the sewage sludge 3 .
FIGS. 6 a and 6 b show a distribution tool configured as a hacking roller 17 . Disc wheels are provided on the hacking roller 17 having a somewhat larger radius than the hacking tools 28 to ensure that the turning device 8 operates reliably for a long period of time and for protecting the hacking tool 28 from being damaged. In the embodiment shown, a plurality of hacking tools 28 are aligned on the hacking roller 29 in a plurality of planes. They are made e.g. from flat steel which could have a profiled cross section. The velocity of the drive device 16 influences the operating power of the hacking roller 17 . The speeds of the drive device 16 and the distribution tool 17 must be adapted to each other to guarantee a proper mixing of the sewage sludge 3 without overloading the drive motors 13 and 19 .
The sludge or deposit (drying product) which is to be dried can be mixed with additives such as wood chips, paper or plant materials (reeds or the like). This increases the caloric content of the mixture comprising the product to be dried and the additives to values in excess of 11 MJ per kg. The dried mixture can then be used as a fuel and is no longer refuse. In addition, the additives can extend the carbon to oxygen ratio of the mixture compared to that of the pure drying product for reducing emissions. Mixture of the drying product with the additives can be effected before or after drying. The mixture process can make transportation of the mixture worthwhile, increase its potential for storage, and increase its caloric content.
The precipitation sections of the solar drier can consist essentially of single grain concrete plates inserted into corresponding depressions in the floor. They can be removed for cleaning purposes. Perforated sheets or grids (e.g. so-called Birko channels) can also be used instead of single grain concrete plates. In this case, the precipitation sections consist essentially of troughs introduced into the floor which are not permeable to water and which can be emptied using drainage pipes. The troughs are filled with coarse grained gravel, fine grained gravel and sand and optionally with fiber material. The covering grid or the perforated sheet are dimensioned in such a fashion that vehicles can travel thereon.
The solar drier is also suitable for the drying and sterilization of animal excrement, wherein other materials can also be added in order to reduce odors. In addition, the drier can be used for the drying of biological refuse, grass or clippings, either alone or together with sewage sludge, and other depositions. In the event that the drier is used to dry biological refuse, thermal applications can be envisioned in addition to the generation of compost therefrom. In addition, the device can be used for drying bulk products such as e.g. coffee, cocoa or rice.
As shown in FIGS. 1 and 2, the turning device 8 can be controlled by a switching or transmission device 30 interacting with the delimiting wall 7 . Alternatively or in addition thereto, an ultrasonic or infrared transmitter 31 can communicate control messages to a receiver 32 disposed on the turning device 8 . Induction loops 33 can also be provided in the floor 5 for controlling the path of the turning device 8 . Means 34 can be provided for tracking and controlling the turning device using satellite navigation. Liquid passing through porous sections 4 can be captured in conduit receptacles 35 . The building 1 can comprise regulated air inlet 36 and air outlet 37 passages, wherein the air outlet passage 37 has a filter 38 . In addition or alternative thereto, a dehumidifier 39 can be used within the building 1 . The caloric content and drying speed can also be increased by plants 40 growing on the sludge.
The features shown in the description, the subsequent claims and the drawing can be important to the invention either individually or in arbitrary combination.
LIST OF REFERENCE SYMBOLS
1 building
2 building enclosure
3 sewage sludge
4 precipitation section
5 drying section
6 floor
7 delimiting wall
8 turning device
9 power cable
11 tracking device
12 frames
13 drive device motor
14 transmission element
15 drive roller
16 drive device
17 distribution tool
18 hinge
19 distribution tool motor
20 connection element
21 frame member
22 frame member
24 drive shaft
25 disc wheels
26 spokes
27 drive means
28 hacker tool
29 hacker shaft
30 Switching or transmission device
31 transmitter
32 receiver
33 induction loops
34 satellite navigation means
35 conduits
36 air inlet
37 air outlet
38 filter
39 dehumidifier
40 plants
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A turning device ( 8 ) for sludge and deposits ( 3 ) is proposed which moves along differing paths spread out on a floor ( 6 ), through the sludge or deposit ( 3 ). The turning device ( 8 ) can be used in a solar drier for sewage sludge or other deposits.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims benefit of U.S. Provisional Application No. 60/692,028 filed Jun. 17, 2005.
FIELD OF THE INVENTION
The present invention relates to a building materials composite, and more particularly to a non-asphaltic roofing underlayment that is breathable, water resistant skid-resistant, and which may be configured or tailored in order to provide a desired level of breathability.
BACKGROUND OF THE INVENTION
In the roofing industry, a roofing underlayment is typically applied to the deck of a roof prior to application of shingles or other roofing material. The primary goal of the roofing underlayment is to shield the roofing deck from asphalt (from the back surface of shingles) which otherwise would necessitate tearing up the whole deck instead of just the shingles—a costly option—at the time of reroofing. Underlayments can also help to reduce “picture framing” in which the outline of the deck panels caused by irregularities in the deck surface may be visible through the roofing material applied to the roofing deck.
In most cases, the roofing underlayment comprises a felt material composed of cellulose fibers, glass fibers and a mixture thereof that is saturated with a bituminous material such as asphalt, tar or pitch. Roofing underlayments that are saturated with a bituminous material are thick composites (typically 20 to 60 mils thick), which can be hazardous to manufacture due to the presence of a flammable bituminous material. Many of the asphaltic underlayments available in the market tend to wrinkle after being applied to a roofing deck. This is especially the case if the underlayments are rained upon. Other common problems are blowing off due to wind (when shingles are yet to be installed) or the formation of splits lengthwise in the underlayments when they are left exposed for several days.
In addition to bituminous-containing underlayments, the roofing industry has also developed non-bituminous, i.e., non-asphaltic, underlayments. The prior art non-bituminous underlayments typically include Triflex 30 (a product made by Flexia Corp. and marketed by W. R. Grace), Titanium UDL (marketed by Interwrap, Inc. of Canada), RoofTopGuard II (marketed by Classic Products, Inc and Drexel Metals), Kaye-Flex UDL (from Kaye Industries, Florida), etc.
Currently, all non-asphaltic underlayments tend to be water-resistant but substantially non-breathable. That is, the non-asphaltic underlayments do not allow air or water vapor to pass through it. As a result, the moisture from the interior of the building is unable to escape to the exterior resulting in damage to the deck and roof over a number of years. Most of the non-asphaltic underlayments also tend to be slippery, especially when wet.
Furthermore, existing breathable underlayments are generally of three types: (1) micro-perforated or (“micro-perfed”) types in which a coated fabric has mechanical perforations to allow moisture vapor to escape from the building structure; (2) microporous types in which a breathable polyolefinic film is sandwiched between two or more layers by means of thermal or ultrasonic or adhesive lamination methods; or (3) a monolithic film extruded using thermoplastic polyurethane or copolyester or its blend resins which provide breathability and waterproofness in a composite structure.
Existing micro-perfed films, however, fail the water shower test as mandated by ASTM D 4869-00. Existing microporous films and monolithic film based concepts—while providing breathability as well as waterproofness—are limited by the properties of the film itself. Hence, tailorability of properties is severely limited especially in the case of monolithic film concepts since resin blend compositions required for a particular breathability and mechanical properties can be difficult to predict. Extrusion coated film may act as a waterproof barrier, a breathable layer, as well as bonding agent between the two protective layers. However, in such cases, the breathability is severely limited (usually less than 10 perms). Additionally, such extrusion coatings tend to be prohibitively expensive.
In view of the drawbacks mentioned above with prior art non-asphaltic breathable underlayments, there is a need for providing a non-asphaltic roofing underlayment that is breathable thereby allowing moisture to escape from inside the building, while preventing water and/or moisture from entering the building. In addition, skid-resistance is a highly desirable property of an underlayment to avoid injuries from roofers sliding off of the roof. Also, sealing around nails or other roof penetrations would provide additional protection towards waterproofing the system.
SUMMARY OF THE INVENTION
The present invention provides an improved non-asphaltic underlayment useful in roof assemblies which comprises a substrate (typically non-waterproof, but can be waterproof) in which at least one layer thereof includes a breathable thermoplastic film selected from (1) a polyurethane based thermoplastic film, (2) an ethylene-methacrylate (EMA) copolymer or ethylene acrylic acid (EAA) based thermoplastic film, or (3) a micro-porous polyolefinic or polyester film that may be filled or unfilled. Combinations and/or multilayered stacks of such breathable thermoplastic films are also contemplated herein. Furthermore, the invention involves combinations of micro-perforated fabric(s) and one or more micro-porous films bonded together by known lamination techniques (such as ultrasonication, thermal, adhesive or a combination thereof, so that desired breathability can be tailored in to the composite structure. Any combination of fabrics or films can be employed.
In a preferred embodiment, the composite of the present invention comprises a breathable and substantially micro-porous film bonded between a breathable micro-perforated coated woven substrate and a breathable spun-bonded non-woven layer. The coated woven scrim and spun-bonded non-woven layer, while breathable, are typically non-waterproof. The substrate can comprise a thermoplastic polymer or copolymer or a felt material. Additionally, by tailoring the micro-perforations (in size, number and type) in the breathable coated woven scrip as micro-pores in the micro-porous film, a suitable combination of layers can be bonded together that affords the desired breathability with a high degree of flexibility and at a relatively lower cost.
The term “non-waterproof” substrate denotes a material that is pervious to water, i.e., a material that permits water permeation from the exterior of the roofing to the interior of the roofing.
The terms “breathability” or “breathable” refers to a material or materials which is permeable to water vapor or moisture having a minimum moisture vapor transmission rate (MTVR) of 3 perms, i.e., about 172 nanograms/m 2 /Pa/sec (or 6.7 g/100 sq.in./atm/24 hours) or greater. The MTVR is measured using a standard ASTM measurement, i.e., ASTM E96-80 Proc. A or other comparable standards such as ASTM D398.
The presence of the breathable film on the substrate makes the resultant composite waterproof and yet imparts breathability of the substrate. The inventive non-asphaltic underlayment of the present invention acts as a barrier to moisture, but allows air and water vapor to pass therethrough. In addition to providing waterproofing to the deck substrate, the presence of one of the aforementioned breathable thermoplastic underlayment on a top side of the deck substrate also imparts improved skid resistance, i.e., high coefficient of resistance, against the non-asphaltic underlayment. Such an underlayment having a skid-resistant surface will also provide improved adhesion of asphaltic P&S adhesive products (like Liberty® from GAF) to the underlayment where the latter is used as a base sheet.
The term “non-asphaltic underlayment” is used in the present invention to describe a roofing composite containing no asphalt, and which is laid down on a roofing deck prior to shingle application.
The present invention also provides a method of manufacturing the non-asphaltic underlayment of the present invention. In broad terms, the method of the present invention comprises applying at least one of the above mentioned breathable thermoplastic films to at least one surface layer of a woven or non-woven, organic or inorganic substrate.
The present invention also provides a roofing system that comprises the inventive non-asphaltic, breathable underlayment and one or more shingles laid-up on the uppermost layer of the underlayment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial representation (through a cross-sectional view) illustrating a non-asphaltic underlayment of the present invention.
FIG. 2 is a pictorial representation (through a cross-sectional view) illustrating another non-asphaltic underlayment of the present invention.
FIG. 3 is a pictorial representation (through a cross-sectional view) illustrating yet another non-asphaltic underlayment of the present invention.
FIG. 4 is a pictorial representation (through a cross-sectional view) illustrating yet another non-asphaltic underlayment of the present invention.
DETAILED DESCRIPTION
The present invention, which provides a non-asphaltic underlayment that is breathable, waterproof and skid resistant, and which encompasses tailorable breathability characteristics, will now be described in greater detail by referring to the following description and drawings that accompany the present application. In the accompanying drawings, like and/or corresponding elements are referred to by like reference numerals.
FIGS. 1-4 of the present application illustrate various embodiments of the present invention. Specifically, FIGS. 1-4 are cross-sectional views showing the non-asphaltic underlayment 10 of the present invention.
FIG. 1 illustrates a three-layer non-asphaltic underlayment 10 in accordance with a preferred embodiment of the present invention and which comprises a breathable thermoplastic film (BTF) 14 bonded between a substrate 12 and spun-bonded or needle-punched or other types of non-woven fabrics 18 made from polypropylene, polyester, fiberglass or a blend of difference synthetic fibers.
In FIG. 2 , there is illustrated a two-piece non-asphaltic underlayment 10 that comprises a substrate 12 having a breathable thermoplastic film 14 bonded to a top surface 11 t of the substrate 12 . The substrate 12 is typically substantially non-waterproof. In this embodiment, the top surface including the breathable thermoplastic film 14 will face in a direction opposite of the roofing deck such that one or more shingles are laid-up directly on the breathable thermoplastic film 14 of the underlayment 10 . Although FIG. 1 shows the breathable thermoplastic film 14 on an upper surface of the substrate 12 , it is also contemplated in the present invention to have an underlayment in which the breathable thermoplastic film 14 is bonded on a bottom surface 11 b of the substrate 12 .
FIG. 3 shows an alternative embodiment of the present invention in which the substrate 12 is sandwiched between two-breathable thermoplastic films 14 using known techniques such as thermal, ultrasonic and/or adhesive bonding. That is, the top surface 11 t and bottom surface 11 b of the substrate 12 both include a breathable thermoplastic film 14 thereon. FIG. 3 thus represents a three-piece underlayment.
In FIG. 4 , there is shown an embodiment in which a tie layer 16 is present between the substrate 12 and the breathable thermoplastic film 14 . The presence of the tie layer 16 improves the adhesion of the breathable thermoplastic film 14 to the substrate 12 . The tie layer 16 , which may also be referred to as a compatibilizer or a bonding agent, may be used in any embodiment of the present invention. If the adhesive bonding agent is non-breathable, it can be applied in discontinuous patterns, e.g. dots or squares.
The substrate 12 employed in the present invention comprises an organic or inorganic reinforcement sheet or film that is capable of withstanding high ambient temperatures. The substrate is typically, but not always, non-waterproof. The reinforcement sheet or film can comprise a thermoplastic polymer or copolymer or a felt material. The substrate may be woven or non-woven, with preference given to a coated woven substrate for imparting superior mechanical properties in both machine and cross-machine direction. The substantially non-waterproof woven or non-woven substrate of the present invention is sometimes referred to in the art as a scrim. A woven substrate is preferable since it provides greater tensile and tear strengths compared with that of comparable non-woven substrate. No asphalt or other like bituminous material is present in or on the substrate 12 .
Illustrative examples of reinforcement thermoplastic polymeric materials that can be employed in the present invention as the substrate 12 include, but are not limited to: polyolefins, such as, for example, polyethylene (high density, linear low density, low density or medium density) and polypropylene; polyethylene terephthalate (PET); polyamides; polyvinyl chlorides (PVC's); polystyrenes; polyacrylics; and any copolymers thereof.
For purposes of definition herein, the term “high density polyethylene” denotes a polyethylene composition having a density of about 0.941 g/cc of higher; the term “medium density polyethylene” denotes a polyethylene composition having a density of about 0.926 to about 0.940 g/cc; and the terms “low density or linear low density polyethylene” denote a polyethylene composition having a density of about 0.90 to about 0.925 g/cc.
Of the various thermoplastic polymeric materials mentioned above, it is preferable to use a thermoplastic reinforcement material that comprises polyethylene, polypropylene or PET. The thermoplastic reinforcement material used as the substrate 12 is made using techniques well-known in the art. The substrate 12 may also be a felt material such as a cellulose fiber mat or a glass fiber mat. These types of substrates are made using techniques well known to those practicing the art.
The substrate 12 may have any thickness associated therewith, but typically the thickness of the substrate 12 is from about 6 to about 60 mils. The substrate 12 is breathable and is usually, but not always, non-waterproof.
In one embodiment, the breathable thermoplastic film 14 is a polyurethane based thermoplastic monolithic film (or thermoplastic polyurethane (TPU)). The polyurethane based thermoplastic film is a polymeric material obtained by first forming a prepolymer of polyether or polyester diols or polyols with excess diisocyanate and then chain-extending the prepolymer by reacting with a diamine or a diol. Copolymers including the TPU are also contemplated as the breathable thermoplastic film 14 .
Suitable TPU's that can be employed as the breathable thermoplastic film 14 are available from Noveon (Esthane®), Merquinsa NA Inc. (Pearlthane®/Pearlcoat®), Dow Chemical Company (Pellethan®), BASF (Elastollan®), Bayer (TEXIN/DESMOPAN®) or Huntsman (AVALON® or IROGRAN®).
In another embodiment of the present invention, the breathable thermoplastic monolithic film 14 is an ethylene methacrylate (EMA) copolymer (such as Elvaloy from DuPont), a polyolefin-based EMAC (such as SP2220 from Eastman Chemical Co.), or an ethylene acrylic acid (EAA) based copolymer. These copolymer films offer similar properties as the TPU, i.e., breathable and yet waterproofing.
In yet another embodiment of the present invention, the breathable thermoplastic film 14 is a micro-porous polyolefinic (polyethylene, polypropylene and other like polyolefins including copolymers thereof) or polyester polymer which may or may not contain a filler therein.
In yet another embodiment of the present invention, the breathable thermoplastic film 14 is a multilayered stack that includes any combination of above-mentioned breathable thermoplastic materials.
The underlayment in accordance with the various embodiments of the present invention may take on, but are not limited to, the following forms and layer combinations: (a) micro-perforated coated woven scrim/micro-porous film/spun-bonded non-woven layer, (b) micro-perforated coated non-woven scrim/micro-porous film/micro-perforated coated woven layer, (c) micro-perforated coated woven scrim/micro-porous film.
The combinations of micro-perforated fabric(s) and one or more micro-porous films may be bonded together by an adhesive or by thermal bonding, however, other known lamination techniques (such as ultrasonication, adhesive or a combination thereof) may be used, such that desired breathability can be tailored in to the composite structure. In the event that that such an adhesive is non-breathable, it can be applied in a discontinuous manner such as dots or squares, in which case the specific pattern with the number of such dots per unit area, and the spacing between them can be varied to design required breathability.
The thickness of the breathable thermoplastic film 14 may vary, but typically it is from about 0.5 to about 10 mils, with a thickness from about 1 to about 3 mils being more highly preferred. Thicker breathable thermoplastic films 14 are also contemplated.
In embodiments in which a tie layer 16 is present, the tie layer 16 comprises a bonding agent, such as, for example, a polyamide, an ethylene copolymer such as ethylene vinyl acetate (EVA), ethylene ethyl acrylate (EEA), ethylene acrylic acid (EAA), ethylene methyl acrylate (EMA) (such as SP2207, SP2403, or SP1307 grades from Voridian) and ethylene normal-butyl acrylate (ENBA). However, the most-preferred material as a tie layer 16 is EMA having a methyl acrylate level of about 18% or greater.
The tie layer 16 may be applied during formation of the substrate by including the bonding agent within the polymerization process, during the formation of the breathable thermoplastic film, or after substrate formation using one of the methods described below.
The breathable thermoplastic film 14 may also be bonded to the substrate 12 by chemical bonding, mechanical bonding and/or thermal bonding. The breathable thermoplastic film 14 may also be bonded using a nip such as that generated by a pair of heat calendar roll, or by using an ultrasonication chamber.
In the case of polyolefinic based materials having filler induced micro-pores, those materials are made breathable upon stretching the film under appropriate conditions well known to those well versed in the art. In one embodiment, polypropylene with CaCO 3 fillers having micro-pores coated onto a glass mat is envisaged as a roofing underlayment that is breathable and yet waterproof. In order to improve the adhesion between filled or unfilled extrusion coated polyolefins such as polyethylene (PE) or polypropylene (PP) and glass mat—necessary for enhanced abrasion resistance—the following specific options are envisaged:
(1) Maleic anhydride grafted PP (blended up to 10%, but more preferably up to 5%) to regular PP batch. MAgPP is commercially available from DuPont (as Fusabond®), Atofina (as Lotadar™ or Orevac™) and other vendors. (2) Titanate or Zirconate coupling agents such as those available from Kenrich Petrochemicals, Inc. for improving the PP (preferably with fillers such as carbon black) bond to glass fibers. Ken-React's CAPS NZ 12/L (zirconate based) or CAPS L 38/L (titanate based) at 5% CAPS by weight of PP or lower, but more preferably 1 to 3% by weight can be used. Slight lowering of extrusion temperatures (typically about 10%) to create high shear for reactive compounding and dispersion of the titanate or zirconate masterbatch in the PP melt so that fiberglass mat can be subsequently coated uniformly. (3) In addition to (1) and (2) above, additional silane treatment to glass may become necessary as intimate mixing of glass fibers with PP (as in an extruder) cannot be done in composite process described herein. The well-known silane agents are aminoalkyltrialkoxysilanes such as 1-dimethylaamino-2-propanol or 2-dimethylamino-2-methyl-1-propanol or 3-aminopropyl triethoxysilane in the presence of a salifying agent (KOH) and an emulsifier such as polyoxyethylene octylphenyl ether.
Skid-resistance of polyolefinic coated underlayments can be increased by incorporating ethyl-vinyl acetate (EVA) or modified EVA such as maleic anhydride grafted EVA (like Fusabond C series sold by DuPont) up to 10% (most preferably 1-3%) by weight of PP.
The underlayments of the present invention can also be coated or sprayed with an algaecide such as, for example, zinc powder, or copper oxide powder; a herbicide; an antifungal material such as Micro-Chek 11P; an antibacterial material such as Micro-Chek 11-S-160; a surface friction agent such as Byk-375, a flame retardant material such as ATH (aluminum trihydrate) available from, e.g., Akzo Chemicals and antimony oxide available from, e.g., Laurel Industries and/or a coloring dye such as T-1133A and iron oxide red pigments, and other products which can impart specific surface functions. The Micro-Chek products are available from the Ferro Corporation of Walton Hills, Ohio. Byk-375 may be obtained from Wacker Silicone Corporation of Adrian, Mich. and T-1133A is sold by Abco Enterprises Inc. of Allegan, Mich. The additional coatings of, e.g., water repellent material, antifungal material, antibacterial material, etc., may be applied to one or both sides of underlayment of the present invention.
The waterproof and breathable underlayment 10 of the present invention is used as a component of a roofing system together with one or more conventional shingles. In this application, the underlayment of the present invention is first applied to the roofing deck and then secured thereto using securing means well-known to those skilled in the art, such as by nail or staple application. Next, one or more shingles are laid-up on the uppermost layer of the underlayment 10 and thereafter the shingle is secured to the roofing deck. The lay up and securing steps are well-known to those skilled in the art. Types of shingles that can be used in the present invention include, but are not limited to: asphalt-containing single or multi-ply organic or inorganic shingles.
It is anticipated that the micro-perfed coated woven scrim layer 12 will be applied on a roof deck with layer 12 facing the roof and non-woven layer 18 as the exposed surface upon which roofers will walk. Underlayment 10 applied in this manner provides a satisfactory frictional surface for roofer to walk on. Alternatively the underlayment 10 can be flipped with micro-perfed coated scrim layer 12 on the upper exposed side coated with an anti-skid substance.
The micro-perforations in underlayment 10 of the present invention are typically formed using pinned perforating rollers. The present invention is not, however, limited in the manner in which the micro-perforations are formed and other methods for perforation are contemplated, including: (1) perforation by heat embossing at temperatures over the melting point of the fiber; (2) perforation by friction calendaring between an appropriately engraved and a smooth roller; (3) perforation by slitting and extension perpendicular to the slits; (4) perforation by passing male-/female rollers; (5) hot needle perforation; and (6) perforation by water jets onto suitable supporting means such as coarse mesh screens or perforated drainage drums with projections in order to provide clear holes. The micro-perforations can be easily manipulated in shape (e.g., oval square, circular, etc.), size (e.g., diameter, area) and density so as to control the degree of breathability of underlayment 10 .
Other factors that influence the extent of perforations are pin density, diameter of the pins at the tips, pin height, and pin profile from the apex to the base. Additionally, the pin tip (apex) can be of different shapes (instead of circular). Alternatively, micro-perfing is possible by electrostatic perforation (ESP) or laser-based techniques. The location of the pin roller can be varied as well. The pin roller may be temperature controlled depending on the line speed and material being perforated. A bank of pin rollers may be employed if necessary. The substrate, fabric or film may run against a support roller to provide additional stability and consistency of perforations.
While the present invention has been particularly described and illustrated with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details may be made without departing from the spirit and scope of the present invention. It is therefore intended that the present invention is not limited to the exact forms and details described and illustrated.
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A building materials composite is provided, having a first perforated coated scrim, a second perforated coated scrim, and a breathable thermoplastic film bonded to and sandwiched between the first and the second perforated coated scrims. Further, a method of manufacturing a building materials composite is provided, the method having the steps of coating a fabric, perforating the coated fabric to make a perforated coated scrim, bonding one side of the perforated coated scrim to one side of a breathable thermoplastic film, and bonding a non-woven fabric to a second side of the breathable thermoplastic film.
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[0001] This application also claims priority to U.S. provisional application Ser. No. 60/776586 filed Feb. 24, 2006.
FIELD OF THE INVENTION
[0002] The field of the invention is modular floor tiles.
BACKGROUND
[0003] Interlocking modular tiles provide a quick and easy option to cover a variety of sizes and shaped surface areas. Simple assembly of the tiles allows users to quickly restore and enhance surface appearance of any undesirable characteristics of the floor surface, such as stains and markings. Usually made of durable material, the tiles also serve as a protective layer of existing floor surface.
[0004] There are many known modular tiles with interlocking elements addressing all manner of various needs. U.S. Pat. No. 5,791,114 to Mandel (August 1998) describes quick assembly interlocking tiles having generally T-shaped connectors. U.S. Pat. No. 6,588,167 to Chang (July, 2003) in which the interlocking elements have a different configuration. U.S. Pat. No. 6,526,705 to MacDonald (March 2003) provides tile with different configuration connectors. While there exist many other tile configurations, many of these are merely for decorative purposes and do not take into consideration the problem of binding, which often exists during installation. Since the connectors have to interlock exactly, slight variations of the tiles tend to grind or “bind” together, causing the tiles to poorly fit around each other. Some of the configuration also creates the problem in which the connectors do not interlock tightly and can cause the floor modules to become disconnected with each other. As one unit of the interlocking tile binds the other, the whole surface of tiles can be uneven, unfitted and unsafe.
[0005] Thus, there is still a need for improvements to interlocking tiles that allow for greater flexibility and easy of use.
[0006] This and all other referenced patents and applications are incorporated herein by reference in their entirety. Where a definition or use of a term in a reference, which is incorporated by reference herein is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
SUMMARY OF THE INVENTION
[0007] The present invention provides modular floor covering systems and methods in which interlocking tiles have mushroom shaped connectors, allowing the tiles to be relatively free from undesirable binding during installation, and providing improved alignment and guidance of the connectors into corresponding receiving tiles.
[0008] In a preferred embodiment, a tile has a body and an interlocking cap structure with a first surface and a second surface; a first curved portion connecting the first surface with a radius of R 1 to the second engaging surface with a radius of R 2 , wherein R 1 >R 2 ; and a stem supporting the cap structure. The cap has a mushroom-like shape.
[0009] The stem also a second surface and a third surface contiguous to the body of the stem. Furthermore, the stem has a second curved portion connecting the second surface with a radius of R 3 to the third engaging surface with a radius of R 4 , wherein R 3 <R 4 .
[0010] In another preferred embodiment, a system for covering a surface has a tile having a body and an interlocking cap structure having a first surface and a second surface; a first portion connecting the first surface with an angle of L 1 to the second engaging surface with an angle of L 2 , wherein L 1 >L 2 , where (L 1 +L 2 ≦180°), and a stem supporting the cap structure.
[0011] The stem also has the second surface and a third surface. The second portion connecting the stem to the second surface has an angle of L 3 and the third engaging surface connecting to the stem has an angle of L 4 , and L 3 <L 4 .
[0012] In preferred embodiments, the body of the tile also has a pattern and a grid around the pattern. The pattern can be raised from the rest of the body. The pattern can be of a square, diamond or other desired shape, The patterns, if raised, is at least 0.04 inches higher than the rest of the grid or the body.
[0013] In yet another preferred embodiment, a floor block has a grid portion defining a cap structure and a plurality of raised pattern that collectively reduce the thickness of the block by a factor of at least 20% relative to corresponding block without the grid portion.
[0014] Contemplated interlocking tiles can be fabricated from any suitable material, including for example polycarbonate, plastic, rubber or other polymeric material.
BRIEF DESCRIPTION OF THE DRAWING
[0015] FIG. 1 is a plain view of an interlocking tile.
[0016] FIG. 2 is a close-up perspective view of the interlocking tile.
[0017] FIG. 3A is a plain view of the interlocking tiles mating together.
[0018] FIG. 3B is a closed up view of the joining pieces of the interlocking tiles.
[0019] FIG. 3C is a side cross-section view of the corner piece of the interlocking tile.
[0020] FIG. 4 is a plain view of an interlocking tile with a surface pattern.
[0021] FIG. 5 is a vertical cross section view of the interlocking tile with the surface pattern.
[0022] FIG. 6 is a close-up perspective view of an interlocking tile with a different configuration.
DETAILED DESCRIPTION
[0023] The present inventive subject matters provides a modular floor covering system with interlocking tiles that are relatively free from undesirable binding during installation, and providing improved alignment and guidance of the connectors into corresponding receiving tiles.
[0024] In FIG. 1 and FIG. 2 , a modular floor covering system 100 generally comprises tile 10 , cap 20 and stem 30 .
[0025] FIG. 2 demonstrates a close-up view of cap 20 and stem 30 on tile 10 . Cap 20 is preferably is a male protruding portion 12 that mates with another tile's female receiving portion 14 . Male protruding portion 112 are connectors of tile 10 and can join other tile by mating with the female receiving portion.
[0026] Preferably, cap 20 comprises two regions: top region 22 and middle region 24 . Top region 22 extends across the cap from one side to another. Similarly, bottom region 28 extends from the based of the cap from one side to the other. Outer edge 34 joins from one side of top region 22 and middle region 24 to form a curve and then joins the other side of top region 22 and middle region 24 , and together form a generally mushroom-shape cap structure.
[0027] Preferably, outer edge 34 connects with top region 22 to form an arch to form an ellipse shape with first radius 26 . Then outer edge 34 preferably curves downward to connect with middle region 24 to form another ellipse with second radius 28 . The downward curves allow for a mushroom-cap like shape, which also preferably means that top radius 26 is greater than middle radius 28 .
[0028] Generally, a circle is defined by one point and the distance radius, R. However, it is preferred that the arch formed by joining outer edge 34 with top region 22 and middle region 24 is of an ellipse. The ellipse is a natural extension of the circle. Instead of having one radius, the ellipse has two points from one given point. Thus, the ellipse is the sum of distances from two radius R 1 and R 2 from the two points to the one given point. The two points are also called the foci of the ellipses. Top radius 26 is the larger radius of the ellipse formed by joining edge 34 to top region 22 then middle radius 28 which is joined by outer edge 34 to middle region 24 .
[0029] The ellipse shape on both sides of the cap allow for the cap to form a mushroom-like shape. More importantly, the ellipse shape allows for the tiles to move relatively freely with each other for installation and use. Since most of the tile are used for floor covering have to withstand heavy foot traffic and use, the tiles have to interlock seamlessly. Existing interlocking modular floor fails to allow binding in which the tiles have some freedom in mating.
[0030] Contiguous to cap 20 , stem 30 supports cap 20 and form a seamless interlocking unit to tile 10 . Similar to cap 20 , stem 30 has middle region 24 and bottom region 32 joined by inner edge 36 . Middle region 24 extends from one side to the other of the stem and the bottom region 32 extends from one tile to another to form a female receiving portion 14 . Female receiving portion 14 receives male protruding portion 10 of another tile to form an interlocking mating mechanism.
[0031] Preferably, an inverted arch is formed joining inner edge 36 with middle region 24 and bottom region 32 . Similar to the cap, the stem forms an ellipse shape with third radius 42 formed by joining inner edge 36 with middle region 24 and fourth radius 44 formed by joining inner edge 36 with bottom region 32 . Here, preferably, fourth radius 44 is larger than third radius 42 . Logically, third radius 42 is the same length as second radius 28 , and first radius 26 is the same length as fourth radius 42 . The difference is that the curve is inverted for first and second radius as opposed to third and fourth radius. The inverted curve allows for the mating mechanism of the female receiving portion to the male protruding portion.
[0032] Preferably, the tiles have the male protruding portion and female receiving portion all along the edges to interlock with other tiles. However, it is contemplated that there are pieces where at least one edge of the tile does not have any male protruding portion or female receiving portion. For instance, tiles that are placed on the outer edge against a straight floor do not need to have connectors.
[0033] In FIGS. 3A , 3 B and 3 C, a modular floor covering system 100 comprises the joining of tiles 10 by interlocking male protruding portions 12 of the individual tile to female receiving portions 14 of the adjoining tile.
[0034] FIG. 3B and FIG. 3C specifically depicts the joining of corner pieces 50 . Corner pieces in general comprises corner male protruding portions 58 mating corner female receiving portion 56 . The corner male protruding portion generally is at the adjacent side of the female receiving portion.
[0035] Similar to male protruding portion 12 and female protruding portion 14 , there is corner cap 54 and corner stem 52 . The corner cap and stem are different than the other cap and stem pieces in that corner pieces have to accommodate the different configuration presented in a corner. Preferably, corner cap 54 retains the characteristics of cap 20 on one side of the cap. On the other side of the corner cap that joins another corner piece of an adjoining tile, there is no outer edge that joins top region with a first radius followed by the outer edge joining the bottom region with a second radius. Instead, the corner cap has corner side edge portion 58 that connects corner top region 60 to corner middle region 62 with corner angle 66 . Corner angle preferably is a right angle or an angle of 90 degrees. Similarly for corner stem 52 , corner inner edge 58 connects corner middle region 62 to corner bottom region 68 with corner angle 70 . Again, corner angle 70 preferably is a right angle or an angle of 90 degrees. This configuration gives rise to a corner male protruding portion that allows for the mating to the female receiving portion of the adjoining tile. Corner male protruding portion is located on one corner of the tile and the female receiving portion is located at the other corner of the same tile. The 90 degree configuration allows the corner pieces to join together seamlessly yet still retain the mushroom-like shape on the tile to allow for extra room and movement.
[0036] Other configuration are also contemplated in that the shape contained is not just an ellipse or oval shape. It can be of an angular shape. As shown in FIG. 4 , tile 100 comprises cap 200 with stem 300 . Similar to a mushroom shape, cap 200 has top region 220 and middle region 240 . Top region 220 extends across the cap from one side to another. Similarly, bottom region 280 extends from the based of the cap from one side to the other. Outer edge 250 joins from one side of top region 220 and middle region 240 to form instead of a curve, a angle, then joins the other side of top region 220 and middle region 240 , and form the same angle.
[0037] Preferably, outer edge 250 connects with top region 220 to form a trapezoid-like shape with first angle 260 . Then outer edge 250 preferably curves downward to connect with middle region 240 to form a straight line with that has second angle 280 . First angle 260 preferably is greater than second angle 280 . The sum of first angle and second angle should not exceed 180 degrees.
[0038] Contiguous to cap 220 , stem 300 supports cap 220 and form a seamless interlocking unit for tile 10 . Similar to cap 220 , stem 300 has middle region 24 and bottom region 320 joined by inner edge 350 . Middle region 240 extends from one side to the other of the stem and the bottom region 320 extends from one tile to another to form a female receiving portion. Female receiving portion receives male protruding portion of another tile to form an interlocking mating mechanism.
[0039] Preferably, a line is formed joining inner edge 350 with middle region 240 and bottom region 320 . Similar to the cap, the stem forms the straight line with third angle 380 by joining inner edge 350 with middle region 240 and fourth angle 360 formed by joining inner edge 350 with bottom region 320 . Here, preferably, fourth angle 360 is larger than third angle 380 . Again, like first and second angle, the sum of third and fourth angle is no larger than 180 degrees.
[0040] In general, a modular floor system can have tiles that are made of one kind of material and have a smooth surface. It is contemplated, however, that the tile can have a surface pattern in which different shapes and sizes of patterns are set in the body of the tile.
[0041] As shown in FIG. 5 , a tile 100 comprises connectors 13 that have male protruding portion 12 and female protruding portion 14 with body 13 in which pattern 16 is set with surrounding grooves 15 . Specifically, pattern 16 is arranged in an orderly fashion that fills the body of the tile. Pattern 16 can be a square, rectangular, triangle, oval or any other desirable shape and pattern. It is also contemplated that the pattern 16 can comprises a combination of different shape within one tile.
[0042] Blocks 16 preferably are formed on the tile by mold injection. It is contemplated that when the tile is manufactured, the blocks or patterns are formed when the tile is formed. It is also possible that the basic mold of the tile with the mushroom-shape like caps and stems are formed first and then blocks and patterns are later on added onto the tile.
[0043] The modular floor covering system can be made of any suitable material or mixture of materials commonly known for floor covering, including clay, stone, wood, polymeric materials, recycled materials and especially material selected from the list consisting of vinyl, rubber, linoleum, and resin. Generally, a co-polymeric material is preferred for conventional modular flooring covering system.
[0044] For example, a preferred formulation of the modular floor covering system has PVC Resin: 32.8%; Calcium Carbonate: 24.9%; Dioctyl Phthalate: 39.8%; Lead (as lead stearate) 2.2%; Titianium Dioxide: 0.18%; Alumina: 0.11%; Benzophenone: 0.05% and dyes: 0.05%. In general, sporting flooring that requires greater use and abuse may require less expensive and synthetic rubber polymers. The mushroom-like shape of the tiles and the material flexibility provides a combinations of specific product application and requirement. It also provides for competitive cost advantages in the marketplace without comprising utility or quality.
[0045] Tiles can be any practical width, thickness, and length. With a given tile, the surface can be of one smooth material in which there are no ridges or grooves. With a patterned tile, the surface can contain ridges and grooves between the connectors and within the pattern as shown in FIG. 5 . Cap can also be any practical width, thickness, and length that corresponds with the overall length, width, thickness of the tile. The width, thickness and length of pattern also can be flexible depending on the desired characteristics of the look and feel of the tiles.
[0046] In one preferred embodiment as shown in FIG. 6 , a side vertical cross section of the tile is shown. The thickness of tile preferably is at least 0.25 inches. It is contemplated that as long as the structural integrity of the tiles are maintained, the tiles can be any thickness. For example, tiles used for heavy duty sporting purposes is contemplated to have a greater thickness. Depending on the material formulation and construction, groove thickness 19 can be different than pattern thickness 21 . Having groove thickness 19 be less than that of pattern thickness 21 , at least 20% of material can be saved. Similarly, connector thickness 17 can also be less than the groove thickness and pattern thickness to save material. The patterns, if raised, preferably is at least 0.04 inches higher than the rest of the grid or the body to not only save material but maintain structural integrity.
[0047] Having the unique mushroom shape of the connectors allow for the tiles to interlock in a more efficient way. Tiles do not have to be aligned exactly during installation and yet they retain durability after installation. Even though the thickness of the connector is less, the structural integrity still stands with the present connector shape. It is also possible, although not desirable from a manufacturing cost standpoint, for different ridges on a given tile to be made of different materials, densities, shapes, colors and so forth.
[0048] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. Moreover, in interpreting the disclosure, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps could be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.
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An interlocking tile system comprises tiles that has a body, interlocking cap structure with a first surface and a second surface; a first curved portion connecting the first surface with a radius of R 1 to the second engaging surface with a radius of R 2 , wherein R 1 >R 2 ; and a stem supporting the cap structure. The cap is a mushroom-like shape. Such configuration of the connector aids in installation by lessening instances of binding and align and guide the caps into their corresponding receiving areas. The tiles are preferably square, and are connected along all four sides.
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BACKGROUND OF THE INVENTION
[0001] This application claims the priority of European application 00114618.2, filed Jul. 7, 2001, the disclosure of which is expressly incorporated by reference herein.
[0002] The invention relates to condensing heat exchangers, and more particularly to condensing heat exchangers employing both a condenser section and a slurper section.
[0003] A condensing heat exchanger is a main component of air conditioning systems. It simultaneously cools and de-humidifies the air to be conditioned. During this process water condenses on the surface of the air side surface (air fins) of the condensing heat exchanger. The condensed water on the air fins has to be separated from the air stream. On earth this is generally done by the gravity forces. For space applications under the absence of gravity the condensed water is sucked off by applying underpressure.
[0004] A prior art design principle (FIG. 1) already proven in several applications, e.g. in spacelab missions, is to add a so called slurper section 3 to the condenser section 1 of the condensing heat exchanger 16 from which the condensed water together with some air is sucked off through the slurpor holes 7 by applying underpressure. However, this design requires that the air flow velocity is high enough to push the condensed water out from the air fins against the capillary forces which tend to hold the water inside the air fins. In case of low air flow velocities and when the distance between neighbouring fins 2 is small a significant amount of water can accumulate inside the air fins and is released spontaneously. This could result in a poor water separation performance of the slurper section.
[0005] The object of the present invention is to provide a condensing heat exchanger in which trapping of the condensate BA inside the condensing section can be decreased and a high water separation can be obtained.
[0006] In accordance with the invention the condensing heat exchanger comprises a capillary bridge, which connects the condensing section and the slurper section of the condensing heat exchanger. The capillary bridge comprises capillary spaces wherein the condensate formed on the fins of the condenser section is transported inside the slurper section by means of capillary forces.
[0007] In a preferred embodiment the capillary space is defined by an interstitial space which is formed by at least one plate arranged in proximity to a section of the internal surface of the slurper section. The water is pulled from the condensing section into the interstitial spaces between the plates and the surface of the slurper section by capillary forces and transported inside the slurper section. By applying, for example, reduced pressure the water together with an air stream penetrates through dedicated slurper holes through which it exits the slurper section.
[0008] The plates can be attached to the surface of the slurper section by means of clamps or bolts. An advantage arising from the use of clamps or bolts for attaching the plates to the slurper section is that the capillary bridge is capable of being added to an existing hardware or being removed after assembly of the condensing heat exchanger.
[0009] In another embodiment of the invention the capillary bridge is formed by a capillary fleece or mesh. The water is pulled by capillary forces from the air fins into the cavities of the fleece or mesh and then exits by applying e.g. reduced pressure together with an air stream through dedicated slurper holes.
[0010] In the case of the capillary bridge comprising plates, the distance between the plates and the internal surface of the slurper section, which affects the capillary force, is adjusted by dedicated spacers. When using a fleece or a mesh as capillary bridge the fleece or mesh is directly applied on the internal surface of the slurper section without spacers. The plate, fleece or mesh can be attached by mechanical treatments e.g. solding or welding.
[0011] In a further embodiment of the invention the surface of the condensing section is coated. Preferably a hydrophilic coating is used. Thus, the transport of the water condensed on the air fins toward the capillary bridge is supported. Other surface treatments, e.g. mechanical, thermal or chemical treatments, which result into a hydrophilic characteristic of the surface are possible.
[0012] The condensing heat exchanger according to the invention can be used under microgravity conditions or under 1 and higher gravity conditions. In the case of using the condensing heat exchanger under micro-gravity conditions, e.g. space applications, the water is extracted from the air stream in the slurper section through applied underpressure. In this application the condensing heat exchanger can be used in any spatial orientation.
[0013] When the condensate should be removed solely by gravity, for example, on earth, the condensing heat exchanger should be oriented in such a manner that the plates forming the capillary bridge are oriented parallel to the gravity force. The water sucked into the capillary bridge by capillary forces is pulled down to the bottom of the capillary bridge by gravity. At the bottom of the capillary bridge a water column is formed. If the height of the water column in the capillary bridge produces a hydrostatic pressure which is greater than the capillary pressure of the capillary bridge the water can leave the capillary bridge. In order not to block the water suction from the fins at the bottom of the condenser section the slurper section including the capillary bridge has to be extended below the bottom of the condensing heat exchanger. So it is guaranteed that the water can leave the slurper section by gravity forces without applying underpressure.
[0014] The present invention is dedicated mainly to space application for use in manned spacecrafts. However, it can also be applied on earth to improve water separation performance of a condensing heat exchanger.
[0015] Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention is described in more detail with reference to the accompanying drawings, in which
[0017] [0017]FIG. 1 is a schematical illustration of a condensing heat exchanger according to the prior art,
[0018] [0018]FIG. 2 is a cross sectional side view along the line X-X′ of the condensing heat exchanger of FIG. 1 with the additional capillary bridge according to a first embodiment of the invention,
[0019] [0019]FIG. 3 is a perspective view showing the arrangement of the condensing heat exchanger according to a first embodiment of the invention,
[0020] [0020]FIG. 4 is a cross sectional side view along the line X-X′ of the condensing heat exchanger of FIG. 1 with the additional capillary bridge according to a second embodiment of the invention, and
[0021] [0021]FIG. 5 is a perspective view of a further embodiment of the condensing heat exchanger especially for use under 1 gravity conditions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] [0022]FIG. 1 shows a 3D schematic illustration of a condensing heat exchanger 16 according to the prior art comprising a condenser section 1 and a succeeding slurper section 3 . The condensing section 1 comprises a stack of alternating air flow channels 4 and water channels 6 . In order to enlarge the internal surface of the condenser section 1 air fins 2 are arranged inside the air flow channels 4 . Inside the condenser section 1 the air passes the air fins 2 in parallel direction, whereas the coolant water 11 flows in the water channels 6 perpendicular to the air flow 10 . The slurper section 3 is adjacent to the condenser section 1 and comprises slurper channels 8 being an extension of the water channels 6 of the condenser section 1 but being separated from the water channel 6 by spacer bars 13 . In the slurper channel 8 slurper holes 7 are provided through which water from the air flow 10 can penetrate into the slurper channel 8 by applying an underpressure. The slurper flow 9 in the slurper channel 8 containing separated water and air is oriented parallel to the coolant water flow 11 in the condenser section 1 .
[0023] [0023]FIG. 2 shows a first embodiment of the capillary bridge according to the invention. A plate 5 is arranged on either side of the air flow channel 4 to form a capillary bridge. The plates 5 are mounted in close proximity to the internal surface of the air flow channel 4 in the slurper section 3 . In the embodiment shown in FIG. 2 the plates 5 are arranged parallel to the internal surface of the air flow channel 4 . Further, the plates 5 are in direct contact with the ends of the air fins 2 of the condenser section 1 . The distance between the plates 5 and the surface of the slurper section 3 is adjusted by dedicated spacers 17 . These spacers 17 are e.g. integrated on the plates 5 . Over a slurper hole 7 the capillary bridge (i.e. the interstitial space between plate 5 and the surface of the air flow channel 4 ) is connected to a slurper channel 8 so that condensed water can be removed. The slurper holes 7 are preferably evenly spaced over the flow width inside the slurper section 3 (see FIG. 1) such that a homogeneous flow in the slurper section 3 can be achieved.
[0024] [0024]FIG. 3 shows a perspective view of a condensing heat exchanger 16 according to a first embodiment of the invention. The air flow 10 in the air flow channel 4 and the slurper flow 9 in the slurper channel 8 are indicated. The plates 5 forming the capillary bridge are mounted in pairs on either side of each air flow channel 4 of the slurper section 3 . The distance between the plates 5 and the air flow channel 5 is maintained by spacers 17 . The spacers 17 and the plates 5 are attached to the surface of the air flow channel 4 by bolts 15 .
[0025] [0025]FIG. 4 shows a second embodiment of the capillary bridge connecting the condensing section 1 and the slurper section 3 according to the invention. The capillary bridge comprises a mesh 12 which is attached on either side of the air flow channel 4 with no spacers between the mesh 12 and the internal surface of the air flow channel 4 . Further, the mesh 12 is in direct contact with the air fins 2 of the condenser section 1 . Thus, the condensed water of the air flow 10 in the condenser section 1 penetrates through the mesh 12 inside the slurper section 3 and towards the slurper holes 7 where the water exits the slurper section 3 through the slurper channel 8 .
[0026] [0026]FIG. 5 shows another embodiment of the condensing heat exchanger according to the invention suitable for use especially under 1 gravity conditions. The condensing heat exchanger 16 comprising the condenser section 1 and the slurper section 3 including the capillary bridge is oriented such that the plate 5 of the capillary bridge is oriented parallel to the gravity force. The water sucked into the capillary bridge by capillary forces is pulled down to the bottom of the capillary bridge by gravity. At the bottom of the capillary bridge a water column is formed. If the height of the water column in the capillary bridge produces a hydrostatic pressure which is greater than the capillary pressure of the capillary bridge the water can leave the capillary bridge.
[0027] In order not to block the water suction from the fins located at the bottom of the condenser section 1 the slurper section including the capillary bridge has to be extended below the bottom of the condensing heat exchanger. The minimum length of the extension 14 is the height of a water column required to establish a hydrostatic pressure greater than the capillary pressure of the capillary bridge, Thus, the length of the extension 14 varies with the distance between the surface of the air flow channel 4 and the plate 5 .
[0028] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.
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The invention relates to a condensing heat exchanger comprising a condenser section containing a plurality of internal fins, on which water is condensed and a succeeding slurper section, in which the condensate is removed. The condenser section and the slurper section are connected by a capillary bridge comprising capillary spaces wherein the condensate formed on the fins is transported by means of capillary forces inside the slurper section.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2015-133318 flied on Jul. 2, 2015.
Background
1. Technical Field
The present invention relates to a droplet driving control device and an image forming apparatus.
2. Related Art
In an apparatus which ejects droplets of ink etc. to form an image, such as an inkjet continuous feed printer, a driving frequency for controlling timing of droplet ejection is set in accordance with image formation speed.
SUMMARY
According to an aspect of the invention, there is provided a droplet driving control device comprising: a droplet ejection control unit which ejects droplets at requested droplet ejection periods; and an adjustment unit which adjusts control of the droplet ejection control unit using at least continuous two of the droplet election periods as one set based on an error of droplet speed with respect to a proper value thereof, so that droplets can be ejected at different droplet ejection periods within a range of the one set, and an average value of the droplet ejection periods within the range of the one set for ejecting the droplets can be equal to each of the requested droplet election periods.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the present invention will be described in detail based or the following figures, wherein:
FIG. 1 is a schematic configuration diagram showing an example of a main configuration portion of a droplet ejection type recording apparatus according to an exemplary embodiment of the invention;
FIGS. 2A and 2B are plan views showing a head and a sectional view showing an internal structure of each droplet ejecting element in the head according to the exemplary embodiment;
FIG. 3 is a block diagram of a control portion according to the exemplary embodiment;
FIG. 4 is a functional block diagram showing blocked parts of period adjustment control in the control portion according to the exemplary embodiment;
FIGS. 5A and 5B are a droplet ejection driving frequency to droplet speed fluctuation amount characteristic graph and a droplet ejection period to droplet speed fluctuation amount characteristic graph respectively;
FIGS. 6A and 6B are timing charts of driving waveforms for ejecting droplets according to the exemplary embodiment and a comparative example respectively;
FIG. 7 is a flow chart showing the flow of a droplet ejection period adjustment control routine according to the exemplary embodiment;
FIG. 8 is a timing chart showing details of correction of a driving waveform in a step 124 of FIG. 7 ; and
FIGS. 9A, 9B, 9C and 9D are a droplet election period to liquid speed fluctuation amount characteristic graph according to a modification, a timing chart of a driving waveform for ejecting droplets according to a comparative example, a timing chart of a driving waveform for ejecting droplets according to a modification (continuous ejection pattern 1), and a timing chart of a driving waveform for ejecting droplets according to a modification (continuous ejection pattern 2) respectively.
REFERENCE SIGNS LIST
10 droplet ejection type recording apparatus
12 ( 12 A, 12 B) image forming portion
14 control portion
16 paper supplying roll
18 discharging roll
20 feeding roller
22 ( 22 A, 22 B) head driving portion
24 ( 24 A, 24 B) head
26 ( 26 A, 26 B) drying device
24 AC, 24 AM, 24 AY, 24 AK head
24 BC, 24 BM, 24 BY, 24 BK head
30 droplet ejecting member
32 nozzle
34 pressure chamber
36 supply port
38 common passage
40 diaphragm
42 piezoelectric element
40 A common electrode
42 A individual electrode
50 CPU
52 RAM
54 ROM
56 I/O
58 bus
60 microcomputer
62 user interface (UI)
64 hard disk (HDD)
66 communication I/F
70 image formation instruction information accepting portion
72 image information importing portion
74 designated image formation speed information extracting portion
76 image formation pattern generating portion
78 droplet ejection period calculating portion
80 determination portion
82 image formation speed setting range storage portion
84 droplet ejection period to droplet speed characteristic table storage portion
86 ejection control selecting portion
88 adjusted ejection period generating portion
90 steady ejection period generating portion
92 driving waveform correcting portion
94 driving instruction portion
DETAILED DESCRIPTION
(Outline of Apparatus)
FIG. 1 is a schematic configuration diagram showing a main configuration portion of a droplet ejection type recording apparatus 10 as an example of an image forming apparatus according to an exemplary embodiment of the invention.
For example, the droplet ejection type recording apparatus 10 is provided with two image forming portions 12 A and 12 B, a control portion 14 , a paper supplying roll 16 , a discharging roll 18 , and a plurality of feeding rollers 20 . The two image forming portions 12 A and 12 B can form images on opposite surfaces of a paper sheet P in one feeding.
In addition, the image forming portion 12 A is provided with a head driving portion 22 A as an example of a droplet ejection control unit. Further, the image forming portion 12 A includes heads 24 A and a drying device 26 A.
Similarly, the image forming portion 12 B is provided with a head driving portion 22 B as an example of a droplet election control unit. Further, the image forming portion 12 B includes heads 24 B and a drying device 26 B.
Incidentally, there is a case where indication of a suffix “A” and a suffix “B” at the ends of signs may be omitted below when it is not necessary to distinguish between the image forming portion 12 A and the image forming portion 12 B and between common members included in the image forming portion 12 A and the image forming portion 12 B.
The control portion 14 drives a not-shown paper feeding motor to control rotation of the feeding rollers 20 which are, for example, connected to the paper feeding motor through a mechanism of gears etc.
A long paper sheet P is wound as a recording medium around the paper supplying roll 16 . The paper sheet P is fed in a direction of an arrow A (paper feeding direction) in FIG. 1 in accordance with rotation of the feeding rollers 20 .
Upon acceptance of image information, the control portion 14 controls the image forming portion 12 A based on color information for each pixel of an image contained in the image information. Thus, the image corresponding to the image information is formed on one image formation surface of the paper sheet P.
Specifically, the control portion 14 controls the head driving portion 22 A. The head driving portion 22 A drives the heads 24 A connected to the head driving portion 22 A in accordance with droplet ejection timings instructed from the control portion 14 , so as to eject droplets as an example of droplets from the heads 24 A and form the image corresponding to the image information on the one image formation surface of the fed paper sheet P.
Incidentally, the color information for each pixel of the image included in the image information includes information expressing the color of the pixel uniquely. In this exemplary embodiment, assume that the color information for each pixel of the image is represented by respective concentrations of yellow (Y), magenta (M), cyan (C), or black (K). Another representation method for expressing the colors of the image uniquely may be used.
The heads 24 A include four heads 24 AC, 24 AM, 24 AY and 24 AK corresponding to the four colors, i.e. the Y color, the M color, the C color and the K color, respectively. Droplets of the corresponding colors are ejected from the respective heads 24 A.
The control portion 14 controls the drying device 26 A to dry the droplets of the image formed on the paper sheet P to thereby fix the image to the paper sheet P.
Then, the paper sheet P is fed to a position opposing to the image forming portion 12 B in accordance with rotation of the feeding rollers 20 . On this occasion, the paper sheet P is turned inside out and fed so that the other image formation surface different from the image formation surface on which the image has been formed by the image forming portion 12 A can face the image forming portion 12 B.
The control portion 14 also executes, on the image forming portion 12 B, similar control to the aforementioned control on the image forming portion 12 A. Thus, an image corresponding to the image information can be formed on the other image formation surface of the paper sheet P.
The heads 24 B include four heads 24 BC, 24 BM, 24 BY, and 24 BK corresponding to the four colors, i.e. the Y color, the M color, the C color and the K color, respectively. Droplets of the corresponding colors are ejected from the respective heads 24 B.
The control portion 14 controls the drying device 26 B to dry the droplets of the image formed on the paper sheet P to thereby fix the image to the paper sheet P.
Then, the paper sheet P is fed to the discharging roll 18 and wound around the discharging roll 18 in accordance with rotation of the feeding rollers 20 .
Incidentally, the configuration of the apparatus for forming images on front and back surfaces of a paper sheet P in one feeding starting at the paper supplying roll 16 and ending at the discharging roll 18 has been described as the droplet ejection type recording apparatus 10 according to this exemplary embodiment. It is however a matter of course that the droplet ejection type recording apparatus 10 may be a droplet ejection type recording apparatus for forming an image on a single surface.
In addition, ink as an example of a droplet includes water-based ink, oil-based ink serving as ink containing a solvent which can be evaporated, ultraviolet-curable type ink, etc. However, assume that water-based ink is used in the this exemplary embodiment. When it is mentioned as “ink” or “droplet” simply in this exemplary embodiment, it may imply “water-based ink” or “water-based ink droplet”.
(Head 24 )
As shown in FIG. 2A , each of the heads 24 applied to the image forming portion 12 has droplet ejecting members 30 which are arranged in a longitudinal direction of the head. Incidentally, the longitudinal direction of the head is a direction intersecting with a feeding direction of the paper sheet P (a direction of an arrow A in FIG. 2A ), and may be referred to as main scanning direction. In addition, the feeding direction of the paper sheet P (the direction of the arrow A in FIG. 2A ) may be referred to as sub-scanning direction.
The layout of the droplet ejecting members 30 is not limited to a single array line in the main scanning direction. In some dot pitch (resolution), a plurality of array lines of droplet ejecting members 30 provided in the sub-scanning direction may be arrayed two-dimensionally in accordance with predetermined rules so that ejection timing in each array line can be controlled in accordance with the array line pitch and feeding speed of the paper sheet P.
As shown in FIG. 2B , the droplet ejecting members 30 are provided with nozzles 32 and pressure chambers 34 corresponding to the nozzles 32 respectively.
A supply port 36 is provided in each of the pressure chambers 34 . The pressure chambers 34 are connected to a common passage (common passage 38 ) through the supply ports 36 .
The common passage 38 has a role of receiving supply of ink from an ink supply tank (not shown) as an ink supply source and distributing the received supply of the ink to the respective pressure chambers 34 .
A diaphragm 40 is attached to an upper surface of a ceiling portion of the pressure chamber 34 in each droplet ejecting member 30 . In addition, a piezoelectric element 42 is attached to the upper surface of the ceiling portion of the pressure chamber. The diaphragm 40 is provided with a common electrode 40 A. The piezoelectric element 42 is provided with an individual electrode 42 A. When a voltage is selectively applied between the individual electrode 42 A of the piezoelectric element 42 and the common electrode 40 A, the selected piezoelectric element 42 is deformed so that a droplet can be ejected from the nozzle 32 and new ink can be supplied from the common passage 38 to the pressure chamber 34 .
Each of the head driving portions 22 ( 22 A and 22 B) is controlled by the control portion 14 (see FIG. 1 ) based on the image information to generate a driving signal for applying a voltage to each of the individual electrodes 42 A of the piezoelectric elements 42 independently.
To eject each droplet, image formation speed (droplet ejection period) which can guarantee designated image quality can be set in a predetermined setting range (particularly with a maximum image formation speed Vmax as an upper limit).
Incidentally, a lower limit of the setting range is not particularly limited. Theoretically, it will go well as long as the lower limit of the setting range is a positive number (a number larger than 0). In addition, the setting may include one or both of paper feeding speed and the resolution in addition to the image formation speed.
When there is a change in the setting of the image formation speed, frequency control (droplet ejection period control) is executed on each of the heads 24 by the head driving portion 22 .
As shown in FIG. 3 , the control portion 14 is equipped with a microcomputer 60 . The microcomputer 60 is provided with a CPU 50 , an RAM 52 , an ROM 54 , an I/O 56 , and a bus 58 . The bus 58 such as a data bus or a control bus connects the CPU 50 , the RAM 52 , the ROM 54 and the I/O 56 to each other.
A user interface (UI) 62 , a hard disk (HDD) 64 , and a communication I/F 66 which is performed by radio (or cable) are connected to the I/O 56 . In addition, a device I/F 68 which serves as a connection terminal to any of external devices (the head driving portions 22 and the drying devices 26 in this exemplary embodiment) is connected to the I/O 56 .
Here, in a specific high-frequency band exceeding the upper limit (Vmax) which can guarantee the image quality, droplet speed or a droplet amount fluctuates in accordance with residual pressure vibration (see a frequency band fm in FIG. 5A and a period range width Tm in FIG. 5B ) of each piezoelectric element 42 . Therefore, the image formation speed is limited to the setting range (upper limit) which is not affected by the pressure vibration.
In other words, at an image formation speed exceeding a frequency corresponding to the maximum image formation speed Vmax serving as the upper limit, a landing position of the droplet on the paper sheet P or the size of the landed droplet varies to thereby lower the image quality.
On the other hand, in this exemplary embodiment, control for suppressing the fluctuation in the droplet speed or the droplet amount is constructed in the frequency band in which the droplet speed or the ink droplet amount fluctuates (the specific high-frequency band exceeding the frequency corresponding to the maximum speed Vmax).
That is, in this exemplary embodiment, period adjustment control is executed in the following control procedures in the control portion 14 .
(Control Procedure 1) When a droplet ejection frequency (droplet ejection period) is determined in accordance with image formation speed, determination is made as to whether residual pressure vibration is less than ±5% or not, based on FIG. 5A or FIG. 5B .
(Control Procedure 2) When the residual pressure vibration is in a range of not less than ±5%, a period Tf1 and a period Tf2 are generated as shown in FIG. 6A . The period Tf1 is shorter by Tc/4 than a designated droplet ejection period Tf0. The period Tf2 is longer Tc/4 than the designated droplet ejection period Tf0. Incidentally, Tc is a period of the residual pressure vibration in FIG. 5B so as to be consistent with Tf0.
(Control Procedure 3) The periods Tf1 and Tf2 generated thus are repeated as one set.
As a result, the periods Tf1 and Tf2 are shifted from the designated period Tc by ±Tc/4 respectively. Accordingly, the residual pressure vibration is secured to be less than ±5%, and the designated period Tf0 is secured in the entire period.
FIG. 4 is a functional block diagram showing blocked parts of period adjustment control in the control portion 14 for suppressing fluctuation in the droplet speed or the droplet amount in control concerned with ejection control of a droplet from each droplet ejecting member 30 . Incidentally, the respective blocked parts of the functional block diagram of FIG. 4 do not limit the hardware configuration of the control portion 14 .
An image formation instruction is accepted from the UI 62 (see FIG. 3 ) by an image formation instruction information accepting portion 70 . The image formation instruction information accepting portion 70 is connected to an image information importing portion 72 and a designated image formation speed information extracting portion 74 .
The image information importing portion 72 imports image information from the communication I/F 66 or the HDD 64 (see FIG. 3 ) based on an image information importing instruction received from the image formation instruction information accepting portion 70 , and sends the imported image information to an image formation pattern generating portion 76 .
On the other hand, designated image formation speed (paper feeding speed and/or resolution) is extracted from the image formation instruction information by the designated image formation speed information extracting portion 74 . The extracted image formation speed is sent to a droplet ejection period calculating portion 78 and a determination portion 80 .
By the droplet election period calculating portion 78 , a droplet period (droplet ejection period) is calculated based on the image formation speed accepted from the designated image formation speed information extracting portion 74 , and sent to the determination portion 80 . Incidentally, although the calculation result may be a droplet ejection frequency (a reciprocal number of the period), it is assumed here that the period is calculated in conformity with FIG. 5B .
An image formation speed setting range storage portion 82 and a droplet ejection period to droplet speed characteristic data table storage portion 84 are connected to the determination portion 80 . Determination about the following two conditions is made by the determination portion 80 .
(Determination 1) Determination is made as to whether the designated image formation speed is within a setting range or not (particularly exceeds a maximum speed Vmax as an upper limit or not)
(Determination 2) Determination is made as to whether fluctuation in droplet speed is within a permissible range or not (for example, ±5% shown in FIGS. 5A and 5B or not). Incidentally, the determination 2 may be made when the designated image formation speed exceeds the setting range in the determination 1.
The determination result made by the determination portion 80 is sent to an ejection control selecting portion 86 . When the designated image formation speed exceeds the setting range in the determination 1 and the fluctuation in droplet speed exceeds the permissible range in the determination 2 (determination that adjustment is necessary), the ejection control selecting portion 86 issues an instruction to an adjusted election period generating portion 88 to generate droplet ejection periods (Tf1, Tf2). The adjusted ejection period generating portion 88 serves as an example of an adjustment unit.
On the other hand, when the designated image formation speed does not exceed the setting range in the determination 1, or when the designated image formation speed exceeds the setting range in the determination 1 but the fluctuation in droplet speed does not exceed the permissible range in the determination 2 (determination that adjustment is not necessary), the ejection control selecting portion 86 issues an instruction to a steady ejection period generating portion 90 to generate a droplet ejection period (Tf0).
The adjusted ejection period generating portion 88 executes adjustment to suppress the fluctuation in droplet speed caused by residual pressure vibration in order to make the droplet speed consistent with the steady ejection period Tf0. More specifically, the adjusted ejection period generating portion 88 generates the period Tf1 and the period Tf2, as shown in FIG. 6A . The period Tf1 is shorter by Tc/4 (see FIG. 6A ) than the steady ejection period Tf0. The period Tf2 is longer by Tc/4 (see FIG. 6A ) than the steady ejection period Tf0. The two periods Tf1 and Tf2 are used as one set and repeated in units of one set of the periods. Thus, deviations of the two periods Tf1 and Tf2 can be cancelled with each other so that the period as a whole can correspond to the original designated period Tf0. Incidentally, Tc is a period of the fluctuation in droplet speed, which is the same as the period Tf0 (see FIG. 5B ).
Incidentally, vibration caused by droplet ejection in each dotted line portion is reduced in driving waveforms in FIGS. 6A and 6B . Although a pulse of the dotted line portion for reducing the vibration is not shown in FIG. 8 and FIGS. 9A to 9D which will be described later, it is preferable that practical driving waveforms are used as driving waveforms including the pulses of the dotted line portions.
The adjusted ejection period generating portion 88 and the steady ejection period generating portion 90 are connected to the image formation pattern generating portion 76 respectively.
The image information is imported from the image information importing portion 72 to the image formation pattern generating portion 76 which generates an image formation pattern based on the image information and the ejection period or periods. The image formation pattern generated by the image formation pattern generating portion 76 is sent to a driving waveform correcting portion 92 .
The driving waveform correcting portion 92 executes correction of landing position of droplets on a paper sheet P. The correction is an event occurring when ejection timings have been adjusted by the adjusted ejection periods. More specifically, as shown in FIG. 8 , a driving waveform is corrected to change the speed of each droplet ejected from each nozzle 32 (see FIG. 2B ).
The driving waveform correcting portion 92 is connected to a driving instruction portion 94 . The driving instruction portion 94 sends a driving signal to the head driving portion 22 (see FIG. 1 ) based on the image formation pattern in which the droplet speed has been corrected by the driving waveform correcting portion 92 if necessary.
An effect of the exemplary embodiment will be described below.
FIG. 7 is a flow chart showing the flow of a droplet ejection period adjustment control routine.
FIG. 7 is the flow chart showing the flow of the period adjustment control routine performed by the control portion 14 for suppressing fluctuation in droplet speed or droplet amount in control concerned with control of ejection of a droplet from each droplet ejecting member 30 .
Determination is made in a step 100 as to whether there is an image formation instruction or not. When the determination results in NO, the routine is terminated. On the other hand, when the determination results in YES in the step 100 , the routine goes to a step 102 in which designated image formation speed information is extracted. Then, the routine goes to a step 104 .
In the step 104 , a droplet ejection period is calculated based on the image formation speed. Next, in a step 106 , image formation speed setting range information (table) is read from the image formation speed setting range storage portion 82 . Then, the routine goes to a step 108 in which determination is made as to whether the image formation speed is within a setting range or not.
When the determination results in YES in the step 108 , the routine goes to a step 110 .
On the other hand, when the determination results in NO in the step 108 , conclusion is made that the image formation speed is out of the setting range. Then, the routine goes to a step 112 in which a “droplet ejection period to droplet speed” characteristic table is read from the “droplet ejection period to droplet speed” characteristic table storage portion 84 . Then, the routine goes to a step 114 .
In the step 114 , an error of droplet speed in the droplet ejection period determined based on the image formation speed is determined.
That is, when determination is made in the step 114 that the error is within a permissible range, the routine goes to the step 110 . On the other hand, when determination is made in the step 114 that the error is out of a permissible range (fox example, not less than ±5%), the routine goes to a step 116 .
In the step 110 , a steady ejection period Tf0 is generated, and the routine then goes to a step 118 . In the step 116 , adjusted ejection periods Tf1 and Tf2 are generated, and the routine then goes to the step 118 .
In the step 118 , image information is imported by the image information importing portion 72 . Next, the routine goes to a step 120 in which an image formation pattern is generated. Then, the routine goes to a step 122 .
In the step 122 , determination is made as to whether it is necessary to correct a driving waveform or not. That is, when the steady ejection period Tf0 is generated, it is not necessary to perform the correction. On the other hand, when the adjusted ejection periods Tf1 and Tf2 are generated, it is necessary to correct the driving waveform by changing droplet speed correspondingly to deviations of the ejection timings.
Therefore, when determination is made in the step 122 that it is necessary to perform the correction (the adjusted ejection periods Tf1 and Tf2 are generated), the routine goes to a step 124 in which the correction of the driving waveform (correction of the droplet speed) is executed (see FIG. 8 and details will be given later). Then, the routine goes to a step 126 .
On the other hand, when determination is made in the step 122 that it is not necessary to perform the correction (the steady ejection period Tf0 is generated), the routine goes to the step 126 without executing the correction.
In the step 126 , a driving signal is outputted to the head driving portion 22 ( 22 A, 22 B). Then, the routine is terminated. In the head driving portion 22 ( 22 A, 22 B), the respective heads 24 are controlled based on the inputted driving signal to execute image formation.
The correction of the driving waveform in the step 124 of FIG. 7 will be described here in detail.
When the adjusted ejection periods Tf1 and Tf2 are generated for ejecting droplets as shown in FIG. 8 , every second droplet is ejected at earlier timing by a period (Tc/4)×2. When every second droplet is ejected at earlier timing by the period (Tc/4)×2, each droplet ejected at the period Tf2 can reach the paper sheet P earlier than each droplet ejected at the period Tf1, as designated by dotted line positions in FIG. 8 . The paper sheet P is fed in a direction of an arrow A in FIG. 8 .
In this case, unstable fluctuation in ejection timing among droplets can be avoided due to the ejection timing control based on the period adjustment. However, for example, in accordance with some threshold for determining whether the image quality is good or poor, the image quality may be determined to be poor.
Therefore, correction is performed in such a manner that an ejection speed VTf2 of the period Tf2 whose ejection timing is earlier by the period (Tc/4)×2 with respect to the period Tf1 is made slower than an ejection speed VTf1 of the period Tf1. The speed correction is set based on a distance (T.D. “Throw Distance”) between the nozzle and the paper sheet.
Due to the correction, the droplets ejected at the period Tf2 are displaced to solid line positions from the dotted line positions in FIG. 8 on the paper sheet P so that an interval between adjacent ones of the droplets can be constant.
Incidentally, the invention is not limited to the case where one of the ejection speeds is adjusted to the other ejection speed. To describe in an extreme manner, the two speeds may be corrected so that the sum of added values of correction ratios can reach 100%.
For example, with an intermediate point as a reference, ejection speed VTf1 of the period Tf1 may be made slower by 50% (period Tc/4) of an amount to be corrected and ejection speed VTf2 of the period Tf2 may be made faster by 50% (period Tc/4) of the amount to be corrected.
(Modifications)
In FIGS. 9A to 9D , driving waveforms for performing continuous ejection driving are used as modifications of the droplet ejection driving waveform, for example, in order to land “large droplets” and “small droplets”.
The continuous ejection driving means driving by which a plurality of droplets can be landed in one and the same position (strictly the positions which can be regarded as one and the same dot though not concentric because the paper sheet P is being fed).
For example, a single driving waveform is prepared (stored) as the driving waveform in advance. Respective pulses can be set ON/OFF independently by the head driving portion 22 A, 22 B (see FIG. 1 ) side.
When a “large droplet” is formed, both pulses are set ON so that droplets can be ejected in the two pulses respectively (continuous ejection driving).
When a “small droplet” is formed, one (front) pulse is set OFF and the other (rear) pulse is set ON so that a droplet can be ejected in the other (rear) pulse.
The modifications show that period adjustment according to the exemplary embodiment and speed correction can be performed even in the continuous ejection driving waveforms.
FIG. 9A is the same period characteristic graph as the period characteristic graph showing the influence of pressure vibration in FIG. 5B . FIG. 9B is an output timing chart of a continuous ejection driving waveform as a comparative example, when period adjustment and speed correction are not executed on the driving waveform.
In the comparative example of FIG. 9B , the driving waveform is affected by pressure vibration in the same manner as the driving waveform (single pulse) in the exemplary embodiment, and further, continuous ejection timings may fluctuate irregularly relatively to one another to thereby accelerate lowering of the image quality in the case of the continuous ejection driving.
FIGS. 9C and 9D are output timing charts of continuous ejection driving waveforms of patterns having different combinations of “large droplets” and “small droplets”.
FIG. 9C is a continuous ejection pattern of a “large droplet”→a “large droplet”→a “large droplet”→a “large droplet”, to which both front and rear pulses are applied. In addition, the amplitude of the rear pulse in each driving waveform is corrected for speed correction in FIG. 9C .
In addition, FIG. 9D is a continuous election pattern of a “large droplet”→a “small droplet”→a “small droplet”→a “large droplet”, to which only rear pulses are applied to the “small droplets”. In addition, the rear pulse of each driving waveform is inevitably selected and the amplitude of the selected rear pulse is corrected for speed correction in FIG. 9D .
In other words, in any continuous ejection pattern in which “large droplets” and “small droplets” are mixed, including FIG. 9C and FIG. 9D , the same pulse (rear pulses) are selected so that speed correction can be made.
Incidentally, although the exemplary embodiment (including the modifications) has a configuration in which two periods are used as one set to maintain a requested period every two periods, three periods or more may be used as one set for generating a driving waveform.
The foregoing description of the embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention defined by the following claims and their equivalents.
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A droplet driving control device includes: a droplet ejection control unit which ejects droplets at requested droplet ejection periods; and an adjustment unit which adjusts control of the droplet ejection control unit using at least continuous two of the droplet ejection periods as one set based on an error of droplet speed with respect to a proper value thereof, so that droplets can be ejected at different droplet ejection periods within a range of the one set, and an average value of the droplet ejection periods within the range of the one set for ejecting the droplets can be equal to each of the requested droplet ejection periods.
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BACKGROUND OF THE DISCLOSURE
The invention is in the field of luminous displays and signs, and more particularly relates to gas plasma display devices.
The production of light by the passage of electricity through gases is a well known phenomenon. Devices utilizing this phenomenon have been widely developed in the form of plasma display devices which display specific numerals, characters, symbols, graphics, and the like. The neon sign is an example of a gas discharge display device, typically including an elongated glass tube filled with neon and a pair of excitation electrodes disposed at opposite ends of the tube. In this example, the rigid tube, or envelope, defines the shape of the illumination pattern. This shape is established at the time of manufacture, and cannot be changed.
Other prior art gas discharge display devices may include a plurality of shaped character electrodes in direct or close contact with an electroluminescent gas within a glass envelope, for example, Nixie tubes. In such devices, selected ones of the shaped electrodes may be energized to obtain a desired character display. Again, the shape of the illumination is predetermined by the shape of the electrode which is established at the time of manufacture of the device.
Still other forms of prior art gas discharge display devices include dielectric-bounded, gas-filled character-shaped channels within an envelope, with a suitable set of energizing electrodes. As in U.S. Pat. No. 3,621,332, a plurality of such channels may be established within a single envelope, with electrodes being arranged for selective activation of one channel at a time. Alternatively, as in U.S. Pat. No.4,584,501, a single elongated channel may be formed in one plate of a two glass plate sandwich arrangement, with energizing channels in an adjacent plate. All of these arrangements are suitable for displaying indicia, but as with the earlier discussed prior art, the shape of the display, i.e. the channel configuration, is determined at the time of manufacture of the device.
Yet other prior art gas discharge devices include generally similar display configurations, but have an addressable matrix in which selected dot regions may be selectively energized. For example, as shown in U.S. Pat. No. 4,035,690, selected ones of overlapping orthongal sets of electrodes may be energized to generate a desired dot matrix character. In that patent, the electroluminescent gas is confined to the interior of a plurality of dielectric spheres disposed between the sets of electrodes. With the dot addressible matrix, substantial flexibility is provided in that any dot pattern graphics may be displayed, for example using conventional bit-mapped graphics techniques. However, as with the other above mentioned prior art, all possible display patterns, i.e. the electrode overlap regions, are established at the time of manufacture of the device.
Yet another form of prior art gas discharge device is disclosed in U.S. Pat. No. 3,629,654. As shown in that patent, a pair of opposed, spaced apart plates are mutually sealed at their perimeter to establish an electroluminescent gas filled cell. A transparent conductive coating is disposed on one outer surface of the cell. A movable external sheet having predetermined shaped conductive regions is pressed against the other outer surface of the cell and an ionizing signal is applied across the conductive coating and the conductive region of the external sheet to generate a visible discharge in the cell having the shape of the conductive regions of the external sheet. This two-element display thus requires a means for positioning the external sheet relative to the cell in order to establish an image.
It is an object of the present invention to provide an improved plasma display device.
Another object is to provide an improved plasma display device which may be user-programmed for the display of a desired image.
Yet another object is to provide an improved plasma display which may be economically and efficiently configured to display a desired image.
SUMMARY OF THE INVENTION
Briefly, the present invention is an electroluminescent gas filled double walled panel with the provision for electrode surfaces on both sides of the gas space, which will allow for a luminous gas (or plasma) discharge to be generated when suitably energized. The electrode surfaces may be indicia-(or other graphic image-)shaped, thus producing a like shaped pattern of light of sufficient visibility to be useful as a sign, indicator or other expression of visible information.
The pattern of at least one of the electrode surfaces may be provided by a secondary manufacturer, for example, a user, through the means of painting, stencilling, silkscreening, lithography or the like. By so providing the latter electrode surfaces, the inherent difficulties and costs of producing signage (for example, using a heat-bent gas discharge tube of conventional neon tube signs) are overcome, while still producing a luminous gas image. Thus, even a small signage producing enterprise, or home user, may readily utilize the display device of the present invention to display a user desired image.
Additionally, the display panel of the present invention is far more robust, durable and safe than its bent tube neon sign counterpart. In some configurations, the display device has transparent electrodes on both sides of the gas space, making the display device usable as a window or glass door simultaneously with its carrying images or information.
The display panel may also find general usage in the architectural and outdoor illumination field, much as its bent tube neon sign counterpart does currently. Similarly, much as artists and designers use light filled tubes as components of graphic and sculptural statements, the light producing display devices of the invention may be used, with or without patterns to the illuminosity, as an artistic and design medium.
More particularly, in accordance with the invention, a display device includes first and second rigid, non-conductive sheet members, each having front and back surfaces, which may be substantially parallel. At least one of the first and second sheet members is transparent.
In a preferred form, the sheet members are substantially planar, but alternative configurations could be employed, such as similar cylindrical or spherical configurations. By way of example, the sheet members may be planar sheets of glass. The first sheet member may be substantially transparent and has a coating region on its front surface adapted to receive a first conductive coating on portions thereof. Typically, this first conductive coating represents the image to be displayed. The first conductive coating may be removable in part to correspond to a modified form of the image. The second sheet member may also be transparent. The first conductive coating may be applied by painting, stencilling, silkscreening, lithography, or the like.
One or more spacer elements mutually position the first and second sheet members so that the back surface of the first sheet member is offset from and opposite the front surface of the second sheet member.
A discharge chamber is established by a gas impervious seal between portions of the back surface of the first sheet member and the front surface of the second sheet member. The discharge chamber defines a closed region in the gap between the back surface of the first sheet member and the front surface of the second sheet member. That closed region underlies at least in part the first conductive coating.
An electroluminescent gas is disposed within the closed region. While other gas mixtures may be used, in the preferred form the electroluminescent gas is a Penning gas mixture comprised substantially of 99% neon, 1% argon, and trace amounts (less than 0.1%) of mercury at a pressure of about 120 torr.
A second conductive coating is disposed on a portion of one of the front and back surfaces of the second sheet member underlying at least in part the closed region and a part of the coating region. An applied drive voltage may be coupled between the first conductive coating and the second conductive coating to energize the device so that a luminous plasma image is established in the portions of the closed region between the overlying portions of those conductive coatings.
In one form of the invention, the spacer includes at least one rigid spacer member disposed within the closed region and extending between the back surface of the first sheet member and the front surface of the second sheet member.
In various embodiments, either or both of the first and second conductive coatings may be substantially translucent, transparent, reflective or opaque. Further, the conductive coating may be disposed on the front surface of the second sheet member and at least in part within the closed region. Alternatively, the second conductive coating may be disposed on the back surface of the second sheet member and at least in part overlying the closed region. A third non-conductive sheet member may overlie the second conductive coating opposite the back surface of the second sheet member. A fourth non-conductive sheet member may overlie the first conductive coating. The latter non-conductive sheets may be used to ensure that a user does not contact the electrodes during use. Further, those added sheets provide increased resistance to breakage of the device as a whole. Also, those sheets, when laminated to the first and second sheets, provide increased stiffness of the chamber-defining walls so that relatively thin sheets may be used for the first and second sheet members, using relatively inexpensive (e.g. polycarbonate) material to form the third and/or fourth sheet members.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects of this invention, the various features thereof, as well as the invention itself, may be more fully understood from the following description, when read together with the accompanying drawings in which:
FIG. 1 shows in exploded form, a display device according to the present invention;
FIG. 1A shows, in section, the portion of the display device of FIG. 1 including the filling stem;
FIG. 2 shows in exploded form, an alternative plasma device configuration;
FIG. 3 shows in perspective view, a plasma display device having a plurality of internal spacers;
FIG. 4 shows in section along lines 4--4, the plasma display device of FIG. 3;
FIG. 5 shows a perspective view of an alternative spacer for use with the device of FIGS. 3 and 4;
FIGS. 6-9 show sectional views of alternative spacers for use with the device of FIGS. 3 and 4; and
FIG. 10 shows in exploded form, an alternative configuration for a plasma display device of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An exemplary luminous (plasma) panel display device 10 is shown in FIG. 1 in exploded form. The device 10 includes two flat and parallel non-conducting, transparent glass sheet members 12 and 14 having "front" surfaces 12a and 14a, respectively, and "rear" surfaces 14a and 14brespectively. As shown, sheet members 12 and 14 are substantially planar, but other forms might also be used, such as cylindrical or conical.
An edge seal and spacer element 6 defines an enclosed hermetic volume (or region) 20 having an electroluminescent gas therein. Overlapping conductive coatings 26 and 28 are disposed on the front surface 12a of sheet member 12 and on the rear surface of 14b of sheet member 14, respectively.
A filling stem 22, extending parallel to the principal plane of volume 20, passes between opposing portions of sheet members 12 and 14 and through spacer member 16 to provide access to chamber volume 20. The outer diameter of filling stem 22 is less than or equal to the distance between the front surface 12a and the back surface 14b. This filling stem 20 permits evacuation and back-filling of the volume 20 following assembly of sheet members 12, 14 and seal/spacer element 16. After back-filling is accomplished, the stem 22 is sealed off. In alternative embodiments, different filling stem configurations may be used. For example, the stem may be placed through a hole drilled through sheet member 12 and fused to the edges of that hole, with the central axis of the stem extending perpendicular to the principal plane of volume 20.
In the preferred embodiment, the sheet members 12 and 14 are soda-lime planar glass sheets. The spacer element 16 is also soda-lime glass. The thickness of the sheets is determined to establish (1) a parallel orientation of the two sheets, producing a gas-enclosing space with uniform gap after filling, and (2) total mechanical and thermal stress on the glass sheet members during the assembly and evacuation of the device 10 which does not exceed the properties of the glass, causing breakage. The preferred embodiment has an enclosed volume which is 15 cm by 15 cm, with an intersheet gap in the range 0.25-1.0 mm, as established by spacer 16. The soda-lime glass sheet members 12 and 14 are 3.0 mm thick. With larger surface areas, thicker glass sheets may be used, and for smaller areas, thinner glass may be used. For glass with higher resistance to temperature stressing and higher mechanical strength, such as borosilicate glass, the thickness required for any specific surface area may also be reduced in comparison to the soda-lime glass sheets used in the illustrated embodiment. For example, a 15 cm by 15 cm chamber formed by Pyrex brand borosilicate glass sheets with a 1 mm gap, may have 2.5 mm sheet thickness without overstressing.
While the present embodiment is a three element construction (i.e. sheet members 12, 14 and spacer element 16), other configurations might also be used, for example, two sheet members in a sandwich configuration where one or both of the adjacent surfaces includes an etched chamber-defining region. In the latter configuration, the peripheral spacer is integral with at least one of the sheet members.
In general, spacing and sealing of the chamber 20 of device 10 is provided by a perimeter seal. Various means of hermetically sealing the sheets 12 and 14 and spacer 16 may be used. For example, vacuum epoxy and conventional sealing glasses are suitable. In the illustrated embodiment, the 15 cm by 15 cm panel 10 uses a 1 mm thick, 1.5 cm wide spacer element 16 which is disposed about the periphery of chamber 20. The sealing is performed with unloaded, 100% solids, Type 360T vacuum epoxy formulated and sold by Epoxy technology of Waltham, Mass. The epoxy seal is obtained with a 10 minute oven bake at 120 degrees C. With this seal, outgassing is less than 5×10 -9 cc/sec, giving the panel 10 a life on the order of at least 6 months.
As an alternative to vacuum epoxy, Corning Pyroceram brand sealing glass powder, code 7575, may be used to seal soda-lime sheets 10 and 12 to each other using 0.25 to 1.0 mm thick glass spacers. With this method of sealing, the powdered sealing glass is applied as a slurry with a nitrocellulose binder dissolved in a vehicle such as amyl acetate. The binder and vehicle are burned off at 350 degrees C., and the sealing is accomplished at 450 degrees C. during a 60 minute bake. Slow cooling is used to provide a relatively stress free panel with substantially no seal outgassing. Panel life of glass sealed panels is limited by the outgassing of the glass itself and sputtering and gas cleanup, some of which can be greatly reduced by vacuum baking and the inclusion of sputtering reducing vapors such as Hg into the gas fill.
Regardless of which sealing techniques are used, careful cleaning of all surfaces is performed, using conventional techniques prior to assembly and sealing of the sheets 12 and 14. For example, a sequence of water and solvent washes with detergents, distilled and deionized water rinses, vapor degreasing and warm air drying are perfectly performed prior to sealing of the panel 10.
Many gases, gas mixtures and gas pressures may be used in the volume 20 to achieve various colors and intensities of light output using ac drive voltages in the range of 280 to 1800 volts, from 5 kHz to 10 MHz, using sine and square wave signals and complex waveforms. Generally, the electroluminescent gas in chamber 20 is a mixture of noble gases with additions of small quantities of secondary gases to create Penning mixes. In the preferred embodiment, a very effective gas fill with maximum intensity of about 100 lumens at a drive power level of 1.5 watt/cm 2 is a Penning mixture made with 99% neon, 1% argon, and trace amounts (less than 0.1% of mercury, filled to a pressure of about 120 torr. Nitrogen could be substantial for the argon in this exemplary mix. The color of the light output from this panel fill is orange-yellow at maximum brightness (using a photo-optically calibrated sensor) but may be varied slightly by changing the frequency and waveform of the driving ac signal, from yellow-orange to orange-red, with a loss in brightness.
To establish the electroluminescent gas in the enclosed volume 20, the panel 10 is first evacuated through the filling stem 22, as coupled to a vacuum pump through a gas filling system with the suitable filters, pressure and vacuum gauges and compressed gas regulators and valves. In the present embodiment, as the filling stem 22 is established prior to assembly of sheet members 12 and 14 and spacer element 16 by first milling matching conical void regions 23a and 23b in opposing portions of the periphery of sheet members 12 and 14, and a hole is cut in the corresponding portion of the spacer element 16. As shown in FIG. 1A, the tubular filling stem 22 is then placed into and sealed to the channel established by the conical void regions and spacer hole at the time of assembly and sealing of sheet members 12 and 22 and spacer element 16. The interior 22a of stem 22 is contiguous to volume 20. Thus, the stem 22 is sealed to the panel 10 with a through channel to the interior space (i.e. volume 20) formed by the combination of the sheet members 12 and 14 and the spacer element 16. In the preferred embodiment, filling stem 22 is attached to the device 10 with low vapor pressure epoxy or with sealing glass.
In alternate embodiments, the stem 22 may extend through one of sheet members 12 and 14 in a direction perpendicular to the sheet member. To establish such a filling stem, a small hole is diamond drilled through the sheet member and the stem end is flared and ground flat on the sealing surface prior to attachment. The stem is then attached using sealing glass or epoxy.
The use of conductive coatings 26, 28 on the glass sheets 12, 14 allows the panel 10 to illuminate when attached to a source of driving voltage. There are several ways to configure the conductive coatings, depending on the desired visual and operational properties of the final panel 10. The panel 10, as shown in FIG. 1 has two conductive coatings 26 and 28, one attached to each of the outer surfaces of the transparent sheets 12, 14 with the electroluminescent gas located between the sheets and not in contact with either coating. Three basic types of conductive coatings identified by their optical properties may be used; namely, translucent, transparent, reflective, and opaque.
Transparent conductive coatings pass light, and have little or nor color, thus making the coating invisible to the eye. Examples of this kind of coating are vacuum evaporated or sputtered metal films, usually gold or aluminum, and indium doped tin oxide films, either sputtered or chemically deposited on the glass sheet. The coating may be applied in a uniform fashion or may be applied as a pattern. Suitable coatings have resistivities on the order 0.1 to 100 ohms/square, are thermally stable at sealing temperatures and are generally scratch and chemically resistant. Etching the coating into patterns for use in defining the illumination zone of the panel may be done by the use of silkscreened, painted or stencilled patterns of resist followed by coating removal with chemical (acid or basic) solutions with local or general application, i.e. bath, spray or wipe, or by mechanical means such as abrasion or scraping.
Reflective conductive coatings reflect light, or reflects some percentage of the light falling on it, and are generally partially transparent and partially reflective. Examples are aluminum, chromium, silver or gold coating with a reflectivity over 10%. The coatings are applied by sputtering, evaporation, chemical deposition or mechanical means, i.e. embossing, and may be applied as patterns or may be uniform and continuous. The resistivity varies from 0.01 to 10 ohms/square for the coatings, and they are generally capable of withstanding sealing temperatures and processing. The coating may be patterned for use as a sign or indicator as described above.
Opaque conductive coatings do not allow the penetration of light to any significant extent. Such coatings allow the view of the gas discharge from one direction only, and give it a higher contrast background. The coating is generally of a paint or ink type consisting of a vehicle, a binder and a conductive component in suspension such as nickel oxide, nickel metal powder, graphite, or mixes of these materials. It may be applied by spraying, rolling, brushing or any of a host of mechanical or chemical means, either as a uniform and continuous coating or as a pattern.
In the embodiment of FIG. 1, front surface 12a of sheet member 12 is adapted to receive the first (indicia-shaped) conductive coating 26. The back surface 14b of coating 14 supports the second conductive coating 28. Electrical contact to the coatings 26, 28 may be made directly, for example, by wiper arms (not shown) or conductive epoxy (not shown), in a manner permitting an applied drive voltage to be applied across those coatings. The various coatings 26, 28 may each be of the transparent, reflective or opaque type, depending upon the desired luminous image characteristics.
By way of example, in the illustrated configuration, the film coating 28 is a transparent 100 ohms per square deposited indium doped tin oxide film coating 28. As shown in FIG. 1, the front surface 12a has received, by silkscreening, a nickel-graphite colloidal suspension coating 26 (e.g. Type 401 conductive paint, manufactured by Acheson Colloids, Inc.). With this configuration, a 30 kHz, 900 volt sinusoidal signal applied across coatings 26 and 28 provides a yellow-orange-colored "A"-shaped display. The configuration illustrated in FIG. 1 is particularly well adapted to receive coating 26 by conventional processes such as silkscreening and the like, due to the overall planar structure of device 10, where the filling stem 22 lies substantially in the same principal plane as the device 10.
FIG. 2 shows a display device 10' similar to that in FIG. 1 where corresponding elements are identified with the same reference designations as in FIG. 1. In FIG. 2, a conductive border strip 30 is disposed on the peripheral portion of the front surface 12a of sheet 12. The border strip 30 is connected to coating 26 by portions 30a and 30b. With this configuration permits a simple connection (at contact 44) for coupling to an externally applied signal.
The embodiment of FIG. 2 also includes a third non-conductive sheet 40 overlying the back surface 14b of sheet 14. Sheet 40 provides an electrical insulation layer for the embodiment of FIG. 2 to protect a user from contacting a drive voltage applied to coating 28, relative to the grounded coating 26. A connector 46 is positioned on sheet 40 and feeds through to coating 28 to provide a convenient means for coupling a drive signal to coating 28. Otherwise, the embodiment of FIG. 2 is similar to and operates in the same manner as the embodiment of FIG. 1.
FIGS. 3 and 4 show a similar configuration to the embodiment shown in FIG. 2, but further including eight raised spacers 55-62 projecting from sheet 12 and extending to sheet 14, all within the enclosed volume 20. The spacers permit a relatively large area pair of sheet members to be used while still retaining a relatively high level of structural rigidity. The spacers also permit use of a relatively broad range of gas pressures in chamber 20. The spacers 55-62 as shown are cylindrical in shape. Alternative forms for those spacers are shown in section in FIGS. 5-9.
In the preferred form of the invention, as shown in FIG. 4, the raised spacers extend only part way between the surfaces 12b and 14a when enclosed volume 20 is filled with electroluminescent gas. With this configuration, during assembly of near-atmospheric pressure (in enclosed volume 20) embodiments, volume 20 can be evacuated and the raised spacers will play a limit on the resultant displacement of the sheet members 12, 14, thereby permitting use of relatively thin sheet members 12, 14. Then, after backfilling with the electroluminescent gas, the raised spacers again extend only partially between surfaces 12b and 14a, permitting a substantially uniform luminescent display across the entire enclosed volume 20.
Another embodiment, device 60, is shown in FIG. 10. Device 60 is similar to that shown in FIG. 1, except that the coating 28 is disposed on the front surface 14a of sheet 14. With this configuration, there is no need for the third sheet 40 since the drive electrode is fully within the enclosed volume 20. Electrical contact is made to coating 28 by a portion 28a which extends beyond the seal/spacer element 16.
Here, the coating 28 is in direct contact with the gas in chamber 20. While better electrical coupling is achieved between coating 28 and the gas, a lower drive voltage may be used and increased edge definition for the image is attained, compared with embodiments where coating 28 is on the back surface 14b. There is, however, a somewhat reduced lifetime of the device due to sputtering that occurs at the coating 28.
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 in all respects 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 which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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A gas discharge display apparatus in the form of an electroluminescent gas filled panel adapted for quickly and inexpensively making a durable and robust luminous sign using image patterns transferred to the panel by painting, silkscreening, stencilling, lithography, or the like. The apparatus generally includes a pair of substantially parallel spaced apart rigid plates, or sheets, enclosing an electroluminescent gas, and having variously located and kinds of conductive surface coatings used as electrodes for energizing the enclosed electroluminescent gas.
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RELATED APPLICATION DATA
[0001] This application claims priority on U.S. provisional patent application 62/169,532 filed Jun. 1, 2015, which is hereby incorporated by reference.
BACKGROUND
[0002] Dispensing a precise and accurate amount of material has many uses. Currently, there are at least two common ways that units of material(s) are dispensed. AS used herein, the terms “unit” and “item” are used to indicate a discrete quantity of a solid or semi-solid material, e.g. one pill or one box. In one method, a human or robotic arm may select units. In a second common method, items may be dispensed at a fixed volume or mass. Some volumetric dispensers do not permit the adjustment of the mass or volume to be dispensed as dispensing needs change. Additionally, many methods may require human input to verify accuracy and precision of the dispense. Human input can result in errors, inaccuracies, and time inefficiency.
[0003] Dispensing a precise and accurate number of units has many uses. Examples of units for which automated dispensing is useful include, but are not limited to: pills, capsules, surgical supplies, medical supplies, food stuffs, shipping materials, and manufactured parts. Currently, there are known mechanisms for the automated or partially-automated dispensing of units. These mechanisms are based on, but are not limited to, selection by: mass, volume, density, imaging, and unique item selection.
[0004] For certain material(s), uses, and limitations, volumetric selection is appropriate. Volumetric dispensing devices have been proposed before. Some known devices have several disadvantages, such as: inability or difficulty with modifying the desired volumes for dispensing, inaccurate dispenses, and jamming.
[0005] Some previous volumetric dispensing devices have made it difficult or impossible to adjust the dimensions of the device to accommodate units of different size. Since materials to be dispensed may have different physical dimensions or shapes, such devices may be unsatisfactory for one's dispensing needs. Furthermore, non-automated adjustments of the dimensions of the device can make it difficult and/or time consuming for individuals to properly adjust controlling the dimensions of the dispensing device and, thus, to properly dispense the desired materials.
[0006] Some known adjustable volumetric dispensing devices have also made it difficult or impossible to dispense a wide range of shapes and dimensions of material(s) due to the eccentricity of the dispensing mechanism. At least one known volumetric dispensing device has two, stacked movable dispensing rings comprising circular openings. Relative rotation of the rings allows for a changeable dispensing opening, which can only form a circular dispensing opening when the two circular openings are perfectly aligned. For all other alignments, a range of elliptical dispensing openings are formed when the circular openings are not aligned. Since the dispensing rings are stacked, the circular openings are offset somewhat in the vertical direction. Mechanisms which rely on this type of elliptically shaped dispensing openings for dispensing materials of different sizes and shapes can result in inaccurate dispensing. As the eccentricity of the dispensing plane increases, the dispensing opening becomes less accurate in its dispensing of less eccentric units. Such mechanisms are also prone to jamming and risk damaging the units being dispensed. This is illustrated below with reference to FIGS. 1-4 .
[0007] As one example of units to be dispensed which have known dimensions, pharmaceutical pills come in a wide variety of shapes and sizes. For example, one known pill is shaped like a right circular cylinder and has a radius of 2 mm. Another pill is in the shape of a capsule and has a major axis length of 19 mm. Another pill is shaped like a right circular cylinder and has a radius of 20 mm. A still further pill is shaped like a three-pointed star.
[0008] FIGS. 1A-4A illustrate three different shaped pills positioned in elliptical openings. For simplification, the elliptical openings are shown as being formed of two gates which are in the same plane, but the prior art known to the present inventors forms these opening with gates which are vertically offset, i.e. not in the same plane, of the type described in the prior art with each Fig. A showing the shape of the pill, each Fig. B showing a top view, each Fig. C showing a perspective view and each Fig. D showing a side view.
[0009] FIGS. 1 and 2 illustrate the same pill having the indicated dimensions shown in FIG. 1A . The drug Bayer® Asprin is an example of a pill having these dimensions. It is assumed that gravity will make it more likely that a pill or other unit will be in its position of lowest potential energy, i.e., “lying down”, in a dispenser reservoir, therefore it is most desirable to provide dispensing openings which are sized to receive the pill when it is in this orientation. FIGS. 1B-1D illustrate that when an elliptical opening is opened sufficiently to receive the pill shown in FIG. 1A , the elliptical opening will also have room to receive two additional pills in a vertical orientation. The extra space or gaps left in the elliptical opening by a single pill in the “lying down” orientation shown in FIGS. 1B-1D is problematic in that it creates a greater likelihood that more than the desired single pill will be dispensed, as well as a greater risk of jamming or pill breakage if another gate tried to move above the illustrated gates. Pill breakage will also increase the likelihood of inaccurate dispensing since a piece of a pill may slip into a gap of a dispensing opening.
[0010] FIGS. 2A-2D illustrate the same pill shown in FIG. 1 and show that it is possible to configure an elliptical opening to receive a vertically oriented pill and thereby leave less of a gap. As noted above, it is believed that it is more difficult to get a pill to enter a dispensing gate in this vertical orientation.
[0011] FIGS. 3A-3D show a pill having dimensions X 2 , y 2 , z 2 , where 2y 2 is less than x 2 . As shown in FIGS. 3B-3D , an opening which can receive this pill in the “lying down” position will accept two of these same pills in a vertical orientation, thus posing a risk of inaccurately dispensing two pills when it is desired to dispense a single pill.
[0012] FIG. 4A shows a pill in the shape of a three-pointed star where x 2 equals y 2 . The drug Xarelto is an example of a pill having these dimensions. FIGS. 4B-4D show that an elliptical opening sized to receive one of these pills in the horizontal or “lying down” orientation will necessarily be dimensioned to receive two of these pills in the same orientation.
SUMMARY
[0013] The disclosed volumetric dispensers and methods dispense one or more units of a material having units with a specific volume. While the embodiments will be described with reference to medicinal pills, it will be appreciated that they are equally capable for use in dispensing other materials having units of uniform dimensions.
[0014] One embodiment comprises three independently controllable and linearly movable gates with linear edges. As used herein, the term “linear” indicates that the edge is not curved when viewed from directly above. The term “linear” does not preclude a gate edge from having a bevel for reasons set forth below. The use of linearly movable gates with linear edges provides smaller gaps or extra spaces when opened to dispense a unit of a known size. This reduces the risk of dispensing errors, jams and damage to the pills. FIGS. 5A-8D correspond to the views of FIGS. 1A-4D , respectively, and show the same configuration of pills, i.e. the same sizes and shapes, in the same orientations. The top views of FIGS. 5B-8B are particularly illustrative in the smaller gaps or extra spaces provided by the linear edges when compared to the corresponding views of FIGS. 1B-4B .
[0015] According to preferred methods, dispensing is accomplished by opening a first gate and a second gate to their respective open dispensing positions, subsequently moving a third gate to its open dispensing position, and then closing one or both of the first gate and second gate to a position which is less than the fully opened dispensing position. The sequential opening and closing of gates permits the dispensing of one unit/pill from the reservoir while preventing the undesired dispensing of a plurality of pills at the same time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIGS. 1A to 1D are diagrams of a pill and top, perspective and side views of that pill in an elliptical opening of the type formed by gates of the prior art.
[0017] FIGS. 2A to 2D are diagrams of the same pill shown in FIG. 1 but with the pill in a vertical orientation, and top, perspective and side views of that pill in a smaller elliptical opening of the type formed by gates of the prior art.
[0018] FIGS. 3A to 3D are diagrams of a second pill and top, perspective and side views of that pill in an elliptical opening of the type formed by gates of the prior art.
[0019] FIGS. 4A to 4D are diagrams of a third pill and top, perspective and side views of that pill in an elliptical opening of the type formed by gates of the prior art.
[0020] FIGS. 5A to 5D are diagrams of the pill shown in FIG. 1 and in the orientation shown in FIG. 1 , and top, perspective and side views of that pill in an opening having linear edges.
[0021] FIGS. 6A to 6D are diagrams of the pill shown in FIG. 2 and in the vertical orientation shown in FIG. 2 , and top, perspective and side views of that pill in an opening having linear edges.
[0022] FIGS. 7A to 7D are diagrams of the pill shown in FIG. 3 and in the orientation shown in FIG. 3 , and top, perspective and side views of that pill in an opening having linear edges.
[0023] FIGS. 8A to 8D are diagrams of the pill shown in FIG. 4 and in the orientation shown in FIG. 4 , and top, perspective and side views of that pill in an opening having linear edges.
[0024] FIG. 9 is a top perspective view of a multi-pill dispenser.
[0025] FIG. 10 is a top perspective view of the base of the multi-pill dispenser shown in FIG. 9 .
[0026] FIG. 11 is a perspective view of the reservoir and vertical gate assembly of the dispenser of FIG. 9 .
[0027] FIG. 12 is a perspective view of the reservoir of the dispenser of FIG. 9 .
[0028] FIG. 13 is a top perspective view of the first gate of the dispenser of FIG. 9 .
[0029] FIG. 14 is a partial exploded, top view of the dispenser of FIG. 9 .
[0030] FIG. 15 is a partial exploded, bottom perspective view of the dispenser of FIG. 9 .
[0031] FIG. 16 is a partial exploded, bottom perspective view of the dispenser of FIG. 9 with sections of the reservoir removed.
[0032] FIG. 17 is a bottom perspective views of the dispenser of FIG. 9 with sections removed.
[0033] FIG. 18 is a top perspective view of the reservoir and gates of the dispenser of FIG. 9 with sections removed.
[0034] FIGS. 19 and 20 are partial side views of the dispenser of FIG. 9 with sections removed showing the Z-gate in raised and lowered positions, respectively.
[0035] FIG. 21 is a partial, view of the three gates of an alternative embodiment showing the beveled edge of the Y-gate.
[0036] FIG. 22 is a partial, view of the three gates of the embodiment shown in FIG. 21 taken from a perspective 90° offset from the perspective of FIG. 21 showing the beveled edge of the X-gate.
[0037] FIG. 23 is a top view of the gates and reservoir of FIG. 21 showing the beveled edges of the X-gate and Y-gate.
[0038] FIG. 24 is an exploded bottom, perspective view of the reservoir and three gates of a single pill dispenser.
[0039] FIG. 25 is a bottom perspective view of the single pill dispenser of FIG. 24 .
[0040] FIGS. 26A-26C are diagrammatic bottom views of an embodiment comprising a first gate and a second gate in the same plane.
[0041] FIGS. 27 and 28 are bottom, perspective views of an embodiment comprising a first gate and a second gate in the same plane with the opening obstructed and open, respectively.
[0042] FIG. 29 is a top perspective view of a multi-pill dispenser with vacuum components.
DETAILED DESCRIPTION
[0043] For purposes of illustration, the disclosed embodiments will be described with reference to pharmaceutical pills, however, it will be appreciated that the disclosed devices and methods can be utilized to dispense other items. For purposes of explanation, it is assumed that the length, width and height dimensions, i.e. dimensions x, y and z for each unit being dispensed are known and fixed. As used herein, the “length” is the longest measurement of the pill taken in the horizontal direction when the pill is at rest on a horizontal surface at its lowest point of potential energy, the “width” is the maximum measurement in a horizontal plane perpendicular to the “length”, and the “height” is the maximum measurement in the vertical plane. For reference, the length, width and height will be referred to as dimensions x, y and z (lower case designations). Corresponding gate positions X, Y and Z are equal to dimensions x, y and z, respectively, plus some desired clearance (“i”) for each dimension. For example, X=x+i where i=0.1 mm. The clearance can be determined by the end user. As used herein, “positions” X, Y and Z refer to a gate which has been opened to provide an opening in the given direction equal to dimension X, Y or Z. For example, a gate opened to position Y has an opening, in the y-direction, equal to y+i.
[0044] A three gate embodiment comprises a reservoir for holding a plurality of pills and three gates which are movable by computer controlled controllers. According to a first method which can be used when all three dimensions of the pill are known, initially all three dimensions x, y, and z are transmitted, by wire or wirelessly, to a microcontroller. The microcontroller then signals the first gate to move horizontally to position X. Once position X is reached, the microcontroller signals the second gate to move horizontally (in a direction substantially perpendicular to the movement of the first gate) to position Y. Once position Y is reached, the microcontroller signals the third gate to move vertically to position Z. As the third gate is moving to position Z, the pill will descend through and below the first and second gates. In one embodiment, the gates are enclosed by a wall that prevents the pills from falling off any of the gates. Once position Z is reached, the pill will be below the first and second gates and at least one of the first and/or second gates will be signaled to close, in order to prevent more units (pills) from being dispensed. As used herein, the term “closed” includes, but is not limited to, a position in which a gate's position is less than the previously transmitted X, Y, or Z, value. As used herein, the term “fully closed” includes, but is not limited to, a position in which a gate's position does not create an opening for dispensing and all gates are stacked on top of each other.
[0045] After the first and/or second gates are entirely closed or at least closed to a point where the openings are smaller than x and y, the third gate is moved further down. As the third gate moves down, the pill is moved off of the third gate in order to be dispensed to the user's desired location. In one embodiment, the pill is moved off the third gate with the assistance of gravity. In this embodiment, the third gate is hinged on one side. As the third gate moves below a predetermined point, a preset ridge forces the third gate to incline towards the desired destination of the pill. In this example, the third gate can be tilted, for example to a 45° angle, causing the pill to fall or slide to the desired destination. Once the pill is at the desired destination, the second gate, if not closed already, is signaled to close. The third gate may be signaled to remain in its position, close, or fully close. The post-dispensing position of the third gate is determined by the end user. In one embodiment, the post-dispensing position of the third gate may be optimized to an intermediate z position to reduce the time between or during dispenses. In another embodiment, the post-dispensing position of the third gate may be fully closed.
[0046] All aspects of the preferred device are controlled by a microcontroller 90 which is in electrical communication with an input device 91 , such as a desktop computer. The opening of the respective gates to positions X, Y, and Z is achieved with microcontroller 90 programmed to allot a certain amount of time while the gate actuators operate at a constant power per unit of distance traveled In another embodiment, the mechanical devices may move at a constant speed and will stop when sensors provide feedback to the microcontroller to detect that positions X, Y, and Z are achieved.
[0047] The determination of which positions (X, Y, and Z) go with each motion device can be set to accommodate limitations of the motion devices installed. For example, in the three gate embodiment, if it is desired to dispense a box having x, y and z dimensions of 3 cm×2 cm×1 cm, respectively, and the first and second gates can only open to a maximum of 3 cm. while the third gate can open to a maximum of 4 cm, the first gate will get position Z. The second gate will get position Y. The third gate will get position X.
[0048] According to a second method, if only two of three dimensions of the items to be dispensed are known, the two known dimensions (positions X and Y, X and Z, or Y and Z) are transmitted, by wire or wirelessly, to the microcontroller. The microcontroller then signals the first gate to open to the first known position. Once the first known position is reached, the microcontroller signals the second gate to open to the second known position. Once the second known position is reached, the microcontroller signals the third gate to move in small increments, e.g. 1 mm increments, until one unit of the material is detected by a photoresistor.
[0049] This detection stops all gates from moving. At this point, the first and/or second gates are closed, in order to prevent more pills from being dispensed. Once the first and/or second gates are closed, the third gate moves further down. As the third gate moves down, one side of the gate is inclined to tilt towards the desired destination of the material(s). For example, the third gate can be tilted to a 45° angle, causing the pill to fall or slide to the desired destination. Once the pill is at the desired destination, the third gate, and the second gate, if not done already, will close. In a preferred embodiment, a sensor is placed to detect the passage of a unit down the chute. A corresponding signal is sent to the microcontroller. An alarm signal can be generated if the sensor detects multiple units passing down the chute during a single dispensing sequence.
[0050] According to a third method, if only one of the three dimensions of the desired items to be dispensed is known, the one know dimension (positions X, Y or Z) is transmitted, by wire or wirelessly, to a microcontroller. The microcontroller then signals one gate, preferably the z or third gate, to the corresponding position. Once the known position is reached, the microcontroller signals the other two gates to move in small increments (ex. 1 mm increments) until a detector detects that the pill has cleared the x and y gates and is resting on the z gate. This detection stops the gates from moving. Alternatively, the two gates corresponding to the unknown dimensions can be moved in small increments but at different rates which correspond to a known shape of the unit being dispensed. Once position Z, the third gate's position after photoresistor-detection is reached, the first and/or second gates are closed, in order to prevent more materials from being dispensed. Once the first and/or second gates are closed, the third gate moves down. As the third gate moves down, one side of the gate is inclined to tilt towards the desired destination of the material(s). Once the third gate tilts to a 45° angle, for example, the unit will fall or slide to the desired destination. Once the unit is at the desired destination, the third gate, and the second gate, if not done already, will close.
[0051] FIGS. 9-20 illustrate a multi-pill, three gate dispenser which can be used for any of the three above-described methods. The dispenser illustrated in FIGS. 9-20 is referred to as “multi-pill” dispenser since it is capable of dispensing pills of different sizes and/or shapes from separate compartments. The dispenser in FIGS. 9-20 comprises a material reservoir 10 , a base 20 , a first gate 30 , second gate 40 , third gate 50 , and microcontroller 90 which is connectable to an input device 91 such as a computer. Reservoir 10 of this illustrated embodiment comprises six separate compartments 11 a - 11 f, each of which comprise a bottom 12 having a reservoir opening 15 and an outer sidewall 18 having a guide slot 19 for movably receiving and supporting the first gate 30 . The interior surface of bottom 12 is inclined toward the reservoir opening 15 . Other embodiments can comprise more or fewer separate compartments. The separate compartments are intended for pills of different sizes and/or different shapes.
[0052] Each of the gates has a linear, i.e. non-curved, edge. X-gate 30 has a linear edge 33 , Y-gate 40 has a linear edge 43 , while Y-gate 50 has a flat landing area 53 which acts as a linear edge when defining the depth of a dispense opening and thereby limits the extent to which a pill or other item being dispensed can descend.
[0053] According to this first illustrated embodiment, there are six first gates 30 , one first gate corresponding to each compartment 11 which rotates with the reservoir 10 and stays under the respective compartment 11 . The first gates 30 are normally completely closed to prevent pills from falling out the reservoir openings 15 at undesired times. As shown in FIG. 11 , the entire reservoir 10 is rotatably mounted on shaft 60 which is driven by a motor 61 located within base 20 . Rotation of reservoir 10 is controlled by controller 90 which, as noted above, is linked to one or more suitable input devices.
[0054] Reservoir 10 is selectively and automatically rotatable to align the desired compartment 11 , and consequently the desired pills, with the dispensing station. Each of the gates at the dispensing station in this illustrated embodiment is linked to a dedicated gate actuator. First gate 30 is linked to a first gate actuator 35 for selectively moving first gate 30 in the x-direction, which in this embodiment is radially, relative to reservoir 10 . First gate 30 comprises an outer flange 31 comprising a recess 32 which is engaged by actuator pin 37 on first gate actuator 35 . Second gate 40 is connected to a second gate actuator 45 for moving second gate 40 in the y-direction which is perpendicular to the x-direction. Third gate 50 is connected to third gate actuator 55 which comprises an actuator arm 57 for moving the third gate 50 in the z-direction. In this illustrated embodiment, the second gate and the third gate are movably positioned below the first gate. The gates in a pill dispenser are preferably fairly thin, e.g. about 1-3 mm, preferably about 2 mm in thickness. The microcontroller 90 is in communication with all three of the gate actuators and controls the timing and movement of the gate actuators. These connections are not shown.
[0055] This first illustrated embodiment has a single dispensing station which comprises the first gate actuator 35 , the second gate 40 , the second gate actuator 45 , the third gate 50 and the third gate actuator 55 . Since there is only one first gate actuator 35 but six first gates 30 , the linkage between first gate actuator 35 and each first gate 30 is selectively disengagable. First gate actuator 35 is selectively movable (in this embodiment, raised) to disengage actuator pin 37 from the recess 32 of the first gate at the dispensing station before the reservoir is rotated. When a compartment is positioned at the dispensing station, the first gate actuator 35 is lowered so that actuator pin 37 is lowered through recess 32 in order to link the first gate actuator 35 to the first gate 30 which is now positioned at the dispensing station. FIG. 17 shows actuator pin 37 engaged with recess 32 in first gate 30 . FIG. 16 is an exploded view of the three gates and gate actuators with arrows indicating their respective directions of movement. FIG. 18 shows a dispensing opening formed by the linear edges of X-gate 30 and Y-gate 40
[0056] One or more sensors are employed to detect a potential jam in the dispensing operation. One way a jam can be detected is a photodetector aligned with the third gate can binarily detect the presence or absence of a pill after positions X, Y, and Z are achieved by the gates. If an absence is detected, the microcontroller or connected computer will initiate a jam clearing program.
[0057] Alternatively, a jam can be detected by a sensor aligned with one of the gates. In one embodiment, a linear potentiometer is aligned with each gate. If a potentiometer detects that a gate cannot close during the dispensing program, the microcontroller or computer will initiate a jam clearing program. The jam clearing program, the microcontroller will signal the gates to fully close in reverse order. The gates will fully close, sequentially, not simultaneously, in the sequence of Z, Y, X. In one embodiment, the X and Y gates have beveled edges. The beveled edges push the pills upwardly during the jam clearing program.
[0058] FIGS. 21 and 22 illustrate two gates of an alternative embodiment which have beveled dispensing edges. FIG. 21 shows a pill P resting on Z-gate 50 . The jam clearing program will first close Y-gate 140 . The beveled edge 143 on Y-gate 140 will raise the pill P up to the position shown in FIG. 22 where the pill rests on Y-gate 140 . Next, the X-gate 130 will then be closed. Beveled edge 133 on X-gate 30 will return the pill P to the reservoir. After the jam clearing program is complete, the microcontroller preferably signals an agitation component, as discussed further, to agitate the reservoir to realign the units in the reservoir. The gates will then be signaled to reinitiate the programmed dispense sequence. Alternatively, the microcontroller will report the first jam to the end user, or a user-determined number of jams, by signaling an alert on a connected audio or visual component, such as a speaker or computer screen.
[0059] Base 20 of the first illustrated embodiment comprises a chute defined by the inner sides of right sidewall 22 , left sidewall 24 and inclined ramp 26 . With reference to FIGS. 19 and 20 , in this embodiment the Z-gate 50 is hingedly connected to actuator arm 57 , which raises and lower Z-gate 50 . This hinge connection is restrictive in that it will only allow rotation motion within a range of angles. The Z gate in a neutral position has an angle of 0° with the horizontal. The Z-gate will be caused to rotate in a direction to align with ramp 26 , i.e. such that the end of the gate closest to the reservoir will be higher than the end of the gate that is closer to actuator arm 57 . As the Z gate is being lowered, a fixed platform 70 underneath the Z-gate and the hinge connection causes the Z-gate to tilt as the Z-gate is lowered past the top of the fixed platform 70 . This slope will cause the unit being dispensed to move down the inclined ramp 26 toward an opening that will eventually lead to the user being able to collect or retrieve said dispensed unit.
[0060] Repetition of the dispensing process can be controlled to dispense one or more of each unit in each of the compartments 11 in dispenser 10 . All of the embodiments can be applied to multi-pill situations. In many situations, the reservoirs are homogenous in their contents. For example, a single reservoir contains identical pills. In this example, the mechanism can dispense n number of pills as long as one of nX, nY, and nZ is less than the physical movement limitations of the gates.
[0061] A second, single pill/unit embodiment is partially illustrated in FIGS. 24 and 25 which are exploded and assembled bottom perspective views, respectively. This embodiment comprises a single compartment reservoir 210 having a bottom opening 215 . The gates operate in the same manner as described above with reference to the embodiment shown in FIGS. 9-20 . A first gate 230 is linked to a first gate actuator 235 , a second gate 240 is linked to a second gate actuator 245 and a third gate 250 is linked to a third gate actuator 2155 .
[0062] FIGS. 26A-26C, 27 and 28 illustrate a third, three-gate embodiment where the first gate and the second gate are in the same plane, preferably a substantially horizontal plane. The third gate is not shown. FIGS. 26A-26C are diagrammatic bottom views of first gate 330 and second gate 340 in three different positions relative to a reservoir opening 315 shown in phantom. According to this embodiment, second gate 340 is linked to first gate 330 so that when the first gate 330 moves in the x-direction, second gate 340 moves the same distance in the x-direction. Second gate 340 also has the ability to move independently of the first gate in the y-direction.
[0063] In FIG. 26A , opening 215 shown in phantom is entirely obstructed by first gate 330 . In FIG. 26B , first gate 330 has moved a distance X to the left relative to opening 315 and second gate 340 has accompanied first gate 330 during this leftward movement. At this point, opening 315 is still entirely obstructed, but the linear border between first gate 330 and second 340 is now aligned under opening 315 . In FIG. 26C , second gate 340 has moved (downwardly on the page) a distance Y thereby leaving an unobstructed section below opening 315 with dimensions X by Y. This embodiment is useful for small items to be dispensed where the thickness of two gates may adversely influence the desired alignment of the item as it passes through the opening past the first gate and the second gate.
[0064] In another embodiment, dispensing can be supplemented with one or more vacuum devices. In FIG. 29 , a vacuum is created by a vacuum pump 607 and is controllable by a microcontroller. The vacuum can be directed toward the z gate with vacuum tip 605 . Alternatively, the area under the gates can be sealed and a vacuum applied with vacuum pump 607 to generate a vacuum without the vacuum tip 605 , so that the vacuum applies a downwardly directed force below the dispensing opening. The vacuum will increase the downward force on the unit to be dispensed, which will assist the unit in falling into the space created by all three gates. The vacuum pump will be turned off by the microcontroller after a photoresistor has detected a unit has fallen onto the z gate.
[0065] The following is additional information relative to some of the components described above.
Reservoir
[0066] The reservoir is shaped and sized to meet the needs of the dispensing. For example, the reservoir may be shaped as a rectangular prism, cylinder, cone, conical frustum, or trapezoidal prism. The bottom surface(s) of each component are preferably inclined toward the dispensing opening. Additionally, the reservoir does need to be fixed in position above the dispensing mechanics. The reservoir can move relative to the dispenser and be removable or movable from the other dispensing mechanics. Multiple reservoirs can be arranged so that either the reservoirs will move to a dispensing station, i.e. the dispensing mechanics or the dispensing mechanics will move to the reservoirs. The “dispensing mechanics” refers to the gates and gate motion devices.
Gates
[0000]
The gates are shaped and sized to meet the needs of the dispensing. For example, the gates may be shaped as rectangular prisms, cylinders, conical, trapezoidal prisms, conical frustums, triangular prisms, or pyramids. Alternatively, the gates may be any shape with a beveled edge to assist the aforementioned jamming program. In one embodiment, the gates are rectangular prisms and the top edges, not adjacent to the motion control device, are have sickled, beveled edges to act like a shovel during a jam.
Motion Devices
[0000]
For the Z-Direction Gate and the Two-Gate XY Method:
The gates may be connected to or integral with the gate actuators which serve as gate motion devices. These motion devices are meant to linearly move the gates. The linear motion devices may be any suitable devices, including one or more of the following: electromechanical linear servos or actuators, electromagnetic linear servos or actuators, solenoids, pneumatic actuators (air or non-air, pneumatic fluid), linear smart-memory alloy component, circular-motion motors or servos attached to linear motion adapters, reciprocating motion components, linear gear racks, chains, belts, threaded rods, or drive-shafts.
Agitating Devices
[0000]
For certain dispensing needs, it may be desirable to agitate the reservoir and its contents to ensure that the material(s) falls into the dispensing opening. This may be achieved with a vibration motor, piezoelectric component, or shaker motor connected to the reservoir. Alternatively, a sweeping arm may be placed inside the reservoir or proximate to gates to agitate the materials. Agitation can be employed during any stage of the dispensing sequence or the jamming program.
Sensors
[0071] Preferably, at least one sensor is placed on or near one or more of the gates to ensure that the desired material(s) has been dispensed. This may be achieved with, for example, a photoresistor, optical sensor, infrared sensor, ultrasonic sensor, pressure sensor, force sensor, or mass sensor. One sensor detects when a unit of material is on the Z-gate and has cleared the X and Y gates, while another detects when it has been dispensed from, e.g. fallen off, the Z-gate. Another sensor may be located proximate to the chute of the mechanism to detect if and how many units have dispensed. Also, a sensor or sensors may be placed on or near each of the gates to ensure that the gates have moved to the desired position(s). This may be achieved with, for example, a potentiometer, photoresistor, infrared sensor, light sensor, ultrasonic sensor, pressure sensor, force sensor, or mass sensor. Sensors may send signals, by wire or wirelessly, to a microcontroller or computer for processing.
Microcontroller and Input Device
[0000]
The microcontroller preferably receives commands or programs by wire or wirelessly. The programs can be used by the microcontroller, for example, to interact with motion devices, sensors, and alarms. It receives these commands or programs from an input device, such as a computer, server, remote control, mobile phone, or tablet. If connected wirelessly, the microcontroller may require a wire-attached wireless module. Wireless communication methods may include Bluetooth, WiFi, WiFi Direct, radio transmission, and/or Near Field Communication (NFC).
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Volumetric dispensers and methods dispense one or more units of a material having units with a volume utilizing independently controllable and linearly movable gates.
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FIELD OF THE INVENTION
This invention relates to overcenter latches for securing a pair of relatively movable members and, more particularly, to such latches which include an elastomeric tension link pivoted to an operating handle providing tensed overcenter engagement with a striker block.
It is well known in the art to use overcenter latches, which include an elastomeric tension link, for releasably securing movable hood members of off-road or sport-utility type vehicles. One example is U.S. Pat. No. 3,985,380 issued Oct. 12, 1976 to Raivio, entitled "Overcenter Type Latch". The Raivio patent, which discloses a latch for relatively movable hood members of a tractor vehicle, includes a retainer of molded plastic secured to one member and having laterally spaced recesses adjacent one end thereof and a striker adjacent the other end thereof. An operating handle has spaced abutments adjacent one end received within the retainer recesses for pivotal movement of the handle between a latched position and an unlatched position. An elastomeric link, pivoted to the operating handle and to the other hood member, is tensed when the handle is in latched position and extends between the spaced recesses and abutments. A manually operated latch, integral with the handle, cooperates with the striker to block movement of the handle to an unlatched position unless the latch is manually released.
SUMMARY OF THE INVENTION
It is a feature of the present invention to provide an overcenter latch assembly for releasably securing a closure to a body panel including an elastomeric link pivotally connected between a body panel bracket and an operating handle. The handle has a pair of laterally spaced apart prongs terminating in arcuate cams adapted for engagement with associated fore and aft transversely extending recesses formed in a closure striker block. Each recess includes a raceway terminating in opposed inboard and outboard pairs of pivot sockets, wherein the inboard and outboard sockets define respective inboard and outboard pivot. axes.
It is yet another feature of the present invention to provide an overcenter latch assembly wherein the elastomeric link and handle are conjointly rotated by the operator about the bracket pivot pin in a latching direction, while the handle is adapted for rotation about its pivot axis relative to the link, enabling the pair of handle cams to be initially received in associated ones of the striker block inboard pair of pivot sockets without any elongation of the link.
It is still another feature of the present invention to provide an overcenter latch assembly wherein, with the handle cams seated in their associated inboard pivot sockets, the operator initially rotates both the handle and the link in the latching direction with the handle pivoting about the inboard pivot axis and the link pivoting about the bracket pin axis. The pair of recess raceways define a first plane disposed at a predetermined slope angle which, upon the handle being initially rotated to a position substantially 90 degrees to the raceway plane, the tensed link causes the handle cams to snap outboard from the inboard sockets and seat in their associated outboard sockets. During latching, this translation of the pivot axis occurs prior to the link being rotated to its maximum tensed overcenter position.
In accordance with the present invention such elastomeric link induced translation of the handle cams to their outboard pivot axis during latching causes the elastomeric link to snap the handle cams into their outboard pivot sockets at the handle's overcenter point. As a result, further tensing rotation of the link required to reach a theoretical link overcenter point where the link would be tensed to its theoretical overcenter tensed length, established by the inboard rotational axis, is obviated. That is, continued rotation of the handle about the outboard pivot axis results in reduced link tensing and, accordingly, reduced operator effort needed to complete the handle and link rotation to their latch engaged mode.
It is still another feature of the present invention to provide an overcenter dual-pivot axis latch assembly that increases the operator effort required to disengage the latch when compared to the effort required to engage the latch. Such latching/unlatching effort differential is achieved because, during unlatching, the handle is initially pivoted about the outboard pivot axis through a predetermined first rotational angle, wherein the link first passes through its theoretical overcenter position at which point it is tensed to its theoretical overcenter tensed length. At this point, however, the slope angle of the raceway plane relative to the handle radially extending plane is less than 90 degrees, thereby preventing the pair of handle cams from snapping inboard to their associated inboard pivot sockets. As a consequence, the operator continues to rotate the handle about the outboard axis through an additional angle further tensing the link, at which point the handle reaches its unlatching overcenter point, i.e. where the radial plane of the handle is substantially normal to the plane of the raceway, allowing the handle cams to snap inboard to their inboard pivot sockets.
It is another feature of the present invention to provide a tension clamping hood latch as set forth above wherein the elastomeric link, upon being rotated to its latched position occupies a recess defined between the striker block side walls, shielding the link from damage.
It is yet another feature of the present invention to provide a tension clamping overcenter latch assembly as set forth above wherein the elastomeric link annular eye portion, pivotally connected to the handle, is adapted to resiliently contact a stop portion on the striker block at a predetermined handle overcenter latching position, thereby obviating latching noise caused by direct overcenter impact of the latch handle on the striker block.
These and other features and advantages of the invention will be more fully understood from the following detailed description of the invention taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a fragmentary perspective view of a vehicle body right hand side and front end portion showing an exterior hood latch according to the present invention;
FIG. 2 is an enlarged fragmentary perspective view showing a portion the right hand hood latch enclosed within a circle denoted "2";
FIG. 3 is a fragmentary front view, with parts broken away, of the hood latch in its closed position;
FIG. 3A is an exploded detail perspective view, with a part broken away, of one pivot pin assembly of the hood latch;
FIG. 4 is a fragmentary side view of the hood latch of FIG. 3;
FIG. 5 is a fragmentary vertical cross sectional view taken on the line 5--5 of FIG. 3;
FIG. 6 is a fragmentary vertical cross sectional view taken on the line 6--6 of FIG. 3;
FIG. 7 is a fragmentary side view of the hood latch in its open position with the operating handle rotated counter-clockwise to a non-engaged position;
FIG. 8 is an elevational view of the striker block taken on the line 8--8 of FIG. 7;
FIG. 9 is a fragmentary side view of the hood latch showing the operating handle pivoted to its initial unlatched over center mode;
FIG. 10 is a view similar to FIG. 8 wherein the operating handle is shown rotated clockwise to its engaged over-center position;
FIG. 11 is an enlarged partially diagrammatic fragmentary sectional view showing the latching sequence;
FIG. 12 is a view similar to FIG. 11, showing the unlatching sequence; and
FIG. 13 is a perspective detail view of the latch handle and striker block.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and specifically to FIG. 1, the right front side of a sport utility type vehicle, such as a "Jeep" vehicle for example, is indicated generally at 10. A panel member or hood closure 12, pivotally supported to the body cowl panel 14, covers the vehicle engine compartment opening when the closure is in its closed position of FIG. 1. When the closure is rotated to its raised position, the compartment is open allowing access to the engine compartment which is bordered by a pair of substantially horizontally disposed side panels 16 and the forward grill 18. The closure 12 is secured to the side panels 16 by a pair of right and left side latch assemblies with only the right side latch assembly being shown generally at 20 in FIGS. 1 and 2.
With reference to FIGS. 3 and 4 the latch assembly 20 comprises a U-shaped clevis bracket 22 of molded plastic material having a base portion 23 secured by bolt 24, shown in FIG. 5 extending through the side panel 16 and retained by underlying nut 25. The bracket 22 has a pair of upstanding apertured ears 26 receiving a longitudinally extending lower pivot pin defining a longitudinally extending lower pivot axis 28. The lower pin 27 rotatably supports one lower end of a stretchable rubber link 30 of symmetrical "dog bone" shape. The link 30 includes an elongated rectangular-sectioned bar 31 formed with an enlarged annular eye 32 at its lower end, having a center bore 33 receiving a lower pivot pin 27. The link 30 has an identical upper annular eye 34, having a center bore 35 receiving a longitudinally extending upper pivot pin 38, defining a longitudinally extending upper pivot axis 29 at its upper end.
As seen in FIG. 3 the upper eye 34 is adapted for pivotal movement between laterally spaced side walls 39 of a plastic operating handle 40 formed of molded plastic material. As best seen in FIG. 13 the handle side walls 39 are joined at one end by an upper end wall 41. The side walls 39 and end wall 41 extend normally from an outer bight wall 42 (FIG. 5) having a contoured outer face terminating at its upper end in a finger gripping flange 43.
In FIG. 3A there is shown a two-piece upper pivot pin 38, molded of suitable plastic material, which pin is the same as the lower pivot pin 27. The pivot pin 38 includes a head cap 38a and a pin shank 38b formed with an integral head 38c. The head cap 38a has an integral collar portion 38d, formed with opposed yield slots 38e, allowing the collar to telescopically receive a free end of the shank 38b. The shank free end is formed with an annular groove 38f adapted for capture by a mating internal rib 38g of the collar in snap action manner.
FIGS. 3, 5 and 13 show a pair of laterally spaced apart fore and aft elongated prongs 44, offset inwardly from and parallel with their associated handle side walls 39. The prongs 44, integral with the upper end wall 41, project downwardly therefrom with each prong 44 terminating at its free end in semi-spherical arcuate cam 45. It will be noted in FIG. 7 that the semi-spherical cam contour is generated about a center of pivot "P" having a radius of curvature "R" of predetermined dimension.. Each cam 45 is adapted to be received in an associated one of a pair of fore and aft laterally spaced apart recesses, generally indicated at 46 in FIG. 13. Each recess 46 is formed in an associated upper edge portion of a pair of laterally spaced apart side walls 48 of U-shaped striker block 50.
Referring to FIG. 4, the striker block 50 is secured by a pair of upper and lower bolts 52, extending through closure 12, and received in associated threaded bores of a backing plate 53 welded to the closure inner surface. With reference to FIG. 6, it will be seen that each upwardly opening elongated recess 46 defines a transversely extending planar raceway 54 of predetermined extent. Each raceway 54 terminates in opposed inboard 56 and outboard 58 pivot sockets. The pair of opposed inboard and outboard pivot sockets 56 and 58 are each sized for pivotal seating of an associated fore or aft prong semi-circular arcuate cam 45 in a manner to be described.
Referring to FIG. 12 it will be seen that the inboard pivot socket 56 is defined by a center of pivot "P1" about which a predetermined radius of curvature "R" generates concave semi-spherical surface of the socket 56. It will be appreciated that the radius of curvature "R" of cam 45, (FIG. 7), has the same dimension as inboard pivot socket radius of curvature "R" of FIG. 12. Consequently, with the pair of handle cams 45 seated in their associated inboard sockets 56, the handle is adapted for pivotal movement about a longitudinally extending inboard pivot axis "F1" which includes the fore and aft pivot centers "P1".
With reference to FIG. 11, each outboard pivot socket 58 is defined by an outboard center of pivot "P2" which has the same radius of curvature "R" as each inboard pivot socket 56. Thus, upon the handle cams 45 being snapped outboard on their associated raceway 54 from the inboard pivot sockets 56 to seat in the outboard sockets 58 the handle 40 is adapted to pivot about an outboard longitudinally extending pivot axis "F2".
In operation, FIG. 7 shows the two members 12 and 16 adapted to be latched, with the striker block 50 in opposed relation to the bracket 22. In the disclosed embodiment, upon the hood closure 12 being lowered, each side edge in-turned flange 60 is positioned over an associated body panel 16 for engagement with an elastomeric panel seal 62. With the latch handle 40 spaced from the striker block 50, the link 30 and handle 40 are first swung clockwise into initial engagement, indicated by dashed radial line "L1" in FIG. 10, with the link 30 remaining in its non-tensed mode, i.e. without the link 30 undergoing any elastic elongation.
With reference to FIG. 9 the pair of cams 45 are shown seated in their associated inboard sockets 56, with the handle 40 adapted to pivot clockwise about inboard longitudinal pivot axis "F1" in the direction of the arrow. In FIG. 11 the handle 40 is shown rotated clockwise through a predetermined angle "A", from initial radial line "H1" to a handle overcenter position, indicated by radial line "H2". It will be seen that during its angle "A" travel the handle pivot pin axis 29 follows arcuate path 68, wherein link 30 is tensed to a predetermined elongation about inboard axis "F1".
It will be noted in FIG. 11 that the handle latching overcenter line "H-2" defines a radially extending plane which intersects the plane of the raceways 54 at an angle of substantially 90 degrees. As a result, the tensed link 30 causes the cams 45 to snap outboard on their associated raceways 54, i.e. the cams 45 translate from their inboard sockets 56 to their outboard sockets 58. The operator continues rotating the handle about the outboard pivot axis "F2", thereby causing the link 30 to swing through its theoretical link overcenter line "L2" to its latched position, indicated by line "L3". FIG. 11 shows the theoretical overcenter line "L2" defining a radial plane that includes axis bracket pivot axis 28, inboard pivot axis "P1", and handle pivot axis 29.
In the example illustrated in FIG. 11, the angle "B" defines the theoretical additional rotational path required if continued handle rotation occurred about the inboard axis "F1" along dashed arcuate line 70. In such a case, the link 30 would undergo an additional extension to a theoretical overcenter tensed length defined by intersection 71 of theoretical overcenter line "L2" with the dashed arcuate line 70. Thus, by virtue of handle cams being snapped outboard to the pivot axis "F2" the handle pivot pin axis 29 travels along a new arcuate path 72 wherein the link tensed length is reduced. In the disclosed embodiment, the angle "A" is about 30 degrees and the angle "B" is about 20 degrees.
With reference to FIG. 11 it will be seen that, upon the handle cams 45 being translated to their outboard pivot sockets 58, the link tensed length decreases as the handle pin moves from its overcenter line "H2" to the handle latched line "L3" along an arcuate path 72. In the latched mode, the link 30 maintains a predetermined portion of its tensed length to resiliently retain the latch handle and link in their "L3" overcenter latched position.
With reference to FIG. 12, the latch 20 is shown in its FIG. 6 latched mode, with the cams 45 shown seated in their associated outboard pockets 58, wherein the handle 50 is adapted for initial pivotal counter-clockwise un-latched movement about outboard longitudinal pivot axis "P2" in the direction of the arrow. The handle 50 is rotated through a predetermined angle "C" from line "L3" to theoretical link overcenter line "L4" defining a plane which includes the lower pin axis 28 and the outboard axis "F2". It will be noted in FIG. 12 that the overcenter line "L4" defines a radially extending plane which intersects the plane of the raceways 54 at a predetermined acute angle "G" of about 80 degrees. As the acute angle "G" is about ten degrees less then the required 90 degrees, the handle 40 must rotate through an additional ten degree angle "D" before the handle cams 45 snap inboard on their raceways 54 to their associated inboard pivot sockets 56.
Thus, during unlatching, as the handle 50 rotates beyond link overcenter line "L4", the link 30 is tensed a predetermined dimension greater than its theoretical overcenter tensed length "L4" dimension. As a result, the effort required for unlatching is substantially increased, thereby insuring against inadvertent unlatching of the hood 12.
It will be noted in FIGS. 7 and 8 that the striker block 50 is formed with an upstanding stop tab 80 symmetrically disposed about its plane of symmetry defined by centerline 82 in FIG. 8. With reference to FIG. 5, it will be seen that the tab 80 is adapted to be contacted by the upper enlarged annular eye 34 of the rubber link 30 upon the latch handle being rotated to its latched position. The stop tab 80 is thus positioned to initially contact the link upper annular eye 36 prior to portions of the handle 40 impacting on the striker 50. Accordingly, the latch 20 provides a resiliently cushioned latching stop thereby obviating a harsh impact noise caused by direct handle to striker block contact.
FIG. 5 shows the rubber link 30 positioned in a recessed manner below the outer exterior portions of the latch striker block and handle in its latched mode. By virtue of this design feature. applicants' latch thereby minimizes the possibility of the link being damaged.
With reference to FIG. 13 it will be seen that the striker recesses 46 are laterally offset inward on the striker side walls 48 to receive their associated laterally offset prong arcuate cams 45 in a complementary manner. It will be noted in FIGS. 3 and 4 that thin outer side wall portions 86 of the striker conceal the offset prong cams 45 when the latch assembly is viewed from the side. Further, it will be observed in FIG. 4 that striker side wall upper edges 88 are positioned in parallel juxtaposed relation to opposed handle side wall lower edges 90, thereby concealing internal portions of the latch such as the prongs 44 and the cams 45.
Although the invention has been described by reference to a specific embodiment, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiment, but that it have the full scope defined by the language of the following claims.
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An overcenter latch for securing a closure to a body panel includes a panel bracket disposed opposite a closure striker block with a rubber link pivotally connecting the bracket and an operating handle. The block has spaced apart outwardly opening recesses each having a transverse raceway providing opposed inboard and outboard pivot sockets. A pair of depending handle prongs, each terminating in an arcuate cam, are adapted to snap overcenter on an associated raceway for pivotal reception between respective inboard and outboard pairs of sockets. The cams are readily positioned in their associated inboard sockets without the link being tensed. During latching, the handle cams are initially rotated about an inboard socket axis to an overcenter point, wherein the link is tensed to a predetermined dimension less than the links theoretical latching overcenter length. At this point the cams snap outboard to their associated outboard pivot socket axis, whereby the handle is rotated to its latched position resulting in reduced operator latching effort. During unlatching, the handle cams are initially rotated about the outboard socket axis to an overcenter point, wherein the link is tensed to a predetermined dimension greater than the link's theoretical latching overcenter length resulting in increased operator unlatching effort, obviating inadvertent unlatching.
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BACKGROUND OF THE INVENTION
This invention relates to a roll for a foil-drawing calender or the like of the type which is substantially solid and has a central longitudinal bore hole, is supported in journals at its ends and has associated devices for compensating deflection caused by the line pressure.
Known rolls of this type have an outside diameter of about 700 mm and a diameter of the central longitudinal bore hole of about 200 mm. If the roll has been manufactured by centrifuging, this longitudinal bore hole depends on the fabrication. In the finished roll it can be used to conduct a fluid heating or cooling medium through the roll.
The term "substantially solid" indicates the considerable remaining wall thickness of the roll body of about 250 mm. The wall thickness is so large that the loss of bending resistance moment due to the longitudinal bore hole as compared with a completely solid roll is not more than 10%.
The practically complete solidness is an integral feature of a roll intended for a foil-drawing calender or similar applications, since such a roll must be capable of calibration, i.e., it must be capable, due to its dimensional stiffness, of equalizing local differences in the thickness or the compressibility of the plastic compound offered and discharging from the roll gap a foil which has a thickness as constant as possible over the width of its web.
The line pressures required in the rolling of plastic foil are very considerable. Thus, line pressures on the order of magnitude of 3700 N/cm are required for rolling low-pressure PVC (polyvinylchloride) and even 6300 N/cm for rolling high-pressure PVC. In spite of the quasi-solidity of the rolls and in spite of the relatively large diameter with the customary working widths of 2 m, such line pressures already lead to deflections of the roll as a whole, which, without special measures, would lead to unpermissible tolerances of the foil thickness at the edges and in the center of the web.
A further integral feature of the known foil-drawing calender is therefore the use of devices for compensating this deflection caused by the line pressure. These devices are very expensive because of the dimensional stiffness of the rolls and the occurrence of high line pressures. Three different measures are taken side by side throughout, namely, what is called roll bending, i.e., the introduction of bending forces which counteract the deflection caused by the line pressure; a bombage, i.e., slight diameter differences along the roll produced by grinding the shape of the roll accordingly; and an oblique adjustment of rolls relative to each other, so that the roll axes of an interacting pair of rolls do not lie in the same plane but the one roll is, in the form of a very steep screw, so to speak, placed around the other roll. The design and structural expense which is necessary to accommodate all three measures in one and the same machine, is obvious.
In spite of this considerable expense, it is not possible today at that to run a large range of line pressures with one and the same machine. Differently designed machines are required for processing softer plastics and for processing harder plastics.
It is an object of the present invention to provide a simpler compensating system for the deflections caused by the line pressure, usable over a larger range of line pressures while retaining the solidity or dimensional stiffness of the roll.
SUMMARY OF THE INVENTION
According to the present invention, this problem is solved by a stationary core arranged in the longitudinal bore hole, inner bearings supporting the core in the longitudinal bore hole at axial locations corresponding to the ends of the working width, and a hydraulic force exerting arrangement which acts in the working plane of the roll in a direction toward the roll gap and against the inside circumference of the longitudinal bore hole.
The roll of the foil-drawing calender is, in practice, designed as a deflection-controller roll. The indispensable solidity of the rolls, which up to now had to be used for foil drawing and similar applications, has been an obstacle to this idea since it seemed that a stationary core could not be accommodated without giving up the solid construction. It has been found, however, that it is indeed possible to accommodate a stationary core in the roll without appreciably jeopardizing the solidity and without substantial reduction of the bending resistance moment. This is related to the fact that the core zones hardly contribute to the bending resistance moment. Thus, it is found that if the longitudinal bore hole of 200 mm already present in the conventional rolls with a diameter of 700 mm is drilled up to 300 mm, a loss of the bending resistance moment of only about 2.7% occurs. With a core having a diameter of somewhat less than 300 mm, the necessary counter-bending forces can readily be supplied with a working width of about 2 m.
The present invention got its start from problems which arise in foil-drawing calenders and is primarily intended for this purpose. It is understood, however, that the present invention is also suited for other applications in which a similar problem occurs, for instance, in rolling mills for rolling aluminum foil. There, too, the important point is the capability of calibration, using the high dimensional stiffness of the roll body.
Any pertinent known embodiment can be considered as a "force exertion arrangement." Thus, the space between the core and the inside circumference of the longitudinal bore hole, for instance, can be subdivided by lengthwise and transverse end seals into longitudinal chambers which can be filled with a hydraulic pressure liquid at least on the side facing the rolling gap (German Pat. No. 14 11 327). This design is preferred because, in this way, the largest effective area of the hydraulic pressure is obtained and this pressure can thereby be kept within limits. In addition, only recesses for the liquid feed lines need to be provided in the core, so that its cross section and thereby its bending strength are substantially preserved.
However, it is also possible to arrange, on the action side, in a longitudinal section of the core, a strip-shaped piston which extends over the length of the core and which is acted upon from the interior of the core by pressure liquid and rests via a pressure shoe against the inside circumference of the longitudinal bore hole, gliding on a film of liquid (German Pat. No. 14 61 066).
Also, a design according to DE-OS No. 22 30 139 should be considered, in which individual support plungers are provided which are distributed over the length of the core and are designed as hydraulic piston/cylinder units and have, on the side facing the inside circumference of the longitudinal bore hole, hydrostatic pressure chambers, by means of which they are braced quasi-hydrostatically against the inside circumference via the liquid.
Finally, combined designs are also usable such as are described in German Pat. No. 30 03 395.
As required by its function, the core must be supported at the ends at the inside circumference of the longitudinal bore hole, if it is to supply the forces which counteract the deflection caused by the line pressure. While purely theoretically, the support can also be arranged in the manner described in German Pat. No. 23 25 721, i.e., without bearings and only by hydraulic support plungers or the like operating in different directions in the action plane, in practice only embodiments in which inner bearings are provided at the ends of the working width should be considered, especially for reasons of properly guiding the core relative to the roll.
Without further measures, these bearings must intercept very considerable forces which are on the order of the total forces generated by the line pressure, i.e., with a line pressure of 6000 N/cm and 2 m working width, in the range of 1200 kN, or about 600 kN per bearing. The two bearings are, therefore, very highly stressed, and it is a further problem that only a diameter corresponding to the diameter of the longitudinal bore hole is available for the bearings, which cannot be exceeded for design reasons. To this is added that the operating speed can be quite considerable and may be entirely in the range of about 100 m/min. The outside diameters obtained for a given bearing load and a given speed in antifriction bearings are pretty well fixed and, in the present case, are considerably larger than the available diameter of the longitudinal bore hole.
A further problem thus arises to design such a roll so that it is permanently operable with bearings which can be accommodated in the limited diameter of the longitudinal bore hole.
The solution of this further problem resides in disposing, in the vicinity of the inner bearings, load-relieving hydraulic force-exertion arrangements supporting the core at the inside circumference of the longitudinal bore hole and acting in the acting plane of the roll in a direction opposite to the said first hydraulic force-exerting arrangements.
The additional hydraulic force-exerting devices in the vicinity of the inner bearings intercept at least a considerable part of the radial forces occuring during operation and acting, in the acting plane, on the inner bearings, so that the bearings need transmit only accordingly smaller forces and, at best, are even practically load-relieved and have only guidance purposes.
The load-relieving hydraulic force-exerting arrangements may comprise any design which also has a hydraulic force-exerting arrangement acting between the bearings against the rolling gap. Both may be identical or also different if this is desirable for design reasons. An important further feature resides in bearing relief in which the core protrudes beyond the inner bearings as seen in the longitudinal direction of the roll, into the region of the outer bearings, and the load-relieving second hydraulic force-exerting arrangements engage at that axial location.
Through this arrangement it is possible to accomplish load-relief of the inner bearings without thereby exerting an additional bending moment on the outer roll body as would be the case if the load-relieving forces were introduced into the outer roll body at a point located, in the axial direction, outside the outer bearings. This effect is positively utilized in German Pat. No. 30 03 396 to influence to bending line of an outer hollow roll.
A roll with a stationary core, in which the outer roll body is supported in its roll journals in the roll housing, is known per se from U.S. Pat. No. 3,703,862. This, however, does not involve a "substantially solid roll", but the outer roll body is relatively thin-walled, so that enough room is available for the inner bearings and the corresponding problems of the roll according to the present invention do not apply.
The present invention also covers a foil-drawing calender or the like which is equipped with at least one of the above-described rolls. Such a calender is characterized by the feature that none of the measures known up to now such as measures for deflection compensation like roll bending, bombage or oblique adjustment are provided, but the required properties are provided only by the shape of the rolls themselves.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section through a roll according to the present invention.
FIG. 2 is a cross section taken along the line II--II in FIG. 1.
FIG. 3 is a cross section along the line III--III in FIG. 1.
FIG. 4 is an enlarged seal detail of the portion framed in FIG. 1 by dashed lines.
DETAILED DESCRIPTION
The roll 10 in FIG. 1 comprises a roll body 1 as well as two roll journals 2 integral therewith, at which the roll is rotatably supported via outer antifriction bearings 3 in a rolling stand 4 not detailed. The roll body 1 cooperates with a counter-roll 5, forming a rolling gap 6. The width of the roll body 1 is selected in accordance with the width of the foil web to be processed.
The roll 10 has, at the end situated at the right, outside the roll stand 4, a stationary feed ring 7 for a fluid temperature medium, for instance, hot water at 220° C. and 32 bar. The feed ring is in communication with axial feed lines 8, distributed over the circumference, in the roll journal 2 to the right in FIG. 1, which are connected via short radial lines to axial heating canals 9 in the roll body 1. At the left end of the heating canals 9, short radial canals lead to axial discharge lines 11 in the left-hand roll journal 2 which are connected to a stationary discharge ring 12, through which the temperature medium is drained from the roll again. The temperature medium can, of course, also have a low temperature in certain cases and serve for cooling the roll 10.
The roll 10 has a central lengthwise through bore hole 13, the diameter of which is small as compared to the outside diameter of the roll body 1, so that the wall thickness of the roll body 1 remains comparable with the diameter of the longitudinal bore hole 13. The roll body 1 can therefore be considered as substantially solid. It has considable dimensional stiffness which permits equalization of pressure differences occurring locally in the roll gap 6 without appreciable local deformation of the roll body 1. With an outside diameter of the roll body 1 of about 700 mm, the diameter of the longitudinal bore hole 13 is about 300 mm, so that a wall thickness of 200 mm still remains.
In the longitudinal bore hole 13, a non-rotatable core 14 is arranged, the diameter of which, in the region of the roll body 1, is only a few millimeters smaller than that of the longitudinal bore 13 which ends in the region of the left roll journal 2 inside thereof and which protrudes from the right roll journal 2 and has there a connection 15 for a double line which consists of a pipeline 17 arranged in a longitudinal bore hole 16 with internal spacing.
In the vicinity of the ends of the roll body 1, the roll body 1 is rotatably supported on the core via antifriction bearings 18 arranged between the inside circumference of the longitudinal bore 13 and the core 14. As seen in the axial direction, between the bearings 18, two oppositely arranged longitudinal seals 19 (FIG. 3) are arranged at half height, i.e., at its widest point, which rest against the inside circumference of the longitudinal bore hole 13 and, in conjunction with transverse end seals designated as, a whole by 20, which are immediately adjacent to the bearings 18, separate the space between the core 14 and the inside circumference of the longitudinal bore 13, into a longitudinal chamber 21 located on the side of the roll gap 6 and a longitudinal chamber 22 located on the opposite side.
Through the pipeline 17 in the longitudinal bore hole 16 of the core 14, pressure liquid is fed in. This liquid arrives via branch lines 23 at the chamber 21. Due to the pressure produced in the chamber 21, the roll body 1 is subjected to a pressure which is directed against the roll gap 6 and remains constant over the lengthwise extent of the longitudinal chamber 21 and thereby practically over the length of the roll body 1. This pressure counteracts the pressure caused by the line pressure and the deflections otherwise generated thereby.
The force exerted by the pressure liquid against the inside circumference of the longitudinal hole 13 naturally requires a counter force which is furnished by the deflection of the core 14 between the bearings 18. So that the core 14 does not touch the inside circumference of the longitudinal hole 13 due to the deflection which, according to FIG. 1 is downward, the core 14 is formed eccentrically in this region, as can be seen at 24, so that a somewhat larger spacing from the inside circumference of the longitudinal bore hole 13 is provided.
In order to counteract the deflection of the roll body 1 downward according to FIG. 1, the forces which must be exerted in the chamber 21 for practical purposes correspond to the total forces exerted by the line pressure on the roll 10. These forces are too large for the bearings 18, since they can have no larger outside diameter than can be accommodated in the longitudinal bore hole 13.
Since the bearings 18 are stressed by forces which attempt to push the core 14, according to FIG. 1, downward, a load relief device is provided which engages at the end regions of the core 14 located outside the bearings 18 within the roll journals 2 and within the outer bearings, and pushes the latter upward.
As may be seen from FIG. 2, there are again provided in this region, longitudinal seals 29 which are arranged at the core at about half height thereof, i.e., at its widest point, rest against the inside circumference of the longitudinal bore 13 with a seal and extend all the way to the transverse end seals 20 (FIG. 1), which are located at the ends of a region 30 (FIG. 1). In the region 30, a longitudinal chamber 31 is divided off by the longitudinal seals 29 on the side facing away from the rolling gap 6, while a longitudinal chamber 32 is situated on the opposite side. The longitudinal chamber 31 is in communication via a branch line 33 with the pipeline 17 for supplying the hydraulic pressure medium. If hydraulic pressure medium is supplied to the chamber 31, the core is subjected to a force which, according to FIG. 1, is directed from the bottom up, is opposed in the vicinity of the roll body 1 to the force exerted on the core 14 and thus load-relieves the bearings 18.
The hydraulic pressure medium supplied to the longitudinal chambers 21 and/or 31 can likewise be cooled or heated in order to enhance the effect of the fluid temperature medium conducted through the heating canals 9.
Any pressure liquid which might pass the longitudinal seals 19 and 29 gets into the chambers 22 and 23 is discharged from there via branch lines and via the space between the inside circumference of the longitudinal hole 16 and the outside circumference 17. The chambers 22 and 23 can also be kept at a predetermined counterpressure, so that a definite resultant pressure determined by the pressure difference acts on the roll body 1.
In the illustrated embodiment the longitudinal chambers 21 and 31 are connected to the same pipe line 17 and therefore carry the same pressure. However, it is also possible to provide a separate pressure supply for the longitudinal chambers 31. Also, if the two longitudinal chambers 31 together are smaller than the longitudinal chamber 21, a far-reaching relief of the bearings 18 can be obtained in this manner by setting a higher pressure in the longitudinal chambers 31.
It is important that the regions 30 or the longitudinal chambers 31 are disposed at the same axial position as the outer bearings 3 because, thereby, the pressure exerted in the longitudinal chambers 31 has no influence on the bending line of the roll body 1.
The transverse end seals 20 are shown only as rectangles in FIG. 1. In FIG. 4, the dash-dotted region designated as 34 in FIG. 1 is shown in detail. The transverse end seal 20 comprises a ring 40 which revolves with the roll body 1 and rests against the inner bearing 18 with a running surface 41 as well as an intermediate ring 43 which is supported on the core 14 via a spherical surface 42 and is movable along the spherical surface 42, with a bearing surface 44 which extends, like the support surface 41, perpendicular to the axis and is arranged opposite surface 41 with spacing. The intermediate ring 43 is connected to the core 14 and accordingly is standing still. Between the revolving bearing surface 41 and the stationary bearing surface 44, a bearing ring with cylindrical bearing rolls 45 is arranged. Bearing rolls 45 hold the intermediate ring 43 at an exact distance from the bearing ring 40. The bearing ring 43 has an external cylindrical extension 46, whose end face 47 is arranged opposite the bearing surface 41 with a spacing of only a few hundredths of a millimeter. This spacing is maintained exactly by the bearing rolls 45. The intermediate ring 43 is pressed against the rolls 45 by axial compression springs 48. The compression springs 48 are braced against the core 14.
The choke effect of the gap 50 between the bearing surface 41 and the end face 47 of the intermediate ring 43 is so strong that only small amounts of pressure liquid pass even at a pressure in the longitudinal chamber 21 of 30 bar or more and the the pressure in the longitudinal chamber 21 can be maintained without difficulty. Even if the core 14 is bent, the intermediate ring 43, which can shift relative to the core 14, maintains its position relative to the bearing ring 40, so that the gap 50 is always maintained in the same manner.
The transverse end seal 20 works without making contact and practically without wear and permits the maintenance of the high pressures in the longitudinal chamber 21 which are required for the operation of the roll 10.
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A roll for a foil-drawing calender or the like which is substantially solid, has a central longitudinal bore hole and has journals supported in outer bearings in a roll stand. In the longitudinal bore hole is a stationary core which is supported, at axial locations corresponding to the ends of the working width, via inner bearings in the longitudinal bore hole and is braced via a hydraulic force-exerting arrangement acting in the working plane of the roll in a direction toward the roll gap and against the inside circumference of the longitudinal bore hole. In the vicinity of the inner bearings and in the region of the outer bearings, load-relieving hydraulic force-exerting arrangements are provided which brace the core against the inside circumference of the longitudinal bore hole and act in the action plane of the roll in the direction opposed to that of the other hydraulic force-exerting arrangement.
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This application is a divisional of Ser. No. 09/174,841, filed Oct. 19, 1998, now U.S. Pat. No. 6,007,583.
BACKGROUND OF THE INVENTION
It is known that the bleaching power of peroxidic bleaches such as perborates, percarbonates, persilicates and perphosphates can be improved such that the bleaching effect starts at lower temperatures, for example at or below 60° C., by adding the precursors of bleaching peroxy acids, which are often referred to as bleach activators.
Many substances are known as bleach activators from the prior art. These are usually reactive organic compounds having an O-acyl or N-acyl group, which in alkaline solution, together with a source of hydrogen peroxide, form the corresponding peroxy acids.
Representative examples of bleach activators are N,N,N',N'-tetraacetylethylenediamine (TAED), glucose pentaacetate (GPA), xylose tetraacetate (TAX), sodium 4-benzoyloxybenzenesulfonate (SBOBS), sodium trimethylhexanoyloxybenzenesulfonate (STHOBS), tetraacetylglycoluril (TAGU), tetraacetylcyanic acid (TACA), di-N-acetyidimethylglyoxine (ADMG) and 1-phenyl-3-acetylhydantoin (PAH). Reference may be made, for example, to GB-A-836 988, GB-A-907 356, EP-A-0 098 129 and EP-A-0 120 591.
Over time, nitrilic bleach activators have gained in importance since they have proven to be extraordinarily bleaching-active. On perhydrolysis, these compounds probably form a peroxyimidic acid, which is the bleaching agent.
Such nitrilic bleach activators and their use as bleach activators in bleaches are described, for example, in EP 303 520, GB 802 035, U.S. Pat. No. 4,883,917, U.S. Pat. No. 5,478,356, U.S. Pat. No. 5,591,378, WO 9 606 912 and WO 9 640 661.
SUMMARY OF THE INVENTION
Surprisingly, it has now been found that aminonitrile N-oxides and salts derived therefrom have a better bleaching effect than bleach activators according to the prior art.
The invention thus provides for the use of aminonitrile N-oxides of the formula (1) or salts thereof, ##STR2## in which R 1 and R 2 independently of one another are substituted or unsubstituted C 1 -C 15 -alkyl, cycloalkyl or aryl radicals which may be substituted by fluorine, chlorine, bromine, C 1 -C 5 -alkoxy, C 1 -C 5 -alkoxycarbonyl, amino, ammonium, carboxyl, cyano or cyanamino, or together with the nitrogen atom to which they are bonded form a ring having from 4 to 6 carbon atoms which may be substituted by C 1 -C 5 -alkyl, C 1 -C 5 -alkoxy, C 1 -C 5 -alkanoyl, phenyl, amino, ammonium, cyano, cyanamino, chlorine or bromine, which ring can contain, in addition to the nitrogen atom and instead of --CH 2 -- groups, one or two oxygen atoms or a group ##STR3## in which R 3 is hydrogen, C 1 -C 7 -alkyl or cycloalkyl, phenyl or C 7 -C 9 -alkylaryl, and
A is a C 1 -C 5 -alkylene, a C 5 -C 10 -cycloalkylene or an arylene radical, as bleach activators. The terms "aryl" and "arylene" in the above formula are preferably "phenyl" and "phenylene" respectively.
The aminonitrile N-oxides to be used according to the invention also include their salts, for example those salts obtained, for example, by reacting the corresponding aminonitrile N-oxide with acids such as, in particular, HCl, HBr, HF, H 2 SO 4 , H 3 PO 4 and other acidic phosphates, pyro-, meta- and polyphosphoric acid, HBF 4 , HPF 6 , H 2 CO 3 , HNO 3 --, citric acid, formic acid, R 4 SO 4 H, R 4 SO 3 H, R 4 COOH, where R 4 is a substituted or unsubstituted C 1 -C 21 -alkyl or aryl radical.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preference is given to aminonitrile N-oxides or salts thereof of the formula 1 in which R 1 and R 2 are C 1 -C 4 -alkyl, in particular methyl, and A is phenylene. The aminonitrile N-oxides and the salts derived therefrom are readily accessible by reacting aminonitriles with oxidizing agents; such reactions are described, for example, in J. Backes "Amine", Methoden der Organischen Chemie (Houben-Weyl), D. Klamann (Ed.) Vol. E 16d (1992), p. 1235-1329 and the literature cited therein.
The invention also provides for the use of these bleach activators in bleaching detergents and cleaners and in paper and textile bleaching. In addition to a peroxide compound and the bleach activator, the detergents and cleaners usually also comprise surface-active compounds and other known ingredients.
Suitable peroxidic bleaches are alkali metal peroxides, organic peroxides such as urea peroxide, and inorganic persalts, such as the alkali metal perborates, percarbonates, perphosphates, persilicates and persulfates. Mixtures of two or more of these compounds are also suitable. Particular preference is given to sodium perborate tetrahydrate and especially sodium perborate monohydrate. Sodium perborate monohydrate is preferred because of its good storage stability and its good solubility in water. Sodium percarbonate may be preferred on environmental grounds. Alkyl hydroperoxides are another suitable group of peroxide compounds. Exqmples of these substances are cumene hydroperoxide and tert-butyl hydroperoxide.
The proportion by weight of the nitrilic bleach activator according to the invention in detergents and cleaners can be from about 0.05 to 20%, preferably from 0.5 to 10%, in particular from 1 to 7.5%, together with a peroxide compound. The proportion by weight of these peroxide compounds is usually from 1 to 60%, preferably from 4 to 30%, in particular from 10 to 25%.
The detergents and cleaners may also comprise, in addition to the bleach activators according to the invention, other suitable bleach activators, for example TAED, tetraacetylglycoluril, glucose pentaacetate, sodium nonanoyloxybenzenesulfonate, benzoylcaprolactam or nitrilic activators. These additional bleach activators can be present in an amount of from 1 to 10% by weight.
The surface-active substance can be derived from natural products, such as soap, or is a synthetic compound from the group consisting of anionic, nonionic, amphoteric, zwitterionic or cationic surface-active substances or mixtures thereof. Many suitable substances are available commercially and are described in the literature, for example in "Surface active agents and detergents", Vol. 1 and 2, by Schwartz, Perry and Berch. The total amount of the surface-active compounds can be up to 50% by weight, preferably from 1% by weight to 40% by weight, in particular from 4% by weight to 25% by weight.
Synthetic anionic surface-active substances are, usually, water-soluble alkali metal salts of organic sulfates and sulfonates having C 8 -C 22 -alkyl radicals, the term "alkyl" including the alkyl substituents of higher aryl radicals.
Examples of suitable anionic detergents are sodium and ammonium alkylsulfates, especially the sulfates obtained by sulfating higher (C 8 to C 18 ) alcohols; sodium and ammonium alkylbenzenesulfonates having a C 9 -C 20 -alkyl radical, especially linear secondary sodium alkylbenzenesulfonates having a C 10 -C 15 -alkyl radical; sodium alkyl glycerol ether sulfates, especially the esters of the higher alcohols derived from tallow oil and coconut oil; the sodium sulfates and sodium sulfonates of coconut fatty acid monoglycerides; sodium and ammonium salts of the sulfuric esters of higher (C 9 to C 18 ) alkoxylated fatty alcohols, especially those alkoxylated with ethylene oxide; the reaction products of the esterification of fatty acids with isethionic acid and subsequent neutralization with sodium hydroxide; sodium and ammonium salts of the fatty acid amides of methyltaurine; alkanemonosulfonates such as those from the reaction of α-olefins (C 8 -C 20 ) with sodium bisulfite and those from the reaction of paraffins with SO 2 and Cl 2 with subsequent basic hydrolysis to give a mixture of different sulfonates; sodium and ammonium dialkylsulfosuccinates having C 7 -C 12 -alkyl radicals; and olefinsulfonates formed in the reaction of olefins, especially C 10 -C 20 -α-olefins, with SO 3 and subsequent hydrolysis of the reaction products. The preferred anionic detergents are sodium alkylbenzenesulfonates having C 15 -C 18 -alkyl radicals, and sodium alkyl ether sulfates having C 16 -C 18 -alkyl radicals.
Examples of suitable nonionic surface-active compounds, which are preferably used together with anionic surface-active compounds, are, in particular, the reaction products of alkylene oxides (usually ethylene oxide) with alkylphenols (C 5 -C 22 -alkyl radicals), the reaction products generally containing from 5 to 25 ethylene oxide (EO) units in the molecule; the reaction products of aliphatic (C 8 to C 18 ) primary or secondary, linear or branched alcohols with ethylene oxide, generally with from 6 to 30 EO, and the adducts of ethylene oxide with reaction products of propylene oxide and ethylenediamine. Other nonionic surface-active compounds are alkyl polyglycosides, long-chain tertiary amine oxides, long-chain tertiary phosphine oxides and dialkyl sulfoxides.
Amphoteric or zwitterionic surface-active compounds can likewise be used in the compositions according to the invention, although in most cases this is not desirable owing to their high cost. If amphoteric or zwitterionic compounds are used, they are generally used in small amounts in compositions predominantly comprising anionic and nonionic surfactants.
Soaps too can be used in the compositions according to the invention, preferably in an amount of less than 25% by weight. They are particularly suitable in small amounts in binary (soap/anionic surfactant) or in ternary mixtures together with nonionic or mixed synthetic anionic and nonionic surfactants. The soaps used are preferably the sodium salts, less preferably the potassium salts, of saturated or unsaturated C 10 -C 24 fatty acids or mixtures thereof. The amounts of such soaps can be from 0.5% by weight to 25% by weight, with smaller amounts of from 0.5% by weight to 5% by weight generally being sufficient for foam control. Amounts of soaps of between 2% and about 20%, in particular between about 5% and about 10%, have a positive effect. This is especially the case in hard water, where the soap acts as an additional builder substance.
The detergents and cleaners generally also include a builder. Suitable builders are calcium-binding substances, precipitants, calcium-specific ion exchangers and mixtures thereof. Examples of calcium-binding substances include alkali metal polyphosphates, such as sodium tripolyphosphate; nitrilotriacetic acid and its water-soluble salts; the alkali metal salts of carboxymethyloxysuccinic acid, ethylenediaminetetraacetic acid, oxydisuccinic acid, mellitic acid, benzenepolycarboxylic acids, citric acid; and polyacetal carboxylates as disclosed in U.S. Pat. No. 4,144,226 and U.S. Pat. No. 4,146,495.
Examples of precipitants are sodium orthophosphate, sodium carbonate and soaps of long-chain fatty acids.
Examples of ion exchangers that are specific for calcium are the various kinds of water-insoluble, crystalline or amorphous aluminum silicates, of which the zeolites are the best-known representatives.
These builder substances can be present in amounts from 5 to 80% by weight, preferably from 10 to 60% by weight.
In addition to the ingredients already mentioned, the detergents and cleaners may comprise any of the conventional additives in amounts which are commonly encountered in such compositions. Examples of such additives are foam formers, such as alkanolamides, especially the monoethanolamides of palm kernel oil fatty acids and coconut fatty acids; antifoams, such as alkyl phosphates and alkylsilicones; antiredeposition agents and similar auxiliaries, such as sodium carboxymethylcellulose and alkyl- or substituted alkylcellulose ethers; stabilizers, such as ethylenediaminetetraacetic acid; softeners for textiles; inorganic salts, such as sodium sulfate; and, in customarily small amounts, fluorescent substances, perfumes, enzymes such as proteases, cellulases, lipases and amylases, disinfectants, and colorants.
The bleach activators of this invention can be used in a large number of detergents and cleaners. These include textile detergents, textile bleaches, surface cleaners, toilet cleaners, dishwasher detergents, and also denture cleansers. The detergents can be in solid or liquid form. For reasons of stability and ease of handling, it is advantageous to use the bleach activators in the form of granules which, in addition to the bleach activator, comprise a binder. Various methods of preparing such granules are described in the patent literature, for example in CA-1 102 966, GB-1 561 333, U.S. Pat. No. 4,087,369, EP-A-0 240 057, EP-A-0 241 962, EP-A-0 101 634 and EP-A-0 062 523. Any of these methods can be used for the aminonitrile N-oxides to be used according to the invention.
The granules containing the bleach activators are generally added to the detergent composition together with the other dry constituents, such as enzymes or inorganic peroxide bleaches. The detergent composition to which the catalyst granules are added can be obtained by various methods, such as by dry mixing, extrusion and spray drying.
In a further embodiment, the bleach activators according to the invention are particularly suitable for nonaqueous liquid detergents, together with a bleaching peroxide compound, such as sodium perborate, in order to give the detergent a high cleaning power for fabrics and textiles. Nonaqueous liquid detergents of this kind, which include pasty and gelatinous detergent compositions, are known in the prior art and are described, for example, in U.S. Pat. No. 2,864,770, U.S. Pat. No. 2,940,938, U.S. Pat. No. 4,772,412, U.S. Pat. No. 3,368,977, GB-A-1 205 711, GB-A-1 370 377, GB-A-1 270 040, GB-A-1 292 352, GB-A-2 194 536, DE-A-2 233 771 and EP-A-0 028 849.
These compositions are in the form of a nonaqueous liquid medium in which a solid phase may be dispersed. The nonaqueous liquid medium can be a liquid surface-active substance, preferably a nonionic surface-active substance; a nonpolar liquid medium, such as liquid paraffin; a polar solvent, such as polyols, for example glycerol, sorbitol, ethylene glycol, possibly in combination with monohydric alcohols of low molecular mass such as ethanol or isopropanol; or mixtures thereof.
The solid phase may consist of builder substances, alkalis, abrasive substances, polymers, and other solid ionic surface-active substances, bleaches, fluorescent substances, and other customary solid ingredients.
The following, nonlimiting examples are intended to give an overview of the embodiments of the invention.
EXAMPLE 1
Synthesis of Para-dimethylaminobenzonitrile N-oxide and the Corresponding Meta-chlorobenzoic Acid Salt
A solution of 13.8 g of meta-chloroperoxybenzoic acid in 200 ml of methylene chloride was added dropwise to a solution of 11.7 g of para-dimethylaminobenzonitrile in 80 ml of methylene chloride at a temperature of from 0° C. to -5° C. over the course of two hours. When no more peroxide was detectable (negative Kl test), the solvent was evaporated on a rotary evaporator. This gave 25.7 g of the meta-chlorobenzoic acid salt of para-dimethylaminobenzonitrile N-oxide. Pure para-dimethylaminobenzonitrile N-oxide was isolated by chromatography on aluminum oxide. 9
Bleaching Tests
The combination of 200 ml of an aqueous solution of reference detergent WMP (Laundry Research Krefeld, 5 g/l in water of German hardness 15°) solution, 150 mg of sodium perborate monohydrate and 50 mg of the particular activator gave a bleach composition. Using this composition, pieces of fabric soiled with the standard soiling BC-1 tea (on cotton, Laundry Research Krefeld) were subjected to a treatment at a temperature of 40° C. in a Linitest apparatus (Heraeus) under isothermal washing conditions. After a wash time of 30 minutes, the pieces of fabric were rinsed with water, dried and ironed, and then the bleaching effect was quantified by determining the differences ΔR.sub.(ACT) in the reflectance before and after bleaching using an ELREPHO 2000 whiteness measuring apparatus (Datacolor). These ΔR.sub.(ACT) values and the ΔR 0 values determined in control experiments without bleach activator were used to calculate the ΔΔR values listed in Table 1, which are a direct measure of the improvement in the bleaching action brought about by the addition of activator:
ΔΔR=ΔR.sub.(ACT) -ΔR.sub.0
The compounds 1-5 are ##STR4##
TABLE 1______________________________________1 2 3 4 5______________________________________ΔΔR 1.0 07 1.2 0.3 0.1______________________________________ mCBA: meta-chlorobenzoic acid salt
The washing experiments show that the aminonitrile N-oxides according to the invention have good bleaching power.
Further advantageous properties of the complexes described are low color damage and low fiber damage.
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Use of compounds of the formula ##STR1## where the radicals R 1 , R 2 and A are as defined in the description, as bleach activators in bleaching detergents and cleaners.
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BACKGROUND
1. Field
The embodiments are generally directed to managing memory, and more specifically to managing memory among heterogeneous computer components.
2. Background Art
A computing device generally includes one or more processing units (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a general purpose GPU (GPGPU), an accelerated processing unit (APU), or the like), that access a shared main memory. The processing units may execute programs (e.g., instructions or threads) that result in accesses to main memory. Because memory accesses may traverse a memory hierarchy including levels of cache and main memory, memory accesses may have different latencies, and may be performed in a different order than what was intended by the programs. In addition there may be conflicts, e.g., when two memory accesses attempt to store data in the same memory location.
Memory accesses are also called memory events, and examples include a store event (i.e., a memory access request to write data to main memory), a load event (i.e., a memory access request to read data from main memory), and synchronization events that are used to order conflicting memory events.
Memory consistency models provide rules for ordering memory events. A type of memory consistency model, release consistency with special accesses sequentially consistent (RCsc), provides a framework for event ordering for parallel programs with synchronization. Current systems that implement an RCsc memory model, a write-through (WT) memory system and a write-combining (WC) memory system, have difficulty with synchronization events such as a store release (StRel) synchronization event.
A StRel synchronization event is a release synchronizing store instruction that acts like an upward memory fence such that prior memory operations are visible to threads that share access to the ordering point before the store event portion of the StRel completes. A load acquire (LdAcq) synchronization event is a synchronizing load instruction that acts as downward memory fence such that later operations cannot occur before the LdAcq operation.
Upon executing a StRel synchronization event in a WT memory system, data is immediately written-through to main memory which is an inefficient use of the precious bandwidth resources to main memory. In addition, the system tracks acknowledgements for individual store completions which is highly inefficient. Further, upon receiving a load acquire synchronization event, the system performs a full cache flush to invalidate clean and potentially stale data which makes data reuse in the presence of synchronization impossible.
The WC memory system uses cache hierarchies to coalesce store events. Executing a StRel synchronization event in the WC triggers a slow and intensive cache flush to determine when the prior stores have completed to a next level of hierarchy. A cache flush entails walking through an entire cache hierarchy to track outstanding store events to completion.
In addition, write-combining caches incur overhead to track dirty bytes in cache lines in the memory hierarchy.
A hierarchical directory/snooping cache coherence protocol solution is a “read for ownership” solution that could support an RCsc memory consistency model, however, the memory access requests to write data encounter long delays. A requesting processor (e.g., a CPU or GPU) has to read or own a memory block before writing to local cache and completing a store event.
BRIEF SUMMARY OF EMBODIMENTS
What is needed therefore, are approaches that enforce an RCsc memory model and can execute release synchronization instructions such as a StRel event without tracking an outstanding store event through a memory hierarchy, while efficiently using bandwidth resources. In embodiments, a requesting processor does not have to read or own a memory block before writing in local cache and completing a store event. Certain embodiments may, in certain conditions, improve the performance of both global synchronization events (e.g., writing to main memory for completion) and local synchronization events (e.g., writing to a common ordering point such as level 2 cache for completion) since the cache hierarchy does not need to be flushed and a store event may not need to reach main memory to complete. Further embodiments include decoupling a store event from an ordering of the store event with respect to a RCsc memory model.
Certain embodiments include a method, computer program product, and a system. For example, a system embodiment includes a set of hierarchical read-only cache and write-only combining buffers that coalesce stores from different parts of the system. In addition, a component maintains a partial order of received store events and release synchronization events to avoid content addressable memory (CAM) structures, full cache flushes, and direct write-throughs to memory. Some embodiments provide RCsc memory model programmability while efficiently using limited bandwidth.
Certain embodiments further include a read-only cache and a write-only combining cache at respective levels in the memory hierarchy to reduce the overhead in managing the write-combining cache. Data written to cache as a result of a store event for example, is called dirty data, and is different than the data that resides in the location in main memory. Dirty data is eventually written to main memory.
Certain embodiments also include a method for receiving a memory event. When the memory event is a store event, the method further includes: writing a first data to a write-only, level n cache, where n is an integer representing the level of cache hierarchy. The method further includes writing, to a level n pool, a store entry that includes an address of the first data in the level n cache, where the level n pool maintains a partial order among the store entry, a prior received store entry, and a release marker entry, and when a release marker is present, ordering the store entry in the level n pool to follow a most-recent release marker. When the memory event is a load event, the method further includes searching a read-only, level n cache for a second data, and determining when the second data is present in a corresponding write-only, level n cache.
A further embodiment includes a computer program product having instructions stored thereon, where the execution of the stored instructions results in a processing unit causes the following steps to be performed. First, a memory event is received. When the memory event is a store event, the next step includes writing a first data to a write-only, level n cache, where n is an integer representing the level of cache hierarchy. Subsequent steps include writing, to a level n pool, a store entry that includes an address of the first data in the level n cache, where the level n pool maintains a partial order among the store entry, a prior received store entry, and a release marker entry, and when a release marker is present, ordering the store entry in the level n pool to follow a most-recent release marker. When the memory event is a load event, the next step includes searching a read-only, level n cache for a second data, and determining when the second data is present in a corresponding write-only, level n cache.
Another embodiment includes a processing unit configured to perform the following functionality. First, the processing unit receives a memory event. When the memory event is a store event, the processing unit writes a first data to a write-only, level n cache, where n is an integer representing the level of cache hierarchy. Subsequently, the processing unit writes to a level n pool a store entry that includes an address of the first data in the level n cache, where the level n pool maintains a partial order among the store entry, a prior received store entry, and a release marker entry, and when a release marker is present, orders the store entry in the level n pool to follow a most-recent release marker. When the memory event is a load event, the processing unit searches a read-only, level n cache for a second data, and determines when the second data is present in a corresponding write-only, level n cache.
Further features and advantages of the embodiments, as well as the structure and operation of various embodiments, are described in detail below with reference to the accompanying drawings. It is noted that the embodiments are not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein.
BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES
The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the embodiments and, together with the description, further serve to explain the principles of the embodiments and to enable a person skilled in the pertinent art to make and use the embodiments. Various embodiments are described below with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout.
FIG. 1 illustrates an APU environment, according to an embodiment.
FIG. 2 illustrates a write-back write-combine system, according to an embodiment.
FIG. 3A illustrates a GPU with separate read-only cache and write-only cache, according to an embodiment.
FIG. 3B illustrates a GPU with separate read-only cache, write-only cache, and dirty read buffers (DRBs) according to an embodiment.
FIG. 4 illustrates a method of handling the receipt of memory events, according to an embodiment.
FIG. 5 illustrates a method of evicting entries, according to an embodiment.
FIG. 6 illustrates a method of handing memory synchronization events, according to an embodiment.
FIG. 7 illustrates a method of evicting entries from a queue, according to an embodiment.
FIG. 8 illustrates an example computer system in which embodiments may be implemented.
The embodiments will be described with reference to the accompanying drawings. Generally, the drawing in which an element first appears is typically indicated by the leftmost digit(s) in the corresponding reference number.
DETAILED DESCRIPTION OF EMBODIMENTS
In the detailed description that follows, references to “one embodiment,” “an embodiment,” “an example embodiment,” etc. indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
The term “embodiments” does not require that all embodiments include the discussed feature, advantage or mode of operation. Alternate embodiments may be devised without departing from the scope of the disclosure, and well-known elements of the disclosure may not be described in detail or may be omitted so as not to obscure the relevant details. In addition, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. For example, as used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Computing devices process data and provide many applications to users. Example computing devices include, but are not limited to, mobile phones, personal computers, workstations, and game consoles. Computing devices use a central processing unit (“CPU”) to process data. A CPU is a processor which carries out instructions of computer programs or applications. For example, a CPU carries out instructions by performing arithmetical, logical and input/output operations. In an embodiment, a CPU performs control instructions that include decision making code of a computer program or an application, and delegates processing to other processors in the electronic device, such as a graphics processing unit (“GPU”).
A GPU is a processor that is a specialized electronic circuit designed to rapidly process mathematically intensive applications (e.g., graphics) on electronic devices. The GPU has a highly parallel structure that is efficient for parallel processing of large blocks of data, such as mathematically intensive data common to computer graphics applications, images and videos. The GPU may receive data for processing from a CPU or generate data for processing from previously processed data and operations. In an embodiment, the GPU is a hardware-based processor that uses hardware to process data in parallel.
Due to advances in technology, a GPU also performs general purpose computing (also referred to as GPGPU computing). In the GPGPU computing, a GPU performs computations that traditionally were handled by a CPU. An accelerated processing unit (APU) includes at least the functions of a CPU and a GPU. The GPU can be a GPGPU.
In an embodiment, a GPU includes one or more compute units (CUs) that process data. A compute unit (CU) includes arithmetic logic units (ALUs) and other resources that process data on the GPU. Data can be processed in parallel within and across compute units.
In an embodiment, a control processor on a GPU schedules task processing on compute units. Tasks include computation instructions. Those computation instructions may access data stored in the memory system of a computing device and manipulate the accessed data. In an embodiment, the data may be stored in volatile or non-volatile memory. An example of volatile memory includes random access memory (RAM). Examples of RAM include dynamic random access memory (DRAM) and static random access memory (SRAM). Volatile memory typically stores data as long as the electronic device receives power. Examples of non-volatile memory include read-only memory (ROM), flash memory, ferroelectric RAM (F-RAM), hard disks, floppy disks, magnetic tape, optical discs, etc. Non-volatile memory retains its memory state when the electronic device loses power or is turned off.
FIG. 1 illustrates an APU environment, according to an embodiment. In the example shown, system 100 is an APU environment that includes CPU 110 , GPU 130 , main memory 150 , and bus 140 .
Bus 140 may be any type of communication infrastructure used in computer systems, including a peripheral component interface (PCI) bus, a memory bus, a PCI Express (PCIE) bus, front-side bus (FSB), hypertransport (HT), or another type of communication structure or communications channel whether presently available or developed in the future.
FIG. 2 illustrates a write-combining (WC) system, according to an environment. WC System 200 includes a conventional GPU and bus 140 . WC System 200 includes CUs 210 a and 210 b , and a multi-tiered write-combining cache including Level 1 (L1) caches 220 a and 220 b , as well as Level 2 (L2) cache 240 . L2 cache 240 is shared among CUs 210 in system 200 . Bus 230 is substantially the same as bus 140 of FIG. 1 .
In WC System 200 , write-combining caches provide coherence for data-race-free programs (e.g., programs free of memory accesses conflicts) by writing updates to an ordering point (e.g., L2 cache 240 or main memory 150 ) at synchronization events. In addition, write-combining caches use a write-back policy that keeps previously written data in cache longer than the WT alternative. This policy increases the chance that the results of two store events coalesce in cache before consuming the limited bandwidth at a synchronization event to evict the data to a next-level cache in the memory hierarchy. However, the cost of a synchronization event in WC System 200 is high. Upon execution of a StRel synchronization event, for example, WC System 200 must perform a full cache flush to find and flush outstanding writes throughout the cache hierarchy to completion to ensure proper ordering of memory events. A write is data written by a store event. WC System 200 searches L1 caches 220 a and 220 b as well as L2 cache 240 to find data previously written, also called dirty data. Once dirty data is found, WC System 200 evicts the dirty data to a next level of cache hierarchy, or main memory 150 if a next-level cache is not present, and waits for acknowledgements to be received before processing another memory event. The cache flush process is a very slow and tedious process to be avoided.
Embodiments utilize separate read-only cache and write-only combining caches to enforce a RCsc model, and avoid tracking outstanding store events via the memory hierarchy. Embodiments utilize extra knowledge to manage a partial order of outstanding writes and release synchronization events separately from the outstanding writes that move through a memory hierarchy. Because store events are not tracked via the memory hierarchy, acknowledgement messages are not needed for store event completions resulting in reduced traffic. In addition, embodiments allow a store event to complete without having to write-through to main memory 150 .
A memory fence is an operation used to delay a memory access until the previous memory access has been performed. Synchronization events utilize memory fences to provide order by making results visible (i.e., available for reading) in a globally shared memory so that other instructions in the computing device may utilize the results.
The RCsc consistency model requires that prior store events that occur before a StRel synchronization event be visible (i.e., readable) in a specified scope (e.g., global or local) and that loads after a LdAcq appear to be executed after the LdAcq. Also, the LdAcqs and StRels themselves obey sequential consistency so a StRel needs to complete the writes before a LdAcq may proceed to read the writes.
A scope is a group of threads that access a shared memory or a common ordering point. Global scope requires global synchronization and a store event is complete when the data written in main memory 150 is visible to other threads in the system. Local scope requires local synchronization and a store event is complete when the data is written to a common ordering point such as a level 2 cache, and is visible to threads that share access to that common ordering point. The ability to synchronize to a local scope when possible, instead of having to synchronize to a global scope provides considerable savings with regards to limited bandwidth access to main memory, reduced latency, and power savings.
In write-combining caches, store events are more costly to support than load events because a write-combining cache allows partial cache line writes without exclusive ownership (i.e., allows multiple writers). A system tracks dirty bytes within a cache line to merge writes to different bytes of the same cache line. Most implementations use a respective dirty byte bitmask for a cache line (e.g., 12.5% overhead for 64-byte cache lines) and write out the dirty portions of a cache line on evictions. Thus, write-combining caches incur overhead for implementing a respective dirty byte mask for a cache line in the memory hierarchy.
Typically, in current GPU and GPGPU applications, the number of load (read) events vastly outnumber store (write) events. And among the store events, a small subset require intermediate visibility before being written to main memory 150 . Thus, the number of read-after-write (RAW) operations is relatively small.
Embodiments reduce the overhead by splitting a write-combining cache at one or more levels into a read-only cache and a write-only combining cache. Because the number of reads is larger than the number of writes, the read-only cache can be larger and the write-only cache can be smaller. The separation of the read-only and write-only cache encourages data path optimizations such as independent and lazy management of write bandwidth while minimizing implementation complexity. And, as GPU threads seldom perform RAW operations, the potential costs of the separation are low.
In an embodiment, a special victim buffer called a dirty read buffer (DRB) can be used to provide dirty bit masks on the smaller write-only cache. The DRB keeps track of writes (dirty data) in the write-only cache and sources requests to read dirty data in the write-only cache (i.e., a RAW operation). As RAW operations are infrequent, the DRB is a simple implementation that separates the read-only and write-only operations.
FIG. 3A illustrates a GPU with separate read-only cache and write-only combining cache, according to an embodiment. System 300 includes a memory hierarchy of read-only caches rL1 370 a , rl1 370 b , and rL2 380 , write-only combining buffers wL1 320 a , wL1 320 b , and wL2 340 , corresponding co-located pool components L1 pool 350 a , L1 pool 350 b and L2 pool 360 , as well as compute units CU 310 a and CU 310 b.
A read-only cache is also called clean cache and contains data identical to the location in main memory 150 . A read-only cache includes at least one of but is not limited to an address that corresponds to a memory location in main memory, a cache tag, a partial address, a cache line, and an indication of whether the cache line or bytes of the cache line are invalid. The bytes are invalid if the bytes are written to a corresponding write-only cache. To search for a cache line in a cache, a system may search for at least one of an address, a cache tag, or a partial address of the cache line.
An example of the indication can include a write-only, cache-present bit. When set, the write-only, cache-present bit indicates, for example, that dirty data (i.e., newly written data will be written to main memory 150 ) exists in the corresponding write-only cache for the same cache line. When clear, the write-only, cache-present bit indicates, for example, that no dirty data exists in the corresponding write-only cache for the same cache line.
The write-only cache can be much smaller than the read-only cache, contains dirty data, i.e., the write-only cache contains data that is different to the location in main memory 150 as it has not yet been written to main memory 150 . A write-only cache includes at least one of but is not limited to an address that corresponds to a memory location in main memory, a cache tag, a partial address, and a dirty byte bitmask.
Pool components contain knowledge to track outstanding store events separately from the ordering of store events in the memory hierarchy that occurs when enforcing an RCsc memory model. Pool components L1 pool 350 a , L1 pool 350 b , and L2 pool 360 contain knowledge that enables system 300 to track which prior writes and corresponding addresses that may not yet be written back to main memory 150 , without having to perform a cache walk, or implementing power-hungry CAM lookups to track acknowledgements.
Pool components L1 pool 350 a , L1 pool 350 b , and L2 pool 360 may be implemented for example, by a synchronization First In First Out (S-FIFO) or a Bloom-filter with signatures as are well known in the art. A pool component may contain entries associated with a store event or a release synchronization event. An entry associated with a store event may include but is not limited to an address in main memory and a thread identity of a store event. A thread identity is used to recognize different threads. An entry associated with a release synchronization event is a release marker that may include but is not limited to a thread identity of a release synchronization event.
The pool and write-only combine cache do not require inclusion. That is, the write-only cache does not need to contain the data associated with all entries in the pool. For example, some data may be evicted early due to cache replacement policies or a load event with a partial hit that causes an early data eviction.
FIG. 3B illustrates a GPU with separate read-only cache, write-only cache, and dirty read buffers (DRBs) according to an embodiment. A dirty read buffer (DRB) may be collocated with a write-only and read-only cache at a corresponding level and the DRB is used to maintain a separation among read-only cache and write-only cache. A DRB may include but is not limited to include an address, and an indication of the dirty bytes in the write-only cache. In addition to the elements shown in FIG. 3A , FIG. 3B includes DRB 1 375 a and DRB1 375 b , as well as DRB2 385 .
When a DRB is present, a read-only cache includes at least one of but is not limited to an address that corresponds to a memory location in main memory, a cache tag, a partial address, and a cache line. Unlike FIG. 3A , an indication of whether the cache line or bytes of the cache line are invalid (e.g., write-only, cache-present bit) is not necessary in the read-only cache as the information is found in the corresponding DRB, and reads to the read-only cache and the corresponding DRB can occur in parallel. When the address is found in the DRB, any corresponding data also found in the read-only cache is considered invalid. Bytes in the read-only cache are invalid if new data is written to the address of the bytes in a corresponding write-only cache. To search for a cache line in a cache, a system may search for at least one of an address, a cache tag, or a partial address of the cache line.
FIG. 4 illustrates a method of handling the receipt of memory events, according to an embodiment. In one example, system 100 and system 300 may be used to demonstrate method 400 . It is to be appreciated that operations in method 400 may be performed in a different order than shown, and method 400 may not include all operations shown. For ease of discussion, and without limitation, method 400 will be described in terms of elements shown in FIG. 1 , FIG. 3A , and FIG. 3B .
Method 400 begins at step 410 and proceeds to step 415 .
At step 415 , memory events such as a store, a load, or a release synchronization are received from a compute unit such as CU 310 a . The memory events are read from a software program e.g., instruction code, in program order.
When a load event is received, at step 420 , method 400 looks for the address of the data in rL1 370 a and checks the write-only, cache-present bit. Method 400 proceeds to step 425 .
At step 425 , if the data is found in rL1 370 a (a hit), and the write-only, cache-present bit is clear, the data is read and method 400 returns to step 415 to await another memory event. The write-only, cache-present bit being clear indicates that there is no dirty data in the corresponding wL1 320 a waiting to be written to main memory 150 and thus the data in rL1 370 is not stale.
At step 425 , when the write-only, cache-present bit is set, (i.e., dirty data for the cache line is present in wL1 320 a ) wL1 320 a is checked to see if the load event can be fully satisfied by the dirty bytes present. If the data is found in wL1, 320 a , the load event (read) is completed and method 400 proceeds to step 415 .
At step 425 , if the data is not found in rL1 370 a (a miss), and the write-only, cache-present bit is clear, method 400 proceeds to step 427 . Also, if a L2 memory hierarchy is not present, method 400 proceeds to step 430 .
At step 425 , when there is a partial hit in wL1 320 a , for example, the write-only, cache-present bit is set, some of the data is found in wL1 320 a , and a Level-2 memory hierarchy is not present, the dirty bytes are written through from wL1 320 a to main memory 150 (not shown). Method 400 proceeds to step 430 .
At step 425 , if the data is partially found in wL1 320 a , the dirty data in wL1 320 a is written to wL2 340 . The read request is sent to the next level of the memory hierarchy to L2 cache hierarchy. Method 400 proceeds to step 427 . As noted earlier, a partial hit is an infrequent occurrence due to the low number of RAW operations.
At step 427 , method 400 looks for the data, or the remaining data in the case of a partial hit, in rL2 380 ; if the data or the remaining data is found in rL2 380 (a hit), and the write-only, cache-present bit is clear, the data is read from rL2 380 and method 400 returns to step 415 to await another memory event.
At step 427 , if the data is not found in rL2 380 (a miss) and the write-only, cache-present bit is clear, method 400 proceeds to step 430 .
At step 427 , when the write-only, cache-present bit is set, (i.e., dirty data for the cache line is present in wL2 340 ) wL2 340 is checked to see if the load event can be fully satisfied by the dirty bytes present. If the data is found in wL2 340 , the read is completed and method 400 proceeds to step 415 .
At step 427 , when the write-only, cache-present bit is set and the data is partially found and read from wL2 340 (a partial hit), the dirty data in wL2 340 is written to main memory 150 . Data at rL1 370 a and rL1 370 b with that address are invalidated, and method 400 proceeds to stop 430 .
At step 430 , the data is read from main memory 150 . Method 400 proceeds to step 415 .
In an embodiment, DRBs are implemented at corresponding levels of the memory hierarchy. Method 400 begins at step 410 and proceeds to step 415 .
When a load event is received, at step 420 , method 400 looks for the address of the data in parallel in rL1 370 a and DRB1 375 a . Method 400 proceeds to step 425 .
At step 425 , if the data is found in rL1 370 a (a hit), and not in DRB1 375 a , the data is read and method 400 returns to step 415 to await another memory event.
At step 425 , when the address is found in DRB1 375 a , (i.e., dirty data for the cache line is present in wL1 320 a ) DRB1 375 a is checked to see if the load event can be fully satisfied by the dirty bytes present. If the data is found in DRB1 375 a , the load event (read) is completed and method 400 proceeds to step 415 .
At step 425 , if the data is not found in rL1 370 a (a miss), or DRB1 375 a , method 400 proceeds to step 427 . Also, if a L2 memory hierarchy is not present, method 400 proceeds to step 430 .
At step 425 , when there is a partial hit in DRB1 375 a , for example, some of the data is found in DRB1 375 a , and a Level-2 memory hierarchy is not present, the dirty bytes are written through from wL1 320 a to main memory 150 (not shown). Method 400 proceeds to step 430 .
At step 425 , if the data is partially found in DRB1 375 a (a partial hit), the dirty data in wL1 320 a is written to wL2 340 . The read request is sent to the next level of the memory hierarchy to L2 cache hierarchy. Method 400 proceeds to step 427 .
At step 427 , method 400 looks for the data, or the remaining data in the case of a partial hit, in parallel in rL2 380 and DRB2 385 ; if the data or the remaining data is found in rL2 380 (a hit), but not in DRB2 385 , the data is read from rL2 380 and method 400 returns to step 415 to await another memory event.
At step 427 , if the data is not found in rL2 380 (a miss) or DRB2 385 , or if L2 memory hierarchy is not present, method 400 proceeds to step 430 .
At step 427 , the address is found in DRB2 385 (i.e., dirty data for the cache line is present in wL2 340 ) DRB2 385 is checked to see if the load event can be fully satisfied by the dirty bytes present. If the data is found in DRB2 385 , the read is completed and method 400 proceeds to step 415 .
At step 427 , when the address is found in DRB2 385 and the data is partially found and read from DRB2 385 (a partial hit), the dirty data in wL2 340 is written to main memory 150 . Data at rL1 370 a and rL1 370 b with that address are invalidated, and method 400 proceeds to stop 430 .
At step 430 , the data is read from main memory 150 . Method 400 proceeds to step 415 .
When a store event is received at step 415 , method 400 proceeds to step 435 .
At step 435 , method 400 writes the data affiliated with an address to wL1 320 a and the data is called dirty data as it is not the same as the memory location at the same address in main memory 150 . The dirty byte bitmask of wL1 320 a is updated to indicate the dirty bytes of cache line associated with the address. In addition, method 400 checks to see if the address is found in rL1 370 a . When the address is found in rL1 370 a , method 400 sets a flag of a cache tag, to indicate that updated data is in the wL1 320 a (e.g., sets the write-only, cache-present bit in the rL1 370 a ). The store operation completes immediately.
In an embodiment, when a DRB is implemented, e.g., DRB1 375 a , the dirty byte bitmask of DRB1 375 a would be updated. In an embodiment, the write-only, cache-present bit would not be needed in rL1 370 a as the read to rL1 370 a can occur in parallel as a read to DRB1 375 a.
While the DRB example is not propagated throughout the rest of the specification, one skilled in the art can readily understand how a DRB could be implemented accordingly.
At step 440 , a store entry is written to L1 pool 350 a that can include but is not limited to the address location in main memory 150 to which the data is to be written, and a thread identity. A thread is a work item involved with the current instruction execution that includes the store event. The L1 pool 350 a maintains a partial order among the store entry, any prior received store entries that may exist, and any release marker entries.
In an example, two groups of prior store entries may exist in L1 pool 350 a that are separated by a release marker described below. While no particular order within a group of prior store entries exists, the first group of prior store entries is ordered to be evicted before the release marker, and the second group is ordered to be evicted after the release marker. Thus there is partial order in the pool.
The store entry is written in L1 pool 350 a to follow the most-recent release marker. In the example, the store entry would be added to the second group of existing prior store entries in no particular order.
Method 400 proceeds to step 415 .
When a release synchronization event such as a release, a StRel, a fence, a kernel end, or a barrier operation is received at step 415 , method 400 proceeds to step 445 . A release marker is written to L1 pool 350 a and ordered to follow any prior write entries in L1 pool 350 a . The entry of the release marker in L1 pool 350 a triggers eviction of any prior write entries from the L1 pool 350 a . Thus, the release marker will be evicted after the prior entries in L1 pool 350 a to ensure proper visibility of prior writes.
At step 450 , if the release synchronization event is a StRel, method 400 proceeds to step 455 . At step 455 , method 400 writes data associated with the store event portion of the StRel to wL1 320 a . At step 460 , a corresponding store entry associated with the store event portion of the StRel is made to L1 pool 350 a and ordered to follow the most-recent release marker. The store entry includes an address location in main memory 150 to which the data is to be written, and a thread identity, for example. Method 400 checks to see if the address is found in rL1 370 a . When the address is found in rL1 370 a , method 400 sets the write-only, cache-present bit in the rL1 370 a ; the write-only, cache-present bit may be a bit or a flag in for example, a cache tag, that indicates that updated data is in the wL1 320 a . The method proceeds to step 415 .
At step 450 , if the release synchronization event is not a StRel, method 400 proceeds to step 415 .
FIG. 5 illustrates a method of evicting entries, according to an embodiment. In one example, system 100 and system 300 may be used to demonstrate method 500 . It is to be appreciated that operations in method 500 may be performed in a different order than shown, and method 500 may not include all operations shown. For ease of discussion, and without limitation, method 500 will be described in terms of elements shown in FIG. 1 and FIG. 3 .
Method 500 depicts the flow of operations when evictions from a pool occur. Evictions can occur, for example, when the number of entries in a pool exceeds a settable maximum value, or when a release marker is added to the pool and triggers prior write evictions. Method 500 includes operations at the L1 pool 350 a and L2 pool 360 , for example.
Method 500 begins at step 510 and proceeds to step 515 .
At step 515 , method 500 proceeds to step 520 to depict L1 pool 350 a eviction operations.
At step 520 , method 500 determines whether L1 pool 350 a evicts a store entry or a release marker entry.
If a release marker is present in L1 pool 350 a and no prior writes exist ahead of the release marker entry, method 500 determines to evict a release marker entry and proceeds to step 525 .
At step 525 , the release marker is evicted from L1 pool 350 a to L2 pool 360 . The release marker is ordered to follow any prior store entries in L2 pool 360 . The addition of the release marker triggers evictions of any prior store entries from L2 pool 360 , before the eviction of the release marker from L2 pool 360 . When a L2 memory hierarchy is not present, the release marker is evicted from L1 pool 350 a , and an acknowledgement is sent to the originating thread that the release is complete.
Method 500 proceeds to step 545 .
At step 520 , if a release marker is present in L1 pool 350 a , the prior store entries in L1 pool 350 a ahead of the release marker are determined to be evicted to a L2 pool 360 , and corresponding data in wL1 320 a are correspondingly evicted to wL2 340 . The prior store entries can be evicted in any order with respect to prior store entries. But, prior store entries and corresponding data in wL1 320 a are evicted before the oldest release marker is evicted. Thus, the written data is guaranteed to be at the next level of the hierarchy by the time the release marker is evicted.
At step 520 , if L1 pool 350 a is determined to evict a store entry, method 500 proceeds to step 530 .
At step 530 , method 500 determines if the corresponding data exists in the wL1 320 a . If the corresponding data does not exist, method 500 proceeds to step 535 . At step 535 , a cache replacement policy as is well known in the art, may be enforced and previously evicted the data from wL1 320 a ; the store entry in L1 pool 350 a is evicted to L2 pool 360 . In addition, a special case of a load event with a partial hit may also cause an early data eviction. Thus, embodiments support early evictions from the memory hierarchy. Method 500 proceeds to step 545 .
At step 530 , if the corresponding data does exist in the wL1 320 a , method 500 proceeds to step 540 .
At step 540 , the store entry in L1 pool 350 a is evicted to L2 pool 360 . In addition, the corresponding data in L1 cache 320 a is evicted to wL2 340 .
When a L2 cache hierarchy is not present (not shown), embodiments include the following: evicting the prior store entry from the L1 pool 350 a ; evicting data, when present, from the wL1 320 a associated with the evicted prior store entry to main memory; when the evicted prior store entry is associated with a StRel release synchronization event, signaling completion of release to the originating thread.
When a L2 cache hierarchy is present and the L2 cache hierarchy is an ordering point (not shown), embodiments further include the following: evicting the prior store entry from L1 pool 350 a ; evicting data, when present, from the wL1 320 a associated with the evicted prior store entry to the ordering point; when the evicted prior store entry is associated with a StRel release synchronization event, signaling completion of release to the originating thread. Thus, a StRel can complete at an ordering point other than main memory, and local synchronization is possible (e.g., receipt of a LdAcq can complete at wL2 340 without having to access main memory 150 ). Note that main memory 150 can also be an ordering point and would be a global ordering point.
Method 500 proceeds to step 545 .
At step 515 , method 500 proceeds to step 545 to depict L2 pool 360 eviction operations.
At step 545 , method 500 determines whether L2 pool 360 evicts a store entry or a release marker entry. Evictions may occur when a release marker entry is added to L2 pool 360 that triggers evictions, or when the number of L2 pool 360 entries exceeds a configurable threshold, for example. If L2 pool 360 evicts a release marker entry, method 500 proceeds to step 550 .
At step 550 , the release marker is evicted from L2 pool 360 . In addition, method 500 transmits an acknowledgment to the originating thread or original requester, CU 310 a , that the release event is complete. The release completion provides assurance that safe forward progress is possible beyond the release synchronization event.
Note that for a StRel release synchronization event, CU 310 a does not need to wait for the acknowledgement, but rather CU 310 a can continue processing other memory events until executing the next LdAcq. But, for barrier and fence release synchronization events, CU 310 a waits until a corresponding acknowledgement is received. Further, additional embodiments enable unsynchronized stores, if allowed by the memory model. These unsynchronized stores would not generate a store entry in L1 Pool 350 a , rather, corresponding data could be written to wL1 320 a . Thus, unsynchronized stores would not load pool components with unnecessary operations.
The method proceeds to step 565 .
At step 545 , if L2 pool 360 evicts a store entry, method 500 proceeds to step 555 .
At step 555 , method 500 determines if the corresponding data exists in the wL2 340 . If the corresponding data does not exist, (e.g., due to a cache replacement policy enforcement) the store entry is evicted from L2 pool 360 and method 500 proceeds to step 565 .
At step 555 , if the corresponding data does exist, method 500 proceeds to step 560 .
At step 560 , the store entry is evicted from L2 pool 360 . In addition, the corresponding data in wL2 340 is evicted to main memory 150 . Further, if the data was from a store event portion of a StRel, method 500 signals completion of release to the originating thread.
Embodiments invalidate the data in rL1 370 a and rL1 370 b associated with the corresponding address. The invalidations may be completed by broadcasting invalidation messages to rL1 370 a and rL1 370 b caches, to ensure release consistency. The invalidations are not critical to performance as the invalidations merely delay release synchronization completions and are bound based on the number of entries in L2 pool 360 when a release synchronization event occurs. Note that write evictions and load requests do not stall waiting for invalidations. In addition, the data in rL1 370 a and rL1 370 b can be invalidated with a flash clear, e.g., when a LdAcq is received, all blocks in the cache are invalidated. The flash clear does not need to be associated with the corresponding address.
Method 500 proceeds to step 565 .
Logically, L1 pool 350 a , L1 pool 320 b , and L2 pool 360 may be implemented per thread identity or group of threads (e.g., wavefront identity).
FIG. 6 illustrates a method of handing memory synchronization events, according to an embodiment. In one example, system 100 and system 300 may be used to demonstrate method 600 . It is to be appreciated that operations in method 600 may be performed in a different order than shown, and method 600 may not include all operations shown. For ease of discussion, and without limitation, method 600 will be described in terms of elements shown in FIG. 1 and FIG. 3 .
The top portion of FIG. 6 includes an execution order of two threads, one from compute unit CU 310 a and another from CU 310 b , communicating a value in a simple system that contains one level of cache including wL1 320 a and wL1 320 b . The lower portion of FIG. 6 illustrates method 600 .
Method 600 begins at step 601 when CU 310 a issues a store event, ST X (1), and writes data, 1, to a cache block in a cache line of wL1 320 a , associated with address X in main memory 150 . In addition, a store entry is added to L1 pool 350 a that can include but is not limited to the address, X, associated with the data and a thread identity. If prior store entries are present, the new store entry is added to the group of prior store entries and no particular order is maintained. However, if a release marker is present, the new store entry would be ordered to follow the most-recent release marker. If prior store entries are present after the most-recent release marker, the new store entry would join that group and no particular order is maintained among the prior store entries.
At step 602 , CU 310 a issues a StRel synchronization event that triggers pool evictions through the memory hierarchy to main memory 150 . A release marker (Rel) entry is added to L1 pool 350 a , and is ordered to follow any prior store entries in L1 pool 350 a , to be evicted after the prior write entries in L1 pool 350 a are evicted.
At step 603 , L1 pool 350 a begins evicting prior write entries ordered before the release marker (Rel). The entry associated with address X is evicted from L1 pool 350 a , and the corresponding data in the cache in wL1 320 a associated with address X is evicted to main memory 150 .
At step 604 , the prior write entries have been evicted from L1 pool 350 a , the release marker (Rel) is evicted from L1 pool 350 a and an acknowledgement is sent to CU 310 a to signal that the release event portion of the StRel is complete.
At step 605 , CU 310 a issues the store event portion of the StRel synchronization event and writes data, 2, to a cache in wL1 320 a associated with address A. In addition, a L1 pool 350 a store entry is added that may include but is not limited to the address, A, associated with the cached data, and a thread identity. In an embodiment, an entry of the store event portion of a StRel to L1 pool 350 a will trigger L1 pool 350 a evictions.
At step 606 , the prior write associated with address A is eventually evicted from L1 pool 350 a (e.g., if the number of pool entries exceed a settable maximum value (not shown) or another release synchronization event occurs (not shown)). When the entry associated with address A is evicted from L1 pool 350 a , the data associated with address A in wL1 320 a is evicted to main memory 150 and signals completion of the release event portion of the StRel synchronization event to other threads in the system. The data at address A in main memory 150 is now visible to all threads in the system.
At step 607 , CU 310 b issues a load acquire LdAcq synchronization event to complete the synchronization. Method 600 searches wL1 320 b , to read the data at address A, and when the address A is not found (a miss), method 600 searches main memory 150 . When the address A and corresponding data, 2, are found and read from main memory 150 (a hit), the data is copied (i.e., loaded) to wL1 320 b and is transmitted to (i.e., read by) CU 310 b.
At step 608 , CU 310 b issues a load event and searches wL1 320 b , to read the data at address X, and when the address X is not found (a miss), method 600 searches main memory 150 . When the address X and corresponding data, 1, are found and read from main memory 150 (a hit), the data is copied to wL1 320 b and is read by CU 310 b.
In an embodiment, a pool can be implemented with a synchronization First In First Out (S-FIFO) that maintains complete order for prior writes as well as a release synchronization event. For example, at step 601 , when a store event occurs, an entry would be made to the tail of an S-FIFO that can include but is not limited to the address, X, associated with the data and a thread identity. If prior writes are present, the new L1 pool 350 a store entry would be added to the tail of the queue and complete order is maintained among the prior writes as well as the release synchronization events.
When the S-FIFO is filled, method 600 would begin to dequeue the S-FIFO. The dequeuing is similar to a pool component exceeding a settable maximum value. The entry at the top of the S-FIFO and the corresponding cache in the wL1 320 a would be evicted to the corresponding next-level S-FIFO and next-level cache, e.g. wL2 340 if present. If the next-level cache is not present, the entry at the top of the S-FIFO is removed (e.g., popped) and the corresponding data in wL1 320 a is written to main memory 150 .
Logically there can be a S-FIFO per thread, but physically the S-FIFO can be implemented as a single FIFO, or as many FIFOs that are partitioned based on thread identity or a group of thread identities. Thus the physical implementation can balance space versus performance concerns. In addition, it is submitted that it is within the knowledge of one skilled in the art to understand that the S-FIFO can also be implemented in an architecture that includes a read-write cache rather than separate read and write caches.
FIG. 7 illustrates a method of evicting entries, according to an embodiment. In one example, system 100 and system 300 may be used to demonstrate method 700 . It is to be appreciated that operations in method 700 may be performed in a different order than shown, and method 700 may not include all operations shown. For ease of discussion, and without limitation, method 700 will be described in terms of elements shown in FIG. 1 and FIG. 3 .
Method 700 depicts the flow of operations when evictions from a queue such as a First In First Out (FIFO) instead of a pool occur. Evictions can occur, for example, when the number of entries in the FIFO exceeds the size of the FIFO and the entry at the head of the FIFO is popped off the FIFO, or when a release marker is added to the tail of the FIFO and triggers prior write evictions. Method 700 includes operations at a L1 FIFO and L2 FIFO (not shown), for example.
Method 700 begins at step 710 and proceeds to step 715 .
At step 715 , method 700 proceeds to step 720 to depict L1 FIFO eviction operations.
At step 720 , method 700 determines whether L1 FIFO evicts a store entry or a release marker entry.
When a release marker is present in L1 FIFO and no prior writes exist ahead of the release marker entry, method 700 evicts a release marker entry and proceeds to step 725 .
At step 725 , the release marker is evicted from the head of L1 FIFO to the tail of L2 FIFO. The addition of the release marker triggers evictions of any prior store entries from L2 FIFO until the release marker itself is evicted from the head of L2 FIFO. When a L2 cache 340 (and hence L2 FIFO) is not present, the release marker is evicted from L1 FIFO, and an acknowledgement is sent to the originating thread that the release is complete.
Method 700 proceeds to step 745 .
At step 720 , if a release marker is present in L1 FIFO, the prior store entries in L1 FIFO ahead of the release marker are evicted in turn, to a L2 FIFO, and corresponding data in wL1 320 a are correspondingly evicted to wL2 340 . The prior store entries are evicted in the order of placement in L1 FIFO. Thus, the written data is guaranteed to be at the next level of the hierarchy by the time the release marker is evicted.
At step 720 , if L1 FIFO evicts a store entry, method 700 proceeds to step 730 .
At step 730 , method 700 determines if the corresponding data exists in the wL1 320 a . When the corresponding data does not exist, method 700 proceeds to step 735 . At step 735 , a cache replacement policy as is well known in the art, may be enforced and previously evicted the data from wL1 320 a ; the store entry at the head of L1 FIFO is evicted to the tail of L2 FIFO. Thus, embodiments support early evictions from the memory hierarchy.
Method 700 proceeds to step 745 .
At step 730 , if the corresponding data does exist in the wL1 320 a , method 700 proceeds to step 740 .
At step 740 , the store entry at the head of L1 FIFO is evicted to the tail of L2 FIFO. In addition, the corresponding data in wL1 320 a is evicted to wL2 340 .
When a L2 cache hierarchy is not present (not shown), embodiments include the following: evicting the prior store entry from the head of L1 FIFO; evicting data, when present, from the wL1 320 a associated with the evicted prior store entry to main memory; when the evicted prior store entry is associated with a StRel release synchronization event, signaling completion of release to the originating.
When a L2 cache hierarchy is present and the L2 cache hierarchy is an ordering point (not shown), embodiments further include the following: evicting the prior store entry from L1 FIFO; evicting data, when present, from the wL1 320 a associated with the evicted prior store entry to the ordering point; when the evicted prior store entry is associated with a StRel release synchronization event, signaling completion of release to the originating thread. Thus, a StRel can complete at an ordering point other than main memory, and local synchronization is possible (e.g., receipt of a LdAcq can complete at wL2 340 without having to access main memory 150 ). Note that main memory can also be an ordering point and would be a global ordering point.
Method 700 proceeds to step 745 .
At step 715 , method 700 proceeds to step 745 to depict L2 FIFO eviction operations.
At step 745 , method 700 determines whether L2 FIFO evicts a store entry or a release marker entry. Evictions may occur when a release marker entry is added to the tail of L2 FIFO that triggers evictions, or when the number of L2 FIFO entries exceeds a configurable threshold, for example. If L2 FIFO determines to evict a release marker entry, method 700 proceeds to step 750 .
At step 750 , the release marker is evicted from L2 FIFO. In addition, method 700 transmits an acknowledgment to the originating thread or original requester, CU 310 a , that the release event is complete. The release completion provides assurance that safe forward progress is possible beyond the release synchronization event.
Note that for a StRel release synchronization event, CU 310 a does not need to wait for the acknowledgement, but rather CU 310 a can continue processing other memory events until executing the next LdAcq. But, for barrier and fence release synchronization events, CU 310 a waits until a corresponding acknowledgement is received. Further, additional embodiments enable unsynchronized stores, if allowed by the memory model. These unsynchronized stores would not generate a store entry in L1 FIFO, rather, corresponding data could be written to wL1 320 a . Thus, unsynchronized stores would not load pool components with unnecessary operations.
The method proceeds to step 765 .
At step 745 , if L2 FIFO determines to evict a store entry, method 700 proceeds to step 755 .
At step 755 , method 700 determines if the corresponding data exists in wL2 340 . If the corresponding data does not exist, (e.g., due to a cache replacement policy enforcement) the store entry is evicted from the head of L2 FIFO and method 700 proceeds to step 765 .
At step 755 , when the corresponding data does exist, method 700 proceeds to step 760 .
At step 760 , the store entry is evicted from the head of L2 FIFO. In addition, the corresponding data in wL2 340 is evicted to main memory 150 . Further, if the data was from a store event portion of a StRel, method 700 signals completion of release to the originating thread.
Embodiments invalidate the data in rL1 caches 370 a and 370 b associated with the corresponding address. The invalidations may be completed by broadcasting invalidation messages to the L1 read-only caches, rL1 cache 370 a and rL1 370 b , to ensure release consistency. The invalidations are not critical to performance as the invalidations simply delay release synchronization completions and are bound based on the number of entries in L2 FIFO when a release synchronization event occurs. Note that write evictions and load requests do not stall waiting for invalidations. In addition, the data in rL1 370 a and rL1 370 b can be invalidated with a flash clear, e.g., when a LdAcq is received, all blocks in the cache are invalidated. The flash clear does not need to be associated with the corresponding address.
Method 700 proceeds to step 765 .
Logically, L1 FIFO and L2 FIFO may be implemented per thread identity or group of threads (e.g., wavefront identity).
In another embodiment, a pool of entries can be implemented with a Bloom-filter with a set of entries. A Bloom filter is an inexact representation of a set of elements. Bloom filters are implemented with an array of bits, and that array is indexed through two or more hash functions. To insert an element in the Bloom filter, the element is hashed and corresponding bits are set. To test membership, the element is hashed and corresponding bits are checked. If all bits are set (e.g., to “1”), the element may be in the set. If any one of the bits is cleared (e.g., to “0”), the element is not in the set. Unlike a mathematical set, Bloom filters have no remove function (though a variant called a counting bloom filter does). A signature is a representation of a set of elements. The pool can be implemented with a Bloom filter, an exact list (and/or array), or a FIFO, for example.
In summary, a prior store event is guaranteed to be ordered in the memory hierarchy whenever the store event has been evicted from a pool, dequeued from a FIFO, or tested for membership in a set using a Bloom-filter.
Various aspects of the disclosure can be implemented by software, firmware, hardware, or a combination thereof. FIG. 8 illustrates an example computer system 800 in which some embodiments, or portions thereof, can be implemented as computer-readable code. For example, the methods 400 - 700 , of FIGS. 4 through 7 can be implemented in system 800 . Various embodiments are described in terms of the example computer system 800 . After reading this description, it will become apparent to a person skilled in the relevant art how to implement the embodiments using other computer systems and/or computer architectures.
Computer system 800 includes one or more processors, such as processor 804 . Processor 804 can be a special purpose or a general purpose processor. Examples of processor 804 are CPU 110 and GPU 130 of FIG. 1 , or a GPGPU, or APU as described earlier. Processor 804 is connected to a communication infrastructure 806 (for example, a bus or network) such as bus 140 of FIG. 1 .
Computer system 800 also includes a main memory 808 , such as random access memory (RAM) such as main memory 150 of FIG. 1 , and may also include a secondary memory 810 . Secondary memory 810 may include, for example, a hard disk drive 812 , a removable storage drive 814 , and/or a memory stick. Removable storage drive 814 may comprise a floppy disk drive, a magnetic tape drive, an optical disk drive, a flash memory, or the like. The removable storage drive 814 reads from and/or writes to a removable storage unit 818 in a well-known manner. Removable storage unit 818 may comprise a floppy disk, magnetic tape, optical disk, etc. that is read by and written to by removable storage drive 814 . As will be appreciated by persons skilled in the relevant art(s), removable storage unit 818 includes a computer usable storage medium having stored therein computer software and/or data.
In alternative implementations, secondary memory 810 may include other similar means for allowing computer programs or other instructions to be loaded into computer system 800 . Such means may include, for example, a removable storage unit 822 and an interface 820 . Examples of such means may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM, or PROM) and associated socket, and other removable storage units 822 and interfaces 820 that allow software and data to be transferred from the removable storage unit 822 to computer system 800 .
Computer system 800 may also include a communications interface 824 . Communications interface 824 allows software and data to be transferred between computer system 800 and external devices. Communications interface 824 may include a modem, a network interface (such as an Ethernet card), a communications port, a PCMCIA slot and card, or the like. Software and data transferred via communications interface 824 are in the form of signals that may be electronic, electromagnetic, optical, or other signals capable of being received by communications interface 824 . These signals are provided to communications interface 824 via a communications path 826 . Communications path 826 carries signals and may be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, an RF link or other communications channels.
In this document, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as removable storage unit 818 , removable storage unit 822 , and a hard disk installed in hard disk drive 812 . Signals carried over communications path 826 can also embody the logic described herein. Computer program medium and computer usable medium can also refer to memories, such as main memory 808 and secondary memory 810 , which can be memory semiconductors (e.g. DRAMs, etc.). These computer program products are means for providing software to computer system 800 .
Computer programs (also called computer control logic) are stored in main memory 808 and/or secondary memory 810 . Computer programs may also be received via communications interface 824 . Such computer programs, when executed, enable computer system 800 to implement the embodiments as discussed herein. In particular, the computer programs, when executed, enable processor 804 to implement the disclosed processes, such as the steps in the methods 400 - 700 of FIGS. 4-7 as discussed above. Accordingly, such computer programs represent controllers of the computer system 800 . Where the embodiments are implemented using software, the software may be stored in a computer program product and loaded into computer system 800 using removable storage drive 814 , interface 820 , hard drive 812 or communications interface 827 . This can be accomplished, for example, through the use of general-programming languages (such as C or C++). The computer program code can be disposed in any known computer-readable medium including semiconductor, magnetic disk, or optical disk (such as, CD-ROM, DVD-ROM). As such, the code can be transmitted over communication networks including the Internet and internets. It is understood that the functions accomplished and/or structure provided by the systems and techniques described above can be represented in a core (such as a processing-unit core) that is embodied in program code and may be transformed to hardware as part of the production of integrated circuits. This can be accomplished, for example, through the use of hardware-description languages (HDL) including Verilog HDL, VHDL, Altera HDL (AHDL) and so on, or other available programming and/or schematic-capture tools (such as, circuit-capture tools).
Embodiments are also directed to computer program products comprising software stored on any computer useable medium. Such software, when executed in one or more data processing device, causes a data processing device(s) to operate as described herein. Embodiments employ any computer useable or readable medium, known now or in the future. Examples of computer useable mediums include, but are not limited to, primary storage devices (e.g., any type of random access memory), secondary storage devices (e.g., hard drives, floppy disks, CD ROMS, ZIP disks, tapes, magnetic storage devices, optical storage devices, MEMS, nanotechnological storage device, etc.), and communication mediums (e.g., wired and wireless communications networks, local area networks, wide area networks, intranets, etc.).
It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments as contemplated by the inventor(s), and thus, are not intended to limit the disclosure and the appended claims in any way.
The disclosure has been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be 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.
The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
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A method, computer program product, and system is described that enforces a release consistency with special accesses sequentially consistent (RCsc) memory model and executes release synchronization instructions such as a StRel event without tracking an outstanding store event through a memory hierarchy, while efficiently using bandwidth resources. What is also described is the decoupling of a store event from an ordering of the store event with respect to a RCsc memory model. The description also includes a set of hierarchical read-only cache and write-only combining buffers that coalesce stores from different parts of the system. In addition, a pool component maintains partial order of received store events and release synchronization events to avoid content addressable memory (CAM) structures, full cache flushes, as well as direct write-throughs to memory. The approach improves the performance of both global and local synchronization events and reduces overhead in maintaining write-only combining buffers.
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BACKGROUND OF THE INVENTION
This invention relates to an induction air handling unit, and in particular a nozzle design for an induction air handling unit.
When a gas is discharged from a duct or when it flows through a restriction in a duct, the momentum of the jet is dissipated through mixing with the downstream surroundings. A by-product of this process is the generation of noise which is radiated to the surroundings. It is well established that the sound power which is generated increases at approximately the eighth power of the jet velocity. The efficiency with which it is radiated into the far field of the surroundings depends strongly on both the rate and the scale of the mixing. For a turbulent jet of given mass flow emerging from an orifice of given cross-sectional area, the total sound power radiated decreases as the rate of mixing of the jet with the surroundings increases.
For many years it has been known that the theory of aerodynamic noise generation from turbulent shear flows advanced by Sir James Lighthill, and published in the Proceedings of The Royal Society of London, (On sound generated aerodynamically, Proc. Roy. Soc. A211, p.564, 1952--see also: Waves in fluids, Cambridge University Press, 1978) is incomplete in that it fails to yield reliable predictions of the noise generated by jets at low Mach number. The incompleteness of the Lighthill theoretical model is understandable when it is realised that it was devised before the discovery by G. L. Brown and A. Roshko (Journal of Fluid Mechanics, 64, 775-816, 1974) that the growth of the mixing layer, from which most of the noise emanates, is not continuous but is dominated by the formation of seemingly deterministic vortex-like structures of a scale which is comparable to or larger than the local thickness of the shear layer, and their non-deterministic, intermittent growth by a succession of "amalgamations" between themselves which appear to be little influenced by the turbulent shear layer which they wrap into their structures like jam into a Swiss roll. The magnitude of the disturbances in the flow is many times that which occurs in a simple turbulent shear flow and hence it is reasonable to surmise that these Brown-Roshko vortices may be generating much of the noise. Recent research by Professor N. W. M. Ko and his student Mr R. C. K. Leung at The University of Hong Kong, which has been submitted for publication in the Journal of Sound and Vibration, has advanced a new concept of the noise generation mechanism based on this surmise. The new concept derives from measurements of the processes by which successive Brown-Roshko vortex structures in the shear layer between the jet and the surroundings "pair" together causing the large scale folding, mixing and the intermittent expansion of the jet cross-section. Ko and Leung have found that if a vortex "ring" formed in the mixing layer at the edge of an axisymmetric jet is to "pair" with its predecessor, it must be accelerated rapidly by the pressure field of the leading vortex until it passes through the "eye" of that leading vortex. It is then rapidly retarded and the two vortices merge to become a single larger vortex. The process can be likened to an "extrusion" of the trailing vortex through the eye of the leading vortex. During this "extrusion" process the rates of change of the acceleration of the trailing vortex are very large. In the subject of Mechanics the rate of change of acceleration is known as the "jerk". It is expressed mathematically as the third derivative of distance with respect to time. (It will be recalled that the first derivative of distance with respect to time is the velocity and the second derivative is the acceleration. In solid mechanics it is well known that "jerk" is frequently accompanied by noise; the collision of two marbles and the tapping of a pencil on a table are typical examples). Associated with this extrusion process is a distortion of the shape of the trailing vortex from a nearly circular doughnut shape into a scalloped shape bearing similarities to the nozzle described herein.
The present invention relates to the design of nozzles which stimulate the rapid mixing of jets which discharge into either free or confined surroundings. Of particular interest is the discharge of conditioned air through nozzles for the purposes of cooling or heating a space. An example of this application which involves discharge into "free" surroundings is the "spot cooling" provided for passengers in aircraft. In this application the background noise level is such that the low level of noise achieved by the subject nozzle is of secondary importance compared with the feature of enhanced mixing with the air in the aircraft cabin. A high rate of mixing will allow the same degree of cooling with a smaller quantity of air supplied at a lower temperature than is used in present practice. This would both save energy and produce a more comfortable local cooling around the head and face of passengers without there being an aggressive draught. When applied to the main air conditioning outlets in the aircraft cabin the enhanced mixing and lower temperature of the supply air would also reduce the volume of air needed to cool the cabin when the aircraft is on the ground in a hot climate, or a higher temperature could be used to heat the aircraft when in flight or on the ground in a cold climate.
Other applications of a similar nature are the "spot" cooling or heating of the driver of, for example, an agricultural tractor, a fork lift truck, an excavator, a Load-Haul-Dump vehicle above or below ground, and a crane, among many others. The driver and passengers or crew of a bus, a heavy transport vehicle, a rail vehicle, an armoured military vehicle, an automobile or other transport vehicle would also benefit from the use of the present nozzles in the conditioned air supply system. Again, in these examples the background noise level is high and the low noise characteristic of the subject nozzle is of secondary interest relative to its ability to achieve rapid mixing of the primary air jet with the surroundings. This ability allows the conditioned air to be admitted close to the occupant of the vehicle without producing an undesirable level of draught. Other applications of the nozzles, in all of which excessive draught is undesirable and in most of which a low level of noise is desirable, are exemplified by "spot" cooling or heating of personal work spaces within a factory, an office, a space craft or a submarine, the cooling of electronic components or equipment, the cooling of processes and mechanisms.
An induction air conditioning system relies on the discharge through nozzles as jets of a first or primary stream of cooled and dehumidified, or heated and if necessary humidified air into a confined space within an induction air conditioning unit before discharging to the conditioned space, herein referred to as the room. One boundary of the confined space within the induction unit takes the form of heat exchange means through which a secondary stream of air, originating from the room, is drawn to replace the quantity of air from within said confined space which is entrained into the primary air jet or jets. This occurs naturally because the entrainment by the primary air jet or jets causes the static pressure in the confined space to be reduced below the pressure surrounding the induction unit. The psychrometric state of the secondary stream of air may be changed as it passes through the heat exchange means. The mixture of the primary air and the secondary air streams is then discharged into said conditioned space to provide the required cooling or heating and to provide ventilation.
In such induction air conditioning systems the primary air stream usually consists of air from outside the building often, but not necessarily, mixed with a proportion of air returned from the conditioned space. This primary air is treated in one or more primary air treatment plants before it is ducted to the induction units so that, after having been mixed with the induced secondary air stream within the induction air conditioning units, it is at the temperature and humidity ratio necessary to offset the sensible and latent heat loads in the conditioned space. When used in conjunction with the invention described in Australian Patent 662336 entitled Air conditioning for humid climates, which is now commonly referred to as the High Driving Potential, or HDP system, the primary air can be deeply cooled and dehumidified before being mixed with the entrained secondary air from the room. The efficient mixing produced by the jets from the multi-lobe nozzles will ensure that the air mixture which reaches the occupants is at the desired temperature and moisture content. The most common application of induction air conditioning systems is to condition the air in the space bounded by the building perimeter walls and an often imaginary line some 3 to 6 meters in from said perimeter walls on each level of the building.
The space so defined is referred to as the perimeter zone. A perimeter zone may be physically defined by partitioned offices or may be open space which merges with the interior zone of the building. A conventional air conditioning system usually feeds the whole of the treated air, at modest pressure, from a plant room or air supply shaft through ducts mounted above the ceiling, and thence to ceiling mounted supply air registers distributed throughout the space. Such supply air ducts, because they convey the whole of the conditioned supply air at low pressure, necessarily have relatively large cross-sections. In combination with the depth of the structural beams associated with the floor slab of the next level of the building, they set the required height of the ceiling space and therefore have a determining influence on the required slab-to-slab spacing. In many cities or parts of cities a height restriction is placed on buildings. Thus the size of the air conditioning ducts in the ceiling has a major influence on the number of levels or floors in the building, and hence on the rentable floor space.
Because perimeter induction units carry only primary treated air and do so at relatively high pressure, they are much smaller in cross-section than are the conventional supply air ducts. In one example in the city of Adelaide in South Australia, the use of an induction system to air condition the perimeter zones of the building allowed thirteen levels to be built within a height restriction appropriate to a conventional twelve story building.
The treated primary air streams in a perimeter induction system supply to the perimeter zone at least that quantity of pre-treated outdoor air which is required, by regulation or by best practice, to ventilate the zone. A common criterion used by designers is to require the primary air to offset heat which is transmitted through the perimeter walls and windows which bound the perimeter zone. The heat exchange means within the perimeter induction units which treat the induced secondary air are designed to offset all other loads which originate within the conditioned space of the perimeter zone including people, electrically powered devices, and lighting.
In addition to the abovementioned advantage of requiring less ceiling space than conventional air conditioning systems, induction systems require smaller and hence less expensive and less intrusive ducts to supply air from the primary air plant to each level of the building and to the conditioned space on each level. They do not require separate plant rooms which intrude into the potentially rentable space. Thus in terms of invested capital they are less expensive both to purchase and to install than are conventional air conditioning systems and they increase the proportion of the building which is counted as rentable space. Hence the return on investment can be larger than for conventionally serviced buildings. These advantages have in the past caused induction air conditioning systems to be preferred by many building owners and developers. Many such systems have been installed in buildings in many countries since the second world war.
Despite the apparent economic advantages of the system from the viewpoint of building developers, and from the viewpoint of building owners who pass on to their tenants the operating costs of the air conditioning, induction air conditioning systems have proved to be less than well received by tenants.
Because the induction units are located within the conditioned space, tenants are exposed to the noise generated by the primary air jets as they entrain the secondary air which is induced from the conditioned space to flow into the units through the heat exchange means. This noise has frequently been cause for complaint by tenants. Research by the Trane Company Inc (J. B. Custer, "The economics and marketing of tenant comfort", Proc. AIRAHFAIR-88, Sydney, AIRAH, 1988) has shown that discontent with the air conditioning, expressed through complaints about the operating cost, "staleness" of the air in the conditioned space, or the noise level, is one of the most common reasons reported by tenants for terminating a building lease. That research also showed that from the building owner's viewpoint, the cost of losing a tenant, finding and installing another is typically equivalent to approximately six months rental income from the leased space. Such losses can rapidly erode the advantage of the lower capital cost per unit of rentable area in the building.
A more important problem which magnifies tenant discontent is that in warmer climates the cooling capacity of that quantity of treated primary air which is required for ventilation is insufficient to offset the transmission load to the perimeter zone. Furthermore the quantity of secondary air which can be induced to flow through the secondary air heat exchange means by the jets supplying only ventilation air as the treated primary air is almost always inadequate to offset the internally generated load within the perimeter zone. Hence it has been necessary to increase the quantity of treated primary air both to offset the transmission load and to induce sufficient secondary air to flow through the secondary air heat exchange means to offset the loads generated within the perimeter zone. The increase of treated primary air is effected by increasing the pressure at which said primary air is supplied to the nozzles.
This increases the velocity at which the primary air is discharged from the nozzles. As indicated above, the noise generated by a jet is approximately proportional to the eighth power of its velocity.
Thus the increased cooling capacity is obtained at the direct cost of treating a greater quantity of hot and/or humid outdoor air. Another potential direct cost of the increased primary air pressure is tenant discontent due to the further increase in the noise radiated from the induction units into the conditioned space. For thirty years after the second world war the cost of energy remained low and operating costs were of small importance, thus the direct cost could be tolerated. That period was also one of rapid economic growth; office space was in short supply and hence tenants were unwilling to terminate a lease. Thus the inconvenience of the noise was tolerated. The very different economic climate of the 1990's with its surfeit of office space in many countries, higher cost of energy and growing concern about global warming has changed the situation substantially. Tenants find relocation both economically and environmentally attractive; owners find that while rental margins remain low and buildings are not fully occupied, operating costs are a serious concern.
To improve the occupational health of existing buildings equipped with induction air conditioning systems, and to improve their profitability for the owners of such buildings, it is an object of this invention to specify a nozzle and a means of profiling one or more of the boundaries of the confined space within existing induction air conditioning units in such manner that the interaction of the two will overcome the abovementioned problems. Similar principles are applicable also for new designs of induction air conditioning system and for the design of zone control boxes for conventional Variable Air Volume (VAV) systems.
It is a further object of the invention to specify a nozzle which can reduce the volume of noise generated at the outlet from a duct or at a change in the cross-section of a duct. More specifically, it is an object of the invention to increase the rate at which a primary air stream can induce a secondary air stream to flow through secondary air heat exchange means so to increase the effectiveness of induction air conditioning units and allow the velocity and hence the supply pressure of the primary air stream, and hence the noise generated by the jets, all to be reduced. As stated above, the noise generated by a jet is approximately proportional to the eighth power of the jet velocity. Hence it is apparent that a reduction in jet velocity can have a dramatic effect on the noise radiated from said induction air conditioning units or from VAV control boxes.
BRIEF SUMMARY OF THE INVENTION
In its broadest form, the invention is an induction air handling unit that uses a primary air flow to induce flow of secondary air through said air handling unit comprising,
an induction chamber having an air flow entrance and an air flow exit, and
a nozzle having an outlet located within said induction chamber, said nozzle being connected to a primary air flow that causes said secondary air flow to be induced through said induction chamber via said air flow entrance and out of said exit, said nozzle characterised by the edge forming said outlet having a scalloped shape.
Preferably, the nozzle design is used in conjunction with a profiled boundary or wall in a duct to promote both efficient mixing of a jet or jets of primary fluid with a surrounding fluid to form a mixture which diffuses into the surrounding medium, and a reduction in the volume of the noise which is generated during the mixing process. The profile of the nozzle at its outlet or exit plane is distorted to form a scalloped edge, preferably with five lobes in the case of an axisymmetric nozzle, or with a sinusoidal or rippled edge with a preferred spatial wavelength in the case of a nozzle which takes the form of a slot. Nozzles can be used solely or in groups to provide one or more streams of conditioned air with flow characteristics which cause the stream or streams to mix efficiently with surrounding air without creating an undesirable level of noise.
The volume of air which can be induced to flow from the surroundings into the induction unit via a heat exchange means is augmented relative to that achieved by existing induction system designs when use is made of a profiled wall, and the noise which is radiated into the occupied space within the building is simultaneously reduced.
The invention comprises at least one scalloped or multi-lobe nozzle, having any shape of the inlet cross-section which may be circular, rectangular or any other shape which then contracts smoothly to a scalloped or lobe-shaped outlet wherein the scalloping or lobes may take any convenient geometric form. The ratio of the perimeter length of said nozzle outlet to its outlet cross-sectional area is to be such as to achieve a higher than conventional rate of mixing between a primary stream of gas or liquid which emerges from said nozzle as a jet, and the surrounding gas or liquid within a confined or unconfined region into which it discharges; that is, to achieve a high rate of entrainment into the primary stream from the gas or liquid within said confined or unconfined space. In an induction air conditioning unit, the mixing and entrainment caused by the primary jet takes place within the confines of the induction unit. An increase in the rate at which said entrainment occurs is technically and commercially desirable, subject to manufacturing and cost constraints. The nozzle of the present invention has at least three and not more than ten lobes, but experiments by the inventors have shown that a five lobe nozzle provides an excellent result and it is now known that this configuration is compatible with new fundamental research on the form of distortion of a Brown-Roshko vortex which results in minimum noise generation when it amalgamates with a neighbour, as described above in relation to the work of Ko and Leung.
The preferred nozzle shape has a perimeter to cross-sectional area ratio which is equal to or greater than one point three times the perimeter to cross-sectional area ratio for a circle of the same area.
In some situations it is appropriate to use a linear or elongate slot-like nozzle rather than one which is disposed around the streamwise axis. If a square cross-section nozzle is employed, the ratio of the perimeter length to the cross-sectional area compared with that for a circular nozzle of the same cross-sectional area is 1.128, which is two divided by the square root of Pi. This same result applies for any rectangular cross-section. The effective perimeter to cross-sectional area of a generally linear/rectangular slot can be increased by scalloping the boundaries at the exit plane. For example, and without prejudice, for a slot with sinusoidal scalloping at its exit plane it is recommended that the peak-to-peak amplitude of the sinusoid divided by its wavelength should be between one and one point eight, with one point five being a preferred value. Again, a perimeter to outlet area ratio relative to that of an equivalent circular nozzle of the same cross-sectional area should be greater than one point three.
The location of said at least one nozzle in the induction air conditioning unit may be such as to allow the induction of secondary air from upstream, from downstream, or from both upstream and downstream relative to said location. The abovementioned increase in cooling capacity may be further increased by causing at least one boundary of the confined space within the induction unit to be formed to a profile which produces a minimum flow cross-section downstream from the location of said secondary air coil and preferably but not essentially also downstream from the location of said primary air nozzles. The throat so formed establishes the point of minimum pressure within the unit and from this point the mixture of the primary air and the induced secondary air diffuses toward the outlet from the unit to reach the pressure prevailing in the conditioned space. The greater the diffusion which can be achieved from the low pressure confined space within the unit to the prevailing pressure in the space into which the flow discharges, the lower will be the pressure within said confined space within the unit. The greater then will be the pressure difference across the secondary air coil. Hence the greater will be the quantity of air which can be induced to flow through said secondary air heat exchange means and so the greater will be the entrainment ratio and hence the cooling capacity of both the secondary air heat exchange means and the total capacity of the whole induction unit. The profiled boundary, and indeed other surfaces within the induction unit, can with advantage be designed and manufactured in a manner which can absorb and dissipate, through viscous damping, part of the noise which is incident upon them.
The contraction of said walls to a throat followed by their expansion as they approach the outlet from the unit generates the well known Venturi effect. The novelty of the use of the at least one profiled wall in the present invention is its use in conjunction with said primary air nozzles. By aligning the at least one profiled wall at the throat of the Venturi with the jet or jets from the primary air nozzle(s) a wall jet effect is created. A wall jet is a jet which flows tangentially to a boundary and thereby helps the boundary layer to maintain sufficient momentum to remain attached to the surface when it is moving into a region of rising static pressure. The wall jet effect also "captures" the jet so it continues to follow the wall as it diverges downstream from the throat. Such an arrangement allows the included angle between the diverging walls leading from the throat to the discharge plane to be increased without the flow separating from said diverging walls, and so achieving the degree of diffusion desired to maintain the low pressure within the unit. Where both walls contract towards and then diverge from said throat, each alternate jet from a line of nozzles can be aligned to cause a wall jet to form on each of the walls. By this combination of means the induction ratio and cooling capacity of the unit can be enhanced considerably and the exit velocity of the air leaving the unit can be kept low, so avoiding the creation of secondary noise such as the rattling of a vane in a supply air grille.
In addition to the improved entrainment and diffusion, the presence of at least one perforated profiled wall built with or without acoustically advantageous backing materials, causes a further reduction in the noise radiated from the induction unit over and above that achieved by the new nozzles alone (D. A. Bies, C. H. Hansen & G. E. Bridges, "Sound attenuation in rectangular and circular cross-section ducts with flow and bulk reacting liner", Jnl. of Sound & Vibration, 146, 1, pp 47-80, 1991).
In induction units where the secondary heat exchange means is located upstream from the primary air nozzles, the profiled side wall may be located between the secondary air heat exchange means and the primary air nozzles immediately upstream from the primary air nozzles. Such a profiled side wall must be designed, according to well established fluid dynamic principles, to inhibit closed-loop recirculations of the entrained secondary air which have been evident within the confined space in the units of this type which have been tested. Elimination of these recirculations increases the quantity of the secondary air which can be entrained through the secondary air heat exchange means. In conjunction with the upstream profiled side wall discussed above, at least one additional profiled side wall may be located downstream from the primary air nozzles.
Profiled side walls may be manufactured from suitably chosen, conventional sheet metal, or they may be formed from a perforated sheet metal plate with an area of perforation not exceeding 25% of a total area of the plate. The void behind the perforated profiled side wall may usefully be filled with a porous material chosen according to the principles established by D. A. Bies and published in the book by D. A. Bies and C. H. Hansen entitled, "Engineering Noise Control", Unwin-Hyman, London, 1988, to attenuate further the noise radiated from the unit. The density of the porous material should be at least 20 kg/m 3 and not greater than 50 kg/m 3 . To minimise the possibility of particles of said porous material being discharged into the conditioned space it should be wrapped in a light, porous material such as nylon. A gap of at least five millimeters is necessary between the inside surface of the perforated profiled side wall and the outer wrapping of the porous material to obtain effective noise attenuation.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described in more detail by reference to a particular embodiment. The wall shape of the nozzle according to this embodiment was generated with the aid of a Computational Fluid Dynamics (CFD) software package to minimise the pressure drop across the nozzle. Design of the internal surface profile of the nozzle for manufacturing was generated by computer analysis. The profiled wall was designed, using the same CFD package as for the nozzle, to maximise the wall jet and venturi effects and hence to maximise, for the prescribed primary air flow rate, the induction of secondary air through the heat exchange means, in this case a chilled water tube and plate fin heat exchanger, into the induction air conditioning unit.
The embodiment described here and illustrated in the accompanying figures in which:
FIG. 1 shows a perspective view of a first multi-lobe nozzle,
FIG. 2 shows a perspective view of a second multi-lobe nozzle,
FIG. 3 shows a cross-sectional view of a prior art induction air handling unit,
FIG. 4 shows a cross-sectional view of an induction air handling unit according to the present invention,
FIG. 5 shows a perspective view of an induction air handling unit with a pair of elongate slot-like nozzles, and
FIG. 6 shows a plan view of an outlet of an elongate slot-like nozzle.
FIG. 1 and 2 illustrate two variations of a nozzle 10 that are both subject of this invention. Each nozzle 10 comprises a lead-in portion 11 and a nozzle exit or outlet 12. The lead-in portion 11 is gradually shaped from a circular entrance to match the outlet shape 12 of the nozzle 10.
As shown in FIG. 1 and FIG. 2, each outlet 12 has a scalloped edge, which in this embodiment comprises five lobes 14 that are radially spaced around a central axis. Each outlet edge 15 is axisymmetric about this central axis. Therefore, the lobes 14 can be said to be generally arranged on a circular path. In addition to the lobes 14, the edge 15 comprises curved connecting sections between each pair of adjacent lobes 14. The embodiment shown in FIG. 1 and FIG. 2 uses five lobes 14.
FIG. 2 shows a moulded nozzle 10. FIG. 3 shows a pressed version. FIG. 1 illustrates the indicative shape of the internal surfaces of the nozzle 10 illustrated in FIG. 3.
FIG. 3 shows a typical induction air handling unit 20. It comprises an induction chamber 21 that normally comprises a series of sheet metal walls. There is an inlet 22, and an exit 23 the nozzle 10 is connected to a primary air source, and directs the primary air source into the chamber 21. The movement of the primary air source within the induction chamber 20 cause a secondary air flow resulting in air movement from the inlet 22 to the exit 23.
An embodiment according to this invention is illustrated in FIG. 4 in which a profiled wall 25 has been incorporated. The profiled wall 25 is positioned between the nozzle 10 and the exit 23 and is shaped so as to produce a venturi effect between the profiled wall and the remaining chamber walls 21. Where possible the jet from nozzle 10 may be aligned with the crest of profiled wall 25 to assist the diffusion of the flow as it approaches exit 23.
FIG. 5 illustrates the use of the nozzle comprising an elongate slot-like aperture 28. In this embodiment, a pair of such nozzles 28 are used. FIG. 6 shows a plan view of the outlet 12 of the nozzle 20. Further, a pair of profiled walls 25 are positioned opposite one another within the chamber 20, and extend across the chamber 20 parallel with the elongate nozzles 28.
In the embodiment shown in FIG. 5, the chamber 20 is designed to have a heat exchanger positioned across the inlet 22. In addition, a further heat exchanger may also be positioned across the exit 23.
A very simple experimental apparatus was designed for testing the invention. It comprised a fan, flexible ducts, a variable speed drive and the induction unit. A Pitot tube connected to a digital manometer was used to measure both static and velocity pressure, a hot wire anemometer was used to measure the velocity of the secondary air at each of thirty locations covering the inlet face of the filter upstream from the secondary air induction coil, and condenser microphones connected to a sound pressure meter and sound analyser, all manufactured by Bruel and Kjaer, were used to measure the acoustic field. The fan and variable speed drive unit were located outside a large, calibrated reverberation chamber and the induction air conditioning unit was mounted within the reverberation chamber. This arrangement facilitated the measurements of total sound power radiated from the unit.
The experiment is devised in two separate sections; an acoustic experiment to measure the sound power radiated from the unit and a fluid mechanic experiment to measure the entrainment ratio and other features of the unit.
The aim of the acoustic experiment was to provide definitive measurements of the spectrum and the sound power level radiating from, first, the induction unit in its several standard configurations and, subsequently, from the same induction unit modified to incorporate individually and collectively the novel features described herein. Round section nozzles of two different sizes were tested in the unmodified induction unit to provide baseline data which could be compared with the specifications of the unit published by the manufacturer. The tests were repeated for full sets of each of two sizes of the multi-lobe nozzles. The experiments spanned a broad range of stagnation pressures in the plenum which is located within the unit upstream from the nozzles. The pressure in this plenum determines the flow velocity and the (primary air) flow rate through each set of nozzles. From the measured sound pressure level both the weighted sound pressure level and the radiated sound power level were calculated.
The fluid mechanic experiment provided information about the secondary and the primary air flows and therefore about the induction efficiency. The primary air flow through the nozzles was varied by using a variable speed drive to vary the speed of the fan. The measured data can be displayed in several ways but most instructive is as the relationship between the entrained air flow rate and the flow of the primary air through the nozzles.
The acoustic and fluid mechanic measurements were taken consecutively for each setting of the fan speed to improve the reliability of the intercomparisons between the data sets.
An indirect means of measuring the volume of the entrained secondary air was adopted. The experiment was performed so that the velocity of the secondary air induced through the induction unit could be measured at each of thirty locations on its inlet. The induced flow velocity was measured at each of the thirty locations. The large number of measurements was necessary because the velocity is not uniform across the inlet and because good accuracy was required to allow reliable estimates of the entrainment ratio to be calculated. The volumetric flow rate of the induced secondary air was calculated by summing the products of each elemental area of the surface and the velocity at its centre. The volumetric flow rate of the primary air (the air which is discharged through the nozzles) was measured by means of an orifice plate in the primary air supply duct. The results for the set of 25 nozzles have been averaged to yield an overall value of the entrainment ratio which can be used as a figure of merit. The entrainment ratio is the algebraic ratio of the volumetric flow rates of the induced and the primary air.
Velocity measurements show that the new nozzle design subject of this invention have significant advantages over the nozzle arrangements which are in common use in induction air conditioning units. The level of turbulence downstream from the nozzle outlets has been increased and this, combined with the larger perimeter of the jet, causes significantly greater entrainment of air from within the confined space within the unit, causing the pressure in that space to be lower than that which is achieved when the conventional nozzles are used. The reduced pressure increases the motive power for the entrainment of the secondary air through the induction heat exchange means. The increased mixing at the outlet from the primary air nozzles also causes the length of the potential core of each jet to be reduced with an accompanying reduction in the generation of noise.
Overall the concept has been to generate intensive mixing between the primary and the secondary air which augments the induction of the secondary air and reduces the noise generated by the primary air jets. Measurements have shown that the improvement in the entrainment is of the order of 19%-35%. This causes the volume of the secondary air that is drawn through the induction heat exchange means to be increased and hence the effectiveness of the induction heat exchange means is also increased. For a given volume flow rate of primary air the secondary coil capacity is, therefore, also increased by 19% to 35%.
Sound pressure measurements have been performed in the reverberation chamber in the Department of Mechanical Engineering, The University of Adelaide. These chambers are built to best available world standards and have hosted much internationally respected research in the fields of acoustics and vibration.
The sound pressure measurements have shown significant reductions of sound pressure and of sound power levels. Considering the spectrum of the sound, for a given flow of the primary air through the induction unit, the spectral noise components measured in octave frequency bands with the new nozzles fitted are from 1 to 7 decibels lower, depending on the band, than with the original circular nozzles. With one only acoustically absorbing perforated side wall in place the noise from the unit is reduced by up to 15 dB-A.
EXAMPLE
A comparison between the conventional round nozzle and the improved five lobe nozzle design, assuming that the secondary air heat exchange means can accept an increased rate of coolant flow to accommodate the increase in cooling capacity associated with the increased secondary air flow rate.
Assume
Pst=350 Pa in the primary air plenum
Round Nozzles
______________________________________Primary air Secondary air______________________________________Vp = 36.8 L/sQp = 446.3 W (Watts of cooling) Qs = 1000 W______________________________________
Total unit capacity is Q=Qs+Qp=1446.3 W.
Five Lobe Nozzles
______________________________________Primary air Secondary air______________________________________Vp = 36.8 L/sQp = 446.3 W Qs = 1.23 × 1000 W = 1230 W______________________________________
Total unit capacity is Q=Qp+Qs=1676 W, which is 16% more than that achieved by the round nozzles.
The addition of a profiled shape on only one wall downstream from the five lobe nozzles allows further gains to be made in the performance of the unit. Over the primary air pressure range tested the increase in the entrainment of the secondary air is 6.5%-10% compared with the operation of the unit with only the five lobe nozzles and no profiled wall. If we assume that the increase in the entrainment of secondary air is 8%, the increase in the capacity of the unit is as shown in the following table:
______________________________________Primary air Secondary air______________________________________Vp = 36.8 L/sQp = 446.3 W Qs = 1.08 × 1230 = 1330 W______________________________________
Total unit capacity is then Q=Qp+Qs=1776 W, which is 23% more than that achieved by the round nozzles. The total increase in the entrainment of secondary air through the heat exchange means is 32% compared with the original unit design.
If we now reduce the pressure upstream from the nozzles to Pst=300 Pa for the five lobe nozzles operating with one profiled wall we find the following:
______________________________________Primary air Secondary air______________________________________Vp = 34.21 L/sQp = 415 W Qs = 1192 W______________________________________
Total unit capacity is Q=Qp+Qs=1607 W, which is 11% more than for base case with round nozzles (which is more than was required for the particular application)! The sound pressure level is reduced by 3-p4 dB(A), which is noticeable. The primary air supply pressure could if desired, be reduced by a further 15-20 Pa to obtain the maximum reduction in the noise while still maintaining the original cooling capacity. However experience shows that the cooling capacity of the majority of perimeter induction systems now in service is less than that which modern design practice would deem to be necessary. The decision on whether to maximise the noise reduction or to provide the increased cooling is a matter for professional judgement in each situation considered. The present invention allows that judgement to be exercised.
In some existing buildings, either because additional cooling capacity has been required, or because changes to the primary air supply ductwork have unbalanced the supply air pressures, primary air pressures in the range from 500 Pa to 600 Pa are being employed. In these cases reduction of the primary air pressure by 100 Pa reduces the primary air supply by about 10-12% without reducing the cooling capacity when the nozzle of this invention is used, the reduction of primary air cooling capacity being offset by increased secondary air cooling capacity. The associated noise is reduced by between 7 dB(A) and 10 dB(A) for such a building.
SUMMARY OF RESULTS
With the new nozzle concept proposed in this invention and with the new profiled wall section installed in the units, the entrainment is significantly increased and electrical power is saved because the fan and motor of the primary air treatment plant do not have to raise the full basic quantity of primary air to such a high pressure. Because the required primary air flow is conservatively only 80% of that required by the basic units, chiller (or boiler) load is reduced. Some additional power is consumed in pumping the additional water to the secondary induction coils. Overall, the total capacity of the air-conditioning system can be increased without additional electrical energy because some primary air capacity is transferred to the secondary air heat exchange means so effectively transferring that portion of the load from the air circuit to the water circuit. It is concluded that typical values which can be claimed for these savings, and for the reductions in the noise from the units, are as follows:
ENERGY SAVINGS
The supply fan will operate with 20% less primary air against a pressure head which is decreased by 30%. Its motor will therefore consume substantially less electrical power.
The chilling plant will be required to cool 20% less primary air. The additional pumping power required to circulate the additional water to the secondary air heat exchange means is small compared with the above savings.
NOISE REDUCTION
The new nozzle design operating in conjunction with the profiled duct boundary, together with the decreased primary air flow, will reduce the noise radiated from the induction unit by at least 7 dB in the absence of any acoustic treatment means, and up to 15 dB with such means.
SUMMARY
The reduction in primary air cooling capacity which accompanies the reduction in the primary air flow is fully offset by a modest increase in the chilled water flow to the secondary air heat exchange means to cool the additional secondary air which is entrained by the combined effects of the new five lobe nozzles and the profiled side wall within the unit.
While the present invention has been described in terms of preferred embodiments to facilitate better understanding of the invention, it should be appreciated that various modifications can be made without departing from the principles of the invention. Therefore, the invention should be understood to include all such modifications within its scope.
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This invention relates to an induction air handling unit of the type that uses a primary air flow to induce flow of secondary air through the air handling unit. It comprises an induction chamber (2) having an air flow entrance (22) and an air flow exit (23) and a nozzle (10) having an outlet (12) located within the induction chamber (20). The nozzle (10) is connected to a primary air flow that causes a secondary air flow to be induced through the induction chamber (20) via the entrance (22) and the exit (23). The nozzle (10) is characterized by the edge (12) forming an outlet that is of a scalloped shape. This has a dramatic effect on producing noise output from the nozzle (10).
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CLAIM OF PRIORITY
[0001] The present invention claims priority to U.S. Provisional Patent Application No. 60/881,170, filed Jan. 19, 2007
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the present invention relate to embedded electronics in walls or panels. A preferred embodiment of present invention relates generally to container security and, more particularly, to a shipping container security system, and to the sub systems used in this system.
[0004] 2. Background of the Invention
[0005] Currently, most electronic devices are provided with a specific housing, which may be small (such as cell phones or alarm clocks) or large (such as televisions or desk top computers). In some instances, electronics in their housings are attached to wall surfaces, with clocks being an example. That is, current electronics that are fixed to structures having separate housings for their protection and mounting.
[0006] As another example, steel containers, such as intermodal shipping containers, which have been in existence for more than fifty years, offer no mechanism for penetrating the container walls electronically with either conducting wires or radiofrequency waves. Thus, inherent difficulty exists in externally inspecting the contents of the container without physically opening the doors, or penetrating by cutting or some other physical means.
[0007] A problem faced by the Government and industry is one of providing an intermodal shipping container capable of detecting various modes of threat, such as insertion of unauthorized materials, tampering, exposure to harmful substances such as chemical or biological threats, as well as tracking and reporting on location and contents. This is the “smart” container versus the often called “dumb box” that has been employed by the industry for more than forty years.
[0008] A number of Federal government programs have been initiated in the last 2-3 years with the goal of developing either a “smart” container or some key portion of a container security system. The goals have included such features as total system security, detection of inserted weapons of mass destruction (WMDs), detection and reporting of tampering, and maintaining fulltime reporting capability to show location. None has dealt so specifically with chemical and biological protection or the use of innovative materials for the container (“hybrid polymer” is the RFP terminology).
[0009] Accordingly, a solution is needed for embedding electronics in walls or panels for various purposes including the transmission of information or data through those walls are panels.
[0010] 3. Description of the Related Art
[0011] A container security system as described by System Planning Corporation (SPC) (Pat. No. 7,098,784) herein referred to as “the SPC Invention”, performs many of the functions to monitor containers, their content, and to detect tampering within a container during transit. This is accomplished through a device is which attached to a container, which performs multiple functions. Some of these functions may include controlling various sensors, collected the data from these sensors and transmitting this data back to a central monitoring station. The central monitoring stations may also send commands and information to individual containers equipment with this device.
[0012] The SPC invention is has all of the electronic elements a in a housing. To install the SPC device on the container it must be mounted or attached which is often a cumbersome operation. In order to facilitate installation on a container, different mounting brackets may be used but these result in additional cost. Also, for the SPC invention, the antenna device to the communication subsystem and the global positioning element is mounted on the exterior of the container. In this case it can be easily damaged, limits the ability to effectively stack containers, and it obvious to any person.
BRIEF SUMMARY OF THE INVENTION
[0013] Embodiments of the present invention offer a solution which can provide an alternative housing. In aspects of the invention, parts of structures can serve as both the protection and support for electronics. That is, embodiments of the invention have the advantage of integrating the functions of electronics and of structures to the improvement of both.
[0014] One preferred embodiment of the invention involves panels, which may or may not provide mechanical functions, into which electronics have been embedded wholly or partially for any purpose.
[0015] The system in the present invention is integrated or built into the container structure. It may be installed in the factory, or variations thereof permanently retrofitted in the field. It is highly concealed, and does not limit the stacking or other common movement of containers during the shipping process. It is lower in cost, more durable, and by integrating the sensors will allow superior performance in the detection of intrusions.
[0016] The preferred embodiments of this invention provides a panel system which is integrated into the container walls. This panel may include a variety of electronic elements, batteries or power elements, sensors, a processing element to collect and interpret the sensor data, and communications devices which may include: a short range wireless or a wireless local area connection (WLAN) communications device; a cellular communications device, and a satellite communications device. The system also may contain a global positioning device.
[0017] Containers offer few means to penetrate the walls electronically with either conducting wires or radio-frequency waves. As a result there is inherent difficulty in externally inspecting the contents of the container without physically opening the doors, or penetrating by cutting or some other physical means. A panel system with embedded electronics will allow immediate and noninvasive inspection and internal communication by a number of means, which include optical, radio-frequency or other modalities of either inspection or communication.
[0018] In the present invention, the panel system is integrated into the roof, base, walls, or door area of the container and become part of the structural elements of the container itself. There are several methods for construction of the antenna comprising;
[0019] The panel system being built directly into the container roof, base, walls, or door area as a permanently affixed device at the time of container manufacture;
[0020] A portion of the container walls, roof, or door being removed, and the panel system being permanently installed replacing the removed section in on the container at the time of container original manufacture, refurbishment, or during field installation;
[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various embodiments of the invention and, together with the description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The present invention is described in detail below with reference to the attached drawings figures, wherein:
[0023] FIG. 1 is a perspective view of a panel in accordance with an embodiment of the invention;
[0024] FIG. 2 shows a three-stage development process in accordance with an embodiment of the invention;
[0025] FIG. 3 is a detailed view of a panel structure in accordance with an embodiment of the invention;
[0026] FIG. 4 is a schematic indication of the variation of the mechanical strength and the electronic utility of a container in accordance with an embodiment of the invention;
[0027] FIG. 5 is a finite element analysis of stresses in container-like box in accordance with an embodiment of the invention; and
[0028] FIG. 6 illustrates RFID testing in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0029] Embodiments of the present invention are directed to a system and method for embedding diverse available electronic components and functions within panels. The panels may be made of non-conducting materials, but electrically conducting panels are possible in some applications. One purpose of the invention is to provide all the functions of modern electronics inside of and near such panels.
[0030] Systems incorporating aspects of this invention have diverse functions and numerous uses, including most broadly, the generation, manipulation, storage, communication and usage of information. Such functions may be accomplished by sensing, computing and actuation of materials and energy within the panels or in the locale of the panels. The functions can be used for monitoring environments and people outdoors and indoors for the purposes of safety, for medical reasons, and for physical, information, homeland and national security, among many others.
[0031] The panels that contain the electronics can serve many other functions in addition to those provided by the electronics. Such functions include (a) structural support, (b) barriers to matter, energy and biological entities on all scales, including the exclusion or inclusion of humans in nearby spaces, (c) sound and impact absorbers, (d) windows for electromagnetic radiation, notably visible light and radio frequency waves, and (e) decorations, among others.
[0032] The panels in embodiments of this invention can have widely varying properties. They might have dielectric properties such that they will transmit any form of radiant energy, especially radiation in the visible and radio-frequency (including microwave) regions of the electromagnetic spectrum. In addition or in distinction to such responses to electromagnetic radiation, the panels might also vary in response to mechanical stresses and, especially, transmit acoustic energy of any frequency. The panels might be transmissive to some of these forms of energy but opaque to others. These and other properties of the panels will depend on the specific applications. For example, transparent materials will be used for applications involving transmission of visible (and nearby infrared or ultraviolet) radiation.
[0033] The panels can be made of any materials, natural or artificial. Woods, leathers and other materials from nature of any type can be used. Man-made materials including, but not limited to, all plastics (polymers), glasses, ceramics, papers and fabrics may be incorporated. Panels that operate by using energy in the acoustic spectrum can be made of any of the above materials or metals or alloys. The panels can be made of one or more materials, that is, embodiments of the invention include composites of all types in addition to a single type of material. The composites might be homogeneous in nature or laminates of any type. These and other characteristics of the panels will depend on the specific application. Plastics are expected to be major materials used for the panels for most functions.
[0034] The panels can have any geometry. If the panels have six sides, any of the pairs of facing sides can have any geometry and separation (distance apart). Facing sides will commonly be flat and parallel, but that is not a restriction. Parallelism of flat sides is not a requirement. Any of the sides can be curved in any manner. In general, the panels can be any three-dimensional shape of any size. Most of the applications will employ panels that are rectangular solids, where two of the facing sides are at a separation considerably smaller than the other two pairs of facing sides. The shape of the two larger sides will commonly be square or rectangular, but it can also be circular, oval or other shapes.
[0035] The electronics embedded in the panels can be of any material and type. Conductors, semiconductors, resistors, glasses, polymers, liquid crystals or all other electronic materials are included in the invention. The electronics can range from individual components to partial or complete functional systems of any type and shape. The embedded electronics can include either or both active and passive components, and they can be any combination of analog or digital devices. The components can be solely electronics, or they can include micro-mechanical or micro-optical functionality. They can be bare or packaged in any manner. Included in the embedded electronics may be (a) sensors of any type for any physical, chemical or biological entity, (b) computing devices of any type, notably microcontrollers, microprocessors, digital signal processors, field programmable gate arrays or combinations of computational devices, (c) memory chips of any kind, including flash and all other types of semiconductor memories, magnetic memories (including disk drives), ferroelectric memories or memories made of any other materials, or (d) application specific integrated circuits of any type, such as radio receivers, transmitters or transceivers. Components ancillary to and supporting of the electronics and their functions, such as, but not limited to, (a) batteries or other energy storage devices, (b) energy sources such as photovoltaic devices, (c) light emitters and detectors, (d) antennas of all types (including ceramic chip-scale antennas and antennas made of embedded wires or foils or conductors applied to laminates of the panels), or (e) acoustic pickups or emitters, are included in the invention. The electronics for the panels need not be monolithic units, but can consist of separated components, modules or systems that are connected by any means to pass information or energy from one part of the electronics to another part. Any means of connection, including electrical conductors, optical conductors and transmission of radiant or acoustic energy through the panel material, are included in the invention. Input devices, such as devices sensitive to touch by humans or other objects, of any type and output devices, such as any flat panel displays (including clocks) are included in embodiments of the invention.
[0036] All types and frequencies of carriers and all protocols for communication of information through solids, liquids and gasses may be incorporated in embodiments of the invention. Examples include, but are not limited to all protocols for satellite communications, cell phones, Wi-Fi and related protocols, BlueTooth, and ZigBee.
[0037] Any of the panels can have embedded into them in any fashion any one or more of the possible electronics. All combinations of panels and electronics are contemplated. The electronics can be embedded in the panels in any manner, by any means and at any time during the production of the panels. The electronics can be made separately and then embedded into the panels, or they can be produced as part of the process of manufacturing the panels. The embedding of the electronics can be partial or full. That is, embodiments of the invention include cases where the electronics are not entirely within the panel, but recessed into the panel to some degree and in some manner. Cases where the electronics span any fraction or the entire thickness of a panel are included in the invention. The materials and means for affixing the electronics to the panels can be of any type, including adhesives and mechanical fasteners.
[0038] Loading of energy and information into the electronics can be done prior to embedding, after embedding and before use or during the useful lifetime of the panels. Loading of either energy or information can be done once or multiple times, depending on the characteristics and uses of the panels. The panels can be used in any orientation and configuration, in combination with any other materials, structures and devices, including electronics, optics and acoustics exterior to the panels. They can be used vertically and incorporated into walls of any structure. The panels can be used as windows for light or any other radiant energy. They can be installed horizontally in the floor or ceiling, or other parts, of a structure.
[0039] Example Types of Uses
[0040] The table below describes potential uses of the invention; it is not inclusive of all potential uses.
[0000]
Type of use
Description of how invention can be used
Transportation
Security portals; transmission of security signals; self-contained
Security Devices
security packages
Entertainment
Wireless communication from TV-satcom; in-home wireless
connectivity; wireless transmission to scoreboard; embedded in
games, TV and other displays, speakers for home and other sound
systems
Toys
Multi-function wireless games; tracking of motion toys; security of
expensive outdoor toys—bicycles, cars, skateboards
Decorative Applications
Wireless control of wall displays, decorative features; window and
security controls: panels that change colors and apparent textures
Home Wireless Device
Combination home security/home appliance controls (wireless);
Control
home environment control; alarm detection/reporting
Automotive applications
Radio/TV signal transmission; security, tracking, alarming; auto
operational function detection and reporting
Trucking Applications
Same as automotive applications, plus cargo monitoring
Railroad Applications
Same as trucking applications
Maritime Applications
Safety and security detection, reporting; boat maintenance reporting
functions; remote control of environment
Aircraft Applications
Safety, monitoring all contents of a plane (including people),
providing information of any type by any means
Home Security
Wireless security, detection of alarms and reporting; remote control
of facilities, functions
Monitoring Devices
Use to detect inter-modal container intrusions, changes, and provide
protection; facility monitoring, control
Photographic usage
Dark room monitoring, control; light detection, alerting
Store & Other security
Concealed system for theft detection, surveillance
Medical
Monitoring treatment centers; monitoring transport of drugs,
pharmaceuticals
Environmental
Monitoring sensitive rooms, areas; detection of changes in clean
facilities; providing data on conditions outside of a structure
incorporating electronic panels.
Reading Electronic ID
Monitoring the presence of and reading identification tags in an area
Devices
by RF or acoustic means
Wireless Sensors
Providing sensors and associated components and communication
of the information from such sensors
People and Animals
Monitoring the location and activities of adults, children and pets
within-and nearby homes or other locations
Homes, Offices, Stores
Obtaining and presenting information within buildings for any
and Factories
purpose
Indoor Location Services
Relaying outdoor signals for determination of locations; providing
location information by any technology
Military Uses
Providing any of the civil functionalities to the military for any
reason.
Miscellaneous
Panels to acquire and present information and provide controls in
any locations, such as an airport, for any reason.
Windows
For any type of energy in any of the above applications
[0041] FIG. 1 is a perspective view illustrating an embodiment of the invention. The displayed container wall may include a polymer-based composite with embedded electronics, sensors, and communications. Filament wound plastics are one type of polymer-based composite that may be implemented.
[0042] In embodiments of the invention, plastics may be used to provide a window approximately one-meter square in a steel box, a twenty-foot container. In other embodiments, the panel will be expanded to include a portion of the filament wound container, and contain embedded sensors and communication devices, including antennas and batteries. The concept is similar to today's smart cards which see daily usage by the billions for a variety of purposes, including security. The smart cards contain varying levels of complexity and electronics, depending on their purpose. Like smart cards, the panel concept involves electronics embedded in plastics. The panel can be viewed as a larger and more structurally sound smart card with different applications. An intermodal container constructed with the panels should pass handling, usefulness, and security tests including chem/bio protection.
[0043] The “Smart” intermodal shipping containers created in embodiments of the invention will be capable of being tracked, traced, scanned for inventory, and provided with chemical, biological and other sensors to meet the Department of Defense (DoD) critical logistical requirements for providing In-Transit Visibility (ITV) in operational theaters.
[0044] An objective is to integrate off-the-shelf technology that can meet the chemical and biological agent detection requirements sought by the Army and demonstrate use of an innovative material for the container, while maintaining many of the other “smart” properties that have been researched, developed and demonstrated.
[0045] FIG. 2 schematically shows the three-stage development process that includes three generations of containers. The third generation “Smart” containers may be hybrids of metal and plastic with electronics embedded in the walls, both vertical and horizontal (as shown) This simple graphic shows the forty year first generation ISO container cross-section (left), evolved in the 2002-2006 timeframe to a second generation system with added internal electronics (sensors, batteries, communications capability), shown in the center graphic. The right-hand schematic shows the panel inserted into the container wall that has had a window cut into the box; the embedded electronics are within the panel.
[0046] FIG. 3 provides more detail regarding the structure of the third panel. The left-hand graphic shows the mounting within the panel of the functional electronics and antennas for radio frequency (RF) transception. The electronics include sensors, a controller, a transceiver chip, and batteries. The right-hand graphic is a through-the-wall cut, showing the location of components in the container, the sensors, and within the panel, the electronics and antennas. The left-panel shows the combination of electronics and antennas, which can be put in the central position, as shown, or elsewhere within the panel. The right figure shows a cross-section of the panel showing the electronics embedded within the polymer. Sensors, including imagers, can be entirely embedded or attached to the interior surface. The latter approach permits the use of different sensor modules for different purposes.
[0047] The container design is intended to be such that it will result in a lower cost manufacturing production system than exists at present and full integration into DoD total asset visibility (TAV) systems. It will meet DoD-specified chemical and biological (CB) sensing and alerting requirements. In addition, the capabilities of the proposed electronic panel system enhance the overall capability of the Army's “smart” container system.
[0048] In embodiments of the invention, a “Smart” ISO container design meets DoD operational and functional requirements for a Wieldable system. Requirements include not only ITV/ATV operability and CB detection, but the analysis of the functional objectives of lowered cost (a cost less than ISO steel boxes), feasibility of operation, and equivalent or improved mechanical capabilities (to be confirmed through finite element analyses) under all operational and environmental conditions. The embodiment will integrate known and existing technologies and materials. The embodiment will meet various objectives including integration into ITV/ATV systems, CB sensing and alerting, manufacturability, withstanding normal operating conditions, structural goals, and weight goals.
[0049] Integration into ITV/ATV systems—A goal is to support the Army's mission of providing timely, customer-focused global mobility through efficient, effective, and integrated transportation from origin to destination. A global track system may be integrated and embedded in the container both in its design (in the eWall™ demonstration) and in prototype fabrication.
[0050] CB sensing and alerting—An objective is to provide CB detection for ISO intermodal containers through a program of material protection, sensing and alerting, where such defense does not currently exist. A multi-layer filament wound “skin” which with embedded electronic panel components will be investigated to replace the generally corrugated steel skin (the steel sheet metal) that forms the current box skin.
[0051] Ability to be manufactured [manufacturability—An alternative material (i.e., the electronic panel and its surrounding material to replace the steel skin) may be implemented with demonstrated manufacturability, to replace the current principally steel boxes employed in the industry. The feasibility of manufacturing and securing nominal size sheets may be demonstrated.
[0052] Withstanding normal operating conditions—The severe stresses imposed by the operating conditions a container must withstand through handling, stacking, imposed gloads, torque, compression loading, and others are addressed and handled. A high strength steel frame may be attached to the skin. The frame and the electronic panel box will be structurally designed to handle all anticipated conditions. Finite element methods (FEM) of analysis will be used to calculate the strength of the container under operating conditions.
[0053] Withstanding extremes of environmental conditions—The environment to which a sea container is exposed is severe, ranging from temperature extremes to severely corrosive sea air, heavy icing conditions, and pounding rain. The container must withstand this environment. Modern materials may be implemented, capable of meeting all anticipated environmental conditions.
[0054] Structural goals—Embodiments of the invention will equal or exceed the strength of a steel box. A modern steel frame and composite sheeting materials may be sized to provide the necessary structural response. Finite element analyses (FEA) can be conducted to study the box strength.
[0055] Weight goals—A fifty percent reduction in weight of the overall box versus steel can be provided to meet a highly desirable commercial goal. Light weight high strength plastic composites may be implemented. Light weight and ultra high strength composites tend to be very expensive, perhaps prohibitively, so an optimum strength versus cost in tradeoff analyses may be required for each application.
[0056] The ISO intermodal shipping container that has been developed over the last 40 years is a basic steel “dumb” box. The labor-intensive manufacturing fabrication method required to fabricate the box has been unchanged in virtually four decades; manufacturing has been outsourced to foreign countries (principally in Asia) to obtain lower prices. New and advanced manufacturing processes using polymer-based composite material, material co-mingling (integration), and dynamic structural design using finite element analysis can be used to investigate the manufacturing process to shift from its current labor intensive single unit fabrication to mass production. with possibly a 50% reduction (estimated) in overall weight.
[0057] A filament wound polymer may be used as a principal polymer-based material, integrated with either the existing steel skeleton or an augmented (to obtain the necessary compressive strength) skeleton for the basic container structural material, incorporating sensors that can detect unauthorized entry and chemical agents, biological agents, explosives, and possibly illegal drugs. The system may be designed to consider future fiber optic sensing systems. Additionally, the container may be fabricated integrating a proprietary security and communication system, such as SPC's GlobalTrak™ container security system.
[0058] Current steel containers are not hardened or integrated in any manner for survivability to a chemical or biological attack. The contents of the all-steel containers may be contaminated in a CB attack. The next generation of ISO “Smart” intermodal shipping containers must be CB hardened, which starts with CB detection, and RFID (Radio Frequency Identification Device) capable.
[0059] Active RFID interrogation is rapidly becoming a requirement. Within an enclosed steel container, RFID interrogation is not easily performed because of the impossibility of radio wave propagation through steel walls Our plastic walls, being transparent to RF waves and yet maintaining structural integrity, will allow penetration of the RFID signals. Disposable low-cost RFID passive tags can be applied at the lowest levels (individual item, case, pallet, etc.) to meet minimum tagging requirements for data acquisition. The features will allow DoD to reach established goals and objectives through providing enhanced CB protection, total asset visibility, improved life cycle costs, accurate financial audits of inventory, and logistical tracking of container movements.
[0060] To summarize, the features may include: (a) A GPS transponder provided for real time tracking capability; this is included with the GlobalTrak System today. (b) Xray transparency; X-rays will easily pass though a non-steel container eWall™, thereby increasing homeland security. (c) The “Smart” container incorporating SPC's GlobalTrak™ system will allow for a single source logistical system capable of wireless encrypted data transmission to handheld as well as fixed data download stations; centralized data retrieval will be possible. (d) Commercial applications for this technology appear to be extensive and include commercial merchant shipping, dry and refrigerated cargos (possibly using a foamed polymer shell). (e) The “Smart” container, particularly as it incorporates the GlobalTrak™ System as its core, will meet Department of Homeland Security directives regarding container security.
[0061] Since containers were first manufactured in the 1960′s, many materials and processes have been used. Large polymer containers have been investigated, and are currently fabricated and used for DoD purposes such as large missile and rocket components. Information concerning these uses and materials will be compiled. Panel development may be assessed to optimize material usage. The state of high-strength polymer development and integration of the steel skeleton and polymer skin (that is, combination of the filament wound plastic and steel structural members) may be implemented.
[0062] FIG. 4 is a schematic indication of the variation of the mechanical strength and the electronic utility of a container shown as a function of the fraction of plastic making up the structure of the container. As polymer replaces metal, the strength will decrease, but the ability to build electronics into the structure of the container increases. Thresholds for strength are known. The shapes of the variations in mechanical strength and electronic utility are merely suggestive.
[0063] FIG. 4 shows the diminished mechanical strength as a function of increased fraction of plastic, as well as increased electronic utility. The eWall™ demonstration using the meter-square window will be located on this graphic at approximately the 2% plastic fraction point.
[0064] FIG. 5 shows finite element analysis of stresses in container-like box Parametric analysis may include finite element analyses (FEA) of portions of the configuration to assist in estimating the mechanical strength of various designs. FIG. 5 is an example of the finite element analysis of a container taken from http://www.clf.rl.ac.ul/Facilities/AstraWeb/AstraGeminilntChamb.htm. It shows a configuration of a chamber similar to a container undergoing finite element analysis.
[0065] Electronic panel windows may include compound sheets approximately 1 meter by 1 meter and testing for RFID transmission into the container. The window will be mounted on the side of the container as shown earlier. The RFID tests will be performed as shown in FIG. 6 .
[0066] FIG. 6 illustrates plan views of the demonstration container showing the location of the RF transmitter (Xmtr) and receiver (Rcvr) for demonstrating the bidirectional transmissibility of the eWall™ to common RF frequencies for RFID and wireless sensors. The Xmtr will be a frequency generator with an antenna, and the Rcvr antenna feeding an RF spectrum analyzer
[0067] In embodiments of the invention, new and potential replacement material and fabrication technology may be implemented. While existing non-conventional materials are used for containers, the employment of such materials, e.g., filament wound plastics and proven fabrication processes, offers exciting opportunities when coupled with GlobalTrak™ system implementation. For example, the GlobalTrak™ device and its communication network can be fabricated to be integral with the container, and certain elements of the system can be molded into the container, making it a totally secure and integrated ‘smart container’ as has been long sought by the USG and industry.
[0068] As the adoption of “smart cards” has revolutionized personal security in terms of efficiency and additional security, so can the eWall™ program and its enhancements to container technology. The container contents can be scanned very efficiently, and 100% of the containers can be rapidly screened. This is a considerable improvement from the screening possible today. the possibility of providing an evolutionary new method for container inspection, and beyond that, it can offer the ground step of application of innovative materials in the modern container market.
[0069] The smart container can help overcome the fears of many regarding security. Costs can be reduced, transit time can be reduced, and labor-intensive human inspections can be basically eliminated. Beyond serving its principal role as an intermodal shipping container, there are other roles suggested. These include providing emergency housing for FEMA emergency operations, providing refrigerated container use, and providing a means of carrying potable water. While such uses have been considered, they have not been found overly attractive. the use of a more fully polymerized container for such purposes may be advisable.
[0070] While particular embodiments of the invention have been illustrated and described in detail herein, it should be understood that various changes and modifications might be made to the invention without departing from the scope and intent of the invention.
[0071] From the foregoing it will be seen that this invention is one well adapted to attain all the ends and objects set forth above, together with other advantages, which are obvious and inherent to the system and method. It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated and within the scope of the appended claims.
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A system and method for a panel system containing embedded electronic elements providing both housing for the electronics and structural support. A preferred embodiment of the system is for a container security system, which is constructed into or conforming onto the roof, walls, door, or base of a cargo container is provided. The panel system may consist of a variety of electronic elements, batteries or power elements, sensors, a processing element to collect the sensor data, and a communications element to transmit outside of the container.
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This invention relates to the preparation of glass ceramic fibers.
In one of its more specific aspects, this invention relates to controlled devitrification of glass fibers to produce glass-ceramic fibers.
BACKGROUND OF THE INVENTION
The method of preparing glass fibers is well known. Such fibers are used for a plurality of purposes such as reinforcements and the like.
Efforts are continuously being taken to improve such glass fibers, particularly as concerns improving modulus and temperature resistance. This invention is directed towards such improvements.
STATEMENT OF THE INVENTION
According to this invention, there is provided a method of treating glass which comprises contacting the glass with a titanium compound to deposit titanium on the surface of the glass and then heat-treating the glass fiber to a temperature within the range of from about 1700° to about 2100° F. for a period of time sufficient to devitrify the glass surface.
In one embodiment of the invention, the titanium compound is contained in an organic liquid.
In another embodiment of the invention, the glass is in the form of glass fibers which, having the titanium compound on their surfaces, are heated to a temperature within the range of from about 1700° F. to about 2100° F.
DESCRIPTION OF THE INVENTION
The method of this invention can be employed in the treatment of any glass, regardless of how formed. It is particularly suitable for employment with S-type glass fibers which can be formed in any manner. The glass will preferably be free of any surface coating. If the glass has been sized, it should be heated cleaned at 1200° to about 1500° F. for about fifteen minutes to remove the coating. By S-type glass is meant a low alkali, magnesia, alumino silicate glass. The following approximate composition is a typical S-type glass:
______________________________________ SiO.sub.2 64.5 Al.sub.2 O.sub.3 25.0 MgO 10.0 Na.sub.2 O 0.22 FeO.sub.3 0.15 CaO 0.12 K.sub.2 O 0.08 TiO.sub.2 0.07______________________________________
The glass can be contacted with any suitable titanium compound which, after the subsequent heat treating step, leaves the titanium on the glass in the form of the oxide. Preferably, the glass will be treated with an organo-titanium compound as the solute dissolved in an organic solvent. Mixtures of organic compounds of other metals can also be contained in the solution, such metals being calcium, magnesium, aluminum and other metals associated with refractory compositions.
In the preferred embodiment of the invention, the glass will be treated with an organic solution consisting essentially of an organic solvent and a titanium-organic complex.
One particularly suitable material is commercially available as DuPont's Tyzor AA and is a 75 percent solution of titanium (acetylacetonate)-(i-propanolate) in which the titanium concentration is about 9.9 weight percent. Actually, any solution effective in depositing titanium oxide on the glass in an amount up to about 15 weight percent is satisfactory.
The titanium-containing solution can be applied to the glass in any suitable manner. Preferably, the glass is simply immersed in the solution at atmospheric conditions for a period of up to about 15 minutes.
After contact between the glass and the titanium-containing solution, the glass is dried and thereafter the glass is heat treated at a temperature within the range of from about 1700° to about 2100° F. for a period of up to about 3 hours.
In one embodiment of the invention, polyethyleneglycol can be added to the organo-titanium solution to minimize wicking during final drying.
The method of this invention is demonstrated by the following example.
EXAMPLE I
S-glass fibers were heat cleaned and contacted with the following solution:
100 g Tyzor AA
200 g iso-propanol (solvent grade)
312 g water
The Tyzor AA, the iso-propanol and the water were mixed to form a first solution. A final solution was formed by stirring in the polyethylene glycol.
S-glass fibers were immersed in the final solution for a period of fifteen minutes and then dried in an oven for 30 minutes at 300° F.
The results of treating S-glass fibers in this manner are shown in Example II.
EXAMPLE II
A series of S-glass fibers was treated in accordance with the above procedure and compared with a series of S-glass fibers not so treated.
Tests were then undertaken to determine the presence and amounts of crystalline phases. Treatments and results were as follows:
______________________________________Titanium Heat Treatment Analysis*Sample Treatment @, °F. MgAl.sub.2 Mg.sub.2 Al.sub.4 Amor______________________________________1 Untreated 1700 10 n.d. 802 Untreated 1900 100 n.d. 03 Untreated 2100 t 100 04 Yes 1700 50 n.d. 505 Yes 1900 60 n.d. 406 Yes 2100 n.d. 100 0______________________________________ *MgAl.sub.2 = MgAl.sub.2 Si.sub.4 O.sub.12 Mg.sub.2 Al.sub.4 = Mg.sub.2 Al.sub.4 Si.sub.5 O.sub.18 Amor = Amorphous Materials t = trace n.d. = not detected Estimated volume Percent of Each Phase by xray diffraction and optical microscopy
Conclusions
1. Samples 1, 2, 3, 4 and 5 contained trace to 100 volume percent MgAl 2 Si 4 O 12 .
2. Samples 1, 4 and 5 contained 40 to 80 volume percent of amorphous materials.
3. Samples 3 and 6 contained 100 volume percent Mg 2 A 4 Si 5 O 18 (cordierite)
The above data indicate that the titanium dioxide has a moderating effect on crystal growth once nucleation (seeding) has taken place in the fiber. The titanium dioxide allows for controlled formation of a glass-ceramic material at moderate temperatures.
Sample 1 (untreated) and sample 4 (treated), when both heated to 1700° F., form glass-ceramic but the treated sample is more ceramic. At 1900° F., sample 2 (untreated) is fully ceramic while sample 5 (untreated) is still about the same glass ceramic as was formed at 1700° F. The titanium dioxide forms glass-ceramic at lower temperature and stabilizes it over a broader temperature range.
The treated fibers have been found to retain their fiberous character as their temperature is raised to 2100° F. while the untreated fibers have been found to slump at that temperature and, ultimately, form a solid ball. Both materials eventually transform to cordierite at about 2100° F.
These data, therefore, indicate that titanium dioxide, in the absence of any refractory metal, has a significant effect on the formation and stabilization of glass-ceramic fibers from S-glass at a temperature of 1700° F.
It will be evident from the foregoing that various modifications can be made to this invention. Such, however, are considered within the scope of the invention.
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A method of depositing a coating consisting essentially of titanium dioxide from an organic solution onto glass in an effort to improve the modulus and temperature resistance of the glass.
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FIELD OF THE INVENTION
The present invention relates to hard drives and problems encountered therewith, particularly adjacent track interference, and methods, arrangements and modules for addressing such problems.
BACKGROUND OF THE INVENTION
In the realm of hard drives, adjacent track interference (ATI) is a growing problem. When a particular track on the hard drive is written a large number of times (e.g., 30,000 times or more) without the adjacent track(s) being written, then the data on those adjacent track(s) can become corrupted. This constant overwrite causes some magnetic flux interference on the adjacent tracks that, over many cycles, can accumulate and leave the adjacent tracks unreadable.
For example, consider a track N as having adjacent tracks N+1 and N−1. If track N is written a large number of times before tracks N+1 or N−1 are also written, then the data on N+1 or N−1 could become corrupted. This is a well documented interaction encountered in magnetic recording.
A seemingly simple solution to this problem involves writing the data to the adjacent tracks before the data can become corrupted. However, complications arise in deciding when and how to rewrite the data on these tracks. There is no-simple counter of how many times the data at any particular sector is accessed; thus, it is essentially never clearly known as to when interference is about to take place. Currently, there are no known effective solutions to adjacent track interference in use at either the hard drive firmware level or the OS/application/driver level. Inasmuch as the first clear indication of ATI is that data has already become corrupted, it would simply be too late to merely save the data at that point, and the files involved would already be lost.
An aggregating factor with ATI is areal density As the areal density increases, the physical area containing the data decreases, thus increasing the percentage of area that represents a “fringe” or “border” area with respect to an adjacent track. Since, with ongoing technological developments, there will continue to be a significant increase in the number of tracks. areal density correspondingly increases. As such trends continue among the physical dimensions and physics of media and write mechanisms, the potential for increasing exposure to ATI will correspondingly increase.
As ATI problems have continued to proliferate, it has been found that common operating system programs have a tendency to cause a large number of writes to specific locations on hard drives. The data on the drives become corrupt when the excessive writes occur, and this often makes the systems unbootable. Indeed, this problem is growing due to increased areal density and OS workload while, at the same time, programs that access and update the information on the hard drive frequently can cause ATI.
SUMMARY OF THE INVENTION
Broadly contemplated herein, in accordance with at least one presently preferred embodiment of the present invention, are new methods and systems for improving existing drive scans and logs to detect future ATI problems and then scrubbing the data before the data becomes corrupt.
In summary, one aspect of the invention provides a method comprising: ascertaining an adjacent track interference potential in at least one track; and averting data corruption via scrubbing data in at least one track with ascertained adjacent track interference potential.
Another aspect of the invention provides a system comprising: a processor; and a memory storing code accessible by the processor to: ascertain an adjacent track interference potential in at least one track; and avert data corruption via scrubbing data in at least one track with ascertained adjacent track interference potential.
Furthermore, an additional aspect of the invention provides a program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform acts, said acts comprising: ascertaining an adjacent track interference potential in at least one track; and averting data corruption via scrubbing data in at least one track with ascertained adjacent track interference potential.
A further aspect of the invention provides a system comprising: a graphics adapter; a processor; and a memory storing code accessible by the processor to: ascertain an adjacent track interference potential in at least one track; and avert data corruption via scrubbing data in at least one track with ascertained adjacent track interference potential.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a computer system according to a preferred embodiment of the present invention.
FIG. 2 is a schematic illustration of data tracks.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For a better understanding of the present invention, together with other and further features and advantages thereof, reference is made to the following description, taken in conjunction with the accompanying drawings, and the scope of the invention will be pointed out in the appended claims.
It will be readily understood that the components of the present invention, as generally described and illustrated in the Figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the apparatus, system, and method of the present invention, as represented in FIGS. 1 through 2 , is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.
Reference throughout this specification to “one embodiment” or “an embodiment” (or the like) 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” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment.
Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
The illustrated embodiments of the invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals or other labels throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the invention as claimed herein.
There is broadly contemplated herein, in accordance with at least one presently preferred embodiment of the present invention, a method for improving existing drive scans and logs to detect future ATI problems and then scrubbing the data before the data becomes corrupt. This solution can be implemented in hard drive firmware and requires no new or dedicated application or driver. “Scrubbing”, as generally understood herein, preferably involves reading data and then writing the same data over itself, to thereby remove any possible effects of ATI.
Current hard drive firmware and SMART data logging track bit errors during sector reads, and during idle time performs scans for corrupt data. If a sector is not readable, then it is marked as potentially bad, and on the next write it is determined to be either unusable or useable. But inasmuch as this action is used to flag bad/damaged sectors, it is only triggered once data cannot be read from a sector. Clearly, this does not address salient ATI issues since ATI has a cumulative effect that can result in a slow increase of bit errors before the sector is completely corrupted. Also, though the target sector may not be read from or written to for a long time, an adjacent sector in the meantime could well be written to enough times to induce damage by way of data corruption.
Referring now to FIG. 1 , there is depicted a block diagram of an illustrative embodiment of a computer system 12 . The illustrative embodiment depicted in FIG. 1 may be a notebook computer system, such as one of the ThinkPad® series of personal computers sold by Lenovo (US) Inc. of Purchase, N.Y. or a workstation computer, such as the lntellistation®, which are sold by International Business Machines (IBM) Corporation of Armonk, N.Y.; however, as will become apparent from the following description, the present invention is applicable to preservation of data on a disk drive by any data processing system.
As shown in FIG. 1 , computer system 12 includes at least one system processor 42 , which is coupled to a Read-Only Memory (ROM) 40 and a system memory 46 by a processor bus 44 . System processor 42 , which may comprise one of the processors produced by Intel Corporation, is a general-purpose processor that executes boot code 41 stored within ROM 40 at power-on and thereafter processes data under the control of operating system and application software stored in system memory 46 . System processor 42 is coupled via processor bus 44 and host bridge 48 to Peripheral Component Interconnect (PCI) local bus 50 .
PCI local bus 50 supports the attachment of a number of devices, including adapters and bridges. Among these devices is network adapter 66 , which interfaces computer system 12 to LAN 10 , and graphics adapter 68 , which interfaces computer system 12 to display 69 . Communication on PCI local bus 50 is governed by local PCI controller 52 , which is in turn coupled to non-volatile random access memory (NVRAM) 56 via memory bus 54 . Local PCI controller 52 can be coupled to additional buses and devices via a second host bridge 60 .
Computer system 12 further includes Industry Standard Architecture (ISA) bus 62 , which is coupled to PCI local bus 50 by ISA bridge 64 . Coupled to ISA bus 62 is an input/output (I/O) controller 70 , which controls communication between computer system 12 and attached peripheral devices such as a keyboard, mouse, and a disk drive. In addition, I/O controller 70 supports external communication by computer system 12 via serial and parallel ports.
FIG. 2 schematically illustrates five parallel tracks on a disk drive labeled consecutively from X−2 to X+2. In contrast with the above, in accordance with a preferred embodiment of the present invention, a new threshold is set for bit errors monitored during a sector read and/or background scans, and this threshold is used to look for ATI signatures (or “red flags”). Preferably, the threshold should take into account the cumulative effects of ATI and be low enough to detect ATI before the sector becomes unreadable. As such, an ATI signature is very specific when looking at the relationship of the bit error rates on one sector and comparing it with the bit error rates on sectors X+1, X+2, X−1, and X−2. If a sector being read during a background scan has a BER (bit error rate) above the threshold, then sectors up to 2 tracks away are preferably checked. If the signature is present where track X−1 has a good BER but track X−2 has an elevated BER, then ATI is suspected as being caused via writing the X−1 track. The same would be the case for the X+1 and X+2 tracks. This relationship of BERs on the surrounding tracks would thus constitute new ATI action criteria.
In FIG. 2 , a sector A, two sectors B and two sectors C are labeled on various tracks. Here, by way of an illustrative and non-restrictive example, the threshold for elevated BER is detected on sector A on track X. It should thus be appreciated that if either sectors B or sectors C also exhibit an elevated BER, with the X+1 or X−1 tracks showing good BER, then ATI is considered as being a cause; these are shaded in FIG. 2 to accordingly indicate that they are at risk for ATI before significant damage has been done. In other words, with the X+1 or X−1 tracks showing good BER, prospective ATI can be detected early enough to avert undue damage, whereas conventional ATI detection methods would normally only be sufficient to prompt intervention after significant data corruption had occurred in one or more tracks.
If the algorithm determines that sectors or tracks are at risk for ATI, then the track X containing the target sector (in this case, sector A) as well as tracks X+2 or X−2 will preferably be scrubbed using a Read/Rewrite command. This read and re-write will effectively undo the effects of ATI and prevent any data corruption.
A signature scan, as discussed and contemplated hereinabove, may be undertaken via essentially any suitable approach. Particularly good results have been observed via the use of a conventional background scan operation as described at the website of T13, a Technical Committee for the InterNational Committee on Information Technology Standards (INCITS) (www.t13.org); in particular, document 1699D AT Attachment-8 (ATA/ATAPI Command Set [ATA8-ACS]) specifies an AT attachment command set between host systems and storage devices. Section 7.52.5 of this document, “SMART Excecute Offline Immediate,” describes offline data scanning that can be particularly employed in the context of the embodiments of the present invention (by way of employing a background reading to obtain signatures as discussed hereinabove).
The BER thresholds (particularly, elevated BER thresholds) as discussed and contemplated hereinabove can be chosen and customized appropriately for the application at hand; preferably they can be determined by the hard drive supplier on the basis of the known data recovery ability of the hard drive(s) in question. Thus, for those hard drives with particularly advanced and sophisticated data recovery capabilities, the BER threshold can likely be set higher, while for those hard drives with limited or compromised data recovery capabilities the BER threshold would likely need to be set lower.
Generally, it is to be appreciated that BER thresholds will be head and media design specific and can vary greatly among drives and in different contexts of HDD (hard drive data) generation, a BER threshold value should thus preferably be determined by each HDD design point. However, despite this apparent wide variability of BER thresholds, in accordance with at least one preferred embodiment of the present invention, a BER threshold value can advantageously be related to the overall error correction capability of the drive. In this posture, a BER threshold that leaves 50% ECC (error correcting code) power on a drive is recognized as being a useful and workable target or approximation in establishing a BER threshold value.
It is to be understood that the present invention, in accordance with at least one presently preferred embodiment, includes elements that may be implemented on at least one general-purpose computer running suitable software programs. These may also be implemented on at least one Integrated Circuit or part of at least one Integrated Circuit. Thus, it is to be understood that the invention may be implemented in hardware, software, or a combination of both.
If not otherwise stated herein, it is to be assumed that all patents, patent applications, patent publications and other publications (including web-based publications) mentioned and cited herein are hereby fully incorporated by reference herein as if set forth in their entirety herein.
Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention.
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Systems and methods for managing adjacent track interference in a hard drive. Adjacent track interference potential is ascertained in at least one track, and data corruption is averted via scrubbing data in at least one track with ascertained adjacent track interference potential.
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BACKGROUND OF THE INVENTION
The invention relates to a pump jack for use in pumping liquids, and more specifically to a pump jack for pumping oil from ground wells. The invention also relates to utilizing resources available at the well head to provide the energy, and motive power required to operate a pump jack.
Conventional pump jacks for pumping various liquids generally comprise a rocker arm pivotally mounted intermediate its ends on a main support member. On one limb (hereinafter referred to as the sucker-rocker limb) of this rocker arm the sucker rods are attached by flexible means to a typical "horsehead" and assembly specifically designed to maintain the sucker rods in vertical alignment within the well. The sucker rods which descend into the well are connected to the piston and pump which are mounted within the well near the bottom or at the level at which the liquid to be pumped is located. Usually, a counterweight is mounted on the opposed limb of the rocker arm (hereinafter referred to as the drive limb) to counter balance the greater weight of the sucker rod and piston assembly. To pivot the rocker arm and thus to reciprocate the sucker rods vertically within the well, the upper end of a motor driven mechanism is mounted fixedly to the drive limb of the rocker arm. Such a motor assembly is usually of the rotary type, and the rotation of a drive shaft mounted to a motor causes the sucker rod to reciprocate in a vertical direction as measured by the motion at the horsehead. Such a motor is either electrical or gasoline driven, in either case requiring attention to the provision of a source of energy either providing gasoline or other burnable hydrocarbon or the running of electrical wires to what is potentially a remote location.
An additional problem that is involved with such a motor driven type of pump jack is that the rotary motion of a motor be it electrical or gasoline driven is at considerably higher shaft speed than the desired speed at which the horsehead is intended to be reciprocated. Therefore, reducing speed, principally by gear reduction or other lever arm type reduction mechanism, and controlling of the speed itself by governors on the motor constitute built-in mechanical inefficiency since the efficiency of such gear reduction and multiple lever connections removes some of the energy available for driving the pump jack in the appropriate reciprocating manner.
In order to correctly operate such a rocker arm type of pump jack a counter weight is mounted on the drive limb of the rocker arm as was mentioned above. The purpose of a counter weight is to offset the considerably larger weight of the piston sucker rods and also of the column of oil residing above the piston which is being lifted by the motion of the pump jack. Such counterweighting systems can be of the over counterweighted or under counterweighted type. An over counterweighted system is one in which the counterweight more than compensates for the weight of the oil, the piston, the sucker rods, and the horsehead in addition to the weight of the sucker rod limb of the rocker arm such that when all power is removed from the system the counterweight will pull the piston to its uppermost position within the well. In such a system the force on the drive limb of the rocker arm tends to push the counterweighted drive limb in an upward direction while pushing the sucker-rod limb with horsehead downward. Simple removal of power will allow the counterweight to lift the column of oil and the piston. It should be noted that on over counterweighted system is an unusual design. The under counterweighted system which is considerably more typical has a counterweight that less than compensates for the above weights on the sucker-rod limb, therefore, when power is removed the horsehead tends to move to a downward position with the counterweight high in the air.
A significant problem in the operation of oil pump jacks is that they tend to be located in remote areas and also tend not to be too close together thereby making the provision of power to operate the pump jacks somewhat of a problem. As was mentioned above, the typical pump motor is either a gasoline engine driven or electrically-driven motor. An electrically-driven motor can be operated by stringing power lines to each of the wells no matter how remote or by local storage batteries which would have to be recharged or renewed on a periodic basis. A gasoline engine requires the provision of gasoline to storage tanks immediately adjacent the engine on a periodic basis in order to maintain the power source. Oil directly from the well cannot generally be burned in a gasoline engine because of the many high burning hydrocarbons that will tend to plug manifolds and carburetors.
The use of the natural gas which is available in most wells in the midwest and in the southwest of the United States has been limited to high gas production wells which are utilized in interstate or intrastate gas pipelines. If quantities of gas are not available in sufficient quantities to make it practical to pipe to such pipelines such gas is merely vented to the atmosphere. In the state of Ohio, such gas is often simply vented to the atmosphere because there is no economic gain from utilizing such small quantities over the vast distances of piping that would be necessary in order to connect to main intrastate or interstate gas lines and the proximity of many gas wells in Ohio or oil wells with some gas production to mountainous areas of the state additionally add to the problems and cost of laying such pipelines for small quantities of gas.
SUMMARY OF THE INVENTION
Therefore, a primary aspect of the present invention is the provision of a pump jack with a motor powered by natural gas available at the well head.
An additional aspect of the present invention resides in the provision of a smooth non-shock type of pump action available because a compressed gas is used as opposed to a substantially incompressible hydraulic fluid.
Another aspect of the present invention is the improvement of a conventional rocker arm type pump jack by providing a pneumatic motor powered by natural gas available from the well head.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a pump jack according to the present invention
FIG. 2 is a schematic flow diagram of a natural gas power source to a pump jack according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a side elevation view of a pump jack according to the present invention. Rocker arm 10 is a rigid member and is divided by a pivotally mounted support member or post 50 at support pad 44 into two sections. The left-hand section is known as the sucker-rod limb of the rocker arm while the right-hand section is known as the drive limb of the rocker arm. The two limbs of the rocker arm will be separately described beginning with the sucker-rod limb.
The sucker-rod limb of the rocker arm is adjustable in length, the main rocker arm 10 being a larger diameter pipe section than the extensible portion 12 of the sucker-rod limb. Adjustment is made by moving slidably disposed extensible portion 12 within the larger diameter rocker arm 10, a bolt 20 is configured to lockably engage the smaller diameter extensible portion 12 by being threaded through a nut 22 which has been welded to pipe 10 and a hole drilled therethrough allowing bolt 20 to be retained within pipe 10 with the tip of said bolt 20 engaging the pipe of extensible portion 12 in a lock position to maintain it at a specifically desired distance of extension. Bolt 20 may be disengaged from the lock position to release pipe 12 for further slidable movement within pipe 10. Horsehead 16 is a device for maintaining the point of application of power vertically above the well 42 even during the rocker-type reciprocating action of the pump jack. The horsehead 16 may be adjusted in order to optimize the action in maintaining a truly vertical disposition of cable 36 to maintain it in alignment with the sucker rods 40 which extend down well 42. The adjustment is provided by a turn buckle 28 which is pivotally connected to both the horsehead and the extensible section of the sucker-rod limb 12, the pivot points being 30 and 32 respectively. Pivot point 32 being attached to an eye lug 34 which is fixedly attached to the extensible section of the sucker-rod limb 12. Completing the description of the sucker-rod limb the cable section 36 is attached to sucker rod 40 via attachment mechanism 38 again to maintain a truly vertical orientation of the sucker rod in the well and vertical application of the force via cables 36.
Looking now to the drive limb of the rocker arm, counterweight 18 is attached to slidably extensible pipe section 14 which is slidably disposed within rocker arm pipe 10 and is lockable by releasable lock mechanism bolt 24 and nut 26 similar to bolt 20 and nut 22 described at the sucker-rod limb. The slidably extensible section 14 may be adjusted in order to optimize the use of the existing size of a counterweight 18 allowing adjustment of the moment thereof. Additionally counterweight 18 may be adjusted in weight by adding metal pieces thereto although such an adding mechanism is not shown, such adjustment of the size of weight 18 is well known to those who are familiar with the art of counterweight pump jacks. The pump jack shown in FIG. 1 is an under-counterweighted pump jack, therefore, the moment about pivot point 48 on the vertical support stanchion 50 is such that when all power is removed from the system the sucker-rod limb will be downwardly disposed with the drive limb and counterweight 18 being disposed high in the air.
The rocker arm assembly 10 is pivotally attached to bearing block 46 via pivot point 48 and is supported by a support saddle 44 attached to the bearing 46. A stanchion 50 is reinforced with a gusset 52 in order to give stability in the horizontal as well as vertical direction. A post of this type is known as a Samson post. The entire stanchion assembly is located on base 54 which is a standard I-beam and steelplate constructed base designed to maintain the stanchion in a rigid vertical position and also to provide support for the drive mechanism stanchions 70. The support base 54 is also designed so that the entire pump jack may be lifted onto a truck bed and transported to a different well site if necessary and therefore has been designed sufficiently strong to be able to withstand the forces not only of the operation of the pump jack but also of moving such a heavy weight down a highway on a flatbed truck.
Turning now to a description of the power-drive system of the pumpjack which is best understood by referring to both FIG. 1 and FIG. 2 together. FIG. 2 being a schematic representation of the natural gas powered motor in a process and instrumentation type of diagram. Inasmuch as the drive system portion of FIG. 1 and the schematic representations of that same system in FIG. 2 describe the same major features, identical numeration has been utilized where appropriate to allow for immediate cross-reference between the schematic FIG. 2 and the structural representation in FIG. 1.
The drive system is supported on the base structure 54 by stanchion 70 and drives against the drive limb portion of the rocker arm at gusset plates 56 which are weldably attached to pipe section 10 of the rocker arm. Therefore the distance between the drive point of attachment of gusset plates 56 is constant with respect to the pivot point 48 along the pipe section 10 of the rocker arm. The drive limb is driven by a pneumatic motor which is more completely described by reference to its elements as follows: A pneumatic type cylinder 60 is pivotably fixed to stanchion base 70 by pivot point 66 which is a pivot pin inserted through holes in gusset plates 68 which are themselves physically attached to stanchion 70, allowing the cylinder base 60 to be able to rotate freely about point 66 in response to the changes in direction of the application of force against the gusset plates 56 during the reciprocating motion of the pump jack. Since the pump jack depicted is an undercounterweighted pump jack the force being applied at gusset plate 56 is a pulling motion tending to pull the drive limb of the rocker arm in a downward position thereby pulling the horsehead up and pulling the column of oil out of the well 42. Then by simply releasing the downward force that is being applied in cylinder 60, the horsehead by its own weight and by the weight of the column of oil will proceed back to the bottom of the well or to the bottom point of the piston/in the well. The downward motion in cylinder 60 is provided by piston 62 mounted within cylinder 60. The driving force of gas within the pneumatic cylinder is provided by gas emanating directly from well 42. The gas which normally exists within a well is extracted from the outer annulus of the well between the oil pipe in which the sucker rods operate and the well casing, via pipe 80. The gas pressure in pipe 80 found in many wells in the state of Ohio would typically be around 200 psig. This gas pressure is then regulated to a constant working pressure by regulator 82 which is a typical diaphragm type gas regulator with pressure indication gauge 84 attached thereto. Referring to FIG. 2, natural gas coming from pipe 80 passes through regulator 82 which is controlled by a downstream sensing line in order to maintain the diphragm opening of the regulator valve and also passes pressure indicating gauge 84 which gives a visual representation of the actual pressure being delivered to the drive system. In a standard diaphragm-type pressure regulator the downstream pressure in a flow condition may be manually adjusted by an adjustment screw on the regulator. The regulated gas then passes to solenoid-operated valve 78 which is a double-acting four-ported solenoid operated valve suitable for such service. One of the ports has been plugged utilizing therefore only three of the ports in this process control design. FIG. 2 shows solenoid valve 78 in its de-energized position, however, since it is a double-acting solenoid valve it does tend to fail as is. The de-energized position chosen was merely one of two positions of operability of a double-acting solenoid valve. In FIG. 2 solenoid valve 78 is shown passing pressure regulated natural gas from the well to the upper side of the piston 62 which resides within cylinder 60. This will produce power on the downstroke which as described above is the desired power direction of cylinder 60 because the subject pump jack is of the under counterweighted type. The lower portion of cylinder 60 is open to the atmosphere since this cylinder operates power only in the downstroke direction. Solenoid valve 78 is then switched electrically at the completion of the downstroke allowing the gas residing above piston 62 within cylinder 60 to be vented via line 64 to low-pressure natural gas line 90 which is available to carry low pressure but usable natural gas in a pure state to some other location within the field or to a commercial low-pressure natural gas line. Switching of the solenoid valve is accomplished by the electrical actuation of a limit switch 72 by two adjustable plate-type limits 74 and 76. Limit plate 74 upon striking limit switch 72 identifies the lower end of the stroke or the end of the power stroke. Limit switch 72 then transmits the electrical signal to the double-acting solenoid valve 78 to shift positions to vent the cylinder 60, thereby initiating a downstroke of the piston in the well. The downstroke is not powered, and is caused only by the under counterweighting condition of the pump jack. On the upstroke, limit 76 engages limit switch 72 again shifting the solenoid valve from the vent position to the power position. Solenoid valve 78 is mounted upon a bracket 88 which is located on the Samson post 50 in order to hold it in rigid relationship to the regulator and natural gas pipe 80. The regulated gas supply to solenoid valve 78 is pipe section 86 and the flexible hose section from limit switch 78 to the uppermost inlet port of pneumatic cylinder 60 is hose 64. Thus, the entire assembly including unregulated gas supply in pipe 80 all the way through to the vent to pipe 90 encompassing the limit switch assemblies, the cylinder 60, piston 62, the regulator and solenoid valve comprises a pneumatic motor that utilizes natural gas as the working fluid.
The operation of natural gas within such a pneumatic motor arrangement inherently tends to cushion the shock loads normally associated with mechanical motor type drive assemblies such as those normally encountered on such a reciprocating pump jack being driven via a rotating electrical or gasoline driven motor. The end of the stroke in the power direction is terminated by the limit switch prior to the piston bottoming out in cylinder 60 and the compressability of the natural gas tends to act as a cushion at the bottom of the cylinder, and since a pneumatic-type fluid, natural gas, is being utilized the rapid shifting of solenoid valve 78 does not produce a hammer or hydraulic lock-type situation but produces a smooth cushioned change of direction of the cylinder. Thereby, the momentum of piston 62 in either the upward or the downward direction tends to be cushioned by the compressible gas in the ends of cylinder 60 eliminating shock loading. Also, natural gas that is usually vented to the atmosphere and lost is utilized at least for its pressure but not for its fuel content at the local well.
It will be apparent to those skilled in the art that numerous changes and modifications may be made in the preferred embodiment of my invention described above. Accordingly, the foregoing description and drawings are to be construed as solely illustrative and not in a limitative sense, the scope of my invention being solely defined by the appended claims.
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A pump jack of the type comprising a rocker arm pivotably mounted intermediate its ends on a support member, said rocker arm being divided by said pivot mounting into a sucker-rod limb and a drive limb wherein the improvement comprises a pneumatic motor pivotably attached to the drive support member and further pivotably attached to the mounting base of the pump jack to provide the power to reciprocate the pump jack. The working fluid of said pneumatic motor being natural gas which is available from the well casing of the well without any interference with the flow of the oil in the oil tube of the well thereby making use of an energy source available at any oil well without having to provide gasoline to drive a rotating type gasoline engine or electricity to drive an electric motor usually of the rotating variety. Also the stroke of a pneumatic cylinder inherently smooths out and eliminates the shock loading at the extremes of motion at the piston mounted to the sucker rods of such pump jack at the bottom of the well.
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BACKGROUND
[0001] Technical Field
[0002] The present disclosure generally relates to advanced transistor geometries and to electro-mechanical devices integrated with microelectronic circuits.
[0003] Description of the Related Art
[0004] Micro-electromechanical systems (MEMs) exist that combine electronic devices with mechanical structures to form electronically controlled moving parts for use as miniature sensors and actuators, for example. A typical MEMs device is shown in FIG. 1 as a planar transistor in which the conduction channel is electrically coupled to the source but detached from the drain. When a current is applied to the gate, the detached end of the conduction channel makes contact with the drain, thereby closing the circuit and turning on the transistor switch. Like other MEMs devices, the electrical portion of the device shown in FIG. 1 is disposed next to the mechanical portion, in substantially the same horizontal plane. As a result, the overall footprint is quite large, on the order of 10×10 μm 2 , whereas state-of-the-art electronic circuits are now measured in nanometers, about a thousand times smaller than MEMs devices. The relatively large size of current MEMs devices limits their production, packing density, precision, sensitivity, and economic value.
BRIEF SUMMARY
[0005] An integrated transistor in the form of a nano-electromechanical switch eliminates current leakage and increases switching speed. The nano-electromechanical switch features a semiconducting cantilever that extends from a portion of the substrate into a cavity. The cantilever flexes in response to a voltage applied to the transistor gate thus forming a conducting channel underneath the gate. When the device is off, the cantilever returns to its resting position, breaking the circuit and restoring a void underneath the gate that does not permit current flow. Hence, the off-state current is forced to be zero, thus solving the problem of leakage. Fabrication of the nano-electromechanical switch is compatible with existing CMOS transistor fabrication processes. Use of a back bias, and a metallic tip on the cantilever can further improve sensitivity of the switch. A footprint of the nano-electromechanical switch can be as small as 0.1×0.1 μm 2 .
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0006] In the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale.
[0007] FIG. 1A is a pictorial perspective view of an existing planar MEMs switch 50 according to the prior art.
[0008] FIG. 1B is derived from a photograph showing a top plan view of the existing planar MEMs switch 50 shown in FIG. 1A , indicating a length scale.
[0009] FIG. 2 is a flow diagram showing steps in a method of fabricating a nanoscale electromechanical switch as illustrated in FIGS. 3A-6B , according to one embodiment as described herein.
[0010] FIGS. 3A-5 are cross-sectional views of the nanoscale electromechanical switch at successive steps during fabrication using the method shown in FIG. 2 .
[0011] FIG. 6A is a cross-sectional view, of a completed nanoscale electromechanical switch, according to a first embodiment.
[0012] FIG. 6B is a top plan view of the completed nanoscale electromechanical switch shown in FIG. 6A .
[0013] FIGS. 7-8C are cross-sectional views of alternative embodiments to the completed nanoscale electromechanical switch shown in FIGS. 6A-6B .
DETAILED DESCRIPTION
[0014] In the following description, certain specific details are set forth in order to provide a thorough understanding of various aspects of the disclosed subject matter. However, the disclosed subject matter may be practiced without these specific details. In some instances, well-known structures and methods of semiconductor processing comprising embodiments of the subject matter disclosed herein have not been described in detail to avoid obscuring the descriptions of other aspects of the present disclosure.
[0015] Unless the context requires otherwise, throughout the specification and claims that follow, the word “comprise” and variations thereof, such as “comprises” and “comprising” are to be construed in an open, inclusive sense, that is, as “including, but not limited to.”
[0016] Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more aspects of the present disclosure.
[0017] Reference throughout the specification to integrated circuits is generally intended to include integrated circuit components built on semiconducting substrates, whether or not the components are coupled together into a circuit or able to be interconnected. Throughout the specification, the term “layer” is used in its broadest sense to include a thin film, a cap, or the like and one layer may be composed of multiple sub-layers.
[0018] Reference throughout the specification to conventional thin film deposition techniques for depositing silicon nitride, silicon dioxide, metals, or similar materials includes such processes as chemical vapor deposition (CVD), low-pressure chemical vapor deposition (LPCVD), metal organic chemical vapor deposition (MOCVD), plasma-enhanced chemical vapor deposition (PECVD), plasma vapor deposition (PVD), atomic layer deposition (ALD), molecular beam epitaxy (MBE), electroplating, electro-less plating, and the like. Specific embodiments are described herein with reference to examples of such processes. However, the present disclosure and the reference to certain deposition techniques should not be limited to those described. For example, in some circumstances, a description that references CVD may alternatively be done using PVD, or a description that specifies electroplating may alternatively be accomplished using electro-less plating. Furthermore, reference to conventional techniques of thin film formation may include growing a film in-situ. For example, in some embodiments, controlled growth of an oxide to a desired thickness can be achieved by exposing a silicon surface to oxygen gas or to moisture in a heated chamber.
[0019] Reference throughout the specification to conventional photolithography techniques, known in the art of semiconductor fabrication for patterning various thin films, includes a spin-expose-develop process sequence typically followed by an etch process. Alternatively or additionally, photoresist can also be used to pattern a hard mask (e.g., a silicon nitride hard mask), which, in turn, can be used to pattern an underlying film.
[0020] Reference throughout the specification to conventional etching techniques known in the art of semiconductor fabrication for selective removal of polysilicon, silicon nitride, silicon dioxide, metals, photoresist, polyimide, or similar materials includes such processes as wet chemical etching, reactive ion (plasma) etching (RIE), washing, wet cleaning, pre-cleaning, spray cleaning, chemical-mechanical planarization (CMP) and the like. Specific embodiments are described herein with reference to examples of such processes. However, the present disclosure and the reference to certain deposition techniques should not be limited to those described. In some instances, two such techniques may be interchangeable. For example, stripping photoresist may entail immersing a sample in a wet chemical bath or, alternatively, spraying wet chemicals directly onto the sample.
[0021] Specific embodiments are described herein with reference to nano-electromechanical switching devices that have been produced; however, the present disclosure and the reference to certain materials, dimensions, and the details and ordering of processing steps are exemplary and should not be limited to those shown.
[0022] Turning now to the figures, FIG. 1A shows an existing planar MEMs switch 50 mounted on top of a substrate. The switch 50 has a source terminal 52 , a gate terminal 54 , a drain terminal 56 , and a cantilever arm 58 of length L having a tip 59 . Each one of the terminals 52 , 54 , 56 , and the cantilever arm 58 , is made of a conductive material, e.g., a semiconductor or metal that conducts electric current. The cantilever arm 58 is a flexible, moveable member, extending out from the source terminal 52 to a distance beyond a nearest edge 60 of the drain terminal 56 . The gate terminal 54 is disposed to the side of the cantilever arm 58 . The cantilever arm 58 is spaced apart from the gate terminal 54 by a short distance so that when the gate terminal 54 is energized, the cantilever arm 58 is drawn toward the gate terminal 54 . Because the tip 59 of the cantilever arm 58 moves more freely than the fixed end nearest the source terminal 52 , the tip 59 can make contact with the drain terminal 56 . When the tip 59 contacts the drain terminal 56 , the switch 50 is closed, permitting flow of electric current between the source terminal 52 and the drain terminal 56 , through the cantilever arm 58 , which acts as a current channel.
[0023] FIG. 1B shows an enlarged view of the planar MEMs switching device 50 superimposed with a 3-μm length scale. The scale indicates that the cantilever arm 58 is about 10 μm long, which is consistent with the sizes of conventional MEMs devices. The overall footprint of the exemplary planar MEMs switch 50 is in the range of about 200 μm 2 .
[0024] FIG. 2 shows steps in a method of fabricating a cantilever switch as a nanoscale transistor device suitable for use in integrated circuits, according to one embodiment. Unlike the planar MEMs switching device 50 , the cantilever switch described herein is integrated into a layered semiconductor structure that forms an extension of the substrate, and the process for fabricating the cantilever switch is fully compatible with conventional CMOS processes. Steps in a method 100 for constructing such a nanoscale cantilever switch on a silicon-on-insulator (SOI) substrate are further illustrated by FIGS. 3-6B , and described below. A second embodiment built on a silicon substrate is shown in FIG. 7 . Additional steps that can be used to construct a third embodiment are illustrated in FIGS. 8A-8C .
[0025] At 102 , a layered stack 122 is formed by epitaxially growing layers of first and second semiconductor materials, e.g., silicon germanium (SiGe) and silicon in an alternating arrangement on an SOI wafer, as shown in FIGS. 3A and 3B . The SOI wafer includes a silicon substrate 114 , a buried oxide (BOX) layer 116 of thickness in the range of about 15-25 nm and, above the BOX layer 116 , an overlying silicon layer 118 having a thickness in the range of about 10-15 nm. Such an SOI wafer is a standard starting material that is commonly used in the semiconductor industry. Alternatively, a silicon wafer can be used as the starting material, and the BOX layer 116 and the overlying silicon layer 118 can be formed as initial steps of the present fabrication process. In one embodiment, a first region of SiGe 120 is formed at a same level as the overlying silicon layer 118 as follows: first, a hard mask having a first layer of silicon dioxide (SiO 2 ) and a second layer of silicon nitride (SiN) is formed on the overlying silicon layer 118 . The hard mask is patterned to remove a portion corresponding to the desired size of the SiGe 120 , and SiGe is epitaxially grown from the exposed surface of the overlying silicon layer 118 . The SiO 2 layer of the hard mask protects the overlying silicon layer 118 from contacting the SiN layer at high temperatures during the epitaxy. Then germanium from the SiGe region is driven downward into the overlying silicon layer 118 using a condensation process that is known in the art. The hard mask layer is then removed to produce the structure shown in FIG. 3A .
[0026] Next, a first additional silicon layer 124 that incorporates a second region of SiGe 126 is formed. In one embodiment, the first additional silicon layer 124 is grown epitaxially from the overlying silicon layer 118 to a thickness in the range of about 15-30 nm. The thickness of the first additional silicon layer 124 will determine the thickness, and will influence the flexibility, of the cantilever for the nanomechanical switch. The first additional silicon layer 124 can be doped in-situ during the epitaxy process, or by implantation, with negative ions, e.g., arsenic or phosphorous, to a concentration in the range of about 8.0 E19-3.0 E20 cm −3 . The first additional silicon layer 124 is then patterned, using a SiO2/SiN hard mask, to form an opening that is surrounded by silicon material. The second region of SiGe 126 can then be grown epitaxially to fill the opening using the same technique just described. The SiO2/SiN hard mask is then removed.
[0027] Next, an additional silicon layer 128 that incorporates a third region of SiGe 130 is formed. In one embodiment, the additional silicon layer 128 is grown epitaxially from the first additional silicon layer 124 to a thickness in the range of about 10-15 nm. The thickness of the additional silicon layer 128 will determine a distance through which the cantilever will need to move to close the switch. Such a distance can be achieved with precision using epitaxy to form the additional silicon layer 128 and the third region of SiGe. The additional silicon layer 128 can be doped in-situ during the epitaxy process, or by implantation, with negative ions, e.g., arsenic or phosphorous, to a concentration in the range of about 1.0-2.0 E20 cm −3 . The additional silicon layer 128 is then patterned, using a SiO2/SiN hard mask, to form an opening that, again, is surrounded by silicon material.
[0028] The third region of SiGe 130 can then be grown epitaxially to fill the opening. The SiO2/SiN hard mask is then removed to produce the structure shown in FIG. 3B .
[0029] At 104 , a conventional transistor gate structure 140 is formed on top of the third region of SiGe 130 , overlying the layered stack. First, a thin layer, e.g., 2-5 nm of a dielectric material, e.g., SiO 2 or a high-k material such as HfO 2 , is deposited, followed by layers of polysilicon and SiN. The SiO 2 , polysilicon, and SiN are then patterned to form the gate structure 140 , including a gate dielectric 148 , a gate electrode 150 , and an insulating cap 152 . Insulating sidewall spacers 154 are then formed in the usual way by conformal deposition of, for example, SiN, followed by anisotropic removal of the SiN portion overlying the gate electrode 150 down to the SiN cap 152 , leaving in place the sidewall portions of the SiN. The transistor gate structure 140 thus formed can be used as a mask for doping the additional silicon layer 128 to reduce resistance of the silicon. It will not matter if dopants are also incorporated into the third region of SiGe 130 , because the SiGe regions in the present structure are sacrificial. Alternatively, a metal gate can be used instead of a polysilicon gate. A metal gate can be formed by any conventional method, e.g., by a replacement metal gate (RMG) process in which, after the transistor structure 140 is formed, the polysilicon gate electrode is removed and replaced by a metal gate electrode.
[0030] At 106 , epitaxial raised source and drain regions 142 , 144 are formed on either side of the transistor gate structure 140 , as shown in FIG. 4 . In one embodiment, the raised source and drain regions 142 , 144 are grown epitaxially from the additional silicon layer 128 and the third region of SiGe 130 to a thickness in the range of about 20-35 nm. The raised source and drain regions 142 , 144 can be doped in-situ with ions of a same polarity as those used to dope the first additional silicon layer 124 . The raised source and drain regions 142 , 144 include facets 146 sloping down to the base of the sidewall spacers 154 .
[0031] At 108 , portions of the raised source and drain regions 142 , 144 are removed by a partially anisotropic etching process to form openings 162 at the base of the transistor gate structure 140 , thus exposing the third SiGe region 130 . The openings 162 are desirably in the range of 3-8 nm, thus leaving about a 5 nm gap between the base of the sidewall spacers 154 and the source and the inner corners of the faceted source and drain regions 142 , 144 .
[0032] At 110 , the SiGe portions of the layered stack are selectively removed to form a cavity 160 surrounding a cantilever arm 164 having a tip 166 , as shown in FIGS. 5, 6A . In one embodiment, removal of sacrificial first, second, and third regions of SiGe, 120 , 126 , 130 , respectively, is accomplished by exposing the layered stack to hydrochloric acid (HCL). The HCL will selectively etch the regions of SiGe, leaving behind various layers of silicon. First, the HCL attacks the third region of SiGe 130 directly below the openings 162 , creating a void underneath the transistor gate structure 140 . Then, because the HCL is a fluid, e.g., a liquid etchant, the HCL will flow into the voids thus created, and continue etching out the second region of SiGe 126 , followed by the first region of SiGe 120 , thus releasing the cantilever arm 164 . The cantilever arm 164 is formed from remaining silicon in the first additional silicon layer 124 so that the cantilever arm 164 extends out from underneath the source region 142 , into the cavity 160 directly below the transistor gate structure 140 . When the SiGe removal step 110 is complete, the cantilever arm 164 can flex freely within the cavity 160 , toward or away from the transistor gate structure 140 , based on an electric potential of the gate electrode 150 relative to an electric potential of the cantilever arm 164 .
[0033] In operation, when a sufficient positive voltage, exceeding a threshold value, is applied to the gate electrode 150 , the doped cantilever arm 164 , is deflected toward the oppositely doped gate. The cantilever arm 164 may flex enough that the tip 166 makes physical and electrical contact with the base of the drain region 144 . When such contact occurs, the electromechanical switch is closed as a current path is established from the source region 142 to the drain region 144 , wherein the cantilever arm 164 serves as a transistor channel. The threshold voltage can be tuned during fabrication by adjusting the thickness of the additional silicon layer 128 . In addition, a voltage, e.g., in the range of about 3-4 V can be applied via a backside electrical contact to the silicon substrate 114 to back-bias the BOX layer 116 , so as to repel the cantilever arm 164 and assist in moving the tip 166 toward the drain region 144 . The BOX layer 116 thus may serve as a back gate. When the voltage applied to the gate electrode 150 no longer exceeds the threshold voltage, the cantilever arm 164 relaxes and returns to its original extended position. Alternatively, the cantilever arm 164 and the source and drain regions 142 , 144 can be positively doped to form a p-type device for which, in operation, a negative voltage is applied to the gate electrode 150 .
[0034] In the extended position, the switch is open, i.e., an open circuit exists between the source 142 and the drain 144 . Thus, in the off state, no current flows through the cantilever arm 164 . Furthermore, because the cavity 160 is positioned directly underneath the transistor gate structure 140 , charge cannot leak from the tips of the source and drain regions 142 , 144 into the substrate. A small amount of charge may migrate from the source and drain regions 142 , 144 into the silicon layers 128 , 124 , 118 in response to localized electric fields. However, a current cannot flow from the source region 142 to the drain region 144 because the electrical path is blocked by either the cavity 160 or the insulating BOX layer 116 . Thus, the off-state leakage current is zero, preventing drainage of electric battery power supplied to the transistor. For the cantilever arm 164 to be flexible enough to open and close the switch, the cantilever arm 164 is designed to have suitable mechanical properties and dimensions that will allow the cantilever arm to respond to voltage levels used in integrated circuits, in the range of about 0.5-1.0 V. In one embodiment, the cantilever arm 164 has an aspect ratio of at least about 4.0, and the threshold voltage is about 0.8V.
[0035] More generally, the switching action can be the result of one or more of a capacitive, electrostatic, or inductive effect. For example, the gate electrode 150 , drain region 144 , and cantilever arm 164 may incorporate electromagnetic materials having magnetic properties that are responsive to the influence of a voltage applied to the gate electrode 150 .
[0036] At 112 , the openings 162 are sealed with a glass material 172 , to form a completed structure as shown in FIG. 6A . In one embodiment the glass material 172 is a spin-on glass (SOG), a material well known in the art. The spin-on glass is a liquid material having a high viscosity at temperatures less than 100 C, which can be cured, following deposition, to form a solid state glass. Alternatively, SiO 2 can be sputtered over the openings 162 to form a seal. Once the openings 162 are sealed, the glass material 172 can then be recessed below the top surfaces of the source and drain regions 142 , 144 .
[0037] FIG. 6B shows that the transistor gate structure 140 is anchored on isolation regions 180 , e.g., silicon dioxide insulating structures separating adjacent devices from one another. The isolation regions 180 extend behind and in front of a cut plane 182 of the cross-sectional views shown in FIGS. 3A-6A . Thus, in FIGS. 5 and 6A , the transistor gate structure 140 appears to be floating over the cavity 160 , but actually, the transistor gate structure 140 forms a bridge that extends over the cavity 160 in a direction transverse to the cut plane 182 .
[0038] FIG. 7 shows a second embodiment of the nanoscale electromechanical switch in which the BOX layer 116 is omitted. In the second embodiment, SiGe can be formed at the same level as the overlying silicon layer 118 by simply growing the SiGe epitaxially from the underlying silicon substrate 114 . Alternatively, the overlying silicon layer 118 can be formed as a SiGe layer and patterned to incorporate regions of silicon, to achieve the same structure shown in FIG. 7 . However, the embodiment shown in FIG. 7 will not have the option of applying a back bias to the device to assist in moving the cantilever arm 164 . Doing so without the BOX layer 116 in place would simply short out the transistor by coupling the source to the drain through the silicon substrate 114 and the intervening additional layers of silicon 118 , 124 , 128 . Alternatively, the second embodiment shown in FIG. 7 can be fabricated using the condensation process described above.
[0039] FIGS. 8A-8C illustrate a third embodiment of nanoscale electromechanical switch 200 in which sensitivity of the device is enhanced by fabricating the tip 166 from a metal, e.g., tungsten (W). Such a modification can be made to step 102 , as shown in FIGS. 8A-8B . FIG. 8A shows incorporating a metal tip 192 into the first additional silicon layer 124 . Following formation of the second SiGe region 126 , a SiN hard mask is deposited and patterned with an opening that aligns with the leftmost end of the doped silicon that will be the cantilever arm 164 . The tip 166 of the cantilever arm 164 is then etched away and replaced with the metal tip 192 , e.g., by depositing tungsten and polishing the tungsten surface to stop on the SiN hard mask. While the SiN hard mask is still in place, the tungsten is recessed and the recessed area is filled with an oxide, e.g., SiO 2 , to form an oxide mask 194 covering the metal tip 192 . The oxide is planarized to stop on the SiN hard mask. Then the SiN hard mask is removed, leaving the oxide mask 194 covering the metal tip 192 . The oxide mask prevents exposure of the metal tip 192 during the subsequent epitaxial growth of the second additional silicon layer and the third region of SiGe. After the cavity 160 is formed ( FIG. 8B ), the oxide mask can be removed in an isotropic dry etch process that is selective to silicon and oxide. In one embodiment, the dry etch process employs a known etchant that is typically used to remove silicon-cobalt-nickel (SiCoNi) films. The etchant can enter the cavity 160 through the opening 162 adjacent to the drain region 144 . FIG. 8C shows the completed third embodiment of the nanoscale electromechanical switch 200 . During operation, a metal tip 196 helps reduce contact resistance between the cantilever arm 164 and the doped drain region 144 .
[0040] It will be appreciated that, although specific embodiments of the present disclosure are described herein for purposes of illustration, various modifications may be made without departing from the spirit and scope of the present disclosure. Accordingly, the present disclosure is not limited except as by the appended claims.
[0041] These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.
[0042] The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments.
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An integrated transistor in the form of a nanoscale electromechanical switch eliminates CMOS current leakage and increases switching speed. The nanoscale electromechanical switch features a semiconducting cantilever that extends from a portion of the substrate into a cavity. The cantilever flexes in response to a voltage applied to the transistor gate thus forming a conducting channel underneath the gate. When the device is off, the cantilever returns to its resting position. Such motion of the cantilever breaks the circuit, restoring a void underneath the gate that blocks current flow, thus solving the problem of leakage. Fabrication of the nano-electromechanical switch is compatible with existing CMOS transistor fabrication processes. By doping the cantilever and using a back bias and a metallic cantilever tip, sensitivity of the switch can be further improved. A footprint of the nano-electromechanical switch can be as small as 0.1×0.1 μm 2 .
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CLAIM OF PRIORITY
[0001] The present application claims priority from Japanese Patent application serial No. 2009-083976 filed on Mar. 31, 2009, the content of which is hereby incorporated by reference into this application.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an evaluating method for integrity of vibration of a steam dryer and a test device of the steam dryer.
[0003] Japanese Published Unexamined Patent Application No. 2007-127633 discloses a technique for performing a scale down test simulating a main steam line equipped with a steam dome of a nuclear reactor, a dryer (steam dryer), and main steam pipes with an air flow which can be handled conveniently and can realize a large flow rate, and evaluating acoustic loading of the steam dryer.
SUMMARY OF THE INVENTION
[0004] The steam flows in the main steam pipes of an actual system, whereas air flows in the scale down test according to Japanese Published Unexamined Patent Application No. 2007-127633. Because the property of the steam and air are different, when a pressure (load) fluctuation phenomenon of the actual system is to be estimated, a similarity rule of the pressure fluctuation phenomenon becomes important. Also, the scale down test using an air flow had a problem that influence of liquid droplets contained in the steam could not be simulated. Therefore, a technique in which property is made more similar to that of an actual system was necessary in order to reduce the influence of a similarity rule and improve evaluation accuracy.
[0005] The object of the invention is to accurately evaluate integrity of vibration of a dryer of an actual system.
[0006] A method for evaluation according to an embodiment of the invention is an evaluating method for integrity of vibration of a steamdryer using a reduced model in a nuclear plant including the steam dryer for reducing moisture of the steam generated inside a steam dome of a nuclear reactor pressure vessel, and a plurality of main steam pipes for transporting the steam to outside, which includes the steps of performing a steam test with the reduced model, calculating fluctuating stress applied to the steam dryer, and confirming integrity of vibration.
[0007] A test device of a steam dryer according to an embodiment of the invention is a test device of a steam dryer manufactured for evaluating integrity of vibration of the steam dryer in a nuclear plant including the steam dryer for reducing moisture of the steam generated inside a steam dome of a nuclear reactor pressure vessel and a plurality of main steam pipes for transporting the steam to outside. The test device includes a plate-like member fixing the steam dryer to the steam dome, a partition plate dividing a space on an upper face side of the plate-like member, and sluice valves disposed in the main steam pipes and switching the main steam pipes to which the steam flows in from the steam dome.
[0008] According to an embodiment of the invention, more accurate evaluation of integrity of vibration of a dryer of an actual system becomes possible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic view of a test device of a BWR main steam line according to a first embodiment;
[0010] FIG. 2 is a schematic view (top view) of the test device of a BWR main steam line according to the first embodiment;
[0011] FIG. 3 is a schematic view (top view) of the test device of a BWR main steam line according to the first embodiment;
[0012] FIG. 4 is a block diagram of a procedure for evaluating integrity of a BWR dryer according to the first embodiment;
[0013] FIG. 5 is a schematic drawing of a procedure for evaluating pressure fluctuation of a BWR dryer according to a second embodiment;
[0014] FIG. 6A is a drawing when a plate-like member of FIG. 2 is viewed from below; and
[0015] FIG. 6B is a drawing when a plate-like member of FIG. 3 is viewed from below.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] Below, embodiments will be described.
First Embodiment
[0017] FIG. 1 is a schematic view of a test device for a BWR main steam line according to the present embodiment. In the embodiment, a steam dome 1 simulating an upper part of a nuclear reactor of an actual system, a steam dryer (dryer) 2 arranged inside the steam dome, main steam nozzles 3 , and main steam pipes 4 are provided. Also, a plurality of stub tubes 5 for steam relief valves and the like are arranged on the main steam pipes 4 . These equipment and structures are manufactured reducingly simulating an actual system. The steam that has flown through the main steam pipes 4 is compressed by a steam compressor 10 disposed downstream. The steam compressor 10 pressurizes the steam and feed the steam again from a lower part of the steam dome 1 .
[0018] More specifically, the steam dryer (dryer) 2 is arranged on an upper face of a plate-like member 21 . A dryer skirt 20 is a cylindrical structural member and is joined with a lower face of the plate-like member 21 . Also, a lower end of the dryer skirt 20 is joined with the steam dome 1 . A partition plate 6 described below is arranged so as to partition a space on the upper face side of the plate-like member 21 . Further, the plate-like member 21 includes a plurality of holes 22 ( FIG. 6A and FIG. 6B ) for feeding the steam from the steam compressor 10 to the dryer 2 . Detailed configuration of FIG. 6A and FIG. 6B will be described separately.
[0019] Sensors 7 are arranged in the dryer 2 , the main steam pipes 4 , and the stub tubes 5 respectively. A measuring instrument 8 measures pressure by a signal from the sensors 7 , and a computer 9 calculates stress from the pressure.
[0020] In a line that returns the steam having flown from the main steam pipes 4 to the steam compressor 10 , a silencer 15 and a water spray device 16 spraying droplets 17 to the steam are arranged. In a line that feeds the steam from the steam compressor 10 to the steam dome 1 , a drain water tank 19 for storing discharged drain water 18 and a silencer 15 are arranged.
[0021] Also, the diameter of a horizontal cross-section of the steam dome 1 of the test device is 1 m or below, whereas that of the actual system is 5-6 m.
[0022] FIG. 2 is a top view of the test device according to the embodiment. The partition plate 6 divides a space on the upper face side of the plate-like member 21 arranged in the steam dome 1 into three. The divided spaces inside the steam dome are referred to as a space 1 A, 1 B, 1 C respectively. Also, the test device includes a main steam pipe 4 a to which the steam flows in from the space 1 A, and a main steam pipe 4 b to which the steam flows in from the space 1 B. In FIG. 2 , two lines are shown, and a test can be performed for each line by being switched by valves 11 a, 11 b (sluice valve). Further, 4 lines of main steam pipes are arranged in an actual system, however 2 lines are eliminated in the test device. Therefore, in the test device, a dryer and a main steam pipe to which the steam flows in for the space 1 C are omitted.
[0023] More specifically, the partition plate 6 is constructed of two members 6 a, 6 b. The member 6 a is arranged so as to partition the horizontal cross-section of the steam dome 1 into ½ each. Also, the member 6 b is arranged so as to partition the horizontal cross-section of the space on the main steam pipes 4 a, 4 b side out of the space partitioned by the member 6 a into ½ each. Further, the member 6 b may be arranged so as to partition the horizontal cross-section of the steam dome 1 into ½ each, as the member 6 a does, to divide the space on the upper face side of the plate-like member 21 into four.
[0024] Furthermore, because the cylindrical steam dome 1 is used in the embodiment, the space on the upper face side of the plate-like member 21 becomes three spaces of 1 A, 1 B, 1 C. However, the spaces used in the test are only 1 A and 1 B. Consequently, the plate-like member 21 is devised so that the steam flows into the space 1 A ( 1 B) only. FIG. 6A shows a view A-A in FIG. 1 of the plate-like member 21 . In the plate-like member 21 , the holes 22 are formed only in a fan-shape region 23 occupying ¼ of the entire area, and holes of a remaining region 24 are blocked. Therefore, when the space 1 A ( 1 B) is to be tested, the plate-like member 21 is arranged so that steam flows into the space 1 A ( 1 B) through the holes 22 of the fan-shape region 23 . By blocking the holes of the region 24 that occupies ¾ out of the entire area of the plate-like member 21 , the steam can be fed only to the space 1 A ( 1 B), and the steam compressor can be made compact.
[0025] Further, it is also possible to divide the space on the upper face side of the plate-like member 21 into two. FIG. 3 is the top view of the test device of the case the space is divided into two. Also, FIG. 6B shows the plate-like member 21 of the case in that the space is divided into two. In the plate-like member of the case in that the space is divided into two, the holes 22 are formed only in the ½ region 23 and holes in the remaining ½ region 24 are blocked.
[0026] The dryer 2 of the actual system is an apparatus for separating water droplets by corrugated plates arranged inside the dryer 2 and drying the steam (separating water droplets) with respect to the steam flowing from the lower part. The test device is manufactured mainly by simulating appearance and a flow passage configuration of the dryer 2 . The steam having passed the dryer 2 causes convection inside the steam dome 1 , and flows into the main steam pipes 4 through the main nozzles 3 . When steam passes the stub tube 5 for a steam relief valve of the main steam pipe 4 , pressure waves resonate inside a closed branch pipe of the stub tube and pressure pulsation is generated. The pressure pulsation generated is transmitted as far as the dryer 2 through the main steam pipe 4 . The present test device can also reproduce pressure pulsation generated in a flow around the main steam nozzles 3 of the steam dome 1 and the dryer 2 .
[0027] In the embodiment, steam flow rate is limited by steam generating capacity of the steam compressor 10 . Therefore, the main steam pipes 4 connected to the steam dome 1 are arranged respectively simulating 2 lines to which the steam of the spaces 1 A and 1 B flows in. Thereby, steam flow rate required for the test is inhibited. However, if only some numbers of lines of the main steam pipes 4 are arranged, a steam flow inside the steam dome 1 may possibly changes. Therefore, the partition plate 6 dividing the inside of the steam dome 1 into three (four) is arranged, and the condition of the steam flow inside the steam dome 1 is brought closer to that of the actual system. Further, the test is performed in plural times by exchanging or switching each line of the main steam pipes 4 , and characteristics of pressure pulsation generated in each main steam pipe are evaluated.
[0028] The pressure pulsation generated can be measured by the sensors 7 arranged in the steam relief valve stub tubes 5 , the main steam pipes 4 , the dryer 2 , and the like. Electric signals obtained by the sensors 7 are processed by the measuring instrument 8 and are evaluated by the computer 9 as pressure fluctuation, displacement fluctuation, or stress fluctuation. The function of the measuring instrument 8 is to take analog voltage output signals from the sensors in, to convert to digital data, and to record them. In the computer 9 , a voltage signal measured by the measuring instrument 8 is converted to a value of strain, acceleration, and pressure. Then, from the obtained value of strain, acceleration, and pressure, the stress generated on the dryer is analyzed.
[0029] For the sensor 7 , a strain gauge, accelerometer, pressure gauge or the like is used. With respect to the pressure gauge and accelerometer, pressure fluctuation distribution and displacement fluctuation distribution inside the steam dome are evaluated using the pressure fluctuation and acceleration of plural points measured. The pressure fluctuation distribution is the distribution representing the magnitude of the pressure fluctuation (pressure amplitude) in a constant time in a space inside the steam dome. Then, the stress fluctuation distribution generated on the dryer is calculated by structural analysis and the like. Also, when the strain gauge is used, the stress fluctuation can be evaluated from the obtained strain fluctuation based on an equation (1) below.
[0000] Stress fluctuation=modulus of longitudinal elasticity×strain fluctuation (1)
[0030] When the stress fluctuation of the dryer thus obtained satisfies an inequality (2) below with respect to the fatigue limit of material, the integrity of vibration of the dryer can be evaluated to be sound.
[0000] Safety factor×stress fluctuation<fatigue limit of material (stress fluctuation value) (2)
[0031] By a series of evaluation procedures described above, integrity of vibration of the dryer with respect to high cycle fatigue can be evaluated.
[0032] By simulating the main steam pipes 4 on respective lines as described above, the steam flow velocity inside the main steam pipes 4 can be made as high as or higher than that of the actual system with a simpler test device. As a result, it becomes possible to generate the pressure pulsation inside the steam relief valve stub tube 5 by the steam flow and to evaluate the transmission characteristic of the pressure pulsation by the test device.
[0033] Also, by arranging the partition plate 6 inside the steam dome, the flow condition inside the steam dome is brought closer to the condition of the actual system. Further, by making the partition plate 6 of a material causing absorption or reflection of the sound, the partition plate becomes a boundary condition of the sound (pressure pulsation), and the tests can become possible under a variety of conditions. Particularly, when the pressure pulsations generated in respective main steam pipes are to be composed, it is preferable to provide a silencing function in order to reduce an influence of the partition plate. The partition plate is manufactured preferably by a silencing material such as a perforated plate, perforated material, porous material, corrugated plate, glass wool, nonwoven fabric, textile, ceramic, and spray material. Also, it is effective to arrange one or a plurality of the partition plate and silencing equipment.
[0034] The knowledge described above is based on the fact that, when the steam flowing inside the steam dome of the actual system is viewed in a horizontal cross-section, the steam flow is symmetric with respect to the fan-shape region occupying ¼ of the horizontal cross-section. Therefore, by arranging the partition plate in the steam dome so as to allow a symmetric flow, the flow similar to that when symmetry is maintained is realized by the partition plate. Consequently, when the partition plate is not provided in FIG. 2 and the steam flows through the main steam pipe 4 b only, it is presumed that the flow becomes an asymmetrical flow without symmetry.
[0035] Also, it is necessary to arrange the partition plate 6 so as not to obstacle a flow of the steam flowing in to the main steam nozzles 3 . Accordingly, it is preferable to arrange the partition plate 6 in the orthogonal direction to the dryer bank face and the horizontal direction as shown in FIG. 1 , FIG. 2 and FIG. 3 . That is, the partition plate 6 is arranged so that the divided dryer is configured symmetrically. Further, in order to confirm the characteristic of the pressure pulsation, it is necessary to faithfully miniaturize the shape of the actual system, and to divide the space above the plate-like member into three (four) or two.
[0036] Furthermore, in order to inhibit the noise generated by the steam compressor and the valves in the test loop, it is preferable that a silencer or the like is arranged in an inlet and an outlet of the test device. In addition, by making the horizontal cross-section of the steam dome 1 semi-circular or fan-shape instead of arranging the partition plate 6 , a similar effect as that of the embodiment can be obtained.
[0037] Only by such simplifications, the steam test became possible. Also, according to the embodiment, since it is enough just to prepare reduced models of the dryer 2 belonging to the spaces 1 A, 1 B and the main steam pipes 4 to which the steam flows in from the space 1 A, 1 B, the number of members to be manufactured can be reduced and the manufacturing cost of a test body can be lowered. Also, the capacity of steam circulation facilities can be lowered, and the manufacturing cost of the steam test loop can be reduced as well. Further, another feature of the embodiment is that all of the strength of the pressure pulsation generated in the steam relief valve stub tube 5 , the transmission characteristic of the pressure pulsation of the main steam line, and the pressure fluctuation load applied to the dryer 2 can be evaluated directly based on the values measured in the test.
[0038] In order to evaluate the characteristic of the pressure fluctuation, the test device is provided with the pressure sensors, strain gauges, accelerometers, and displacement gauges in respective locations. When a technique in which an acoustic velocity is obtained from the difference of the property fluctuation among a plurality of points and the property is evaluated is employed, the pressure fluctuation can be evaluated more accurately. Also, when the strain gauges are arranged on the main steam pipes 4 , if the pipe thickness is thick, the sensitivity of the sensor lowers. Therefore, by making only the sensor attaching section thin, measurement can be performed with high accuracy while securing safety. In particular, a straight pipe section of a descending pipe arranged in the vicinity of the main steam nozzle 3 is close to the dryer 2 inside the steam dome 1 . Therefore, it is preferable to arrange the strain gauges with the thickness of the straight pipe section being changed to thin.
[0039] FIG. 4 shows a procedure for evaluating integrity of a BWR dryer according to the embodiment. In the evaluation technique, the test is performed on each main steam pipe that is different in shape. Therefore, in step S 1 , the inside of the steam dome is divided by the partition plate, and the tests are performed plural times.
[0040] First, in order to test the pressure fluctuation distribution of the space 1 A, the steam is fed to the main steam pipe 4 a through the space 1 A. Then, the pressure fluctuation distribution of the space 1 A is calculated as step S 2 . In this case, the space of the steam dome is divided, and the shape of the space is different from the shape of the actual system. Therefore, in step S 3 , the pressure fluctuation distribution of the space 1 A is corrected by an analysis to the pressure fluctuation distribution X inside the steam dome without the partition plate which is similar to the actual system. This correction can be performed by an acoustic analysis. In this regard, the acoustic analysis is performed for each case with the partition plate and without the partition plate, and the influence of presence/absence of the partition plate is evaluated. Thus, it is possible to correct the pressure fluctuation distribution of the case with the partition plate to the pressure fluctuation distribution of the case without the partition plate.
[0041] Similarly, in order to test the pressure fluctuation distribution of the space 1 B, the steam is fed to the main steam pipe 4 b through the space 1 B. Then, the pressure fluctuation distribution is calculated in the space 1 B as step S 4 . Next, in step S 5 , from the pressure fluctuation distribution in the space 1 B, a pressure fluctuation distribution Y inside the steam dome without the partition plate is calculated by correction. The calculation method for the pressure fluctuation distribution Y is similar to that for the pressure fluctuation distribution X.
[0042] In step S 6 , by adding up the pressure fluctuation distribution X and Y described above, the pressure fluctuation distribution when the steam is fed to the main steam pipes 4 a , 4 b from the steam dome can be calculated. Because the sound (pressure pulsation) can be linearly treated, the pressure fluctuation distribution by the main steam pipes 4 a , 4 b can be calculated by adding up the individual pressure fluctuation distribution. As described above, the pressure fluctuation distribution of the entire space inside the steam dome 1 (the space totaling the spaces 1 A, 1 B, 1 C) is estimated by adding up two pressure fluctuation distribution evaluated in the tests for the main steam pipes 4 a, 4 b.
[0043] A technique for adding up the pressure fluctuation distribution will be described more specifically. If the pressure of a time point t is X1 in the coordinate a of the pressure fluctuation distribution X and the pressure of a time point t is Y1 in the coordinate a of the pressure fluctuation distribution Y, the pressure added up can be evaluated by X1+Y1.
[0044] Also, in step S 7 , the pressure fluctuating load applied to the dryer 2 is estimated and evaluated based on the pressure fluctuation distribution in the entire space inside the steam dome. Further, when the pressure fluctuation distribution obtained in respective main steam pipes is to be overlapped, the phase of each pressure fluctuation distribution should be considered. The actual phenomena have no correlation between each line. Therefore, evaluation is made conservatively so as to increase the pressure fluctuation (fluctuating stress) by imparting a variety of phase variations.
[0045] Then, the calculated pressure fluctuating load is inputted to a structural analysis model simulating the dryer 2 . The pressure fluctuating load is measured under a steam condition equivalent to that of the actual system. Therefore, the measured values can be inputted to the analysis model only by simple alteration of frequency and the like. The structural analysis is thus performed in step S 8 , and the fluctuating stress applied to each portion of the dryer 2 is calculated.
[0046] Lastly in step S 9 , integrity of vibration of the dryer 2 is confirmed by comparing the calculated fluctuating stress with the fatigue limit of the material.
[0047] More specifically, integrity of vibration of the dryer is evaluated to be sound when the inequality (2) is satisfied, and integrity of vibration of the dryer is evaluated to have a problem when the inequality (2) is not satisfied.
[0048] As described above, integrity of vibration of the actual dryer can be evaluated with high accuracy by performing the steam test on the reduced model simulating the main steam pipes and the steam relief valve stub tube arranged on the main steam pipes.
[0049] In performing the steam test on the reduced model, if the entirety of the steam dome and the steam dryer (dryer) is to be modeled, the scale of the test becomes large. Accordingly, the required steam flow rate becomes enormous, and it becomes hard to perform the test. Therefore, according to the embodiment, as a measure for reducing a spatial region in the steam dome, the partition plate is arranged inside the steam dome and the actual system is partly modeled. An influence affecting to generation and strength of the pressure pulsation inside the main steam pipes by equipment inside the steam dome (steam dryer) is small. Therefore, the partition plate can be arranged inside the steam dome to divide the space inside the steam dome.
[0050] Also, the inventors found out that the pressure pulsations of respective main steam pipes showed a weak correlation with each other. Therefore, the line of themain steam pipe is divided, and the steam test is performed plural times. Consequently, modeling of all lines is not required, and the scale can be reduced. Further, the magnitude of the pressure pulsation varies in characteristic and strength for each main steam pipe. Therefore, if the shape of the main steam pipe is different, the test must be performed on each main steam pipe.
[0051] Further, because the sound (pressure pulsation) can be linearly treated, the pressure pulsations measured in the individual main steam pipes can be composed. Furthermore, by adding up and evaluating respective pressure pulsations, the individual pressure pulsation applied to the dryer can be evaluated.
[0052] Also, by arranging a sound absorbing material on the partition plate, errors in overlapping the pressure pulsations can be reduced and the reflected waves generated at the partition plate can be controlled or inhibited.
[0053] The main steam pipes are manufactured reducingly to a degree the steam relief valve can be simulated. Only by such simplification, the test using the steam under the same condition with that of the actual system becomes possible. By arranging the dryer inside the steam dome and employing the steam for liquid, it becomes possible to evaluate integrity of vibration of the dryer directly with high accuracy by the sensors arranged in the dryer. Also, according to the embodiment, employment of the steam becomes possible. Further, by performing the test in which the steam relief valve stub tube is modeled, direct measurement and evaluation of the magnitude of the pressure pulsation generated in the steam relief valve stub tube and the like becomes possible. Furthermore, because it is difficult to secure the heat quantity for generating the steam for them, an operation in which the steam is circulated by a steam compressor is preferable.
[0054] The pressure pulsation that is generated inside the main steam pipes is also generated inside a dead leg, branch pipe, steam dome, and the like in addition to the steam relief valve stub tube. A similar technique can be applied to the pressure pulsation of them as well. The object of the embodiment is all pressure pulsations that may be generated inside the main steam pipe line and the steam dome.
Second Embodiment
[0055] The present embodiment shows an exemplary case in which the space inside the steam dome is divided into two, and two lines of the main steam pipes are provided for each space. FIG. 5 is a schematic drawing of a procedure for evaluating pressure fluctuation of a BWR dryer according to the embodiment. As shown in FIG. 5 , the space inside the steam dome is divided into two, 1 E and 1 F. Also, the main steam pipes to which the steam flows in from the space 1 E are 4 a , 4 b , whereas the main steam pipes to which the steam flows in from the space 1 F are 4 c , 4 d.
[0056] First, in the test, the steam flows into the main steam pipes 4 a , 4 b from the space 1 E, and the pressure fluctuation distribution of the space 1 E is calculated ((a) in FIG. 5 ). This pressure fluctuation distribution is corrected in the same manner as in the first embodiment, and the pressure fluctuation distribution X of the entire steam dome is calculated ((b) in FIG. 5 ). Similar calculation is performed with respect to the space 1 F, and the pressure fluctuation distribution Y is calculated ((c), (d) in FIG. 5 ).
[0057] Then, by adding up the pressure fluctuation distribution X and Y, the pressure fluctuation distribution of a case in which the steam is fed to the main steam pipes 4 a - 4 d from the steam dome can be calculated ((e) in FIG. 5 ).
[0058] The method for evaluating integrity of vibration of the dryer using this pressure fluctuation distribution is similar with that of the first embodiment.
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The object of the invention is to accurately evaluate integrity of vibration of a dryer of an actual system.
The evaluating method for integrity of vibration of a steam dryer using a reduced model in a nuclear plant including the steam dryer for reducing moisture of steam generated inside a steam dome of a nuclear reactor pressure vessel, and a plurality of main steam pipes for transporting the steam to outside includes the steps of performing a steam test with the reduced model, calculating fluctuating stress applied to the steam dryer, and confirming integrity of vibration.
According to the invention, it is possible to evaluate the pressure fluctuation of a dryer of an actual system more accurately.
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This is a division of application Ser. No. 07/919,071, filed Jul. 23, 1992, now U.S. Pat. No. 5,196,787.
TECHNICAL FIELD OF THE INVENTION
This invention relates in general to integrated circuits, and more particularly to a test circuit for screening parts.
BACKGROUND OF THE INVENTION
The production of integrated circuits typically includes two testing stages: DC testing and AC testing. The DC testing is typically performed after the fabrication of the circuits on a semiconductor wafer using a "bed of nails" probe. The measurements taken during DC testing typically include power supply current, output sink and source current, input and output logic high/low voltages, along with other such tests. DC testing can be performed quickly for each circuit on the wafer, therefore, it is relatively inexpensive.
After DC testing, the wafers are assembled into individual integrated circuits. Very often, assembly is performed at a remote location. After assembly, AC testing is performed on the packaged units. Importantly, the speed at which an integrated circuit may operate is determined. Because of processing variations, the speed of the chips may vary from wafer-to-wafer, and even between individual circuits on a single wafer.
In many cases, parts are "screened" to classify individual integrated circuits at various speeds. For example, a part may be produced in three versions: 16 MHz, 20 MHz and 25 MHz. It would be advantageous to predict the speed of an individual integrated circuit prior to assembly; however, an expensive AC test is required to perform such measurements. Because of the cost involved in performing AC testing after processing stage, screening is generally performed after assembly.
Therefore, a need has arisen in the industry to provide a method and apparatus for predicting AC delays after processing without the need for expensive test equipment.
SUMMARY OF THE INVENTION
In accordance with the present invention, a testing method and apparatus for performing the same is provided which substantially eliminates or prevents the disadvantages and problems associated with prior testing method.
In the present invention, DC characteristics of one or more components in the integrated circuit are measured. These DC characteristics are used to estimate AC characteristics indicative of the speed of the integrated circuit.
This aspect of the present invention provides several technical advantages over the prior art. The DC measurements may be performed after fabrication using inexpensive test equipment. Hence, integrated circuits may be sorted for speed at low cost, and before packaging of the individual integrated circuits.
In one aspect of the present invention, a test circuit is associated with each integrated circuit. The test circuit contains components whose characteristics should correspond to actual components used on the integrated circuit. By applying predetermined signals to a package pin which is coupled to the test circuit and to the power source, the test circuit may be enabled.
This aspect of the invention provides the technical advantage of providing test circuitry on each integrated circuit which may be enabled using external package pins. The package pins used for testing may also be used in the normal operation of the integrated circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 illustrates a schematic representation of the test circuit of the present invention;
FIG. 2 illustrates a graphical representation of the data provided by the test circuit of FIG. 1 for a plurality of circuits having known characteristics; and
FIG. 3 illustrates a graphical representation of the correlation between the data provided by the test circuit in FIG. 1 and the actual propagation delay of the circuit.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment of the present invention is best understood by referring to FIGS. 1-3 of the drawings, like numerals being used for like and corresponding parts of the various drawings.
FIG. 1 illustrates a schematic representation of the test circuit of the present invention. The test circuit 10 includes a Zener diode 12 connected between a first node 16 (hereinafter "NODE1") and the base of an NPN transistor 20. NODE1 is also connected to the collector of the NPN transistor 20 and the collector of an NPN transistor 22. The base of NPN transistor 20 is connected to the first end of a resistor 26. The base of NPN transistor 22 is connected to the emitter of transistor 20 and to the collector of an NPN transistor 28. The emitter of transistor 22 is connected to the collector of an NPN transistor 30. The base of NPN transistor 30 is connected to the collector of an NPN transistor 32, the base of transistor 32, the second end of resistor 26, the first end of a resistor 34 and the collector of an NPN transistor 36. The bases of transistors 28, and 36 are connected to the first ends of resistors 38 and 40. The second end of resistor 38 is connected to V cc . The second end of resistor 34 is connected to the anode of diode 44. The second end of resistor 40, the emitters of transistor 28 and 36, the cathode of diode 44 and the emitters of transistors 30 and 32 are connected to ground.
The test circuit 10 is provided on each individual circuit fabricated on the wafer. The values for resistors 26 and 34 are chosen to be consistent with typically resistor values used on the integrated circuit. Transistors 30 and 32 are chosen such that their size ratio will proximate a minimum beta of the transistors. For example, for a minimum beta of 50, transistor 30 would be chosen to be 50 times the size of transistor 32.
In operation, NODE1 is connected to a pin on the integrated circuit. The test circuit 10 is enabled when V cc is taken to 0 volts (ground) and a voltage above the Zener breakdown voltage is applied to NODE1. Typically, the Zener diode 12 is designed such that it has a breakdown voltage of 5-6 volts. When the Zener diode breaks down, current may flow into transistors 30 and 32, resistors 26 and 34 and diode 44. By ramping the voltage at NODE1 and measuring the current through NODE1, it is possible to determine whether the betas of transistors 30 and 32 and the resistor values of resistors 26 and 34 are both high, both low, both nominal, or are any mixture of high, nominal or low parameters.
For example, to test for a minimum beta value of 50, transistor 30 is fabricated such that it has an area which is 50 times the area of transistor 32. If the betas of transistors 30 and 32 are greater than 50, almost all of the current through resistor R1 will conducted through transistor 32, resulting in a relatively low amount of current drawn into the base of transistor 30. Since the emitter currents of transistor 30 and 32 ratio directly with area, transistor 30 will draw more current because transistor 32 has more current. The amount of current drawn through transistor 30 will correspond directly to the current drawn through NODE1 via transistor 22. On the other hand, if the betas of transistors 30 and 32 are low, the current conducted through transistor 30 will decrease, resulting in a decreased current through NODE1.
Similarly, if the value of resistor 26 is high, less current will be supplied to the base of transistor 30 resulting in a lower current through NODE1. If the resistive value of resistor 26 is low, more current will be generated in the base of transistor 30, resulting in a high current through NODE1.
The Schottky diode forward bias voltage with respect to the base-emitter junction, forward bias voltage may be monitored by the test circuit 10. As the forward bias voltage of diode 44 increases, less voltage across resistor 34 is needed to drive the same current through transistors 30 and 32. Similarly, if the forward bias voltage across diode 44 is low, more voltage is necessary across resistor 34 to maintain the same current through transistors 30 and 32. The voltage across resistor 34 will be directly related to the current through NODE1.
Since the test circuits 10 are provided along with each individual circuit, resistors 26 and 34, diode 44 and transistors 30 and 32 are located very close to the devices used in the actual circuit. The variations between components on the test circuit 10 and the actual circuit will be very small because of their close proximity. Thus, if resistor 26 is 10 percent above the nominal value, then the resistors on the actual circuit will be 10 percent above nominal value as well. Similarly, if the transistors 30 and 32 are designed to have a beta of 50, but have an actual value of 60 in the test circuit 10, then it is very probable that the similarly designed transistors in the actual circuit will also have a beta which is 20 percent greater than nominal. The Schottky diode forward bias voltage will also correspond to the Schottky forward bias voltage of diodes on the actual circuit.
Generally, the primary factor in determining the speed of the circuit is the resistive values. The second most important factor is the beta of the transistors.
FIG. 2 illustrates I-V (current versus voltage) curves at NODE1 for five different circuits having test circuits 10 which known resistor and beta values. TABLE I sets forth the resistor and beta values for each circuit, along with the slope of the I-V curve at 9 volts and the actual propagation delay of the circuit.
TABLE I______________________________________TEST CIRCUIT VALUES AND RESULTSRUN RESISTOR BETA d(Rx) @9 V T.sub.pHL______________________________________R0 NOM. 100 -4.91 mA/V 3.86 nsR1 +20% 50 -3.40 mA/V 4.33 nsR2 -20% 100 -6.04 mA/V 3.65 nsR3 +20% 100 -4.03 mA/V 4.10 nsR4 -20% 50 -4.98 mA/V 3.86 nsR5 NOM. 50 -4.09 mA/V 4.11 ns______________________________________
FIG. 3 illustrates a plot of the propagation delays of the actual circuit as a function of the slope of the I-V curve at 9 volts.
As can be seen in FIG. 3, the propagation delay for each circuit correlates closely with the slope of the respective IV curve. For example, to screen four nanosecond parts, only those individual circuits having a slope of less than-4.4 mA/V would be chosen.
Thus, it is a technical advantage of the present invention that an approximate speed for a given circuit may be determined using DC measurements of specified components.
Referring again to FIG. 1, it should be noted that the test circuit 10 will not affect the normal operation of the actual circuit to which it is connected. Whereas NODE1 is connected to a package pin, the test circuit will operate only when NODE1 is raised to a voltage sufficient to breakdown the Zener diode 12 and when V cc is collapsed to ground, such that transistors 28 and 36 cutoff. The actual circuit, on the other hand, will not operate once V cc is connected to ground.
Transistors 20 and 22 are used to provide collector current for transistor 30 along with BV ceo breakdown protection for transistor 30.
While the present invention has been described in connection with a bipolar implementation, it should be noted that other technologies, such as MOS could be similarly employed.
Although the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
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A test circuit (10) is connected to a package pin of an integrated circuit via the first node (16). By setting the voltage on the package pin to a sufficient voltage, the test circuit becomes operable to measure DC characteristics of devices in the test circuit. The DC characteristics of the test circuit devices, such as resistors (26 and 34), diodes (44) and transistors (30 and 32) are used to estimate the AC characteristics of the actual integrated circuit. The AC characteristic estimations may be used to screen parts into various speed classes.
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CROSS-REFERENCE TO RELATED APPLICATION
This non-provisional patent application claims priority under 35 USC § 119(e) to U.S. provisional patent application, Ser. No. 60/428,533, filed Nov. 22, 2002, the disclosure of which is incorporated by reference.
FIELD OF THE INVENTION
The present invention relates in general to message-based voice communications and, in particular, to a system and method for providing multi-party message-based voice communications.
BACKGROUND OF THE INVENTION
Historically, the spoken word has been the preferred and, prior to the advent of writing, principal medium for communication in human society, particularly for social networking. Writing evolved as an alternate medium for communication, beginning with ancient civilizations that needed to track food and livestock inventories. Unlike the spoken word, writing offered a more precise and persistent medium that functioned independently from the time and place of expression. Thus, even the earliest forms of writing allowed for so-called “time-shifting,” which enables a message composed by a sender to be read at a later time by a recipient.
The advent of the electronic age greatly increased the evolution of enhanced forms of spoken and written communication. Currently, the telephone offers the mainstream technology for transacting voice communications with over 90% of the households in the United States having telephone service. In addition, wireless telephone usage has grown dramatically in the last decade with an estimated one billion wireless telephone users worldwide. Electronic mail (email) and text messaging offer the closest equivalent technology for written communication, spurred by the rapid growth and development of the Internet and the proliferation of personal computer usage. In 1999, an estimated 130 million people used email in the United State alone, with at least 600 million email users worldwide.
Traditionally, voice and text communications have followed different usage paradigms. Voice communications, via a telephone, are instantaneous, real-time, and primarily one-to-one communications methods. Written communications, via email, are time-shifted and often one-to-many or many-to-many communication methods with an implied means for persistently chronicling communications through email storage.
Over time, both forms of communication have accumulated features reminiscent of the other. For instance, voicemail and conference calling respectively allow time-shifted and one-to-many or many-to-many voice communications. Analogously, voice mail attachments to conventional email messages allow instantaneous receipt of verbal communications contemporaneous to email message receipt.
Recently, text messaging, popularly referred to as Instant Messaging, introduced a new category of electronic written communications. Text messaging combines the immediacy of telephone voice communication with the textual format of email communications. Text messaging moves the email paradigm into near real-time by enabling users to compose and exchange messages during an interactive session. Text messaging provides a rapid form of two-way written communication that still allows a sender to review a message prior to dispatch. Additionally, the use of sessions enables group communication through chat forums and can be used to unilaterally inform users about the availability of other group members. This past year, there were over 220 million text messaging users worldwide.
Operationally, text messaging begins with a signed-on user composing a text message and dispatching the text message to another signed-on user. Upon receipt, the message is displayed on the screen of the recipient in a near-instataneous fashion and the other user can compose a reply for dispatch back to the first user.
Text messaging has been implemented in several formats. Instant Messaging operates as an adjunct to traditional email clients as an add-on Internet-based application. The Short Messaging Service (SMS) is a wireless telephone variant of Instant Messaging, which has grown rapidly in popularity, especially in Europe. Independent of the type of text messaging employed, users are able to keep a log of transmitted and received messages.
Both telephonic and electronic written communications have helped society keep up with the accelerating pace of modern living and, at the same time, have contributed to this acceleration. For instance, wireless telephone and messaging communications now enable people to perform multiple tasks almost anywhere. However, both forms of communication have limitations. Telephone communication, for example, requires the full attention of the user and the ability to respond in real-time to the other party. Conversely, text messaging enables a user to defer sending a response until convenient, but requires the user to read each message on a display and to manually compose a response through typing, both difficult activities to perform while mobile.
Wireless push-to-talk voice communication is described in U.S. Patent Application Publication No. US 2002/0,039,895 A1 to Ross et al, published Apr. 4, 2002, the disclosure of which is incorporated by reference. A wireless telephone digitizes the voice of a user in response to the depression of a push-to-talk button, either physical or virtual. The digitized voice is sent to a base station, which places the data on a server. Other wireless telephones can recover the data for conversion back to digitized voice. However, users must activate the push-to-talk button to transact a voice communication and session-based voice communications between individual and ad hoc moderatable discussion groups are not contemplated.
A position-linked chat system, method and computer product, is described in U.S. Patent Application Publication No. US 2002/0,007,396 A1 to Takakura et al., published Jan. 17, 2002, the disclosure of which is incorporated by reference. A server device includes a chat room controller, which generates a plurality of chat rooms based on a geographical standard; a chat room selector, which selects a chat room in which a user on a specific terminal can participate based on information relating to the current position of that terminal, and a voice controller, which mixes voices of users transmitted from the terminals of respective users participating in the same chat room. However, session-based forms of voice messaging communication that flexibly allow participation in multiple, simultaneous and moderatable discussion groups are not contemplated.
Wireless chat automatic status tracking is described in U.S. Patent Application Publication No. US 2001/0,031,641 A1 to Ung et al, published Oct. 18, 2001, the disclosure of which is incorporated by reference. A technique and apparatus provide status tracking of a presence or location of a mobile wireless device, even outside of a particular wireless system. In one disclosed embodiment, a wireless chat tracking system utilizes a change in mobile registration status to automatically notify a chat group system outside the wireless network of current status information activity. However, session-based forms of voice messaging communication that flexibly allow participation in multiple, simultaneous and moderatable discussion groups are not contemplated.
Chat server and wireless chat devices are described in U.S. Patent Application Publications Nos. US 2002/0,016,163 A1 and US 2002/0,094,803 A1, both to Burgan et al., respectively published on Feb. 7, 2002, and Jul. 18, 2002, the disclosures of which are incorporated by reference. A wireless communication system includes a system controller, radio frequency (RF) transmitter, RF receiver, transmit antenna, receive antenna, chat server, and a plurality of wireless communication devices. The chat server manages the communication of a plurality of chat discussions, facilitating substantially real-time communication among the wireless communication devices within the wireless communication system. However, users must activate the push-to-talk button to transact a voice communication and session-based voice communications between individual and ad hoc moderatable discussion groups are not contemplated.
Accordingly, there is a need for an approach to providing for a system and method that provides flexible voice communications between a plurality of individuals and discussion groups, preferably through a centralized voice message server and personal communication device clients, which automatically detect voice communications responsive to a user activated “attention.”
SUMMARY OF THE INVENTION
One embodiment of the present invention provides a system and method for providing flexible message-based communications between two or more individuals logically interconnected over a centralized messaging infrastructure. A voice message server interfaces to a plurality of personal communication devices (PCDs) over a wireless data network. Each PCD includes an “Attention” button that alerts the PCD to begin processing voice messages. Voice messages are forwarded to the voice message server and are queued, stored and played to the user of the receiving PCD. Each user must be signed on in a voice messaging session and can participate in one or more moderatable and simultaneous discussion groups.
An embodiment provides a system and method for providing flexible message-based communications over a centralized messaging infrastructure. A plurality of symmetric digital voice messages are processed. One or more voice message sessions are centrally transacted over a digital data network. Each such digital voice message is transiently stored. A plurality of devices is logically interconnected by routing each transiently stored digital voice message between the interconnected devices.
A further embodiment provides a system and method for providing flexible message-based communications with personal communication devices over a centralized messaging infrastructure. Digital voice messages including digitized voice originate through a plurality of personal communication devices. The one or more personal communication devices are communicatively interfaced over a digital data network. The digital voice messages are processed. Each digital voice message is received from at least one such personal communication device. The digital voice message is transiently stored. The digital voice message is sent to at least one such personal communication device identified in the digital voice message.
Still other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein is described embodiments of the invention by way of illustrating the best mode contemplated for carrying out the invention. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modifications in various obvious respects, all without departing from the spirit and the scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a system for providing multi-party message-based voice communications, in accordance with the present invention.
FIG. 2 is a block diagram showing the logical structure of a PCD for use in the system of FIG. 1 .
FIG. 3 is a process flow diagram showing the processing of a voice message by the system of FIG. 1 .
FIG. 4 is a Venn diagram showing individual and group relationships as managed by the system of FIG. 1 .
FIG. 5 is a data structure diagram showing a schema for organizing a voice message exchanged through the system of FIG. 1 .
FIG. 6 is a block diagram showing the logical structure of a voice message server for use in the system of FIG. 1 .
FIG. 7 is a block diagram showing the physical components of a PCD used by the system of FIG. 1 .
DETAILED DESCRIPTION
Multi-Party Message-Based Voice Communications System
FIG. 1 is a block diagram showing a system 10 for providing multi-party message-based voice communications, in accordance with the present invention. Multiple personal communication devices (PCDs) 11 are communicatively interfaced with a voice message server 12 over a wireless data network 14 , such as the General Packet Radio Service (GPRS), to provide voice-messaging services. Other forms and configurations of wireless data networks are feasible, as would be recognized by one skilled in the art. Each PCD 11 provides voice communications through voice messaging by converting analog voice signals into digital voice messages 13 exchanged via a digital data stream transmitted over the wireless data network 14 . PCDs 11 are further described below with reference to FIG. 2 . The voice message server 12 provides message routing, security and session management, as further described below with reference to FIG. 6 .
In an alternate embodiment, the functionality of a PCD is provided through a PCD proxy 16 located in a proxy message server 15 . The proxy message server 15 operates in place of an actual PCD 11 and individual PCD proxies 16 are assigned to conventional cellular telephones 17 operating over a conventional cellular wireless network 18 , as is known in the art. The PCD proxy 16 accepts incoming voice messages 21 received via the voice message server 12 to the cellular telephone 17 and forwards outgoing voice messages 22 received via the cellular telephone 17 .
In a further alternate embodiment, PCD logic 20 is integrated directly into cellular telephones 19 operating over the conventional cellular wireless network 18 with the PCD logic 20 being communicatively interfaced with the voice message server 12 over the wireless data network 14 . The PCD-enabled cellular telephone 19 provides conventional real-time cellular telephone service while the PCD logic 20 offers time-shiftable voice communications through voice messaging. Other configurations, topologies, and arrangements of PCDs 11 , PCD proxies 16 , PCD logic 20 , cellular telephones 17 and 19 , voice message servers 11 , proxy message servers 15 , and related system components and interconnections are feasible, as would be recognized by one skilled in the art.
Personal Communication Device
FIG. 2 is a block diagram showing the logical structure 30 of a PCD 11 for use in the system 10 of FIG. 1 . The PCD is functionally divided into a voice message processing and control module 31 and message storage module 32 . The voice message processing and control module 31 includes logic for converting analog voice signals into digitized form, managing message queuing and storage, and controlling voice processing functions, including standby and active modes activated via an “Attention” button, as further described below with reference to FIG. 7 . The message storage module 32 includes a message buffer 33 for assembling outgoing voice messages, a message queue 34 for transitorily storing voice messages, and a message store 35 for persistently storing saved voice messages.
Voice Message Processing
FIG. 3 is a process flow diagram showing the processing 40 of a voice message 13 by the system 10 of FIG. 1 . A user begins by signing into the voice message server 12 to initiate a voice messaging session (Step {circle around ( 1 )}). The user then sends one or more voice messages 13 by speaking through the PCD 11 (Step {circle around ( 2 )}). Typically, a copy of the sent voice message 13 will also be stored in the message store 35 of the PCD 11 . Note that for purposes of discussion, a PCD 11 is referenced with respect to the processing 40 of a voice message 13 , although the processing 40 could equally be performed by a PCD proxy 16 or PCD logic 20 , as would be recognized by one skilled in the art. Accordingly, unless otherwise explicitly stated, references to PCD 11 will apply equally and interchangeably to the PCD proxy 16 and PCD logic 20 .
The voice message server 12 then forwards the voice message 13 to the PCD 11 of the intended recipient or recipients (Step {circle around ( 3 )}). Upon receipt, the receiving PCD 11 stores, queues and plays the received voice message to the user (Step {circle around ( 4 )}). Likewise, the recipient user can send back a voice message 13 in reply and a voice message exchange will continue until the user terminates by signing out of the voice message server 12 to end the voice messaging session (Step {circle around ( 5 )}).
The system 10 is fully symmetric in the sense that any user can send or receive messages at any time. A user can manipulate a PCD 11 to listen to previous voice messages 13 that have been sent or received and can also forward. edit and resend voice messages 13 . In addition, a voice message 13 can be sent from one user to many users or from many users to many users, such as in a voice conference scenario. Importantly, the user interface of each PCD 11 enables time-shiftable voice communications through user controllable store and forward messaging functionality inherent to the PCDs 11 , as well as in the voice message server 12 , described below with reference to FIG. 6 .
Individual and Group Session Management
FIG. 4 is a Venn diagram showing individual and group relationships 50 as managed by the system 10 of FIG. 1 . Voice messaging is provided through user sessions during which a user of a PCD 11 is either signed on or signed off of a voice message server 12 . The concept of a signed-on user functions independently from physical PCDs 11 . The system 10 tracks sign-on users, which are each assigned to a voice messaging session. A signed-on user can be associated with one or more PCDs 11 , and only signed-on users can receive or send voice messages 13 .
A user is either signed-off 51 or signed-on 52 . Here, Users A, B, and C are signed off while Users D though K are signed on. In addition, two or more users can participate in a discussion group 53 , 54 , 55 . A discussion group 53 , 54 , 55 is a set of signed-on users who communicate between each other in a separate user session. When a member of a discussion group sends a voice message 13 , all other members receive the same voice message 13 . One-to-one communications are achieved by establishing a discussion group 53 that has exactly two users.
Users can join different discussion groups 53 , 54 , 55 . More users can also join multiple discussion groups. Here, Users D and E participate in their own discussion group 53 , Users F through I participate in another discussion group 54 , and Users H, J, and K participate in yet another discussion group 55 . Note User H is participating in two separate discussion groups, 54 , 55 . A user participating in multiple discussion groups 53 , 54 , 55 receives voice messages 13 from all of the groups. If a user specifies an active discussion group 53 , 54 , 55 , a voice message 13 is sent only to the members of that group.
Voice Message Format
FIG. 5 is a data structure diagram showing a schema 60 for organizing a voice message 13 exchanged through the system 10 of FIG. 1 . A voice message 13 is identified by at least a user ID 61 and a discussion group ID 62 . Other types of identifiers are possible in addition to the user ID 61 and discussion group ID 62 , as would be recognized by one skilled in the art. The voice message server 12 uses the user ID 61 and discussion group ID 62 in determining appropriate message processing.
In addition, in the described embodiment, each voice message 13 further includes a message ID 63 and time-stamp 64 , preferably consisting of a standardized date and time marker, such as GMT. The actual digitized voice message is stored in the message body 65 , preferably compressed in an encrypted form.
Voice Message Server
FIG. 6 is a block diagram showing the logical structure 70 of a voice message server 12 for use in the system 10 of FIG. 1 . The voice message server 12 is logically structured into four modules. A control module 71 handles control messages received from PCDs 11 to handle sign-on, sign-off, and group discussion requests and other voice messaging commands.
A database manager module 72 interfaces with a voice message server 12 to two databases, a user and discussion group database 77 and a personal information database 78 . The user and discussion group database 77 maintains a list of signed-on users and discussion groups. The personal information database 78 maintains personal information about system users that is used during sign-on.
A queue manager 73 performs the store-and-forward processing of transient voice messages 13 , which are staged in a message queue 79 pending dispatch. Finally, a voice processing module 74 includes speech recognition 76 and text-to-speech 75 logic, as is known in the art. Note that the voice message server 12 , in conjunction with the user interface of each PCD 11 , enables time-shiftable voice communications through user controllable store and forward messaging functionality.
PCD Physical Component Structure
FIG. 7 is a block diagram showing the physical components 90 of a PCD 11 used by the system 10 of FIG. 1 . In the described embodiment, each PCD 11 comprises a wide area data network radio 91 , antenna 92 and modem 93 , a microphone 94 and an earphone or speaker 95 , a digital signal processor (DSP) 96 , a man-machine interface 100 , such as buttons or a keypad, a central processor unit (CPU) 97 , memory 98 , and a battery or power source 99 .
The man-machine interface 100 includes an “Attention” button 101 , which is activated by a user to notify the PCD 11 to commence voice message processing. Unlike a push-to-talk button, the “Attention” button 101 transitions the PCD 11 from a standby mode into an active mode, whereby voice inputs are monitored and processed. The DSP 96 processes the voice signals to distinguish between speech and ambient noise and third-party conversations. The “Attention” button 101 can be used to temporarily deactivate the PCD 11 during a session when a continuous communication stream is not desired.
Sound is captured by the microphone 95 and transformed to an electrical signal. The digital signal processor 96 digitizes and processes the sound to remove noise and echo and to identify the beginning and ending points of speech. Each identified digitized sound segment is further encoded into one or more voice messages 13 that are sent over the wireless data network 14 to the message server 12 .
In the described embodiment, each voice message 13 is numbered, time-stamped and identified by a user ID 61 . Further, the voice messages 13 are preferably encrypted using secret keys known only to the PCD 11 and the voice message server 12 and compressed in an encrypted form. Similarly, voice messages 13 received by the PCD 11 from the voice message server 12 are decompressed, decrypted, concatenated if required, and converted into an electrical signal and played to the user via the earphone 95 .
The PCD physical form factor can be in the form of self-contained headphones packaged as a small device clipped to clothing and connected via an electrical wire to a combination earphone and microphone ensemble.
In an alternate embodiment, the user uses a conventional landline or wireless cellular telephone that is in communication with a PCD proxy 16 over a telephone network. Typically, the PCD proxy 16 resides at a stationary location similar to that of the voice message server 12 and functions similarly to a PCD 11 .
PCD proxies 16 lack the earphones and microphones and instead connect to the telephone network. Each PCD proxy 16 can receive sound from the telephone instrument and process the sound in the same manner as a PCD 11 by sending voice messages 13 to the voice message server 12 . Each PCD proxy 16 also receives voice messages 13 from the voice message server 12 and processes the messages in the same manner as a PCD 11 by sending the resulting sound to the telephone instrument.
In a further alternate embodiment, PCD functionality can be embedded directly into a wireless cellular telephone. Speech first is recorded by the PCD logic 20 for transmission later and received speech is first stored by the PCD logic 20 and later played to the user.
Multi-Party Message-Based Voice Communications Method
In the described embodiment, each PCD 11 is operated and controlled by the user using voice commands. A user can instruct the PCD 11 to record, review, and send a voice message 13 . The user can also instruct the PCD 11 to replay older voice messages 13 , skip through messages, and provide various message playback and storage management features.
During operation, a PCD 11 continuously listens for a voice input. Each PCD 11 is equipped with an “Attention” button to assist a PCD 11 in determining when a voice input is actually intended, since ambient sound and third-party voice conversations could inadvertently trigger an unintentional transmission of a voice message 13 . To use the “Attention” button, a user momentarily presses and releases the button to indicate to the PCD 11 that a voice input requires parsing as operational commands. Additional buttons can also be added to duplicate the function of some or all PCD voice commands.
Although similar to two-way radio communication, PCD-to-PCD communication is transacted exclusively through the voice message server 12 and no direct peer-to-peer communications occur.
User Sign-On
To sign-on, a user operates a PCD 11 to provide authentication information that is checked against the personal information database 78 to verify the identity of the user. Once verified, a user ID 61 is added to the user and discussion group database 77 and a PCD ID is associated with the user ID 61 . The user is now signed-on.
To sign-off, the user operates the PCD 11 to instruct the voice message server 12 to perform sign-off. The PCD 11 can automatically sign-off a user when the same PCD 11 is used to sign-on another user, or the PCD 11 can allow multiple users to be signed-on at the same time, such as by supporting several different system identities.
In the described embodiment, a user-name is associated with each user ID. A user can query the system to find out whether another user is signed-on by specifying a user name.
Discussion Groups
A discussion group is a list of user IDs 61 . Each discussion group has a discussion group ID and an associated discussion-group-name. To join a discussion group, a user must be signed-on. The user then instructs the PCD 11 to send a control message to the voice message server 12 requesting to join a discussion group. The voice message server 12 adds an entry to the discussion group list in the user and discussion group database with the requesting user ID 61 . Similarly, the user can ask to be removed from a discussion list.
When a user signs on, the message server automatically creates a discussion group whose only member is that user. The name of that discussion group is identical to the user-name of the signing on user. A user also can create and name a discussion group.
A user can query the voice message server 11 to check whether another user is a member of a discussion group that the first user has created, or to check for a list of all participating users of a discussion group.
Message Server
The voice message server 13 manages message queues for discussion groups. Upon the receipt of a voice message 13 from a PCD 11 , the voice message server 12 obtains the discussion group ID 62 and adds the voice message 13 to the appropriate queue.
The voice message server 13 also scans all queues in a timely manner. For each queue, the voice message server 13 obtains a list of users that are members of that discussion list. The voice message server 13 then builds a sub-list of the signed-on users and generates a list of the PCDs 11 that are associated with the sign-on users that are members of the discussion group. The voice message server 12 takes the voice message 13 at the head of the queue and sends the message to all PCDs 11 that belong to that list. The voice message server 12 then removes the message 13 from the queue and moves to the next queue. In an alternate embodiment, the voice message server 12 keeps old voice messages, and the PCD 11 enables a user to fetch queued messages that had been delivered before the user signed on.
Discussion Group Moderator
A signed-on user who is a member of a discussion group can be the moderator of a discussion group. During a moderated discussion, the voice message server 12 first sends each voice message 13 for the discussion group to the moderator. The moderator reviews the voice message 13 and can accept or reject the message. An accepted voice message 13 is sent to the remainder of the group. The moderator also can annotate the voice message 13 .
While the invention has been particularly shown and described as referenced to the embodiments thereof, those skilled in the art will understand that the foregoing and other changes in form and detail may be made therein without departing from the spirit and scope of the invention.
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One embodiment of the present invention provides a system and method for providing flexible message-based communications between two or more individuals logically interconnected over a centralized messaging infrastructure. A voice message server interfaces to a plurality of personal communication devices (PCDs) over a wireless data network. Each PCD includes an “Attention” button that alerts the PCD to begin processing voice messages. Voice messages are forwarded to the voice message server and are queued, stored and played to the user of the receiving PCD. Each user must be signed on in a voice messaging session and can participate in one or more moderatable and simultaneous discussion groups.
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BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates to semiconductor memory devices, and more particularly, to a semiconductor memory device having a sense amp over-driving structure and method of over-driving a sense amplifier thereof.
[0003] 2. Discussion of Related Art
[0004] As a driving voltage of semiconductor memory devices is gradually lowered, the processing speed thereof requires the high speed and several technical solutions for satisfying the requirement have been proposed. One of them is a sense amp over-driving method in which a sense amplifier is driving with a driving power being divided into two. However, the sense amp over-driving method has a drawback in that current of a memory device is excessively consumed due to excessive over-driving.
[0005] Of the existing over-driving methods, there is a blind method. In the blind method, when a restore line RTO connected to a PMOS transistor of a sense amplifier (not shown) and a restore line /S connected to a NMOS transistor of the sense amplifier are enabled, an external power supply voltage (VDD) and a cell power supply voltage (Vcore) are shorted for a predetermined pulse period to prevent the cell power supply voltage (Vcore) from lowering. The blind method, however, has a drawback in that excessive current is consumed since current is supplied to the corresponding whole bank.
SUMMARY OF THE INVENTION
[0006] An advantage of the present invention is that it prevents current consumption by excessive over-driving by over-driving only a sense amplifier of a corresponding memory block after dividing a memory core region into a plurality of memory blocks.
[0007] A semiconductor memory device having a sense amp over-driving structure according to a first aspect of the present invention includes a plurality of memory blocks having sense amplifiers, a sense amp over-driving controller that combines a plurality of block select signals for selecting the memory blocks and a sense amp over-driving signal and generating a plurality of block over-driving signals, and a sense amp over-driver that over-drives only sense amplifier of a memory block in which an actual operation is performed in response to the plurality of block over-driving signals.
[0008] A sense amp over-driving method of a semiconductor memory device according to a second aspect of the present invention includes the steps of dividing a memory core region into a plurality of memory blocks having sense amplifiers, combining a plurality of block select signals for selecting the memory blocks and a sense amp over-driving signal for over-driving the sense amplifiers and generating a plurality of block over-driving signals, and over-driving only sense amplifiers of a memory block in which an actual operation is performed, of the plurality of memory blocks in response to the plurality of block over-driving signals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a block diagram showing a semiconductor memory device having a sense amp over-driving structure according to a preferred embodiment of the present invention;
[0010] FIG. 2 is a circuit diagram showing a sense amp over-driver and a sense amplifier shown in FIG. 1 ;
[0011] FIG. 3 is a timing diagram showing waveforms of signals of FIG. 1 ; and
[0012] FIG. 4 shows a current waveform by sense amp over-driving of FIG. 1 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] The present invention will now be described in connection with preferred embodiments with reference to the accompanying drawings.
[0014] FIG. 1 is a block diagram showing a semiconductor memory device having a sense amp over-driving structure according to a preferred embodiment of the present invention.
[0015] Referring to FIG. 1 , the semiconductor memory device includes memory blocks BK 0 to BK 3 , sense amp over-driving controllers 110 - 1 , 110 - 2 and sense amp over-driver units 120 - 1 , 120 - 2 .
[0016] Only four memory blocks are shown in FIG. 1 . However, the number of memory blocks may be varied depending on the size of a bank. Furthermore, sense amplifier regions (SA) on upper/lower sides of a memory cell region (MC). The sense amp over-driving controllers 110 - 1 , 110 - 2 and the sense amp over-driver units 120 - 1 , 120 - 2 are disposed on right and left sides of the memory blocks BK 0 to BK 3 .
[0017] The sense amp over-driving controller 110 - 1 logically combines block select signals (BS 0 to BS 3 ) and a sense amp over-driving signal (SAOVDP) and generates a block over-driving signal (BSAOVDP 0 to BSAOVDP 4 ) for over-driving a sense amplifier within the sense amplifier region (SA) of a corresponding memory block.
[0018] The sense amp over-driving controller 110 - 1 includes NOR gates NR 1 to NR 5 , inverters IV 1 to IV 5 and NAND gates ND 1 to ND 5 . The NOR gates NR 1 performs a NOR operation on a ground voltage (VSS) and a block select signal (BS 0 ). The NOR gates NR 2 performs a NOR operation on the block select signals (BS 0 , BS 1 ). The NOR gates NR 3 performs a NOR operation on the block select signals (BS 1 , BS 2 ). The NOR gates NR 4 performs a NOR operation on the block select signals (BS 2 , BS 3 ). The NOR gates NR 5 performs a NOR operation on the block select signal (BS 3 ) and the ground voltage (VSS). The inverters IV 1 to IV 5 invert output signals of the NOR gates NR 1 to NR 5 , respectively, and output inverted signals.
[0019] The NAND gate ND 1 performs a NAND operation on the output signal of the inverter IV 1 and the sense amp over-driving signal (SAOVDP) and generates a block over-driving signal (BSAOVDP 0 ) for over-driving a sense amplifier within the sense amplifier region (SA) of the first memory block BK 0 .
[0020] The NAND gates ND 2 performs a NAND operation on the output signal of the inverter IV 2 and the sense amp over-driving signal (SAOVDP) and generates a block over-driving signal (BSAOVDP 1 ) for over-driving a sense amplifier of the sense amplifier region (SA) of the first or second memory block BK 0 or BK 1 .
[0021] The NAND gates ND 3 performs a NAND operation on the output signal of the inverter IV 3 and the sense amp over-driving signal (SAOVDP) and generates a block over-driving signal (BSAOVDP 2 O) for over-driving a sense amplifier within the sense amplifier region (SA) of the second or third memory block BK 1 or BK 2 .
[0022] The NAND gates ND 4 performs a NAND operation on the output signal of the inverter IV 4 and the sense amp over-driving signal (SAOVDP) and generates a block over-driving signal (BSAOVDP 3 ) for over-driving a sense amplifier within the sense amplifier region (SA) of the third or fourth memory block BK 2 or BK 3 .
[0023] The NAND gates ND 5 performs a NAND operation on the output signal of the inverter IV 4 and the sense amp over-driving signal (SAOVDP) and generates a block over-driving signal (BSAOVDP 4 ) for over-driving a sense amplifier within the sense amplifier region (SA) of the fourth memory block BK 4 .
[0024] The sense amp over-driver units 120 - 1 over drives sense amplifiers of a corresponding memory block in response to the block over-driving signals (BSAOVDP 0 to BSAOVDP 4 ), and includes PMOS transistors MP 1 to MP 5 .
[0025] The PMOS transistor MP 1 applies a current, which is generated by the external power supply voltage (VDD), to the restore line RTO shown in FIG. 2 , which will be described later, in response to the block over-driving signal (BSAOVDP 0 ) when the block select signal (BS 0 ) becomes logic high, thus over-driving corresponding sense amplifiers of the first memory block BK 0 .
[0026] The PMOS transistor MP 2 applies a current, which is generated by the external power supply voltage (VDD), to the restore line RTO in response to the block over-driving signal (BSAOVDP 1 ) when the block select signal (BS 0 or BS 1 ) becomes logic high, thus over-driving corresponding sense amplifiers of the first or second memory block BK 0 or BK 1 .
[0027] The PMOS transistor MP 3 applies a current, which is generated by the external power supply voltage (VDD), to the restore line RTO in response to the block over-driving signal (BSAOVDP 2 ) when the block select signal (BS 1 or BS 2 ) becomes logic high, thus over-driving corresponding sense amplifiers of the second or third memory block BK 2 or BK 3 .
[0028] The PMOS transistor MP 4 applies a current, which is generated by the external power supply voltage (VDD), to the restore line RTO in response to the block over-driving signal (BSAOVDP 3 ) when the block select signal (BS 2 or BS 3 ) becomes logic high, thus over-driving corresponding sense amplifiers of the third or fourth memory block BK 3 or BK 4 .
[0029] The PMOS transistor P 5 applies a current, which is generated by the external power supply voltage (VDD), to the restore line RTO in response to the block over-driving signal (BSAOVDP 4 ) when the block select signal (BS 3 ) becomes logic high, thus over-driving corresponding sense amplifiers of the fourth memory block BK 4 .
[0030] FIG. 2 shows a sense amp over-driver MP shown in FIG. 1 , sense amplifier drivers MP 11 , MN 11 within the sense amplifier region (SA) and one sense amplifier SA 1 . Though one sense amplifier is shown the sense amplifier region (SA), it is assumed that a plurality of sense amplifiers exists in the sense amplifier region (SA).
[0031] FIG. 3 is a timing diagram showing waveforms of signals of FIG. 1 .
[0032] In FIG. 3 , the sense amp over-driving signal (SAOVDP) is generated as a high pulse at the moment when the sense amplifier enable signals (SAP, SAN) are enabled as logic high after the block select signal (BS) is enabled as logic high.
[0033] A method of over-driving sense amplifiers within the first memory block BK 0 will be described below as an example with reference to FIGS. 2 and 3 .
[0034] If the first block select signal (BS 1 ) is enabled as logic high, the sense amplifier enable signals (SAP, SAN) are driven as logic high after a predetermined time elapses. If the sense amp over-driving signal (SAOVDP) becomes a high pulse, the sense amp over-driving controllers 110 - 1 , 110 - 2 generate the block over-driving signals (BSAOVDP 0 , BSAOVDP 1 ) of a low pulse. Therefore, the PMOS transistors MP 1 , MP 2 , MP 6 , MP 7 within the sense amp over-driver units 120 - 1 , 120 - 2 are turned on, so that a current generated by the external power supply voltage (VDD) is applied to the restore line RTO. At this time, the sense amplifier drivers MP 11 , MN 11 within the sense amplifier region (SA) shown in FIG. 2 are already turned on before the sense amp over-drivers MP 1 , MP 2 , MP 6 , MP 7 are turned on. Therefore, if the sense amp over-drivers MP 1 , MP 2 , MP 6 , MP 7 are turned on, a current by the external power supply voltage (VDD) and a current by the cell power supply voltage (Vcore) become short and only sense amplifiers of a selected memory block BK 0 are over-driven accordingly.
[0035] As described above, only sense amplifiers of a memory block in which an actual operation is performed are over-driven using the block select signal (BS), and sense amplifiers of a memory block in which an actual operation is not performed are not over-driven. It is thus possible to prevent current consumption incurred by excessive over-driving.
[0036] FIG. 4 shows a current waveform by sense amp over-driving of FIG. 1 . Only sense amplifiers of a memory block in which an operation is actually performed are over-driven. Therefore, it can be seen that current by over-driving is not excessively consumed. In FIG. 4 , ODR indicates a case where over-driving is performed and NODR indicates a case where over-driving is not performed.
[0037] As described above, according to the present invention, only sense amplifiers of a memory block requiring an operation are over-driven. Therefore, existing excessive current consumption can be saved, which is very effective in low-power design.
[0038] Although the foregoing description has been made with reference to the preferred embodiments, it is to be understood that changes and modifications of the present invention may be made by the ordinary skilled in the art without departing from the spirit and scope of the present invention and appended claims.
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The present invention relates to a semiconductor memory device in which current consumption incurred by excessive over-driving can be prevented by dividing a memory core region into a plurality of memory blocks and then over-driving only sense amplifiers of a corresponding memory block.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C.§119 to Italian Patent Application No. MI2006A002385.
BACKGROUND
[0002] The present invention regards a hub usable in a bicycle wheel having a disc brake.
[0003] In bicycle wheels with disc brakes, the brake disc is normally mounted so as to make the disc integral in rotation with the wheel. Known solutions to using disc brakes are flawed in that they either have limited mechanical resistance or they require a relatively thick hub that adds undesired weight or compelxity to the hub.
[0004] The problem underlying the present solutions result in the art desiring a hub suitable for a disc brake hub that can be easily mounted without requiring technical solutions which weigh down the hub or complicate its manufacture.
SUMMARY OF THE INVENTION
[0005] The present invention comprises a tubular body extended axially along a rotation axis of the wheel that includes a coupling profile for reception and locking in position a brake disc. The hub is further characterised by having the disc coupling profile and the locking portion physically separated from each other along the axis of the tubular body. Using this configuration means that the disc position and locking portion are independent from each other and can be chosen and sized in an optimal manner without mutual constraints.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Further characteristics and advantages of the invention will be evident from the following description of several embodiments thereof, made with reference to the attached drawings. In such drawings:
[0007] FIG. 1 is a view along the longitudinal axis of a hub according to a first embodiment of the invention, with a partial section;
[0008] FIG. 2 is a perspective view of the tubular body of a hub acording to a first embodiment of the invention;
[0009] FIG. 3 is a side elevation of FIG. 2 in the direction III;
[0010] FIG. 4 is an enlarged view of the circled detail of FIG. 3 ;
[0011] FIG. 5 is a view along the longitudinal axis of a hub according to a second embodiment of the invention, with a partial section;
[0012] FIG. 6 is a perspective view of the tubular body of a hub according to a second embodiment of the invention;
[0013] FIG. 7 is a view along the longitudinal axis of a hub similar to the hub group of FIG. 5 , assembled with a brake disc and a locking ring, and with a partial section;
[0014] FIG. 8 is an exploded view of the assembly of FIG. 7 ;
[0015] FIG. 9 is a side elevation of a bicycle which incorporates hub asemblies according to the invention;
[0016] FIG. 10 is an enlarged scale view of a portion of the hub group of FIG. 1 .
[0017] FIG. 11 an alternative form of the end the tubular body of present invention that is devoid of threads.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] As shown in FIG. 9 , a bicycle 1 typically comprises a frame 2 , a front wheel 3 and a rear wheel 4 , each of which has spokes 5 , and, in this instance, each wheel is equipped with a disc brake assembly 6 .
[0019] With reference in particular to FIGS. 1-4 , a hub 10 according to the invention for use with the front wheel 3 of the bicycle 1 comprises a tubular body 11 , extended around a longitudinal axis X extending between the ends 12 and 13 corresponding with the rotational axis of the wheel 3
[0020] The tubular body 11 is externally provided with two series of protuberances 14 and 15 , not illustrated in detail since they are not concerned with the embodiments of the present invention, for the coupling to the spokes 5 . Inside the tubular body 11 , a spindle 17 is supported by first and second rolling bearings, respectively 18 and 19 . The spindle 17 is of a known construction with right and left terminal portions 20 and 21 , firmly fixed to close the opposite ends of the spindle 17 and shaped so as to provide connection seats 22 and 23 to the frame 2 of the bicycle 1 . The bearing 18 is of a known one ball row type, while the bearing 19 is of a two ball row type with balls of lesser diameter than those of the bearing 18
[0021] Two annular closing caps 24 and 25 are provided between the spindle 17 and the tubular body 11 , equipped with respective seals 26 and 27 towards the tubular body 11 . The first annular cap 24 (on the right in FIGS. 1 and 2 ) is screwed on the spindle 17 while the second annular cap 25 is mounted or pressed on with force applied on the spindle 17 itself.
[0022] It is noted that the mounting of the spindle 17 in the tubular body 11 provides that the left annular cap 25 goes in abutment—towards the left, with reference to FIG. 1 —against a projecting flange 29 of the left terminal portion 21 (in turn made integral with the spindle 17 , such as by gluing) and abutment—from the right—the inner race 19 a of the second bearing 19 . The outer race 19 b of the same left bearing 19 abutments against a shoulder 31 formed in the tubular body 11 ; the shoulder 31 therefore defines a housing seat of the left bearing 19 in the tubular body 11 . The right bearing 18 race 18 b is in abutment against a shoulder 32 formed in the tubular body 11 and its inner race 18 a is in abutment against the right annular cap 24 . It will be understood that the right annular cap 24 , which is screwed on the spindle 17 , serves to register the bearing coupling between the spindle 17 and the annular body 11 . The annular cap 24 is open ring shaped, and is tightened closed in the mounting on the spindle 17 by means of a transverse grub screw (only indicated schematically with 34 ), to prevent the loosening of the annular cap 24 .
[0023] The tubular body 11 has a disc seat 40 for receiving and locking a brake disc (see element 280 in FIG. 7 ). The disc seat 40 comprises an outer portion of the tubular body 11 shaped according to a predetermined coupling profile. With this term it is intended that the profile of the disc seat 40 has geometric characteristics such as to permit the transmission of a torsional movement between the tubular body 11 and the brake disc mounted on the seat with a matching profile. The predetermined profile can be for example a polygonal profile, or an altered circular profile (for example, levelled along a chord) or another profile. In the preferred embodiments, the coupling profile is a splined profile, with ribs 44 and grooves 45 oriented in a direction parallel to the X axis, see FIG. 2 . The ribs 44 define a maximum diameter D c of the splined profile, while the grooves 45 define a minimum diameter d f of the splined profile. The shoulder 47 on body 11 provides an axial abutment position for a brake disc ( 280 ) mounted on the disc seat 40 .
[0024] On the side of body 11 opposite the shoulder 47 , a thread 50 is formed for the coupling with a nut which holds the brake disc ( element 280 in FIG. 7 ) on the disc seat 40 , preferably against the outer shoulder 47 . As can be seen from FIG. 4 , the thread 50 extends over the outside of the tubular body 11 between a right end 52 and a left end 53 and has an outer diameter D e and a core diameter d n .
[0025] The disc seat 40 and the thread 50 are sized and separately positioned on the tubular body 11 so as to be axially separated by a intermediate portion of tubular body 11 or circumferential groove 60 that is part of neither of them. Thus, there exist a position along the longitudinal X axis in which only the disc seat 40 is present and positions in which only the thread 50 is present; there are no positions in which both the disc seat 40 and the thread 50 are present together or overlapping.
[0026] The following conditions are present in the preferred embodiments:
the thread 50 is closer than the disc seat 40 to the second end 13 of the tubular body 11 , i.e. the left end 53 of the thread 50 is closer than the left end 43 of the disc seat 40 to the left end 13 of the tubular body 11 ; the crest diameter D c is greater than the outer diameter D e ; the bottom diameter d f is greater than the core diameter d n ; the bottom diameter d f is greater than the outer diameter D e ; the second end 43 of the disc seat 40 is located between the first end 52 of the thread 50 and the first end 12 of the tubular body 11 ; the radial extension of the ribs 44 and grooves 45 between the bottom diameter d f and the outer diameter D e is comprised between 0.5 and 2 mm, and preferably between 0.5 and 1 mm.
[0033] With respect to the predetermined coupling profile, it is preferred that the ribs 44 and grooves 45 have a trapezoidal shape which is symmetric with respect to a radial plane R (see FIG. 4 ). The number of the ribs 44 is preferably between 10 and 60, more preferably between 20 and 60, and most preferably between 40 and 60. The number of the grooves 45 is of the same range as that selected for the ribs 44 .
[0034] With reference in particular to FIGS. 5 and 6 , a hub 110 for the rear wheel 4 of the bicycle 1 comprises a tubular body 111 , extended around a longitudinal axis Y which is parallel to the longitudinal axis X. Except as described below, the hub 110 is as described with respect to hub 10 similar elements have similar numbers plus 100.
[0035] Unlike the hub 10 , the hub 110 comprises a pinion-carrier group 170 , rotatably mounted on the spindle 117 by means of rolling bearings 171 and 172 , and coupled to the tubular body 111 by means of a freewheel connection 173 , close to the first end 112 thereof. The pinion-carrier group 170 is of know construction and will not be described in detail below.
[0036] An annular closure cap 125 is then provided between the spindle 117 and the tubular body 111 , equipped with a seal 127 towards the tubular body 111 . The annular cap 125 is screwed on the spindle 117 .
[0037] It is noted that the mounting of the spindle 117 in the tubular body 111 provides that the inner race 118 a of the right bearing 118 goes in abutment—towards the right, with reference to FIG. 5 —against a shoulder 129 formed on the spindle 117 , while the outer race 118 b of the same right bearing 118 receives a shoulder 132 in abutment, formed in the tubular body 111 ; the shoulder 132 therefore defines a housing seat of the right bearing 118 in the tubular body 111 . The left bearing instead has its outer race 119 b in abutment—towards the right—against a shoulder 131 formed in the tubular body 111 and its inner race 119 a in abutment—towards the left—against the annular cap 125 ; the shoulder 131 therefore defines a housing seat of the left bearing 119 in tubular body 111 . In this manner, it is understood that the annular cap 125 , which—as said—is screwed on the pin 117 , serves as register element of the bearing coupling between the spindle 117 and the annular body 111 . The annular cap 125 is open ring shaped and in the mounting is tightened closed on the spindle 117 by means of a transverse grub screw (indicated only schematically with 134 ), in order to prevent the loosening of the annular cap 125 .
[0038] A disc seat 140 is provided outside the tubular body 111 for reception and locking in rotation of a brake disc (not shown in FIGS. 5 and 6 ). The disc seat 140 comprises an outer portion of the tubular body 111 comprised between a first right end 142 and a second left end 143 , shaped according to a form coupling profile, equal to that of the disc seat 40 of the hub 10 . In particular, the form coupling profile of the disc seat 140 of the hub group 110 is a splined profile, with ribs 144 and grooves 145 , oriented in a direction parallel to the Y axis. The ribs 144 define a maximum crest diameter D c of the splined profile, while the grooves 145 define a minimum bottom diameter of the splined profile.
[0039] Close to the disc seat 140 , in proximity to its right end 141 , the tubular body 111 comprises an outer shoulder 147 which provides an axial abutment position for a brake disc mounted on the disc seat 140 .
[0040] Still close to the disc seat 140 , near its left end 143 , a thread 150 is provided formed on an outer portion of the tubular body 111 , for the coupling with a threaded ring nut (not shown in FIGS. 5 and 6 ) which holds a brake disc (it too not shown in FIGS. 5 and 6 ) on the disc seat 140 against the outer shoulder 147 . The thread 150 , equivalent to the thread 50 of the hub 10 , extends along the outside of the tubular body 111 between a right end 152 and a left end 153 and has an outer diameter D e and a core diameter d n .
[0041] The disc seat 140 and the thread 150 are sized and positioned on the tubular body 111 so as to be axially separate, in the sense specified above. More in particular, the following relations are valid in the hub 110 :
the thread 150 is closer than the disc seat 140 to the second end 113 of the tubular body 111 , i.e. the left end 153 of the thread 150 is closer than the left end 143 of the disc seat 140 to the left end 113 of the tubular body 111 ; the crest diameter D c is greater than the outer diameter D e ; the bottom diameter d f is greater than the core diameter d n ; the bottom diameter d f is greater than the outer diameter D e ; the second end 143 of the disc seat 140 is located at the first end 152 of the thread 150 , i.e. the disc seat 140 and the thread 150 are adjacent along the Y axis.
[0047] One or more holes 154 are made in the thread 150 for the access to the locking grub screw 134 of the annular cap 125 .
[0048] With reference in particular to FIGS. 7 and 8 , a hub 210 is shown for the rear wheel 4 of the bicycle 1 , substantially equal to the hub 110 , except for insignificant details of elements extraneous to the present invention, such as the pinion carrier group 270 and the annular cap 225 . Therefore, this hub 210 will not be described in detail; its elements, equivalent to the hub 110 , are marked by the same reference numbers plus 100 .
[0049] The hub 210 also comprises a brake disc 280 and a threaded ring nut 290 . The brake disc 280 comprises a peripheral disc portion 281 which is firmly fixed to a central mounting ring 282 ; a central hole 284 is made in the mounting ring 282 , provided with a splined profile matching the splined profile of the disc seat 240 . The brake disc 280 is mounted with the mounting ring 282 on the disc seat 240 , locked in rotation by the coupling between the splined profiles of the disc seat 240 and the central hole 284 . The ring nut 290 pushes the brake disc 280 against the outer shoulder 247 , thus ensuring that the brake disc 280 remains in engagement on the disc seat 240 .
[0050] In FIG. 10 , the second bearing 19 of the hub 10 is illustrated in greater detail; the bearings 119 and 219 of the hubs 110 and 210 are equivalent to the bearing 19 , and thus that illustrated in FIG. 10 and described below also holds for the bearings 119 and 219 .
[0051] As already stated, the bearing 19 has two ball rows, a first row 91 closer to the first end 12 of the tubular body 11 and a second row 92 closer to the second end 13 of the tubular body 11 . The first ball row 91 runs along a first inner runway 93 made on the inner race 19 a and on a first outer runway 94 made on the outer race 19 b ; the second ball row 92 runs along a second inner runway 95 made on the inner race 19 a and a second outer runway 96 made on the outer race 19 b.
[0052] The runways 93 - 96 have rounded, particularly semicircular section; the first outer runway 94 is wider than the other runways 93 , 95 and 96 , in particular it has a radius section R 2 greater than the radius R 1 of the other runways.
[0053] In this manner, the first ball row 91 substantially supports only radial loads and not also axial loads, which are left to the second ball row 92 . This ensures a greater slidability of the bearing 19 . The fact that the radial load is left to the second row 91 , closer to the second end 13 of the tubular body 11 , ensures a greater stiffness to the set. The choice, then, of having the runway 94 wider on the outer race 19 b rather than on the inner race 19 a is due to the consideration that a wider runway reduces the contact area of the balls of the runway, thus increasing the specific pressure; this phenomenon—potentially a source of problems—is more easily acceptable on the outer race 19 b , which has a greater circumferential extension than the inner race 19 a and therefore lower specific pressures.
[0054] FIG. 11 shows an alternative embodiment 311 of the tubular body that differs from the tubular body of FIGS. 1-4 because its axially outermost portion 395 of the second end 313 is not threaded. In this way the beginning of the thread 350 is preserved from being damaged by lateral shocks. In the illustrated embodiment the axially outermost portion 395 has an outer diameter Do that is lower or equal to the core diameter d n of the thread 350 . Between the thread 350 and the disc seat 340 is interposed a smooth portion 360 which can have the same outer diameter D e e of the thread 350 , as in FIG. 11 , or can be a groove.
[0055] It is known that, in a hub according to the invention, such as the hubs 10 , 110 and 210 , the disc seat 40 , 140 , 240 does not interfere with the thread 50 , 150 , 250 , improving the mechanical stress conditions in the material of the tubular body 11 , 111 , 211 , which can therefore be designed with a relatively very small thickness.
[0056] Moreover, due to the axially separate position of the thread 50 , 150 , 250 with respect to the disc seat 40 , 140 , 240 , the radial size is much reduced, such that—by possibly employing a reduced left bearing 19 , 119 , 219 , for example with double ball row—it is possible to keep the diameter of the brake disc 40 , 140 , 240 very small, and thus keep that of the tubular body 11 , 111 , 211 very small, equivalent to that of a tubular body of a hub for a wheel that does not have a disc brake.
[0057] Finally, the presence of the second bearing 19 , 119 , 219 inside the tubular body 11 , 111 , 211 at the disc seat 40 , 140 , 240 contributes to considerably stiffening the tubular body itself, precisely where the braking torque is applied, permitting risk-free mounting even of brake discs 280 with large diameters and great breaking power, such as those typical of so-called downhill bicycles, without requiring an excessive diameter of the tubular body 11 , 111 , 211 .
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The present invention provides a bicycle hub that is usable with a disc brake. The hub has a tubular body extending along a longitudinal axis between the ends thereof. One end of the hub is configured to mate with and retain a brake disc on a disc seat that has a predetermined configuration. Spaced from the disc seat along the longitudinal axis there is a fastener portion of the hub which is configured to receive a fastener that locks the disc on the hub. The disc seat and fastener portion are separated by section of the tubular body that does not form any part of either the disc seat or the fastener portion
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BACKGROUND OF THE INVENTION
U.S. Pat. No. 4,017,318 discloses two basic methods for preparing photosensitive colored glasses or polychromatic glasses, as they have more recently been termed, each method being founded in a sequence of irradiation and heat treating steps. The glasses described in that patent evidence a wide variation in base compositions but each requires the presence of silver, an alkali metal oxide which is preferably Na 2 O, fluoride, and at least one other halide selected from the group of chloride, bromide, and iodide. The glasses are subjected to high energy or actinic radiations selected from the group of high velocity electrons, X-radiations, and ultra-violet radiations in the range of about 2800A-3500A. The heat treatments comprehend exposures to temperatures between about the transformation range of the glass up to about the softening point thereof. Where ultra-violet radiation constitutes the effective actinic radiation, CeO 2 is recited as being a necessary constituent of the glass composition.
In the first of the two methods described, the glass is initially irradiated with high energy or actinic radiations to cause the development of a latent image in the glass. The duration of this exposure and the flux thereof, i.e., the energy/unit area of the irradiation, determine the final color which will be exhibited by the glass. Thereafter, the glass is exposed to a heat treatment at a temperature between about the transformation range and the softening point of the glass to effect the precipitation in situ of colloidal silver particles which act as nuclei.
Where a transparent colored glass is desired, this heat treatment will be conducted only for so long as to cause the precipitation of colloidal silver nuclei with the possible growth thereon of extremely small microcrystals of alkali metal fluoride-silver halide, e.g., NaF + (AgCl and/or AgBr and/or AgI). Where an opal glass is to be produced, the heat treatment will be prolonged for a sufficient length of time and at a sufficiently high temperature not only to promote the precipitation in situ of colloidal silver nuclei, but also to cause the growth of said microcrystals on the silver nuclei to a great enough size to scatter light.
Subsequently, the nucleated glass is cooled, customarily to room temperature but, in any event, to a temperature at least 25° C. below the strain point of the glass, and re-exposed to high energy or actinic radiation. This second exposure process acts to develop the color, the hue of which was determined by the previous exposure. Finally, the glass is again heated to a temperature between about the transformation range and the softening point of the glass to bring out the desired color therein.
Whereas the mechanism of color production was not fully understood, it was believed that the quantity of silver precipitated and the geometry of the precipitated particles, as well as perhaps the refractive index of any crystals developed, decide the color exhibited. Nevertheless, because the colors can be attained with very minor amounts of silver, it was postulated that at least one of the following situations obtained: (1) the presence of discrete colloidal particles of silver less than about 200A in the smallest dimension; (2) metallic silver was deposited within alkali fluoride-silver halide microcrystals, the silver-containing portion of the microcrystals being less than about 200A in the smallest dimension; and (3) metallic silver was deposited upon the surface of the microcrystals, the silver-coated portion of the microcrystals being less than about 200A in the smallest dimension. The microcrystals are present in a concentration of at least about 0.005% by volume.
The patent noted that the use of consecutive or interrupted heat treatments, either after the initial irradiation to high energy or actinic radiation or after the second irradiation step, can be useful in intensifying the final color produced. Consequently, although the reaction mechanism underlying that phenomenon is not completely comprehended, experience indicated that two or more heat treatments at temperatures between the transformation range and the softening point of the glass do not alter the color developed, but can promote a more vivid color than a single heat treatment of equal or longer duration.
The patent also observed that the identity of the color developed in the glass was depended upon the duration and flux of the initial exposure to high energy or actinic radiation. Thus, the least exposure yielded a green coloration followed by blue, violet, red, orange, and yellow as the exposure time and/or flux was increased.
The second general method for preparing photosensitive colored glass disclosed in U.S. Pat. No. 4,017,318, supra, involves the production of glass articles exhibiting a single color, but which color can be varied over the full range of the visible spectrum. Such glasses were formed from compositions wherein the silver content was partially thermoreduced in a heat treating step at temperatures between the transformation range and the softening point of the glass without a previous irradiation by high energy or actinic radiation. This heat treatment can conveniently be conducted during the customary annealing of the initially formed article. Subsequently, the so-conditioned or presensitized glass is subjected to high energy or actinic radiation followed by heat treatment at temperatures between the transformation range and the softening point of the glass.
The monochrome color produced is dependent upon the concentrations of silver and the thermoreducing agent included in the glass composition. SnO is stated to be the preferred agent for that purpose. The color displayed by the glass progressively changed from green through blue, violet, red, orange, and yellow with increased amounts of thermoreducing agent where the silver concentration is held constant.
As is evident, this latter method eliminates the need for the first exposure to high energy or actinic radiation but has the disadvantage of permitting the development of only one color in a given article of glass, since the initial thermal reduction determines the final color to be produced. The subsequent exposure and heat treatment merely bring out that color.
United States application Ser. No. 778,160, filed Mar. 16, 1977 by Joseph Ference, describes an improvement upon the method for producing polychromatic glasses disclosed in U.S. Pat. No. 4,017,318, supra, wherein the time required for developing the color is shortened and the colors, themselves, are often more vivid.
The preferred embodiment of the invention contemplates four basic steps:
(1) a glass article is formed having a composition coming within the ranges set out in U.S. Pat. No. 4,017,318;
(2) the glass article is exposed to high energy or actinic radiation for a sufficient length of time to develop a latent image therein;
(3) the high energy or actinic radiation is removed and the glass article heated to a temperature between the transformation range and the softening point of the glass for a sufficient length of time to cause nucleation and growth of microcrystals consisting of alkali fluoride containing at least one silver halide selected from the group of AgCl, AgBr, and AgI; and then
(4) the glass article is re-exposed to high energy or actinic radiation while at a temperature between about 200°-410° C. for a sufficient length of time to cause metallic silver to be deposited as discrete colloidal particles less than about 200A in the smallest dimension, and/or deposited on the surface of said microcrystals, the portion of the microcrystal coated with silver being less than about 200A in the smallest dimension, and/or deposited within said microcrystals, the silver-containing part of the microcrystal being less than about 200A in the smallest dimension, said microcrystals having a concentration of at least 0.005% by volume.
Where desired, the initial irradiation by high energy or actinic radiation may also be undertaken at temperatures between about 200°-410° C. That practice is optional, however, since it does not appear to improve significantly the intensity of the final color developed within the glass, although it does have the advantage of reducing the time required for nucleation and incipient crystallization. Moreover, should this initial irradiation of the glass at elevated temperatures be prolonged for an extended period of time, the glass will take on a permanent yellowish cast. Such a phenomenon is, of course, unwanted where a spectrum of colors is desired.
In summary, both U.S. Pat. No. 4,017,318 and U.S. application Ser. No. 778,160 teach that, where the development of a variety of colors is desired in polychromatic glasses, two exposures to high energy or actinic radiation are demanded. In actual practice, the first irradiation treatment is commonly of relatively short duration, e.g., a few minutes will frequently be sufficient, whereas the second exposure is of much longer duration, i.e., typically one hour or longer even when combined with the second heat treatment as disclosed in U.S. application Ser. No. 778,160. It can readily be appreciated that the energy required for the exposure step, i.e., the energy required for the high intensity radiation for an extended period of time, adds a very substantial factor to the cost of the finished article. Furthermore, the need for irradiation places constraints on the sizes of articles that can be so-treated and the overall speed of production.
Accordingly, it would be highly desirable if polychromatic glass articles could be produced exhibiting a variety of colors of high intensity without the requirement of a lengthy irradiation step.
SUMMARY OF THE INVENTION
The general features required for the production of the operative color centers in polychromatic glasses are reasonably well understood. Thus, as is explained in U.S. Pat. No. 4,017,318, the first irradiation and heat treatment give rise to the development of silver particles which act as nuclei for the growth of microcrystals of alkali fluoride plus AgCl and/or AgBr and/or AgI. As can be seen in the transmission electron micrographs appended to that patent, the crystals exhibit an acicular or pyramidal morphology having silver concentrated at the tip thereof. During the second exposure plus heat treatment, this silver is reduced thereby yielding elongated metallic particles which absorb light at wavelengths determined by the length: width aspect ratio of the particles and the polarization of the incident light.
Laboratory study has demonstrated that the wavelength sensitivity for both the first and the second irradiation steps is identical where ultra-violet radiations constitute the actinic radiation, and that the maximum sensitivity corresponds to the maximum of the Ce +3 absorption which peaks near 3000A. This circumstance necessarily leads to the conclusion that the mechanics of both exposures is founded in the production of photoelectrons which function as reducing agents for the silver.
The first exposure to high energy or actinic radiation is inherently quite efficient because the silver is relatively uniformly dispersed within the glass as are, it is postulated, the photoelectrons. During the second exposure, there is again produced a homogeneous cloud of photoelectrons, but these must now locate the highly localized silver-containing sites produced during the first exposure. This circumstance, resulting in long reaction paths, is believed to constitute the reason for the lengthy second exposure.
The present invention is founded in the discovery that the second irradiation with high energy or actinic radiation can be eliminated and colors equivalent in variety and intensity secured where the nucleated glass is fired in a reducing atmosphere; one that preferably consists of a hydrogen gas-containing environment. A temperature of at least 350° C., but not greater than about the strain point of the glass, is required. At temperatures much above the strain point, the color centers become altered.
The instant invention is operable with the glasses illustratively disclosed in U.S. Pat. No. 4,017,318. Those glasses consist essentially, in weight percent on the oxide basis, of about 10-20% Na 2 O, 0.0005-0.3% Ag, 1-4% F, an amount of at least one halide selected from the group consisting of Cl, Br, and I at least sufficient to react stoichiometrically with the Ag, but not more than a total of about 4%, and the remainder SiO 2 . Where ultra-violet radiation having wavelengths between about 2800A-3500A constitutes the actinic radiation, about 0.01-0.2% CeO 2 will be incorporated into the composition. Furthermore, where Sb 2 O 3 and/or SnO are employed as thermoreducing agents, about 0.1-1% Sb 2 O 3 and/or about 0.01-1% SnO will be included, the total Sb 2 O 3 + SnO not exceeding about 1%.
In the production of monochrome bodies, Ag will be present in an amount of at least 0.002%, SnO in at least 0.02%, and fluoride will preferably not exceed about 2%.
Also, in like manner to that patent, the concentration of the microcrystals in the colored transparent glasses will not exceed about 0.1% by volume and the size thereof will not exceed about 0.1 micron in diameter. Customarily, where transparent articles are desired, the silver content will be maintained below about 0.1% by weight, the fluoride concentration will be held below about 3% by weight, and the total of the remaining halides will not exceed about 2% by weight. The addition of up to 18% by weight ZnO and up to 10% by weight Al 2 O 3 can be very useful in improving chemical durability, melting and forming capabilities, and other physical properties of the base glass. Those additions provide the preferred glass compositions of the invention.
An atmosphere of hydrogen constitutes the most effective reducing atmosphere from the standpoint of speed in operation. Other reducing environments less hazardous than hydrogen alone are well known to the art, however, e.g., forming gas (a mixture of N 2 and H 2 gases), cracked ammonia, and mixtures of CO and CO 2 . Numbers of forming gases are commercially marketed, e.g., 92% N 2 , 8% H 2 , 90% N 2 , 10% H 2 , and 80% N 2 , 20% H 2 , any of which will be operable.
DESCRIPTION OF PREFERRED EMBODIMENTS
The following table reports compositions, expressed in parts by weight on the oxide basis as calculated from the batch, of glasses operable in the instant invention. Because it is not known with which cation(s) the halides are combined, they are merely listed as halide, in accordance with conventional glass analysis practice. Furthermore, inasmuch as the contents of silver are very low, they are simply tabulated in terms of Ag. Finally, since the sum of the individual components closely approximates 100, for all practical purposes each constituent may be deemed to be included in weight percent.
The actual batch ingredients other than the halides can comprise any material, either the oxide or other compound, which, when melted together with the remaining batch, will be converted into the desired oxide in the proper proportions. The halides are commonly added as alkali metal halides. Where Sn +2 is utilized as a thermoreducing agent, it is frequently incorporated in the batch in the form of a halide.
Up to as much as 50% by weight of the halide constituents and up to as much as 30% by weight Ag may be lost via volatilization during the batch melting step. The addition of extra quantities of those components to compensate for such losses, however, is well within the technical ingenuity of the glass technologist.
Although the exemplary compositions in the following table involved laboratory scale melting experiments, it will be appreciated that large-scale commercial melts utilizing pots or continuous glass melting tanks can be undertaken with compositions of the subject invention. The compositions recited below were compounded, the ingredients ballmilled together to assist in achieving a homogeneous melt, and thereafter melted in a furnace operating at about 1450° C. for about 4 to 6 hours with stirring. The melts were cast into steel molds to yield glass blocks of various sizes and configurations, and discs about 3 inches in diameter and 0.125 inch thick were pressed. The glass articles were immediately transferred to annealers operating at about 375°-450° C.
TABLE______________________________________ 1 2 3 4______________________________________SiO.sub.2 72.0 72.0 72.0 72.0Na.sub.2 O 16.2 16.2 16.2 16.2ZnO 5.0 5.0 5.0 5.0Al.sub.2 O.sub.3 6.9 6.8 6.8 6.8F 2.5 2.8 2.8 2.8CeO.sub.2 0.05 0.1 0.1 0.1Br 1.1 0.2 0.4 0.4Sb.sub.2 O.sub.3 0.2 0.5 0.5 0.3Ag 0.01 0.03 0.03 0.03SnO 0.05 0.12 0.12 0.09______________________________________
In the following illustrative examples, a 2500 watt mercury vapor lamp system having substantial intensity at a wavelength of about 3000A provided the source of actinic radiation. Other sources of ultra-violet radiation can obviously be utilized and, as has been pointed out above, high energy electrons and X-radiations are also effective in securing the necessary photoreduction of silver ions.
EXAMPLE 1
A pressed disc was prepared from each composition recited in the above table and samples thereof about 1 × 0.5 inch × 1.5 mm were ground and polished. Strips of masking tape opaque to ultra-violet radiations were placed over sections of each sample running in the same direction. The strips were so positioned as to divide the top surface area of the samples into three approximately equal longitudinal portions.
The samples were then exposed at ambient temperature to the ultra-violet lamp in the focal plane of the system. The tapes were successively removed to form horizontal areas of glass exposed for periods of 30, 60, and 105 seconds, respectively. The exposed samples were thereafter transferred to an electrically fired furnace, heated at about 10° C./minute to 510° C., held at that temperature for about 1 hour, and then cooled to room temperature.
The samples were transferred to an electrically fired furnace tube through which hydrogen gas was passed at a flow rate of about 0.3 l/min. After purging the tube with the hydrogen gas, the glass samples were subjected to about 5 minutes treatment at a temperature of about 475° C. A slight coloration could be discerned in each. Further treatment to 15 minutes resulted in definite coloration in each sample with progressively longer exposures yielding even more intense colors.
The strip portions of the samples exhibited the following colors, based upon the length of the initial exposure to ultra-violet light:
30 seconds -- blue-green
60 seconds -- blue
105 seconds -- reddish
EXAMPLE 2
A pressed disc having composition 1 from the above table was cut into samples about 1 × 0.5 inch × 1.5 mm. which were ground and polished. Strips of masking tape were placed over sections thereof in like manner to that described in Example 1. Also in accord with Example 1, sections of the samples were exposed to ultra-violet radiation for periods of 30 seconds, 60 seconds, and 105 seconds, respectively, heated at about 10° C./minute to 510° C., and held at that temperature for about 1 hour.
The samples were then treated in a forming gas (92% N 2 , 8% H 2 ) atmosphere at about 450° C. with a gas flow of about 0.3 l/min. Definite coloration was observed after 8 hours and more pronounced tints were achieved only after about 15 hours exposure. The strips displayed colors similar in hue to those of Example 1. It will be appreciated that the use of a forming gas containing a greater proportion of hydrogen gas will result in a faster rate of color development.
As is well recognized in the art, the rate of hydrogen permeation into glass is influenced both by temperature and the pressure of the hydrogen-containing atmosphere. Hence, the diffusion rate is increased when the temperature of contact with the reducing atmosphere is elevated and/or the pressure thereof is raised. Thus, as the pressure of a hydrogen-containing environment is raised above ambient pressure, the rate of color production will be increased. Also, the use of a wet reducing gas, e.g., forming gas that has been passed through liquid water or otherwise combined with water vapor, can sometimes be more effective than gas in the dry state.
Yet, the treatment temperature must not be so high and/or the treatment carried out for so long a period that the color centers become thermally altered. For example, treatment of composition 1 in hydrogen gas at a temperature of about 510° C. (approximately the strain point of the glass) resulted in a totally yellow article, thereby indicating thermal destruction of the color centers. Likewise, where composition 1 was subjected to forming gas at about 470° C. for about 16 hours, a totally yellow body was produced. Finally, the severity of the reducing environment also plays an important role, as is illustrated via a comparison of Examples 1 and 2. Thus, the pure hydrogen gas atmosphere in Example 1 was very effective at 450° C., whereas the forming gas required much longer exposure periods to yield similar results. Finally, glass composition also appears to have an effect upon the rate of the thermoreduction reaction. For example, a glass more permeable to the diffusion of hydrogen will increase the reaction rate. In this connection, it has been demonstrated that increasing the Na 2 O content of a glass decreases the hydrogen permeation rate substantially.
In sum, the optimum temperature for the thermoreducing treatment will desirably be as high as possible to maximize hydrogen diffusion into the glass, but below about the strain point of the glass. Therefore, where pure hydrogen gas is employed, treatment temperatures between about 425°-475° C. are preferred. A temperature of about 500° C. is believed to be a practical maximum to permit ready control of color production. At temperatures much below about 350° C., the rate of color production, even with pure hydrogen gas at elevated pressures, becomes so slow as to be relatively impractical.
The present invention is also operable where the development of monochrome colors is desired. Thus, for example, a glass containing a thermoreducing agent, such as composition 1 of the above table, can be cooled slowly enough from the melt or reheated to a temperature between the transformation range and softening point of the glass to cause partial thermoreduction of the silver. Thereafter, exposure of the glass to a gaseous reducing atmosphere at a temperature between about 350° C. and the strain point of the glass will cause the production of color therewithin.
This method permits the development of color within a glass without the need for any irradiation to high energy or actinic radiation, but, of course, only a single color can be produced.
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The present invention primarily comprises an improvement upon the method for producing photosensitive colored glasses or polychromatic glasses utilizing two sequences of exposure to high energy or actinic radiation followed by heat treatment. The invention contemplates replacing the second exposure/heat treatment step with a heat treatment conducted in a reducing atmosphere at a temperature of at least 350° C., but below the strain point of the glass. The resultant articles can be particularly useful in ophthalmic applications.
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BACKGROUND OF THE INVENTION
The invention relates to a sewing machine, and more particularly relates to a feed dog dropping system of the sewing machine which is operated to displace the feed dog from an upper operative position to a lower inoperative position and vice versa in dependence upon a selected stitch pattern. The same applicant's copending U.S. patent application Ser. No. 6,685, now U.S. Pat. No. 4,236,469, dated Dec. 2, 1980 discloses a similar system including an electromagnetic device such as a solenoid which is energized to connect a feed control pulse motor to a transmission linkage operatively connected to a plunger device which is operated to displace the feed dog from the upper operative position to the lower inoperative position.
Such a prior art requires a considerably large sized solenoid for a limited space of the machine housing and makes the structure considerably complex, and moreover such a system is costly.
SUMMARY OF THE INVENTION
The invention has been provided to eliminate such defects and disadvantages of the prior art. For attaining this object, the present invention provides a control member secured to the control shaft of a control motor such as a pulse motor, which is turned in a predetermined range to control the horizontal feeding movement of the feed dog. The control member is turned in one direction beyond the predetermined range to operate a feed dog switching mechanism into a set condition, and is turned in the opposite direction within a predetermined range to operate the feed dog switching mechanism into an operative condition, thereby to displace the feed dog from the upper operative position to the lower inoperative position. The control member is turned again in said one direction to release the feed dog switching mechanism allowing the same to return to the initial condition for displacing the feed dog from the lower inoperative position to the upper operative position. Then the control member is turned again in the opposite direction within the predetermined range for controlling the horizontal feeding movement of the feed dog.
It is a primary object of the invention to provide a feed dog dropping system of simple structure as well as of a smooth and positive operation.
It is another object of the invention to reduce the production cost of such a system.
The other features and advantages of the invention will be apparent from the following description of a preferred embodiment in reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of the invention,
FIG. 2 is an exploded view of the invention, and
FIGS. 3-A, 3-B and 3-C are explanatory operational views of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In reference to FIG. 1, the numeral 1 is a mount secured to a suitable part within the machine housing (not shown). A control motor such as a pulse motor is secured to the rear side of the mount 1 for controlling the horizontal movement of the feed dog of the sewing machine. The numeral 2 is a rotatable control shaft of the pulse motor extended through the mount 1 to the front side thereof. A horizontal feed control member 3 is a secured to the end of the motor shaft 2 and is connected to one end 5 of the transmission link 4, the other end of which being connected to an adjustable feed regulator (not shown) for regulating the horizontal movement of the feed dog. The mount 1 is formed with a stopper 6 having opposite abutments 7 and 8 to be engaged by the abutments 9 and 10 of the feed control member 3 respectively to forcibly stop the rotation of the pulse motor for the sake of safety. Actually the pulse motor is to be stopped just before the feed control member 3 engages the stopper 6. The maximum counterclockwise position of the pulse motor at which it stops corresponds to a position of the feed regulator adjusted to the resultant feeding amount 4 mm of the feed dog in the forward direction. On the other hand, the maximum clockwise position of the pulse motor at which it stops corresponds to the feeding amount 4 mm of the feed dog in the rearward direction. However, in this respect, the actual feeding amount is 2.5 mm to the maximum and the spare rotational movement of the pulse motor is utilized to switch the function of the feed dog as will be mentioned herein later. FIG. 1 shows the relative positions of constituent parts to hold the feed dog in the operative position for the standard horizontal feeding in the forward direction.
In reference to FIGS. 1 and 2, the numeral 11 is a bracket secured to the mount 1. As shown, the bracket 11 is formed with a collar 12 on which a cam element 13 and an arm 14 are turnably mounted. The bracket 11 is provided with a transverse pin 15 on which a lever 16 is turnably mounted. The lever 16 is forked at the upper part 17 thereof for receiving therein the transverse pin 18 of the arm 14. The bracket 11 is provided with another transverse pin 19 on which an operating lever 20 is turnably mounted. The transverse pin 21 of the operating lever 20 engages the cutout 22 of the cam element 13 through an opening 23 of the bracket 11. The operating lever 20 is provided with other two transverse pins 24 and 25 which are spaced from each other. In the condition of FIG. 1 showing the standard forward feed control of the sewing machine, the operating lever 20 is turned in the clockwise direction to the maximum and the pin 25 is locked out of the travelling path of the pawl 26 of the feed control member 3 allowing the maximum counterclockwise turning movement of the feed control member 3. On the other hand, the pin 24 of the operating lever 20 is locked in the travelling path of the pawl 26 to engage the pawl 26, thereby to block the clockwise rotation of the feed control member 3 at the angular position thereof for providing the feeding amount 2.5 mm in the rearward direction.
A cam follower 27, which is formed with a follower portion 29 and a pawl 31, is turnably mounted on the pin 28 of the arm 14. The follower 27 is, at the follower portion 29 thereof, normally pressed against the cam face 30 or 33 of the cam element 13 by a tension spring 34 which is at one end connected to the pin 35 of the arm 14 and is at the other end connected to the pin 36 of the cam follower 27. When the follower 27 engages the lower cam face 30 of the cam element 13, the pawl 31 of the follower 27 is in a position spaced from the pawl 32 of the feed control member 3 as shown in FIG. 1. If the feed control member 3 is turned in the clockwise direction, the pawl 26 of the feed member 3 engages the pin 24 of the operation lever 20. As the feed control member 3 is further turned, the operation lever 20 is turned in the counterclockwise direction, and then the cam element 13 is turned in the clockwise direction. As a result, the follower portion 29 of the follower 27 engages the higher cam face 33 of the cam element 13, and the follower 27 is turned in the clockwise direction and the pawl 31 of the follower 27 is displaced to a position between the pawls 26 and 32 of the feed control member 3, so that the pawl 31 may be engaged by the pawl 32 when the feed control member 3 is turned in the counterclockwise direction. In this condition, if the feed control member 3 is turned in the counterclockwise direction, the part 37 of the feed control member 3 engages the pin 25 of the operating lever 20 to turn the lever 20 in the clockwise direction, thereby to turn the cam element 13 in the counterclockwise direction. Thus, the follower 27 is returned to the initial position as shown in FIG. 1 where the follower portion 29 of the follower 27 engages the lower cam face 30 of the cam element 13.
An L-shaped lever 38 is turnably mounted on a plate 40 secured to the mount 11 and is normally biased in the clockwise direction by a spring (not shown) in FIGS. 1 and 2. The L-shaped lever has one end 41 which is normally in engagement with the lower transmission part 42 of the lever 16, and has the other forked end 43 which is operatively connected to the device for changing the vertical position of the feed dog (not shown). As aforementioned, FIG. 1 shows the condition of parts for holding the feed dog in an operative position for producing the standard feeding amount. If the lever 16 is turned in the counterclockwise direction, the feed dog is displaced down to the inoperative position.
With the foregoing structure of the invention, the operation thereof is as follows:
The horizontal feed control motor such as a pulse motor having the rotatable control shaft 2 is driven and stopped by an electric control device which is selectively operated from a pattern selecting device usually arranged on the front face of the sewing machine, though these devices are not shown. Further this invention includes a micro-computer memorizing various program control signals, stitch control signals, etc. If the pattern selecting device is selectively operated, the micro-computer is operated to discriminate if the selected pattern requires the fabric feeding function of the feeding dog. If the feeding function is required, the micro-computer sets the feeding device at a predetermined feeding amount per stitch of the selected pattern.
As mentioned hereinbefore, FIG. 1 shows the condition of parts making the feeding device operative in accordance with a selected pattern. If the machine operator selects a stitch pattern such as the basting stitch requiring no feeding function, the pulse motor shaft 2 and accordingly the horizontal feed control member 3 is turned in the clockwise direction, and the pawl 26 of the feed control member 3 comes to engage the pin 24 of the operating lever 20 as shown in FIG. 3-A. As the feed control member 3 is further turned, the feed control member 3 turns the operating lever 20 in the counterclockwise direction. Then, the cam element 13 is turned in the clockwise direction as shown in FIG. 3-B. The follower portion 29 of the follower 27, therefore, engages the higher cam face 33 from the lower cam face 30 of the cam element 13. The follower 27 is turned in the clockwise direction and the pawl 31 of the follower 27 is displaced into the travelling path of the pawl 32 of the feed control member 3. Then the motor shaft 2 turns the feed control member in the counterclockwise direction. Therefore, the pawl 32 of the feed control member engages the pawl 31 of the follower 27 and turns the follower 27 in the clockwise direction as shown in FIG. 3-C, and therefore, the arm 14 is turned together in the same direction. As a result, the transmission lever 16 is turned in the counterclockwise direction, and therefore the L-shaped lever 38 is turned in the counterclockwise direction in FIG. 2. Thus, the L-shaped lever 38 displaces the feed dog down into the inoperative position, and then the pulse motor is stopped to hold the feed dog in the inoperative position until the pattern selecting device is newly operated to select a different pattern requiring the fabric feeding function of the feed dog.
During the counterclockwise rotation of the feed control member 3 from the condition in FIG. 3-A to the condition in FIG. 3-C, the release part 37 of the feed control member 3 engages the pin 25 of the operating lever 20 to turn the same in the clockwise direction. The cam element 13 is, therefore, turned in the counterclockwise direction and is returned to the position as shown in FIG. 3-A where the lower cam face 30 is opposite to the follower portion 29 of the follower 27 while the follower 27 remains in engagement with the feed control member 3 as shown in FIG. 3-C where the follower 27 is spaced from the cam element 13.
In the condition of FIG. 3-C, if the machine operator selects a different pattern requiring the feeding function of the feed dog, the motor shaft 2 turns the feed control member 3 in the clockwise direction. When the feed control member 3 is turned to a position as shown in FIG. 3-A, where the follower 27 is released from the feed control member 3 and returned, by the tension spring 34, to the initial position where the follower portion 29 of the follower 27 engages the lower cam face 30 of the cam element 13. Then the transmission lever 16 is turned in the clockwise direction by a spring (not shown) normally biasing the L-shaped lever 38 in the clockwise direction. Thus, the L-shaped lever 38 returns the feed dog up to the operative position.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions, differing from the types described above.
While the invention has been illustrated and described as embodied in a sewing machine with feed dog dropping system, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
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A sewing machine with a feed dog vertically displaceable between an upper operative position and a lower inoperative position has a control element connected with a control shaft of a control motor and turnable by the latter within a predetermined range in two opposite directions, a cam element displaceable from an inoperative position to an operative position by the control element during turning of the latter in one of the directions, a cam follower normally engaging the cam element and displaceable from an inoperative position to a set position by the cam element during displacement of the latter from its inoperative position to its operative position and being further displaceable to an operative position by the control element during turning of the latter in the other of the directions, and a transmitting element operatively connected with the cam follower and the feed dog and operated by the cam follower during displacement of the latter from its set position to its operative position so as to displace the feed dog from its upper operative position to its lower operative position.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of PCT/JP2016/063945 filed on May 11, 2016, the contents of which are incorporated by reference herein in their entirety.
BACKGROUND
[0002] The disclosed embodiments relate to a wire rope comprising multiple metal element wires.
[0003] In a conventional wire rope, multiple metal element wires are twisted together to form the wire rope. In general, wire ropes have advantages such as excellent impact resistance and good flexibility as compared with a single metal element wire. Further, wire ropes are often subjected to repeated bending, and thus desirably have good durability under such usage conditions.
[0004] For example, Japanese Patent Application Laid-Open No. 2004-327254 describes an aluminum twisted wire (a wire rope) in which spaces between twisted wires inside an outermost aluminum twisted wire layer are filled with grease to improve the life time of the wire rope (see FIG. 1 and the like).
[0005] Further, Japanese Patent Application Laid-Open No. H08-144182 describes a twisted wire rope having an improved life time, which can be prepared by (1) forming an uneven surface on each surface of multiple metal element wires, (2) forming element twisted wires by twisting the multiple metal element wires each having the uneven surface, (3) twisting the element twisted wires and then applying a resin coating around the twisted element twisted wires, and (4) filling spaces between the resin coating and the element twisted wires with grease (see FIG. 2 and others).
[0006] Further, Japanese Patent Application Laid-Open No. 2004-124342 describes an inner wire rope having an improved abrasion resistance and the like, which can be prepared by subjecting side strands to deforestation processing to make surface contacts between a core strand and the side strands, and sealing lubricating oil between the core strand and the side strands (see FIG. 1 and the like).
[0007] However, a step of grease filling is inevitably required when manufacturing the wire ropes described in Japanese Patent Applications Laid-Open Nos. 2004-327254, H08-144182, and 2004-124342, although containing grease in the wire ropes can improve their durability.
[0008] Further, the wire ropes described in Japanese Patent Applications Laid-Open Nos. 2004-327254, H08-144182, and 2004-124342 cannot be used in medical devices to be inserted into a patient's body because these wire ropes are filled with grease within the wire ropes. Therefore, there is a need to develop a wire rope having an improved durability without containing grease for use in medical devices.
SUMMARY
[0009] The disclosed embodiments have been developed to address the above problem. An object of the disclosed embodiments is to provide a wire rope having improved durability without containing grease, and in particular a wire rope with improved durability which can be used in a medical device to be inserted into a patient's body.
[0010] In order to achieve the above object, the disclosed embodiments include a wire rope comprising multiple metal element wires wound together, and in which the multiple metal element wires include at least one special metal element wire that has a first hardness at an outer periphery in a cross-section thereof that is higher than a second hardness at the center in the cross-section thereof. The special metal element wire can impart improved durability to the wire rope without requiring the use of grease, enabling the wire rope to be used in a medical device.
[0011] As defined herein, a “special metal element wire” is a metal element wire in which the hardness at the outer periphery of the metal element wire is higher than at the center of the metal element wire.
[0012] The at least one special metal element wire may be arranged at the center of the wire rope. This can further improve the durability of the wire rope.
[0013] Moreover, the wire rope may consist only of the at least one special metal element wire and multiple side metal element wires in contact with the at least one special metal element wire. This can further improve the durability of the wire rope.
[0014] The at least one special metal element wire may have a circular cross-section, and the multiple side metal element wires may each have an approximately trapezoidal cross-section. The cross-section is “approximately trapezoidal” if it resembles a trapezoid having 4 defined sides, even if the sides and/or corners are partially or even completely curved. This can even further improve the durability of the wire rope.
[0015] Furthermore, a bundled wire rope may be formed by twisting together a plurality of any one of the wire ropes discussed above. This can further improve durability.
[0016] Moreover, the wire rope may comprise, at its center, a twisted wire in which multiple special metal element wires are twisted together. This can improve the flexibility of the wire rope.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 shows a cross-sectional view of a wire rope according to the disclosed embodiments.
[0018] FIG. 2 shows a first hardness distribution in a cross-section of a special metal element wire.
[0019] FIG. 3 shows a second hardness distribution in a cross-section of a special metal element wire.
[0020] FIG. 4 shows a side view of a wire rope according to the disclosed embodiments.
[0021] FIG. 5 shows a cross-sectional view taken along line A-A in FIG. 4 .
[0022] FIG. 6 shows a side view of a wire rope according to the disclosed embodiments.
[0023] FIG. 7 shows a cross-sectional view taken along line B-B in FIG. 6 .
[0024] FIG. 8 shows a cross-sectional view of a wire rope according to the disclosed embodiments.
[0025] FIG. 9 shows a cross-sectional view of a wire rope according to the disclosed embodiments.
DETAILED DESCRIPTION OF EMBODIMENTS
[0026] Below, embodiments of the present invention will be described with reference to the drawings.
[0027] FIG. 1 shows a cross-sectional view of a wire rope according to the disclosed embodiments. FIG. 2 shows a first hardness distribution of a cross-section of a special metal element wire used for the wire rope. FIG. 3 shows a second hardness distribution of a cross-section of a special metal element wire used for the wire rope.
[0028] With reference to FIG. 1 , a wire rope 1 comprises a core wire 3 (which corresponds to the “special metal element wire”) located at the center, and 6 side wires 5 ( 5 a , 5 b , 5 c , 5 d , 5 e , and 5 f ) wound around the core wire 3 .
[0029] The core wire 3 is a metal element wire having a circular cross-section. There is no particular limitation for the material of the core wire 3 , but stainless steel is used for purposes of this discussion.
[0030] A peripheral part (outer periphery, or outer edge) of the core wire 3 in a cross-section has a higher hardness than a center of the core wire 3 in the cross-section. That is, the core wire 3 is configured to have a structure where only the surface region (surface) of the core wire 3 is hardened, but the inside of the core wire 3 is not hardened. This structure allows the core wire 3 to have both flexibility and improved resistance to abrasion due to contact between the core wire 3 and the side wires 5 .
[0031] Note that conventionally known methods such as swaging and wire drawing can be used in order to obtain a metal element wire (e.g., the core wire 3 ) in which a hardness of the peripheral part in a cross-section of the metal element wire is higher than that of the center in the cross-section.
[0032] Further, the hardness of the core wire 3 may increase in a second-order fashion toward the outer periphery from the center in a cross-section of the core wire 3 as shown in FIG. 2 , or may increase in a linear fashion. Alternatively, the core wire 3 may include a constant-hardness region in the vicinity of the center of the core wire 3 that spans from the center to an intermediate position of the core wire 3 in a cross-section, and the hardness may increase from the intermediate position toward the outer periphery as shown in FIG. 3 .
[0033] Note that the hardness described in FIGS. 2 and 3 is expressed in the Vickers hardness as measured with a Vickers hardness meter, and has a unit of “HV.”
[0034] The hardness of the center of the core wire 3 in FIG. 2 is about 650 HV, while the hardness at the outer periphery is about 700 HV, showing a difference of 50 HV. The hardness of the core wire 3 in FIG. 3 is constant at about 650 HV in the vicinity of the center of the core wire 3 , while it is about 700 HV at the outer periphery, showing a difference of 50 HV.
[0035] Note that the experiments performed by the present applicant demonstrated that the flexibility and abrasion resistance were improved even when the hardness at the center in a cross-section was only 550 HV, and the hardness at the outer periphery in the cross-section was only 580 HV.
[0036] In contrast, the flexibility of the wire rope 1 was impaired and the durability decreased when the hardness of the entire region in a cross-section of the core wire 3 was, for example, 700 HV.
[0037] The side wires 5 ( 5 a , 5 b , 5 c , 5 d , 5 e , and 5 f ), which are metal element wires each having a circular cross-section, are spirally wound around the core wire 3 in the longitudinal direction. There is no particular limitation for the material of the side wires 5 ( 5 a , 5 b , 5 c , 5 d , 5 e , and 5 f ) as well, but stainless steel is used for purposes of this discussion. Tungsten may also be used.
[0038] In the wire rope 1 , the core wire 3 having a hardness of the peripheral part in a cross-section higher than that of the center is arranged at the center of the wire rope 1 such that the multiple side wires 5 ( 5 a , 5 b , 5 c , 5 d , 5 e , and 5 f ) all make contact with the core wire 3 . This can improve the durability of the wire rope 1 .
[0039] Below, another wire rope of the disclosed embodiments will be described with reference to FIGS. 4 and 5 . Throughout this disclosure, descriptions will be omitted for parts that have already been described, to which the same reference numbers will be assigned in the figures. FIG. 4 shows a side view of the wire rope, and FIG. 5 shows a cross-sectional view taken along line A-A in FIG. 4 .
[0040] With reference to FIGS. 4 and 5 , a wire rope 11 comprises a core wire 3 located at the center of the wire rope 11 , and 6 side wires 15 ( 15 a , 15 b , 15 c , 15 d , 15 e , and 15 f ) wound around the core wire 3 .
[0041] The side wires 15 ( 15 a , 15 b , 15 c , 15 d , 15 e , and 15 f ), which are metal element wires each deforestation-processed into an approximately trapezoidal shape, are spirally wound around the core wire 3 in the longitudinal direction. There is no particular limitation for the material of the side wires 15 ( 15 a , 15 b , 15 c , 15 d , 15 e , and 15 f ), but stainless steel is used for purposes of this discussion. Tungsten may also be used.
[0042] In the wire rope 11 , the core wire 3 having a hardness of the peripheral part in a cross-section higher than that of the center is arranged at the center of the wire rope 11 such that the 6 side wires 15 ( 15 a , 15 b , 15 c , 15 d , 15 e , and 15 f ) each having an approximately trapezoidal cross-section all make surface contact with the core wire 3 . The wire rope 11 has an approximately circular cross-sectional outer periphery. This can improve not only the torque transmissibility of the wire rope 11 (the torque transmissibility to one end of a wire rope when the other end of the wire rope is rotated), but also the durability of the wire rope.
[0043] FIG. 6 shows a side view of a wire rope according to the disclosed embodiments, and FIG. 7 shows a cross-sectional view taken along line B-B in FIG. 6 .
[0044] With reference to FIGS. 6 and 7 , a wire rope 101 comprises the core wire rope 11 shown in FIGS. 4 and 5 located at the center, and 6 side wire ropes 21 , 31 , 41 , 51 , 61 , and 71 wound around the core wire rope 11 . That is, the wire rope 101 is a bundled wire rope.
[0045] The side wire ropes 21 , 31 , 41 , 51 , 61 , and 71 each have a similar structure to that of the core wire rope 11 , and are spirally wound around the core wire rope 11 in the longitudinal direction.
[0046] That is, the side wire rope 21 comprises a core wire 3 a located at the center (which corresponds to the “special metal element wire”) and 6 side wires 25 ( 25 a , 25 b , 25 c , 25 d , 25 e , and 25 f ) wound around the core wire 3 a ; the side wire rope 31 comprises a core wire 3 b (which corresponds to the “special metal element wire”) located at the center and 6 side wires 35 ( 35 a , 35 b , 35 c , 35 d , 35 e , and 35 f ) wound around the core wire 3 b ; the side wire rope 41 comprises a core wire 3 c (which corresponds to the “special metal element wire”) located at the center and 6 side wires 45 ( 45 a , 45 b , 45 c , 45 d , 45 e , and 45 f ) wound around the core wire 3 c ; the side wire rope 51 comprises a core wire 3 d (which corresponds to the “special metal element wire”) located at the center and 6 side wires 55 ( 55 a , 55 b , 55 c , 55 d , 55 e , and 55 f ) wound around the core wire 3 d ; the side wire rope 61 comprises a core wire 3 e (which corresponds to the “special metal element wire”) located at the center and 6 side wires 65 ( 65 a , 65 b , 65 c , 65 d , 65 e , and 65 f ) wound around the core wire 3 e ; and the side wire rope 71 comprises a core wire of 3 f (which corresponds to the “special metal element wire”) located at the center and 6 side wires 75 ( 75 a , 75 b , 75 c , 75 d , 75 e , and 75 f ) wound around the core wire 3 f.
[0047] The wire rope 101 is formed by twisting a plurality of wire ropes, each of which has arranged at its center a core wire having a hardness of the peripheral part in a cross-section higher than that of the center such that 6 side wires each having an approximately trapezoidal cross-section all make contact with the core wire, each wire rope being configured to have an approximately circular cross-sectional outer periphery. This can further improve not only the torque transmissibility of the wire rope 101 (the torque transmissibility to one end of a wire rope when the other end of the wire rope is rotated), but also the durability of the wire rope 101 .
[0048] FIG. 8 shows a cross-sectional view of a wire rope 81 according to the disclosed embodiments. The wire rope 81 comprises a core twisted wire 13 located at the center, 4 inner side wires 82 arranged at the outside of the core twisted wire 13 , and 8 outer side wires 85 wound around the core twisted wire 13 and the inner side wires 82 .
[0049] The core twisted wire 13 comprises 4 metal element wires ( 13 a , 13 b , 13 c , and 13 d (each corresponds to the “special metal element wire”), and each metal element wire has a circular cross-section. There is no particular limitation for the material of the metal element wires ( 13 a , 13 b , 13 c , and 13 d ), but stainless steel is used for purposes of this discussion.
[0050] Here, the metal element wires ( 13 a , 13 b , 13 c , and 13 d ), which constitute the core twisted wire 13 , each have a hardness of the peripheral part in a cross-section higher than that of the center in the cross-section. That is, each metal element wire ( 13 a , 13 b , 13 c , and 13 d ) has a structure in which only the surface of the metal element wire is hardened, but the inside of the metal element wire is not hardened. Further, the core twisted wire 13 is formed by twisting four of these metal element wires. This can improve the flexibility and durability of the core twisted wire 13 .
[0051] Moreover, 4 inner side wires 82 ( 82 a , 82 b , 82 c , and 82 d ) are arranged at the outside of the core twisted wire 13 . Each of the inner side wires 82 ( 82 a , 82 b , 82 c , and 82 d ) has a circular cross-section and a diameter smaller than that of each metal element wire ( 13 a , 13 b , 13 c , and 13 d ) of the core twisted wire 13 . Note that there is no particular limitation for the material of the inner side wires 82 ( 82 a , 82 b , 82 c , and 82 d ), but stainless steel is used for purposes of this discussion.
[0052] Further, 8 outer side wires 85 ( 85 a , 85 b , 85 c , 85 d , 85 e , 85 f , 85 g , and 85 h ), which are metal element wires each having a circular cross-section, are arranged at the outside of the core twisted wire 13 and the inner side wires 82 ( 82 a , 82 b , 82 c , and 82 d ). Note that there is no particular limitation for the material of the outer side wires 85 ( 85 a , 85 b , 85 c , 85 d , 85 e , 85 f , 85 g , and 85 h ), but stainless steel is used for purposes of this discussion.
[0053] In the wire rope 81 , the core twisted wire 13 (formed by twisting 4 metal element wires each having a hardness of the peripheral part in a cross-section higher than that of the central part) is arranged at the center. This can further improve the flexibility and durability of the wire rope 81 .
[0054] FIG. 9 shows a cross-sectional view of a wire rope 91 . The wire rope 91 comprises a core twisted wire 23 located at the center, 4 inner side wires 92 arranged at the outside of the core twisted wire 23 , and 8 outer side wires 95 wound around the core twisted wire 23 and the inner side wires 92 .
[0055] The core twisted wire 23 comprises 4 metal element wires ( 23 a , 23 b , 23 c , and 23 d , and each of the metal element wire has a circular cross-section. There is no particular limitation for the material of the metal element wires ( 23 a , 23 b , 23 c , and 23 d ), but stainless steel is used for purposes of the discussion.
[0056] Here, among the metal element wires ( 23 a , 23 b , 23 c , and 23 d ) of the core twisted wire 23 , the metal element wire 23 d has a hardness of the peripheral part in a cross-section higher than that of the center in the cross-section. That is, the metal element wire 23 d is configured to have a structure in which only the surface of the metal element wire is hardened, but the inside of the metal element wire is not hardened (the metal element wire 23 d corresponds to the “special metal element wire”). On the other hand, the metal element wires 23 a , 23 b , and 23 c each have an approximately constant hardness profile throughout a cross-section.
[0057] Further, the core twisted wire 23 is formed by twisting the 4 metal element wires. This can further improve the flexibility of the core twisted wire 23 .
[0058] Moreover, 4 inner side wires 92 ( 92 a , 92 b , 92 c , and 92 d ) are arranged at the outside of the core twisted wire 23 . Each of the inner side wires 92 ( 92 a , 92 b , 92 c , and 92 d ) has a circular cross-section and a diameter smaller than that of each metal element wire ( 23 a , 23 b , 23 c , and 23 d ) of the core twisted wire 23 . Note that there is no particular limitation for the material of the inner side wires 92 ( 92 a , 92 b , 92 c , and 92 d ), but stainless steel is used for purposes of this discussion.
[0059] Furthermore, 8 outer side wires 95 ( 95 a , 95 b , 95 c , 95 d , 95 e , 95 f , 95 g , and 95 h ), which are metal element wires each having a circular cross-section, are arranged at the outside of the core twisted wire 23 and the inner side wires 92 ( 92 a , 92 b , 92 c , and 92 d ). Note that there is no particular limitation for the material of the outer side wires 95 ( 95 a , 95 b , 95 c , 95 d , 95 e , 95 f , 95 g , and 95 h ), but stainless steel is used for purposes of this discussion.
[0060] In the wire rope 91 , the core twisted wire 23 formed with the metal element wires each having a hardness of the peripheral part in a cross-section higher than that of the central part is arranged at the center of the wire rope 91 . This can improve the flexibility and durability of the wire rope 91 .
[0061] Although disclosed embodiments of wire ropes are described above, the present invention shall not be limited to these embodiments. The present invention can be practiced with various modifications made without departing from the scope of the present invention.
[0062] For example, as described above, the side wires 5 , 15 , 25 , 35 , 45 , 55 , 65 , and 75 in the wire ropes 1 , 11 , and 101 are each formed with 6 metal element wires. The number of metal element wires is, however, not limited to 6, and 3 or more may be sufficient.
[0063] Moreover, the core twisted wires 13 and 23 are described as being formed by twisting 4 metal element wires. The number of metal element wires is, however, not limited to 4, and two or more may be sufficient.
[0064] Moreover, the outer side wires 85 and 95 in the wire ropes 81 and 91 each comprise 8 metal element wires. The number of metal element wires is, however, not limited to 8, and any number may be used as long as the core twisted wire 13 or 23 is covered.
[0065] Moreover, the inner side wires 82 and 92 are provided in the wire ropes 81 and 91 , but the inner side wires 82 and 92 may not be present.
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A wire rope having improved durability and that can be used in a medical device to be inserted into a patient's body. The wire rope includes a core wire and side wires. The core wire is a special metal element wire that has a hardness at an outer periphery in a cross-section thereof that is higher than that at a center in the cross-section thereof. The wire rope does not include grease.
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FIELD OF THE INVENTION
The present invention pertains to composition-of-matter and use of water soluble polymers in the form of novel, self-inverting, water-in-oil emulsions. The polymers contained in these emulsions can be used for sludge dewatering, enhanced oil recovery, retention aids in papermaking, coal tailings, metal ore and plating waste treatments, etc.
BACKGROUND OF THE INVENTION
Water-soluble polymers contained within the discrete phase of water-in-oil emulsions, the so-called inverse emulsions, are a common article of commerce. Practically every company which sells to the industries in which high molecular weight water-soluble polymers are used markets the polymers in the form of these emulsions.
When first introduced to the marketplace, these emulsions consisted of a hydrocarbon continuous phase, the discrete phase containing the highly concentrated high molecular weight polymer and water (usually about 50% polymer and 50% water), and the emulsifying surfactant, which was of the oil-soluble, low HLB type. These emulsions were relatively stable, and required an "activator", added to the water of dilution, in order to invert in a reasonable time. (In order to be used, it is necessary to have the high molecular weight polymer in dilute aqueous solution). Although it has been claimed that the emulsions would invert without the use of an activator, it was found that this took an impractically long time, or impractically high agitation rates, to be commercially useful. In some cases, inversion without the activator did not occur at all. The activator is a water-soluble, high HLB-type surfactant. However, many users of these emulsions found that it was inconvenient to have a "two-barrel" treatment program, consisting of the emulsion in one drum, and the activator in the second drum. Each of these required its own concentration for use, with two separate feed rates that needed to be carefully monitored, i.e., if too little activator was used, the emulsion did not invert properly, and if too much activator was fed, the emulsion inverted too rapidly, which would cause feeding problems and gelation.
In recent years, the so-called "self-inverting" emulsions have been introduced. In these inverse emulsions, the inverting surfactant is contained in the emulsion package itself, thus only one drum is required for use. Because of the convenience of this approach, practically all inverse emulsions sold today are of the self-inverting type. However, these products are not without their own problems. The principal deficiency of these emulsions is their instability, caused by the presence of the destabilizing inverting surfactant. This leads to a shortened shelf life. In addition, these products must be agitated before use, since some settling occurs even with short storage times. In addition, the inverting surfactant, which is the last ingredient to be added to the formulation, again to minimize stability problems, must be carefully monitored in order to avoid the same kinds of problems alluded to above for the addition of activator. It would be advantageous if the inverse emulsion did not require a separate step of adding an inverting surfactant.
It is thus an object of this invention to provide a self-inverting water soluble polymer contained within a water-in-oil emulsion.
It is a further object of this invention to provide a self-inverting water-soluble polymer contained within a water-in-oil emulsion which inverts easily and does not require an inverting surfactant.
It is still a further object of this invention to provide a self-inverting water-soluble polymer contained within a water-in-oil emulsion which polymer is used to flocculate suspended inorganic and organic matter contained primarily in aqueous systems--such as those set forth in Flesher et al., hereinafter described and incorporated herein by reference.
PRIOR ART
Flesher et al., U.S. Pat. No. 4,702,844 describe a process for flocculating aqueous suspensions using a flocculant comprising acrylamide copolymers together with an ethylenically unsaturated monomer bearing certain similarity to the monomers which comprise a key part of our invention. This prior art differs from the present invention in a number of significant ways, the totality of which clearly makes the present invention quite different from that of Flesher et al. Firstly, the quantity of ethylenically unsaturated monomer in '844 which is useful is from 1.0 to 90% by weight of the total amount of the copolymers, whereas the similar monomer of the present invention provides the desired properties when used from about 0.01% to about 10%. Although the concentration of this key monomer in the present invention slightly over laps the concentration of the ethylenically unsaturated monomer in the '844 patent, the range is so different as to indicate both different mechanism of action of the monomers in the two inventions, and non-obviousness of the instant invention. Most significant is the fact that the '844 patent is only obliquely related to inverse emulsion systems. In addition, the ethylenically unsaturated monomer in the '844 patent requires preferentially a hydrocarbyl group containing at least 8 carbon atoms at the end of the alkoxyl part of the molecule (see claim 1, column 11, lines 35-36, column 4, lines 54-57, and all Examples). Although it is disclosed in '844 that the "R" group can be a polyoxyalkylene chain where the alkylene groups are propylene or higher (column 4, lines 55-57), this teaching does not appear to be consistent with the best mode of the invention, where the hydrocarbyl group of at least 8 carbons and preferably 10 to 24 carbon atoms is required to provide the necessary hydrophobicity (col. 3, lines 16-22). The key monomer of the present invention either does not require a hydrocarbyl "R" group, or, when present, the "R" group (designated as R 3 in Formula I of this application, which appears later herein) is required to be of chain length 4 or less, with the possibility that a chain length up to 7 might be successfully utilized. In addition, the '844 patent appears to be operative with anionic, cationic, and nonionic polymers, whereas the present invention is only operative with anionic and cationic polymers, again indicating the significant differences between the present invention and that of the '844 patent.
European Patent Application 0,126,528 (Allied Colloids Limited) discloses "dispersing systems" (i.e., emulsifying surfactants) and "distributing systems" (i.e., inverting surfactants), together with "polymerization stabilizers" for improving the stability, viscosity, and inverting characteristics of inverse emulsions. This very complex invention is not prior art for the present invention because: the "polar liquids" used in the dispersing and distributing systems are very different from the key monomers of the present invention; the "polymerization stabilizers", made using monomers similar to the key monomers of the instant invention, are not incorporated into the flocculant polymer as are the instant alkoxylated acrylate monomers. Indeed, the polymerization stabilizers of '528 appear to be insoluble in water, in that they are dissolved in the hydrocarbon continuous phase of the inverse emulsion. The polymerization stabilizers of '528 are also of low molecular weight (page 9, lines 1-5, in which oligomeric materials are disclosed), whereas the polymers of the present invention which incorporate the alkoxylated acrylate monomers are of very high molecular weight, indicating the very different nature of the two polymers. In addition, the disclosure of '528 reveals that the complex use of polar liquids apparently "encapsulates" (page 15, lines 14-21) the water soluble polymer, very analogous to the mode of action of an inverting surfactant. The essence of our invention is that an inverting surfactant is not necessary to allow the water-in-oil emulsion to easily invert into water.
DETAILED DESCRIPTION OF THE INVENTION
The present inventors have discovered a class of monomers, when copolymerized with water-soluble monomer(s) in inverse emulsion form, provide novel compositions which are self-inverting without the necessity of adding an inverting surfactant. The novel compositions invert rapidly when diluted into water. The novel compositions are useful in a number of applications. The class of monomers which imparts the self-inverting characteristics to the water-soluble high molecular weight polymers contained in the water-in-oil emulsions without the necessity of an inverting surfactant can be depicted by Formula I: ##STR1## Wherein R 1 is hydrogen or methyl;
R 2 is hydrogen, methyl or ethyl;
R 3 is hydrogen or C 1 -C 4 alkyl;
n is a number from 1-100
The monomer may be selected from the group comprising poly(ethyleneoxy), poly(propyleneoxy) and poly(butyleneoxy) ester derivatives of acrylic acid or methacrylic acid, although choice of these monomers is not limiting.
These acrylate ester comonomers can terminate in a free hydroxyl group, or be end-capped with a C 1 -C 4 alkyl group such as methyl, ethyl, butyl, and the like. Preferred are monomers in which R 3 is hydrogen. Many of the comonomers can be prepared according to the teachings in U.S. Pat. Nos. 3,896,161; 4,075,411; 4,268,641; and 4,390,401. The comonomers can also be prepared with blocks of ethyleneoxy units followed by blocks of propyleneoxy units, or vice-versa, or a random mixture of both. Preferred is polypropylene glycol monomethacrylate, having 5-6 moles of propylene oxide, sold as PPGMM by Alcolac Chemical Corp. (R 1 , R 2 =methyl, R 3 =hydrogen, n=5-6 in Formula 1).
The monomer of Formula I is a minor component of a water-soluble anionic or cationic copolymer of acrylamide. It is expected that water-soluble polymers based on other monomers than acrylamide, such as methacrylamide, acrylic acid, methacrylic acid, maleic acid, itaconic acid, lower alkyl esters of the above acids, and the like, would also be useful in accordance with the invention. The primary factors in designing the copolymeric system will be its water-solubility, ability to form high molecular weights, and cost. Polymers comprised of acrylamide together with anionic and cationic co-monomers are preferred, but it is not to be construed that the invention is limited to these monomers.
Equivalents to a second monomer together with acrylamide are also within the scope of the instant invention. These would include moieties created when reactions are conducted on the polymer, such as hydrolysis of acrylamide to form an anionic functionality (functionally equivalent to copolymerizing acrylic acid with acrylamide), well-known reactions to form cationic functionalities on acrylamide polymers, or the like.
Typical cationic comonomers polymerized with acrylamide can be selected from dialkylaminoalkyl(meth)acrylamides, dialkylaminoalkyl (meth)acrylates and quaternary salts thereof, and diallyl dialkyl ammonium chloride. The quaternary ammonium salts may be obtained by quaternization of the tertiary amine compounds of said amides or acrylates with the customary quaternizing agents, preferably methyl chloride or dimethyl sulfate.
Preferred monomers comprise dimethylaminoethylacrylate, diethylaminoethylacrylate, dimethylaminoethylmethacrylate, diethylaminoethylmethacrylate, dimethylaminopropylmethacrylamide, dimethylaminopropylacrylamide, and methyl chloride or dimethyl sulfate quaternary salts of the above compounds, and diallyl dimethyl ammonium chloride.
Typical anionic comonomers copolymerized with acrylamide can be selected from acrylic acid, methacrylic acid, maleic acid, itaconic acid, and the like, and water-soluble salts thereof. These salts can include, but are not limited to, the sodium, potassium, and ammonium salts.
The mole percent of the comonomers in the polymers may vary within certain limits, provided that the total adds up to 100%. Preferably, the total of acrylamide and the ionic comonomer (anionic or cationic) will vary from about 90% to about 99.99%. The mole content of the monomer represented by Formula I will be about 0.01% and is expected to go as high as about 10% mole percent with 0.01% to 5% being preferred.
The molecular weight of the polymers described above may vary over a wide range, e.g., 10,000-30,000,000. The invention, however, finds its greatest usefulness when the acrylamide copolymers have molecular weights in excess of 1,000,000.
The copolymers are prepared by a water-in-oil emulsion technique. Such processes have been disclosed in U.S. Pat. No. 3,284,393; U.S. Pat. No. Re. 28,474, and U.S. Pat. Re. No. 28,576, herein incorporated by reference. The technique comprises:
Preparation of an aqueous phase, ranging from about 50% to about 90% by weight of the total emulsion, which aqueous phase is comprised of water, monomers as described above, chelating agents and initiator(s), if the particular initiator(s) chosen are water-soluble. Ethylenediamine tetraacetic acid or diethylenetriamine pentaacetic acid and their salts are suitable, but not limiting, chelating agents. The water-soluble initiator may be selected from peroxides, persulfates, bromates, and azo-type initiators such as 2,2' azobis-(2-amidinopropane) dihydrochloride, etc. Sulfites, bisulfites, sulfur dioxide, and other reducing agents used with oxidizing initiators to form an initiating redox pair may also be used. If a reducing agent is used, it is added as described below. The total amount of monomers will range from about 30% to about 80%, by weight, based on the total weight of the aqueous phase.
Preparation of an oil phase, ranging from about 10% to about 50% by weight of the total emulsion, which oil phase is comprised of a liquid organic hydrocarbon and water-in-oil emulsifying agents. A preferred group of hydrocarbon liquids include both aromatic and aliphatic compounds. Thus, such organic hydrocarbon liquids as benzene, xylene, toluene, mineral oils, kerosenes, naphthas and the like may be used. Oils commonly used for this purpose are the deodorized kerosenes, such as the commercially available materials sold under the trademarks of AMSCO OMS, Isopar M, and LOPS. The oil phase may optionally contain the initiator(s), if the particular initiator(s) chosen are oil-soluble. Typical would be 2,2,'-azo-bis(isobutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile) and benzoyl peroxide, and the like. It is well known to those skilled in the art that the initiator(s) can be chosen to be either water- or oil-soluble depending on the particular needs of the system.
The water-in-oil emulsifying agent is usually a low HLB surfactant. Typical emulsifiers are mono and digylcerides, sorbitan fatty acid esters and lower N, N-dialkanol substituted fatty amides, and the like, and are also described in U.S. Pat. Re. No. 28,576.
A mixture of emulsifying surfactants, rather than single emulsifier, may be preferred. The concentration of emulsifier can be from about 3% to about 30% by weight, based on the total weight of the oil phase. Polymeric surfactants such as modified polyester surfactants (Hypermer, ICI) and maleic anhydride-substituted ethylene copolymers (PA-14 or 18, Chevron) may also be added to improve the mechanical stability and increase the solids content of the emulsion.
After the aqueous phase and oil phase have been prepared separately, the aqueous phase is then homogenized into the oil phase. Homogenizers, high shear pumps, or high speed agitators that are capable of mixing the two phases into a homogeneous water-in-oil emulsion may be used. Any of the techniques to prepare the inverse emulsions well known to those skilled in the art may be used. The particle size of the resulting emulsion is usually less than 10 μm and preferably less than 2 μm. After the emulsion is prepared, the system is then sparged with nitrogen to remove all oxygen from the system. The emulsion is under constant agitation or circulation. Polymerization is then initiated by adding a reducing agent from a redox pair or by heat to induce the decomposition of initiator in the emulsion. The temperature of the reaction medium is maintained at about 20° C. to about 75° C., preferably about 35° C. to about 55° C.
After the polymerization is substantially complete, a solution of sodium metabisulfite, sodium bisulfite or SO2 gas is further added to stabilize the emulsion and to remove any residual monomers.
As differentiated from the prior art, no inverting surfactant is added to the resulting emulsion.
The water-in-oil emulsion thus produced rapidly disperses and dissolves into an aqueous solution upon being added to water. Within minutes, a maximum solution viscosity is obtained.
The following examples are set forth for purposes of illustration only and are not to be construed as limitations on the present invention except as set forth in the appended claims. All parts and percentages are by weight unless otherwise specified. For all viscosity determinations, Surfonic N-95 inverting surfactant was added to the aqueous salt solutions.
EXAMPLE 1
Procedure For Preparing PPGMM Containing Emulsion
Aqueous Phase: to a suitable vessel were added 26.3 parts of deionized water, 100.65 parts (59 mole per cent) of acrylamide (50.0% aqueous), 123.84 parts (40 mole per cent) of acryloyloxyethyltrithylammonium chloride (AETAC) (75 % aqueous), and 4.91 parts (1 mole percent) of polypropyleneglycol monomethacrylate (PPGMM, Alcolac, 99%). To this solution were added 0.30 parts of disodium ethylenediamine tetraacetic acid solution (Versenex, Dow, 50.0% aqueous), 0.95 parts of t-butylhydroperoxide (t-BHP),(2.5% aqueous) and 0.03 parts of 2,2'-azobis-(2-amidinopropane) dihydrochloride (V-50, Wako).
The oil phase was prepared by dissolving 6.17 parts of sorbitan monooleate (Arlacel 80, ICI) and 2.65 parts of polyoxyethylene(5) sorbitan monoleate (Tween 81, ICI) in 89.14 parts of deodorized kerosene (LOPS, Exxon). The aqueous phase was then added to the oil phase using a Silverson Homogenizer. The mixture was homogenized at medium speed and then at high speed to obtain the desired viscosity range.
The emulsion was charged to a suitable reaction vessel and purged with nitrogen gas for 30 minutes with stirring. With continued stirring, 4.96 parts of dilute sodium metabisulfite solution was slowly pumped into the reactor over a period of 2.5 hours while maintaining the reactor at 40°-45° C. The emulsion was then heated at 45° C. or 1.5 hours. To the emulsion was then added 5.0 parts of a 30.0% aqueous sodium metabisulfite solution. The emulsion was stirred at 45° C. for an additional 0.5 hour before being cooled to room temperature and filtered.
The resulting emulsion dissolved readily in water to give a viscous polymer solution. A 0.3% solution of this polymer in 4.0% aqueous NaCl had a viscosity of 24.9 cps.
EXAMPLE 2
The apparatus and procedure were similar to that described in Example 1, with a slight change in the emulsifying surfactants. This example contained a higher total concentration of the emulsifying surfactants (same ratio) than in Example 1. All other quantities were the same as in Example 1.
The formulation is as follows:
______________________________________Aqueous Phase:AMD (50%) 100.65 partsAETAC (75%) 123.84PPGMM (99%) 4.91DI Water 26.29t-BHP (2.5%) 0.95Versenex 80 0.30V-50 0.03 256.97 partsOil Phase:Arlacel 80 7.46 partsTween 81 3.19LOPS 89.14 99.79 partsTotal Weight: 356.76 partsOverall Solids: 41.8%______________________________________
The resulting emulsion required approximately one hour of agitation in order to completely invert in water to form a viscous polymer solution. A 0.3% solution of this polymer in 4.0% aqueous NaCl had a viscosity of 23.8 cps. This emulsion was stable at ambient conditions for 2 months and also remained homogeneous after 3 freeze-thaw cycles.
COMPARATIVE EXAMPLE A
The apparatus, weights and procedure were similar to that described in Example 1, except that no PPGMM monomer was used. The resulting emulsion contained 60 mole per cent of acrylamide and 40 mole per cent of acryloyloxyethyltrimethylammonium chloride. The formulation was a follows:
______________________________________Aqueous Phase:AMD (50%) 102.36 partsAETAC (75%) 123.84DI Water 22.54t-BHP (2.5%) 0.95Versenex 0.30V-50 0.03 250.02Oil Phase:Arlacel 80 6.01 partsTween 81 2.57LOPS 86.73 95.31Total Weight: 345.33 partsOverall Solids: 41.8%______________________________________
The emulsion was stabilized with 5.0 parts of a 30.0% aqueous solution of sodium metabisulfite as in Example 1. A portion of the emulsion was removed and designated as Comparative Example A.
An inverting surfactant mixture was then added to the remaining emulsion at a concentration of 2.8% based on the emulsion. The inverting surfactant mixture was composed of two water soluble surfactants: C 11 -C 15 secondary alcohol ethoxylate (Tergitol 15-S-7, Union Carbide) and sodium dioctylsulfosuccinate (Aerosol OT-S, Cyanamid). The inverting agent mixture was added to the emulsion over 0.5 hour while holding at 45° C. The emulsion was stirred for another 0.5 hour at 45° C. and finally cooled and filtered off. This emulsion was designated as Comparative Example B.
Comparative Example B dissolved readily in water to give a viscous solution. A 0.3% solution of this polymer in 4.0% aqueous NaCl had a viscosity of 22.8 cps.
EMULSION INVERSION STUDY
An inversion study was conducted to evaluate the emulsions. In a large beaker, 600 g of deionized water was stirred at 600 rpm with a constant speed agitator. A calculated amount of emulsion, to yield a 0.1% active weight of polymer in solution was added. The emulsions were all 41.8% active polymer. The viscosity of the resulting solution was measured over a period of time. A rapid increase in solution viscosity and no clumps in the aqueous phase usually indicated a good inversion. Examples 1 and 2, and Comparative Examples A and B are described above. Comparative example C was prepared by adding the PPGMM to the emulsion after the polymerization, thus it was not incorporated into the polymer. Composition of the polymers used in the study are shown in Table I, and the results of the study are shown in Table II.
TABLE I______________________________________COMPOSITION OF THE POLYMERSSample Mole % AMD Mole % AETAC Mole % PGMM______________________________________1 59.0 40.0 1.02 59.0 40.0 1.0A 60.0 40.0 0.0B 60.0 40.0 0.0C 60.0 40.0 1.0*______________________________________ *Monomer added after polymerization
TABLE II______________________________________EMULSION INVERSION STUDY Total Time BulkExample Stirred (min) Visc. (cps) Appearance______________________________________1 2.0 320 small amt. of clumps 5.0 475 homogeneous 10.0 475 small amt. of clumps 30.0 415 homogeneous2 2.0 5 finely divided solids 5.0 24 finely divided solids 10.0 67 finely divided solids 15.0 96 less solids 30.0 165 less solids 60.0 375 less solids 90.0 420 homogeneousA 2.0 9 many solids 5.0 29 many solids 10.0 48 many solids 15.0 59 many solids 20.0 65 less solids 25.0 71 less solids 30.0 73 less solids 40.0 76 less solids 50.0 80 less solids 60.0 83 less solids 180.0 125 solids still presentB 2.0 249 no solids; gel on shaft 5.0 235 homogeneous 10.0 235 no solids; gel on shaft 30.0 220 homogeneousC 2.0 14 many solids 5.0 24 many solids 10.0 31 many solids 15.0 35 many solids 20.0 40 less solids 25.0 46 less solids 30.0 `49 less solids 60.0 61 solids still present______________________________________
This inversion study shows that the instant invention with the PPGMM containing polymer and without inverting surfactants (Example 1) inverts as well as the prior art emulsion (Comparative Example B, with inverting surfactants added). Both of these solutions reached a maximum viscosity and became homogeneous in 5 minutes. The decrease in solution viscosity of Examples 1 and B after 10 minutes of stirring is considered an artifact of the high shear conditions. Comparative Example A shows that a similar emulsion but without either PPGMM or inverting surfactants required a very long time to invert in water.
Comparative Example C shows that a similar emulsion with PPGMM monomer added after the polymerization also inverted very slowly in water. These results show that the PPGMM monomer is not acting as an inverting surfactant itself and proves that the PPGMM is incorporated into the polymer (Example 1).
Example 2 was prepared with a higher concentration of the emulsifying surfactants than in Example 1 in order to study the effect on emulsion stability. It has been discovered that the rate at which these emulsions invert into water appears to be inversely related to their stability over time. Similarly to emulsions prepared with inverting surfactants, there is a narrow range of concentration of the "minor component" monomer in which the emulsions will remain as a water-in-oil emulsion and still invert quickly to the oil-in-water form upon introduction to water. If the copolymer contains too much of the PPGMM, for example, the emulsion may invert upon standing. Example 2 contains the same mole % of PPGMM as Example 1 but requires a longer time to dissolve and exhibits better long term stability than Example 1. The initial HLB value of the emulsion prior to polymerization may also affect the rate of inversion and long term stability of the emulsion system.
Additional comparative studies were conducted using two allyl ether monomers of the Flesher '844 patent, compared with two examples of the instant invention.
Example 3 was a repeat preparation of Example 1, and the monomer that was used in Example 4 to impart self-inverting characteristics to the inverse emulsion was similar to the hydrophobic allyl ether monomers of the Flesher the '844 patent, wherein in Formula (a) of the '844 patent (column 5, line 37) R=C alkyl (butyl), R 1 and R 2 =hydrogen, Q=CH 2 O, n is about 10, and m is zero, i.e., allyl ether having 10 moles of ethoxylation, with a butyl endcap.
The monomer was prepared similarly to the hydrophobic monomers described below, from the reaction of butyl chloride with polyethylene glycol monoallyl ether having 9.6 moles of ethoxylation. This monomer will be referred to as PEGMAE-C4. This monomer was soluble in water.
Comparative Examples D and E, hydrophobic allyl ether monomers described in the '844 patent, were prepared from the reaction of octyl and octadecyl chlorides with polyethylene glycol monoallyl ether (9.6 moles of ethylene oxide, Alcolac DV-1880). The structure of the compounds synthesized (confirmed by C13 NMR) corresponds to the preferred monomers (a) of the '844 patent, shown in Column 5, line 37, wherein R' and R 2 are hydrogen, Q=CH 2 O, n is about 10, m is zero, and R is either 8 or 18. These monomers will be referred to below as PEGMAE-C8 and PEGMAE-C18, respectively. These monomers were not water soluble.
EXAMPLE 3
AMD/AETAC/PPGMM Emulsion
The apparatus, charge and procedure were similar to that described in Example 1. The resulting emulsion contained 59.5 mole % of acrylamide, 40.0 mole % of acrylyloxyethyltrimethylammonium chloride, and 0.5 mole % of PPGMM.
The formulation is shown as follows:
______________________________________Aqueous Phase: AMD (50%) 101.50 parts AETAC (75%) 123.84 PPGMM (99%) 2.45 DI water 22.14 t-BHP (2.5%) 0.65 EDTA (5.6%) 2.68 253.26Oil Phase: Arlacel 80 6.87 parts Tween 81 2.95 Soltrol 145 88.40 98.22 Total Weight: 351.48 parts overall Solids: 41.6%______________________________________
A 0.3% solution of the resulting polymer in 4.0% aqueous NaCl had a viscosity of 23.0 cps.
EXAMPLE 4
AMD/AETAC/PEGMAE-C4 Emulsion
The apparatus, charge and procedure similar to that described in Example 3 were used, substituting PEGMAE-C4 for PPGMM. The resulting emulsion contained 59.5 mole % of acrylamide, 40.0 mole % of acrylyloxyethyltrimethylammonium chloride, and 0.5 mole % of PEGMAE-C4. The formulation was as follows:
______________________________________Aqueous Phase: AMD (50%) 101.50 parts AETAC (75%) 123.84 PEGMAE-C4 3.22 DI water 23.70 t-BHP (2.5%) 0.95 Versenex 0.30 V-50 0.03 253.54Oil Phase: Arlacel 80 7.15 parts Tween 81 3.06 Soltrol 145 88.25 98.46 Total Weight: 352.00 parts Overall Solids: 41.8%______________________________________
A 0.3% solution of the resulting polymer in 4.0% aqueous NaCl had a Brookfield viscosity of 21.8 cps.
COMPARATIVE EXAMPLE D
AMD/AETAC/PEGMAE-C8 Emulsion
The apparatus, charge and procedure similar to that described in Example 3 were used, substituting PEGMAE-C8 for PPGMM. The resulting emulsion contained 59.5 mole % of acrylamide, 40.0 mole % of acrylyloxyethyltrimethylammonium chloride, and 0.5 mole % of PEGMAE-C8. The formulation was as follows:
______________________________________Aqueous Phase: AMD (50%) 101.50 parts AETAC (75%) 123.84 PEGMAE-C8 3.56 DI water 23.95 t-BHP (2.5%) 0.65 Versenex 0.30 V-50 0.03 254.10Oil Phase: Arlacel 80 7.16 parts Tween 81 8.13 Soltrol 145 93.41 108.70 Total Weight: 362.83 parts Overall Solids: 40.6%______________________________________
A 0.3% solution of the resulting polymer in 4.0% aqueous NaCl had a Brookfield viscosity of 17.4 cps.
COMPARATIVE EXAMPLE E
AMD/AETAC/PEGMAE-C18 Emulsion
The apparatus, charge and procedure similar to that described in Example 3 were used, substituting PEGMAE-C18 for PPGMM. The resulting emulsion contained 59.5 mole % of acrylamide, 40.0 mole % of acrylyloxyethyltrimethylammonium chloride, and 0.5 mole % of PEGMAE-C18. The formulation was as follows:
______________________________________Aqueous Phase: AMD (50%) 101.50 parts AETAC (75%) 123.84 PEGMAE-C18 4.40 DI water 24.56 t-BHP (2.5%) 0.95 Versenex 0.30 V-50 0.03 255.58Oil Phase: Arlacel 80 7.21 parts Tween 81 8.09 Soltrol 145 88.95 104.25 Total Weight: 359.83 parts Overall Solids: 41.2%______________________________________
A 3.0% solution of the resulting polymer in 4.0% aqueous NaCl had a Brookfield viscosity of 19.9 cps.
The composition of the polymers is shown in Table III, and the inversion studies are shown in Table IV.
TABLE 111__________________________________________________________________________COMPOSITION OF THE POLYMERSExampleDescription Mole % AMD Mole % AETAC Mole % Monomer__________________________________________________________________________3 PPGMM 59.5 40.0 0.54 PEGMAE-C4 59.5 40.0 0.5D PEGMAE-C8 59.5 40.0 0.5E PEGMAE-C18 59.5 40.0 0.5__________________________________________________________________________
Inversion studies similar to those previously described were then conducted by using the polymers described in Table III. Results are shown in Table IV.
TABLE IV______________________________________EMULSION INVERSION STUDY Conc. Total Time ViscosityExample (wt. %) Stirred (min.) (cps) Appearance______________________________________3 0.1 2.0 25.0 many solids " 5.0 71.0 " " 10.0 402.5 few solids " 15.0 432.5 " " 20.0 452.5 homogeneous " 30.0 485.0 " " 40.0 470.0 "4 " 2.0 21.0 many solids " 5.0 50.0 " " 10.0 70.0 " " 15.0 78.0 " " 20.0 84.0 less solids " 25.0 89.0 " " 30.0 94.0 " " 40.0 104.5 " " 60.0 135.5 " " 90.0 171.0 some solids still presentD 0.1 2.0 17.0 many solids " 5.0 48.0 " " 10.0 62.0 " " 15.0 67.0 " " 20.0 78.0 " " 25.0 85.0 less solids " 30.0 92.0 " " 40.0 96.0 " " 60.0 124.0 " " 90.0 140.0 some solids still presentE 0.1 2.0 10.0 many solids " 5.0 29.0 " " 10.0 43.0 " " 15.0 49.0 " " 20.0 55.0 " " 25.0 59.0 " " 30.0 65.0 " " 40.0 67.0 less solids " 60.0 69.0 " " 90.0 73.0 "______________________________________
This inversion study shows that neither of the hydrophobic allyl ether monomers of the '844 patent impart self-inverting characteristics to the inverse emulsions. Example E (R=C18 alkyl) showed no better breaking than comparative Example A (AMD/AETAC with no inverting surfactant added). Example D (R=C8 alkyl) inverted slightly better than Example E, but still unacceptably slowly. Neither of the comparative examples fully inverted within the time frame of the study, as evidenced by their not achieving the full viscosity achieved by Example 3. Example 4 was able to achieve higher viscosity than either comparative example, but still not the full viscosity of Example 3. Its inverting behavior is considered marginal.
It is believed that at least one reason that the hydrophobic monomers of the '844 patent do not impart self-inverting characteristics to the emulsions is because of their insolubility in water, which prevents their being incorporated into the polymer structure to the extent that the monomers of the instant invention are incorporated.
Additional emulsions were prepared by incorporating PPGMM into anionic and nonionic polymers.
EXAMPLE 5
Anionic Inverse Emulsion Containing PPGMM
Aqueous Phase: to a suitable reactor were added 90.6 parts deionized water, 124.5 parts of acrylamide (50.0% aqueous), 27.5 parts glacialacrylic acid (99%), and 2.6 parts PPGMM. To this solution were added 3.2 parts of disodium ethylenediamine tetraacetic acid solution (5.6% aqueous), 8.2 parts ammonium hydroxide (30.0% aqueous), and 0.8 parts of t-BHP (1.4% aqueous). The monomer composition was 69.5 mole % acrylamide, 30.0 mole % acrylic acid, and 0.5 mole % PPGMM.
The oil phase was prepared by dissolving 4.9 parts of sorbitan monooleate (Arlacel 80, ICI) and 2.1 parts of polyoxyethylene (5) sorbitan monooleate (Tween 81, ICI) in 89.3 parts of deodorized kerosene (LOPS, Exxon). The aqueous phase was then added to the oil phase using a Silverson Homogenizer. The mixture was homogenized at medium speed and then at high speed to obtain the desired viscosity range.
The emulsion was charged to a suitable reaction vessel and purged with nitrogen gas for 30 minutes with stirring. Then, 3.6 parts of sodium metabisulfate as a 0.50% aqueous solution was slowly added over 3.5 hours. The reducing agent was added at such a rate as to maintain the reaction at 40°-45° C.
The emulsion was stabilized by adding 7.0 parts of a 30.0% aqueous solution of sodium metabisulfite over 0.5 hours while maintaining the reaction at 40° C. The emulsion was stirred at 40° C. for an additional 0.5 hours and then cooled and filtered to remove any particles. The resulting emulsion required approximately one hour of agitation in order to completely dissolve in water. Although the anionic emulsion appeared to invert slower than the cationic counterparts, our new inversion technology is applicable to anionic emulsion systems.
EXAMPLE 6
Nonionic Inverse Emulsion Containing PPGMM
Aqueous Phase: to a suitable vessel were added 53.7 parts deionized water, 193.3 parts of acrylamide (50.0% aqueous), and 2.8 parts of PPGMM (99.5 mole per cent acrylamide, 0.5 mole percent PPGMM). To this solution were added 6.9 parts of disodium ethylenediaminetetraacetic acid solution (5.6% aqueous), and 0.5 parts of t-butylhydroperoxide (1.4% aqueous).
Oil phase: 6.4 parts of sorbitan monooleate (Arlacel 80, ICI) and 2.7 parts of polyoxyethylene (5) sorbitan monooleate (Tween 81, ICI) were dissolved in 90.9 parts of deodorized kerosene (LOPS, Exxon).
The aqueous phase was then added to the oil phase using a Silverson Homogenizer. The mixture was homogenized at medium speed and then a high speed to obtain the desired viscosity range.
The emulsion was charged to a suitable reaction vessel and purged with nitrogen gas for 30 minutes with stirring, followed by the addition of 3.86 parts of sodium metabisulfite as a 0.50% aqueous solution over a period of 4 hours. The reducing agent was added at such a rate as to maintain the reaction at 40°-45° C.
The emulsion was then stabilized by adding 6.8 parts of a 30.0% aqueous solution of sodium metabisulfite over 0.5 hours while maintaining the reaction at 40° C. The emulsion was stirred at 40° C. for an additional 0.5 hours and then cooled and filtered to remove any particles. The resulting emulsion inverted very poorly into water. Only after extensive agitation did the emulsion begin to invert. After one hour of stirring at 600 rpm the solution viscosity was only 65 cps. It appears that the present invention is not applicable to the nonionic emulsion system.
Sludge Dewatering Test
To confirm activity of the polymers prepared according to the invention, a polymer prepared similar to Example 1 was evaluated against a commercial material with the same cationicity. Sludge from a southwest refinery was used. Equivalent performance was obtained by a capillary suction test (CST).
While this invention has been described with respect to particular embodiments thereof, it is apparent that numerous other forms and modifications of this invention will be obvious to those skilled in the art. The appended claims and this invention generally should be construed to cover all such obvious forms and modifications which are within the true spirit and scope of the present invention.
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The present disclosure is directed to water-in-oil emulsion polymers which are used to flocculate matter suspended in aqueous systems. The disclosure and invention are particularly relevent to emulsion polymers which are self-inverting.
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FIELD OF THE INVENTION
[0001] The present invention relates to an implantable hernia repair prosthesis for reinforcing and repairing damaged tissue or muscle walls and methods for making same.
BACKGROUND OF THE INVENTION
[0002] Various prosthetic mesh materials have been proposed to reinforce the abdominal wall and to close abdominal wall defects utilizing different repair prostheses and methods of installation. The methods of executing a surgical repair can be segregated into two main approaches. The repair can be made exclusively from the anterior side (closest to the surgeon) of the defect by dissecting the sac free of the fascia and pressing it back into the pre-peritoneal space and providing permanent closure of the defect. The closure can be provided through the application of space filling prostheses and overlay patches (tension-free techniques) or can be accomplished through the use of sutures (tension techniques).
[0003] An example of a tension free anterior repair is to fold a sheet of surgical mesh fabric into a multi-layer cone configuration and then to insert the mesh plug into a hernia defect to occlude the void. Such a multi-layer prosthesis is inherently stiff, may not fully conform to variations in the contour of the defect, and is subject to shrinkage that potentially could lead to recurrent herniation. The stiff, multi-layered mesh plug also may be susceptible to kinking and buckling during placement.
[0004] U.S. Pat. No. 5,356,432, discloses an implantable prosthesis that is a conical plug formed of a knitted polypropylene monofilament mesh fabric. Longitudinal pleats are hot molded into the mesh body to enhance the flexibility of the conical implant, ideally allowing the implant to closely match the contour of the herniated opening when compressed within the defect. When the device is installed into a fascial defect, the tip of the conical shaped plug presses into and against the visceral sac, potentially enabling long-term erosion of the peritoneum and underlying viscera. The device, in one embodiment, has filler material incorporated into the interior of the formed mesh cone in an attempt to minimize contraction of the device during healing. As collagen scar tissue grows into the prosthetic material, the cross linking of the maturing collagen fibers causes the scar tissue (and encapsulated plug device) to contract. This contraction of scar tissue within the defect and plug causes the surrounding diseased tissue to be subjected to tension, thus enabling re-occurrence of the hernia along the edge of the conical plug. The use of the device requires the passage of a pre-expanded plug through the hernia defect and relies upon the radial expansion force of the single layer mesh cone and filler leaves to occlude the defect. Additionally, since the plug is secured in position by anchoring to the surrounding diseased tissue, the device may dislodge and migrate within the pre-peritoneal space.
[0005] Alternatively, a defect may be repaired through the use of posterior approaches that provide various prosthetic devices in the pre-peritoneal space to prevent the peritoneum from entering the fascial defect. These devices, in some cases, require the use of laparoscopic techniques and, in other cases, require the application of the prosthesis from a remote location under the defect to be repaired. Examples of posterior approaches are disclosed in U.S. Pat. Nos. 5,116,357, 5,254,133 and 5,916,225. However, in many cases, procedures utilizing such devices are complicated, in addition to requiring the use of general anesthesia and costly disposable instrumentation to support the laparoscopic surgery.
[0006] Accordingly, the prior art lacks an implantable hernia repair prosthesis for occluding and repairing damaged muscle and tissuewall ruptures, that is adaptable to irregularities in the shape of the defect, is simple to install, does not require the use of general anesthesia during installation and resists radial collapse due to tissue incorporation.
SUMMARY OF THE INVENTION
[0007] The limitations of prior art hernia prostheses are overcome by the present invention which includes a hernia repair prosthesis having an occlusive member for aiding in the occlusion of a defect in fascia tissue. The occlusive member is convertible from a first configuration with a first axial length and a first major radial extent to a second configuration with a second axial length and a second major radial extent. The second axial length is less than the first axial length and the second major radial extent is larger than the first major radial extent. The occlusive member has a pair of subsections, each having an apex and each flaring outwardly therefrom towards a terminal end. The apexes are disposed at opposite ends of the occlusive member with the terminal ends overlapping. The pair of subsections are conjoined proximate the overlapping terminal ends.
[0008] In accordance with a method for forming the subsections, a surgical fabric is thermoset on a male die and may be stretched or heat shrunk to aid in conforming the surgical fabric to the contours of the male die.
DESCRIPTION OF THE FIGURES
[0009] For a better understanding of the present invention, reference is made to the following detailed description of various exemplary embodiments considered in conjunction with the accompanying drawings, in which:
[0010] [0010]FIG. 1 is a perspective view of a prosthesis according to the present invention prior to assembly of all of its component parts;
[0011] [0011]FIG. 2 is a perspective view of the assembled prosthesis depicted in FIG. 1;
[0012] [0012]FIG. 3 is a schematic view of the prosthesis depicted in FIG. 2 when positioned within a defect in the fascia;
[0013] [0013]FIG. 4 is a schematic view of the prosthesis depicted in FIG. 3 after deployment, i.e. radial expansion, within the defect;
[0014] [0014]FIG. 5 is a schematic view of a die for making pleated conical elements of the prosthesis of FIGS. 1 - 4 ;
[0015] [0015]FIG. 6 is a perspective view of a prosthesis in accordance with a second embodiment of the present invention;
[0016] [0016]FIG. 7 is an exploded view of the prosthesis depicted in FIG. 5;
[0017] [0017]FIG. 8 is a schematic view of a die for making pleated conical elements of the prosthesis of FIGS. 6 and 7;
[0018] [0018]FIG. 9 is a perspective view of a forming station for forming a prosthesis in accordance with the present invention, e.g., as shown in FIGS. 6 and 7;
[0019] [0019]FIG. 10 is a perspective view of a prosthesis in accordance with a third embodiment of the present invention;
[0020] [0020]FIG. 11 is a perspective view of a prosthesis in accordance with a fourth embodiment of the present invention; and
[0021] [0021]FIG. 12 is a schematic view of the prosthesis of FIG. 11 within a fascia defect.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The present invention provides implantable prostheses for reinforcing and repairing weakened abdominal walls and methods for making such prostheses. The prostheses are formed of a biologically compatible, flexible and porous medical textile suitable for reinforcing tissue and occluding tissue defects. The implantable prostheses are indicated particularly for the repair of hernias in the abdominal cavity, including inguinal (direct and indirect), femoral, incisional and recurrent, and provide at least a partial posterior repair. The prostheses are able to be inserted easily in a stress-free condition into a fascia defect from an anterior approach and are capable of expanding radially, at least partially into the pre-peritoneal space, to substantially occlude and conform to the fascia wall of a fascia defect. Alternatively, a posterior approach may be used, if the surgeon prefers. The prostheses are suitable for the repair of varying sizes and shapes of hernias and can be anchored to the surrounding healthy tissue to prevent migration, thus extending beyond the edge of the defect on the anterior side of the defect. Other features of the present invention will become apparent from the following detailed description when taken in connection with the accompanying drawings that disclose multiple embodiments of the invention. The drawings are for the purpose of illustration only and are not intended as a definition of the limits of the invention.
[0023] The prostheses of the present invention comprise a hollow, radially-expandable member for placement within and occlusion of a fascia defect. By radially-expandable, it is meant that the cross sectional area of the member expands from an initial, non-expanded configuration having an initial cross sectional area, sized such that the member may be placed within a fascia defect in a stress-free condition, to a final, expanded configuration having a final cross sectional area greater than the initial cross sectional area and effective to occlude all of, or at least a substantial portion of, the fascia defect. This member can be manufactured out of biocompatible absorbable or non-absorbable surgical mesh material.
[0024] An exploded view of a prosthesis of the present invention is illustrated in FIG. 1. Prosthesis 10 comprises radially-expandable member 12 , having first and second conical members 14 a , 14 b . Each conical member 14 a , 14 b has longitudinal pleats 16 terminating at apex 18 and base 20 of each conical member 14 a , 14 b , respectively. The number and spacial relationship of longitudinal pleats 16 are effective to enhance the axial rigidity of the prosthesis 10 while being placed within the defect. Preferably, the pleats 16 are thermoformed into the mesh body of each conical member 14 a , 14 b . Conical member 14 b has a flange portion 19 that facilitates the relative alignment and attachment of conical members 14 a , 14 b , as more fully described below in reference to FIGS. 6 and 7. Looped suture 22 , with a non-reversing knot 24 , is passed through opposing conical members, 14 a , 14 b . Overlay sheet 26 , e.g., formed from polypropylene surgical mesh, is fixedly attached to apex 18 of one of opposing conical members 14 a , 14 b through the use of looped suture 22 . Overlay sheet 26 is utilized to attach and secure the prosthesis to the surrounding healthy tissue. Optionally, prosthesis 10 may comprise one or more tubular structures 28 , e.g., made from polypropylene surgical mesh and contained within cavity 30 within conical members 14 a , 14 b . Tubular structure 28 provides additional axial rigidity to the prosthesis during handling and insertion of the device into the defect. Tubular structure, as used herein, is meant to include those structures where the cross sectional configuration is tubular in nature. Tubular structure specifically includes cylindrical rolls of materials, e.g. meshes, where the cross section configuration is circular, as well as structures where the cross sectional configuration may be elliptical, triangular, rectangular, etc. The tubular structure 28 also improves the radial expandability of the prosthesis when it is compressed axially and the cylinder collapses, ensuring a solid expansion of the prosthesis against and below the tissue or wall structure defining the defect.
[0025] Suture 22 is passed through the opposing conical members 14 a , 14 b , passing from the apex of one through the apex of the other. Suture 22 then is looped and returned back through the inner conical members 14 a , 14 b in the opposite direction. Looped suture 22 can be passed through the tubular structure 28 axially (or through the ends of the tubular structure 28 , perpendicular to the axis thereof, as shown by dotted line 22 ′) causing it to buckle, or collapse, when looped suture 22 is constricted during use. In the particular embodiment illustrated, both ends of looped suture 22 are passed through flat overlay sheet 26 . Non-reversing knot 24 is tied in looped suture 22 and flat overlay sheet 26 is held in proximity to apex 18 of the upper one of the conical members 14 a , 14 b . The dead tail of the knot 24 is trimmed to length. The finished prosthesis is subjected to sterilization prior to use.
[0026] The assembled prosthesis of FIG. 1 is illustrated in FIG. 2. Prosthesis 10 may be fabricated from any biocompatible medical woven, knitted or non-woven textile. In preferred embodiments, the prosthesis is fabricated from medical grade polypropylene mesh including knitted polypropylene monofilament mesh fabrics such as those available from Ethicon, Inc. under the Prolene trademark, as well as meshes available from Ethicon, Inc. under the Vicryl trademark. Other mesh materials useful in the invention include those available under the Marlex, Dacron, Teflon and Merselene trademarks. Alternatively, the desired effect of forcing tissue re-generation under the overlay patch can be accomplished through the selection of biocompatible absorbable materials for use in the fabrication of the expandable member. Examples of suitable materials are Vicryl and Panacryl sutures, available from Ethicon, Inc, and Polysorb suture, available from United States Surgical Corporation. Radially-expandable member 12 comprises conical members 14 a , 14 b fixedly attached one to the other proximate respective bases 20 . Conical members 14 a , 14 b are configured to have an initial, non-expanded, major diameter that is substantially the same size or less than the diameter of the defect to be repaired. While the conical members 14 a , 14 b are (with the exception of flange 19 ) shown in the figure to be identical in structure, embodiments in which one is taller than the other are contemplated by the invention. The conical members 14 a , 14 b are positioned in opposition one to the other and bases 20 are aligned by flange 19 . Once bases 20 are aligned, conical members 14 a , 14 b are fixedly attached to each other proximate the respective bases 20 , e.g., in and around flange 19 , as more fully described below. Bonding of the conical members 14 a , 14 b may be accomplished by stitching, gluing, welding or any other known form of attachment. Prosthesis 10 includes at least one flat sheet of mesh rolled into a tubular structure 28 (FIG. 1) and permanently located within cavity 30 (FIG. 1) formed by fixedly attached conical members 14 a , 14 b .
[0027] Tubular structure 28 may be fabricated from a flat sheet of polypropylene mesh that, once rolled into cylindrical shape, can been secured about its circumference with suture. Alternatively, tubular structure 28 may be formed by rolling a flat sheet of mesh into the cylindrical configuration and welding, stitching or otherwise bonding the rolled sheet at the ends. Tubular structure 28 (FIG. 1) is disposed inside cavity 30 (FIG. 1) formed by fixedly attached opposing conical members 14 a , 14 b and extends axially from the internal apex 18 of one to the internal apex 18 of the other. Tubular structure 28 aids in providing axial rigidity to the prosthesis when it is inserted into the defect.
[0028] As shown in FIGS. 3 and 4, after hernia sac 40 has been dissected and/or ligated, prosthesis 10 is inserted into fascia defect 43 . Once hernia sac 40 is free from walls 44 of defect 43 in fascia 42 , hernia sac 40 is pressed back into the abdominal cavity. Apex 18 of the lower one of the conical members 14 a , 14 b is inserted into defect 43 , causing peritoneum 46 to invert inwards into the abdominal cavity. Prosthesis 10 is inserted until overlay sheet 26 is flush with anterior side 48 of fascia 42 . Free end 23 of suture 22 is pulled while prosthesis 10 is held in a forward position, i.e., flush with anterior side 48 of fascia 42 . The tightening of suture 22 causes the opposing conical members 14 a , 14 b to be drawn together. The compression of the conical members 14 a , 14 b causes them to collapse axially onto themselves, thus causing the diameter of conical members 14 a , 14 b to expand radially and pleats 16 to open up or expand into a relatively flattened position, i.e., with a greater major diameter and a lesser axial length. This same action causes tubular structure 28 , located within cavity 30 , to buckle, collapse and expand radially outward. Knot 24 is pulled until it is fully tightened.
[0029] Free end 23 of suture 22 may be provided with a needle to enable attachment of the prosthesis 10 to the surrounding healthy tissue by sewing overlay sheet 26 into place. Alternatively, free end 23 of suture 22 can be trimmed off after final deployment and the overlay patch can be attached in place through the use of additional sutures, or may remain in a flattened condition in the anterior space.
[0030] The prosthesis 10 is able to accommodate the spermatic cord structures since it is pleated. When it is expanded, it relies only on the radial expansion force generated from the compression of the opposing textile conical members 14 a , 14 b to enlarge their diameters, as opposed to the use of additional semi-rigid rings or other rigid or semi-rigid members. Preferably, prostheses of the present invention do not comprise such rigid or semi-rigid devices. This ensures that the device is fully compliant to the natural anatomical structures.
[0031] The final configuration of expanded prosthesis 10 , as seen in FIG. 4, both occludes fascia defect 43 on posterior side 47 and is expanded to fill the inner diameter of defect 43 in wall 44 . The expansion of radially expandable member 12 on posterior side 47 of defect 43 prevents peritoneum 46 from entering defect 43 . Additionally, this posterior expansion ensures that the repair is secure from re-herniation through the defect, since the conical mesh is forced into a relatively flat condition. As the scar tissue grows into the flattened conical layers, it is compressed further in the axial direction by scar tissue contraction. With the inclusion of overlay patch 26 , located on anterior side 48 of defect 43 , it is virtually impossible for the device to migrate either anteriorly or posteriorly.
[0032] While radial expansion of the member may be effected by means for radially-expanding the member as discussed and depicted herein, prostheses that are self-expanding, i.e. self-collapsing, when placed in position within the fascia defect are included within the scope of the present invention. Such devices may be constructed such that they will deploy, i.e. collapse axially and radially-expand to occlude the defect, when positioned within a defect in response to conditions of the body surrounding the defect
[0033] [0033]FIG. 5 shows a simplified diagram of an exemplary die system for forming the conical member 14 a described above. The conical member 14 a with longitudinal pleats 16 may be thermoformed from a generally flat disk of surgical mesh that has been placed over a male die element (mandrel) 32 having the same shape as the conical member 14 a shown in FIGS. 1 - 4 , i.e., a cone featuring a plurality of longitudinal valleys 16 ′ (to form the pleats 16 ) and intervening land surfaces 17 ′ (to form the lands 17 of the conical member 14 a ). After the surgical mesh ( 14 a ) has been placed over the outer surface of the male die element 32 , a mating female die (clamp) element 33 is urged against the male die element 32 to press the surgical mesh ( 14 a ) into the surface features of the male die element, i.e., the longitudinal valleys 16 ′ and intervening land surfaces 17 ′, to impart the desired three dimensional shape to the mesh and to form the conical member 14 a . The female die element 33 may be formed from a plurality of individual blade elements 34 , preferably removably or hingedly attached to a common hub or pivot point and having an open configuration (shown in dotted lines) and which fold together to a closed configuration to press into the longitudinal valleys 16 ′. The conical member 14 a clamped by blade elements 34 may then be heated to impose a set on the surgical mesh 14 a such that it will retain the die shape after cooling and removal from the die set 32 , 34 . Any excess mesh 14 a may then be trimmed off. As an alternative to the blade elements 34 , the female die element 33 may have a continuous surface that is complementary to the surface of the male die element 32 , or may have a plurality of individual extensions (not shown) elastically, rather than pivotally emanating from a common hub to form a cage structure for pressing the surgical mesh 14 a into the longitudinal valleys 16 ′ to form the longitudinal pleats 16 and to stretch the mesh 14 a over the land surfaces 17 ′ of the die 32 .
[0034] [0034]FIGS. 6 and 7 show an alternative radially expandable member 112 formed from conical members 114 a and 114 b . In contrast to the preceding expandable member 12 , wherein two substantially identical conical members 14 were held in alignment and then secured together in opposition at the bases 20 of the cone shape, i.e., by gluing, stitching or welding at the flange 19 , conical member 114 a is attenuated such that it does not extend all the way to base line 120 . As before, the conical members 114 a , 114 b are self aligning for the purpose of assembly. Conical member 114 b has a conical portion 115 extending from the apex 118 b to a base line 120 . Base line 120 represents a redirection of the surgical mesh and a great diameter of the conical member 114 b and the expandable member 112 as a whole. A flange portion 119 of the conical member 114 b extends from the base line 120 and converges toward apex 118 a , mimicking the shape of the conical portion 115 in reverse or mirror image. Conical member 114 a has the same shape as conical portion 115 and matingly fits within the open end 121 defined by the flange portion 119 , i.e., aligned by respective pleats 116 and lands 117 . Conical member 114 a overlaps flange portion 119 as shown by dotted line 123 , providing an area for gluing or welding conical members 114 a and 114 b . The extent of conical members 114 a and 114 b can be varied to provide greater or lesser overlap. For example, conical member 114 a could be identical to conical member 114 b , providing a large area of overlap on either side of base line 120 . Alternatively, conical member 114 a can have a lesser extent than conical member 114 b , as shown, such that there is a single layer of material present at the base line 120 , which promotes bending at the baseline 120 and radial expansion of the expandable member 112 .
[0035] The manufacture of the radially expandable member 112 calls for the formation of the conical members 114 a , 114 b and their subsequent assemblage. FIG. 8 diagrammatically shows a die system that can be employed to form the conical member 114 b , which includes a male die element 132 with conical portion 132 a and conical flange portion 132 b . A female die element 133 has a plurality of moveable blade elements 134 , each having a conical portion 134 a and a conical flange portion 134 b for engaging the conical portion 132 a and conical flange portion 132 b , respectively, of the male die element 132 . Either the conical portion 134 a and/or the conical flange portion 134 b of the blade element 134 is moveable from an open position (shown in dotted lines) to a closed position, either by virtue of hinges or by virtue of its being formed separately as a separate die element, i.e., the female die 133 may have a plurality of components. Alternatively, the female die element 133 may be in the form of a cage with multiple flexible fingers emanating from a common hub for pressing the mesh ( 114 b ) into the longitudinal valleys 116 ′ of the conic portion 132 a and the valleys 116 ″ of the flange portion 132 b .
[0036] [0036]FIG. 9 shows a forming station 135 with a male die 132 (not visible) captured within the movable blade elements 134 of female die element 133 . The blade elements 134 may be pivotally secured to the base 136 or, as shown, are removably retained in complementary shaped slots 137 and clamped in a closed position by flange 138 . The blade elements 134 have a relief slot 139 for accommodating excess mesh material and/or a retention band for clamping the mesh on the male die 132 . An orientation pin 140 may be utilized to position the mesh material in the forming station to achieve a selected orientation of the wales, warps, wefts, etc, promoting distortion-free forming of the material as the blade elements 134 are urged into position clamping the material against the male die 132 . Optimal forming may require a particular sequential order of clamping the blade elements 134 , depending upon the material, e.g., 114 b used.
[0037] While the surgical mesh used to form the conical member 114 a may be cut or otherwise formed in any selected two dimensional shape, a disk shape may be used to illustrate the relationship between the respective surface areas of the surgical mesh material 114 b and the male die element 132 . More specifically, for a male die element 132 having a conical portion 132 a with a given altitude A and base B, the surface area thereof has two components, viz., that attributable to the surface area of the lands 117 ′ and that attributable to the surface area of the longitudinal valleys 116 ′. Since the width of the valleys 116 ′ of the die 132 directly decreases the land 117 ′ area of the die 132 , the total surface area may be controlled by varying the depth and shape of the longitudinal valleys 116 ′, which can be selected to “use” a desired amount of the surface area of the surgical mesh 114 b . Similarly, the longitudinal valleys 116 ″ in the conical flange portion 132 b of the male die element 132 may have a selected depth, shape etc. such that the surface area of the flange portion 132 b may be altered by varying these dimensions. The valley 116 ′ dimensions for the conical portion 132 a may be different than the valley 116 ″ dimensions of the conical flange portion 132 b . Alternatively, the valley 116 ′, 116 ″ dimensions may be consistent and symmetrical.
[0038] The foregoing observations concerning the surface areas of the conical portion 132 a and conical flange portion 132 b are noteworthy in that a given disk-shaped sample of surgical mesh has a surface area that increases radially in accordance with the relationship (πr 2 ). The surface of a cone increases from the apex 118 to the base 120 in accordance with the relationship πrs; where s=(r 2 +b 2 ) ½ . As a consequence, the area of the material disk increases along its radius, as does the area of the conic portion 132 a from the apex to the base. Any mismatch of surface areas must be accounted for by stretching the mesh. The flange portion 132 b of the male die element 132 exhibits a departure from the surface area of the material disk, in that while the converging flange portion 132 b of the die 132 increases the total surface area, it does so at a decreasing rate (due to its convergence) at the same time that surface area of the mesh 114 b increases by the square of the radius. Accordingly, after the surgical mesh material extends beyond the great diameter of the male die 132 (at base B) and starts to cover the converging conical flange portion 132 b of the die 132 , an excess of mesh material must be accounted for in order to bring the mesh into conformance with the die 132 shape.
[0039] In accordance with a first approach, the die 132 is formed with a valley 116 ″ number (frequency) and depth (magnitude) such that the surface area of the mesh material 114 b matches that of the flange 132 b but is less than that required to cover the surface area of the conical portion 132 a (including the surface area of the valleys 116 ′) proximate to the great diameter at base B without stretching. In accordance with this method, the surgical mesh material 114 b is wrapped over the male die element 132 covering both the conical portion 132 a and the conical flange portion 132 b of the die 132 . The female die element 133 is then clamped over the male die element 132 forcing the mesh material 114 b into the valleys 116 ′, 116 ″ provided in the male die element 132 . Because the surface area of the material 114 b is less than that of the die 132 , the material 114 b will be stretched thinner in the areas where the surface areas of the material 114 b and the die 132 do not match. This results in the mesh 114 b being thinner and more porous in those areas where it is stretched, primarily in the area of the great diameter proximate base B. This thinning in the area of the base B of the conical portion 132 a enhances the hinge effect present at baseline 120 of the expandable member 112 , promoting the expansion of the expandable member 112 .
[0040] Once the mesh has been conformed to the surfaces of the complementary die elements 132 , 133 , the mesh is heated, e.g., by convection, radiation and/or conduction through the die elements 132 , 133 . Heating relieves the stress in the highly oriented, drawn fibers of the surgical mesh 114 b allowing the mesh to permanently set in the shape imposed upon it by the dies 132 , 133 . The female die 133 can then be removed and the mesh cooled prior to removal from the male die 132 . In using the foregoing technique, the mesh 114 b must be securely held against the male die element 132 to prevent it from creeping along the surface of die 132 prior to its being clamped tightly by the female die element 133 . The same process may be undertaken to form conical member 114 a . If the extent of 114 a is chosen such that no flange 119 is present (as shown in FIG. 7) the foregoing considerations concerning matching the respective surface areas of the mesh 114 a and the male die 132 are simplified.
[0041] An alternative approach for forming conical member 114 b is to use a male die 132 with a surface area less than that of the surgical mesh 114 b , in particular, in the area of the flange portion 132 b of the die 132 . The mesh 114 b is clamped to the male die element 132 such that there is an excess of mesh material 114 b distributed in the valleys 116 ′, 116 ″ of the die 132 . The mesh 114 b is then heated by convection to an elevated temperature, causing the fibers of the mesh 114 b to stress relieve and to shrink. The shrinkage of the mesh 114 b causes the surface area of the mesh to be reduced through a localized reduction in porosity in the conical flange portion 119 . This method does not involve the same forces that induce the slippage of mesh on the face of the male die 132 and eliminates the excess mesh material that might otherwise result in irregularities in the finished conical element 114 b , such as everted pleats.
[0042] As can be appreciated from FIGS. 6 and 7, the finished conical elements 114 a and 114 b nest together in natural alignment due to the alignment of the pleats 116 and lands 117 . Having thus been aligned, the overlap between 114 a and 114 b can be joined by a variety of conventional means including adhesives or welding. One advantageous method includes utilizing a plurality of metal pins 141 (see FIG. 6) to form a backing cage for the overlap area of 114 a and 114 b during exposure to ultrasonic welding. While only one pin 141 is shown, it should be appreciated that a series of pins 141 would be used to provide multiple ultrasonic welds around the circumference of the expandable element 112 .
[0043] As yet another approach to forming the expandible element 112 , internal stiffening ribs can be formed within the pleats 116 through the controlled application of heat and clamping the mesh in the dies 132 , 133 , viz., by differential shrinkage of the mesh to form stiffening ribs. More specifically, a mesh disk is provided having a greater surface area than that of the male die 132 , i.e., if the mesh 114 b were pressed against the surface of the male die 132 (including the lands 117 ′, 117 ″ and valleys 116 ′, 116 ″) there would be excess mesh 114 b , particularly in the flange area 132 b of the die 132 . The mesh 114 b is applied over a cold male die element 132 . A female die 133 having independently moveable blade elements 134 for abutting against the land areas 117 ′. 117 ″ of the male die 132 and independently moveable portions for abutting against the valleys 116 ′, 116 ″ in the male die 132 is applied over the mesh 114 b to clamp the land areas 117 only. This leaves the pleats 116 free to assume any position relative to the valley areas 116 ′, 116 ″ of the male die 132 . In practice, the unclamped pleats 116 tend to bulge out from the surface of the male die 132 . The unclamped pleats 116 are subject to heating to a point that the exposed mesh undergoes shrinkage. The die itself is cool and the lands 117 of the mesh that are clamped in the die are shielded from heating. The heating may be done by convection, radiation (heat lamp) or other conventional methods. While the mesh 114 b is still hot, the moveable portions of the female die 133 that correspond to the pleats 116 , i.e., that insert into the valleys 116 ′, 116 ″ of the male die 132 , are applied to the mesh 114 b to clamp the exposed hot pleats 116 into the valleys 116 ′, 116 ″ of the male die 132 . The female die 133 is dimensioned relative to the male die 132 to produce a selected thickness for the mesh material in each area, i.e., in the land areas 117 and the pleat areas 116 . The heat source is removed and the mesh 114 b is allowed to cool while clamped in the die to retain its set shape. Because the pleats 116 were exposed to heating and experienced shrinkage, the density of the pleats 116 is greater (lower porosity) than the lands 117 . When conical elements 114 a , 114 b formed in this manner are mounted together in opposition, as explained above, the high density regions of the mesh, i.e., the pleats 116 , act as stiffening ribs. When the radially expandable member 112 is axially collapsed, the higher density and more rigid pleats 116 resist bending and force the lands 117 apart to deploy the radially expandable member 112 . The same concept for forming stiffened, higher density regions in the conical members 114 a , 114 b described above can be generally applied to surgical mesh to form mesh products with selected stiffened regions. More particularly, by clamping certain regions of the mesh in a cold die with other slack portions subject to heating and shrinkage, zones of higher density/greater rigidity of any devised shape or distribution can be formed.
[0044] Referring to FIG. 10, prosthesis 110 includes overlay patch 126 slidably attached to radially-expandable member 112 . As shown, filament 150 is passed through looped suture 122 and affixed at its terminal ends to overlay patch 126 . When radially expandable member 112 is placed in the defect, overlay patch 126 may be maneuvered to one side to effect attachment to fascia 142 .
[0045] [0045]FIG. 11 shows a prosthesis 210 having an overlay patch 226 slidably attached to a radially expandable member 212 by an elongated filament 250 . The radially expandable element 212 has conical portion 214 b with a flange (shown by dotted line 223 ) that is covered by conical portion 214 a , which extends to baseline 220 . As in the previous embodiment, the filament 250 is joined to the overlay patch 226 at two spaced points 252 , 254 , e.g., by tying, plastic welding or by being restrained from pulling through the overlay patch 226 material by knots or enlarged ends that exceed the size of the pores of the material of the overlay patch 226 . Intermediate the points of connection 252 , 254 , the filament 250 extends substantially parallel to the overlay patch 226 . While a single filament 250 is shown, a plurality of parallel filaments 250 may be utilized. The radially expandable member 212 is moveable along the filament(s) 250 defining a motion “track” relative to the overlay patch 226 .
[0046] Because the expandable member 212 is slidable on the filament 250 , the expandable member 212 may be positioned relative to the overlay patch 226 to maximally conform to the anatomy of the patient and the surgical repair encountered, as shown in FIG. 12. More particularly, the expandable member 212 may be inserted into the facia void and then the position of the overlay patch 226 may be adjusted to coincide with the position of maximally effective surgical attachment, viz., to be amenable to attaching the overlay patch 226 to healthy tissue, to bridge over weak, unhealthy tissue, and also to conform to the patients' local anatomical shape. The overlay patch 226 may have any desired shape, such as a keyhole, oval, circular or rectangular shape.
[0047] It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as defined in the appended claims.
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A hernia repair prosthesis with an occlusive member for inserting into and/or backing the herniated tissue. The occlusive member is convertible from a first configuration with a first axial length and first major radial extent to a second configuration with a second axial length and a second major radial extent. The second axial length is less than the first axial length and the second major radial extent is larger than the first major radial extent. The occlusive member has a pair of subsections, each having an apex, lands and pleats and each flaring outwardly therefrom towards a terminal end. The apexes are disposed at opposite ends of the occlusive member with the terminal ends overlapping. The pair of subsections are conjoined proximate the overlapping terminal ends. The terminal end of one or both of the subsections may be in the form of a conic flange mimicking the lands and pleats of the other subsection providing automatic alignment and nesting to aid in the attachment of the two subsections. In accordance with methods for forming the subsections, a surgical fabric is thermoset on a male die and may be stretched or heat shrunk to aid in conforming the surgical fabric to the contours of the male die. The subsections may be joined by ultrasound.
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RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 08/936,175, filed Sept. 24, 1997 now U.S. Pat. No. 6,132,342, such application being incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a rocking chair and, more specifically, to a rocking chair and foot rest which provide enhanced therapeutic benefits.
BACKGROUND OF THE INVENTION
Although rocking chairs are typically used in social settings, the rocking motion can be beneficial as a form of exercise. In particular, rocking chairs can provide a valuable mode of exercise for residents of retirement or minimum to medium care facilities. Residents of retirement or minimum to medium care facilities often do not exercise, even moderately, due to lack of motivation, suitable exercise equipment, and/or a supportive community to encourage exercise. Although specialized exercise equipment has been used in the care of the elderly for many years, most equipment is associated with physical therapy or other scheduled exercise sessions.
Exercising while relaxing in pleasant surroundings and engaging in social activities in a supportive group has advantages. Participants can exercise while not feeling exercised and can conduct their social activities at the same time. In addition, the physical exertion and the awareness of the passage of time becomes secondary, as attention is diverted away from the exercise by their social activities at the time. Further, these social activities occur daily and would therefore encourage daily exercise.
An exercise system incorporating the use of a rocking chair affords a unique opportunity for exercise to be performed in a relaxed, casual environment. However, by itself, rocking in a conventional rocking chair results in only very light exercise. Leg action in a rocking chair is limited by the person's leg length compared to the height and depth of the rocking chair seat. Most people need the majority of their leg and foot length just to reach the floor, leaving very little leg extension reserve for the rocking motion. The soles of the feet often just reach the floor so that rocking is accomplished by raising the heels and pushing with the balls of their feet. Accordingly, a person may only push off the floor with their feet and not benefit from any exercise potential of the rocking chair. In addition, the thighs are flat against the seat which restricts exercise motion and effort in the thigh muscles.
Further, conventional rocking chairs are designed to facilitate the rocking motion. Accordingly, conventional rocking chairs comprise a rocking means, such as rockers or other devices that work with a rocking motion, that minimizes the effort required to maintain a rocking motion. As a result, the use of conventional rocking chairs produces only minimal fitness benefits.
The exercise potential of conventional rocking chairs is also limited since many people find that the known rocking chairs are not comfortable for a variety of reasons. First, the user's legs are often not long enough to comfortably reach the floor and produce a satisfying rocking motion. The rocking motion is therefore not under the user's control as much as if the feet remained in contact with the floor throughout the entire rocking cycle. Many people prefer to have their feet in contact with the floor, both for comfort and control of the rocking motion. Second, after a time, the user's body tends to slide away from the back of the rocking chair resulting in discomfort. As the body slides away from the back of the rocking chair, the user's body takes on a slouched position which tends to be uncomfortable. In light of the foregoing, the user is unable to maintain the rocking motion for extended periods of time in conventional rocking chairs.
Although footstools have been used in connection with rocking chairs for comfort and to elevate the feet, the known footstools cannot be adjusted to yield maximal exercise benefit by providing optimal comfort and a more vigorous rocking motion. Further, as the user continues to rock, the known footstools tend to slide along the ground and do not help to keep the user's body against the back of the chair. As a result, the user may feel less secure and relaxed. Although footstools of different heights have been used, the problems persist.
In light of the foregoing, it would be highly beneficial to utilize a rocking chair as part of an exercise program. To optimize the exercise benefits, the rocking chair should be provided with means for controlling the effort needed to maintain the rocking motion. In addition, the user's feet should be maintained in contact with a stationary surface throughout the rocking cycle, the rocking cycle should start with the thighs and calves at about right angles, and body contact should be maintained with the back of the rocking chair.
SUMMARY OF THE INVENTION
In accordance with the present invention, an exercise system comprising a rocking chair is provided for enhancing the therapeutic benefits derived from use of the rocking chair. The rocking chair comprises a seat with a back support positioned relative to the seat such that when a user sits on the seat, the user's back is positioned against the back support. The seat and back support are maintained above the ground by a base or frame. Rocking means are positioned below the base or frame for enabling the chair to maintain a rocking motion. The rocking means may comprise one or more rockers having a curved surface, whereby the rocking chair is capable of being rolled along the curved surface of the rocker in a smooth rocking motion. Alternatively, the rocking means can comprise other known devices for producing a rocking or lilting motion, such as platform rockers, spring-based rocking systems, and linear motion gliders.
The therapeutic nature of the exercise system is enhanced by providing the rocking chair with rocking resistance means. The rocking resistance means comprises one or more weights which are attached to the rocking chair. The weights insure that the force required to maintain a rocking motion contains an additional force beyond the typical force necessary to maintain a rocking motion in a conventional rocking chair. The weights can be attached to the rocking chair either by positioning the weights over a bar or by clamping the weights to the rocking chair.
To further enhance the therapeutic nature of the exercise system, a footstool is provided. The footstool comprises a foot rest which is positionable with respect to the rocking chair such that the feet of a user are supported on a foot support surface of the foot rest when the user is seated upon the rocking chair. The footstool further comprises means for adjusting the height and angle of the foot rest. By adjusting the position of the footstool with respect to the rocking chair, the height of the footstool, and the angle of the footstool, it is possible to selectively emphasize the exercise of specific muscle groups in the leg.
A method for selectively exercising specific muscle groups in a subject's legs is also described. The method comprises the step of adjusting a rocking resistance means of an exercise system comprising a rocking chair to require an additional force to be applied to the rocking chair to maintain a rocking motion. The subject is then seated in the rocking chair and allowed to move the chair in a rocking motion by extending and flexing his or her legs. The comfort of the subject and the therapeutic benefits of the exercise system are enhanced by positioning and maintaining the subject's feet on a foot rest of a footstool throughout the rocking motion. The position of the footstool with respect to the rocking chair, as well as the height and angle of the foot rest, are adjusted to selectively exercise specific muscle groups in the subject's legs. For example, the footstool and foot rest can be adjusted to selectively emphasize the exercise of either the subject's calf or thigh muscles.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view of a rocking chair and footstool in accordance with the present invention;
FIG. 2 is a perspective view of a second embodiment of a rocking chair and footstool in accordance with the present invention;
FIG. 3 is a perspective view of a third embodiment of a rocking chair and footstool in accordance with the present invention;
FIG. 4 is a perspective view of a weight as shown in FIG. 3;
FIG. 5 is a perspective view of a clamp as shown in FIG. 3;
FIG. 6 is a front end view of an alternate embodiment of a footstool in accordance with the present invention;
FIG. 7 is a side plan view of an inner surface of an end piece of the footstool shown in FIG. 6;
FIG. 8 is a top plan view of a foot piece of the footstool shown in FIG. 6;
FIG. 9 is a cross-sectional view of the foot piece shown in FIG. 8 taken along the 9 — 9 line;
FIG. 10 is a cross-sectional view of the foot piece shown in FIG. 8 taken along the 10 — 10 line;
FIG. 11 is a side plan view of a weight as shown in FIG. 1; and
FIG. 12 is a side plan view of a weight as shown in FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An exercise system in accordance with the present invention is shown in FIG. 1 . The exercise system comprises a rocking chair 15 having a seat 16 and a back support 17 . The back support 17 is positioned relative to the seat 16 such that when a user is seated in the seat 16 , the user's back rests against the back support 17 . The seat 16 and back support 17 are maintained at a predetermined height with respect to the ground by a base or frame 18 .
The frame 18 comprises four vertical posts or legs, 20 - 23 , positioned at or near the corners of the seat 16 . The posts, 20 - 23 , extend away from the seat 16 toward the ground to thereby support the seat 16 and back support 17 above the ground. As can be readily seen, the lengths of the posts, 20 - 23 , extending below the seat 16 determine the height of the seat 16 . As shown in FIG. 1, the left and right rear posts, 22 and 23 , extend above the seat 16 and are integrally formed as part of the back support 17 .
Arm rests 25 are optionally provided to enable the user to comfortably rest his or her arms on the arm rests 25 while the user is seated in the rocking chair 15 . Toward that end, the left and right front posts, 20 and 21 , are extended to project above the seat 16 for securing the arm rests 25 relative to the seat 16 . A rear portion 26 of each arm rest 25 is secured to the back support 17 in order to better stabilize the arm rests 25 . Further, padded sections 27 can be provided on the arm rests 25 for the user's comfort.
Two curved rockers 30 are provided for enabling the rocking chair 15 to move in a rocking motion. One of the rockers 30 is affixed to the posts, 21 and 22 , at the left edge of the seat 16 to extend from the front to the rear of the chair 15 with the curved surface 31 of the rocker 30 oriented downwardly. The other rocker 30 is similarly affixed to the posts, 21 and 23 , at the right edge of the chair 15 . Accordingly, the chair 15 is capable of being rolled simultaneously along the curved surfaces 31 of the two rockers 30 in a smooth rocking motion.
To increase the effort needed to produce and maintain a rocking motion with the rocking chair 15 and thereby increase the therapeutic benefits of the chair 15 , weights 35 are attached to the rocking chair 15 . The weights 35 are attached to the chair 15 by positioning the weights 35 on a bar 38 which extends between the posts, 20 and 21 , at the left and right front corners of the chair 15 . Toward that end, the weights 35 are shaped to enable the weights 35 to be easily placed on, maintained in position about, and removed from the bar 38 . As shown in FIG. 11, each weight 35 comprises a generally rectangular block of a dense material, such as iron, having a notch 36 . The notch 36 is shaped to mate with the round bar 38 so that the weights 35 can be easily and reversibly positioned over the bar 38 . The weights 35 provide resistance which counteracts the force necessary to create the rocking motion. Accordingly, the user is required to apply more force in order to sustain the rocking motion.
A counter 40 is affixed to the chair 15 in a position which is readily viewed by the user while seated in the rocking chair 15 . The counter 40 provides the user with information regarding the number of rocking cycles completed and/or the length of time that the user has been rocking. As shown, the counter 40 is attached to one of the legs, 20 - 23 , of the chair 15 .
The exercise system further comprises a footstool 42 . The footstool 42 comprises a generally rectangular frame 43 having side bars 44 positioned along the left and right sides, 46 and 47 respectively, of the footstool 42 . A transverse strut 49 extends between one of the side bars 44 at the left side 46 of the footstool 42 and one of the side bars 44 at the right side 47 of the footstool 42 .
Four vertical posts or legs, 51 - 54 , are positioned at or near the corners of the frame 43 . The posts, 51 - 54 , extend toward the ground to support the frame 43 above the ground. As can be readily seen, the lengths of the posts, 51 - 54 , determine the height of the frame 43 . Feet 56 are provided at the ends of the posts, 51 - 54 , nearest the ground to stabilize the footstool 42 . The feet 56 also serve as an impediment to sliding by increasing friction between the footstool 42 and the ground. One of the feet 56 interconnects the two posts, 52 and 54 , at the right side 47 of the footstool 42 and the other foot 56 interconnects the two posts, 51 and 53 , at the left side 46 of the footstool 42 .
The footstool 42 further comprises a foot rest 58 , positioned on the frame 43 , for providing a surface 59 upon which the user's feet may be placed while seated in the chair 15 . The rear end 60 of the foot rest 58 is pivotally attached to the left and right rear posts, 53 and 54 , so that the foot rest 58 can pivot about a pivot axis parallel to the ground. Accordingly, the height of the forward end 61 of the foot rest 58 above the ground can be adjusted by pivoting the foot rest 58 about the pivot axis. A restraining bar or catch 63 is used to restrain the foot rest 58 from pivoting. As shown in FIG. 1, the restraining bar 63 is wedged between the forward end 61 of the foot rest 58 and the transverse strut 49 . Toward that end, the restraining bar 63 has a notch which is shaped to mate with the transverse strut 49 thereby preventing the restraining bar 63 from inadvertently disengaging from the transverse strut 49 . Varying the length of the restraining bar 63 , varies the height of the forward end 61 of the foot rest 58 above the ground and, hence, the slope from the forward end 61 toward the rear end 60 of the foot rest 58 .
In operation, the user attaches an appropriate amount of weight to the chair 15 by positioning one or more weights 35 over the bar 38 . Preferably, a series of weights 35 having different masses are provided to allow the user to vary the weight over a broad range. The footstool 42 is then positioned in front of the chair 15 with the rear end 65 of the footstool 42 nearest the chair 15 . The user then sits in the chair 15 with his or her back against the back support 17 . The user's feet are then placed on the foot rest 58 of the footstool 42 . The angle of the foot rest 58 and the distance between the footstool 42 and the chair 15 are then adjusted for the user's maximum comfort and to provide adequate leg extension for the rocking motion. Specifically, the footstool 42 is adjusted such that the user's feet maintain contact with the upper surface 59 of the foot rest 58 throughout the rocking cycle, the rocking cycle starts with the user's thighs and calves at about right angles, and body contact is maintained with the back support 17 of the rocking chair 15 . In addition, the exercise of specific muscle groups can be emphasized by varying the position of the footstool 42 with respect to the chair 15 , as well as the height and angle of the foot rest 58 . For example, the height and angle of the foot rest 58 and the position of the footstool 42 can be selected to emphasize the exercise of the calf muscles or the thigh muscles, including the quadriceps and hamstrings. The user then maintains a rocking motion for a predetermined number of rocking cycles or length of time. Alternatively, the user can continue to rock for as long a period of time as the user's fitness level will allow.
A second embodiment of an exercise system in accordance with the present invention is shown in FIG. 2 . The rocking chair 115 and footstool 142 in FIG. 2 are in many respects identical to the rocking chair 15 and footstool 42 of FIG. 1, except for differences in aesthetic design. However, the bar 138 which extends between the posts, 120 and 121 , at the left and right front corners of the chair 115 is a rectangular bar, as opposed to the round bar 38 of the embodiment shown in FIG. 1 . Accordingly, as shown in FIG. 12, the notch 136 provided in each of the weights 135 is shaped to mate with the rectangular cross-section of the bar 138 . The use of rectangular bar 138 helps to insure that the weights 135 do not rotate about the bar 138 as the chair 115 is rocked. Further, in the embodiment of FIG. 2, the seat 116 is provided with padding to enhance the comfort level of the user, thereby enabling the user to maintain the rocking motion for longer periods of time.
A third embodiment of an exercise system in accordance with the present invention is shown in FIG. 3 . The rocking chair 215 and footstool 242 in FIG. 3 are in many respects identical to the rocking chair 15 and footstool 42 of FIG. 1, except for differences in aesthetic design. However, the weights 235 are attached to the chair 215 using one or more clamps 267 . A clamp 267 in accordance with the present invention is shown in FIG. 5 . The clamp 267 comprises an angled bar 268 with an eyelet 268 positioned at one end and a U-shaped clasp 270 at the other end. The eyelet 269 is designed to enable the clamp 267 to be attached to the bottom surface of the seat 216 by, for example, a nail or screw. The clasp 270 is used to securely, but releasably, hold a weight 235 . Accordingly, the weight 235 is shaped to mate with the U-shaped clasp 270 . As shown in FIG. 4, the weight is essentially dumbbell shaped having a generally cylindrical portion 271 with a widened section 272 at each end. The angle of the bar 268 and the width of the widened sections 272 are selected such that the cylindrical section 271 of the weight 235 can be held by the U-shaped clasp 270 of the clamp 267 when the clamp 267 is attached to the seat 216 .
An alternate embodiment of a footstool 342 in accordance with the present invention is shown in FIG. 6 . The footstool 342 comprises a base 343 in the form of a generally rectangular plate. When the footstool 342 is in use, a bottom surface 375 of the base 343 is in contact with the ground, thereby increasing friction between the footstool 342 and the ground.
End pieces 376 , in the form of generally rectangular plates, are attached to the base 343 by brackets 377 . The end pieces 376 are positioned at right angles to the base 343 with the end pieces 376 being generally parallel and spaced apart. Grooves 378 can be provided in a top surface 374 of the base 343 for additional support to maintain the end pieces 376 in place. As shown in FIG. 7, an inner surface 380 of the end pieces 376 comprises a plurality of bores 381 . Further, the bores 381 of one of the end pieces 376 are arranged in a mirror-image pattern to the bores 381 of the other end piece 376 . Accordingly, each bore 381 on one of the end pieces 376 is diametrically opposed and aligned with one of the bores 381 on the other end piece 376 .
The footstool 342 further comprises a foot rest 358 . As shown in FIGS. 8-10, the foot rest 358 has a generally flat upper surface 359 . Bars 382 , extending from the front end 361 to the rear end 360 of the foot rest 358 along the left and right sides of the foot rest 358 , are positioned along a bottom surface 384 of the foot rest 358 . Each bar 382 comprises a series of at least two bores 385 which extend completely through the bar 382 from the left side to the right side of the foot rest 358 . The bores 385 on one bar 382 are arranged to be aligned with the bores 385 on the other bar 382 . Accordingly, the foot rest 358 can be placed between the end pieces 376 such that a rod 386 can be positioned simultaneously through one of the bores 381 in one of the end pieces 376 , one of the bores 385 in one of the bars 382 , the diametrically opposed bore 381 in the other end piece 376 , and the diametrically opposed bore 385 in the other bar 382 . Accordingly, the height of the rear end 360 of the foot rest 358 above the ground is adjustable by inserting a first rod 386 through the appropriate bores 381 closest to the rear end 360 of the foot rest 358 . Once the rear end 360 of the foot rest 358 has been positioned at the desired height, the slope of the foot rest 358 is adjusted by inserting a second rod 386 through bores 385 and appropriate bores 381 closer to the front end 361 of the foot rest 358 .
It will be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It should therefore be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention as set forth in the claims.
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An exercise system comprising a rocking chair and a footstool. The rocking chair comprises a seat, a back support, a base, and rocking means. Rocking resistance means are provided for requiring that an additional force be applied to the rocking chair to maintain a rocking motion. The footstool comprises a foot rest positionable with respect to the rocking chair such that the feet of a user are supported on a foot support surface of the foot rest when the user is seated upon the rocking chair. Means for adjusting the height and angle of the foot rest are also provided. A method for selectively exercising specific muscle groups in a user's legs with the exercise system is also described.
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BACKGROUND OF THE INVENTION
The present invention relates to an arrangement for displacing a closure of an opening in a cassette accommodating photosensitive material between closed and opened positions, the arrangement being particularly suited for use in a device for exposing an image, such as an image of a data carrier, onto the photosensitive material through the opening.
Devices of the last-mentioned type are already known and usually they are equipped with a projecting arrangement which projects the image of the data carrier onto the photosensitive material, such as film, accommodated in the cassette, through the opening which is unobstructed by the closure while the projection of the image takes place, with an opening arrangement which is operative for unlatching the closure which, in order to avoid accidental displacement thereof towards its open position during the transportation or the handling of the cassette, is latched in its closed position, and for displacing the closure from its closed position into its open position and then back into its closed position after the image-projecting operation has been concluded, as well as with a control arrangement which controls the performance of the unlatching, opening, projecting and closing operations in the desired sequence. In some of the conventional constructions of the opening arrangement, the latter includes a carriage which carries an entraining member that engages the closure and/or the latching means therefor, the carriage being movable in opposite directions along the path of displacement of the closure relative to the cassette which is properly positioned in the aforementioned device so that the entraining member entrains the closure for joint travel with the same and with the carriage from its closed into its open position and then back to its closed position in which the closure light-tightly obstructs the opening of the cassette.
One opening arrangement of this type has been disclosed in the German published publication DE-AS No. 20 21 494, wherein the entraining member is arranged on a holder which is pivotally mounted on the carriage, the axis of pivoting of the holder relative to the carriage extending normal to the direction of displacement of the carriage. A helical spring applies torque to the holder. In addition thereto, the holder is equipped with a guiding roller which is lifted as it engages the cassette during the initial phase of the displacement of the carriage towards its position corresponding to the open position of the closure until the roller engages the top surface of the cassette, which results in the pivoting of the holder relative to the carriage toward and into the position in which the entraining member engages the closure of the cassette.
Such a construction is relatively complicated and, as a result of that, also prone to malfunction. The radius of pivoting of the entraining member is relatively small, so that it can easily happen that the entraining member will engage the edge of a bore which is provided in the cassette closure for accommodating the entraining member. In addition thereto, the proper functioning of the pivoting mechanism can be assured only when the cassettes have substantially the same thickness or height. In addition thereto, there exists the danger that, when the closure offers substantial resistance to movement, or when the closure becomes stuck or jammed, the entraining member is expelled from the bore in the closure against the action of the spring which biases the same into the bore. If this effect occured during the displacement of the closure towards its closed position, the entraining member would contact and scratch the photosensitive material present in the cassette and the cassette would finally be removed from the device with the closure still in its partially or fully open position. Then, in the event that the photosensitive material has already been previously exposed with an image, such as an x-ray image, the original image-forming operation would have to be repeated, which would, in the example given, expose the patient to additional amounts of radiation. Thus, it may be seen that the conventional construction of the opening arrangement leaves much to be desired.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to avoid the disadvantages of the prior art.
More particularly, it is an object of the present invention to provide an arrangement for displacing a closure of an opening in a cassette accommodating photosensitive material between its closed and opened positions, which is not possessed of the disadvantages of the conventional arrangements of this type. Still another object of the present invention is to so construct the arrangement of the type here under consideration as to render it possible to achieve a safe and unproblematical displacement of the closure in a simple and inexpensive manner.
It is a further object of the present invention to so design the arrangement as to take into consideration the danger of blocking or discontinuance of displacement of the closure, particularly towards its closed position.
A concomitant object of the present invention is to develop an arrangement of the type here under consideration which is simple in construction, inexpensive to manufacture, easy to use, and reliable nevertheless.
In pursuance of these objects and others which will become apparent hereafter, one feature of the present invention resides in an arrangement for displacing a closure of an opening in a cassette accommodating photosensitive material in a predetermined path between closed and open positions thereof, particularly for use in a device for exposing an image onto the photosensitive materials through the opening, which arrangement, briefly stated, comprises a support; an entraining member; a means for mounting the entraining member for displacement along the predetermined path, including a mounting member (particularly a mounting plate) and a carriage displaceable relative to the latter and carrying the entraining member; means for supporting the mounting member on the support for movement with the carriage and with the entraining member between a retracted and an extended position of the entraining member in which the entraining member respectively is spaced from the path and extends into the path and engages the closure for entraining the same for displacement between the closed and open positions during the displacement of the carriage relative to the mounting member (or plate); means for moving the mounting member (particularly a cam rotatably mounted on the support and having a cam surface, and a cam follower on the mounting member and engaging the cam surface); and means for displacing the carriage (particularly a crank transmission which includes a crank rotatably mounted on the support and a connecting link articulated to the crank and loosely connected to the carriage). Advantageously, the member is mounted on the support for pivoting relative thereto.
When the arrangement is constructed in this manner in accordance with the present invention, it is achieved that the entraining member is lowered into the aforementioned bore of the closure substantially perpendicularly to the plane of the closure. As a result of the tracing of the cam surface which, in accordance with a currently preferred concept of the present invention, is rotated jointly with the crank, there is achieved a simple actuation of the mounting member and, simultaneously, synchronization of the displacement of the carriage with the movement of the entraining member with the carriage and the mounting member on which the latter is mounted, between the retracted and extended positions of the entraining member.
Advantageously, the mounting member is mounted on the support for pivoting about an axis which is parallel to the path of displacement of the carriage relative to the mounting member, and the distance between the entraining member and the pivoting axis is so selected as to substantially correspond to the length of the range of displacement of the carriage. This contributes to the aforementioned substantial perpendicularity of the trajectory of movement of the entraining member to the plane of the closure.
Particularly simple and otherwise advantageous embodiment of the present invention is obtained when the displacing and moving means includes a common rotary member which has an annular portion of a larger diameter which constitutes the cam and has an axial face which constitutes the cam surface, and a second annular portion of a smaller diameter which adjoins the larger-diameter annular portion next to the cam surface and has the connecting link articulated thereto so as to constitute the crank. In this connection, it is particularly advantageous when the cam follower includes a roller rotatably supported on the mounting member and when the roller has a circumferential surface of a conical configuration, in which instance the cam surface is inclined relative to the axis of the rotary member at an angle conforming to that of the roller. It is further advantageous when the cam surface includes a substantially V-shaped recess bounded by two slowly rising cam surface portions. Then, it is further advantageous when the recess and the point of articulation of the connecting link to the smaller-diameter portion of the rotary member is located substantially at the same radial line of the rotary member.
According to a further facet of the present invention, the connecting link is connected to the carriage for limited relative movement. Advantageously, this limited relative movement is achieved when the carriage has an aperture, and the connecting link includes a projection which is freely received in the aperture in all positions of the mounting member.
A further feature of the present invention resides in the manner in which the entraining member is mounted on the carriage. In accordance with a further aspect of the present invention, the entraining member is affixed to a mounting element (such as a lever) supported on the carriage for movement (pivoting) relative thereto in such a trajectory that the entraining member travels substantially along the path of displacement of the carriage relative to the latter when the resistance of the closure to displacement exceeds a predetermined limit. Then, detecting means is provided in accordance with this aspect of the present invention, the detecting means preferably including a switch mounted on the carriage and having an actuating element which extends into the trajectory of a movement of the mounting element (lever) at least when the extent of travel of the mounting element (lever) exceeds a predetermined limit. The mounting element (lever) is preferably urged, especially by a spring, toward an operative position thereof, the biasing means (spring) opposing the travel of the mounting element (lever) out of the operative position with a force which keeps the mounting element (lever) in the operative position unless the resistance of the closure to displacement exceeds the predetermined limit. The switch may be operative for reversing the direction of motion of the crank transmission when the blockage or stoppage of the displacement of the closure takes place as the entraining member entrains the latter for movement toward its open position, so that the closure is returned into its closed position without having ever reached its open position. Then, the switch may also actuate a warning device which indicates that the closure has been returned to its closed position without ever reaching its open position and, consequently, without exposure of the image onto the photosensitive material, so that the operating personnel will become aware of this fact and will be able to take appropriate measures.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. A closure-displacing arrangement for a film-containing cassette, both to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a somewhat diagramatic perspective view of an arrangement of the present invention;
FIG. 2 is a top plan view of the arrangement depicted in FIG. 1;
FIG. 3 is a cross-sectional view taken on line III--III of FIG. 2;
FIG. 4 is partially sectioned side elevational view of a detail of the arrangement of FIG. 1, showing details of construction of a rotary moving and displacing member used in the arrangement of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing in detail, and first to FIG. 1 thereof, it may be seen that the reference numeral 1 has been used to identify a support table of the arrangement of the present invention. A first abutment member 2 and a second abutment member 3 extending at right angles to the first abutment member 2 are provided on the support table 1. A switching element 4 is accommodated in the abutment member 3, this switching element 4 responding to the contact of a film cassette therewith and, hence, with the abutment member 3. In a similar manner, the abutment member 2 may accommodate another switching element of a conventional construction which has been omitted from the drawing and which may extend into a standardized depression in the film cassette so that it will not be actuated when the cassette assumes its desired position. Thus, the combination of these two switching elements serves for detecting the presence and the correct position of a cassette relative to the device in question.
Support elements or pillars 5 are arranged outwardly of the range of movement of the cassette, these pillars 5 carrying a holding plate 6. A motor 7 is mounted on the upper side of the holding plate 6, and a rotary member 9 which is constructed as a crank and cam disc is mounted on a downwardly extending shaft 8 of the motor 7 for joint rotation therewith. Furthermore, a carrier bracket 10 is affixed at the upper side of the holding plate 6, and a tension spring 11 is connected to the carrier bracket 10 at one of its ends, while its other end is connected to a mounting plate 12. The mounting plate 12 is tiltably mounted on the holding plate 6 and underneath the same, in a manner yet to be described in connection with FIGS. 1 and 2. The mounting plate 12 has two lateral portions 12a, and a shaft 13 passes through such lateral portions 12a. A carriage 14 is mounted on the shaft 13 for displacement longitudinally thereof, the carriage 14 carrying an entraining member 37 or an entraining arrangement which is constructed in a manner which will be discussed below. The carriage 14 is connected to a connecting link 15 which, in turn, is articulated to the rotary member 9 as shown, for instance, in FIG. 2 at 34. An opening 12b is provided in the mounting plate 12, and the entraining member 37, which is invisible in FIGS. 1 and 2, extends through this opening 12b into the opening of the properly positioned cassette which is situated underneath the mounting plate 12.
Details of the arrangement which as been just discussed in general terms in connection with FIG. 1 will now be described with reference to FIGS. 2 to 4. As shown in FIG. 2, a U-shaped rail or support 16 is affixed to the lower side of the holding plate 6. The U-shaped rail 16 has two lateral portions 16a which rotatably support a shaft 17. Lateral portions 12c of the mounting plate 12, which are bent opposite to the lateral portions 12a, are rotatably supported on the shaft 17. The mounting plate 12 has a substantially square shape, and the opening 12b is remote from the point of mounting of the plate 12 on the shaft 17. In this manner, there is obtained a relatively huge pivoting radius at the region of the opening 12b, so that the entraining member 37 is moved, during the pivoting of the mounting plate 12, toward the cassette arranged underneath the latter, substantially perpendicularly to the plane of the closure of the cassette.
The carriage 14 also includes a generally U-shaped plate 18 which has lateral portions 18a and a rectangular recess 18b. An aperture 19 is also provided in the plate 18, and a pin-shaped projection 20 extends into the aperture 19 from below, the pin-shaped projection 20 being mounted on that end of the connecting link 15 which is remote from the rotary member 9. Furthermore, the mounting plate 12 is provided with a slot-shaped opening 21 through which the pin-shaped projection 20 of the connecting link 15 extends in the upward direction into the aperture 19 and in which the projection 20 is guided during the displacement of the carriage 14.
A lever 22 is mounted on the carriage 14 for pivoting about an axle 23, and an upwardly extending pin 24 is affixed thereto. The pin 24 cooperates with a roller 25 forming a part of an actuating element of a microswitch 26, in such a manner that the microswitch 27 is depressed or closed in the normal or rest position of the lever 22 shown in full lines in FIG. 2, and open in the displaced or working position of the lever 22 which is illustrated in FIG. 2 in broken lines. The lever 22 is urged towards its rest position by means of a tension spring 27 one end of which is connected to the pin 24 and the other end of which is connected to a lateral part 18a of the carriage plate 18. Additionally, as may best be seen in FIG. 3, a bore 28 is provided in the lever 22, which receives the upper end of a mounting element 29 which mounts the entraining member 27 on the lever 22. The mounting element 29 may be integral with the entraining member 37, or it may be a discrete member which clamps or it otherwise rigidly connected to the entraining member 37 proper.
At the lateral part 12a of the mounting plate 12 which is close to the rotary member 9, there is mounted a roller 30 equipped with a conical cam follower portion 32, for rotation about an axle 31. As may be seen in FIG. 4, the conical portion 32 cooperates with a curve or a cam surface 33 of the rotary member 9. FIG. 4 also shows the bolt 34 or a similar element which passes through the rotary member 9 in parallelism with its axis of rotation and which constitutes the pivoting element about which the connecting link 15 pivots.
The rotary member 9 is illustrated in FIG. 4 in a partially sectioned view. The rotary member 9 includes a cam portion which is essentially formed by a cylindrical ring 9a having a downwardly facing end face which is so shaped as to constitute the cam surface 33. Herein, the cam surface 33 includes only an essentially V-shaped depression 35 which is defined by slowly ascending or descending inclined surfaces 35a and 35b. The cam surface 33 is provided with a slight inclination in the radial direction in accordance with the shape of the conical portion 32 of the roller 30.
The rotary member 9 further includes a crank portion which is constituted by a cylindrical ring 9b which is located next to the ring 9a and has a smaller diameter than the latter. The bolt 34 which has already been mentioned above passes through this crank part 9a at one location, and one end of the connecting link 15 is connected thereto for pivoting thereabout. In order to facilitate the representation of these features in the drawing, the bolt 34 and the depression 35 of the cam surface 33 are depicted in FIG. 4 as being situated at different locations of the rotary member 9. However, it is to be mentioned in this connection that the deepest point of the depression 35 and the axis of the bolt 34 are in reality situated at the same radial line of the rotary member 9, or at least substantially so. FIG. 3 illustrates a cross section taken on line III--III of FIG. 2 in which further details of the carriage 14 and the components cooperating therewith are shown. It may be seen that the lever 22 has a U-shaped cross section including two arms interconnected by a bight, the lower arm which is identified by the reference numeral 22a being shorter than the upper arm. The upper arm is mounted for angular displacement about the axle 23. A bore is provided in the lower arm 22a, and the mounting element or bolt 29 which carries the entraining member 37 passes through this bore and is guided therein. A compression spring 36 is arranged between the inner surface of the upper arm of the U-shaped lever 22 and a support ring 29a which is supported on the bolt 29 at the vicinity of the inner surface lf the lower arm 22a of the lever 22, the compression spring 36 surrounding the bolt 29 and pressing the same, together with the entraining member 37 which projects downwardly beyond the same, in the downward direction toward the cassette.
The opening 12b in the mounting plate 12 is surrounded by a distancing frame 38 on which there is supported a circumferentially complete strip 39 of foamed rubber or a similar resilient material.
FIG. 3 further illustrates only a part of a cassette which is supported on the table 1, the cassette 40 being partially sectioned to show a cassette opening 41, a guiding plate 42, a shiftable or displaceable closure 43 for the opening 41, and a bore 44 provided in the closure 43. The cassette is of a conventional construction, and reference may be had to a commonly owned co-pending application by Bauer et al, Ser. No. 162,523, filed on June 24, 1980, for details of the construction of the cassette which may be handled by the apparatus of the present invention.
A cover plate 45a is mounted on the abutment projections 2 and 3, the plate 45a extending parallel to the base plate or table 1 and having an opening 46 through which the light-sealing strip 39 is guided during the pivoting of the mounting plate 12 until it contacts the upper surface of the cassette 40 to form a light-impermeable barrier around the opening 41. The cover plate 45a merges into a hood 45 which surrounds the arrangement of the present invention and prevents ambient light from reaching the opening 41 of the cassette 40.
Having so described the construction of the arrangement of the present invention based on FIGS. 1 to 4, the operation of this arrangement will now be briefly discussed.
In the rest position of the arrangement, the roller 30 or, more particularly, the conical portion 32 thereof, is situated in the depression 35 of the rotary member of disc 9, so that the mounting plate 12 assumes the position illustrated in FIG. 3. The carriage 14 assumes the position which is illustrated in FIG. 2. As the cassette 40 is introduced into the proper position thereof in which it abuts the abutment projections 2 and 3, the switching elements 4 on the abutment projections 3 and 2 are actuated or not actuated (depending on the construction of the cassette and the type of the switching elements), as a result of which the motor 7 is energized. As a result of this, the rotary member or disk 9 commences its rotation, as a result of which the cam surface 33 pushes the roller 30 in the downward direction, so that the mounting plate 12 is also pivoted about the axis 17 in the same direction. As the mounting plate 12 is lowered, the sealing strip 39 approaches the upper surface of the cassette 40 until it contacts the same and prevents passage of ambient light toward the opening 41 of the cassette 40. Simultaneously therewith, the entraining member 37 penetrates into the bore 44 of the closure 43 where it unlatches, in a conventional manner, the latching mechanism of the closure 37. As the disc 9 continues its rotation, the contecting link 15 is pulled by the same, as a result of which the carriage 14 is displaced in the rightward direction as considered in FIG. 2. The closure 43 is thus entrained by the entraining member 37 for joint displacement with the same and with the carriage 14 on which the entraining member 37 is mounted by means of the bolt 29, the lever 22 and the axle 23, so that the closure 43 moves towards its open position, that is, rightwardly as considered in FIG. 3. When the closure 43 reaches its open position, an image can be projected onto the now accessible region of the film accommodated in the cassette 40, by conventional projecting means which have been ommitted from the drawing in order not to unduly encumber the same. Advantageously, this exposure of the image onto the region of the film which is juxtaposed with the opening 41 takes place at the moment when the connecting link 15 assumes its dead-center position corresponding to the open position of the closure 43. Then, as the rotary disc 9 continues its rotation, the closure 43 is again displaced, this time towards its closed position, inasmuch as the carriage 14 is now displaced by the link 15 in the leftward direction as seen in FIG. 2. When the disc 9 reaches its dead-center position corresponding to the closed position of the closure 43, the depression 35 of the cam surface 33 is aligned with the roller 30 provided with the conical portion 32, so that the mounting plate 12 is lifted by the force of the spring 11, so that the entraining member 37 is retracted from the bore 44 of the closure 43 and the cassette 40 is freed.
In the event that the closure 43 of the cassette 40 offers a substantial amount of resistance to displacement or, should it be impossible, for one reason or another, to fully displace the closure 43 into its open position, the entraining member 37 is arrested at the corresponding position. However, inasmuch as the disc or rotary member 9 continues its rotation at first, also the carriage 14 continues its displacement. As a result of arrest of the entraining member 37 and thus of the bolt 29 carrying the same, and of the further displacement of the carriage 14, the lever 22 is rotated about the axis 23 in the counterclockwise direction against the opposition of the force of the spring 27, until it reaches the broken-line position shown in FIG. 2, as a result of which the arm or actuating element of the switch 26 which is mounted on the carriage 14 assumes its open position. This opening of the switch 24 results in a signal which is transmitted, in a conventional manner, to a control device for the motor 7, which control device causes the reversal of the direction of rotation of the motor 7. This results in a situation where the only partially opened closure 43 is again closed, and the cassette 40 can be removed from the arrangement without having any image projected on the film accommodated therein, but also without the film being damaged by ambient light. In an advantageous manner, the aforementioned switching operation of the switch 26 is used, in a conventional manner, for activating a warning device which indicates to the operating personnel that the exposure of the image or data onto the predetermined region of the film accommodated in the cassette 40 has not taken place and that the closure 43 of this particular cassette 40 is defective.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.
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An arrangement for opening and closing a closure of an opening in a film cassette includes a rotary member which has a cam surface provided thereon and a connecting link articulated thereto. A cam follower roller is mounted on a mounting plate which is mounted on a support for pivoting about an axis parallel to the direction of displacement of the closure between its open and closed positions, and the connecting link is loosely connected to a carriage which is supported on the mounting plate for displacement along the path of displacement of the closure and carries an entraining member which engages the closure upon pivoting of the mounting plate from its retracted to its extended position toward the respective cassette and entrains the closure of movement with the carriage, during the rotation of the rotary member. The entraining member is mounted on the carriage by means of a lever which cooperates with a micro switch that reverses the rotation of the rotary member when the lever is pivoted as a result of jamming of the closure.
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This is a divisional of copending application Ser. No. 07/541,777 filed on June 21, 1990, which was a division of application Ser. No. 07/427,576 filed on Oct. 27, 1989, now U.S. Pat. No. 4,961,691
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to gas compressors, and more particularly, to an integral gas compressor and internal combustion engine adapted for use on flammable gases such as natural gas.
2. Description of the Prior Art
Reciprocating gas compressors are well known in the art, and generally such compressors are powered by a separate prime mover such as an electric motor or gas powered internal combustion engine. Electric motors have a disadvantage in flammable gas applications in that they often must be of a type which is at least partially explosive proof. These types of motors are relatively expensive. A disadvantage of using an electric motor of a separate internal combustion engine for driving compressors is that the drive train must include a power transmission means such as a coupling, V-belt drive, gear drive or chain drive. The present invention solves these problems by providing a gas compressor which is integral with the internal combustion engine which drives it. Preferably, the unit is constructed by modifying a portion of the cylinders in the internal combustion engine into a gas compression section.
Conversion of portions of engines into air compressors is known in the art. For example, U.S. Pat. No. 2,133,769 to Jones discloses an engine-compressor unit with one side of a V-shaped engine being converted to an air compressor. The engine discloses a Ford V-8, but other engine makes may be used. A compressor head is installed on one bank of cylinders of the engine in place of the engine head, and intake and exhaust valves are installed in the compressor head. In this apparatus, air is drawn directly into the individual inlet valves, and there is no manifolding of the inlet. The Jones apparatus is designed for use with atmospheric air only, and does not address the problems involved with handling gases with inlet pressures above atmospheric pressure or gases which are flammable, such as natural gas. The present invention provides a integral compressor and engine specifically adapted for flammable gases including manifolding all of the valve inlets together, monitoring the oil viscosity in the crankcase to insure that the gas has not diluted the oil, and venting the crankcase so that flammable gases will not build up therein.
It is well known in the art that air compressors designed for atmospheric air are not well adapted for use with incoming gases above atmospheric pressure, and particularly are not well adapted, and may even be unsafe, for use with flammable gases. Thus, the prior art air compressor engine conversions are totally unsuitable for applications other than atmospheric air.
SUMMARY OF THE INVENTION
The present invention includes an internal combustion engine which has a portion thereof converted to a gas compressor and a method of use thereof. The invention is particularly well adapted for use with flammable gases, such as natural gas. A method of the invention for transferring natural gas comprises the steps of removing an engine head and associated engine valve and other components from a cylinder block of an internal combustion engine, installing a compressor head assembly on the cylinder block, supplying natural gas to an inlet side of the compressor head assembly, energizing the internal combustion engine and compressing natural gas in a cylinder bore aligned with the compressor head assembly, and discharging compressed gas from the compressor head assembly to a downstream location, such as a wellhead or pipeline. The compressor head assembly comprises one or more compressor valves disposed therein with an inlet flow path thereto and means to hold the valves in place. The method may also comprise manifolding a plurality of inlet flow paths in the compressor head assembly when more than one valve is used.
In preferred embodiments, the method of transferring natural gas further comprises the step of venting natural gas from a crankcase of the engine to a fuel inlet portion of the engine and another step of sensing viscosity of oil in a crankcase of the engine and deenergizing the engine when the viscosity drops below a predetermined level. Cooling of the natural gas after compression thereof may also be provided.
The compressor of the present invention may be said to comprise a cylinder, a piston reciprocably disposed in the cylinder, a head attached to the cylinder, a concentric valve having an operating position in the head, a valve chair attached to the head such that the valve is held in the operating position wherein the valve chair defines an inlet flow path in communication with an inlet portion of the valve and an outlet flow path in communication with an outlet portion of the valve, and an inlet manifold attached to the head and in communication with the inlet flow path wherein the manifold encloses the valve chair. Sealing means may be provided between the inlet manifold and the head, and further sealing means may also be provided between the inlet and outlet flow paths. In the preferred embodiment, the compressor is integral with an internal combustion engine such that a plurality of cylinder bores in a first bank of the cylinder block of the engine contain engine pistons and the cylinder bores in a second bank of the cylinder block contain compressor pistons. Studs and nuts are used to hold the valve chairs to the head and also to hold the inlet manifold to the head.
Sensing of the oil viscosity in the pressure lubricated compressor crankcase is accomplished by connecting a valve to an oil pressure source in the crankcase, discharging the oil from the valve to a reservoir portion of the crankcase, such as the oil pan, and measuring of pressure drop across the valve which corresponds to a viscosity of the oil. The valve may be adjusted such that pressure drop across the valve is at a predetermined initial level when the oil is fresh and the viscosity thereof substantially known. A signal may be generated in response to the pressure drop through a means such as a differential pressure switch gauge, and a prime mover for the compressor, such as an integral engine, is deenergized in response to the signal. Another valve may be connected to the oil pressure source upstream from the first mentioned valve, and this other valve may be adjusted for controlling a flow rate of the oil to the first mentioned valve.
It is an important object of the present invention to provide a natural gas compressor with an integral internal combustion engine. It is another object of the invention to provide a method of transferring natural gas by modifying cylinders in an internal combustion engine into a gas compressor.
A further object of the invention is to provide an integrated gas compressor and internal combustion engine with means for preventing flammable gas buildup in the crankcase thereof.
Still another object of the invention is to provide a method and apparatus for sensing oil viscosity in a gas compressor crankcase and deenergizing a prime mover for the compressor when the oil viscosity drops below a predetermined level.
Additional objects and advantages of the invention will become apparent as the following detailed description of the preferred embodiment is read in conjunction with the drawings which illustrate such preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a side elevation view of a compressor package using the integral gas compressor and internal combustion engine of the present invention.
FIG. 2 is a plan view of the package shown in FIG. 1.
FIG. 3 shows an end view of the integral gas compressor and internal combustion engine of the present invention.
FIG. 4 is a detailed view of the gas compressor portion of the apparatus of the present invention taken along lines 4--4 in FIG. 3.
FIG. 4a is an enlargement of a portion of FIG. 4.
FIG. 5 is a view of the compressor section taken along lines 5--5 in FIG. 4.
FIG. 6 illustrates a top view of the compressor section with the inlet manifold removed.
FIG. 7 shows a bottom view of the inlet manifold.
FIG. 8 is a cross section taken along lines 8--8 in FIG. 6.
FIG. 9 presents a schematic showing the oil viscosity sensing apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and more particularly to FIGS. 1 and 3, the integral gas compressor and internal combustion engine of the present invention is shown, and generally designated by the numeral 10, as forming a portion of a compressor package 12. Integral gas compressor and internal combustion engine 10 will also be referred to herein as simply compressor 10. Compressor package 12 as illustrated is of a type particularly well adapted for use in recovering natural gas from a well, but may be used for other flammable gases or gases with elevated inlet pressures. The invention is not intended to be limited to the illustrated compressor package 12. FIGS. 1 and 2 have been greatly simplified to eliminate much of the piping and wiring associated with package 12. The omitted items are known in the art and not necessary for an understanding of the invention.
Compressor 10 in package 12 is mounted on a skid or baseplate 14 by a mounting means 16 of a kind known in the art. Compressor 10 is preferably constructed by modifying a known internal combustion engine, such as a 460 cubic inch Ford V-8 engine.
Referring now also to FIG. 3, the V-shaped configuration of compressor 10 may be seen. Compressor 10 includes a cylinder block 18 with a crankcase portion 20 at the lower end thereof. Below crankcase 20 is an oil pan 22. Cylinder block 18, crankcase 20 and oil pan 22 are standard components of the original Ford or other engine. At the upper end of cylinder block 18 is an engine manifold with a carburetor 26 and air cleaner 28 connected thereto. Connected to cylinder block 24 on the left bank of cylinders, as viewed in FIG. 3, is a standard engine head 30 with a valve cover 32 thereon. An exhaust manifold 33 carries away the exhaust gases of the engine. This left side of compressor 10 remains basically a standard engine and includes all of the normal engine components such as valve train, spark plugs, wiring, etc. For simplicity, these engine components are not illustrated.
The right side of compressor 10, as viewed in FIG. 3, is the modified side of the engine used for gas compression. A compressor head 34 is attached to cylinder block 18 on the right bank of cylinders. It will be seen by those skilled in the art, that compressor head 34 replaces engine head 30 on this side. Connected to compressor head 34 is a compressor inlet manifold 36. Attached to inlet manifold 36 is a flange 38. Details of the compressor side of apparatus 10 will be further discussed herein.
Referring again to FIGS. 1 and 2, an inlet tank and liquid separator 40 is attached to skid 14. A valve 42 is in communication with tank 40 and is adapted for connection to the source of the gas to be compressed. In one embodiment, this gas would be natural gas from a wellhead (not shown). Tank 40 is of a kind generally known in the art and includes a means for separating liquids out of the incoming gas. A pump 44 is connected to tank 40 by a line 46 and is used to pump liquids collected in tank 40 to any desired location.
At the top of tank 40 is a connection 48 having a flange 50 connected thereto. A line or hose 52 with flanges 54 and 56 on opposite ends thereof interconnects flange 50 and flange 38 on inlet manifold 36. Thus, line 52 is an inlet or suction line to compressor 10.
Positioned adjacent to tank 40 is a fuel vessel 58 with a pressure relief valve 59 connected thereto. Relief valve 59 may be piped away as desired. Fuel vessel 59 has an inlet 60 adapted for connection to a fuel source, such as the natural gas wellhead. A line 60 with a regulator 62 therein interconnects fuel vessel 58 and crankcase 20 of compressor 10. Another line 64 with a regulator 66 therein interconnects fuel vessel 58 with carburetor 26 on the engine.
A standard engine radiator 68 is positioned adjacent to compressor 10 and connected thereto by radiator hoses 70 and 72 of a kind known in the art for cooling of both the compressor and engine sides. A fan (not shown) of a kind known in the art may be used to draw air across radiator 68.
At the opposite end of skid 14 is an aftercooler 74, of a kind known in the art, which is used to cool gas discharged from compressor 10. Aftercooler 74 is of a finned tube type with a fan shroud 76 connected thereto with a cooling fan 78 rotatably disposed therein. A drive shaft 80 extends from compressor 10 to drive fan 78.
A discharge line 82 connects the outlet of compressor head 34 with aftercooler 74. A combination pressure gauge and shutoff switch 84 is disposed in discharge line 82 to deenergize the engine portion if the compressor discharge pressure exceeds a predetermined level.
An aftercooler outlet line 86 is connected to aftercooler 74 and extends toward the opposite end of skid 14 such that a threaded end 88 of line 86 is positioned generally adjacent to tank 40. A drain valve 90 may be positioned in line 86, preferably adjacent to aftercooler 74, so that moisture and other liquids may be drained from aftercooler 74 as necessary.
An electrical control panel 92 for controlling the apparatus may be positioned on skid 14. Control panel 92 is of a kind generally known in the art, and the connections thereto are omitted for clarity.
Turning again to FIG. 3, standard engine pistons 94 are reciprocably disposed in the cylinders on the left bank of cylinder head 18, and the engine pistons are connected to crankshaft 96 by connecting rods 98. Again, pistons 94. crankshaft 96 and connecting rods 98 are the original components of the modified engine used to construct compressor 10.
In the right bank of cylinder block 18 are a plurality of reciprocably disposed compressor pistons 100. Each compressor piston 100 is connected to crankshaft 96 by additional connecting rods 98. Compressor pistons 100 may be of special configuration, but connecting rods 98 are preferably the same used in the original engine.
Referring now to FIGS. 6 and 8, the details of compressor head 34 and the components therein will be discussed. Compressor head 34 is positioned adjacent to cylinder block 18 with a sealing means, such as gasket 102, disposed therebetween. Compressor head 34 defines a plurality of valve pockets 104 therein with one valve pocket for each cylinder bore 106 in cylinder head 18. Each valve pocket 104 is substantially coaxial with the corresponding cylinder bore 106 and includes a first bore 108 and a relatively smaller second bore 110 therein. An annular shoulder 112 extends between first bore 108 and second bore 110.
A concentric compressor valve 114, of a kind generally known in the art, is disposed in each of valve pockets 104. Each valve 114 comprises an upper body 116 and a lower body 118. A center post 120 is engaged with lower body 118 and extends upwardly therefrom and through upper body 116. A set screw or dowel pin 122 prevents separation of center post 120 and lower body 118 and further prevents relative rotation therebetween. A lock nut 124 is threadingly engaged with an upper end 126 of center post 120 to clamp upper body 116 against lower body 118.
Upper body 116 has an outside diameter 126 adapted for close, spaced relationship with first bore 108 in valve pocket 104. Lower body 128 has a first outside diameter 128 which is substantially the same size as outside diameter 126. Lower body 118 further has a second, smaller outside diameter which is in close, spaced relationship with second bore 110 in valve pocket 104. An annular shoulder 132 extends between first outside diameter 128 and second outside diameter 130 on lower body 118. A sealing means, such as valve gasket 134, provides sealing engagement between lower body 118 and valve pocket 104 in compressor head 34.
Upper body 116 defines a plurality of inlet ports 136 therein, and lower body 118 defines a plurality of outlet ports 138 therein in communication with a recess 140. A suction or inlet valve plate 142 is disposed in recess 140 and covers inlet ports 136 when in a closed position. A leaf spring 144 or other type of spring is also disposed in recess 140 and biases suction valve plate 142 toward its closed position.
Radially outwardly of outlet ports 138, lower body 118 defines an inlet port 146. Radially outwardly of inlet ports 136, upper body 116 defines outlet ports 148 therein which are in communication with a recess 150. A discharge or outlet valve plate 152 is disposed in recess 150 and covers inlet port 146 when in a closed position. At least one spring 154 is disposed in recess 150 to bias discharge valve plate 152 toward its closed position.
A valve chair 156 has an outside diameter 158 which extends into first bore 108 of valve pocket 104. A sealing means, such as O-ring 160, provides sealing engagement between valve chair 156 and compressor head 34. Valve chair 156 also includes an upper flange portion 162 adjacent to top surface 164 of compressor head 34. Flanged portion 162 is spaced from top surface 164 such that a gap 165 is defined therebetween.
Outside diameter 158 is the outer surface of a substantially cylindrical outer wall 166. A substantially cylindrical inner wall 168 is disposed radially inwardly from outer wall 166. Inner wall 168 defines a suction or inlet flow passage 170 in communication with inlet ports 136 in upper body 116 of valve 114. Outer wall 166 and inner wall 168 define an annular discharge or outlet flow path 172 therebetween which is in communication with outlet ports 148 in upper body 116 of valve 114. A sealing means, such as gasket 174, is provided between the lower end of inner wall 168 and the upper end of upper body 116 for sealing engagement between valve chair 156 and valve 114. It will be seen that gasket 174 also sealingly separates inlet flow path 170 and discharge flow path 172.
Outer wall 166 of valve chair 156 defines a plurality of openings 176 therein. Openings 176 are in communication with a discharge passageway 178 defined in compressor head 34. As seen in FIG. 6, discharge passage 178 interconnects all of valve pockets 104 in compressor head 34, thus forming an internal discharge manifold within the compressor head.
Still referring to FIG. 6, compressor head 34 has a discharge flange 180 at one longitudinal end thereof, and the discharge flange defines a discharge opening 182 therethrough. Discharge opening 182 is a longitudinally outer end portion of discharge passageway 178. Discharge flange 180 is adapted for connection to a corresponding flange 184 at one end of discharge line 82. This connection is also shown in FIGS. 1, 2, 4 and 5.
In FIG. 6, four valve chairs 156 are illustrated and identified as 156A, 156B, 156C and 156D. A plurality of short studs 186 and long studs 188 extend from compressor head 34 through corresponding holes in flange portions 162 of valve chairs 156. In the preferred embodiment, two long studs 188 extend through valve chair 156A adjacent to longitudinal end 190 of compressor head 34. Two short studs 186 extend through the other holes in valve chair 156A. One long stud 188 extends through the upper right corner, as viewed in FIG. 6, of valve chair 156B, and short studs 186 extend through the other holes in valve chair 156B. In a similar fashion, a long stud 188 extends through the lower left corner of valve chair 156C, and three short studs 186 extend through the other holes in valve chair 156C. The stud arrangement for valve chair 156D is essentially a mirror image of that for valve chair 156A. That is, two long studs 188 extend through valve chair 156D adjacent to discharge flange 180, and two short studs 186 extend through the other holes in valve chair 156D.
Short studs 186 are of sufficient length that a nut 192 may be engaged therewith to clamp the corresponding valve chair 156 against compressor head 34, as best seen in FIG. 8. Nuts 192 are similarly engaged with each long stud 188. It will be seen that gap 165 insures that valve chair 156 bears against gasket 174 and valve 114 bears against gasket 134 when the valve chair is clamped in place by nuts 192.
Referring now to the bottom view of inlet manifold 36 shown in FIG. 7, a plurality of holes 194 are defined through top portion 196 thereof. Holes 194 are located to correspond with long studs 188 extending from compressor head 34. Long studs 188 are of sufficient length so that they will extend upwardly through holes 194 in inlet manifold 36 when the inlet manifold is installed as shown in FIGS. 4 and 5. A nut 198 is engaged with each stud 188 to fasten inlet manifold 36 in place. A sealing means, such as gasket 200, provides sealing engagement between top portion 196 of inlet manifold 36 and the corresponding nut 198 and stud 188.
Referring to FIGS. 4, FIG. 4a and 7, a substantially rectangular groove 202 is defined in the bottom of inlet manifold 36. A sealing means, such as O-ring 204, is disposed in groove 202 to provide sealing engagement between inlet manifold 36 and top surface 164 of compressor head 34. Inlet manifold 36 defines a substantially rectangular inner wall 206 which fits around all of valve chairs 156 when the inlet manifold is installed. Thus, it will be seen by those skilled in the art that 0-ring 204 seals against top surface 164 of compressor head 34 at a position thereon outwardly of all of valve chairs 156. It will be seen that an inner cavity 208 defined by wall 206 in inlet manifold 36 is thus in communication with each of inlet flow paths 170 in valve chairs 156.
At the upper end of inlet manifold 36 are a pair of opposed elbow portions 210 which are joined at a neck portion 212. Elbow portions 210 have holes 211 therein in communication with inner cavity 208 in inlet manifold 36. Neck portion 212 is attached to flange 38, previously described. Thus, a flow path is formed between flange 38 and cavity 208 in inlet manifold 36, and thus a path is formed to direct gas into inlet flow paths 170 in compressor 10.
Referring again to FIG. 8, compressor piston 100 defines a plurality of piston grooves 214 therein. Disposed in each groove 214 are a pair of piston rings 216. Each pair of piston rings 216 in a single groove 214 are positioned such that any circumferential gaps 217 in the piston rings are substantially diametrically opposed from one another so that gas leakage by the piston rings into the compressor crankcase are minimized.
Referring now to FIG. 9, an oil viscosity sensing system of the present invention is shown and generally designated by the numeral 220. A first needle valve 222 is placed in communication with an oil passage 224 from an oil pressure source such as engine bearing header 226 which is a part of crankcase 20 or cylinder block 18. A downstream side of first needle valve 222 is connected to a first tee 238 which in turn is connected to a second needle valve 230 and a first side 232 of a differential pressure switch-gauge 234. A second side 236 of switch gauge 234 and the downstream side of second needle valve 230 are connected to a second tee 238. Second tee 238 is also connected back to crankcase 20 through an oil passage 240.
OPERATION OF THE INVENTION
After the engine has been converted to form compressor 10 and the apparatus installed in package 12, it is ready for operation such as the compression of natural gas from a wellhead. A line from the wellhead is connected to inlet valve 42 on tank 40, and the appropriate connection is also made to inlet line 60 on fuel vessel 58. Similarly, threaded end 88 of discharge line 86 is connected to whatever is downstream, such as a storage vessel or pipeline.
If the gas being handled is suitable as fuel for the engine portion of compressor 10, this fuel flows from fuel vessel 58 through fuel line 64 into carburetor 26. Pressure regulator 66 insures that the fuel pressure at carburetor 26 is maintained at a constant, predetermined level as required by the carburetor. The engine portion of compressor 10, which is the left side as seen in FIG. 3, operates in a normal manner to rotate crankshaft 96 and thus operate the compressor side, which is the right side of FIG. 3. In this way, compressor pistons 100 are reciprocated within cylinder bore 106.
As previously described, the gas enters inlet manifold 36 of compressor 10 through hose 52. The gas is then in communication with each of inlet flow paths 170, and thus in communication with each of compressor valves 114.
Referring to FIG. 8, as piston 100 moves downwardly from its top dead center position, a variably sized volume 218 is formed in cylinder bore 106. When the pressure in volume 218 drops below that of the incoming gas in inlet flow path 170, a pressure differential is formed across suction valve plate 142. When the force exerted by this pressure differential exceeds that exerted by spring 144, suction valve plate 142 will be moved downwardly to its open position, and the gas and inlet flow path 170 will flow through inlet ports 136 in upper body 116 and outlet ports 138 in lower body 118 into volume 218. When the gas pressure in inlet flow path 170 and in volume 218 are substantially equalized, it will be seen that spring 144 will return suction valve plate 142 to its closed position.
As piston 100 reaches its bottom dead center position, and starts to move upwardly again within cylinder bore 106, the gas in volume 218 is obviously compressed. Eventually, the gas pressure in volume 218 exceeds the downstream gas pressure in discharge flow path 172 such that a pressure differential is formed across discharge valve plate 152. When the force exerted by this pressure differential exceeds that exerted by spring 154, discharge valve plate 152 is moved upwardly to its open position that the compressed gas is forced out of volume 218 through inlet port 146 in lower body 118 and outlet ports 148 in upper body 116, and thus into discharge flow path 172 and discharge passage 178 in compressor head 34. When the pressures in volume 218 and discharge flow path 172 are substantially equalized, spring 154 will return discharge valve plate 152 to its closed position, so the cycle may start again.
The gas transferred by compressor 10 is discharged through discharge opening 182 into discharge line 82. The compressed gas is at an elevated temperature and flows into aftercooler 74 for cooling and eventual discharge to the downstream location through discharge line 86.
Even though piston rings 216 are designed to minimize leakage thereby, there will always be some gas leakage, and the result is a gas buildup in crankcase 20 of compressor 10. Crankcase 20 is, of course, the original automotive component and is not designed for significant pressurization, so a means is provided to vent the crankcase. In the case Of flammable or other hazardous gases, obviously this venting cannot be to the atmosphere. In the embodiment shown, the gas is vented through line 60 back to inlet vessel 58. Regulator 62 regulates the pressure and is adapted to open when the crankcase reaches a predetermined level and thereby allow gas to enter inlet vessel 58 at a constant, predetermined level. Should too much gas accumulate in fuel vessel 58, the excess is exhausted through relief valve 59. Relief valve 59 may be piped away to another location. Thus, a means is provided for venting crankcase 20 to prevent the accumulation of gas therein.
Even with the venting of crankcase 20, the low pressure gas that is present will eventually result in some contamination of the engine oil. For example, the use of natural gas or other hydrocarbons, will eventually dilute the oil until its viscosity is so low that it will no longer properly lubricate the engine bearings. The present invention includes oil viscosity sensing means 220 to prevent damage to the compressor when the oil viscosity falls below a predetermined level.
Referring to FIG. 9, when the engine portion of compressor 10 is running, engine bearing oil pressure is supplied to first needle valve 222. Needle valve 222 is adjusted so that only a predetermined volume of oil flows therethrough. It will be seen that differential pressure switch gauge 234 is adapted for actuating in response to the differential pressure across second needle valve 230. By adjusting second needle valve 230, a set point or initial level for the differential pressure is obtained. This adjustment is preferably made when the oil in crankcase 20 of compressor 10 is new and has a substantially known viscosity. As the oil in crankcase 20 is gradually diluted, the viscosity thereof is reduced. This reduction is viscosity results in a reduction in differential pressure across second needle valve 230 as oil flows therethrough in viscosity sensing system 220. Differential pressure switch gauge 234 is set to actuate when this differential pressure across second needle valve 230 drops below a predetermined level which corresponds to the minimum oil viscosity level. Differential pressure switch gauge 234 is connected to the controls of the engine portion of compressor 10 and will deenergize the engine when actuated. Thus, the engine portion of compressor 10 is shut down when the oil viscosity falls below a predetermined level so that damage to the bearings and other drive components in crankcase 20 is avoided.
It will be seen, therefore, that the integral gas compressor and internal combustion engine of the present invention is well adapted to carry out the ends and advantages mentioned as well as those inherent therein. While a presently preferred embodiment of the apparatus has been described for the purposes of this disclosure, numerous changes in the arrangement and construction of parts may be made by those skilled in the art. All such changes are encompassed within the scope and spirit of the appended claims.
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An integral gas compressor and internal combustion engine. The compressor is built by converting a portion of an internal combustion engine to a compressor by removing the original engine head and valve train and replacing these with a compressor head assembly. The compressor head assembly includes compressor valves and valve chairs for holding the compressor valves in place. An inlet manifold encloses all of the valve chairs and places all of the inlet flow paths through the valve chairs in communication with a gas source. The head defines a discharge passageway therethrough which is in communication with a discharge opening. A venting system is provided to vent any gas that might build up in the compressor due to leakage past the piston rings and to transfer this vented gas to a fuel inlet of the engine, as desired. An oil viscosity sensing system is provided for sensing the oil viscosity in the crankcase and shutting down the engine when the viscosity drops below a predetermined level.
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FIELD OF THE INVENTION
[0001] The invention relates to a starting device for a discharge lamp, and in particular to a starting device for a high-pressure discharge lamp adapted to be located remotely from the ballast.
BACKGROUND OF THE INVENTION
[0002] High-Intensity Discharge (HID) lamps produce light by driving current through a gas filled arc-tube. A light emitting discharge arc is produced between two electrodes exposed within the arc-tube. A starting device is required to initiate the arc between the two electrodes. Typically, the starting device must produce a pulse of several kilovolts across the two electrodes in order to initiate the arc and start the lamp.
[0003] Many conventional HID lamps require a ballast and starting circuit to generate a starting pulse and to supply the operating lamp with the necessary operating current. Conventional starting circuits charge a capacitor to a certain value until an automatic switch closes allowing the capacitor to discharge through the primary winding of a transformer. The primary winding is inductively coupled to a secondary winding, and the combination of the rapidly discharging capacitor through the primary winding, along with the winding ratio of the secondary winding to the primary winding, generates a pulse of sufficient voltage and duration across the electrodes of the HID lamp to initiate operation. Unfortunately, conventional ballasts and starting circuits have to be located relatively close to the HID lamp because parasitic impedances in the conductors connecting the HID lamp to the starting circuit tend to attenuate the starting pulse. Because of this effect of parasitic impedances, many ballast manufacturers place a maximum “lamp-to-ballast” distance on every ballast-starter combination that is offered. These distances typically range from 2 to 75 feet, depending on the ballast and the ignitor circuit being used.
[0004] It would be advantageous to provide a starting circuit which is capable of starting and operating an HID lamp such that the lamp could be located at an unrestricted distance from the ballast.
SUMMARY OF THE INVENTION
[0005] The above-described disadvantages are overcome and other advantages are realized by providing a starting circuit in accordance with the present invention. According to the first embodiment of the invention, an ignitor circuit for a discharge lamp is provided which comprises a voltage input terminal, an ignitor output terminal, and a first capacitor having first and second capacitor terminals. The first capacitor terminal is connected to the voltage input terminal. The ignitor circuit further has a transformer having a primary winding inductively coupled to a secondary winding. An automatic switch is connected in series with the primary winding. The switch and primary winding are connected across the first capacitor, and the secondary winding is connected between the starting circuit voltage input terminal and the output or “lamp” terminal. A resistor is connected between the second capacitor terminal and the common terminal, and the second capacitor is connected across the resistor. The second capacitor is selected to have a value such that it represents a low impedance path for the high-frequency pulse generated by the transformer. Therefore, the pulse is de-coupled from the input lines and is presented across the electrodes of the discharge lamp.
[0006] In another embodiment of the present invention, an ignitor circuit for a discharge lamp is provided that comprises input terminals, an ignitor output terminal and a first capacitor having first and second capacitor terminals. The first capacitor terminal is connected to one of the input terminals. The ignitor circuit also has a transformer having a primary winding inductively coupled to a secondary winding. Furthermore, an automatic switch is connected in series with the primary winding, such that the switch and primary winding are connected across the first capacitor. The secondary winding is connected to the voltage input terminal and the ignitor output terminal. A resistor is connected between the second capacitor terminal and a common terminal, and a second capacitor is connected between the first input terminal and the second input terminal. In this embodiment the second capacitor presents a low impedance path for the high-voltage pulse generated by the transformer such that the pulse is applied across the terminals of the HID lamp.
[0007] In the third embodiment of the invention, an ignitor circuit for a discharge lamp is provided that comprises a voltage input terminal, an ignitor output terminal, and a transformer having a primary winding inductively coupled to a secondary winding. A resonant circuit is connected between the voltage input terminal and a common terminal, wherein the resonance circuit comprises the primary winding connected in series with an automatic switch and a first capacitor. The first capacitor is connected to the voltage input terminal. A second capacitor is connected in series to the secondary winding, such that the second capacitor and secondary winding are connected across the ignitor terminal and the common terminal. Finally, and inductor device is connected between the voltage input terminal and the ignitor terminal. In this manner, the high-frequency pulse generated in the secondary winding of the transformer is present across the terminals of the discharge lamp through the low impedance path of the secondary capacitor. Furthermore, the pulse is de-coupled from the input terminals by the inductor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] These and other advantages and novel features of the invention will be more readily appreciated from the following detailed description and in conjunction with the accompanying drawings in which:
[0009] [0009]FIG. 1 is a circuit diagram of a first embodiment of the invention;
[0010] [0010]FIG. 2 is a circuit diagram of a first embodiment of the invention, including an optional tertiary winding;
[0011] [0011]FIG. 3 is a circuit diagram of a second embodiment of the invention;
[0012] [0012]FIG. 4 is a circuit diagram of a second embodiment of the invention, including an optional tertiary winding; and
[0013] [0013]FIG. 5 is a circuit diagram of a third embodiment of the invention.
[0014] Throughout the drawing figures, the same reference numerals will be understood to refer to the same parts or components.
DETAILED DESCRIPTION OF THE INVENTION
[0015] An ignition circuit 100 according to the present invention is illustrated in FIG. 1. The circuit 100 includes a voltage input terminal 102 and a common terminal 104 . These input terminals are preferably connected to the outputs of a ballast, which can be located at any distance from the starting circuit due to the de-coupling nature of the circuit design. The circuit 100 also includes an HID lamp 106 . The circuit also includes a transformer 108 comprising a primary winding 110 and a secondary winding 112 . The primary winding of the transformer 108 is connected in series with an automatic switch 114 . The automatic switch preferably has a break-over voltage of 240V. However, a wide range of possible break-over voltages are contemplated to be within the scope of the invention. A first capacitor 116 is connected across the primary winding 110 and the automatic switch 114 . The capacitor preferably has a value of 0.33 uF. A first terminal of the first capacitor 116 is connected to the voltage input terminal 102 . The secondary winding 112 of the transformer 108 is also connected to the voltage input terminal 102 . The other terminal of the secondary winding 112 is connected to one terminal of the HID lamp 106 . A resistor 118 , preferably 5 k ohms, is connected between the first capacitor and the common terminal 104 . Finally, a second capacitor 120 is connected across the resistor 118 . The second capacitor 120 preferably has a value of 0.01 uF. It is to be understood that the values suggested for the capacitors are merely exemplary, and a wide range of possible values is contemplated to be within the scope of the invention.
[0016] In operation, the output of a ballast is applied to the voltage input terminal 102 . Current through resistor 118 charges capacitor 116 until the voltage across automatic switch 114 reaches a break-over voltage. Once automatic switch 114 begins to conduct, current flows through a primary winding 110 , inducing a voltage across primary winding 110 . Due to transformer action, a corresponding voltage is induced across secondary winding 112 . The high-frequency pulse across the secondary winding 112 is applied to the HID lamp 106 . The voltage of the high-frequency pulse is determined by the winding ratio between the primary winding 110 and the secondary winding 112 . The winding ratio is preferably 8 to 1 so that a pulse of sufficient voltage (preferably 3400V) is applied across HID lamp 106 to cause an arc between the exposed terminals in the lamp. The values of the first capacitor 116 and the second capacitor 120 are selected such that they present a low impedance path for the high-frequency pulse induced in secondary winding 112 . Therefore, the high-frequency, high-voltage pulse is applied across the lamp terminals. Due to the low impedance path through the capacitors 116 , 120 , the pulse is de-coupled from the voltage input terminals 102 and 104 .
[0017] [0017]FIG. 2 illustrates an embodiment of the present invention similar to FIG. 1 with the addition of an optional tertiary winding to the transformer. Transformer 208 includes primary winding 210 and secondary winding 212 connected in a manner similar to the transformer 108 depicted in FIG. 1. A tertiary winding 222 is added to the circuit 200 and connected between the common terminal 104 and the second terminal of the HID lamp 106 . In this embodiment of the circuit, the winding ratio between the primary winding 210 and the secondary winding 212 is preferably 4 to 1. The winding ratio between the primary winding 210 and the tertiary winding 222 is also preferably 4 to 1. In this embodiment, when automatic switch 114 begins to conduct and the voltage across capacitor 116 is applied to primary winding 210 , corresponding voltages are induced in both secondary winding 212 and tertiary winding 222 . The voltages that are induced in secondary winding 212 and tertiary winding 222 are applied to the terminals of HID lamp 106 . The values of capacitors 116 and 120 are selected such that they present a low impedance path to the high-frequency pulse generated in secondary winding 212 and tertiary winding 222 . Thus, the high-frequency pulse is de-coupled from inputs 102 and 104 .
[0018] [0018]FIG. 3 illustrates a second embodiment of the present invention. The starter circuit 300 includes a voltage input terminal 102 and a common terminal 104 . These input terminals are preferably connected to the outputs of a ballast, which can be located at any distance from the starting circuit due to the de-coupling nature of the circuit design. The circuit provides a high-voltage pulse to HID lamp 106 . In order to begin an arc between the electrodes within the lamp enclosure, a transformer 308 is provided to generate the high-voltage pulse from stored energy via capacitor 116 received from the ballast or other voltage source. A primary winding 310 of the transformer 308 is connected in series with an automatic switch 114 . A capacitor 116 is connected across the automatic switch 114 and the primary winding 310 , and also has one of its terminals connected to the voltage input terminal 102 . A resistor 118 is connected between the second terminal of the capacitor and the common terminal 104 . Current through resistor 118 and capacitor 116 charges capacitor 116 until the voltage across it reaches the break-over voltage of automatic switch 114 . When the voltage of capacitor 116 reaches the break over voltage, automatic switch 114 begins to conduct and capacitor 116 discharges rapidly through primary winding 310 . Secondary winding 312 is inductively coupled to primary winding 310 such that a voltage is induced in secondary winding 312 which corresponds to the winding ratio between primary winding 310 and secondary winding 312 . Capacitor 320 is connected between voltage input terminal 102 and common terminal 104 . The value of capacitor 320 is selected such that it provides a low-impedance path for the high-frequency pulse induced in secondary winding 312 (preferably 0.01 uF). The high-voltage pulse is therefore applied across the terminals of HID lamp 106 , and decoupled from input terminals 102 and 104 .
[0019] An ignitor circuit in accordance with the second embodiment of the invention is illustrated in FIG. 4 and also comprises an optional tertiary winding 422 . In the ignitor circuit depicted at 400 , a three-winding transformer 408 delivers a high-voltage, high-frequency pulse to HID lamp 106 . Capacitor 116 is charged until the voltage across the capacitor reaches the break-over voltage of automatic switch 114 . When automatic switch 114 begins to conduct, the charge accumulated in capacitor 116 begins discharging through primary winding 410 . A voltage appears across winding 410 , and because primary winding 410 is inductively coupled to secondary winding 412 and tertiary winding 422 , corresponding voltages are induced in the secondary and tertiary windings, respectively. The voltages induced in secondary winding 412 and tertiary winding 422 are related to the voltage induced in primary winding 410 by the winding ratio between the primary winding and the secondary winding and between the primary winding and the tertiary winding. Capacitor 320 is connected between voltage input terminal 102 and common terminal 104 . The value of capacitor 320 is selected so that the high-voltage, high-frequency pulse generated in windings 412 and 422 has a low impedance path between the terminals of HID lamp 106 .
[0020] A third embodiment of the present invention is depicted in FIG. 5. Starter circuit 500 includes a voltage input terminal 502 and common terminal 504 . The circuit 500 supplies a starting pulse to HID lamp 506 . Transformer 508 includes primary winding 510 and secondary winding 512 . Primary winding 510 forms part of a resonant circuit with capacitor 516 , which is activated by automatic switch 514 . As the voltage input terminal 502 increases, the voltage across automatic switch 514 also increases until the break-over voltage is reached, at which time automatic switch 514 begins conducting. When the automatic switch 514 begins conducting, current is forced through primary winding 510 inducing a voltage across winding 510 . The values of capacitor 516 and the inductance of winding 510 and the electrical resistance of automatic switch 514 and primary winding 510 are selected so that a high frequency pulse is generated across winding 510 when the automatic switch 514 begins conducting.
[0021] Secondary winding 512 is inductively coupled to primary winding 510 , so that a high-voltage pulse corresponding to the winding ratio between secondary winding in 512 and primary winding 510 is generated across secondary winding 512 . Capacitor 518 is connected between HID lamp 506 and secondary winding 512 . The value of capacitor 518 is selected such that the capacitor presents a low impedance path to the high frequency pulse induced in secondary winding 512 . This high-frequency, high-voltage pulse is applied directly across HID lamp 506 causing an arc and starting the lamp. The high-voltage, high-frequency pulse is de-coupled from voltage input 502 by inductor 520 which is connected between the HID lamp and voltage input terminal 502 .
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A starter circuit is provided for starting an HID lamp. The circuit decouples the high voltage starting pulse from the input lines (ballast output lines) so that the starter can function properly regardless of the distance between the ballast and the lamp.
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BACKGROUND OF THE INVENTION
The present invention relates generally to diverter valves and, more particularly, to slide plate diverter valves of the type utilized in directing the flow of viscous materials such as molten thermoplastic polymers under relatively high pressures.
In many manufacturing operations involving the formation of products from molten thermoplastic material, e.g., plastic extrusion, injection molding, and blow molding operations, it is desirable, if not essential, that the operation be carried out on a continuous flow basis. Additionally, it is common practice in such operations to filter impurities from the thermoplastic material by passage through a suitable filtration unit. Necessarily, such filtration units require periodic cleaning and, accordingly, to accommodate such cleaning and also permit the manufacturing operation to proceed on a continuous basis, dual filters are typically utilized with a diverter valve situated in the flow line to selectively direct the fluid material through one of the filters while the other is inactive for periodic cleaning and maintenance and otherwise to serve as a back-up to the operating filter.
It is therefore critical in such manufacturing operations that the diverter valve be capable of functioning reliably over extended periods of time, which objective is complicated by the severe temperature and pressure conditions under which such valves often operate. In particular, molten thermoplastic materials often have temperatures in excess of 400 degrees Fahrenheit and even as high as 600 degrees Fahrenheit or more and often flow at pressures in excess of 1000 PSI up to 5000 PSI. Such materials may also be corrosive in nature. Other requirements placed on such valves are that their configuration must be such that the fluid flow characteristics do not differ between the alternate operating dispositions of the valve and, especially, the flow passageways through the valve must be configured to avoid any stagnation in the fluid flow which could cause certain thermoplastic materials to undergo changes in their physical or chemical character.
One such diverter valve which addresses these objectives in commercial practice is a diverter valve of the slide plate type disclosed in Blanchard U.S. Pat. No. 4,334,552. Basically, this valve provides a manifold defining inlet and outlet fluid flow passages opening at a sealing face thereof through respective ports, a slide plate defining a fluid flow passageway at a sealing face thereof in facing surface contact to the manifold sealing face, and a backing plate disposed at the opposite side of the slide plate to sandwich it between the backing plate and the manifold, with a plurality of bolts connecting the manifold and backing plate for clamping them together to hold the respective sealing faces of the manifold and the slide plate in metal-to-metal surface contact with substantially zero clearance therebetween. The Blanchard patent teaches that the bolts effectively function as a spring to enable the valve to absorb and accommodate fluctuations in fluid pressure.
Disadvantageously, it has been observed in practice that the valve of the Blanchard patent tends to suffer sticking of the slide plate making it difficult to move the slide plate smoothly and position it accurately, which is believed to be due to the clamping forces exerted by the valve on the slide plate. It has also been observed in practice that, during changeovers between the opposite limit positions of the slide plate, the valve will produce startlingly loud reports. While the cause of such reports has not been definitely determined, it is believed that the reports result from the fact that the bolts permit a limited but sufficient amount of relative lateral movement of the backing plate with respect to the manifold that, upon actuation of the slide plate, the backing plate tends to move with the slide plate until resisted by the bolts and then to snap back into the original disposition of the backing plate. Regardless of the cause of such reports, the reports cause users of such slide plate diverter valves to be characteristically fearful of the possibility of valve failure and, as a result, it is quite common for users to severely over-torque the bolts in an attempt to better secure the valve but, disadvantageously, such steps may actually exacerbate the problems with sticking and inaccurate position of the slide plate as well as weakening the valve and increasing the risk of failure.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide an improved slide plate diverter valve of the general type of Blanchard U.S. Pat. No. 4,334,552 which overcomes the aforedescribed disadvantages.
Briefly summarized, the present invention accomplishes this objective by providing this type of slide plate diverter valve with a suitable means for rigidifying the manifold and the backing plate with respect to one another to prevent movement of the backing plate relative to the manifold in response to sliding movement of the slide plate.
Preferably, the manifold and backing plate are rigidified by provision of a pair of shear plates disposed between the manifold and the backing plate at opposite lateral sides of the slide plate and by forming each of the shear plates as well as the manifold and the backing plate with aligned recesses in which dowels are securely seated thereby to connect each shear plate to both the manifold and the backing plate against relative movement of any thereof longitudinally and transversely of the direction of sliding movement of the slide plate.
The shear plates are of a thickness, i.e., the dimension between the manifold and the backing plate, which is essentially identical to the corresponding thickness dimension of the slide plate so that the clamping force exerted by the clamping means is shared by the slide plate and the shear plates to prevent the application of excessive clamping force on the slide plate and, in turn, to contribute to the ease of actuation of sliding movement of the slide plate. For similar purposes, the shear plates are provided with bearing plates disposed in opposed facing relation for guiding engagement with opposite longitudinal side surfaces of the slide plate.
In the preferred embodiment, each shear plate is formed with openings through its thickness which receive the bolts clamping the manifold and backing plate together.
The respective faces of the manifold and the backing plate which oppose one another to contact the opposite faces of the slide plate are formed to a predetermined minimum hardness, preferably of a value of at least about 56 measured at room temperature according to the Rockwell C Hardness Scale. To achieve this purpose, the inward slide face of the backing plate and the sealing face of the manifold are preferably formed of a nickel-based hard-surfacing alloy.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a diverter valve according to the preferred embodiment of the present invention;
FIG. 2 is an exploded perspective view of the diverter valve of FIG. 1;
FIG. 3 is a vertical cross-sectional view of the diverter valve of FIG. 1 taken lengthwise along line 3--3 thereof; and
FIG. 4 is another lengthwise cross-sectional view of the diverter valve of FIG. 1 taken along line 4--4 thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the accompanying drawings and initially to FIG. 1, a diverter valve constructed in accordance with the preferred embodiment of the present invention is indicated generally at 10 and basically comprises a manifold block 12 for receiving incoming fluid flow and discharging outgoing fluid flow through passageways therein as described hereinafter, a slide plate 14 which serves as a movable valve member for controlling communication between the passageways of the manifold block 12, a backing plate 16 disposed opposite the slide plate 14 from the manifold block 12 sandwiching the slide plate therebetween, and a series of bolts 18 secured by nuts 20 for clamping the backing plate 16 to the manifold block 12 to urge the slide plate 14 into sealed relationship with the manifold block 12. According to the present invention, the backing plate 16 and the manifold block 12 are rigidified with respect to one another by a pair of side rails 22 which are rigidly connected to each thereof to function as shear plates resisting such relative movement.
As best seen in FIG. 2, the manifold block 12 is formed from a solid metallic block of a parallelepiped shape the lower lengthwise face of which is symmetrically truncated angularly at the opposite ends of the block. The flat elongate upper longitudinal surface of the manifold block 12 forms a sealing face 30 for sealing surface contact with the slide plate 14. A series of three passageways 24,26,28 are formed through the valve block 12, the passageways opening at the sealing face 30 through respective ports 24',26',28' spaced equidistantly along the length of the sealing face 30, with the central passageway 26 extending therefrom through an approximately 90 degree turn to open at one lateral side face 32 of the manifold block 12 through another port 26'' and with each end passageway extending angularly from its respective port 24',28' outwardly to open at a respective truncated face 34,36 of the manifold block 12 through respective ports 24'',28''.
The manifold block 12 is preferably formed of a low carbon steel or another suitable metallic material which, together with the mass of the manifold block 12, enables it to withstand the high temperatures and pressures described above associated with the pressurized conveyance of molten thermoplastic materials and the like. As will be understood, since the sealing face 30 will operate in surface contact with the movable slide plate 14, it is essential that the sealing face 30 be extremely hard, flat and smooth. For this purpose, the sealing face 30 is finished with a suitable surfacing to provide the desired hardness, preferably by means of a spray weld deposition of a nickel-based hard-surfacing alloy such as achieved by the "Colmonoy" surfacing produced by Wall Colmonoy Corp. of Detroit, Mich., and then the sealing face 30 is ground and lapped to a very fine degree of flatness. By way of example but with limitation, it is contemplated to be preferable for valves handling molten thermoplastic material that the surface hardness of the sealing face 30 be of a value of at least 56 as measured at room temperature according to the Rockwell C Hardness Scale.
The slide plate 14 is an elongate metallic block of parallelepiped shape having parallel upper and lower faces 38,40 and parallel lateral side faces 42,44, with the lower face 40 forming a sealing face for sealing surface engagement with the upper sealing face 30 of the manifold block 12. The sealing face 40 of the slide plate 14 is formed with an elongate lengthwise-extending recess 46 of a longitudinal dimension corresponding to the lengthwise dimension between diametrically opposite points on the ports 24'',26'' (which, as will be noted, is identical in dimension to the corresponding spacing between the ports 26'' and 28''), of a widthwise dimension corresponding to the diameters of the ports 24'',26'',28'', and arcuately shaped at its ends in correspondence to the circumference of the ports 24'',26'',28''. In this manner, the recess 46 is configured to form a passageway precisely bridging the ports 24'',26'' or the ports 26'',28'' when the slide plate 14 is slidably positioned to locate the recess 46 over either such pair of ports (hereinafter referred to as the two limit positions of the slide plate 14) for pressurized fluid flow between the ports. Suitable position indicators, limit switches, or stops (not shown) may be provided to determine such limit positions of the slide plate. Importantly, the exact correspondence of the recess 46 to each bridged pair of ports in the two limit positions of the slide plate 14 serves to minimize the creation of additional turbulence in the fluid flowing between the ports and to substantially avoid any isolated regions of stagnated fluid flow.
As those persons skilled in the art will readily recognize and appreciate, the port 26'' in the side face 32 may serve as either an intake or discharge port for fluid flow purposes, depending upon the particular application of the valve. In applications wherein the port 26'' serves as a fluid intake port into the valve 10, the ports 24'',28'' serve as alternate discharge ports for fluid flow under the control of the slide plate 14. Alternatively, the ports 24'',28'' may serve as alternative intake ports into the valve 10, with the slide plate 14 controlling diversion of the two incoming fluid flows to the common discharge port 26''.
The slide plate 14 is preferably fabricated of hot work tool steel or a corresponding metallic material suitable to withstand the high temperatures and pressures associated with operation of the valve in handling molten thermoplastic material. Likewise, it is equally important that the respective faces 38,40 and 42,44 be extremely flat, smooth and parallel with one another to achieve a satisfactory zero clearance metal-to-metal interface seal between the sealing face 40 of the slide plate 14 and the sealing face 30 of the manifold 12, as well as to best facilitate smooth sliding movement of the slide plate 14 and, for this purpose, the respective surfaces of the slide plate 14 are lapped to extremely close tolerances. One end of the slide plate 14 is formed with a clevis portion 47 for connection of the slide plate 14 to a suitable linear actuator (not shown) for actuating sliding movements of the slide plate 14 between its limit positions.
The backing plate 16 is also formed of a parallelepiped block of a suitable metallic material, such as a low carbon steel, the lateral and longitudinal dimensions of the backing plate 16 corresponding to that of the upper sealing face 30 of the manifold block 12. For suitable flatness and hardness, the lower face 48 of the backing plate 16, which is in metal-to-metal sliding surface contact with the upper face 38 of the slide plate 14, is lapped and finished with a hardened surfacing, such as the same spray weld deposit of the "Colmonoy" nickel-based hard-surfacing alloy formed on the sealing face 30 of the manifold block 12.
Each of the side rails 22 is an elongate parallelepiped metal bar, which may also be hot work tool steel or a like suitable metal, of a lengthwise dimension corresponding to that of the manifold block 12 and the backing plate 16 and a vertical thickness or height identical to that of the slide plate 14, for which purpose the upper and lower surfaces 50,52 are lapped to extremely close tolerances to correspond precisely in flatness and dimension to the vertical thickness of the slide plate 14. The respective inwardly-facing lateral side surfaces 54 of the side rails 22 are formed with recesses 56 adjacent their opposite ends, with an aluminum bronze bearing plate 58 being fittedly inserted into each recess 56 for guiding engagement with the opposite lateral side faces 42,44 of the slide plate 14.
Each of the upper and lower surfaces 50,52 of each of the side rails 22 are formed with a pair of recesses 60 and, correspondingly, each opposite lateral side of the upper sealing face 30 of the manifold block 12 and of the lower face 48 of the backing plate 16 are formed with a correspondingly-located pair of recesses 62,64 which align with the side rail recesses 60. These recesses 60,62,64 are respectively fitted snugly with a total of eight dowel pins 66 which connect and secure the side rails 22 to the manifold block 12 and the backing plate 16 rigidly against relative movement thereof both longitudinally and transversely with respect to the direction of sliding movement of the slide plate 14.
The opposite longitudinal sides of the upper sealing face 40 of the manifold block are also formed with a plurality of threaded bores 68 in alignment with the dowel recesses 62 and the side rails 22 and the backing plate 16 are formed with a correspondingly spaced plurality of unthreaded bores 70,72 which align with one another and with the threaded bores 68. The threaded bolts 18 extend downwardly through the bores 70,72 in the backing plate 16 and the side rails 22 and are threadedly engaged in the threaded bores 68 in the manifold block 12, with the upper ends of the bolts 18 extending exposed upwardly beyond the upper surface of the backing plate 16 whereat the nuts 20 threadedly engage the exposed end of the bolts 18. The nuts 20 are tightened on the exposed ends of the bolts 18 to a predetermined torque to exert a predetermined clamping force securing the manifold block 12, the backing plate 16 and the side rails 22 together and urging the slide plate 14 into zero clearance metal-to-metal sealing engagement of its lower sealing face 40 with the sealing face 30 of the manifold block 12.
Since the vertical thickness dimension and flatness of the side rails 22 are identical to that of the slide plate 14, the clamping force of the nut and bolt assemblies 18,20 is fully applied directly to the slide plate 14 to achieve an effective seal against fluid leakage while, at the same time, the side rails 22 effectively share the clamping load with the slide plate 14 so that the force required to actuate sliding movement of the slide plate 14 between its limit positions is minimized.
The provision of the dowel pins 66 seated in the respective recesses 60,62,64 of the manifold block 12, the backing plate 16 and the side rails 22 effectively rigidifies these components with respect to one another to resist any tendency for relative movement of the backing plate 16 during sliding actuation of the slide plate 14, which should minimize or eliminate the occurrence of loud reports from the valve 10 as have been experienced with conventional slide plate diverter valves. At the same time, the present diverter valve 10 should be relatively safer and less subject to the risk of potential failure than such conventional diverter valves while still being just as reliable in operation and just as effective in sealing against fluid leakage as conventional diverter valves.
An additional advantage of the present diverter valve 10 over conventional slide plate diverter valves is that the present valve is not contemplated to have any need for periodic lubrication over its serviceable life, beyond the original lubrication of the component parts performed during manufacturing assembly, thus enabling the elimination of any lubrication fitting such as typically provided with conventional valves.
It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.
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An improved slide plate diverter valve having a manifold block and a backing plate with a linearly reciprocable slide plate sandwiched and clamped therebetween is provided with side rails between the manifold block and backing plate along opposite lengthwise sides of the slide plate secured by dowel pins to each thereof to rigidify the manifold block and backing plate against relative movement, eliminating any tendency of the backing plate to move relative to the manifold block in response to sliding actuation of the slide plate.
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CROSS-REFERENCE TO RELATED PATENT APPLICATION
This patent application claims the benefit of U.S. Provisional Patent Application No. 60/564,012, filed Apr. 21, 2004. The disclosures set forth in the referenced provisional application are incorporated herein by reference in their entirety, including all information as originally submitted to the United States Patent and Trademark Office.
BACKGROUND OF THE INVENTION
A variety of brewing apparatus have been developed to combine heated water with a brewing substance such as ground coffee or tea material in order to infuse the material and produce a brewed beverage. There are many ways to combine the water with the brewing substance. One way is to place the substance in a filter device such as a disposable filter paper and place the filter paper and brewing substance in a brewing funnel or basket. The water is mixed with the brewing substance in the filter thereby allowing the brewed substance to filter through the paper leaving the saturated brewing substance in the filter paper. The saturated substance and used filter paper can be thrown away.
Another way of brewing beverage is to encapsulate the brewing substance in a filter material. The brewing substance in the filter material provides a convenient package for handling a predetermined quantity of brewing substance. The filter material provides a package or container for the brewing substance. This package allows the brewing substance to be handled prior to brewing and after brewing without complication or mess.
Such brewing substances pre-packaged in filter material are referred to as “pods” or “sachets.” Pods can be compressed while packaging in the filter material or left in a generally loose condition. Pods are generally shaped in a circular shape having a generally flattened configuration. The pods often are provided in the shape of a disc or puck. Pods generally range in a size from approximately 45-60 mm and contain approximately 9-11 grams of brewing substance. The typical pod is used to produce approximately 8 ounces of brewed beverage.
By way of background, it may be detrimental to initiate a brewing cycle in a brewer when the heated water reservoir or tank is “dry.” While the tank may not be totally devoid of water it may be so low that the result, the absence of water, is at least approximately the same as if the tank were dry. In this regard, such brewers include a reservoir which is used to retain a quantity of water which is heated and then subsequently used during a brewing cycle. It is detrimental to initiate a brewing process with a dry tank since it will cause the heating device or element of the tank to rapidly heat the air in the tank and possibly damage the heating element. In some situations, the heating element may be damaged during a single cycle when the level of water is sufficiently low or there is no water in the tank and, in other situations, perhaps, multiple heating cycles may be required before damage occurs. The reason for the generally rapid heating is that the empty or dry tank is a volume which merely contains air. Under normal operating conditions, this volume would contain water which would absorb the heat generated by the heating element. In contrast, when the tank is dry, the air rapidly heats, potentially resulting in damage to the heating element and possibly other system components.
As such, it is desirable to provide an apparatus, system and method for preventing a “dry plug” condition. In other words, it is desirable to prevent the system from initiating a heating cycle of the tank when an insufficient amount of water is retained in the tank after plugging in or providing power to the system. As such, it would be desirable to provide a system which prevents initiating a heating cycle when an insufficient amount of water is retained in the tank without control of the user such that it will prevent the user from damaging the apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
The organization and manner of the structure and function of the invention, together with the further objects and advantages thereof, may be understood by reference to the following description taken in connection with the accompanying drawings, and in which:
FIG. 1 is an illustration of a brewer which includes a dry plug prevention system;
FIG. 2 is a general diagrammatic illustration of a schematic of the brewer as disclosed; and
FIG. 3 is a general diagrammatic illustration of a gear pump as used in one embodiment as disclosed.
DETAILED DESCRIPTION
While the present disclosure may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, embodiments with the understanding that the present description is to be considered an exemplification of the principles of the disclosure and is not intended to be exhaustive or to limit the disclosure to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings.
Terms including brew, brewer, beverage and beverage making as used herein are intended to be broadly defined as including but not limited to the brewing of coffee, tea and any other brewed beverage. This broad interpretation is also intended to include, but is not limited to any process of infusing, steeping, reconstituting, diluting, dissolving, saturating or passing a liquid through or otherwise mixing or combining a beverage substance with a liquid such as water without a limitation to the temperature of such liquid unless specified. This broad interpretation is also intended to include, but is not limited to beverage substances such as ground coffee, tea, liquid beverage concentrate, powdered beverage concentrate, freeze dried coffee or other beverage concentrates, to obtain a desired beverage or other food.
While a “pod” is described herein, it is envisioned that any form of beverage making and/or brewing apparatus, beverage brewing substance device, holder, filter structure or other substance delivery media or vehicle may be used. It is envisioned that the present apparatus, system and method of operation could be utilized with other beverage making and dispensing apparatus which in addition to or substitution for brewing, the apparatus may use concentrates such as freeze dried concentrates, gel, liquid, powder or any other form of concentrate which will operate with the disclosed apparatus, system and method as well as equivalents thereof and any modifications which might be required to modify the apparatus, system and method to be used with such other substances, if necessary.
With reference to FIG. 1 , a brewer or beverage dispenser 20 is shown. The brewer 20 includes a dispensing area 22 for placement of a container such as a cup or other vessel for dispensing a beverage therein. The brewer 20 includes a housing 24 having an upper portion 26 and a base portion 28 . It should be noted that the brewer 20 could take any of many different appearances or housing designs and still be within the scope of the present disclosure. Further, while reference is made to a brewer which employs a “pod” or beverage dispenser is referred to herein, it should be understood that the disclosure as provided herein relating to an apparatus, method and system for controlling a brewer or dispenser may be usable with many other types of brewers and water heating devices which provide a reservoir or tank to retain a quantity of water for heating by any one of various heating apparatus or methods.
With reference to FIG. 2 , the brewer 20 is shown in a diagrammatic form illustrating the mechanisms employed in the apparatus and used in conjunction with the system and method as disclosed herein. The brewer or system 20 includes a water reservoir 30 for retaining a quantity of water. The system includes a water delivery system 32 through which water is delivered to a heated water reservoir 34 for controllable heating by a heating element 36 . It will be appreciated that other heating systems may be used to provide heat to the reservoir 34 and the contents of the reservoir, such as water. It is envisioned that the interpretation of the reservoir 34 , heating device 36 , water delivery system 32 and reservoir 30 will be broadly interpreted to include many different variations and embodiments of these components either alone or in combination with other components to achieve the objectives of the present disclosure. By way of further description, with reference to FIG. 2 , water is heated in the heated water reservoir and dispensed through a water delivery line 38 to a beverage assembly 40 . The beverage assembly 40 is configured in the form of a substance retaining drawer 25 which is selectably insertable on the upper portion 26 of the dispenser 20 . The beverage assembly 40 includes a cavity 27 (for retaining a quantity of beverage substance 130 ). The beverage substance 130 is shown in FIG. 2 as a pod but may be any number of other beverage substances as noted herein.
The water delivery system 32 includes several components. An entry end 42 of a water supply line 44 is connected to a check valve assembly 46 between the reservoir 30 and the supply line 44 . A pump feed end 48 of the water supply line 44 is spaced from the entry end 42 and connects to a pump assembly 50 . The pump assembly 50 is illustrated as a gear pump of known construction. It is envisioned that other pumps may also provide the operation, function, apparatus and system as disclosed herein. The gear pump 50 will be referred to herein in the interest of continuity of this description. However, the reference to “pump” 50 should be broadly construed to include all other embodiments which function with the apparatus, system and method as disclosed and hereafter developed to provide the pumping.
The pump 50 generally provides a positive pumping action on water supplied from the reservoir 30 via the supply line 44 . Water pumped from the pump assembly 50 is moved through an inlet line 52 to the heated reservoir 34 . The heated reservoir 34 defines a cavity 54 which retains a quantity of water for heating by a heating device or element 36 . Water is passed from the heated reservoir 34 through the water delivery line 38 as described above. Water delivery line 38 includes a check valve 56 .
With references to FIGS. 1 and 2 , a displaceably slidable lid 58 is provided for revealing an opening 60 for dispensing water into the reservoir 30 . Water may also or alternatively be introduced into the reservoir by a plumbed connection 62 which provides pressurized water 64 through the supply line 48 through the check valve system 46 to the reservoir. Pressurized water 64 entering the supply line 44 is resisted by the pump assembly 50 when the pump 50 is not operating. The check valve assembly 46 allows passage of water into the reservoir 30 and subsequent dispensing of water from the reservoir 30 . A controllable valve 66 is attached to the supply line 44 and coupled to a controller 70 via line 72 . The controller 70 , as will be described in greater detail hereinbelow, controls the opens and closes the valve in response to signals from a control panel 74 or other input device, also coupled to the controller over line 76 . Additionally, in this embodiment, water level sensor assembly 78 can be provided in association with the reservoir and coupled to the controller 70 over line 80 . When the water level sensor assembly 78 indicates a sufficient level of water in the reservoir 30 , the controller 70 operates the valve 66 to a closed position to cease filling of the reservoir 30 . Other forms of level sensors may be used and are fully within the scope of the present disclosure, including resistive, capacitive, optical, and sonic, as well as any other form of level sensing device coupled to the controller 70 .
Also included in the apparatus and system is a flow meter 84 and check valve assembly 86 . The check valve assembly 86 includes at least one check valve and possibly two check valves 88 , 90 . One check valve 88 communicates with the inlet line 52 . A second check valve 90 is connected to a side routing line 92 . This check valve system 86 facilitates movement of water from the pump assembly 50 to the heated reservoir 34 through the first check valve 88 . In a system which employs the second check valve 90 , some degree of flow is allowed to return through the side routing line 92 from the heated reservoir 34 to the pump 50 through check valve 90 . The operation of the check valve assembly 86 facilitates the release of some degree of pressure downstream of the pump 54 when a brewing cycle ends. However, this check valve assembly 86 also prevents the heated water reservoir 34 from completing draining.
Additionally, the flow meter 84 provided in the water delivery system 32 is positioned on the cold or unheated side of the heated water reservoir 34 and pump so as to prevent the accumulation of lime in the flow meter 84 . The flow meter 84 is coupled to the controller 70 over line 106 . In other words, the flow of water flowing through the line 44 and the flow meter 84 has not been heated. In a heated water system, lime and other mineral deposits may tend to form on elements in the heated section or downstream of the heated section. Since lime is discouraged from developing by placing the flow meter 84 on the cold water, or upstream, side of the water delivery system 32 , the accumulation of lime and other minerals is discouraged and, therefore, does not require or may require less cleaning. By eliminating or reducing the accumulation of lime, the reliability of the system increases and the maintenance associated with the system decreases. The flow meter 84 , while shown positioned between the inlet line 44 and pump 50 , may alternatively be positioned between the pump 50 and the reservoir 34 and maintain the benefits as described.
A thermostatic sensor 94 is positioned inside the heated water reservoir 34 and coupled over line 96 to the controller 70 . The controller 70 obtains information from the thermostat 90 and controls operation of the heating element 36 in response thereto.
The system includes a power connection 100 which is coupled to various elements including, but not limited to, the controllable valve 66 , pump assembly 50 , air purge 102 , heating element 36 , and controller 70 . Power can be provided through power delivery systems of known construction to other components and systems and subassemblies where a power source is needed. The power may be provided directly to the components or may be provided in low voltage DC form by use of an appropriate power transformer. For example, while the heating element or heating device 36 may be provided with power which has not been stepped down or transformed, the other elements may operate at a lower voltage such as 12V DC in the interest of control, efficiency and reliability.
The controller 70 is also coupled to the flow meter 84 over line 106 . The controller operates as a system that controls the operation of the brewer and prevents a “dry plug” condition. A dry plug condition occurs when power is provided to the heating element 36 in advance of the placement of water or at least a sufficient quantity of water into the heated reservoir 34 . The dry plug condition can result in potential damage or unnecessary wear to the system and can be controlled by the controller 70 in accordance with the description herein and the teachings of the method, apparatus and system herein. The controller 70 can also be configured to acknowledge various calibration steps for certain operations when the brewer 20 is first energized. In other words, after initial assembly of the brewer 20 , the controller 70 is configured to recognize when it is first being powered up or when the brewer is powered up after being turned off or not used for an extended period of time.
For example, when a user purchases a brewer employing the present disclosed apparatus and system and method of operation, the controller 70 will recognize that the brewer is plugged in or energized for the first time and that it has not been previously used. This configuration of the controller 70 may also occur by an automatic reset which will occur when the brewer 20 is unplugged or de-energized for a predetermined period of time. After satisfying the predetermined period of time, the brewer will switch over to a “new” or unplugged condition. In this situation, the controller essentially resets as if it were a new brewer requiring the user to recalibrate the system. This requirement for calibrating when it is first used or recalibrating when it has not been used for an extended period of time helps to reduce problems associated with the absence or reduction of water which may occur when the brewer is first being set up for use and after an extended period of time in which it has not been used. Further, the controller 70 can be programmed to time out to shut off the heating element after a predetermined period of time, for example days, weeks or months to prevent excessive evaporation of water in the reservoir.
Using the apparatus, system and method as disclosed, once the controller 70 is powered up via power source 100 , the controller 70 will monitor operation of the flow meter 84 to detect a predetermined number of counts or metering counts. The number of counts relates to the quantity or volume of water which is pumped by the pump 50 to fill the heated reservoir 34 to a desired level. By monitoring the number of counts or volume of water that is pumped, the heated water reservoir will be filled to a sufficient level to allow heating of the water in the tank. If the counts are not monitored, the tank will not have a sufficient quantity of water before the heating element 36 is activated, and thus, there may be a risk to damaging the heating element 36 , reservoir 34 or other components of the system. Also, if the pump 50 does not function the flow meter 84 will sense no counts and the system will prevent heating of the reservoir 34 .
By monitoring the flow meter 84 for a predetermined number of counts, a predetermined quantity of water will be placed in the heated water reservoir 34 before the heater 36 is activated. If a sufficient number of counts are not detected, the controller 70 will prevent activation of the heater 36 . If a sufficient number of counts of the flow meter 84 have been detected, the controller 70 will permit activation of the heater.
Once a predetermined number of counts are detected by the controller 70 , the system will be available to brew beverage, the pump will be allowed to continue to operate to deliver water to the hot water tank and to displace hot water in the tank. It should be noted that a threshold criteria in addition to the number of flow meter 84 counts is to monitor the temperature of the water in the heated water reservoir 34 . Once the temperature of the water in the reservoir 34 has reached a desired brewing temperature as detected by the thermostatic sensor, the pump 50 will then be allowed to continue to operate and pump water from the inlet line 44 to displace water from the reservoir 34 to displace heated water from the reservoir 34 for the brewing cycle in combination with the temperature of the water in the reservoir and/or the operation of the flow meter 84 .
In this regard, a generally known quantity of water is pumped by the pump 50 in a given period of time. This information can be used in combination with the assumption that water is flowing through the line 44 to the pump 50 to operate the pump 50 for a predetermined number of cycles which translates into a predetermined quantity of water being dispensed into the reservoir 34 . In this regard, the pump 50 can be in the form of the gear pump as shown in FIG. 3 or in the form of other types of suitable pumps, such as piston operated pumps, peristaltic pumps or other systems that may be devised for suitable use with such a brewing system.
In use, once the system is activated the pump 50 will be operated in response to instructions from controller 70 for a predetermined time based on the number of cycles detected by the flow meter 84 . If a predetermined number of cycles has been detected the heater will be activated. If other conditions are detected the system may activate an alert by way of controller 70 to the corresponding display/control panel 74 . The display may be visual, auditory or any other means for reporting the condition.
Additionally, it is envisioned that the dry plug method may be employed in a system which provides line fed water through the line 44 without the use of a pump. In this regard, the system may operate to fill the reservoir 34 using line pressure water 64 . In this situation, the flow meter 84 can monitor the flow of water into the reservoir 34 and provide confirmation when a sufficient quantity of water has been dispensed into the reservoir 34 to safely allow activation of the heater 36 .
Also coupled with the water delivery system 32 is a purging assembly 111 . The purging assembly 111 includes the controllable air pump 102 coupled to the controller 70 . In use, at the end of a brewing cycle, the controller 70 operates the air pump 102 to provide a purging volume, flow or pulse of air through an air line 112 . The air line 112 communicates with the delivery line 38 or the beverage assembly 40 . A check valve 113 is provided on the line 112 to prevent backflow from the beverage assembly 40 . When air is pumped through line 112 , remaining water in the pod 130 is moved out of the beverage assembly 40 and into the cup 114 . By purging or moving air through the line and into the line 112 and into the beverage assembly 40 the air helps displace and remove excess water on top of the pod 130 that remains in the beverage assembly or drawer. This helps prevent complications when removing the pod 130 from the assembly 40 . Additionally, the air purging helps insure most of the water in the pod is removed so that the beverage or coffee 115 dispensed into the cup 114 has the benefit of all of the possible flavor components and materials available during a brewing cycle. Further, the air purge helps remove or clear remaining brewing or coffee products such as oils and particulate matter which might be otherwise be retained in the beverage assembly 40 . This removal helps to minimize or eliminate flavor transfer to the next brewing substance used in the next brewing cycle.
The reservoir 30 can be configured to be removable from the housing 24 . At least one, and possibly a plurality of locating legs 116 are provided at the lower portion 28 of the reservoir 30 . The legs 116 engage corresponding receptacles 118 on the corresponding portion of the housing 28 . In this regard, the legs 116 engage the receptacles 118 to help positively locate the reservoir 30 relative to the check valve system 46 . This helps to engage the check valves to provide proper operation of the check valve system. Additionally, a reservoir detecting sensor assembly 120 is was provided with the reservoir 30 and housing 24 . The sensor assembly 120 includes a device carried on the reservoir 30 and the housing 24 for detecting proper placement of the reservoir on the housing. The sensor assembly 120 is coupled to the controller 70 for operation as described in further detail below.
Also provided on the brewing assembly 20 is a mechanical or other form of a lock or retaining system 124 and an assembly detecting sensor 126 . The assembly detecting sensor 126 indicates whether the conditions of the sensor permit brewing through the brewing assembly 40 . The sensor 126 is coupled to the controller 70 . Also provided on a user accessible control panel are a selectable control 140 , a power switch 142 and a brew cycle activation control 144 . The power switch 142 activates and deactivates the power to the system to turn the system on and off. The power system may be located on the front or any other location which is deemed suitable for operation of the brewer 20 . The selectable control 140 allows a user to select a quantity of liquid to be dispensed during the brewing cycle. The quantity of water has an effect on the flavor and characteristics of the brewed beverage as well as adjusting the volume of water. The brew cycle activation switch 144 allows a user to set up all the various components for a brew cycle including the brewing substance 130 and cup 114 and then activate the switch 144 to initiate the brewing cycle.
With reference to the operation of one embodiment of the drawer 25 of the beverage assembly 40 as referred to hereinabove can be found in related provisional application entitled “Apparatus System and Method for Retaining Beverage Brewing Substance” filed Feb. 9, 2005, application Ser. No. 11/055,411. Additional information relating to the adjustable control 140 can be found in related provisional application entitled “Adjustable Volume Brewer” filed Nov. 5, 2004, U.S. application Ser. No. 04/037,106. Additional information related to the spray head system 27 and method for delivering water to the brewing assembly 40 can be found in U.S. Provisional Application entitled “Water Delivery System, Method and Apparatus” filed Nov. 8, 2004, application Ser. No. 10/983,466. Each of the above-referenced applications and the materials set forth therein is incorporated herein in its entirety by reference.
In use, the user dispenses a quantity of water into the reservoir 30 through the opening 60 or the reservoir 30 is automatically filled by the plumbed line 62 receiving line pressure from the facility plumbing. Upon placement of a brewing substance 130 in the brewing assembly 40 , the system checks to determine if the detection sensor 126 senses a closed brewing assembly 40 . If the controller 70 obtains appropriate information indicating that the brewing assembly 40 is, in fact, closed, the brewing cycle will be allowed to proceed. If the controller 70 detects that the brewing assembly 40 is not closed, the process will be stopped and some form of indicator or other indicia may be provided on display 74 coupled to the controller 70 . Assuming that the assembly 60 is closed or that any indicated error has been resolved, the brewing cycle continues.
Proceeding with the brewing cycle during an initial set-up, the controller 70 will operate in one of the ways described hereinabove to provide some water to the heated water reservoir 34 before activating the heater 36 . In this way, the system 20 prevents a “dry plug” condition in which the plug or power source 100 can provide power to the controller but is prevented from activating the heater 36 until the desired quantity of water has been dispensed into the heated water reservoir 34 .
This filling of the heated water reservoir 34 is different than other systems which rely upon level sensing devices positioned in the reservoir. By use of the controller 70 to operate and monitor conditions of related components, there is no need to provide a level sensing device and the associated issues related to maintenance, wear, reliability and cost. Once the system has satisfied the initial fill condition of the heated water reservoir, the heater 36 can be energized to heat the water contained therein subject to additional filling provided by the line 44 and pump 50 .
The brewing process then continues with the initiation of the operation of the pump 50 as controlled by the controller 70 to pump a desired quantity of water through the heated water reservoir 34 .
Pumping of water into the heater assembly 34 results in displacing heated water from the reservoir 34 through the water delivery line 38 . Alternatively, the heating assembly 34 can start with preexisting temperature and heat the liquid to a desired temperature as sensed by the thermostat 94 . Either way, the controller 70 operates the pump 50 for a pre-determined period of time relating to a quantity or volume of water which is to be dispensed to the brewing assembly 40 to produce a desired quantity of brewed beverage. Additionally, the pump 50 can be intermittently controlled to dispense several smaller quantities of water totaling the total volume of water for brewing throughout the brewing cycle to produce a desired brewing result.
During the brewing process, water flows through the water delivery line 38 and into the brewing assembly 40 . At the conclusion of the brewing cycle, operation of the pump 50 is ceased whereby the check valve assembly 56 prevents continued flow of water into the pump assembly 50 . It should be noted, however, that if the embodiment of the brewer includes the valve assembly 86 , some back flow of water from the heater assembly 34 into the pump 50 may occur without draining the heated water tank. The check valve 88 on the water delivery line 52 allows water to flow through during the pumping process but prevents continued flow at the end of the pumping process. The purge assembly 110 is operated at the end of the pumping cycle to push a volume of air through the associated water delivery line 38 and through the corresponding brewing assembly 40 . This helps to purge liquid in the brewing substance 130 and prevent dripping from the brewing assembly 40 at the end of the brewing cycle.
If the brewing assembly 40 is opened, the sensor 126 senses this change and stops the brewing cycle. This helps minimize the quantity of water being dispensed through the water delivery system 32 .
Additionally, at the end of a brewing cycle, the controller 70 will detect whether the sensor 126 has been cycled. This is useful to detect whether the pod 130 , which has been used in the previous brewing cycle, has been removed from the assembly 40 . If the sensor 126 has been cycled, the controller 70 will assume that the pod has been removed. If the controller 70 does not detect cycling of the sensor 126 , it will assume that the pod has not been removed, prevent the start of a brew cycle, and provide some indicia at the display 74 to indicate to the user that the brew pod needs to be changed. The indicia provided at the display 74 may be in the form of lights, audio responses, visual displays or any other form of indicia which will indicate the status, operation or other related information associated with the brewer 20 .
An example of the gear pump 50 as used in the present disclosure might be the type as provided in B&D Pumps, Inc. of Huntley, Ill. Such gear pumps include, for example, a driving gear and a driven gear 200 , 202 . The pumps rotate and operate as shown diagrammatically in FIG. 4 . The supply line 44 supplies water to the pump, whereupon it is moved by rotation of the driving gear and driven gear 200 , 202 to create an output pressure in the inlet line 52 .
The gears 200 , 202 come into and out of mesh to produce flow. The driving gear 200 is operated by a controllable motor coupled to the controller to provide a positive drive. Once the gears 200 , 202 come out of mesh they create an expanding volume on the inlet side 48 of the pump. Liquid flows into the cavity 204 and is trapped by the gear teeth 206 as they rotate. Liquid travels around the interior of the housing 208 in pockets 210 formed between the teeth 206 and the housing 208 . The releasing of the gears on the outlet side 52 tends to force liquid through the outlet port under pressure. Such gear pumps generally provide a constant displacement such that flow is at least generally proportional to the RPM of the drive gear. In one embodiment, the pump 50 is placed at a position which is generally lower than the volume or head of the reservoir 30 to provide a priming action on the pump 50 . The head in the reservoir or line pressure from the inlet line provides positive pressure on the pump to prime it for a brew cycle. While the gear pump 50 is a suitable choice, other pumps may be substituted. Gear pumps may be preferable for some applications because they are relatively quiet and provide long life at an affordable component price range.
One of the advantages of a gear pump (as shown and described herein) is that when the pump is stopped, pressure from the heater assembly 34 such as from expansion water from the tank is allowed to bleed off through the pump 50 . This bleeding-off helps to reduce the drip out by reducing the positive pressure at the water delivery line 52 such that the pressure tends to flow back through the gear pump and into the reservoir 30 .
While embodiments have been illustrated and described in the drawings and foregoing description, such illustrations and descriptions are considered to be exemplary and not restrictive in character, it being understood that only illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. The applicant has provided description and figures which are intended as an illustration of certain embodiments of the disclosure, and are not intended to be construed as containing or implying limitation of the disclosure to those embodiments. There are a plurality of advantages of the present disclosure arising from various features set forth in the description. It will be noted that alternative embodiments of the disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of the disclosure and associated methods that incorporate one or more of the features of the disclosure and fall within the spirit and scope of the present disclosure as set forth in the claims.
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A beverage making apparatus for producing a desired beverage using a heated brewing substance. The apparatus includes a system and method for preventing initiating of a heating cycle when an insufficient amount of water is retained in the apparatus. Additional features of the brewer are provided to facilitate movement of water through the system.
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This application is a continuation-in-part of application Ser. No. 632,551 filed July 19, 1984, now abandoned.
BACKGROUND OF INVENTION
The television and movie industries have increasingly utilized the versatility of a helicopter to film scenes from the air such as vista or panorama views, automobile chases and zoom close-up shots of characters on the ground for added visual effects created by this type of filming. Unfortunately, all helicopters, by their design have a tremendous amount of vibration emitted when the helicopter is in the air, whether it is moving or operating in a stationary hovering position. The turbulence also creates for a non-stable or even a rocking motion of the helicopter while in flight. For example, the swerving back and forth of a helicopter in flight is called yaw or even the pitching of the helicopter which rocks back and forth along its longitudinal axis are problems encountered in actual flight conditions. As a result the cameraman and camera being in the airplane, will correspond with the movement of the helicopter to ruin the camerman's filming sequence. The vertical vibrations inherent in the helicopter is three times that of the horizontal vibration. This is because, as the blades are rotating, the retracting blades stall and create a buffeting effect against the wind as they come around from the back. This is where quite a bit of the vibration is created. Secondly, the pitch of the helicopter blades create a buffeting. The other places where cameras are quite often used is on a moving vehicle to shoot scenes following another car as for example a chase scene or to follow the actors walking over rough terrain where a hydraulic camera mounted boom cannot be used. Either way, the moving vehicle or the following the actors on foot generates vibrations and jerky movements. The movements are transmitted to the camera which results in a fuzzy exposed film, or tape, or a poorly shot scene because of the jerking effect or the vibration caused by the underlying movement of the vehicle or the cameraman. The need was apparent to invent a device which would isolate the movement and to prevent transmission of the vibrations, for example from the helicopter to the camera itself. Hence, the present device was invented to solve these vibration problems.
SUMMARY OF THE INVENTION
The vibration isolator instrument/camera mount is hingedly mounted on a mounting means such as a vertical post or a back pack of some type. A boom has an arm and a camera fully articulated camera tray hanging from one end of the boom. The boom is supported by a connecting brace which connects the other end of the boom to the mounting post. There are two doughnut shaped or double doughnut shaped air springs which are placed between the connecting bar and the boom which is the only connection between the two. All movement or vibration which starts at the mounting post and travels to the connecting bar will be almost entirely dissipated by having these two air springs absorb the vibrations and to isolate the boom and therefore the instrument on the boom from any isolations which have their source in the mounting post. The two air springs and the connecting bar have their axes inclined to the same angle for reducing the overall height of the camera mount and thereby making it a more compact unit. The two air springs are mounted in a cantilevered fashion such that when the horizontal boom is tilted downwardly or there is weight placed on the camera tray, both air springs will compress and when the boom is pivoted or tilted upwardly, both the springs will expand. This added feature tends to keep the boom in a generally horizontal configuration. By adjusting the air pressures of either air spring the generally horizontal attitude of the boom can be changed. The tops and bottoms of each air spring have bolt hole plates for receiving bolts from the various brackets to securely hold the top of the air spring to the connecting bars and the bottoms of the air springs to the boom. The end of the boom has an arm descending therefrom which in turn has a clamp for holding a ball joint having a camera tray attached to the upper end of the ball and a handlebar attached at the lower end of the ball.
There is added versatility in the movement of the boom by means of the pivotal or hinge connection between the camera mount and the mounting post to allow for a tilting of the camera of the entire boom which can be accomplished by pulling down on the handlebars. The boom can be pivoted about the mounting post to allow for a general sweeping of the camera or a given panorama viewing of the scene which can be accomplished by this particular connection. There is also a movable arm at the end of the boom which holds the camera tray. The arm can be rotated about the axis of the boom for raising the level of the camera relative to the cameraman's eye and the arm can be pivoted in a plane parallel with the boom axis as another movement at the disposal of the cameraman. This vibration isolator mount can be used to mount other instruments other than the camera, such as a telescope or gun where the support vehicle transmits vibration to the mount and it is necessary for the accuracy of the instrument to minimize or eliminate any vibrations from passing from the vehicle to the instrument itself. The mount is disclosed and shown as an adjunct for filming from the side door of a helicopter. However, the mount could be a post in a bed of a pick-up truck or a mounting seat of some kind on the roof of a studio car or on a movable telescopic boom attached to a filming car. The mount could be adapted to be supported on a back pack of some type so that the boom could come over the shoulder of the cameraman and the cameraman could shoot while walking to minimize the joustling effect caused when a person walks. The camera isolation mount is useful wherever the supporting vehicle is moving and therefore has vibrations or other types of movements which should not be transmitted to the camera. Otherwise, there would be poor resolution; the clarity of the exposed film or tape is reduced because of the vibration. This vibration is especially prevalent in a helicopter where by the very engineering and design of the helicopter, even when it is hovering or in a stationary position, there is a tremendous amount of vibration. The vibration is transmitted to a camera mount or a cameraman holding a camera free style which results again in a poorly developed film or tape.
In an alternative embodiment of the invention, there is provided a gas spring and an adjustment dial for counterbalancing the weight of the camera when placed on the camera mount. The adjustment dial is at its minimum rotation without any camera mounted on the camera tray. After the camera is placed upon the camera tray, the weight of the camera will cause the boom to tilt downwardly. The preliminary adjustment to the boom causes the boom to be at a generally horizontal attitude with the camera mounted. After this preliminary adjustment, the cameraman is positioned on the seat and then fine tunes the adjustment dial for his own particular preference. The gas spring positioned between the mount and the camera boom functions as a buffer or stabilizer after the adjustment dial has been zeroed in. The compressed gas spring resists up and down pivotal movement of the boom, and the boom will return to its preset position or attitude by the user of the device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a front elevational view of the camera mount and the modified helicopter seat as if one were looking through the windshield of the helicopter. The boom is projecting from the passenger's door. Arc A indicates that the helicopter has a horizontal vibration when it is airborne causing the helicopter seat to rock back and forth at a high frequency; however, the boom and camera tray remain stationary during this movement because of the absorption of the movement by the air springs. The extent of the movement of the helicopter is exaggerated in the figures.
FIG. 2 is a side elevational view taken from the viewpoint of the pilot's eyes and showing in arc B that the movement of the helicopter, when it is pitching back and forth, still allows the steady positioning of the camera tray and camera because the air springs are compensating for the pitch movement of the helicopter.
FIG. 3 is another front elevational view of the camera mount indicating by arc C and the arm that the boom and camera tray can be pivoted or reciprocated in a vertical plane.
FIG. 4 is a top plan view of the camera mount indicating that the boom and camera tray can be reciprocated in the horizontal plane as indicated by arc D and is accomplished by rotation at the mounting post.
FIG. 5 shows the top plan view where there is pivotal movement of the arm while the boom is stationary as indicated by arc E.
FIG. 6 shows that when the boom and arm and helicopter movement are stationary, that the camera tray can be pivoted in a horizontal plane about its axis along the arc F.
FIG. 7 is a front elevational view showing where the motion of the helicopter is stationary; the boom is stationary, the arm is stationary and the camera tray can be rotated in the vertical plane of the ball point axis along the arc G.
FIG. 8 shows a side elevational view looking into the door of the passenger side indicating that the camera tray can be pivoted in the vertical plane along the arc H.
FIG. 9 is a side elevational view of the mount attached to a helicopter seat and illustrating the counterbalancing adjustment from an at rest position to a nearly maximum downward pivot of the boom. This view shows the opposite side of the mount from that shown in FIGS. 1, 3, and 7.
FIG. 10 is an enlarged fragmentary view of the adjustable stabilizer and supportive structure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 7 is a front elevational view of the vibration isolator camera mount, and the modified helicopter seat with the mounting post. This view is taken as if one were looking through the windshield of the helicopter from the outside. The boom normally projects transversely from the flight path of the helicopter. That is, the cameraman is shooting from the side of the helicopter. FIG. 7 shows the stationary position of the mount without any movements other than illustrating the articulation of the camera mount and tray. In FIG. 7, there are basically two parts to the disclosure. The vibration isolator camera mount is generally described as No. 10.
The mounting means 12 includes the modified helicopter seat 14, vertical mounting post 16 and the hinge means 18 for attachment to the vibration isolator camera mount.
The camera mount generally described as 10 is further described as follows: There is a generally vertical connecting bar 50 which is pivotally attached at one end to the hinge 18 of the mounting means 12. The connecting bar 50 is generally in a slanted configuration to reduce the overall height of the camera mount for allowing use in smaller spaces such as a helicopter cockpit. There is disclosed a generally horizontal boom indicated by No. 52. At the rear of the boom is a first base plate 54 which is welded to the boom 52 at the end of the boom and having a generally 45° rake to the base plate 54. Somewhat forward of this first base plate 54 is a second base plate 56 which corresponds to the first base plate 54 and is also welded to the boom.
Referring back now to the connecting bar 50, the upper end of the bar has a first bar bracket 60 welded to its top. The base of the connecting bar 50 has a second bar bracket 62 clearly shown in FIG. 2. The second base plate 56, the second bar bracket 62, the first bar bracket 60, and the first base plate 54 all have bases at the same angle of inclination so that the first air spring 80 and the second air spring 82 are attachable between their respective brackets and also in the same longitudinal attitude as the connecting bar 50. The entire combination here is generally described as a spring means. The first air spring 80 is generally described as a first spring means and the second air spring 82 is generally described as a second air spring means. The axis of the first spring 80, the second spring 82, and the connecting bar 50 are all inclined to the same angle. The first air spring 80 and the second air spring 82 are attached in a cantilevered position. The two air springs are in an opposed relationship so that when the boom 52 is tilted downwardly, both air springs are compressed and when the boom 52 is tilted upwardly, both springs expand to the same extent. The top and bottom to either air spring is identical other than in the sense that the connecting bolts may have a different pattern when it is connected to the bar bracket 60 versus the base plate 54. The air springs 80 and 82 generally have a double doughnut shape with an unrestricted air passage between the two doughnut cavities. The springs are made by Goodyear Tire Company. They are generally described as a super cushion air spring which is a hollow spring having double convolute bellows. The diameter of each doughnut is 31/2 inches. There is a pneumatic valve on each spring for applying pressurized air to modify the air pressure within the air springs. The amount of air pressure is generally about 5 lbs., per square inch when there is a 30 to 35 lb., camera mounted on the camera tray. Both air springs are offset from the center of gravity of the mount to correspond with the boom 52 to create a balanced mount when it is attached to the mounting post 16.
The air spring 80 has a top plate which receives bolts from the first bar bracket 60 to secure the connecting bar to the top of the air spring 80. Likewise, the bottom of the spring also has a plate for receiving bolts which are passed through the base plate 54 and are screwed into the bottom of the air spring for securing the spring to the plate. The bottom of the air spring 82 has a plate for receiving bolts passed through the second base plate 56 for securing the bottom of the second air spring 82 to the boom. The top of the second air spring 82 is secured or attached to the second bar bracket 62 by a plate for threadably receiving bolts passed through the second bar bracket 62 for securing the two together.
In another embodiment of this invention, each air spring could be substituted by other damping means such as a helical coil in place of each air spring (not shown), or a helical coil in combination with a shock absorber connecting the base plates and the bar brackets (also not shown).
Now referring to FIG. 8 which shows a side-elevational view of the camera mount as if one were viewing into the door of the passenger side of the helicopter. The horizontal boom 52 is shown from the end view and to this boom 52 is attached an arm 100 which is secured to the end of the boom by a clamping means 102. The clamping means is used to hold the arm in a stationary position. The arm is rotatable about the boom's axis by unloosening the clamp 102 and setting the arm 100 at any angle desired. The arm has a second joint 104 which is more clearly shown in FIG. 5 which allows the arm to be pivoted in a horizontal plane about its axis along the arc E. This joint can be tightened down with a bolt to inhibit the movability of the arm in this arc. Attached to the base of the arm 100 is a ball joint means 105 disclosed as a spherical ball object clamped between two frames to allow universal movement of the camera tray 106 which is attached at one end of the ball joint 105. The ball joint has a camera tray attached at its upper end and a handle bar 108 attached at its lower end so that by moving the handle bars the camera tray will be changed in its attitude correspondingly. Shown in FIG. 8, the camera tray can be pivoted in the vertical plane along the arc H and in FIG. 6 it is indicated that the camera tray can be pivoted in a horizontal plane about its axis along the arc F. The base of the camera is attached to the top of the camera tray as is shown in phantom lines in FIG. 1. The camera used can be a 1/2 inch video tape camera for example, or a 35 mm camera. The weight of the camera can range upwards of 35 lbs. The tension spring means 13 can be adjusted to compensate for the various weight factors of the cameras used in the shooting sequences. It is forseeable that other instruments could be mounted at the upper end of the ball joint. For example, the camera tray could be modified to act as a mount for a machine gun, or another type of weapon; it could be modified to hold a telescope or even a SLR camera. None of these instruments are disclosed and shown in the drawings but it is to be understood that the application for this mount would be applicable for a wide variety of instruments wherein the sensitivity of the instrument requires isolation of vibrations from the mounting vehicle.
FIG. 9 illustrates an alternative embodimant of the invention which utlilizes an adjustable stablizer for counterbalancing the weight of a camera placed upon the camera tray. In the one embodiment, as shown in FIG. 7, there is disclosed a tension spring 13 which is adjustable by rotating a knurled knob 11. These two features are replaced by another type of means as disclosed in FIG. 9 and further enlarged in FIG. 10. There is disclosed a leg 200 attached to the base of the connecting bar 50. There is a brace means, illustrated as a brace 202, being rigidly attached to the mounting post 16. The brace 202 forms a housing and a track for a locator 204 which is a metal block having a threaded whole therethrough. The locator 204 is of such dimension that it can travel on the track of the brace 202. There is illustrated a dial 206 attached to a threaded rod 208, which in turn is meshed with the locator 204. By rotationg the dial counterclockwise or clockwise, the locator will slide back and forth within the confines of this track. The lower end of the leg 200 has a connection means and there is a point at the base of the locator 204 which also has a connection means. Between these two connection means there is attached a gas spring 210. This gas spring is not to be confused with the two air springs 80 and 82. This gas spring 210 replaces the tension spring 13 in this alternative embodiment. The gas spring is a generic term used for this telescoping type of shock absorber. It is made by a company entitled Sacks in the Federal Republic of Germany. The Sacks gas spring contains a type of nitrogen air and fluid so that the gas spring can extend and contract but will only do so under a uniform amount of resistance either in the telescoping, or the extendsion, or the contraction of the spring. One purpose of this adjustable stablizer is to counterbalance the effect of the weight of the camera when placed upon the camera tray.
The resistance to the downward tilting of the boom is modified by the attitude of the gas spring 210 relative to the leg 200, because as the dial 206 rotates the locator 204, the angle between the gas spring 210 and the leg 200 increases. The geometry between the locator 204, the gas spring 210 and the bottom of the leg 200 is such that as the gas spring moves from the vertical towards the horizontal, there is more resistance created on the base of the leg 200. This can be seen in FIG. 10 in phantom lines where the gas spring is at its minimum and its maximum orientation. As can be seen, when the gas spring is at its minimum vertical orientation and, in this case, the adjustment dial will be at its minimum, there is no resistance being placed on the base of the leg 200. The forced relationship is such that when the gas spring is in the vertical orientation, there is no force--very little if any resistance applied to the leg 200 and, accordingly, the pivoting of the leg will be based upon the general distribution of the weight over the pivot mount. In one embodiment, the gas spring 210 could be mounted horizontally and to another lower brace extending from the mounting post. However, it is unneccessary to position the gas spring in the totally horizontal attitude to have the maximum resistance to the pivoting of the boom. However, the gas spring has a limitation on the track length as disclosed in FIG. 10. Within these preactical maximum angular displacements of the gas spring 210 relative to the vertical, it was found sufficient to adjust the added weight ofthe camera tray and this also minimized the space taken up by this counterbalancing brace. The interior of the helicopter is so confining initially that any added features to the camera mount must be very compact to avoid taking up the entire seat space available within a helicopter. However, this is not a critical limitation when the camera is mounted for use in other types of vehicles where the interior space is not critical. In another embodiment not disclosed it could be conceivable that there would be a lower brace attached to the post extending from the post so that there is a space for placement of a gas spring horizontally between the lower mounting post and the bottom of the leg 200.
The weight of the camera or an instrument will cause the boom to pivot downwardly. The boom should be in a generally horizontal position when filming so that the attitude of the boom has to be brought back up to the horizontal position. This is done by turning the dial 206 which in turn causes the locator to go forward or backwards which in turn causes the attitude of the gas spring 210 to go from the vertical to a slanted position. At its maximum slanted position would be the position where there is the most resistance to the leg 200. By turning the dial the boom will rise to a generally horizontal level. This is the zeroing in position for any type of camera to be mounted on the camera tray. In use, the gas spring 210 also functions as a resistance whenever the boom is pivoted on the mounting post by the cameraman. Either pivoting the boom upwardly or downwardly is met with the resistance of the gas spring 210. This built in resistance after the boom has zeroed in causes the boom to go at its at rest position which has been dialed in to be a generally horizontal attitude. At the present, these Sacks gas springs are purchased with a pre-set presssure. A 90-lb. pressure has been found to be appropriate whenever the instrument, such as a camera weighing between 0-17-lbs. A 120-lb. pressure has been found to be appropriate when the camera or instrument weight ranges from 12 to 30-lbs. However, it is foreseeable that one gas spring could have an adjustable air pressure so that the one gas spring would be compatible with any weight of camera and the pressure would be adjusted to correspond with the weight of the instrument on the camera tray.
OPERATION OF THE CAMERA MOUNT
The mount is constructed so that there will be several axes which provide movement for the cameraman to give him unlimited versatility when positioning the camera or shooting a particular scene while sitting in the helicopter seat. FIG. 1 indicates the pitching or rocking back and forth or vibration of the helicopter seat shown greatly exaggerated in FIGS. 1 and 2. The camera tray, and accordingly the camera, will remain stationary because these vibrations are absorbed by the air springs. FIG. 3 shows the tilting ability of the entire camera mount by the pivotal movement on the hinge 18.
The movement of the boom 52 is shown through the arc C. FIG. 4 is a top plan view illustrating that the entire camera mount can be rotated about the mounting post by means of the rotation clamp 17 which can be loosened to provide this rotation ability.
FIG. 5 indicates that the arm 100 can be swung back and forth along the arc E. FIG. 6 indicates that the camera tray 106 be can be pivoted or rotated about the arc F by means of turning the handlebars FIG. 7 indicates that the camera tray can be rotated vertically about the arc G by turning the handlebars and FIG. 8 indicates that the camera tray can again be rotated about the arc H in the z plane. As indicated the camera tray can be rotated in the xyz plane by means of the ball joint combination. The mount can be initially adjusted for a particular cameraman for use. For example, the horizontal boom has a telescopic extension and has a clamp 53 which can be loosened to telescope out the boom to extend it or contract it. As previously stated, the tension spring 13 has the knob 11 which can be turned in or out to adjust the tension between the end of the bar 50 and the mounting post 16. This tension restricts the tilting movement as indicated in FIG. 3 and to counter the weight of the various types of instruments placed on the camera tray. The air pressure and the air springs can be adjusted to modify the amount of the tensioning effect of this device. The spring 13 could be replaced with a hydraulic shock absorber/coil spring combination.
In an alternative embodiment of this tension adjusting means there is illustrated a leveler stablizer in FIGS. 8 and 9. In this embodiment, after the instrument has been placed on the camera, the boom will droop or pivot downwardly because of the weigth of the camera. To counterbalance this effect, the dial length is rotated so that the boom returns to its generally horizontal position. When the cameraman needs to pull down or raise the boom by pushing up or down on the handlebars, he is met with resistance caused by the gas spring. This resistance always causes the boom then to return to its at rest adjusted horizontal postion.
DESCRIPTION OF THE MOUNTING MEANS
FIG. 1 has the base of the seat cut away, the helicopter seat to indicate that there is a brace 15 which acts as a support for the vertical post 16. The helicopter seat disclosed here has the same dimensions as the seat in the passenger side of a helicopter and the original seat can be removed and this modified seat inserted in its place. The camera mount can be used in combination with other mounting means. For example, this type of mount would be very useful when filming from a moving vehicle such as a pick-up or a studio truck of some kind. In this situation the mounting post 16 could be directly bolted to the bed of the pick-up. Again it could be a modified seat bolted into the aforesaid vehicle. Additionally, there could be a modified holster or back pack which would hold the mounting post in some way so that the springs and brace bracket would be behind the walking cameraman and the boom would be projecting over the right shoulder of the cameraman and the arm and the camera tray and the handlebars would be roughly at chest level so that the cameraman could site directly into the view finder of the camera. In effect, this would be a type of articulated camera mount.
The mounting post 16 can be modified to telescope up and down to adjust for varying heights and clearances, especially in different models of helicopters.
While the present invention has been shown and described herein in what is conceived to be the best mode contemplated, it is recognized that departures may be made therefrom within the scope of the invention which is therefore not to be limited to the details disclosed herein, but is to be afforded the full scope of the invention.
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The vibration isolator and camera mount/instrument mount is mounted on a modified helicopter seat and mounting post. The entire mount is attached to the post by a connecting bar which in turn holds the horizontal boom. The boom has an arm attached on one end which holds a ball joint for holding a camera tray and handlebar for a full xyz planar movement of the camera. Between the boom and connecting bar are two opposed air springs which are positioned in a cantilevered format so that any vibration which passes from the helicopter seat to the mounting bar is absorbed by the pair of air springs. The air springs are pneumatic and comprised of an inflatable pair of doughnut shaped structures which absorb the vibration and therefore isolates and stops any transmission of vibrations to the boom. The camera is isolated from the foundation's vibrations. The air springs also function to maintain the boom in the generally horizontal position. There are several articulations or adjustments built into this mount so that the cameraman can follow or shoot the assigned scene with very little effort in moving the eye of the camera and the various articulations allows the cameraman an almost infinite amount of angles to focus in on the particular scene. The mount itself can be adapted for use in a land vehicle or strapped onto the back of the cameraman for walking and filming the scene at the same time.
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TECHNICAL FIELD
[0001] The present invention relates generally to micro electro-mechanical system (MEMS) radio frequency (RF) devices and methods for forming the same and, more particularly, to a tunable RF MEMS switch with a piezoelectric thin film actuator.
BACKGROUND OF THE INVENTION
[0002] Heretofore, radio frequency (RF) microelectromechanical system (MEMS) switches have utilized an electrostatic force or electrothermal actuation to actuate the RF MEMS switch. In a typical electrostatic RF MEMS switch, at least 30 volts may be required to open and close the switch. Consequently, the switch is not suitable for applications such as commercial handheld products, which typically operate on 3 volts or less. The electrostatic RF MEMS switch also is limited in its operation, as it can only be open or closed, that is, either in contact or not in contact. For this reason, the electrostatic RF MEMS switch is not suitable as a tunable capacitor, as such devices typically require controlled variance in the displacement of the actuation beam.
[0003] Electrostatic RF MEMS switches also suffer from a well known problem known as stiction, which occurs when surface tension forces are higher than the spring restoring force of the actuator beam. Stiction may be caused by a wet etching process used during fabrication, which may leave some moisture or meniscus which pulls the beam towards the electrode and prevents the beam from releasing. Alternatively, or additionally, stiction may occur during operation, whereby the beam stays in a deflected position due to capillary forces, electrostatic attraction, or direct chemical bonding. Stiction is a major problem of electrostatic RF MEMS switches, oftentimes rendering the switch inoperable.
[0004] Electrostatic RF MEMS devices also may require additional fabrication steps, particularly RF MEMS devices requiring high quality frequency performance. Such devices are typically fabricated using RF-compatible substrate materials such as GaAs, ceramics, and high resistivity silicon. According to one technique, an RF circuit is fabricated from an RF-compatible substrate and an actuator is fabricated on a silicon wafer, and then the circuit and actuator are assembled using flip chip technology. Since the silicon has a low resistivity which may interfere with the RF performance of the circuit, typically a switch manufacturer removes the silicon, leaving only the actuator on the RF circuit. For high volume applications, this additional silicon removal step may be quite costly.
[0005] Electrothermal actuated devices also are not without drawbacks. The function of an electrothermal actuator depends on the mismatching of the thermal expansion rates of different dimensioned actuator beams. The electrothermal actuator has some limitations such as slower tuning and more space requirements. Moreover, the manufacturing process of electrothermal actuators involves critical design considerations such as temperature distribution and heat sink placement. In operation, the beam is heated by applying a current (Joule heating), causing the beam to move due to the differing expansion rates of the materials forming the beam. Once actuated, however, the beam must cool down in order to return to its original position. Controllably cooling down the beam is difficult, as the amount of time to sufficiently cool the beam oftentimes is not ascertainable or is met with inconsistent results. Although the actuator may be made smaller to reduce its cooling time, the cooling time still cannot be controlled effectively to vary the interelectrode spacing and hence the capacitance between the electrodes. For this reason, the electrothermal MEMS switch is usually employed as a one-way switch rather than a two-way switch or a tunable capacitor.
SUMMARY OF THE INVENTION
[0006] The present invention provides a radio frequency (RF) microelectromechanical system (MEMS) device with a piezoelectric thin film actuator. The RF MEMS device provides one or more improved performance characteristics such as a low operating voltage, a variable RF tuning capacity, fewer stiction problems, simplified fabrication, and an improved switching time. Also, the RF MEMS device is relatively small in size and relatively inexpensive to manufacture, making it a desirable for a wide variety of military and commercial applications. For example, the RF MEMS device may be applied in low signal loss switches, phase shifters, filters and receivers for radar and communication products, and wireless consumer and infrastructure products. Moreover, advantageously, the RF MEMS device may be employed as a tunable capacitor in which the interelectrode spacing between a conducting path electrode and an RF path electrode is controllably varied by an actuator beam in order to selectively vary the capacitance between the electrodes.
[0007] According to one particular aspect of the invention, there is provided an RF MEMS device, including an RF circuit substrate and an RF conducting path disposed on the RF circuit substrate, a piezoelectric thin film actuator, and a conducting path electrode. The piezoelectric thin film actuator has a proximal end that is fixed relative to the RF circuit substrate and a cantilever end that is spaced from the RF circuit substrate. The conducting path electrode is disposed on the cantilever end of the piezoelectric thin film actuator. The cantilever end of the piezoelectric thin film actuator is movable between a first position whereat the conducting path electrode is spaced from the RF path electrode and a second position whereat the conducting path electrode is spaced from the RF path electrode a second distance, wherein the second distance is less than the first distance.
[0008] In an embodiment of the invention, the piezoelectric thin film actuator includes a first electrode, a second electrode, and a piezoelectric layer disposed between the first and second electrodes such that when a voltage potential is applied to the first and second electrodes, the piezoelectric layer expands or contracts longitudinally.
[0009] In another embodiment of the invention, the piezoelectric thin film actuator includes an elastic layer disposed on the second electrode such that the elastic layer converts the longitudinal expansion or contraction of the piezoelectric layer into transverse movement of the cantilever end of the piezoelectric thin film actuator.
[0010] In another embodiment of the invention, the first electrode and second electrode include a layer of platinum or other suitable conducting material. Also, the elastic layer of the piezoelectric thin film actuator may include a layer of silicon nitride or a layer of silicon dioxide.
[0011] In an embodiment, the piezoelectric layer has a thickness between about 4500 and about 5500 Angstroms (Å). The elastic layer may have a thickness in the range of between about 0.95 microns (μm) and about 1.65 microns (μm). The first and second electrodes may have a length in the range of about 300 microns (μm) and about 500 microns (μm). In an embodiment, the first and second electrodes have a width between about 100 microns (μm) and about 150 microns (μm).
[0012] In another embodiment of the invention, the conducting path electrode is transverse the longitudinal extent of the piezoelectric thin film actuator and has a width between about 90 microns (μm) and about 110 microns (μm).
[0013] In yet another embodiment of the invention, the RF path electrode includes an RF-in path electrode and an RF-out path electrode, each extending transverse the piezoelectric thin film actuator, wherein the RF-in and RF-out path electrodes are spaced apart by a gap L. In such arrangement, the conducting path electrode may be transverse the longitudinal extent of the piezoelectric thin film actuator and have a length at least as long as the gap L between the RF-in and RF-out path electrodes.
[0014] In an embodiment of the invention, the conducting path electrode is spaced from either of the first and second electrodes by an isolation region to prevent any electric field from the conducting path electrode to the first and second electrodes, or vice versa.
[0015] In an embodiment of the invention, the RF circuit substrate includes a GaAs layer.
[0016] According to another aspect of the invention, there if provided a method for manufacturing an RF MEMS device, including the steps of providing an RF circuit substrate with an RF conducting path disposed on the RF circuit substrate, fabricating a piezoelectric thin film actuator having a proximal end and a cantilever end, providing a conducting path electrode on the cantilever end of the piezoelectric thin film actuator, assembling the piezoelectric thin film actuator to the RF circuit substrate so that the proximal end is fixed relative to the RF circuit substrate and the cantilever end is spaced from the RF circuit substrate, and so that the cantilever end of the piezoelectric thin film actuator is movable between a first position whereat the conducting path electrode is spaced from the RF path electrode and a second position whereat the conducting path electrode is spaced from the RF path electrode a second distance, and wherein the second distance is less than the first distance.
[0017] In an embodiment of the invention, the step of forming the piezoelectric thin film actuator includes providing a multi-layer material including a protective layer, a semiconductor layer, an elastic layer, a first conductor layer, a piezoelectric layer, and a second conductor layer, the piezoelectric layer being disposed between the first and second conductor layers. The step of forming the piezoelectric thin film actuator may include, for example, patterning and etching the first conductor layer, the piezoelectric layer and the second conductor layer to form a first electrode, a piezoelectric layer, and a second electrode. The step of providing the conducting path may include patterning and etching the first conductor layer, the piezoelectric layer and the second conductor layer to form the conducting path electrode, wherein the conducting path electrode is spaced from either the first or second electrode by an isolation region formed by the piezoelectric layer. The step of providing the conducting path electrode may include patterning and etching a trench region in the semiconductor layer which has a footprint larger than the cantilever ends of the respective first and second electrodes and the piezoelectric layer disposed therebetween. Still further, a portion of the elastic layer laterally of and longitudinally beyond the cantilever end of the first and second electrodes and the piezoelectric layer therebetween may be removed to thereby release the cantilever end of the piezoelectric thin film actuator from the elastic layer to enable the cantilever end to be moved within the trench region.
[0018] In another embodiment of the invention, the step of assembling the piezoelectric thin film actuator to the RF circuit substrate includes using flip chip technology to assemble the piezoelectric thin film actuator to the RF circuit substrate.
[0019] To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1 a is a top plan view of a radio frequency (RF) microelectromechanical system (MEMS) device in accordance with the present invention.
[0021] [0021]FIG. 1 b is a side elevational view of the RF MEMS device of FIG. 1 a as seen from the plane 1 b - 1 b in FIG. 1 a.
[0022] [0022]FIG. 1 c is a cross-sectional view of the RF MEMS device of FIG. 1 a as seen from the plane 1 c - 1 c in FIG. 1 a.
[0023] [0023]FIG. 1 d is a cross-sectional view of the RF MEMS device of FIG. 1 a as seen from the plane 1 d - 1 d in FIG. 1 b.
[0024] [0024]FIG. 2 is a flow chart of a method of making a radio frequency (RF) microelectromechanical system (MEMS) device in accordance with the present invention.
[0025] [0025]FIG. 3 a is a top plan view of a multi-layer material which illustrates a starting structure of the method of making the RF MEMS device in accordance with the present invention.
[0026] [0026]FIG. 3 b is a side elevational view of the starting structure of FIG. 3 a as seen from the plane 3 b - 3 b in FIG. 3 a.
[0027] [0027]FIG. 4 a is a top plan view of an intermediate structure of the method of making the RF MEMS device in accordance with the present invention.
[0028] [0028]FIG. 4 b is a side elevational view of the intermediate structure of FIG. 4 a as seen from the plane 4 b - 4 b in FIG. 4 a.
[0029] [0029]FIG. 5 a is a top plan view of an intermediate structure of the method of making the RF MEMS device in accordance with the present invention.
[0030] [0030]FIG. 5 b is a side elevational view of the intermediate structure of FIG. 5 a as seen from the plane 5 b - 5 b in FIG. 5 a.
[0031] [0031]FIG. 6 a is a top plan view of an intermediate structure of the method of making the RF MEMS device in accordance with the present invention.
[0032] [0032]FIG. 6 b is a side elevational view of the intermediate structure of FIG. 6 a as seen from the plane 6 b - 6 b in FIG. 6 a.
[0033] [0033]FIG. 7 a is a top plan view of an intermediate structure of the method of making the RF MEMS device in accordance with the present invention.
[0034] [0034]FIG. 7 b is a side elevational view of the intermediate structure of FIG. 7 a as seen from the plane 7 b - 7 b in FIG. 7 a.
[0035] [0035]FIG. 8 a is a top plan view of an intermediate structure of the method of making the RF MEMS device in accordance with the present invention.
[0036] [0036]FIG. 8 b is a side elevational view of the intermediate structure of FIG. 8 a as seen from the plane 8 b - 8 b in FIG. 8 a.
[0037] [0037]FIG. 9 a is a top plan view of an intermediate structure of the method of making the RF MEMS device in accordance with the present invention.
[0038] [0038]FIG. 9 b is a cross-sectional view of the intermediate structure of FIG. 9 a as seen from the plane 9 b - 9 b in FIG. 9 a.
[0039] [0039]FIG. 10 a is a top plan view of an intermediate structure of the method of making the RF MEMS device in accordance with the present invention.
[0040] [0040]FIG. 10 b is a cross-sectional view of the intermediate structure of FIG. 10 a as seen from the plane 10 b - 10 b in FIG. 10 a.
[0041] [0041]FIG. 10 c is a side elevational view of the intermediate structure of FIG. 10 a as seen from the plane 10 c - 10 c in FIG. 10 a.
[0042] [0042]FIG. 11 a is a cross-sectional view of an RF MEMS device achieved as a result of the method of making an RF MEMS device in accordance with the present invention.
[0043] [0043]FIG. 11 b is a side elevational view of an RF MEMS device achieved as a result of the method of making an RF MEMS device in accordance with the present invention.
[0044] [0044]FIG. 11 c is a cross-sectional view of the RF MEMS device of FIG. 11 b as seen from the plane 11 c - 11 c in FIG. 11 b.
DETAILED DESCRIPTION OF THE INVENTION
[0045] In the detailed description which follows, identical components have been given the same reference numerals, regardless of whether they are shown in different embodiments of the present invention. To illustrate the present invention in a clear and concise manner, the drawings may not necessarily be to scale and certain features may be shown in somewhat schematic form.
[0046] Referring initially to FIGS. 1 a - 1 d, a radio frequency (RF) microelectromechanical system (MEMS) device 10 according to the present invention is shown. The device 10 includes a semiconductor substrate 14 , a piezoelectric thin film actuator 16 mounted on the substrate 14 , a conducting path electrode 18 driven by the piezoelectric thin film actuator 16 , conductive bumps 22 which are connected to an external voltage source (not shown) and provide the voltage necessary for operating the device 10 , an RF circuit substrate 24 , and RF-in and RF-out path electrodes 32 and 34 mounted on the RF circuit substrate 24 so as to be spaced from the conducting path electrode 18 . The piezoelectric thin film actuator 16 is fabricated in conjunction with the semiconductor substrate 14 and transferred to the RF circuit substrate 24 using flip chip technology, for example. It is noted that in the illustrated embodiment the bumps shown in the right side of FIGS. 1 a - 1 d act as spacers, although the bumps could alternatively form part of another device, if desired.
[0047] The piezoelectric thin film actuator 16 may comprise any suitable material having piezoelectric properties, for example, lead zirconate titanate (PZT). Because the invention was conceived and developed in the context of a PZT piezoelectric material, it is described herein chiefly in such context. However, the underlying principles of the invention could be achieved with other piezoelectric materials with advantageous results.
[0048] The PZT thin film actuator 16 includes a pair of electrodes 40 and 42 , a piezoelectric layer 44 made of lead zirconate titanate (PZT) disposed between the electrodes 40 and 42 , and an elastic layer 50 disposed between the electrode 40 (the upper electrode in FIGS. 1 b and 1 c ) and the semiconductor substrate 14 .
[0049] An isolation layer 52 is provided adjacent the elastic layer 50 and prevents or at least substantially reduces electrical arcing between the 40 and 42 . The PZT thin film actuator 16 has a fixed proximal end 54 (the left end in FIGS. 1 a - 1 c ) adjacent the semiconductor substrate 14 and a free distal end 56 (the right end in FIGS. 1 a - 1 c ) extending into a trench region 60 of the substrate 14 . The PZT thin film actuator 16 thus forms a cantilever beam which is moveable within the trench region 60 .
[0050] In the illustrated exemplary embodiment, the conducting path electrode 18 is transverse the longitudinal extent of the PZT thin film actuator 16 . Thus, in FIGS. 1 b and 1 c the conducting path electrode is perpendicular to the plane of the page. Similarly, the RF-in and RF-out path electrodes 32 and 34 are transverse the longitudinal extent of the PZT thin film actuator 16 , as is shown in FIG. 1 d.
[0051] The RF MEMS device 10 in accordance with the invention may be used as a switch with controllable displacement or as a tunable capacitor for varying the capacitance between the electrodes 32 and 34 . During operation, the RF MEMS device 10 changes the distance of the gap between the conducting path electrode 18 and the RF-in and RF-out path electrodes 32 and 34 . More particularly, as the voltage source increases and decreases the voltage potential applied to the electrodes 40 and 42 , the PZT layer 44 changes its dimension in length, that is, the PZT layer 44 respectively expands and contracts. The elastic layer 50 , in turn, converts the expanding and contracting of the PZT layer 44 into upward and downward movement of the cantilevered or distal end portion 56 of the PZT thin film actuator 16 . When bent downward, the distal end 56 urges the conducting path electrode 18 closer to or in contact with the RF-in and RF-out path electrodes 32 and 34 . When bent upward, the distal end 56 urges the conducting path electrode 18 away from the RF-in and RF-out path electrodes 32 and 34 .
[0052] The PZT thin film actuator 16 thus actively controls the displacement between the conducting path electrode 18 and the RF-in and RF-out path electrodes 32 and 34 . The amount of displacement depends on mainly the driving voltage, and the dimensions of the PZT thin film actuator 16 , including the dimensions of the PZT layer 44 and the elastic layer 50 . As will be appreciated, alternative piezoelectric materials may have different piezoelectric properties than that of PZT and, consequently, alternative embodiments which may have such alternative piezoelectric materials may result in different amounts of displacement.
[0053] When employed as a switch, the RF MEMS device 10 can close the spacing between the conducting path electrode 18 and the RF-in and RF-out path electrodes 32 and 34 , and thus turn on the switch, or open the spacing and thus turn off the switch. The RF MEMS device may also employed as a tunable capacitor in which the interelectrode spacing between the conducting path electrode 18 and the RF-in and RF-out path electrodes 32 and 34 is controllably varied by the PZT thin film actuator 16 in order to selectively vary the tuning capacitance therebetween.
[0054] It has been found that the RF MEMS device 10 with the PZT thin film actuator 16 provides accurate and precise beam displacement control with improved tuning capacitance range, eliminates or substantially reduces static charges collecting on the conducting path electrode 18 and the RF path electrodes 32 and 34 , improves tuning reliability, improves switching speed, provides high RF performance, and reduces the required driving voltage. It has been found, for example, that the RF MEMS device 10 operates on one or two volts instead of the approximately 30 to 40 volts used for a conventional RF MEMS switch. Also, as was previously alluded to, because the displacement of the PZT thin film actuator 16 can be varied by varying the voltage applied to the RF MEMS device 10 , the RF MEMS device 10 may be used as either a tunable capacitor or an RF MEMS switch. Accordingly, the RF MEMS device 10 is not limited to the on/ff nature of electrostatic switches. The switching time of the RF MEMS device 10 is on the order of nanoseconds, which is comparatively better than that of electrothermal RF MEMS switches, which typically have a switching time on the order of milliseconds or microseconds. In addition to the foregoing functional advantages, the RF MEMS device 10 is a relatively simple structure packaged in a relatively small volume.
[0055] The steps of a method 100 for fabricating a radio frequency (RF) microelectromechanical system (MEMS) device 110 in accordance with the present invention are outlined in the flow chart shown in FIG. 2. FIGS. 3 - 10 illustrate various steps of the method 100 . It will be appreciated that the method 100 and the RF MEMS device 110 described below are merely exemplary, and that suitable variations in materials, thicknesses, and/or structures may alternatively be used in the method 100 and/or the RF MEMS device 110 .
[0056] Initially in step 102 , a multi-layer starting material or stack used to form an RF MEMS device 110 in accordance with the invention is provided. As is shown in FIGS. 3 a and 3 b, the stack includes a semiconductor substrate 112 , a protective layer 114 below the substrate 112 , and an elastic layer 116 atop the substrate 112 . A first conductor layer 120 , a piezoelectric layer 126 , and a second conductor layer 130 are atop the elastic layer 116 , in that order. In the illustrated exemplary embodiment, the piezoelectric layer 126 is made of lead zirconate titanate (PZT). As will be appreciated, alternative suitable piezoelectric materials may be employed as the piezoelectric layer 126 .
[0057] It will be appreciated that well-known materials and methods may be used to form the stack shown in FIGS. 3 a and 3 b. A suitable semiconductor substrate 112 material may be silicon (Si), for example. The protective layer 114 and elastic layer 116 may be made of silicon nitride (Si 3 N 4 ) or silicon dioxide (SiO 2 ), for example. The conductor layers 120 and 130 may be made of platinum (Pt) or other suitable conducting materials. Also, although not specifically shown in the several figures, an adhesion layer made of, for example, tantalum (Ta), may be disposed between the conductor layer 120 and the elastic layer 116 to improve the adhesion of the conductor layer 120 to the elastic layer 116 .
[0058] In the illustrated exemplary embodiment of the method 100 for fabricating the RF MEMS device 110 , the PZT layer 126 has a thickness between about 4500 and about 5500 Angstroms (Å), and the elastic layer 116 has a thickness between about 0.95 microns (μm) and about 1.65 microns (μm) for silicon nitride, and between about 1.35 microns (μm) and about 1.65 microns (μm) for silicon dioxide.
[0059] In step 140 of the method 100 , the top conductor layer 130 is patterned and etched down to the PZT layer 126 . In particular, portions of the conductor layer 130 are removed, thereby leaving an upper conductor pad 144 , an upper PZT actuator electrode 146 , a conducting path electrode 152 , and three spacers or bumps 154 , 155 and 156 , as shown in FIGS. 4 a and 4 b.
[0060] It will be appreciated that suitable selective etching methods are well-known in the art. For example, a mask may be placed on the stack to protect portions of the underlying layers. Formation of the mask may involve depositing a photoresist on the stack, patterning the photoresist, exposing portions of the photoresist such as by selective light exposure, and removing unexposed portions of the photoresist through use of a suitable etching technique, for example, dry etching or wet etching.
[0061] In the illustrated exemplary embodiment of the method 100 of fabricating the RF MEMS device 110 , the upper PZT actuator electrode 146 has a length (from left to right in FIG. 4 a ) between about 300 microns (μm) and about 500 microns (μm), and a width between about 100 microns (μm) and about 150 microns (μm). The conducting path electrode 152 has a width (from left to right in FIG. 4 a ) between about 90 microns (μm) and about 110 microns (μm). The length of the conducting path electrode 152 (from top to bottom in FIG. 4 a ) is based mainly on the width of the conducting path electrode 152 , as well as an RF circuit to which the stack is later mounted, and the distance between the RF-in conducting path and the RF-out conducting path, described below in greater detail with reference to FIGS. 10 a - 10 c. The distance between the distal end of the upper PZT actuator electrode 146 (the rightmost portion of the upper PZT electrode in FIG. 4 a ) and the conducting path electrode 152 is at least about 100 microns (μm). It will be appreciated that other dimensions may also be suitable, depending on, for example, the desired amount of deflection to be provided by the PZT thin film actuator beam.
[0062] Thereafter, in step 160 , the PZT layer 126 is patterned and etched down to the bottom conductor layer 120 . In step 160 , a new photoresist is deposited and patterned so that portions of the PZT layer 126 are removed, thereby leaving the upper conductor pad 144 , the upper PZT actuator electrode 146 , the conducting path electrode 152 , and the three bumps 154 , 155 and 156 , as well as a PZT isolation region 170 , as shown in FIGS. 5 a and 5 b. The PZT isolation region 170 provides high isolation in that it prevents any electric field of the conducting path electrode 152 from extending to the upper PZT actuator electrode 146 , or vice versa. In the illustrated exemplary embodiment, the isolation region 170 is at least about 100 microns (μm) wide.
[0063] In step 180 , illustrated in FIGS. 6 a and 6 b, a pattern and etch of the bottom conductor layer 120 is performed to form a lower conductor pad 184 and a lower PZT actuator electrode 186 , leaving the structure shown in FIGS. 6 a and 6 b. Thus, much of the surface area that is removed from the bottom conductor layer 120 is similar to that which was removed from the top conductor layer 130 and the PZT layer 126 , except that the bottom conductor layer 120 additionally forms the lower conductor pad 184 . The lower conductor pad 184 is about the same size and shape in plan view as the upper conductor pad 144 (FIG. 6 a ), and includes a conducting leg or path 188 extending to the lower PZT actuator electrode 186 , which is disposed below the PZT layer 126 and the upper PZT actuator electrode 146 .
[0064] In step 190 , an isolation layer 192 of silicon nitride or silicon dioxide is deposited on the structure shown in FIGS. 7 a and 7 b, and then patterned for the existing conducting path electrode 152 and three bumps 154 , 155 and 156 , as well as for the formation of a new bump 204 (to be formed later) in the upper left corner of FIG. 7 a, and a bridge post 194 on the upper conductor pad 144 and the upper PZT actuator electrode 146 . The isolation layer 192 prevents or at least substantially reduces electrical arcing between the upper and lower PZT actuator electrodes 146 and 186 .
[0065] In step 200 , a new photoresist (not shown) is deposited on the structure shown in FIGS. 7 a and 7 b, and then patterned for the existing conducting path electrode 152 and three bumps 154 , 155 and 156 , the new bump 204 (to be formed later), and a bridge base 208 (also to be formed later) extending from the upper conductor pad 144 to the upper PZT actuator electrode 146 . Thereafter, in step 220 , illustrated in FIGS. 8 a and 8 b, a relatively thin layer, for example one micron (μm), of TiAu 222 is sputtered on the photoresist layer. The photoresist layer controls the deposit of the TiAu to the conducting path electrode 152 , the bridge base 208 and the bumps 154 , 155 , 156 and 204 . The TiAu base layer 222 improves the adhesion of a conductive layer such as gold (to be deposited later). As will be appreciated, any suitable material to improve the adhesion of gold may be used, for example, NiCr/Au, Ta/Au, or Cr/Au. For the sake of clarity, the TiAu layer of the conducting path electrode 152 and the bumps 154 , 155 , 156 and 204 is shown in FIGS. 8 a and 8 b to identify the positions at which the TiAu is sputtered on the underlying material.
[0066] Thereafter, in step 230 , a photoresist 232 (FIGS. 9 a and 9 b ) is deposited on the structure shown in FIGS. 8 a and 8 b, and then patterned for the conducting path electrode 152 , the bridge base 208 and the bumps 154 , 155 , 155 and 204 . In step 240 , a layer of gold 238 is then plated on the exposed portions not covered by the photoresist 232 to form the conducting path electrode 152 , a bridge on the bridge base 208 , and the bumps 154 , 155 , 156 and 204 . As is shown in FIG. 9 b, the height of the gold bumps 154 , 155 , 156 and 204 is greater than the height of either the gold bridge 208 or the gold conducting path electrode 152 . As will be appreciated, alternative materials to gold may be used, for example, copper.
[0067] Next, in step 250 , a protective layer (not shown) made of, for example, silicon nitride is deposited on the top surface of the stack of FIGS. 9 a and 9 b. The protective layer provides a mask or etch protection for the top surface. Then, in step 260 , the bottom protective layer 114 is patterned to form a trench region 262 . As is shown in FIGS. 10 a and 10 b, the semiconductor layer 112 is etched to form the trench region 262 therein. The trench region 262 has a footprint larger than the distal end of the upper and lower PZT actuator electrodes 146 and 186 and the PZT layer 126 disposed therebetween. The depth of the trench region 262 is through the thickness of the semiconductor layer 112 , that is, to the elastic layer 116 . The width of the trench region 262 (from top to bottom in FIG. 10 a ) is greater than the length of the conducting path electrode 152 , and the length of the trench region 262 (from left to right in FIG. 10 a ) is greater than the combined width of the isolation region 170 and the conducting path electrode 152 .
[0068] In step 270 , the top protective layer and the bottom protective layer 114 are etched. Then, in step 280 , illustrated in FIGS. 10 a - 10 c, the photoresist layer 232 for gold plating is removed, the TiAu layer that is not the conducting path electrode 152 is removed, the bridge 208 and the bumps 154 , 155 , 155 and 204 are removed, and the photoresist layer for the TiAu sputtering is removed.
[0069] In step 290 , also illustrated in FIGS. 10 a - 10 c, the elastic layer 116 is removed in the region 292 laterally of, and the region 294 longitudinally beyond, the distal end of the upper and lower PZT actuator electrodes 146 and 186 and the PZT layer 126 . Removing the elastic layer 116 in such a manner releases the distal end of the PZT thin film actuator 296 from the semiconductor substrate 112 . The distal end of the PZT thin film actuator 296 is thus movable up and down (in FIG. 10 b ) within the trench region 262 and, in this regard, functions in a manner similar to a cantilever beam. As will be appreciated, the desired amount of flexure in the cantilevered end of the PZT thin film actuator 296 may be defined by the length of the trench region 262 and the length of the cantilevered end of the PZT thin film actuator 296 .
[0070] Thereafter, in step 300 , illustrated in FIGS. 11 a - 11 c, the PZT thin film actuator 296 is mounted to an RF circuit substrate 302 using, for example, flip chip technology. The RF circuit substrate 302 in one embodiment is made of a suitable RF compatible material, for example, GaAs or ceramics. The resulting structure is the RF MEMS device 110 . As is shown in FIGS. 11 a and 11 b, the bumps 154 , 155 , 156 and 204 provide spacing between the PZT thin film actuator 296 and the RF circuit substrate 302 . Also, because the height of the bumps 154 , 155 , 156 and 204 is greater than the height of either the bridge 208 or the conducting path electrode 152 , the bridge 208 and conducting path electrode 152 are elevated from the RF circuit substrate 302 .
[0071] As is shown in FIG. 11 c, an RF-in conducting path 304 and an RF-out conducting path 306 are disposed on the RF circuit substrate 302 . The RF-in and RF-out conducting paths 304 and 306 are spaced apart by a gap L. As was alluded to above, the length of the conducting path electrode 152 is based mainly on the width of the conducting path electrode 152 and the gap L between the RF-in and RF-out conducting paths 304 and 306 . In the illustrated exemplary embodiment of the RF MEMS device 110 , the gap L between the RF-in and RF-out conducting paths 304 and 306 is about 100 microns (μm) and the length of the conducting path electrode 152 is about 250 microns (μm).
[0072] Although the invention has been shown and described with respect to certain illustrated embodiments, equivalent alterations and modifications will occur to others skilled in the art upon reading and understanding this specification and the annexed drawings. In particular regard to the various functions performed by the above described integers (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such integers are intended to correspond, unless otherwise indicated, to any integer which performs the specified function of the described integer (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.
[0073] The present invention includes all such equivalents and modifications, and is limited only by the scope of the following claims.
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A radio frequency (RF) micro electro-mechanical system (MEMS) device and method of making same are provided, the device including an RF circuit substrate and an RF conducting path disposed on the RF circuit substrate, a piezoelectric thin film actuator, and a conducting path electrode. The piezoelectric thin film actuator has a proximal end that is fixed relative to the RF circuit substrate and a cantilever end that is spaced from the RF circuit substrate. The conducting path electrode is disposed on the cantilever end of the piezoelectric thin film actuator. The cantilever end of the piezoelectric thin film actuator is movable between a first position whereat the conducting path electrode is spaced from the RF path electrode and a second position whereat the conducting path electrode is spaced from the RF path electrode a second distance, wherein the second distance is less than the first distance. The RF MEMS device is particularly useful as a tunable capacitor. The RF MEMS device requires lower operating voltage, and provides variable RF tuning capacity, fewer stiction problems, simplified fabrication, and an improved switching time.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of prior International Application PCT pplication No. PCT/KR2015/002111 filed on Mar. 5, 2015, which claims the benefit of priority from Korean Patent Application No. 10-2014-0026922 filed on Mar. 7, 2014 and Korean Patent Application No. 10-2015-0030387 filed on Mar. 4, 2015. The disclosures of International Application PCT Application No. PCT/KR2015/002111 and Korean Patent Application Nos. 10-2014-0026922 and 10-2015-0030387 are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a technique of drug delivery, and more particularly, to a micelle which includes a bubble capable of delivering a drug effectively to a human body and is manufactured by using cavitation caused by ultrasounds; and a method for manufacturing the micelle.
BACKGROUND OF THE INVENTION
[0003] In general, a microbubble has a shell and includes gas in the shell. As it is found out in the recent studies that microbubbles have an excellent effect of enhancing contrast of ultrasonic images, studies for using such microbubbles as ultrasonic contrast agents are on a trend.
[0004] FIGS. 1A and 1B are exemplary diagrams that explain conventional microbubbles used as ultrasonic contrast agents.
[0005] By referring to FIG. 1A , the microbubbles used as ultrasonic contrast agents may have an engineered shape.
[0006] More specifically, given through Cryo-TEM images, the microbubbles used as the ultrasonic contrast agents can be confirmed to be comprised of internal gas 11 and a thin shell 13 protecting the gas as shown in FIG. 1B .
[0007] In general, the gas 11 contained in the microbubble may be inert gas with a high stability. The shell 13 protecting the gas may increase the stability of the microbubble 10 and may be comprised of a variety of substances including bio-compatible lipid, phospholipid, protein, etc.
[0008] However, recently, studies not only for introducing microbubbles as ultrasonic contrast agents but also for introducing them to a drug delivery system are actively conducted.
[0009] As a conventional technique, since ultrasounds can cause cavitation effectively in case of microbubbles used as ultrasonic contrast agent, efforts to make a drug be delivered to a human body are made by forming a very thin shell with the size of less than tens of nanometers (by uniformly attaching a required drug or a ligand binding substance to the shell 13 of the microbubble.
[0010] However, according to the conventional technique, since the drugs are combined with the surfaces of the shells, the drugs may be lost while the microbubbles are moved to a target position. Thus, the conventional microbubbles cannot perform a role effectively as drug carriers. In addition, the conventional microbubbles cannot load a great amount of drugs.
SUMMARY OF THE INVENTION
[0011] It is an object of the present invention to solve all the aforementioned problems.
[0012] It is another object of the present invention to provide a micelle, including a microbubble, capable of delivering drug safely to a human body efficiently.
[0013] It is still another object of the present invention to provide a method for manufacturing a micelle easily applicable to treatment of all diseases.
[0014] In accordance with one example embodiment of the present invention, a micelle includes a microbubble formed by irradiating ultrasounds to a solution into which liquefied inert gas and a drug for treatment of a disease are mixed together and evaporating the liquefied inert gas, wherein the micelle comprises: the microbubble as a form of cavity, wherein the micelle is a unit structure enclosed by a shell, and wherein the micelle delivers the drug to a human body.
[0015] In accordance with one example embodiment of the present invention, the unit structure is capsule-shaped.
[0016] In accordance with one example embodiment of the present invention, the microbubble is a space formed by the evaporation of the liquefied inert gas in the solution due to cavitation caused by the ultrasounds.
[0017] In accordance with one example embodiment of the present invention, the liquefied inert gas is perfluorobutane.
[0018] In accordance with one example embodiment of the present invention, the solution is manufactured by mixing perfluorobutane and a pre-manufactured mixture in which at least one of saline solution, glycerol, propylene glycol, and powdered phospholipid at temperature range between −15° C. and 5° C. and then mixing the drug for the treatment of the disease.
[0019] In accordance with one example embodiment of the present invention, the shell provides a space where the drug left in a liquid state after the evaporation of the liquefied inert gas.
[0020] In accordance with one example embodiment of the present invention, the drug loaded to the unit structure is changeable to make the micelle applicable to treatment of at least one disease.
[0021] In accordance with another example embodiment of the present invention, a method for manufacturing a micelle capable of delivering a drug, includes the steps of: manufacturing a first solution by mixing liquefied inert gas and a pre-manufactured mixture; manufacturing a second solution by mixing the drug for treatment of a disease with the first solution; and forming a microbubble in the micelle by irradiating ultrasounds to the second solution to create cavitation in the second solution.
[0022] In accordance with another example embodiment of the present invention, the pre-manufactured mixture is manufactured by mixing at least one of saline solution, glycerol, propylene glycol, and powdered phospholipid.
[0023] In accordance with another example embodiment of the present invention, at the step of manufacturing the first solution, perflouorobutane as the liquefied inert gas is mixed with the pre-manufactured mixture at temperature range between −15° C. and 5° C.
[0024] In accordance with another example embodiment of the present invention, at the step of manufacturing the second solution, the micelle is applicable to treatment of at least one disease by changing the drug to be mixed with the first solution.
[0025] In accordance with another example embodiment of the present invention, at the step of forming the microbubble in the micelle, the microbubble is formed by the evaporation of the liquefied inert gas in the second solution due to cavitation caused by the ultrasounds if the ultrasounds are irradiated to the second solution and the capsule-shaped micelle, which includes the microbubble as a form of cavity and is enclosed by a shell that provides a space, where the drug left in a liquid state after the evaporation of the liquefied inert gas, is formed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:
[0027] FIGS. 1A and 1B are exemplary diagrams that explain conventional microbubbles used as ultrasonic contrast agents.
[0028] FIG. 2 is an exemplary diagram illustrating a configuration of a micelle including a bubble for drug delivery in accordance with an example embodiment of the present invention.
[0029] FIG. 3 is an exemplary diagram explaining shapes of micelles including bubbles for drug delivery in accordance with an example embodiment of the present invention.
[0030] FIG. 4 is an exemplary diagram explaining a composition ratio of a micelle including a bubble for drug delivery in accordance with an example embodiment of the present invention.
[0031] FIG. 5 is an example explaining detail components of a micelle including a bubble for drug delivery in accordance with an example embodiment of the present invention.
[0032] FIGS. 6A and 6B show exemplary diagrams explaining a method for identifying a drug loaded to a micelle including a bubble for drug delivery in accordance with an example embodiment of the present invention.
[0033] FIGS. 7A to 7C illustrate exemplary diagrams in which a drug loaded to a micelle including a bubble for drug delivery is identified through confocal images in accordance with an example embodiment of the present invention.
[0034] FIGS. 8A to 8D depict exemplary diagrams in which a drug loaded to a micelle including a bubble for drug delivery is identified through microscopic images in accordance with an example embodiment of the present invention.
[0035] FIG. 9 is an exemplary diagram in which the drug loaded to a micelle including a bubble for drug delivery is identified through electrophoresis in accordance with an example embodiment of the present invention.
[0036] FIG. 10 is a graph representing a result identified through electrophoresis in accordance with an example embodiment of the present invention.
[0037] FIG. 11 is a flow chart explaining a method for manufacturing a micelle including a bubble for drug delivery in accordance with an example embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] The present invention may be applied to various changes and have several embodiment examples. Specific example embodiments will be illustrated in drawings and detailed explanation will be made. But it must be understood that these are not intended to limit the present invention to the specific example embodiments and include all changes, equivalents or substitutes included in the thought and technical scope of the present invention. In the drawings, like numerals refer to the same or similar functionality throughout the several views.
[0039] Terms such as first, second, A, and B may be used to explain a variety of components, but the components must not be limited by such terms. The terms are used only for the purpose of distinguishing one component from others. For example, a first component may be named as a second one without being out of the scope of the rights of the present invention and similarly, the second component may be named as the first one. A term “and/or” includes one or combination of items written in the plural forms.
[0040] When a certain component is mentioned to be “connected” or “accessed” to another one, it may be directly connected or accessed to the another component but it must be understood that there may be another component in-between. Meanwhile, when a certain component is mentioned to be “directly connected” or “directly accessed” to another one, it must be understood that there is no component in-between.
[0041] The terms used in this application are used only to explain specific example embodiments, but this is not intended to limit the present invention. Unless otherwise apparently specified in a context, a single expression includes a plural expression. In the present application, it must be understood that terms such as “include”, “have” are intended to designate that there exists characteristics, numerals, steps, motions, components, parts, or their combinations in the specification but the possibility of being or adding one or more other characteristics, numerals, steps, motions, components, parts, or their combinations is not excluded.
[0042] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meanings generally understood by a person having ordinary skill in the technical field of the present invention. The terms generally used and pre-defined must be interpreted to have the same meanings to those in the context of relevant technology, and unless clearly defined in the present application, they are not construed as having ideal or excessively formal meanings.
[0043] Detailed explanation on desirable example embodiments in accordance with the present invention will be made below by referring to the attached drawings.
[0044] FIG. 2 is an exemplary diagram illustrating a configuration of a micelle including a bubble for drug delivery in accordance with an example embodiment of the present invention and FIG. 3 is an exemplary diagram explaining shapes of micelles including bubbles for drug delivery in accordance with an example embodiment of the present invention.
[0045] FIG. 4 is an exemplary diagram explaining a composition ratio of a micelle including a bubble for drug delivery in accordance with an example embodiment of the present invention and FIG. 5 is an example explaining detail components of a micelle including a bubble for drug delivery in accordance with an example embodiment of the present invention.
[0046] By referring to FIGS. 2 to 5 , a shape of a micelle 20 which includes a microbubble may be explained.
[0047] In the past, a microbubble was used as an ultrasonic contrast agent, but, recently, studies for making the microbubbles play a role for drug delivery have been actively conducted.
[0048] Therefore, a bubble was set to be formed by strongly shaking, or irradiating strong ultrasounds while gas was mixed with a shell. This causes the shell to exist between the gas and a liquid as a polar fluid to thereby create a monolayer. Herein, the monolayer includes hydrophobic parts of the shell which contact the gas and hydrophilic parts thereof which contact a solution.
[0049] To make the shell thick, as the case may be, a method for removing moisture from the shell by freezing the shell rapidly at lower pressure and then additionally attaching a substance to the shell was used. However, it was difficult to include a fluid in the shell if several procedures were not repeated.
[0050] Therefore, after a micelle was made by rapidly mixing a mixture liquid with a lipid (typically, phospholipid) or irradiating ultrasounds to a fluid and then rapidly freezing it at ultra-low pressure for the evaporation of some liquid in the micelle, the left shell after the evaporation of the liquid was made to be used again. However, a phospholipid bilayer shell may be formed, but it was difficult to allow enough amount of drug to be contained inside the micelle.
[0051] Accordingly, the present invention proposes a method for forming a micelle which includes a microbubble, a shell, and an intermediate layer between the microbubble and the shell where a drug is loaded by mixing gas at a state of liquid with a solution and then raising the temperature of the mixed solution in use of ultrasounds. Herein, the boiling point of the gas may be relatively high.
[0052] Herein, the micelle 20 may have the liquid part and the microbubble capable of delivering a drug in the liquid part to a target position. The micelle 20 in accordance with the present invention is more effective than the conventional micelle which loads a drug in its surface of a shell because the micelle 20 can load a greater amount of the drug.
[0053] The micelle 20 may include a microbubble 21 , a shell 23 and a drug 25 .
[0054] In detail, the micelle 20 includes the microbubble 21 with a form of cavity to deliver the drug to a human body. Further, the micelle 20 has a shape of capsule enclosed by the shell 23 . Between the microbubble 21 and the shell 23 , the drug 25 may be loaded for disease treatment.
[0055] First of all, the microbubble 21 may mean a space formed from the evaporation of liquefied inert gas included in a solution due to cavitation caused by ultrasounds. In detail, the ultrasounds are irradiated onto the solution, in which the liquefied inert gas and the drug for disease treatment are mixed together.
[0056] Herein, the inert gas may be perflouorobutane but it is not limited to this. This inert gas may be easily mixed with a pre-manufactured mixture because the boiling point of the perflouorobutane is −2.56° C.
[0057] Besides, the solution is manufactured by mixing the perfluorobutane and the pre-manufactured mixture in which at least one of saline solution, glycerol, propylene glycol, and powdered phospholipid at temperature range between −15° C. and 5° C. and then mixing the drug for the treatment of the disease.
[0058] The reason of mixing the pre-manufactured mixture with the perflouorobutane at the temperature range between −15° C. and 5° C. is that the pre-manufactured mixture may be easily mixed.
[0059] The drug 25 for the disease treatment may be included in liquid left after the liquefied inert gas is evaporated from the solution and it may be loaded between the microbubble 21 and the shell 23 . Herein, since the drug mixed in the solution can be changed, the micelle 20 can deliver various kinds of drugs to various human body. Therefore, it may be applied to treatment of a variety of types of diseases.
[0060] The shell 23 may make the drug reach the human body safely by maintaining the space where the drug is loaded.
[0061] In detail, as shown in FIG. 3 , the micelles 20 include the microbubbles 21 which are represented as relatively brightest parts; the drugs 25 which are represented as dark parts enclosing the microbubbles 21 ; and the shells 23 formed outermost to keep the space where the drugs 25 are loaded. Therefore, the micelles 20 may be capsule-shaped.
[0062] For example, each of the micelles 20 may mean an echogenic liposome which can be affected by ultrasounds. The Liposome mostly has a shape of capsule such as circular or oval shape. As illustrated in FIG. 4 , the microbubble 21 corresponds to gas core with a portion of 45.20% of the micelle 20 , the drug 25 at the state of liquid occupies 47.34% of the micelle 20 , and the shell 23 occupies 7.46% of the micelle 20 .
[0063] More specifically, as shown in FIG. 5 which represents an echogenic liposome, if radiation is applied to a solution in which phospholipid such as DPPC and DPPA is mixed through a transducer of ultrasound equipment, hydrophilic parts may access the liquid and hydrophobic parts avoid the liquid. Herein, the hydrophobic parts may be assembled with one another. This may cause a bilayer structure with a thickness of approximately 7 nanometers to thereby form the shell 23 .
[0064] At the time, the microbubble 21 formed by perflouorobutane and the drug 25 including siRNA effective to a gene therapy may be contained inside the shell 23 .
[0065] Accordingly, when the echogenic liposome is destroyed, siRNA as a drug once protected inside the shell 23 may be delivered to the human body.
[0066] As explained above, the drug 25 for the disease treatment may be loaded to the micelle 20 and then be delivered to the human body. Detailed methods for identifying a drug loaded in the micelle will be explained in FIGS. 6 to 10 below.
[0067] FIGS. 6A and 6B show exemplary diagrams explaining a method for identifying a drug loaded to a micelle including a bubble for drug delivery in accordance with an example embodiment of the present invention.
[0068] Besides, FIGS. 7A to 7C illustrate exemplary diagrams in which a drug loaded to a micelle including a bubble for drug delivery is identified through confocal images in accordance with an example embodiment of the present invention; FIGS. 8A to 8D depict exemplary diagrams in which a drug loaded to a micelle including a bubble for drug delivery is identified through microscopic images in accordance with an example embodiment of the present invention; and FIG. 9 is an exemplary diagram in which the drug loaded to a micelle including a bubble for drug delivery is identified through electrophoresis in accordance with an example embodiment of the present invention.
[0069] In addition, FIG. 10 is a graph representing a result identified through electrophoresis in accordance with an example embodiment of the present invention.
[0070] By referring to FIG. 6 , a drug loaded in the micelle can be identified by removing siRNA from a solution, in which siRNA with a size of 3 μm is mixed with a predetermined mixture, i.e., a mixture of micelles and perflouorobutane with a ratio of 1:100, through a vialmixer, in use of a 3-way stopcock, a syringe filter, and RNase as an enzyme cutting RNA.
[0071] For example, if a 100 μm micelle is manufactured and a drug is loaded in the micelle, a syringe filter with a size of 10 μm is installed and the syringe is compressed. Then, as the size of siRNA is smaller than that of the filter, the siRNA is filtered by a vial just as shown in FIG. 6A and only the micelle is left. At the time, if RNase is added and then extraction is performed with a 3-way stopcock as shown in FIG. 6B to remove the siRNA that might be left in the shell of the micelle, only the micelle from which the drug has been removed is left. It can be found out not only that the drug has been loaded to the micelle but also which kind of drug has been loaded through this.
[0072] As explained above, the micelle and the drug loaded in the micelle may be visually identified by using a variety of methods.
[0073] First of all, they can be identified through confocal images as shown in FIG. 7 .
[0074] More specifically, FIG. 7A is an original image including multiple micelles A in different sizes and shapes and FIG. 7B is an image identified by fluorescently staining siRNA B with the wavelength of 488 nm. If the image of FIG. 7C , which is an image acquired by combining FIG. 7A and the FIG. 7B , is looked into, even though the RNA has been removed with the RNase, it can be found out that the position of siRNA B appearing in the fluorescent image is similar to that of the micelles A. Through this, it can be identified that the drug siRNA is protected by the micelle.
[0075] In addition, the micelle and the drug loaded in the micelle can be identified through microscopic images as illustrated in FIG. 8 .
[0076] More specifically, FIG. 8A is an original image including multiple micelles in different sizes and shapes and FIG. 8B is an image visualized by fluorescently staining the lipid, i.e., substance of the shell of the micelle, with the wavelength of 534 nm. Besides, FIG. 8C is an image visualized by fluorescently staining siRNA as a drug contained in the micelle with the wavelength of 488 nm. If the image of FIG. 8D , which is an image acquired by combining FIG. 8B and FIG. 8C , is looked into, it can be found out that FIG. 8B depicting the image of the shell of the micelle and FIG. 8C representing the siRNA contained in the micelle, are overlapped approximately by 88%. Through this, it can be noticed that the drug contained in the micelle is capsuled and protected by the shell of the liposome.
[0077] Finally, the micelle and the drug loaded in the micelle can be identified through electrophoresis as illustrated in FIG. 9 .
[0078] More preferentially, I in FIG. 9 is an image representing pure siRNA and II therein is an image showing a state of the pure siRNA to which the ultrasounds have been irradiated. Besides, III is an image illustrating a pure micelle, and IV is an image depicting a state of the micelle mixed with the siRNA. V is an image illustrating a state of the mixture of the micelle and the siRNA to which the ultrasounds have been irradiated while VI shows a state in which the shell is removed from the mixture of the micelle and the siRNA by using a filter and VII illustrates a state in which ultrasounds are irradiated after the shell has been removed from the mixture of the micelle and the siRNA by using the filter. Besides, VIII depicts a state in which RNase is added after the siRNA has been mixed with the micelle and IX is an image representing a state in which the ultrasounds are irradiated after RNase inhibitor is used to remove the RNase left after the RNase has been applied to the mixture of the micelle and the siRNA.
[0079] The respective results of electrophoresis as shown in FIG. 9 can be identified through graphs expressing percentages according to a band line as shown in FIG. 10 . In comparison between a bar graph f illustrating the course of VI in FIG. 9 and a bar graph g representing the course of VII, if the ultrasounds are irradiated after the shell is removed from the micelle mixed with the siRNA by using the filter, it can be confirmed that the band line increases roughly by 20% because the siRNA having been protected by the shell gives an influence over the band signal due to the destruction of the shell of the micelle. Accordingly, it can be drawn that the siRNA is protected by the micelle through this.
[0080] Additionally, it can be confirmed from a bar graph h illustrating the course of VIII in FIG. 9 that the band signal barely appears due to the dissipation of the siRNA by the RNase because the siRNA has been mixed with the micelle and then the RNase has been added. Furthermore, it can be identified through a bar graph i depicting the course of IX in FIG. 9 that the band signal of approximately 20% is formed due to the siRNA left in the micelle.
[0081] Through this, it can be easily identified that the drug can be loaded in the micelle for treatment of diseases.
[0082] FIG. 11 is a flow chart explaining a method for manufacturing a micelle including a bubble for drug delivery in accordance with an example embodiment of the present invention.
[0083] By referring to FIG. 11 , a method for manufacturing the micelle may include steps of: manufacturing a first solution by mixing liquefied inert gas and a pre-manufactured mixture at a step of S 100 ; manufacturing a second solution by mixing a drug with the first solution at a step of S 200 ; and forming a microbubble in the micelle by irradiating ultrasounds to the second solution at a step of S 300 .
[0084] More specifically, to manufacture the micelle, the first solution is manufactured by mixing the liquefied inert gas and the pre-manufactured mixture at a step of S 100 .
[0085] Herein, the pre-manufactured mixture may be manufactured by mixing at least one of saline solution, glycerol, propylene glycol, and powdered phospholipid.
[0086] For example, to manufacture the first solution, saline solution of 50 ml and glycerol of 2.5 ml are mixed first and then propylene glycol of 52.5 ml is mixed. Then, Dipalmitoyl Phosphatidyl Choline (DPPC) of 0.1 g and Diphenoxy Phosphoryl Azide (DPPA) of 0.01 g are mixed with the above-mentioned mixture including the saline solution, the glycerol and the propylene glycol; and then a revised mixture including the saline solution, the glycerol, the propylene glycol, DPPC and DPPA is heated through a hot plate at 60° C. roughly for 30 minutes, thereby completing the manufacture of the “pre-manufactured mixture” mentioned at the step of S 100 . At the time, because DPPC and DPPA are powder like substances, the heating time through the hot plate may refer to a time when DPPC and DPPA are all melt but it is not limited to this. The time can be adjusted depending on the temperature.
[0087] After that, the pre-manufactured mixture of 2000 μl is extracted by using a micropipette and then kept in a vial of 2 ml. Then, the liquefied inert gas of 20 μl is mixed with the pre-manufactured mixture of 2000 μl kept in the vial of 2 ml by using the micropipette and then it is shaken for 45 seconds by using a Vialmix device.
[0088] Herein, perflouorobutane is used as the inert gas in that the boiling point of the perflouorobutane is −2.56° C. and the perflouorobutane can be easily mixed with the pre-manufactured mixture. Accordingly, the liquefied perflouorobutane and the pre-manufactured mixture may be mixed together at the temperature range between −15° C. and 5° C. at which they can be easily mixed.
[0089] Thereafter, the first solution can be manufactured by filtering it (the mixture of the inert gas and the pre-manufactured mixture) in use of a membrane filter of 100 μm selected by referring to a bubble size.
[0090] Herein, the perflouorobutane is used as the inert gas but it is not limited to this.
[0091] Then, as explained above, the second solution may be manufactured by mixing a drug for diseases treatment with the first solution at a step of S 200 .
[0092] Accordingly, if the drug to be put into the first solution is changed, an appropriate drug applicable to treatment of at least one of diseases, e.g., cancers, skin diseases, brain diseases, and gene therapies, can be loaded to the micelle.
[0093] Therefore, the micelle which includes a microbubble can be created by irradiating the ultrasounds into the second solution to cause cavitation in the second solution at a step of S 300 .
[0094] Herein, the cavitation caused by ultrasounds means a phenomenon in which an empty space filled with gas is created in a liquid solution due to ultrasounds. In detail, the gas in the liquid gathers at a place at which the pressure is low in the liquid solution if the ultrasounds are irradiated into the liquid solution.
[0095] In other words, if the ultrasounds are irradiated to the second solution, the microbubble can be formed in the second solution due to the evaporation of the liquefied inert gas through the cavitation caused by the ultrasounds.
[0096] At the time, the drug left after the liquefied inert gas has been evaporated in the second solution is loaded at a liquid state in an intermediate layer between the microbubble and the shell and the shell may enclose the drug to allow the drug at the liquid state to be delivered safety to the human body by maintaining the intermediate layer at the liquid state.
[0097] As a result, the micelle may be formed to include a microbubble as a form of cavity and has a shape of a capsule enclosed by the shell and the drug can be safely delivered to the human body.
[0098] As explained above, in accordance with one example embodiment of the present invention, the micelle and a method for manufacturing the micelle can deliver the drug safely to the human body efficiently.
[0099] Besides, it is easily applicable to the treatment of all diseases because a drug to be loaded may be changed depending on a type of a disease.
[0100] Explanation has been made by referring to the desirable example embodiments of the present invention, but it could be understood that a person having ordinary skill in the technical field of the present invention may modify and change the present invention variously within the scope not exceeding the thought and area of the present invention described in the scope of the claims below.
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Disclosed are a micelle containing bubbles for drug delivery and a method for manufactuing the same. The micelle formed according to the present invention includes microbubbles fromed by evaporating the liquiefied inert gas due to the irradiation of ultrasonic waves to a solution in which the liquefied inert gas is mixed with a drug for disease treatment, and the micelle is formed as a unit structure in which the microbubbles are contained in a cavity and the cavity is enclosed in a shell, and delivers the drug to the human body. Therefore, the micelle can protect a material of the drug, which is delivered to the human body, as well as deliver a larger amount of the drug than the existing technique, and can be easily applied to the treatment of various diseases.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the general art of beds, and to the particular field of accessories for beds.
2. Discussion of the Related Art
Many people become bedridden for various times. These times can vary from a day or two to permanent. Such bedridden people often eat in bed as well as watch television, read, work or the like while they remain bedridden. The art contains many examples of trays and supports that can be used for these purposes.
Most of the known trays and supports require a person to place the tray or support in position adjacent to the bedridden person so that person can use the tray or support. After use, the tray or support must be removed which, again, requires the assistance of someone other than the bedridden person. Thus, the person is dependent on someone else to carry out such a basic task. This requires the bedridden person to wait for meals, and/or for cleanup after meals until someone can assist them. This is inconvenient and poor for morale.
Still further, once a tray is positioned, a bedridden person may shift his or her position. This may place the person in an awkward position relative to the tray. The person may then have to request further assistance in re-positioning the tray.
Furthermore, as mentioned above, bed trays are often multi-use items which support books, work, and the like, in addition to food trays and items associated with eating. Each use may have an ideal position relative to the bedridden person, and each of these positions may be different from other positions. Thus, each time a bedridden person desires to change a use of the tray, he may be forced to request assistance.
Therefore, there is a need for a support tray for use by a bedridden person which can be moved into the most effective location without assistance.
Presently, bed trays are often stored away from a bed in order to keep them out of the way when they are not in use. This requires assistance and produces the above-discussed drawbacks. This also may be wasteful of valuable space.
Therefore, there is a need for a support tray for use by a bedridden person which can be stored in a location that is readily accessible when needed so no assistance is required to move the tray into a use position.
PRINCIPAL OBJECTS OF THE INVENTION
It is a main object of the present invention to provide a support tray adjacent to a bed.
It is another object of the present invention to provide a support tray for use by a bedridden person which can be moved into the most effective location without assistance.
It is another object of the present invention to provide a support tray for use by a bedridden person and which can be stored in a location that is readily accessible when needed so no assistance is required to move the tray into a use position.
SUMMARY OF THE INVENTION
These, and other, objects are achieved by a bed tray unit which comprises a bed having a head section, a foot section, two sides, a longitudinal axis extending between the head section and the foot section, and a transverse axis extending between the two sides; a tray-mounting rail connected at one end thereof to the foot section of the bed and at a second end thereof to the head section of the bed and extending in the direction of the longitudinal axis of the bed, the tray-mounting rail being located adjacent to one side of the bed; a tray unit movably mounted on the tray-mounting rail to move between adjacent to the foot section of the bed and adjacent to the head section of the bed; a motor unit mounted on the tray unit and having a rotatable output shaft; a roller mounted on the output shaft of the motor unit for rotation therewith and engaging the tray-mounting rail; and a control unit connecting the motor unit to a power source when the control unit is in an “on” condition.
The bedridden person can move the tray out of the way when the tray is not in use, but can also move the tray into the most effective position when desired without requiring any assistance from someone else.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a perspective view of a bed tray unit embodying the present invention.
FIG. 2 is a side elevational view of a bed with the bed tray unit of the present invention mounted thereon.
FIG. 3 is a perspective view of a remote control unit used to control the bed tray unit of the present invention.
FIG. 4 is a schematic indicating a motor unit that is used in the bed tray unit embodying the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Other objects, features and advantages of the invention will become apparent from a consideration of the following detailed description and the accompanying drawings.
Referring to the Figures, it can be understood that the present invention is embodied in a bed tray unit 10 that can be used to locate a bed tray in either a stored location when not in use or in a position that is most convenient for a person in a bed. Bed unit 10 can be positioned as desired by the person in the bed without requiring assistance from anyone else.
As shown in the figures, bed unit 10 comprises a bed unit 12 which includes a foot section 14 , a head section 16 , and a longitudinal axis 18 extending between foot section 14 and head section 16 . First and second sides, such as side 20 shown in FIG. 2, are both identical and are on opposite sides of a centerline of the bed unit. A transverse axis, indicated in FIG. 2 by indicator 22 , extends into the plane of the paper with FIG. 2 thereon, and extends between the first and second sides 20 of the bed unit 12 .
A tray-mounting rail 30 is located adjacent to side 20 of the bed unit and includes a foot portion 32 which includes a J-shaped mounting plate supporting section 34 . The J-shaped mounting plate supporting section 34 includes a first end 36 and a second end 38 as well as a curved portion 40 . A linear portion 42 is located in a horizontal plane and extends in the direction of transverse axis 22 of the bed unit 12 . A foot end mounting plate 44 on second end 38 of the foot portion 32 is fixed to foot section 14 of the bed unit when the tray-mounting rail 30 is mounted on the bed unit 12 as shown in FIG. 2 .
A curvilinear central section 48 of tray-mounting rail 30 has a curved section 50 which has a first end 52 connected to the first end 36 of the foot portion 32 of the tray-mounting rail 30 and is contained in a vertical plane and is spaced apart from the plane containing curved portion 40 of the J-shaped mounting plate supporting section 34 . Curved section 50 is spaced apart from first end 36 of the foot portion 32 of the tray-mounting rail 30 . A linear section 54 is connected to curved section 50 of the curvilinear central section 48 and extends in the direction of the longitudinal axis 18 of the bed unit 12 . Linear section 54 has a second end 56 located near head section 16 of the bed unit 12 .
Tray-mounting rail 30 further includes a head section 60 which includes a first curved portion 62 connected to second end 56 of the linear section 54 of the curvilinear central section 48 and is contained in the vertical plane. Head section 60 further includes a linear portion 64 having a first end 66 connected to first curved portion 62 of head section 60 and is contained in the vertical plane. Linear portion 64 of the head section 60 further including a second end 68 .
A second curved portion 70 of the head section 60 has a first end 72 connected to second end 68 of linear portion 64 of the head section 60 and is contained in the vertical plane. Second curved portion 70 includes a second end 76 and a linear section 78 which has a first end 80 connected to second end 76 of the second curved portion 70 of the head section 60 and extends in the direction of the transverse axis 22 of the bed unit 12 . Second curved portion 70 further includes a second end 82 . A head end mounting plate 86 is mounted on the second end 82 of the linear section 78 of the head section 60 and is fixed to head section 16 of the bed unit 12 when the tray-mounting rail 30 is mounted on the bed unit 12 .
A tray unit 90 is movably mounted on the tray-mounting rail 30 to move on the central section of the tray-mounting rail 30 between adjacent to the foot portion 32 of the tray-mounting rail 30 and adjacent to the head section 60 of the tray-mounting rail 30 . This movement is indicated in FIG. 2 by double-headed arrow 92 with the tray 90 being shown in a use position 94 in FIG. 2 with a stored position being indicated in dotted lines at position 96 in FIG. 2 .
The tray unit 90 includes a connecting arm 100 slidably mounted on the tray mounting rail 30 . The connecting arm 100 includes a rail-encircling portion 102 and a hollow arm 104 . The connecting arm 100 of the tray unit 90 extends in the direction of the transverse axis 22 of the bed unit 12 and has a distal end 106 spaced apart from the rail-encircling portion 102 .
A food-supporting tray 108 is connected to the distal end 106 of the connecting arm 100 and includes a first end 110 connected to the distal end 106 of the connecting arm 100 , a second end 112 spaced apart from the first end 110 of the tray 108 in the direction of the transverse axis 22 of the bed unit 12 , a tray longitudinal axis 114 which extends between the first end 110 of the tray 108 and the second end 112 of the tray 108 and which extends in the direction of the transverse axis 22 of the bed unit 12 , a first side 116 , a second side 118 , a tray transverse axis 120 which extends between the first side 116 of the tray 108 and the second side 118 of the tray 108 and extends in the direction of the longitudinal axis 18 of the bed unit 12 , a tray bottom surface 122 , and a tray top surface 124 . A plurality of indentations, such as cup holder indentation 126 , bowl holder indentation 128 and utensil holder indentation 130 are defined in the tray top surface 124 . Other indentations can be used without departing from the scope of the present disclosure, and the indentations shown are considered as examples of the many different types of indentation that can be used as will occur to those skilled in the art based on the teaching of the present disclosure.
A motor unit 140 is shown in FIG. 4 and is mounted on the tray unit 90 and includes a motor 142 mounted on tray bottom surface 122 . Motor 142 can be any suitable motor, including an electric motor, or the like, as will occur to those skilled in the art. A drive shaft 144 is connected to the motor 142 for rotation and extends through the hollow arm 104 of the connecting arm 100 of the tray unit 90 . A drive roller 146 is mounted on the drive shaft 144 of the motor unit 140 for rotation therewith. Drive roller 146 is located in rail-encircling portion 102 of the connecting arm 100 of the tray unit 90 . The drive roller 146 engages the central section of the tray mounting rail as by friction or by a gear on the drive roller and a rack in the central section, or the like.
A power source 150 , such as a battery pack or the like, is associated with the motor 142 . A control unit 152 connects the power source 150 to the motor 142 when the control unit 152 is in an “on” configuration and disconnects the motor 142 from the power source 150 when the control unit 152 is in an “off” configuration.
A remote control unit 160 is shown in FIG. 3 and includes a transmitter 162 for transmitting a control signal 164 to the control unit 152 of the motor unit 140 .
A person merely operates the remote control unit 160 to move the tray 108 into the desired location. The remote control unit 160 can have a forward button which connects the motor 142 to the power source 150 in one direction to move the tray from the dotted line position 96 shown in FIG. 2 toward the solid line position 94 shown in FIG. 2, a reverse button which connects the motor 142 to the power source 150 in a manner to move the tray 108 in a direction from the solid line position 94 shown in FIG. 2 to the dotted line position 96 shown in FIG. 2, and an “off” button which disconnects the motor 142 from the power source 150 and thus turns the motor 142 off, and an “on” button which connects the motor 142 to the power source 150 to turn the motor 142 on (with the motor 142 disconnected from the drive shaft 144 and thus “idles” the motor 142 ) to simply turn the motor 142 on. Other configurations can be envisioned by those skilled in the art based on the teaching of the present disclosure and such other configurations are intended to be included in the scope of the present disclosure.
It is understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangements of parts described and shown.
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A tray unit is mounted on a rail adjacent to a bed and includes a motor driven tray that can move along the rail. A remote control unit controls operation of the tray so the tray can be moved by a bedridden person into a position convenient for the person.
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CROSS-REFERENCED APPLICATIONS
This application relates to, and claims the benefit of the filing date of, U.S. provisional patent application Ser. No. 61/473,587 entitled METHOD AND APPARATUS FOR REAMING WELL BORE SURFACES NEARER THE CENTER OF DRIFT, filed Apr. 8, 2011, the entire contents of which are incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods and apparatus for drilling wells and, more particularly, to a reamer and corresponding method for enlarging the drift diameter and improving the well path of a well bore.
2. Description of the Related Art
Extended reach wells are drilled with a bit driven by a down hole motor that can be steered up, down, left, and right. Steering is facilitated by a bend placed in the motor housing above the drill bit. Holding the drill string in the same rotational position, such as by locking the drill string against rotation, causes the bend to consistently face the same direction. This is called “sliding”. Sliding causes the drill bit to bore along a curved path, in the direction of the bend, with the drill string following that path as well.
Repeated correcting of the direction of the drill bit during sliding causes friction between the well bore and the drill string greater than when the drill string is rotated. Such corrections form curves in the well path known as “doglegs”. Referring to FIG. 1 a , the drill string 10 presses against the inside of each dogleg turn 12 , causing added friction. These conditions can limit the distance the well bore 14 can be extended within the production zone, and can also cause problems getting the production string through the well bore.
Similar difficulties can also occur during conventional drilling, with a conventional drill bit that is rotated by rotating the drill string from the surface. Instability of the drill bit can cause a spiral or other tortuous path to be cut by the drill bit. This causes the drill string to press against the inner surface of resulting curves in the well bore and can interfere with extending the well bore within the production zone and getting the production string through the well bore.
When a dogleg, spiral path or tortuous path is cut by a drill bit, the relatively unobstructed passageway following the center of the well bore has a substantially smaller diameter than the well bore itself. This relatively unobstructed passageway is sometimes referred to as the “drift” and the nominal diameter of the passageway is sometimes referred to as the “drift diameter”. The “drift” of a passageway is generally formed by well bore surfaces forming the inside radii of curves along the path of the well bore. Passage of pipe or tools through the relatively unobstructed drift of the well bore is sometimes referred to as “drift” or “drifting”.
In general, to address these difficulties the drift diameter has been enlarged with conventional reaming techniques by enlarging the diameter 16 of the entire well bore. See FIG. 1 a . Such reaming has been completed as an additional step, after drilling is completed. Doing so has been necessary to avoid unacceptable increases in torque and drag during drilling. Such additional reaming runs add considerable expense and time to completion of the well. Moreover, conventional reaming techniques frequently do not straighten the well path, but instead simply enlarge the diameter of the well bore.
Accordingly, a need exists for a reamer that reduces the torque required and drag associated with reaming the well bore.
A need also exists for a reamer capable of enlarging the diameter of the well bore drift passageway and improving the well path, without needing to enlarge the diameter of the entire well bore.
SUMMARY OF THE INVENTION
To address these needs, the invention provides a method and apparatus for increasing the drift diameter and improving the well path of the well bore. This is accomplished, in one embodiment, by cutting away material primarily forming surfaces nearer the center of the drift. Doing so reduces applied power, applied torque and resulting drag compared to conventional reamers that cut into all surfaces of the well bore.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following Detailed Description taken in conjunction with the accompanying drawings, in which:
FIGS. 1 a and 1 b are a cross-section elevations of a horizontal well bore;
FIG. 2 is a representation of a well bore illustrating drift diameter relative to drill diameter;
FIG. 3 is a representation an eccentric reamer in relation to the well bore shown in FIG. 2 ;
FIG. 4 is a magnification of the downhole portion of the top reamer;
FIG. 5 is illustrates the layout of teeth along a downhole portion of the bottom reamer illustrated in FIG. 1 ;
FIG. 6 is an end view of an eccentric reamer illustrating the eccentricity of the reamer in relation to a well bore diameter;
FIG. 7 is an end view of two eccentric reamers in series, illustrating the eccentricity of the two reamers in relation to a well bore diameter;
FIG. 8 illustrates the location and arrangement of Sets 1, 2, 3 and 4 of teeth on another reamer embodiment;
FIG. 9 illustrates the location and arrangement of Sets 1, 2, 3 and 4 of teeth on another reamer embodiment;
FIG. 10 is a perspective view illustrating an embodiment of a reamer having four sets of teeth;
FIG. 11 is a geometric diagram illustrating the arrangement of cutting teeth on an embodiment of a reamer;
FIG. 12A-12D illustrate the location and arrangement of Blades 1, 2, 3, and 4 of cutting teeth;
FIG. 13 is a side view of a reamer tool showing the cutting teeth and illustrating a side cut area; and
FIGS. 14A-14D are side views of a reamer tool showing the cutting teeth and illustrating a sequence of Blades 1, 2, 3, and 4 coming into the side cut area and the reamer tool rotates.
DETAILED DESCRIPTION
In the following discussion, numerous specific details are set forth to provide a thorough understanding of the present invention. However, those skilled in the art will appreciate that the present invention may be practiced without such specific details. In other instances, well-known elements have been illustrated in schematic or block diagram form in order not to obscure the present invention in unnecessary detail. Additionally, for the most part, specific details, and the like have been omitted inasmuch as such details are not considered necessary to obtain a complete understanding of the present invention, and are considered to be within the understanding of persons of ordinary skill in the relevant art.
FIG. 1 is a cross-section elevation of a horizontal well bore 100 , illustrating an embodiment of the invention employing a top eccentric reamer 102 and a bottom eccentric reamer 104 . The top reamer 102 and bottom reamer 104 are preferably of a similar construction and may be angularly displaced by approximately 180° on a drill string 106 . This causes cutting teeth 108 of the top reamer 102 and cutting teeth 110 of the bottom reamer 104 to face approximately opposite directions. The reamers 102 and 104 may be spaced apart and positioned to run behind a bottom hole assembly (BHA). In one embodiment, for example, the eccentric reamers 102 and 104 may be positioned within a range of approximately 100 to 150 feet from the BHA. Although two reamers are shown, a single reamer or a larger number of reamers could be used in the alternative.
As shown in FIG. 1 , the drill string 106 advances to the left as the well is drilled. As shown in FIG. 2 , the well bore 100 may have a drill diameter D1 of 6 inches and a drill center 116 . The well bore 100 may have a drift diameter D2 of 5⅝ inches and a drift center 114 . The drift center 114 may be offset from the drill center 116 by a fraction of an inch. Any point P on the inner surface 112 of the well bore 100 may be located at a certain radius R1 from the drill center 116 and may also be located at a certain radius R2 from the drift center 114 . As shown in FIG. 3 , in which reamer 102 is shown having a threaded center C superimposed over drift center 114 , each of the reamers 102 (shown) and 104 (not shown) preferably has an outermost radius R3, generally in the area of its teeth 108 , less than the outermost radius R D1 of the well bore. However, the outermost radius R3 of each reamer is preferably greater than the distance R D2 of the nearer surfaces from the center of drift 114 . The cutting surfaces of each of the top and bottom reamers preferably comprise a number of carbide or diamond teeth 108 , with each tooth preferably having a circular cutting surface generally facing the path of movement P M of the tooth relative to the well bore as the reamer rotates and the drill string advances down hole.
In FIG. 1 , the bottom reamer 104 begins to engage and cut a surface nearer the center of drift off the well bore 100 shown. As will be appreciated, the bottom reamer 104 , when rotated, cuts away portions of the nearer surface 112 A of the well bore 100 , while cutting substantially less or none of the surface 112 B farther from the center of drift, generally on the opposite side of the well. The top reamer 102 performs a similar function, cutting surfaces nearer the center of drift as the drill string advances. Each reamer 102 and 104 is preferably spaced from the BHA and any other reamer to allow the centerline of the pipe string adjacent the reamer to be offset from the center of the well bore toward the center of drift or aligned with the center of drift.
FIG. 4 is a magnification of the downhole portion of the top reamer 102 as the reamer advances to begin contact with a surface 112 of the well bore 100 nearer the center of drift 114 . As the reamer 102 advances and rotates, the existing hole is widened along the surface 112 nearer the center of drift 114 , thereby widening the drift diameter of the hole. In an embodiment, a body portion 107 of the drill string 106 may have a diameter D B of 5¼ inches, and may be coupled to a cylindrical portion 103 of reamer 102 , the cylindrical portion 103 having a diameter D C of approx. 4¾ inches. In an embodiment, the reamer 102 may have a “DRIFT” diameter D D of 5⅜ inches, and produce a reamed hole having a diameter D R of 6⅛ inches between reamed surfaces 101 . It will be appreciated that the drill string 106 and reamer 102 advance through the well bore 100 along a path generally following the center of drift 114 and displaced from the center 116 of the existing hole.
FIG. 5 illustrates the layout of teeth 110 along a downhole portion of the bottom reamer 104 illustrated in FIG. 1 . Four sets of teeth 110 , Sets 110 A, 110 B, 110 C and 110 D, are angularly separated about the exterior of the bottom reamer 104 . FIG. 5 shows the position of the teeth 110 of each Set as they pass the bottom-most position shown in FIG. 1 when the bottom reamer 104 rotates. As the reamer 104 rotates, Sets 110 A, 110 B, 110 C and 110 D 110 A, 110 B, 110 C and 110 D pass the bottom-most position in succession. The Sets 110 A, 110 B, 110 C and 110 D of teeth 110 are arranged on a substantially circular surface 118 having a center 120 eccentrically displaced from the center of rotation of the drill string 106 .
Each of the Sets 110 A, 110 B, 110 C and 110 D of teeth 110 is preferably arranged along a spiral path along the surface of the bottom reamer 104 , with the downhole tooth leading as the reamer 104 rotates (e.g., see FIG. 6 ). Sets 110 A and 110 B of the reamer teeth 110 are positioned to have outermost cutting surfaces forming a 6⅛ inch diameter path when the pipe string 106 is rotated. The teeth 110 of Set 110 B are preferably positioned to be rotated through the bottom-most point of the bottom reamer 104 between the rotational path of the teeth 110 of Set 110 A. The teeth 110 of Set 110 C are positioned to have outermost cutting surfaces forming a six inch diameter when rotated, and are preferably positioned to be rotated through the bottom-most point of the bottom reamer between the rotational path of the teeth 110 of Set 110 B. The teeth 110 of Set 110 D are positioned to have outermost cutting surfaces forming a 5⅞ inch diameter when rotated, and are preferably positioned to be rotated through the bottom-most point of the bottom reamer 104 between the rotational path of the teeth 110 of Set 110 C.
FIG. 6 illustrates one eccentric reamer 104 having a drift diameter D3 of 5⅝ inches and a drill diameter D4 of 6 1/16 inches. When rotated about the threaded axis C, but without a concentric guide or pilot, the eccentric reamer 104 may be free to rotate about its drift axis C2 and may act to side-ream the near-center portion of the dogleg in the borehole. The side-reaming action may improve the path of the wellbore instead of just opening it up to a larger diameter.
FIG. 7 illustrates a reaming tool 150 having two eccentric reamers 104 and 102 , each eccentric reamer having a drift diameter D3 of 5⅝ inches and a drill diameter D4 of 6 1/16 inches. The two eccentric reamers may be spaced apart by ten hole diameters or more, on a single body, and synchronized to be 180 degrees apart relative to the threaded axis of the body. The reaming tool 150 having two eccentric reamers configured in this way, may be able to drift through a 5⅝ inch hole when sliding and, when rotating, one eccentric reamer may force the other eccentric reamer into the hole wall. An eccentric reaming tool 150 in this configuration has three centers: the threaded center C coincident with the threaded axis of the reaming toll 150 , and two eccentric centers C2, coincident with the drift axis of the bottom eccentric reamer 104 , and C3, coincident with a drift axis of the top eccentric reamer 102 .
FIGS. 8 and 9 illustrate the location and arrangement of Sets 1, 2, 3 and 4 of teeth on another reamer embodiment 200 . FIG. 8 illustrates the relative angles and cutting diameters of Sets 1, 2, 3, and 4 of teeth. As shown in FIG. 8 , Sets 1, 2, 3 and 4 of teeth are each arranged to form a path of rotation having respective diameters of 5⅝ inches, 6 inches, 6⅛ inches and 6⅛ inches. FIG. 9 illustrates the relative position of the individual teeth of each of Sets 1, 2, 3 and 4 of teeth. As shown in FIG. 9 , the teeth of Set 2 are preferably positioned to be rotated through the bottom-most point of the reamer between the rotational path of the teeth of Set 1. The teeth of Set 3 are preferably positioned to be rotated through the bottom-most point of the reamer between the rotational path of the teeth of Set 2. The teeth of Set 4 are preferably positioned to be rotated through the bottom-most point of the reamer between the rotational path of the teeth of Set 3.
FIG. 10 illustrates an embodiment of a reamer 300 having four sets of teeth 310 , with each set 310 A, 310 B, 310 C, and 310 D arranged in a spiral orientation along a curved surface 302 having a center C2 eccentric with respect to the center C of the drill pipe on which the reamer is mounted. Adjacent and in front of each set of teeth 310 is a groove 306 formed in the surface 302 of the reamer. The grooves 306 allow fluids, such as drilling mud for example, and cuttings to flow past the reamer and away from the reamer teeth during operation. The teeth 310 of each set 310 A, 310 B, 310 C, and 310 D may form one of four “blades” for cutting away material from a near surface of a well bore. The set 310 A may form a first blade, or Blade 1. The set 310 B may form a second blade, Blade 2. The set 310 C may for a third blade, Blade 3. The set 310 D may form a fourth blade, Blade 4. The configuration of the blades and the cutting teeth thereof may be rearranged as desired to suit particular applications, but may be arranged as follows in an exemplary embodiment.
Turning now to FIG. 11 , the tops of the teeth 310 in each of the two eccentric reamers 300 , or the reamers 102 and 104 , rotate about the threaded center of the reamer tool and may be placed at increasing radii starting with the #1 tooth at 2.750″ R. The radii of the teeth may increase by 0.018″ every five degrees through tooth #17 where the radii become constant at the maximum of 3.062″, which corresponds to the 6⅛″ maximum diameter of the reamer tool.
Turning now to FIGS. 12A-12D , the reamer tool may be designed to side-ream the near side of a directionally near horizontal well bore that is crooked in order to straighten out the crooks. As shown in FIG. 12A-12D , 30 cutting teeth numbered 1 through 30 may be distributed among Sets 310 A, 310 B, 310 C, and 310 D of cutting teeth forming four blades. As plotted in FIG. 11 , the cutting teeth numbered 1 through 8 may form Blade 1, the cutting teeth numbered 9 through 15 may form Blade 2, the cutting teeth numbered 16 through 23 may form Blade 3, and the cutting teeth numbered 24 through 30 may form Blade 4. As the 5¼″ body 302 of the reamer is pulled into the near side of the crook, the cut of the rotating reamer 300 may be forced to rotate about the threaded center of the body and cut an increasingly larger radius into just the near side of the crook without cutting the opposite side. This cutting action may act to straighten the crooked hole without following the original bore path.
Turning now to FIG. 13 , the reamer 300 is shown with the teeth 310 A of Blade 1 on the left-hand side of the reamer 300 as shown, with the teeth 310 B of Blade 2 following behind to the right of Blade 1, the teeth 310 C of Blade 3 following behind and to the right of Blade 2, and the teeth 310 D of Blade 4 following behind and to the right of Blade 3. The teeth 310 A of Blade 1 are also shown in phantom, representing the position of teeth 310 A of Blade 1 compared to the position of teeth 310 D of Blade 4 on the right-hand side of the reamer 300 , and at a position representing the “Side Cut” made by the eccentric reamer 300 .
Turning now to FIGS. 14A-14D , the extent of each of Blade 1, Blade 2, Blade 3, and Blade 4 is shown in a separate figure. In each of the FIG. 14A-14D , the reamer 300 is shown rotated to a different position, bringing a different blade into the “Side Cut” position SC, such that the sequence of views 14 A- 14 D illustrate the sequence of blades coming into cutting contact with a near surface of a well bore. In FIG. 14A , Blade 1 is shown to cut from a 5¼″ diameter to a 5½″ diameter, but less than a full-gage cut. In FIG. 14B , Blade 2 is shown to cut from a 5⅜″ diameter to a 6″ diameter, which is still less than a full-gage cut. In FIG. 14C , Blade 3 is shown to cut a “Full Gage” diameter, which may be equal to 6⅛″ in an embodiment. In FIG. 14D , Blade 4 is shown to cut a “Full gage” diameter, which may be equal to 6⅛″ in an embodiment.
The location and arrangement of Sets of teeth on an embodiment of an eccentric reamer as described above, and teeth within each set, may be rearranged to suit particular applications. For example, the alignment of the Sets of teeth relative to the centerline of the drill pipe, the distance between teeth and Sets of teeth, the diameter of rotational path of the teeth, number of teeth and Sets of teeth, shape and eccentricity of the reamer surface holding the teeth and the like may be varied.
Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
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The present invention provides a method and apparatus for increasing the drift diameter and improving the well path of the well bore, accomplished in one embodiment by cutting away material primarily forming surfaces nearer the center of the drift, thereby reducing applied power, applied torque and resulting drag compared to conventional reamers that cut into all surfaces of the well bore.
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FIELD OF THE INVENTION
This invention relates generally to a cleaner apparatus, and more particularly to an improved cleaning blade and drop seal actuator and seal in a cleaning system.
BACKGROUND OF THE INVENTION
In the process of cleaning a photoreceptor or photoconductor, a cleaning blade is used to clean the imaging surface and toner is removed from the imaging surface which accumulates at the cleaning edge of the cleaning blade. As a result, toner contamination of the xerographic area occurs when the cleaning edge of the cleaning blade is retracted from the imaging surface. The toner that has accumulated at the cleaning edge falls down the imaging surface length during retraction. The toner contamination may result in copy quality defects and decreased operating efficiency of various xerographic components. In order to achieve engineering reliability, service and customer satisfaction goals improvements in cleaning blades and seals are desired to reduce such toner contamination problems.
The following disclosures may be relevant to various aspects of the present invention and may be briefly summarized as follows:
U.S. Pat. No. 5,966,565 relates to a cleaning seal with a soft cleaning seal tip that provides a seal between a cleaning housing and a photoconductive member in an electrophotographic machine. The cleaning seal is made of a relatively stiff material so that the cleaning seal can collect and support toner removed from the photoconductive member. In the absence of the soft cleaning seal tip, the relatively stiff material of the cleaning seal contacting the photoconductive member excessively scratches the photoconductive member. The soft cleaning seal tip solves this problem by providing a relatively soft surface on the photoconductive member, resulting in fewer scratches on the photoconductive member. The composite cleaning seal provides sufficient force to remove and support the toner removed from the photoconductive member while cushioning the force of the relatively stiff cleaning seal against the photoconductive member.
U.S. Pat. No. 5,442,422 relates to an apparatus for cleaning an imaging surface with a hybrid cleaner that includes the implementation of a contamination seal in a cleaner unit. The contamination seal captures falling accumulated toner from a blade edge and in a brush nip, due to gravitation, which contaminates the xerographic area when the cleaner blade and disturber brush are retracted from the imaging surface. The contamination seal rests along the length of a blade portion that extends from a blade holder. In this position, the contamination seal does not touch the imaging surface to cause scratches nor does it interfere with the blade's ability to clean the imaging surface. Implementation of the contamination seal contains toner emission within the cleaner from the blade edge and brush nip.
U.S. Pat. No. 4,910,560 relates to a cleaning device provided with a blade adapted to contact the peripheral surface of a photosensitive drum and wipe residual toner off of the photosensitive drum. A duct is disposed separately from the blade, and is adapted to remove the toner wiped off by the blade by air suction. In the interval between the blade and the duct, there is disposed a sealing member which serves to prevent ambient air from entering the duct through the interval. This sealing member is fixed either on a stationary region of a holder for the blade or on the basal end part of the blade integrated with the holder or on the outer surface of the duct, and contacts the duct if mounted on the holder or the blade, or contacts the blade or holder if mounted on the duct.
U.S. Pat. No. 4,640,608 relates to a cleaning method which includes a cleaning blade being brought into pressure contact with a photoconductor at least prior to the movement of the photoconductor, and moving the cleaning blade away from the surface of the photoconductor after the movement of the photoconductor is stopped with completion of a copying process. A stationary seal member allows uncleaned toner on the photoconductor to pass therethrough but does not permit the toner removed by the cleaning blade to pass therethrough.
U.S. Pat. No. 4,400,082 relates to a cleaning apparatus for removing toner remaining on a moving photoconductive member which has a resilient blade in bearing contact with a surface of the photoconductive member and reciprocatingly movable laterally of the direction of movement of the surface, a seal member provided at each end of the photoconductive member and having a width in the direction of the lateral movement of the blade equal to at least the range of lateral movement of the corresponding end of the blade, a seal member being disposed in contact with the rear seal member being disposed in contact with the rear surface of the blade in the range of lateral movement of the blade end. Toner particles are thereby prevented from falling from the blade off the end of the photoconductive member.
All documents cited herein, including the foregoing, are incorporated herein by reference in their entireties.
SUMMARY OF INVENTION
In embodiments, there is provided an electrostatographic apparatus including a first member having a length, a first end, and a second end. The first end is for removing particles from a photoreceptor surface. The first end is adapted to move from an operative position contacting the photoreceptor surface to an inoperative position spaced from the photoreceptor surface. The second end is adapted to pivot and includes a second member associated therewith. A third member is spaced from the first member and has a length and a free end. The second member is adapted to contact the third member as the first member is moved to an inoperative position causing the third member to move an angular distance.
In other embodiments, there is provided a customer replaceable unit including a cleaning blade assembly having a first end and a second end. The first end is for removing particles from a photoreceptor surface. The first end is adapted to move from an operative position contacting the photoreceptor surface to an inoperative position spaced from the photoreceptor surface. The second end has a protrusion thereon. A seal including a length and a free end is adapted to move from a first position to a second position as the first end of the cleaning blade assembly moves away from the photoreceptor surface and the protrusion contacts the seal at a position located a distance from the free end.
In further embodiments, there is provided an apparatus for cleaning particles from a surface including a cleaning blade for removing particles from the surface. The cleaning blade is adapted to move between an operative position contacting the surface to remove particles therefrom and an inoperative position spaced from the surface. The cleaning blade includes a free blade end movable between the operative position and the inoperative position, and a pivot end for rotating about a pivot. A seal is movable between a first position and a second position in response to a protrusion on a portion of the pivot end moving in contact with the seal to urge the seal in the direction of the surface. The seal comprises a flexible sheet chosen from the group of materials consisting of polyester thermoplastics, polycarbonate, polyurethane, polyethylene, and polypropylene.
In yet other embodiments, there is provided a cleaning station for cleaning toner from an endless photoconductive member in an apparatus including a cleaning housing. A cleaning blade assembly is supported by the cleaning housing. The cleaning blade assembly includes a first end and a second end. The first end is for removing particles from a photoconductive member. The first end is adapted to move from an operative position contacting the photoconductive member to an inoperative position spaced from the photoconductive member. The second end includes a protrusion thereon. A seal includes a length and a free end and is sufficiently stiff so that the seal can support the toner removed from the photoconductive member. The seal is located after the cleaning blade has removed the toner from the photoconductive member. The seal is movable from a first position to a second position as the first end of the cleaning blade assembly moves away from the photoconductive member such that the protrusion contacts the seal at a position located a distance from the free end.
In other embodiments, there is provided a method of preventing toner contamination including: accumulating toner from a photoconductive surface on a free end of a blade, the blade comprising a pivot end including a protrusion thereon; and rotating the free end of the blade away from a surface causing the protrusion on the pivot end to pivot and contact the seal urging the seal to move toward the surface.
Still other aspects of the invention will become readily apparent to those skilled in the art from the following detailed description, wherein embodiments are shown and described, simply by way of illustration. As will be realized, the invention is capable of other and different embodiments and methods of construction, and its several details are capable of modification and interchangeability in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic elevational view of an embodiment of an electrophotographic printing machine utilizing an embodiment of a drop seal actuator;
FIG. 2 shows accumulation of toner at a cleaning edge of a cleaning blade in an operative position and a seal in contact with a photoreceptor;
FIG. 3 shows retraction of a cleaning edge of the cleaning blade away from a photoreceptor and the drop seal actuator in contact with a seal; and
FIG. 4 shows the return of a cleaning blade to an operative position and into contact with a photoreceptor and accumulation of toner falling into the container.
DETAILED DESCRIPTION OF THE INVENTION
While the principles and embodiments of the present invention will be described in connection with an electrostatographic reproduction apparatus, it should be understood that the present invention is not limited to that embodiment or to that application. Therefore, it should be understood that the principles of the present invention and embodiments extend to all alternatives, modifications, and equivalents thereof.
For a general understanding of the features of the present invention, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to identify identical elements. FIG. 1 schematically depicts an electrophotographic printing machine incorporating the features of the present invention therein. It will become evident from the following discussion that the component with a precision aperture of the present invention may be employed in a wide variety of devices and is not specifically limited in its application to the particular embodiment depicted herein.
Referring to FIG. 1 of the drawings, schematically illustrated is an electrophotographic printing or copying machine including a document positioned in a document handler 27 on a raster input scanner (RIS) 28 . The RIS 28 contains document illumination lamps, optics, a mechanical scanning drive and a charge coupled device (CCD) array. The RIS 28 captures the entire original document and converts it to a series of raster scan lines. This information is transmitted to a controller or electronic subsystem (ESS) 29 which controls a raster output scanner (ROS) 30 described below.
The electrophotographic printing machine generally employs a photoconductive belt 210 . The photoconductive belt 210 may be made from a photoconductive material coated on a ground layer, which, in turn, is coated on an anti-curl backing layer. Photoconductive Belt 210 moves in the direction of arrow 230 to advance successive portions sequentially through the various processing stations disposed about the path of movement thereof. Photoconductive Belt 210 is entrained about stripping roller 14 , tensioning roller 16 and drive roller 20 . As drive roller 20 rotates, it advances photoconductive belt 210 in the direction of arrow 230 .
Initially, a portion of the photoreceptor surface or photoconductive surface 12 of the photoconductive belt 210 passes through charging station A. At charging station A, the corona generating device indicated generally by the reference numeral 22 charges the photoconductive belt 10 to a relatively high, substantially uniform potential.
At an exposure station, B, a controller or electronic subsystem (ESS) 29 receives the image signals representing a desired output image and processes these signals to convert them to a continuous tone or greyscale rendition of the image which is transmitted to a modulated output generator, for example the raster output scanner (ROS), 30 . Preferably, ESS 29 is a self-contained, dedicated minicomputer. The image signals transmitted to ESS 29 may originate from a RIS 28 as described above or from a computer, thereby enabling the electrophotographic printing machine to serve as a remotely located printer for one or more computers.
Alternatively, the printer may serve as a dedicated printer for a high-speed computer. The signals from ESS 29 , corresponding to the continuous tone image desired to be reproduced by the printing machine, are transmitted to ROS 30 . ROS 30 includes a laser with rotating polygon mirror blocks. The ROS 30 will expose the photoconductive belt 210 record an electrostatic latent image thereon corresponding to the continuous tone image received from ESS 29 . As an alternative, ROS 30 may employ a linear array of light emitting diodes (LEDs) arranged to illuminate the charged portion of photoconductive belt 210 on a raster-by-raster basis.
After the electrostatic latent image has been recorded on the photoconductive surface 12 , photoconductive belt 210 advances the latent image to a development station, C, where toner, in the form of liquid or dry particles, is electrostatically attracted to the latent image using commonly known techniques. The latent image attracts toner particles from the carrier granules forming a toner powder image thereon. As successive electrostatic latent images are developed, toner particles are depleted from the developer material. A toner particle dispenser 44 , dispenses toner particles into developer housing 46 of developer unit 38 .
After the electrostatic latent image is developed, the toner powder image present on photoconductive belt 210 advances to transfer station D. A print sheet 48 is advanced to the transfer station, D, by a sheet feeding apparatus, 50 . Preferably, sheet feeding apparatus 50 includes a nudger roll 51 which feeds the uppermost sheet of stack 54 to nip 55 formed by feed roll 52 and retard roll 53 . Feed roll 52 rotates to advance the sheet from stack 54 into vertical transport 56 . Vertical transport 56 directs the advancing sheet 48 of support material into registration transport 120 of the invention herein, described in detail below, past image transfer station D to receive an image from photoconductive belt or photoreceptor belt 210 in a timed sequence so that the toner powder image formed thereon contacts the advancing sheet 48 at transfer station D. Transfer station D includes a corona generating device 58 which sprays ions onto the back side of sheet 48 . This attracts the toner powder image from photoconductive surface 12 to sheet 48 . The sheet 48 is then detacked from the photoreceptor belt 210 by corona generating device 59 which sprays oppositely charged ions onto the back side of sheet 48 to assist in removing the sheet from the photoreceptor belt 210 . After transfer, sheet 48 continues to move in the direction of arrow 60 by way of belt transport 62 which advances sheet 48 to fusing station F.
Fusing station F includes a fuser assembly 70 which permanently affixes the transferred toner powder image to the sheet 48 . Preferably, fuser assembly 70 includes a heated fuser roller 72 and a pressure roller 74 with the powder image on the sheet 48 contacting fuser roller 72 . The pressure roller 74 is cammed against the fuser roller 72 to provide the necessary pressure to fix the toner powder image to the sheet 48 . The fuser roller 72 is internally heated by a quartz lamp (not shown). Release agent, stored in a reservoir (not shown), is pumped to a metering roll (not shown). A trim blade (not shown) trims off the excess release agent. The release agent transfers to a donor roll (not shown) and then to the fuser roller 72 .
The sheet 48 then passes through fuser assembly 70 where the image is permanently fixed or fused to the sheet 48 . After passing through fuser assembly 70 , a gate 80 either allows the sheet 48 to move directly via output 84 to a finisher or stacker, or deflects the sheet 48 into a duplex path 100 , specifically, first into single sheet inverter 82 here. That is, if the sheet 48 is either a simplex sheet, or a completed duplex sheet having both side one and side two images formed thereon, the sheet 48 will be conveyed via gate 80 directly to output 84 . However, if the sheet 48 s being duplexed and is then only printed with a side one image, the gate 80 will be positioned to deflect that sheet 48 into the inverter 82 and into the duplex path 100 , where that sheet 48 will be inverted and then fed to acceleration nip 102 and belt transports 110 , for recirculation back through transfer station D and fuser assembly 70 for receiving and permanently fixing the side two image to the backside of that duplex sheet, before it exits via output 84 .
After the sheet 48 is separated from photoconductive surface 12 of photoreceptor belt 210 , the residual toner/developer and paper fiber particles adhering to photoconductive surface 12 are removed therefrom at cleaning station E. Cleaning station E includes a rotatably mounted fibrous brush in contact with photoconductive surface 12 to disturb and remove paper fibers and a cleaning blade to remove the non-transferred toner particles. The blade may be configured in either a wiper or doctor position depending on the application. Subsequent to cleaning, a discharge lamp (not shown) floods photoconductive surface 12 with light to dissipate any residual electrostatic charge remaining thereon prior to the charging thereof for the next successive imaging cycle.
The various machine functions are regulated by controller 29 . The controller 29 is preferably a programmable microprocessor which controls all of the machine functions hereinbefore described. The controller 29 provides a comparison count of the copy sheets, the number of documents being recirculated, the number of copy sheets selected by the operator, time delays, jam corrections, and the like. The control of all of the exemplary systems heretofore described may be accomplished by conventional control switch inputs from the printing machine consoles selected by the operator. Conventional sheet path sensors or switches may be utilized to keep track of the position of the document and the copy sheets.
Reference is now made to FIG. 2, which shows a partial elevational view of a cleaning station E. The cleaning station E includes a cleaning blade 200 that contact the photoreceptor belt 210 . This cleaning station E is partially enclosed in a housing 220 . A brush (not shown) may be located upstream from the cleaning blade 200 and upstream from the direction of motion shown by arrow 230 , of the photoreceptor belt 210 . The brush may be used to mechanically clean and loosen toner 240 from the imaging surface of the photoreceptor belt 210 . The cleaning blade 200 removes the toner 240 and other debris particles loosened and/or left behind by the brush from the photoreceptor belt 210 . The cleaning blade 200 is attached to a cleaning blade holder 250 . As the brush and cleaning blade 200 clean the imaging surface, toner 240 removed from the imaging surface accumulates at the cleaning edge of the blade 200 . The cleaning blade 200 may be mounted to a the blade holder 250 , which is mounted pivotally about a pivot point 270 .
A seal 260 may be mounted in the cleaning station E below the cleaning blade 200 . The seal 260 is movable and flexible and may contact or be slightly spaced from the photoreceptor belt 210 . The seal 260 can be made from materials such as: polycarbonate, polyurethane, polyethylene, polypropylene, polyester thermoplastics (e.g. Mylar) or any other material with low resistance to set. The seal 260 is stiff enough to prevent toner 240 from escaping past the seal 260 , when the seal 260 is in contact with the photoreceptor belt 210 .
Reference is now made to FIG. 3, which shows a partial elevational view of a cleaning station E. In operation, a technical service representative may pull out a drawer (not shown) from the machine after the machine has been shut off. When the drawer is open, a handle 290 or a similar mechanism for rotation is exposed that allows the technical service representative to rotate the cleaning blade 200 away from the photoreceptor belt 210 , cause the photoreceptor 210 to assume a relaxed state, and to urge the end of the seal 260 further in the X direction to approach or contact the relaxed photoreceptor belt 210 as a drop seal actuator 295 urges and applies pressure to the seal 260 . The seal 260 may move an angle θ which, depending on embodiment geometry, may range up to 25 degrees. The photoreceptor belt 210 illustrated is in a generally relaxed state and the free end of the seal 260 may extend further in the X direction past where the photoreceptor belt 210 where located when in an operational state as shown in FIGS. 2 and 4. Applying pressure to the seal 260 on the photoreceptor belt 210 improves the capture of toner 240 during cleaning blade 200 retraction. The movement of the cleaning blade 200 away from the photoreceptor belt 210 as shown by arrow 300 causes the drop seal actuator 295 to move into contact with the seal 260 . The toner 240 falls down the length of the seal 260 and is gathered and held at the intersection of the seal 260 and the drop seal actuator 295 . The seal 260 directs accumulated toner 240 at the cleaning blade 200 away from the xerographic area and into a waste container 280 .
The purpose of the drop actuator seal 295 is to reduce or eliminate a toner contamination problem in the xerographic area. The increased pressure to the seal 260 upon retraction of the cleaning blade 200 and use of the drop seal actuator 295 in the cleaning system helps to prevent the contamination of the xerographic area and components, allowing for a cleaner copier or printer and help to improve copy quality, operating efficiency, reliability and life of various xerographic components such as charge devices, erase lamps and sensors. If the seal 260 has an attack angle too great, includes material that is too stiff, or has an edge that is too rough, then undue photoreceptor abrasion can occur. Premature photoreceptor abrasion greatly lessens photoreceptor life thus lowering CRU life. If the seal 260 does not extend far enough or it is installed unevenly, then toner 240 can easily pass over it and land onto a scorotron below. Any scorotron contamination reduces print quality and lowers the CRU life.
The drop seal actuator 295 simultaneously moves into position as the cleaning blade 200 moves out of its run position. Also, the photoreceptor belt 210 is relaxed as the cleaning blade 200 moves out of its cleaning position. The seal 260 has a position A during operation. Upon retraction of the cleaning blade 200 during the process of CRU removal, the drop seal actuator 295 contacts the seal 260 , and urges the seal 260 out of position A in the direction toward the relaxed photoreceptor belt 210 , and moves the seal 260 an angle θ from position A to a position A′. The end of the seal 260 in its position A′ extends further in the X direction to a region where the photoreceptor belt 210 may have been positioned in its operational position. The end of the seal 260 is then positioned to catch loose toner 240 falling from the cleaning blade 200 and photoreceptor belt 210 . Toner 240 and other debris is then directed along the seal 260 and eventually into the waste container 280 . The angle θ depends on the geometry of the cleaning unit and positioning of the relaxed photoreceptor belt 210 . The seal 260 in position A′ may be arcuate or include a straight portion depending on the position of the photoreceptor belt 210 , how far the seal 260 extends in the X direction, whether the end of the seal 260 contacts the photoreceptor belt 210 , and geometry. In embodiments, angle θ may range up to 25 degrees.
In FIG. 4, shown is a partial elevational view of a cleaning station E. The cleaning blade 200 is shown in contact with the photoreceptor belt 210 and the drop seal actuator 295 is shown moved away from the seal 260 . The seal 260 is in a free state without contact or pressure from the drop seal actuator 295 . Toner 240 previously directed or captured by the seal 260 and drop seal actuator 295 is gravitationally urged toward the waste container 280 as the cleaning blade 200 is returned to it's operative position A and the drop seal actuator 295 simultaneously moved out of contact and spaced away from the seal 260 . The printer or copying machine is now ready for operation again.
In the embodiments, the movement of the seal 260 over an angular distance θ may range up to 25 degrees when the a first member such as a cleaning blade 200 is in an inoperative position. The angular distance θ may be increased during the process of moving the first member to an inoperative position. A third member such as a seal 260 may not be straight when a second member such as a protrusion the drop seal actuator 295 or protrusion 295 contacts the third member and applies pressure thereto. The second member may be a protrusion on an end of a cleaning blade. The second member may have a length, width, and thickness and be selectively positioned on the cleaning blade. There may be no opening between the second member and the third member when the second member contacts the third member. The third member may be substantially straight when the first member is in an operative position and the second member is out of contact from the third member. The third member may not be substantially straight when the first member is in an inoperative position and the second member is in contact with third member. The first member may be made of metal, the second member may be made of a urethane and the third member may be made of mylar. The urethane may be a foam. The second member and the first member may be made of one piece and the same material. The cleaning blade may be removable away from the photoreceptor surface. The apparatus may further include a waste container adapted to receive particles. The third member may include a flexible sheet chosen from the group of materials consisting of polyester thermoplastics, polycarbonate, polyurethane, polyethylene, and polypropylene. The particles may be captured by the seal and directed therealong into the waste container. The seal may be between 2-5 mils thick and be made of at least one of Mylar, and polyester. The seal may have a thickness of about 3 mils.
In the embodiments, the method may further include: capturing between the seal and the protrusion loose toner falling from the cleaning blade; allowing the toner to be directed along a length of the seal into the waste container; returning the cleaning blade into contact with the imaging surface; moving the protrusion out of contact with the seal and causing the seal to straighten; locating the seal with respect to the cleaning blade so that toner removed and falling past the cleaning blade is supported by the cleaning seal.
In summary, the drop seal actuator 295 is a mechanical device that provides additional protection from toner droppings falling from a cleaner system onto the charging system. The drop seal actuator 295 is useful in systems where, for example, a Xerographic CRU has a cleaner system that is directly above the charging system. In operation, while removing the CRU from the machine, the customer actuates a belt module handle 290 which moves a cleaning blade away from the photoreceptor belt 210 . When the blade 200 moves from a photoreceptor belt 210 , excess toner 240 may spill from the cleaning blade 200 . To prevent contamination from falling onto the a charge scorotron, a seal 260 is located between the cleaning system and the charging system. During normal run, the seal 260 may lightly touch the photoreceptor. At CRU removal, photoreceptor belt 210 is relaxed and the seal 260 is urged and repositioned toward the relaxed photoreceptor belt 210 by contact of the drop seal actuator 295 with the seal 260 . The seal 260 then catches and directs loose toner 240 away from the charging system and reduces contamination of the charging system.
While this invention has been described in conjunction with various embodiments, it is evident that many alternatives, modifications, and variations thereof will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications, and variations and their equivalents.
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An apparatus for cleaning an imaging surface with a cleaning blade including a drop seal actuator that urges a seal into position and then collects toner in a cleaner unit. The seal captures falling accumulated toner from the cleaning blade which may contaminate the xerographic area when the cleaning blade is retracted from the imaging surface. Implementation of the drop seal actuator in contact with the seal positions the seal to contain toner within the cleaner unit.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 13/441,841, filed on Apr. 7, 2012, which claims priority to U.S. provisional patent application No. 61/472,788, filed on Apr. 7, 2011, the disclosure of which is incorporated herein by reference, as though set forth in full.
FEDERALLY SPONSORED RESEARCH
Not Applicable
SEQUENCE LISTING OR PROGRAM
Not Applicable
RELEVANT PRIOR ART
U.S. Pat. No. 5,640,343, Jun. 17, 1997—Gallagher et al.
U.S. Pat. No. 7,224,601, May 29, 2007—Panchula
U.S. Pat. No. 7,529,121, May 5, 2009—Kitagawa et al.
BACKGROUND
Magnetic random access memory (MRAM) using spin-induced switching is a strong candidate for providing a dense and fast non-volatile storage solution for future memory applications. Each MRAM includes an array of memory cells. FIG. 1 shows a schematic view of MRAM cell employing a spin-induced writing mechanism according to a prior art. The cell comprises a magnetoresistive element (or magnetic tunnel junction) J, a selection transistor T, a bit line BL, a word line WL, and a source line SL. The bit and word lines are formed in different layers and intersect each other in space. The magnetoresistive (MR) element J and the selection transistor T are connected in series and disposed in a vertical space between intersecting bit and word lines. They are connected to the source line SL at one end and to the bit line BL at another end. The word line is connected to a gate terminal of the selection transistor T. The MR element J comprises at least a pinned (or reference) layer 12 with a fixed direction of magnetization (shown by a solid arrow), a free (or storage) layer 16 with a reversible magnetization direction (shown by a dashed arrow), and a tunnel barrier layer 14 disposed between the pinned and free magnetic layers. The direction of the magnetization in the free layer 16 can be controlled by a direction of a spin-polarized current I S running through the element J in a direction perpendicular to a film surface. Resistance of the MR element depends on a mutual orientation of the magnetizations in the magnetic layers 12 and 16 . The resistance is low when the magnetizations in the layers 12 and 16 are parallel to each other (logic “0”), and high when the magnetizations are antiparallel (logic “1”). Difference in the resistance between two magnetic states can exceed several hundred percent at room temperature.
FIG. 2 shows a circuit diagram of a portion of MRAM 20 with spin-induced switching according to a prior art. The MRAM 20 includes an array 22 of memory cells C 11 -C 33 (other cells are not shown) disposed in a vertical space between pluralities of parallel bits and word lines at their intersections. Each memory cell comprises an MR element J and transistor T connected in series. A plurality of parallel bit lines BL 1 -BL 3 is connected to a bit line driver 24 . A plurality of the word lines WL 1 -WL 3 is connected to a word line driver 26 . A plurality of the parallel source lines SL 1 -SL 3 is connected to a source line driver 28 . Selection of a memory cell in the array 22 is provided by applying a suitable signal to appropriate bit and word lines. For instance, to select the memory cell C 22 that is located at the intersection of the bit line BL 2 and the word line WL 2 , the signals need to be applied to these lines through the drivers 24 and 26 , respectively.
Cell size is one of key parameters of the MRAM. It substantially depends on the size and number of selection transistors supplying a spin-polarized write current to a MR element. The number of the transistors controlling the write current usually vary from one to two per a MR element. It depends on a saturation current of a selection transistor and magnitude of the spin-polarized current required to cause switching of the MR element. Frequently, especially for MR elements having in-plane magnetization in magnetic layers, one selection transistor cannot provide the required spin-polarized current due to its saturation. This obstacle prevents the MRAM cell size reduction.
Another important parameter of MRAM is a write speed. The write speed depends on a magnitude of the spin-polarized current running through the MR element. High speed (short duration of the write current pulse) requires higher magnitude of the spin-polarized current that can be limited by the saturation current of the selection transistor or by a breakdown of the tunnel barrier layer.
The present disclosure addresses to the above problems.
SUMMARY
Disclosed herein is a magnetic memory device that comprises a substrate, a memory cell including a magnetic tunnel junction which comprises a free ferromagnetic layer having a reversible magnetization direction directed substantially perpendicular to the substrate in an equilibrium state, a pinned ferromagnetic layer having a fixed magnetization direction, and an insulating tunnel barrier layer disposed between the pinned ferromagnetic layer and the free ferromagnetic layer, a first electrical circuit for applying a first current to a first conductor comprising ferromagnetic cladding to produce a bias magnetic field applied along a hard magnetic axis of the free ferromagnetic layer, the first conductor is electrically coupled to the free ferromagnetic layer, a second electrical circuit for applying a second current to a second conductor to cause a spin momentum transfer in the free ferromagnetic layer, the second conductor is electrically coupled to the pinned ferromagnetic layer, wherein a magnitude of the bias magnetic field and a magnitude of the spin momentum transfer in combination exceed a threshold and thus reverse the magnetization direction of the free ferromagnetic layer when the first write current and the second write current are applied to the memory cell at the same time.
Also disclosed a magnetic memory device that comprises a substrate, a first plurality of electrically conductive lines formed on the substrate, a second plurality of electrically conductive lines formed on the substrate and overlapping the first plurality of lines at a plurality of intersection regions, a plurality of memory cells formed on the substrate and arranged in an array, each memory cell being located at an intersection region and comprising a magnetic tunnel junction which includes a free ferromagnetic layer having a reversible magnetization direction directed substantially perpendicular to the substrate in an equilibrium state, a pinned ferromagnetic layer having a fixed magnetization direction, and an insulating tunnel layer disposed between the pinned ferromagnetic layer and the free ferromagnetic layer, each magnetic tunnel junction is electrically coupled to one of the first plurality of lines at the free ferromagnetic layer and to one of the second plurality of lines at the pinned ferromagnetic layer, wherein the magnetization direction of the free ferromagnetic layer is reversed by a spin-polarized current flowing through the magnetic tunnel junction in a direction perpendicular to the substrate.
Also disclosed a method for writing to a magnetic memory device that includes a plurality of magnetic tunnel junctions formed on a substrate and arranged in columns and rows, each magnetic tunnel junction comprising a free ferromagnetic layer having a reversible magnetization direction directed substantially perpendicular to the substrate in an equilibrium state, a pinned ferromagnetic layer having a fixed magnetization direction, and an insulating tunnel barrier layer disposed between the free ferromagnetic layer and the pinned ferromagnetic layer, the method includes applying a bias current to a bit conductive line comprising ferromagnetic cladding and being electrically coupled to a row of magnetic tunnel junctions at the free ferromagnetic layer to produce a bias magnetic field along a hard magnetic axis of the free ferromagnetic layer, applying a first current to a conductive word line electrically coupled to a column of magnetic tunnel junctions at the pinned ferromagnetic layer to produce a spin momentum transfer in the free ferromagnetic layer of a magnetic tunnel junction located at a first intersection region of the bit conductive line and the word conductive line, wherein the bias current and the first current are applied at the same time, and a joint effect of the bias magnetic field and the spin momentum transfer causes a reversal of the magnetization direction of the free ferromagnetic layer of the magnetic tunnel junction located at the first intersection region.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a memory cell with spin-induced switching according to a prior art.
FIG. 2 is a circuit diagram of a magnetic random access memory with spin-induced switching according to a prior art.
FIGS. 3A and 3B is a circuit diagram of magnetic random access memory with a spin-induced switching according to an embodiment of the present disclosure illustrating writing of logic “0” and logic “1” to a memory cell.
FIG. 4 is a schematic view of a memory cell with a spin-induced switching according to an embodiment of the present disclosure.
FIG. 5 is a schematic view of a memory cell with a hybrid switching mechanism.
FIG. 6A is a circuit diagram of magnetic random access memory with hybrid switching mechanism illustrating writing a logic “0” to a memory cell according to another embodiment of the present disclosure.
FIG. 6B is a circuit diagram of magnetic random access memory with hybrid switching mechanism illustrating writing logic “1” to several memory cells simultaneously according to another embodiment of the present disclosure.
FIG. 7 is a circuit diagram of the magnetic random access memory shown in FIG. 6A during a read operation.
EXPLANATION OF REFERENCE NUMERALS
12 pinned (or reference) magnetic layer
14 tunnel barrier layer
16 free (or storage) magnetic layer
20 , 30 , 60 magnetic random access memory (MRAM)
22 array of memory cells
24 bit line driver
26 word line driver
28 source line driver
52 conductor
54 magnetic flux concentrator
56 non-magnetic gap
BL, BL 1 , BL 2 , BL 3 bit line
C 11 -C 33 memory cell
J, J 11 -J 33 magnetic tunnel junction
SA 1 -SA 3 sense amplifier
SL, SL 1 , SL 2 , SL 3 source line
T, T 11 -T 33 selection transistor
Tb 1 -Tb 6 bit line transistor
Ts 1 -Ts 3 read transistor
Tw 1 -Tw 6 word line transistor
WL, WL 1 , WL 2 , WL 3 word line
DETAILED DESCRIPTION
Embodiments of the present disclosure will be explained below with reference to the accompanying drawings. Note that in the following explanation the same reference numerals denote constituent elements having almost the same functions and arrangements, and a repetitive explanation will be made only when necessary.
Note also that each embodiment to be presented below merely discloses an device or method for embodying the technical idea of the present disclosure. Therefore, the technical idea of the present disclosure does not limit the materials, structures, arrangements, and the like of constituent parts to those described below. The technical idea of the present disclosure can be variously changed within the scope of the appended claims.
Refer now to the drawings, FIG. 1 , FIG. 4 , and FIG. 5 illustrate exemplary aspects of MR element. Specifically, these figures illustrate the MR element having a multilayer structure with a perpendicular direction of magnetization in magnetic layers. The direction (or orientation) of the magnetization in the magnetic layers are shown by solid or dashed arrows. The magnetization in the magnetic layer can be directed perpendicular or in-plane to surface of the magnetic layers. The MR element can store binary data by using steady logic states determined by mutual orientation of the magnetizations in the magnetic layers separated by a tunnel barrier layer. The logic state “0” or “1” of the MR element can be changed by a spin-polarized current running through the element in the direction across the tunnel barrier layer or perpendicular to a film surface.
The MR element herein mentioned in this specification and in the scope of claims is a general term of a tunneling magnetoresistance (TMR) element using an insulator or semiconductor as the tunnel barrier layer. Although the above mentioned figures each illustrate the major components of the MR element, another layer (or layers) such as a seed layer, a pinning layer a cap layers, and others may also be included.
FIGS. 3A and 3B show a circuit diagram of a portion of MRAM 30 according to an embodiment of the present disclosure. The memory includes an array 22 of memory cells C 11 -C 33 , a plurality of parallel bit lines BL 1 -BL 3 connected at their end to a bit line driver 24 , and a plurality of parallel word lines WL 1 -WL 3 connected at their end to word line driver 26 .
Each memory cell comprises an MR element without a selection transistor. The MR element is connected to the appropriate bit and word lines at its ends and disposed at the intersection of the lines in a vertical space between them. Schematic view of the memory cell of the MRAM 30 is shown on FIG. 4 . The MR element J comprises at least a pinned magnetic layer 12 having a fixed magnetization direction (shown by a solid arrow), a free magnetic layer 16 having a variable (or reversible) magnetization direction (shown by a dashed arrow), and a tunnel barrier layer 14 disposed between the pinned and free magnetic layers. The free magnetic layer 16 can be made of a magnetic material with a substantial spin-polarization and has a the magnetization directed substantially perpendicular to a layer surface in its equilibrium state. For example, the free magnetic layer 16 can be made of (Co 30 Fe 70 ) 85 B 15 (% atomic) alloy having a thickness of about 1.5 nm. The pinned magnetic layer 12 can be made of a magnetic material with a substantial spin-polarization and has the magnetization directed substantially perpendicular to a layer surface. For example, the pinned magnetic layer can be made of the (Co 30 Fe 70 ) 85 B 15 (% atomic) alloy having a thickness of about 2.5 nm. The tunnel barrier layer 14 can be made of MgO having a thickness of about 1.1 nm. The free, tunnel barrier and pinned layers form a substantially coherent texture having a BCC (body-centered cubic) structure with (001) plane orientation. The MR element with this crystalline structure provides a substantial tunneling magnetoresistance (TMR≧100% at room temperature) and a density of spin-polarized write current of about 1·10 6 A/cm 2 or less. These parameters are essential for MRAM.
In the MRAM 30 shown in FIGS. 3A and 3B the pluralities of the conductive bit and the word lines intersect each other but spaced from each other in direction perpendicular to a plane of substrate (not shown). Each of the memory cells C 11 -C 33 comprises an appropriate MR element J 11 -J 33 that is disposed at an intersection of a bit and word line in the vertical space between them. The MR element is electrically connected to the intersecting bit and the word lines by its opposite ends. For instance the memory cell C 22 comprises the MR element J 22 disposed at the intersection of the bit line BL 2 and the word line WL 2 . The MR element J 22 is electrically connected to the word line WL 2 at its first end and to the bit line BL 2 at its second end.
The bit lines BL 1 -BL 3 extend in an X-direction. They are electrically connected at one end to a bit line driver 24 that includes CMOS transistors Tb 1 -Tb 6 . For example, the bit line BL 2 is connected by one end to a common drain terminal formed by a n-type transistor Tb 3 and p-type transistor Tb 4 . A source terminal of the p-type transistor Tb 4 is connected to a power supply. A source terminal of the n-type transistor Tb 3 is connected to a ground. Similarly the bit lines BL 1 and BL 3 are connected to the pairs of CMOS transistors Tb 1 , Tb 2 and Tb 5 , Tb 6 , respectively. Gate terminals of the transistors Tb 1 -Tb 6 are connected to the bit line driver 24 . The bit line driver 24 operates as a row selection switch.
The word line WL 1 -WL 3 extend in an Y-direction crossing the X-direction. One end of the word line WL 1 -WL 3 is connected to the word line driver 26 . The driver 26 comprises a plurality of read/write circuits. Each of the read/write circuits includes at least a pair of CMOS transistors comprising one of p-type transistors Tw 2 , Tw 4 or Tw 6 and one of n-type transistors Tw 1 , Tw 3 or Tw 5 connected in series to each other, and a sense amplifier SA 1 -SA 3 . Each of the transistors pairs Tw 1 and Tw 2 , Tw 3 and Tw 4 , Tw 5 and Tw 6 is connected to a power supply at a source terminal of the appropriate p-type transistor and to the ground at a source terminal of the appropriate n-type transistor. The word line is connected to a common drain terminal of the CMOS transistor pair and to one input terminal of the sense amplifier SA through a read transistor Ts. For example, the word line WL 2 is connected by its end to the common drain terminal formed by the transistor Tw 3 and Tw 4 and to the first input terminal of the sense amplifier SA 2 through the read transistor Ts 2 . Second input terminal of the sense amplifier SA 2 is connected to a reference element (not shown). Gates of the transistors Tw 1 -Tw 6 are connected to the word line driver 26 . The driver 26 operates as a column selection switch.
The sense amplifier SA 1 -SA 3 comprises at least two inputs. One input of the amplifier is connected to the end of the word line WL 1 -WL 3 and to the common drain terminal of the transistor pair by mean of the read transistor Ts 1 -Ts 3 . The other input of the sense amplifier is connected to a reference element (not shown). The sense amplifier judges a data value of the MR element inside of the selected memory cell based on a reference signal Ref.
The memory 30 shown in FIGS. 3A and 3B comprises the array 22 of the MR elements J 11 -J 33 disposed above the silicon wafer (not shown). The selection transistors Tb 1 -Tb 6 and Tw 1 -Tw 6 may be positioned along a perimeter of the array 22 . The wafer area located underneath of the memory array is not occupied by the selection transistors and can be used for another circuits. Hence the present design can provide a substantial reduction of a chip/die size. Moreover, the peripheral location of the selections transistors provides a possibility of using large selection transistors or several transistors providing a substantial write current that is essential for high speed writing.
The MRAM 30 shown in FIGS. 3A and 3B employs a spin-induced switching mechanism of the MR elements. According to spin-induced switching the orientation of magnetization in the free layer 16 can be reversed by a spin-polarized current I S running through the MR element ( FIG. 4 ). Electrons of the write current have a substantial degree of spin polarization that is predetermined by magnetic properties of the pinned layer 12 . The spin-polarized electrons running through the free layer 16 transfer a moment of their spins causing the magnetization in the free layer to change its direction. Polarity of the magnetization in the free layer 16 can be controlled by a direction of the spin-polarized current I S running through the MR element. The direction of the spin-polarized current in the MR element shown on FIG. 4 corresponds to writing a logic “0” or to parallel orientation of magnetizations in the free 16 and pinned 12 magnetic layers.
FIG. 3A shows writing of a logic “0” to the MR element J 22 of the memory cell C 22 . A switching current I S is produced in the MR element by applying appropriate input signals to the gate of the transistor Tb 4 ( Write 0 ) and to the gate of the transistor Tw 3 (Write 0). Both transistors are partially opened. The spin-polarized current I S is running from the power supply through the transistor Tb 4 , bit line BL 2 , MR element J 22 , word line WL 2 , and transistor Tw 3 to the ground. The appropriate bit and word lines, and MR element are shown in bold. For the MR element having a configuration shown in FIG. 4 the current I S is running from the free layer 16 to the pinned layer 12 through the tunnel barrier layer 14 . The spin-polarized conductance electrons are moving in opposite direction from the pinned layer 12 to the free layer 16 . For the giving direction of the current I S the magnetization in the free layer 16 will be directed in parallel to the magnetization direction of the pinned layer 12 . This mutual orientation of the magnetizations corresponds to a low resistance state of the MR element or to a logic “0”.
FIG. 3B illustrates writing logic “1” to the MR elements J 22 . The write current I S is supplied to the MR element J 22 by simultaneously applying an appropriate input signal to the gate of the transistors Tb 3 (Write 1) and Tw 4 ( Write 1 ). The transistors are partially opened and the current I S is running from the transistor Tw 4 to the transistor Tb 3 through the word line WL 2 , MR element J 22 , and bit line BL 2 (shown in bold). In the MR element J 22 having a configuration shown in FIG. 4 the spin-polarized current I S is running from the pinned layer 12 to the free layer 16 . This direction of the spin-polarized current will orient the magnetization in the free layer 16 anti parallel to the magnetization direction of the pinned layer 12 . This mutual orientation of the magnetizations corresponds to a high resistance state or to a logic “1”.
According to theory, the magnitude of the minimal spin-polarized current that is required to reverse the magnetization direction in the free layer is given by
I C 0 = - ( 2 e h ) αM S V g ( θ ) p H EFF ( 1 )
where e is an electron charge, h is Plank constant, α is Gilbert's damping constant, M S is saturation magnetization of the free layer material, V is volume of the free layer, and p is a spin polarization of the current. The factor g(θ) depends on the relative angle θ between vectors of magnetization (shown by arrows in FIG. 4 ) in the pinned 12 an free 16 layers. The value of the factor g(θ) is minimal and close to zero when the vectors of the magnetizations in the free and pinned layers are parallel or anti parallel to each other (θ is equal to 0 or 180 degrees). The factor g(θ) has its maximum value when the vectors of magnetizations in the layers are perpendicular to each other (the angle θ is equal to 90 or 270 degrees). Effective magnetic field H EFF acting on the free layer depends on a direction of magnetization (in-plane or perpendicular) in the pinned and free layers. The effective field is given by the following equations for the in-plane and for perpendicular magnetic materials, respectively:
H EFF// =H K// +2π M S +H APP +H DIP (2)
H EFF⊥ =H K⊥ ,−4π M S +H APP +H DIP , (3)
where H K// and H K⊥ , is a field of uniaxial crystalline anisotropy of in-plane and perpendicular magnetic material, respectively; H APP and H DIP are applied external field and the dipole field from the pinned layer acting on the free layer. The factor −4πM S arises from the demagnetizing field of the thin film geometry of the free layer having the perpendicular anisotropy. The same factor for the free layer with in-plane anisotropy is equal to +2 πM S . Hence, the MTJ with perpendicular anisotropy may require substantially smaller (depends on H K and M S ) switching current than that with similar parameters but having the in-plane anisotropy.
The direction of the magnetization in the free layer 16 of the MR element in its equilibrium states can be parallel or anti-parallel to the magnetization direction in the pinned layer. At these conditions the switching current that is required to reverse the magnetization in the free layer has its maximum value. Moreover, the magnitude of the current depends significantly on the duration of a current pulse. The magnitude of the switching current is almost inverse proportional to the pulse duration. Hence, the high speed writing (short current pulse) requires high switching current. Magnitude of the switching current is limited by the probability of a tunnel barrier layer breakdown. The above obstacles limit switching speed and endurance of MRAM with spin-induced switching.
The equation (1) suggests that the spin-polarized write current can be reduced significantly by changing the angle θ between the vectors of the magnetization in the free and pinned layers. Since the orientation of magnetization in the pinned layer 12 is fixed, the angle θ can be changed by tilting the magnetization in the free layer 16 from its equilibrium state. Tilt of the magnetization of the free layer 16 can be provided by applying a bias magnetic field along a hard magnetic axis of the free layer 16 .
FIG. 5 shows a schematic view of the memory cell comprising an MR element with perpendicular magnetization in the pinned 12 and free 16 magnetic layers along with adjacent bit BL and word WL lines. In addition to the spin-polarized switching current I S a bias current I B is further supplied to the bit line BL. The bias current I B running through the bit line BL produces a bias magnetic field H B (shown by arrow) that is applied along the hard axis of the free layer 16 . To increase the bias magnetic field locally, in vicinity of the MR element to further reduce the required bias current I B , the bit line BL comprises a conductive wire 52 and a magnetic flux concentrator (magnetic flux cladding) 54 . The magnetic flux concentrator 54 is made of a soft magnetic material having a high permeability and a low coercivity such as NiFe. The flux concentrator 54 comprises a non-magnetic gap 56 formed on a side of the bit line BL facing the MR element. The free layer 16 is disposed adjacent to the non-magnetic gap 56 where the bias magnetic field H B has a maximum. Additional layers, such as a seed layer can be placed between the free layer 16 and the bit line BL. Insertion of the additional layer (or layers) between the free magnetic layer 16 and the bit line BL results in a reduction of the bias field. The magnetic field H B decreases almost inverse proportionally with a distance between the free layer 16 and the bit line surface containing the non-magnetic gap 56 . FIG. 5 illustrates one exemplary implementation where a magnetic cladding is wrapped around a bit line that carries the bias current. Other magnetic flux cladding designs may also be used. The magnetic flux cladding can be used for a word line as well.
The bias magnetic field H B generated by the bias current I B is proportional to the current. For example, the current of 0.1 mA can generate a bias magnetic field of about 10 Oe in the vicinity of the MR element made with 65 nm technology node. The magnitude of the bias field H B is not sufficient to cause an unwanted reverse of the magnetization in the memory cells exposed to the bias field. The reversal of the magnetization can be achieved when both the bias magnetic field and spin-polarized current affect the MR element simultaneously. Hence the proposed hybrid writing mechanism provides a good selectivity of the memory cell in the array and significant reduction of the spin-polarized current I S . That is important for achieving a high endurance of MRAM operating at high speed, especially.
FIGS. 6A and 6B show a circuit diagram of a portion of MRAM 60 employing a hybrid write mechanism. The memory 60 comprises two bit line drivers 24 connected to the opposite ends of the of the bit lines BL 1 -BL 3 . The word lines WL 1 -WL 3 are connected at one end to the word line drivers 26 .
To write a logic “0” to the MR element J 22 ( FIG. 6A ) a bias current I B is supplied to the bit line BL 2 by applying appropriate input signal to the gate of transistor Tb 3 ( Write 0 ) and to the gate of the transistor Tb 4 (Write 0). The bias current I B running through the bit line BL 2 produces a bias magnetic field that is applied along the hard axis of the free layer. The bias field causes a tilt of the magnetization vector in the free layer from its equilibrium state that is perpendicular to the film surface. The magnitude and duration of the bias magnetic field can be controlled effectively by the input signal “ Write 0 ” and “Write 0” applied to the gate of the transistor Tb 3 and Tb 4 . The bias current I B alone cannot cause a reversal of the magnetization in the MR element J 22 and adjacent the bit line BL 2 elements J 21 and J 23 . Switching of the magnetization in the free layer is a joint effect of the bias magnetic field and a spin momentum transfer of polarized electrons of the current I S running through the MR element. To cause switching a spin-polarized current I S is supplied to the MR element J 22 . The current I S is running from the transistors Tb 3 to the transistor Tw 3 through the MR element J 22 located at the intersection of the bit line BL 2 and word line WL 2 (shown in bold). Simultaneous effect of the bias magnetic field and spin-polarized current results in a logic state reversal of the MR element J 22 .
The input signals applied to the gate of the transistors Tb 3 , Tb 4 , and Tw 4 should be synchronized in time. Pulses of the currents I B and I S can overlap each other partially (shifted in time) or completely. Order of the pulses at partial overlapping can be any. The transistor Tb 4 should be opened while any of the transistors Tb 3 or Tw 4 are opened.
The memory 60 also provides a possibility of simultaneous writing to the several MR elements having electrical contact with the energized bit line BL 2 ( FIG. 6B ). The bias current is supplied to the bit line BL 2 by applying an appropriate input signal to the gate of the transistors Tb 3 ( Write 1 ) and Tb 4 (Write 1). The bias current I B produces a bias magnetic field along the entire line and tilts the direction of the magnetization in all MR elements adjacent to the bit line. This field is not sufficient to cause a reversal of the magnetization directions in the energized MR elements. To accomplish reversal a spin-polarized current needs to be applied to the element. FIG. 6B shows a circuit diagram of a portion of memory 60 during writing logic “1” to the memory cells C 22 and C 23 simultaneously when a bias current is applied to the line BL 2 . The appropriate input signals “ Write 1 ” are applied to the gate of the transistors Tw 4 and Tw 6 connected to the end of the word lines WL 2 and WL 3 , respectively. The MR elements J 22 and J 23 located at the intersection of the word lines WL 2 and WL 3 with a bit line BL 2 are experienced to cumulative effect of the bias magnetic field produced by the bas current I B and spin-polarized current I S running through the elements.
Data can be written to the memory cells C 21 , C 22 , C 23 at the same time by applying an appropriate signal to the gate of the transistors Tw 1 or Tw 2 , Tw 3 or Tw 4 , Tw 5 or Tw 6 . Simultaneous writing to several memory cells can provide significant reduction a write energy per bit by means of more effective use of bias current.
Transistors Tb 1 -Tb 6 connected to the bit lines BL 1 -BL 3 and the transistors Tw 1 -Tw 6 connected word lines WL 1 -WL 3 are experienced to different magnitudes of the current running through them during writing. Therefore they can have different saturation current that can be achieved by using different size of transistors or by using several transistors. For instance the transistors Tb 1 -Tb 6 can have larger saturation current than the transistors Tw 1 -Tw 6 . The transistors Tw 1 -Tw 6 control the switching spin-polarized current in the MR elements of the array 22 .
FIG. 7 shows a circuit diagram of the memory 60 according in read mode of operation. To read the data stored in the memory cell C 22 an appropriate input signal needs to be applied to the transistors Tb 3 ( Read ), Tw 3 (Read), and Ts 2 (Read). A signal produced by a read current I R running through the J 22 represents a read signal that is proportional to a resistance of the MR element: high resistance for a logic “1” and a low voltage for the logic “0”. The read current I R is smaller than the spin-polarized write current I S and cannot cause the reverse of the magnetization in the free layer of the J 22 especially due to absence of the bias current I B . The read signal is applied to one input of a sense amplifier SA 2 through the opened transistor Ts 2 . A reference read signal Ref from a reference memory cell (not shown) is applied to another input of the sense amplifier SA 2 . An output of the amplifier SA 2 provides an information about data stored in the memory cell C 22 .
The MR elements of the disclosed MRAMs can use magnetic materials with in-plane and/or perpendicular direction of the magnetization.
While the specification of this disclosure contains many specifics, these should not be construed as limitations on the scope of the disclosure or of what may be claimed, but rather as descriptions of features specific to particular embodiments. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.
It is understood that the above embodiments are intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the embodiments should be, therefore, determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
While the disclosure has been described in terms of several exemplary embodiments, those skilled in the art will recognize that the disclosure can be practiced with modification within the spirit and scope of the appended claims. Specifically, one of ordinary skill in the art will understand that the drawings herein are meant to be illustrative, and the spirit and scope of the disclosure are not limited to the embodiments and aspects disclosed herein but may be modified.
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A method for writing to a magnetic memory comprising: providing a plurality of magnetic tunnel junctions arranged into columns and rows, applying a first current to a first conductive line coupled to a row of magnetic tunnel junctions at their ends adjacent to a free ferromagnetic layer to produce a bias magnetic field; and applying a second current to a second conductive line electrically coupled to a column of magnetic tunnel junctions at their ends adjacent to a pinned ferromagnetic layer to produce a spin momentum transfer in the free ferromagnetic layer of a first magnetic tunnel junction disposed at a first intersection region formed by the first conductive line and the second conductive line; wherein a joint effect of the first and second currents applied simultaneously reverses a magnetization direction of the free ferromagnetic layer of the first magnetic tunnel junction. Other embodiments of the magnetic memory are disclosed.
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CROSS REFERENCE TO RELATED APPLICATIONS
This patent application is a Divisional of, and claims priority to under 35 U.S.C. §120, U.S. patent application Ser. No. 09/623,847, filed on Jul. 31, 2000 now abondoned, entitled, “Minimum Till Seeding Knife” and having Terry Emerson Summach and Bradley T. Summach as the Inventors. The full disclosure of U.S. patent application Ser. No. 09/623,847 is hereby fully incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to a method of farming, a farm implement and a knife or knife assembly which may be used as part of no-till or minimum-till farming practices primarily for placement in the ground of seed and/or fertilizer and other materials. The invention works in all field conditions, and in particular it operates with minimum soil disturbance in minimum till and zero till farming practices, better allows passage of trash in such practices, and does not cause the hair-pinning of crop residue as is often caused by disc-type openers. As a result, the method provides a simple, reliable and inexpensive procedure and tool which can be used in all farming practices so that multiple types of equipment are not required by farms for various soil conditions.
BACKGROUND OF THE INVENTION
Important advantages have been found in soil preparation, and seed and fertilizer delivery in employing no-tilling or minimum tilling methods which cause minimum disturbance to the soil. This is particularly important in dry land conditions where the soil is subject to moisture and topsoil loss if conventional tilling methods are used.
It is usually desirable when employing no-till farming practices to disturb the soil surface as little as possible. The surface will be covered with the residue from previous crops, and the surface layer will contain old root structure. This plant material can serve to retain moisture below the surface and to assist in securing the soil against runoff and erosion. Particularly in dry land conditions it is beneficial to retain this covering. Tools available to seed into zero till or minimum till conditions have encountered problems.
Fertilizing prior to seeding is a method utilized by some farmers. While broadcasting the fertilizer on the surface is a method that does not disturb the surface, it is very inefficient, as much of the fertilizer can be lost due to runoff surface water. Placement of fertilizer at a level well below the level that seed will be place has been utilized. Tilling and fertilizing is disclosed in Great Britain patent No. 1,574,412 issued to Ede in 1980. In that prior art device an angled tilling blade for deeply penetrating the soil is shown with a central duct and a number of separated orifices for providing fertilizer in vertically separated bands. To maintain those desirable characteristics of the surface structure in zero till conditions major surface disturbance is not acceptable.
Zero till devices have been developed to deposit high concentration bands of fertilizer in furrows. If the seed is placed in close proximity to a high concentration of fertilizer, burning of the newly germinated plant will result. To avoid this one technique has been to separate the seeds by a soil layer from the fertilizer.
In the U.S. Pat. No. 5,396,851 issued to Beau jot in 1995 fertilizer is deposited by a first vertical blade which cuts a deeper furrow. A second blade cuts a second furrow in which to deposit seed. Other devices such as disclosed in U.S. Pat. No. 4,798,151 issued to Rodrigues in 1989 form a deep fertilizer furrow, and a shallower shelf above the fertilizer on which to plant the seed. In both cases, to minimize soil disturbance only a narrow furrow is cut. It is grown to prepare soil when using traditional tilling methods to cut out weed growth prior to or at the time of a seeding operation.
U.S. Pat. No. 1,085,825 issued in 1914 to Rubarth discloses a subsurface tilling blade for use with a traditional turning plowshare. The tilling blade its curved to angle the cut and includes a horizontal blade on the opposite side. The blades are shown to include an arrangement in overlapping fashion to cut the full width of the subsurface to remove weeds and old growth. Seeding and fertilizing are separate operations.
U.S. Pat. No. 5,005,497 issued in 1991 to Kolskog discloses a deep banding knife for delivering seed and fertilizer with an additional transverse rod for disrupting weed growth. The banding knife makes a substantially vertical cut in the soil. The rod disrupts the subsoil to loosen soil and cut weeds. The transverse rods can be arranged in parallel to remove weeds completely.
Adaptations of these concepts have been used for deep placement of fertilizer in fully tilled row-crop situations.
In traditional zero till farming practice, no till furrows are separated by undisturbed areas of soil and weeds. Typically a herbicide application is necessary to control weeds which would otherwise compete with the crop growth and possibly contaminate the harvest. Herbicide is an expensive additional operation.
A further problem encountered by seeding implements particularly in zero till conditions is the accumulation of trash during seeding which impairs their operation. Many devices for seeding in zero till conditions provide a blade which penetrates the soil substantially vertically. Trash gathers around the blade and is dragged with the device. This can impair operation. It also removes the desired moisture retaining cover. In an effort to combat this problem the Beau jot discussed above is adapted to lift over obstacles, such as crop stubble, interrupting seeding. Such a technique reduces trash accumulation, but reduces seeding efficiency.
A deep sowing tool has been disclosed for rice seeding in relatively wet conditions in USSR patent No. 372,962 issued in 1973 using a tilling blade and deep seed delivery to cover seeds and to reduce the need to water. This is not suitable for zero tilling, as tilling using this tool is deep in order to cause deep soil aeration. The blade of this prior art design penetrates the soil essentially vertically, with an angled blade portion cutting more deeply. The blade portion of this design would also be subject to accumulation of trash.
Significant soil disruption occurs as vertical furrow parting tools are drawn through surface soils at relatively high velocity, especially in high trash conditions or with unprepared soils. Additional energy is imparted to the soil, throwing and turning the soil.
It is desired for minimum soil disruption to pass through the soil surface and any trash cleanly without undue lifting or turning of the soil. While disk openers have the ability to cut through most trash, some straw will not cut easily, and is pushed into the furrow, a result commonly called hairpinning. This can displace seeds, as well as drying out the seed bed. As well, effective no-till disc opener designs are relatively expensive.
The prior art fails to provide teaching to or a suggestion of any method or device for operation in zero or min-till conditions which provides tilling and/or seeding, fertilizing or weed clearing in a single pass without significantly disrupting the soil or the order of the soil structure and avoid hairpinning. It is desired to provide the advantages of tilling seeding and weed clearing without trash accumulation.
SUMMARY OF THE INVENTION
The invention provides a ground opening knife for use in no-till or minimum-till farming operations primarily in conjunction with seed and/or fertilizer placement adjacent a soil cut-line generally in the direction of travel comprising connection mechanism adapted to mount the knife on a farm implement, and a blade comprising a lower portion, said lower portion adapted to open soils along the direction of travel, said lower portion adapted to extend into the soil but no more than 6 inches measured vertically, said lower portion adapted to be oriented in a direction having a 1 st component of between 30 and 60 degrees below horizontal in a plane transverse to the said direction of travel, and a 2 nd component forward in the direction of travel.
The knife may include an upper portion adjacent said lower portion adapted to extend away from the surface of the soil and is adapted to pass through materials or residue on the surface of the soil or associated with the passage of the knife though the soil.
The knife may also include an extension extending substantially laterally from said lower portion and provides support for material delivery tubes at various locations along the blade and extension.
The knife may also include in extension to form a secondary furrow adjacent the said lower portion intermediate the surface of the soil and the lowermost end of the said blade and may include an extension of said leading edge generally forward in the direction of travel.
The invention also provides a method of no-till or minimum-till farming operation primarily in conjunction with seed and/or fertilizer placement adjacent a soil cut-line aligned generally in the direction of travel comprising forming a furrow in the soil extending from said soil cut-line no more than 6″ into the soil measured vertically, and forming the said furrow by cutting the soil along a direction having a 1 st component of between 30 and 60 degrees below the horizontal in a plane transverse to the said direction of travel, and a 2 nd component forward in the direction of travel.
The method substantially minimizes any disturbance of the cut soil either above the said furrow or below it or both whether distribution or particulate or other materials is included at the same time within the furrow being formed.
The invention also provides a no-till or minimum-till farm implement primarily for use in conjunction with cultivation or materials placement adjacent a plurality of soil cut-lines generally parallel and in the direction of travel comprising a support frame structure, a plurality of around opening knives attached to said support structure, spaced from each other in a direction transverse to the direction of travel of the implement and each adapted to cut the soil along adjacent ones of said cut-lines, each said knife having a blade comprising a lower portion, said lower portion adapted to extend into the soil but no more than 6 inches measured vertically between the surface of the soil and the lowermost extremity of the said blade, said lower portion adapted to be oriented in a direction having a 1 st component of between 30 and 60 degrees below horizontal in a plane transverse to the said direction of travel, and a 2 nd substantial component forward in the direction of travel.
The farm implement may include an extension of the blade extending laterally across a substantial portion of said spacing between adjacent said cut-lines when viewed in a plan view.
The invention will be more clearly understood to those skilled in the art with the following detailed description of preferred embodiments with reference of the following drafting's in which:
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a plan view of a single knife according to the present invention;
FIG. 2 is a side view of the embodiment of FIG. 1 ;
FIG. 3 is a front view of the embodiment of FIG. 1 ;
FIG. 4 is a plan view of a further embodiment according to the present invention;
FIG. 5 is a side view of the embodiment of FIG. 4 ;
FIG. 6 is a front view of the embodiment of FIG. 4 ;
FIG. 7 is an isometric view of the embodiment of FIG. 4 arranged on an implement for operation; and
FIGS. 8-1 through 8 - 3 are front, top and side elevations respectively of another embodiment of the invention adapted for double shooting of materials in seeding. Like references are used throughout to designate like elements.
FIG. 9 is a plan view of an agricultural implement for planting seeds. Which incorporates the seeding knives of the invention;
FIG. 10 is a horizontal front elevation of an angled seeding knife, in use;
FIG. 11 is a side elevation of the knife of FIG. 10 , from the left side of FIG. 10 , and FIG. 11 includes a cross-section on the line X—X of FIG. 10 ;
FIG. 12 is a rear elevation of knife of FIG. 10 ;
FIG. 13 is a right side elevation of the knife of FIG. 10 ;
FIG. 14 is a cross-section of a blade of the knife of FIG. 10 , the cross-section being taken in a plane at right angles to a knife-edge of the blade;
FIG. 15 is a front elevation corresponding to FIG. 10 of another angled seeding knife;
FIGS. 16 , 17 , 18 are further elevations of the knife of FIG. 15 ;
FIG. 19 is a pictorial elevation of a replaceable tip, of the knife of FIG. 15 ;
FIG. 20 is an elevation of the body of the knife of FIG. 15 , and is shaded to show the configuration thereof.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment of the single knife of the present invention is as shown generally at 10 in FIGS. 1–3 . In FIG. 1 , arrow designated 1 shows the direction of travel of the knife 10 through the soil when working.
As shown in FIG. 7 , the knife 10 is typically attached to a cultivator-type frame or implement generally indicated at 2 to be towed by a tractor in a direction of travel 1 primarily in cooperation with a tow-between or tow-behind seed supply carrier (not shown) having a repository of seed, fertilizer or other material and fluid passages for connection with the knife 10 . The frame 2 is shown in general outline only.
The knife 10 includes a shank 12 which serves as a connection for mounting the knife 10 selectively on the implement in a known fashion ( as at 3 in FIG. 7 ). As shown in FIG. 7 , an appropriate spacing 4 for seeding or tilling operations will be selected, determining the number and spacing of knives 10 mounted across the width of the implement. The shank 12 preferably has a pair of holes 13 (See FIG. 1 ) for mounting bolts or the mounting could be provided in any conventional manner such as a knock-on taper mounting system or other known mounting mechanism.
Knife 10 includes a blade 14 formed to penetrate the soil along a soil-cut line 11 oriented in the direction of travel. Penetration of the soil occurs at an angle A which has both substantial lateral (A 1 ) and forward (A 2 ) components as shown in FIGS. 3 and 1 , respectively, of approximately 35–55 degrees to the surface 5 of the soil to be tilled. Preferably each of lateral and forward components A 1 and A 2 respectively is 45 degrees. Soil penetration (d) is by the lower portion of the blade 14 as at 6 in FIG. 3 and is no more than 6 inches, consistent with minimum till or no till farming practices.
Knife 10 includes a blade 14 formed to penetrate the soil along a soil-cut line 11 oriented in the direction of travel. penetration of the soil occurs at an angle A which has both substantial lateral (A 1 ) and forward (A 2 ) components of approximately 35–55 degrees to the surface 5 of the soil to be tilled. preferably each of lateral and forward components A 1 and A 2 respectively is 45 degrees. Soil penetration is by the lower portion of the blade as at 6 in FIG. 3 and is no more than 6 inches, consistent with minimum till or no till farming practices.
The lateral component A 1 of angle A determines the final angle of the furrow cut into the soil. The angled furrow allows seed to be planted ensuring soil cover.
The blade is also angled significantly forwardly by component A 2 of angle A. Preferably, a lower end 17 of a cutting edge 16 is significantly in advance of the upper end 15 of the cutting edge 16 . Deeper soil is cut and lifted in advance of cutting the surface soil allowing the surface to be cut along cut-line 11 more easily and without undue lateral disruption. Vertical motion is limited. The forward component of angle A of the blade cuts through the surface and trash layers last without accumulating trash on the knife 10 . Leading edge 16 is preferably continuous from its lower end 17 to its upper end 15 .
The blade 14 had a leading cutting edge 16 and a pair of opposing angled surfaces 18 a and 18 b which form a wedge shaped profile. The profile shape is determined by the furrow opening required. Edge 16 may be in 2 parts, one below the surface and another above, but preferably extends continuously above the surface sufficient to move trash and other materials aside without accumulation. Also preferably it is formed aligned with the leading edge of the lower portion of the blade 14 .
Preferably surface 18 b is inclined slightly from the horizontal to avoid sliding contact with the soil below the blade 14 and minimize soil disturbance below the cut.
Also preferably, the rear surface of blade 14 is also angled forwardly and downwardly so as to assist in the creation of a small temporary cavity behind the blade as it travels through the soil.
The overall effect is to provide a method and knife whereby primarily vertical motion is imparted to the soil to permit the blade 14 passage and then a return substantially vertical motion is permitted whereby the soil may return to its approximate original location.
Adjacent the trailing surface 20 of the blade 14 , a conduit 22 may be secured for delivering seeds or other material.
The conduit 22 may have an outlet 24 near the lower end 17 of the blade 14 as shown in FIGS. 1 and 2 , and as a result the outlet 24 is adjacent the lowest area of the furrow cut by the blade 14 . The seed delivery conduit 22 is protected from damage as the blade 14 is advanced through the soil by the blade body 14 . The outlet 24 is also shielded from becoming clogged with earth by this arrangement.
Additional conduits along the blade for fertilizer, herbicide or other materials may be similarly located (not shown in FIGS. 1–3 )
The preferred method provides the steps of forming an angled no-till or minimum till furrow by a knife 10 which furrow cutting motion has both a substantial forward and a substantial lateral component both above and below the ground to a depth (d) of 6 inches.
In a preferred method, seed and fertilizer are scattered from adjacent outlets in a pattern across the width of the furrow. The outlets may be spaced apart to appropriate depths and separation, for example, placing fertilizer outlet at the lowest end of the blade for the deepest application and a seed outlet spaced above it on the angled blade 14 .
Another preferred embodiment is shown in FIG. 8 in which FIG. 8-1 shows the embodiment in a front view, FIG. 8-2 in a plan view and FIG. 8-3 is a side elevation.
In FIGS. 8-1 through 8 - 3 , the embodiment is shown in conjunction with the knife and method shown in FIGS. 1 to 3 with an additional double shoot extension 8 . Leading edge 16 of the lower portion 7 is extended further forward and downward as best depicted in FIG. 8-3 . As seen in the front view of FIG. 8-1 , this will provide a secondary furrow or ledge intermediate the surface of the soil 5 and the lower end 17 . FIGS. 8-1 through 8 - 3 show this embodiment as forming a v-shaped furrow particularly suited to the deposit of particulate material such as seed which would be retained in this groove. The extension 8 could have other shapes to form a ledge or other shape as required.
An extension 8 depends from the leading edge 16 and may be provided with a delivery conduit 19 .
This double shoot method forms a seed or other material positioning shelf or secondary furrow within the angled furrow with a specific spacing from the lowermost extremity.
An alternate embodiment of the invention is shown in FIGS. 4–6 . The knife 10 includes a blade 14 as described above. The knife 10 further includes an extension blade 30 that extends substantially horizontally form the blade 14 preferably at its lowermost end 17 . The extension blade 30 has a leading cutting edge 36 , which preferable forms a continuation of or a 3 rd part if also the leading ledge 16 . Edge 36 is substantially horizontal and is preferably oriented transverse to the direction of travel. The cutting edge 36 is formed between an upper surface 32 angled upwardly and rearwardly and a lower surface 33 which is substantially horizontal. The lower blade surface 33 may preferably be angled to the rear, upwardly about 2 degrees, or notched, to reduce drag.
The extension blade 30 increases the width of the knife 10 as shown in FIG. 7 . This extends the cultivating and/or planting area for greater seed bed utilization, or may be selected for greater spacing between seed planting while still effectively cutting existing plant roots to condition more of the width of soil. The extension blade 30 may be varying in width for different spacing considerations.
Outlets for seed, fertilizer and other addictives may be spaced apart in or on the extension blade 30 to form distinct rows (not shown) and are preferably adjacent the rear surface thereof or may provide for broadcast across the width of extension 30 .
Outlets 24 may also be placed at the corner between the angled blade 14 and the extension 30 as shown in FIGS. 4 and 5 , or higher on the angled blade 14 for vertical separation such as for herbicide application nearer the soil surface.
As seen in FIG. 7 , a plurality if knives shown including extension 30 on an implement frame in outline may be arranged spaced in continuous or overlapping arrangement on the implement 2 so that the full width of soil is conditioned. The number and spacing will depend on the crop and planting conditions. Suitable placement of outlets along extension 30 would result in a generally scattered seed and fertilizer delivery in behind each knife 10 . In this case the complete width of the soil may also be cut by the blade extension without being dragged and fouling the knife 10 .
The extension blade 30 may be positioned to travel under the path of the angled blade 14 of the adjacent knife 10 .
Knives 10 are mounted to an implement or cultivator frame 2 as in FIG. 7 . A wing section of the frame 2 is illustrated in outline form. Additional central and wing sections are not shown. The frame 2 is carried on loads bearing wheels (not shown) which support the frame 2 in a raised position for travel and in operative position.
Adjustment of the height if the frame 2 in a known fashion accurately controls furrow depth (d). Depths (d) may typically range from ½ inch to 4 inches or up to 6 inches. Alternatively, a ground following linkage may be used to attach each knife 10 to the frame 2 with the depth being controlled by a wheel attached to each knife assembly.
In use, the knifes 10 arranged in parallel fashion on an implement or overlapping arrangement on an angled draw bar are drawn by a tractor together with a seed carrier provided with reservoirs of seed and fertilizer material and a fluid delivery system operatively connected with the conduits 22 on the knives 10 . The frame 2 is advanced with the leading cutting edges 16 and, optionally, edge 36 facing in the direction of travel 1 . The deposit of material is controlled by the speed of advance of the tractor in a known fashion.
The knife 10 will not normally produce overlapping furrows without the blade extension 30 being present, or being long enough to result in an overlapped cut with adjacent rows as the placement would be too close. Weed control with herbicides is necessary in those circumstances.
As seeding occurs, fertilizer can be added simultaneously in controlled concentration, or at a desired depth or spacing from the seed. Fertilizer is more efficiently used without loss from runoff. Further fertilizer is placed to be available to the crop and not at the surface for weeds. A substance delivery of fertilizer is particularly effective if gaseous fertilizer, such as ammonia, is used. The knife provides a variety of options for placement with minimum adjustment and cost.
It may be desired to seed an area progressively in time for continuous harvest. Or with different additives, or with different crop. Since the process is a complete single pass operation, each seeding will include complete weeding and fertilizing more accurately than if separate steps are made which might leave areas untouched.
The invention may also be used as a light tilling tool for minimum soil disturbance without seeding or fertilizer outlets. This would cut weeds and provide minimum soil aeration. The knife advantageously does not turn the soil which would incorporate weed seeds from the surface into the soil to germinate.
Additional embodiments of the present invention will be apparent to persons of skill in the art.
FIG. 9 is a plan-view diagram of an implement 120 which carries thirty-five angled-knife seeders 123 in four rows. The implement 120 has a centre section 124 , and two hinged wings 125 . The wings 125 can be folded upwards for road-transport and storage of the implement. The centre section 124 includes a hitching mechanism 126 whereby the implement can be towed by a tractor.
It will be noted that some of the angled-knife seeders 123 slope to the left, and some to the right. Thus, there is no, or only a small, net sideways force on the implement. The left seeders and the right seeders are kept separate. In banks, since the configuration of the seeders is not suitable for close-pitched left-right mountings thereof.
Press-wheels 127 are provided. One in-line behind each seeder. to roll over. And to close the ground. After the seeds have been deposited by the seeders.
The seeders are attached each to a respective mounting bar 128 , which is suspended from the frame 129 of the implement, the suspension mechanism including the usual break-back-spring mountings 130 .
FIG. 10 is front view of one of the angled-knife seeders 123 . FIG. 10 shows the seeder being dragged forwards, i.e. out of the paper, as indicated by the arrow 132 . FIG. 1 is a lateral or side elevation, showing the seeder being drawn through the ground, and moving to the left as indicated by arrow 132 . FIG. 11 includes an inset cross-section, taken on line +—+of FIG. 10 . It is emphasized that line +—+is vertical, i.e. the inset cross-section in FIG. 11 lies in a vertical plane.
As shown from the front view, FIG. 10 , the seeder or knife 123 has an angled blade 134 which extends down into the ground to a depth, typically of about 10 cm. The depth is determined by the needs of the type of seeds being planted; planting seeds deeper than 10 cm would be unusual, and 15 cm can be regarded as a maximum planting depth.
The angled knife cuts an angled slit-opening in the ground, and the seeds are deposited therein. The seeds to be planted are sullied from a hopper on the implement, and are blown along a hose by mechanism of a fan which forces an air flow in the hose. The hoses are of flexible plastic tubing, one for each seeder (the hoses are not shown in FIG. 9 ).
Each flexible hose is clipped to a respective conduit 135 , which is built into the seeder 123 . The conduit is structurally integrated into the back-side of the angled-knife-blade 134 , and runs down the back-side 136 of the blade. The conduit ends in a discharge mouth 137 , from which the seeds emerge, and fall down into the slit-opening. The discharge mouth 137 is near the bottom of the knife blade, whereby the seeds are deposited more or less at the bottom of the slit opening.
The conduit 135 is shown in the rear view of the seeder, FIG. 12 , and in the opposite side-elevational view to FIG. 11 , FIG. 13 . The upper end of the conduit terminates at a port 138 , into which the flexible hose can be secured.
The knife blade has an over-surface 139 and an under-surface 140 . These surfaces are respective flat planes which meet at a line, that line being the knife-edge 142 . The blade is generally triangular in cross-section. In that the surfaces 139 , 140 slope back from the knife edge, to a maximum thickness of the blade at the back-side 136 thereof. The conduit 135 is accommodated within the thickness of the back-side of the blade.
FIG. 14 is a cross-section of the blade 134 and shows the dimensions thereof. The FIG. 14 cross-section is taken in a plane at right angles to the knife-edge. The dimension 143 is the distance between the over-surface 139 and the under-surface 140 at the back-side if the blade, which in this case is 32 mm; and dimension 145 is the distance from the knife-edge 142 to the mid-point of the conduit 135 , which in this case is 70 mm. The conduit 135 has an internal diameter if 24 mm. The angle between the over-surface 139 and the under-surface 140 , in the cross-section at right-angles to the knife-edge, is called the wedge angle 146 , which in this case is 25 degrees.
Not only is the angled blade 134 angled to the side, at a side-slope-angle 147 , as shown in FIGS. 10 and 12 , but the blade is also given a forward pitch angle 148 , as shown in FIGS. 11 and 13 . In this case, the side-slope angle 147 is 45 degrees, and the forward pitch angle is also 45 degrees.
The leading knife-edge 142 is positioned such that when the blade is viewed from in front. Only the over-surface 139 can be seen. The under-surface 140 is invisible. That is to say, the knife edge is at the lowermost point of every vertical cross-section taken through the blade 134 . Thus, the portion of soil that lies in the path of the blade lies in the path of the over-surface 139 of the blade. The over-surface has the wedge angle 146 , and the soil is therefore driven upwards, by the wedge angle. The uplift travel of the soil is determined by the vertical height 149 of the over-surface 139 , as presented to the oncoming soil, which in this case is about 8 cm.
FIG. 15 is a front elevation of another design of angled-knife seeder 150 . In this case, the above-ground portion of the seed conduit 152 is positioned to one side of the above-ground shank 153 . This location of the conduit provides access for the nuts and bolts which are used at 154 to fix the seeder to the mounting bar 128 . However, although access for the nuts and bolts is good, the extra width of the shank 153 can be obtrusive, and can cause soil debris created by the passing of the angled blade to hang up such that the wide shank 153 can act like a bulldozer blade.
A deflector surface 156 is provided, for deflecting soil debris away from the front face of the shank 153 . The deflector surface 156 is angled to deflect the debris downwards, and to the side. The nub 157 serves also to break the upward flow of the debris, and to keep the shank 153 clear.
It may be noted that, in FIG. 1 , the triangular gusset-surface 159 was disposed at an angle that included a downwards component, and so the gusset-surface 159 also served to deflect up-flowing debris downwards, and sideways, away from the shank 12 of the knife. Thus, the deflector-surface can be on the outside ( FIG. 15 ) or the inside ( FIG. 1 ) of the angle between the shank and the blade. Providing downward-facing deflector surfaces on both the inside and the outside also is possible, except that the designer should take care that the knife is not weakened thereby, at the transition 160 ( FIG. 15 ), 162 ( FIG. 1 ), between the shank 12 and the angled blade 14 .
FIGS. 16 , 17 , 18 are other views of the knife of FIG. 15 . It will be noted that this knife includes a separable and replaceable tip 163 . The tip shown separately in FIG. 19 . FIG. 20 is a shaded view of the back of the body 164 of the knife, and shows not only how the conduit in this design is molded into the shape of the knife, but shows also a spline 165 on the body, which forms the mounting base for the replaceable tip 163 . The tip 163 is held to the spline 165 by mechanism of a pin which engages the pin-receiving-hole 167 . The spline 165 is prism-shaped, having a triangular cross-section like that of the blade itself but smaller, and the tip 163 includes a socket that is complementary to the conduit 152 . Once pinned in place, the tip 163 is very securely constrained against all modes of movement relative to the body 164 . The pin serves only to keep the tip from falling down the spline, but the force tending to make the tip 163 move in that mode minimal: all the heavy forces between the tip 163 and the body 164 are supported by the chunky spline 165 .
The conduit 152 continues inside the spline 165 . It is important that the seeds are deposited close to the bottom of the cut opening; with the conduit inside the spline, even though the bottom part of the knife comprises the tip, the conduit goes to the bottom of the opening. (It would be inefficient to cut the opening deeper that the planting depths of the seed, so the discharge mouth of the conduit should be as near the bottom of the knife as possible.) On the other hand, the prudent designer would seek to avoid calling for the manufacture of a (tubular) extension of the conduit in the tip casting. Putting the conduit in the spline puts the discharge mouth of the conduit more or less at the bottom of the trench, even though the knife has a replaceable tip.
It will be noted that the lower extremity 168 of the knife edge 169 on the body 164 is rounded convexly, whereas the upper extremity 172 of the knife edge 170 on the tip 163 includes a tag 173 which is rounded concavely. Thus, debris traveling up the knife edge can readily pass smoothly over the transition between the two knife edges 169 , 170 . The designer should see to it that the knife edges do not contain interruptions, upon which soil-debris could be snagged. Forming the body 164 with a large convex radius is easy from the casting-manufacture standpoint; it is much easier to control the quality of a concavely-curved tag on the tip casting than on the body casting.
The knife edge 170 in the tip 163 can be blunter than the knife edge 169 on the body 164 . The tip 163 operated more deeply, where debris, even if imperfectly cut, tends to be brushed off the knife edge 170 by the pressing passing soil. On the body 164 , the knife edge 169 itself has to do all the cutting of debris and vegetation, with little assistance from the passing soil, since, being shallower, the passing soil might more easily be deflected. It is noted that, if it happened, a hang-up of imperfectly cut material on the knife edge would be a quite serious problem, as it would quickly lead to disruption and disturbance of a large area of soil around the slit opening.
Conventionally, when seeding has been done with seeding knives (as opposed to discs, etc) the seeding knife has been held vertically. When the seeding knife is held at a side-slope-angle, as described herein, the manner in which the soil is opened for receiving the seeds is considerably changed.
When the knife is at a side-slope-angle of about 45 degrees to the horizontal, what happens is that a flap 174 of soil is lifted temporarily by the passing blade 134 , and then the flap is lowered gently back after the seeder knife 123 has passed. As a result, the layers of the soil are preserved, during seeding. In other words, it is possible for a farmer to plant seed without disturbing the stratification of the soil. It may be noted that the press wheels 127 serve to press the flap 174 back down, and assist in the maintenance of stratification: thus the function of the press wheel is more in harmony with the action of the angled blade, than in the case of a press when linked with, for example, a non-angled (vertical) seeding knife.
Maintenance of soil stratification is important in currently-favored minimum-till farming regimes, because moisture in the layers a few centimeters down is not dissipated; weed seeds on the surface remain on the surface and do not germinate; and stalks and vegetation at the surface remain intact, providing cover and moisture retention. On the other hand, the angled knife, especially when a wing extension is provided below ground, cuts and severs the roots of any vegetation that might be present, whereby weeds and unwanted plant growth are destroyed simply by mechanical action. Using herbicide to destroy weeds is expensive and can be dangerous, and has to be done as “reach” of the angled knife can be enough to sever the roots of weeds and other growth not only around the seed openings, but over the whole area of ground between the openings.
The fact that the flap of soil is pushed upwards by the angled blade does not mean that the soil is compressed: if the soil were pushed downwards or sideways, it would become compressed and perhaps smeared, since there is no where for the deflected soil to go; but when the soil is urged upwards, the soil simply moves upwards. Of course, lifting deeper solid would involve lifting the weight of all the soil above, so lifting without compression only works down to shallow depths. Thus, it would not be possible to lift a flap of soil without compressing it if the soil were more than 10 or 15 cm deep. But it is recognized that seed planting is done predominantly at shallower depths than that; and it is recognized that the depths down to which an angled blade can cause the soil to simply lift without being compressed is a suitable depth to enable planting of nearly all types of seeds.
If the knife were nearly vertical, i.e. if the knife were angled over at more than about 60 degrees to the horizontal, the lifting action that occurs with the angled knife would become negligible. With the 45-degree angle, most of the movement of the soil that occurs is a riding up of the soil over the front edge of the knife. At an angle of 60 degrees, the soil tends to be bulldozed, or chiseled, rather than slit or cut. Insofar as the soil is pushed to the side by the knife, the soil is compressed, and smeared, rather than gently lifted.
Of course, the knife must emerge from the ground surface, and the very shallow soil around the point of emergence inevitably is lifted too much, and tends to fly away. However, this effect is less disturbing than inserting a vertical chisel into the ground.
If the knife were more nearly horizontal, this fly-away lifting of the shallow soil might be too much. Besides, if the knife were nearly horizontal, although the knife would still lift the flap of soil, the knife blade would need to be too long in order to get down to the seed planting depth, which would mean that too much soil was being moved for a given planting depth, and which would be poor mechanically.
Tests have shown that the slap-lifting, stratification-maintaining, advantageous effects of the angles blade are largely lost if the blade is angled (i.e. the side-slope-angle) more than about 55 degrees or less than about 35 degrees. 60 degrees and 30 degrees can be regarded as the practical limits. It has been found that the force required to draw the angles blade through the ground is at a minimum when the blade is at about 45 degrees. It may be noted that the minimum draw force is an indication of minimum ground disturbance, which is what makes for minimum-till agriculture.
The leading knife-edge of the angled blade should be lowermost into the ground. That is to say, the soil approaching the blade should “see” only the over-surface of the blade. Thus, all the soil that is deflected is deflected upwards. If some of the soil were driven downwards, or horizontally sideways, it would be compressed or smeared, and seeding is most effective and efficient when the seeds are placed on and in soil that has not just been compressed.
The effective but gentle lifting as desired has been obtained with angled blades where the blade has been so presented that the over-surface has been about 7 cm high, measured in a vertical sense, from the leading knife edge to the back of the over surface. (The thickness of the blade, measured in a plane at right angled to the leading edge, preferably is between 25 and 45 mm.) The angle between the over-surface of the blade and the under-surface, called the wedge angle, is a key factor in determining the lift of the blade, and good results have been obtained when the wedge angle lies between 20 and 30 degrees.
Preferably, the over-surface should be a single flat plane over its whole area, but it is recognized that it id the front of the over-surface of the blade that is key to the performance, i.e. the front 4 cm of the over-surface contiguous with the knife edge.
Preferably, the blade is generally triangular as to its cross-sectional shape, the three sides of the triangle being the over-surface, the under-surface, and the back-side of the blade. (The back-side is not, as shown, a flat plane.) It is recognized that the triangular is a good shape, in that it leads to a suitable angle for the over-surface of the blade, in order for the over-surface to deflect soil dynamically; also, the bottom face can be easily set to not touch the soil passing-by underneath the blade; also, the bottom face can easily be set to not touch the soil passing-by underneath the blade; also, the thick back-side has to be thick to accommodate the conduit. In short, the triangular shape is a highly efficient shape for performing the soil-moving operations required for seeding, for accommodating the seed conduit, and (not least) is a food shape for providing mechanical strength and rigidity in just the right amounts for the task.
The designer should see to it that the knife is reasonably short, in the travel direction. Length would just lead to extra drag, and perhaps smearing of the soil, the aim should be to combine efficient use of surfaces and angles to give smooth lift-then-fall-back movement of the soil, without disturbing the soil, and while maintaining stratification. The designer should see to it that the surfaces are angled enough, and are long enough for that, and of course the knife has to be strong and rigid enough to be struck occasionally by stones etc without being damaged. It is recognized that the angled blase as described herein is a design that handles these conflicting requirements very advantageously.
The conduit preferably should be in the size range of 15 to 25 mm diameter, for proper seed conveyance. It is recognized that such a size of conduit is wee-suited to being located behind the triangular angled blade, as described. The blade surfaces, i.e. the over-surface and the under-surface, slope towards the conduit as two simple flat planes, straight from the knife edge.
As mentioned, the functions of the blade require that the blade be wide enough for its surfaces to be so angled as to be effective; and the blade must also be strong enough; beyond that, the blade should preferably be short. Good results have been obtained when the blade is about 7 cm, or at least between 5 cm and 10 cm, in width, from the knife-edge to a mid-point inside the conduit.
The blade should have forward pitch to ensure the soil debris can clear, by riding upwards along the knife edge, and out of the soil. It will happen sometimes that some material are not cut, or not cut immediately, by the knife edge, and will be piled up ahead of the knife edge, thereby blunting the knife edge. The angled knife should have forward pitch to counteract this. Of course, conventional vertical seeding knives have had forward pitch.
Preferably, the seed conduit should be integral with the knife unit. If separate, the conduit has to be attached to the knife unit. The conduit should not get in the way, not least above ground, where the conduit can contribute to snagging of soil debris. Therefore, the conduit should lie in line behind the knife. Whilst this is clearly achievable below the ground, above ground putting the conduit in line with the knife structure is not so good, because the shank of the knife is attached to the mounting bar by bolts passing through from front to back, and putting the conduit behind the shank would deny access to the bolts/nuts.
The designer also want the point of attachment of the flexible seed hose to be high, out of harm's way, and also wants to provide room for a clip for attaching the hose into the conduit. The designer either can put the conduit on a stalk that protrudes out behind the shank (which suits fabricated construction (FIG. 2 )), or can put the conduit to one side of the shank (which suits casting ( FIG. 16 )). Or, the conduit may be finished lower down, below where the shank is bolted to the mounting bar ( FIG. 11 ), although now the flexible hose might be vulnerably close to the ground. Putting the conduit to one side of the shank ( FIG. 16 ) gives access to the fixing bolts, but now the front face of shank is thereby widened, so it is even more important to take measures against snagging of the above-ground soil debris on the shank.
One of the benefits of the angles blade configuration lies in the ability to deposit two types of items simultaneously, e.g. seeds and fertilizer, which preferably should be kept spaced apart, upon planting. Simultaneous deposition of both seeds and fertilizer ( FIG. 8 ) is simplified by the fact that the knife is at an angle, while ensuring same are kept spaced apart. If the knife were vertical, both items would fall to the bottom of the trench, and it would be difficult to keep the items apart. On vertical knife seeders, it is conventional to provide side ledges; for fertilizer, however, the protrusions on the vertical knifes that produce such side ledges have also compressed the soil.
Generally, the farmer wishes to plant as many rows of seeds as possible in a single pass if the seeder implement. In one of the machines described herein, thirty-five seeders are provided on a single implement. The smallest number that might practically be contemplated would be about eighteen seeders per implement. The large number of seeders is appropriate for single-pass seeding operations at shallow depth, in that a tractor can easily provide the force necessary to draw a large number of shallow seeders through the ground. This may be contrasted with the conventional usage of angled cutters to break up hard-pan sub-soil, i.e. caked clay and soil some 50 cm or more below ground. Sometimes, these deep angled-cutters have been used to prepare ground for seeding, but in that case the seeding has been done separately, as a follow-up seeding operation, using conventional seed drills. (Breaking up hard-pan also can be done for other purposes, e.g. to improve drainage.) The conventional large, deep, hard-pan angled-cutters were angled simply in order to cover more ground. They were constructed so as to cause maximum disturbance to the soil, at a large depth; they required large forces to draw them through the ground, so that only a small number, say four to five, could be pulled by a tractor. The use of an angled blade as described herein to lift shallow flaps of soil with minimum disruption, and to lower the soil flap back down without disturbing stratification, makes a clear contrast with the use of deep angled cutters to break up hard-pan. It is emphasized that the gentle, minimum-till, operations described can take place only at shallow depths.
In the above aspects, the invention is defined by reference to an implement, in which the angled blades are mounted for operation, In another aspect, the invention can be defined with respect only to the knife unit itself, independently of the implement. In this case, the definition makes use of the shank of the knife, and of the axis of the shank. When the shank is provided with two bolts, one above the other, for attachment to the mounting bar, the shank axis (in a frontal view of the shank) is the line that runs through the bolts. However, even if the shank is mounted by mechanism other than two bolts vertically in-line, the shank still has an axis, which can be determined by the geometry of the shank in a particular case. The major features of the invention, the blade lies at an angle to the shank in front view, and the shallow depth of the blade, are present in this definition.
As mentioned above, sometimes the conventional vertical knife seeders have included, as an accessory, a mechanism for providing a side ledge to the vertical trench. As mentioned, grains of fertilizer are deposited on or in this side ledge, whereby the fertilizer can be kept spaced apart from the seeds. The fertilizer rests on the ledge, while the seeds fall down to the bottom of the vertical trench.
An example of such vertical-knife-with-side-ledge structure is depicted in Canadian patent publication CA-2,099,555 (Henry, 1995). Henry's structure includes a first conventional vertical knife-blade, for cutting a vertical slit in the ground, with the associated delivery pipe for depositing seeds at the bottom of the vertical slit. Henry also shows a ledge-cutting accessory. The accessory is fixed to the back of the vertical knife-blade. Thus, in the design of Henry, two injectors are shown: one for injecting seeds, and the other for injecting fertilizer.
Regarding Henry's vertical knife-blade cutter/fertilizer-injector: when viewed from the side, Henry's knife blade is angled, such that the bottom extremity of the knife-blade leads the rest of the knife-blade as the knife-blade travels through the ground. It is conventional, and very common, for vertical seeding-trench knife-blades to be angled forwards, i.e. bottom-edge leading. In the front view, Henry's knife-blade is not angled at all.
Regarding Henry's side-ledge cutter/fertilizer-injector: when viewed from the side Henry's ledge-cutter is so angled as to be “bottom-edge-trailing”. That is to say, the bottom extremity of the ledge-cutter lags, or trails, as the ledge-cutter travels through the ground. In the front view, Henry's ledge-cutter makes an angle to the horizontal of about 45 degrees.
Neither of the blades or cutters of Henry will achieve the “gentle up-and-over” effect, which is the aim of the present invention. This is because neither of the blades or cutters of Henry has an over-surface and an under-surface, which meet at a line, where the line defines the leading knife edge of the blade, and where the knife edge, thus defined, has a side-slope angle of between 30 degrees and 60 degrees.
Defined with the respect only to the knife unit itself, independently of the implement. In this case, the definition makes use of the shank of the knife, and of the axis of the shank. When the shank is provided with two bolts, one above the other, for attachment to the mounting bar, the shank axis (in a frontal view of the shank) is the line that runs through the bolts. However, even if the shank is mounted by mechanism other than two bolts vertically in-line, the shank still has an axis, which can be determined by the geometry of the shank in a particular case. The major features of the invention, that the blade lies at an angle to the shank in front view, and the shallow depth of the blade, are present in this definition.
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The present invention relates to a knife for and a method of zero till or minimum till seeding and fertilizing. The knife is particularly adapted for dry land conditions producing minimum solid disturbance and very shallow operation. The knife has a high penetration angle preferably of 45 degrees which permits the blade to enter high trash surface cover with little tendency to plug due to trash accumulation. The blade has a forward angle of attack, the lower cutting edge advancing before the upper cutting edge, serving to make a clean cut in the soil surface without accumulating trash. Seed and/or fertilizer conduits are attached to or incorporated in the trailing face of the blade in which the outlets may be spaced for controlled placement of the materials. By the method a furrow is cut having a substantial transverse component in an operation with a substantial forward component. A preferred embodiment includes a horizontal extension blade for cutting a horizontal swath at a shallow depth through weed growth. Conduits may be secured to the extension to allow greater separation and control of material placement. The knives may be arranged in overlapping configuration on the draw bar to affect weed cutting, seeding and fertilizing of a complete with of soil in a single pass.
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[0001] The present application claims the benefit of German Patent Application Serial Number 102010046536.4, filed Sep. 27, 2010 and German Patent Application Serial Number 102010054341.1, filed Dec. 13, 2010.
FIELD OF THE INVENTION
[0002] The invention relates to a process for applying a fire-protection coating to a substrate, and also to a substrate thus coated.
BACKGROUND OF THE INVENTION
[0003] In the fitting-out of internal spaces, wood surfaces, in particular wood veneers, are often used on cladding, furniture, or the like. The coating here is intended firstly to improve the appearance of the surface and secondly to provide protection, for example from mechanical stresses. In particular instances, this type of coating also has the function of improving fire protection.
[0004] By way of example, when furniture or cladding is installed into the interior of an aircraft there is a need to comply with fire-performance requirements under air traffic legislation. A component of this type is subjected, for example, to a Bunsen burner fire test with 60 s of exposure to a flame at a temperature of 860° C. Extinguishment of the component must occur within 15 s after the end of flame application. The distance between the point of flame application and the most distant point burnt by the flame on the surface of the specimen is not permitted to be more than 155 mm (FAA CS 25.853 (a)).
[0005] From public prior use, it is known that wood can be provided with flame-retardant impregnation. A disadvantage here is that this type of impregnation can discolor the wood and sometimes acts as plasticizer within a clearcoat layer subsequently applied. There can also be impairment of adhesion of a coating layer on the impregnated surface. It is also known from public prior use that clearcoat can be provided with chemical fire-protection compositions. Here again, a disadvantage is that discoloration of the wood surface can occur, and that the flame retardants can have an undesirable plasticizing effect.
SUMMARY OF THE INVENTION
[0006] It is an object of the invention to provide a process and a coated substrate of the type mentioned in the introduction, where these combine good surface properties with good fire protection.
[0007] The process of the invention achieves said object via the following steps:
a) applying a first clearcoat layer to the substrate; b) applying an intumescent fire-protection layer to the first clearcoat layer; c) applying a second clearcoat layer to the intumescent fire-protection layer.
DESCRIPTION OF THE DRAWING
[0011] FIG. 1 shows a representation of a cross-sectional view of a substrate having a veneer surface and a first clearcoat layer, a fire-protection layer, and a second clearcoat layer.
DEFINITIONS
[0012] Some terms used for the purposes of the invention will first be explained. A substrate is by way of example a piece of furniture, a wall cladding, or the like. Preference is given to a substrate with a wood surface.
[0013] The substrate can have been manufactured from solid wood, or can preferably be composed of a wood veneer on a supportive structure. The supportive structure can comprise a particle board, a sandwich structure, or the like.
[0014] The term clearcoat designates a coating which is in essence transparent and which does not hide a structure located thereunder, for example woodgrain.
DESCRIPTION OF THE INVENTION
[0015] An intumescent fire-protection layer is applied as intermediate layer on said first clearcoat layer. An intumescent fire-protection layer comprises substances which increase their volume on exposure to heat and thus have a flame-retardant effect. Intumescent fire-protection mixtures which are suitable for producing an appropriate coating are disclosed by way of example in DE 197 51 434 A1.
[0016] In the invention, a second clearcoat layer is applied to the intumescent fire-protection layer. The first and second clearcoat layer can also be applied in a plurality of respective individual layers for the purposes of the invention.
[0017] The invention thus permits both that region of the entire coating that faces toward the substrate and that region that faces toward the exterior surface to have the properties of the clearcoat used, so that the resistance of the surface to exterior stresses and the interaction with the substrate are determined entirely via the properties of the clearcoat. The intumescent fire-protection layer has been inserted rather in the manner of a sandwich between two clearcoat layers and cannot therefore have any disadvantageous effect either on the surface properties of the entire coating or on the interaction with the substrate (in particular wood). Design of the fire-protection layer in the form of intumescent layer also permits achievement of particularly good flame retardancy.
[0018] It is preferable that the first and/or second clearcoat layer have been selected from the group consisting of polyurethane coatings, polyester coatings, and poly(meth)acrylate coatings. These comprise coatings which are in particular used for coating of wood and of wood veneer surfaces in the prior art.
[0019] Hardening of polyurethane coatings occurs via reaction of polyisocyanates with hydroxylated compounds. The hydroxy component can by way of example comprise polyesters, polyethers, or acrylic resins. Polyester coatings usually cure via polyaddition of unsaturated compounds. The same applies to poly(meth)acrylates. Examples of suitable coatings are described in Ullmann's Encyclopedia of Industrial Chemistry, 6 th edition, volume 24, pp. 594 (Paints and Coatings); and volume 39, pp. 515 (Wood, surface treatment) specifically for wood surfaces. The cited disclosure is also incorporated within the subject matter of the present application.
[0020] The intumescent fire-protection layer in the invention can comprise an intumescent synthetic resin. An intumescent synthetic resin based on melamine/formaldehyde resin is particularly suitable. The intumescent fire-protection layer can also in particular comprise flame-retardant compounds, such as phosphoric ester. Suitable intumescent compositions are described by way of example in DE 197 51 434 A1, the disclosure of which is incorporated by way of reference. Intumescent fire-protection mixtures of this type are available commercially by way of example from AISCO Chemieprodukte GmbH as K1+K2 2-Component Fire Protection System.
[0021] The intumescent fire-protection layer can be applied in the invention with a thickness of from 40 to 200 μm, preferably from 60 to 120 μm, in particular by way of example approximately 80 μm.
[0022] The clearcoat layers and/or the intumescent fire-protection layer is/are preferably applied by spraying, in particular with a spray gun. Application by spraying can give a high-quality coating. Intumescent fire-protection compositions of the prior art are generally applied by way of example with a spreader. They are generally intended for fire protection on articles where visual quality of the surface is not critical.
[0023] In the invention it is preferable to adjust the viscosity of the intumescent mixture for producing an intumescent fire-protection coating of the invention in such a way as to permit application by a spray gun. Mixtures suitable for application by a spray gun are generally those of viscosity 16 s or greater (measured to DIN 53211 with a 4 mm flow cup). Preferred viscosity ranges are from 16 to 100 s, preferably from 17 to 80 s, more preferably from 19 to 60 s. The viscosity can be adjusted with a suitable solvent, such as water.
[0024] The intumescent fire-protection layer can comprise an additive for compatibilization with the clearcoat layers. Examples of suitable compounds for compatibilization of intumescent fire-protection compositions based on melamine/formaldehyde with polyurethane clearcoats are polyether siloxanes, which are added at a concentration of, for example, about 1% by weight to the intumescent fire-protection composition.
[0025] Appropriate polyether siloxanes are obtainable by way of example from Evonik as TEGO Wet 270.
[0026] The invention further provides a substrate with a fire-protection coating, wherein the coating comprises:
a) a first clearcoat layer on the substrate; b) an intumescent fire-protection layer on the first clearcoat layer; c) a second clearcoat layer on the intumescent fire-protection layer.
[0030] The invention further provides a substrate with a fire-protection coating, obtainable via a process of the invention.
[0031] An example of the invention is explained below, using the drawing, which is a diagram of the structure of a substrate coated in the invention.
[0032] The substrate used comprises a honeycomb sandwich panel with maple veneer adhesively bonded thereto.
[0033] The clearcoat layer is produced by using Crystallites® 2K PUR Top-Klarlack from Zweihorn. The manufacturer's instructions indicate that coating component and hardener component are used in a ratio by weight of 10:1.
[0034] The intumescent fire-protection mixture used comprises the K1+K2 2-Component Fire Protection System from AISCO Chemieprodukte GmbH. The manufacturer's instructions indicate that component K1 and component K2 are mixed in a ratio by weight of 6:4. Viscosity is then adjusted appropriately via dilution with 20% by weight of water, and 1% by weight of TEGO Wet 270 additive from Evonik (polyether siloxane) is incorporated by mixing.
[0035] The first clearcoat layer is applied by spraying onto the wood veneer of the sandwich panel until a closed-pore surface is produced. Once the material has been permitted to harden, said first clearcoat layer is subjected to an appropriate degree of abrasion, and then the intumescent fire-protection layer is applied by spraying at a thickness of 80 μm. This is likewise permitted to harden, and is subjected to an appropriate degree of abrasion. Once said intumescent fire-protection layer has been subjected to an appropriate degree of abrasion and thus activated, the second clearcoat layer is applied in two spray passes thereto.
[0036] A further inventive example is explained below.
[0037] The substrate used comprises a sheet of solid maple wood.
[0038] The clearcoat layer is produced by using Duritan® Two-Pack Pore Surfacer, Duritan® Three-Pack High-Solid Filling Primer, and Duritan® Three-Pack High-Solid High-Gloss Varnish from Zweihorn. The manufacturer's instructions indicate that component A and component B of the Pore Surfacer are used in a ratio by weight of 1:1, and coating component, hardener component, and activator component of the Filling Primer and of the High-Gloss Varnish are used in a ratio by weight of 100:100:2.
[0039] The intumescent fire-protection mixture used comprises the pyroplast-HW 300 fire-protection system from RÜTGERS Organics GmbH. The manufacturer's instructions indicate that component K1 and component K2 are mixed in a ratio by weight of 6:4.
[0040] Viscosity is then adjusted appropriately via dilution with 30% by weight of water, and 1% by weight of TEGO Wet 270 additive from Evonik (polyether siloxane) is incorporated by mixing.
[0041] The Duritan® Two-Pack Pore Surfacer is applied to the wood substrate in order to fill the pores of the wood. After curing via excitation with UV radiation, Duritan® Three-Pack High-Solid Filling Primer is applied by spraying until a closed-pore surface is produced. Layers of wet thickness 100 μm are applied here and are individually hardened via UV excitation. Said clearcoat layer is leveled by abrasion, and the intumescent fire-protection layer is then applied by spraying, at a wet thickness of 100 μm. This is permitted to harden via air-drying, and is subjected to an appropriate degree of abrasion. Once said intumescent fire-protection layer has been subjected to an appropriate degree of abrasion and thus activated, a further clearcoat layer made of Duritan® Three-Pack High-Solid Filling Primer is applied in two spray passes thereto. Finally, once the coating has been leveled by fine abrasion a final coating of Duritan® Three-Pack High-Solid High-Gloss Varnish is applied. After hardening via excitation with UV light, the final coating layer is polished to give high gloss: 90 gloss units.
[0042] The adhesion of the coating of the invention to DIN EN ISO 4624 is about 2 MPa.
[0043] The fire test described in the introduction to the description is found in the standard FAA CS 25.853 (a). When the coating of the invention is subjected to this test, the afterflame time is 0 s and the burnt section measures 85 mm.
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The invention relates to a process for applying a fire-protection coating to a substrate using a process comprising the steps of applying a first clearcoat layer to the substrate, applying an intumescent fire-protection layer to the first clearcoat layer, and applying a second clearcoat layer to the intumescent fire-protection layer.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present invention claims priority to U.S. Provisional Patent Application Ser. No. 60/830,040, filed on Jul. 11, 2006, which is incorporated herein by reference in its entirety.
FIELD OF INVENTION
[0002] The present invention relates to the field of matching profiles, and more specifically, matching job seeker profiles with job description profiles, and to manage access to personal contact information.
BACKGROUND OF THE INVENTION
[0003] The Internet based job search has become one of the fastest growing on-line businesses. In 2005, the annual revenue growth of on-line job sites was 20% to 30% and the total revenue of all job sites was around $1.75 billion. The conventional Internet based job search models can be divided into two groups. The first group is represented by the so called “job boards” which allow employers to post job openings and job seekers to submit their resumes. This group is exemplified by companies such as Monster.com, CareerBuilder.com, Indeed.com, or SimplyHired.com. The search technology is focused on matching key words, such as “sales” and “director” as well as various job related categories such as industry, salary, location, and job title. Consequently, the end results of this type of search is a broad match between key words and categories not a quantitative match between resumes and job positions. Therefore, a typical search yields hundreds of job postings/resumes with no quantitative measure (such as a match score) for the end user to gauge how closely a resume matches a particular job.
[0004] The second group attempts to overcome the limitations of the first group and uses more accurate technologies to match resumes with appropriate job descriptions. This group is exemplified by companies such as Market10. Similar systems were also described in several patents. When using this technology, job seekers and employers are first asked to fill out extensive profiles which become representations of their resumes and jobs, respectively. Second, the resume profiles and job description profiles are compared with each other in a plurality of profile categories such as Experience, Travel, Skills, Work Authorization, and Salary. The match between a resume and a job description is represented by a single match score (or “One Score”). The value of the “One Score” is typically on a scale 0-100% or 0-10. The higher the score the better the fit is between a resume and a job description. In some “One Score” models, job seekers can see a general view of (e.g. view score range instead of an actual value) how they scored in the individual profile categories. For example, the total “One Score” might be 85% while category scores for Travel and Skills might be in a range 0-50% and 50-100%, respectively. Although “One Score” models provide a good overall idea how well a job seeker's profile matches job description profile, they do not provide immediate information on what type of profile variable to change to increase the score. Specifically, job seekers are left with the following dilemma:
1. Do I increase my “One Score” by making changes in my personal preferences, such as willingness to travel? (Willingness to travel is a matter of personal preference and the change can be made instantly in a profile if a job seeker so decides.) 2. Or, do I increase my “One Score” by making changes in one of my fundamental capabilities to perform a job, such as industry experience. (Industry experience is fundamental capability and would require significant career change decision and definitely additional effort and time.)
[0007] In “One Score” models, one must run several scenarios to determine which variable change would increase the score, that of personal preference or that of fundamental capability.
[0008] Each scenario consists of changing one's profile, one variable change at a time and observing the corresponding impact on the “One Score”—a very time consuming and inefficient process.
[0009] Furthermore, since the “One Score” models lump together both types of variables, personal preferences and fundamental capabilities, their results often obscure the true picture of the job market. In the “One Score” models, it is possible for a job seeker with fewer job related skills to achieve a higher score than a job seeker with more job related skills but who has restrictive, but potentially easy to change, personal preferences (e.g. amount of job related travel). Therefore, the “One Score” models are prone to situations where a less qualified job seeker would have a higher matching score and thus a higher probability to get a job.
[0010] Another limitation of the existing job matching models is the inflexibility to control of one's contact information. In current job search models employers can access a job seeker's contact information in two ways: “Public” or “Private”. Generally, “Public” access means that the contact information is included with a job seeker's profile and is publicly available to any employer who shows interest in the job seeker. While this option permits contacting a job seeker directly and immediately, it dramatically compromises the privacy and confidentiality of the job seeker. This is even more important on internet job search sites where the contact information can be exposed to millions of people. Furthermore, especially when a job seeker's skills are in high demand, one may end up inundated with a high number of unqualified and unsolicited requests to consider a new job position. Some job search models do allow job seekers to block specific companies from accessing their otherwise publicly accessible contact information. While this helps to protect the privacy of a job seeker from, for example, his or her current employer, the risk of being exposed to unqualified calls and requests from all other companies remains.
[0011] To eliminate the risks of making contact information public, current job search models offer a “Private” option that allows job seekers to remain anonymous. In this case, a job seeker can choose to be contacted by a potential employer indirectly, for example via an anonymous email, thus protecting one's privacy and confidentiality. Then, in order to establish direct communication with a potential employer, the job seeker must receive and respond to the anonymous email revealing his/her contact information. The downfall of this option however is that a job seeker would need to perform additional steps in order to establish direct communication with an employer slowing down the entire recruiting process—a clear disadvantage of this option. The time lost with this option may cause a job seeker to miss a potential “dream job” while the employer may end up hiring a job seeker who might not have been the best fit but who was able to be contacted more quickly. In the worst case, the job position may go unfilled.
[0012] Furthermore, the “Private∞ option is typically selected by “passive candidates” or “hidden talent” who are often the best talent in the field. They are successful and happy with their current employer and not actively searching for a job, however, they might consider a new job if the right opportunity arose. Unfortunately, due to the limitations of the “Private” option, the best talent represented by “passive candidates” is difficult to reach and therefore rarely recruited through the current internet job search models.
[0013] Therefore, there is a need for a more efficient way to access a job seeker's contact information. The new access option described in this invention is based on the matching score between job seeker's profile and a job description profile (“Score” option). The contact information protected by the “Score” option is by default private but becomes temporarily public only to employers whose job profile matching score with a job seeker's profile is very high. The “Score” option would release a job seeker's information only when the matching score exceeds a limit specified by the job seeker.
SUMMARY
[0014] Given the limitations of prior approaches and the current high demand for fast and accurate job matching, best talent=best job, it would be highly desirable to provide job seekers and employers with a much more efficient approach that eliminates limitations of “One Score” models—in particular, an approach which calculates and presents two separate match scores simultaneously (“Two Score” model). In the “Two Score” model, one score represents one's fundamental capability to perform a job (“Fundamental Score”) and the other score represents one's fundamental capabilities and personal preferences (“Total Score”). Therefore, the fundamental capability of a person to perform a job is always measured separately and thus not obscured by personal preferences.
[0015] In addition, there is a need for a definition of a finite set of fundamental categories which objectively describe the job seeker's fundamental capabilities to perform a job regardless of his/her personal preferences.
[0016] As well, there is yet a further need for providing a breakdown of the “Fundamental Score” into individual fundamental category scores to give job seekers additional insight into the capabilities they may lack or, better yet, excel in for a particular job.
[0017] The “Two Score” model significantly improves the job matching accuracy by maintaining two separate matching scores. Both job seekers and employers can instantly see whether the quality of the match is due to their personal preferences or due to their fundamental capabilities to perform a job. At the same time, using the “Fundamental Score”, the “Two Score” model informs job seekers/employers about all employment/talent possibilities in the market at all times which they are not able to see with the current models without incurring additional effort. Moreover, it guarantees that a job seeker never misses a job opportunity which perfectly fits his/her capabilities regardless of the personal preferences specified in his/her profile. Similarly, employers never overlook the best talent despite the salary, travel, and other preferences they specified in the job description profile.
[0018] In addition, by providing partial scores, structured according to the fundamental capability categories, job seekers are guided as to what training or experience one may consider to acquire in order to have a better chance to land a specific job. Likewise, it directs employers to the categories which need to be changed in order to attract a larger number or a different caliber of job seekers.
[0019] Furthermore, no additional effort is required from job seekers in order to simultaneously see all jobs in the market of which they are capable. This “Two Score” model is particularly attractive for “passive candidates”, who do not want to spend time tweaking their profiles but, at the same time, do not want to miss the right opportunity.
[0020] The “Score” option creates, in one embodiment of the present invention, desirable efficiency for job seekers and employers by accelerating communication when a job seeker is highly qualified for a job. It saves employers who are unable to directly contact the well qualified job seeker from hours to days of waiting. At the same time, the “Score” option protects a job seeker from annoying unqualified calls from employers and recruiters. Furthermore, it makes the on-line job search models more attractive to a larger number of job seekers, such as “hidden talent” and higher level professionals and executives, who traditionally have not used the job search models but have relied on other means of job finding. The “Score” based access to contact information ensures that the best talent can be quickly reached by employers who have the best matching jobs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The foregoing and other features and advantages of the present invention will be more fully understood from the following detailed description of illustrative embodiments, taken in conjunction with the accompanying drawing in which:
[0022] FIG. 1 is a block diagram depicting an approach to matching profiles according to an embodiment of the present invention;
[0023] FIG. 2 is a flow diagram depicting an approach for generating “Two Score” job matching results;
[0024] FIG. 3 is a block diagram defining “Fundamental Categories” and “Fundamental Sub-categories”;
[0025] FIG. 4 is a flow diagram depicting a routine for specifying privacy settings including “Score” option; and
[0026] FIG. 5 is a flow diagram depicting a routine for releasing contact information based on “Score” option.
DETAILED DESCRIPTION
[0027] The invention provides simultaneously two separate matching score results (“Two Score”) to job seekers and employers. Therefore, job seekers and employers are not limited by “one score” matching models which obscure the true picture of the job market, and hide employment opportunities that do not meet personal preferences. In the “Two Score” model, the first score quantifies a match across all profile categories (“Total Score”) which includes both personal preferences and fundamental capabilities to perform job. The second score quantifies a match across only the fundamental capability categories (“Fundamental Score”). The “Fundamental Score” is defined by seven distinct categories and at least one value for each category must be specified before a matching calculation takes place. The “Total Score” includes the “Fundamental Score” and an unlimited number of personal preferences. The personal preferences may or may not be specified for the matching calculation to take place. The “Total Score” is always less than or equal to the “Fundamental Score”.
[0028] In addition, the invention provides a method of access to a job seeker's contact information based on the value of the matching score (“Score” option). Therefore, job seekers and employers are not limited by the rigidity of current methods on job search Web sites, where contact information is either public or private. The “Score” option keeps a job seeker's information private by default and makes it public to employers only when the matching score exceeds the limit specified by the job seeker. While the “Score” option herein is described in connection with a job seeker's contact information, it should be clear that the “Score” option can be used to protect any other type of information of any other user of the score based models.
[0029] FIG. 1 is a block diagram that illustrates an approach for matching job seeker profiles (provided by job seekers) and job description profiles (provided by employers) according to various embodiments described herein. As used herein, the term “job seeker” refers to any person or entity that possesses capabilities to perform a certain job. Examples of job seekers include employed or unemployed individuals, independent contractor, freelancers, temporary worker and the like and the invention is not limited to any particular type of job seeker. As used herein, the term “employer” refers to any person or entity that is searching for a job seeker who can perform a job described in the job description. Examples of employers include, employers, hiring entities, contracting entities and the like and invention is not limited to any particular type of employer. Either “job seeker” or “employer” may also refer to a third party intermediary who acts in the interest of “job seeker” or “employer”. Examples of the intermediaries include recruiting agencies, employment agencies, “headhunters”, staffing agencies, temporary employment agencies, personal agents, personal managers, and the likes and the invention is not limited to any particular type of an intermediary.
[0030] Although the approach to profile matching described herein is in connection with job seeker profiles and job description profiles for illustration purpose only, it should be amply clear that the invention is not limited to this specific job search domain and that the invention can be applied to and adapted to various other domains where pairs of entities (e.g. job seekers and employers) need to be matched. Examples of the other domains include real-estate (e.g. buyers and home sellers), dating (e.g. relationship between two parties), legal (e.g. lawyers and cases), placement (e.g. candidates with residency positions), financial (e.g. financial advisors and client), and the likes.
[0031] This embodiment supports the “Two Score” matching model and “Score” option to access a contact information over the Internet. The server system 110 includes a matching engine 111 , a job seeker profile database 112 , a job position profile database 113 , various Web pages 114 , a server engine 116 , and a matching engine database 115 . The job seeker profile database contains information about various job seekers. The job seeker information includes contact information, fundamental capability information, personal preference information, favorite profile information, and supporting information. The contact information herein is any information that facilitates communication between the job seekers and employers via electronic message transmission, e-mail, electronic form submission, a telephone call, phone messaging, facsimile messaging, pager and/or beeper messaging, physical mailing address, fax number, instant messaging, and other appropriate communication methods. The fundamental capability information contains any information related to the seven categories as defined in FIG. 3 . The personal preference information includes but is not limited to any job seeker preferences, such as compensation level, commuting distance to workplace, amount of job related travel, health benefits, work environment, size of company (in terms of revenue, number of employees), type of company (start-up, private, public), type of position (full-time or part-time), level of security clearance, level of work authorization (citizen or work visa), etc. In this invention, there is no limit on the number of job preferences. The favorite profile information includes information about job description profiles which job seeker decides to store for later use. The supporting information may include information such as job seeker's resume, cover letter, or the like. The job position profile database contains the same type of information as the job seeker database; i.e. contact information, fundamental capability information, personal preference information, favorite profile information, and supporting information. The supporting information, in case of a job position profile, may contain job description, company description, and the like. The matching engine calculates matching scores between job seeker profiles and job description profiles. The matching engine can employ any conventionally available algorithm suitable for comparing two multidimensional profiles. For example, the algorithm can be a simple weighted average, neural network, expert system, or the like. A preferred algorithm is a weighted average. The matching engine database includes information required by the matching engine to calculate the matching scores. This information includes various weights, indices, coefficients, thresholds, constrains or the likes. The server engine receives HTTP requests to access the Web pages identified by URLs and provides the Web pages to the various job seeker and employer systems. The Web pages provide a graphical user interface for job seekers and employers to perform various tasks on the Web site. Those tasks include but are not limited to entering information into the profile databases, requesting the calculation of matching scores, viewing the matching results and corresponding profiles, communicating with other job seekers or employers, and the like.
[0032] Job seekers and employers access as well as interact with the Web pages through Web browsers 120 over the Internet 130 as shown in FIG. 1 .
[0033] One skilled in the art would appreciate that the “Two Score” matching approach can be used in various environments other than the Internet. For example, the “Two Score” matching approach can also be in an e-mail environment in which job seekers and employers can specify profile information and receive corresponding matching results. Also, various communication channels may be used such as LAN, WAN, peer-to-peer communication (such as Skype), and point-to-point dial up connection. Also, the server system may be made up of any combination of hardware or software that can calculate and present matching scores based on job seeker and employer profiles. The job seeker and employer systems can comprise any combination of hardware or software that can interact with a server system. These systems may include personal computers, personal data organizers (PDA), wireless mobile devices (cell phones), television-based systems, internet browsing appliances, or various other consumer products which allow inputting and viewing information.
[0034] FIG. 2 is a flow diagram depicting an approach for generating “Two Score” job matching results. To calculate the “Two Score” matching results the matching engine needs to have information about both a job seeker and a job description. The process described in FIG. 2 is identical for both the job seeker side and the employer side, therefore only the job seeker side is explained in this section.
[0035] The process starts by asking a job seeker a series of questions in step 210 . The questions vary in type. For example, some questions can be multiple choice where a job seeker selects one or more choices from a provided list (e.g. select a company from a list of companies.); or the questions can ask for key words (or tags) which relate to a job seeker's capability or preference (e.g. “sales”, “automotive”, “financial advisor”; or the questions can ask for a numeric value (e.g. “10.5” for years of experience). One skilled in the art would appreciate that other types of questions can be used in this process, such as questions asking to rank or order multiple parameters based on specific criteria (e.g. Rank/order the following parameters based on importance to you: compensation, amount of travel, dress code). Each question is related to either fundamental capability parameter (“Fundamental Parameter”) or personal preference parameter (“Preference Parameter”). In the step 211 , the server engine determines whether the question is related to a “Fundamental Parameter” that is used in the calculation of the “Fundamental Score” or to a “Preference Parameter” that is used in the calculation of the “Total Score”. If it is “Fundamental Parameter”, the server engine allows a job seeker in step 212 to proceed to the next step only if he or she answers the question, unless a minimum number of “Fundamental Parameters” for a specific “Fundamental Category” has been already specified. In step 213 , the answer to the question is stored in the job seeker profile. If the server engine determines in step 211 that the question relates to “Preference Parameter”, a job seeker may or may not answer the question in step 215 . In step 216 , the answer is stored into the job seeker profile. A blank answer is interpreted later by the matching engine 111 as “no preference”. Then the server engine continues to step 220 .
[0036] In step 214 , the server engine checks if the minimum “Fundamental Parameters” were specified. Only if the minimum “Fundamental Parameters” were specified for each “Fundamental Category” will the process continue to step 217 where the matching engine will calculate “Fundamental Scores” between the job seeker profile and the job position profiles in the database 113 . In step 218 , the “Fundamental Scores” are compared with a predefined minimum threshold. If none of “Fundamental Scores” is higher than the threshold, then the job seeker is informed that “No match” was found in step 219 , else the matching engine continues to step 220 and calculates the “Total Score” for all job description profiles whose “Fundamental Score” is higher than the threshold. In step 221 , the server system displays a list of job description profiles, each showing simultaneously two scores: “Fundamental Score” and “Total Score”. Then the server engine continues to step 222 . In step 222 , if the job seeker decides that he or she wants to change any profile parameter settings then process loops back to step 210 , else the process is completed.
[0037] FIG. 3 is a block diagram defining “Fundamental Categories” and “Fundamental Sub-Categories”. Both, a job seeker profile and a job description profile, share the same structure of seven “Fundamental Categories” 310 and three “Fundamental Sub-Categories”. “Education” is the only category that is comprised of three sub-categories “School” 318 , “Field of Study” 319 , and “Degree” 320 . Each “Fundamental Category” and “Fundamental Sub-Category” can have one or more “Fundamental Parameters”. Each “Fundamental Parameter” can have one or more values that can be of various types. For example, a value can be an index to a list of items (e.g. “2” for the second company on a list of companies), a key word or a tag (e.g. “sales”, “automotive”, “financial advisor”), or a numeric value (e.g. “10.5” for years of experience).
[0038] The category INDUSTRY is comprised of parameters that describe knowledge of and experience in particular industry. Typical parameters in this category include but are not limited to industry names (e.g. automotive), company names (e.g. Microsoft), or product name (e.g. cell phone).
[0039] The category FUNCTION is comprised of parameters that describe functional responsibilities. Typical parameters in this category include but are not limited to department name (e.g. marketing), functional title (e.g. direct sales manager), or specialization (e.g. Web designer).
[0040] The category LEVEL is comprised of parameters that describe financial or other responsibilities related to the level in a company hierarchy. Typical parameters in this category include but are not limited to a number of levels from CEO (e.g. 3), sale quota responsibility (e.g. $10,000,000), or facility responsibility (e.g. 10 retail stores).
[0041] The category MANAGEMENT is comprised of parameters that describe management experience. Typical parameters in this category include but are not limited to number of direct reports (e.g. 5), number of functional reports (e.g. 10), or total number of people under ones management (e.g. 100).
[0042] The category SKILLS is comprised of parameters that describe knowledge and experience of various methods, techniques, tools, processes, technologies, foreign languages, etc. Typical parameters in this category include but are not limited to software tools (e.g. SAP), business processes (e.g. auditing), or methods (e.g. Six Sigma).
[0043] The sub-category EDUCATION/SCHOOL is comprised of parameters that describe educational institution. Typical parameters in this category include but are not limited to university name (e.g. Harvard), training institute (e.g. Sandler sales institute), or university category (e.g. “Ivy League”).
[0044] The sub-category EDUCATION/FIELD OF STUDY is comprised of parameters that describe field of study or training. Typical parameters in this category include but are not limited to study major (e.g. chemistry), special training (e.g. negotiation), or course work (e.g. number theory).
[0045] The sub-category EDUCATION/DEGREE is comprised of parameters that describe professional degree or certification. Typical parameters in this category include but are not limited to university degrees (e.g. Master), professional certifications (e.g. Certified Public Accountant), or program certifications (e.g. Microsoft Certified Professional).
[0046] The category YEARS OF EXPERIENCE is comprised of parameters that specify years of various types of experiences. Typical parameters in this category include but are not limited to years of functional experience (e.g. years of marketing experience), years of industry experience (e.g. years of automotive experience), or total years of experience.
[0047] The “Fundamental Score” is calculated only when at least one “Fundamental Parameter” is specified for categories Industry, Function, Level, Management, Skills, and Years of Experience and at least one “Fundamental Parameter” is specified for the “Fundamental Sub-Categories” School, Field of Study, and Degree. Therefore, at minimum, nine values must be specified before the “Fundamental Score” is calculated. An example of the nine values which satisfy the minimum requirement is provided in table below:
[0000] “Fundamental “Fundamental “Fundamental Parameter” Parameter” Number Category/Sub-Category” Description Value Type Value 1 INDUSTRY Industry Name Index to a list of 5 industries 2 FUNCTION Functional Title Key Word “Marketing Manager” 3 LEVEL Level of Numerical Value 10,000,000 Responsibilities 4 MANAGEMENT # of people within Numerical Value 100 a span of control 5 SKILLS Tools and Key Word “Microsoft Methods Office” 6 EDUCATION/SCHOOL School Attended Index to a list of 23 schools 7 EDUCATION/FIELD OF Major Type Index to a list of 14 STUDY majors 8 EDUCATION/DEGREE Degree Type Key Word “Master” 9 YEARS OF EXPERIENCE Years of Numerical Value 4.5 experience in FUNCTION
The “Two Score” results are presented in the following ways:
On an employer screen:
[0000]
Fundamental
Latest Title
Location
Latest Employer
Total Score
Score
Product
MA
ABC company
67%
82%
Manager
On a job seeker screen:
[0000]
Fundamental
Job Title
Location
Company Name
Total Score
Score
VP of Sales
MA
XYZ company
77%
85%
[0050] FIG. 4 is a flow diagram depicting a routine for specifying privacy settings with the “Score” option. A job seeker is provided with three options which determine his privacy settings. “Public” option that makes one's contact information public, “Private” option that keeps one's contact information confidential, and “Score” option that releases one's contact information only when a matching score value is higher than or equal to the “Privacy Limit” specified by a job seeker.
[0051] The privacy option settings Web page is initially set the “Private” option by default in step 410 . A job seeker can modify this setting and can choose from the three options. If either the “Public” or “Private” option is specified in step 415 , the privacy settings are stored in step 414 and the process is completed. Else, a job seeker can specify “Score” option in 415 . If no privacy option is specified, the routine loops back to default the “Private” option setting. If the “Score” option is selected, in step 412 the job seeker is required to specify the “Privacy Limit” which, when exceeded by a matching score, will trigger the release of the contact information. Step 413 loops back to step 412 until the job seeker specifies the limit. Once the “Privacy Limit” is specified the privacy settings are stored in step 414 and the process is completed.
[0052] The matching score which is compared with the specified “Privacy Limit” can be either the “Fundamental Score” or the “Total Score” or any other score representing a match between a pair of profiles. One skilled in the art would appreciate that the “Score” option can be defined by any Boolean combination of two or more scores. An example of the two score combination can be illustrated as follows:
[0053] “Release the contact information if “Total Score”>70% AND “Fundamental Score”>90%.
[0054] In similar fashion, the “Score” option can be used in combination with any other general privacy options such as a company block (blocking certain companies to access the contact information), a date of the job description profile posting, and the like.
[0055] The “Score” option may also be used to trigger release of other information in a profile (e.g. salary level) in addition to personal contact information.
[0056] The “Score” option is presented to an end user in the following way:
[0000]
Specify your Privacy and Confidentiality option:
Option
Select Only One Option
Conditional Expression
Private
Public
Score
Yes
Minimum Score: 95%
[0057] FIG. 5 is a flow diagram depicting a routine for releasing personal information based on the “Score” option. This routine assumes that a job seeker has selected the “Score” option and specified “Privacy Limit” in the privacy settings. In step 510 , the routine is initiated by an employer's request for a job seeker's resume. In step 511 , if the matching score is higher than or equal to the “Privacy Limit”, a job seeker's contact information is released to an employer in step 512 and a job seeker is notified that his or her contact information has been released in step 513 . One skilled in the art would appreciate that the conditional statement in step 511 can be any Boolean expression including a combination of two or more scores and/or other general privacy options as described in FIG. 4 . The notification is accomplished by any communication method that uses a job seeker's contact information or combination thereof. Whether or not the “Privacy Limit” was met, the resume is released to an employer in step 514 and a jobs seeker is notified that a resume has been released in step 515 . The notification is accomplished by any communication method that uses a job seeker's contact information or combination thereof
[0058] Although the illustrative embodiments described above present the two scores simultaneously, one skilled in the are should recognize that the scores may be presented in a variety of ways, such as presenting one score first and the other score in somewhat delayed fashion, e.g. at a push of a button, as a sorting order, on a separate screen, in a separate area of a screen, in a separate email, etc., without deviating from the scope of the invention.
[0059] While the illustrative embodiments presented above describe certain groupings or combinations, one skilled in the art should recognize that the seven groups may be grouped or combined into any number of groups or combinations thereof, e.g. the LEVEL category may be combined with MANAGEMENT category into a new category MANAGEMENT LEVEL, without deviating from the scope of the invention.
[0060] Further, while the illustrative embodiments detail a “Two Score” system in which the users are presented with two evaluative scores, one skilled in the art should recognize that additional scores may be presented, e.g. a “Three Score” option, etc., to the user without deviating from the scope of the invention.
[0061] Further, while the illustrative embodiments describe a correspondence to a variety of parameters, one skilled in the art should recognize any correspondence or weighting can be given to the parameters, or any combination thereof, e.g. adding “Personal Parameters” to “Fundamental Parameters” and allowing weights associated with “Personal Parameters” to be set to zero such that in the end the “Fundamental Parameters” are the greatest significance in the calculation, without deviating from the scope of the invention.
[0062] Although the present embodiments above describe calculating a “Fundamental Score” if a minimum number of “Fundamental Parameters” are specified, one skilled in the art should recognize that any number of Fundamental Parameters or combination thereof, may be used to calculate a “Fundamental Score”, without deviating from the scope of the invention.
[0063] Although the present embodiments describe a method and system in which a “Total Score” is less than or equal to a “Fundamental Score”, one skilled in the art should recognize that the “Personal Preferences” may be permitted to increase the “Total Score” so that “Total Score” is greater than “Fundamental Score”, without deviating from the scope of the invention.
[0064] Although the present embodiments describe combining the “Score” option with the job seeker's contact information, one skilled in the art should recognize that the “Score” option may be combined with any other information without deviating from the scope of the invention.
[0065] Although embodiments of the present invention are described in terms of a job seeker resume it should be understood that, in various embodiments, the resume comprises a job application, profile or other compilation of information within the scope of the invention. Similarly, in various embodiments of the invention a job description may comprise a profile, listing, specification or other compilation of information within the scope of the present invention.
[0066] Although the scores and results detailed above in the illustrative embodiments are presented in a numerical format, one skilled in the art should recognize that the results may be presented in a number of ways, e.g. color code, sorting order, bar chart, line graphs, pie charts, image, etc., without deviating from the scope of the invention.
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A system and method for an on-line matching of job seekers with job openings and for score-based access to contact information is disclosed. Both the job seekers and the job openings are identified by their profiles and each profile has multiple parameters. The profile parameters are divided into two distinct categories, fundamental capabilities to perform a job and personal preferences regarding a job, to ensure that both the objective and subjective pictures of the job market are preserved. Correspondingly, two matching scores are calculated sequentially and the results presented simultaneously to job seekers and employers. A user's contact information is released only if the matching score meets the user's specified limit. The two score approach as well as the method for score-based access to contact information can work either together or separately in a variety of profile matching models.
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This is a division of application Ser. No. 849,728, filed Nov. 9, 1977.
BACKGROUND OF THE INVENTION
With the advent of stricter governmental controls for engine emissions and increased concern to reduce weight of passenger vehicles, there arises a need for conserving the residual heat of exhaust gases of an internal combustion engine so that downstream equipment in a vehicle exhaust system may operate with higher efficiency and effectiveness to reduce the emission levels of the engine and conserve fuel. This need has become quite apparent to the automotive industry and is currently under intense development effort. Any solution to this problem must be simple, durable, and yet not introduce any additional problems.
Heat loss, experienced by the exhaust gases as they travel from the combustion zone through the exhaust passage of the engine block, can be considerable. Such heat loss is accomplished by conduction, convection and radiation. Minimizing heat loss within the exhaust passage is important for at least two principal reasons, (a) to maintain a high temperature of the exhaust gases therein to induce oxidation, and (b) to reduce the heat loss to the surrounding coolant in the block and head so as not to prematurely dissipate an unduly large number of heat units.
The prior art has approached such problems in principally three modes comprising: (1) use of cast-in-place type liners which have been either of the single metal layer or single refractory element design, or dual metal or refractory layers; (2) the use of insertable type liners which are added independently of the fabrication of the engine housing, such liners also being of the single layer heat resistant alloy metal design or double layer metal design or multiple layers of ceramic including air spaces or foamable paste therebetween; and (3) the use of applied coatings directly to the prefabricated engine housing passage walls, including asbestos and other ceramic materials. The disadvantage to employing cast-in-place type liners to date has been principally a lack of bonding; shrinkage and solidification of the cast metal around the liner has lead to localized poor bonding and/or separation which eventually provides for leaks and inadequate insulation. The principal disadvantage to the insertable type liner is that they insufficiently control heat transfer by not conforming closely to the wall of the exhaust passage resulting in a poorly trapped air space and a reduction in the insulating factor resulting from sealing difficulties. Coatings have proved disadvantageous because of their fragile nature which is particularly troublesome when the cast housing is subjected to post mechanical or chemical treatments tending to fracture or chip such coatings. Moreover, such coatings require multiple steps which result in increased manufacturing costs.
SUMMARY OF THE INVENTION
A primary object of this invention is to provide a new and improved method of making exhaust passage insulating liners for an automotive engine, the method being characterized by (a) increased economy of fabrication and material while providing for improved bonding of the liner to other components of the engine system, and (b) has a decreased total coefficient of heat transfer from the exhaust passage wall compared to prior art liners.
Yet still another object of this invention is to provide a low cost heat insulating liner for the exhaust passage of an engine which liner not only minimizes heat transfer across the total thickness of the lining assembly but also provides a low specific heat at the inner structure of the liner to minimize chill to the exhaust gases passing therethrough particularly during a cold start. The inner structure should additionally provide increased resistance to oxidation at high temperatures.
Yet still another object of this invention is to provide an improved exhaust port liner meeting the above objects and which has an extended operating life of at least 5000 hours and is characterized by a high resistance to erosion both from chemicals and mechanical abrasion either during use or during fabrication of the engine housing.
Features pursuant to the above objects comprise (a) the use of a three zone liner wall assembly, (b) the supporting structure for the assembly is comprised of a mild carbon steel sleeve having by weight less then 0.06¢ carbon and less than 0.2% impurities, (c) an outer zone consisting essentially of a thin sleeve of room-temperature-curable silicone having a thermal conductivity of about 0.008 BTU (ft.)/hr.ft 2 .° F., (d) an intermediate zone having trapped air spaces defined by foam or fiber wool, and (e) an innermost zone comprised of a weldable heat resistant and chemically resistant alloy consisting essentially of iron-chromium-aluminum.
SUMMARY OF THE DRAWINGS
FIG. 1 is a sectional view of a portion of an engine housing illustrating the positioning of an insertable type liner according to the principles of this invention;
FIG. 2 is an enlarged fragment of the sectional view of the three zoned wall system of the liner displayed in FIG. 1;
FIG. 3 is a view similar to FIG. 2, but illustrating a portion of a cast-in-place type liner assembly according to the principles of this invention.
DETAILED DESCRIPTION
The purpose of the liner of this invention is to minimize the heat loss through the exhaust port walls thus increasing the exhaust gas temperature to induce hydrocarbon oxidation, improve the downstream thermal reactor and/or catalyst efficiency, reduce the heat transfer to the engine coolant, and to all of the above by way of a low cost assembly. To function as an efficient port liner, the materials and the construction of the liner walls must meet the following requirements for this invention: (a) the heat transfer across the assembly wall from the exhaust gases to the cast metal must be minimized, preferably to less than 25% of the heat loss experienced by an unlined passage, (b) the materials used in each zone of the assembly must be thermally stable at the gradient temperature experienced at each respective zone, (c) the inner skin material for the liner should (i) have a very low specific heat of about 0.10 BTU/lb./° F., to minimize chill to the exhaust gases during cold startup operations, (ii) have low thermal mass, (iii) possess good chemical oxidation resistance and withstand thermal temperatures up to 1600° F., and (iv) yield at least 3000 hours of service life in an engine exhaust environment. In addition, the supporting sleeve for the assembly should withstand the chemical erosion caused by the molten metal during casting if of the cast-in-place type assembly and the exposed surfaces of the liner should withstand the mechanical erosion caused by the exhaust gases or the mechanical shock and abrasion caused by shot-peening, employed during cleanup of the engine housing.
APPARATUS
To meet the above criteria, one preferred mode of the present invention provides for an exhaust port liner with at least three zones, the outermost zone A is comprised of a room-temperature-curing silicone resine, such as a solventless polysiloxane with a melting point of 200°-220° F. and a thermal conductivity of about 0.008 BTU.ft./hr.ft 2 , °F. In the presence of a catalyst such as argon or metallics, the silicone is thermoset through the condensation of the hydroxyl groups. One such compound is polymethyl siloxane silicone made by General Electric or Dow Corning. The silicone is formed as a thin sleeve and is thermally stable at temperatures up to 200° F. which is the temperature environment for the thin layer juxtaposed to the water-cooled engine housing. The thickness of the silicone sleeve is about 0.01 inch or less.
The intermediate zone B is comprised of one or more trapped air spaces preferably occupied by ceramic fiber wool or mat such as aluminum silicate or cordierite (the latter is a ceramic consisting of magnesium aluminum silicate 2MgO.2Al 2 O 3 .5 SiO 2 , or other stable low thermal conductivity ceramic. The fiber may be employed in the mat form on collected wool; each form serves to define numerous trapped air spaces giving the intermediate zone a thermal conductivity value of 0.5 BTU.ft./hr.ft 2 .°F. The ceramic is stable at temperatures of 400°-600° F. which are experienced in this zone.
The third or innermost zone C is comprised of an inner sheet metal skin, the metal consisting essentially of a low aluminum-chromium steel containing approximately 18% chromium, 2% or less aluminum, and the remainder iron. In some instances the alloy may contain a small amount of yttrium at about 0.5%. Such chemistry provides for a thermal conductivity of 12.5 BTU.ft./hr.ft 2 .°F. and provides for weldability to the mild carbon steel outer skin while at the same time providing for resistance to chemical erosion at a relatively low cost. Because the inner skin has a high strength and is not deep-drawable, fabrication must be by stamping and subsequent welding along predetermined seams.
The supporting structure for the liner assembly, which is juxtaposed at passage wall and encloses the assembly, is comprised of a mild carbon sheet steel designed to have a melting temperature higher than the melting temperature of a cast iron engine housing into which the liner is implanted or inserted. The cast iron should be typically of the grey iron type having a chemistry consisting of 3-4% carbon, 1-2% silicon and the remainder Fe. For nodular iron, 0.5% or less MgO is present. The melting temperature for such a grey cast iron is about 1150°-1200° C. and the melting temperature for the low carbon sheet steel, required for this invention should be above 1500° C. To maintain such elevated melting temperature for the outer skin steel, the carbon content of the low carbon steel should be at 0.06% or less and impurities should be 0.2% or less. The steel sleeve prevents heat shorts which occur with prior art cast-in-place metal liners, since in the past the molten metal penetrated through the liner metal by solution creating metal-to-metal at heat shorts for thermal transfer.
Mounting of the three zones of the liner asembly to the supporting sleeve is promoted by welding of the inner skin to the support sleeve, as described later in connection with the method of making, thereby enveloping zones A and B. The intermediate zone B is held in place to the inner skin C during assembly or welding by the adhesive qualities of a silicone plastic coating which subsequently deteriorates under operating temperature conditions of liner use. Similarly, the adhesive qualities of the outer zone provides positioning as coating during assembly, but the integrity of later zone is maintained stable throughout the operating life of the liner since the use temperature at the zone A never exceeds 200° F.
Metal cost is a most important factor in the present automotive engine market; mild carbon steel has a current price range of about 5-10 cents per pound and it is possible to obtain supplies of low aluminum-chromium steel for the inner skin at a price level of about $1.40 per pound. All other chemically resistant sheet metals are considerably more expensive or not weldable for the purpose as stated above, or cannot withstand a 1200° F. temperature gradient which is necessary for the inner skin. Thus the selection of these two metals with their accompanying physical characteristics in combination serve an important economical consideration.
The sizing of the liner is relatively important, the outer skin A must have a thickness of 0.01 inches or less, the intermediate zone B should have a thickness in the range of 0.06-0.08 inches, the inner skin C should have a thickness of about 0.025-0.030 inches, and the supporting mild carbon steel sleeve should have a ply thickness of 0.015-0.018 inches for an insertable type liner, but 0.045-0.06 inches for a cast-in-place liner. The total assembly should have a thickness of about 0.125 inches across the three zones and steel sleeve; the clearance between the outer surface of the steel sleeve and the passage of the engine housing containing the liner, should be 0.015-0.05 inches if the liner is of the insertable type. This latter spacing is filled by a room-temperature-curing silicone applied as a coating before insertion. The average thermal conductivity for the steel sleeve and assembly will be about 1.5 BTU.ft./hr.ft 2 .°F.
In the event the engine housing containing such liner is comprised of aluminum alloy, it will typically be an aluminum-silicon alloy having a melting temperature in the range of about 600° C. In that event the supporting sleeve will still be preferably comprised of plain carbon steel, although a substantially pure aluminum sheet metal having a thickness of about 0.025 may also be used. For cost reasons, however, the supporting sleeve should be low carbon iron, irrespective of whether a cast-in-place or insertable type liner.
METHOD--Insert Type
A preferred method of fabricating a liner of the insert type, as illustrated in FIGS. 1-3, is as follows:
1. Form a sand core to define an exhaust passage 10 in a metal casting 11, the core providing for a predetermined passage configuration as shown in FIG. 1. The passage configuration is comprised of a cylinder 14 and an elbow 15 providing an abrupt turn at the innermost end; the elbow 15 is interrupted by a flattened shoulder 16 to provide a valve guide entrance. The core is adapted to extend from the sidewall 12 of the intended casting to the lowermost wall 13 of the intended casting, the planes of such walls being at an angle with respect to each other of about 75°. Several of these cores may be employed as a cluster to define a series of exhaust passages in accordance with conventional art.
2. After having placed the core in proper position within a mold, a casting for an engine head is formed thereabout using cast iron having a chemistry consisting of 3-4% carbon, 1-2% silicon and the remainder iron.
3. Male and female dies are formed to define a liner support sleeve 17. The two dies are employed to deep-draw a selected metal blank, the product of such deep-drawing producing a configuration conforming closely to the configuration of the cast exhaust passage with a substantially uniform clearance of about 0.015 inches. The support sleeve 17 has an annular flange 17a at one end adapted to abut and fit tightly against the outer sidewall 12 of the engine head; sleeve 17 has a cylindrical channel 17b adapted to extend from the flange into the elbow of the passage 10 adjacent its entrance.
4. Employing said male and female drawing dies, a blank of mild carbon steel having, by weight, less than 0.06% carbon and less than 0.2% impurities. The low carbon steel blank is drawn to the configuration as illustrated which extends in most cases a distance of 2-3 inches from the flange 17a.
5. Male and female stamping dies are defined to form an inner skin or zone C for said liner assembly. The inner skin is a metal cylinder 20 adapted to nest within the outer metal support sleeve 17 and provide for a predetermined spacing therebetween of about 0.08 inches, except at the leading and trailing portions where the metal sleeve and inner skin are brought together for joining and assembly.
6. Forming a cylinder with an open longitudinal seam 20, using the stamping dies. The cylinder of skin 20 conforms to the configuration of the sleeve 17 except that it is spaced inwardly said 0.08 inches. The inner skin 20 is formed from a blank of temperature resistant low aluminum-chromium steel. Preferably the chemistry should contain 18% chromium, 2% aluminum and the remainder iron; in some cases the addition of yttrium in an amount of about 0.5% may be desired. The seam 20 is closed by appropriate welding.
7. The completed inner and outer skins are brought together for assembly at the leading and trailing portions 21-22 and are spot welded together.
8. Prior to welding, a mat of ceramic fiber is implanted between the skins and held in position temporarily, particularly during welding, by use of a room-temperature-curable silicone rubber compound. The compound is spread on the mat prior to implantation, both on the inner as well as outer surface of the mat to define two coatings 24 and 25 (the latter constituting the outer zone of the liner assembly); each at a thickness of 0.01 inches maximum.
9. After the support sleeve and inner skin have been welded together, the outer surface of the support sleeve 17 is also coated with a room-temperature curable silicone rubber compound, the coating 25 being in the thickness range of 0.010-0.050 inches.
10. The liner assembly is then inserted into the cast exhaust passage 10 so that flange 17a abuts the sidewall 12 of the casting and the silicone compound coating 25 is in intimate contact with the walls of the passage 10. Thus, the liner will be supported not only by the silicone compound coating throughout its longitudinal extent but also by the flange 17a which is secured to the casting such as by bolts.
METHOD--Cast-in-place
In the event the liner assembly is desired to be of the cast-in-place type, the fabrication method is modified so that the supporting sleeve 17 has a contour and dimension such that it will be entrained by the molten metal poured therearound and act as an anchored outer skin. The support sleeve, of course, will not carry any silicon coating because the molten metal will have an intimate metallurgical bond between the casting and the outer skin. The support sleeve 17 will maintain its integrity during casting because its melting temperature (1500° C.) will be adequately elevated beyond that of the temperature of the molten material to prevent dissolution. The molten cast iron should have a chemistry consisting of standard nodular iron grade or grey iron grade, thereby providing for a melting temperature of about 1200° C. The melting temperature of the support sleeve 17 will be greater than 1500° C. as mentioned earlier. The liner is, of course, prepared and assembled prior to being cast-in-place similar to the previous process for the insert type, except that when it is assembled it is employed as a core element and the molten metal cast therearound to mutually reach therewith and provide a tight metallurgical bond throughout the entire outer surface of sleeve 17. The positioning of the cast-in-place liner is illustrated in FIG. 3.
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A method and apparatus for insulating the exhaust passage of an internal combustion engine is disclosed. A three-zone liner assembly is provided with an outer zone comprised of a room temperature vulcanizing silicone sleeve, an inner zone comprised of a stamped and seam welded high strength Al-Cr-steel alloy, and an intermediate zone consisting of a ceramic wool mat. The liner assembly is supported or enclosed within a mild carbon sheet metal sleeve metal which in turn may be bonded to the engine passage wall by use of a room-temperature-vulcanized silicone if of the insert type, or by fusion bonding during casting if of the cast-in-place type.
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BACKGROUND OF THE INVENTION
The present invention relates generally to devices adapted for use in donning footwear and more particularly to a novel device adapted for use in donning a ski boot and to a method of using said device.
The difficulties associated with donning tight-fitting articles of footwear of the type having a closed-heel are well-chronicled and are attributable in large part to the fact that while, in many instances, it is desirable to make such footwear as rigid as possible to provide protection to a foot disposed therein, such rigidity makes the insertion of a foot into the article of footwear more difficult. One common approach to this problem has been the use of a conventional shoe horn. Examples of other types of devices that are designed for use in donning footwear are disclosed in the following U.S. patents, all of which are incorporated herein by reference: U.S. Pat. No. 6,318,607, inventor Koskela, which issued Nov. 20, 2001; U.S. Pat. No. 6,065,654, inventor Evensen, which issued May 23, 2000; U.S. Pat. No. 5,974,701, inventor Busch, which issued Nov. 2, 1999; U.S. Pat. No. 5,927,573, inventors Votino et al., which issued Jul. 27, 1999; U.S. Pat. No. 5,806,729, inventor Ramon, which issued Sep. 15, 1998; U.S. Pat. No. 5,741,569, inventors Votino et al., which issued Apr. 21, 1998; U.S. Pat. No. 5,392,800, inventor Sergi, which issued Feb. 28, 1995; U.S. Pat. No. 4,718,135, inventor Colvin, which issued Jan. 12, 1988; U.S. Pat. No. 4,667,861, inventors Harrington et al., which issued May 26, 1987; U.S. Pat. No. 3,591,226, inventors Elmore et al., which issued Jul. 6, 1971; and U.S. Pat. No. 28,927, inventor Wheeler, which issued Jun. 28, 1860.
As can readily be appreciated, the aforementioned difficulties associated with the donning of tight-fitting footwear are especially acute in the case of ski boots, which must be particularly rigid and tight-fitting to afford optimal protection and support to the ski boot wearer. Unfortunately, however, because of the size, shape and rigidity of most ski boots, most shoe horns and other devices of the type discussed above are of little use in helping one to don a ski boot. As a result, the typical way in which a skier dons a ski boot is to insert her foot into the boot while, at the same time, manually spreading apart the cuff portions of the boot disposed on opposite sides of the boot tongue. However, as can readily be appreciated, this task is often too onerous for many children and other weaker individuals. Consequently, it is often necessary for such individuals to enlist the aid of a second person to spread apart the opposing cuff portions of the boot while the skier inserts her foot into the boot. As can be imagined, where there are many individuals in need of assistance and a limited number of people available for help, the foregoing procedure can become quite time-consuming and can even cause a delay to those individuals who are helping others from donning their own ski boots. Moreover, it can readily be appreciated that the task of spreading apart the opposing cuff portions can be tiring, both to those working on their own ski boots and to those working on the ski boots of others.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a novel device adapted for use in donning a ski boot.
It is another object of the present invention to provide a device as described above that overcomes at least some of the problems discussed above in connection with the donning of ski boots.
It is still another object of the present invention to provide a device as described above that is adapted to be used either by the skier wishing to don her own ski boot or by a first individual wishing to help a second individual to don a ski boot.
It is still yet another object of the present invention to provide a device as described above that has a minimal number of parts, that can be mass-produced and that is easy to operate.
According to the above and other objects to be described or apparent from the description which follows, there is provided herein a device suitable for use in donning a ski boot, said device comprising (a) a first handle; (b) a second handle; (c) a first spreader; (d) a second spreader; and (e) means for coupling said first and second handles to said first and second spreaders so that said first and second spreaders may be pivoted away from one another by pivoting said first and second handles away from one another.
In a preferred embodiment, the device comprises a wheel mounting bracket, the wheel mounting bracket comprising a proximal end, a distal end and a longitudinally-extending slot disposed therebetween. A wheel is rotatably mounted within the longitudinally-extending slot and is shaped to include a proximal extension and a distal extension. A first handle is fixed to the distal end of the wheel mounting bracket, and a second handle is fixed to the distal extension of the wheel. The first and second handles are mirror images of one another viewed along their respective longitudinal axes, each of the first and second handles being a unitary structure. The first handle is shaped to include a generally rectangular intermediate portion, a generally rectangular proximal end, a trapezoidal intermediate portion, and a distal end. The proximal end of the first handle is of reduced width as compared to the generally rectangular intermediate portion. The trapezoidal intermediate portion is disposed between the generally rectangular intermediate portion and the proximal end, said trapezoidal intermediate portion tapering in width from said generally rectangular intermediate portion to said proximal end. The distal end is of intermediate width as compared to the generally rectangular intermediate portion and the proximal end. The sides of the distal end are turned upwardly, the remainder of said first handle being coplanar.
A first spreader is fixed to the proximal extension of the wheel, and a second spreader is fixed to the proximal end of the wheel mounting bracket. The first and second spreaders are mirror images of one another viewed along their respective longitudinal axes, each of the first and second spreaders being a unitary structure. The first spreader is shaped to include generally rectangular first intermediate portion. An upwardly extending, generally rectangular second intermediate portion extends distally from said generally rectangular first intermediate portion. A generally rectangular third intermediate portion extends distally from said upwardly extending, generally rectangular second intermediate portion, said generally rectangular third intermediate portion extending generally parallel to said generally rectangular first intermediate portion. The first spreader also includes a generally rectangular distal end of reduced width as compared to said generally rectangular third intermediate portion, a trapezoidal fourth intermediate portion disposed between said generally rectangular third intermediate portion and said proximal end, said trapezoidal fourth intermediate portion tapering in width from said generally rectangular third intermediate portion to said distal end. The first spreader further includes a proximal end extending proximally from said generally rectangular first intermediate portion and curving upwardly away therefrom.
The wheel is provided with a plurality of teeth along its periphery. A pawl, which is pivotally mounted on the wheel mounting bracket, is engageable with the teeth and is biased towards the teeth by a spring clip so that the pawl engages the teeth in a ratchet-type manner as the handles are pivoted away from one another. To pivot the handles back towards one another (once the device has been successfully used), one pivots the pawl away from the wheel, thereby releasing the pawl from engagement with the teeth.
It is a further object of the present invention to provide a method of using said device to facilitate donning a ski boot or to facilitate removal of a ski boot from a wearer.
For purposes of the present specification and claims, it is to be understood that certain terms used herein, such as “on,” “over,” and “in front of,” when used to denote the relative positions of two or more components of the device, are used to denote such relative positions in a particular orientation and that, in a different orientation, the relationship of said components may be reversed or otherwise altered.
Additional objects, as well as features and advantages, of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention. In the description, reference is made to the accompanying drawings which form a part thereof and in which is shown by way of illustration various embodiments for practicing the invention. The embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are hereby incorporated into and constitute a part of this specification, illustrate various embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings wherein like reference numerals represent like parts:
FIG. 1 is a side view of one embodiment of a device adapted for use in donning a ski boot, said device being constructed according to the teachings of the present invention;
FIG. 2 is a perspective view of the device of FIG. 1;
FIG. 3 is an enlarged fragmentary perspective view of the device of FIG. 1;
FIG. 4 is an enlarged fragmentary perspective view of the device of FIG. 1, the bracket member thereof not being shown to reveal components otherwise obscured thereby;
FIG. 5 is an enlarged perspective view of the handle shown in FIG. 1;
FIG. 6 is an enlarged perspective view of the spreader shown in FIG. 1;
FIG. 7 is an enlarged perspective view of the wheel shown in FIG. 1;
FIG. 8 is an enlarged perspective view of one of the bolts shown in FIG. 1 used to secure the top spreader to the wheel;
FIG. 9 is an enlarged perspective view of the wheel mounting bracket shown in FIG. 1;
FIG. 10 is an enlarged perspective view of the shoulder screw shown in FIG. 1;
FIG. 11 is an enlarged perspective view of the nut shown in FIG. 1;
FIG. 12 is an enlarged perspective view of the pawl shown in FIG. 1;
FIG. 13 is an enlarged perspective view of the pin shown in FIG. 1; and
FIG. 14 is an enlarged perspective view of the clip shown in FIG. 1 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIGS. 1 through 4, there are shown various views of one embodiment of a device adapted for use in donning a ski boot, said device being constructed according to the teachings of the present invention and being represented generally by reference numeral 11 .
Device 11 comprises a pair of identical handles 13 - 1 and 13 - 2 , handles 13 - 1 and 13 - 2 facing away from one another in a mirror image orientation for reasons to become apparent below. Referring now to FIG. 5, handle 13 - 1 is shown by itself; it being understood that the description of handle 13 - 1 to follow applies to handle 13 - 2 as well, albeit in a mirror image orientation. Handle 13 - 1 is an elongated unitary structure, preferably made of a durable metal or a durable molded plastic. Handle 13 - 1 is shaped to include a flat, generally rectangular intermediate portion 14 - 1 , a flat, generally rectangular proximal end 15 - 1 , a flat, trapezoidal intermediate portion 16 - 1 , and a distal end 17 - 1 . Proximal end 15 - 1 is of reduced width as compared to intermediate portion 14 - 1 . Portion 16 - 1 is disposed between intermediate portion 14 - 1 and proximal end 15 - 1 and tapers in width from intermediate portion 14 - 1 to proximal end 15 - 1 . Distal end 17 - 1 is of intermediate width as compared to intermediate portion 14 - 1 and proximal end 15 - 1 . The sides 18 - 1 and 18 - 2 of distal end 17 - 1 are turned upwardly (or, in the case of handle 13 - 2 , downwardly) to facilitate the grasping of distal end 17 - 1 by a user, the remainder of handle 13 - 1 being coplanar.
Referring back now to FIGS. 1 through 4, device 11 further comprises a pair of identical spreaders 21 - 1 and 21 - 2 , spreaders 21 - 1 and 21 - 2 facing away from one another in a mirror image orientation for reasons to become apparent below. Referring now to FIG. 6, spreader 21 - 1 is shown by itself, it being understood that the description of spreader 21 - 1 to follow applies to spreader 21 - 2 as well, albeit in a mirror image orientation. Spreader 21 - 1 is an elongated unitary structure, preferably made of a durable metal or a durable molded plastic. Spreader 21 - 1 is shaped to include an elongated, flat, generally rectangular intermediate portion 23 - 1 , an upwardly bent (or, in the case of spreader 21 - 2 , downwardly bent), generally rectangular intermediate portion 25 - 1 extending distally from intermediate portion 23 - 1 , a flat, generally rectangular intermediate portion 27 - 1 extending distally from intermediate portion 25 - 1 and generally parallel to intermediate portion 23 - 1 , a flat, generally rectangular distal end 29 - 1 , distal end 29 - 1 being of reduced width as compared to intermediate portion 27 - 1 , a flat, trapezoidal intermediate portion 31 - 1 , portion 31 - 1 being disposed between intermediate portion 27 - 1 and proximal end 29 - 1 and tapering in width from intermediate portion 27 - 1 to distal end 29 - 1 , and a proximal end 33 - 1 extending proximally from intermediate portion 23 - 1 and curving upwardly (or, in the case of spreader 21 - 2 , downwardly) away therefrom.
Referring back now to FIGS. 1 through 4, device 11 further comprises means for coupling together handles 13 - 1 and 13 - 2 and spreaders 21 - 1 and 21 - 2 so that spreaders 21 - 1 and 21 - 2 may be pivoted away from one another in a ratchet-type manner. Said coupling means comprises, in the present embodiment, a wheel 51 and a wheel mounting bracket 61 . Wheel 51 , which is also shown separately in FIG. 7, is a unitary structure preferably made of a durable metal or a durable molded plastic. Wheel 51 is shaped to include a central annular portion 52 and a pair of off-center lateral extensions 53 and 55 , extensions 53 and 55 extending parallel to one another from opposite points around the periphery of annular portion 52 . Annular portion 52 is shaped to include a central transverse opening 54 , the purpose of which will be discussed below, and a plurality of teeth 56 , the purpose of which will also be discussed below, teeth 56 being located below extension 55 along a segment of the periphery of portion 52 . Handle 13 - 2 is fixedly secured (by an adhesive or other suitable means not shown) to the bottom surface of extension 53 , extension 53 having a recessed area 58 so that handle 13 - 2 lies flush with the remainder of extension 53 . Spreader 21 - 1 is fixedly secured by a pair of bolts 59 (one such bolt 59 being shown separately in FIG. 8) to the top surface of extension 55 , extension 55 having a recessed area 60 so that spreader 21 - 1 lies flush with the remainder of extension 55 . As can readily be appreciated, bolts 59 could be replaced with an adhesive or other suitable means.
Wheel mounting bracket 61 (which is shown separately in FIG. 9) is an elongated unitary structure, preferably made of a durable metal or durable molded plastic. Bracket 61 is shaped to include a distal portion 63 , a proximal portion 65 and an intermediate portion 67 , intermediate portion 67 interconnecting distal portion 63 and proximal portion 65 . Distal portion 63 and proximal portion 65 extend generally parallel to one another in different planes, with intermediate portion 67 extending downwardly from distal portion 63 to proximal portion 65 . Handle 13 - 1 is fixed (by an adhesive or other suitable means) to the top surface of distal portion 63 , distal portion 63 having a recessed area 69 on its top surface so that handle 13 - 1 lies flush with the remainder of distal portion 63 . Spreader 21 - 2 is fixedly secured by a pair of bolts 59 to the bottom surface of proximal portion 65 . As can readily be appreciated, bolts 59 could be replaced with an adhesive or other suitable means. A longitudinal slot 71 , which extends from distal portion 63 to proximal portion 65 , is provided in bracket 61 , wheel 51 being received in slot 71 . A first pair of transverse openings 73 - 1 and 73 - 2 are formed in bracket 61 , openings 73 - 1 and 73 - 2 communicating with slot 71 and being aligned with opening 54 of wheel 51 . A shoulder screw 75 (shown separately in FIG. 10) is inserted through opening 73 - 1 , opening 54 and opening 73 - 2 , respectively, and is secured in place with a nut 77 (shown separately in FIG. 11 ), screw 75 serving as an axle about which wheel 51 is permitted to rotate.
Said coupling means further comprises a pawl 81 (which is shown separately in FIG. 12 ). Pawl 81 , which is an elongated unitary structure, preferably made of a durable metal or durable molded plastic, is shaped to include a generally rectangular lower portion 83 and a hook-shaped upper portion 85 . Pawl 81 extends transversely through longitudinal slot 71 of bracket 61 and is pivotally mounted on a pin 87 (which is shown separately in FIG. 13) so that upper portion 85 of pawl 81 is adapted to engage teeth 56 of annular portion 52 . The aforementioned pivotal mounting of pawl 81 on pin 87 is achieved by insertion of pin 87 through a transverse opening 89 in pawl 81 and through a pair of transverse openings 91 - 1 and 91 - 2 provided in bracket 61 .
Said coupling means further comprises resilient means for biasing upper portion 85 of pawl 81 towards teeth 56 of annular portion 52 . In the present embodiment, said biasing means comprises a spring clip 95 . Clip 95 , which is an elongated unitary structure, preferably made of a resilient metal or resilient molded plastic, is shaped to include a proximal portion 97 and a distal portion 99 . Proximal portion 97 , which is generally flat and rectangular in shape, is sandwiched between the top surface of spreader 21 - 2 and the bottom surface of proximal portion 65 and is secured in place by bolts 59 . Distal portion 99 is hook-shaped and is adapted to engage upper portion 85 of pawl 81 in such a manner as to bias upper portion 85 distally towards teeth 56 of annular portion 52 for a ratchet-type action.
To use device 11 for the donning of a ski boot, one first rotates device 11 about 90 degrees about its longitudinal axis so that spreaders 21 - 1 and 21 - 2 are positioned side-by-side, as opposed to stacked (as shown in FIGS. 1 through 4 ). One then grasps handles 13 - 1 and 13 - 2 with one's hands and inserts spreaders 21 - 1 and 21 - 2 between the opposing cuff portions of the ski boot to be donned. Next, one pivots handles 13 - 1 and 13 - 2 away from one another until spreaders 21 - 1 and 21 - 2 have correspondingly been pivoted away from one another and have opened the ski boot sufficiently for the wearer's foot to be inserted thereinto. Because of the ratchet-type action of device 11 , even if one ceases to apply a pivoting force to handles 13 - 1 and 13 - 2 , spreaders 21 - 1 and 21 - 2 do not revert to their original orientation until desired. Once the ski boot has been donned and it is desirable to pivot spreaders 21 - 1 and 21 - 2 back towards one another, one simply pivots lower portion 83 of pawl 81 towards annular portion 52 , thereby releasing upper portion 85 of pawl 81 from teeth 56 , and pivots handles 13 - 1 and 13 - 2 back towards one another.
As can readily be appreciated, device 11 can be used both by a person wishing to don her own ski boot(s) or by a person wishing to help another person to don one or more ski boots. In addition, it should also be appreciated that device 11 , in addition to being used to don a ski boot, can also be used to open a ski boot to permit its removal from a wearer. Lastly, it should further be appreciated that device 11 is not limited to use in the donning or removal of ski boots and can be used to don or to remove other types of footwear.
The embodiments of the present invention recited herein are intended to be merely exemplary and those skilled in the art will be able to make numerous variations and modifications to it without departing from the spirit of the present invention. All such variations and modifications are intended to be within the scope of the present invention as defined by the claims appended hereto.
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A device suitable for use in donning a ski boot and a method of using the device to don a ski boot. According to a preferred embodiment, the device comprises a wheel mounting bracket, the wheel mounting bracket comprising a proximal end, a distal end and a longitudinally-extending slot disposed therebetween. A wheel is rotatably mounted within the longitudinally-extending slot and is shaped to include a proximal extension and a distal extension. A first handle is fixed to the distal end of the wheel mounting bracket, and a second handle is fixed to the distal extension of the wheel. A first spreader is fixed to the proximal extension of the wheel, and a second spreader is fixed to the proximal end of the wheel mounting bracket. The wheel is provided with a plurality of teeth along its periphery. A pawl, which is pivotally mounted on the wheel mounting bracket, is engageable with the teeth and is biased towards the teeth by a spring clip.
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REFERENCE TO RELATED APPLICATION
[0001] This application is a non-provisional of, and claims priority to and the benefits of, U.S. Provisional Patent Application 61/622,588 filed on Mar. 11, 2012, the entirety of which is hereby incorporated by reference.
BACKGROUND
[0002] Silicon carbide, (SiC), is an important ceramic material for technological applications at extreme temperatures due to its exceptional physical and mechanical properties, such as high hardness, high thermal conductivity, low thermal expansion and resistance to erosion, corrosion and oxidation. SiC is also used as a reinforcement material in metal matrix composites such as aluminum.
[0003] Components fabricated from SiC materials have surfaces that come close to the hardness of diamond and possess excellent resistance to abrasion.
[0004] Recently, SiC nanowires and nanorods have attracted interest because of their novel physical properties resulting from quantum confinement. The electrical and optical properties due to low-dimensional nanostructures can be tailored for potential applications in nanoelectronics, nanosensors, and biotechnology. Nanocrystalline materials have mechanical properties that are largely governed by their ultimate sizes due to their large surface areas where most of the atoms are localized.
[0005] Consequently, it is possible to produce nanocrytalline/nanorod composites that are superhard materials that have promise for applications in the emerging field of miniaturized moving parts in microelectro-mechanical systems. In solid state electronic devices, quantum well (QW) structures play an important role where the charge carriers are confined at a nanometer length scale.
[0006] Recently, to avoid the effects of different chemical species in hetrostructure superlattice devices, SiC has been proposed as a promising candidate material of choice due to the presence of two stable and well-understood polytype phases. These α (4H) and β (3C) phases provide a variation of 1 eV energy gap. It was proposed that the 3C inclusions in 4H or 6H SiC behave like quantum wells. In addition, it is very promising material for power electronics and biomedical applications due to its high breakdown voltage and chemical inertness, respectively.
[0007] Discovery of new forms of SiC such as nanoporous structures have opened new horizons of applications in electronics. In addition, nanocrystalline SiC can have important applications in gem, optical, and metallurgical polishing, and Ni—SiC composite coatings for integrated circuit engine components.
[0008] Silicon carbide has many polytypes arising from the different scheme of stacking layers of C and Si atoms; the most common (α-SiC, 4H) is formed at temperatures greater than 1700° C. and has a modified hexagonal crystal structure (Wurtzite). The beta configuration (β-SiC, 3C), exhibits a zinc-blende crystal structure (diamond), and can be formed at temperatures below 1700° C. Due to the close proximity of silicon and carbon on the periodic table, the silicon to carbon bonds are highly covalent in nature.
[0009] In many of the applications for SiC nanostructures, large quantities are required and must be produced using a simple, inexpensive method. It is also important to note that currently there is a significant problem in sustainability due to the large quantities of rice husk that are a byproduct of white rice. The elemental composition of rice consists of elements such as Si, C, Fe, Mn, Ca etc. Because large quantities of rice are being consumed every year generating millions of tons of rice husks per year, disposing this agricultural waste is a big challenge.
[0010] Burning the rice husks in air only produces the extremely fine silica ash which poses health hazard. Therefore it is important to identify a means to successfully eliminate this waste, or better yet, repurpose it towards a useful end.
[0011] It has been shown that rice husk material provides an appropriate precursor material for the formation of SiC nanostructures via various techniques as well as from other methods. Silicon carbide can be produced by processes involving multiple steps consisting of heating rice husks in an inert atmosphere to temperatures higher than 1300° C. A single step method also was adopted by using plasma reactor using graphite electrodes.
[0012] In this disclosure, we describe a novel, simple, and single-step process in which raw rice husks, sorghum, peanuts, walnuts, almonds, pistachios, nut shells, maple leaves, fruit pits such as from dates, peaches, mango, and corn husk materials and others that contain silica can be converted directly to a collection of cubic β-SIC nanostructures using a method involving rapid heating in a vacuum using conventional heating or a millimeter-microwave beam that increases the localized temperature up to 1900° C.
SUMMARY OF DISCLOSURE
Description
[0013] This disclosure involves a new method for the formation of abundant quantities of SiC from rice husk, sorghum, peanuts and peanut shells, walnuts, almonds, pistachios, nut shells, maple leaves, fruit pits such as from dates, peaches, mango, and corn husk materials and others that have silica content using conventional heating or microwave processing and the formation of the nanoparticle and nanorods of SiC in abundant quantities in a pure form using an inexpensive processing of agriculture waste.
[0014] Silicon carbide, SiC, is an advanced ceramic material that has been in existence for many years but is finding important technological applications at extreme temperatures because of its high hardness, thermal conductivity, and resistance to erosion, corrosion and oxidation.
[0015] SiC is also included among the family of reinforcement materials in metal matrix composites such as aluminum. Indeed, components fabricated from SiC materials have surfaces that come close to the hardness of diamonds and possess excellent resistance to abrasion. Nanocrystalline materials have mechanical properties that are largely governed by their ultimate sizes due to their large surface areas where most of the atoms are localized.
[0016] Consequently, it is possible to produce nanocrytalline/nanorods composites that are superhard materials which will have promise for applications in the emerging field of miniaturized moving parts in microelectro-mechanical systems. Additionally, nanocrystalline SiC can have important applications in gem polishing, optical polishing, metallurgical polishing, and Ni—SiC composite coatings on integrated circuit engine components.
DESCRIPTION OF THE DRAWINGS
[0017] The following description and drawings set forth certain illustrative implementations of the disclosure in detail, which are indicative of several exemplary ways in which the various principles of the disclosure may be carried out. The illustrated examples, however, are not exhaustive of the many possible embodiments of the disclosure. Other objects, advantages and novel features of the disclosure will be set forth in the following detailed description when considered in conjunction with the drawings.
[0018] FIG. 1 is an XRD scan of rice husk treated at 1900° C. in air showing the cristabolite phase of SiO 2 .
[0019] FIG. 2 is an XRD scan of rice husk treated at 1900° C. in vacuum showing the β-SiC phase.
[0020] FIG. 3 is a TEM micrograph of SiC samples obtained after microwave processing them at 1900° C. in vacuum. SiC powder particles get sintered to one another. Their sizes vary between 100-300 nm in diameters.
[0021] FIG. 4 illustrates: (a) particle showing stacking faults; (b) the corresponding diffraction pattern in the [011] zone; and (c) diffraction pattern from another particle showing twined spots close to [110] zone.
[0022] FIG. 5 illustrates Raman scattering data of microwave processed rice husk sample at 1900° C. in vacuum showing the TO and LO line of β-SiC and D and G lines of graphitic like material.
[0023] FIG. 6 illustrates: (a) FTIR reflection spectra collected from three different regions within the sample; and (b) zoomed in view of the spectra within 650-1250 cm −1 spectral range.
[0024] FIG. 7 illustrates X-ray diffraction patterns of the sorghum leaves taken with copper radiation (a) showing peaks from the α-Quartz phase; (b) after treating at 1500° C. in Argon atmophere showing the presence of graphite and the presence of 6H—SiC and β-SiC phases; and (c) after treating in oxygen at 800° C., showing a trace amount of 6H—SiC and cubic β-SiC phases.
[0025] FIG. 8 illustrates X-ray diffraction patterns of the peanut shells taken with copper radiation (a) showing peaks from the amorphous phase; (b) after treating at 1500° C. in Argon atmophere showing the presence of carbon and the presence of 2H—SiC and β-SiC phases; and (c) after treating in oxygen at 800° C., showing a trace amount of 2H—SiC which are shown by arrows and cubic β-SiC phases.
[0026] FIG. 9 illustrates X-ray diffraction patterns of the maple leaves taken with copper radiation (a) showing peaks from the α-Quartz phase; and (b) after treating at 1500° C. in Argon atmophere showing the presence of 2H—SiC and β-SiC phases.
[0027] FIG. 10 illustrates X-ray diffraction patterns of the corn husk taken with copper radiation (a) showing peaks from the α-Quartz phase; and (b) after treating at 1500° C. in Argon atmosphere showing the presence of cubic β-SiC phases.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Samples of rice husks were transformed to β (3C)—SiC by microwave processing in controlled conditions of temperature in a vacuum. This simple and fast way of producing the powdered samples of silicon carbide is technologically important if this material is to be used for electronics, sensors, biotechnology and other applications.
[0029] Using x-ray diffraction it was found that the microwave processed sample at 1900° C. consists of β (3C)—SiC phase. Raman scattering measurements confirmed the formation of β (3C)—SiC phase.
[0030] The transmission electron microscopy revealed the presence of stacking faults along the [111] direction. The presence of 6H/4H stacking faults in 3C phase is explained in terms of their total energies. The presence of these stacking faults with a ˜1 eV band offset between the host 3C and hexagonal stacking fault imply that these stacking faults provide a conduction barrier, and the interfaces between the stacking fault and host lattice acts as a heterojunction that may provide potential utility for various opto-electronic applications.
[0031] Silicon carbide has many polymorphs; the most common (α-SiC) is formed at temperatures greater than 1700° C. and has a hexagonal crystal structure (Wurtzite). The beta modification (β-SiC), with a zinc blende crystal structure (diamond), is formed at temperatures below 1700° C. Silicon carbide, due to the close proximity of silicon and carbon on the periodic table, is a highly covalent material that forms tetrahedral coordination between carbon and silicon atoms. These tetrahedra form a close-packed structure and occur in the alpha and beta phases. Beta silicon carbide takes the diamond cubic structure and is a very stable structure.
[0032] In this disclosure, we describe a unique and fast single step process in which the raw rice husks, sorghum, peanuts and a variety of other nuts and/or the shells, fruit pits from various fruits such as dates, peaches, mango, maple leaves, and/or corn husk materials, and/or various others that have silica content, some of which can considered to be agricultural waste, are converted directly to a cubic β-SiC using a rapid heating in a vacuum using conventional heating or a millimeter-microwave beam to a temperature reaching 1900° C. In addition to corn husk materials, either the stalks or leaves will produce SiC as both have a high enough silica (SiO2) content. In addition to peanuts and peanut shells, any nuts such as pistachios, almonds, walnuts, etc. will produce SiC and give similar results. Furthermore, this list is only meant to be illustrative and not exhaustive as, for an additional example, leaves that have high silica content will also produce SiC by our unique and simple process.
[0033] FIG. 3 shows the x-ray diffraction scan of as-synthesized sample from rice husk after processing at 1900° C. in the microwave set-up. Clearly all the peaks are identifiable with β-SiC phase. The x-ray data analysis shows a lattice parameter of 4.359±0.003 Å which is in agreement with the equilibrium lattice parameter of 4.3589 Å. The crystallite size calculated from the full width at half maximum (FWHM) of (111), (220) and (311) diffraction peaks of β-SiC phase and Scherrar's formula is about 15 nm.
[0034] This analysis was also confirmed by Raman measurements shown in FIG. 5 where the TO and LO mode of β-SiC phase are identified.
EXAMPLE 1
[0035] A compact of compressed rice husk material is rapidly heated in a vacuum by a millimeter-wave beam to a temperature of about 1900° C., held at this temperature for a few minutes, and then cooled. During this process the rice husk material reacts to form silicon carbide and other products.
[0036] The frequency of the beam was 83 GHz, the total beam power was about 5 kW, and the power density was about 0.3 kW/cm 2 .
[0037] The rice husk compact was held in a covered boron nitride crucible with a view hole for temperature measurement. A BN crucible was used because it is able to withstand the millimeter-wave beam and does not couple to it.
[0038] The compact was directly heated to high temperature by the intense 83 GHz beam. The synthesis of SiC was verified by x-ray diffraction measurements and Raman spectroscopy.
[0039] The modest (mechanical pump) vacuum environment prevents oxidation and silica formation.
[0040] Heating to temperatures below 1500° C. did not produce SiC.
EXAMPLE 2
[0041] Samples of rice husks were obtained. The husks were milled into a fine powder using a SPEX jar mill in a Polycarbonate jar with Polytetrafluoroethylene milling media. The rice husk powder was mixed in a mortar and pestle with a Polyvinyl alcohol (PVA) binder in a ratio of 0.95 rice husk to 0.05 PVA by weight.
[0042] Several 0.5 in. pellets were then pressed using a Carver press and homemade die set. A compact of compressed rice husk material was rapidly heated in a vacuum using a millimeter-wave beam to a temperature of about 1900° C., held at this temperature for a few minutes, and then cooled.
[0043] The total heating and cooling time using this method was 10 min. During this process the rice husk material reacts to form SiC and other products.
[0044] The frequency of the beam was 83 GHz, the total beam power was about 5 kW, and the power density was about 0.3 kW/cm 2 with the microwave radiation directed at the sample.
[0045] The rice husk compact was held in a covered boron nitride crucible with a thru hole provided to allow for accurate temperature measurements using an optical pyrometer. A BN crucible was used due to its ability to withstand the millimeter-wave beam and not couple to it, thereby ensuring the heat was locally delivered to the rice husk only.
[0046] Following the thermal treatment, the pellets were structurally characterized using electron microscopy on a JEOL JSM-7001FLV SEM and for further nanostructure analysis via TEM, samples were prepared by transferring a few drops of alcohol containing fine rice husk powder to a carbon coated fine mesh Cu-grid, and were imaged using Phillips CM 30 and JEOL 2200 FX transmission electron microscopes.
[0047] X-ray diffraction data was collected using a Rigaku 18 kW generator and a high resolution powder diffractometer. Monochromatic CuKα radiation was used for all scans.
[0048] In an effort to verify the crystalline phase of the SiC nanostructures and the other components within the subsequent powder created through this process, Raman scattering of the compact was stimulated using the 514 nm laser line of a Coherent Innova 90 Argon Ion laser.
[0049] The laser line was focused on the sample through a 100×0.75 NA Mitutoyo objective providing a laser spot <1 μm in diameter. The Raman scattered light was collected in back-reflection geometry through the same objective and was focused through a 200 μm optical fiber onto the thermoelectrically cooled CCD array of an Ocean Optics QE65000 spectrometer. Reflection spectra were acquired with a Nicolet Continuum FT-IR microscope using a 15×(0.58 NA) objective.
[0050] Rice husk pellets were processed in a microwave setup at temperatures up to 1900° C. both in air and vacuum atmospheres and in general produced a black powder after it was removed from the chamber.
[0051] FIG. 1 shows an X-ray diffraction scan of microwave processed rice husk samples fired at 1900° C. in air for a duration of five minutes. The sample processed in air shows the presence of predominantly cristabolite phase of SiO 2 . A least square refinement of the data gives lattice parameters of a=4.973±0.001 Å and c=6.924±0.006 Å in agreement with the literature value.
[0052] The crystallite size was estimated from the full width at half maximum of the diffraction peaks and using Scherrer's formula and was found to be 33 nm.
[0053] FIG. 2 shows the x-ray diffraction scan of the sample processed in vacuum at 1900° C. The main peaks can be identified with β-SiC structure, which is cubic Moissanite-3C with a space group of F4 3 m. The x-ray data analysis shows a lattice parameter of 4.359±0.003 Å, which is in agreement with the equilibrium lattice parameter of 4.3589 Å. The small shoulder to the left side of the (111) peak is attributed to the presence of stacking faults in the SiC nanorods observed in the TEM images and described in the following paragraphs.
[0054] A bright-field TEM image of the spherical SiC particles is presented in FIG. 3 and demonstrate the high density of stacking faults present. The particle size ranged from 100 to 300 nm in diameter. Such particles get sintered at high temperature with each other.
[0055] FIG. 4( a ) shows one such particle illustrating the high density of stacking faults oriented along the (111) plane. The corresponding selected area electron diffraction pattern (SAEDP) from one such particle close to the [01 1 ] zone axis is shown in FIG. 4( b ). The diffraction spots, the d-spacing and the angle between planes, conforms to β-SiC crystal. The d-spacing of (111) planes was observed to be around 2.52 Å. The streaks along the 111 direction in the diffraction pattern are due to thin stacking faults. In some particles, one could observe (111) twins, FIG. 4( c ), as well as stacking faults.
[0056] In order to confirm the β-SiC phase and identify other chemical components of the resultant powder, Raman spectroscopy was performed. FIG. 5 shows the Raman spectra for the husk sample fired at 1900° C. in vacuum that exhibits strong modes at 790, 970, 1350 and 1570 cm −1 .
[0057] Consistent with the observations from X-ray diffraction, the peaks at 790 cm −1 and 970 cm −1 are identified as the TO and LO phonon modes of β SiC, which can clearly be distinguished from the spectra of the hexagonal or rhombohedral polytypes, such as 4H, 6H or 15R. In addition, the presence of the modes at 1350 and 1570 cm-1 can be attributed to carbonaceous species, most likely graphitic in nature due to the absence of carbon nanotube like nanostructures within the TEM images. Another possibility is that these modes are due to the presence of graphene or graphitic layers created on the surface of the β SiC nanostructures, which is consistent with recent measurements demonstrating epitaxial graphene growth on 3C—SiC substrates under temperatures in the range of 1500-1600° C.
[0058] FTIR reflection spectra collected from three different regions within the sample are presented in FIG. 6( a ). In these spectra, a few characteristic features are observed, the first being the presence of an overall low reflectance (high absorbance) background across the entire IR spectral range investigated (8000 to 667 cm −1 ; 1.25 to 15 μm) which is associated with the strong absorbance, which is presumably due to the carbonaceous species, or the graphitic or graphene layers present within the sample. Such a strong absorption cannot be explained via the SiC alone this material tends to be IR transparent over most of this spectral range.
[0059] An additional feature of the spectra is observed out beyond 1000 cm −1 . A zoomed in view of the spectra within this spectral range is provided in FIG. 6( b ). From least squares fitting of these peaks to Gaussian functions, we identified the presence of peaks located at approximately 976, 907 and 814 cm −1 , which considering the error in the fits provides peak positions that are consistent for the reported location of the phonon modes of β SiC in the literature of 797, 881, and 972 cm −1 . The strong absorption over this band when coupled with the random nature and simplicity in fabrication may also indicate that such structures may provide utility as optical obscurants, limiters or in modifying thermal emissivity.
[0060] Because SiC exhibits polytypism, with over 215 polytypes having currently been identified, significant theoretical work has been done to discuss the origin of various polytypes. The manifestation of polytypsm could be attributed to the kinetic factors during the growth procedure. These polytypes can be described as distinct metastable thermodynamic phases controlled by external parameters such as pressure and temperature.
[0061] As the polytype is characterized by a stacking sequence with a long periodicity along the stacking axis, only slight modifications in that sequence can lead to dramatic variations in the local crystalline structure and therefore form a superlattice-like structure. These have been explored in a SiC (4H) to a large degree due in part to these stacking faults consisting of 3C SiC layers that upon electron-hole pair recombination are observed to expand and contract, and further induce the well-reported drift in the forward voltage within bipolar SiC devices.
[0062] In addition, in-grown stacking faults, which do not expand or contract, but are induced during growth, are also well reported and consist of various modifications in the stacking order of the material. Such stacking faults have also been reported within the β SiC polytype, exhibiting a hexagonal stacking order with a much larger band gap, and thus do not induce the same deleterious effects that are observed in the a SiC devices. Due to the large offset in the conduction band between the α and β phases (˜1 eV), such stacking faults could be useful in the formation of quantum well structures or heterostructures depending which phase is predominant (e.g. β SiC stacking faults in a SiC structures will provide a quantum well, and heterojunctions will be created in the reverse structure). Because of large energy band gap, large thermal conductivity, high hardness, and high saturation value of electron density, such a superlattice structure will be useful for high-temperature and high-power device applications.
[0063] Among the several polytypes the cubic-zinc-blende structure or 3C, the 4H and 6H hexagonal structures have the lowest formation energies. The ground state properties of these polytypes have been calculated using density-functional theory (DFT) with the plane-wave pseudopotential method. It was found that the energy sequence is found to follow 4H<6H<3C, however, it is important to note that the differences in the formation energies differ only by 1-4 meV between 4H and 3C depending on the calculation method used. Such small energy variations are easily compensated by other sources, such as electron hole pair recombination, for instance, and therefore the formation of stacking faults is common.
[0064] In the nanostructures presented here, the presence of these stacking faults, which are on the order of a few atomic layers in thickness and therefore significantly thinner than the Bohr radii (˜2.7 nm in 3C SiC), along with the ˜1 eV band offset between the host 3C and hexagonal stacking fault stacking order imply that these stacking faults provide a conduction barrier, and the interfaces between the stacking fault and host lattice acts as a heterojunction that may provide potential utility for various opto-electronic applications.
EXAMPLE 3
[0065] Silica content of sorghum leaves is about 9 to 15% of the dry matter and is much higher than found in temperate forages and most other cereal crop residuals.
[0066] We ground the dry leaves of the sorghum plants to produce fine powder and subsequently formed circular disks. Silicon carbide 3C (cubic) phase was obtained from these disks by pyrolysis using either thermogravimetric analysis or microwave heating by controlling the processing temperature in an inert environment of argon at temperatures above 1500° C.
[0067] Using x-ray diffraction it was found that the pyrolised sample consists of cubic β-SiC phase and a trace amount of 6H SiC phase.
[0068] FIG. 7 shows an overlay of three diffraction patterns. The untreated sample showed the presence of silica (SiO 2 ) in the crystalline form having α-quartz phase and all the peaks in FIG. 7( a ) can be accounted based on this phase. The diffraction pattern of the pyrolyzed sample at 1500° C. in Ar-atmosphere is presented in FIG. 7( b ) and shows the presence of graphite and peaks corresponding to the β-SiC phase with a trace amount of 6H SiC.
[0069] Once SiC is formed, we treated in oxygen atmosphere at 800° C. to get rid of graphite and other unwanted carbonaceous impurities. The diffraction pattern in FIG. 7( c ) shows the presence of β-SiC phase only. These results were confirmed by Raman Scattering measurements, scanning and transmission electron spectroscopy.
[0070] These experiments were conducted using conventional furnace heating and microwave heating. Both the stalks and the seeds of the sorghum plant showed amorphous diffraction pattern for as-received sample and subsequent heat treatment did not produce any SiC phases or for that matter any crystalline SiO 2 .
[0071] The transmission and scanning electron microscopy results indicated the presence of nanoparticles with nanometer dimensions and nanorods with length of several microns.
EXAMPLE 4
[0072] Billions of pounds of nut shells and fruit pits which are produced annually all over the world go as an agriculture waste product. In this research, we investigated the formation of SiC from the peanut shells.
[0073] We ground the nut shells to produce fine powder and subsequently formed circular disks. Silicon carbide 3C (cubic) phase was obtained from these disks by pyrolysis using either thermogravimetric analysis or microwave heating by controlling the processing temperature in an inert environment of argon at temperatures above 1500° C.
[0074] Using x-ray diffraction it was found that the pyrolyzed sample consists of cubic β-SiC phase and a trace amount of 2H—SiC phase.
[0075] FIG. 8 shows an overlay of three diffraction patterns. The untreated sample showed the presence of amorphous peaks FIG. 8( a ). The diffraction pattern of the pyrolyzed sample at 1500° C. in Ar-atmosphere is presented in FIG. 8( b ) and shows the presence of carbonacious and peaks corresponding to the β-SiC phase with a trace amount of 2H SiC.
[0076] Once SiC is formed, we treated in oxygen atmposphere at 800° C. to get rid of unwanted carbonaceous impurities. The diffraction pattern in FIG. 8( c ) shows the presence of β-SiC phase and trace amount of 2H—SiC phase. These results were confirmed by Raman Scattering measurements, scanning and transmission electron spectroscopy.
[0077] These experiments were conducted using conventional furnace heating and microwave heating.
[0078] The transmission and scanning electron microscopy results indicated the presence of nanoparticles with nanometer dimensions and nanorods with length of several microns.
EXAMPLE 5
[0079] Billions of pounds of maple leaves which are generated annually, especially during the Fall season, all over the world go as an agriculture waste product. In this research, we investigated the formation of SiC from the maple leaves.
[0080] We ground the dry maple leaves to produce fine powder and subsequently formed circular disks. Silicon carbide 3C (cubic) phase was obtained from these disks by pyrolysis using either thermogravimetric analysis or microwave heating by controlling the processing temperature in an inert environment of argon at temperatures above 1500° C.
[0081] Using x-ray diffraction it was found that the pyrolyzed sample consists of 2H—SiC phase.
[0082] FIG. 9 shows an overlay of two diffraction patterns. The untreated sample showed the presence of α-Quartz peaks FIG. 9( a ). The diffraction pattern of the pyrolyzed sample at 1500° C. in Ar-atmosphere is presented in FIG. 9( b ) and shows the presence of 2H SiC. These results were confirmed by Raman Scattering measurements, scanning and transmission electron spectroscopy.
[0083] These experiments were conducted using conventional furnace heating and microwave heating. The transmission and scanning electron microscopy results indicated the presence of nanoparticles with nanometer dimensions and nanorods with length of several microns.
EXAMPLE 6
[0084] Billions of pounds of corn husks and stalks are available as an agricultural waste. However, corn ash is also being used in applications such as concrete for construction projects. In this research, we investigated the formation of SiC from the corn husks. SiC will be a better material in contrast to ash.
[0085] We ground the dry corn husks to produce fine powder and subsequently formed circular disks. Silicon carbide 3C (cubic) phase was obtained from these disks by pyrolysis using either thermogravimetric analysis or microwave heating by controlling the processing temperature in an inert environment of argon at temperatures above 1500° C.
[0086] Using x-ray diffraction it was found that the pyrolyzed sample consists of cubic 3C—SiC phase.
[0087] FIG. 10 shows an overlay of two diffraction patterns. The untreated sample showed the presence of α-Quartz peaks FIG. 10( a ). The diffraction pattern of the pyrolyzed sample at 1500° C. in Ar-atmosphere is presented in FIG. 10( b ) and shows the presence of cubic 3C—SiC. These results were confirmed by Raman Scattering measurements, scanning and transmission electron spectroscopy.
[0088] These experiments were conducted using conventional furnace heating and microwave heating.
[0089] The transmission and scanning electron microscopy results indicated the presence of nanoparticles with nanometer dimensions and nanorods with length of several microns.
[0090] As discussed, this disclosure involves a new method for the formation of abundant quantities of SiC from rice husk or other materials using either conventional heating or microwave processing and the formation of the nanoparticle and nanorods of SiC in abundant quantities in a pure form using an inexpensive processing of agriculture waste. As such, an abundant, renewable resource now can provide SiC, an important industrial material.
[0091] The method disclosed herein involves a high efficiency and low cost process. Impurities are minimized. Furthermore, the method does not require plasma formation and control.
[0092] Large quantities of the nanoparticles of β-SiC can be obtained from the agricultural waste of rice husks using microwave processing them in vacuum with controlled conditions of temperature (about 1900° C.). This simple and cheap way of producing these nanoparticles is important if this material is to be used for electronics, nanosensors, and biotechnology. X-ray diffraction, Raman scattering, and TEM, show that there is a simultaneous formation of β-SiC from the pyrolysis of rice husks in the microwave set-up. Transmission Electron Microscopy and Raman Spectroscopy show the presence of β-SiC nanoparticles with stacking faults. The presence of 6H/4H stacking faults in 3C phase makes a quantum-well like structure that can be utilized in opto-electronics as well as other applications.
[0093] The above examples are merely illustrative of several possible embodiments of various aspects of the present disclosure, wherein equivalent alterations and/or modifications will occur to others skilled in the art upon reading and understanding this specification and the annexed drawings. In addition, although a particular feature of the disclosure may have been illustrated and/or described with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Also, to the extent that the terms “including”, “includes”, “having”, “has”, “with”, or variants thereof are used in the detailed description and/or in the claims, such terms are intended to be inclusive in a manner similar to the term “comprising”.
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This disclosure concerns a method of making silicon carbide involving adding one from the group of rice husk material, sorghum, peanuts, maple leaves, and/or corn husk material to a container, creating a vacuum or an inert atmosphere inside the container, applying conventional heating or microwave heating, heating rapidly, and reacting the material and forming silicon carbide (SiC).
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RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/984,491, filed Apr. 25, 2015, the disclosure of which is incorporated herein by reference.
FIELDS OF THE INVENTION
[0002] The invention presented here relates to an ultraviolet sterilization system used for removing or reducing microbes from bottled water prior to use, or more specifically a portable ultraviolet sterilization drinking system for reducing or removing microbes from drinking water.
BACKGROUND
[0003] Each year millions of humans are infected with water borne pathogens. The World Health Organization has reported that 1.8 million people die every year from diarrheal disease, including cholera, 90% are children under 5 years old. These are preventable cases which are caused by drinking water contaminated with pathogens. This is mostly an issue within the developing regions, but also can become an issue in industrialized nations in times of war, or natural disasters such as floods, earthquakes, tsunamis, or any type of civil unrest or terrorism which may affect centrally distributed and disinfected tap water.
[0004] It is know that UV-C radiation is one type of energy source that is capable of disinfecting water. There are numerous methods and devices for ultraviolet radiation disinfection. UV-C disinfection mechanism is characterized by sufficiently exposing the DNA and/or RNA of micro-organisms to photon energies that can impart direct dissociation of the chemical chain, such as a break or nick in the chain, thereby disrupting the cellular replication cycle and continued growth of the organism. Higher photon energy with shorter wavelength photons, like ultraviolet light, produces much greater disinfection compare to visible light, UV-A, UV-B, or other sources. This is why ultraviolet light within the UV-C band (wavelength of approximately 210 nanometers to approximately 290 nanometers, also known as the “disinfection band”) is the most efficacious and preferred range for disinfection applications.
[0005] Wadstrom in U.S. Pat. No. 7,837,865 discloses a device using a combination of solar heat and ultraviolet light however, there are no ultraviolet disinfection parameters or indication mechanism, nor is there a means by which the user would know that the stored water has been irradiated and completely disinfected.
[0006] Lantis et al. in US Pat. Appl. No. 2013/0056425 described a solar-based portable water disinfection system. Lantis et al. utilizes a security cap seal wherein the seal is affixed around the base of the cap and cured with UV light to represent disinfected water. However, the bottle in Lantis et al does not address continued use after the seal is broken for use and subsequent UV disinfections are required.
[0007] There is a need for a practical device capable of rapidly purifying a small volume of water suing continued use. The present invention addresses this need using a portable device containing an ultraviolet irradiation source. It is well know that ultraviolet light (UVC) is one energy source that is capable of disinfecting water. Non-thermal disinfection mechanisms are well known and characterized by sufficiently exposing the DNA and/or RNA of micro-organisms to photon energies that can impart direct damage to the chemical compounds defining the DNA/RNA chain, thereby breaking the cellular replication cycle and continued growth of the organism.
SUMMARY
[0008] The present invention describes a portable water purification system for use in a standard water bottle. Accordingly, a water bottle having a germicidal UV-C water purification unit includes a water container with a threaded opening at the top onto which a cap containing a UV-C ultraviolet light source and related components are housed to provide an irradiation cycle for disinfecting the volume of water stored in the reservoir container. One 90 second UV irradiation cycle provides a complete disinfecting treatment of 750 ml of water, suitable for drinking. The system is capable of providing up to 10,000 treatment cycles, completing a single cycle in 90 seconds. A UV-C bulb within the cap and system electronics provides sterilizing UV radiation. An LCD screen on the top of the cap verifies the process.
[0009] In addition, the device has a built in LED light for illuminating the immediate area around the user, making it useful as a lantern in remote locations. The LED is located on the cap for quick and easy activation. An optional carbon fiber filter insert is provided to additional remove particles, benefiting the taste and reducing the order.
[0010] The portable system provides safe drinking water in regions where water contaminants may be suspect. It is useful in camping, hiking, cycling, traveling, and general use.
[0011] The embodiments of the present invention are shown in the drawings and summarized below. It is to be understood, however, that there is no intention to limit the invention to the forms described in this Specification. One skilled in the art can recognize that there are numerous modifications that would embody the spirit and scope of the invention as expressed in the claims.
DESCRIPTION OF THE FIGURES
[0012] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.
[0013] FIG. 1 . Drawing showing cap attached to the top of the 750 ml water container. The cap houses the UV-C source to disinfect the water stored within the container.
[0014] FIG. 2 . Drawing showing underside of cap with UV source and LED light.
[0015] FIG. 3 . Diagram showing the steps associated in a 1 cycle UV purification procedure.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The device described in the present invention provides a system for significantly reducing or eliminating microbes found in bottled water where the source was from a suspect source such as, but not limited to, taps, streams, or spigots. The process generally requires filling up the 750 ml bottle from the source, turning on the device, agitating the water and drinking. The purification system eliminates or reduces bacteria, viruses and protozoan cysts and can be used either during the day or at night. Immediately after completing the disinfection process, the water is available to drink. Further, the purified water can be stored in the container after drinking and either treated again by the disinfection process or emptied and refilled to treat another 750 ml of water from a suspect source.
[0017] As shown in FIG. 1 the purification device contains a cap ( 15 ) housing the UV-C lamp, LED light, and associated electronic controls. The cap is threaded onto a 750 ml transparent container ( 10 ). The container is molded along the top lip of the opening to optionally support a carbon filter insert ( 19 ). With the carbon filter insert removed, the water ( 18 ) stored in the container ( 10 ) is exposed to UV-C irradiation ( 17 ). The carbon filter insert can be replaced for continued filtration during drinking.
[0018] FIG. 2 shows the underside of the cap ( 15 ) which houses an insulated UV-C tube ( 25 ) arched around the LED light ( 26 ) in the center portion of the cap. An LCD display on the top of the cap (not shown) provides the countdown to the completed cycle which ensures that the water treatment is simple and intuitive. The cap can be used for 10,000 cycles. A USB cable plugs into the cap for recharging.
[0019] The device has applications in camping, hiking, outdoor use, indoor use, travel (hotel or airplane) or to use as an emergency source for water. It is easy to carry or can be attached to a bicycle or other transportation device.
[0020] The device produces UV disinfected water through a quick and easy method of sterilization without the need of sunlight or other anti-microbial agents (see FIG. 3 ). Water is collected from a source with the 750 ml container bottle. The source can include water from taps, streams, spigots, and the like. Once collected the bottle is capped by rotating a threaded portion of the specialized UV-C emitting cap with the threaded portion of the container, forming a tightly sealed unit. A start button on the cap is pressed once and held for 3 seconds to begin the cycle. A digital display counts down from 90 seconds. The suspect water in the storage container is then agitated periodically. At 0 seconds the cycle is complete and the water is safe to drink, effectively and easily reducing microbe contaminants.
[0021] Following treatment by the UV-C source, the user can optionally unscrew the cap and replace the carbon filter insert. Carbon filtering acts to adsorb pollutant molecules or contaminants in the water and trap these molecules inside the pore structure of the carbon substrate, resulting in the further purification of the water. Typical particle sizes removed by carbon filters will range from 0.5 to 50 micrometers. The carbon filter component acts to remove chlorine, sediment, and volatile organic compounds to improve the taste and any odor in the water.
[0022] Another embodiment incorporates an LED light for use as a visible light source to illuminate the immediate area around the user when camping or such. As shown in FIG. 2 , the LED light ( 26 ) is located in the center of the underside of the cap. Unscrewing the cap from the container or simply activating the light when attached to the container acts as a light source for an alternative use. Activation of the LED light is accomplished by pushing the activation button on the top of the cap for 3 seconds. The LED light can be turned off by pressing the same button once.
[0023] The cap having the UV-C source can be thoroughly cleaned by washing with a soft cloth and a mild soap solution. The soap is rinsed from the device and dried with a clean soft cloth.
[0024] The contents of the articles, patents, and patents applications and all other documents and electronically available information mentioned or cited herein, are hereby incorporated by reference in their entirety to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
[0025] The terms and expressions used herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms of excluding any equivalents of the features shown and described or portions thereof. It is recognized that various modification are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and other features, modification and variation of the invention embodied therein herein disclosed may be used by those skilled in the art, and that such modification and variations are considered to be within the scope of this invention.
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The invention disclosed herein provides a UV purification system within a portable water bottle having a cap and container. More specifically, the present invention is a portable water bottle that provides UV disinfection and water storage having a cap that contains a ultraviolet (UV-C) emitting source to purify stored water for immediate use. Optionally, a carbon filter means is inserted between the cap and container to further purify the water.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit, and is a continuation-in-part of both U.S. Provisional Application No. 60/535,463 filed 09 Jan. 2004 and U.S. Provisional Application No. 09/579,921 filed 14 Jun. 2004, and is a continuation-in-part of the following provisional and nonprovisional applications: Ser. No. 10/647,603 (Docket No. 7148-108A-US), filed 25 Aug. 2003; Ser. No. 10/744,708 (Docket No. 7148-111A-US), filed 23 Dec. 2003; Application No. 60/535,463 (Docket No. 7148-117-PR), filed 09 Jan. 2004; and any of their predecessor applications.
REFERENCE REGARDING FEDERAL SPONSORSHIP
[0002] Not Applicable
REFERENCE TO MICROFICHE APPENDIX
[0003] Not Applicable
[0004] 1. Field of the Invention
[0005] The present invention relates to a diverter, a liquid level indicator and a liquid conditioner and, more particularly, to improved devices and methods therefor for use in a urinal, such as in a waterless urinal.
[0006] 2. Description of Related Art and Other Considerations
[0007] In waterless urinals, such as described in U.S. Pat. No. 6,053,197 and No. 6,xxx,xxx [Ser. No. 09/855,735 (filed 14 May 2001)] and U.S. patent application, Ser. No. 10/143,103 (filed 07 May 2002), it has been observed that urine can be directed with some intensity through the opening of the cartridge and impinge with sufficient force on the sealant therein to adversely affect its sealing function collect and that, because of blockages within the cartridge, urine can collect on its upper surface and possible flow therefrom to create a sanitary problem. Further, in the mechanism described in above-mentioned U.S. Pat. No. 6,xxx,xxx, such collected urine may corrode or otherwise disrupt the mechanical and electrical operations of the liquid flow meter described therein.
SUMMARY OF THE INVENTION
[0008] These and other problems are successfully addressed and overcome by the present invention, along with attendant advantages, by placing a diverter atop the upper wall of the cartridge and over the opening therein for avoiding direct access of urine to the opening. The diverter is spaced from the upper wall to provide a urine flow passage. An indicator, such as a float, can be incorporated in the diverter to provide a visible signal of the presence of collected urine on the cartridge upper wall. Further, a pre-treatment chemically-constituted tablet or other substance may be incorporated in the diverter to provide sanitizing and/or deodorizing means. Additionally, one or more post-treatment chemically-constituted tablet or pellets may be placed at the outlet of the cartridge to protect the drain pipe from corrosion and other harm.
[0009] Several advantages are obtained derived from these arrangements. The life of the cartridge is increased. Fewer replacements of cartridges are possible. The need to service cartridges is minimized. Profitability is increased.
[0010] Other aims and advantages, as well as a more complete understanding of the present invention, will appear from the following explanation of exemplary embodiments and the accompanying drawings thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a view, in cross-section, of a cartridge for use in a urinal with a first embodiment of a urinal diverter positioned thereon and secured to its top;
[0012] FIG. 2 is an exploded view, in perspective, of the cartridge, per se, illustrated in FIG. 1 ;
[0013] FIGS. 3 and 4 are perspective views taken respectively from the top and bottom of the cartridge, per se, shown in FIG. 1 ;
[0014] FIGS. 5-7 respectively are side, top and bottom views of the cartridge, per se, shown in FIG. 1 ;
[0015] FIG. 8 is a cross-sectional view of the cartridge, per se, shown in FIG. 5 taken along line 8 - 8 thereof;
[0016] FIG. 9 is a cross-sectional view of the cartridge, per se, shown in FIG. 5 taken along line 9 - 9 thereof;
[0017] FIG. 10 is cross-sectional view of the cartridge, per se, shown in FIG. 7 taken along line 10 - 10 thereof;
[0018] FIGS. 11 and 12 are perspective views of the bottom portion of the cartridge, per se, depicted in FIGS. 1-10 , taken respectively from its upper and under sides
[0019] FIGS. 13-15 respectively are side, top and bottom views of the cartridge bottom portion shown in FIGS. 11 and 12 ;
[0020] FIG. 15A is a cross-sectional view of a detail of the cartridge bottom portion taken along cutaway line 15 A of FIG. 15 ;
[0021] FIG. 16 is a cross-sectional view of the cartridge bottom portion taken along line 16 - 16 of FIG. 13 ;
[0022] FIG. 16A is a cross-sectional view of a detail of the cartridge bottom portion taken along cutaway line 16 A of FIG. 16 ;
[0023] FIG. 17 a cross-sectional view of the cartridge bottom portion taken along line 17 - 17 of FIG. 16 ;
[0024] FIG. 18 is a cross-sectional view of the cartridge bottom portion taken along line 18 - 18 of FIG. 15 ;
[0025] FIG. 19 is a cross-sectional view of the cartridge bottom portion taken along line 19 - 19 of FIG. 15 ;
[0026] FIG. 20 is a bottom view, in perspective, of a second embodiment of the diverter illustrated in FIG. 1 , with a urine pre-treatment tablet and a retainer for the tablet latched to the diverter;
[0027] FIG. 21 is a cross-sectional view of the diverter, tablet and retainer taken along line 21 - 21 of FIG. 20 ;
[0028] FIG. 22 is a perspective view of the underside of the diverter shown in FIG. 23 ;
[0029] FIGS. 23 and 24 respectively are top and side views of the second embodiment of the diverter, per se, illustrated in FIG. 22 ;
[0030] FIG. 24A is a cross-sectional view of a standoff spacer detail of the diverter taken along cutaway line 24 A of FIG. 24 ;
[0031] FIG. 24B is a cross-sectional view of the standoff spacer detail of the diverter taken along cutaway line 24 B of FIG. 24 ;
[0032] FIG. 24C is a perspective view of the standoff spacer detail and pre-treatment tablet retainer latch of the diverter illustrated in FIGS. 24, 24A and 24 B;
[0033] FIG. 25 is a cross-sectional view of the diverter taken along line 25 - 25 of FIG. 23 ;
[0034] FIG. 25A is a cross-sectional view of a detail of the diverter taken along cutaway line 25 A of FIG. 25 ;
[0035] FIG. 26 is a bottom view of the diverter, per se, depicted in FIG. 22 ;
[0036] FIG. 27 is a cross-sectional view of the diverter taken along line 27 - 27 of FIG. 26 ;
[0037] FIG. 27A is a cross-sectional view of a detail of the diverter taken along cutaway line 27 A of FIG. 27 ;
[0038] FIG. 27B is a cross-sectional view of a detail of the diverter taken along cutaway line 27 B of FIG. 27 ;
[0039] FIG. 28 is a perspective view of the retainer, per se, depicted in FIGS. 20 and 21 ;
[0040] FIGS. 29 and 30 are top and side views of the retainer depicted in FIG. 28 ;
[0041] FIG. 31 is a cross-sectional view of the retainer taken along line 31 - 31 of FIG. 30 ;
[0042] FIG. 32 is a perspective view of the urine pre-treatment tablet, per se, depicted in FIGS. 20 and 21 ;
[0043] FIG. 33 is a cross-sectional view of the pre-treatment tablet taken along line 31 - 31 of FIG. 32 ;
[0044] FIG. 34 is a side view of the cartridge-gripping core of the cartridge key illustrated in FIG. 29 ;
[0045] FIG. 35 is a perspective view of the first embodiment of the diverter, pre-treatment and retainer depicted in FIG. 1 ;
[0046] FIGS. 36 and 37 respectively are top and bottom views of the first embodiment of the diverter, pre-treatment and retainer depicted in FIG. 35 ;
[0047] FIG. 38 is a side view of the tip side of the first embodiment of the diverter, pre-treatment and retainer depicted in FIG. 35 ;
[0048] FIG. 39 is a cross-sectional view of the first embodiment of the diverter, pre-treatment and retainer taken along line 39 - 39 of FIG. 38 ;
[0049] FIG. 40 is a side view of the first embodiment of the diverter, per se, depicted in FIG. 1 ;
[0050] FIG. 40A is a cross-sectional view of a detail of the diverter taken along cutaway line 40 A of FIG. 40 ;
[0051] FIG. 41 is a cross-sectional view of the diverter, per se, taken along line 41 - 41 of FIG. 40 ;
[0052] FIG. 41A is a cross-sectional view of a detail of the diverter taken along cutaway line 41 A of FIG. 41 ;
[0053] FIG. 42 is a perspective view tablet a float used in the diverter depicted in FIG. 1 ;
[0054] FIG. 43 is a side view of the float illustrated in FIG. 42 ;
[0055] FIG. 44 is a cross-sectional view of the float taken along line 44 - 44 of FIG. 43 ;
[0056] FIG. 45 is a perspective view of a see-through protective cap used in the diverter depicted in FIG. 1 ;
[0057] FIG. 46 is a side view of the protective cap shown in FIG. 45 ;
[0058] FIG. 47 is a cross-sectional view of the protective cap taken along line 47 - 47 of FIG. 46 ;
[0059] FIGS. 48 and 49 are perspective views of a plug placeable in the bottom portion of any of the cartridges depicted in FIGS. 1-5 , 7 - 10 and 53 - 55 ;
[0060] FIGS. 50-52 respectively are side, bottom and bottom views of the plug shown in FIGS. 48 and 49 ;
[0061] FIGS. 53 and 54 are perspective views of cartridges, similar to the cartridge illustrated in FIG. 1 , with alternatively packaged post-treatment chemicals, embodied respectively as sticks and spheroids, used to treat urine as it exits the cartridge; and
[0062] FIG. 55 is a perspective view of a cartridge placed in a part of a waterless urinal as connected to a drain pipe.
DETAILED DESCRIPTION
[0063] Accordingly, as depicted in FIGS. 1-19 , an odor trap 98 comprises a cartridge 100 , which is sometimes referred to as an “oil sealant-preserving drain odor trap.” Cartridge assembly 100 , acting as a flow trap for urine or other generally fluid waste products, comprises a top portion 102 and a bottom portion 104 . Wastewater 103 , such as a fluid with urine therein, and an oily liquid odor sealant 105 floating on the wastewater is contained within the cartridge. Alternate embodiments of a diverter, such as diverter 270 , can be secured to top portion 102 .
[0064] Top portion 102 has a cylindrical configuration defined by a tubular wall 106 terminated by an opening 108 at its lower end and a top wall 110 at its upper end. The top wall is sloped downwardly to a flat, generally horizontal flat center portion 112 in which an entry opening 114 is disposed, to act as a urine inlet. As depicted in FIG. 6 , opening 114 comprises a tripartite arrangement of three arced slots 114 a, 114 b and 114 c. A hole 115 is centrally positioned within center portion 112 . As will be described with respect to FIGS. 20-47 , slots 114 a, 114 b and 114 c and hole 115 are adapted to hold either of the two diverters depicted therein to cartridge 100 . Top portion 102 is further provided with three keys 116 of which one may be of different length than the other two (e.g., see FIG. 2 ) for purposes of properly placing and orienting cartridge 100 within a urinal, as more fully described in U.S. Pat. No. 6,644,339 (the parent application of above-noted Ser. No. 10/647,603).
[0065] Top wall 110 is provided with a recess 117 , for example as shown in FIG. 5 at its outer periphery to accept a seal, such as O-ring seal 228 (see FIG. 44 ). Recess 117 has a small dimension sufficient to minimize the trapping of urine therein.
[0066] Top wall 110 of top portion 102 is further provided with three openings 118 which act as air vents that communicate with the interior of cartridge 100 . In the event that one or two may become clogged, such as by urine when the urinal is in use, there will be at least one that remains open. Openings 118 also provide a means by which a tool may be inserted therein for the purpose of inserting and removing the cartridge into and from a urinal, as also described in above-noted co-pending provisional application No. 60/535,463, now patent application Ser. No. xx/xxx,xxx [Attorney Docket No. 7148-125]. Accordingly, for purposes of their use as tool engagement means, it is preferred that the outermost two openings be approximately diagonally opposed to one another. However, the placement or use of these openings may be otherwise designed to accommodate other tool configurations.
[0067] As best shown in FIG. 9 , the interior of top portion 102 is divided by a bowed vertical separator 120 into two compartments, respectively an inlet compartment 122 and an outlet compartment 124 . Vertical separator 120 is secured or molded to the interior surface of tubular wall 106 and to the underside of top wall 110 in any convenient manner. The bottom end of the vertical separator terminates in an end or terminus 121 b which is disposed to be connected to a baffle 150 . When top and bottom portions 102 and 104 are placed together and a discharge section 128 ( FIGS. 11-19 ) of bottom portion 104 extends into outlet compartment 124 , inlet compartment 122 and outlet compartment 124 have generally equal volumes. It is important that the compartment volumes be made as equal as possible to ensure that the pressures on both sides of vertical separator 120 remain equal during use of the cartridge. Such pressure equality helps to minimize syphoning or, alternatively, to maximize resistance to syphoning between the compartments and, of particular importance, of sealant 105 from the inlet compartment to the outlet compartment. Thus, the usable life of the cartridge is improved by avoiding premature failure thereof. Additionally, any impediment to liquid flow in minimized.
[0068] Vertical separator 120 is bowed, e.g., curved or bent, to accommodate centrally positioned entry opening 114 which needs to fully communicate with inlet compartment 122 . The illustrated curved bowing of the vertical separator further enables air vent openings 118 also to communicate with the inlet compartment. It is to be understood, however, that the vertical separator need not be curved as illustrated; it may take any configuration that will effect its purpose, that is, to provide equally volumed compartments and to oblige the communications of openings 114 with the inlet compartment. Therefore, for example, if the air vent openings were not used as a means to cooperate with a cartridge inserting and removing tool, as above described, and/or entry opening 114 were not centrally positioned in top wall 110 , or for any other reason apart from its compartment volume-defining purpose, vertical separator 120 may be otherwise configured.
[0069] Bottom portion 104 , as depicted in FIGS. 2 and 11 - 19 , comprises a pan 126 and a discharge section 128 extending upwardly therefrom. The pan includes a wall 130 terminating at an edge 132 ( FIG. 16 ) which provides a tongue-in-groove engagement with tubular wall 106 at its lower end opening 108 , as best seen in FIG. 17 , to provide a fluid-tight engagement between top and bottom portions 102 and 104 . The inner surfaces of pan 126 are rounded to prevent sharp angled corners and are smoothed to enhance fluid flow and to discourage build up of matter and bacteria or other debris.
[0070] Upwardly extending discharge section 128 , which as described above extends into outlet compartment 124 of top portion 102 , includes a tube 134 that communicates with outlet compartment 104 and opens at an exit port area 136 through pan 126 for discharge of fluids, e.g., wastewater fluid 103 , and other undesired matter from the outlet compartment to a drain 220 ( FIG. 55 ). The discharge section also includes a pair of tubular chambers 138 for receipt of post-treatment chemicals for treating the exiting urine, as contained in control stick 224 a or pellets 224 b ( FIGS. 53-55 ), as more fully described in co-pending application, Ser. No. ______ (provisional application No. 60/579,921). Chambers 138 are closed at walls 140 (see FIGS. 11 and 18 ) at one of their ends at the uppermost part of upwardly extending discharge section 128 to prevent flow of fluids thereinto from the outlet compartment, and are open at their other ends 142 (see FIGS. 12 and 18 ).
[0071] As shown in FIGS. 16, 16A and 19 , a flow director 144 in tube 134 adjacent exit port area 136 comprises an angled part which is adapted to direct fluid flow towards ends 142 of tubular chambers 138 for impacting control stick or pellets 224 . Such directed fluid flow is also implemented by a pair of vertically extending ribs 145 which are formed on the walls of tube 144 , and by an inclination on top wall 140 towards tube 134 and ribs 145 .
[0072] A key 146 and a keyway 148 are provided respectively on the interior surface of tubular wall 106 (see FIGS. 2 and 9 ) and on the backside of upwardly extending discharge section 128 (see FIGS. 11, 13 and 16 ). The key and keyway are disposed to provide an orientation and proper alignment between top and bottom portions 102 and 104 and, through the orienting mechanism of keys 116 with the urinal, to place exit port area 136 adjacent exterior drain 220 from cartridge 100 .
[0073] As depicted in FIGS. 2 and 8 , a baffle 150 is disposed to be secured to curved vertical separator 120 for improved direction and flow of fluids through the cartridge in a region from inlet compartment 122 to outlet compartment 124 , as more fully described in co-pending patent application, Ser. No. xx/xxx,xxx (U.S. Provisional Application No. 60/579,921, filed 14 Jun. 2004) [Attorney Docket 7148-119-US].
[0074] Cartridge 42 is provided with an upper wall 44 in which a central opening 46 may be disposed. Opening 46 may comprise a simple hole or one configured as a tripartite arrangement of three arced slots 46 a, 46 b and 46 c, centered about a generally horizontal flat center portion 48 as best shown in FIG. 1A . A hole is centrally positioned within center portion 112 . As will be described with respect to FIGS. 36-43 , slots 114 a, 114 b and 114 c and hole 115 are adapted to hold either of the two diverters depicted therein to cartridge 100 . In the illustrated configuration, cartridge 42 is disposed to receive urine through central opening 46 and transported to a drain such as may be connected to a urinal. Such a cartridge may take any form, for example, as described in U.S. Pat. Nos. 6,053,197, 6,245,411, 6,644,339 and 6,xxx,xxx [Ser. No. 09/855,735 (filed 14 May 2001)].
[0075] One embodiment of the urine diverter depicted in FIGS. 20-27 . Here a diverter 170 is positionable atop cylinder upper wall 110 , e.g., as shown in FIG. 1 , for protectively covering cartridge openings 114 and 115 at center portion 112 , primarily to provide a circuitous path for flow of urine to the opening. Therefore, urine is prevented from directly contacting and entering into the openings. Diverter 170 includes a shell 172 and, if desired, a deodorant and/or sanitizing tablet 210 and a tablet retainer 200 (see FIGS. 28-33 ) for retaining the tablet within shell 172 . The diverter is slightly spaced from upper wall 110 of cartridge 100 to assure a clear path for flow of the urine and to space retainer 200 and tablet 210 from the cartridge upper wall. As shown in detail in FIGS. 24 and 24 A- 24 C, such spacing is effected by use of a standoff 182 , depending from shell 172 and comprising a large portion 182 a and a smaller portion 182 b. Portion 182 b is made as small as possible to permit the smallest contact of the diverter with the cartridge and, therefore, to provide the largest possible unobstructed flow path.
[0076] Shell 172 , as for example shown in FIGS. 21 and 27 , comprises an upper surface 184 , terminated by a periphery 186 with a downwardly depending flange 188 , and a central opening 190 . Upper surface 184 slopes downwardly towards periphery 186 to encourage flow of urine towards the periphery. Inwardly-facing bumps or protuberances 191 are formed on large portion 182 a of standoffs 182 , as best shown in FIGS. 27 and 27 B.
[0077] A tubular housing 194 (see FIGS. 21, 22 and 26 ) preferably of cylindrical configuration is secured at one end to the under surface of shell 172 and terminates in a securing mechanism 198 at its free end. A smaller diameter, slightly conical end 102 is formed at the free end, and is sized to form an interference fit within opening 115 in top cartridge upper wall 110 .
[0078] With reference to FIGS. 28-31 , tablet retainer 200 comprises and open-structured cup 202 for supporting a tablet 210 (see FIGS. 32 and 33 ) and for exposing the tablet to any urine collected in top wall 110 of top portion 102 . The open-structured cup comprises an outer ring-like member 204 , an inner ring-like member 206 , and a plurality of spokes 208 connecting inner and outer ring-like members 206 and 204 . The dimension of the periphery of outer ring-like member 206 and that of the inner surface on flange 184 of shell 172 are correlated to enable the outer ring-like member to fit within the flange and to latch over bumps 191 so as to latch retainer 200 to shell 172 and, thereupon, to hold tablet 210 in position as shown in FIGS. 20 and 21 and spaced slightly above cartridge top wall 110 . In addition, tablet 210 is configured generally as a donut having an inner cylindrical opening 212 which is adapted to fit over the outer periphery of inner ring-like member 204 .
[0079] The contents of tablet 210 include a formulation of citric acid, quaternary ammonium and triclosan, and a binder to hold the formulation together. The citric acid is used (1) to adjust the ph in the cartridge, between 5.5 and 3.0 ph to ensure that the contents remain acidic, and to prevent alkalinity which would otherwise degrade the sealant, (2) to inhibit biological growth and/or (3) to act as a cleaning agent, e.g., to remove scale and other minerals, stains, etc., within the cartridge and drain pipe. The binder, a polymer binding medium which holds and permits release of the agents held therein. It is believed that the quaternary ammonium comprises a surfactant having a negative ion which is adapted to combine with a positive ion surfactant and to form precipitants. The problem to be avoided is to inhibit the breakdown of the sealant by positive ion surfactants, such cleaning agents used in urinals. While a negative ion surfactant, such as Hyamine 1622, trademark of Rohm and Haas, has been found to be useful, the requirement is one that militates against the breakdown of the sealant. Triclosan, trademark of ______, is a biocide which is designed to combine with polymers and to protect the sealant from bacteria. The binder is formulated from a slightly soluble material, e.g., N, N-ethylenebisstearamide, which can be slowly worn away by water such as to the extent that its life will last at least to the life of the cartridge.
[0080] Another embodiment of the urine diverter depicted in FIGS. 35-47 . Here diverter 270 is positionable atop cylinder upper wall 110 , as shown in FIG. 1 , for protectively covering cartridge openings 114 and 115 at center portion 112 , primarily to provide a circuitous path for flow of urine to the opening. Therefore, urine is prevented from directly contacting and entering into the openings. Diverter 270 includes a shell 272 , a urine level detector, comprising a float 274 and a see-through protective cap 276 , and, if desired, a deodorant and/or sanitizing tablet 210 and a tablet retainer 200 (see FIGS. 28-33 ) for retaining the tablet within shell 272 . The diverter is slightly spaced from upper wall 110 of cartridge 100 to assure a clear path for flow of the urine and to space retainer 200 and tablet 210 from the cartridge upper wall. As shown in detail in FIGS. 40 and 40 A, such spacing is effected by use of a standoff 282 , depending from shell 272 and comprising a large portion 282 a and a smaller portion 282 b. Portion 282 b is made as small as possible to permit the smallest contact of the diverter with the cartridge and, therefore, to provide the largest possible unobstructed flow path.
[0081] Shell 272 , as for example shown in FIGS. 41 and 41 A, comprises an upper surface 284 , terminated by a periphery 286 with a downwardly depending flange 288 , and a central opening 290 . Upper surface 284 slopes downwardly towards periphery 286 to encourage flow of urine towards the periphery and away from opening 290 . Further, a rim 292 surrounds opening 290 also to encourage the outward urine flow and, in particular, to prevent urine from entering opening 290 . Inwardly-facing bumps 291 are formed on large portion 282 a of standoffs 282 .
[0082] A tubular housing 294 (see FIGS. 35 and 37 - 41 ) preferably of cylindrical configuration is secured at one end 296 ( FIG. 41 ) to the under surface of shell 272 about opening 290 and terminates in a latching mechanism 298 at its second end 300 . An inwardly directed circular protuberance 302 is formed at end 300 . The second end is also formed with cut-away portions 304 which dissect protuberance 302 into legs 303 to permit a bending of the latching mechanism. Latching mechanism 298 comprises pairs of facing teeth 306 at the ends of legs 303 which are adapted to latch into arced slots 114 a, 114 b and 114 c of cartridge top portion 102 for securing diverter 270 to cartridge 100 .
[0083] Also formed in the under surface of shell 272 about opening 290 and within the interior of tubular housing 294 is a recess 296 ( FIG. 41 ) in which a ring 298 of ferromagnetic material (see FIG. 35 ) is molded.
[0084] With reference now to FIGS. 42-44 , float 274 comprises a generally tubular body 318 from which a stem 320 extends from its upper surface. Its lower surface 322 is concavely formed so that any liquids thereon will flow off the concave surface and not collect thereon or leave deposits after the liquid has evaporated. A plurality of ribs 324 are placed about body 318 , and extend slightly below concave surface 322 so as to help any liquid to collect and form drops for facilitating the removal of liquid from the float. Ribs 104 are configured with a generally triangular cross-section to form outer peripheries having a small surface which, in aggregation, delineate a cylindrical surface that fits closely within the inner surface of shell-depending tubular cylindrical housing 324 . Accordingly, ribs 324 permit the float to move between the under surface of shell 272 and cartridge upperwall 110 . The float is retained within tubular cylindrical housing 294 on protuberances 302 therein. Insertion of the float within the housing is permitted by flexure of its lower or second end 300 through the medium of cut-away portions 304 . Float 274 preferably is molded from a material that can be tinted so as to make it easily viewable, such as by a bright red and/or florescent shade, especially from the top of stem 320 . When tablet retainer 200 is used, a passage within inner ring-like member 204 enables contact of the float with any urine collected in the upper wall of cartridge 100 .
[0085] A magnet 326 , having the shape of a toroid, is secured to float 274 about its stem 320 and, upon upward movement of the float, latches to ferromagnetic washer 298 and holds the float against shell 272 .
[0086] Protective cap 276 , as illustrated in FIGS.45-47 , is configured to resemble a mushroom and comprises an enlarged head 330 and a relatively smaller stem 332 extending therefrom. Stem 332 is recessed to form a hollow 334 , and is sized to extend through shell upper surface opening 292 and thereby to receive float stem 320 . An indentation 336 ( FIG. 47 ) is formed beneath enlarged head 330 adjacent hollow stem 332 and helps to discourage flow of urine onto the hollow stem. Indentation 336 thus acts as an adjunct to rim 292 formed about shell opening 290 to help in controlling the flow of urine. Protective cap 276 is formed from a clear or translucent material, such as of acrylic plastic, to enable viewing of float 274 and, in particular, the top of its stem 320 .
[0087] As shown in FIGS. 48-52 , a plug 410 is disposed to be attached to bottom portion 104 within a part of exit port area 136 and to operate as a closure to open ends 142 of tubular chambers 138 . A pin 412 extends from the top side of plug 412 and is disposed to engage with a keyed interference fit coupling within an opening 414 (see FIGS. 34B and 46 ) in bottom portion 104 to join the two parts together. Both pin 412 and opening 414 have mating ribs that, when inter-engaged, orient plug 410 with tubular chambers 138 . The plug is formed with a pair of tubular openings 416 having the same dimensions as those of tubular chambers 138 of bottom portion discharge tube section 128 . One side of tubular openings 416 is formed to provide an open basket-like weave 418 with openings 420 , and a base 422 which is adapted to support a holder of post-treatment discharge control chemical agents, configured as sticks 424 a or pellets 424 b. It is through openings 420 that fluid is directed by the two-part flow director comprising angled ledge 144 and ribs xxx in tube 134 .
[0088] A pair of such post-treatment discharge control sticks 424 a or pellets 424 b, of which one each is illustrated in FIGS. 53 and 54 and identified generally in FIG. 55 by indicium 424 , are disposed to be placed within tubular chambers 138 . Each one of pellets 424 b, as having a spheroid shape, rests against the inner wall of tubular chambers 138 with a smaller contact than does the contact between stick 424 a with the inner wall and, therefore, is the preferable shape, as being more likely to move downwardly as fluid slowly erodes the post-treatment discharge chemicals. Each post-treatment discharge control stick or pellet includes citric acid and, if desired, quaternary ammonium, a biocide and cleaning agents held in a time-release binder. Its use is primarily as a descaling agent to help maintain a clean drain pipe, and especially in environments where the cartridge use pattern is such that additional descaling is needed. The post-treatment discharge control sticks or pellets may be used alone or in conjunction with pretreatment control tablet 410 .
[0089] When all the above-described components are assembled together, they form cartridge 100 as depicted, for example, in FIGS. 1 and 36 . This assembled cartridge is then adapted to be placed within a waterless urinal 426 , a portion of which is illustrated in FIG. 55 , which is coupled to a drain 420 with exit port area 136 as provided through the orienting mechanism of keys 116 . An O-ring seal is placed within recess 117 in the periphery of top wall 110 .
[0090] While pretreatment control tablet 410 and post-treatment discharge control agents 424 a or 424 b are described herein as integral parts of the present invention, it is to be understood that they can be used alone, in other environments. In a like manner, cartridge 100 of the present invention may employ other means, aside from tablet 410 and agents 424 , to obtain the desired anti-bacterial, cleaning, etc., purposes. Furthermore, both the tablet and stick/pellet agent can be composed of any number of other agents and ingredients depending upon the end result desired. Also, the diverter may be used alone, without any pretreatment tablet.
[0091] Although the invention has been described with respect to particular embodiments thereof, it should be realized that various changes and modifications may be made therein without departing from the spirit and scope of the invention.
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A diverter ( 170, 270 ) atop the upper wall ( 110 ) of a cartridge ( 100 ) and over the opening ( 114, 115 ) therein avoids direct access of urine to the opening and the sealant ( 105 ) within the cartridge. The diverter is spaced by standoffs ( 182, 282 ) from the upper wall to provide a urine flow passage. A float ( 274 ) can be incorporated in the diverter to provide a visible signal of the presence of collected urine on the cartridge upper wall. A pre-treatment chemically-constituted tablet ( 210 ) held by a retainer ( 200 ) in the diverter provides sanitizing and/or deodorizing means. Post-treatment chemically-constituted tablets ( 224 a ) or pellets ( 224 b ) placeable at the outlet of the cartridge protect the drain pipe from corrosion and other harm.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an automatic tool changer for machine tools which are controlled automatically, e.g., NC machine tools.
2. Description of the Prior Art
In this type of known machine tool, an automatic tool changer which, on one hand, takes out from a tool magazine accomodating a large number of tools the desired tool for machining and supplies it to a spindle of the machine tool and which, on the other hand, removes the used tool from the spindle for replacement with the tool required for the next machining operation must be simple in construction and smooth, positive and fast in operation.
To meet these requirements, many different automatic tool changers have been propsed and generally these known automatic tool changer employ the single arm for affecting the demounting and mounting of tools between the spindle and the tool magazine thus giving rise to a disadvantage that the tool changing time is long.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an automatic tool changer so constructed that while the used tool on a spindle is being removed by the tool grip of one arm, the tool grip of the other arm holds the tool required for the next machining operation and stands by, thereby reducing the tool changing time.
It is another object of the invention to provide an automatic tool changer capable of effecting the desired tool changing as simply and quickly as possible.
To accomplish the above objects, an automatic tool changer according to the invention features that a pair of arms each having a tool grip and adapted to perform a separate tool changing operation are arranged in the vicinity of the spindle of a machine tool between the spindle and the tool magazine. Also, the tool changing operations of the arms are simplified as far as possible, to allow the tool magazine to accomodate as many tools as possible and simplify the apparatus. The tool magazine is composed of an endless chain including a large number of tool pots arranged at predetermined intervals and each having an axis parallel to the spindle.
In accordance with the invention, due to the provision of a pair of arms which are each provided with a tool grip and arranged so as to separately perform their tool changing operations in the vicinity of the spindle of a machine tool, after the operation of removing the tool used for the preceding operation from the spindle has been performed by one of the arms, the other arm which has gripped the tool required for the next operation at the tool magazine and has been standing by performs the operation of fitting the tool into the spindle and these operations are performed alternately thereby decreasing the tool changing time considerably. Also, since the tool changing operation of each arm comprises only simple movements such as lateral movement, longitudinal movement and 90-degree turning movement thus making the arm extremely simple in construction and since a so-called absolute address system is used in which each tool is positively returned to its specific tool spot, there are the advantageous effects of eliminating any erroneous tool selection and so on.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cutaway front view of an embodiment of the present invention;
FIG. 2 is a sectional view taken respectively along the line II--II of FIG. 1; and
FIG. 3 is a sectional view taken respectively along the line III--III of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 to 3, numeral 1 designates a spindle of a machine tool which incorporates therein a mechanism for engaging and disengaging a holder fitted with a tool. Numeral 2 designates a tool magazine composed of an endless chain 4 including a large number of tool pots 3 which form receptacles for holders fitted with tools and arranged at regular intervals in such a manner that their axis extend parallel to the spindle 1. The endless chain 4 is reversely movable circularly and laterally in FIG. 1 or similarly movable vertically in a case where it is mounted vertically (not shown). Each tool pot 3 is provided therein with a mechanism (not shown) for engaging and disengaging a holder fitted with a tool. Numeral 5 designates a driving sprocket for the endless chain 4 and the other driven sprocket over which the endless chain 4 is extended is not shown. As shown in FIG. 2, a rotary shaft 6 of the driving sprocket 5 is supported in bearings 8 provided in a housing 7 and it is driven by a motor 11 through gears 9 and 10. Also, an encoder 12 is connected to the end of the rotary shaft 6 through gears 13 and 14 to detect the number of revolutions of the rotary shaft 6 and a cylinder unit 15 is detachably mounted on the gear 10 fixedly mounted on the rotary shaft 6 to determine the number of revolutions of the rotary shaft 6 or the indexed position of the endless chain 4 operable in association with the rotary shaft 6 in accordance with the detection signal from the encoder 12. Numeral 16 designates a box-type casing enclosing the endless chain 4 and the housing 7 of the driving sprocket 5 is attached to the back side of the casing 16. Numeral 17 designates a cover attached to the front side of the casing 16 and it is attached to arm supporting bases (see FIG. 3) which will be described later.
Then, as shown in FIGS. 1 and 3, supporting bases 19 having a pair of guide bars 18 parallel to the endless chain 4 are attached to the casing 16 in the space of the parallel extending endless chain 4. The suppoting bases 19 are provided with a pair of arm supporting slide bases 20 adapted to be moved toward and away in the opposite directions along the guide bars 18. Numeral 21 designates cylinder units for sliding the slide bases 20 in the just-mentioned manner and they are arranged between the slide bases 20 and the supporting bases 19. A supporting plate 22 is extended from each of the slide bases 20 across the back of the endless chain 4 and the base end of a rotary plate 23 is pivotably attached to each supporting plate 22 by a pin 24. Then, the pair of rotary plates 23 are arranged on the sides of the spindle 1 near thereto. Each of the rotary plates 23 is adapted to make a 90-degree turn about the pin 24 and for this purpose a cylinder unit 25 is connected between each rotary plate 23 and the associated slide base 20. Also, as shown in FIG. 3, a slide support 26 is vertically fitted to the forward end of each rotary plate 23 so as to extend towards the from along the side of the casing 16 and an arm 28 or 29 having a tool gripping claw 27 is slidably mounted on the slide support 26 through slide guides 30. Numeral 31 designates an arm sliding cylinder unit provided between the slide support 26 and the arm 28 or 29.
The tool gripping portion of each of the arms 28 and 29 includes an arcuate fixed support 33 formed with a tool positioning notch 32 at its central portion and the tool gripping claw 27 having its base and pivoted by a pin 34 to the fixed support 33 at around the peripheral end thereof and its central portion connected to a clamp rod 35 by a pin 36 so as to be opened and closed. Then, at the 90°-turned position of each rotary plate 23, the tool gripping portion is opposed perpendicularly to the axis of the spindle 1 or it is brought into a position where it is engaged with the annular groove (not shown) of the tool-fitted holder accomodated in the tool pot 3. Also provided at the base end of the clamp rod 35 is a cam follower 38 adapted to engage with a cam groove 37 formed in the slide support 26 so that during the tool gripping the clamp rod 35 is projected against the spring force of a spring 39 and the tool gripping claw 27 is closed thereby gripping the tool. In other words, the holder fitted with the tool is formed with the annular groove (not shown) so that during the tool gripping the tool gripping claw 27 in the open condition is inserted into the annular groove and it is then closed thus gripping the tool-fitted holder by the fixed support 33 and the tool gripping claw 27.
With the construction described above, the operation of the automatic tool changer according to the invention will now be described.
Where the used tool fitted to the spindle 1 is to be replaced with the tool required for the next operation, the arms 28 and 29 are standing by in the conditions as shown in FIG. 1. In other words, the left arm 28 is placed on a lateral axis 40 of the spindle 1 at a position close and opposite thereto and its tool gripping claw 27 is open. On the other hand, the right arm 29 has its rotary plate 23 turned through 90 degrees about the pin 24 so that the tool required for the next operation and located at the position indexed by the circular movement of the endless chain 4 in the tool magazine 2 is gripped through its holder and it is standing by in this condition. Then, in the illustrated condition, the slide base 20 of the left arm 28 is first moved to the right toward the spindle 1 through the lateral movement cylinder unit 21 so that, when a stage is reached where the fixed support 33 and the tool gripping claw 27 of the arm 28 come near to the annular groove of the tool-fitted holder on the spindle 1, the arm 28 is slightly moved toward the surface side of the paper in the figure by the longitudinal movement cylinder unit 31. As a result, the clamp rod 35 is projected against the spring pressure of the spring 39 due to the engagement between the cam groove 37 and the cam follower 38 and the tool gripping claw 27 is closed thereby gripping the tool-fitted holder on the spindle 1. Then, the lock of the tool-fitted holder is released on the spindle 1 by the engaging and disengaging mechanism which is not shown and the arm 28 is moved further in the direction of the surface of the paper thereby removing the tool-fitted holder from the spindle 1. After the arm 28 gripping the used tool has been returned to the initial position, the right arm 29 which is gripping the tool for the next operation and standing by now removes the tool for the next operation from the tool pot 3 and then its rotary plate 23 is turned through 90 degrees by the turning cylinder unit 25 thereby positioning the arm 29 above the lateral axis 40 of the spindle 1 to oppose it. Then, in the like manner as was the case with the left arm 28, the arm 29 is brought near to the spindle 1 and the tool for the next operation is inserted and fitted to the spindle 1. During the insertion, the tool gripping claw 27 of the arm 29 is opened to release the lock on the holder of the tool and simultaneously the holder fitted with the tool is locked by the engaging and disengaging mechanism of the spindle 1. After the tool for the next operation has been fitted to the spindle 1 in this way, the arm 29 is retreated to a position exactly symmetrical with the illustrated left arm 28 and it stands by for the next tool changing operation. After the completion of the replacement of the used tool with the new tool for the next operation, the desired machining is started by using the new tool and during the machining the left arm 28 is turned by 90 degrees thereby returning the used tool into the given tool pot 3 of the endless chain 4. Then, the left arm 28 again grips the next tool and stands by. The resulting conditions are exactly in an inverse symmetrical relation with the conditions of FIG. 1.
In accordance with the present invention, the above-described embodiment is to be considered as illustrative only and many changes and modifications may be made by those skilled in the art without departing from the scope of the invention. For instance, the slide bases may be of the type which make planary movement in the directions of two axes perpendicular to each other and also the tool gripping portion of each arm may be made of an U-shaped or arcuate resilient member.
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During the automatic changing of tools between a spindle of a machine tool and a tool magazine, a changing operation of causing one of a pair of tool changing arms to stand by in the vicinity of the spindle to remove the used tool and another changing operation of causing the other tool changing arm to grip the tool to be used for the next operation on the tool magazine and stand by are performed alternately thereby reducing the tool changing time.
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